SU1660753A1 - Device for automatic adjustment of flow rate of reagents - Google Patents

Abstract

The invention relates to the automation of technological processes of mineral processing and can be used in systems for automatic control of the consumption of reagents. The purpose of the invention is to improve the accuracy of regulation. The device contains a main indicator electrode 1 installed in a flow electrolytic cell (EL) 2, a comparison electrode 3 installed in flowing ELY 4, a unit 5 for adjusting the electrochemical potential of electrode 3, a measuring unit 6, a memory unit 7, a regulator 8, an adjustable valve with the actuator 9, the sampler 10 installed to the reagent supply point, the sampler 11 installed after the reagent supply point, pumps 12 and 13 (used if there is no possibility of feeding the sample of the liquid phase of the pulp into ELA 2 and 4 The control unit, the control valve 14 and the time unit 15. When the device is operating, it is possible to automatically adjust the potential value of the reference electrode 3 supplied to the measuring unit 6 to a value corresponding to the characteristic of the indicator electrode 1 when measuring the concentration of controlled ions in the liquid phase of the flotation pulp. This construction of the circuit eliminates the influence on the accuracy of adjustment of differences in the calibration characteristics of electrodes 1 and 3. 2 sludge.

Description

eight

7 et

w

P

ate

Reagent

I- 5 "

SL

and

4of

I

I

oh oh vj

ate with

J

reagent supply points, pumps 11 and 13 (used when there is no possibility of feeding the sample of the liquid phase of the pulp into ELY 2 and 4 by gravity), control valve 14 and time block 15. When the device operates, the potential of the reference electrode 3 is automatically applied. It relates to the field of automation of technological processes in the supply of minerals and can be used in systems for automatic control of reagent consumption.

The purpose of the invention is to improve the accuracy of regulation.

Fig, 1 shows the dependence of the potentials of the seven argentite electrodes EA-2 on the concentration of xanthate in solution; figure 2 - structural diagram of the proposed device.

The device comprises a main indicator electrode 1, located in the flow cell 2, and a comparison electrode 3, located in the flow cell 4.

The measuring electrode 3 is connected to the first input of the correction unit 5, and the electrode 1 to the first input of the measuring unit 6, the output of which is connected to the first input of the memory 7 and the second input of the correction 5. The output of the memory block 7 is connected to the input of the regulator 8, the output of which is connected to the actuator 9, the sampler 10 is installed before the reagent feed point and hydraulically connected to the input of the cell 4 through the pump 11, the sampler 12 is installed after the reagent feed point and through the pump 13 and the normally open channel of the distributor, the valve 14 is hydraulically connected to the inlet of the cell 2, the drain pipes of the sucker 2 and 4 are connected between the oboe. The normally closed valve channel 14 is connected to the output of the sampler 10. The corresponding outputs of the time unit 15 are connected to the third input of the memory unit 7, the control input of the distribution valve 14 and the third input of the correction unit 5, the output of which is connected to the second input of the measuring unit 6.

As can be seen from the graph (Fig. 1), the potentials of the electrodes in the same plant xanthate vary within fairly wide limits, with the change in xanthogenate concentration by the same value in most cases

measuring unit 6, to a value corresponding to the characteristics of the indicator electrode 1 when measured, the concentration of controlled ions in the liquid phase of the flotation pulp. This design of the circuit eliminates the influence on the accuracy of adjustment of differences in the calibration characteristics of the electrodes 1 and 3, 2, or 2.

Changes in potential of argentite electrodes are different. Similar dependences of the potentials of the indicator electrodes are observed on other variables of the liquid phase of the pulp. The difference in the calibration characteristics of the main and additional indicator electrodes has a significant effect on the accuracy of controlling the concentration of detected ions, and hence the accuracy of controlling the consumption of reagents.

This is of particular importance at low concentrations of the detected ions in the liquid phase of the pulp.

The device works as follows.

A representative sample of the liquid phase of the pulp before the point of supply of reagents from the sampler 10 through the pump 11 enters the electrolytic cell 4, in which the reference electrode 3 is installed. A representative sample of the liquid phase of the pulp after the point of supply of the reagent C of the sampler 12 through the pump 13 and the normally open channel of the distribution valve 14 enters the electrolytic cell 2, in which the main indicator electrode 1 is installed. The electrode cells are connected hydraulically through the drain nozzles. An electrical signal (electrochemical potential) from the main indicator electrode 1 is fed directly to the input of the measuring unit 6, and from the comparison electrode 3 to the input of the unit 6 a signal is corrected in block 5. The block 6 measures the potential difference between the main indicator electrode m reference electrode. A signal proportional to this difference enters through memory block 7 to regulator 8, which with the help of a control valve with an actuator 9 changes the flow rate of the reagent supplied to the flotation process, ensuring that the potential difference is maintained at a given level.

