A METHOD AND ARRANGEMENT FOR PREVENTING THE SPREADING OF UNPLEASANT ODOURS FROM LAVATORY BASINS

Abstract: An arrangement for preventing the spreading of unpleasant odours from lavatory basins. The arrangement includes an array of inlet openings (10) through which air is delivered at overpressure to the lavatory basin, and an array of outlet openings (11) through which air is extracted from the basin space by suction. The inlet openings (10) for air under overpressure are disposed so that the air exiting therefrom will form a turbulent air layer of given overpressure in the upper part of the basin space, whereas the outlet openings (11) are disposed so that air is extracted from the basin space essentially at a level which lies beneath the air layer. The invention also relates to a method for preventing the spreading of unpleasant odours from a toilet basin.

Description: A METHOD AND ARRANGEMENT FOR PREVENTING THE SPREADING OF UNPLEASANT ODOURS FROM LAVATORY BASINS The present invention relates to a method for prevent- ing the spreading of unpleasant odours from a lavatory basin, where air is delivered at a pressure above atmospheric pressure to the space in the lavatory basin, through an array of inlet openings, and is withdrawn from said space by suction, through an array of outlet openings. The invention also relates to an arrangement for carrying out the method. The prevention of the dispersion of unpleasant smells from lavatory basins to the surroundings is a common desire. This particularly applies to public lavatories and works lavatories, as well as domestic lavatories. Many attempts have been made to extract air by suction directly from the lavatory basin, in some cases while supplying additional air to the basin. The U.S. Patent Specification No. 4,087,871 describes an arrangement in lavatory basins where overpressures and subpressures are utilized in different procedural stages. In this case, pressurized air in the form of warm drying air is delivered to the toilet basin. The air is extracted by suction from the basin, with the aid of subpressure, although without supplying addi¬ tional air. The U.S. Patent Specification No. 2,849,727 teaches a method in which pressurized air is delivered to the basin and extracted therefrom by suction with the aid of subpressure. The air flows in a horizontal plane in the form of a laminar flow. DE 1,910,999 teaches an arrangement which operates at both overpressure and subpressure, where the air flows in a single plane. EP-A2-0 182 464 describes an arrangement in which air is removed from a lavatory basin by suction, through outlet openings which lie on a lower level than the openings through which air is delivered to the basin space. The incoming air is also sucked into the basin and is, therefore, unable to form an effective air curtain. None of the earlier known solutions is totally satis¬ factory from the aspect of efficiency, and a prime object of the present invention is to provide for the purpose of preventing unpleasant smells from spreading from lavatory basins to the surroundings a method which is much more effective than those solutions proposed hitherto. Another object of the invention is to provide an arrangement for use in carrying out the method. The invention is based on the realization that it is necessary to create a curtain of air under overpressure which will prevent airborne smells from passing there¬ through, and that it is also necessary to create in said space, beneath said curtain, a region of sub- pressure which will remove the air in said space by suction. In accordance with the invention, a method of the kind defined in the first paragraph of the description is particularly characterized in that the air under over- pressure is delivered to the space in the lavatory basin at a level which is higher than the level at which air is sucked from said basin and in a manner such as to generate a turbulent layer of air of given overpressure in the upper part of said space, and in that suction of air from said space is effected sub¬ stantially at a level beneath said air layer. Thus, the turbulent air layer forms between the body of the user and the outer wall of the lavatory basin an overpressure curtain which seals against the smells rising up from beneath the cushion. When the space beneath the air curtain is connected to a suction line, there is generated in said space a subpressure which further ensures that no bad air will penetrate up through the curtain. The air is preferably delivered to said space in the form of inwardly and obliquely downwardly directed air jets, and the inwardly directed air jets are preferably directed so as to intersect one another and thereby amplify turbulence. The main characteristic features of an arrangement for carrying out the method are set forth in Claim 4. According to one preferred embodiment of the inventive arrangement, both the inlet and the outlet openings are disposed in the lavatory basin seat and are each con¬ nected to a respective circumferential chamber therein, of which one chamber is connected to a pressure line and the other to a suction line. In order to ensure that the inlet openings will con¬ stantly be open, said openings are conveniently diε- posed on the underside of a circumferentially extend- ing, inwardly projecting part of the seat. The arrangement also includes a spring-biased switch which, when applying a load to the seat is activated for controlling the means operative to generate said pres- sure and said suction. These means may be provided with time delay means which cause the arrangement to remain active over a predetermined length of time subsequent to releaving the load on the lavatory seat. The invention will now be described in more detail with reference to the accompanying drawing, in which Figure 1 is a perspective view of a lavatory basin provided with an inventive seat, and shows the seat partially cut away; and Figure 2 is a vertical sectional view of the arrange¬ ment illustrated in Figure 1. In the drawings, the reference numeral 1 identifies the basin of a lavatory or water closet, the reference numeral 2 identifies the lid of said basin, and the reference 3 identifies the lavatory seat. As is evident from the drawings, the seat 3 is divided by a wall 6 into two circumferentially extending chambers 4 and 5. Connected to the upper chamber 4 is a conduit 7 for the supply of air at overpressure. Connected to the chamber 5 is a corresponding suction conduit 8. In the illustrated embodiment, the lavatory seat 3 has an inwardly projecting part 9 on the undersurface of which air inlet openings 10 are arranged. These open¬ ings are protected, so as not to become blocked by the person seated on the toilet. The bottom chamber 5 is provided, in a similar manner, with air outlet openings 11 on the underside of the lavatory seat. The air inlet openings 10 are so disposed that air jets exiting from said openings will be directed obliquely downwards and obliquely inwards, i.e. not all of the air jets are directed towards the centre of the seat opening, but so that said jets intersect one another. This will amplify the turbulence that occurs in the air layer immediately inwards of the inlet openings 10, this layer forming an air cushion having a given over¬ pressure in relation to the pressure prevailing in the basin space located beneath said layer, said space being connected to the suction conduit 8 via the open- ings 11 and the chamber 5. As will be understood, the aforedescribed arrangement provides an effective barrier against the egress of ill-smelling air from the lavatory basin, combined with the effective removal by suction of said air directly from the basin. Thus, in order to achieve this effect, it is important that the air inlet openings for com¬ pressed air are located at a higher level than the air- outlet openings connected to a source of subpressure. The reference numeral 12 identifies a spring biased switch which is activated when the seat 3 is subjected to load. The switch is incorporated in a compressor and pump supply circuit, such that the compressor and pump will be started up immediately someone sits on the seat. The arrangement will also preferably include a time delay means which holds the compressor and pump activated over a predetermined length of time after the load on the seat has been removed, said delay time being resettable. In the aforegoing, there has been described a preferred embodiment of the invention, this embodiment being particularly advantageous since it can be put into effect simply by modifying the lavatory seat. The seat can be adapted to each individual lavatory basin or can be constructed so as to fit the most common, standard basin models. The pressure and suction conduits 7 and 8 can therewith be respectively connected to a separate compressor and pump or to channels provided in the toilet space and subjected respectively to overpressure and subpressure. The aforesaid compressor and pump may also be incorporated in the actual lavatory basin itself. Instead of providing the air channels in the lavatory seat, the channels may be formed directly in the lavatory basin in conjunction with its manufacture. Neither need the lavatory seat have the illustrated and described construction with the provision of channels, but can be constructed in any desired manner that will retain the desired function.

