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介绍了加拿大Millar Western浆厂通过采用蒸发器而大幅度减少废水排放的情况。该厂是世界上第一个成功实现废水零排放系统的工厂,其废水回收系统使浆厂用水量比相同规模浆厂少,且不会向当地河流排放污水。该厂通过采用3个降模式蒸汽压缩蒸发器,使热磨机械浆废水的固含量从2%浓缩35%,再由2个靠蒸汽带动的浓缩器进一步将废水固含量浓缩至70%左右。利用该系统6.7m3/min的废水中有6.5m3/min的废水可以回收,并用于制浆过程。固体在锅炉中燃烧,熔融物铸成块状贮存,以便进一步回收。
Describes how the Millar Western pulp mill in Canada can drastically reduce wastewater emissions through the use of evaporators. The plant is the first plant in the world to successfully achieve a zero-emission system for wastewater. Its wastewater recovery system allows the mill to use less water than the same size pulp mill and will not discharge sewage to the local river. By adopting three drop-mode steam compression evaporators, the plant concentrates 35% of the solid content of the hot mill mechanical pulp wastewater from 2%, and further concentrates the solid content of the waste water to about 70% by two condensers driven by steam. With the system 6.7m3 / min of waste water, 6.5m3 / min of wastewater can be recovered and used in the pulping process. The solid is burned in a boiler and the melt is cast in blocks for further recovery.