Submersible pumping equipment

Abstract

 Submersible equipment has a pumping unit 1 to transfer water and entrained solids from a suction end 2 to a discharge end 3.
A jet-pump 13, operated by intake pump 11, entrains water and silt, sand, gravel etc through ducting supported on arms 19, 22 pivoted at 18, 20, 21 and 31 and operated over wide movement ranges by piston/cylinders e.g. 23, 33. This material is expelled through pivoted discharge ducting 40, 45, which can alternatively be replaced by a flexible tube anchored at its outer end. Dredging of trenches or areas, underwater land fill, sampling of the sea-bed e.g. for diamondiferous gravel, and water-jet blasting can be carried out even in the surf zone or areas of debris or shark attack.

Description

[0001] This invention relates to pumping equipment and more especially to submersible pumping equipment suitable for handling and transfer of entrained solids underwater. The equipment of the invention is useful for example in suction-dredging, underwater landfill or dumping, or underwater jet-blasting of resistant bottom layers.

[0002] It is known to provide a submersible framework supporting a suction pump, having suitable flexible tubing attached to the pump inlet and outlet. In use, such equipment is lowered from a service vessel, usually to stand on the sea-bed or other underwater base surface, and operated by an associated diver. Typically, the diver directs the suction pipe, and is in telephone contact with an operator on the service vessel handling controls for the pump and associated equipment, whereby the diver can instruct for the starting or termination of suction.

[0003] To be useful the equipment should be of high power and capacity. This means that in addition to the normal hazards of deep diving, the diver must ensure that, for example, the suction on the sea-bed material does not prejudice his own safety, or that the exhaust from the material being deposited does not cause such turbulence and mechanical disturbance as to hazard his position. In practice, this means that the diver operating such equipment has a tendency to instruct for its operation in short bursts, interspersed with visual or tactile exploration of the cavity (or deposit) formed by the flow of water.

[0004] The present invention provides submersible pumping such equipment with articulated rigid arms supporting or constituting suction and exhaust ducting, the arms being exactly controllable as to position by an operator remote from the pump whereby a programme of excavation or deposition can be carried out in a predetermined fashion and optionally recorded.

[0005] In one aspect the invention provides submersible equipment comprising a framework carrying a submersible jet-pump unit with a suction inlet and a discharge outlet;the framework having pivoted, directly or indirectly, at one end thereof and at a substantially vertical pivot the inner end of one of a first pair of articulated arms supporting or constituting suction ducting; and the framwork having attached at the other end thereof discharge ducting adapted to be capable of discharge placement at a fixed location remote from the framework.

[0006] The discharge ducting may be an elongate flexible hose, having at its outer end (a) a diffuser means to minimise the tendency of the hose to move about and (b) securing means for attachment to an anchor. In this form of the invention a diver may be used to position the discharge end of the equipment, but is of course not needed for operation of the equipment per se.

[0007] Alternatively, the discharge ducting may be constituted by, or supported by, a second pair of rigid articulated arms pivoted directly or indirectly at the other end of said framework.

[0008] Both expedients give fixed, remote, discharge. The use of an anchored flexible hose is preferred for fixed discharge points further from the equipment, e.g. 30 - 50 m. distant.

[0009] A jet-pump is a submersible pump in which a jet of water is pumped into a housing to create vacuum conditions such as to entrain water through a second, suction inlet and pass the combined streams, and any entrained solids, through a common discharge outlet. Thus, the framework will usually support a primary pump for the jet (e.g. a clean water impeller pump) preferably of a type with more than one water outlet attachable to operate the jet-pump. The framework can optionally support a suitable stabilising vane or rail; base skids; and a suitable hoisting sling. Alternatively, the framework and its attachment as described above can be capable of assembly or disassembly in relation to an undersea sledge, which may be provided with motive power e.g. a hydraulic power pack, or with replacement and/or supplementary operating power sources, and/or retractable stabilising feet.

[0010] The first pair of arms is preferably distinct from, although supporting, the suction ducting. In a preferred embodiment, the inner end of the inner arm of the first pair is attached by a substantially horizontal and transverse pivot to a connecting piece itself connected to the substantially vertical pivot. (This therefore constitutes an "indirect"pivotal linkage). In such a case the outer end of the inner arm is pivoted usually also by a horizontal transverse pivot, to a point intermediate the ends of the outer arm.

