SU1346714A1 - System for controlling temperature in sulfate pulp digester - Google Patents

Abstract

This invention relates to pulp and paper production. The proposed system allows to increase the efficiency of temperature rise control in the digester. The signal is proportional to the result of the comparison measured by sensor 6 and set from the operator-operator of the temperature from controller 7 through the block Lto-i t 3i & 1 bar & 1 baroque solution rm 2s (L co ;; O5 vj

Description

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Comparison 21 and relay 25 enters an automatic valve 26 or 27, changing its degree of opening on the steam supply line to heat exchanger 2 or 3. The alkaline efficiency value measured by sensor 13 calculates in differentiation unit 14 the rate of alkali efficiency change, which is compared in block 15 with a given value. When the value of the found value is lower than the preset, timer 16 is turned on and commands for alternate opening of relay 17-19 are generated, with which the multiplication blocks 20, 22 occur depending on the task of calculating the value of the correction signal. This signal arrives at block 21. This is also where the additional correction signal comes in, which is generated in comparison block 23, which is given and calculated by the measured 6 sensor.

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The invention relates to pulp and paper production and can be used to control the temperature rise in a pulping vessel.

The aim of the invention is to increase the efficiency of control.

The drawing shows a block diagram of a temperature rise control system in a sulphate pulp digester.

The scheme contains a boiling boiler 1, heat exchangers 2 and 3, hydraulic pumps 4 and 5 of the cooking solution, a sensor 6 of the temperature of the cooking solution connected to the steam flow controller 7, a differentiation unit 8 and an adder 9. The sensors 10 and 11 of the condensate temperature are connected to a relay 12 , the output of which is connected to the adder 9. The solution efficiency analyzer 13 is connected through the differentiation unit 14 and the comparison unit 15 to the timer 16, the outputs of which are connected to the inputs of the relay 17-19. The relay outputs are 17-19 and multiplication units 20 with the input of comparison unit 21. The outputs of blocks 20 and 22 multiply respectively from relay 19

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rate of change of temperature of the cooking liquor. In block 9, the measured values of the solution temperature sensor 6 and the condensate temperature sensor 10 or 11 are subtracted, and the difference signal is compared in block 28 with a predetermined value, and when the task is exceeded, the terminal receives a signal to turn off the hard drive drive, fixing the value of the task controller. Based on a comparison of the current and specified values of the concentration of the active component in the condensate of the heat exchanger, which are introduced into the terminal, the smallest difference is determined. Based on the value found, a heat exchanger selection signal is generated, which, through the switch 29 and the key circuit 30, controls the valves 26, 27, 33-36 and switches the sensors 10 and 11 using relays 12, 25, 31 and 32. 1 sludge.

and 18. Differentiation unit 8 through comparator unit 23 and relay 24 is connected to the input of comparator unit 21, the output of which through relay 25 is connected to automatic valves 26 and 27. The output of adder 9 is connected to comparator unit 28. The switch 29 is connected via a circuit of 30 keys to the inputs of the relays 12, 31 and 32. The outputs of the relay 31 are connected to

valves 33 and 34, and the outputs of the relay 32 - with valves 35 and 36. The inputs of blocks 7 and 29 and the output of block 28 are connected to the operator-cooker terminal.

The control system operates as follows.

The signal from the temperature sensor 6 of the cooking solution enters the regulator 7 of the heating steam flow rate as a variable. The adjustment task signal comes from the operator’s cooker terminal according to a hard program (pattern) and is proportional to the difference between the set and measured values. A signal is released in the controller, which through the comparison unit 21 changes the opening degree of the valves 26 and 27 on the steam supply lines to the heat source

A 2 or 3 bar. The signal is corrected by the change in the effective alkali measured by the analyzer 13, from where the signal enters differentiation unit 14, where the rate of change in alkali efficiency is determined, is compared in block 15 with a given value and, if the speed is low, then the output A signal I is generated, which turns on timer 16. At a time ttt equal to the delay in the system, command signals of time 1 are generated, which alternately open relay 17-19, through which the correlation signals of the degree of valve opening 26 and 27. They are formed as the sum of the signal from the setter and the signals obtained by multiplying the reference signal by the coefficients in multiplication blocks 20 and 22. The correction signal enters the comparison unit 21, where by subtracting the magnitude of the valve opening signal decreases, the adjustment of which is additionally corrected for the change in temperature of the cooking solution, the signal of which from sensor 6, after differentiation of block 8, is compared in block 23 with the specified value and, if the speed is low, then a signal 1 is generated at the output of the block, which opens the relay 24, through which the correction signal enters the comparison block 21, increasing the signal.

