GB2492045A

GB2492045A - Water harvesting system

Info

Publication number: GB2492045A
Application number: GB1109541.1A
Authority: GB
Inventors: Steve Healey
Original assignee: Polypipe Ltd
Current assignee: Polypipe Ltd
Priority date: 2011-06-07
Filing date: 2011-06-07
Publication date: 2012-12-26
Also published as: GB201109541D0

Abstract

A filtering apparatus 1 for liquid comprises a chamber 3, inlet 4 for liquid with debris therein, a first outlet 5, a second outlet 6 and filter 7 for filtering liquid. The inlet and second outlet have a flow path P therebetween, and liquid filtered by the filter leaves the chamber via the first outlet. The second outlet is arranged to receive debris and liquid that has not left the chamber via the first outlet. In one aspect, the flow path at the inlet is laterally offset from a notional central axis of the chamber so that liquid is supplied tangentially to a wall of the chamber. In another aspect, the flow path immediately before the filter is oblique to a tangent to a point on the surface of the filter where the flow path meets the filter. Preferably, the filter comprises a plastics mesh. The chamber may comprise a third outlet (8, Fig. 3) as an overflow.

Description

Water Harvesting System The present invention relates to a water harvesting system.

Water harvesting systems are known, in which grey water can be recycled and reused.

Water harvesting can also be used to collect rain water to then be used as grey water in a home, for example. In the case of rain water collection, rain water is collected from rooftops of a building, via existing gutters and dowripipes, and is then filtered in order to remove debris such as leaves and the like, which have also been collected. However, such filters can be easily blocked, so reducing or even stopping their function and causing a blockage in the system which must be manually cleared. Additionally, a problem with many filters known in the art is that as the flow rate into the filter increases, the efficiency of the filter decreases.

The present invention seeks to overcome or mitigate at least one of the disadvantages

of the prior art.

According to an aspect of the invention, there is provided a filtering apparatus for liquid, comprising: a chamber having an inlet for liquid with debris therein, a first outlet and a second outlet; and filtering means for filtering liquid, wherein liquid filtered by the filtering means leaves the chamber via the first outlet, and the second outlet is arranged to receive debris and liquid that has not left the chamber via the first outlet.

The filtering apparatus may comprise a body or housing including the chamber. The body or housing may define a flow path for liquid from the inlet to the second outlet.

The flow path at the inlet may be laterally offset from a notional central axis of the chamber. Such a notional axis may be vertical. Depending on the shape of the chamber, this arrangement may allow the flow path to follow the surface of the chamber in a swirling motion.

The filtering means may be positioned in the flow path. Furthermore, the inlet may be oriented to supply liquid substantially tangentially to the wall of the chamber.

By providing the second outlet as described, the filtering apparatus is less prone to clogging. This is because even if the flow rate of liquid into the chamber is larger than the flow rate of liquid out of the chamber via the first outlet, for example if the filtering means is clogged with debris, or if the first outlet is not sufficiently large to allow the same flow rate out of the chamber, then liquid can leave the chamber via the second outlet. Thus there is less likely to be an accumulation of liquid, in particular rainwater or greywater, in downpipes connected to the inlet, and so such downpipes can continue to pipe rainwater away from rooftops and greywater away from baths and showers.

Furthermore, the supplying of liquid substantially tangentially to the wall of the chamber causes the flow of liquid in the chamber to swirl around the chamber helping clear debris from the filtering means.

The second outlet also allows debris that has been trapped by the filtering means and prevented from leaving the chamber via the first outlet to be removed from the chamber by liquid flowing out of the second outlet. Consequently, the filtering apparatus, and in particular the filtering means, needs less manual cleaning or unclogging.

The flow path immediately before the filtering means may be oblique to a tangent to a point on the surface of the filtering means where the flow path meets the filtering means, so that the flow of liquid in the flow path can remove debris trapped by the filtering means. This means that the flow of liquid in the flow path is better able to remove trapped debris from the filtering means. This is because the flow of liquid is not forcing the trapped debris directly onto the filtering means.

The filtering means may comprise wedge-shaped wires defining apertures therebetween, the tips of the wedges of the wedge-shaped wires pointing downstream of the filtering means. A filtering means of this type is less prone to clogging than a conventional mesh filter because the narrowest part of each aperture is at the upstream side of the filtering means.

The filtering means may be positioned in the first outlet. Alternatively, the filtering means may be positioned between the inlet and the first outlet.

The first outlet may be positioned on a notional central axis of the chamber.

Alternatively, the second outlet may be positioned on a notional central axis of the chamber. The notional central axis may be vertical.

The second outlet may be positioned nearer the bottom of the chamber than the filtering means, possibly at the bottom of the chamber, thereby allowing debris and liquid that has not left the chamber via the first outlet to flow towards the second outlet by gravity. This contributes to keeping liquid flowing freely through the filtering means because the liquid is directed to the second outlet by gravity.

The filtering means may be positioned nearer the bottom of the chamber than the inlet, whereby the flow of liquid from the inlet into the chamber is more effectively directed at the filtering means and can flow more freely.

