| 摘要 |
A method for the recovery of sulphur compounds, volatile alcohols such as methanol, as well as by-products such as turpentine and the like, which are formed in connection with pulping, from the blow-expansion condensates from the evaporating series of a digestery, from turpentine mother liquors, or from other liquids in a separate treatment unit. The liquids are treated in a vacuum stripping unit by means of a proportion of secondary steam which is obtained from the last step of a multi-stage evaporating plant. The excess of secondary steam is condensed by means of indirect condensation in a first surface condenser, whose exhaust vapors, together with the vapors leaving the stripping unit and with gases that are to be removed from the evaporating steps, are condensed by means of indirect condensation in a second surface condenser. The condensate from the second surface condenser is used as return flow into the stripping unit, and the gases leaving the condenser are, by means of a vacuum device, passed into the condensate tank of the evaporating plant. The gas fraction obtained from the condensate tank is removed to a separate treatment, as well as the condensate fraction produced therein is either recirculated to the treatment or recovered separately. The purified liquid from the stripping unit is recirculated to the process. |
