DEVICE FOR SEPARATION OF FOAM AND LIQUID FROM AN AIR STREAM

Abstract: The present invention relates to a foam and liquid isolating device, which is designed to be connected to partly a suction generating conduit (28, 52) and partly to a conduit (15, 51) for an air flow, which sucks in foam and/or liquid into a container (1, 53), including valve means (6, 7, 54), designed to stop the air flow, when there is a risk that liquid will penetrate into the suction generating conduit (28, 52), as well as a filter (19, 50), through which the air flow passes. A valve body (7, 18, 54) is movably mounted between an open and a closed position and designed to, when it is influenced by the pressure difference between first and second spaces, which are placed upstreams of and downstreams of respectively the filter (19, 50) in the flow direction of the air flow, occupy a closed position at a certan fall of pressure across the filter.

Description: DEVICE FOR SEPARATION OF FOAM AND LIQUID FROM AN AIR STREAM TECHNICAL FIELD The present invention relates to a device, which isolates foam and liquid, of the type which is designed to be connected partly to a suction generating conduit and partly to a conduit for an air stream, which sucks in foam and/or liquid into a container, and which includes valve means, designed to stop the air stream, when there is a risk that liquid may penetrate into the suction generating conduit, and a filter, through which the air stream passes. BACKGROUND ART Devices of this type may be grouped into two categories. A first category includes devices for a professional use, which are relatively sophisticated machines having a high capacity and specially adjusted construction, which guarantees, that the electrical motor, which drives the suction fan, is not damaged by penetrating moisture or liquid. The second category includes simple devices, in which a closed container is provided with an opening for a tube, designed to suck liquid and foam into the container, as well as an additional opening for the connection of household vacuum cleaner. These devices often lack means designed to stop liquid and foam from reaching the vacuum cleaner. In those instances, where these devices include safety means, they are floating body-devices, which stop the air flow, when the container is filled with liquid. However, these elements do not stop the air flow, when the container is filled with foam, which implies that moisture nevertheless penetrates into the vacuum cleaner bag and the vacuum cleaner for the rest, which may result in a considerable drawback as well as damages to the vacuum cleaner and in adverse situations also in personal injuries. BRIEF DESCRIPTION OF THE INVENTION The object of the present invention is to suggest a simple device of the type mentioned in the introduction, designed to be used above all in households as a supplement to a vacuum cleaner. By means of the device it will be possible to always make use of a "tool" designed for foam washing of carpets, upholstered pieces of furniture and the like, provided a vacuum cleaner is available. Such a "tool" must be inexpen¬ sive and not bulky, but at the same time it must be reliable in that respect that liquid and foam must not penetrate into the vacuum cleaner, causing the drawbacks and the risks this would imply. This and other objects are achieved by designing the foam and liquid separation device with a valve body, which is movable between an open and a closed position and designed to, when it is influenced by the pressure difference between first and second spaces, which in the flow direction of the air flow are placed upstreams of and downstreams of respectively the filter, occupy a closed position for a certain fall of pressure across the filter mentioned in the preamble. In case a passage between the first and the second spaces includes a vertical portion, in which at least one part of the valve body is ovably mounted, the valve body can, if the fall of pressure across the filter is moderate or non-existent, be designed to occupy an open position while being influenced by the force of gravity. One condition for this is that the second space is placed in connection with the upper orifice of the vertical portion. The vertical portion of the passage and that part of the valve body, which is movable in it, then form a slide device, which guides the movement of the valve body, cross-sections of that part of the valve body, which is movably mounted in the vertical part of the passage, corresponding to cross-sections of the vertical portion in such a way, that a sealing and easily running fit is obtained between those parts of the passage and the valve body, which slide against each other.