The first outlet may be positioned nearer the bottom of the chamber than the second outlet, possibly at the bottom of the chamber.

The wedge-shaped wires of the filtering means may form a tubular filter, and may be disposed all around the circumference of the tubular filter. This allows liquid to pass through the tubular filter in all around its circumference.

The wedge-shaped wires of the tubular filter may extend lengthways, or in a circumferential direction, or may extend around the circumference of the tubular filter in an oblique direction to the lengthways direction of the tubular filter.

The filtering means may have a substantially flat or planar surface. In situ, when the apparatus is installed or in use, the surface of the filtering means may be vertical or inclined from the vertical. This allows trapped debris to be removed by gravity from the filtering means even when liquid is not flowing through the filtering apparatus. The direction of inclination may be in the same vertical plane as that of the direction of the flow path immediately before the filtering means, or it may be in a different vertical plane.

The filtering apparatus may comprise a body or housing, and the filtering means may comprise a bracket for joining the filtering means to the body or housing.

The filtering means may comprise a spigot for locating the filtering means in the first outlet.

The chamber may comprise a concave or bowl-shaped section. If the chamber comprises a concave section, the flow of liquid may curve around the sides of the chamber, and may be spiral. This allows a smooth flow of liquid around the sides of the chamber, leading to a good flow rate of liquid. The chamber may comprise a hemispherical concave section and a cylindrical section adjoining the hemispherical section. The first outlet and filtering means may be in the hemispherical section. The first outlet and filtering means may also or instead be in the cylindrical section adjoining the hemispherical section.

The chamber may have a third outlet which is preferably an overflow outlet positioned nearer the top of the chamber than the filtering means. The third outlet may be positioned nearer the top of the chamber than the second outlet. The overflow outlet allows liquid to leave the chamber if the chamber becomes excessively full.

The third outlet may be connected downstream of the chamber to the second outlet.

Thus the second and third outlets may feed into a drainage system.

The first outlet may comprise a plurality of apertures. The filtering means may be a mesh made of plastic, or of metal. In this case, if the filtering means is positioned in the first outlet then a plurality meshes will be positioned in the apertures of the first outlet.

Such meshes are well-known and easily procured, and furthermore can easily be replaced if broken. Meshes may be provided in the first outlet so that they can be easily installed and removed, allowing them to be changed to suit the location at which the apparatus is used. For example, rainwater harvested at one location may contain debris of a different general size to that harvested at another location.

The filtering apparatus may be positioned above a reservoir for receiving liquid which has left the chamber via the first outlet. This avoids the need for further connections to the first outlet, leading to better access to the first outlet and to the filtering means if positioned in the first outlet.

The apparatus is particularly suited to filtering water, which is usually rainwater with debris such as sticks, leaves or the like therein. A lid for the chamber may be provided to allow the chamber to be pressurised thereby increasing the flow of liquid through the chamber.

According to another aspect of the invention, there is provided a filtering apparatus for liquid, comprising an inlet for liquid with debris therein, a first outlet and a second outlet; and filtering means for filtering liquid; wherein the inlet and the second outlet have a flow path therebetween, and the filtering means is for filtering liquid leaving the flow path via the first outlet, and the second outlet is arranged to receive debris and liquid that has not left the flow path via the first outlet.

At least part of the flow path may be defined by the filtering means, and possibly the whole of the flow path may be defined by the filtering means.

The filtering means may allow liquid to leave the flow path in at least one direction. This provides an improved flow rate of liquid leaving the filtering means compared to conventional filtering apparatuses which allow liquid to leave in only one direction.

Furthermore, the filtering means may allow liquid to leave the flow path in an opposite direction or opposite directions to the at least one direction.

The filtering means may comprise a filter, the filter defining at least part of the flow path, the filter allowing liquid to leave the flow path. The filtering means may define a passageway containing the flow path. The filtering means may comprise a tubular filter.

The wedge-shaped wires of the filtering means may form a tubular filter. The wedge-shaped wires may be disposed all around the circumference of the tubular filter, so allowing liquid to leave the tubular filter all around its circumference. The wedge-shaped wires of the tubular filter may extend lengthways, or in a circumferential direction, or may extend around the circumference of the tubular filter in an oblique direction to the lengthways direction of the tubular filter.

The filtering means may comprise two like filter units. Each filter unit may comprise a bracket for joining the fitter units together. The filtering apparatus may further comprise a housing for the filtering means, and the housing may comprise two like housing units.

Two joined brackets may interposed between the housing units. The housing may comprise two openings, for the inlet and second outlet, respectively. Each filter unit may comprise a spigot for locating the filter unit in an opening of the housing. The housing may comprise an outlet for filtered liquid to leave the housing.

Embodiments of the invention will now be described, purely by way of example, with reference to the accompanying drawings in which: Figure 1 is a part-sectional plan view of a filtering apparatus according to a first embodiment of the invention; Figure 2 is a magnified plan view of part B of the filtering apparatus of Figure 1; Figure 3 is elevation view of the filtering apparatus of Figure 1; Figure 4 is a magnified plan view of part A of the filtering apparatus of Figure 1; Figure 5 is an isometric view of the filtering apparatus of Figure 1; Figure 6 is an elevation view of the filtering apparatus of Figure 1.

