SU1005804A1 - Method of carrying out rectification process in cyclic mode - Google Patents

Abstract

A METHOD FOR CARRYING OUT THE RECTIFICATION PROCESS IN THE CYCLIC REGIME in a multi-stage column, which consists in alternating steam and liquid supply to the column, characterized in that, in order to increase the capacity and stability of the column operation, during the period of liquid supply, the CC steam flow to the condenser is cut off.

Description

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C71

00 1 The invention relates to the field of processes and apparatus and can be used in various sectors of the industry for carrying out the process of rectification. There is a known method of rectifying in a cyclic mode, which consists in alternating steam and liquid supply to the Cl column. The disadvantages of this method are low productivity of the rectification column due to sharp pressure fluctuations in the cube at the moments of transition from one cycle period to another, as well as instability of operation of the column with a large number of contact stages (more than 10-12) due to the formation of pressure difference in the period of the fluid supply. The known method consists in alternately supplying the main column of steam and liquid with discharging the vapor phase from the bottom and feeding it into the additional column during supplying the liquid phase to the main column 2j. The disadvantage of this method is that when steam is not supplied to the column, a ground pressure vacuum is created in the condenser due to condensation of the remaining vapor in the column. Under the action of this vacuum, a stream of vapor from the column into the condenser prevents the liquid from flowing from the plates (nozzle) by itself, increasing the duration of the time for which the liquid flows. In columns with the number of plates exceeding 10-12, this phenomenon leads to unstable operation of the apparatus, up to their choking. In addition, the alternate operation of the main and additional columns makes it almost impossible to select the optimal cycle times for each column, since changing the cycle times of a single column entails automatic change. The same parameters of the additional column. The aim of the invention is to increase the capacity of the stability of the operation of the column. This goal is achieved by the fact that according to the method of carrying out the process in a cyclic mode, consisting in alternating supply of steam and liquid to the column, during the period of liquid 2 bones cut off the flow of steam from the column to the condenser. For this, a shut-off valve is installed on the steam line connecting the top of the column to the condenser, the operation of which is synchronized with the operation of the shut-off valve installed on the steam line from the cube to the column. In order to prevent the pressure in the cube from increasing during liquid periods, the supply of heating steam to the cube boiler is cut off. The drawing shows the scheme of the proposed method. The scheme includes distillation column 1, condenser 2, 3 with boiler 4, intermediate tank 5, shut-off valves OK-1, OK-2, OK-3, installed on the heating steam lines, working steam from one cube to the column and the steam line, connecting column with condenser, respectively. All shut-off valves are normally open or normally closed. The method is carried out as follows. During steam periods, the shut-off valves OK-1, OK-2 and OK-3 are open. In this case, the heating steam enters the boiler C and causes the mixture to evaporate in the cube 3 Couples of the mixture, entering the column 1, come in contact with the liquid in the column and enter the condenser 2. Condensate flows by gravity into intermediate tank 5, from where a part of it the reflux is fed to the upper plate and accumulates on it during the whole steam period, the other part is taken as distillate. During this period, there is no liquid flow through the column. At the end of the steam period, the OK-1, OK-2 and OK-3 valves are closed and the heating steam into the boiler, the steam mixture from the bottom into the column 1, and the steam from column 1 into the condenser 2 are cut off. and the period of draining of the liquid from the plates (nozzle) begins. A part of the flowing liquid in the right quantity is discharged in the form of the finished product, the rest part goes to the cube 3 for circulation. At the end of the period of draining, the valves OK-1, OK-2 and OK-3 open

and the steam flow period begins. Further cycles are repeated.

The power supply of the column can be carried out both continuously and cyclically. In the latter case, the line of the feed mixture must be installed

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Nutrition

shut-off valve and its work to synchronize with the operation of the valve OK-2.

The proposed method, in comparison with the known method, allows to increase the throughput of the plate-type sanding columns by 1.5 times, and the packed ones - by 1.1 times.

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Claims (1)

(5 * 0 METHOD OF RECTIFICATION PROCESS IN CYCLE MODE in a multi-stage column, which consists in alternately supplying steam and liquid to the column, characterized in that, in order to increase the throughput and stability of the column, during the period of liquid supply, the vapor stream is cut off from the column into capacitor.