MEMBRANE PUMP

Abstract

 A membrane pump for suction and delivery of a fluid of interest comprising a head portion, a bottom portion, at least one side wall extending along a main axis A between the head and bottom portions, and at least one flexible membrane movable along a working direction substantially parallel to the main axis A to determine suction and delivery of the fluid of interest F. The pump further includes a fluid of interest delivery port configured to allow delivery of the fluid of interest, a fluid of interest suction port configured to receive fluid of interest on suction in a hydraulic circuit of the pump, and at least one intercepting element configured, during a pump operating condition, to selectively interdict and allow fluid communication between the suction port and said internal volume, and between the delivery port and the internal volume.

Description

FIELD OF THE FOUND

[0001] The present invention relates to a membrane pump for suction and delivery of liquids. In particular, the invention finds application in the field of land reclamation and/or where it is necessary to suck up underground liquids mixed with sediment: such liquids may be pollutants and/or corrosive chemicals. The present invention is further directed to a system comprising membrane pump and a method for suction and delivery of liquids in the field of land reclamation and/or where it is necessary to suck in polluting liquids and/or corrosive chemicals.

STATE OF THE ART

[0002] In the field of technology related to soil and groundwater remediation processes, shown schematically in Figure 1, immersion piston pumps are commonly used to extract polluted fluid, for example, containing corrosive chemical reagents. The piston pump has an elongated shape and a maximum radial footprint that allows it to fit inside underground conduits: such underground conduits are run from the ground floor by means of drilling machines so as to reach the depth from which the liquid needs to be extracted. Underground pipelines commonly have a size of about 4" (about 10 cm in diameter). A larger conduit size would imply more drilling work, consequently increasing the cost and time of drilling: conversely, a smaller conduit size would make it difficult or impossible to insert a suitable pump for this purpose.

[0003] Piston pumps commonly used in the industry must necessarily be immersed in the fluid to enable its suction: however, the fact that the piston pump is immersed in polluted fluid encourages corrosion phenomena in the pump itself, generating malfunctions and requiring frequent maintenance. Additionally, piston pumps include an electric motor capable of moving the piston: this results in the need to carry power via a cable inside the underground conduit to the fluid to be sucked, with associated electrocution risks for operators.

[0004] In the case where the polluted fluid is no more than 4 meters below the walking level, the use of membrane pumps is known. The limitation of such membrane pumps lies in their size, which does not allow their insertion inside the underground conduit (having, as previously written, a diameter of about 10 cm): for this reason, to date, the membrane pump is placed on the ground at the ground level GL and a suction pipe is lowered inside the underground conduit until the polluted fluid is reached. If the polluted fluid is more than 4 meters below the ground level, the membrane pumps do not have the capacity to suck in the underground fluid.

[0005] Such membrane pumps can be pneumatic type, in which a flow of compressed air determines the alternating motion of the membranes, or electric type, in which an electric actuator/motor determines the alternating motion of the membranes.

[0006] Note that double membrane pumps are mainly used in this technical field.

OBJECTIVE OF THE INVENTION

[0007] It is therefore the objective of the present invention to solve at least one of the drawbacks and/or limitations of the previous solutions.

[0008] A first goal is to reduce or avoid pump corrosion due to the immersion of the pump in the fluid to be sucked in.

[0009] An additional purpose is to reduce downtime due to pump failure.

[0010] An additional purpose is to reduce the service costs of pumps in the reclamation industry.

[0011] An additional purpose is to reduce electrocution risks when it is necessary to suck fluid at great depths, such as greater than 4 or 5 meters and up to 50 to 60 meters.

[0012] These objectives and others, which will appear more from the following description, are substantially achieved by a membrane pump (1) in accordance with one or more of the following claims and/or aspects.

SUMMARY

[0013] Aspects of the invention are described below.

[0014] In a 1st aspect, a membrane pump (1) is provided for suction and delivery of a fluid of interest (F), called a membrane pump (1) comprising a carrier pump body:

• a head portion (2);
• a bottom portion (3) opposite to said head portion (2);
• at least one side wall (4) extending along a main axis (A) between said head portion (2) and said bottom portion (3), said side wall (4) defining, in combination with the head portion (2) and the bottom portion (3), an internal volume (5) of said membrane pump (1),
  said internal volume (5) comprising a working circuit and a hydraulic circuit;
• at least one flexible membrane (6) placed within said internal volume (5) and movable along a working direction substantially parallel to the main axis (A), said at least one membrane (6) being configured to move at least partially along said working axis in reciprocating motion to result in a suction phase and a delivery phase of the fluid of interest (F);
• a delivery port (9) of the fluid of interest (F) configured to allow delivery of the fluid of interest (F);
• a suction port (8) of the fluid of interest (F) configured to receive the fluid of interest (F) in said hydraulic circuit of the pump (1),
• at least one intercepting element (7) configured, during a pump use condition, to interdict or allow fluid communication between:

  ∘ the suction port (8) and said hydraulic circuit, and between

  ∘ the delivery port (9) and said hydraulic circuit,

• at least one power port (10) configured to receive, in the working circuit, a working fluid under pressure or electrical energy to determine the alternating movement of said at least one membrane (6);
  and in which:
  • said head portion (2) carries the delivery port (9) and power port (10), and
  • said bottom portion (3) carries the suction port (8).

[0015] In a 2nd aspect, a membrane pump (1) is provided for suction and delivery of a fluid of interest (F), said membrane pump (1) comprising a carrier pump body:

• a head portion (2);
• a bottom portion (3) opposite to said head portion (2);
• at least one side wall (4) extending along a main axis (A) between said head portion (2) and said bottom portion (3), said side wall (4) defining, in combination with the head portion (2) and the bottom portion (3), an internal volume (5) of said membrane pump (1),
  said internal volume (5) comprising a working circuit and a hydraulic circuit;
• at least one flexible membrane (6) placed within said internal volume (5) and movable along a working direction substantially parallel to the main axis (A), said at least one membrane (6) being configured to move at least partially along said working axis in reciprocating motion to result in a suction phase and a delivery phase of the fluid of interest (F);
• a delivery port (9) of the fluid of interest (F) configured to allow delivery of the fluid of interest (F);
• a suction port (8) of the fluid of interest (F) configured to receive the fluid of interest (F) in said hydraulic circuit of the pump (1),
• at least one intercepting element (7) configured, during a pump use condition, to interdict or allow fluid communication between:

  ∘ the suction port (8) and said hydraulic circuit, and between

  ∘ the delivery port (9) and said hydraulic circuit,

• at least one power port (10) configured to receive, in the working circuit, a working fluid under pressure or electrical energy to determine the alternating movement of said at least one membrane (6).

[0016] A 3rd aspect is directed to a pumping plant (100) comprising:

• a membrane pump (1) optionally according to the previous aspects, and
• a pressurized working fluid source, particularly a compressor configured to provide a pressurized gas flow rate, comprising at least one working fluid delivery connector connectable, via a working fluid piping, to the power port (10) of the membrane pump (1), optionally wherein said pressurized working fluid source is configured to provide a substantially constant flow rate of pressurized working fluid over time.

[0017] A 4th aspect is directed to a method of pumping a fluid of interest (F) for land reclamation, said method comprising the steps of:

• provide a membrane pump (1) including a carrier pump body:

  ∘ a head portion (2);

  ∘ a bottom portion (3) opposite to said head portion (2);

  ∘ at least one side wall (4) extending along a main axis (A) between said head portion (2) and said bottom portion (3), said side wall (4) defining, in combination with the head portion (2) and the bottom portion (3), an internal volume (5) of said membrane pump (1);

  ∘ at least one flexible membrane (6) placed within said internal volume (5) and movable along a working direction substantially parallel to the main axis (A), said at least one flexible membrane (6) being configured to move in reciprocating motion to result in a suction phase and a delivery phase of the fluid of interest (F);

  ∘ a delivery port (9) of the fluid of interest (F) configured to allow the discharge of the fluid of interest (F), said delivery port (9) being located on the head portion (2) of the membrane pump (1);

  ∘ a suction port (8) of the fluid of interest (F) configured to receive the fluid of interest (F) in a hydraulic circuit of the pump (1), said suction port (8) being located on the bottom portion (3) of the membrane pump (1),

  ∘ at least one intercepting element (7) configured, during a pump use condition, to selectively interdict and allow fluid communication between:

  ▪ the suction port (8) and said internal volume (5), and

  ▪ a delivery port (9) and said internal volume (5),

  ∘ at least one power port (10) configured to receive, in a working circuit, energy necessary for the movement of said at least one membrane (6);
  and in which:

  ∘ said head portion (2) carries the delivery port (9) and power port (10), and

  ∘ said bottom portion (3) carries the suction port (8);

  the method further including the following steps:
  • connect a suction pipe (8a) to the suction port (8);
  • connect a delivery pipe (9a) to the delivery port (9);
  • prepare a piezometric pipeline (110) inserted deep into the soil to be reclaimed;
  • insert said membrane pump (1) inside the piezometric conduit (110), in which the head portion (2) of the pump (1) faces the soil surface, while the bottom portion (3) of the pump (1) faces a depth of the piezometric conduit (110),
  • lower the membrane pump (1) within said piezometric pipeline to a reservoir of the fluid of interest (F) to a depth where:

    ∘ the membrane pump (1) is above a level of the fluid of interest, particularly outside the fluid of interest; and

    ∘ the suction pipe (8a) is at least partially embedded within the fluid of interest (F) contained in the basin.

[0018] A 5th aspect is directed to a method of pumping a fluid of interest (F) for land reclamation, said method comprising the steps of:

• provide a membrane pump (1) including a pump body carrying:

  ∘ a head portion (2);

  ∘ a bottom portion (3) opposite to said head portion (2);

  ∘ at least one side wall (4) extending along a main axis (A) between said head portion (2) and said bottom portion (3), said side wall (4) defining, in combination with the head portion (2) and the bottom portion (3), an internal volume (5) of said membrane pump (1);

  ∘ at least one flexible membrane (6) placed within said internal volume (5) and movable along a working direction substantially parallel to the main axis (A), said at least one flexible membrane (6) being configured to move in reciprocating motion to result in a suction phase and a delivery phase of the fluid of interest (F);

  ∘ a delivery port (9) of the fluid of interest (F) configured to allow delivery of the fluid of interest (F),

  ∘ a suction port (8) of the fluid of interest (F) configured to receive the fluid of interest (F) in a hydraulic circuit of the pump (1),

  ∘ at least one intercepting element (7) configured, during a pump use condition, to selectively interdict and allow fluid communication between:

  ▪ the suction port (8) and said internal volume (5), and

  ▪ a delivery port (9) and said internal volume (5),

  ∘ at least one power port (10) configured to receive, in a working circuit, energy necessary for the movement of said at least one membrane (6);

  the method by further including the following steps:
  • connect a suction pipe (8a) to the suction port (8);
  • connect a delivery pipe (9a) to the delivery port (9);
  • prepare a piezometric pipeline (110) inserted deep into the soil to be reclaimed;
  • insert said membrane pump (1) inside the piezometric pipeline (110), in which the head portion (2) of the pump (1) faces the soil surface, while the bottom portion (3) of the pump (1) faces a depth of the piezometric pipeline (110),
  • lower the membrane pump (1) within said piezometric pipeline to a reservoir of the fluid of interest (F) to a depth where:

    ∘ the membrane pump (1) is above a level of the fluid of interest, particularly outside the fluid of interest; and

    ∘ the suction pipe (8a) is at least partially embedded within the fluid of interest (F) contained in the basin.

