Disc filter

Claim 1

A rotary vacuum disc filter comprising a plurality of filter sectors, wherein each sector is constructed to be assembled with similar sectors to form a generally circular disc, each said sector having a larger dimension in the radial direction than in the axial direction, said sector including a forming member on each side thereof, said forming members being spaced from each other in the axial direction, each said forming member being porous and shaped to form outwardly facing, radially extending ridges and valleys, flexible filter material shaped to be applied to radially outer portions of each side of said sector, on the outside of said forming members, and mounted on said sector, means causing the filter material so mounted to follow the ridges and valleys of the forming member to which it is applied, means including said filter material defining a chamber in said sector for receiving filtrate passing inwardly through said filter material, said sectors being assembled to form a generally circular filter, said circular filter being rotatably mounted to rotate about the axis of the circle of said filter, means for causing said filter to perform its filtering action in sectors which are partially submerged in a mixture of solids and liquids to be filtered, means operative during the partial submersion of each of said sectors to cause a pressure differential across the filter media due to the existence of atmospheric pressure on the outside of said filter media and the provision of subatmospheric pressure on the inside of said filter media, and means operative during a portion of the time when the sector is not partially submerged for directing a short sharp blow of high pressure air outwardly through said filter media for detaching accumulated filter cake from said filter media.