SU994464A1 - Method for automatically controlling batch process of cellulose acetate production - Google Patents

Description

one

This invention relates to automated periodic multistep processes of disastrous processes and may be io-j. used in the production of acetates; lyupozy.

A known method of automatic control of a cellulose acetylation process by a periodic process consists in the stabilization of the temperature of the reaction mixture by a change in the flow rate; xyd1 bn in an adherent torus jacket 11.

The disadvantage of this method is the preserved accuracy of maintaining the quality of the finished product due to the fact that the temperature of the reaction mixture in acetyl-5 torus is not constant at varying input parameters of the product.

The closest to the invention is the method of autosalatic uravl - 20 or a periodic process of producing cellulose acetate, carried out in several successive stages, which occurs in regulating the temperature of the reaction mixture by changing the flow rate of the refrigerant 2.

The disadvantage of this method is the low accuracy of filter maintenance. Capacity and transparency of acetyl and tselgaoloza separate control of temperature regimes in the apparatus of the technological line without taking into account their joint influence on the output indicators of the final product.

The aim of the invention is to improve the accuracy of maintaining the filterability and transparency of cellulose acetate.

This goal is achieved by the fact that according to the method of automatic control of the periodic process of producing cellulose acetate, carried out in several successive stages, which involves controlling the temperature of the reaction mixture by changing the refrigerant flow rate, adjust the temperature of the reaction mixture in acetyl toe according to the temperature of the reaction mixture of the preceding batch of cellulose in the setter .

and the temperature of the reaction mixture in Bfcicu is corrected with a tail in time by one stage of adatilation of the temperature of the reaction mixture in the acetyl torus.

The drawing shows a control circuit CHC-1 W implementing the proposed method.

Acetyl torus 1 and viewer 2 have shirts 3 and 4, respectively, in which refrigerant is supplied via pipelines 5 and. 6

The temperature control system of the adherent torus includes a temperature sensor 7, a controller, 8,

software device 9 and the regulating, 1 "spike 10. Of the similar elements

Tov 11-14 consists of a system for regulating the temperature mode of the view.

The temperature mode of the acetyl torus is corrected by correction unit 15 depending on the temperature of the reaction mixture in the precipitator when processing the next party of the reaction mixture recorded by the election device 16 according to the signal from the program device 13, the temperature of the detector is also corrected by the correction unit 15 depending on the dependency. . on the temperature of the other batch of the reaction mixture in the acetyl torus, the temperature being recorded by a selective device 17

.a signal from the software device 9, which is delayed in time to

. one stage of cross-linking.

The automatic control method is carried out as follows.

Cellulose is loaded into adyleter 1, the temperature of the reaction mixture in it is maintained by the controllers 8 in accordance with the task from the software device 9.

The quality of the i / output product (transparency and transparency) depends on the temperature of the reactive mixture in the acetyl torus and the precipitator: this dependence is obtained statistically and has the following form:

, 5 -ДДТа, „a, .Т1Ь ,,, 1:31,

where Ta yyiax.Cj3- is the maximal one (temperature of the j-th batch of the reaction mixture in the acetyl torus when treated with the second acetyl mixture; Ta Сjj- temperature, j} -th batch of the reaction mixture in the Viewer at the end of the methylene chloride distillation.

Indicator Y according to GOST for finished products should be within.

According to the well-known T MnepaTypeTB Q j-i} supplied by the electoral device 16 to the block 15, block 15 pfic- reads the value of n &} l} 3 °° P - - - b chGGD-L

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3.4

 "

2

After the end of the processes in acetator 1, the reaction mixture is squeezed into the expander 2. The actual value of the temperature Ta tj 3 due to a change in the temperature of the refrigerant and the acetylating mixtures drops from the calculated Ta .j 3 Value, from "C) through the selective device 17 with a delay of one stage enters the correction block that calculates

T byuvt / Ci TO

"VKi-JJ 4.5- 6DTaw oyOZ

: 4MxUi-.

The value of TByyj C l is entered into the software device 13 and implemented by the controller 12 ..

The use of the invention improves the accuracy of the quality of the finished product due to the implementation of optimal control of temperature conditions in the acetyl torus in the expander.

Claims (2)

1. Authors sdtsdedelstvo USSR № 617453, cl. From 08 To 3/06, 1976. 2. USSR Author's Certificate MO 694515 BJuC O8 B 3 / O6, 1978 (prototype).