FILTER

Abstract

The present invention discloses a filter comprising a tube extending from a first end to a second end and having a bore with an internal cross-sectional area. The tube comprises an inlet with an inlet cross-sectional area which is positioned through the first end of the tube. The tube also comprises an outlet with an outlet cross-sectional area, wherein the inlet cross-sectional area is less than the outlet cross-sectional area and so debris small enough to enter the inlet will tend not to block the outlet, which is larger. The filter further comprises a plurality of further inlets, often slots, in the tube between an outside thereof and the bore. In a preferred embodiment, the first end may be tapered and especially dome shaped. This helps to direct debris towards an outside of the tube, where it is less likely to be drawn into the filter and potentially block it or a downstream component, such as a nozzle. The filter may be attached to a pipeline and a nozzle.

Claims

1. A filter comprising: a tube extending from a first end to a second end, the tube having a bore with an internal cross-sectional area; an inlet to the tube, the inlet being positioned through the first end of the tube and the inlet having an inlet cross-sectional area; an outlet from the tube the outlet having an outlet cross-sectional area; a plurality of further inlets in the tube between an outside thereof and the bore; wherein the inlet cross-sectional area is less than the outlet cross-sectional area.

2. A filter according to claim 1, wherein the inlet cross-sectional area is less than the internal bore cross-sectional area.

3. A filter as claimed in any preceding claim, wherein the combination of the inlet and the plurality of further inlets provides a K-factor equivalent or greater than the K-factor of an open tube of the same dimensions as the tube of the filter.

4. A filter as claimed in any preceding claim, wherein the first end is tapered such that the centre of the first end extends longitudinally further than an outer portion of the first end.

5. A filter as claimed in any preceding claim, wherein the first end is dome-shaped.

6. A filter as claimed in any preceding claim, comprising a pipeline mounting means for mounting it to a pipeline.

7. A filter as claimed in any preceding claim, comprising a nozzle mounting means for mounting a nozzle thereto.

8. A filter as claimed in any preceding claim, wherein the further inlets comprise slots.

9. A filter as claimed in any preceding claim, wherein the further inlets extend generally parallel to the longitudinal direction from the first to the second end.

10. A filter as claimed in any preceding claim, wherein the further inlets extend for up to 75% or up to 50% of the length of the tube.

11. A filter as claimed in any preceding claim, wherein the further inlets extend for a portion of the tube between the first end and a middle of the tube.

12. A filter as claimed in any preceding claim, wherein there is at least 4 further inlets, optionally up to 20 or up to 24.

13. A filter as claimed in any preceding claim, wherein the further inlets have a width of at least 1 mm or optionally, a width of 1-3 mm or 1.5-2.5 mm.

14. A filter as claimed in any preceding claim, wherein spacing between the further inlets is 50%-150% larger than the width of the slots.

15. A filter as claimed in any preceding claim, wherein the cross-sectional area of the inlet has a height to width ratio of at most 2:1, optionally at most 1.5:1 or at most 1.1:1.

16. A filter as claimed in any preceding claim, wherein the internal cross-sectional area of the tube has a height to width ratio of at most 2:1 optionally at most 1.5:1 or at most 1.1:1.

17. A nozzle apparatus, comprising a filter as claimed in any preceding claim, and a nozzle with a nozzle outlet, the nozzle outlet having a nozzle outlet cross-sectional area.

18. A nozzle apparatus as claimed in claim 17, wherein the inlet cross sectional area is less than the nozzle outlet cross-sectional area.

19. A nozzle apparatus as claimed in claim 17 or claim 18, wherein the further inlets are of a suitable length where two in combination equals or exceeds the flow required to give the corresponding K-Factor of a nozzle attached to the filter in use.

20. A pipeline apparatus comprising a filter as claimed in any one of claims 1 to 16, attached to a pipeline.

21. A pipeline apparatus as claimed in claim 20, comprising a nozzle.

22. A pipeline apparatus as claimed in claim 21, comprising a reducing bush connecting the nozzle to the pipeline, wherein the length of the tube extends beyond the reducing bush.

