Ultra- or hyperfiltration unit - with membranes on both sides of open=ended porous support tubes and hollow flange for hanging pipes and removing filtrate

摘要

An ultra- or hyperfiltration installation is equipped with filtration membranes applied to both the inner and outer walls of open ended porous support pipes which are mounted in a hollow flange within the pressurised vessel. The hollows in the flange coincide with interruptions in the membrane to allow te weak soln. to flow from within the walls of the tubes into the flange hollow and thence via interconnecting ducts to a discharge connection. The joint between membrane and flange is sealed above and below the flange hollow to prevent communication between the high and low concentration fluids. The bolts holding the clamping assembly for the flanges together are pref. hollow to allow a forced circulation to be maintained through the tubes and from the upper to the lower side of the flanges within the pressure vessel. The seal between flange and membrane is pref. effected by means of elastic 'O' rings compressed by the flange clamping assembly after insertion of the tubes. Since both sides of the support tubes are used for the filtration, the yield for a given size of vessel and number of tubes is effectively double that of the conventional filtration unit.