Method of recovering paint booth filters

Abstract

A filter frame and media capable of withstanding repeated heating to high temperatures in an oxidizing environment, and a method of cleaning the same for indefinite use in a method of operating industrial paint booths. Progressive density, heat resistant, and preferably metal media paint booth filters are provided for replacement of existing filters in industrial paint booths. The filters are structurally resistant to cyclic heating to high temperature in an oxidizing bake-off oven where the paint residue accumulated on the filters is reduced to ash. After cooling, the ash is removed, and the filters returned to service, and the cycle is repeated. The filter comprises a frame section and a mesh media section which has a plurality of mesh portions. The mesh portions are preferably arranged in a series M.sub.1, M.sub.n-1, M.sub.n, wherein n is a positive integer of 4 or more, that are sized with the free face area A.sub.n of each mesh portion n so that the overall mesh media section has a progressive density characteristic. Thus, an excessive amount of material is not captured at the first mesh portion M.sub.1 so as to avoid 'face blinding' of the filter. In paint booth operation, when the filter has completed its operating cycle, typically as determined by a air flow velocity, dirty filter elements are removed and the filter is heated remove paint residue, and producing ash. After cooling and ash removal, the filter is returned to service.