化机浆黑液蒸发浓缩工艺及装置的设计与应用

Design and Application of Evaporation and Concentration Process and Equipment for Black Liquor in Chemimechanical Pulp

关键词:  化机浆  黑液  两段蒸发  MVR蒸发  强制循环蒸发

Key Words:chemimechanical pulp  black liquor  two-stage evaporation  MVR evaporation  forced circulation evaporation

摘要:本文介绍了蒸汽机械再压缩（MVR）+强制循环蒸发工艺及装置的技术方案，重点分析了MVR蒸发器的设计要点，并分别对一、二段蒸发系统中的设备选型、排布形式、参数指标，以及蒸发冷凝水的分级排放措施进行了阐述，综合讨论了MVR+强制循环蒸发工艺在化机浆黑液蒸发浓缩及碱回收处理中的应用实践。该技术方案较好地解决了化机浆黑液蒸发浓缩中存在的蒸发水量大、结垢现象严重、设备清洗频繁等技术问题。经过MVR+强制循环两段蒸发浓缩后，化机浆黑液中的固形物含量>65%，与传统多效蒸发相比，综合节能>60%。

Abstract:This study introduced the technical scheme of mechanical vapor recompression (MVR)+Forced circulation evaporation process and device, focused on analyzing the design points of MVR evaporator, and elaborated on the equipment selection, layout and format, parameter indicators, and graded discharge measures of evaporation condensate in the first and second stage evaporation systems. It comprehensively discussed the application practice of MVR+Forced circulation evaporation process in the evaporation and concentration of chemical slurry black liquor and alkali recovery treatment. This technical solution effectively solved the technical problems of large evaporation water volume, severe scaling phenomenon, and frequent equipment cleaning in the concentration and evaporation of chemical pulp black liquor. After MVR+Forced circulation two-stage evaporation concentration， the solid content in the chemical slurry black liquor was greater than 65%， which was more energy-efficient than 60% compared to traditional multi effect evaporation.