[0019] A 6th aspect is directed to a method of pumping a fluid of interest (F) for land reclamation, said method comprising the steps of:

• provide a membrane pump (1) including a pump body carrying:

  ∘ a head portion (2);

  ∘ a bottom portion (3) opposite to said head portion (2);

  ∘ at least one side wall (4) extending along a main axis (A) between said head portion (2) and said bottom portion (3), said side wall (4) defining, in combination with the head portion (2) and the bottom portion (3), an internal volume (5) of said membrane pump (1);

  ∘ at least one flexible membrane (6) placed within said internal volume (5) and movable along a working direction substantially parallel to the main axis (A), said at least one flexible membrane (6) being configured to move in reciprocating motion to result in a suction phase and a delivery phase of the fluid of interest (F);

  ∘ a delivery port (9) of the fluid of interest (F) configured to allow the discharge of the fluid of interest (F), said delivery port (9) being located on the head portion (2) of the membrane pump (1);

  ∘ a suction port (8) of the fluid of interest (F) configured to receive the fluid of interest (F) in a hydraulic circuit of the pump (1), said suction port (8) being located on the bottom portion (3) of the membrane pump (1),

  ∘ at least one intercepting element (7) configured, during a pump use condition, to selectively interdict and allow fluid communication between:

  ▪ the suction port (8) and said internal volume (5), and

  ▪ a delivery port (9) and said internal volume (5),

  ∘ at least one power port (10) configured to receive, in a working circuit, energy necessary for the movement of said at least one membrane (6);
  and in which:

  ∘ said head portion (2) carries the delivery port (9) and power port (10), and

  ∘ said bottom portion (3) carries the suction port (8);

  the method by further including the following steps:
  • connect a delivery pipe (9a) to the delivery port (9);
  • prepare a piezometric pipeline (110) inserted deep into the soil to be reclaimed;
  • insert said membrane pump (1) inside the piezometric conduit (110), in which the head portion (2) of the pump (1) faces the soil surface, while the bottom portion (3) of the pump (1) faces a depth of the piezometric conduit (110),
  lower the membrane pump (1) within said piezometric pipeline deep into a reservoir of the fluid of interest (F)

[0020] In a 7th aspect in accordance with any of the preceding aspects, said pump (1) extends transversely along a lateral direction (B) substantially orthogonal to said main axis (A) to define an extension in width (W) of less than 15 cm, more particularly less than 12 cm, more particularly said width being less than 10,2 cm (4 in.), optionally said width being between 5 cm and 11 cm, more particularly between 7 cm and 11 cm, more particularly between 7 cm and 9 cm, more particularly substantially equal to 8 cm, more particularly wherein said extension in width defines a maximum transverse pump footprint.

[0021] In an 8th aspect in accordance with any of the preceding aspects, said pump extends longitudinally along said main axis (A) to define an extension in length between 10 cm and 50 cm, more particularly between 13 cm and 40 cm, more particularly between 16 cm and 30 cm, wherein said length is measured between a plane of the head portion (2) and a plane of the bottom portion (3).

[0022] In a 9th aspect in agreement with any of the previous aspects, said pump extends:

• longitudinally along said main axis (A), particularly axially, to define an extension in length (L), and
• transversely along a lateral direction substantially orthogonal to said main axis (A) to define an extension in width,

in which said extension in length (L) being greater than said extension in width (W), specifically said extension in length being at least 1.5 times greater than said extension in width, specifically said extension in length being between 2 and 5 times greater than said extension in width.

[0023] In a 10th aspect in accordance with any of the preceding aspects, the delivery port (9) extends along an axis substantially parallel to the main axis (A) of the pump, specifically said delivery port (9) being configured to direct the fluid of interest (F) axially along a direction substantially parallel to or coincident with the main axis (A) of the pump.

[0024] In an 11th aspect in accordance with any of the preceding aspects, the suction port (8) extends along an axis substantially parallel to the main axis (A) of the pump, specifically said suction port (8) being configured to receive the fluid of interest (F) axially along a direction substantially parallel to or coincident with the main axis (A) of the pump.

[0025] In a 12th aspect in accordance with any of the previous aspects, the power port (10) extends along an axis substantially parallel or coincident with the main axis (A) of the pump.

[0026] In a 13th aspect in accordance with any of the previous aspects, the delivery port (9) extends along an axis substantially parallel to the main axis (A) of the pump, specifically said delivery port (9) being configured to generate an axial discharge of the fluid of interest (F) substantially parallel to the main axis (A) of the pump.

[0027] In a 14th aspect in accordance with any of the preceding aspects, the suction port (8) is configured to connect to, or includes, an suction port pipe (8a) extending between:

• a first end connection to the suction socket (8), and
• a second end configured to be immersed, particularly partially, in the fluid of interest (F),

said suction line extending away from the side wall (4) of the pump, in particular away from a body of said pump, in particular of a length of less than 8 meters, in particular of less than 6 meters, more particularly of less than 4 or 5 meters, optionally said length of the suction line (8a) being between 10 cm and 8 meters, in particular between 30 cm and 6 meters, more particularly between 1 m and 6 meters, optionally between 1 meter and 4 meters.

[0028] In a 15th aspect in accordance with the previous aspect, said suction pipe (8a) includes an internal passage lumen having a diameter between 0.6 cm and 1, 5 cm, more particularly between 0.4 cm and 1 cm, more particularly between 0.5 cm and 0.8 cm, optionally substantially equal to 0.6 cm (1/4").

[0029] In a 16th aspect in accordance with any of the preceding aspects, the suction port (8) includes an internal passage lumen having a diameter between 0.6 cm and 1.5 cm, specifically between 0.4 cm and 1 cm, more specifically between 0.5 cm and 0.8 cm, optionally substantially equal to 0.6 cm (1/4").

[0030] In a 17th aspect in accordance with any of the preceding aspects, the delivery port (9) is configured to connect to, or includes, a delivery pipe (9a) extending between:

• a first end connection to the delivery port (9), and
• a second end configured to bring the fluid of interest (F) to the surface up to the level of the footing (GL),

optionally said pipe extending away from the side wall (4) of the pump, in particular away from a body of said pump, by a length of less than 80 meters, in particular less than 65 meters.

[0031] In an 18th aspect in accordance with any of the preceding aspects, said delivery pipe (9a) includes an internal passage lumen having a diameter between 0.6 cm and 1, 5 cm, more particularly between 0.4 cm and 1 cm, more particularly between 0.5 cm and 0.8 cm, optionally substantially equal to 0.6 cm (1/4"). In a 19th aspect in accordance with any of the preceding aspects, the delivery port (9) includes an internal passage lumen having a diameter between 0.6 cm and 1, 5 cm, specifically between 0.4 cm and 1 cm, more specifically between 0.5 cm and 0.8 cm, optionally substantially equal to 0.6 cm (1/4").

[0032] In a 20th aspect in accordance with any of the preceding aspects, said membrane pump (1) is configured to allow a maximum dry suction height of between 1 meter and 6 meters, more particularly between 2 meters and 5 meters, more particularly between 3 meters and 4 meters, said maximum dry suction height being specifically defined as the maximum distance, during a pump use condition, between the fluid level of interest (F) and said pump.

[0033] In a 21st aspect in accordance with any of the preceding aspects, said pump (1) presents substantially cylindrical form to define a section, orthogonal to the main axis (A), of the side wall (4) having substantially circular form, particularly wherein said side wall (4) of the pump presents cylindrical form extending between the head portion (2) and the bottom portion (3).

[0034] In a 22nd aspect in accordance with any of the preceding aspects, the head portion (2) is extends radially substantially orthogonal to the main axis (A) of the pump, optionally the head portion comprising a substantially flat end surface bearing the delivery port, power port, and optionally the discharge port (11). In a 23rd aspect in accordance with any of the preceding aspects, the bottom portion (3) extends radially substantially orthogonal to the main axis (A) of the pump, optionally the bottom portion encompassing a respective substantially flat extremal surface bearing the suction port.

[0035] In a 24th aspect in accordance with any of the previous aspects, the side wall defines a maximum radial footprint of the pump (1), the delivery port (9), the suction port (8) and optionally the power port (10) being within said maximum radial footprint.

[0036] In a 25th aspect in accordance with any of the preceding aspects, the side wall (4) is devoid of pressure ports or delivery ports of the fluid of interest (F) or suction ports of the fluid of interest (F).

[0037] In a 26th aspect in agreement with any of the preceding aspects, the side wall (4) defines a lateral surface substantially free of discontinuities.

[0038] In a 27th aspect in agreement with any of the previous aspects, the side wall (4) defines a substantially constant lateral footprint.

[0039] In a 28th aspect in agreement with any of the previous aspects, said power port (10) includes:

• a pressure port (10a) arranged on the head portion (2) of the pump and configured to receive as an input, in the working circuit, a working fluid (G) under pressure configured to determine the alternating movement of at least one membrane (6) along the respective working direction,

  said internal volume including said working circuit, and in which said working circuit is configured to carry said working fluid (G),

  said working fluid (G) being specifically a pressurized gas, e.g., compressed air; or

• an electrical port or an inlet for an electrical cable for supplying power to an electric motor or actuator operatively connected, directly or indirectly, to the at least one membrane (6) and configured to determine the alternating movement of the at least one membrane (6) along the working direction, said electric motor or actuator being housed within the internal volume (5) of the pump.

[0040] In a 29th aspect in accordance with any of the preceding aspects, said pump further includes a discharge port (11) of the working fluid (G), said discharge port (11) being configured to allow the working fluid (G) to escape subsequent to a suction and/or delivery phase of the pump,
and in which said discharge port (11) is placed on the head portion (2) of the pump.

[0041] In a 30° aspect in accordance with any of the preceding aspects, the discharge port (11) of the working fluid (G) extends along an axis substantially parallel to the main axis (A) of the pump, specifically said discharge port (11) being configured to discharge the working fluid (G) axially along a direction substantially parallel to the main axis (A) of the pump.

[0042] In a 31st aspect in accordance with any of the preceding aspects, the pump includes a hook 12 constrained to the gripping portion and configured to engage with a rope or chain to allow deep recovery of the pump during a condition of its use, in particular said hook 12 being at least one of a carabiner, eyebolt, or hook 12 closed or open, in particular said hook 12 being sized to bear in tension the weight of the pump.

[0043] In a 32nd aspect according with any of the previous aspects,

• the head portion (2) of the pump carries the delivery port (9), power port (10), gas/air port (11) and hook (12); and
• the bottom portion (3) carries the suction port (8).

[0044] In a 33rd aspect in accordance with any of the previous aspects, the working direction of said at least one membrane (6) is substantially coincident with the main axis (A) of the pump, particularly where said at least one membrane (6) and said side wall (4) of the pump being concentric to each other.

[0045] In a 34th aspect in accordance with any of the preceding aspects, said membrane pump (1) includes, among said at least one membrane (6), a single working membrane (6a), said working membrane (6a) being the only membrane (6) of said membrane pump (1) to contact, during a condition of pump use, the fluid of interest (F) to determine suction and delivery of the fluid of interest (F).

[0046] In a 35th aspect in agreement with any of the previous aspects, said working membrane (6a) is:

• separated from the head portion (2) of the pump by a first distance (d1), and
• separated from the bottom portion (3) of the pump by a second distance (d2),

  in which said first distance (d1) is greater than said second distance (d2),

  optionally in which said first distance (d1) is about twice as long as said second distance (d2).

[0047] In a 36th aspect in accordance with any one of the preceding aspects, an intercepting element (7) is interposed between said suction port (8) and said working membrane (6a), said working membrane (6a) being selectively in fluid communication with the suction port (8) via said at least one intercepting element (7).

[0048] In a 37th aspect in accordance with any of the previous aspects, said working membrane (6a) extends in thickness between a first and a second surface, and in which:

• the first surface defines at least part of the hydraulic circuit and is configured to contact, during a pump use condition, the fluid of interest (F), particularly the first surface being facing the bottom portion (3);
• the second surface defines at least part of the working circuit and is configured to contact the working fluid (G) to determine the alternating motion of said working membrane (6a), particularly the second surface being facing the head portion (2).

[0049] In a 38th aspect in accordance with any of the previous aspects, said pump includes a pumping volume (20) axially interposed between the working membrane (6a) and the suction port (8),
and in which the pump is configured to define a suction phase of the fluid of interest (F) and a delivery phase of the fluid of interest (F), in which:

• during the suction phase, the working membrane (6a) moves away from the bottom portion (3) d increase said pumping volume suitable for receiving the fluid of interest (F),
  during said suction phase the fluid of interest (F) contacting said working membrane (6a);
• during the delivery phase, the working membrane (6a) moves closer to the bottom portion (3), reducing the pumping volume,

  the delivery phase by pressurizing the fluid of interest (F) to direct it to the delivery port (9),

  during said delivery phase the fluid of interest (F) contacting said working membrane (6a);

  in which the working fluid (G) determines said suction phase and said delivery phase.

[0050] In a 39th aspect in accordance with any of the preceding aspects, said pump comprises a working shaft (13) movable along a working direction and extending in length between a first and a second end along said working direction.

[0051] In a 40th aspect in accordance with the preceding aspect, said first end of the working shaft (13) is constrained to a membrane (6) of said at least one membrane (6), in particular said first end of the working shaft (13) being constrained to the working membrane (6a), such that an axial movement of said membrane (6) results in a concomitant axial movement of the working shaft (13), in particular said working direction being parallel or coincident with said main axis (A).