- Those forces, which then influence the valve body, which is guided to move vertically, when the device occupies its normal position, is the force of gravity and an upwardly directed force, which equals the product of the pressure difference between the first and the second spaces and the cross-sectional area of the vertical portion. The upwardly directed force is the resultant of all the pressure forces, which influence the valve body. Those parts of the valve body, which are designed to stop the air flow, and the corresponding valve seats can be mounted in the second space. The liquid separation unit is then supplemented with a separate floating body, which works as a valve and stops the air flow, when the liquid level in the container reaches a certain value. Those parts of the valve body, which are designed to stop the air stream, and the corresponding valve seats can also be mounted in the first space, which usually includes the container. These parts can be designed as a floating body, an integrated valve element being obtained, which stops the air flow or stream, when the fall of pressure across the filter increases to a certain value and/or when the liquid level in the container reaches a certain value. BRIEF DESCRIPTION OF THE DRAWINGS In the following description reference is made to the accompanying drawings, in which: Fig. 1 is a lateral view of the device, one half of which is shown in section according to a first embodiment of the invention, as well as a specially designed container for liquid and foam; Fig. 2 shows a horizontal section along line II-II in Fig. 1; Fig. 3 shows the gaps in a cylindrical part of the curved disk or cap, which covers the container; and Fig. 4 shows a section through the device according to the invention in another embodiment, in which buckets, often used in a household, can be used as a container for liquid and foam. DESCRIPTION OF A PREFERRED EMBODIMENT In a preferred embodiment according to Figs. 1, 2 and 3 the device according to the invention comprises a specially designed vessel 1, designed for sucked-in foam and liquid. The vessel is on its inner side provided with an annular upwardly projecting contact edge 2. A curved disk 4 is supported by this contact edge 2 and is an integral part of a unit 5 designed for foam and liquid separation. The latter includes only three movable parts, i.e. one floating body 6, one reducing valve 30, and one conical disk-shaped valve body 7, provided with four claws 18, which project axially and vertically and are evenly distributed along a circle. Unit 5 comprises also a casing 8 with a cylindrical portion 9 having an upper part 9a and a lower part 9b. The latter has a smaller diameter than the former. Thus, an outer annular stop edge 10 is formed, which is turned downwards and forms a first annular valve seat for the conical valve disk 7. Also, an inner annular stop edge 24 is formed, which is turned upwards. A second annular valve seat 11 is made up of the lower edge on casing 8, which edge also has an outer flange 12, which is welded or glued to or in another way permanently united with the upper side of curved disk 4. In cylinder 9 a casing 13 is introduced having a lower portion 14, with a reduced diameter, through which portion 14 liquied is trans¬ ported, which is sucked in through a suction conduit 15 and downwards into vessel 1. Disk or cover 4 comprises a circumferential part with a downwardly projecting outer edge 3, a cylindrical portion 16, and a conical portion 17, which has the same shape as and has the same dimension as conical valve disk 7. In the central area there is a central opening 27, Fig. 2, which is circular with four circular sector-shaped recesses 26, which mate with the four claws 18, which are circular sector-shaped in the same way. Said four claws 18 form the central part of the movable valve body, which also includes conical valve disk 7. The appearance of the circular sector-shaped recesses 26 and claws 18 is shown in the horizontal section, which is shown in Fig. 2. In the cylindrical part 16 of disk 4 there are perforations, i.e. openings, which are designed as vertical gaps 71, which due to produc¬ tion-technical reasons are designed in such a way, that a clearance in the tool is to be used. Gaps 71 are separated by posts 72, Fig. 3. Outside cylindrical portion 16 on the rigid disk or cover 4 there is a filter 19. According to this embodiment filter 19 is made of a semi-rigid, porous polymeric material, which is sold by the firm PIAB, Akersberga, Sweden, under trade name WON. The material is sold with different thicknesses. In a preferred embodiment of the invention grade VYON 7 is used, which has a thickness of 0.75 mm. This material has a mean pore size, measured according to the bubble pressure method, b.s. 1752: 1963, of 90 mm. A floating body 6 has the shape which is shown in Fig. 1. It principally comprises an annular trough having a bottom part 22, an inner cylindrical wall 23, and an outer annular lateral wall 20 with an upper sealing edge 20a, which when floating body 6 is lifted by liquid in vessel 1 is pressed and seals against the inner side of disk 4. A central portion 21 of the upper side of bottom part 22 seals against the lower edge of tube 9b, when floating body 6 is in its uppermost position. Since the upper part of central cylindrical portion 23 of floating body 6 is provided with tongues 25 having projecting hooks 25a, it can be inserted into lower part 9b of tube 9 from below, tongues 25 being pressed inwards. When hooks 25a have passed stop surface 24, tongues 25 will spring outwards again and consequently, floating body 6 will be positioned in the way shown in the drawings. Floating body 6 will now be displaceably coupled with tube 9 and is able to be displaced to its lowest position, in which hooks 25a are in contact with stop surface 24. Floating body 6 can from this position be displaced upwards, tube 9 guiding it. In its upper position the movement of floating body 6 is limited, since its edge 20a seals against the lower side of disk 4. The dot/dash-outline shown in Fig. 1 shows floating body 6 in its lowermost position. The device works in the following way. In its starting position floa¬ ting body 6 is in its lower open position, hooks 25a being supported by stop surface 24. Valve body 7 is also positioned