A SET OF PARTS FOR BEING ASSEMBLED TO FORM AN EJECTOR PUMP AND A METHOD OF USING AN EJECTOR PUMP

Abstract

 A set of parts for being assembled to form an ejector pump for pumping a medium using a motive fluid, the set of parts comprising a pump housing, a first nozzle member for introducing the motive fluid into the pump housing, a second, alternative nozzle member for introducing the motive fluid into the pump housing, a pipe having a constriction part for constricting a fluid flow and a diverging part for diffusing the fluid flow, the pump housing having a first inlet opening adapted to receive the first nozzle member, a second inlet opening adapted to receive the second nozzle member, and an outlet adapted to be connected in fluid communication with the constriction part of the pipe, so that the ejector pump is adapted to be assembled into a first and a second configuration, wherein in the first configuration the first nozzle member is received in the first inlet opening to serve to introduce the motive fluid into the pump housing, the second nozzle member does not serve to introduce the motive fluid into the pump housing, and the second inlet opening serves as a suction inlet for said medium, and in the second configuration the second nozzle member is received in the second inlet opening to serve to introduce the motive fluid into the pump housing, the first nozzle member does not serve to introduce the motive fluid into the pump housing, and the first inlet opening serves as a suction inlet for said medium.

Description

Introduction

[0001] The present invention relates to an ejector pump for pumping a medium using a motive fluid

Background art

[0002] An ejector pump uses the venturi effect of a converging-diverging nozzle to convert pressure energy of a motive fluid into a velocity energy which creates a low pressure zone that draws in and entrains the medium to be pumped. After the converging zone the mixed fluid of motive fluid and entrained medium is conveyed through a constricted zone in which the velocity of the mixed fluid reaches a maximum. Subsequently, the mixed fluid passes through a diverging zone in which the mixed fluid expands, resulting in a pressure drop and a velocity decrease.

[0003] The ejector pump has been developed into various designs and uses. A suitable example includes US 2,275,627, which discloses a pumping system for supplying water at a sufficient high pressure. The pumping system includes a combination of a centrifugal pump and an ejector pump to obtain higher pressures. The motive fluid enters the ejector pump through an inlet having a curved pipe segment immediately prior to the nozzle.

[0004] Another example is disclosed in US 2,350,401, which relates to an in-line injector for transport of hot (538°C to 1093°C) gaseous products of combustion from a furnace.

[0005] An example of an ejector pump with a nozzle part having a variable geometry is found in EP 2204562 A2, the dimensions of the nozzle part may be changed to optimize flow in relation to ambient temperature. Further development on this nozzle part is found in US 2010/0040482 A1, where the nozzle part is described as detachable, , US 2010/0040482 A1 discloses an ejector pump with a nozzle part attached in a way allowing detaching of the nozzle part. The disclosed nozzle part further has an adjustable nozzle outlet with at least two concentric arc nozzle portions, which each can rotate relative to the other, thereby changing the size and geometry of the nozzle mouth to allow for easy adjustments.

[0006] Also US 5,535,770 describes a type of ejector device where a nozzle member is removably attached to the other structural parts of the ejector, to allow for the nozzle member to be exchanged to change the pumping characteristics of the ejector.

[0007] Today, ejector pumps of various designs and types may be purchased from the present applicant.

Summary of the invention

[0008] On this background one object of the invention is to provide an ejector pump which is well functioning, versatile and cost efficient in production.

[0009] According to the present invention this object is met by means of a set of parts comprising; a pump housing; a first nozzle member for introducing the motive fluid into the pump housing; a second, alternative nozzle member for introducing the motive fluid into the pump housing; a pipe having a constriction part for constricting a fluid flow and a diverging part for diffusing the fluid flow, the pump housing having a first inlet opening adapted to receive the first nozzle member, a second inlet opening adapted to receive the second nozzle member, and an outlet adapted to be connected in fluid communication with the pipe, so that the set of parts is adapted to be assembled into a first and a second ejector pump configuration, wherein in the first ejector pump configuration the first nozzle member is received in the first inlet opening to serve to introduce the motive fluid into the pump housing, the second nozzle member does not serve to introduce the motive fluid into the pump housing, and the second inlet opening serves as a suction inlet for said medium, and in the second ejector pump configuration the second nozzle member is received in the second inlet opening to serve to introduce the motive fluid into the pump housing, the first nozzle member does not serve to introduce the motive fluid into the pump housing, and the first inlet opening serves as a suction inlet for said medium.

[0010] The set of parts according to the present invention allows changing between different ejector pump configurations of the assembled ejector pump instead of having to replace the entire ejector pump with another. This greatly improves the cost efficiency of the ejector pump. With the set of parts according to the present invention it is thus possible to change the configuration of the ejector pump e.g. from an in-line motive to an angular motive ejector pump, allowing e.g. to change between different motive fluids or pumping medias, possibly without having to change or replace the adjoining piping. This significantly improves the versatility and applicability of the ejector pump without compromising efficiency.

