SU990917A1 - Method of control of washing unit with drum filters - Google Patents

Description

(5) METHOD OF MANAGING THE WASHING UNIT WITH DRUM FILTERS

one

The invention relates to pulp and paper production and can be used to control a drum filter washing machine.

A known method of controlling a washing installation with drum filters, which consists in measuring the flow rate of washing water for washing, the productivity of the washing installation, the degree of delignification of the washed pulp, determining the residual alkalinity of the washed pulp according to measured values and regulating the flow of washing water by the found P. values

The disadvantage of this invention is the low efficiency of the sizing process.

The purpose of the invention is to increase the efficiency of the washing process.

This goal is achieved by the fact that according to the method of controlling a washing installation with drum filters, which consists in measuring the flow rate of rinsing water for washing, the productivity of the washing installation, the degree of depignification of the washed pulp, and determining the residual alkalinity of the washed pulp according to the measured values

To and regulate the supply of wash water, using the values found, the rotational speed of the last drum is measured; on the filter, the concentration of the liquor in the intermediate filter bath of the last filter, the alkalinity of the washing water and its temperature on the last filter, measure the measured residual alkalinity of the pulp according to the measured values and adjust the frequency of rotation of the filter drum and the flow of water for washing depending on the corrected value residual alkalinity, cellulose, in addition, the actual value of residual alkalinity is additionally measured and the found value of residual alkalinity is again corrected by it, and the limit value of the rotational speed of the drum is adjusted according to the measured productivity of the washing installation. The drawing shows an installation that implements a control method. The installation includes a filter 1, the last filter 2, the wash water flow sensor 3, the wash water temperature sensor k, the wash water alkalinity sensor 5, the last drum turn frequency sensor 6, the cellulose alkalinity sensor 7 in the intermediate filter bath 2, the installation capacity sensor 8, a sensor 9 for the degree of delignification of the pulp entering the washing, the computing unit 10, the controllers 11 and 12, the actuator 13 is changed and the rotational speed of the filter drum 2 ,. the actuator C changes the water consumption for washing, the cellulose residual alkalinity sensor 15; The operation of the installation is as follows. The measured values of the sensors 3 are fed to the computing unit 10 where the residual alkalinity of the washed pulp is determined according to the following relationship: Z - bo b X tb b ,,% ,, tb4X4tb5X6 b6 6 7 where Z is the residual alkalinity of the washed pulp, X - mountain consumption whose water, x is the temperature of hot water, x is concentrated liquor in the intermediate bath of the last filter, X / is the drum rotation frequency, X- is the flushing capacity of the installation, x is the degree of duplication of cellulose, X7 is the alkalinity of the hot water ratios. After determining the residual alkalinity, the magnitude of the control actions is calculated, for which the difference between the found value of the residual alkalinity of the washed out cellulose and the upper limit value of the residual alkalinity is found. The resulting difference is equated to control actions by their coefficients A - biX B4, X4, where D is the difference between the found and the upper limit value of residual alkalinity, b DB coefficients, X is the flow rate of hot water, Xd frequency of rotation of the filter drum. In the calculation, each control action is checked for permissible pre-bids. -V-from V to IVwaxi 4VY in 4 4niax, whereby the limit values for the rotation frequency of the filter drum are adjusted depending on the capacity of the washing installation, measured by sensor 8, according to the following VYlin 2 dependence. Q, -K, Q; where n, (n) is the lower (upper preiTrtH VW is the individual value of the rotation frequency of the filter drum, Q is the productivity of the washing installation, K-) JK2. coefficients. The calculated values of the control actions from the block 10 are fed to the controllers 11 and 12, which act on the actuators 13 and H and adjust the frequency of rotation of the drum of the filter 2 and the flow of wash water. The sensor 15 measures the actual residual alkalinity in the washed pulp at fixed points in time and compares with the value found for the same point in time. The correction of the coefficients of the mathematical model, by which the residual alkalinity is determined, is carried out according to the following dependencies: R- -T Zgi.N-Zp,) - nttixj) o, ivO, a5; where B- is the sequence number of the refined coefficient of the mathematical model,

2d) N The actual sign of residual alkalinity in the N step,

2p N - calculated residual alkalinity value at step N, J - convergence parameter D

washing installations J 0,1-0,25, N - step number.

Thus, the proposed method allows to increase the efficiency of the cellulose washing process.

Claims (1)

1. France Patent No. ZStSSU, cl. D 21 C 9/02, 19777