Abstract: A supersaturated solution of ground bauxite and caustic soda is fed to a plurality of stirrer tanks in a product cascade. Each of these stirrer tanks of the product cascade has three vertically spaced zones with differing solid contents, a central vertical shaft and at least three vertically spaced paddles carried on the shaft and each extending into a respective one of the zones. The paddles are so constructed as to differently act on the solid in dependence upon the solid contents in each zone.

Abstract: An apparatus and method for the continuous thermal sterilization of packings on rotating or reciprocating shafts to prevent the entry or exit of microorganisms, wherein the thermal sterilization of the packings results from a flow of steam condensate about the packings, characterized in that at least one part of the steam condensate is circulated in a closed cycle. As a result of circulating in a closed cycle, the required quantity of steam is reduced and energy losses are decreased. The apparatus and method are particularly useful for installations carrying out biological processes.

Abstract: The present invention is directed to an agitator for dispersing media in liquids within a vessel through the formation of interfering currents within the liquid. The interfering flow pattern agitator includes a shaft turnably mounted within the vessel, at least one stirring arm with two ends, one of which is fixed to the shaft, and mounted at the other end of each stirring arm, a plurality of component blades.