[0052] In a 41st aspect in accordance with any of the preceding aspects from 39, said working shaft (13) is movable between a first position and a second position, and in which the pump comprises a pumping volume (20) axially interposed between the working membrane (6a) and the suction port (8),
in which:

• in the first position, the working shaft is arranged in a position proximal to the bottom portion (3), the working membrane (6a) by defining, in conjunction with a portion of the pump hydraulic circuit, a minimum pumping volume interposed axially between the working membrane (6a) and the suction port (8).
• in the second position, the working shaft is arranged in a position distal to the bottom portion (3), the working membrane (6a) by defining, in combination with a portion of the pump hydraulic circuit, a maximum pumping volume interposed axially between the working membrane (6a) and the suction port (8),

  in particular said minimum pumping volume being less than said maximum pumping volume to generate, when the shaft moves from the second to the first position, a thrust on the fluid of interest (F) toward the delivery port (9),

  and in particular where the working shaft, when arranged in the distal position, has a distance, measured with respect to the bottom portion of the pump, greater than a similar distance when the working shaft is arranged in the proximal position.

  In a 42nd aspect in accordance with any of the previous aspects from 39, said working shaft (13) is positionable in a neutral position interposed, according to the main axis (A), between the first position and the second position,

and in which:

• in the first position of the working shaft, the membrane (6) is flexed, relative to a natural unstressed conformation, as the bottom portion (3) approaches;
• in the second position of the working shaft, the membrane (6) is flexed, relative to the natural unstressed conformation, away from the bottom portion (3);
• in the neutral position of the working shaft, the membrane (6) is in the natural unstressed conformation, called the neutral position defining a substantially flat surface of said membrane (6).

[0053] In a 43rd aspect in accordance with any of the preceding aspects, the pump (1) comprises a return membrane (6b), optionally substantially equal in structure to the working membrane (6a), constrained to the second end of the working shaft (13),and extending in thickness between a first and second main extension surface, where:

• the first surface is communicating with the working circuit and facing the bottom portion (3) of the pump (1),
• the second surface faces the head portion of the pump (1),
  called the return membrane (6b) by defining a respective axis orthogonal to the first and second main extension surfaces, called the axis of the return membrane being parallel or coincident with the main axis (A) of the pump (1).

[0054] In a 44th aspect in accordance with any of the previous aspects, the return membrane (6b) is separated from the hydraulic circuit.

[0055] In a 45° aspect in accordance with any of the preceding aspects, the pump includes an elastic return element operatively connected to the working shaft (13) and configured to generate an axial return force on the working shaft (13) opposite to a contextual working force generated, at least during an operating condition of the pump (1), by the working fluid (G), in particular said return force being directed toward the neutral position, and in particular said elastic return element being a passive element.

[0056] In a 45° aspect in accordance with any of the previous aspects, the elastic return element is constrained to the second end of the working shaft (13).

[0057] In a 46th aspect in accordance with any of the previous aspects, the elastic return element includes a return membrane (6b), optionally called a return membrane (6b) being substantially the same in structure as said working membrane (6a).

[0058] In a 47th aspect in accordance with any of the preceding aspects, said at least one membrane (6) has a substantially circular shape extending radially along a main plane of extension, said main plane of extension being substantially orthogonal to the main axis (A) of the pump,
in particular said working membrane (6a) has a substantially circular shape extending radially along a main extension plane, said main extension plane being substantially orthogonal to the main axis (A) of the pump.

[0059] In a 48th aspect in accordance with any of the previous aspects, the return membrane (6b) has a substantially circular shape extending radially along a respective main extension plane, said respective main extension plane being substantially orthogonal to the main axis (A) of the pump.

[0060] In a 49th aspect in agreement with any of the previous aspects, said pump includes:

• a working membrane (6a) configured to contact the fluid of interest (F) and to determine suction and discharge of the fluid of interest (F), said working membrane (6a) being the only membrane (6) of said membrane pump (1) to contact, during a condition of use of the pump, the fluid of interest (F), specifically said working membrane (6a) being the only membrane (6) of said membrane pump (1) to be in fluid communication with the suction port (8) and/or delivery port (9),
• a return membrane (6b);
• a working shaft (13) movable along one working direction and extending in length between a first and second end along said working direction,

  in which said first end of the working shaft (13) is constrained to the working membrane (6a), and in which said second end is constrained to the return membrane (6b),

  such that an axial movement of said working membrane (6a) and of said return membrane (6b) results in a simultaneous axial movement of the working shaft (13), particularly said working direction being parallel or coincident with said main axis (A).

[0061] In a 50th aspect in accordance with any of the previous aspects, the pump includes:

• the working circuit configured to accommodate the working fluid (G), said working circuit being connectable, through the at least one intercepting element (7), in fluid communication with the pressure port (10a), and
• the hydraulic circuit configured to accommodate the fluid of interest (F), called the fluid circuit of interest (F) being selectively connectable, through the at least one intercepting element (7), in fluid communication with the suction port (8) and delivery port (9),
  and in which said working circuit is fluidically separated from the hydraulic circuit by said at least one membrane (6), particularly by said working membrane (6a).

[0062] In a 51st aspect in agreement with any of the previous aspects,

• the working membrane (6a) is in fluid communication with the working circuit and the hydraulic circuit, specifically said working membrane (6a) separating the hydraulic circuit from the working circuit,
• said return membrane (6b) is communicating with the working circuit and is separated from the hydraulic circuit, particularly where the return membrane (6b) is placed entirely within the working circuit.

[0063] In a 52nd aspect in accordance with any of the previous aspects, the pump, during a suction phase of the fluid of interest (F), is configured to direct the working fluid (G) to the return membrane (6b) resulting in the following sub-phases:

• deformation of the return membrane (6b) determined by the working fluid (G) under pressure;
• movement of the working shaft (13) in approaching the head portion (2);
• deformation of the working membrane (6a) determined by the movement of the working shaft (13);
• increase in pumping volume to result in the suction of the fluid of interest through to the suction port (8).

[0064] In a 53rd aspect in accordance with any of the preceding aspects, the pump, during a delivery phase of the fluid of interest (F), is configured to direct the working fluid (G) to the working membrane (6a), resulting in the following sub-phases:

• deformation of the working membrane (6a) determined by the working fluid (G) under pressure;
• movement of the working shaft (13) in approaching the bottom portion (3);
• deformation of the return membrane (6a) determined by the movement of the working shaft (13);
• reduction of pumping volume to determine the discharge of the fluid of interest through to the delivery port (9).

[0065] In a 54th aspect in accordance with any of the previous aspects, the supply phase is determined by the working membrane (6a), while the suction phase is determined by the return membrane (6b).

[0066] In a 55th aspect in accordance with any of the preceding aspects, the working membrane separates the hydraulic circuit from the working circuit, particularly where the working membrane is in fluid communication with the hydraulic circuit on one side and with the working circuit on the opposite side, and where the return membrane is in fluid communication with the working circuit and separated from the hydraulic circuit.

[0067] In a 56th aspect in accordance with any of the previous aspects, the working membrane and the return membrane are distinct from each other and spatially separated.

[0068] In a 57th aspect in accordance with any of the preceding aspects, a prevalence of said membrane pump (1) is determined by the movement of said at least one membrane (6), in particular it is determined by the alternating movement of said one and only one working membrane (6a).

[0069] In a 58th aspect in accordance with any of the preceding aspects, the at least one intercepting element (7) of the pump (1) comprises a first intercepting element (7a) located at the suction port (8), and a second intercepting element (7b) located at the delivery port (9), said first and second intercepting elements (7a, 7b) being inserted within the hydraulic circuit of the pump (1).

[0070] In a 59th aspect in accordance with the previous aspect, said first intercepting element (7a) includes a respective one-way valve configured for:

• allow the passage of the fluid of interest (F) in a suction direction from the suction port (8) to the hydraulic circuit, specifically to the pumping volume of the hydraulic circuit, and
• to interdict the passage of the fluid of interest (F) in a non-return direction out of the suction port (8), specifically from the pumping volume to and out of the suction port (8),

and in which said second intercepting element (7b) comprising a respective one-way valve configured for:

• allowing the passage of the fluid of interest (F) in a direct discharge direction out of the delivery port (9), and
• interdicting the passage of the fluid of interest (F) or gas or a fluid in a non-return direction from the delivery port (9) to the hydraulic circuit.

[0071] In a 60th aspect in accordance with any of the previous aspects, the first intercepting element (7a) is interposed between the suction port (8) and the hydraulic circuit, specifically between the suction port and the pumping volume, and the second intercepting element (7b) is interposed between the delivery port (9) and the hydraulic circuit, specifically between the delivery port and the pumping volume.

[0072] In a 61st aspect in accordance with any of the previous aspects, the first intercepting element (7a) is placed at the bottom (3) portion of the pump (1), while the second intercepting element (7b) is placed at the head (2) portion of the pump (1).

[0073] In a 62nd aspect in accordance with any of the previous aspects, the at least one intercept element includes:

• a floating ball (15) between an open position, where fluid passage is allowed, and a closed position where fluid passage is prohibited,
• an o-ring gasket (16), specifically an o-ring, configured to contact, in the closed position, said floating ball,

and in which said floating sphere is movable between the open position and the closed position as a function of a fluid crossing direction.

[0074] In a 63rd aspect in agreement with any of the previous aspects, the sphere has a diameter Ds and the ring seal has a diameter, specifically an inner diameter, Dg,
where Dg<Ds.

[0075] In a 64th aspect in accordance with any of the preceding aspects, the first intercepting element (7a) includes the ring gasket (16) interposed between the respective floating ball (15) and the suction port (8), and the second intercepting element (7b) includes the floating ball (15) interposed between the respective ring gasket (16) and the delivery port (9).

[0076] In a 65th aspect in accordance with any of the preceding aspects, the pump comprises at least a first body and a second body that are distinct and bound together to define a single pump body of said membrane pump (1), said first body comprising at least the bottom portion (3) and part of the side wall (4), and said second body comprising the head portion (2) and part of the side wall (4).

[0077] In a 66th aspect in accordance with the previous aspect, said first and second bodies face each other along a plane basically orthogonal to the main axis (A) of the pump.

[0078] In a 67th aspect in agreement with any of the previous aspects from 65, the at least one membrane (6), particularly the single working membrane (6a), is interposed between the first body and the second body. In a 68th aspect in accordance with any of the previous aspects from 65, said working membrane (6a) defines a fluid-tight seal between the first and second bodies.

[0079] In a 69th aspect in accordance with any of the previous aspects, the pump comprises at least a first body, a second body, and a third body that are distinct and bound together to define a single pump body of the membrane pump (1),

said first body including at least the bottom portion (3) and part of the side wall (4),

said second body comprising the head portion (2) and part of the side wall (4),

said third body by including part of the side wall (4),

said third body being interposed, according to the direction of the main axis (A), between the first and second bodies,

in which said first and third bodies face each other along a first plane of support substantially orthogonal to the main axis (A) of the pump,

and in which said second and third bodies face each other along a second support plane substantially orthogonal to the main axis (A) of the pump.

[0080] In a 70th aspect in accordance with the previous aspect, said first and second support planes are basically parallel to each other, and in which the working membrane (6a) is interposed between the first body and the third body to define a fluid-tight seal, optionally in which the return membrane (6b) is interposed between the second body and the third body to define a fluid-tight seal.

[0081] In a 71st aspect in accordance with any of the preceding aspects, the pump includes clamping bolts each extending in length along a direction substantially parallel to the main axis (A) of the pump, said clamping bolts traversing the first and second bodies, in particular traversing the first body, second body and third body, to determine a constraint between said bodies and to define the membrane pump (1) as a single body.

[0082] In a 72nd aspect in accordance with any of the preceding aspects, the working membrane (6a) is made of elastic material, especially rubbery or silicone material.

[0083] In a 73rd aspect in accordance with any of the previous aspects, the fluid of interest (F) is in liquid form, specifically the fluid of interest (F) comprising a liquid and solid particles, e.g., soil and sand.

[0084] In a 74th aspect in accordance with any of the previous aspects, the fluid of interest (F) includes a liquid in the group among: water, a corrosive liquid, a polluting liquid, petroleum, solvents, chemical agents, hydrocarbons, chemical solvents.

[0085] In a 75th aspect in accordance with any of the previous aspects, the internal volume (5) includes the hydraulic circuit and the working circuit.

