SU1511256A1 - Method of automatic control of orthoxylene - Google Patents

Abstract

The invention relates to the field of automation of chemical-technological processes, can be used in the chemical industry in the automation of oxidation processes in cone-tube reactors: on a solid catalyst and allows to increase the selectivity of the process. The control circuit contains pipeline (T) 1, evaporator 2, pipeline 3, computing unit 4 for calculating the ratio of the difference between the maximum temperature of the reaction mixture and the temperature of the refrigerant in the annular space to the sum of air flow and ortho-xylene, regulator (P) 5, valve ( K) 6, P7, K8, P9 ratios, T10 reactor 11, T12, pump 13, steam generator 14, T15, P16 level, K17, P18 pressure, K19, P20 temperature, damper 21, sensors (D) 22-25 temperatures, D26 coolant temperature, D27 and 28 air flow and ortho-xylene. 1 il.

Description

steam

W

: d

Water

one

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3151

The invention relates to the automation of chemical and technological processes and can be used in chemical industry during the aztomatization of oxidation processes in solid-shell shell-and-tube reactors.

The purpose of the invention is to increase the selectivity of the process,

The drawing shows a structural diagram of the system for automatically controlling the process of orthoxy oxidation, which implements the proposed method.

The scheme contains pipeline I, an evaporator 2, a pipeline 3, a computing unit 4, a regulator 5 and an ortho-xylene supply valve 6, a regulator 7 and an air supply valve 8, a ratio controller 9, a pipeline 10, a reactor 11, pipelines 12, a pump 13, steam generator 14, pipeline 15, level controller 16, valve 17, controller 18, pressure, valve 19, temperature controller 20, valve 21, reactor temperature sensors 22-25, coolant temperature sensor 26, sensors 27 and 28 air flow and ortho-xylene,

The method is carried out as follows.

Ortho-xylene via line 1 enters the evaporator 2, where it evaporates in the air flow through line 3, the flow rate of orthoxylene is controlled by regulator 5 using valve 6, and air consumption by regulator 7 by valve. 8. The ratio of air flow rates to orthoxylol is maintained by regulator 9, the vapor-gas mixture through conduit 10 enters the reaction zone of shell-and-tube reactor 11, in which the orthoxylene oxidation reaction takes place. The heat generated by the reaction is removed by the refrigerant flowing through conduit 12 through pump 13, part of the refrigerant is transferred to the steam generator 14, the heat in which is removed by the water entering the steam generator 14 through conduit 15c. The water level in the steam generator 14 is controlled by a regulator 16 level by means of valve 17, - Steam pressure in the steam generator is maintained by regulator 18 with valve 19i

The temperature control of the refrigerant in the reactor 11 is made

five

;

0

50

0

5 0 5 about 5

the controller 20 changes the flow rate of the refrigerant supplied to the steam generator using the damper 21, the temperature of the reaction mixture from four sensors 22-25 and the temperature of the refrigerant from sensor 26 enters the computing unit 4 to calculate the difference between the maximum temperature of the reaction mixture and the temperature of the refrigerant in the annular space .

The flow rates of orthoxylene from sensor 27 and air from sensor 28 are transferred to computing unit 4 to calculate the volumetric rate of the reactants in the tubular reactor,

Using the computing unit 4, the ratio of the difference between the maximum temperature of the reaction mixture and the temperature of the refrigerant in the annulus to the sum of the flow rates of air and orthoxylene is calculated.

Stabilization is carried out in any known way by 1 m, for example, according to GO-1D-law of regulation J As a result, the task for the refrigerant is sent from the computing unit to the controller 20.

The proposed method allows to increase the selectivity of the process by 0.5-5.0%,

Claims (1)

Invention Formula: The method of automatic control of the orthoxylene oxidation process, including regulation of the air flow into the reactor is proportional to the orthoxylene consumption in the reactor, regulation of the refrigerant temperature in the annular space of the reactor by affecting the refrigerant consumption in the steam generator, which differs: so that, in order to increase the process selectivity, measure the longitudinal temperature profile of the reaction mixture in the reactor tubes and determine the maximum temperature of the reaction mixture, calculate the ratio of the difference maximum temperature of the reaction mixture and the temperature of the coolant in the annulus to the amount of air flow into the reactor and the orthoxylene and stabilize this calculated attitude change of the coolant temperature in the annulus.