[0011] These advantages are achieved by the different possible assemblies, and thus possible ejector pump configurations, offered by the set of parts according to the present invention. The first and the second inlet openings of the pump housing are each adapted to function as the suction inlet when no nozzle member is mounted therein. This allows for the selection of an optimal configuration according to the circumstances under which the medium is to be pumped. By mounting the selected nozzle member to the pump housing in the appropriate inlet opening and mounting the pipe to the outlet opening of the housing, the ejector pump is assembled in one configuration. It then further needs to be arranged so that the suction inlet of the pump housing is in liquid connection with a suction medium, and the nozzle member is in liquid communication with the motive fluid.

[0012] In general, ejector pumps are sturdy, and in use they often have no moving parts. With the set of parts according to the present invention the sturdy construction of the assembled ejector pump is maintained, while the versatility is improved.

[0013] The set of parts according to the present invention can be made from different materials dependent on the intended use. For some uses, e.g. some uses within the marine industry such as; filling and stripping of ballast tanks; stripping of bilges from the bottom of a vessel; stripping of all sorts of mediums from cargo holds, including oil, gas, water and sewage; stripping of bilge from chain lockers, ventilation of exhaust or other gasses; removal of ashes from incinerators; stripping and filling of peak tanks; priming of centrifugal pumps or other pumps; and vacuum creation, suitable materials may be chosen from the group comprising bronze, aluminum-bronze, cast-iron, stainless steel, other precious and non-precious metals, alloys, and combinations thereof. For other industries, such as some of the different industries of processing e.g. chemicals, petrochemicals, petroleum, food and drugs, the above mentioned materials may also be suitable, as well as other materials. The materials can be chosen based on the need for specific characteristics, such as resistance to corrosives, durability in harsh working conditions, strength to size, or strength to mass ratio, etc.

[0014] The set of parts of the present invention may be assembled into an ejector pump which may be used for suction of any fluid. When the assembled ejector pump in use has no moving parts, the ejector pump is sturdy and need no or little maintenance. Thus, mediums having included sand and powder, such as coal powder may be pumped. Liquids, which may be pumped by the present invention, include sewage water and bilge. The ejector of the invention may also be used for fuel and oil for transferring or stripping since the explosive risk may be lowered or eliminated. Other types of fluids to be pumped include the removal of water from ballast tanks and cargo tanks. Gasses to be pumped by the ejector pump of the present invention include smoke, potentially explosive gasses, and air. Thus, engine rooms of e.g. ships may be ventilated by suction of smoke, and ballast or cargo tanks may be emptied by pumping the gasses. Due to the absence of moving parts even gasses easily ignited may be pumped.

[0015] The housing and the pipe may generally be produced in metal. Suitable materials include bronze, aluminum-bronze, cast-iron and stainless steel. For maritime usage a bronze type is generally recommended to avoid excessive corrosion. The nozzle, which may be separable from the nozzle member, may be prepared in any durable material. Usually it is preferred to prepare the nozzle from stainless steel. A suitable stainless steel includes AISI 329.

[0016] The motive fluid may be a liquid or a gas. Most common is the use of water and air, less common is the use of exhaust gasses and other gasses. A liquid medium like water is generally preferred for pumping other liquids. Basically, the ejector can be motivated by any medium up to a certain viscosity level. The source providing the motive fluid, may be a centrifugal pump or similar pumps capable of delivering the pressure of the motive fluid necessary for sucking the medium to be pumped at the desired velocity. Typically, the motive fluid is entering the ejector of the invention at a pressure of 2-12 bar. The ejector pump may be designed in a variety of lengths and capacities. Usually, the length of the ejector is not below 40cm to obtain a satisfactory capacity (m3/h) and efficiency. The length does usually not exceed 4.5m for practical reasons. Most suitable, the length is between 1 m and 3m.

[0017] Different additional ejector pump configurations may be facilitated by the set of parts according to the present invention, e.g. a third (or more) ejector pump configuration(s) may be facilitated, e.g. by including a third (or more) inlet opening(s), allowing a third (or more) nozzle member(s) to introduce the motive fluid into the pump housing, and/or a third (or more) inlet opening(s) to serve as suction inlet(s) for said medium. The third (or more) ejector pump configuration(s) may be provided, e.g. to provide an ejector pump type in which a number of nozzle members are provided circumferentially, or in different positions, to inject motive fluid (possibly multiple different motive fluids) from different directions, and/or to provide an ejector pump type in which a number of medium inlets are provided to facilitate pumping of multiple medias simultaneously, in combination or alternately. The third (or more) configuration(s) may be combined with any of the other configurations.

[0018] For example, a first ejector pump configuration can be a straight configuration wherein the motive fluid exits the ejector pump in a direction substantially equal to the direction in which it entered the ejector pump, thus the motive fluid may pass through a straight nozzle member of the ejector pump. Continuing the example, a second ejector pump configuration can be an angled configuration where the motive fluid exits from the ejector pump in a direction substantially different from the direction in which it entered the ejector pump, thus the motive fluid may pass through an angled nozzle member of the ejector pump. Continuing the example, a third ejector pump configuration can be a revised configuration of any one of the first and second configuration where multiple nozzle members may be used, e.g. for introducing multiple motive fluids, or more inlet openings may be provided, e.g. for pumping multiple medias.

[0019] The terms "essentially straight" and "essentially parallel" when used in the present application are to be understood as allowing the actual embodiment to deviate 10% or less from straight and parallel, respectively.

