Filtration arrangement and method
AssigneeDonaldson Company, Inc.
InventorsBrad E. Kahlbaugh, Susan B. Reinhart, Denis J. Dudrey, John T. Herman
Life of this patent
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Abstract
Constructions and methods are described for collecting particulate material from gas streams. In one specifically described arrangement, a region of uniform or constant density depth media is oriented upstream of a region of gradient density depth media. In another, a preferred region of gradient density depth media is constructed, to effect particulate collection in a preferred manner. Preferred constructions described herein, utilize a pleated paper filter oriented downstream of depth media, to advantage.
Claims18
A filter construction comprising:
- (a) an upstream region of substantially constant density depth media having a percent solidity of no greater than about 3%;
- and
- (b) a downstream region of gradient density depth media;
- (i) said region of constant density depth media being constructed and arranged for operational loading therein of at least 65% by weight of retained solids within said filter construction;
- and
- (ii) said region of gradient density depth media being constructed and arranged for operational loading therein of at least 50% by weight of retained solids not retained within said upstream region, but which are retained within said filter construction.
A filter construction having an upstream side and a downstream side;
- said filter construction including:
- (a) a paper filter arrangement oriented adjacent said filter construction downstream side;
- and,
- (b) a depth media filter arrangement oriented upstream of said paper filter arrangement;
- said depth media arrangement comprising:
- (i) at least four layers of depth media each of which has a different percent solidity at least the other from three of the at least four layers of depth media within the depth media arrangement;
- said at least four layers of depth media including a most upstream layer of depth media and being arranged in stages oriented in downstream progression;
- (ii) none of said layers of depth media, except optionally said uppermost layer of depth media, comprising more than 25% by volume of depth media in said depth media filter arrangement;
- (iii) said most upstream layer of depth media comprising less than 50% by volume of depth media in said depth media filter arrangement;
- (iv) said most upstream layer of depth media having a percent solidity of 1-2%;
- and,
- (v) a next three downstream layers of depth media from said most upstream layer each having a greater percent solidity than a next upstream layer;
- and, each having a percent solidity no more than about 50% greater than a next upstream layer.
A method of filtering particulate material from a gas stream;
- said method including the steps of:
- (a) collecting at least 65% by weight of total particulates collected from the gas stream in a constant density depth media having a percent solidity of no greater than about 2%;
- (b) collecting at least 50% by weight of total particulates collected from the gas stream but not collected in the constant density depth media, in a gradient density depth media;
- said step of collecting in a gradient density depth media being conducted after said step of collecting in a constant density depth media;
- and,
- (c) collecting a remainder of total particulates collected from the gas stream with a paper filter;
- said step of collecting with a paper filter being conducted downstream from said step of collecting in a gradient density depth media.
Dependencies are inferred from the claim text.