SU893265A1 - Grinding process control method - Google Patents

Description

one

The invention relates to the crushing and grinding of various materials and can be applied in the automation of grinding processes, for example, in the production of cement.

There is a known method for automatically controlling the grinding process by maintaining a predetermined ratio between the signal of the electroacoustic generator and the intermediate variable of the Mill and the flow rate of the Material 1 fed into it.

The disadvantage of the method is low control accuracy, due in particular to the effect of various interferences on the sensor signal of the intermediate variable.

The closest to the proposed technical entity is a method of controlling the grinding process, which includes measuring an intermediate variable, modeling the section of the mill between, its entrance and the control point of the intermediate variable, measuring the signal proportional to the material flow fed to the mill, previously passed through the model, correction of the sensor signal of the intermediate variable signal obtained from the output

the model, and the change in the flow rate of the material fed to the mill until a constant value of the ratio between this material flow rate and the corrected sensor signal of the intermediate change is reached. Noah.

The method is to maintain

10 ratios between the flow rate of the material fed to the mill and the converted intermediate variable sensor signal, for which the converted intermediate variable sensor signal is corrected by a signal proportional to the total material flow rate supplied to the mill, previously passed through the model corresponding to the section of the mill between its input and the control point of the intermediate signal, after which the corrected signal is filtered by a frequency filter that suppresses interference

25, and is fed to a ratio block, which generates a signal for a change in the flow rate of the material fed to the mill, which is simultaneously fed to the input of the mill model 2.

The known method does not provide a sufficiently high quality of control, since its purpose is only to compensate for measurement errors, whereas the magnitude of the signal of the intermediate variable substantially depends on the perturbations acting on the mill.

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

The goal is achieved by the fact that in the method of controlling the grinding process, including measuring an intermediate variable, modeling the section of the mill between its input and the control point of the intermediate variable, measuring the signal proportional to the material flow rate to the mill, passes the sensor signal intermediate by a variable signal derived from the model output, and a change in the flow rate of the material fed to the mill until a constant value is reached by the ratio between material consumption and corrected sensor signal of an intermediate variable, additionally correct the change in material consumption proportional to the corrected sensor signal of an intermediate variable, and the proportionality coefficient takes discrete values depending on the signs of the products of the sensor deviation value of the intermediate variable lOT of a given value and a signal proportional to its second derivative, on the corrected sensor signal intermediate About

An additional change in the consumption of materials allows one to more precisely hold the specified value of the intermediate variable and, thereby, more accurately withstand the specified value of the specific surface area of the finished product. The latter allows narrowing the quality tolerance zone of the finished product and increasing the average output of the small items.

The package shows a block diagram of a control device that implements the proposed method.

The device contains a mill 3 clinker 3.2x15, sensor transducer 2 intermediate variable with a converter, model 3, implemented in a microprocessor, the corresponding section of the mill between its input and control point intermediate variable, corrector 4, block 5 mismatch of correlation unit b, computing unit 7 and disturbance correction unit 8 and dispenser 9. Blbki 7 and. 8 are implemented in a microprocessor.

The input of the converter transducer 2 is connected to the inputs of the corrector 4 and the error block 5, to the second input of which the specified value XQ of the signal of the intermediate variable x is fed. The output of the error block 5 is connected to the inputs of the computing unit 7 and the block 6 of the correlation. The output of the latter is connected to the inputs of the metering device 9 and model 3. The output of the model 3 is connected to the second input of the corrector 4, the output of which is connected to the inputs of the computational unit 7 and the disturbance correction unit 8. The second input of the latter is connected to the output of the computing unit 8, and the output to the input of the mill 1. The output of the dispenser 9 is connected to the input of the mill 1.

 The method is carried out as follows.

The intermediate variables x from the output of the transducer 2 are fed to the inputs of the corrector 4 and block 5, the error is not, and the error signal. AX from the output of the last is fed to the input of the block b, the ratio that generates the signal y1 supplied to the input of model 3 and at the same time a control signal for the dispenser 9 controlling the flow rate Q of materials fed to the mill. The signal x1 from the output of model 3 is fed to the input of equalizer 4, at the output of which a signal φ is formed, proportional to the difference X and x1. The signal is fed to the input of the computing unit 7 and the disturbance correction unit 8. A signal proportional to the second derivative of the signal U x and signals proportional to the product of signals (} on Dx and f to a signal proportional to the value of the second derivative of the signal lx are generated in the computing unit 7. At the output of the computing unit 7, the signal K is generated (P1, P2 ), depending on the signs of the signals, proportional to the products obtained. If we denote the first product of A1, the second is P2, then the law of formation of the signal K (III, P2) has the form

P1 0. P2 O N K1

P1 O, P2 O V-K2

P1 O, P2 O kZ

P1 O, P2 O K4

Thus, at the output of the computing unit 7, one of the four fixed values of the signal K is generated. (P1, P2).

In block 8, a signal y2 is generated, which is proportional to the magnitude of the signal Φ and depends on the signal K (P1, P2), and the signal y2 is additionally changed by the flow rate of the materials fed to the mill. Thus, the consumption of materials is determined by the equation and y1 4-y2.

Claims (1)

Claim A method of controlling the grinding process, including measuring an intermediate variable, modeling the mill section between its input and the intermediate variable control point, measuring a signal proportional to the flow rate of material supplied to the mill, previously passed through the model, correcting the sensor signal of the intermediate variable with the signal received from the model, and changing the flow rate of material supplied to the mill until a constant value is reached VNIIPI Order 11316/6 Circulation 664 Signed - - - - - - - - · - - - - - - - - - - - - - - - - - - - - - Branch of PPP Patent, Uzhhorod, st. Design, 4 by the ratio between this material flow rate and the adjusted sensor signal of the intermediate variable, characterized in that, in order to improve the accuracy of control, additionally carry out the adjustment of the measurement of material consumption proportionally to the corrected signal of the sensor of the intermediate variable, and the proportionality coefficient takes discrete values depending from product signs of the deviation of the sensor signal of the intermediate variable from the set value and signal, Prop its second derivative, on the adjusted sensor signal of an intermediate variable.