in its lower position and is then supported by conical portion 17. Filter 19 is clean and exposed to the interior of vessel 1. In case conduit 26 is connected to a vacuum cleaner, a vacuum is obtained in vessel 1 and air, water and impurities can be sucked through conduit 15 and flow downwards into vessel 1. When filter 19 gradually will be filled with impurities, moisture and/or foam, the flow resistance in the filter will increase. When this resistance has increased to such a degree that it exceeds a certain level, a lifting force, which is exerted on valve body 7, more exactly on claw-shaped cylindrical sectors 18, which project downwards through and block circular sector-shaped bypass openings/recesses 26 in the central opening in the central conical part 17 in such a way, that air cannot pass through these bypass openings/recesses 26, will exceed the force of gravity exerted on valve body 7, with the result that valve body 7 will be sucked upwards towards casing 8, claw-shaped sectors 18 being guided in control means, which comprises partly cylindrical portion 9b and partly recesses/bypass openings 26 at the inner edge of the opening in conical portion 7. This movement continues and is fast. The movement is similar to the movement of a pneumatic piston, until it is stopped by seat surfaces 10 and 11. In this way the air passage between vessel 1 and connection piece 28 via filter 19 is closed, and the risk that liquid will reach the vacuum cleaner is eliminated. In case liquid is rising in vessel 1, before filter 9 has been stopped up, floating body 6 will be lifted by the liquid, and when it has reached its upper position, it will function as a valve and will stop, the air flow/stream through the filter. Floating body 6 then with edge 20a sealingly contacts the lower side of curved disk 4, and with inner portion 21 of bottom part 22 sealingly contacts a lower edge 31 on tube-shaped portion 9b. In the outer wall of casing 8 a rubber connection piece 29 is mounted. The suction conduit from the vacuum cleaner is pressed into the rubber connection piece, which is flexible and provides a tight connection. The inner opening of the connection piece is somewhat smaller than end tube 28 on the vacuum cleaner tube. It was mentioned above that the device for sucking liquid and foam is provided with a reducing valve 30. The reason for this is that there is a large difference between the suction force of different vacuum cleaners - from very strong industrial vacuum cleaners to household vacuum cleaners. Consequently, there is a need to be able to control the suction force in order to avoid that valve 7 be closed prematurely. Valve 7 can be calibrated by means of reducing valve 30. When the device is stored, the tube and the rest of the equipment details can be placed in vessel 1 and in this way a compact unit is obtained, which facilitates the storage of the device e.g. in a cleaning cupboard. Filter 19 can be fastened by glue, e.g. by means of a double-coated tape. It can also be fastened with a nylon tape. It is simple to exchange filter 19, particularly if it is fastened e.g. with a tape. The filter can be rinsed and in case it has become wet, it can be dried by blowing air through it from the vacuum cleaner. The vacuum cleaner tube is then inserted into the exhaust connection of the vacuum cleaner and air is blown by means of the vacuum cleaner into the opening, which is designed for suction. In this way air is blown through the filter, which dries up in a few minutes. In Fig. 4 a device according to an alternative embodiment of the invention is shown, which comprises a supporting disk 44, which is designed to be placed on top of an ordinary bucket 53. Supporting disk 44 is plane and circular and its outer diameter is somewhat larger than the outer diameter of the largest buckets usually used in a household, e.g. about 45 cm. The device has only two movable components, i.e. a floating valve 54, being shaped as an annular trough, and suction control means 30. The device also comprises a removable filter 50. All the non-movable parts are stationarily mounted on supporting disk 44. The device includes a suction connection, which has the same function and construction as rubber connection piece 29, which is described above. The connection comprises an annular sealing device made of rubber, into which nozzle end 52 on an ordinary vacuum cleaner tube can be inserted. The suction connection has an annular rubber flange 29a, which seals and retains the nozzle end of the vacuum cleaner tube. The device is also provided with a foam suction connection 43, to which a tube 51 designed to suck in liquid and foam is connected. The suction connection with rubber connection piece 29 is inserted into an annular space 46, which surrounds a vertical cylindrical passage 45, into which foam suction connection 43 opens with that end, which is opposite to that end, which is connected to tube 51, designed to suck liquid and foam. The central part of supporting disk 44 or the cover is provided with a cylindrical portion 47, which is perforated with holes 48. Adjacent the central area of supporting disk 44, disk 44 is provided with a conical part 61 and in the central area a circular opening. Annular space 46 is limited at the top by a casing 49 and in the central area by a cylindrical tube 49c, which is the central part of casing 49. At the bottom, annular space 46 is limited by central mainly conical part 61 of supporting disk 44 and by cylindrical perforated portion 47 with holes 