RU1797939C - Method of regulating temperature in the reaction vessel - Google Patents

Abstract

Usage: in the chemical industry for process control. SUMMARY OF THE INVENTION: a method for controlling the temperature in a reactor consists in taking a series of temperature measurements at a given point in the reactor, determining its arithmetic mean value and changing the speed of the mixer depending on the largest modulus of temperature deviation; ratios from the indicated arithmetic mean value thereof. 1 ill.

Description

The invention relates to process control and can be used in chemical production to control processes in reactors.

An object of the invention is to improve product quality by maintaining a predetermined temperature throughout the reactor volume.

The drawing shows a block diagram of a device for implementing the method.

In the reactor 1 with a cooling system 2 and a stirrer 3, driven by an electric motor 4 in this way, the reactants are mixed. The temperature is measured using a sensor 5 and the measurement result is entered into a microprocessor device 6, which controls the speed of the electric motor 4 and the on / off of the metering pump 7 on: line for supplying reagent N 2 to the reactor 1.

An example implementation of the method is in a reactor for fractionating blood plasma.

The reagent No. 1 is blood plasma with an initial temperature of + 6 ° С, of a reagent (Sfe 2 is a solution of ethyl alcohol at minus 18 ° С, of a refrigerant is a brine at minus 20 ° С. The process of mixing the reagents is accompanied by heat generation. A cornea is used. a mixer, a temperature sensor with an inertia of 0.5 s. A microprocessor device is used that can read an analog signal, operate according to an algorithm, output a discrete output signal, and also perform stepwise (discrete) control of the asynchronous three-phase rotational speed In the course of the reaction, the temperature of the medium decreases from plus 6 to minus 5 ° C, and the amount of supplied reagent N 2 increases linearly with decreasing temperature of the medium.

4 CE

ABOUT

CA) O

Application of the method allows to realize the required linear dependence, providing the required accuracy of temperature control in the entire reactor volume - 0.5 ° C. :

A series of 20 measurements are taken, the intervals between which are 0.5 s. The next series of measurements begins after 10 s. After the previous series is finished, After the end of the next series of measurements, the microprocessor device 6 calculates the arithmetic mean value and the largest absolute deviation from the average in the series. If the arithmetic mean is lower than the required temperature (calculated according to the amount of reagent No. 2 currently supplied, by more than 0.25 ° C, device 6 gives a signal to turn on the metering pump 7 on the supply line of reagent No. 2, and the flow of the latter begins. If the average exceeds the required temperature by 0.25 ° C, the flow of reagent No. 2 is stopped (the amount of supplied reagent No. 2 is calculated by the device in proportion to the operating time of the metering pump controlled by it). nenie from the average is greater than 0,25 ° C; unit makes a transition to step motor 4 with higher cha0

5

0

5

0

rotation rate; if the deviation is less than 0.20 ° C - a step with a lower frequency.

Claims (1)

Thus, the deviation of the average temperature in the reactor from the required value of ± 0.25 ° C and the deviation of local temperatures from the average value of ± 0.25 ° C, i.e. the required control accuracy is provided. SUMMARY OF THE INVENTION A method for controlling the temperature in a stirred reactor, which consists in measuring the temperature at a selected point in the reactor, comparing its value with a predetermined one and changing the flow rate of the supplied reagent, which consists in that, in order to improve the quality of the product by maintaining the set temperature in the whole volume of the reactor, the temperature at a selected point of the reactor is determined by a series of its measurements over a given time interval, and the arithmetic mean value of the temperature in of this series of measurements and change the frequency of rotation of the mixer depending on the largest modulus of the temperature deviation from the indicated arithmetic mean value in the specified series of measurements.