Method for retrofitting a false bottom underdrain filter system
AssigneeTetra Process Technologies div of Capital Controls, A Severn Trent Services Co
InventorGary Hunkele
Life of this patent
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Abstract
A method for retrofitting a gravity filter with a porous plate filter media support that increase filter production by increasing the depth of the media, allows installation of an air backwash system in filters having a monolithic underdrain system, and reduces turbulence and head loss in granular filtration systems. The method comprising removal of existing media and gravel media-support bed and installation of a porous plate media support. The porous plate can have multiple layers of fine sized and coarse sized pores. The porous plate is positioned between the media and the filter bottom and is securely anchored to the monolithic underdrain system thereby allowing uniform distribution of backwash, inhibiting media penetration of the filter bottom and avoiding seal failures.
Claims9
A method for retrofitting a gravity filter having a monolithic false bottom filter underdrain system comprising a concrete bottom wherein the concrete bottom forms cone-shaped depressions, the underdrain system further comprising porcelain spheres positioned within the depressions to support a media and gravel media-support bed, the method comprising the steps of:
- (a) removing the existing media and gravel media-support beds from the filter underdrain system;
- (b) removing the porcelain spheres from the depressions;
- (c) replacing the gravel media support bed and porcelain spheres with at least one continuously porous plate over at least one cone-shaped depression, said continuously porous plate having pores sized for uniform distribution of backwash and comprising at least two layers, a first relatively coarse pore size layer beneath a juxtaposed second relatively fine pore size layer;
- (d) anchoring said continuously porous plate to the concrete bottom;
- and
- (e) replacing the media removed in step (a).
Dependencies are inferred from the claim text.