GB2233679A

GB2233679A - Ventilating water closet pans

Info

Publication number: GB2233679A
Application number: GB8914775A
Authority: GB
Inventors: Jasjeet Singh
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-06-27
Filing date: 1989-06-27
Publication date: 1991-01-16
Also published as: GB8914775D0; FR2648843A1

Abstract

Apparatus for ventilating a toilet pan consists of a nozzle (2) which is mounted in or immediately to one side of the gap between seat and bowl to which is connected a tube (3) leading to suction means (4) adapted to suck air through the nozzle and vent it to the external atmosphere or into the stack pipe. The nozzle may be a separate nozzle introduced between seat and bowl or it may be built into one or the other. <IMAGE>

Description

Apparatus for removing foul smells from toilets This invention relates to an apparatus for removing foul smells from rooms containing toilets.

When the toilet is used, the air in the toilet and the room is full of foul smells. Some such rooms are fitted with smali extractor fans.But the main drawback of such an arrangement is that the bad smells first spread out into the whole room before being extracted bv the @@@ which is normally high up near the ceiling.Some people use air tres.'ner,, to get rid of bad smells.But this procedure only help to mask partially,the Loul Previously, and particularly In the past few years there have bee number of attempts made to devise a means to extract foul air cirectly from the water closet pan through a number of holes, which extend substantially in and around the toilet seat and connected by a r-?e an extractor fan. uch a procedure can at best resuit oniv in partial success because with such a plurality of holes/openings the rate of displacement of air will be very slow and feeble with the result that most of the foul air will contaminate the room atmosphere before being sucked completely through the holes.

The most essential requirement is to suck the foul air from within the toilet seat area as quickly as possible. In other words an air-stream must be created almost instantly.

According to the present invention the foul smeil.before it get chance to spread into the whole room, is caught in an air-stream create by a specially shaped single nozzle The creation c the alr-strealt ir based on the principle that if air is sucked from an enciosed or nes enclosed space with the aid of a nozzle or an orifice an a slit or an opening similiar in shape to that of the mouth o the nozzie or sirie is placed directly opposite and level with the nozzle then an air stream will be set up instantly.

In the present situation the clearance between the underside of the toilet seat and the top surface of the porcelain bowl (because of the rest rubber studs) serves the purpose of a slit as well as for the placing of the special nozzle.Although the 'slit' extends sideways along the rim of the bowl,the above principle is utilised to a good measure all the same. The bottom part of the body of the occupant of the toilet seat serves as a lid for effectively enclosing the space within the bowl.

The back end of the nozzle is in the shape of a neck to which is attached a tube which may be made of a plastics material. The other end of the tube may be attached to the inlet side of a small vacuum motor.The outlet of the vacuum motor takes the sucked air to the outside atmosphere or it may be introduced into the stack pipe. The nozzle can also be in the shape of a cavity creates in the toilet seat mater a itself.

The nozzle may also be located /in-built in the porcelain of the bowl,the back end of which can be in the shape of a receptacie to receive the tip of the plastic tube leading to the vacuum motor. In thIs case the nozzle may be pointing up a little so that its axis meets the 'slit' opposite and across the bowl.

For the existing toilets the entire system consisting of the nozzle, the connecting tubes and the vacuum motor can be manufactured as one unit. The nozzle in this case can be of such a design so that it can be easily clamped to the underside of the toilet seat.

The air is sucked by the aid of a + 50 watt motor with a suitable vane/propellor mechanism.The suction tube has an internal diameter of about 13 to 16mm.

Previously the use of a 10 or 12 watt motor has been suggested. ThIs is too low a power to cause an appreciable air flow, let alone creating an air stream, especially when its use is advocated in conjunction with a number of holes around the rim of the toilet seat.

The special nozzle can be a convergent-divergent or simply a divergent type.Although the convergent divergent type has a slight edge over the simple divergent type in terms of efficiency, it may not be possible to locate it under the toilet seat because of its greater height.In that situation the divergent type nozzle is more practical.

