The invention relates to an improvement in nozzles/screen for fluid flow distribution/collection used In fluid flow distribution/collection used In fluid processing units. Improvement in conventions nozzle/screen comprises a flow restricting cylindrical body to have ring washer shape aperture control at inlet/outlet. The improved nozzle/screen comprises outer casing made of stacked flat rings with micro opening between said stacked ring providing uniform throughout its periphery. A central conduit having holes for flow of fluid entering through the said outer casing. The said conduit having means to regulate fluid flow.

The invention relates to an improvement in nozzles/screen for fluid flow distribution/collection used In fluid flow distribution/collection used In fluid processing units. Improvement in conventions nozzle/screen comprises a flow restricting cylindrical body to have ring washer shape aperture control at inlet/outlet. The improved nozzle/screen comprises outer casing made of stacked flat rings with micro opening between said stacked ring providing uniform throughout its periphery. A central conduit having holes for flow of fluid entering through the said outer casing. The said conduit having means to regulate fluid flow.

A modular underdrain system is disclosed. The modular underdrain system may comprise an intermediate modular component having a first peripheral side including a first mating portion and a second peripheral side including a second mating portion. The first peripheral side may comprise at least one transfer orifice. An intermediate plate member is disposed intermediate the first peripheral side and the second peripheral side along a width dimension. The intermediate plate member may comprise a metering pipe opening. A metering pipe may be sized to be positioned within the metering pipe opening.

A modular underdrain system is disclosed. The modular underdrain system may comprise an intermediate modular component having a first peripheral side including a first mating portion and a second peripheral side including a second mating portion. The first peripheral side may comprise at least one transfer orifice. An intermediate plate member is disposed intermediate the first peripheral side and the second peripheral side along a width dimension. The intermediate plate member may comprise a metering pipe opening. A metering pipe may be sized to be positioned within the metering pipe opening.

The present disclosure provides improved methods for conducting a wash cycle in a filtration unit. The methods may be used alone or in combination with one another to achieve the improvements described herein. Filtration units adapted for carrying out the novel methods are also provided. Through the use of the methods and filtration units described, significant economic benefits are obtained without a significant increase in the costs of the filtration unit or in the costs of operation of the filtration unit.

The present disclosure provides improved methods for conducting a wash cycle in a filtration unit. The methods may be used alone or in combination with one another to achieve the improvements described herein. Filtration units adapted for carrying out the novel methods are also provided. Through the use of the methods and filtration units described, significant economic benefits are obtained without a significant increase in the costs of the filtration unit or in the costs of operation of the filtration unit.

A pool filter system includes a filter housing with an open interior. A pleated filter container in the open interior of the filter housing has a pleated filter side wall and divides the interior of the filter housing into an pleated filter compartment and an particulate filter compartment surrounding the pleated filter side wall. The pleated filter side wall has a plurality of pleated filter container openings. A particulate filter medium is within the particulate filter compartment, and a pleated filter is within the open interior of the pleated filter compartment. A water inlet communicates with the particulate filter compartment, and a water outlet communicates with the pleated filter compartment. The pleated filter container openings in the pleated filter container side wall have a dimension that is less than the diameter of the particulate filter medium. A backwash assembly and a method of filtering pool water is also disclosed.

A pool filter system includes a filter housing with an open interior. A pleated filter container in the open interior of the filter housing has a pleated filter side wall and divides the interior of the filter housing into an pleated filter compartment and an particulate filter compartment surrounding the pleated filter side wall. The pleated filter side wall has a plurality of pleated filter container openings. A particulate filter medium is within the particulate filter compartment, and a pleated filter is within the open interior of the pleated filter compartment. A water inlet communicates with the particulate filter compartment, and a water outlet communicates with the pleated filter compartment. The pleated filter container openings in the pleated filter container side wall have a dimension that is less than the diameter of the particulate filter medium. A backwash assembly and a method of filtering pool water is also disclosed.

A filter is provided including a vessel having an input positioned near the top of the vessel for contaminated fluid; the vessel containing media; a drain screen; a propeller rotatable on a drive shaft extending downwardly from the top of the vessel; a deflector plate below the drain screen to impel media outwardly from the center of the vessel; a plurality of baffles positioned on side walls of the vessel; and a drain to remove fluid from the vessel.

A filter is provided including a vessel having an input positioned near the top of the vessel for contaminated fluid; the vessel containing media; a drain screen; a propeller rotatable on a drive shaft extending downwardly from the top of the vessel; a deflector plate below the drain screen to impel media outwardly from the center of the vessel; a plurality of baffles positioned on side walls of the vessel; and a drain to remove fluid from the vessel.