Figure 7 is an elevation view of a filtering means according to a second embodiment of the invention.

Figure 8 is a sectional view of the filtering means of Figure 7 taken along A-A.

Figure 9 is a magnified view of part E of Figure 8.

Figure 10 is a plan view of a filtering apparatus according to the second embodiment of the invention.

Figure 11 is a sectional view taken of the filtering apparatus of Figure 10 taken along B-B. Figure 12 is an elevation view of a filtering means according to a third embodiment of the invention.

Figure 13 is a sectional view of the filtering means of Figure 12 taken along C-C.

Figure 14 is a magnified view of part F of Figure 13.

Figure 15 is a plan view of a filtering apparatus according to the third embodiment of the invention.

Figure 16 is a sectional view of the filtering apparatus of Figure 15 taken along D-D.

Referring to Figures 1 and 2 of the accompanying drawings, a filtering apparatus I comprises a body 2 including a chamber 3 suitable for receiving liquid. In the present embodiment, the body is formed in one piece, but multi-piece construction would be possible. The chamber 3 has an inlet 4 for liquid with debris therein, a first outlet 5, and a second outlet 6. Filtering means 7 is provided for filtering liquid. The body 2 defines a flow path P for liquid from the inlet 4 to the second outlet 6. The filtering means 7 is positioned in the flow path P. Liquid filtered by the filtering means 7 leaves the chamber 3 via the first outlet 5. The flow of liquid immediately before the filtering means 7 is laterally oblique to a tangent to a point on the surface of the filtering means 7 where the flow of liquid meets the filtering means 7. In this embodiment, the upstream surface of the filtering means 7 is substantially planar. In this embodiment, the filtering means 7 is angled to be oblique to the flow path P immediately before the filtering means 7. Therefore, the filtering means is oriented such that the flow path P immediately before the filtering means forms an oblique angle with the surface of the filtering means. The second outlet 6 is arranged to receive debris and liquid that has not left the chamber 3 via the first outlet 5. Such debris may have been prevented from leaving the flow path P by the filtering means 7.

The chamber 3 is defined by one or more surfaces of the body 2. An overflow outlet 8 is provided in addition to the first and second outlets St 6, above those outlets to allow escape of liquid from the chamber 3 if the level of liquid rises to a predetermined level.

The chamber 3 has a concave hemispherical section and cylindrical section adjoining the open end of the hemispherical section.

The inlet 4 is connected to an inlet passageway through which liquid can flow to the inlet 4 and into the chamber 3. Figure 3 shows an inlet pipe 9 containing the inlet passageway. The filtering means 7 is a mesh made of plastics material. Alternatively, the mesh could be made of another material such as metal as is known in the art. The mesh is provided within the first outlet 5, the edges of the mesh being flush with the surface of the body 2 defining the hemispherical section of the chamber 3. The second outlet 6 is connected to a main outlet passageway through which liquid can flow from the chamber 3 and second outlet 6. Figure 3 shows a main outlet pipe 10 containing the main outlet passageway. The main outlet passageway is connected to a drainage system. Figure 3 shows a drain pipe 11 leading to the drainage system. The overflow outlet 8 is connected to an overflow outlet passageway through which liquid can flow from the chamber 3 and overflow outlet 8. Figure 3 shows an overflow pipe 12 containing the overflow outlet passageway. The overflow passageway is connected to the main outlet passageway and drainage system.

The junctions of the inlet pipe 9, the main outlet pipe 10 and the overflow pipe 12 with the body 2 are all sealed with a sealing means, in this embodiment with 0' rings 13.

The filtering apparatus 1 will be described in its "upright" position, that is when the rim of the body 2 is in a horizontal plane. In this position the hemispherical section of the chamber 3 is directly below the cylindrical section of the chamber 3.

The second outlet 6 is positioned in the bottom of the chamber 3, at the lowest point in the hemispherical section of the chamber 3, and on a notional central vertical axis of the chamber 3. The inlet 4 is positioned in the hemispherical section of the chamber 3.

The inlet 4 is positioned above the filtering means 7 and the second outlet 6.

Furthermore, the filtering means 7 is positioned above the second outlet 6.

Referring to Figure 2, the chamber 3 has a flow path P for liquid from the inlet 4 to the second outlet 6. The direction of the flow path P at the inlet 4 is laterally offset from a notional central vertical axis of the chamber 3. Due to the chamber 3 being concave, and the relative positioning of the inlet 4 and the second outlet 6, the flow path P forms a spiral shape around the surface of the body 2 which defines the chamber 3. In particular, the inlet 4 and the inlet passageway are arranged such that the direction of the flow path P at the inlet 4 is laterally offset from a notional central vertical axis of the chamber 3. Thus, liquid entering the chamber 3 from the inlet 4 with sufficiently high velocity flows in a horizontal direction along the surface of the body 2 defining the chamber 3. In embodiments, the inlet passageway contained in the inlet pipe 9 is substantially horizontal as it approaches the inlet 4. As a result, the flow of liquid enters the chamber 3 substantially horizontally.

