SU591220A1 - Method of extremum control of ball mill throughput - Google Patents

Description

Inventions le can be used in enterprises for the production of building materials, ore dressing and others.

A known method of extreme control of the performance of ball mills and analyzing the signal of the current sensor of a drive motor of a mill G is a method that, in order to search for VC information about the critical performance of mills, the current signal is continuously triggered, delayed by sec, the absolute value of the average delay time, compare with. permissible deviation, on the basis of which it is concluded that the side of the extremum is the aggregate productivity. This method has the disadvantage that, due to the presence of two branches of the extreme dependence of the current on the load of the mills, a real change in the current can be due to both overloading and a staggered decrease in the ore supply, for example, when driving the gutters.

There is another known method of extreme control of the performance of ball mills, including a change in the signal of the noise emitted by the mill and a change in the supply of ore to mill 2. This method is closer to the described invention, but it does not provide high performance.

The purpose of the inventions is to “ensure the glaximal but the permissible performance of the small-pieces

This is achieved by the fact that in the method of extreme control and the performance of ball mills, including measuring the signal myMaj supplied by millicles, the change in the ore supply to the mills additionally calculates the averaged value of the noise signal over the length of the noise signal over the time signal and interval, and the change in the supply of ore to chalk is carried out upwards / if the magnitude of the difference of the noise signals over the average interval between the average value and the sum of the average meaning

the noise signal at the small and the interval and its ttroizvopnoy negative and vice versa, the change in the supply of ore to the mill is carried out in the direction of reduction, if the value of the calculated difference is positive.

The increase in the supply of raw materials or the deterioration of its ability to lead to a slight increase in the mill circulation. For each unit at a certain amount of ball loading, lining state and a whole number of other factors that occur at the considered time point, the total load or filling of a millstone material should not exceed some critical value. Exceeding this value leads to disruption of the grinding regime due to avalanche-like growth of the circulating load. A phenomenon known by the name of overload or mill blockage develops. The productivity of (juhoon ore, corresponding to the critical magnitude of filling, is maximum.

The following collection is offered.

operations, providing the location to search for information about the critical performance of the mill.

- determination of the average value

a signal of noise on the timing of the time interval, which allows to reflect the occurrence of such low-frequency processes as lining wear and mercury loading;

- determination of the average value

of the noise signal in a small interval, we can estimate the change in the degree of loading of the noise source |

 determining the derivative of the averaged value of the noise signal on a small aHTepaanSt, which can be predicted to predict the variation of the noise signal,

The drawing shows a block diagram of a system implementing an elogenetic pr-indip control.

Sensor 1 is removed from the output, proportional to the intensity of the noise emitted by mill 2, in a closed loop with classification ash 3, the resulting signal is given Ra & strokes of blocks 405 that calculate the signal values, respectively, for a long DT and the maximum flt time intervals . The output of block 5 is fed to the input of block 6, which calculates the ratio of the last difference in time and the previous averaged signal with the interval At, the duration of this interval, parallel to the outputs of the blocks. 4 and 5 are connected to the inputs of the computing device 7. The output of block 6 is also connected to one of the inputs of the computing device 7. The computing device determines the sign of the difference of the signal obtained from the output of block 4 and takes the algebraic sum of the output signals with some coefficient blocks 5, 6. If the sign of the difference is negative

then from the output of the computing device 7 to the actuating mechanism 8 a control signal is supplied, providing an increase in the supply of ore to the mill. If the sign of the difference is positive, the control signal to reduce the ore supply is given.

Formula of invention

A method of extreme control of the performance of ball mills, which includes measuring the noise signal emitted by the mill, and changing the ore feed to the mill, characterized in that, in order to ensure the maximum permissible performance, the average signal values of the noise signal are additionally calculated over long and short time intervals and the derivative of the average the value of the noise signal at a small interval, and the change in the ore supply in the mill is carried out in the direction of increasing, if the magnitude of the difference between the mean HAND noise signal on Prolonged interval in usreonen UTB avacheev sum signal noise at small interval and its derivative is negative, and vice versa, edited schenie feed ore in mvlnvdu .osuschestyp dissolved in side umengsheni, eslts eelichsha vychnspennoy difference is positive.

The source of information taken into account with expert ze;

1. USSR Author's Certificate No. 244098, class B 02 C 25 / OO, 1973.

2. USSR Author's Certificate No. 175380, class B 02 C 25 / OO, 1974.