GB2090019A

GB2090019A - Jigging machine

Info

Publication number: GB2090019A
Application number: GB8138131A
Authority: GB
Original assignee: Kloeckner Humboldt Deutz AG
Current assignee: Kloeckner Humboldt Deutz AG
Priority date: 1980-12-20
Filing date: 1981-12-17
Publication date: 1982-06-30
Also published as: DE3048204A1; AU7757681A; IN157256B; FR2496496B3; FR2496496A1; JPS57132558A

Abstract

A jigging machine with valve control for dressing coal or other minerals has a number of individually controlled functional elements and auxiliary systems, at least some of which are electrically interlocked, and an electronic control device for controlling the various elements and systems and having a programmable memory.

Description

SPECIFICATION Jigging Machine The invention relates to a jigging machine more particularly a jigging machine with valve control, for dressing coal or other minerals, the jigging machine having individually controlled functional units and auxiliary systems which are interlocked at least in some cases electrically with respect to each other, these functional elements and auxiliary systems being material feed and outlet devices etc.

Jigging machines for dressing coal or other minerals have in the past had mechanical, hydraulic or pneumatic controls for their separate functional elements and auxiliary systems, which controls were located in switch gear cabinets. In the majority view held by experts in the field of ore preparation only these controls provide adequate functional reliability in the rough conditions of an ore preparation plant. In the case of controlling certain valves, electronic control is already known (U.S. Patent Specification No. 4 019 981), however this specification is restricted to the control only of valves and does not control the functional elements for auxiliary systems.

The invention seeks to improve the control of individual functional elements and auxiliary systems etc of a jigging machine and to make the relative interlocking of individual functional elements and auxiliary systems and the operation of the jigging machine variable. In addition, the invention seeks to alter the control rapidly and without difficulty.

According to the invention, there is provided a jigging machine with valve control for dressing coal and other minerals, which has individually controlled functional elements and auxiliary systems, at least some of which are interlocked electrically, wherein the jigging machine has an electronic control device with a programmable memory.

When using an electronic control device with a programmable memory, more particularly a freely programmable memory, it is as simple to change the control of the functional elements and auxiliary systems of the jigging machine when desired by means of changing the program as it is to provide different links or interlocks etc. It is not necessary to rewire switchgear or produce new circuit boards if such a system is used. Surprisingly the functional reliability of an electronic control with a programmable memory is greater than that of the known control using contactors: and even the rough conditions in an ore preparation plant (with dust, moisture, vibrations, and fluctuations in temperature) do not result in failures in a control device having integrated circuits.

The control device may have a screen for display of the program fed in. By displaying the program which has been fed in, the program can be changed considerably particularly if the program is in the form of a switching plan. Any specialist in this field who is able to design switching plans is able to change the program.

The program fed in may include a switching plan preferably constructed with relays and switches to a suitable current path at the time for switching. At all times there is a good overall view of the individual switching and interlocking functions because of the programmed switching plan which can be shown, preferably in all its details, on the screen. There is also the possibility of leaving the circuit with relay technology. The switching plan produces a conductive connection in the form of a current path at the moment when the control path occurs, this current path corresponding to the known fixed wiring controls using relays. This means that there is no necessity for the operating staff or for the operator of the control device to redesign the system. A clear switching is provided which corresponds in essence to known switching.The only difference is that it does not have to be maintained continuously but is formed only at the switching time. It is held in the memory in the form of construction commands during the rest of the time.

The control devices may be provided with time functions with 0.01 sec steps. Since there are time functions in the control device, it is possible to control the jigging machine valves, among other things, by means of the control device. Therefore, a special control unit is not necessary for the jigging machine valves nor is the complicated control for this required but rather the operation and control unit in accordance with the invention can take over the control of the jigging machine valves too.

In addition, the control device may, if desired, have a switching diagram for controlling the valves with 0.001 circuit sec displacement steps.

The switching diagram may have limit value circuit elements for controlling the valves. It is advantageous to use limit value circuit elements because continuous control of the jigging machine valves can be dispensed with, surprisingly. A relatively large correction only has to be carried out when a limit value is exceeded or the value falls below a limit value. The limit value circuit elements react to irregularities in the pulsating motion which are monitored continuously for example by means of a probe in the pulsation chambers.

