Abstract: Described, is a membrane and its method of manufacturing which membrane is an electroformed metal foil having areas of high perforation density (higher than 150000/cm.sup.2) and unperforated areas and in particular also unperforated areas having greater thickness than the other areas.The membrane is produced in a process comprising a two step photolithographic procedure in which canals formed in the first photolithographic step are used to ensure good vacuum contact during the second photolitographic step in which the high density pattern is formed in the photolacquer used.The invention also relates to a separation device incorporating one or more membranes according to the invention.

Abstract: The invention relates to a continuously working crystallizer in the shape of an oblong vessel with at its one end a supply and at its other end a discharge for the solution, with a rotatable driven horizontal shaft extending in lengthwise direction of the vessel and provided with discs extending in transverse direction, said discs being provided with a passage opening for the solution, said discs dividing the vessel in a number of sections succeeding in lengthwise direction to each other, each section having one or more cooled wall surfaces and conduits being provided for supplying and discharging a cooling fluid which is flowing along these cooled wall surfaces.

Abstract: An installation for treating materials, comprising a tightly closed zone having a gastight inlet- and outlet, a shaking gutter with perforated bottom plate covered by a flexible plate with apertures, the whole being accommodated in the closed zone. The flexible material is able to move from the bottom plate, so that a fluid can pass from below the bottom through the bottom and the flexible plate. A fluid inlet opens below the bottom.The shaking gutter has a frequency of 200 to 400 vibrations/minute and an amplitude from 10 to 40 mm.

Abstract: An apparatus for pressing liquids from compressible material comprising a feed path leading to a pair of rollers, followed by an expression path bounded by a portion of the periphery of the main roller and a cage spaced from and surrounding said portion, the feed path being constituted by a horizontal shaker gutter with a metering device for controlling the thickness of the layer of material supplied by the gutter, depending upon the power consumption of the rollers.