GB1585482A

GB1585482A - Monilithic pack pumping system

Info

Publication number: GB1585482A
Application number: GB7044/77A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1977-02-18
Filing date: 1977-02-18
Publication date: 1981-03-04
Also published as: ZM2178A1; ZA78925B; FR2381187A1; DE2806523A1; AU3349278A; NL7801856A; JPS5452306A

Description

(54) MONOLITHIC PACK PUMPING SYSTEM (71) We BRU JOHN BUCKNER of Southlea, Lymington Bottom Road, Four Marks, Alton, Hampshire formerly of No. 3 Windsor Close, High Ridge, Alton Hampshire and DAVID JOHN RELF of Rowan House, The Close, Farnham, Surrey, formerly of 41 Highfield Avenue, Aldershot, Hampshire, both British subjects, do hereby declare the invention for which we pray that a patent be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to hydraulically operable pumping apparatus and ancillaries therefor, and to a method of pumping a viscous, pulpy or plastic fluid employing such apparatus and ancillaries suitable for use in monolithic packing.

Monolithic packing is being developed to provide early resistance (or controlled collapse) packs for reinforcing tunnels in mines such as coalmines. Basically a coal or crushed rock/ cement mix is pumped into specially constructed formwork at the coal face to form a monolithic support pack which is extended as the coal face progresses. The pack is arranged initially to support the roof at each end of the coal face while the coal cutting machinery advances. The weight on the roof of the tunnel causes the pack to collapse slowly into the void that is left after the coal, or other ore being mined, has been removed. A pumping mixture, such as slurry of bentonite and water, is added to the coal/cement mix. To avoid the need constantly to move the pumping equipment, it is necessary to provide equipment capable of pumping the mix over long distances up to about 2000 metres or perhaps more.

According to a first aspect of the present invention there is provided a pumping apparatus and ancillaries which comprises: (a) a pumping station including a pump for pumping viscous pulpy or plastic fluid such as a pump comprising a hopper for a viscous pulpy or plastic fluid to be pumped, two hydraulic cylinders arranged in parallel each containing a reciprocable piston, two delivery cylinders in communication with the hopper and each containing a reciprocable piston driven by the pistons of the hydraulic cylinders, delivery outlet, a cranked valve in communication at one end with the outlet and movable from a first position in which the other end communicates with one said delivery cylinder to tion in which it communicates with another said delivery cylinder, and means for moving the valve from said first position to said second position and from said second position to said first position; (b) at least two hydraulic pumps arranged to drive the pump of the pumping stations and to provide a source of hydraulic power for a predetermined number of other auxiliary appliances; (c) drive means, such as an electric motor arranged to drive the said hydraulic pumps either directly or by way of a multi-station gearbox; and (d) a hydraulic reservoir for the hydraulic fluid for the hydraulic pumps, through which reservoir the hydraulic fluid is constrained to follow a devious path and which includes a magnetic weir filter together with one or more other filter devices for filtering the hydraulic fluid.

Referring to the pumping station of the present invention it is preferred that this be generally along the lines of that described and claimed in our copending British Patent Application No.28196/77 (Serial No 1585794) or our British Patent No. 1 478591. since the pump there described has been found to be particularly advantageous when employed in the present invention. However other pumps of generally similar configuration may be employed as desired. Preferably the hopper of the pumping station is of the remix type;i.e. agitation devices are provided therein for agitating the viscous fluid to be pumped. Such a device may for example consist of blades or paddles affixed to the swing valve or of rotatable paddles mounted upon the hopper and driven independently of the actual pump station.Suitably the drive for such paddles is derived from the said one or more hydraulic pumps. It is preferred that the paddle blades be demountable from the hopper for reasons which will become apparent hereinafter.

One of the features of the pumping apparatus is its capacity to drive auxiliary appliances such as for example a bunker conveyor for feeding slurry or particulate matter to a mixer where it is mixed with other materials such as bentonite and cement before being fed to the hopper. This capacity may be provided by ensuring that the electric motor of this apparatus is arranged to drive a plurality of pumps each with a separate output, and/or that the output flow of one or more of the pumps be split by means of a flow divider. When more than one pump is to be employed they may be on the same or separate shafts.

