GB2088090A - An arrangement and a method for directing a jet of fluid - Google Patents

Abstract

An arrangement for directing a jet of fluid includes a nozzle mounted for pivoting in two mutually perpendicular planes, a first hydraulic actuating ram for effecting movement of the nozzle in one plane, a second hydraulic actuating ram for effecting movement of the nozzle in the other plane and means for controlling automatically the rams. These means include a control unit including a microprocessor, in which unit can be stored a representation of a movement pattern for the nozzle which can be read out for controlling automatically the rams.

Description

SPECIFICATION An arrangement and a method for directing a jet of fluid According to this invention from one aspect, there is provided an arrangement for directing a jet of fluid, the arrangement including a nozzle mounted for pivoting movement in two mutually perpendicular planes, a first hydraulic actuating ram for effecting movement of the nozzle in one plane, a second hydraulic actuating ram for effecting movement of the nozzle in the other plane and means for controlling automatically the rams, which means includes a control unit including a microprocessor, in which unit can be stored a representation of a movement pattern for the nozzle which can be read out for controlling automatically the rams.

According to this invention from another aspect, there is provided a method of directing a jet of fluid using a nozzle mounted for pivoting movement in two mutually perpendicular planes, there being a first hydraulic ram for effecting movement of the nozzle in one plane and a second hydraulic actuating ram for effecting movement of the nozzle in the other plane, in which method a representation of a movement pattern for the nozzle is stored in a control unit which includes a microprocessor and the said representation is read out to control automatically the said rams.

This invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 shows a water jet monitor; Figure 2 is a block diagram of a control unit for the monitor; and Figure 3 shows means for providing a voltage supply for the control unit.

China clay is extracted from kaolinised granite by directing a powerful water jet at the pit face to wash a sand-clay-water mix into a stream to the pit bottom. This clay stream is then pumped to processing plant for sand removal, de-watering, further treatment and drying.

To assume a good yield of the desired clay quality, and to ensure material is removed from the pit face in a safe manner, the water jet must be moved across the face in a pattern and at a speed carefully decided in relation to the face characteristics. There will now be described a water jet monitor for directing a water jet at a pit face automatically in accordance with predetermined characteristics decided by an operator.

The monitor is a modification of that described in British Patent Specification No. 1,422,532.

Referring to Figure 1 , the monitor, like that described in the aforesaid specification, has a nozzle 1 from which a high-velocity jet of water issues when the monitor is in use, the jet being directed at an area where the china clay is to be washed out. The water is supplied to the nozzle under high presure through a supply pipe 2 which is secured to a base 3 and which is further arranged in the form of a loop or coil 4 for countering the reaction thrust of the jet, the supply pipe terminating at the nozzle 1. The supply pipe, above the base, includes a first bearing 5 for pivoting the nozzle 1 about a vertical axis, and a second bearing 6 situated at the beginning of the loop 4 for pivoting the nozzle about a horizontal axis.Pivoting movement of the nozzle is effected by means of hydraulically-operated actuating rams 7 and 8 connected respectively to the bearings 5 and 6 so that the nozzle 1, and hence the jet of water, can be moved in a horizontal or vertical direction or both. The actuating rams 7 and 8, which are double-acting, are operated by oil under pressure fed via flexible conduits 10, 11 and 12, 13. The flexible conduits are attached to the cylinders by self-sealing releasable couplings.

Reference numeral 13 denotes a clamp whereby the nozzle can be swung around so that the jet of water can be directed at an area outside the normal maximum horizontal swing.

The monitor described in the aforesaid patent specification is controlled automatically by hydraulic means and left unmanned. There will now be described a modification whereby the hydraulic control is replaced by electronic control.

The monitor is provided with a transducer 14 for sensing vertical movement and a transducer 1 5 for sensing horizontal movement, the transducers comprising rotary potentiometers for sensing angular movements, and signals from the transducers are fed back to a control unit including a microprocessor via leads 1 6 and 1 7 respectively, which could for example be 30 metres long. An operator still has the hand-operated hydraulic valves for manual control but in parallel with them are four electrically-operated solenoid valves, the only other control the operator having being a four position control switch of the control unit for off, record, stand-by and play.

The control unit is shown in block diagrammatic form in Figure 2 within the dot-dash outline A is a self-contained unit which requires a 12 volts power supply.

The control unit includes a pair of input isolation amplifiers 18 and 19 for receiving inputs on the leads 1 6 and 1 7 respectively from the transducers 14 and 1 5. The outputs of the amplifiers 18 and 1 9 are connected to inputs of an analogue to digital converter device 20 having an eight line output data bus DB1, the lines of the bus DB1 being connected to respective ones of eight data inputs of a peripheral interface adapter 21, which is an integrated circuit of type MC6812CP to provide thereto digital versions of values from the transducers 14 and 1 5. The lines of an eight line data bus DB2 of the adapter 21 are connected to respective ones of eight data inputs of an erasable programmable read-only memory (EPROM) 22 and also to respectives ones of eight data inputs of a microprocessor 23. The EPROM 22 is of type TM S2516J M and the microprocessor 23 is of type MC6802CP.There is also provided a random access memory (RAM) arrangement comprising four individual RAMs 24, 25, 26 and 27 each of type MD2 11 4L, and four lines of the data bus DB2 are connected to respective ones of four data inputs of RAM 24 and also to respective ones of four data inputs of RAM 26, the other four lines of data bus DB2 being connected to respective ones of four data inputs of RAM 25 and also to respective ones of four data inputs of RAM 27. The lines of an eight line address bus AB1 of the microprocessor 23 are connected between the microprocessor 23 and the EPROM 22 and also to respective ones of eight address inputs of each of RAMs 24, 25, 26 and 27.The lines of a four line address bus AB2 output from the microprocessor 23 are connected to respective ones of four address inputs of the peripheral interface adapter 21. . Outputs of the peripheral interface adapter 21 are connected via output amplifiers 28, 29, 30 and 31 to respective ones of the above-mentioned electrically-operated solenoid valves (designated in Figure 2 by reference numerals 32, 33, 34 and 35). Another output of the adapter 21 is connected to an alarm device 36 which includes a siren and control inputs of the adapter 21 are connected to the above-mentioned four position control switch (designated in Figure 2 by reference numeral 37).

