Method and device for performing alkali concentration by utilizing synthesis waste heat of hydrogen chloride

Abstract

The invention provides a method and device for performing alkali concentration by utilizing the synthesis waste heat of hydrogen chloride. The method is characterized in that the method comprises the following steps: preheating a first-concentration caustic soda solution in a first preheater, and performing one-effect evaporation and two-effect evaporation to obtain a second-concentration causticsoda solution; and preheating the second-concentration caustic soda solution in a second preheater, and then performing heat exchange with the hydrogen chloride gas synthesized in a combustion reaction to obtain a third-concentration caustic soda solution and low-pressure superheated steam, wherein the heat source of the first preheater is the third-concentration caustic soda solution, the heat source of the second preheater is the hydrogen chloride gas obtained through heat exchange, and the heat sources of the one-effect evaporation and two-effect evaporation are the low-pressure superheated steam. The invention also provides a device for implementing the method. By adopting the method provided by the invention, the synthesis waste heat of hydrogen chloride can be fully complemented andutilized, the equipment number of the device can be greatly reduced and the device has a very simple structure.

Description

technical field [0001] The invention relates to a production method and equipment of chlor-alkali chemical products, in particular to a method and device for alkali concentration by using waste heat from hydrogen chloride synthesis. Background technique [0002] In industrial production, the synthesis of hydrogen chloride is carried out in a synthesis furnace, and its synthesis reaction is an exothermic reaction. Therefore, in the production process of hydrogen chloride, the synthesized hydrogen chloride gas must be cooled. The hydrogen chloride gas cooling medium in the prior art is generally water, and what is produced is low-pressure steam or hot water, and the heat of the low-pressure steam or hot water cannot be fully utilized. At present, technological innovation is often carried out around how to improve the furnace type. The hydrogen chloride synthesis of chlor-alkali production equipment generally uses graphite two-in-one steam (or hot water) synthesis furnace, and...

AI Technical Summary

Problems solved by technology

[0006] The invention solves the technical problems in the prior art that the thermal resources of hydrogen chloride synthesis, alkali concentration and solid alkali production are not fully complementary, the number of single equipment in the production device is large, and the equipment structure is complicated

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