48. Casing 49 is fastened, by means of welding or gluing, to supporting disk 44. The glue joint or the welding joint between casing 49 and supporting disk 44 is designated 64. Between central cylindrical part 49c of casing 49 and the central circular opening of supporting disk 44 an annular gap 65 is formed. In its lower end, tubular part 49c of casing 49 is equipped with four snap-in devices designed as tongues 66, each one placed between two apertures or grooves 67. Tongues 66 are in their lower ends provided with outwardly directed hooks 68. Filter 50 is flexible and is tape-shaped and placed around perforated cylindrical part 47. The used filter material is the same flexible icroporous polymeric material as is used in the device according to Fig. 1. Floating valve 54 is designed as a trough-shaped disk valve with an outer conical part 72 and a central cylindrical part in the form of a tube 73, the thickness of material being matched with gap 65 between supporting disk 44 and central cylindrical part 49c of casing 49 in such a way, that an easily running and yet sufficiently sealing fit will be obtained. Since the lower part of tube 49c is provided with tongues 66 having outwardly projecting hooks 68, the central cylindri¬ cal tube of floating valve 54 can be pushed onto tube 49c from below, tongues 66 being pressed inwards.When floating valve 54 with its central tube-shaped part 73 passes the lower edge of tube 49c, tongues 66 will spring outwards again and consequently, floating valve 54 will be positioned in the way shown in the drawings. Valve body 54 will then be movably connected to tube 49c and can reach a lowermost position, in which valve body 54 contacts hooks 68. From this position floating valve 54 can be pushed upwards while being guided by tube 49c. In its uppermost position the movement of floating valve 54 is limited, because its outer edge 55 seals against the lower side of the plane part of supporting disk 44. The dash line-contour in Fig. 4 shows valve 54 in its uppermost position. Provided the device is positioned on a container or a bucket, which is shown in Fig. 4, supporting disk or cover 44 being sealingly applied to upper edge 56 of bucket or container 53, liquid and foam can be sucked into the interior of container 53 through connections 43 and , central vertical passage 45. In container 53 liquid and foam are separated from the air flow and liquid and foam are isolated downwards towards the bottom of container 53. The air flow then continues through filter 50 and holes 48 in cylindrical part 47, which is desig¬ ned as a filter holder, into annular space 46 in order to continue from this space through connection 52 to the vacuum cleaner. Valve 54 is pressed downwards by its own weight in such a way that it will reach its lowest position. The air flow generates a vacuum in container 53, which means that the supporting disk is firmly retained on container 53. In case foam or water splash reach filter 50, e.g. in connection with the displacement of container 53 jointly with the device according to the invention, the flow resistance through filter 50 will increase. The porosity of the filter material is then chosen in such a way, that floating valve 54 will be sucked upwards and will seal with edge 55 against suppor- ting disk 54, if 60-80% of filter 50 is soaked. The air passage through filter ' 50 from container 53 to space 46 and the vacuum cleaner tube will then be completely blocked. In this way the risk of obtaining a penetration of foam or liquid into the vacuum cleaner will be eliminated. Floating valve 54 will be lifted during said closing movement, because a fall of pressure is generated between container 53 and space 46, since filter 50 will be wet throughout. The resulting fall of pressure implies, that floating valve 54 is influenced by a vertical upwardly directed force, which is proportional to the pressure difference and to the cross-sectional area of the annular space, which is formed by gap 65. The air passage from container 53 to space 46 and vacuum cleaner conduit 28 is also blocked, when the liquid level in the container rises to such a level, that valve body 54, which is designed as a floating body, is lifted and reaches its uppermost position, sealing against supporting disk 44, liquid and foam being stopped from reaching space 46. Even if container 53 tipped, floating valve 54 would reach its closed position, since its weight is adjusted in such a way, that it due to the vacuum from the vacuum cleaner is pulled towards its closed position, when the device slants more than about 60° . In this way water and foam are also in this case stopped from penetrating into the vacuum cleaner. This function of the device can be explained in this way: The guide surfaces between tube parts 49c and 54c have a minor friction and the control means has a compara¬ tively large length as compared to the diameter. When valve 54 is tilted, its force of gravity component, which is perpendicular to supporting disk 44, decreases, the pressure difference between the air in annular space 46 and in container 53 pulling valve 54 in such a way, that its edge 55 will seal against supporting disk 44. The function of reducing valve 30 has been described above. All the elements, which the described devices comprise (except the filter), preferably are made of a plastic material, particularly a thermoplastic material, e.g. polyethylene, polypropylene, polyamide och polyacrylate. However, those parts can also be made of other materials.

