The Control Method of Yield Estimation in Caustic Soda Automated Production

Abstract

The invention discloses a control method for estimating a yield in automatic caustic soda flake production. The method is characterized in that an industrial control system controls an overall process of inputting, reaction, and discharging of concentrator alkali lye. A heat exchanger and a flowmeter are separately arranged before each of three base concentrators and a re-checking counting photoelectric switch is added during a packaging process; and an alkali lye feeding flow at an alkali lye feeding stage is used as a main regulation parameter and a packaging photoelectric switch value is used as a main parameter. A flow switching procedure, a packaging courting comparison and accumulation procedure, a daily cumulative production and monthly cumulative production calculation procedure and a procedure of reverse setting of an alkali lye entrance flow are added, so that the alkali lye feeding flow and the counting yield can reach ideal controlling standards and thus reaction becomes stable and the product quality can be optimized. Meanwhile, the control method has the following advantages: the operation becomes convenient; the influence on the product quality by any human factor can be eliminated; automatic controlling of the caustic soda flake procedure can be realized; and the process parameter detection precision and control precision can be improved.

Description

technical field [0001] The invention relates to a control method for output estimation in the production of caustic soda in the field of automatic control, in particular to a control method for reverse estimation of the output in the production process of caustic soda. Background technique [0002] At present, the process technology of known membrane method to produce caustic soda is very mature. The main process flow is: the 31-32% raw material lye from the ionic membrane electrolysis process is concentrated from 32% to 61% in the falling film evaporator, and the heating source uses medium-pressure steam and secondary steam and evaporates under vacuum; The 61% lye passes through the falling film concentrator, using molten salt as the heat carrier, and finally condenses it into a molten lye with a concentration of 98-98.5%, which flows to the distributor for vapor-liquid separation, and then is evenly distributed to the immersion tank of the caustic soda machine. After cool...

AI Technical Summary

Problems solved by technology

[0003] 1. The main problem is that the lye flowmeter at the entrance of the 1# pre-concentrator, 2# pre-concentrator and the final concentrator at the original control site is an electromagnetic flowmeter. The maximum temperature of the lye in the final concentrator can reach 460 °C, and the electromagnetic The flowmeter cannot work normally due to the strong corrosive effects of high temperature and lye; there are also ultrasonic flowmeters, but due to the fan and electromagnetic oscillator facilities installed on site, the interference is large during operation, and the ultrasonic flowmeter also cannot work normally.

Serious hidden dangers to normal production

[0004] 2. The total production and packaging output of each day and each shift and the output of each shift need to be determined manually by checking the number of bags, which increases the workload and intensity

[0005] 3. The automatic industrial control system fails to strictly control the relevant process indicators according to the preset control. Because the flow meter is not working properly, the operator mostly judges, operates or estimates the operation of the automatic control valve based on actual operating experience

Not only is it difficult to achieve the ideal production status, but it is also difficult to achieve the expected product control status, which affects product quality

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