Claims: I 7 CLAIMS 1. A method for preventing the spreading of unplea¬ sant odours from a lavatory basin, in which air under overpressure is delivered to the basin space through an array of inlet openings and is extracted by suction from said space through an array of outlet openings, c h a r a c t e r i z e d by delivering air under overpressure to the basin space at a higher level than the level at which air is extracted from said space and in a manner such as to create in the upper part of said space a turbulent air layer of given overpressure; and by extracting said air from said space substantially at a level located beneath said air layer. 2. A method according to Claim 1, c h a r a c ¬ t e r i z e d by delivering the air to said space in the form of inwardly and obliquely downwardly directed air jets. 3. A method according to Claim 2, c h a r a c ¬ t e r i z e d by directing the inwardly directed air jets so that they cross one another, thereby amplifying said turbulence. 4. A arrangement in a lavatory basin for preventing the spreading of unpleasant odours therefrom, compris¬ ing an array of inlet openings (10) through which air under overpressure is delivered to the basin, and an array of outlet openings (11) through which air is extracted from said space by suction, c h a r a c ¬ t e r i z e d in that the inlet openings (10) for air under overpressure are located at a higher level than said outlet openings (11); in that said inlet openings are so disposed as to create a turbulent air layer of given overpressure in the upper part of said space; and in that the outlet openings (11) are disposed so that extraction of air from said space is effected substan¬ tially at a level beneath said air layer. 5. An arrangement according to Claim 4, c h a r ¬ a c t e r i z e d in that the inlet openings (10) are located close to the upper edge of said space and are directed inwards and obliquely downwards; and in that the outlet openings (11) are located at a lower level. 6. An arrangement according to Claim 5, c h a r ¬ a c t e r i z e d in that said inlet openings (10) are directed so that the air jets exiting therefrom will cross one another and therewith amplify the turbulence. 7. An arrangement according to any one of Claims 4-6, c h a r a c t e r i z e d in that both the inlet and the outlet openings (10, 11) are formed in the lavatory seat (3) of a lavatory basin (1); and in that said openings (10, 11) are each connected with a respective circu ferentially extending chamber (4, 5) in said seat, of which chambers one (4) is connected to a pressure conduit (7) and the other (5) to a suction conduit (8). 8. An arrangement according to Claim 7, c a r ¬ a c t e r i z e d in that the inlet openings (10) are located on the underside of a circumferentially extend- ing, inwardly projecting part (9) of the seat (3). 9. An arrangement according to any one of Claims 4-8, c h a r a c t e r i z e d in that it includes a spring biased switch (12) which is activated when load is exerted on the seat (3) such as to control the pressure and suction generating devices. 10. An arrangement according to Claim 9, c h a r ¬ a c t e r i z e d in that said arrangement includes a time delay means which functions to hold the pressure and suction generating devices in an active state for a period of time after the load on the seat (3) has been removed.

Inventors: SJOEBERG LARS, SJOEBERG, LARS
Applicants: SJOEBERG LARS, SJOEBERG, LARS
Application year: 1990
Main classification: E03D9
IPC codes: E03D9