Ultrafiltration disc filter appts. - in which stationary disc filters are swept by spiral recycling of concentrate to keep filter surfaces clean

摘要

Appts. comprises filter discs mounted coaxially on a common filtrate collection pipe and contained inside a cylindrical housing. An overflow line comprising a pressure regulating valve returns excess liq. back to the supply tank. The filter discs are all stationary and the discharge duct for the concentrate leaves the filter housing near one end in a tangential direction and is connected through a circulating pipe and return line to a feed duct which re-enters the filter housing also tangentially in the same direction of rotation but at its opposite end. The feed line contains a metering pump having a delivery capacity equal to or only slightly larger than the max. filtrate flow from the appts. The use of stationary filter discs simplifies the layout and construction of the plant of revolving discs. The tangential flow in the same direction at inlet and outlet keeps the filter surfaces clean at very little energy expense. The power demand of the metering pump is low.