To increase output to a single appliance two or more of the pumps may be run in tandem fashion. The output of the pumps may be varied by conventional means. The pumps may be either fixed or variable displacement pumps in which latter case the control thereby afforded is generally sufficient. When a fixed displacement pump is to be controlled it is advantageous to pass the output therefrom through a flow divider to split the flow into 2 or 3 flows e.g. in a 2:1 or 4:2:1 ratio. By then passing each flow into a single multiple control valve with a single output the flow can be varied, in the case of a two-way divider between 0/3, 1/3,2/3 and 3/3 and in the case of a threeway divider, between 0/7, 1/7, 2/7, 3/7,4/7, 5/7, 6/7 and 7/7. Similarly, if a four-way divider is employed, 15 different settings may be obtained.Alternatively or additionally each hydraulic pump may be of the variable displacement type to vary the output capacity of the pumps.

Any suitable electric motor may be chosen to drive the pumps, the requirements for the motor being simply those of sufficient power output and of meeting the safety margins needed for any particular application. In practice an electric motor having a power output of from 60 to 150 H.p. has been found to be suitable.

The tank or reservoir for the hydraulic fluid is, as has been stated, of devious or sinuous path type incorporating a magnetic weir filter together with one or more other filters. In particular it is preferred that it be generally cuboid and divided both horizontally and vertically to form four horizontally extending chambers.

In such a tank the hydraulic fluid is arranged to pass horizontally along a first lower chamber, upwardly into and back along a first upper chamber and over a magnetic weir filter sideways into a second upper chamber. From here it is arranged to pass along the said second upper chamber, travel downwardly into a second lower chamber and then pass back along said second lower chamber to pass out of the tank through one or more filter devices.

The tank inlets and outlets and inlets and outlets for the hydraulic pumps are preferably so dimensioned that large bore hydraulic piping may be employed to interconnect them.

Although the pumping apparatus of the present invention may be employed to pump any viscous pulpy or plastic material, it is particularly suited to the pumping of slurries such as liquid concrete or a slurry of rock or coal with cement and bentonite. The latter mixture is used to build early resistance roadside packs for reinforcing tunnels and faces in mines such as coal mines. It is thus important that the apparatus of the present invention meet the required safety parameters when it is to be employed in, for example, a coal mine of the National Coal Board and that each individual item of the apparatus be in accordance with National Coal Board Specifications.

An embodiment of a monolithic pack pump ing system according to the present invention will now be described by reference to the accompanying drawings in which: Fig. 1 is a perspective partially cut-away view of a pumping station and remix hopper for use with the pumping system; Fig. 2 is a block diagram of an embodiment of a monolithic pack pumping system according to the invention.

Referring to Fig. 1, the pumping station 10 comprises two parallel hydraulic cylinders 100,102 arranged to be actuated by an oil, an emulsion or a fire-resistant liquid under pressure. Two piston rods 104, 106 pass into two parallel delivery cylinders 108,110 coaxial with said hydraulic cylinders and have pistons 112,114 secured to the ends thereof.

The open ends 116, 118 of the delivery cylinders 108, 110 are mounted in one wall of a feed hopper 120. In an opposite wall of the feed hopper 120 is mounted a delivery pipe line 122 provided in the hopper with a cranked end-piece or S-shaped valve 124. The end piece 124 can rotate about the axis of the delivery pipeline 122 between a first position in which it covers an open end 116 of a delivery cylinder 108 and a second position in which it covers the open end 118 of the delivery cylinder 110. The end piece 124 is caused so to swivel by means of a lever arm 126 attached to the end piece 124, pivoted about a shaft 128 the other end 130 of which lever arm is arranged to be transversely reciprocated by means of opposed hydraulic cylinders 132,134.

Mechanical triggers ]36 situated adjacent the end of the stroke of the piston rods 104, 106 cause the direction of flow of the hydraulic fluid and hence the direction of movement of the piston rods 104, 106 and delivery pistons 112, 114 to change, i.e.

causing reciprocation of the pistons 112, 114 in opposite directions relative to each other.

The feed hopper 120 is provided with a transversely extending rotatable shaft 138 to which are attached agitator blades 140 for agitating the fluid to be pumped. The shaft 138 is arranged to be driven by a radial piston hydraulic motor 141. The shaft 138 is preferably readily detachable from the hopper 120.

The hopper 120 can be arranged to be pivotable away from the position shown in the drawings, about pivot hinges 144 so as to facilitate cleaning and maintenance of the pumping station but that is not necessary. In its operative position the hopper 120 is arranged to bear against a peripheral seal so as to prevent leakage of the material to be pumped.

