SU1109720A1 - Device for adjusting monomer concentration of mixture - Google Patents

Abstract

A DEVICE FOR REGULATING THE CONCENTRATION OF A SINGLE MONOMER containing a monomer flow sensor connected via an output through a monomer flow controller to an actuator on the monomer line in the azeotropic drying column, a return fraction flow sensor connected by a code through a return fraction flow controller with a return flow fraction controller connected with a return flow fraction controller connected with a return flow control meter with a monomer through the azeotropic drying column. fractions in the azeotropic drying column, the charge flow sensor for the batteries, the outputs of which are connected to the corresponding flows of the block for determining the total load batteries for serially connected isoprene concentration sensor in the return fraction, a unit for determining the difference of isoprene concentrations in the monomer and return fractions, and a task determination unit for the monomer flow controller, the output of which is connected to the second input of the monomer flow controller and to the first input of the task determination unit flow controller for return fraction connected with output c. the second input of the return flow control regulator, the isoprene concentration sensor in the monomer stream, the output of which is connected to the second input of the isoprene concentration difference determination unit in the monomer stream and the return fraction, as well as the isoprene concentration sensor in the charge, characterized by the fact that device, it contains a buffer tank installed after the azeotropic drying column, series-connected sensor and charge level controller in the buffer tank, series-connected block determining the load on the azeotropic drying column, the load determining block on the azeo-U tropic drying column, the determining block (/} the imbalance between loads on the azeotropic drying column and the battery, the averaging unit and the load matching unit between the azeotropic column with the drying and batteries, and a block for determining the rate of change of the charge level, an isoprene concentration regulator in the charge, and a block for determining the difference between a given isoprene concentration in the charge and the isoprene concentration in the return fraction, the input of which is under Is connected to the output of an isoprene concentration sensor in the return fraction, and the output is connected to the second input of the task determination unit to the monomer flow controller, the input of the determination unit of the rate of change in the charge level is connected to the output of the charge level sensor in the buffer tank, and the output to the second input of the load matching unit between the azeotropic drying column and the batteries, the third input is connected to the output of the charge level regulator in the buffer tank, even

Description

Vertical input to the output of the block for determining the total load on the batteries and the second input of the block for determining the imbalance between the loads on the azeotropic dehydration column and the battery, and the output to the third input of the block for determining the setting of the monomer consumption regulator and the second input of the block for determining the setting of the return flow controller fractions, the inputs of the unit for determining the load on the aerootropic drying column are connected respectively to the outputs of the monomer consumption sensor and the return fraction flow sensor, the output of the isoprene concentration sensor in The charge is connected to the input of the isoprene concentration regulator in the charge, which is connected with the output to the fourth input of the determination unit for setting the monomer flow controller.

one

The invention relates to the automation of polymerization processes and can be used in the production of synthetic rubber, such as SKI, SKD, etc., in the chemical and petrochemical industry.

A device for automatically controlling the concentration of monomer in the charge is known, which contains sensors and flow controllers for the monomer and the return fraction supplied to the azeotropic drying column of the charge, sensors for the concentration of monomer in the flow of monomer, return flow and charge, connected to the units for determining the flow controllers for the monomer and return fractions.

The device also contains charge charge sensors for batteries, connected to the inputs of the block for determining the total load on the batteries, a cube level sensor connected to the controller, and subtractors and smart knobs, the input of the subtractor unit the charge stream, its output is connected to the first input of the multiplication unit, the second input of which is connected to the output of the block for determining the total load on the batteries, the output of the multiplying unit is connected to the input of the CO level regulator.

However, this device is characterized by insufficient accuracy of adjusting the concentration of monomer in the charge, which is caused by the following reasons:.

significant inertia columns azeotropic drying, resulting in information on the concentration of monb)

measure (isoprene) in the charge enters the device with a delay of 4060 minutes after changing the control parameters (monomer costs and return fraction) J

fluctuations of the charge level in the azeotropic drying column caused by the level correction for the total load on the batteries and the duration of the monomer concentration analysis in the charge (fluctuations of the indicated charge level worsen the temperature conditions in the column and the mass exchange between the liquid and vapor phases, and consequently, reduce the quality of charge cleaning from impurities, such as moisture;

the absence of accounting in the device of a given value of the monomer concentration in the charge, which practically excludes the use of the device in order to stabilize the monomer concentrations in the charge.

