[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 1
4, 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.
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.