[0086] A 76th aspect is directed to a pumping plant (100) comprising:

• a membrane pump in accordance with any of the above, and
• a pressurized working fluid source, particularly a compressor configured to provide a pressurized gas flow rate, including at least one working fluid delivery connector that can be connected, via a working fluid pipeline, to the power port (10) of the membrane pump (1),

optionally in which said pressurized working fluid source is configured to provide a substantially constant flow rate of pressurized working fluid over time.

[0087] In a 77th aspect in accordance with any of the previous aspects, said working fluid source is configured to provide:

• a working fluid pressure between 2 bar and 8 bar, and
• a working fluid flow rate between 0.5 L/min and 4 L/min.

[0088] In a 78th aspect in accordance with any of the preceding aspects, said plant includes a piezometric conduit defining an internal lumen and configured to insert deep into a soil during an operating condition, said piezometric conduit being configured to receive within itself said membrane pump.

[0089] In a 79th aspect in agreement with any of the preceding aspects, called piezometric conduit presence substantially tubular shape with circular cross-section, called piezometric conduit defining an inner lumen diameter between 6 cm and 16 cm, in particular between 8 cm and 13 cm, in particular substantially equal to 10 cm.

[0090] In an 80th aspect in accordance with any of the previous aspects, said piezometric pipeline has a maximum length of less than 80 meters, particularly less than 65 or 60 meters.

[0091] In an 81st aspect in accordance with any of the preceding aspects, the method includes a step of feeding, through the pressure port, the working circuit of the membrane pump (1) with a flow of working fluid, particularly pressurized gas, said flow of the working fluid being at substantially constant pressure and/or flow rate.

[0092] In an 82nd aspect in accordance with any of the above, said working fluid is supplied at a pressure between 2 bar and 8 bar and a flow rate between 0.5 L/min and 4 L/min.

[0093] An 83rd aspect is directed to a use of a membrane pump (1) for the suction of a fluid of interest for land reclamation, said membrane pump being in agreement with any of the previous aspects.

[0094] An 84th aspect is directed to a use of a membrane pump (1) for the suction of a fluid of interest in the chemical industry, said membrane pump being in agreement with any of the previous aspects,

[0095] and where the fluid of interest (F) includes a liquid in the group between a corrosive liquid, a polluting liquid, petroleum, chemical agents, hydrocarbons, chemical solvents and acids.

[0096] In an 85th aspect in accordance with any of the preceding aspects, the membrane pump (1) includes a valve system (50) configured to determine suction and delivery phases of the fluid of interest.

[0097] In an 86th aspect in accordance with the preceding aspect, the valve system (50) is arranged in the internal volume (5) of said membrane pump (1).

[0098] In an 87th aspect in accordance with any of the preceding aspects from 85, the valve system (50) is configured to direct the working fluid (G) under pressure, arriving from the pressure port (10a), selectively to the working membrane (6a) or to the return membrane (6b).

[0099] In an 88th aspect in accordance with any of the preceding aspects from 85, the valve system (50) is configured to determine alternating motion of the shaft (13) to determine suction and delivery phases of the fluid of interest.

[0100] In an 89th aspect in accordance with any of the preceding aspects from 85, the valve system (50) is interposed between the working membrane (6a) and the return membrane (6b).

[0101] In a 90th aspect in accordance with any of the preceding aspects from 85, the valve system (50) comprises the working shaft (13), a shuttle (60), and a distributor (70), wherein the distributor (70) is mounted on the working shaft (13), and the shuttle (60) is interposed radially between the working shaft (13) and the distributor (70).

[0102] In a 91st aspect according to the previous aspect, the distributor (70) is fixed relative to the membrane pump body (1).

[0103] In a 92nd aspect in accordance with any of the previous aspects from 90, the shuttle (60) is movable axially relative to the distributor (70) axially along the working axis of the shaft (13).

[0104] In a 93rd aspect in accordance with any of the preceding aspects from 90, the working shaft (13) is movable axially along its working axis with respect to both the shuttle (60) and the distributor (70).

[0105] In a 94th aspect in accordance with any of the preceding aspects from 90, the shuttle is axially movable between a first position in which the shuttle (60) is abutting against a first bottom stroke (72) of the distributor (70), and a second position in which the shuttle is abutting against a second bottom stroke (73) of the distributor (70).

BRIEF DESCRIPTION OF THE DRAWINGS

[0106] Some embodiments and some aspects of the invention will be described below with reference to the attached drawings, provided for illustrative purposes only and therefore not limiting in which:

• Figure 1 is a perspective view of a pumping plant in accordance with the present invention;
• Figure 2 is a front view of a membrane pump in accordance with the present invention;
• Figures 3-4 are perspective views of a membrane pump in accordance with the present invention;
• Figures 5a-5c are cross-sectional views of a membrane pump in accordance with the present invention in which the transition from the suction phase (Figure 5a) to the delivery phase (Figure 5c) is shown;
• Figure 6 is a schematic view of a pumping system in accordance with the present invention;
• Figure 7 is a perspective view of a membrane pump in accordance with the present invention in which the side wall has been hidden to highlight the membranes and valve system;
• Figure 8 is a perspective view of the membrane pump valve system in accordance with the present invention;
• Figure 9 is an exploded view of the membrane pump valve system in accordance with the present invention;
• Figure 10 is a front view of the working shaft of the membrane pump in accordance with the present invention;
• Figure 11 is a perspective view of the shuttle of the membrane pump valve system in accordance with the present invention;
• Figure 11a is a sectional view of Figure 11 above;
• Figures 12a-12c are cross-sectional views of the membrane pump valve system in accordance with the present invention.

DEFINITIONS AND CONVENTIONS

[0107] Note that in this detailed description corresponding parts illustrated in the various figures are shown with the same numerical references. The figures may illustrate the subject matter of the invention by means of representations that are not to scale; therefore, parts and components illustrated in the figures related to the subject matter of the invention may relate only to schematic representations.

DETAILED DESCRIPTION

Membrane pump 1

[0108] A membrane pump for the suction of a fluid of interest F is denoted with number 1, as shown schematically in Figure 2.

[0109] The membrane pump of the present invention can be used in the field of reclamation, where the removal of a fluid, such as a corrosive liquid or pollutant liquid, present underground is necessary. Such a pump is then configured to extract such a fluid of interest from the ground and pump it to a storage center, such as a cistern.

[0110] Specifically, during soil remediation operations, a piezometric column is inserted into the ground to a predefined depth underground: such a piezometric conduit effectively defines a conduit or pipe that connects the liquid present underground with the ground level GL (see Figure 6). Such a piezometric column may have an internal lumen size, e.g., an internal diameter, between 5 cm and 15cm, specifically between 7.5 cm and 12.5 cm. Commonly, such piezometric pipeline has a cylindrical cross section having an inner diameter of about 10 cm (4").

[0111] The membrane pump of the present invention is then configured to be lowered inside the piezometric pipeline to a predefined depth to allow extraction of the fluid of interest.

[0112] Alternatively, such a pump can be used in the chemical industry, where it is necessary to move or remove a chemically corrosive fluid, such as solvents, combustible liquids such as petroleum or gasoline, or generically chemical agents having acid or basic PH.

[0113] In general terms and in accordance with any embodiment of the present membrane pump, the fluid of interest is a liquid: the fluid of interest F may include water, a corrosive liquid, a pollutant liquid, petroleum, solvents, or chemical agents.

[0114] The membrane pump 1 of the present invention comprises a pump body carrying a head portion 2, a bottom portion 3 opposite to the head portion 2, and at least one side wall 4 extending along a main axis A between the head portion 2 and the bottom portion 3. The head portion 2, the bottom portion 3, and the side wall 4 define a membrane pump body 1 and a respective internal volume 5.

[0115] The pump preferably has a length, measured along the A-axis, between 10 cm and 50 cm, specifically between 13 cm and 40 cm, more specifically between 16 cm and 30 cm. This length measurement is defined between respective ends of the head portion and the bottom portion. Specifically, this length is measured between an end plane of the head portion 2 and an end plane of the bottom portion 3.

[0116] Pump 1 also extends transversely along a lateral direction B substantially orthogonal to the main axis A to define an extension in width W of less than 15 cm, specifically less than 12 cm: more specifically, the width of the pump is less than about 10 cm (equivalent to about 4").

[0117] Extension in width defines a maximum cross-sectional footprint of the pump.

[0118] The pump has elongated shape along the main axis A, such that the extension in length L is greater than the extension in width. For example, the extension in length L may be at least 1.5 times greater than the extension in width W, alternately between 2 and 5 times greater than the extension in width.

[0119] In the embodiment shown in the present figures, the side wall of the pump body defines a maximum cross-sectional footprint of the pump. In other words, all components of the present membrane pump are placed within that maximum transverse footprint defined by the side wall of the pump.

[0120] The membrane pump of the present invention has a substantially cylindrical shape such that a section of the pump along a plane orthogonal to the main axis A defines a substantially constant circular cross-section along the axis A. Alternatively, in an embodiment not shown in the accompanying drawings, the membrane pump of the present invention may have a variable lateral footprint along the main axis A. The head portion 2 preferably has a cylindrical shape extending radially away from the main axis A and substantially orthogonal to the main axis A of the pump. The head portion comprises an end surface substantially flat orthogonal to the axis A. Similarly, the bottom portion 3 extends radially substantially orthogonal to the main axis A along a respective substantially flat extremal surface. The length of the membrane pump 1 can thus be defined by the distance interposed between the extremal surface of the head portion and the respective extremal surface of the bottom portion, to define a cylindrically shaped pump body.

[0121] The pump body, and in particular the side wall 4, the head portion 2, and the bottom portion 3, are made of polymeric material, especially POM-C POM-C filled for Atex zone, PVDF, PP, and PP filled for atex zone. Alternatively, the pump body can be made of metal material, such as aluminum or aisi 316. Pump 1 also includes a delivery port 9 of the fluid of interest F configured to allow pressure delivery of the fluid of interest F. The delivery port 9 is located on the head portion 2 of the membrane pump 1: specifically, the delivery port 9 extends along an axis substantially parallel to the main axis A of the pump, such that, during a pump operating condition, the fluid of interest F flows axially along a direction substantially parallel to or coincident with the main axis A of the pump. In a embodiment, as shown in Figures 2 and 3, the delivery port 9 extends along an axis substantially coincident with the main axis A. In the embodiment shown in the attached figures, delivery port 9 extends away from the pump body to define a male delivery connector. In an embodiment not shown in the attached figures, the delivery port 9 can extend axially toward the internal volume 5 of the pump body to define a female delivery connector. The delivery port 9 has an internal passage lumen having a diameter between 0.6 cm and 1.5 cm, specifically between 0.4 cm and 1 cm, more specifically between 0.5 cm and 0.8 cm, optionally substantially equal to 0.6 cm (1/4").

[0122] The delivery port 9 is also configured to connect to a discharge pipe 9a, as shown in Figures 2 and 6 extending between a first end connection to the delivery port 9, and a second end configured to bring the fluid of interest F to the surface at ground level GL. The pipe extends away from the pump casing by a length that varies according to the needs of the location where it is installed: in this regard, the membrane pump of the present invention is configured to result in a maximum PH fluid head (see Figure 6) of less than 80 meters, particularly less than 65 or 60 meters. The delivery pipe 9a can then extend, during a pump use condition, for a length sufficient to cover a height difference present between pump position and the ground level equal to the maximum PH head of the pump, as schematically shown in Figure 6. Similar to the passage lumen of delivery port 9, delivery pipe 9a includes an internal passage lumen having a diameter between 0.3 cm and 1.25 cm, specifically between 0.4 cm and 1 cm, more specifically between 0.5 cm and 0.8 cm, optionally substantially equal to 0.6 cm (1/4").

[0123] As shown in Figures 2 and 4, the delivery port 9 is located on the end surface of the head portion 2 and extends away from the head portion from that end surface.

[0124] The membrane pump 1 of the present invention also includes a suction port 8 of the fluid of interest F configured to allow suction of the fluid of interest F: the suction port 8 is located on the bottom portion 3 of the membrane pump 1.

[0125] Suction port 8 is located on the bottom portion 3 of membrane pump 1: specifically, suction port 8 extends along an axis substantially parallel to the main axis A of the pump, such that, during a pump operating condition, the fluid of interest F flows axially along a direction substantially parallel to or coincident with the main axis A of the pump. In an embodiment, as shown in Figures 2 and 3, the suction port 8 extends along an axis substantially coincident with the main axis A.

