| 摘要 |
A Method of Recovering Heat as well as Fractions Containing Volatile Alcohols and Sulphur Compounds from Black Liquor in Connection with Pulping A method of recovering heat as well as fractions containing volatile alcohols and sulphur compounds from black liquor obtained from pulping. In a vapour generator, water is, by means of vapour, liberated at a high temperature and under a high pressure from the expansion of black liquor removed from a digester, indirectly vapourized into low-pressure vapour, which is used for vapour treatment of chips before their introduction into the digester. The condensate produced in the vapour generator is, under pressure control, passed into a condenser device, which is operated at a pressure that is lower than the pressure in the black liquor escaping from the digester, preferably at the atmospheric pressure. The condensate fraction formed in the condenser device as well as the uncondensed gas fraction are cooled by means of indirect cooling and the volatile alcohols and sulphur compounds are recovered from these fractions. Waste water, preferably secondary condensate from the evaporation plant, is used as the vapourization liquid in the vapour generator. |
