SU770509A1 - Method of automatic regulation of evoporation process - Google Patents

Description

The invention relates to the field of automation of technological processes and can be used in power engineering, food, chemical, petroleum and other industries.

There is a method of automatic control of the evaporation process by changing the supply of the initial solution depending on the level of the solution in the apparatus with a correction for the flow of Phlegm [].

The closest in technical essence to the invention is a method of automatic control 15 of the evaporation process by changing the flow rate of the source medium depending ^{on 4} on the level and position of the valve on the supply line of the source medium [2].

The known method with respect to the '20 evaporator has the disadvantage that the method does not provide the required accuracy of support

concentration levels at variable loads, when there are perturbations on the side of heating steam or on the side of the consumer of secondary steam. The regulator in these cases responds in the right direction with a large delay, which significantly reduces the _# 30

the quality of maintenance of the regulated parameter and does not exclude the injection of concentrate into the secondary steam pipeline, causing a sharp deterioration in its quality.

The aim of the invention is to improve the accuracy of maintaining the level of concentrate (reducing dynamic deviations) and improving the quality of transients.

This goal is achieved by the fact that the flow rate of the source medium additionally change depending on the differentiated sum of the signals of the heating steam pressure at the inlet to the evaporator and the pressure of the secondary steam at the evaporator outlet ^

The drawing shows a diagram of the automatic control of the evaporation process.

The automatic control scheme consists of a pipeline for supplying evaporated medium with valve 1, heating section 2, pipeline for supplying heating steam with valve 3, regulating unit 4, level sensor 5 changing the level of evaporated medium, sensor 6 according to the position of valve 1, pressure gauge 7 vaporizer vapor pressure gauge

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8, measuring the pressure of the secondary steam at the outlet of the evaporator, differentiator 9.

The method of automatic control of the level of the concentrate is as follows.

The evaporated medium (water) enters the evaporator through a pipeline through a control valve 1, with which it maintains the level of the evaporated medium (concentrate). The medium is heated to boiling and evaporates using the heat given off by the heating steam supplied to the heating section 2 through the valve 3. The valve 1 is controlled by the regulating unit 4, which receives signals from the sensors

5 on the level of concentrate from the sensor

6 according to the position of the valve 1 and the sum of the signals from the pressure gauges 7 and 8, previously passed through the differentiator.

Using the proposed method allows to increase the accuracy of concentrate level control by 1.5 times and reduce the overrun of the control valve in transient conditions by 2 times.

Claims (1)

Claim 5 A method of automatic control of the evaporation process by changing the flow rate of the original sredts depending on the level of the evaporated medium in . the evaporator and the valve position on the source medium supply line and heating steam supply ·, characterized in that, in order to improve the accuracy of maintaining the solution level, the source medium flow rate is additionally changed 15 depending on the differentiated sum of the heating vapor pressure signals at the inlet to the evaporator and the pressure of the secondary vapor at the evaporator outlet.