Mobile pumping system

Abstract

A dredging system comprising a barge 30, at least one directional jet 60 to move the barge, a dewatering pump to extract fluid from near a bed of a waterbody, and a sparging device. The dewatering pum

Description

Technical Field

[001] The present invention generally relates to a mobile pumping system for recovering solids or viscous liquids from a waterbody. In particular, but not exclusively, the invention relates to a mobile pumping system for recovering a salt solution from near a bed of a waterbody, such as a pond, lake, reservoir, river, estuary, or the like. Background

[002] To recover minerals from a salt brine, the liquid brine is typically first extracted from deep wells normally located around a salt flat. This liquid brine is pumped into ponds for salt recovery in a subsequent drying process. During this drying process other chemicals and salts are obtained from the liquid brine through precipitation, crystallisation, or some other chemical process. Some of these salts are deposited as solids at the bottom of the pond, thereby reducing its depth. After a few months, the pond needs to be drained and then machinery is used for mechanical removal of all the salts that have accumulated at the bottom of the pond due to the drying process. Normally, this takes approximately 3 months, and it is inefficient and expensive.

[003] A similar problem occurs in ponds in mining processing plants where solids settle to the bottom of the pond. The pond is periodically drained and the solids on the bottom of the pond are mechanically removed.

[004] In both cases, the processing is discontinuous because intervention is required to remove the solids build-up.

[004] There is a need for new or improved system and / or method for preventing solids buildup on the bed of a waterbody, and / or continuously processing the salts in the waterbody in a more efficient manner. Summary

[006] According to a first aspect there is provided a pumping system for a salt slurry from near a bed of a brine pond, the pumping system comprising: (i) a primary floating platform configured to float on a surface of the pond, the primary floating platform having a central opening; (ii) at least one hydraulic directional jet coupled to the primary floating platform for moving the primary floating platform over the surface of the pond; (iii) a winch mounted on the primary floating platform; (iv) a submersible pump coupled to the winch via a winch cable extending through the central opening, the submersible pump operable to extract liquid from near a bottom of the pond , the submersible pump including a downwards directed sparger device for breaking up salt solids which have accumulated on a bed of the pond and to suspending the broken up salt solids in a liquid to form a brine and thereby enable pumping thereof by the submersible pump; and (v) an auxiliary floating platform tethered to the primary 02 05 24 floating platform to allow some independent movement of each platform, and configured to float on a surface of the pond, and including an auxiliary pump for providing hydraulic power to the primary floating platform.

[007] Optionally, the floating platform comprises a barge.

[008] Optionally, the floating platform comprises a plurality of directional jets. In some embodiments, each directional jet may be oriented, or capable of being oriented, in a different direction, to facilitate movement of the floating platform in any direction on the surface of the waterbody. This enables the floating platform to be moved above an area of the waterbody bed that needs to have solids removed therefrom.

[009] Optionally, the pump comprises a slurry pump that is able to pump a relatively high concentration of solids entrained in water. In some embodiments, solids having a mass concentration (Cw) of over 70% may be pumped by the submersible slurry pump. The mass concentration is the ratio of the weight of the solids in a given volume of slurry to the total mixture weight (the weight of the solids plus the water). In some embodiments, the dso of solids in the slurry may be greater than 150 microns.

[010] Optionally, the sparger device comprises a sparger ring having apertures directed downwards.

[011] Optionally, the ring surrounds a pump chamber of the dewatering pump.

[012] Optionally, the floating platform further comprises a global positioning system.

[013] Optionally, the floating platform further comprises a depth measurement device (such as a transducer) to enable the floating platform to detect a depth of the waterbody. The transducer may use sonar, lidar, or the like.).

[014] Optionally, the floating platform further comprises a pressure sensor mounted on or near the submersible pump for detecting a pressure at the depth of the pump. This may be used to measure and control the depth of the submersible pump.

[015] The pumped fluid may comprise slurry.

[016] According to an unclaimed aspect there is provided a pumping system comprising: (i) a mobile barge for floating on a waterbody, the barge including a hydraulic directional jet for moving the barge over the surface of the waterbody; (ii) a dewatering pump coupled to the mobile barge and operable to extract liquid from near a bottom of the waterbody, the dewatering pump including a sparger device for breaking up solids on the waterbody bed to suspend the solids in liquid and thereby allow them to be pumped out by the dewatering pump; (iii) an auxiliary pump coupled to the dewatering pump and operable to provide high pressure fluid to the sparger device thereof.

