Box filter apparatus

Claim 1

A disposable filter assembly including: a) a housing comprising mating channel-shaped male and female portions, the mating male and female portions forming a box-shaped fluid chamber defined by an upper plenum wall having an inlet therein, a lower plenum wall having an outlet therein, a pair of opposed side walls connecting the upper plenum wall and the lower plenum wall, and a pair of opposed, open, end walls, each of said pair of opposed side walls including a generally vertical wall portion of an upper housing portion and an upstanding ridge of a lower housing portion along substantially the entire length of said side walls, the generally vertical wall portion of the upper housing portion having moved laterally inwardly toward the upstanding ridge, and away from a generally vertical wall portion of the lower housing portion as a result of an ultrasonic welding process being used to bond the upper housing portion to the lower housing portion, b) a corrugated filter element extending across said box-shaped fluid chamber, from one of the opposed side walls to the other, and across a line of fluid flow between the inlet and the outlet, a pleat at each end of said corrugated filter element mechanically held in a fluid-tight seal in a generally vertical position, between said generally vertical wall portions of the upper housing portion and the upstanding ridge portions of the lower housing portions, said filter element held in position by lateral forces applied by said generally vertical wall portions and said upstanding ridge portions, and c) end caps closing said opposed end walls and sealing said filter element to said end caps.