; The closest to the technical essence of the invention is a device for automatic control of the monomer in the charge, containing sensors and flow controls of the monomer and the return fraction, which is fed into the azeotropic drying column of the charge, sensors of the monomer concentration, return fraction and charge, sensors battery consumption by batteries, connected to the inputs of the block for determining the total load on the batteries, the unit for determining the difference between the monomer concentrations in the charge and return fractions, the unit for determining the difference and between monomer concentrations in monomer and reflux fractions and determine

given to the monomer and return fraction controllers.

At the same time, the last blocks are connected. The cherkes blocks for determining the monomer concentration jpasHocTH with со, responding with monomer concentration sensors in the monomer streams ,. 1 of the return fraction and the charge and with the block of determination of the total load | ia of the battery, and the output with control of the consumption of the monomer and the return fraction.

According to the information on the total load on the batteries and on the monomer concentrations in the monomer streams, the return fraction and the charge in the determination units specified by the controller, the regulatory effects on the monomer consumption and the return fraction of the TS3 are formed.

OAttaKo for the known device is also characterized by insufficiently high control accuracy of the monomer concentration in the charge, which is due to the presence of delay in the control panels due to the considerable inertia of the aeotropic drying column, and also because the device does not use the specified value of the controlled parameter.

The aim of the invention is to improve the accuracy of the device by increasing the accuracy of controlling the concentration of the monomer in the mixture.

The goal is achieved by the fact that a device for controlling the concentration of monomer in the charge, containing a monomer flow sensor connected via a code through a monomer flow controller to an implanting mechanism on the monomer line to an aerootropic drying column, a return flow meter connected to the output through a return fraction flow regulator with an actuator on the return fraction line to the azeotropic drying column, charge flow sensor for batteries m, the outputs of which are connected to the corresponding inputs a unit for determining the total load on batteries, successively connected isoprene concentration sensor in the return fraction, a unit for determining the difference in isoprene concentrations in the monomer and return fractions, and a task determination unit for the monomer flow controller, the output of which is connected to the second input of the monomer flow regulator and

the first input of the block defining the task to the flow controller of the return fraction connected with the output to the second input of the return flow controller

fraction, isoprene concentration sensor in the monomer stream, the output of which is connected to the second input of the unit for determining the difference of isoprene concentrations in the monomer stream and return

fractions, as well as the sensor of isoprene concentration in the charge, contains buffer j capacity, installed after the azeotropic drying column, sequentially. connected sensor and charge level regulator in the buffer tank, the load sensing unit on the azeotropic drying column connected in series, the unbalance detection unit between the loads on the casing

azeotropic dehydration and battery, averaging unit and load matching unit between azeotropic drying column and battery, as well as a unit for determining the rate of change of level

the charge, the regulator of isoprene concentration in the charge and the unit for determining the difference between the specified concentration of isoprene in the charge and the concentration of isprene in the return fraction, the input

which is connected to the output of the isoprene concentration sensor of the return fraction, and the output is connected to the second input of the determination unit of the monomer flow controller, the input of the determination unit of the rate of change of the charge level is connected with the output of the charge level sensor in the buffer tank, and the output of the second input of the matching unit loads between the azeotropic column

drying and batteries, the third input of which is connected to the output of the charge level regulator in the buffer tank, the fourth input to the output of the block for determining the total load on the batteries and to the second input of the block for determining the imbalance between the loads on the azeotropic drying column and the battery,. and the output to the third input of the task determination unit of the monomer flow controller and to the second input of the task determination unit of the return flow rate controller, the inputs of the load sensing unit on the azeotropic drying column are connected respectively to the outputs of the monomer flow sensor and the return fraction flow sensor, the output of the concentration sensor isoprene in the charge is connected to the inlet of the isoprene concentration regulator in the charge, which is connected with the output to the fourth input of the determination unit to the monomer flow controller.