[0020] In an embodiment of the set of parts according to the present invention each nozzle member has a first section with a flange or fitting for attaching the nozzle member to the pump housing in the associated receiving inlet opening and a second section connecting the first section to a third section, the third section forming a nozzle for discharging the motive fluid in the pump housing, the second and third sections of that of the first and second nozzle members, which serves to introduce the motive fluid into the pump housing, preferably being positioned inside the pump housing. The opening of the nozzle formed by the third section of that of the nozzle members, which serves to introduce the motive fluid into the pump housing, can preferably be substantially axial with the outlet opening of the pump housing and/or the pipe, thereby providing a substantially straight flow direction of the motive fluid after being ejected from said opening of the nozzle.

[0021] In an embodiment of the set of parts according to the invention the first nozzle member is substantially straight, the first ejector pump configuration being a substantially straight configuration providing flow of the motive fluid in a substantially straight direction through the pump housing, the first inlet opening being provided at a side of the housing opposite to the outlet adapted to be connected in fluid communication with the pipe. When the first nozzle member is substantially straight, an assembled ejector pump is provided having an overall motive fluid stream direction substantially axial with the outlet opening of the pump housing and/or the pipe, thereby providing a substantially straight flow direction of the motive fluid through the entire nozzle member, and through the entire ejector pump housing. The second inlet opening, which serves as the suction inlet, is preferably positioned at a side of the housing so that an axis of the second inlet opening forms an angle with an axis of the outlet opening different from zero degrees. By the suction inlet being positioned substantially non-axial with said diffuser channel member, suction is created from a direction substantially angled to the overall motive fluid stream direction.

[0022] In an embodiment of the set of parts according to the present invention the second nozzle member is angled, the second ejector pump configuration being an angled configuration providing flow of the motive fluid in an angled direction through the pump housing, the second inlet opening being provided at a side of the housing not directly opposing the outlet adapted to be connected in fluid communication with the pipe, so that the average direction of the motive fluid at the point of ejection from the nozzle, is substantially axial with said outlet. Hereby, when the second nozzle member is angled, an assembled ejector pump is provided having a suction inlet in a position substantially axial with the outlet opening and/or the pipe. Generally, an "angled nozzle member" is defined as a nozzle member where the general direction of the flow of the motive fluid at the entry into the nozzle member is not coaxial with the general direction of the flow of the motive fluid at the exit point from the nozzle member. Thus, from entering the angled nozzle member until exiting the angled nozzle member through the nozzle the average direction of the motive fluid is changed. The change in direction may be by a degree of between 10-170 degrees, preferably 40-140 degrees, more preferred 60-120 degrees, most preferred 80-100 degrees or 90 degrees. The average direction of the motive fluid is to be understood as the direction of the "centre of mass". When the second nozzle member is angled, the angle may also be provided by an angular centre section (the second section). When the second nozzle member is angled, the second inlet opening of the pump housing, may be provided in a position so that, when the second angled nozzle member is fitted correctly therein, the opening of the third section of the nozzle member, forming the nozzle, is positioned within the pump housing, substantially coaxial with the outlet opening of the pump housing.

[0023] In an embodiment of the set of parts according to the invention the second section of the second nozzle member further is a channel for changing the average direction of the motive fluid, the channel of the second section comprises a rear wall, said rear wall being essentially straight in a direction essentially parallel to the average direction of the motive fluid stream, and the cross section in a plane perpendicular to the average flow direction of motive fluid in the channel of the second section decreases in the flow direction. The decreasing cross-section in the motive fluid direction provides for an increased pressure of the motive fluid. Hereby, the second nozzle member has resulted in an improved efficiency of about 5-10%. It is presently believed that the motive fluid stream is deflected when it impinges on the essentially straight rear wall of the channel in a way that increases the currents in the stream so that a more turbulent stream is created in a least a part of the channel. The at least partly turbulent motive fluid stream will entrain more medium to be pumped when ejected from the second nozzle member. The decreasing cross sectional area increases the pressure in the stream and/or increases the velocity. An increased average velocity when the stream enters the third section is generally desired to increase the turbulent currents.

[0024] In an embodiment of the set of parts according to the invention the angle between the initial average flow direction of the motive fluid in the fitting of the first section and the rear wall of the channel of the second section is between 100° and 160°, and/or the essentially straight rear wall of the channel of the second section is rounded in a direction perpendicular to the average direction of the motive fluid stream, and/or the geometrical shape of the channel of the second section can be described by the movement of a generatrix, and/or the angle between the generatrix and the flow direction of the motive fluid varies between 100° and 160°, and/or the joint between the channel of the second section and the third section forms a break. To obtain the best result the angle between the initial average flow direction of the motive fluid in the fitting of the first section and the rear wall of the channel of the second section is between 100° and 160°. In the event the angle in too close to 90° the deflection of the fluid will be with a lower direction of the motive fluid towards the nozzle. In the event the angle is too high the direction of the fluid will not be changed significantly and the entering into the third section will be too abrupt. The rounded wall increases the flow velocity of the micro currents thereby contributing to the formation of a turbulent stream. When describing the geometrical shape of the channel of the second section by the movement of a generatrix, the geometrical shape may be a cylinder, a frustoconical, or a polygon. The geometrical shape may also be a cone having suitable cutting plans to allow for a connection to the first and the third section. The altitude of the cone may be 3 to 10 times the weighted diameter of the cutting plane at the end abutting the first section. The angle between the generatrix and the flow direction of the motive fluid may vary between 100° and 160°. The break that may be formed between the channel of the second section and the third section may provide for a discontinuous flow of the motive fluid, which will enhance the turbulent streaming.

