SU1715418A1 - Method of control of two-stage preparation of raw material slime - Google Patents

Abstract

The invention relates to methods for controlling the technological processes of the building materials industry and can be applied in metallurgy and other industries similar in technology. Allows you to improve the quality of management. To achieve this goal, the level of sludge in the mixer between the grinding stages is measured, the grinding fineness is measured discretely after the second grinding stage, the raw material consumption is changed to the first stage by an amount proportional to the grind fineness deviation from the task, the second stage is calculated grinding, the change in the slurry consumption to the second stage is carried out by an amount equal to the calculated value of the change in consumption, if it is less than the value of the change in the flow rate to the first stage, and by an amount equal to Changes in raw material consumption at the first stage, if it is less than the estimated value of the slurry consumption at the second stage, the slurry consumption at the second stage is changed according to the level in the mixer when it reaches the maximum or minimum value and at the time from the second slurry change a stage of a value equal to the average residence time of the raw material at the first grinding stage. 1 il. (L

Description

The invention relates to methods of controlling the technological processes of the building materials industry and can be applied in metallurgy and other industries similar in technology.

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

In this method, simultaneously with the change in raw material consumption at the first stage of grinding, the slurry consumption at the second stage of grinding is also changed, and the amount of change in consumption at the second stage is introduced taking into account the fulfillment of three conditions. The first;

The magnitude of the change in the flow rate is determined on the basis that by the time the flow of the first stage at the entrance to the mixer changes, the level in the mixer does not exceed the maximum permissible values. Second: the condition of maintaining the level of sludge in the mixer within the minimum and maximum permissible values, as soon as the level in the mixer reaches the maximum permissible value, the sludge flow to the second stage begins to be controlled by the level in the mixer, which prevents the mixer from overflowing or emptying,

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The third condition is satisfied that the sludge flow control is also transferred to the second stage in terms of the filling level of the mixer, as soon as the current time elapsed from the moment of change in the flow rate of the first stage reaches the average residence time of the material at this stage.

The drawing shows a block diagram of a control system that implements a method for managing a two-stage preparation of raw sludge. The diagram shows the flow of raw materials of lime pulp-I, nepheline sludge - H, clay slurry - T, raw sludge-III.

These feedstock flows into the grinding equipment 1 of the first stage, the mixer 2 with a constant cross-sectional area in height, then into the grinding equipment 3 of the second stage.

The control system for the preparation of raw sludge in the grinding equipment 1 and 3 and in the mixer 2 contains a meter 4 grinding grinding after the second stage of grinding, connected to the controller 5 of grinding grinding, a sensor 6 of the cuttings in the mixer 2 between the stages, sensor 7 consumption of raw sludge on the second stage of grinding, the sensors 8.9 and 10 of the costs of the corresponding raw materials for the first stage of grinding, the regulators 11,12, 13 and 14 with the corresponding actuators 15,16,17 and 18, the slag flow rate control unit 19 for the second stage, the unit 20 control settings edeleniem raw materials.

The method is carried out as follows.

The grinding fineness is measured in a second stage with a meter 4, the level of sludge in the interstage mixer 2 is measured using a sensor 6; determine the value of the correction signal (the measurement value of the raw material consumption to the first stage) as a value proportional to the deviation of the sludge grinding fineness from the task, using the tuner regulator 5; In block 19, the maximum permissible value of the change in the filling volume of the mixer is determined as the difference between the minimum permissible filling volume and its current value, if the magnitude of the correction signal is negative, and the raw material consumption in the first stage is also changed by the correction signal value , change the assignment of local systems for stabilization of limestone pulp, nepheline sludge and clay slurry flow rates in proportion to their shares in total consumption, and sludge consumption for the second

using the block 19. change the task of the local system for stabilizing the consumption of raw sludge by an amount equal to

Aqli

DOC VH AQp, if I AQii I SDS I

p AQi if I AQn I AQ | I,

AVn

T

the estimated value of the change in the slurry flow rate to the second stage;

., AH (t) -S

 XV-speed change

filling volume at a given time interval;

A H (t) is the change in level at a given time interval;

3 is the cross-sectional area of the stirrer;

A Vn is the maximum allowable change in the filling volume of the mixer;

A Vn (Nmin - H (t)) - S is the maximum allowable decrease in the filling volume of the mixer;

A Vn (Hmax - H (t)) - S is the maximum allowable increase in the filling volume of the mixer;

Nmin, H max, H (t) are respectively the minimum, maximum allowable and current levels of the agitator;

T is the residence time of the material at the first grinding stage;

A QI K-D / 9 is the magnitude of the correction signal (the value of the change in the consumption of raw materials for the first stage), where A / o Ps -pi is the deviation from the setting of the grinding fineness;

K - proportionality coefficient is determined experimentally for each production.

After performing these operations, in block 19, the filling volume of the mixer 2 with sludge is estimated to be the maximum or minimum allowable value and whether the current time elapsed after the introduction of the correction signal exceeds the value T, and if one of these conditions is met, the sludge flow to the second stage changes in proportion to the magnitude of the deviation from the reference level in the mixer, the definition of this flow change is made in block 19, from which the change signal is fed to the input of the local controller 11. providing, together with the dates 7 and the actuator 15 required flow change.

Total distribution; The raw material flow rate AQi is produced in proportion to the share of each flow in this total flow.

(block 20), i.e. The change in lime consumption of the pulp will amount AQn KbrAQi of nepheline sludge AQH KH AQi of the clay pulp AQr Kr-AQi, where Ki, Kg, Kn are the shares of the costs of the corresponding flows in their total consumption Ki + Kg + Kn 1.

In the control system that implements the method, 4 fineness of grinding is used as a measuring instrument - a physical laboratory that performs the determination of the coarseness value by sieve analysis by the percentage content of the sludge sample residue on a 0.08 mm sieve; A membrane level gauge was used as a level 6 sensor, and induction flow meters were used as flow sensors 7, 8, 9, 10.

Improved control quality reduces power consumption.

Claims (1)

The invention The method of managing a two-stage preparation of raw sludge, including measuring the level of sludge in the mixer between stages, discrete measurement of the tonine grinding after the second stage of grinding and changing the consumption of raw materials and sludge, respectively, in the first and second stages, differs from in order to improve the quality of control, the change in the consumption of raw materials in the first stage is carried out by an amount proportional to the deviation of the toni of grinding from the task; the rate of change in the volume of the agitator’s filling volume is determined by the change in level at a predetermined interval determined maximum allowable reduction of volume increase for FPI complements stirrer at respectively negative and positive value of feed flow rate changes on the first stage calculated value changes of slurry flow to the second stage by the formula 4Q, where VH AH (t) S / At is the rate of change of the filling volume of the mixer; AH (t) is the level deviation; S is the cross-sectional area of the stirrer, At -time between level measurements; AVn is the maximum allowable change in the filling volume of the mixer; T is the residence time of the material in the first grinding stage, the change in the slurry consumption to the second stage is carried out by an amount equal to the calculated value of the change in consumption, if it is less than the change in raw material consumption in the first stage, and by an amount equal to the change in raw material consumption in the first stage, if it is less than the calculated value of the change in the sludge flow to the second stage, the change in the sludge consumption to the second stage b will be at the level in the baler when it reaches the maximum or minimum value and at the time from the end The rate of change in the slurry consumption to the second stage is equal to the average residence time of the raw materials in the first grinding stage. 16 8, AND