[0011] The suction ducting supported thereby can either be constituted by separate rigid pivotally interconnecting portions in communication at their innermost end via flexible ducting member to the jet pump suction inlet, or be a supported length of flexible hose, or be more rigid hose but with flexible joint portions. Preferably, the suction ducting possesses three successive portions, defining between themselves two pivotal or flexible intercommunications. The"inner of these communications can lie at the pivot point between the arms of the first pair of arms; the outer intercommunication can lie at the outer end of the outer arm.

[0012] Preferably, there are separate, selectively and remotely, controllable piston-cylinder arrangements controlling each relevant pivot or intercommunication. These may be provided with read-out and/or logging facilities to give an immediate and/or permanent record of position.

[0013] The "discharge" end preferably comprises the elongate flexible hose, as discussed above. If it does utilises the support arms, these may have the same mutual arrangement as at the "suction" end of the equipment. Usually, however, any rigid arms of the second pair are actually constituted by rigid discharge ducting. In such a case the inner end of the inner discharge ducting arm unit of the pair preferably has a transverse horizontal pivotal (or flexible) intercommuniaation with a discharge end piece of the jet-pump; and similarly the pivotal (or flexible) intercommunication with the outer discharge ducting unit is preferably transverse and horizontal. Again, selective and separate positioning . can be :provided by separate piston-cylinder arrangements for each such intercommunication, and each can be provided with a remote read-out and/or logging facility.

[0014] Other aspects of the invention include (a) a method of dredging whether of an area or a trench, in which the above equipment is used e.g. by continuous pumping as the first pair of arms is moved (ii) a method of selective excavation using equipment e.g. for sampling gravel in alluvial diamond mining, for example by selective positioning followed by suction,possibly constrained within a temporary confining surround of known dimension (iii) a method of underwater emplacement of solid material using the equipment, by continuous or intermittent placement of the discharge ducting of the equipment and (iv) methods of undersea materials handling in general using such equipment, whether by suction, placement or jet-blasting especially in areas of excessive diver risk due to the current, animate or inanimate floating or submerged hazards, or sea-bed slope or conditions.

[0015] The invention will be further described with reference to the accompanying drawings in which:-

Figure 1 is a diagrammatic representation in side view of one embodiment, and

Figure 2 shows diagrammatically part of a variant embodiment with a different discharge pipe end.

[0016] The assembly shown in Figure 1 can be considered in three main portions,namely the pumping unit generally indicated at 1, the suction unit 2, and the discharge unit 3.

[0017] The pumping unit 1 has a tubular support framework 4 (vented to allow flooding and draining) with a lifting sling 5 connected at 6 and 7 having an eye 8 for attachment to a suitable lifting cable. Support framework 4 at its lower end has tubular base skids 9 and a stabilizing sail or vane 10 in case it is desired to work with the unit suspended rather than standing on the sea bed. The operative portion of the pumping unit has an intake pump housing 11 with outlets 12, to provide a motive flow of water. As shown, one outlet 12 is attached to the inlet of a jet-pump housing. The jet-pump also possesses suction inlet 1₄, diffuser 15 and mixing chamber 13 and discharge outlet 16. Typically, it possesses a solidly constructed mild steel body providing two 6" suction ports. Other components to receive a.suction relief valve system, and an easily operated clean-out door to remove blockages etc. from the jet pump body. The discharge mixing chamber is a casting designed to withstand the continuous pumping of highly abrasive materials, i.e. sand,gravel etc. The jet pump typically has a designed throughpass of 6" which allows the pumping of trash and particles up to a 51" sphere.

[0018] To one end of the framework 4 is located a swivel mounting 17.

[0019] Suction unit 2 generally comprises an arrangement of pivoted rigid articulated arms, supporting pivotally intercommunicating suction pipe portions, for controlled movement by hydraulic piston-cylinder arrangements about the various pivot points.