[0025] In an embodiment of the invention the set of parts further comprises an adapter fitting for adapting that of the first or second inlet opening of said pump housing which, when the ejector pump is assembled in one of said first and second ejector pump configurations, serves as the suction inlet for the medium. Including an adapter fitting for adapting the inlet serving as the suction inlet facilitates increased versatility and may allow fitting of a greater variety of adjoining piping etc. to the suction inlet.

[0026] A second aspect of the present invention relates to use of a set of parts according to an embodiment of the first aspect of the present invention, assembled to form an ejector pump of the first or second ejector pump configuration, for pumping a medium using a motive fluid. The medium may suitably be a liquid, but it is also possible to pump a gas using an ejector pump assembled from the set of parts of the invention. The medium may enter the assembled ejector pump through a piping. The piping may be connected to an inlet opening through suitable fastening means such as rivets, blots and nuts etc. Optionally, gaskets may be used between two or more of the different parts of the set of parts according to the present invention, when assembling them into an ejector pump, to improve imperviousness of the joint between parts. Advantages similar to those described above in relation to the first aspect of the invention are achieved by this second aspect.

[0027] A third aspect of the invention relates to a method for assembly of an ejector pump for pumping a medium using a motive fluid comprising the steps of; providing a set of parts according to the first aspect of the invention, selecting one of said first and second ejector pump configurations, assembling the ejector pump according to said selected one of said first and second ejector pump configurations with a selected one of the first and second nozzle members received in the associated inlet opening of the pump housing. It is to be understood and acknowledged that this aspect of the invention may also be applicable to variations of embodiments having more than the aforementioned first and second ejector pump configurations. Advantages similar to those described above in relation to the first aspect of the invention are achieved by this third aspect.

[0028] In an embodiment of the third aspect of the present invention the method comprises the further steps of, previous to the steps of the aforementioned embodiment, providing a first ejector pump according to one of said first or second ejector pump configurations, and disassembling said first ejector pump, providing a set of parts according to the first aspect of the invention, and assembling a second ejector pump, the second ejector pump being assembled according to the other of said first and second ejector pump configurations, with the other of said first or second nozzle member received in the associated inlet opening of the pump housing.

[0029] In another embodiment of the third aspect of the invention the method comprises the further step of introducing the motive fluid into the assembled ejector pump through the selected nozzle member to pump said medium through the ejector pump.

[0030] In an embodiment of any one of the first, the second or the third aspects of the invention the suction inlet is connected in fluid communication to a reservoir of the medium, such as a ballast tank or bilge of a ship or boat, and/or the selected nozzle member is connected to a source of motive fluid, such as a pressurized motive fluid tank.

Short description of the drawings

[0031] In the following, exemplary embodiments of the set of parts, the use, and the method according to the invention will be described with reference to the drawings in which:

Figs. 1A, 1B and 1C show a pump housing of a first embodiment of the set of parts according to the present invention, shown in a perspective view, a bottom view and a sectional view along the line A-A in Fig. 1B, respectively.

Figs. 2A and 2B show a first nozzle member of the first embodiment of the set of parts, shown in a perspective view and a sectional view along a centre plane of the view in Fig. 2A, respectively.

Figs. 3A and 3B show a second nozzle member of the first embodiment of the set of parts, shown in a perspective view and a sectional view along a centre plane of the view in Fig. 3A, respectively.

Figs. 4A and 4B show a pipe of the first embodiment of the set of parts, shown in a perspective view and a sectional view along a centre plane of the view in Fig. 4A, respectively.

Figs. 5A, 5B and 5C show an adapter fitting of the first embodiment of the set of parts, shown in a perspective view, a top view and a sectional view along the line A-A in Fig. 5B, respectively.

Figs. 6A and 6B show an ejector pump assembled from the first embodiment of the set of parts according to a first ejector pump configuration, shown in a perspective view and a sectional view along a centre plane of the view in Fig. 6A, respectively.

Figs. 7A and 7B show an ejector pump assembled from the first embodiment of the set of parts according to a second ejector pump configuration, shown in a perspective view and a sectional view along a centre plane of the view in Fig. 7A, respectively.

Fig. 8 is a schematic representation of an embodiment of the method according to the invention for assembly of an ejector pump from the first embodiment of the set of parts.

Fig. 9 shows a view similar to that of Fig. 7B of an ejector pump assembled in a second ejector pump configuration from a second embodiment of the set of parts according to the invention.

Fig. 10 shows a pump housing of the second embodiment of the set of parts, fitted with a second nozzle member of the second embodiment of the set of parts, from a bottom view.

Fig. 11 shows a front view of the pump housing of the second embodiment of the set of parts, fitted with the second nozzle member of the second embodiment of the set of parts, of Fig. 10.