In embodiments, the inlet passageway in the inlet pipe 9 may be angled away from the horizontal causing the liquid flowing into the chamber 3 from the inlet 4 to be angled accordingly. Thus, the flow can be aimed at a filtering means 5 which is above or below the inlet 4.

The filtering means 7 is positioned in the flow path P. The filtering means 7 is also positioned within the hemispherical section of the chamber 3. The first outlet 5 comprises a plurality of apertures through which liquid can leave the chamber 3. In this embodiment, each aperture has a filtering means 7 therein. The apertures are positioned at a substantially constant height around the surface of the body 2 defining the chamber 3. Figure 1 shows the first outlet 5 comprising three apertures. Figure 4 shows an enlarged view of two of the apertures of the first outlet 5. In embodiments, the first outlet may comprise a single aperture.

In embodiments, the apertures, and filtering means 7 therein, may be positioned at varying heights around the surface of the body 2 defining the chamber 3. This would allow different filtering means 7, for example meshes of differing sizes, for different flow rates of liquid into the chamber 3. Thus, a high flow rate of liquid would encounter a filtering means 7 in an aperture at a greater relative height, and a low flow rate of liquid would encounter a filtering means 7 in an aperture at a lesser relative height. The filtering means 7 in the aperture at the greater relative height might be a mesh of larger size than a mesh in the aperture at the lesser relative height. As a result, when the flow rate into the chamber 3 is high, the liquid encounters the larger mesh which has less restriction on the flow out of the chamber 3, so reducing overflowing of the chamber 3.

On the other hand, when the flow rate into the chamber 3 is low, the liquid encounters the smaller mesh which removes more debris from the liquid leaving the chamber 3 through the first outlet 5.

Referring to Figure 3, when liquid flows into the chamber 3 through the inlet 4 with sufficiently high velocity and flow volume, the flow of liquid will follow the flow path P, first encountering the filtering means 7 in the three apertures of the first outlet 5, and then, due to the sloping surface of the body 2 defining the hemispherical section of the chamber 3, leaving the chamber 3 through the second outlet 6. Some of the liquid from the flow may have left the chamber via the first outlet 5. Debris carried into the chamber 3 by the flow of liquid will be prevented from leaving the chamber 3 via the first outlet 5 by the filtering means 7. This debris trapped by the filtering means 7 (residue) may be dislodged from the filtering means 7 by the continuing flow of liquid.

The residue may then be carried by the flow out of the chamber 3 via the second outlet 6. Alternatively, the residue may dislodge itself from the filtering means 7 due to the upstream surface of the filtering means being inclined from the horizontal. The residue may then move towards the second outlet 6 of the chamber 3 due to the sloping surface of the body 2 defining the chamber 3. This offers an advantage that the filtering means 7 is less likely to become clogged with debris since much of the debris initially trapped will then leave the chamber 3 through the second outlet 6.

The chamber 3 may begin to fill up with liquid if the flow of liquid into the chamber 3 exceeds the flow of liquid out of the chamber 3. If the chamber 3 becomes excessively full of liquid, the liquid will reach the overflow outlet 8 at the top of the chamber 3. The overflow outlet 8 provides another outlet for liquid to leave the chamber 3 to prevent the chamber 3 filling completely with liquid and overflowing.

Referring to Figures 1, 3, 5 and 6, the body 2 is positioned above a filtered liquid reservoir 14. The reservoir 14 is made from plastic and has an outer surface which is corrugated. The reservoir 14 is closed apart from apertures 15 which allow liquid leaving the chamber 3 via the first outlet 5 to fall into the reservoir 14 where it is collected. The apertures 15 are circular in cross-section. Aperture walls 16 forming a surface of circular cross-section are provided above the apertures 15. The aperture walls 16 guide liquid which has left the chamber 3 via the first outlet 5 into the reservoir 14. Often this liquid will not fall directly downwards from the first outlet 5.

Variations on the first embodiment are envisaged and will be described.

The inlet 4 may not be positioned in the hemispherical section of the chamber 3, but it may be positioned in the cylindrical section instead.

The chamber may have a different sectionai shape than a circle. For example, the chamber may have an elliptical cross-section, or other shapes may be envisaged by those skilled in the art.

In the first embodiment the chamber does not have a lid. A lid for the chamber may nonetheless be provided, and this is within the scope of the invention.

Figure 7 shows a filtering means 7 which is suitable for use in the filtering apparatus 1 of the second embodiment of the invention. Referring to Figures 7 and 8, the filtering means 7 comprises a tubular filter 23 with a bracket 20 at one end, and a spigot 22 at the other end. The filter 23 defines a passageway which passes through the bracket 20 and the spigot 22. In this embodiment the filter 23 is provided to filter liquid flowing from outside the filtering means 7 through the filter 23 to inside the filtering means 7.