The drawing shows the functionals 5 on the scheme of the proposed device. The scheme contains a mixer 1 monomer flows and a return fraction, a column 2 of azeotropic drying of the charge, a buffer tank 3, a monomer flow control loop consisting of a monomer flow sensor 4, a monomer flow controller 5, an actuator 6, a return fraction flow control loop, 5 consisting of a return flow fraction sensor 7, a return flow control regulator 8, an actuator 9, isoprene concentration sensors 10-12 in the corresponding-20 flows of the monomer, a return fraction and - charge, sensors 1 3-16 batch consumption for batteries, sensor 17 and charge level controller 18 in buffer tank 3, isoprene concentration regulator 19 5 in charge, speed determining unit 20 Changes in charge level 21, load determination unit 21 in azeotropic drying column, unit 22 determining the total load on the batteries, unit 22 for determining the imbalance between the loads on the batteries and the azeotropic drying column, unit 24 averaging the imbalance between the loads on and the column, unit 25 for matching the rudder between the azeotropic drying column and batteries, unit 26 for determining p the concentration of isoprene in the monomer stream and the return fraction, block 27 for determining the difference 40 between a given isoprene concentration in the charge stream and the concentration

isoprene in the flow of the return fraction, blocks 28 and 29 of the definition of tasks to the regulators 5 and 8 monomer consumption

and return fraction.,

).

Monomer (isoprene-rectified) and returnable (isopentane-isoprene) fraction are fed to the mixer inlet T, from where the charge with monomer concentration of 16-18% by weight enters the azeotropic drying column. In the column 2, the charge is cleaned of impurities (mainly moisture). ) and through the buffer tank 3, the distribution is distributed among the batteries, which are a chain of series-connected polymerization agents.

The quality and economic performance of the polymerization process, which is essential in the production of rubber, depends on the accuracy of controlling the monomer concentration. Therefore, it is necessary to control the concentration of monomer with a high accuracy.

A device for automatically controlling the concentration of monomer in the mixture works as follows.

According to information from sensors 4 and 7 of the monomer consumption and the return fraction in block 21, the determination of the load on column 2 A signal is formed that is proportional to the load on column 2,

bj + r-1

one...

where 7 output signals from sensors 4 and 7,

P is the output signal from block 21.

The battery load determination unit 22 summarizes the signals from the sensors 13-16 of the charge to the batteries:

P.i, + Pl4 Pl5 Pl6.

22

where - P - signals from sensors 13-16 consumption of the charge on the battery; 2g output with

block 22.

The unbalance determination unit 23 between the loads on the battery and the column generates a signal proportional to the difference

p - p t-22,

23

where Pjj is the output signal from block 23. Block 24 averages for a certain period of time, for example, 1 hour, the signal coming from block 23

 ,)

23i

244

where Pjji and 24i are output signals from blocks 23 and 24 to the current i-and averaging step;

n is the number of steps of averaging.

According to information from the level sensor 17 in the buffer tank 3, the regulator 18 forms a regulating signal, for example, according to the P-law of regulation

KM WG - P

).