[017] Optionally, the auxiliary pump also provides high pressure water to feed the hydraulic directional jet to allow the barge to move to desired areas of the waterbody. The desired areas may, for example, have the highest salt deposits on the waterbody bed. 02 05 24 Optionally, the mobile barge comprises a plurality of directional jets. In some embodiments, each directional jet may be oriented, or capable of being oriented, in a different direction, to facilitate movement of the barge in any direction on the surface of the waterbody. Control of the directional jets may be implemented using valves that control the flow of fluid from the auxiliary pump.

[019] Optionally, the dewatering pump comprises a submersible pump.

[020] Optionally, the submersible pump comprises a slurry pump that is able to pump a relatively high concentration of solids entrained in water. In some embodiments, solids having a mass concentration (Cw) of over 70% may be pumped by the submersible slurry pump. The mass concentration is the ratio of the weight of the solids in a given volume of slurry to the total mixture weight (the weight of the solids plus the water). In some embodiments, the d50 of solids in the slurry may be greater than 150 microns.

[021] Optionally, the submersible pump is coupled to the mobile barge by a string (such as a cable, rope, or the like) that can be wound or unwound to adjust the depth of the submersible pump. The string may comprise any convenient material, such as metal.

[022] Optionally, the sparger device comprises a sparger ring.

[023] Optionally, the ring surrounds a pump chamber of the dewatering pump.

[024] Optionally, the high pressure fluid comprises high pressure water from the waterbody.

[025] Optionally, the submersible pump may be maintained within 3 metres of a bed, or at a desired depth.

[026] Optionally, the mobile barge further comprises a global positioning system.

[027] Optionally, the mobile barge further comprises a depth measurement device (such as a transducer) to enable the mobile barge to detect a depth of the waterbody. The transducer may use sonar, lidar, or the like.).

[028] Optionally, the mobile barge further comprises a pressure sensor mounted on or near the submersible pump for detecting a pressure at the depth of the pump.

[029] Optionally, the auxiliary pump comprises a vertical pump having a volute that may be immersed in the waterbody to pump fluid therefrom.

[030] The pumped fluid may comprise slurry.

[031] By virtue of these aspects, a pumping system is provided that can continuously remove salts and other solids either in solution or as a slurry and provide them to a processing facility. Removing solids from the waterbody bed avoids the need to dredge the bed or drain the waterbody and mechanically remove the solids build-up. By providing positioning and depth information, the pumping system is able to map the waterbody bed and identify areas with the greatest solids build-up. The mobile pumping system may prioritise pumping at those areas. 02 04 25

[019] According to an unclaimed aspect there is provided a method of recovering a slurry from a pond, the method comprising: (i) moving a first and second floating platform, which are tethered to each other to allow some independent movement of each platform, over the surface of the pond using at least one hydraulic directional jet to locate an area of the pond where solids have accumulated on the bed and that needs removal; (ii) using fluid in the pond to hydraulically break up the accumulated solids on the pond bed at the located area to suspend the solids in liquid to form a slurry; (iii) extracting slurry from the area near a bottom of the pond using a pump.

[020] The method may further comprise using an auxiliary pump to provide high pressure fluid to move the floating platform and to break up solids on the waterbody bed.

[021] The method may comprise the further steps of: measuring a depth of the waterbody bed, and lowering a submersible pump to within 3 metres of the measured depth.

[022] The fluid may comprise a liquid, such as brine, or a two-phase fluid such as water having solids suspended therein.

[023] According to an unclaimed aspect there is provided a submersible pump for pumping solids from near a bed of a waterbody, the submersible pump comprising: (i) an impeller mounted in a volute for pumping slurry, (ii) a downwards directed sparger device; and (iii) an inlet to the sparger device for receiving high pressure fluid from an external pump whereby the sparger device directs the high pressure fluid to break-up solids on the waterbody bed to suspend the solids in liquid and thereby enable pumping thereof by the submersible pump.