The filter 23 comprises a plurality of wedge-shaped wires 24. Each wedge-shaped wire 24 has a triangular cross-section. In this embodiment, the filter 23 is formed by the wires 24 being disposed Iengthways from one end of the filter 23, at an interface with the spigot 22, to the other end of the filter 23, at an interface with the bracket 20. The wires 24 are disposed all around the circumference of the filter 23. In embodiments, each wedge of the wedge-shaped wires 24 is symmetrical about an axis between its tip and blunt end.

The wires 24 define therebetween wedge-shaped apertures 25 through which liquid can pass. The wires 24 have a regular side-by-side arrangement, and are oriented so that each tip of the wedge of a wire 24 points inwards in a direction perpendicular to the general surface of the filter 23 at that point. Thus the tips point downstream of the filtering means 7, and the width of each aperture 25 increases from the outside to the inside of the filter 23.

When liquid passes through the filter 23, debris having dimensions larger than the width of apertures 25 contained in the liquid is prevented from passing through the filter 23 by the wires 24. As a result of the width of the apertures 25 being smallest at the outside surface of the filter 23, less debris becomes trapped in the filter 23. This is because, for example, a particle which has passed through the width of an aperture 25 at the outside surface of the filter 23 generally then passes right through the rest of the aperture 25 and into the inner passageway of the filter 23.

The filter 23 further comprises a plurality of support bands 26 disposed at regular intervals along the length of the filter 23. In this embodiment the support bands are steel. Each support band is disposed on the inside of the filter 23, against the inner surface of the filter 23. In this embodiment, each support band is disposed against blunt ends of the wedges of the wires 24. The support bands 26 support the wires 24 helping the filter 23 maintain its shape.

Referring to Figures 10 and 11, a filtering apparatus I comprises a body 2 including a chamber 3 suitable for receiving liquid. The chamber 3 has an inlet 4 for liquid with debris therein, a first outlet 5, and a second outlet 6. Filtering means 7 is provided for filtering liquid. The body 2 defines a flow path P for liquid from the inlet 4 to the second outlet 6. The filtering means 7 is positioned in the flow path P. Liquid may be filtered by the filtering means 7 by passing through the filter 23 to the inside of the filter 23.

This liquid then leaves filtering means 7 via the first outlet 5. The flow of liquid immediately before the filtering means 7 is laterally oblique to a tangent to a point on the surface of the filtering means 7 where the flow of liquid meets the filtering means 7.

The second outlet 6 is arranged to receive debris and liquid that has not left the chamber 3 via the first outlet 5.

The filtering apparatus I will be described in its "upright" position, that is when the rim of the body 2 is in a horizontal plane. In this position the hemispherical section of the chamber 3 is directly below the cylindrical section of the chamber 3.

The chamber 3 is defined by one or more surfaces of the body 2. Additionally, the chamber 3 is defined by the filtering means 7. An overflow outlet 8 is provided in addition to the first and second outlets 5, 6, above those outlets to allow escape of liquid from the chamber 3 if the level of liquid rises to a predetermined level. The chamber 3 has a generally concave hemispherical section and cylindrical section adjoining the open end of the hemispherical section.

In this embodiment, the first outlet 5 is positioned in the bottom of the chamber 3, at the lowest point in the hemispherical section of the chamber 3, and on a notional central vertical axis of the chamber 3. The inlet 4 is positioned in the hemispherical section of the chamber 3.

The spigot 22 of the filtering means 7 fits tightly into an opening 31 in the body leading away from the first outlet 5 in the bottom of the chamber 3. The spigot 22 is sealed in the opening 31 with an 0' ring 32. The filter 23 stands upright in the chamber 3. The outer edge of the bracket 20 is attached by bolts 18 and sealed using a seal 17 to the rim of the body 2, so holding the filtering means 7 in place. Furthermore, because the top of the chamber 3 is sealed in this way, the liquid in the chamber 3 may be pressurised to force more liquid through the filtering means 7 without the liquid overflowing out of the top of the chamber 3.

As described for the first embodiment, the body 2 defines a flow path P from the inlet 4 to the second outlet 6, and the filtering means 7 is positioned in the flow path P. However, in this embodiment, as shown in Figures 10 and 11, the second outlet 6 is positioned diametrically opposite in the chamber 3 to the inlet 4. The direction of the inlet 4 and the direction of the second outlet 6 are substantially parallel in this embodiment. Furthermore, in this embodiment, the overflow outlet 8 is positioned directly above the second outlet 6, and their directions are parallel.

In this embodiment, the tubular filter 23 of the filtering means 7 has apertures all around its circumference. The tubular filter 23 is positioned upright in the first outlet 5. If the flow rate into the filtering apparatus I is small then only the bottom end of filter 23 will be in contact with the flow, and will allow liquid to leave the flow path P to pass through the filter 23 to the inside of the filter 23. As the flow rate into the filtering apparatus I increases, more of the filter 23 will be in contact with the flow. Therefore, more of the flow will be filtered by the filtering means 7. If the flow rate into the filtering apparatus I is so large that the flow is in contact with the whole of the outer surface of the filter 23, it may be possible to increase the flow through the filtering means I further by raising the pressure of the liquid in the chamber 3, so forcing more liquid through the filter 23.

