GB2127371A - Vertical silo/top reclaim multiple feed sump - Google Patents

Abstract

Apparatus for providing surge capacity to a slurry transportation system input and for delivering a slurry of constant and predetermined concentration is provided by boring a vertical shaft or tank 12 in the ground of a diameter and depth to provide the required surge capacity and emptying the slurry input into the tank 12. A pump 18 supported by a winch 16 and cable 17 is controllably lowered into the sump by an amount necessary to draw a predetermined fluid-to-solids slurry into the pipeline. The output of the pump is coupled to the slurry transportation system through a concentration determination apparatus which communicates with the winch, lowering or raising the pump as necessary to increase or decrease the concentration. <IMAGE>

Description

SPECIFICATION Apparatus for use with a slurry transportation system This invention relates to apparatus for use with a slurry transportation system.

This invention may be used to provide an economical in-mine apparatus for providing a surge capacity to a slurry system by accepting slurry from a number of mine faces individually or simultaneously and delivering a slurry to the hoist system at a constant rate and at a constant concentration.

The following examples of prior art arrangements are known.

U.S. Patent No. 4,037,335 discloses a winch and cable supported pump for removing unconsolidated material from the bottom of a basin. The controls on the winch are strictly to prevent plugging of the pump. The Patent does not disclose the need for control of the winch to maintain concentration in a slurry system.

U.S. Patent No. 3,990,748 to Ghusn et al discloses a cable supported pumping apparatus.

The U.S. patent to Blanchard, No. 590,084, discloses a winch controlled suction apparatus for emptying grain from the hold of a ship.

Neither the Ghusn patent nor the Blanchard patent discloses the use of the apparatus in a slurry system for holding and concentrating control.

The U.S. Patent to Otterson, No.

1,166,712, discloses a small sump and an apparatus for emptying the sump on a need basis.

In typical embodiments of the present invention the apparatus includes a shaft sunk in the mine floor. The shaft has a diameter and depth sufficient for the surge capacity needed.

A cable supported pump is lowered into the slurry filled shaft and pumped out at a predetermined concentration. A concentration detector controls the winch that lowers or raises the cable in order to maintain the concentration in the pipeline from the pump at a predetermined concentration. The apparatus will provide the subsequent hoist system with the most economical concentration to pump and hoist, and will provide same continuously during the operation of the hoist system thereby preventing hoisting of varying concentration thus rendering the system uneconomical.

According to the present invention there is provided apparatus for use in combination with a slurry transportation system, and for receiving a slurry from a slurry input of varying concentrations and delivering a slurry to a slurry output of a constant predetermined concentration while providing a limited surge capacity between said input and said output, said apparatus comprising:: (a) a substantially vertical holding tank having an open top, side walls and a closed bottom and having its width substantially less than its depth; (b) discharge means having its outlet positioned over the open top of said tank; (c) a winch apparatus driven by a controllable motor and a cable attached around said winch apparatus; (d) a suction pump having a suction inlet and an outlet, said suction pump attached to said cable so that operation of said winch apparatus will raise or lower said suction pump along the axis of said tank; (e) flexible pipe means coupling the output of said suction pump to the output of said slurry system; and (f) means for determining the concentration in said slurry output system and for lowering or raising said pump through said winch motor means, in inverse, relation to the concentration deviation of said slurry from a predetermined concentration.

The accompanying figure illustrates a preferred embodiment of the invention for providing surge capacity and constant concentration to a subsequent slurry hoisting system. A mine tunnel 10 has a roof 11 and a floor 9.

The apparatus of this invention is formed in floor 9 and comprises a shaft generally referred to by arrow 1 2. Shaft 1 2 is formed in the usual manner by digging, blasting or, depending on the depth from the surface, by boring. Shaft 1 2 is generally the diameter of the tunnel 10 but could be smaller or larger depending on the intended capacity of the shaft and the difficulty in digging or supporting the shaft. The walls 1 3 can be further stabilized by a steel liner by reinforced cement or brick, or any other usual means for lining the walls of an underground shaft or tank. It is preferable that the bottom 14 also be lined to prevent heaving of the bottom and to contain the fluids if fractures are located in the bottom region.