The value of the setting of the temperature of the cooking solution to the controller is corrected by the difference in temperature between the measured temperature of the cooking solution and the condensate temperature from sensors 10 or 11, which through relay 12 enter the adder 9, where the difference between the measured temperatures of the cooking solution and the condensate is determined. In block 8, it is compared with a predetermined value and, if greater than it, the signal I enters the terminal and turns off the hard program drive, fixing the value of the task to the controller.

Based on the result of comparing the current values of the concentration of the active component in the terminal of each heat exchanger and the set value, their minimum difference is determined by which a heat exchanger selection signal n is generated, which is connected through the switch 29 by closing the circuits in the key circuit 30

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generating command signals for relays 12, 25, 31, and 32, followed by the procedure for closing and opening valves 26 and 27, steam, 33 and 34 medium, 35, and 36 upper circulation of cooking solution and switching sensors U and 1 1.

Claims (1)

Invention Formula A temperature control system in the sulphate pulp digester containing the digester, the temperature sensor of the cooking liquor on the supply line to the heat exchanger connected to the inlet of the adder, the output of which is connected to the first input of the comparator unit, the temperature difference setting unit connected to the second input of the comparator unit, output which is connected with the first input of the terminal, a temperature sensor at the exit from the heat exchanger, a steam flow controller, versions (a mechanism on the heating steam supply line, characterized in that Improving control efficiency, it has additional heat exchangers with actuators on the steam supply line, temperature sensors at the outlet of the heat exchanger, a cooking solution efficiency analyzer, additional comparison units, defermentation units, multiplication units, a switch, a key diagram, setting units of the nominal rate of change of efficiency and the rise of the temperature of the cooking solution, timer, relay, unit for the correction of the rate of change in efficiency and the rise in temperature of the cooking solution, block measuring the current and setpoint setpoint values of the active KOMnoHeHf condensate heat exchangers, while the output of the cooking solution temperature sensor is connected to the first input of the steam flow controller, the output of which is connected to the first input of the second comparator unit, and through the first differentiation unit comparison unit, the output of the third comparison unit is connected with the first input of the relay, the output of which is connected to the second input of the second comparison unit, and its second input is St. in contact with the setpoint adjuster of the rated temperature rise, while the second input of the relay is connected to the setpoint adjuster 513467 correction of the rate of temperature rise, the second input of the steam flow regulator connected to the first output of the terminal, the second and third input of which is connected to the current measuring unit and the setpoint setpoint of the active component concentration in the heat exchanger condensate, while the temperature sensors at the output Q from the heat exchangers are connected to the first input of the second relay, the output of which is connected to the second input of the adder, the sensor of the effectiveness analyzer of the cooking solution being connected through the second differentiation unit of communication n the first input of the fourth unit, i comparator, a second input coupled to the velocity setting unit changes the nominal efficiency varoch- 20 Editor A. Shandor Compiled by N.Nikolsky Tehred L. Serdyukova Proofreader V. But ha Order 5100/28 Circulation 340 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-3-, Raushsk nab. 4/5 . - - ...-.-.-. - „.“. - - ... i, .- - ". - - - - .. - - Production and printing company, Uzhgorod, st. Project, 4 6 the fourth block is compared to the timer, and the timer outputs are connected to the first inputs of the third, fourth and fifth relays, and the setting knob for correcting the rate of change in the effectiveness of the cooking solution is connected to the second input of the third relay and the second inputs of the fourth and fifth relays, while the outputs of the third, fourth and fifth relays are connected to the second input of the second comparator unit, and the output of the second comparator unit is connected to the input of the sixth relay, the second output rminala connected through the switch circuit and the corresponding key switch with the actuators on the steam supply line.