23. A pipeline apparatus as claimed in any one of claims 20 to 22, wherein the filter is added to an end of the pipeline, and extends therein, substantially parallel to the main longitudinal axis of the pipeline.

24. A pipeline apparatus as claimed in any one of claims 20 to 22, wherein the filter is added to the pipeline, and extends therein, substantially at a right angle to the main longitudinal axis of the pipeline.

25. A pipeline apparatus as claimed in claim 24, wherein the first end extends into the central 10% of the pipeline.

26. A pipeline apparatus as claimed in claim 24, wherein the first end extends into the central 3-4% of the pipeline.

27. A nozzle apparatus, comprising: a filter comprising a tube extending from a first end to a second end, the tube having a bore with an internal cross-sectional area; an inlet to the tube, the inlet being positioned through the first end of the tube and the inlet having a first inlet cross-sectional area; an outlet from the tube the outlet having an outlet cross-sectional area; a plurality of further inlets in the tube between an outside thereof and the bore; a nozzle with a nozzle outlet, the nozzle outlet having a nozzle outlet cross-sectional area; wherein the inlet cross-sectional area of the filter is smaller than the outlet cross-sectional area of the nozzle.

28. Use of a filter as claimed in any one of claims 1 to 16, with a nozzle.

29. Use of a filter as claimed in any one of claims 1 to 16, with a sprinkler system for firefighting/fire containment.

30. Use of a filter as claimed in any one of claims 1 to 16, with a burner head for hydrocarbons.

31. Use of a filter as claimed in any one of claims 1 to 16, in a pipeline.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0088] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying figures, in which:

[0089] FIG. 1 shows a side view of a filter arrangement in accordance with one aspect of the present invention;

[0090] FIG. 2 shows a three-dimensional view of a filter arrangement;

[0091] FIG. 3 shows a filter arranged in a pipeline connected with a tubular connector;

[0092] FIG. 4 shows a filter arranged in a pipeline connected with an elbow connector;

[0093] FIG. 5 shows a filter arranged in a pipeline connected with a T-junction connector;

[0094] FIG. 6a is a cross-section perspective view of a filter with an inlet located in the side wall in accordance with another aspect of the present invention;

[0095] FIG. 6b is a perspective view of the FIG. 6a filter spaced between a pipe shown in cross-section, and a nozzle in a first arrangement;

[0096] FIG. 7a is a front perspective view of the FIG. 6a filter spaced between a pipe, shown in cross-section, and a nozzle in a second arrangement;

[0097] FIG. 7b is a front view of the FIG. 7a filter and pipe in the second arrangement;

[0098] FIG. 8 is a perspective view of the FIG. 6a filter spaced between an elbow connector connected to a pipe, shown in cross-section, and a nozzle in a third arrangement; and

[0099] FIG. 9 is a perspective view of the FIG. 6a filter spaced in between a weld let adaptor in a pipe, shown in cross-section and a nozzle in a fourth arrangement.

DETAILED DESCRIPTION

[0100] FIGS. 1 and 2 show a side and three-dimensional view of a distinct embodiment of a filter 10 in accordance with one aspect of the present invention.

[0101] The filter 10 is formed from a tube 12 extending from a first end to a second end. An inlet 18 is positioned through the first end of the tube and the inlet has a cross-sectional area less than the cross-sectional area of the outlet 16 of the tube 12 and normally less than the outlet of an associated nozzle in use.

[0102] The inlet 18 also has a cross-sectional area less than the cross-sectional area of the internal bore of the tube 12.

[0103] Slots 20 extend longitudinally along the first part of the side wall 13 of the tube 12 from the first end of the tube to a threaded bush 22. The slots are 1 mm and above in width and, in this example, are of a suitable length where two of the slots equals the flow required to give the corresponding K-Factor of the associated nozzle. For such embodiments, the volume of water that will pass through two slots will be greater or equal to the flow required by the nozzle. The K-factor is defined as the flow rate of a nozzle given by q=K√{square root over (p)}, where q is the flow rate in litres per minute, p is the pressure at the nozzle (or filter) in Bar and K is the K-factor. Consequently, if the inlet 18 becomes blocked, then the slots will allow the correct operating volume of fluid through to the nozzle. The volume required in such embodiments is three times the volume required to feed the nozzle at all times. Therefore, the inlet 18 plus four slots 20 can equal three times the dispersion flow rate of the nozzle. For high viscosity fluids, the slots 20 will be larger in order to reduce blocking. For example, where the fluid is water, the slot width is 1 mm, whereas for foam the slot 20 width is 1.5 mm or greater. The number of slots 20 may be, for example, 4 to 24 or greater depending on the dimensions of the filter 10. In other embodiments, the slots need not provide the flow rate described above for this embodiment.

