SU1053846A1 - Method of automatic regulation of rectification - Google Patents

Abstract

A method of automatic regulation of the rectification process by regulating the level of liquid refrigerant in a reflux condenser by influencing the refrigerant supply to it of vapor pressure at the outlet of the column and discharging the refrigerant vapor from the reflux condenser, characterized in that, in order to improve the quality of the product, an account accumulated. vapor pressure of the refrigerant in the reflux condenser with a correction on the composition of the product at the outlet of the refrigerant exposure to the refrigerant from the reflux condenser.

Description

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O5 The invention relates to the control of distillation columns of gas separation plants. There is a method for automatically regulating the composition of product vapors after a distillation column reflux condenser by adjusting the refrigerant supply to the reflux condenser according to pressure in the upper part of the distillation column 1. The method for automatically adjusting the rectification process by adjusting the liquid refrigerant level is closest to the proposed technical essence and the achieved result in the reflux condenser by the influence on the refrigerant supply to it, the vapor pressure at the outlet of the column by the influence on the discharge refrigerant vapor from a dephlegmator 2. The disadvantages of the known method of automatically controlling the composition of the vapor after the reflux condenser are the inertia of the system for controlling the supply of refrigerant to the reflux condenser, the inability to ensure the specified quality of the product when the composition of the feed at the entrance to the distillation column changes. The purpose of the invention is to provide the required product quality with varying composition and flow rate of the column due to an increase in the quality of regulation. The goal is achieved by the fact that, according to the method of automatic regulation of the rectification process, the vapor pressure of the refrigerant in the reflux condenser is additionally regulated by adjusting the composition of the product at its exit by affecting the refrigerant vapor withdrawal from the reflux condenser. The drawing shows a diagram of the implementation of the method. The method is carried out as follows. The feed enters the middle part of the distillation column 1 as a liquid to separate it. Enriched with a volatile component, the vapors rise up the column, pass through partial reflux condenser 2, where they partially condense and return to column 1 as reflux. The liquid flows down the plates and enters the column cube 1. Level 3 regulator, acting on the control valve 4, provides the necessary level of liquid B cubed columns. To reduce the losses of the target component, the flow rate control of the coolant is made by the regulator 5 with correction by the content of the target component measured by the gas analyzer 6 in the forehead fluid, acting on the control valve 7. The product pressure at the outlet of the reflux condenser is provided by the pressure regulator 8 acting on the control valve 9 The flow rate of the refrigerant in the reflux condenser 2 is provided by adjusting the level 10 of the liquid refrigerant in the reflux condenser by acting on the control valve 11 on the refrigerant supply line. and in the dephlegmator. The vapor pressure of the refrigerant in the reflux condenser is provided by the pressure regulator 12, to the chamber whose job the signal of the gas analyzer 13 is applied, acting on the control valve 14 on the refrigerant vapor discharge line from the reflux condenser. When the pressure in the reflux condenser changes, the temperature level of the incoming refrigerant changes due to the change in pressure drop across the control valve I. As a result, the amount of reflux varies, which affects the quality of the product. In terms of the content of the target component, the gas analyzer 13 issues a signal to the regulator 12 to change the pressure of the refrigerant vapor in the reflux condenser 2. The degree of condensation of the vapor in the reflux condenser 2 and, accordingly, the internal reflux change both by changing the refrigerant flow rate and by changing the temperature differential. As the feed flow rate of the distillation column 1 increases, the number of vapors rising up the column decreases. The level of the bottom liquid begins to increase, the level regulator 3, acting on the control valve 4, stabilizes the level of the liquid in the bottom of the column 1. The content of the target component in the bottom liquid increases. The gas analyzer 6 corrects the setting of the flow controller 5, acting on the coolant supply valve 7 to the cube of the column 1, in order to increase the coolant flow rate. The number of pagros going up the column increases. However, due to the lack of reflux, the quality of the product obtained is deteriorated. The gas analyzer 13 outputs a signal to the pressure regulator 12 in the direction of decreasing the vapor pressure of the refrigerant in the reflux condenser 2. The pressure drop across the control valve 11 increases and, therefore, the temperature level of the refrigerant entering the reflux condenser 2 decreases. The quality of the product is increased. As the feed flow rate of the distillation column decreases, the number of vapors rising up the column initially increases. The level of the bottom liquid begins to fall, the level 3 regulator, acting on the control valve 4, stabilizes the level of the liquid in the bottom of the column 1. The content of the target component in the bottom liquid decreases. The gas analyzer 6 coordinates the task of the flow controller 5 acting on the coolant supply valve 7 to the cube of the column 1 in order to reduce the flow of the heat carrier.

The number of vapors going up the column is reduced. Due to an excess of reflux, the content of the target component in the resulting product increases. The gas analyzer 13 outputs a signal to the pressure regulator 12 in the direction of increasing the pressure of the refrigerant vapor in the reflux condenser 2. The pressure drop across the control valve 11 decreases and, consequently, the temperature level of the reflux condenser 2 refrigerant of the agent rises. The content of the target component in the resulting product reaches the specified value.

When changing the composition of the feed of distillation column 1, the operation of the circuit is similar.

The expected economic effect is to improve the quality of the product obtained by improving the quality of regulation with varying consumption and composition of the initial feed of the distillation column.

The use of the invention allows to obtain an economic effect in the amount of 30 thousand rubles.

Claims (1)

METHOD FOR AUTOMATIC REGULATION OF THE RECTIFICATION PROCESS by controlling the level of liquid refrigerant in the reflux condenser by influencing the supply of refrigerant to it with vapor pressure at the outlet of the column and the removal of refrigerant vapor from the reflux condenser, characterized in that, in order to improve the quality of the resulting product by improving the quality of regulation, they additionally regulate the pressure refrigerant vapor in the reflux condenser with correction for the composition of the product at the outlet of it by affecting the discharge of refrigerant from the reflux condenser. SU „.1053846 -------: --------------> >