SU472944A1 - Method for automatic control of ethylene polymerization or copolymerization process - Google Patents

Description

and having a period of said pressure fluctuations reduces the values of all temperatures to the length of the reactor.

(A) adjusting the position of the maximum temperature point in the middle of the reactor, which determines the position of the reaction core, without changing the overall temperature level in the reactor, suggests simultaneously changing the short-term decrease in pressure in the reactor and the period of the indicated pressure fluctuations.

When shifting, the maximum temperature points in the middle of the reactor to the beginning of the reactor do not automatically increase the short-term decrease in pressure in the reactor, which contributes to moving the maximum temperature to the end of the reactor and increasing the corresponding period of pressure fluctuations, experimentally found for this reactor, to maintain the level. Mnuretur in the reactor.

The proposed method of automatic re-elimination of the polymerization process, for example, ethylene can be carried out in the system of automatic control of the polymerization process of ethylene, a block-film of one of the variants of which is shown in the drawing.

The system for automatically controlling the polymerization of ethylene in a tubular reactor 1 consists of a pressure sensor .2, sensors 3, 4, 5, 6, temperature, their number is determined by specific technological features of the process but the length of the reactor, unit 8, the maximum temperature in the middle of the reactor, unit 9 of finding the position of the maximum temperature along the length of the reactor, the adder 10, the regulator 11 of the position of the maximum temperature point along the length of the reactor, the generator 12 of periodic pressure drops in the reactor, A torus 13 of pressure in the reactor, a regulator 14 of the maximum temperature in the middle of the reactor, a valve 15 on the line of initiator supply to the reactor, a valve 16 at the outlet of the reactor.

The automatic control system works as follows.

The pressure in the reactor measured with YuMOP1YO sensor 2 dai.leni. regulate through the adder 0 and the valve iC ia vygpds p :; reactor 1 with. pp. regulator GL .laujicip Fi reactor.

The maximum temperature in the middle of the reactor is determined with the help of t, 3, 4, 5, G, 7 temperatures but the length of the RS; -: torus and block 8, the maximum

temperatures in the middle of the reactor are regulated by a valve 15 pa lnn nodachi and a desiccator into the reactor with a 1H1 regulator 14 of the maximum temperature in the middle of the reactor.

By means of the generator 12, periodic pressure drops in the reactor through the adder 10 and the valve 16 at the outlet of the reactor periodically reduce the pressure in the reactor), but the magnitude of the pressure decrease in the period

pressure fluctuations are set by regulator 11, depending on the magnitude of the deviation of the maximum point of the thermal axis to the middle of the reactor, determined by the glint 9 of finding the position

temperature along the length of the reactor, from opg 1 to the small o-value determined previously according to the task of the average molecular weight of the polymer.

Subject invention

A method for automatic polymerization of polymerization of ethylene by the method of high pressure in tubular reactors by short-term periodic pressure reductions in the reactor by 5-25% of the nominal value, as well as by stabilizing the pressure in the reactor and stabilizing the maximum temperature in the middle of the reactor by affecting the flow rate the initiator to the reactor, so that, with the aim of introducing accuracy in regulating the temperature regime in the reactor, adjust the position of the max. The same temperature along the reactor length by simultaneously changing the period of pressure reduction in the reactor and the magnitude of the pressure decrease.