[0104] The filter 10 is adapted to connect to a standard nozzle (not shown) typically used for fire sprinkler systems. Once the filter 10 is connected to a nozzle, the inlet 18 has a cross-sectional area less than the cross-sectional area of the outlet of the nozzle.

[0105] A bush thread is provided to connect the filter to a nozzle. In this portion of the filter, the filtering mechanism is dormant, but this portion provides structural support and enables for faster production as this portion requires less machining to manufacture.

[0106] The inner chamber of the filter 10 is sized such that the diameter (or other dimension) is matched to the inlet of the nozzle. This allows full flow into the nozzle without restriction to the flow in the inner chamber of the filter 10. This region will be free flowing without debris that would normally block the nozzle's exit orifice.

[0107] The benefits of this embodiment are that it can work in any position of pipe from Elbow/Tee/Down Pipe and Up Pipe with it being positioned out with the concentric flow path, the first inlet should be within the ID of the main flow path with the slots being positioned in a debris entrapment area in the pipe line (Elbow Cavity—Tee Cavity—Weld Let Cavity) out with concentric flow path.

[0108] This will mean that there will be a reduced risk of operator installation error as NPT threads do not always match up with each other and this can manipulate the positioning of the filters to the concentric flow path. The strength of this filter is also improved as the slots are not the full body length of the internal section of the adaptor, in this embodiment, but are based specifically on two slots to allow the correct flow through to the nozzle, this also enables manufacture time to be reduced without compromise to flow.

[0109] Each size of filter is given a K-Factor of its own to ensure that the K-Factor of the nozzle is always achieved when choosing the correct variation for any nozzle with any fluid.

[0110] In one example, the inlet 18 has a diameter of approximately 3.9 mm compared with a nozzle outlet diameter of approximately 4 mm and a filter outlet of 14 mm. In an alternative embodiment, if the nozzle has an exit diameter of 10 mm the inlet 18 diameter to the filter is 9.9 mm or less. The inlet 18 and the slots 20, in this embodiment, are sized such that the flow rate through the filter 10 is equal to the flow rate through a tube having an open bore of similar size. Consequently, without wishing to be bound by theory, the flow of fluid through the nozzle is equivalent to the full bore flow rate of an equally sized tube open ended tube.

[0111] The first end of the filter 10 is a debris deflector formed in a tapered or dome-shaped end 19 such that the centre of the first end extends longitudinally further than an outer portion of the first end. The shape of the first end of the tube 12 encourages debris flowing through the pipeline to proceed in a flow direction away from the inlet 18.

[0112] The curvature of the debris deflector 19 limits the availability of flat areas of impact (i.e. surfaces at substantially 90 degrees to the direction of flow) for flowing debris and encourages debris in the flow to flow beyond the inlet 18. The rounded end section of the filter limits the point of fixture for debris close to the inlet, and any debris flowing in the pipeline is forced around the filter and down past the filter into the debris entrapment area 28 within the pipe (shown in FIGS. 3, 4 and 5). The smooth edge/surface of the debris deflector reduces friction of the filter which propels debris away from the inlet. The cylindrical shape and/or curved surfaces also provide a smoother flow path of water or delivery fluid for example oil or firefighting foam. The cylindrical and/or curved surfaces further reduce the areas where salt crystallisation can begin allowing a free flow area.

[0113] FIG. 3 shows the filter 10 arranged in a pipeline 40. The filter 10 is connected to a pipe 30, a tubular coupling 32 and a reducing bush 26. Debris 60 flows around the dome-shaped end 19 of the filter 10 and into the tubular coupling 32.

