SU1305652A1 - Method of controlling process for cooking sulphate cellulose - Google Patents

Abstract

The aim of the invention is to increase the efficiency of controlling sulphate pulp pulping in paper production. Based on the measured temperature values of the cooking liquor at the outlet of the heat exchanger 9 and the sulfidity of the white liquor coming from the sensors 8 and 11, in block 12, the current value of the integral kinetic criterion is calculated. The signal from block 12, corrected in block 13 of the summation, enters block 16, from which, as a result of its comparison with the value set by the setting unit 17, a command is issued to the actuating mechanism 18 on the weight line of the mass. In block 19, the prediction of the measured 10 values of the sensor and the signals from sensors 8 and 11, as well as from the dial 21 of the required parking time in block 20, is used to calculate the integral kinetic criterion. In block 22, the value of the integral-kinetic criterion is summed with the signal coming from block 13. The obtained value is compared in block 23 with the reference from setpoint 17, and the error signal is fed through setpoint 24 to the PI temperature controller, which issues a command to the executive mechanism 26 on the steam supply line to the heat exchanger 9, 1 Il. GB 2 (L with about СЛ Oi СЛ ГЧЭ

Description

1130

The invention relates to pulp and paper production and can be used to control the sulphate pulping process.

The purpose of the invention is to demonstrate the effectiveness of control.

The drawing shows a block diagram of a control system implementing the proposed method.

The system works as follows. The sensor signal 1 of the loaded chips in the cooking boiler 2 enters the 3 liquor metering unit, which, by the signal of the active concentration of white liquor 4 and the backlight 5 signal, shows the required amount of liquor, the liquor consumption is controlled by the flow meter 6, the signal of which dispenser 3 calculates the volume of liquors poured in according to the formula

V

m

Hello

V - the number of poured liquor j

signal setting unit 5 of the amount of active alkali;

 m,

q

the weight of the chip, determined by the signal of the level of the chip, the concentration of the active alkali.

In case of equal filled and required volumes of liquor, the dispenser 3 feeds the signal to the actuator 7, the signal of the cooking liquor temperature sensor 8 at the outlet of the heat exchanger 9, the signal of the effective alkali concentration sensor 10 and the signal of the white liquor sulphidity 11, which determines are the current value of the integral-kinetic criteria for the dependence

k K

)) olt,

de

kj

to reaction rate constant

S (t) - sulphidity of liquor; oCji / i is the reaction order for the corresponding components} C (t) is the current value of the concentration ° -

A - constant for a given wood species

0 (t) - current temperature value} tgjt - time of the beginning and end of the cooking process.

The value found is added in summation unit 13 to the signal from correction unit 14. In the latter, the value of the forging parameter is calculated from the signals of setpoint 15 in accordance with the expression

e

V - "(((.: - Y

C (K D

(v - v)

; Str 1 UL I

indirect parameter-, matching factor-.

parameters, depending on the characteristics of the disturbing influences, are the actual and required values of the stiffness of the pulp.

Where

In comparison block 16, the signals from block 14 and setpoint generator 17 of the required criterion are compared, after which the control signal from block 16 is fed to actuator 18 on the mass blowing line.

According to the signals of the effective alkalinity sensor 10 in the cooking liquor, the forecast block 19 calculates the curve of the change in the concentration of the effective alkali based on

C (t)

C (tz) - C (t: i)

35

H

where C (t) is the value of the concentration of effective alkali, measured after impregnation at the moment of time, the last measured value of the concentration of effective alkali at the Stage of welding at the moment of time

H

time value

C (t,) t -1 current

The calculation unit 20 according to the signals of the forecast unit 19, the white liquor sulfidity sensor 11, the cooking solution temperature sensor 8 and the setting unit 2t of the required stand duration calculates the predicted value of the integral-kinetic criterion using the formula.

st

iK (t) .S .0 (1 :). dt,

9

where (t,) ki-e- l i

6 (t,)

t

with t

-the temperature at the stage of welding;

-the duration of the stand ..

From block 20, the signal is fed to the input of adder 22, in which it is added to the value of the integral-kinetic criterion reached at the time of the start of the forecast. Adder output

connected to the input of the comparator unit 23, fO are numbered according to the measured values; the grand input of which is given a signal

from the set point 17. Output signal

unit 23 comparison is fed to the input

setpoint 24. Signal from setpoint 24

the end of the integral-kinetic criterion and the value of its prediction at a given time at the end of the process at the temperature of the station is heated to the input of the PI controller 25 of the so-called welding boiler at the temperature of the station while heating the temperature of the actuator 26 on the line supplying steam to heat exchanger.

Editor N. Rogulich

Compiled by N. Nikolsky

Tehred And Popovich Corrector. Cherni

Order 1450/45 Circulation 864 Subscription VNIIPI USSR State Committee

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

. Production and printing company, Uzhgorod, st. Project, 4

5652

four

Claims (1)

Claims The method of controlling the process of sulphate dellusserization by adjusting the temperature of alkali depending on its measured value, characterized in that, in order to increase the efficiency of control, the effective alkali concentration and the sulphidity of white liquor, the magnitude of the integral-kinetic criterion and its prediction value the specified time of the end of the process at the tempo-atupe of the station during this heating is boiled down to achieve the predicted value of the integral kinetic criterion given ins.