Removing volatile impurities from granules by distillation sweating

The physicochemical foundations of distillation sweating and the kinetics o f the removal or volatile impurities from granules are considered. Expressi ons are suggested for estimating the separation efficiency in this combined process. Diphenyl, naphthalene and caprolactam granules have been purified . The influence of the nature of the separated components, the process cond itions, and scale factors on the rate and efficiency are examined. The adva ntages of distillation sweating over ordinary distillation, sublimation, an d fractional melting are demonstrated.