[024] These and other aspects will be apparent from the following specific description, given by way of example only, with reference to the accompanying drawings, in which:

[025] Fig. 1 is a schematic view of a mobile pumping system according to a first embodiment of the present invention, where the mobile pumping system is floating on a waterbody and providing fluid to a salt processing system;

[026] Fig. 2 is a schematic view showing the mobile pumping system of Fig. 1 in more detail; and

[027] Fig. 3 is a schematic view showing part of the mobile pumping system of Fig. 1 (the submersible pump) in more detail. Detailed Description

[028] Reference is now made to the drawings, and particularly to Fig. 1, which is a schematic view of a mobile pumping system 10 according to an embodiment of the present xt CM O CM invention, where the mobile pumping system is floating on a waterbody 12 and providing fluid to a salt processing system 14. In this embodiment the waterbody 12 is a brine pond from which salts are recovered using the salt processing system 14, which located on or near a bank of the pond.

[042] The waterbody 12 is formed in a dip in the surrounding land 16 and includes water (containing brine) 18. An original bed 20 of the land in the dip has received salt deposits 22, which reduce the depth of the waterbody 12. An upper surface of the salt deposits 22 forms a deposited waterbody bed 24. The pumping system 10 floats on a surface 26 of the waterbody 12. The brine is more dense than clean water so it tends to sink to near the bottom of the waterbody 12; whereas clean water tends to be located near the surface 26.

[043] Reference is now also made to Fig. 2, which is a schematic view showing the mobile pumping system 10 in more detail. The mobile pumping system 10 comprises a primary barge 30 and an auxiliary barge 32.

[044] The primary barge 30 is used to extract fluid (liquid and solids suspended in liquid) from near the deposited waterbody bed 24. The primary barge 30 comprises a floating platform 40 on which a winch 42 is mounted for winding and unwinding a cable 44 attached thereto. A submersible pump 46 is coupled to the free end of the cable 44 and depends from the winch 42. The cable 44 is sufficiently long to allow the submersible pump 46 to be lowered to the original bed 20, if required.

[045] A controller 50 is mounted on the floating platform 40 and controls the operation of the primary barge 30. In particular, the controller 50 monitors various sensors on the barge 30. These sensors include a depth sensor 52, an underwater pressure sensor 54, and a GPS sensor 56. The depth sensor 52 comprises a commercially available transducer, such as a GT20 sensor, available from Garmin (trade mark). The underwater pressure sensor 54 comprises a commercially available sensor, such as a PS3417 Hydrostatic submersible pressure transmitter, available from IFM (ifm electronic ltd). Based on the readings from the sensors 52, 54, the controller 50 can raise or lower the submersible pump 46 so that it is close to the deposited waterbody bed 24. In this embodiment, the submersible pump 46 is lowered to between 1m and 0.5m from the deposited waterbody bed 24.

[046] The primary barge 30 includes a plurality of each directional jets 60 mounted beneath the floating platform 40. The jets 60 are oriented in different directions so that they can be selectively activated to facilitate movement of the floating platform 40 in any direction on the waterbody surface 26. The controller 50 selectively activates the jets 60 based on a desired located on the waterbody 26 surface to which the primary barge 30 is to move, or at which the primary barge 30 is to remain.

[047] The primary barge 30 also includes an output pipeline 62 that connects the submersible pump 46 to the salt processing system 14 so that fluids are pumped from the water 24 near the deposited waterbody bed 24 thereto. In some embodiments, where the output pipeline 62 is particularly long, one or more repeater pumps (not shown) may be provided in the output pipeline 62 to boost the pumping distance.

[048] The primary barge 30 also includes a pipe manifold 64 having a plurality of outputs. Each directional jet 60 is coupled to one of the pipe manifold outputs. Each pipe manifold output includes an isolation valve (not shown) selectively actuatable by the controller 50. One of the pipe manifold outputs is also coupled to the submersible pump 46, as described in waterbody bed that has solids needing removed; (ii) hydraulically breaking up solids on the waterbody bed at the located area to suspend the solids in liquid; (iii) extracting fluid from the area near a bottom of the waterbody using a pump.

[033] The method may further comprise using an auxiliary pump to provide high pressure fluid to move the floating platform and to break up solids on the waterbody bed.

[034] The method may comprise the further steps of: measuring a depth of the waterbody bed, and lowering a submersible pump to within 3 metres of the measured depth.

[035] The fluid may comprise a liquid, such as brine, or a two-phase fluid such as water having solids suspended therein.

[036] According to a fourth aspect there is provided a submersible pump for pumping solids from near a bed of a waterbody, the submersible pump comprising: (i) an impeller mounted in a volute for pumping slurry, (ii) a downwards directed sparger device; and (iii) an inlet to the sparger device for receiving high pressure fluid from an external pump whereby the sparger device directs the high pressure fluid to break-up solids on the waterbody bed to suspend the solids in liquid and thereby enable pumping thereof by the submersible pump.