[0126] In the embodiment shown in the attached figures, the suction port 8 extends away from the pump body to define a male suction connector. In an embodiment not shown in the attached figures, the suction port 8 can extend axially toward the internal volume 5 of the pump body to define a female suction connector. Suction port 8 includes an internal passage lumen having a diameter between 0.6 cm and 1.5 cm, specifically between 0.4 cm and 1 cm, more specifically between 0.5 cm and 0.8 cm, optionally substantially equal to 0.6 cm (1/4").

[0127] Membrane pump 1 is configured to allow a maximum dry suction height H_asp , as shown in Figure 6, between 1 meter and 6 meters, specifically between 2 meters and 5 meters, more specifically between 3 meters and 4 meters, called the maximum dry suction height being specifically defined as the maximum distance, under a pump use condition, between the fluid level of interest F and said pump.

[0128] Suction port 8 is also configured to connect to a suction line 8a extending between a first end connection to suction port 8, and a second end configured to be partially submerged in the fluid of interest F. The suction tubing extends away from the pump body 1 by a length of less than 8 meters, more particularly less than 6 meters, more particularly less than 4 or 5 meters. The length of this suction line 8a can therefore be between 10 cm and 8 meters, more particularly between 30 cm and 6 meters, more particularly between 1 m and 6 meters, optionally between 1 meter and 4 meters.

[0129] Similar to suction port 8, suction pipe 8a includes an internal passage lumen having a diameter between 0.6 cm and 1, 5 cm, more specifically between 0.4 cm and 1 cm, more specifically between 0.5 cm and 0.8 cm, optionally substantially equal to 0.6 cm (1/4").

[0130] As shown in Figures 2 and 4, suction port 8 is located on the end surface of bottom portion 3 and extends away from the bottom portion from that end surface.

[0131] In accordance with the above description, side wall 4 defines a maximum radial footprint of pump 1, where the delivery port 9 and suction port 8 are within this maximum radial footprint. Side wall 4 is therefore free of pressure ports, fluid delivery ports of interest F and fluid suction ports of interest F. Preferably, the side wall 4 defines a lateral surface substantially free of discontinuities so as to facilitate its insertion into the piezometric pipeline.

[0132] Pump 1 further includes a working fluid G discharge port 11 configured to allow the working fluid G to escape subsequent to a suction and/or delivery phase of the pump. Such a discharge port 11 can be configured to connect to a discharge line so as to carry the discharged working fluid away from the membrane pump, or such a discharge port can be free, i.e., the working fluid G is discharged at the discharge port itself. As shown in Figures 2 and 4, the discharge port is preferably arranged on the head portion, particularly on the end surface of the head portion. The discharge port 11 extends along an axis substantially parallel to the main axis A of the pump 1: in particular, the discharge port 11 is being configured to discharge the working fluid G axially along a direction substantially parallel to the main axis A of the pump 1. In an embodiment as shown in the attached figures, the discharge port is radially offset from the main axis A and at a predefined distance from the main axis A.

[0133] Pump 1 may also include a filter placed to cover the discharge port to prevent debris from entering the internal volume 5 through the discharge port.

[0134] In an alternative embodiment, discharge port 11 can be housed on the bottom portion of pump 1, specifically on the end surface of the bottom portion 3 of pump 1, and extend along an axis substantially parallel to the main axis A of pump 1.

[0135] In a further embodiment, the pump 1 includes two or more, e.g., three, discharge ports 11 that are distinct from each other and each configured to discharge the working fluid G in the suction or delivery phase of the fluid of interest. The two or more discharge ports may be arranged on the head portion of the pump only: in such a case, the head portion includes the delivery port 9, a power port 10, and the discharge port 11.

[0136] Alternatively, a first discharge port can be placed on the head portion of the pump, while a second discharge port can be placed on the bottom portion of pump 1.

[0137] Pump 1 may further include a hook 12, shown in Figures 2 and 4, configured to attach to a rope or chain to allow deep recovery of the pump during one of its conditions of use. The hook 12 may include at least one of a carabiner, an eyebolt, or a closed or open hook 12. Hook 12 is sized to bear the weight of the pump in tension: in particular, the hook can be made of steel.

[0138] Pump 1 includes at least one flexible membrane 6 placed within the internal volume 5 and movable along a working direction substantially parallel to the main axis A: membrane 6 is configured to move in reciprocating motion to determine suction and delivery of the fluid of interest F. In particular, the working direction of membrane 6 is substantially coincident with the main axis A of the pump.

[0139] In accordance with an embodiment, membranes 6 extend radially with respect to the main axis A and have a substantially circular shape. In particular, membrane 6 and side wall 4 of the pump are concentric to each other.

[0140] The membranes 6 are made of material having elastic properties: in particular, such material may include NBR-VITON rubber, PTFE.

[0141] The pump further includes a power port 10 configured to provide power necessary for the movement of said at least one membrane 6. The power port 10 may include a pressure port 10a disposed on the head portion 2 of the pump and configured to receive as an input a working fluid G under pressure capable of causing alternating movement of the membrane(s) 6 along the working direction. The working fluid G may be a pressurized gas, such as compressed air, placed in fluid communication with the internal volume 5 of the pump. Alternatively, in accordance with an embodiment not shown in the attached figures, the power port 10 includes an electrical port or inlet for an electrical cable to supply power to an electric motor or actuator operatively connected, directly or indirectly, to the membrane(s) 6. The motor or actuator is housed within the internal volume 5 of the pump 1 and is configured to determine the alternating movement of the membrane(s) 6 along the working direction.

[0142] In the case where the present pump includes a pressure port 10a, the pump 1 includes a working circuit configured to accommodate the working fluid G: the working circuit is connectable, via an intercepting element 7, in fluid communication with the pressure port 10a. The working circuit G is then configured to receive the working fluid and direct it to the membrane(s) 6 to determine the suction and delivery phases of the fluid of interest.

[0143] The pump also includes a hydraulic circuit configured to accommodate the fluid of interest F: The fluid circuit of interest F is selectively connectable, via at least one intercepting element 7, in fluid communication with the suction port 8 and delivery port 9. The working circuit is fluidically separated from the hydraulic circuit by the at least one membrane 6. The hydraulic circuit is then configured to receive the fluid of interest F from the suction port 8, and push it under pressure out of the pump 1 through the delivery port 9.

[0144] Following in the description will be a detailed description of the components responsible for allowing and interdicting the flow of working fluid to the pump's membrane(s) 6, determining its alternating movement:
this movement of the membrane(s) 6 determines, as we shall see in detail, a suction phase and a delivery phase of the fluid of interest F.

[0145] In an embodiment shown in Figures 5a-5c, the pump includes a single working membrane 6a: that working membrane 6a is the only membrane of pump 1 configured to contact, during a pump use condition, the fluid of interest F to determine suction and discharge of the fluid of interest F. In other words, the pump includes no other membranes configured both to determine the flow of the fluid of interest and to contact the fluid of interest during a pump use condition.

[0146] In more detail, the working membrane 6a extends in thickness between a first and a second working surface. The first surface defines at least part of the hydraulic circuit and is configured to contact, during a pump operating condition, the fluid of interest F: in particular, the first surface faces the bottom portion 3. The second surface defines at least part of the working circuit and is configured to contact the working fluid G to determine the alternating movement of said working membrane 6: in particular, the second surface faces the head portion 2.

[0147] In accordance with an embodiment shown in the attached figures, the working membrane is separated from the head portion 2 of the pump by a first distance d1, and separated from the bottom portion 3 of the pump by a second distance d2: the first distance d1 is greater than the second distance d2. Optionally, the first distance d1 is about double the second distance d2.

[0148] The return membrane 6b preferably has a circular shape and comprises a central portion and a perimeter portion, the perimeter portion being firmly constrained to the pump body of pump 1.

[0149] The pump also includes a pumping volume 20 axially interposed between the working membrane 6a and the suction port 8, or between the working membrane 6a and the bottom portion 3: this pumping volume 20 is variable according to the movement of the working membrane 6a.

[0150] The pump also includes a working shaft 13 movable along one working direction and extending in length along the working direction between a first and a second end. The working shaft 13 defines a cylindrical body defining a section, orthogonal to the working axis, with a circular shape. In particular, the work axis coincides with the axis in length of the cylindrical body: further the work axis may coincide with the main axis of pump 1.

[0151] The first end of working shaft 13 is constrained to working membrane 6a, such that an axial movement of the membrane results in a simultaneous axial movement of working shaft 13.

[0152] The working shaft is constrained to the central portion of the working membrane 6a, while the perimeter portion of the return membrane is fixed and firmly constrained to the pump body 1. During the axial movement of the working shaft 13, the perimeter portion of the working membrane is fixed, while the central portion moves at the same time as the working shaft 13, to alternately deform the membrane. The working shaft 13 is entirely inserted into the internal volume 5 of the pump 1: in particular, the working shaft is essentially entirely inserted into the working circuit. More specifically, the working circuit accommodates the second end of the working shaft and a shaft body interposed between the first and second ends of the working shaft: the first end, bound to the working membrane 6a, may be communicating with the hydraulic circuit. In other words, the portion of the shaft included in the working circuit is substantially larger than a portion of the shaft communicating with the hydraulic circuit. Specifically, the portion of the shaft between the second surface of the working membrane 6a and the second end of the shaft is entirely inserted within the working circuit: in contrast, the portion of the shaft between the first surface of the working membrane 6a and the first end is inserted into the hydraulic circuit of pump 1. For this proposal, the working shaft 13 is constrained to the working membrane 6a by defining a seal configured to fluidically isolate the hydraulic circuit from the working circuit.

[0153] The working shaft is preferably made of AISI 304 or 316 metal material, e.g., stainless steel, or polymeric material.

[0154] The working shaft 13 is axially movable between a first and a second extremal position. In the first position, the working shaft is in a proximal position with respect to the bottom portion 3: in particular, the working membrane 6a, when the working shaft is arranged in the first position, defines, in combination with a portion of the pump hydraulic circuit, a minimum pumping volume axially interposed between the working membrane and the suction port 8.

[0155] In contrast, in the second position, the working shaft is in a position distal to the bottom portion 3: in particular, the working membrane 6a, when the working shaft is arranged in the second position, defines, in combination with a portion of the pump hydraulic circuit, a maximum pumping volume 20 interposed axially between the working membrane and the suction port 8.

[0156] Specifically, the working shaft, when arranged in the distal position, presents a greater distance, measured with respect to the bottom portion of the pump, than a similar distance when the working shaft is arranged in the proximal position. Similarly, the minimum pumping volume, defined by the working membrane when the working shaft is in the proximal position, has a smaller volumetry than the maximum volume defined by the working membrane when the shaft is in the distal position. The ratio of the maximum pumping volume to the minimum pumping volume defines a compression ratio that is useful in determining a delivery phase of the fluid of interest F to the delivery port.

[0157] The pump 1 may include a return membrane 6b constrained to the work shaft and substantially the same in structure as the work membrane 6a: in particular, the return membrane is constrained to the second end of the work shaft 13. Thus, return membrane 6b is configured to allow axial movement of the working shaft along the working direction: in particular, during an axial movement of the working shaft, return membrane 6b is configured to flex and deform axially. The return membrane 6b may be made of an elastic material, such as silicone or rubber, and may have a substantially circular shape.

[0158] The return membrane can at least partially define the working circuit: in particular, the return membrane can isolate the working circuit from the external environment, thus effectively defining a separation membrane. The return membrane is thus in communication of the working circuit and configured to contact the working fluid in at least one use condition.

[0159] Return membrane 6b is located entirely within the inner volume 5 of pump 1 and in a position adjacent to the head portion 2 of the pump: in particular, return membrane 6b is located at a distance d1 with respect to the head portion, and at a distance d2 with respect to the bottom portion 3, where this distance d2 is greater than the distance d1. In other words, return membrane 6b is closer to the head portion 2 than to the bottom portion 3.

[0160] The return membrane 6b comprises a central portion and a perimeter portion: the working shaft 13 is constrained to the central portion of the return membrane 6b, while the perimeter portion of the return membrane is fixed and firmly constrained to the pump body 1. During the axial movement of the working shaft 13, the perimeter portion of the return membrane is fixed, while the central portion moves at the same time as the working shaft, to alternately deform the membrane.

[0161] The return membrane extends in thickness between a first surface facing the and communicating with the working circuit, and a second surface facing the head portion of the pump and preferably in fluid communication with an external environment: an increase or decrease in working fluid pressure results in the movement of the return membrane, and consequently the movement of the working shaft 13.

