Patent ID: 8739320

Claim:
A low-maintenance oil-sealed odor trap cartridge for installation in a waterless urinal, comprising an outer chamber having a substantially vertical outer wall that extends around a continuous loop, configured with a level upper rim and extending downwardly therefrom; a bottom plate that extends inwardly from a lower edge of the outer wall to a central exit opening; an exit stand-pipe with a bottom end forming an upward continuation of the central exit opening, extending upwardly therefrom to a designated overflow level near the level of the upper rim; a cover that extends outwardly so as to engage the upper rim and that is configured with urine entry openings made and arranged to direct urine from above to enter said outer chamber; a partition wall having an upper end attached to said cover, extending around a continuous loop located between the outer wall of said chamber and said exit stand-pipe, extending vertically down to a level lower end located at a designated clearance dimension from said bottom plate, thus forming an inner wall surface of said outer chamber and an outer wall surface of an inner chamber having an inner wall surface formed by an outer surface of said exit stand-pipe; a liquid-flow-diverting structure having at least one helical fin, located within said outer chamber and configured with a flat horizontal cross-sectional shape extending between an outer wall surface of said partition and an inner wall surface of said outer chamber, extending around at least a portion of said partition in an inclined helix shape from a top helix end located in an uppermost region of said outer chamber wall to a bottom helix end located in a lowermost region of said partition wall; thus creating a liquid flow path that descends in said outer chamber in a helical path directed by said liquid-flow-diverting structure to a bottom region thereof, thence in a horizontal inward radial direction, flowing under the lower end of said partition wall, upwardly in the inner chamber to the overflow level, thence further horizontally and radially inwardly, flowing over the upper end of said partition wall thence downwardly through said exit stand-pipe and the bottom exit opening to an external wastewater drainage system.