Figure 12 shows a filter component 200 which is suitable for use in the filtering apparatus 101 of the third embodiment of the invention. Referring to Figures 12 and 13, the filter component 101 comprises a tubular filter 123 with a bracket 120 at one end, and a spigot 122 at the other end. The filter 123 defines a passageway which passes through the bracket 120 and the spigot 122. ln this embodiment the filter 123 is provided to filter liquid flowing from inside the filter component 101 through the filter 123 to outside the filter component 101.

The filter 123 comprises a plurality of wedge-shaped wires 124. Each wedge-shaped wire 124 has a triangular cross-section. In this embodiment, the filter 123 is formed by the wires 124 being disposed lengthways from one end of the filter 123, at an interface with the spigot 122, to the other end of the filter 123, at an interface with the bracket 120. The wires 124 are disposed all around the circumference of the filter 23.

The wires 124 define therebetween wedge-shaped apertures 125 through which liquid can pass. The wires 124 have a regular side-by-side arrangement, and are oriented so that each tip of the wedge of a wire 124 points outwards in a direction perpendicular to the general surface of the filter 123 at that point. Thus the tips point downstream of the filter component 200, and the width of each aperture 125 increases from the inside to the outside of the filter 123.

When liquid passes through the filter 123, debris having dimensions larger than the width of apertures 125 contained in the liquid is prevented from passing through the filter 123 by the wires 124. As a result of the width of the apertures 125 being smallest at the inside surface of the filter 123, less debris becomes trapped in the filter 123. This is because, for example, a particle which has passed through the width of an aperture 125 at the inside surface of the filter 123 generally then passes right through the rest of the aperture 125 to the outside of the filter 123.

The filter 123 further comprises a plurality of support bands 126 disposed at regular intervals along the length of the filter 123. In this embodiment the support bands are steel. Each support band is disposed on the inside of the filter 123, against the inner surface of the fUter 123. In this embodiment, each support band is disposed against the blunt ends of the wedges of the wires 124. The support bands 126 support the wires 124 helping the filter 123 maintain its shape.

Referring to Figures 15 and 16, a filtering apparatus 101 for liquid comprises an inlet 104 for liquid with debris therein, a first outlet 105 and a second outlet 106, and filtering means 107 for filtering liquid. The filtering apparatus 101 comprises two of the filter component 101 shown in Figure 12. The filter components 200 are arranged so that their brackets 120 face each other. The brackets 120 are joined together so that the passageway defined by the filter 123, bracket 120 and spigot 122 of each filter component 200 is aligned.

The filtering apparatus 101 shown in Figure 16 is described with a flow of liquid moving through the filtering apparatus 101 from left to right. However, the flow could move from right to left by connecting a supply of liquid to the feature named second outlet 106.

The filtering means 107 defines a flow path P from the inlet 104 to the second outlet 106. Liquid which has entered the filtering means 107 through the inlet 104 can leave the flow path P via the first outlet 105. In this embodiment, the first outlet comprises the filters 123 of the two filter components 200. Debris having dimensions larger than the width of apertures 125 is prevented from passing through the first outlet 105 and so remains in the filtering means 107. The wedge-shaped cross-section of wires 124 of the filter component 200 minimises the amount of debris that is trapped in the filter component 200. This minimises blocking of the filter component 200 because the debris which has been prevented from passing through the filter component 123 can be moved further along the flow path P by the continuing flow of liquid, towards the second outlet 106. Liquid and debris may then leave the filtering apparatus 101 via the second outlet 106.

In this embodiment, the tubular filter 123 of the filter component 200 has apertures all around its circumference. Thus, in the filtering apparatus 101, the first outlet 105 is provided all around the circumference of the tubular filter 123 of the filtering means 107. When the filtering apparatus is installed so that the passageway defined by the filter 123 is substantially horizontal, if the flow rate into the filtering apparatus 101 is small then only the bottom of the circumference of the tubular filter 123 will be in contact with the flow, and wilt allow liquid to leave the flow path P and filtering means 107 via the first outlet 105. On the other hand, if the flow rate into the filtering apparatus 101 is large then the whole of the circumference of the tubular filter 123 will be in contact with the flow, and will allow liquid to leave the flow path P and filtering means 107 via the first outlet 105.

In this embodiment, the filtering apparatus comprises a housing 102 for the filtering means 107. The housing 102 comprises two parts, each part having a first opening 130 and a second opening 131. Each part also has an open face through which the filtering means 107 passes. The joined brackets 120 of the filter components 200 are interposed between the two parts of the housing 102 at the open faces. The two parts of the housing 102 are joined together by bolts 118 around the outer edges of the brackets 120.

The first openings 130 are to the side of the filtering means 107 and are directed substantially perpendicularly to the flow path P. In this embodiment, the first openings are directed downwards allowing the flow of liquid from the first outlet 105 to be directed.