Detailed description of the drawings

[0032] Figs. 1A to 5C show different views of individual parts of a first embodiment of the set of parts according to the present invention.

[0033] The set of parts comprises a hollow pump housing 2 shown in Figs. 1A to 1C having an interior open volume 2a enclosed by a generally substantially cubically shaped housing wall 2b. The pump housing 2 has a first circular inlet opening 3 adapted to receive a first nozzle member 18 shown in Figs. 2A and 2B, a second circular inlet opening 19 adapted to receive a second nozzle member 4 shown in Figs. 3A and 3B, and a circular outlet 5 adapted to be connected in fluid communication with a pipe 8 shown in Figs. 4A and 4B. The inlet openings 3, 19 and the outlet 5 are connected to each other via the volume 2a. The first inlet opening 3 is provided in an end face 20 of the pump housing 2, i.e. the face positioned facing left in Fig. 1C. The second inlet opening 19 is provided in a bottom face 21 of the pump housing 2, i.e. the face positioned facing downwards in Fig. 1C. The outlet 5 is provided in an opposing end face 22 of the pump housing 2, i.e. the face positioned facing right in Fig. 1C. The first inlet opening 3 and the outlet 5 are each provided with an inner threading 23 and 24, respectively. On the bottom face 21 of the pump housing 2, four bolt holes 25 are provided.

[0034] The set of parts further comprises the first nozzle member 18 shown in Figs. 2A and 2B for introducing the motive fluid into the pump housing 2. The first nozzle member 18 comprises a first hollow section 11 a, a second hollow section 12a, and a third hollow section 15a. The three sections 11 a, 12a, and 15a share an axis 100 through an interior open volume 18a within the nozzle member 18. The first section 11 a is provided with a flange 29a and an outer threading 30. The outer threading 30 matches the inner threading 23 of the pump housing 2. The first section 11 a of the first nozzle member 18 also has an inner threading 31 a. The third section 15a of the first nozzle member 18 has an inner threading 32a, and a separable nozzle 16a with an outer threading 34a matching the inner threading 32a.

[0035] The set of parts further comprises the second nozzle member 4 shown in figs. 3A and 3B for introducing the motive fluid into the pump housing 2. The second nozzle member 4 has a first hollow section 11 with an axis 101, a second hollow section 12, and a third hollow section 15 with an axis 102. The three sections 11, 12, and 15 provide and share an interior open volume 4a. The first section 11 has an inner threading 31. The first section 11 is also provided with a flange 29. The flange 29 has four bolt holes 25b matching the four bolt holes 25 on the bottom face 21 of the pump housing 2. The flange 29 is provided with a circular groove 35 in a top face 36 of the flange 29, i.e. the face positioned facing upwards in Fig. 3B. The second section 12 of the second nozzle member 4 is angled to form a 90° angle between the axis 101 of the first section 11 and the axis 102 of the third section 15. The third section 15 has an inner threading 32 and a separable nozzle 16 with an outer threading 34 matching the inner threading 32.

[0036] The set of parts further comprises the pipe 8 shown in Figs. 4A and 4B. The pipe 8 has a first circular opening 37 and a second circular opening 38 sharing an axis 103 through an interior open volume 8a. The pipe 8 has a constriction part 6 (also termed "throat") for constricting a fluid flow and a diverging part 7 (also referred to as a "diffuser") for diffusing the fluid flow. The constriction part 6 having a cylindrical inner surface having an essentially constant diameter. The length of the constriction part 6 may vary and serves the function of stabilizing the currents in the mixed fluid. The constriction part 6 of the pipe 8 is connected to the diffuser 7 in which the cross-sectional area of the inside volume increases along the flow direction. Around the first opening 37, the pipe 8 is provided with an outer threading 39 matching the inner threading 24 of the outlet 5 of the pump housing 2. Around the second opening 38, the pipe 8 is provided with an outer threading 40.

[0037] The set of parts further comprises a hollow adapter fitting 41 shown in Figs. 5A, 5B and 5C. The adapter fitting 41 has a first circular opening 42 and a second circular opening 43 sharing an axis 104. The first opening 42 is provided with an outer threading 44. The second opening 43 is provided with a flange 29c. The flange 29c has four bolt holes 25c matching the four bolt holes 25 on the bottom face 21 of the pump housing 2. The flange 29c is provided with a circular groove 35c in a top face 36c of the flange 29c, i.e. the face positioned facing right in Fig. 5C.

[0038] Figs. 6A and 6B show an ejector pump assembled according to a first ejector pump configuration of the first embodiment of the set of parts, shown in a perspective view and a sectional view along a centre plane of the view in Fig. 6A, respectively. The ejector pump assembled according to the first ejector pump configuration is an assembly of the pump housing 2 shown in Figs. 1A, 1B, and 1C, the first nozzle member 18 shown in Figs. 2A and 2B, the pipe 8 shown in Figs. 4A and 4B, and the adapter fitting 41 shown in Figs. 5A, 5B, and 5C. Accordingly, the second nozzle member 4 is not used in this first ejector pump configuration. The first nozzle member 18 is fitted in the first inlet opening 3 of the pump housing 2 by engaging the outer threading 30 with the inner threading 23. Thus, the second section 12a, the third section 15a, and the separable nozzle 16a are positioned within the open interior volume 2a of the pump housing 2, and the opening of the separable nozzle 16a is substantially coaxial with the outlet 5 and the pipe 8. The pipe 8 is fitted in the outlet 5 of the pump housing 2 by engaging the outer threading 39 with the inner threading 24. This connects the first opening 37 with the interior open volume 2a. The adapter fitting 41 is aligned with the second inlet opening 19, fitted to the bottom face 21 of the pump housing 2, and fastened by four bolts 46a, each applied through one of the four bolt holes 25c in the adapter fitting 41, into the corresponding one of the bolt holes 25 of the pump housing 2. The configuration of the assembled ejector pump is so that a motive fluid, when the ejector pump is in use, flows substantially straight through the ejector pump.

