Continuous solvent extraction and filtration - in revolving inclined drum pref with contraflow

摘要

In a method of continuously extracting and filtering solid and opt. liquid constituents from a mixture such as a slurry or mash, the mixture is introduced to the higher end of a revolving, pref. generally cylindrical drum with an inclined axis and, progressing down the drum, passes through alternating filtering and solvent-receiving zones; a selective solvent which extracts certain of the constituents of the mixture is fed into the solvent-receiving zones and the liquid contg. the dissolved constituents is drained from the drum, the remaining material from which these constituents have been extracted leaving at the lower end of the drum. The prefd. appts. comprises a drum with solvent-receiving zones of relatively large diameter, alternating with filtering zones of smaller diameter having a perforated drum wall. Soln. from the sump at each stage is fed as solvent to the next stage higher up the drum.