Filter apparatus

Claim 1

A filtering apparatus of the type including a tank, a carriage movable along a carriage path over the tank, porous means defining a filter bed support having a bed of filter material thereon, a plurality of partitions extending transverse to the carriage path and spaced apart therealong defining a plurality of fluid receiving compartments below the porous means, a plurality of filtrate ports spaced apart along a port locus paralleling said carriage path with each filtrate port communicating with a respective one of the fluid receiving compartments, a water inlet communicating with the tank above the bed of filter material, means for limiting the upper liquid level in the tank to a predetermined upper level below the top of the tank, a filtered fluid launder extending along said port locus and communicating with said filtrate ports, a filtered water outlet communicating with the filtrate launder, means controlling flow to the filtered water outlet for maintaining a minimum liquid level in the launder that is above the top of the bed of filter material and below said predetermined upper level in the tank, backwash means carried by said carriage and including a backwash pump and a backwash head movable along a path paralleling said port locus sequentially into juxtaposition with each of said filtrate ports to supply backwash fluid thereto, a waste water outlet, a waste water trough extending lengthwise of said tank and communicating with the waste water outlet, flow measuring notch type weir means associated with said apparatus for measuring flows at rates corresponding to a desired backwash rate and having an inlet side and a discharge side, a collector hood carried by said carriage for movement therewith along a path adjacent the upper surface of the bed, a waste water pump connected to the collector hood for pumping waste water therefrom, waste water conduit means connected to the waste water pump and having an outlet for delivering the waste water into said waste water trough, backwash conduit means for delivering fluid from the backwash pump to the backwash head, adjustable backwash flow control means in said backwash conduit means for adjusting the rate of flow of fluid therethrough from a backwash pump to the backwash head to the desired backwash rate, means including valve means connected to the backwash conduit means between said backwash flow control means and said backwash head for selectively shutting off flow from the backwash pump to the backwash head and for delivering flow from the backwash pump to the inlet side of the weir means for measurement of the rate of flow from the backwash pump through the backwash flow control means, adjustable waste water flow control means in the waste water conduit means for adjusting the rate of flow of fluid therethrough, and means for selectively shutting off flow of fluid from the waste water conduit means to the waste water outlet and for delivering fluid from the waste water conduit means to the inlet side of the weir means for measurement of the rate of flow of fluid from the waste water pump through the waste water flow control means.