GB695605A - Pressure filtering process and apparatus - Google Patents

Abstract

695,605. Press filters. HOFFMANN, J. Aug. 2, 1951 [Aug. 5, 1950], No. 18332/51. Class 46 Liquid is separated from mashes and solid.liquid mixtures of similar consistency such as fats, oils, and juices from vegetable or animal raw materials using press-filter hydraulically actuated pressure filter plates 5, 6, Fig. 1, firstly by a preliminary operation stage without movement of the filter plates 5, 6 and then by subsequent pressurefiltration stage in which the filter plates approach each other there being suction applied to the filter plates in both the stages. The suction is uniformly distributed over the full area of the plates. The solid-liquid mixture may be supplied to the filter chamber 9 under gravity from an elevated chamber 12 or from a compressedair loaded chamber. The pressure feeding the mixture into the chamber is less than the suction. The mixture is fed tangentially into the filter chamber 9. When the solid-liquid mixture is used at a high temperature the vaporized fluid extracted from the filter plates through the conduits 7 by suction created by a pump 15, is liquified in a condenser 16. The filtering medium of the filter plates, e.g. nickel mesh is supported on a ribbed surface forming channels 18, Fig. 2, which are closed at their ends by an annular ring 20 and communicate at one end through slits 21 in the ring 20 with a semi-annular duct 22 in communication with an air intake pipe 8 and similarly on the opposite half of the plate the ducts 18 communicate with a similar semiannular duct and with the suction pipe 7, Fig. 1, so that after each pressing stage, air can be drawn through pipes 8, duct 22, slits 21 into the channels 18 over the back surface of the filter plates for discharge through the pipes 7 carrying therewith any fluid particles adhering to the ribbed supporting surface and filtering medium.