Filter system having multiple filter elements and back flushing assemblies

#The present invention relates to filters generally and more particularly to filters which are cleanable by backflushing.

#There are known various types of filters for use in agricultural, domestic and industrial applications. One particularly successful type of filter is the disc filter, which is exemplified in some of the following U.S. patents of the present applicant: U.S. Pat. Nos. 4,005,884; 4,012,176; 4,026,806; 4,042,504; 4,045,345; 4,067,812; 4,077,371; 4,207,181; 4,271,018; 4,295,963; 4,312,374.

#The present invention seeks to provide an improved backflushable multi-stack filter.

#The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which:

#FIGS. 1A and 1B are side sectional illustrations of a multi-stack backflushable filter constructed and operative in accordance with a preferred embodiment of the present invention in respective filtering and backflushing orientations;

#FIG. 2 is a side sectional illustration of a semi-automatic multi-stack backflushable filter constructed and operative in accordance with a preferred embodiment of the present invention in a filtering orientation; and

#Reference is now made to FIGS. 1A and 1B, which illustrate a multi-stack backflushable filter constructed and operative in accordance with a preferred embodiment of the present invention and comprising a housing 10 including a body portion 12, supported on a base 14, a removable top cover 16, and a bottom portion 18. Bottom portion 18 defines a fluid inlet 20 which communicates with a backflush control valve 22, typically manually operated and of conventional construction, which provides selectable communication between either one of an upstream fluid inlet 24 or a backflush drain 26 with the fluid inlet 20, which also serves an a backflush outlet.

#A filter assembly 28, comprising a plurality of cylindrical filters 30, such as disk filter stacks, typically four in number, is disposed within housing 10. The filter assembly defines an upstream surface, here the outer surface of each of the cylindrical filters 30, which communicates with the upstream fluid inlet 24 during filter operation and with the backflush drain 26 during backflush operation.

#The filter assembly also defines a downstream surface, here the inner surface of each of the cylindrical filters 30 which lies adjacent an axial and normally cylindrical volume 32 located within each of the cylindrical filters. The downstream surface communicates via cylindrical volume 32 and a manifold 34 with a downstream fluid outlet 36 via a housing outlet 38.