[037] These and other aspects will be apparent from the following specific description, given by way of example only, with reference to the accompanying drawings, in which:

[038] Fig. 1 is a schematic view of a mobile pumping system according to a first embodiment of the present invention, where the mobile pumping system is floating on a waterbody and providing fluid to a salt processing system;

[039] Fig. 2 is a schematic view showing the mobile pumping system of Fig. 1 in more detail; and

[040] Fig. 3 is a schematic view showing part of the mobile pumping system of Fig. 1 (the submersible pump) in more detail. Detailed Description

[041] Reference is now made to the drawings, and particularly to Fig. 1, which is a schematic view of a mobile pumping system 10 according to an embodiment of the present invention, where the mobile pumping system is floating on a waterbody 12 and providing fluid to a salt processing system 14. In this embodiment the waterbody 12 is a brine pond from which salts are recovered using the salt processing system 14, which located on or near a bank of the pond.

[042] The waterbody 12 is formed in a dip in the surrounding land 16 and includes water (containing brine) 18. An original bed 20 of the land in the dip has received salt deposits 22, which reduce the depth of the waterbody 12. An upper surface of the salt deposits 22 forms a deposited waterbody bed 24. The pumping system 10 floats on a surface 26 of the more detail below, via a sparger fluid pipe 66. An input to the pipe manifold 64 is coupled to an auxiliary pipe 68. The auxiliary pipe 68 is used as a conduit for high pressure water and also acts as a tether so that the auxiliary barge 32 is towed by the primary barge 30 wherever the primary barge 30 moves.

[049] The auxiliary barge 32 includes a floating platform 70 on which is mounted an auxiliary pump (which is a vertical pump in this embodiment) 72. The auxiliary pump 72 includes a volute 74 at a lower end which, in use, is submerged into the water 18 to provide a source of fluid and the pump output is coupled to the auxiliary pipe 66 to provide high pressure water thereto. In this embodiment, the high pressure water will depend the characteristics of the waterbody bed 24 and solids being pumped, but may be between 100 and 300 kPa. In this embodiment, the auxiliary pump 72 is not used for dewatering, instead it is used to provide hydraulic power to the primary barge 30. The primary barge 30 uses this hydraulic power for two main purposes. The first purpose is to move the floating platform 40 to (or to maintain the floating platform 40 in) a desired position using the directional hydraulic jets 60. The second purpose is to provide the submersible pump 46 with high pressure fluid to break up the solids on the deposited waterbody bed 24, as described below in more detail.

[050] Reference is now also made to Fig. 3, which is a schematic view showing the submersible pump 46 in more detail. The submersible pump 46 comprises a waterproof drive housing 80 which houses a motor (not shown) that powers the rotation of a drive shaft (not shown) that is attached to an impeller (not shown). A lower end of the submersible pump 46 includes a perforated strainer basket 82 (having a large number of relatively small apertures therein) that prevents large items of debris (e.g. sticks, twigs, or the like) from reaching (and potentially blocking) the impeller. These features are conventional for certain submersible pumps, such as the WARMAN SHW (trade marks) submersible pump, available from The Weir Group PLC (www.global.weir).

[051] The submersible pump 46 also includes a sparger device 84 that defines apertures (not clearly visible in Fig. 3) that are directed downwards towards the deposited waterbody bed 24. The sparger fluid pipe 66 is coupled to a sparger device inlet 86 of the sparger device 84 and provides high pressure water thereto, via the pipe manifold 64, in the direction shown by arrow 87.

[052] As shown by broken lines 88 in Fig. 3, directional jets of water (sparger jets) are forced through the sparger device apertures towards the deposited waterbody bed 24 such that, in use, solid particles are dislodged therefrom forming a slurry in the area indicated by broken cylinder 90. This enables the slurry to be pumped out by the submersible pump 46 and delivered to the salt processing system 14.

[053] The controller 50 may be programmed with algorithms so that it can operate autonomously, directing itself to areas above the waterbody bed that require salt removal, measuring the depth, lowering the submersible pump to the required depth, actuating the pump 72, and detecting when the salt deposits 22 have been removed. If desired, the primary barge 30 (and the auxiliary barge 32) may be controlled remotely, from a panel, computer, tablet or any controller device.

