SU587136A1 - Device for automatic control of process of liquid-phase oxidation of cyclohexane in a reactor - Google Patents

Description

The invention relates to devices for the automatic control of a liquid-phase process for the synthesis of cyclohexane in the production of caprolactam and can be used in local control systems in the chemical industry.

A device for automatic control is known, comprising reagent consumption sensors, interdependent computing units, averagers, a summing unit, a division unit, an optimizer, a ratio controller and output concentration til.16

The known device has a limited scope due to the lack of concentration sensors for a number of products, in particular for the products of cyclohexane oxidation.

The closest to the present invention is an automatic control device containing a process model connected through a task correction block with flow controllers 2S doses of main reactants (a comparison unit connected with its inputs to the analyzer of the composition of the reaction gases and the process model, and output - with blo: com correction job 2.30

However, this device does not take into account disturbances associated with the disturbance of heat balance, which reduces the accuracy of its operation.

The purpose of the invention is to improve the accuracy of the device when controlling the process of liquid-phase oxidation of cyclohexane in the reactor.

Claims (2)

The goal is achieved by the fact that the known device for automatic control of the process of liquid-phase oxidation of cyclohexane in the reactor, contains a process model connected through a correction unit to set by the flow regulators of the main reactants, a comparator unit connected to the analyzer of the composition of the reaction gases and a process model, and an output with a task correction unit, further comprises a steam condensate flow meter entering the reactor to remove heat from the reaction zone, an averager and a unit for calculating the thermal effect of the reaction, connected to the output of a steam condensate flow meter, two comparison units connected by one input to the process model j. and with other inputs, with an averager for one comparison unit and a jneHHH calculation unit of the reaction thermal effect for another comparison unit, two squares, one of KOTOF 3X connected to the input of a known comparison unit, the other with the output of the comparison unit connected to the thermal effect calculation unit, The outputs of the quadrants are connected via the additionally entered A integrato1 with the correction block, two adders connected by inputs to the process model and the correction blocks, and the outputs 0l to the regulators of the basic reagents. The drawing shows a diagram of the proposed device. The device consists of a steam condensate flow meter 1, an averager 2 of a block 3 for calculating the thermal effect of blocks 4–6 of a comparison of those associated with morel 7 and an averager 2, block 3 and an analyzer 8 for the composition of the reaction gases. The outputs of the 4-6 comparison blocks are connected to the quad 9, the system 10 stabilization input in the reaction zone, and the quad 11. The device contains a task correction block 12 connected through the integrato 13 14 to the quad dial 9 and 11, totalizer 4 15 16, associated with the regulators 17 and 18 of the flow rates of the main reagents. The device works as follows. Information about how much the oxidation reactor is supplied to model 7. In this case, the values of the average ratio of the gap condensates of the thermal effect of the reaction and the composition of the gas generator are determined; which are compared by comparison blocks with ay & Departure of anachena, determined by an averager and a block. The 3 numerical simulated effect of the signal from the distance & n I of the steam condensate, and the composition of the outgoing gases is determined directly by the analyzer 8. The Scoil cell signal of the comparison block 4 is the setpoint for the stabilization system 10 in which it is stabilized. by extracting the condensate flow rate, which is subsequently fed to the reactor to remove the thermal zone. Mismatch signal: Comparison unit 6 enters through quad 11 and integrator 14 to task correction block 12, controllers 17 and 18. Regulators 17 and 18 change the flow rates of the main reactants of the reactions, determined by the model model 7 and the composition of the reaction gases. The error signal of the thermal effects from the output of the comparison unit 5 through a similar circuit consisting of the quadrant 9 and the integrator 13 is fed to the adjustment of the parameters of the task correction unit 12. In this way, the control actions of the oxidation process are corrected by the mismatch of thermal effects between the signal emitted by model 7 and the signal calculated by unit 3 for steam condensate consumption, process disturbances that disturb the heat balance are taken into account, and the control process accuracy is increased by approximately 15% . Apparatus of the Invention A device for automatic process control of a liquid-phase oxidation of cyclohexane in a reactor, comprising a process model connected via a task correction unit to the main reactant flow controllers, a comparator unit associated with its inputs to the analyzer of the composition of the reaction gases and the process model, and the output from a task correction unit, characterized in that, in order to improve the accuracy of the device, it additionally contains a decoder of steam condensate entering the reactor for removal heat from the reaction zone, averager and a thermal effect calculation unit connected to the output of a steam condensate flow meter, two comparison units connected by one input to the process model, and different inputs from the average for a comparison comparison block and a thermal effect calculation block for another Comp | | e (ME}, two quadrs, one of which is connected to the input of a known comparison unit, the other with the output of this comparison unit connected to the thermal effect calculation unit, with the outputs linked through an additional input from integrators correction unit, two adders are connected to the inputs of the process model and the correction unit, and outputs - to the regulator tori basic reagents costs. Sources of information taken into account in the examination: 1.Certificate of certificate number 254903, cl. Q 05 D 21/00, 1968. 2. Certificate of author No. 17.9518, cl. q 05 P 21/02, 1965;