Before the hopper 120 can be pivoted it is necessary to first remove either end piece 124 or shaft 138 and agitator blades 140. In either case quick release devices such as over centre clamp toggles may be employed for this purpose.

Referring now to Figure 2, there is shown a monolithic pack pumping system 12 according to the invention. The system 12 comprises an electric motor 14 having a shaft 16 coupled to a gearbox 17. Three output shafts of the gearbox 17 are connected respectively to an hydraulic pump 18, two hydraulic pumps 19, 20 in tandem and two hydraulic pumps 21,22 in tandem. An hydraulic reservoir 40 is arranged to supply hydraulic fluid to the pumps.

The outputs of the pumps 19, 20 are coupled through relief valves 23a, 23b and filters 24a, 24b to high pressure outlets 25a, 25b respectively. The outlets 25a and 25b are coupled by way of flexible lines through a pressure intensifier/flow divider 26 to a selector valve 28, the two outlets of which are coupled to the concrete pump 10. The selector valve 28 is operable to provide the output of one of the pumps 19,20 or both of the pumps 19,20 to drive the pistons 112 and 114 of the concrete pump 10 at a first, higher rate or a second, lower rate depending upon the pumping rates of the pumps 19,20 and the division ratio of the divider 26. The selector valve 28 also has a neutral position in which it disconnects both pumps 19, 20 from the pump 10.When the selector valve 28 is set to "the second rate" the pressure of the hydraulic fluid applied to the cylinders 100, 102 can be intensified by virtue of the use of the flow divider 26. The intensifier/divider 26 may be one as marketed by Commercial Hydraulics Limited.

The pump 18 is coupled through a relief valve 30, an hydraulic motor 31, relief valve 32 and filter 33 to an outlet 34. The motor 31 is arranged to drive a fan 3 la for an oil cooler in the return line to the hydraulic reservoir 40. The outlet 34 is coupled by way of a flexible line to a flow divider 36 having three outputs 36a, 36b and 36c. The outlet 36a is coupled to drive the pistons in the hydraulic cylinders 132 and 134 to operate the pivot axle 124 in the pump 10. The outlet 36b is coupled to drive the motor 141 for the remix paddles 140 in the hopper 120 to ensure that the plastic material in the hopper is continuously mixed.

The outlet 36c is coupled to drive the screw 37 of a trough mixer 38 which receives coal slurry, water and bentonite. The screw ensures a homogeneous mix of the contents of the mixer 38 before the mixture is fed to the hopper 120 in the pump 10.

Hydraulic pump 21 is coupled by the way of a relief valve 42 and filter 43 to an outlet 44.

The outlet 44 is coupled by way of a flexible hose to drive a hydraulic motor 46 for a bunker conveyor belt 47 arranged to deliver coal dross to the mixer 38.

Hydraulic pump 22 is coupled by way of a relief valve 48 and filter 49 to an outlet 50. The outlet 50 is coupled by way of a flexible hose to drive an hydraulic motor 52 arranged to rotate mixer blades 53 in a tank 54 for holding bentonite and water.

A separate pump (not shown) is provided to pump the bentonite slurry to the mixer tank 38.

The speed selection valve 28 is provided to change the speed of reciprocating of the pistons together with a lever (not shown) for almost instantaneous reversal of the direction of travel of the pistons. This latter device is invaluable if a blockage or obstruction should occur during pumping.

The dimensions of the pumping station are such that the hopper 120 has a capacity of 0.75 yds3 the charging height of the hopper 120 is 38" and the internal diameter of each delivery cylinder 108, is 8".

The whole pumping station 12 is mounted upon skids.

One of the features of the apparatus of the present invention is its ability to provide power for applications other than just for the pumping station.

Although two pumps 19, 20 running in tandem are used to drive the pistons 112, 114, one larger pump could be substituted for these if desired, twin pumps are preferred for sizereasons and to meet user specification more readily. As has been described above the flow from these pumps is passed through a 2:1 flow divider 26 and then into a multiple control valve so that the available output is thereby obtainable.

Each of the radial piston pumps 18 to 22 is rated at 24 gallons/minute. As an alternative to the two pairs of pumps 19,20 and 21,22, a single pump could be employed the output of which is divided into the required number of outputs.

The electric motor 14 is rated at 150 Hp.

