SU965502A1 - Method of emergency automatic protection of chemical process - Google Patents

Description

The invention relates to the management of chemical processes and relates, in particular, to reactors with agitators used in semi-continuous potentially dangerous chemical-technological processes, and can be used in the chemical, pharmaceutical and pharmaceutical, vitamin and other industries.

A known method of automatic emergency protection of a chemical process by acting on the supply of reagent and coolant, depending on the amount of power consumed by the electric motor of the machine 1.

Closest to the proposed technical essence is a method of automatically protecting a chemical process by affecting the supply of reagent and coolant to the jacket of the reactor, depending on the temperature difference. at the inlet and outlet of the coolant 2.

A disadvantage of the known device is that the signal received at the input and output of the coil almost linearly depends on the flow rate of the heat transfer fluid, which varies widely at the time of the automatic control system, due to

which does not provide reliability, protection.

The purpose of the invention is to increase the reliability of protection. .

The goal is achieved by stabilizing the flow rate of the coolant circulating through the stirring sensor / and measuring the temperature difference between the coolant at the inlet and outlet 10 of the stirring sensor, depending on which effect on the reactant and heat transfer agent.

In chemical-technological processes, driven in reactors with a shank and cooling jacket, the possibility has been revealed by monitoring the presence of stirring in the reactor with the help of a thermal stirring sensor.

In the processes under consideration, the difference in temperature at the inlet and outlet of the thermal mixing sensor characterizes the amount of heat transfer from the reaction mass to the coolant, which, with the known design of the sensor parameters and coolant properties, depends mainly on the heat transfer coefficient of the reaction mass to the sensor and from the sensor to the coolant . When organizing

Claims (2)

30 of the constant temperature and the net speed of the heat transfer medium in the heat mixing sensor, the difference in the input and output of the mixing sensor mainly depends on the velocity of the reaction mass and the change in the heat transfer coefficient of the reaction mass to the sensor. It was established experimentally that when the core mixer stops at the reactor, the temperature difference at the inlet and outlet in the heat mixing sensor changes by a factor of 14, which will make it possible for protection purposes, when the main problem is the operational simplicity and high reliability, to neglect a small dependency ( greater than 5.0 - 10% of the useful signal) temperature difference from other influencing factors (for example, the specific weight of the reaction mass, its coefficient of volume expansion, etc.). Thus, the heat coefficient of reaction of the reaction mass characterizes the speed of movement of the reaction mass and is determined by the temperature difference between the inlet and the outlet of the thermal mixing sensor. The expression for the heat transfer coefficient has the form,. A-tC & otft F (rio {BH-4tc & where At is the temperature difference between the inlet and the output of the mixing sensor; c is the heat capacity of the coolant G is the mass flow rate of the coolant; g / "is the heat transfer coefficient between the sensor wall and F -. average heat exchange area - average temperature difference between the coolant and the reaction mass. In the drawing the scheme for implementing the method is presented.The diagram contains reactor 1 with a stirrer 2, reagent supply valve 3, three-flow valve 4 supplying a regulated heat transfer fluid through pipe 5 or an emergency cooler Through pipe 6 into the jacket 7 of the reactor, the flow regulator and the Mixing sensor 9, the temperature sensors 10 and 11 at the inlet and outlet of the stirring sensor, the secondary device 12, the regulating unit 13 and the protection unit 14. The control of the process is carried out as follows. The control unit 13 from the secondary device 12 receives a signal about the difference in temperature at the inlet and outlet of the mixing sensor 9. When the agitator stops, when the deviation of the temperature difference reaches a predetermined sign of the formation of a warning signal, the protection unit 14 generates a protective effect on the reagent supply ensemble using valve 3 and supplying an emergency cooler to the jacket of the reactor through valve 4. Using this method allows to increase the productivity of the reactor by 12-14%. The economic effect calculated on only one. The production process of Grignard reagent for the production of a vitamin is 100 thousand rubles. The invention method of automatic emergency protection of a chemical process by affecting the supply of reagent and coolant fed to the reactor jacket, is characterized in that, in order to increase the reliability of the protection, the flow rate of the coolant circulating through the stirring sensor is measured and the temperature difference of the coolant is measured at the inlet and outlet of the mixing sensor, depending on which effect on the supply of the reagent and the heat carrier. Sources of information taken into account during the examination 1. USSR author's certificate No. 306868, cl. At 01 J 3/00. 2. USSR author's certificate number 521003, cl. B 01 J 1/00, 1974.