Sequential swinging precoat removal and renewal system, filter so equipped and method

摘要

A precoat renewal system for a filter, such as a disc filter. The renewal system includes a plurality of nozzles coupled to spray piping and valving with each nozzle being positioned for spraying an area of one side of a disc. The nozzles and at least a portion of the spray piping is movable such that the nozzles may be displaced relative to the discs. The nozzles and piping are arranged in groups or zones with each zone covering a specified percentage of the discs in the filter and each zone representing about 40% or less of the surface area of the filter media of the discs in the filter. Each zone is configured such that high pressure fluid may be supplied to that particular zone for removal of a precoat layer on the disc. The system may be configured so that other zones may be concurrently washed with a lower pressure fluid. The zones may be sequentially or otherwise segmentally provided with high pressure fluid until the precoat layers of each respective zone have been removed and renewed. A filter system and a method of treating a precoat layer on a disc-type filter including a plurality of filter discs are also disclosed.