After a certain time, depending on the characteristics of a particular object (for example, when determining the concentration

The xanthate in the liquid phase of the collective flotation pulp at the processing plant is 2 hours), the electrochemical potential of the reference electrode entering the measuring unit 6 is adjusted. For this purpose, the time unit 15 sends a signal to the memory unit 7 to memorize the current value of the potential difference (during the entire period of adjustment, the regulator 8 will be given a signal proportional to this difference), switches the control valve 14 and turns off the pump 13, ensuring the supply of at the same time required to replace the sample of the liquid phase of the pulp in cell 2 and to establish the potential of the main indicator electrode (for example, for the operating conditions of the device at the processing plant it is 5 min), block 15 sends a signal to the correction unit 5 to switch on the compensation of the potential difference, which comes through the second input of the correction unit from the measuring unit 6. In the correction process, this voltage value taken from the source A stabilized DC power supply unit of the correction unit connected in series with the reference electrode, at which the potential difference between the main indicator electrode and the reference electrode (measured by block 6) is zero, i.e. the magnitude of the potential of the reference electrode entering block 6 becomes equal to the potential of the main indicator electrode. Thus, their calibration characteristics are conditionally equalized for each specific case.

Then, after a certain time required to perform the above operations (for example, 2 minutes), unit 15 sends a signal to return the distribution valve 14 to its original position and stop the adjustment process by unit 5. At the same time, the voltage value removed from the source of stabilized DC power supply the adjustment block remains unchanged until the next correction cycle,

After a certain time after replacing the sample of the liquid phase of the pulp in the electrolytic cell 2 for a sample coming from the sampler 12 to establish the potential of the main indicator electrode 1 (for example, 5 minutes), unit 15 sends a signal to. unit 7 for resetting the memory and sending a signal from unit 6 directly to the controller 8.

Thus, the evaluation of the monitored ions in the liquid phase of the pulp is made by the potential of the main indicator electrode, and the variable perturbing parameters are measured by the corrected potential of the reference electrode, the value of which at each particular moment corresponds to the potential of the main indicator electrode, if it were conditions

The equation of characteristics of the indicator electrodes improves the accuracy of control of the concentration of monitored ions, and

5 therefore, the accuracy of reagent consumption control.

The unit 5 for adjusting the electrolytic potential of the reference electrode can be performed, for example,

0 based on a source of stabilized direct current voltage (e.g., type IPSS-01) connected in series with a reference electrode. The value set on

Its voltage should be equal in magnitude and inverse to the sign of the potential difference between the main, indicator electrode and the reference electrode, when one and the other enters the electrolyte cells.

0 same sample liquid phase of the pulp. This condition can be fulfilled, for example, by a device consisting of an amplifier (for example, of the type U1M-01UHL4), the input of which is given a signal proportional to the difference

5 potentials between the main indicator electrode and the reference electrode, and the output is connected to the control winding of a reversing motor (for example, type D-32P1), which is connected via a gearbox to

0 by a slider of a rheochord included in a circuit of a source of stabilized direct current voltage. If there is voltage imbalance at the input of the amplifier, the motor moves the slider to the side

5 to reduce the imbalance to the value determined by the dead band of the amplifier. Thus, an additional voltage will be applied to the reference electrode circuit, at which the difference of potentials between the main indicator electrode and the reference electrode (input to the measuring unit 6) will be zero.

As a measuring unit 6, for example, an industrial P-215 converter can be used.

The storage device 7 can be performed, for example, on the basis of a recording device type KSPZ or DISK-250, in which for a specified time

the control winding of the reversing motor is switched off.

The time unit 15 can be executed, for example, on the basis of a time relay of the type VL-68 or VL-70 with a range of shutter speeds of 0.1-100 and 0.1-1000 minutes.

As the controller 8, for example, a P25-type regulating device can be used.

Claims (1)

Apparatus for automatically controlling reagent consumption, comprising a measuring electrode and a comparison electrode, a measuring unit, a regulator, the output of which is connected to the input of the actuator with a regulating valve for supplying reagents to the flotation machine, in order to improve the control accuracy, the device is equipped control valve, correction unit, memory unit, time unit, two samplers and two flow-through electrolytic cells, indicator rny electrodes are installed in flow electrolytic Sks, IU // 1 five It. 3 cells located outside the flotation machine, while the main indicator electrode is connected to the first input of the measuring unit, and the comparison electrode to the first input of the correction unit, the output of which is connected to the second input of the measuring unit, the output of the latter is connected to the second input of the correction unit and the first memory input of the memory , the output of which is connected to the input of the regulator, the output of the temporary block is connected to the control input of the distribution valve, the third correction input and the second input of the memory block, drain p The electrolytic flow cells are connected to each other, the cell input with the reference electrode is hydraulically connected to a sampler installed in front of the reagent supply point, and the cell input to the main indicator electrode is hydraulically connected through a normally open channel of the distribution valve to the sampler installed after the reagent supply point, and through a normally closed channel - with a sampler installed in front of the reagent feed point.