Claims: CLAIMS 1. A foam and liquid isolating device, which is designed to be connected partly to a suction generating conduit (28, 52) and partly to a conduit (15, 51) for an air flow, which sucks in foam and/or liquid to a container (1, 53), including valve elements (6, 7, 54), designed to stop the air flow, when there is a risk that liquid will penetrate into the suction generating conduit (28, 52), as well as a filter (19, 50), through which the air flow passes, c h a r a c t e ¬ r i z e d by a valve body (7, 18, 54), which is movable between an open and a closed position and designed to, when it is influenced by the pressure difference between first and second spaces, which are placed upstreams of and downstreams of respectively said filter (19, 50) in the flow direction of the air flow, occupy a closed position at a certain fall of pressure across the filter. 2. A foam and liquid isolating device according to claim 1, c h a r a c t e r i z e d by at least one passage (26, 65), functio¬ ning as a bypass-conduit for air past the filter and/or exerting a lifting force on the valve body due to the pressure difference across the filter. 3. A foam and liquid isolating device according to claim 2, c h a r a c t e r i z e d in that said passage has a vertical portion (26, 65), in which at least one part of the valve body (7, 18, 54) is movably mounted to, when the fall of pressure across the filter (19, 50) is moderate or non-existent, occupy an open position when influenced by the force of gravity, which influences the valve body (7, 18, 54). 4. A foam and liquid isolating device according to the preceding claims, c h a r a c t e r i z e d in that those parts of the valve body (7, 18, 54), which are designed to stop the air flow, as well as the corresponding valve seats are mounted in said second spaces. 5. A foam and liquid isolating device according to the preceding claims, c h a r a c t e r i z e d in that those parts of the valve body (7, 18, 54), which are designed to stop the air flow, as well as the corresponding valve seats are mounted in said first spaces. 6. A foam and liquid isolating device according to any of the prece¬ ding claims, c h a r a c t e r i z e d in that at least one of the valve elements (54, 6) is designed as a floating body, which stops the air flow, when the liquid level in the container (1, 53) reaches a certain level. 7. A foam and liquid isolating device according to any of the prece¬ ding claims, c h a r a c t e r i z e d in that the valve body (7, 18, 54) is designed to occupy a closed position, when the fall of pressure reaches a value, which corresponds to a 60-80% wetting of the filter. 8. A foam and liquid isolating device according to any of the prece¬ ding claims. c h a r a c t e r i z e d in that the position of valve body (7, 18, 54) is controlled by the inclination of the isolating device, the valve body occupying a closed position, when the inclina¬ tion of the device exceeds a certain inclination angle. 9. A foam and liquid isolating device according to any of the prece¬ ding claims, c h a r a c t e r i z e d by an upper movable valve element (7, 18) and a lower movable valve element (6), the movement of the upper valve element being influenced by the fall of pressure across the filter (19) as well as by the inclination of the isolating device. 10. A foam and liquid isolating device according to any of the prece¬ ding claims, c h a r a c t e r i z e d in that the valve body is guided vertically in a cylindrical guide means (26, 65) with an easily running fit, the length of said guide means being at least the same as the diameter of the guide means. 11. A foam and liquid isolating device according to claim 10, c h a r a c t e r i z e d in that said guide means is the same as said bypass-passage. 12. A foam and liquid isolating device according to any of the prece¬ ding claims, c h a r a c t e r i z e d in that it includes a plane, preferably circular sealing disk (44) , which supports said isolating device and covers on one side open containers (53) having different configurations, e.g. household buckets of different sizes, as well as seals against the upper edge (56) of said containers and forms a firm joint with such a container, when it is influenced by that vacuum, which is generated in said container during a foam and liquid isolation process.

Inventors: JOSEFSSON THURE, JOSEFSSON, THURE
Applicants: BE CLEAN PRODUKT I BORAAS AKTI, BE-CLEAN PRODUKT I BORAAS AKTIEBOLAG
Application year: 1990
Main classification: A47L7
IPC codes: A47L7