The second openings 131 are coaxial with the flow path P. Each second opening 131 contains a spigot 122 of a filter component 200 in a tight fit, sealed with an O' ring 132.

In this embodiment, the housing 102 comprises two parts, and the filtering means 107 comprises two parts. This allows the filtering apparatus 101 to be taken apart easily to be cleaned by hand, as required by some national building regulations.

The third embodiment described is preferred, but variations on that embodiment are envisaged. For example, in the third embodiment, the filter 23 is formed by the wires 24 being disposed Iengthways along the filter 23. Alternatively, the wires 24 may be disposed circumferentially around the circumference of the filter 23.

The filtering apparatus of this invention is particularly suitable for filtering rainwater collected from the roofs of buildings. Such rainwater often acquires debris in the form of leaves, sticks or matter deposited on roofs of buildings and washed off by rainwater into the harvesting system.

Claims

CLAIMS: 1. A filtering apparatus for liquid, comprising: a body including a chamber, the chamber having an inlet for liquid with debris therein, a first outlet and a second outlet; and filtering means for filtering liquid; wherein the body defines a flow path for liquid from the inlet to the second outlet, liquid filtered by the filtering means leaving the chamber via the first outlet, and the second outlet is arranged to receive debris and liquid that has not left the chamber via the first outlet, and wherein the flow path at the inlet is laterally offset from a notional central axis of the chamber.
2. A filtering apparatus for liquid, comprising: a body including a chamber, the chamber having an inlet for liquid with debris therein, a first outlet and a second outlet; and filtering means for filtering liquid; wherein the body defines a flow path for liquid from the inlet to the second outlet, the filtering means being positioned in the flow path, liquid filtered by the filtering means leaving the chamber via the first outlet, and wherein the flow path immediately before the filtering means is oblique to a tangent to a point on the surface of the filtering means where the flow path meets the filtering means, and the second outlet is arranged to receive debris and liquid that has not left the chamber via the first outlet.
3. A filtering apparatus for liquid, comprising: a chamber having an inlet for liquid with debris therein, a first outlet and a second outlet; and filtering means for filtering liquid; wherein the inlet is oriented to supply liquid substantially tangentially to the wall of the chamber, liquid filtered by the filtering means leaving the chamber via the first outlet, and the second outlet is arranged to receive debris and liquid that has not left the chamber via the first outlet.
4. A filtering apparatus as claimed in claim 1, wherein the flow path immediately before the filtering means is oblique to a tangent to a point on the surface of the filtering means where the flow of liquid meets the filtering means.
5. A filtering apparatus as claimed in claim 2, wherein the flow path at the inlet is laterally offset from a notional central axis of the chamber.
6. A filtering apparatus as claimed in any preceding claim, wherein the filtering means comprises wedge-shaped wires defining apertures therebetween, the tips of the wedges of the wedge-shaped wires pointing downstream of the filtering means.
7. A filtering apparatus as claimed in any preceding claim, wherein the filtering means is positioned in the first outlet.
8. A filtering apparatus as claimed in any one of claims I to 6, wherein the filtering means is positioned between the inlet and the first outlet.
9. A filtering apparatus as claimed in any preceding claim, wherein the first outlet is positioned on a notional central axis of the chamber.
10. A filtering apparatus as claimed in any one of claims I to 8, wherein the second outlet is positioned on a notional central axis of the chamber.
Ii. A filtering apparatus as claimed in any preceding claim, wherein the chamber has a top and a bottom, and the second outlet is positioned nearer the bottom of the chamber than the filtering means.
12. A filtering apparatus as claimed in any preceding claim, wherein the chamber has a top and a bottom, and the second outlet is positioned at the bottom of the chamber,
13. A filtering apparatus as claimed in any preceding claim, wherein the chamber has a top and a bottom, and the filtering means is positioned nearer the bottom of the chamber than the inlet.
14. A filtering apparatus as claimed in any one of claims I to 11, or 13, wherein the chamber has a top and a bottom, and the first outlet is positioned nearer the bottom of the chamber than the second outlet.
15. A filtering apparatus as claimed in any one of claims 1 to 11, 13 or 14, wherein the chamber has a top and a bottom, and the first outlet is positioned at the bottom of the chamber.
16. A filtering apparatus as claimed in claim 6 or in any preceding claim dependent thereon, wherein the wedge-shaped wires form a tubular filter.
17. A filtering apparatus as claimed in claim 16, wherein the wedge-shaped wires are disposed all around the circumference of the tubular filter.
18. A filtering apparatus as claimed in claim 16 or 17, wherein the wedge-shaped wires of the tubular filter extend lengthways.
19. A filtering apparatus as claimed in claim 16 or 17, wherein the wedge-shaped wires of the tubular filter extend in a circumferential direction.
20. A filtering apparatus as claimed in any one of claims I to 15, wherein the filtering means has a substantially flat surface.
21. A filtering apparatus as claimed in claim 3, comprising a body including the chamber.
