Functional diagram of the automation of rectification of the return solvent from the shop I-5p from toluene

Isopentane-isoprene-toluene fraction with a toluene concentration of 0.5 ¸ 3% wt. from the I-5p workshop enters the parallel operating distillation columns pos. 156 / 1.2, equipped with 51 plates, on one of the plates 24, 26, 42, depending on the composition.

The consumption of isopentane-isoprene-toluene fraction, in agreement with the shop I-5p, is supported by the flow regulator pos. 8023 / 1.2, the valve of which is installed on the pipeline for supplying raw materials to the column.

Heating of the cubic part of the column pos. 156 / 1.2 is produced by secondary steam 0.15 MPa (1.5 kgf / cm2), supplied to the annular space of the heat exchanger pos. 157 / 1.4, and hot water supplied to the annular space of the heat exchanger pos. 157/2.3.

The secondary steam enters the steam collector in the heat exchanger pos. 157/1.4, the secondary steam consumption is recorded by the flow recorder pos. 567. Steam pressure in front of the heat exchanger pos. 157 / 1.4 is measured by the device pos. 605/1.2. Steam pressure in the heat exchanger pos. 157/1.4 is supported by the pressure regulator pos. 8004, the valve of which is installed on the steam pipeline 1.0 MPa (10 kgf / cm2).

The temperature of the cube of the column pos. 156 / 1.2 is maintained no more than 95 ° C, measured by the device pos. 705.

Steam consumption in the heat exchanger pos. 157/1.4 is supported by the flow regulator pos. 879/1, the valve of which is installed on the steam pipeline to the heat exchanger pos. 157/1.4 with level correction in the cube of the column pos. 156/1.2.

Pressure in the cube of the column pos. 156/1.2 should not exceed 0.18 MPa (1.8 kgf/cm2). A blockage is provided, which is triggered when a pressure of 0.18 MPa (1.8 kgf / cm2) is reached in the cube of the column pos. 156 / 1.2, while closing the shut-off - control valve pos. 879/1 on the steam pipeline 0.15 MPa (1.5 kgf/cm2) to the heat exchangers pos. 157/1.4.

Steam condensate after the heat exchanger pos. 157 / 1.4, enters the tank pos. 133/3.4.

Hot water consumption from workshop I-2 to the heat exchanger pos. 157/2.3 is supported by the flow regulator pos. 500, the valve of which is installed on the hot water pipeline to the heat exchanger pos. 157/2.3.

Pairs of isopentane-isoprene fraction from the top of the column pos. 156 / 1.2 enter the annular space of the dephlegmator pos. 158/1.2 cooled with industrial water.

Hydrocarbon condensate from the dephlegmator pos. 158/1.2 flows into the container pos. 159/1, from where the pump pos. 160/1, part of the product is fed into the column in the form of phlegm, and the excess is pumped out to department I-1a of the raw material shop No. 2. The constancy of the phlegm flow into the column pos. 156/1.2 is supported by the regulator pos. 876/1, the valve of which is installed on the reflux pipeline in the column pos. 156/1.2. Reflux number in the column pos. 156 / 1.2 is maintained at least 0.2. Level in the tank pos. 159/1 is supported by the flow regulator pos. 877/1, the valve of which is installed on the pipeline for pumping out the isopentane-isoprene fraction to department I-1a of the raw material shop No. 2.

Uncondensed vapors from the dephlegmator pos. 158/1.2 enter the annular space of the condenser pos. 151/3 cooled by ground water.

Uncondensed in the condenser pos. 151/3, the gases enter the compressor suction in the I-3 workshop, and the condensate flows into the tank pos. 159/1.2.

The pressure of the top of the column pos. 156/1.2 no more than 0.1 MPa (1.0 kgf/cm2) is maintained by the pressure regulator pos. 880 / 1.2, the valve of which is installed on the return industrial water pipeline from the dephlegmator pos. 158/1.2.

Bottom liquid column pos. 156 / 1.2 (isopentane-isoprene-toluene fraction) with a toluene concentration of not more than 40% wt., is pumped out by the pump pos. 161a / 1 to department I-1a of the raw material shop No. 2.

The consumption of isopentane-isoprene-toluene fraction is supported by the flow regulator pos. 878/1, the valve of which is installed on the discharge pipe of the pump pos. 161a/1.

Draining the bottom water from the tank pos. 159/1,2 is provided in the container pos. 851/2.