七效两段法蒸发系统节能优化应用OA

Aiming at the problems of low evaporation efficiency,severe liquid caustic entrainment in steam,high steam consumption and excessive circulating water usage existing in the evaporation unit during the production of alumina by the low-temperature Bayer process,technical transformation was carried out by adopting the full countercurrent seven-effect two-stage evaporation process to replace the original six-effect single-stage evaporation process,equipped with split-type falling film evaporation equipment and cyclone demisters,and a single-tank design was applied for the evaporation condensate tank.After the transformation,evaporation capacity increased from 300 t/h to over 400 t/h.Average total steam consumption decreased by 24 t/h,and the steam-to-water ratio decreased by 0.1 t steam/t water.This achieves daily steam savings of 1,680 t and electricity savings of 64,000 kWh.Based on the enterprise's annual production capacity of 1.5 million tons of alumina,this translates to annual steam savings of approximately 536,400 tons.