The control device may have a switching plan which locks the outlet valves when starting up the jigging machine until the operating condition is reached. This type of circuit diagram makes sure that the pulsation chambers are filled with sufficient operating air via the inlet valves first, ready for starting up and that the outlet valves are opened at the beginning of the pulsating motion.

Therefore, the machine is started up automatically in a completely functionally reliable and rapid manner.

The control device may have a switching plan which terminates the pulsating motion of the jigging machine when the supply of the mineral mixture is interrupted either under control and/or without control. As a result, when there are no minerals to be dressed. the machine is prevented from being rinsed out and the optimum layer formation on the jigging bed, provided during the jigging process, is retained. Material losses and incorrect extraction due to stoppages is therefore avoided completely in this way.

The control device may have a switching plan which relieves the auxiliary system in their ready for operation position for a predetermined time when there are interruptions in the pulsating motions. As a result, if there is a fairly short stoppage of the jigging machine, it is possible to start up again immediately. Therefore material supply can be resumed after only a short interruption and the jigging process can be resumed immediately.

The control device may have a second plan which starts up the jigging machine by starting up the individual functional elements and auxiliary systems in a predetermined sequence after feeding in suitable signals indicating readiness for operation. This also means that the starting after fairly long stoppages, for example after repairs, is fully automated.

The switching plan for startup is such that in the first instance the transporting devices are switched on for transporting the individual components of the mineral mixture and after starting up the transporting devices the valve control for the pulsating motion is switched on and after starting up the transporting devices and all functional elements of the jigging machine the feed device for the mineral mixture are started up.

This process has proved to be efficient and reliable since the machine cannot be allowed the over-fill during start up if there is a sudden failure of a system under any circumstances.

Finally, in order to carry out the invention an electronic control device with a programmable memory more particularly a freely programmable memory may be used to control the individual functional elements of the jigging machine and its auxiliary systems. The invention can then be implemented with all of its advantages.

The invention will now be described in greater detail, by way of example, with reference to the drawings, in which: Fig. 1 shows a jigging machine in schematic view with its essential functional units and auxiliary devices; Fig. 2 is a block diagram of the main interlocks of the system; Fig. 3 shows a block diagram for stroke control; Fig. 4 shows a block diagram for the starting up process and, Fig. 5 shows a block diagram for control of feed material flow.

In Fig. 1. 1,2,3,4,5 and 6 designate individual compartments of the jigging machine with the related inlet and outlet valves 11,12,13,14,1 5 and 16, preferably disk valves. The inlet and outlet valves draw the operating air from the jigging machine from the expansion chamber 1 7. The latter is connected to a compressor 1 9 via the line 18. The valves 11,12,13,14,15 and 16 are pneumatically actuated. They receive their actuating air from the control valves 21,22,23,24,25 and 26. The control air is supplied to the valves 21,22,23,24,25 and 26 via the supply line 27 which is connected to the normal operating air network of the dressing plant.

(Air pressure > = 4 bar).

The control air pressure is fed to the control device 10 from a manometer 28 through a line 28'. Similarly, operation of the compressor 19 is sensed by the control device 10 via a line 19'. The operating air present in the expansion chamber 1 7 is measured by means of the control manometer 20 and is fed to the control device 10 through the line 20'. In addition, an air pressure control valve 29 is arranged on the expansion chamber 17 and its function is hydraulic. It is supplied with pressure oil via the line 29' as is a safety valve 30 which operates automatically.

In contrast to the pneumatic control system for the operating air, the outlet devices 32 and 34 are hydraulic. An hydraulic station 8 with an oil supply container 9, both of which are connected to the control device 10' via lines 8', 8" and 9' respectively, serve to supply pressure oil.

The pressure oil lines 31' and 32' run from the pressure oil station 8 to the tailings outlet devices 31 and 32. The outlet floats are connected to the control device 10 via the measurement lines 31" and 32". Similarly the pressure oil station 8 is connected to the middlings outlet devices 33 and 34 via the pressure oil lines 33' and 34'.

Measurement lines 33" and 34" are present here too and lead to the control device 10.