[0020] Connecting piece 18 is pivoted around a generally vertical axis of swivel mounting 17 by means of a hydraulic piston-cylinder arrangement (not shown). The lower end of rigid arm 19 is pivoted to the connecting piece about a horizontal transverse axis at 20 by a further piston-cylinder arrangement, also not shown. Arm 19 can thus pivot through 180°. The upper end of arm 19 is pivoted about a horizontal pivot 21 to a position near the upper end of arm 22. The angle between arms 19 and 22 is changeable by a piston-cylinder arrangement 23, itself pivotally attached at 24 and 25. Arms 19 and 22 are typically 3 m. long.

[0021] Rigid suction pipe portion 26 (e.g. of 10 cm bore) lies along arm 19, and is put in communication at its inner end 27 with suction inlet 14 of jet-pump 13 by means of a large-gauge flexible heavy-duty hose member 28. At its outer end 29, and at the general location of pivot point 21 the suction pipe portion 26 is pivotally in communication with a second rigid suction pipe portion 30 lying along arm 22. Portion 30, at its outer end 31, is itself pivotally in communication with an outermost suction pipe portion 32. Relative angular movement of portions 30 and 32 is ensured by piston-cylinder arrangement 33, pivoted at 34 near one end of arm 22 and at 35 to bracket 36 itself pivoted at 37 to an intermediate point of arm 22 so as to move link-rod 38 itself pivotally connected at 39 to the outermost portion 32.

[0022] Alternatively, hose (possible with flexible interconnections) can be supported along arms 19 and 22. Such hose may pass over a hose support cradle where the arms meet.

[0023] Discharge unit 3 has a rigid inner discharge pipe unit 40 pivotally intercommunicating at 41 with jet-pump outlet 16. Angular movement about this intercommunication is provided by further piston-cylinder arrangement 42 pivoted at its inner end (not shown) to framework 4 and at its outer end 43 to bracket 44. The unit 3 also has a rigid outer discharge pipe unit 45 pivotally intercommuncating at 46 to the inner unit 40. Angular movement about this intercommunication 46 is provided by piston cylinder arrangement 47 pivoted at 48 to bracket 44 and at 49 to rigid extension 50 of outerpipe unit 45.

[0024] Where hole 59 is used, as shown in Figure 2, typically a diffuser outlet 60 and anchor 61 are attached to the outer end .(which can be typically 30 m distant) for positioning by a diver. Such hose 59 can be of 15 cm internal diameter, and, like the suction hose, be made of suitable synthetic polymer e.g. rigid polyvinylchloride. Figure 2 also shows a sledge mounting 58 for deplaceable pump equipment.

[0025] In use, intake pump 11 pumps water through outlet 12 into the jet-pump 13. This jet-pump entrains through suction inlet 14 water in the suction pipes, which in turn entrains water entering at the end of the outermost suction pipe unit 32 and any adjacent solids such as silt or gravel. The two streams of water are mixed in chamber 15 and pumped out through outlet 16 into the two discharge pipe units.

[0026] It will be apparent that the followng modes of use are available: -

1: Simple bulk suction, with free discharge down-tide, by a suitable remotely-controlled programme of operation of the various hydraulic piston-cylinder arrangements.

2. Selective excavation at spaced predetermined locations, with the possibility of logging the locations and results obtained e.g. for evaluation purposes.

3. Controlled back-filling operations by suitable manipulation of the element of discharge pipe unit 3.

4. Trenching operations e.g. by extension of the rigid arms of the suction unit without any swivelling around mounting swivel 18.

5. Large-bore gravel sampling operations, e.g. for alluvial diamond mining. This can conveniently be done by emplacing an openended cylindrical extension around the outermost end of the suction-pipe unit, optionally with auxiliary water flow (e.g. from the unused outlet 12, of the intake pump 11).

6. Use in the surf-zone or in rapidly-running water e.g. in power station intakes.

7. Use in zones not permitting overhead stationing of a control vessel,e.g. in conditions of floating ice or other floating debris.

8. Use in water containing submerged hazards, or sharks or like risk.

9. Use in steeply shelving locations, or with fine bottom layers, by free suspension of the unit rather than bottom standing.

