Abstract: A piston pump installation, and method of operation the same, for conveying sludge-type materials and granulated and solid materials with added fluid, comprising one or more, preferably two, cylinders arranged adjacent and parallel to one another with axially reciprocating pistons therein. Each cylinder having a valve provided at its front end, and a drive and control device located at the rear, opposite end. The valve located at the front of each cylinder is structured as a slide valve or so that it can turn and is connected to a suction main on one side and to a delivery pipe on the other side, the suction main and the delivery pipe preferably being perpendicular to the longitudinal axis of the cylinder. Each valve having a valve body with an inlet orifice and a cutting edge as well as an overlapping surface. The inlet orifice in the valve body being designed as a flow connection between the suction main and the cylinder as well as between the cylinder and the delivery pipe.

Abstract: Radioactive particles are removed from waste or process water and encapsulated by a filtration process wherein the water is filtered through a filter medium composed of a thermoplastic organic polymer. The filter cake so obtained is dried and converted to a solid encapsulating medium by the application of heat and/or pressure. The filter medium comprises, at least partially, a thermoplastic polymer which is wettable by water but non-swelling in water and has a melting point of 100.degree. to 300.degree. C.

Abstract: In a filtration process for filtering or clarifying aqueous suspensions of finely divided solid materials, a filter aid comprising polyolefin fibrids, e.g., polyethylene or polypropylene fibrids, is added to the suspension to be filtered. The filter aid comprising polyolefin fibrids which have been rendered hydrophilic may also be used to precoat a filter medium.