[054] It will now be appreciated that these embodiments have the advantage of providing a mobile pumping system 10 that can map the deposited waterbody bed 24 to identify areas of large solids build up that need to be broken down. The mobile pumping system 10 can then move, or be moved, to the areas having the largest build up of solids, and the solids can be broken up and pumped out by the submersible pump 46. If all of the solids build up has been removed, the brine liquid near the original bed 20 can be pumped out for processing by the salt processing system 14 or any slurry processing system plant for mining applications or solids processing.

[055] At least some of these embodiments provide an autonomous pumping system for dredging solid materials from brines or any other type of ore, slurry or liquid with solids, from tanks, ponds, pools or any other damp or natural river or liquid reservoir. As an example, it is used for removing salt solution from a pond to allow continuous processing and improve its efficiency

[056] Various modifications may be made to the above described embodiments. For example the solids may not be salts, the waterbody may be seawater or a natural pond, lake, or river, and other types of sensors may be used than those described.

[057] In some embodiments, the submersible pump 46 may be replaced with a pump mounted on the floating platform and having an elongate snout that can be lowered to the vicinity of the waterbody bed. The snout may have a sparger device located beside or around it, and the auxiliary pump 72 may be coupled to an inlet of the sparger device.

[058] In some embodiments, the auxiliary pump 72 may be used to provide a dewatering function to empty water from the waterbody (not liquid brine, just normal water near the top of the waterbody). In some embodiments, a different processing system may be used than the salt processing system 14. Reference Numerals Mobile pumping system 10 Waterbody 12 Salt processing system 14 Surrounding land 16 Water (containing brine) 18 Original bed 20 Salt deposits 22 Deposited waterbody bed 24 Waterbody surface 26 Primary barge 30 Auxiliary barge 32. Floating platform 40 Winch 42 Cable 44 Submersible pump 46 Controller 50 Depth sensor 52 Underwater pressure sensor 54 GPS sensor 56 Directional jets 60 Output pipeline 62 Pipe manifold 64 Sparger fluid pipe 66 Auxiliary pipe 68 Floating platform 70 Auxiliary pump 72 Volute 74 Waterproof drive housing 80 Strainer basket 82 Sparger device 84 Sparger device inlet 86 Arrow showing high pressure fluid direction 87 Sparger waterjets 88 Slurry area 90 02 04 25

Claims

1. A pumping system for pumping a slurry from near a bed of a pond, the pumping system comprising:(i) a first floating platform configured to float on a surface of the pond, the first floating platform having a central opening;(ii) at least one hydraulic directional jet coupled to the floating platform for moving the floating platform over the surface of the pond;(iii) a winch mounted on the first floating platform;(iv) a submersible pump coupled to the winch via a winch cable extending through the central opening, the submersible pump including a downwards directed sparger device for breaking up solids which have accumulated on a bed of the pond to suspend solids accumulated on the bed of the pond in a liquid to form a slurry and thereby enable pumping thereof by the submersible pump; and(v) a second floating platform tethered to the first floating platform to allow some independent movement of each platform, and configured to float on a surface of the pond, and including an auxiliary pump for providing hydraulic power to the first floating platform2. The pumping system of claim 1, wherein the auxiliary pump provides high pressure fluid to the sparger device.

3. The pumping system of claim 1 or 2, wherein the auxiliary pump provides high pressure fluid to feed the at least one hydraulic directional jet to allow the floating platform to move to desired areas of the pond.

4. The pumping system of claim 1 or 2, wherein the floating platform comprises a plurality of directional jets, each directional jet being oriented, or capable of being oriented, in a different direction, to facilitate movement of the floating platform in any direction on the surface of the waterbody.

5. The pumping system of any preceding claim, wherein the sparger device comprises a sparger ring having apertures therein directed downwards.

6. The pumping system of claim 5, wherein the sparger ring surrounds a pump chamber of the dewatering pump.

7. The pumping system of any preceding claim, wherein the floating platform further comprises a global positioning system.

8. The pumping system of any preceding claim, wherein the floating platform further comprises a depth measurement device.

9. The pumping system of claim 8, wherein the depth measurement device is arranged to determine the thickness of solids accumulated at the bed of the pond at various areas in the pond.

10. The pumping system of any preceding claim, wherein the floating platform further comprises a pressure sensor mounted on or near the submersible pump for detecting a pressure at the depth of the pump.04 25

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