Abstract: An apparatus for treating material with liquid has defined therein a cylindrical chamber, suspended above the bottom of which is a receptacle for holding the material to be tested, the bottom of which receptacle is permeable to the treatment liquid. Above the receptacle there is arranged a duct with inlets at its end and outlets disposed above the receptacle. In use, a magnetic stirrer drives a vortex of liquid up the side wall of the chamber and liquid from the vortex enters the duct from which liquid pours down onto the material to be treated in the receptacle and is then recycled. The apparatus includes one or more of the improvements that suspension of the receptacle and duct is by means which does not interfere with the vortex, that the area of the inlets is maximized by forming them with an arcuate profile, and that the bore in the duct is formed such that the wall above the bore is relatively thick and a suspending rod can be screwed thereinto.

Abstract: An apparatus for treating solids with a liquid at elevated or ambient temperatures comprises an assembly of vertical Pot (1) sealed by Lid (3) in which Pot (1) contains the liquid and horizontal low level stirring means (6) inducing a liquid vortex and contains disposed above stirring means (6) horizontal spokes (9) offering minimum interference with the vortex and contains vertical open cylinder (11) bottomed by central apertured layer (10), being liquid permeable but supporting solids impermeably. The vortex rises through spokes (9) up internal vertical wall of Pot (1) and into diagonally opposite inlets (18) of horizontal tube (16) suspended internally from lid (3) above cylinder (11). Liquid downpours through exit (19) of tube (16) through solids in cylinder (11) and through layer (10) to re-enter the vortex.