混合油负压蒸发改造实践

Modification of Miscella Vacuum Evaporation

应用混合油负压蒸发 ,存在DTDC因不同含溶量的脱脂豆粕脱溶、DTDC内部出现压力波动导致蒸发系统负压下降、循环冷却水温度高的现象。设计新建厂时可以应用先进的混合油负压蒸发技术 ;在对已有 10 0 0t/d的正压蒸发系统改造负压蒸发系统中 ,增加第一蒸发器 (升膜式 )换热面积 ,由 0 3m2 /t料增加为 0 5 5m2 /t料 ,第一蒸蒸汽入口改为 2个 ,接口改变径型 ,内部列管由Φ19改为Φ2 5 ,管间距由 4 0mm改为 5 0mm以减少汽阻 ,调整原冷凝器配置面积 ,将一台冷凝器改为 2台并联 ,同样增加管径和管间距。整个系统增加 2台蒸汽喷射泵 ,蒸汽用量由原 380～ 4 0 0kg/t降为 2 90kg/t ,同时减少补充冷却水量 2 5 %。

In the process of the miscella vacuum evaporation,different content of moist defatted soy meal and fluctuation of pressure can result in low vacuum and high temperature in cooling water circulation system. For new project, the designer can apply the advanced vacuum evaporation system.We modified the 1 000 t/d evaporation system from normal pressure to vacuum,improved the ratio of the heat exchange area of the 1 # evaporator from 1∶0 3 to 1∶0 55( m 2 /t soybean), another inlet for the vapor was added ,type of joint's diameter was changed, the pipe diameter inside was increased from DN19 to DN25,and the distance between the pipes increase to 50 mm from 40 mm for reducing resistance inlet of vapor, the cooling water inlet for condensers have been arranged in parallel connection, the pipe diameter and the distance between pipes inside condensers have been increased, 2 steam jets used for the system, the result of the improvement show us that steam consume from 380～400 kg/t to 290 kg/t and 25% of cooling water have been saved.