SU886993A1 - Disintegrating unit automatic control method - Google Patents

Description

one

The invention relates to a technique for grinding materials, and specifically to methods for automatically controlling the process of grinding materials in a ball mill .5

There is a method for optimizing the operation of grinding units with a closed cycle based on measurements of parameters such as the noise of the mill, the energy performance of the drive motor, the magnitude of the circulating load, and the weight of the input and output of the unit. Optimization of the operation mode of the unit is achieved by searching for the extreme value of the monitored parameter by trial steps and is estimating the degree of closeness of the operating point to the extremum after exposure to the trial step 1.

The disadvantage of this method is the loss of productivity caused by the fluctuations of the operating point relative to the extremum of the static characteristics of the grinding unit, but since extreme adjustments are based on the use of test stimuli, 25 these oscillations do not respond to elimination.

There is also known a method of automatic control of the grinding unit, which includes measuring the amount of material

the rial in the aggregate, the periodic increase in ore feed by the size of the test rod, the measurement of filling increment, the effect on the ore feed depending on the size and sign of the increment, and the finding of extremism of productivity 2.

This method is as follows.

The trial steps of incrementing the ore feed are made, after which the result of the test rod is evaluated and, depending on the ratio between the solid input and output flow, the system gives one of the commands to change the ore feed:

1) the input flow rate is equal to the output flow rate - this means that the mill operates in a stable area and maximum performance is not achieved, a command is given to further increase the ore feed;

2) the flow rate at the outlet is less than the flow rate at the inlet — this is a sign that the unit produces less material than is loaded into it, and therefore accumulation of circulating sands occurs, a command is given to amuse the ore feed;

3) the flow rate at the output exceeds the flow rate at the inlet - this is a sign that the unit returns to operation at a reduced circulating load, and therefore the controller does not interfere with the operation of the unit until the input and output flow rates are equal again. From this point on, a new cycle of operation of the regulator begins again.

The disadvantage of this method is the lack of accuracy in finding the extremum, since the BMeojaTe ibCTBO regulator occurs in a cyclic order and the system fluctuates around the position corresponding to the maximum processing, which is accompanied by a loss of productivity and fluctuations in the content of the control class at the mill output.

The aim of the invention is to improve the quality of control. This is achieved by the fact that in the method of controlling the grinding; 1 unit assembly, including measuring the amount of material in the unit, a non-periodic increase in ore feed by the size of the test strip, a measurement of the filling increment, the effect on the ore intani finding an extremum of performance stops the test leads and stabilizes the found value of productivity, and when the filling direction does not deviate from the specified value carried out again periodically increase the initial ore feed at velichiiu schaga probe.

The proposed method is illustrated in the drawing.

The method is implemented as follows.

A ball mill in a closed cycle with a classifier is put into operation at the value of the initial ore feed Q obviously lower than the optimal one (see drawing a). At the time point /, the control system is turned on and the search part starts to give a command to test the ore feed increase -f-AQ periodically at intervals of time A. The analyzing unit extracts from the signal of the LEAD the filling value of the mill with grinded material I (see drawing b). The magnitude and sign (see drawing c) of the increment are separated from the filling signal. Depending

DL OUT of value - a command is given to change the value.

ore feed and control system switching in accordance with the following algorithm. Case 1;

AW // D

  & t J

incremental value

where is the current

d

filling; (df j por.- threshold value

positive increment. A positive increment of the fill value is not

the threshold value is exceeded, therefore, the mill is not loaded, and it is necessary to continue the trial steps to increase the ore nitann. Case 2:

f-) nop.

t {t J

A positive increment of magnitude and a complete value exceeds the threshold value, which means that the worker begins to unload. Overloading is caused by a sharp increase in the circulating load at the transition of the operating point through the extremum point to the unstable zone of the static characteristic.

A command is given to stop the test steps and reduce the ore feed by an amount Q, ironizing the depth at which the operating point approaches the unstable zone.

 (t / h)

where C is the proportionality coefficient. The mill begins to unload and the rotation becomes negative.

Case 3:

Aya & t

pore

M

threshold value of negative increment. The negative increment of the fill value exceeds the absolute value of the negative threshold.

This means that the overload has ended and a command is given to restore the ore yarn + Q to Velnchin, a slightly lower ore consumption at the time of the command to reduce the feed

+

where / C is the recovery coefficient.

The mill begins to load again and the operating point comes to the area of optimal performance, not entering

tt /

unstable zone. Increment - DAN

Wits positive. Case 4:

dl

- switch m)

Positive hindrance falls below the switching threshold of the system. A command is given to disable the search structure and enable the stabilization structure of the optimized, full content value. No further growth of filling occurs.

AA, the value is approaching zero

d

G5 value.

Claims (1)

Claim The method of automatic control of the grinding unit, including measuring the amount of material in the unit, periodically increasing the ore supply by the value of the test step, measuring the increment of the filling, the effect on the ore supply depending on the magnitude and sign of the increment and finding the extremum of productivity, characterized in that, in order to increase management qualities, after finding the performance extreme, stop trial steps and stabilize the found performance value, and when off If the filling increment from the set value is changed, the ore supply is periodically increased again by the value of the test step.