摘要 |
An improved liquid filtration system is provided which comprises, in combination, a tank or other vessel having a central cavity and a liquid inlet tube and liquid outlet tube spaced apart. A porous, rigid, self-supporting removable filter is placed in the tank between the liquid inlet and liquid outlet and forms part of the system. The filter comprises a plurality of modules, each module comprising a self-supporting body of granules cemented together by set organic resin such as epoxy resin and disposed in a frame of, for example, fiberglass-reinforced nylon. Preferably, the modules are steeple shaped, placed in a circle or wheel configuration and removably secured to a cross plate fixed to the walls inside the tank. The upstream portion of the filter body in each module preferably contains a layer of fine aggregate while the downstream portion of the filter body preferably contains a layer of larger aggregate. The filter is relatively small and is positioned above the outlet to define a liquid redistribution space therebetween, which space facilitates improved back washing. The filter can be removed for cleaning and replacement and is light in weight. The filter supports a mass of loose particles of filtering medium disposed in the tank above the rigid filter. The system is light in weight, very efficient, inexpensive and durable. |