Automatic control method for pipeline purging in caustic soda production

Abstract

The invention relates to an automatic control method for pipeline purging in caustic soda production. An operation station and a production field control terminal which are electrically connected in abidirectional mode are included. The operation station is provided with a one-key purging start control button; the production field control terminal comprises a rising film concentrator, a U-shapedbent pipe, a final concentrator, a distributor and a caustic soda flake machine which are connected in sequence; a caustic soda flake machine purging control unit is arranged between an outlet of thedistributor and an inlet of the caustic soda flake machine; a final concentration bottom purging and steam seal switch control unit is arranged between an alkali inlet of the final concentrator and abottom outlet of the final concentrator; and a rising film concentrator outlet pipeline purging control unit is arranged at an outlet of the rising film concentrator. According to the automatic control method for pipeline purging in caustic soda production provided by the invention, DCS automatic program control is adopted, so that the steam purging switching sequence is not easy to make mistakes;one-key automatic operation is achieved, so that the operation is carried out easily and conveniently; the manual operation frequency can be reduced, so that the safety coefficient of operators is improved; and the purging process is completed by operation station personnel, and field operation is not needed, so that the labor intensity of front-line personnel is reduced. The method can be widelyapplied to the caustic soda production process.

Description

technical field [0001] The invention relates to the technical field of chemical industry, in particular to an automatic control method for pipeline purge in caustic soda production. Background technique [0002] In caustic soda production, since 98% alkali has a high melting point and is easy to crystallize, steam purging must be performed after the device is shut down to discharge caustic soda, so as to prevent the remaining lye from crystallizing in the pipeline and blocking the pipeline after the temperature of the residual lye drops, causing the pipeline to be blocked when starting up again. And the uninterrupted purging of steam after parking can effectively reduce the adhesion of sulfur-containing substances in the air dust to the caustic soda machine system. [0003] In the prior art, the pipeline purge of the caustic soda plant is manually controlled, which has the following defects: First, the operation process is complicated and the production operation requirement...

AI Technical Summary

Problems solved by technology

[0003] In the prior art, the pipeline purge of the caustic soda plant is manually controlled, which has the following defects: First, the operation process is complicated and the production operation requirements are high. The condensed water should be drained first. When the condensed water is completely drained, the steam can enter the equipment. After turning off the steam when starting up, the drain valve should be opened. Human operation is prone to errors, and the switch sequence may be wrong, which may cause air hammer in the steam pipeline and blockage of the alkali pipeline. , causing parking in severe cases; second, large steam consumption; third, frequent human contact, which increases the human safety factor, and caustic soda steam purge positions are located on the second to fifth floors, and the locations are scattered, and the ambient temperature on site is too high. physical exertion

Images