[0162] As shown in Figures 5a to 5c, the return membrane 6b is separated from the hydraulic circuit.

[0163] The membrane pump of the present invention may further comprise an elastic return element operatively connected to the working shaft 13 and configured to generate an axial return force on the working shaft 13 suitable for returning the shaft to a neutral position. Such an axial force may be opposite in direction with respect to a contextual working force generated, at least during an operating condition of the pump 1, by the working fluid G. In particular, such a return element is configured to store an energy resulting from an axial movement of the shaft during a suction or delivery phase of the pump, and to return at least part of this energy in the form of an elastic force along a direction opposite to the aforementioned axial movement of the shaft.

[0164] The elastic return element may include a spring, tensile or compression, connected to the working shaft. Alternatively, the elastic element may be defined by the return membrane previously described.

[0165] The membrane pump of the present invention further comprises at least one intercepting element 7 configured, during a pump use condition, to selectively interdict and allow fluid communication between the suction port 8 and the internal volume 5, and between the delivery port 9 and the internal volume 5. Specifically, the at least one intercepting element 7 of the pump includes a first intercepting element 7a located at the suction port 8, and a second intercepting element 7b located at the delivery port 9: the first and second intercepting elements 7a, 7b are both inserted within the hydraulic circuit of the pump 1. The first intercepting element 7a includes a respective one-way valve configured to allow the fluid of interest F to flow in a suction direction from the suction port 8 to the hydraulic circuit, in particular to the pumping volume of the hydraulic circuit. The one-way valve is also configured to interdict the passage of the fluid of interest F in a non-return direction out of the suction port 8, specifically in a direction from the pumping volume to and out of the suction port 8. In other words, the first intercepting element 7a allows fluid to flow and enter pump 1, and at the same time prevents fluid already contained in the pump from escaping from the suction port.

[0166] Similarly, the second intercepting element 7b includes a respective one-way valve configured to allow the fluid of interest F to pass in a direct flow direction out of the delivery port 9. The second intercepting element 7b is also configured to interdict the passage of the fluid of interest F or gas or a fluid in a non-return direction running from the delivery port 9 to the hydraulic circuit. In other words, the second intercepting element allows fluid of interest to flow out of the discharge valve, and at the same time prevents fluid from flowing back into pump 1 through the second intercepting element.

[0167] The first intercepting element 7a is interposed between the suction port 8 and the hydraulic circuit, specifically between the suction port and the pumping volume, while the second intercepting element 7b is interposed between the discharge port 9 and the hydraulic circuit, specifically between the discharge port and the pumping volume. In more detail, the first intercepting element 7a is placed at the bottom portion 3 of pump 1, while the second intercepting element 7b is placed at the head portion 2 of pump 1. The interception element defining the check valve can be made in accordance with different embodiments: one embodiment of the interception element is described in this patent application. However, this embodiment should not be understood in a limiting way but is only intended to show a preferred embodiment. In this regard, the interception element includes a ball 15 floating between an open position, in which fluid passage is allowed, and a closed position in which fluid passage is interdicted. The intercepting element also includes a ring seal 16 configured to contact, in the closed position, the floating sphere: in an embodiment shown in the attached figures, the ring seal includes an o-ring. The floating ball is movable between the open and closed positions depending on the direction of fluid passage: in other words, the direction of the fluid of interest determines the movement of the floating ball. When the ball contacts the o-ring seal, the intercepting element prevents the passage of fluid: conversely, when the ball is spaced away from the o-ring seal, the intercepting element allows the passage of fluid.

[0168] The first intercepting element 7a comprises the ring gasket 16 interposed between the respective floating ball 15 and the suction port 8, while the second intercepting element 7b comprises the floating ball 15 interposed between the respective ring gasket 16 and the delivery port 9.

[0169] The sphere has a diameter Ds and the ring seal has a diameter, specifically an inner diameter, Dg, such that Dg<Ds. This allows the ring seal to receive at least part of the sphere inside the ring, such that the sphere entirely contacts a circular surface of the seal.

[0170] In the embodiment shown in the attached figures, the pump comprises at least a first body 30 and a second body 40 that are distinct and constrained together to define a single pump body: the first body 30 comprises the bottom portion 3 and part of the side wall 4, while the second body 40 comprises the head portion 2 and part of the side wall 4.The first and second bodies face each other along a plane substantially orthogonal to the main axis A of the pump.

[0171] In an embodiment in which the pump includes a single working membrane and return spring, this membrane is interposed between the first body and the second body: specifically, working membrane 6a defines a fluid-tight seal between the first body 30 and the second body 40.

[0172] In accordance with a further embodiment shown in the attached figures, the pump comprises the first body 30, the second body 40, and a third body 41 distinct and bound together to define a single pump body of the membrane pump. The third body is interposed, according to the direction of the main axis A, between the first and second bodies, and comprises at least a portion of the side wall 4. In particular, the first body 30 and the third body 41 face each other along a first support plane substantially orthogonal to the main axis A of the pump, while the second body 40 and the third body 41 face each other along a second support plane substantially orthogonal to the main axis A of the pump and spaced apart from the first support plane. Specifically, the first and second support planes are parallel to each other and spaced by an amount equal to an extension in length of the third body.

[0173] In the embodiment in which the pump includes the third body, the working membrane 6a is interposed between the first body 30 and the third body 41: specifically, the working membrane 6a defines a fluid-tight seal between the first body 30 and the third body 41.

[0174] In the embodiment in which the pump includes the third body, the return membrane 6b is interposed between the second body and the third body to define a fluid-tight seal between the second and third bodies.

[0175] The first, second and third bodies each have a basically cylindrical shape having the same diameter.

[0176] The pump also includes two or more clamping bolts, specifically 4 or more, each extending in length along a direction substantially parallel to the main axis A of the pump: each bolt includes a threaded rod passing through the first and second bodies and the third body, to determine a constraint between said bodies to define the membrane pump 1 into a single body.

[0177] The pump is configured to define a suction phase of the fluid of interest F and a delivery phase of the fluid of interest F.

[0178] During the suction phase, the working membrane 6a moves away from the bottom portion 3 to define the maximum pumping volume, interposed between the working membrane and the bottom portion 3, capable of accommodating the fluid of interest F. Specifically, the movement of the working shaft from the first to the second position determines the suction phase of the fluid of interest through the suction port: during the suction phase, the fluid of interest F contacts the working membrane 6a.

[0179] In an embodiment comprising working membrane 6a and return membrane 6b, the suction phase is determined by the return membrane axially moved by the working fluid G: specifically, during the suction phase, the working fluid is directed toward the return membrane 6b to move the working shaft from the first to the second position.

[0180] Specifically, during a suction phase of the fluid of interest F through the suction port 8, the pump is configured to direct the working fluid G toward the return membrane 6b, the return membrane 6b determines or helps move the working shaft 13 along the working axis toward the head portion, and the working membrane 6a is pulled by the working shaft 13 away from the bottom portion 3 to define the maximum pumping volume.

[0181] Alternatively, in an embodiment comprising the working membrane 6a and a spring as an elastic return element, and in which the return membrane 6b is absent, the suction phase is determined by the force determined by the spring, while the delivery phase is determined by the working fluid G acting on the working membrane 6a: specifically, during a suction phase of the fluid of interest F through the suction port 8, the spring determines or helps move the working shaft 13 along the working axis toward the head portion, and the working membrane 6a is pulled by the working shaft 13 away from the bottom portion 3 to define the maximum pumping volume.

[0182] During the suction phase, the first intercepting element 7a is in the open position to allow the fluid of interest to flow into the pumping volume: in particular, the fluid of interest itself, by exerting pressure on the floating ball of the first intercepting element directed toward the pumping volume, causes the opening of the first intercepting element 7a. Conversely, during the suction phase, the second intercepting element 7b is in the closed position, to prevent the backflow of the fluid of interest from the delivery port 9 into the hydraulic circuit.

[0183] Conversely, during the delivery phase, the working membrane 6a moves closer to the bottom portion 3 to define the minimum pumping volume, interposed between the working membrane and the bottom portion 3, to place the fluid of interest F under pressure. Specifically, the movement of the working shaft from the second to the first position determines the delivery phase of the fluid of interest to the delivery port 9: during the delivery phase, the fluid of interest F contacts the working membrane 6a.

[0184] Note that, in an embodiment comprising working membrane 6a and return membrane 6b, the working fluid is selectively active on both the working membrane and the return membrane: thus, the working fluid actively contributes to both the suction phase and the delivery phase. In other words, the suction phase and the delivery phase are both originated by the working fluid: in particular, the working fluid G determines the movement of the working membrane 6a and the return membrane 6b, which in turn move the working shaft 13 to the first and second positions.

[0185] Specifically, during a phase of delivery of the fluid of interest F through the delivery port 9, the pump is configured to direct the working fluid G toward the working membrane 6a, the working membrane 6a determines or contributes to movement of the working shaft 13 along the working shaft toward the bottom portion to define the minimum pumping volume: contextually the return membrane 6b is pulled from the working shaft toward the bottom portion, or the spring of the return element is loaded by the movement of the working shaft toward the bottom portion.

[0186] During the delivery phase, the first intercepting element 7a is in the closed position to prevent the pressure exerted by the working membrane 6a on the fluid of interest from causing the fluid to flow out of the suction port: in particular, the fluid of interest itself, by exerting pressure on the floating ball of the first intercepting element directed toward the suction port, causes the first intercepting element 7a to close. Conversely, during the delivery phase, the second intercepting element 7b is in the open position, to allow the fluid of interest to flow through the delivery port 9 out of the hydraulic circuit.

Valve system 50 of the membrane pump 1

[0187] Figures 7 to 12c show a valve system 50 of the previously described membrane pump 1. Valve system 50 is configured to direct the working fluid G under pressure, arriving from pressure port 10a, selectively to either working membrane 6a or return membrane 6b, thereby determining the alternating motion of shaft 13 and the suction and delivery phases of the fluid of interest.

[0188] Figure 7 shows membrane pump 1 in which the first body 30, second body 40, and third body 41 have been removed to make the interior of pump 1 visible. Specifically in Figure 8, the working membrane 6a, the return membrane 6b, and the valve system 50 interposed between the working membrane 6a and the return membrane 6b are clearly visible.

[0189] The valve system, shown in figure 9 in an exploded view, includes shaft 13, a shuttle 60, and a distributor 70.

[0190] Shaft 13 is shown in greater detail in Figure 10 and has a substantially cylindrical shape extending between the first and second ends 13a, 13b. Shaft 13 includes a side wall 13c extending along the working axis of shaft 13 and interposed between the first and second ends 13a, 13b. The side wall 13c of the shaft 13 includes grooves defining a change in the outer diameter of the side wall 13c. These grooves define, when the valve system is assembled as in Figure 8, passages for the working fluid: in other words, the axial movement of shaft 13 results in the concomitant movement of these grooves to define passages of the working fluid as a function of the axial position of working shaft 13, as described below and as depicted in Figures 12a-12c.

[0191] In particular, the shaft of the present invention includes a central groove 14 preferably equidistant from the first and second ends 13a, 13b of the working shaft 13. The central groove 14 is interposed between a first and second end portions 14a, 14b of the working shaft, wherein the central groove 14 has a diameter D1_s , while the first and second end portions have a diameter D2_s , such that D2_s <D1_s . A difference between D1_s and D2_s defines a groove depth for air passage between 0.1 mm 0.4 mm. In other words, the central groove 14 defines a section of the working shaft 13 that is smaller in diameter than the adjacent closure portions.

[0192] The working shaft 13 also includes a first and second tapered portions 17a, 17b, such that the first closure portion 14a is interposed between the central groove 14 and the first tapered portion 17a, and the second closure portion 14b is interposed between the central groove 14 and the second tapered portion 17b. The first and second tapered portions 17a, 17a have a diameter D3_s having a smaller diameter than the diameter of the first and second closure portions 14a, 14b. The diameter D3s of the first and second portions can be substantially equal to the diameter D1s of the central groove 14.

[0193] The working shaft 13 can be made by a turning process to define the first groove 14, the first and second closing portions 14a, 14b, and the first and second tapered portions 17a, 17b.

[0194] The shaft further comprises a first and second end portions 18a, 18b respectively adjacent to the first and second ends of work shaft 13: specifically, the first end portion 18a is interposed between the first tapered portion 17a and the first end, while the second end portion 18b is interposed between the second tapered portion 17b and the second end of work shaft 13.

