Continuous reverse flow extractor for soluble substances - for use with products which swell or form slurries with the solvent

摘要

To provide the largest possible extraction surface and to provide the correct ratio between particles size and the flow rate of the solvent, the construction provided has a spiral arrangement for transporting the product in the extraction chamber. Pref. two spiral conveyors are provided operating one inside the other. They have opposite threads and are driven by separate motors, so that their relative speeds can be adjusted, and e.g. one can be driven in the flow direction of the solvent and the other in the direction of flow of the product. The arrangement is of partic. use with products which are difficult to extract.