The electric motor in this particular instance is to National Coal Board Regulations in respect of fire proofing and safety, as indeed are all other components in this embodiment of the pumping apparatus. This electric motor is capable of driving the pumping station to give a maximum hourly output of 40 yds3, a pressure upon the viscous fluid to be pumped in excess of 1100 psi, and a thrust rating in excess of 22 tons.

Generally it is preferred that the electric motor has a maximum power output of from 60 to 200 Hp.

The tank or reservoir 40 for the hydraulic fluid is generally of the type designated as NCB Bretby but has been modified to meet the particular demands placed upon it in this Application. As shown in the drawings it is designed to hold 115 imperial gallons and is fitted with a magnetic weir filter, one or two "AutoKlean" filter devices, an oil temperature cut-out safety device and an oil level safety device. It is also fireproof to National Coal Board Specifications.

It is connected to the pumping apparatus by means of large bore piping to reduce frictional losses.

It is to be noted that the electric motor and the gearbox and the pumps are all mounted on the same pair skids to form a "power pack".

The tank can be included on the skids or can be located at a distance from the power pack as required.

For the convenience of the operator all the controls necessary for operating and controlling the apparatus may be mounted adjacent one another.

One of the requirements of the National Coal Board is that the maximum permitted pressure on the fire resistant hydraulic fluid is 2000 psi at pump source. For economic and practical reasons it is highly desirable that the pressure in the hydraulic cylinders of the pumping station be considerably greater than 2000 psi. To achieve this it is preferred to employ a pressure intensifier such as that marketed by Commercial Hydraulics Limited.

In a modification of the pumping station of the present invention a safety device is provided so that when a grille or screen over the hopper 120 is lifted the pressure source for the hydraulic change over rams 130, 134 of the valve 124 is connected to tank so as to effectively stop the valve. Additionally the hydraulic circuit for driving the pumping pistons can be switched to neutral to stop the reciprocating of the pistons in their respective cylinders.

WHAT WE CLAIM IS: 1. A pumping system which comprises: (a) a pumping station including a pump for pumping viscous pulpy or plastic fluid as a pump comprising a hopper for a viscous pulpy or plastic fluid to be pumped, two parallel hydraulic cylinders each containing a reciprocable piston, two delivery cylinders in communication with the hopper and each containing a reciprocable piston; a delivery outlet, a cranked valve in communication at one end with the outlet and movable from a first position in which the other end communicates with one said delivery cylinder to a second position in which it communicates with another said delivery cylinder, and means for moving the valve from said first position to said second position and from said second position to said first position; (b) at least a first hydraulic pump arranged to drive the pump of the pumping station and a second hydraulic pump arranged to provide a source of hydraulic power for a predetermined number of other auxiliary appliances;; (c) drive means arranged to drive the said hydraulic pumps and (d) a hydraulic reservoir for the hydraulic fluid for the hydraulic pumps, through which reservoir the hydraulic fluid is constrained to follow a devious path and which includes a magnetic weir filter together with one or more other filter devices for filtering the hydraulic fluid.

2. A system according to claim 1, in which the drive means is arranged to drive the hydraulic pumps directly, and the pumps include means for varying the delivery rate thereof.

3. A system according to claim 1, in which the drive means is arranged to drive the hydraulic pumps by way of a multi-station gearbox.

4. A pumping system comprising a pumping station including a pump for pumping a viscous, pulpy or plastic fluid, a first hydraulic pumps means coupled to drive the pump of the pumpng station, a second hydraulic pump means arranged to provide a source of hydraulic power for a predetermined number of auxiliary appliances a gear box having output shafts connected to said hydraulic pump means, and an input shaft coupled to drive means, and an hydraulic reservoir for the hydraulic fluid for the hydraulic pumps, through which reservoir the hydraulic fluid is constrained to follow a devious path and which includes a magnetic weir filter together with at least one other filter device for filtering the hydraulic fluid.

5. A system according to claim 4, in which the pump in the pumping station comprises a hopper for a viscous, pulpy or plastic fluid to be pumped, two parallel cylinders each containing a reciprocable piston two delivery cylinders in communication with the hopper and each containing a reciprocable piston, a delivery outlet, a cranked valve in communication at one end with the outlet and movable from a first position in which the other end communicates with one said delivery cylinder to a second position in which it communicates with another said delivery cylinder and hydraulic means for moving the valve from said first position to said second position and from said second position to said first position.

6. A system according to any one of the preceding claims, in which the first hydraulic pump means is coupled to the pump of the pumping station by way of a flow divider and a selector valve whereby the pump of the pumping station can be driven at least at first, higher and second lower rates.