[0039] Figs. 7A and 7B show an ejector pump assembled according to a second ejector pump configuration of the first embodiment of the set of parts, shown in a perspective view and a sectional view along a centre plane of the view in Fig. 7A, respectively. The ejector pump assembled according to the second ejector pump configuration is an assembly of the pump housing 2 shown in Figs. 1A, 1B, and 1C, the second nozzle member 4 shown in Figs. 3A and 3B, and the pipe 8 shown in Figs. 4A and 4B. Accordingly, the first nozzle member 18 and the adaptor fitting 41 are not used in this second ejector pump configuration. The second nozzle member 4 is fitted in the second inlet opening 19 in the bottom face 21 of the pump housing 2 and fastened by four bolts 46b, each applied through one of the four bolt holes 25b in the second nozzle member 4 into the corresponding one of the bolt holes 25 of the pump housing 2. Thus, the second section 12, the third section 15, and the separable nozzle 16 are positioned within the open interior volume 2a of the pump housing 2, and the opening of the separable nozzle 16a is substantially coaxial with the outlet 5 and the pipe 8. The pipe 8 is fitted in the outlet 5 of the pump housing 2 by engaging the outer threading 39 with the inner threading 24. This connects the first opening 37 with the interior open volume 2a. The configuration of the assembled ejector pump is so that a medium, when the ejector pump is in use, flows substantially straight through the ejector pump.

[0040] It should be understood and acknowledged that the above described first embodiment is an example of the set of parts according to the first aspect of the invention, and that the first aspect of the invention is broader than the exemplified embodiment. The first and second inlet openings may be provided in other positions from those shown in the figures, e.g. the second inlet opening may be positioned in one of the other surfaces of the pump housing. There may be additional inlet openings, e.g. for additional nozzle members. The angle and form of the second nozzle member may be different from what is shown in the drawings, and there may be additional nozzle members. The pump housing may have a different shape than the one shown in the drawings, e.g. it may be rounded, have an elliptical shape, be cylindrical, etc.

[0041] According to the second aspect of the invention the use of the ejector pump assembled according to the first ejector pump configuration of the first embodiment of the set of parts, as shown in Figs. 6A and 6B, will comprise that a motive fluid enters the first nozzle member 18 via the first section 11a. It then passes through the second section 12a, the third section 15a and the separable nozzle 16a before being ejected into the open interior volume 2a of the pump housing 2. A medium is sucked into the open interior volume 2a, via the adapter fitting 41 through the second inlet opening 19. The mix of motive fluid and medium exits the pump housing 2 through the outlet 5, enters the pipe 8 through the first opening 37, and flows through the constriction part 6 of the pipe 8 and hence the diffusion part 7, in a direction substantially coaxial with the initial average direction of the motive fluid upon its entry into the first section 11a of the first nozzle member 18. Thus, the average direction of the mix of motive fluid and medium will upon its exit from the pump housing 2 be substantially coaxial with the average direction of the motive fluid as it entered the first section 11 a of the first nozzle member 18. This first ejector pump configuration is hence a substantially straight configuration.

[0042] According to the second aspect of the invention the use of the ejector pump assembled according to the second ejector pump configuration of the first embodiment of the set of parts, as shown in Figs. 7A and 7B, will comprise that a motive fluid enters the second nozzle member 4 via the first section 11. It then passes through the second section 12, wherein the average direction of the motive fluid is changed by 90° due to the angle of the second section 12, and then through the third section 15 and the separable nozzle 16, before being ejected into the open interior volume 2a of the pump housing 2. The medium is sucked into the open interior volume 2a through the first inlet opening 3. The mix of motive fluid and medium exits the pump housing 2 through the outlet 5, enters the pipe 8 through the first opening 37, and flows through the constriction part 6 and hence the diffusion part 7 in a direction substantially perpendicular to the initial average direction of the motive fluid upon its entry into the first section 11 of second nozzle member 4. Thus, the average direction of the mix of motive fluid and medium will upon its exit from the pump housing 2 be substantially perpendicular to the initial average direction of the motive fluid when it entered the first section 11 of the second nozzle member 4. This second ejector pump configuration is hence a substantially angled configuration.