[0195] The first and second end portions 18a, 18b may have a smaller D4s diameter than the diameter of the first and second tapered portions 17a, 17b.

[0196] The first and second end portions 18a, 18b are configured to bind to the working membrane 6a and the return membrane 6b, respectively.

[0197] As shown in Figure 10, the working shaft 13 is symmetrical with respect to a central plane orthogonal to the working axis of the shaft and equidistant from the first and second ends of the working shaft 13. In particular, the working shaft is axisymmetrical.

[0198] Valve system 50 also includes shuttle 60 presenting substantially cylindrical shape and coaxial to shaft 13. Shuttle 60 includes a main channel 61 extending axially between a first and second end of shuttle 60a, 60b: working shaft 13 is inserted into main channel 61.

[0199] The difference between the maximum shaft diameter and the inner diameter of the main channel 61 of shuttle 60 is defined by the machining tolerances.

[0200] Shuttle 60 is shown in detail in Figure 11 and includes an outer side wall 62 extending between the first and second ends 60a, 60b: side wall 62 includes a central groove 63 and a first and second side groove 64, 65.

[0201] The central groove 63 is axially interposed between the first and second lateral grooves 64, 65: the central groove 63 is also laterally bounded by a respective first and second closure portions 63a, 63b presenting an outer diameter greater than the outer diameter of the central groove 63, to define said central groove. Shuttle 60 also includes a first through-hole 66 between the central groove 63 and the main channel 61, so that, at least under one condition of use, working fluid can pass from the central groove 63 to the main channel 61.

[0202] The first lateral groove 64 of shuttle 60 is interposed between the first end 60a of the shuttle and the central groove 63: in particular, the first lateral groove 64 is bounded laterally by a respective first and second closure portions 64a, 64b presenting an outer diameter greater than the outer diameter of the first lateral groove 64, to define said lateral groove 64.

[0203] Shuttle 60 also includes a second through-hole 67 between the first side groove 64 and the main channel 61, so that, at least under one condition of use, working fluid can pass from the first side groove 64 to the main channel 61.

[0204] Similarly, the second lateral groove 65 of shuttle 60 is interposed between the second end 60b of the shuttle and the central groove 63: in particular, the second lateral groove 65 is bounded laterally by a respective first and second portions of closure 65a, 65b presenting an outer diameter greater than the outer diameter of the second lateral groove 64, to define said lateral groove 65.

[0205] Shuttle 60 also includes a third through-hole 68 between the second side groove 65 and the main channel 61, so that, at least under one condition of use, working fluid can pass from the second side groove 65 to the main channel 61.

[0206] The central groove 63 and the first and second side grooves 64, 65 can have the same outer diameter. The main channel 61 of the shuttle 60 also includes a first and a second inner groove 69a, 69b as shown in the cross-sectional view of Figure 11a, in which the first inner groove 69a is axially interposed between the center groove 63 of the side wall and the first side groove 64. Similarly, the second inner groove 69b is axially interposed between the center groove 63 of the side wall and the second side groove 65. The first and second inner grooves 69a, 69b are respectively in fluid communication with the first and second extremal holes 69', 69", wherein the first extremal hole is located at the first end of the shuttle, and the second extremal hole is located at the second end of the shuttle 60. In particular, the first and second extremal holes have an axis substantially parallel to a central axis of the main channel 61 of the shuttle. The valve system also includes distributor 70 shown in Figure 9 and configured to supply, with working fluid G, shuttle 60. Distributor 70 is mounted on the working shaft, such that shuttle 60 is radially interposed between working shaft 13 and distributor 70. In the embodiment shown in Figure 9, the distributor 70 is made in three distinct parts: a center distributor 71, a first bottom stroke 72, and a second bottom stroke 73, in which the center distributor 71 is axially interposed between the first bottom stroke 72 and the second bottom stroke 73.

[0207] The first stroke bottom 72 includes a first outer groove 72a and a through-hole 72b that places in fluid communication an inner volume of the first stroke bottom with the first outer groove 72a. The second stroke bottom 73 includes a second outer groove 73a and a through-hole 73b that places in fluid communication an inner volume of the second stroke bottom with the second outer groove 73a.

[0208] The central distributor 71 includes an outer groove 71a and a through-hole 71b that places an inner volume of the central distributor in fluid communication with the outer groove 71a.

[0209] The distributor 70 is fixed relative to the membrane pump body 1. In contrast, shuttle 60 is movable axially with respect to distributor 70 axially along the working axis of shaft 13. Working shaft 13 is movable axially along its working axis with respect to both shuttle 60 and distributor 70.

[0210] Specifically, the shuttle is axially movable between a first position in which shuttle 60 is abutting against the first bottom stroke 72 of distributor 70, and a second position in which the shuttle is abutting against the second bottom stroke 73 of distributor 70.

[0211] Figures 12a-12c schematically show the operation of the valve system, and of the working fluid path, during the suction and delivery phases of the present membrane pump 1.

[0212] Figure 12a shows a cross-sectional view of membrane pump 1, in which the working shaft is in the second position, specifically in a position proximal to the head portion 2. Shuttle 60 is arranged in the first position.

[0213] In such a condition, the working fluid is configured to enter the working circuit through the pressure port 10a, access the outer center groove 71a of the distributor 70, pass through the through-hole 71b, access the center groove 63, pass through the bore 72c of the bottom 72 of the distributor 70, and contact with the working membrane 6a. In this condition, the working membrane 6a is placed under pressure by the working fluid, such that the membrane tends to move axially toward the bottom portion 3, concurrently moving the working shaft 13 axially to define the first position of the working shaft 13, shown in Figure 12b below.

[0214] Figure 12b then shows a cross-sectional view of membrane pump 1, in which the working shaft is in the first position, specifically in a position proximal to the bottom portion 3. Shuttle 60 anchor is arranged in the first position. In such a condition, the working fluid is configured to enter the working circuit through the pressure port 10a, access the outer center groove 71a of the distributor 70, pass through the through-hole 71b of the distributor 70, access the center groove 63 of the shuttle 60, pass through the through-hole 66 of the shuttle 60, pass through the first inner groove 69a of the shuttle 60, and pass through the end hole 69'. In this way, the working fluid generates an increase in pressure between the shuttle and the first end groove 72 of the distributor 70, thus resulting in the movement of shuttle 60 from the first to the second position, the latter shown in Figure 12c.

[0215] Figure 12c then shows a cross-sectional view of membrane pump 1, in which the working shaft is in the first position, specifically in a position proximal to the bottom portion 3, and shuttle 60 is arranged in the second position. In such a condition, the working fluid is configured to enter the working circuit through the pressure port 10a, access the outer central groove 71a of the distributor 70, pass through the through-hole 71b of the distributor 70, access the central groove 63 of the shuttle 60, transit through the bore 73c of the bottom port 72 of the distributor 70, until contacting with the return membrane 6b. In this condition, return membrane 6b is pressurized by the working fluid, such that membrane 6b tends to move axially toward the head portion 2 of pump 1, concurrently moving working shaft 13 axially to define the second position of working shaft 13, shown in Figure 12a below.

Pumping plant 100

[0216] The present invention is also directed to a pumping system 100 comprising the membrane pump in accordance with any of the appended claims and in accordance with the preceding description.

[0217] The system also includes a piezometric pipeline 110 defining an internal lumen and configured to be inserted deep into soil. The piezometric conduit has a substantially tubular shape with a circular cross-section, having an inner lumen diameter Dp between 6 cm and 16 cm, in particular between 8 cm and 13 cm, in particular substantially equal to 10 cm. The piezometric pipeline presents a maximum length of less than 80 meters, in particular less than 65 or 60 meters.

[0218] The piezometric conduit is configured to receive inside it the membrane pump 1 previously described: the pump is lowered inside the piezometric conduit to a predefined depth to draw in the fluid of interest. In this regard, the piezometer conduit has an inner diameter equal to or greater than the lateral footprint of the membrane pump 1: in particular, the inner diameter of the piezometer conduit is greater than the outer diameter of the membrane pump 1, such that a gap exists between the pump and the piezometer conduit when the pump is lowered to depth.

[0219] The system also includes a pressurized working fluid source 111 G, specifically a compressor configured to provide a pressurized gas flow rate: this source 111 includes a working fluid delivery connector 111 that can be connected, via a working fluid pipeline 112, to the pressure port 10a of the membrane pump 1. The pressurized working fluid source is configured to provide a substantially constant flow rate of pressurized working fluid over time. Specifically, the working fluid source is configured to provide a working fluid pressure between 2 bar and 8 bar, and a working fluid flow rate between 0.5 L/min and 4 L/min.

[0220] The system may also include a control unit operationally connected to the power source, such as the compressor, and configured to turn the power source on and off depending on one or more fluid parameters.

Method 200 of fluid suction

[0221] It is also an object of the present invention to provide a method 200 of pumping a fluid of interest F for the remediation of soils or the suction of corrosive products/liquids from a site.

[0222] The method includes a step of setting up a membrane pump in accordance with the above description. The method also includes the following steps:

• connect a suction pipe 8a to the suction port 8;
• connect a delivery pipe 9a to the delivery port 9;
• prepare a piezometric pipeline 110 inserted deep into the soil to be reclaimed;
• insert said membrane pump 1 inside piezometric pipeline 110, in which the head portion 2 of pump 1 faces the ground surface, while the bottom portion 3 of pump 1 faces a depth of piezometric pipeline 110,
• lower the membrane pump 1 within said piezometric pipeline to a reservoir of the fluid of interest f to a depth where:

  ∘ membrane pump 1 is above a level of the fluid of interest, particularly outside the fluid of interest; and

  ∘ the suction line 8a is at least partly embedded within the fluid of interest f contained in the basin.

[0223] The method also includes a step of feeding, through the pressure port, the working circuit of membrane pump 1 with a flow of working fluid, particularly pressurized gas, said working fluid flow being at essentially constant pressure and/or flow rate.

Claims

1. A membrane pump (1) for suction and delivery of a fluid of interest (F), said membrane pump (1) comprising a pump body carrying:

- a head portion (2);

- a bottom portion (3) opposite to said head portion (2);

- at least one side wall (4) extending along a main axis (A) between said head portion (2) and said bottom portion (3), said side wall (4) defining, in combination with said head portion (2) and said bottom portion (3), an internal volume (5) of said membrane pump (1),
said internal volume (5) comprising a working circuit and a hydraulic circuit;

- at least one flexible membrane (6) placed within said internal volume (5) and movable along a working direction substantially parallel to the main axis (A), said at least one membrane (6) being configured to move at least partially along said working axis in a reciprocating movement to determine a suction phase and a discharge phase of the fluid of interest (F);

- a delivery port (9) of the fluid of interest (F) configured to allow delivery of the fluid of interest (F);

- a suction port (8) of the fluid of interest (F) configured to receive the fluid of interest (F) as a suction in said hydraulic circuit of the pump (1),

- at least one intercepting element (7) configured, during a use condition of the pump, to interdict or allow fluid communication between:

∘ the suction port (8) and said hydraulic circuit, and between

∘ the delivery port (9) and said hydraulic circuit,

- at least one power port (10) configured to receive, in the working circuit, a working fluid under pressure or electrical energy to determine the alternating movement of said at least one membrane (6);
and wherein:

- said head portion (2) carries the delivery port (9) and power port (10), and

- said bottom portion (3) carries the suction port (8).

2. Pump according to the preceding claim, wherein said pump (1) extends transversely along a lateral direction (B) substantially orthogonal to said main axis (A) to define an extension in width (W) of less than 15 cm, in particular less than 12 cm, more particularly said width being less than 10.2 cm (4"), said width being in particular between 5 cm and 15 cm, more in particular between 7 cm and 13 cm, more in particular between 7 cm and 10 cm, more in particular substantially equal to 8 cm, and wherein said extension in width (W) defines a maximum transverse dimension of the pump, and wherein said pump extends longitudinally along said main axis (A) to define an extension in length (L), said extension in length (L) being greater than said extension in width (W), said extension in length (L) being at least 1.5 times greater than said extension in width (W), in particular said extension in length being between 2 and 5 times greater than said extension in width,
wherein said pump (1) is substantially cylindrical in shape and defines a section, orthogonal to the main axis (A), of the side wall (4) substantially circular in shape, in particular wherein said side wall (4) of said pump (1) is cylindrical in shape extending between the head portion (2) and the bottom portion (3).

