| 摘要 |
In a process for the straight distillation and/or fractionation of fatty acids which entails a preliminary step, in which the crude fatty acids are de-gassed and the first runnings are removed, furthermore a main step, at the end of which most of the fatty acid vapours are condensed, and finally a final step for removing the pitch, the heat of condensation obtained in the fatty acid condensation is utilised for generating steam in the form of low-pressure ejector steam, which is used directly for operating the steam-jet vacuum plant. Moreover, excess ejector steam can be employed as so-called 'special steam' for lowering the boiling points of the fatty acids to be worked up and for enhancing the degasification process. The relevant plant for the straight distillation and/or fractionation of fatty acids provides, at the end of the main step, a tube-bundle condenser as condensation device, in which condensation of the fatty acid vapours takes place at the external walls of the tubes whose internal walls are wetted with a continuously renewed film of water. The cooling surfaces which face the product can be sprinkled with a cold, if appropriate supercooled, fatty acid film so that the fatty acid vapours are condensed exclusively on a falling film of fatty acid.
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