In order to support the roof 11 over the shaft or tank 12, arches 1 5 are placed and anchored. Several arches 1 5a may be used to support the roof. The arches would normally be placed radially around the shaft between floor 1 2 and roof 11 as needed or required.

At the peak of arches 1 5 or 1 5a is attached a winch 1 6 in any usual manner. A cable 1 7 is wrapped around winch 1 6 and extends to pump 1 8 and attached thereto providing means for raising or lowering pump 1 8. Pump 1 8 includes a mouth 1 9 connected to a pump housing 20 having an impeller therein therein (not shown). The impeller is connected to a motor 21. An output 22 for pump 18 is formed at housing 20 and is coupled to a flexible pipe 23. The other end of pipe 23 is connected to pipe 24, through a densitometer 25 to the inlet 26 of the hoisting equipment which is generally illustrated by box 27.The hoisting equipment 27 generally includes pumps, pump controls, valves, computers and other necessary generating equipment. Such a system is completely illustrated in copending patent application U.S. Serial No. 351,101 filed February 22, 1982, to Sweeney, Shaw and Webb entitled "Method and Apparatus for Sequence Control of Vertical Movements of Slurried Particulates" and U.S. Serial No.

351,102 filed February 22, 1982, to the same inventors entitled "Method and Apparatus for Process Control of Vertical Movement of Slurried Particulates".

From the hoisting equipment 27 the slurry is generally hoisted up a pipe 28 to a processing plant 29. At that location the coal or other product and carrying fluid such as water, is separated, the water clarified and returned down pipe 30 to the mine face equipment 31. Such equipment is clearly described in United States patent No. 3,941,425 to Eric H. Reichl entitled "Mobile Slurry Handling System". Details of mine face equipment 31 will not be further described.

Slurrying equipment (not illustrated) which is part of mine face equipment 31 provides slurry which is transmitted down a pipe 32 to an outlet 33 to sump 1 2 where it falls to the bottom of the sump. Additional water may be added, if necessary, to sump 1 2 through a pipe 34 which is controlled by a valve 35 coupled to water return pipe 30.

In order to provide control of the winch, signals corresponding to density changes are transmitted from density measuring apparatus 25 through wire 36 to winch control apparatus 37. Winch control apparatus 37 converts the density signals to control signals for winch 1 6. Such control is transmitted from the winch control apparatus through wire 38 to winch 1 6. A manual control 47 coupled through a wire 48 can also operate the winch when automatic control is not desired.

If too much water accumulates in sump 1 2, then the excess water must be removed. Such removal is accomplished by pump 39 which may be mounted in a chamber 40. A weir 41 transfers water from sump 1 2 to chamber 40 when the water reaches the height of weir 41.

Pump 39 will then transfer water in chamber 40 through pipe 42 to a small sump 43 where the water can be temporarily stored. As necessary, water in sump 43 can be transferred via pump 44 through pipe 45 to pipe 30 through a check valve or valve 46.

Operation In operation, water from processing plant 29 is pumped down pipe 30 to mine face equipment 31. Coal, for example, is removed from the mine face and slurried, then transported through pipe 32 to outlet 33 where it is deposited into sump 1 2. Other mine faces (not shown) can, likewise, be producing coal, slurrying the coal and transporting the coal through other pipes 32a, for example, to outlets 33a to sump 12. Although only two are illustrated, the sump 1 2 can operate with any number of outlets 32, so long as sump 1 2 is designed to accommodate the anticipated quantity. Pump 18 is initially controlled through manual control 47 which commands winch control 37 through wire 48.As the winch unwinds pump 18 will come in contact, first with the fluids in sump 1 2, and eventually with the coal. Once the pump mouth 19 begins to suck water, the manual control 47 can be switched to automatic and the density measuring equipment 25 will automatically continue to rapidly lower pump 18 until coal is being sucked into mouth 1 9. As the density increases as measured at 25, the lowering rate decreases. When the density reaches the predetermined value, for example between 45 and 55 percent, the winch control 37 will stop the further lowering of pump 18. As coal is removed, then continued lowering is required. Also, slurry is being deposited from outlets 33 or 33a. If the rate of deposit exceeds the pump capacity, the concentration will quickly exceed the allowable percentage as measured by equipment 25.Winch control 37 will then be commanded to raise pump 18 to readjust the concentration to the predetermined range.