When a viscous fluid such as air flows along a lenght of pipe of constant diameter it loses energy owing to the effect of viscosit-v etc. To maintain the flow against these losses there must be a difference between the pressures at the two ends of the system i.e. the pressure at the upstream end must be higher than at the outlet end. The constricted section of the nozzle, namely the throat(or the mouth in the case of a divergent nozzle) 15 utilised to create this pressure difference by reducing its cross section area to 85-900 of the inner cross-section area of the suction tube.

Specific embodiment of the invention is described by reference in the accompanying drawings in which; Fig.1 shows in perspective the toilet seat 1 with the cavity 2(nozzle),the attached tube 3,and the vacuum motor 4.

Fig.2 illustrates at (a) the cross-section view along XY of the seat material embodying the nozzle 2.At (b) is shown the plan view of the section of toilet seat 1 embodying the nozzle.

Fig.3 illustrates at (a) in perspective the nozzle 2 located/inbuilt in the porcelain of the bowl,the back end of which can be iF the shape of a receptacle to receive the tip of the plastic tube 3.At ttv is shown the sectional side view. The nozzle 2 is shown here pointing up a little so that its axis meets the 'slit' 5 opposite and across the bowl.

The toilet seat 4 is shown resting on rubber studs 6.

Fig.4 shows the cross-section view of the convergent-divergent type of nozzle at (a) and the front at (b).With due regard to the practical considerations the lenght of the nozzle (L+x) may be taken around 80mm.It is found from experience that a lenght of ductdivergent section in this case)following the constriction improves the effeciencv,be-ause the conversion of velocity pressure to steady pressure is complete not at the outlet of the expansion but at some distance downstreamrowing to changes in the velocity profile downstream.

It is also found that if the inlet lenght is short( as is dictated by the small measurements in the present situation) the outlet should be about 4 to 5 times longer. Consequently the lenght x is taken as 20% of L.The angle of convergence of section z Is about 20.This angle is derived empirically and is a function of the distance between the nozzle throat and the 'slit' facing it,which measures about 30cms in an averarne toilet bowl. If this distance is greater then this angle will be smaller and vice versa.

The angle of divergence of section L is derived from the expresslot.

y/L = tan X or x = 3.96 Angle of divergence = 2x = 7.9z or 8 Fig.5 shows the cross-section view of the divergent type nozzle at (a) and the front view of the mouth of nozzle at (b).

The inside dimensions of the nozzle,especially its height are determined by the clearance between the underside of the toilet seat and the top surface of the porcelain bowl.Since the average clearance is about 10mm the height B of the mouth of the divergent nozzle can be safely taken as 4mm . Since the cross-section area of the mouth of the nozzle is to be 85~90we to that of the internal cross-section area of the suction tube,the the width of the nozzle mouth A works out to be about 30mm .The lenght C of the nozzle is about 80mm and the end tapers down and shapes into a neck to receive the tip of the suction tube The corners at the rear end of the nozzle are smoothed out curves so that least resistance is offered to the airflow.

Other nozzle dimensions may be used. Those skilled in the art will readily appreciate how these dimensions may be determined.

Claims

1. Apparatus for removing foul smells from toilets which comprises a nozzle mounted adjacent the rim of the toilet bowl and having a laterally extending slit shape, a tube attached to the nozzle and means connected to the other end of the tube for sucking air through the nozzle and venting it to the outside atmosphere or into the stack pipe.

2. Apparatus according to Claim 1, wherein the nozzle is located between the toilet bowl and toilet seat at the back of the bowl.

3. Apparatus according to Claim 1, wherein the nozzle is set in a cavity in the toilet seat or formed in the toilet seat.

4. Apparatus according to Claim 1, wherein the nozzle is built into the porcelain of the bowl.

51 Apparatus according to any of Claims 1 to 4, wherein the tube between the nozzle and suction means has an internal diameter of 13 to 16:cm.

6. Apparatus according to any of Claims 1 to 5, wherein the suction is provided by a motor driven vane/propeller mechctnism, rhe power of the motor being substantially 50 watts.

7. Apparatus according to any one of the preceding Claims, wherein the nozzle has an initially reducing cross sectional area followed by an increase in its cross sectional area.

8. Apparatus for removing foul smells from toilets substantially as hereinbefore described with reference to the accompanying drawings.