7. A system according to claim 6, in which the flow divider is a pressure intensifier/flow divider whereby the pressure of the hydraulic fluid applied to the pump of the pumping station can be intensified when the selector valve is set to select the lower pumping rate or rates.

8. A system according to any one of the preceding claims, further comprising a first mixer tank for mixing the fluid to be pumped, and the second hydraulic pump means is coupled to drive a first hydraulic motor for driving a conveyor to convey a constituent

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. magnetic weir filter, one or two "AutoKlean" filter devices, an oil temperature cut-out safety device and an oil level safety device. It is also fireproof to National Coal Board Specifications. It is connected to the pumping apparatus by means of large bore piping to reduce frictional losses. It is to be noted that the electric motor and the gearbox and the pumps are all mounted on the same pair skids to form a "power pack". The tank can be included on the skids or can be located at a distance from the power pack as required. For the convenience of the operator all the controls necessary for operating and controlling the apparatus may be mounted adjacent one another. One of the requirements of the National Coal Board is that the maximum permitted pressure on the fire resistant hydraulic fluid is 2000 psi at pump source. For economic and practical reasons it is highly desirable that the pressure in the hydraulic cylinders of the pumping station be considerably greater than 2000 psi. To achieve this it is preferred to employ a pressure intensifier such as that marketed by Commercial Hydraulics Limited. In a modification of the pumping station of the present invention a safety device is provided so that when a grille or screen over the hopper 120 is lifted the pressure source for the hydraulic change over rams 130, 134 of the valve 124 is connected to tank so as to effectively stop the valve. Additionally the hydraulic circuit for driving the pumping pistons can be switched to neutral to stop the reciprocating of the pistons in their respective cylinders. WHAT WE CLAIM IS:

1. A pumping system which comprises: (a) a pumping station including a pump for pumping viscous pulpy or plastic fluid as a pump comprising a hopper for a viscous pulpy or plastic fluid to be pumped, two parallel hydraulic cylinders each containing a reciprocable piston, two delivery cylinders in communication with the hopper and each containing a reciprocable piston; a delivery outlet, a cranked valve in communication at one end with the outlet and movable from a first position in which the other end communicates with one said delivery cylinder to a second position in which it communicates with another said delivery cylinder, and means for moving the valve from said first position to said second position and from said second position to said first position; (b) at least a first hydraulic pump arranged to drive the pump of the pumping station and a second hydraulic pump arranged to provide a source of hydraulic power for a predetermined number of other auxiliary appliances;; (c) drive means arranged to drive the said hydraulic pumps and (d) a hydraulic reservoir for the hydraulic fluid for the hydraulic pumps, through which reservoir the hydraulic fluid is constrained to follow a devious path and which includes a magnetic weir filter together with one or more other filter devices for filtering the hydraulic fluid.

material of the fluid to be pumped such as coal dross to said mixer tank.

9. A system according to claim 8, further comprising a second tank for containing a pumping agent such as a mixture of bentonite and water, and third hydraulic pump means driven from said gear box and coupled to drive a second hydraulic motor for driving mixing means in said second tank.

10. A system according to claim 9, as dependent upon claim 1 or claim 5, comprising a fourth hydraulic pump means driven from said gearbox and coupled to drive a third hydraulic motor for controlling operation of said hydraulic means for moving said valve between its said first and second positions.

11. A system according to claim 10, in which the third hydraulic motor is coupled to an input of a flow divider, a first output of which is coupled to drive said hydraulic means for moving said valve.

12. A system according to claim 11, in which the hopper is provided with remix paddles arranged to be driven by a fourth hydraulic motor and a second output of the flow divider is coupled to drive the fourth hydraulic motor.

13. A system according to claim 11 or 12, in which a third output of the flow divider is coupled to drive mixer means in the first mixer tank.

14. A system according to claim 10, 11, 12 or 13, in which the third hydraulic motor is arranged to drive cooling means for the hydraulic fluid of the system.

15. A system according to any one of the preceding claims, in which the pumping station comprises a pump as described and claimed in our copending Patent Application No. 28196/ 77 Serial No. 1585794 or our British Patent No. 1 478591.

16. A system according to any one of the preceding claims, in which the drive means for said gearbox is an electric motor.

17. A monolithic pack pumping system comprising a system according to any one of the preceding claims.

18. Pumping apparatus substantially as described with reference to and as illustrated in the accompanying drawings.