As coal is removed by pump 18, it is transferred up pipe 23 to pipe 24. In the embodiment illustrated, pipe 23 is a floating pipe since it is desirable to always have pipe 23 above the mouth 1 9 and layer of coal. A large section of pipe 23 could easily become buried in coal from outlets 33 and 33a, thus making it extremely difficult to remove pump 12, particularly if pump 1 2 is stopped for any period of time when coal is leaving outlet 33.

Other systems could be used, however, to keep pipe 23 in position, such as a cable attached to pipe 23 which would maintain tension on pipe 23 at all times.

As the slurry passes up pipe 24, it passes through density measuring apparatus 25 which is preferably a well known radioactive density measuring apparatus. As previously mentioned, information as to density is transmitted through wire 36 to winch control apparatus 37 for control of the winch 16 and pump 1 8 position. Coal slurry then passes to hoist equipment 27 where the slurry is pressurized sufficiently to pass up pipe 28 to processing plant 29.

Excess water can be removed from sump 1 2 when the water level rises above wire 44.

Chamber 40 will fill and be removed by pump 39 and transferred through pipe 42 to storage sump 43. Here the water can be eventually returned to the system by being removed by pump 44 through pipe 45 and check valve 46 to pipe 30.

This system has several advantages over previously known slurry systems. First, the construction of a shaft is well known in the mining industry. Large caverns need to be evacuated underground to construct a sump as described in United States patent No.

4,143,921 issued to William T. Sweeney and Thomas Plate, for example. Secondly, complex pump support equipment, superstructures and tramming equipment need to be engineered, installed and maintained underground. Hose handling for such a sump is a complex problem, and the control of slurry outlet is complex if the outlets are distributed along the sump so that the material will be evenly distributed. Since the space is so limited, maintenance is a complicated problem.

The sump of this invention requires a shaft to be constructed using known and understandable mining technology. The arch supports 15, 15a for the roof and winch 1 6 are state of the art mining technology. Thus, anyone competent in this art can install them without special knowledge or equipment. The winch 1 6 is used in mining presently and should pose no problem as to installation or maintenance. The suspended pump 1 8 and floating hose 23 require no complex mounting or controls. When maintenance problems occur, the pump need only be raised by cable 1 7 and winch 16 to the top of sump 1 2 and the pump 1 8 pulled over the floor for replacement or repair.

Since no special evacuation, support or high technology is required for the above system, the cost of installation will be dramatically reduced over the sump described in patent No. 4,143,921 or structures of similar nature.

A holding sump for a slurry transportation system has been described that is easily constructed by mining personnel with known technology. The sump is not only efficient but easily maintained. The pump for the sump can be easily controlled to provide a constant concentration of slurry for the subsequent hoist system and can be easily maintained, if necessary.

It is obvious that changes can be made in the application and still be within the spirit and scope of the invention as disclosed in the specification and appended claims.

Claims (5)

1. Apparatus for use in combination with a slurry transportation system, and for receiving a slurry from a slurry input of varying concentrations and delivering a slurry to a slurry output of a constant predetermined concentration while providing a limited surge capacity between said input and said output, said apparatus comprising:: (a) a substantially vertical holding tank having an open top, side walls and a closed bottom and having its width substantially less than its depth; (b) discharge means having its outlet positioned over the open top of said tank; (c) a winch apparatus driven by a controllable motor and a cable attached around said winch apparatus; (d) a suction pump having a suction inlet and an outlet, said suction pump attached to said cable so that operation of said winch apparatus will raise or lower said suction pump along the axis of said said tank; (e) flexible pipe means coupling the output of said suction pump to the output of said slurry system; and (f) means for determining the concentration in said slurry output system and for lowering or raising said pump through said winch motor means, in inverse relation to the concentration deviation of said slurry from a predetermined concentration.

2. Apparatus as claimed in Claim 1 wherein said holding tank is formed by sinking a shaft in a floor of a mine.

3. Apparatus as claimed in Claim 2 wherein said winch apparatus is supported over said vertical holding tank by a plurality of arch support structures.

4. A slurry transportation system including apparatus as claimed in any one of Claims 1 to 3.

5. Apparatus as claimed in Claim 1 and substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.