SU367871A1 - AUTOMATIC REGULATION METHOD - Google Patents

Description

one

There is a known method of automatic regulation of the technological mode of a benzene distillation column with plates of the ferrule type by changing the supply of live steam into the column.

However, B The known method does not ensure the maintenance of a given value of benzene hydrocarbons in a non-benzene absorption oil.

In order to eliminate this drawback in the proposed method, the change in the supply of live steam into the column is carried out with simultaneous correction for the temperature of the incoming oil, the temperature of the iara and the temperature of the surrounding air.

FIG. 1 is a diagram of the automatic regulation of the technological mode of the distillation column; in fig. 2 is a diagram of a computing device.

The automatic regulation of the proposed method is carried out as follows. Sensor signals proportional to the measured parameters of the process — the temperature of the incoming saturated oil (/ k 2), steam consumption (3-4), steam temperature (5-6), ambient air temperature (7-8) - are received as air signals in computing device 9 where the equation of communication is implemented

Y b, + btXi, i

where Y is the content of benzene hydrocarbons in the bleaching oil absorption oil, weight. %; Xi - temperature absorption oil

at the entrance of the column, ° C; X - steam consumption per column, t / h; Az - steam temperature, ° С;

Hz - ambient temperature,

° Сbo is the free term of the equation; bi - coefficient with unknown. The output signal of the computing device 9 is proportional to the content of benzene hydrocarbons: in the gas-free absorption oil. This signal is compared with the reference and the variance is processed to regulate the change in steam supply to the column. In this way, the desired optimum steam consumption per cellar is achieved for specific working conditions.

For COLUMNS with drip-type plates, steam consumption can be increased to certain Limits. At steam consumption above the limit, oil is transferred to the higher plate ("choking") and the column mode is disrupted. As shown

Experimental studies The limiting value of steam consumption is a function of the temperature of the flow of its oil. The pneumatic signal, proportional to the temperature of the incoming oil, is fed to the programming unit 10, the output of which is proportional to the maximum steam consumption. This signal and the signal from the controller 11 are sent to a block that is configured to pass a minimum signal. Thus, the maximum steam consumption per column will not exceed the critical value.

The computing device (Fig. 2) consists of standard elements-pneumatic automation. The pneumatic signals of the sensors / and 8 are fed to the elements of multiplication 12-15 by a constant coefficient. The output signals of these elements are fed to the adders 16-18. The setting units 19-20 serve to input into the device a free, member of the equation. The output signal of the computing device 9 from the adder 21 is fed to the secondary device and through the amplifier 22 to the controller //.

Subject invention

A method for automatically adjusting the process mode of a benzene distillation column with dummy plates by changing the steam supply to the column, characterized in that, in order to maintain a given value of benzene hydrocarbons in the benzene absorption oil, the change of steam to the column is carried out with simultaneous correction on the temperature of the incoming oil, the temperature of the steam and the ambient temperature.