Probes 41,42,43,44,45 and 46, the signals of which are transmitted to the control device 10 via the line bunch 41' to 46' and cause control of the servo valves via a limit value switching plan are located in the pulsation chambers of the jigging bed compartments 1,2,3,4,5 and 6.

In the lower part of the jigging machine, the supply line 35 for washing water and outlet compartments 36 and 37 are located. Beneath them are the transportation elements (not shown) for the tailings and the middlings, e.g. dewatering bucket elements. A material control float 38 is arranged on the front portion of the jigging machine for general interlock control and especially for preventing washing out during short interruptions in the supply of material. The said float 38 indicates the height of the bed via the line 38' to the control device 1 0.

In Fig. 2 the essential outer auxiliary function groups of the jigging machine are indicated block form. The jigging machine together with its control, which is designated 50, receives signals 51' from a compressor 51, signals 52' from washing water level measuring device 52, signals 53' and 54' from the two pressure switches 53 and 54 for the controlled and operating air and signals 55' from lubricating oil station 55 and signals 56' from a pressure oil station 56.

Furthermore, the jigging machine receives signals 57 from the pure coal path 57, signals 58' from a middlings transportation path 58 and signals 59' from a tailings transportation path 59. If all of the signals occur at the control of the jigging machine 50, an AND element 60 is actuated by a signal 61' from the operating air fan 61 to start up the raw coal path 62. It is advantageous, but not essential, to pass signals 63' and 64' to the jigging machine, these signals indicating to the jigging machine that the remaining paths of the dressing plant are in full operation since only then can fault free operation over a long period be ensured.

Fig. 3 shows a block diagram for the stroke control of the jigging machine with a probe 70 in an operating air chamber 71, for example, and this circuit operates as follows: The probe 70 passes a signal 70' to a transmitter 72 which passes the signal, converted into an input signal 72', to limit value circuit elements 73 and 74. In addition, one limit value circuit element, the limit value circuit element 73 for example, is used as the upper limit of the reversal point of the pulsating motion and the other limit value circuit, element 74, is used as the limit value circuit element for the lower limit of the reversal point of the pulsating motion. The limit values which are set in the limit value circuit element are at between 80% and a 100% of the operating air chamber height for the upper limit and between 0% and 20% of the operating air chamber height for the lower limit.

The limit value circuit elements 73 and 74 pass signals 73' and 74' to the AND elements 76 and 77 when the preset limit values are reached and the switch on signal 75' for the automatic/control is present at these AND elements 76 and 77. If the switch on conditions are fulfilled, the AND elements pass signals 76' and 77' to both the switching elements 78 and 79 -preferably electronic circuit breakers- and to the electronic valve control. This operates with pulses within the hundredth or thousandth of a second range, as available. The difference is only visible in the frequency of switching. The electronic/control unit which integrates with the control device and which can be constructed separately as a peripheral unit, is designated 69.

In Fig. 4 in which the block diagram is shown for the starting process of the machine, 70 designates the probe and 71 the pulsating chamber. The block diagram for the starting process operates as follows: the probe 70 passes a pulsation liquid level signal 80' to a transmitter 81 which passes the signal to a limit value circuit element 82, converted into an input signal 81'. A signal 82' is emitted by the limit value circuit element 82 when the preset limit value is reached, this signal 82' being fed to an AND element 84 by the signals 83' of the valve control which is present if this valve control is switched on.The AND element 84 passes a control signal 84' - if the AND precondition is met - to an AND element 86 in the form of the signal 85' if desired after processing of the signal in the device 85 or after producing an output from the device 85. The AND element 86 passes the opening signal 86' from the outlet valve when the signals 85' and 87' are provided together with 87', the signal from the valve control member 87 for switching on the valve control of the outlet valve. Regular beat movement of the jigging machine can begin.

A value in the range 70% to 95% of the exciter chamber height, more particularly 80%, is preferably set as the limit value. This value may be designated as AH.