[0043] Fig. 8 is a schematic representation of an embodiment of the method according to the third aspect of the invention for assembly of an ejector pump of either the first ejector pump configuration or the second ejector pump configuration, from the first embodiment of the set of parts. The pump housing 2 and the pipe 8 are used in both configurations. The selection of the first or the second ejector pump configuration is made by the user. By selecting the first ejector pump configuration, and using the first nozzle member 18 and the adapter fitting 41, an ejector pump of the first ejector pump configuration, i.e. as shown in Figs. 6A and 6B is assembled by fitting the first nozzle member 18 in the first inlet opening 3 of the pump housing 2 by engaging the outer threading 30 with the inner threading 23, fitting the pipe 8 in the outlet 5 of the pump housing 2 by engaging the outer threading 39 with the inner threading 24, aligning the adapter fitting 41 with the second inlet opening 19, and connecting the adapter fitting to the bottom face 21 of the pump housing 2 using four bolts 46a, each applied through one of the four bolt holes 25c in the adapter fitting 41, fastened into the corresponding one of the bolt holes 25 of the pump housing 2. Whereas by selecting the second ejector pump configuration, and using only the second nozzle member 4 instead of the first nozzle member 18 and the adapter fitting 41, an ejector pump of the second ejector pump configuration, i.e. as shown in Figs. 7A and 7B is assembled by fitting the second nozzle member 4 in the second inlet opening 19 of the pump housing 2 using four bolts 46a, each applied through one of the four bolt holes 25b in the second nozzle member 4, fastened into the corresponding one of the bolt holes 25 of the pump housing 2, and fitting the pipe 8 in the outlet 5 of the pump housing 2 by engaging the outer threading 39 with the inner threading 24.

[0044] A set of parts according to the invention, assembled into an ejector pump in one of the first or second ejector pump configurations, may be disassembled prior to assembly into another ejector pump configuration according to the method described above.

[0045] Figs. 9 to 11 show a depiction of a second ejector pump configuration of an ejector pump assembled from a second embodiment of a set of parts according to the invention. Generally, in Figs. 9 to 11 the reference numerals used in the description above of the first embodiment are used to denote similar elements or elements of similar function. In the second embodiment of the set of parts, the pump housing 2 is a revised version of that shown in Figs. 1A, 1B, and 1C, wherein the pump housing 2 is widening in diameter from the first inlet opening 3, towards a centre part, where the diameter of the pump housing 2 is constant, and narrowing in diameter from the centre part to the outlet 5. The first inlet opening 3 is provided with a flange 9 around the outer perimeter of the inlet. Also, the second nozzle member 4 is a revised version of that shown in Figs. 3A and 3B, where the connection between the first section 11 and the second section 12 forms an elbow. The angle between the average flow direction of the motive fluid and the second section 12 is 125° at the outer part of the motive fluid stream and 135° at the inner part of the motive fluid stream. The second section 12 comprises a rear wall 13, which is essentially straight in a direction parallel to the average direction of the motive fluid stream. The essentially opposing wall 14 of the second section 12 in contact with the inner part of the motive fluid stream is straight and formed to provide for a decreasing cross section of the motive fluid as it is guided through the second nozzle member 4. The decreasing cross-section in the motive fluid direction provides for an increased pressure of the motive fluid. In the third section 15 a separable nozzle 16 is provided. The second section 12 and the third section 15 are connected so as to form an elbow. The tip of the separable nozzle 16 debouches into a converging part 17 of the housing. The jet of motive fluid ejected from the tip of the separable nozzle 16 forms a decrease in pressure around the tip. The decrease in pressure results in a sucking effect so that the medium to be pumped is entrained into the outlet pipe 8.

[0046] Fig. 9 shows a view similar to that of Fig. 7B of an ejector pump assembled from the set of parts of the second embodiment according to the present invention, in an alternative second ejector pump configuration 1. The ejector pump assembled according to the alternative second ejector pump configuration 1 is an assembly of the revised pump housing 2, the revised second nozzle member 4, and the revised pipe 8. The second nozzle member 4 is fitted in the second inlet opening 19. Thus, the second section 12, the third section 15, and the separable nozzle 16 are positioned within the pump housing 2 and the opening of the separable nozzle 16 is substantially coaxial with the outlet 5 and the pipe 8. The pipe 8 is fitted in the outlet 5 of the pump housing 2. The configuration of the assembled ejector pump 1 is so that the medium to be pumped, when the ejector pump is in use, flows substantially straight through the ejector pump 1. When in use, the motive fluid enters the second nozzle member 4 via the first section 11. It then flows through the second section 12, wherein the average direction of the motive fluid is changed due to the angles between the first section 11 and the second section 12 and between the second section 12 and the third section 15. Then the motive fluid stream passes through the third section 15 and the separable nozzle 16 before being ejected into the open interior volume 2a of the pump housing 2. The medium is sucked into the open interior volume 2a through the first inlet opening 3. The mix of motive fluid and medium exits the pump housing 2 through the outlet 5, enters the pipe 8, and flows through the constriction part 6 and hence the diffusion part 7, in a direction substantially perpendicular to the initial average direction of the motive fluid upon its entry into the first section 11 of the second nozzle member 4.

[0047] Fig. 10 shows the revised pump housing 2 of the second embodiment of the set of parts, fitted with the revised second nozzle member 4 of the second embodiment of the set of parts, shown from a bottom view. The inner structure of the second nozzle member 4 shows the inner walls of the second section 12. It will be noticed that the channel has rounded walls perpendicular to the average flow direction of the motive fluid. It is also noticed that the structure demarks the elbow between the first and the second section.