22. A filtering apparatus as claimed in any one of claims 1, 2 or 4 to 21, wherein the filtering means comprises a bracket for joining the filtering means to the body.
23. A filtering apparatus as claimed in any preceding claim, wherein the filtering means comprises a spigot for locating the filtering means in the first outlet.
24. A filtering apparatus as claimed in any preceding claim, wherein the chamber comprises a concave section.
25. A filtering apparatus as claimed in claim 24, wherein the flow path of liquid from the inlet to the second outlet is spiral.
26. A filtering apparatus as claimed in any preceding claim, wherein the chamber comprises a cylindrical section.
27. A filtering apparatus as claimed in any preceding claim, wherein the chamber further comprises a third outlet.
28. A filtering apparatus as claimed in claim 27, wherein the third outlet is an overflow outlet.
29. A filtering apparatus as claimed in claim 27 or 28, wherein the chamber has a top and a bottom, and the third outlet is positioned nearer the top of the chamber than the filtering means.
30. A filtering apparatus as claimed in claim 27, 28 or 29, wherein the chamber has a top and a bottom, and the third outlet is positioned nearer the top of the chamber than the second outlet.
31. A filtering apparatus as claimed in any one of claims 27 to 30, wherein the third outlet is connected downstream of the chamber to the second outlet.
32. A filtering apparatus as claimed in any preceding claim, wherein the first outlet comprises a plurality of apertures.
33. A filtering apparatus as claimed in any preceding claim, wherein the filtering apparatus is positioned above a reservoir for receiving liquid which has left the chamber via the first outlet.
34. A filtering apparatus as claimed in any preceding claim, wherein the liquid is water.
35. A filtering apparatus as claimed in any preceding claim, further comprising a lid for the chamber.
36. A filtering apparatus for liquid, comprising: an inlet for liquid with debris therein, a first outlet and a second outlet; and filtering means for filtering liquid; wherein the inlet and the second outlet have a flow path therebetween, and the filtering means is for filtering liquid leaving the flow path via the first outlet, and the second outlet is arranged to receive debris and liquid that has not left the flow path via the first outlet.
37. A filtering apparatus as claimed in claim 36, wherein the filtering means comprises wedge-shaped wires defining apertures therebetween, the tips of the wedges of the wedge-shaped wires pointing downstream of the filtering means.
38. A filtering apparatus as claimed in claim 36 or 37, wherein at least part of the flow path is defined by the filtering means.
39. A filtering apparatus as claimed in claim 36 or 37, wherein the whole flow path is defined by the filtering means.
40. A filtering apparatus as claimed in any one of claims 32 to 39, wherein the filtering means allows liquid to leave the flow path in at least one direction.
41. A filtering apparatus as claimed in claim 40, wherein the filtering means allows liquid to leave the flow path in an opposite direction or opposite directions to the at least one direction.
42. A filtering apparatus as claimed in claim 36 or 37, wherein the filtering means comprises a filter, the filter defining at least part of the flow path, the filter allowing liquid to leave the flow path.
43. A filtering apparatus as claimed in any one of claims 36 to 42, wherein the filtering means defines a passageway containing the flow path.
44. A filtering apparatus as claimed in claim 36, wherein the filtering means comprises a tubular filter.
45. A filtering apparatus as claimed in claim 37 or any preceding claim dependent thereon, wherein the wedge-shaped wires form a tubular filter.
46. A filtering apparatus as claimed in claim 45, wherein the wedge-shaped wires are disposed all around the circumference of the tubular filter.
47. A filtering apparatus as claimed in claim 45 or 46, wherein the wedge-shaped wires of the tubular filter extend lengthways.
48. A filtering apparatus as claimed in claim 45 or 46, wherein the wedge-shaped wires of the tubu'ar filter extend in a circumferential direction.
49. A filtering apparatus as claimed in claim 45 or 46, wherein the wedge-shaped wires of the tubular filter extend around the circumference of the tubular filter in an oblique direction to the lengthways direction of the tubular filter.
50. A filtering apparatus as claimed in any one of claims 36 to 49, wherein the filtering means comprises two like filter units.
51. A filtering apparatus as claimed in claim 50, wherein each filter unit comprises a bracket for joining the filter units together.
52. A filtering apparatus as claimed in any one of claims 36 to 51, further comprising a housing for the filtering means.
53. A filtering apparatus as claimed in claim 52, wherein the housing comprises two like housing units.
54. A filtering apparatus as claimed in claim 53 when dependent on claim 51, wherein the two joined brackets are interposed between the housing units.
55. A filtering apparatus as claimed in claim 52, 53 or 54, wherein the housing comprises two openings, for the inlet and second outlet, respectively.
56. A filtering apparatus as claimed in claim 55 when dependent on claim 50, wherein each filter unit comprises a spigot for locating the filter unit in an opening of the housing.
57. A filtering apparatus as claimed in any one of claims 52 to 56, wherein the housing comprises an outlet for filtered liquid to leave the housing.
58. A filtering apparatus, substantially as hereinbefore described with reference to any of the accompanying drawings.