SU924054A1 - Device for automatically controlling polymerization process - Google Patents

Description

The invention relates to the automation of polymerization processes and can be used in the production of synthetic rubber.

A device for automatic control of the polymerization process, comprising: η sensors and conversion and temperature controllers and non-linear blocks of the type "limit * ^1, the outputs of the nonlinear units of type" restriction "is connected to one ^one of the inputs of all temperature controllers its zone other than the first regularity ^to In the first zone, in the first zone, the inputs of non-linear blocks of the “limitation” type are directly connected

with the output of the conversion controller, and in the remaining zones are connected via an adder with the output of the conversion controller and a conversion sensor at the input. zones (1).

The disadvantages of this device are the low accuracy of the regulation of conversion and temperature, which

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due to the fact that when the output from the conversion controller is beyond acceptable limits, nonlinear blocks of the "restriction" type form signals that are equal in their value to the limits and remain at this level even when the regulating signal from the conversion regulator changes the direction of its movement and approaches the value of the limit. The signal at the output of the “restriction” block will begin to change only after the signal from the conversion regulator returns to the permissible zone, which causes a delay in the correction of the setpoint to the temperature regulator and leads to significant fluctuations in the controlled parameter.

Closest to the proposed

is a device for automatic control of the process of polymerization, containing cost sensors

and charge and catalyst concentrations92405 * "

ra, temperature sensor in the reaction zone, catalyst flow controller,

a catalyst consumption determination unit connected by its inputs to

loaded with sensors [2). five

However, the known device has limited capabilities in terms of the accuracy of temperature control in the reaction zone due to the presence of a relatively large delay 10 in the control channels.

The purpose of the invention is to improve the accuracy of temperature control in the reaction zone.

This object is achieved by the fact that the device 15 for automatic control of the polymerization process, comprising: sensors costs and the concentration of the charge and the catalyst temperature sensor in the reaction zone, the controller distribution stroke _m of the catalyst, the catalyst flow determining unit, coupled to its inputs from said sensors, provided with block method of determining the rate of change of the signal, a nonlinear block of the "limited" type and an adder, and the output of the block for determining the consumption of the catalyst is connected in series through the block of determination signal change rate, and a nonlinear adder block type "restriction ¹¹ to the inlet of the catalyst flow regulator, the output of the nonlinear unit type" restriction "is connected to an input of the adder.

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The drawing shows a block diagram of the proposed device.

The device contains a reactor 1, a charge flow sensor 2, a catalyst flow sensor 3, charge and catalyst concentration sensors 4 and 5, a flow controller 6 and an actuator 7> a temperature sensor 8 in reactor 1, a catalyst flow measurement unit 9, a velocity determination unit 10, adder 11 and non-. Line unit 12.

The polymerization mixture, which is a solution of monomer (isoprene) in a solvent (isopentane), is fed to the reactor 1, where the polymerization process is carried out in the presence of a catalyst. The parameters that indirectly characterize the polymerization process are the reaction temperature, the monomer conversion, the polymer concentration at the outlet from re-, where C actor 1, the power consumed

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45

50

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the motor of the reactor agitator * 1. The accuracy of regulation of these parameters determines the homogeneity of the obtained rubber, as well as the technical and economic performance of the subsequent stages of production. The proposed device can be used to regulate any of the listed parameters.

Device for automatic control of the polymerization process works as follows.

By the signals input from the sensor 2 flow charge sensors 4 and 5 "concentration of the charge and the catalyst, the reaction temperature transducer 8, determination unit 9 generates a signal flow of the catalyst, which is a manipulated variable by the catalyst flow and exclude restrictions on the expression rate of ^T e)] "" ₍ with _and

When ^ ·

Where

'Sh

the specified dosage of the catalyst at the time the device is put into operation (set by the operator),

T is the magnitude of the signal from the sensor 8 reaction temperature; temperature controller settings, constant values; ϊ - current time; given reaction temperature

the magnitude of the signal from the sensor 2 flow charge; the magnitude of the signal from the sensor 4 concentration of the charge;

- the magnitude of the signal from the sensor 5 concentration of the catalyst;

output signal of block 9 · Next, the output signal of block 9 οι is delimited using block 10 of diameter 1 1 and nonlinear block 12. To do this, the specified signal is sent to block 10 for determining the speed of the control action without taking into account restrictions, while the output signal of block 10 is determined by :

block 10 output

determine the speed.

5 924054 6

The signal from the 1O unit (6g _{<£ 3} ·) is fed to the first input of the adder 11, to the second input of which the output signal of the nonlinear block 12 (.6 to the corresponding control action at the previous step.

The adder 11 simmiruet these signals by the expression

, ₀

The output signal of the adder 11 is fed further to the input of the nonlinear block 12 of the "restriction" type, which at its output forms a signal, the value of which depends on the input, 5

signal as follows:

where 0 * · is the output signal from the nonlinear block 12 of the type "limiting",

^ ΚΓπίη '^ Κ τηαΧ ~ the minimum and maximum 25 input signal limit (set by the operator).

Nonlinear block output

12 (5 to wyz -,) is fed to the input of the summer ₃₀ and also to the master input of the catalyst consumption regulator 6. The controller 6 changes by the actuator 7 results in catalyst flow and the controlled variable temperature in the reaction zone ³⁵ to za- given value.

When using the inventive device to control the polymerization process according to another indirect parameter (rather than temperature) Conversion ⁴⁰ For instance measures should the input unit 9 instead of the signal s. sensor 8 temperature signal from the sensor

conversion, enter in block 9 the set value of the conversion and the corresponding values of the tuning parameters to regulate the conversion.

The use of the proposed device allows to improve the accuracy of temperature control.

Claims (1)

Claim A device for automatic control of the polymerization process, containing flow sensors and concentration of the charge and catalyst, a temperature sensor in the reaction zone, a catalyst consumption regulator, a catalyst consumption determining unit connected by its inputs to said sensors, characterized in that accuracy of temperature control in the reaction zone, it is equipped with a block for determining the rate of change of the signal, a nonlinear limiting block and an adder, and the output of the flow rate determination block is recuperators connected in series through the signal determining unit changes the speed, and a nonlinear adder block type "restriction" to the entrance of the catalyst flow regulator, the output of the nonlinear unit type "restriction" is connected to the adder WMOs house.