GB2296514A

GB2296514A - Odour trap for a waste water drain

Info

Publication number: GB2296514A
Application number: GB9524895A
Authority: GB
Inventors: Brian Donald Collins
Original assignee: Evac AB
Current assignee: Evac AB
Priority date: 1994-12-05
Filing date: 1995-12-05
Publication date: 1996-07-03
Also published as: GB9424506D0; GB9524895D0

Abstract

An odour trap, particularly for a urinal, is capable of being attached to or integrally moulded with an existing bottle trap 1, 2 or 'S' bend and comprises a system of baffles and weirs 7, 8 proportioned so that a layer of aromatic or active bio-remedial oil separates the contaminated charge of liquid from the surrounding atmosphere thereby eliminating noxious odours. <IMAGE>

Description

AN ODOUR TRAP FOR A WASTE WATER DRAIN This invention relates to an odour trap for a waste water drain and more particularly, but not exclusively, to a urinal odour trap.

In a conventional bottle trap or 'S' bend a volume of water is trapped, isolating the drain from the inlet, with one surface exposed to the drain and the other surface exposed to the atmosphere. Contaminants from the drain are in contact with one water surface penetrating the bulk of the water and emerging at the water surface exposed to the atmosphere, thus rendering the required isolation ineffective.

It is an object of the invention to inhibit the return of foul odours from both diluted urine and any other pollutants.

Equally important is the virtual elimination of water consumption arising from the flushing cycle which, in any conventional system represents a considerable financial outlay.

The present invention consists in an odour trap for a waste water drain, comprising at least one annular weir arranged to surround an inlet down pipe and to trap a volume of contaminated liquid such that in use a layer of oil floats on the liquid in the down pipe and isolates the liquid from the surrounding atmosphere.

Specific embodiments of the invention will now be described by way of example, referring to the accompanying drawings in which Figure 1 is an axial section of a bottle trap including a urinal odour trap according to the invention, and Figure 2 is an axial section of an 'S' bend including a urinal odour trap according to another embodiment of the invention.

Referring to Figure 1 an air/liquid tight bowl comprises an upper part 1 carrying the inlet down pipe 3 and a lower part 2 containing the baffle and weir assembly described below.

The two bowl halves are joined by male/female threaded collars 4 and sealed from the atmosphere by a seal 5. An outlet branch 6 is part of the upper bowl half 1, so that inlet down pipe 3 and outlet branch 6 may be connected to existing pipework ie: upper bowl half 1 to the existing urinal bowl and outlet branch 6 to the drain.

The baffle and weir assembly consists of two concentric sleeves 7 and 8 joined by a number of ribs 9 to form a single unit centred laterally against the outlet down pipe 3 by a number of ribs 10 and positioned vertically by a number of legs 11 which may be trimmed to suit varying manufacturers' lower bowl depths or may be an integral moulding to suit.

The following is the charging procedure: Oil charge: In the initial operation a small amount of aromatic and/or bio-remedial oil (approximately 20 ml) is added to the assembled wet unit, this oil/fluid is then floated to the outer annulus 12 by an additional small charge of water to fill the bowl assembly. Any excess of oil will be floated upwards by the rising water charge until annuli 10 and 12 are full, finally a further charge of oil (20 ml) is added resulting in oil layers isolating the contaminated aqueous volume.

Water charge: Water poured down inlet 3 will pass upwards through annulus 10, then down annulus 12 and thence into the lower bowl, rising in the bowl until it reaches the lowest point of outlet 6 which establishes the level in both the bowl and annulus 12.

Referring to Figure 2 an 'S' bend trap is shown with a vertical leg sufficient to contain a down pipe 14 ending at a height below the outlet branch 15 and fitted with a bowl 16 forming an annulus through which the contaminant stream is transported to the branch 15 whilst the aromatic and/or bio-remedial oil layer 18 plays the isolating role described in the analysis above for the trap as in Figure 1.

An important advantage of the invention is the dramatic economy in water consumption. In existing conventional system's regular flushing results in high costs which are virtually eliminated because replenishment of oil only is required every three to five days, together with any of the normal associated day to day cleaning procedures.

Claims

1 An odour trap for a waste water drain comprising at least one annular weir arranged to surround an inlet down pipe and to trap a volume of contaminated liquid such that in use a layer of oil floats on the liquid in the down pipe and isolates the liquid from the surrounding atmosphere.

2 An odour trap as claimed in claim 1 wherein the oil comprises at least one aromatic or bio-remedial oil.

3 An odour trap as claimed in claim 1 or 2 being integrally moulded with a bottle trap or 'S' bend.

4 An odour trap as claimed in claim 1 or 2 which can be removably fitted within a bottle trap or 'S' bend and having a plurality of legs, a portion of which legs can be cut off to adjust the height of the or each weir.

5 An odour trap substantially as described herein with reference to Figure 1 or Figure 2 of the accompanying drawings.