3. Pump according to any one of the preceding claims, wherein the delivery port (9) extends along an axis substantially parallel to the main axis (A) of the pump, said delivery port (9) being configured to direct the fluid of interest (F) axially along a direction substantially parallel to or coincident with the main axis (A) of the pump,
and wherein the suction port (8) extends along an axis substantially parallel to or coincident with the main axis (A) of the pump, said suction port (8) being configured to receive the fluid of interest (F) axially along a direction substantially parallel to or coincident with the main axis (A) of the pump, and wherein optionally the power port (10) extends along an axis substantially parallel or coincident with the main axis (A) of the pump.

4. Pump according to any one of the preceding claims, wherein the suction port (8) is configured to connect to, or comprises, a suction tube (8a) extending in length between:

- a first end for connection to the suction port (8), and

- a second end configured to be immersed, particularly partially, in the fluid of interest (F),

said suction tube extending away from the body of said pump by a length of less than 12 meters, more particularly less than 10 meters, more particularly less than 6 meters,

and wherein the delivery port (9) is configured to connect to, or includes, a delivery tube (9a) extending in length between:

- a first end for connection to the delivery port (9), and

- a second end configured to bring the fluid of interest (F) to the surface,
said tube extending away from the side wall (4) of said pump, in particular away from a body of said pump, of a length of less than 80 meters, in particular less than 65 meters.

5. Pump according to any one of the preceding claims, wherein said membrane pump (1) is configured to allow a maximum dry suction height (H_asp) between 0 meter and 5 meters, more particularly between 2 meters and 4 meters, more particularly between 3 meters and 4 meters,
said maximum dry suction height being defined as the maximum distance, during a use condition of the pump, between the level of the fluid of interest (F) and said pump, in particular between the level of the fluid of interest (F) and said at least one membrane (6).

6. Pump according to any one of the preceding claims, wherein the head portion (2) extends radially substantially orthogonal to the main axis (A) of the pump, the head portion comprising an end surface of the pump that is substantially flat, said end surface carrying the delivery port (9), the power port (10) and optionally an exhaust port (11),
and wherein the bottom portion (3) extends radially substantially orthogonal to the main axis (A) of the pump, the bottom portion (3) comprising a respective substantially flat end surface of the pump carrying the suction port (8).

7. Pump according to any one of the preceding claims, wherein the side wall defines a maximum radial footprint of the pump (1), the delivery port (9), the suction port (8) and optionally the power outlet (10) being within said maximum radial footprint,
and in which the side wall (4) is devoid of power inlets (10), delivery port (9) and suction port (8), in particular where the side wall (4) defines a lateral surface substantially free of discontinuities and defining a substantially constant lateral footprint.

8. Pump according to any one of the preceding claims, wherein said power port(10) includes a pressure port (10a) disposed on the head portion (2) of the pump and configured to receive as input, in the working circuit, the working fluid (G) under pressure configured to determine the alternate movement of the at least one membrane (6) along the respective working direction,

said internal volume comprising said working circuit, and wherein said working circuit is configured to transport said working fluid (G),

said working fluid (G) being in particular a pressurized gas, e.g. compressed air,

and wherein said pump further comprises a exhaust port (11) for the working fluid (G), said exhaust port (11) being configured to allow the working fluid (G) to be discharged following a suction and/or delivery phase of the pump,

and wherein said exhaust port (11) is disposed on the head portion (2) of the pump,

said exhaust port (11) for the working fluid (G) extending along an axis substantially parallel to the main axis (A) of the pump.

9. Pump according to any one of the preceding claims, wherein said membrane pump (1) comprises, between said at least one membrane (6), a working membrane (6a), said working membrane (6a) being configured to contact, during a use condition of the pump, the fluid of interest (F) to determine suction and delivery of the fluid of interest (F),

said working membrane (6a) extending in thickness between a first and a second surface, wherein:

- the first surface defines at least part of the hydraulic circuit and is configured to contact, during a condition of use of the pump, the fluid of interest (F), the first surface being directed towards the bottom portion (3);

- the second surface defines at least part of the working circuit and is configured to contact the working fluid (G) to determine the reciprocating movement of said working membrane (6a), said second surface being directed towards the head portion (2),

said working membrane fluidically separating the hydraulic circuit from the working circuit, and wherein said pump includes a pumping volume (20) axially interposed between the working membrane (6a) and the suction port (8),

and wherein the pump is configured to define a suction step of the fluid of interest (F) and a discharge step of the fluid of interest (F), wherein:

- during the suction step, the working membrane (6a) moves away from the bottom portion (3) to increase said pumping volume (20) to receive the fluid of interest (F) from the suction port (8),

- during the delivery step, the working membrane (6a) moves towards the bottom portion (3) to reduce the pumping volume (20), the delivery step pressurizing the fluid of interest (F) to direct it towards the delivery port (9),

and in which the working fluid (G) under pressure determines, during a use condition, said suction step and said discharge step.

10. Pump according to any one of the preceding claims, wherein said pump comprises a working shaft (13) movable along said working direction and extending in length between a first and a second end along said working direction,

wherein said first end of the working shaft (13) is constrained to the working membrane (6a), such that an axial movement of said working membrane (6a) results in a simultaneous axial movement of the working shaft (13),

and wherein the pump (1) includes:

- an elastic return element, in particular a spring, connected to the second end of the working shaft (13) and configured to generate an axial return force on the working shaft (13) opposite to a contextual working force generated, at least during an operating condition of the pump (1), by the working fluid (G),

or

- a return membrane (6b), optionally substantially the same in structure as the working membrane (6a), constrained to the second end of the working shaft (13), and extending in thickness between a first and a second main extension surfaces, wherein:

∘ the first surface is communicating with the working circuit and facing the bottom portion (3) of the pump (1),

∘ the second surface faces the head portion of the pump (1),

said return membrane being separate from the hydraulic circuit,

and wherein the delivery step is determined by the working membrane (6a), the suction step being determined by the return membrane (6b).

11. Pump according to the preceding claim, wherein the pump (1) comprises the return membrane (6b), in which:

- the working membrane (6a) is in fluid communication with the working circuit and with the hydraulic circuit, in particular it separates the hydraulic circuit from the working circuit, and

- said return membrane (6b) is communicating with the working circuit and is separated from the hydraulic circuit,
and wherein the pump (1), during a suction step of the fluid of interest (F), is configured to direct the working fluid (G) to the return membrane (6b) to determine the following sub-steps:

- deformation of the return membrane (6b) toward the head portion (2) caused by the working fluid (G) under pressure;

- movement of the working shaft (13) towards the head portion (2);

- deformation of the working membrane (6a) toward the head portion (2) caused by the movement of the working shaft (13);

- increase in pumping volume (20) to determine suction of the fluid of interest (F) through the suction port (8);
and wherein the pump, during a discharge step of the fluid of interest (F), is configured to direct the working fluid (G) to the working membrane (6a), resulting in the following sub-phases:

- deformation of the working membrane (6a) toward the bottom portion (3) determined by the working fluid (G) under pressure;

- movement of the working shaft (13) towards the bottom portion (3);

- deformation of the return membrane (6b) toward the bottom portion (3) caused by the movement of the working shaft (13);

- reduction of the pumping volume (20) to determine the delivery of the fluid of interest (F) through the delivery port (9).

12. Pump according to any one of the preceding claims, wherein the at least one intercepting element (7) of the pump (1) comprises a first intercepting element (7a) located at the suction port (8), and a second intercepting element (7b) located at the delivery port (9), said first and second intercepting elements (7a, 7b) being inserted within the hydraulic circuit of the pump (1),
and wherein said first intercepting element (7a) includes a respective one-way valve configured to:

- allow the fluid of interest (F) to flow in an incoming suction direction from the suction port (8) toward the hydraulic circuit,

- interdict the passage of the fluid of interest (F) in an outgoing direction from the suction port (8), and wherein said second interception element (7b) comprising a respective one-way valve configured to:

- allow the fluid of interest (F) to pass in a discharge direction out of the delivery port (9), and

- interdict the passage of the fluid of interest (F) or gas or a fluid in an incoming direction from the delivery port (9) toward the hydraulic circuit,

and wherein:

- the first intercepting element (7a) is placed between the suction port (8) and the hydraulic circuit, in particular between the suction port and the pumping volume,
the first intercepting element (7a) being placed at the bottom portion (3) of the pump (1),

- the second intercepting element (7b) is placed between the delivery port (9) and the hydraulic circuit, in particular between the delivery port and the pumping volume,
the second intercepting element (7b) being placed in correspondence with the head portion (2) of the pump (1).

13. Pump according to any one of the preceding claims, wherein the pump comprises at least a first body (30), a second body (40), and a third body (41) that are distinct and bound together to define a single pump body of the membrane pump (1),

said first body (30) including at least the bottom portion (3) and part of the side wall (4),

said second body (40) comprising the head portion (2) and part of the side wall (4),

said third body (41) comprising a portion of the side wall (4),

said third body being interposed, according to the direction of the main axis (A), between the first and second bodies,

wherein said first and third bodies face each other along a first support plane substantially orthogonal to the main axis (A) of the pump,

and wherein said second and third bodies face each other along a second support plane substantially orthogonal to the main axis (A) of the pump,

said first and second support planes being substantially parallel to each other,

and in which the working membrane (6a) is interposed between the first body and the third body to define a fluid-tight seal,

and in which the return membrane (6b) is interposed between the second body and the third body to define a fluid-tight seal.

14. Pumping plant (100) including:

- a membrane pump (1) in accordance with any one of the preceding claims, and

- a source (111) of pressurized working fluid (G), in particular a compressor configured to provide a pressurized gas flow rate, comprising at least one working fluid delivery connector connectable, via a working fluid line, to the pressure port (10a) of the membrane pump (1),

- a piezometric conduit (110) defining an internal lumen, said piezometric conduit being configured to be inserted deep into a soil during an operational condition of remediation,

said piezometric conduit presenting a substantially tubular shape in particular with circular section, said piezometric conduit defining an internal lumen diameter comprised between 6 cm and 16 cm, in particular between 8 cm and 13 cm, in particular substantially equal to 10 cm, said membrane pump (1) being configured to be lowered deep within said lumen of the piezometric conduit (110).

15. A method of pumping a fluid of interest (F) for soil remediation, said method comprising the steps of:

- providing a membrane pump (1), optionally according to any one of claims 1 to 13, for suction and delivery of a fluid of interest (F), said membrane pump (1) comprising a pump body carrying:

∘ a head portion (2);

∘ a bottom portion (3) opposite to said head portion (2);

∘ at least one side wall (4) extending along a main axis (A) between said head portion (2) and said bottom portion (3), said side wall (4) defining, in combination with said head portion (2) and said bottom portion (3), an internal volume (5) of said membrane pump (1),
said internal volume (5) comprising a working circuit and a hydraulic circuit;

∘ at least one flexible membrane (6) placed within said internal volume (5) and movable along a working direction substantially parallel to the main axis (A), said at least one membrane (6) being configured to move at least partially along said working axis in an alternating movement to determine a suction step and a delivery step of the fluid of interest (F);

∘ a delivery port (9) of the fluid of interest (F) configured to allow delivery of the fluid of interest (F);

∘ a suction port (8) of the fluid of interest (F) configured to receive the fluid of interest (F) as a suction in said hydraulic circuit (1) of the pump,

∘ at least one intercepting element (7) configured, during a use condition of the pump, to interdict or allow fluid communication between:

▪ the suction port (8) and said hydraulic circuit, and between

▪ the delivery port (9) and said hydraulic circuit,

∘ at least one power port (10) configured to receive, in the working circuit, a working fluid under pressure or electrical energy to determine the alternating movement of said at least one membrane (6);
and in which:

∘ said head portion (2) carries the delivery port (9) and power port (10), and

∘ said bottom portion (3) carries the suction port (8),

the method including the following steps:

- connecting a suction tube (8a) to the suction port (8);

- connecting a delivery tube (9a) to the delivery port (9);

- providing a piezometric conduit (110) inserted deep into the ground to be remedied;

- inserting said membrane pump (1) within the piezometric conduit (110), wherein the head portion (2) of the pump (1) faces the soil surface, and the bottom portion (3) of the pump (1) faces a depth of the piezometric conduit (110),

- lower the membrane pump (1) within said piezometric conduit toward a basin of the fluid of interest (F) up to a depth where:

∘ the membrane pump (1) is above a level of the fluid of interest, particularly outside the fluid of interest; and

∘ the suction tube (8a) is at least partially drowned within the fluid of interest (F) contained in the basin.

Drawing