1 adjustment of the regulator 18; the output signal from the sensor 17i is a signal from the manual setting unit of the regulator 18, corresponding to the specified value of the charge level in the tank 3} and the output signal from the regulator 18. According to the information from the specified Sensor 17, the block 20 determining the rate of change of the charge level generates a signal Р „, and Р signal from the sensor. Level 17 at the current jth and previous and first steps to calculate the rate of change of the level; discreteness (step of calculating the rate of change of level, output signal from block 20; According to information from the regulator 18 and blocks 20, 22 and 24 in block 25, the matching of loads between the column and the batteries produces a signal proportional to the given column load 2 + P ,, + p. 25 22 24 th where Pjy is the output signal from block 25 According to information from the monomer concentration sensor 12 / in the charge stream, the regulator 19 generates a regulating signal, for example, according to the P-law of regulator adjustment of the regulator 19; output signal from the sensor 12.; Back signal from the tasks 12 ka 11, the integration time Jg, the output signal from controller 19. According to the information from sensors 10 and It monomer concentration in monomer and return fractions, block 26 generates a signal proportional to the difference between the indicated monomer concentrations P P l 2b where P is the output signals from sensors 10 and 100, Pjjj is the output signal from block 26 .. Block 27 for determining the difference between a given monomer concentration in the charge stream and the monomer concentration in the return flow and generates a signal proportional to the difference in concentration - P. 12 1 o (A where P is the signal corresponding to a given monomer concentration in the flow mixture, is set by the operator i manually in block 27, the output signal from block 27 .. According to information from the controller 19, blocks 25-27 lo 28 determining the setting of the monomer consumption controller 5 generates a signal proportional to the regulating effect on the monomer consumption 28 where P is a signal from the output of block 28. According to information from blocks 25 and 28, the task 29 regulator of the consumption controller 8 of the return fraction forms a sigal proportional to the regulating effect at the expense of the cart the gate fraction P29 P2S - 28 where Pjg is the output signal: block 29, Regulators 5 and 8 according to information from sensors 4 and 7 of the monomer flow rate and the return fraction, will act on the valves 6 and 9, reduce the values of the indicated flow rates to the specified values Ignal values from blocks 28 and 29.

Claims (1)

DEVICE FOR REGULATING MONOMER CONCENTRATION IN A CHARGE CONTAINER, containing a monomer flow sensor connected via an output through a monomer flow regulator to an actuator on the monomer line to an azeotropic drying column, a return fraction flow sensor connected by an output through a flow regulator to a return flow fraction with an actuator on the return fraction line in azeotropic drying column, charge flow sensor for batteries whose outputs are connected to the corresponding inputs of the unit for determining the total load on b tare, serially connected isoprene concentration sensor in the return fraction, a unit for determining the difference in the concentration of isoprene in the monomer and return fraction flow and a task determination unit for the monomer flow controller, the output of which is connected to the second input of the monomer flow controller and to the first input of the task determination unit for the return fraction controller associated with the output of the second input of the flow regulator of the return fraction, the isoprene concentration sensor in the monomer stream, the output of which is connected to the second at the input of the unit for determining the difference in the concentrations of isoprene in the flow of monomer and return fraction, as well as a sensor for the concentration of isoprene in the charge, characterized in that, in order to increase the accuracy of the device, it contains a buffer tank installed after the azeotropic \ drying column, connected in series with the sensor and a regulator of the charge level in the buffer tank, a series-connected unit for determining the load on the azeotropic drying column, a unit for determining the load on the azeotropic column, § tropic drying, unbalance determination unit between the loads on the flask of azeotropic dehydration and the battery, the averaging unit and the load balancing unit between the azeotropic column with dehydration and the batteries, as well as the unit for determining the rate of change of the charge level, the isoprene concentration regulator in the charge, and the unit for determining the difference between the given isoprene concentration in the charge and the concentration of isoprene in the return fraction, the input of which is connected to the output of the sensor for the concentration of isoprene in the return fraction, and the output to the second input of the unit for determining the task to the monomer flow regulator, in One of the unit for determining the rate of change of the charge level is connected with the output of the charge level sensor in the buffer tank, and the output with the second input of the load balancing unit between the azeotropic drying column and the batteries, the third input of which is connected to the output of the charge level controller in the buffer tank, is 1109720 the input is to the output of the unit for determining the total load on the battery and the second input of the unit for determining the imbalance between the loads on the columns of azeotropic dehydration and the battery, and the output is to the third input of the unit for determining the task of the regulator Flow monomer and the second input determination unit job flow controller · ". the return fraction, the inputs of the unit for determining the load on the azeotropic drying column are connected respectively to the outputs of the monomer flow sensor and the flow fraction return sensor, the output of the isoprene concentration sensor in the charge is connected to the input of the isoprene concentration regulator c. charge, connected to the fourth input of the unit for determining the task of the monomer flow regulator.