A power regulator 38 is provided for energising the various components of the control unit, being fed from an incoming power supply of 12 volts.

The operation procedure is as follows. The operator switches the control switch 37 to record.

With the hand-operated valves, he moves the water jet in a wash pattern across the face from which clay is to be washed at a desired speed and covers as much or as little of the face as is required by making a number of sweeps. The control unit is in a.condition whereby outputs from the transducers 14 and 1 5 are processed by the analogue to digital converter 20, the adapter 21 and the microprocessor 23 under the control of a program stored in the EPROM 22, and there is stored in the RAM arrangement 24, 25, 26 and 27 a representation of the wash pattern being carried out by the operator, the data on data bus DB2 representing this wash pattern being received by the EPROM 22 and the microprocessor 23, the RAMs 24, 25, 26 and 27 being addressed via the address bus AB1 under the control of the program in the EPROM so that the data is stored in the RAM arrangement. When the operator has completed the pattern he requires, which could last as long as ten minutes or as little as a few seconds, he switches the control switch 37 to stand-by. The representation of the wash pattern he has just completed will remain in the RAM arrangement 24, 25, 26 and 27 until the control switch 37 is switched back to record or switched off.On switching the switch 37 to play, the control unit is set to a condition whereby the monitor will move to the first recorded position in the RAM arrangement and then will repeat the wash pattern that the operator had put in, using the solenoid valves 32, 33, 34 and 35 to control the hydraulic rams, the RAMs 24,25,26 and 27 being addressed via the address bus AB 1 to feed data to the adapter 21 via the data bus DB2 under the control of the program in the EPROM 22. On completion of the pattern, the monitor is moved back to the first recorded position and repeats the pattern. This will continue until an operator resumes control by switching the switch 37 to stand-by, record or off.

The switch 37 is connected with the alarm 36 so that the latter sounds to indicate the change of switch position when the switch is switched to the record position and also, on completion of the pattern by an operator, the alarm will sound when the switch is switched to the stand-by position.

Moreover, if the pattern takes ten minutes, the control unit is such that the alarm will sound to indicate the RAM arrangement is full and, to avoid the representation of the wash pattern being erased from the RAM arrangement, the switch 37 should immediately be switched to the stand-by position. When the switch 37 is switched to the stand-by position, the monitor can be used under manual control without affecting the representation which was recorded in the RAM arrangement. Only if the switch is turned off or to record will the wash pattern representation be erased from the RAM arrangement. The control unit is such that the above-mentioned alarm sounds after short periods only and if a continuous alarm is sounded, this means the automatic system is faulty. If this only occurs when play is selected, then one attempt may be made to record and replay a different wash pattern.When it is not possible to clear an alarm, the switch 37 should be switched to off and the monitor not used until the fault has been repaired. With the switch 37 in the play position, the control unit is such that again the alarm will sound to indicate a change of switch position. The monitor can be stopped at any time and manual control resumed by switching the switch 37 to off or stand-by.

Referring to Figure 3, to provide a voltage supply to the control unit, a high pressure water jet to an input 39 is used to propel a Pelton wheel assembly 40 which is coupled via a bearing 41 to a standard car alternator 42. Reference numeral 43 denotes a cover for the Pelton wheel assembly.

A water pressure of 2001b per square inch is required to drive the Pelton wheel assembly, which results in an electrical output from the alternator of 12 volts at 1 5 amps direct current.

Water consumption is of the order of 6 gallons per minute. A battery is connected to the alternator to provide the initial field current.

Claims (8)

1. An arrangement for directing a jet of fluid, the arrangement including a nozzle mounted for pivoting movement in two mutually perpendicular planes, a first hydraulic actuating ram for effecting movement of the nozzle in one plane, a second hydraulic actuating ram for effecting movement of the nozzle in the other plane and means for controlling automatically the rams, which means includes a control unit including a microprocessor, in which unit can be stored a representation of a movement pattern for the nozzle which can be read out for controlling automatically the said rams.

2. An arrangement according to claim 1, including first and second transducers for providing to the said control unit inputs representative of movement of the nozzle in the said one and the said other plane respectively for the said control unit to store the said representation.

3. An arrangement according to claim 2, including analogue to digital convension means responsive to the said inputs for producing a digital output for use in providing the said representation.

4. An arrangement according to any preceding claim, wherein the control unit includes random access memory means for storing the said representation and from which the said representation can be read out.

5. An arrangement according to any preceding claim, wherein the control unit includes programmable read only memory means for holding a program to control the microprocessor for storing the said representation in and reading it from the control unit.

6. A method of directing a jet of fluid using a nozzle mounted for pivoting movement in two mutually perpendicular planes, there being a first hydraulic ram for effecting movement of the nozzle in one plane and a second hydraulic actuating ram for effecting movement of the nozzle in the other plane, in which method a representation of a movement pattern for the nozzle is stored in a control unit which includes a microprocessor and the said representation is read out to control automatically the said rams.

7. An arrangement for directing a jet of fluid, substantially as herein described with reference to the accompanying drawings.

8. A method of directing a jet of fluid, substantially as herein described with reference to the accompanying drawings.