SU1202622A1 - Method of controlling the process of dry grinding in ball-tube mill - Google Patents

Description

The invention relates to the field of the automation of fine grinding of charge additives, coal and building materials and can be used in the automation of ventilated drum mills of a closed loop, in the mining, construction; refractory, chemical industry

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

The drawing shows the scheme of the proposed method.

The essence of the method is that when approaching the extreme value of the finished product's performance, the value of the circulating load increases dramatically, the filling of the mill drum increases, and therefore, at a constant step of the extreme regulator, you can switch to an extreme value of the controlled parameter at a certain step and call STiiM its overload. Therefore, it is necessary to vary the step size depending on the magnitude of the circulating load — the greater the increment of the circulating load per unit of time, the closer the extreme performance value nd to the finished product, the smaller the subsequent step of the extreme regulator should be. If, after some time of stabilization of the maximum productivity value, the value of the circulating load has significantly decreased, this means that the grinding conditions have improved, i.e. it is possible to further increase the productivity of the mill, and for this it is necessary to re-enable extreme regulation. If as a result of a sharp deterioration in the quality parameters of the grinding mill (increasing its size, hardness, humidity) the mill is overloaded, the extreme controller does not have time to work to reduce raw material consumption, eliminate extreme regulation and forcefully (for example, cut-off) reduce the consumption of raw materials in the mill to corresponding to the normal operation of the mill under the worst grinding conditions, i.e. at the worst quality of raw materials or regime parameters (reduction of ball loading, wear of drum lining, etc.) under these specific conditions. A positive effect in the implementation of the method is to increase the productivity of the crushed equipment, which leads to energy savings.

The method is carried out as follows.

in a way.

The value of the circulating load of the mill is measured, for example, by the frequency of operation of the cone closures (flashing lights) in the separator return channel by the sensor 1.

The mill capacity of the finished product is measured, for example, using a frequency sensor 2 measuring the density and

Dust flow rate behind the separator.

The consumption of raw materials in the mill is measured using an extreme stepper type regulator 3, with the direction

The pitch is determined depending on the sign of the increment of the mill output by the finished product, and the pitch value is determined depending on the magnitude and sign of the increment of the circulating load. For this purpose, for example, a signal is sent to increment the circulating load on the key device 4, which has two outputs. Positive signal increment arrives

to the first output of the key device associated with the first input of the subunit of forming the step size of the extremum regulator 3, through which the inversely proportional change of the step size depends on the signal magnitude at the input. The second output of the key device receives a negative increment of the signal of the circulating load, the second output of the key device is connected with the second input of the subunit of the formation of the step size, through this input a direct proportional change is made

step size depending on the size of the input signal.

After finding the maximum rtpti-performance over the finished class, it is stabilized, for which, for example, the step-forming unit is turned off using a key device located in the most extreme controller. With this from the exit

extreme regulator to the input of the actuator 5 consumption of raw materials (feeder) is constantly receiving a signal corresponding to the maximum performance. The value of the circulating load corresponding to the maximum performance is memorized, for example, with the help of a storage unit on the comparator 6, which is triggered when the 6jioKa deactivation of the formation of the pitch of the extremal regulator.

If after some time the circulating load has decreased by 8-12% compared to a fixed value (the indicated values are chosen to exceed random fluctuations of the circulating load, usually 6-9% of the fixed value), the key device 7 is activated, which includes an extremal controller step shaping unit, and the search for a new extremum begins.

If the mill is in overload condition, an abrupt

an increase in the circulating load, the key device 8 is triggered, disconnecting the output of the extreme regulator 3 from the actuator 5 and turning on the input

the last signal source corresponding to the mill performance specification under the worst grinding conditions.

Using the method allows

to increase the productivity of grinding mill charge additives (lime and bentonite) in the conditions of the pelletizing and calcining factory concentrate on average by 5-6%, which leads

to save the time of the mill and, consequently, to save energy consumption for grinding.

Editor N. Dankulich

Compiled by V.Alekperov

Tehred M. Parotsay Proofreader L. Pilipenko

Order 8348/7 Circulation 583 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Branch PPP Patent, Uzhgorod, st. Project, 4

Claims (1)

METHOD OF PROCESS CONTROL, DRY GRINDING IN A BALL DRUM MILL, including fixing emergency overloads when they occur, extreme regulation of productivity of the finished product by changing the consumption of raw materials, disabling extreme regulation after reaching maximum productivity, stabilization of the achieved maximum productivity, characterized in that, with In order to improve the quality of control, measure the value of the circulating load of the mill, the amount of reduction of cir culling load per unit time, change the algebraic value of the step of extreme regulation, fix the value of the circulating load corresponding to the maximum. mill productivity for the finished product, and after stabilization of the achieved maximum productivity, they include extreme performance control with a decrease in the circulating load by 8-12% compared to the set value, and when an emergency load occurs, extreme control is additionally disabled, and the change in the algebraic value of the extreme control step carry out inversely with the magnitude of the increment of the circulating load and in direct proportion reduction to the quantity of circulating load per unit time. SU .. „1202622