Filter system

Claim 1

A precoat filter system comprising a tank having a bottom wall and upwardly spaced and opposed side and end walls respectively, for use when filtering fluid having therein fine and relatively coarse particles; a. an elongated recirculation header in said tank located adjacent the intersection of one of said side walls and said bottom wall and extending along the length of said one side wall, said recirculation header having a plurality of orifices along the length thereof directed to discharge fluid through said orifices, along said bottom wall toward and upwardly along said other side wall and through the body of fluid within the upper portion of said tank and then downwardly along said one side wall in a continuous circular path throughout said tank to thus create a high velocity fluid vortex in said tank having an axis generally parallel to said recirculation header; b. a plurality of horizontally spaced filter elements provided within said tank and each having filter surfaces vertically disposed thereon with each filter surface subjected to the action of said high velocity fluid vortex, said fluid vortex serving to remove from said filter surfaces the heavier impurities and some of the relatively coarse particles accumulated thereon without removing all of said relatively fine particles from said filter surfaces, whereby said relatively fine particles can be use repeatedly to accomplish efficient filtering; c. a suction pipe connected to each of said filter elements for drawing the filtered fluid therefrom; d. pump means connected to said tank, to said recirculation header, and to said suction pipe and provided with valve means for selectively controlling recirculation within said tank of the filtered fluid drawn therefrom by said pump from said tank, or to discharge the filtered fluid drawn from said suction pipe, or to recirculate the filtered fluid drawn from said suction pipe and to force the same through the recirculation header for further filtering.