10. Use for jet-blasting, typically with a doubled pump capacity and a smaller jet, not capable of manual handling.

[0027] It will thus be apparent that the device and its utility extends beyond the mere replacement of a diver by mechanical arms. The ability to move and place the suction unit so that it can bore straight down in a given location is greater than that obtainable with a diver who must always remain conscious of his own safety bearing in mind the adjacent operation of such heavy equipment. Moreover, a controlled pattern of accurately sized samples can be rapidly taken over an area, especially in alluvial mining where normal samples obtained by drilling may be be sufficiently bulky to be statistically reliable. Moreover, use of this equipment enables operation in the surf zone or in rapidly-running water, or in water containing surface material or entrained solids. The equipment also allows suction, or backfill, operations to be carried out at short notice in locations which are inaccessible in the time available, or otherwise uisafe, for divers. Also, it allows for control from a vessel which can be remote from the unit itself or control from a location on a river bank rather than in a service vessel.

[0028] Various modifications may be made in the equipment. For example, as indicated above, a surrounding cylindrical shell can be provided around the outermost suction pipe portion 32, fed by a flexible auxiliary water supply connected to the unused outlet 12, to facilitate the suction of reproducible samples of large bulk. Also, a rake member can be associated with the equipment, possbily on the tubular framework 4 for operation by movement of the whole equipment, but more preferably on a rigid arm e.g. arm 22 for prior raking movements to remove construction debris or waste from the sea-bed prior to suction.

Claims

1. Submersible equipment for underwater handling and transfer of entrained solids characterised in that it comprises a framework carrying a submersible jet-pump unit with a suction inlet and discharge outlet; the framework having pivoted directly or indirectly at one end thereof and at a substantially vertical pivot,the inner end of one of a first pair of articulated arms supporting or constituting suction ducting; and the framework having attached at the other end thereof discharge ducting adapted to be capable of discharge placement at a desired fixed location remote from the framework.

2. Submersible equipment as claimed in claim 1 characterised in that the first pair of arms supports the suction ducting, (a) the inner end of the inner arm of the first pair being attached by a substantially horizontal and transverse pivot to a connecting piece itself connected to the substantially vertical pivot and (b) the outer end of the inner arm of the first pair being pivoted by a horizontal transverse pivot to a point intermediate the ends of the outer arm.

3. Submersible equipment as claimed in claim 2 characterised in that the suction ducting is constituted by separate rigid pivotally interconnecting portions in communication at their innermost end via a flexible ducting member to the jet pump suction inlet.

4. Submersible equipment as claimed in claim 2 characterised in that the suction ducting is a supported length of hose flexible at least at intercommunication portions near the pivot interconnections.

5. Submersible equipment as claimed in claim 1 characterised in that the discharge ducting is an elongate flexible hose having at its outer end (a) a diffuser means to minimise the tendency of the hose to move about and (b) securing means for attachment to an anchor.

6. Submersible equipment as claimed in claim 1 characterised in that the discharge duct is, or is supported by, a second pair of rigid articulated arms pivoted directly or indirectly at the other end of said framework.

7. Submersible equipment as claimed in claim 6 characterised in that the discharge ducting is constituted by two rigid lengths themselves constituting the second pair of arms, the inner end of the inner length having a transverse horizontal pivotal, or a flexible, interconnection with a discharge end piece of the pump and the outer end of the inner length similarly having a transverse horizontal pivotal, or a flexible, interconnection with the outer length.

8. Submersible equipment as claimed in any one preceding claim, characterised in that each pivot or flexible interconnection of the suction or dischage ends is controlled by a separate, selectively and remotely controllable, piston-cylinder arrangement.

9. A method of underwater materials handling or transfer, by suction, deposition or jet-blasting, characterised in that the submersible equipment as claimed in any one preceding claim is utilised.

10. A method as claimed in claim 9, characterised in that dredging of a trench or area is effected by continous or discontinuous pumping as the first pair of arms is moved.

11. A method as claimed inclaim 9 characterised in that selective sampling excavation is effected by selective positioning of the first pair of arms followed by suction.

12. A method as claimed in claim 11 characterised in that a temporary confining surround of known dimension is emplaced at each selective location prior to suction.

13. Amethod as claimed in claim 9, characterised in that material is deposited in a desired underwater location by continous or intermittent placement of the discharge ducting.

Drawing