七效蒸发料浆闪蒸级数的选择研究

Study on the selection of slurry flash stages of seven-effect evaporation

各行各业为实现国家提出的碳排放控制目标都进行了大量卓有成效的工作,氧化铝行业对于母液蒸发这个耗能大户也进行了深入的研究。本文以七效蒸发为例,分别介绍了料浆4级自蒸发和3级自蒸发两种工艺流程,对两种流程进行了对比分析,分别测算了两种流程下蒸水量、进料温度、沸点升和换热面积的分布,循环水需求差异,以及由此导致的热损失差异,并分别给出了两种流程下的综合汽耗,对于确定最佳生产运行模式给出了建议,为氧化铝行业的从业者更好的理解通过蒸发工艺调整助力行业绿色低碳发展提供了借鉴。

A large amount of effective work has been carried out in various industries to achieve the national carbon emission control goals,and the alumina industry has also conducted in-depth research on the energy consumption of spent liquor evaporation.This paper takes seven-effect evaporation as an example to introduce two process flows of 4 stage slurry flash and 3 stage slurry flash,and conducts a comparative analysis of the two processes.The distri-bution of water evaporating amount,feed temperature,boiling point rise and heat exchange area under the two processes are calculated,in addition to the differences in circulating water demand and the resulting heat loss.The comprehensive steam consumption under the two processes is also provided,and suggestions are given to determine the optimal production and operation mode,thus providing some reference for alumina industry counterparts to better understand how to adjust the evaporation process to assist in the green and low-carbon development of the industry.