Process for combining seven-effect tube plate with falling-film evaporators

Abstract

The invention relates to a process for combining seven-effect tube plate with falling-film evaporators. The process particularly includes sequentially connecting tube falling-film evaporators with first, second and third effects and plate falling-film evaporators with fourth, fifth, sixth and seventh effects with one another by pipelines. The process has the advantages that the tube falling-film evaporators and the plate falling-film evaporators are effectively combined with one another, the tube falling-film evaporators are used for realizing the high-temperature effects, accordingly, the effective temperature difference can be increased, and the effects of the evaporators and the service lives of the evaporators can be guaranteed; the process can be effectively operated under the condition of low effective temperature difference and is favorable for scar cracking and falling, and accordingly normal operation and the service lives of the evaporators can be guaranteed; secondary condensed water is low in alkali content, the alkali content of the secondary condensed water is generally lower than 10 mg/l, and accordingly the secondary condensed water can be fed to boilers again after being subjected to simple treatment; the superheating temperature of secondary steam can be appropriately lowered, and accordingly excellent evaporation heat exchange procedures can be carried out.

Description

technical field [0001] The invention relates to a technique of a seven-effect tube-sheet combined falling-film evaporator, which belongs to the technical field of alumina production. Background technique [0002] With the large-scale expansion of the domestic aluminum industry, the competition in the aluminum industry is becoming increasingly fierce. In the future, cost advantage will become the first factor for the survival of the fittest. Where is the advantage of cost competition? Is a strong player in the competition. Increasing the number of effects of the evaporator is of course an effective way to reduce energy consumption, but neither the world's most advanced tube-type falling-film evaporator nor plate-type falling-film evaporator can be simply extended to seven effects, otherwise the evaporator group Both investment and production and maintenance costs will rise sharply, which will lead to no competitive advantage in overall cost. In this context, we have actively...

AI Technical Summary

Problems solved by technology

Increasing the number of effects of the evaporator is of course an effective way to reduce energy consumption, but neither the world's most advanced tube-type falling-film evaporator nor plate-type falling-film evaporator can be simply extended to seven effects, otherwise the evaporator group Both investment and production and maintenance cos

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