[0048] Fig. 11 shows a front view of the revised pump housing of the second embodiment of the set of parts, fitted with the revised second nozzle member 4 of the second embodiment of the set of parts, similar to that of Fig. 10. The separable nozzle 16 is visible. The separable nozzle is provided coaxially with the outlet 5 so as to provide for an ejection of the motive fluid into the constriction part of the pipe.

Claims

1. A set of parts for being assembled to form an ejector pump for pumping a medium using a motive fluid, the set of parts comprising
a pump housing,
a first nozzle member for introducing the motive fluid into the pump housing,
a second, alternative nozzle member for introducing the motive fluid into the pump housing,
a pipe having a constriction part for constricting a fluid flow and a diverging part for diffusing the fluid flow,
the pump housing having a first inlet opening adapted to receive the first nozzle member, a second inlet opening adapted to receive the second alternative nozzle member, and an outlet adapted to be connected in fluid communication with the pipe,
so that the set of parts is adapted to be assembled into a first and a second ejector pump configuration, wherein
in the first ejector pump configuration the first nozzle member is received in the first inlet opening to serve to introduce the motive fluid into the pump housing, the second nozzle member does not serve to introduce the motive fluid into the pump housing, and the second inlet opening serves as a suction inlet for said medium, and
in the second ejector pump configuration the second nozzle member is received in the second inlet opening to serve to introduce the motive fluid into the pump housing, the first nozzle member does not serve to introduce the motive fluid into the pump housing, and the first inlet opening serves as a suction inlet for said medium.

2. A set of parts according to claim 1, wherein each nozzle member has a first section with a flange or fitting for attaching the nozzle member to the pump housing in the associated receiving inlet opening and a second section connecting the first section to a third section, the third section forming a nozzle for discharging the motive fluid in the pump housing, the second and third sections of that of the first and second nozzle members, which serves to introduce the motive fluid into the pump housing, preferably being positioned inside the pump housing.

3. A set of parts according to any one of claims 1 or 2, wherein the first nozzle member is substantially straight, the first configuration being a substantially straight configuration providing flow of the motive fluid in a substantially straight direction through the pump housing, the first inlet opening being provided at a side of the housing opposite to the outlet adapted to be connected in fluid communication with the pipe.

4. A set of parts according to any one of the previous claims, wherein the second nozzle member is angled, the second configuration being an angled configuration providing flow of the motive fluid in an angled direction through the pump housing, the second inlet opening being provided at a side of the housing not directly opposing the outlet adapted to be connected in fluid communication with the pipe, so that the average direction of the motive fluid at the point of ejection from the nozzle, is substantially axial with said outlet.

5. A set of parts according to claims 2 and 4, wherein the second section of the second nozzle member further being a channel for changing the average direction of the motive fluid,
the channel of the second section comprising a rear wall, said rear wall being essentially straight in a direction essentially parallel to the average direction of the motive fluid stream, and the cross section in a plane perpendicular to the average flow direction of motive fluid in the channel of the second section decreases in the flow direction.

6. A set of parts according to claim 5, wherein
the angle between the initial average flow direction of the motive fluid in the fitting of the first section and the rear wall of the channel of the second section is between 100° and 160°, and/or
the essentially straight rear wall of the channel of the second section is rounded in a direction perpendicular to the average direction of the motive fluid stream, and/or
the geometrical shape of the channel of the second section can be described by the movement of a generatrix, and/or
the angle between the generatrix and the flow direction of the motive fluid varies between 100° and 160°, and/or
the joint between the channel of the second section and the third section forms a break.

7. A set of parts according to any one of the previous claims, further comprising an adapter fitting for adapting that of the first or second inlet opening of said pump housing which, when the ejector pump is assembled in one of said first and second ejector pump configurations, serves as the suction inlet for the medium.

8. Use of a set of parts according to any one of the previous claims, assembled to form the first or second ejector pump configuration, for pumping a medium using a motive fluid.

9. A method for assembly of an ejector pump for pumping a medium using a motive fluid, comprising the steps of
providing a set of parts according to any one of claims 1 to 7,
selecting one of said first and second ejector pump configurations,
assembling the ejector pump according to said selected one of said first and second ejector pump configurations with a selected one of the first and second nozzle members received in the associated inlet opening of the pump housing.

10. A method according to claim 9, comprising the further steps of
previous to the steps of claim 9 providing a first ejector pump according to one of said first or second ejector pump configurations, and
disassembling said first ejector pump,
wherein in said assembling step the ejector pump is a second ejector pump, the second ejector pump being assembled according to the other of said first and second ejector pump configurations.

11. A method according to claim 9 or 10, comprising the further step of
introducing the motive fluid into the assembled ejector pump through the selected nozzle member to pump said medium through the ejector pump.

12. A set of parts according to any one of claims 1 to 7 or a use according to claim 8 or a method according to any one of claims 9 to 11,
wherein the suction inlet is connected in fluid communication to a reservoir of the medium, such as a ballast tank or bilge of a ship or boat, and/or
said selected nozzle member is connected to a source of motive fluid, such as a pressurized motive fluid tank.

Drawing