In Fig. 5 a circuit which prevents the machine from being washed out in the case of sudden failure of the raw minerals is shown. 91' designates the signal from a censor in Fig. 5 - say from a movement detector for a material supply device - and 92' designates the signal from a material detector or a float. This signal first of all acts on the limit value switch 93. When the fixed limit value for the minimum material quantity is exceeded, the limit value switch 93 emits the signal 93' which acts on the AND element 94, as does the signal 91' from the movement detector.

When the two signals 91' and 93' are present, the AND condition is fulfilled and the AND element 94 emits the signal 94' in turn which indicates that the material supply is functioning correctly.

The signal 94' first of all acts on the short term timing element 95 which can be set at between say 0 and 100 seconds. If the signal 94' is not present i.e. if the supply of materials is interrupted or the minimum layer height is not present on the jigging bed, then the short term timing element initially maintains its signal 95' until the set time has expired. If in the meantime there is no new signal 94' from the AND element 94, the short term timing element 95 cuts off the signal 95'.

The switching device 96 switches off the operating air of the jigging machine or opens the by-pass on loss of the signal 95'. In any case the pulsating motion of the separating liquid stops.

When using a by-pass, particularly favourable and rapid reconnection of the jigging machine is possible.

The freely programmable control of jigging machines, some of the circuits used for these jigging devices having been shown by way of example, is formed in accordance with the invention as an individual device for the switching control room of the group of jigging machines.

Without going beyond the scope of the invention, this control device may also be integrated into a computer system which controls the whole of the dressing plant. An integrated component is then formed without the effect and mode of operation in accordance with the invention being changed thereby.

Claims

1. A jigging machine with the valve control for dressing coal and other minerals, which has individually controlled functional elements and auxiliary systems, at least some of which are interlocked electrically, wherein the jigging machine has an electronic control device with a programmable memory.

2. A jigging machine in which the memory is a freely programmable memory.

3. A jigging machine according to claim 1 or 2, wherein the control device has a screen for displaying the program fed into it.

4. A jigging machine according to claim 1, 2 or 3, wherein the program which is fed in includes a circuit arrangement which switches to a suitable current path at the switching time.

5. A jigging machine according to claim 4, wherein the circuit arrangement is based on relays or contactors.

6. A jigging machine according to any one of claims 1 to 5, wherein the control device has time functions with 0.01 sec-steps.

7. A jigging machine according to any one of claims 1 to 5, wherein the control device has a circuit arrangement for controlling the valves.

8. A jigging machine according to claim 7, wherein the valves are controlled with adjusting steps of 0.01 sec.

9. A jigging machine according to claim 7 or 8, wherein the circuit arrangement for controlling the valves has elements for measuring the limit value of the valves.

10. A jigging machine according to any one of claims 1 to 9, wherein the control device has a switching plan which locks the outlet valves when starting up the jigging machine until the operating condition is reached.

11. A jigging machine according to any one of claims 1 to 10, wherein the control device has a circuit arrangement which terminates the pulsating movement of the jigging machine when there are controlled and/or uncontrolled interruptions in the supply of the mineral mixture to be treated.

12. A jigging machine according to any one of claims 1 to 11, wherein the control device has a circuit arrangement which, when there are interruptions in the pulsating motion, leaves the auxiliary systems in and 'ready for operation' position for a predetermined time.

13. A jigging machine according to any one of claims 1 to 12, wherein the control device has a circuit arrangement which starts up the jigging machine by starting up the individual functional elements and auxiliary systems in a predetermined sequence after input of suitable signals indicating that they are ready for operation.

14. A jigging machine according to claim 13, wherein the circuit arrangement is so formed that the transporting devices which transport the individual components of the mineral mixture are switched on first.

1 5. A jigging machine according to claim 13 or 14, wherein the circuit arrangement is so formed that the valve control for the pulsating motion is switched on after starting up the transporting devices ready for transportation.

16. Ajigging machine according to claims 13, 14 or 1 5 wherein the circuit arrangement is so formed that the feed device for the mineral mixture is started up after the transportation devices and all of the functional elements of the jigging machine have been started up.

1 7. A jigging machine according to any one of the preceding claims, wherein an electronic control device with a programmable memory, more particularly with a freely programmable memory is used to control its individual functional elements and auxiliary systems.

1 8. A jigging machine substantially as described herein with reference to the drawings.