Method for reducing energy consumption of mother liquor evaporation processes

Abstract

The invention provides a method for reducing energy consumption of mother liquor evaporation processes, which relates to an energy-saving method for mother liquor evaporation processes during alumina production. The method is characterized in that a process comprises the following steps: (1) adjusting the air exhaust quantity of a vacuum pump through a vacuum-pump soft-water booster pump, a soft water valve and a reflux valve so as to improve the vacuum degree of an evaporation system; (2) utilizing secondary steam produced by a condensed-water flash evaporator and a mother-liquor self-evaporator to preheat mother liquor with each effect through an indirect preheater; and (3) allowing condensed water to enter the condensed-water flash evaporator through a steam trap and then enter a backwater tank through an automatic condensed-water monitoring-redirecting device. The method has the advantages of increasing the machine-hour capacity of evaporators by 2 percent, reducing steam consumption by 10 percent and improving backwater rate by 8 percent.

Description

technical field [0001] The invention relates to a method for reducing energy consumption of a mother liquor evaporation process, relating to an energy-saving method used in the mother liquor evaporation process in the alumina production process. Background technique [0002] The energy consumption of the mother liquor evaporation process is an important part of the energy consumption of the alumina production process. The energy consumption of the process includes the consumption of fresh steam, the recovery and utilization of flashing steam, the recovery and utilization of condensed water, the consumption of electricity and the consumption of circulating water. [0003] In the current production process, the energy consumption of the mother liquor evaporation process mainly has the following problems: (1) By controlling the amount of circulating water to adjust the final effect vacuum degree, thereby reducing the final effect boiling point to improve the utilization effect o...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to address the shortcomings of the above-mentioned prior art, and to provide a method that can effectively overcome the waste of steam caused by the low vacuum degree of the mother liquor evaporation system in the alumina production process, the serious steaming of the condensed water, and the direct preheating of the solution. The method of reducing the energy consumption of the mother liquor evaporation process caused by the low water return rate caused by the untimely water change and the pollution of the condensed aqueous solution of various effects