[0114] The portion of the tube 12 adjacent to the reducing bush 26 is substantially solid. The slots 20 extend in a portion of the tube 12 substantially outwith the reducing bush 26. In this example, 95% of the portion of the tube 12 adjacent to the reducing bush 26 is free from slots 20.

[0115] The slots 20 are located substantially within the debris entrapment area 28. In use, the debris flows in the pipeline 30, around and down past the filter 10 into the debris entrapment area 28.

[0116] FIG. 4 shows the filter 10 arranged in a pipeline 40, connected to the pipeline via an elbow connector 44.

[0117] FIG. 5 shows the filter 10 arranged in a pipeline 40, connected to the pipeline via a T-junction connector 42.

[0118] With the above-described arrangement small debris that enters the inlet 18 is able to pass freely through the filter 10 and into and out of the nozzle. Because the inlet 18 has a smaller cross-sectional area to the outlet of the nozzle, the risk of blockages in the nozzle caused by flowing debris is significantly reduced.

[0119] Additionally, the combination of the inlet 18 and the slots 20 provides the filter 10 with a K-factor equivalent or greater than the K-factor of an open tube of the same dimensions as the tube 12 of the filter 10. The filter 10 filters debris from the flow while maintain full bore flow to the nozzle.

[0120] Improvements and modifications may be made, without departing from the scope of the invention.

[0121] Various modifications to the detailed designs as described above are possible.

[0122] For example, FIG. 6a shows a distinct embodiment of a filter 110 comprising a tube 112 having a bore (not shown) extending therethrough, a side inlet 114 in a side wall 113, an end inlet 118, and an outlet 116. Slots 120 extend longitudinally along the first part of the side wall 113 of the tube 112 from the end inlet to a threaded bush 122.

[0123] The threaded bush 122 is a mounting means provided over the tube 112 at the outlet 116 end, and is used to secure in a pipeline or a reducing bush as described further below. An inner thread (not shown) is also provided at the outlet end, for connection to a nozzle.

[0124] The end inlet 118 is provided on a dome 119, which extends from the tube 114. The end inlet 118 has a smaller diameter (and therefore cross-sectional area) than the outlet 116. In contrast, the diameter of the side inlet 114 is the same as that as the bore of the tube 114, and the outlet 116.

[0125] Moreover, the outlet 116 has a plane which is through the cross-section of the tube 112, at right angles to the main longitudinal axis thereof. Whilst the side inlet 114 is in a side of the tube 112, and has a plane which is generally at right angles to the plane of the outlet 116.

[0126] The end inlet 118 has a cross-sectional area the same full bore as a nozzle 150 (shown in FIG. 6b) to be greater than the nozzle's k-factor.

[0127] The benefits of such features will become apparent in the following description on in use arrangements.

[0128] FIG. 6b illustrates the filter 110 in a pipe 130 via a tubular coupling 132 and reducing bush 134. A nozzle 150 is received into the bore of the tube 112 at the outlet 116 via the internal thread. In use, fluid flows through the pipe 130 in the direction of arrow 136. Large pieces of debris, liable to block the nozzle 150 are inhibited to flow through the most direct inlet (the end inlet 118) because of its reduced size. Debris that can and does flow therethrough tends to be small enough to be less likely to cause blockages in the nozzle 110. But in any case, the dome shape or bevelled edge 119 of the end of the tube 112 also encourages the debris to go past the end inlet 118 and combined with the flow pressure, gather outside of the filter 110, rather than enter the side inlet 114

[0129] Fluid flow and pressure, is nonetheless maintained through the side inlet 114, and the slots 120. Thus the embodiment provides the benefit of full bore pressure applied to the nozzle because the inlet 114 is not restrictive in size, but also a reduced likelihood of blockages, because it is orientated at right angles to the outlet 116, i.e. on the side of the tube 112 where debris is likely to pass by, partly driven by in use fluid pressure.

[0130] In FIGS. 7a and 7b, the filter 110 is provided in a T-piece connector 142 of a pipeline 140. A nozzle 150 is provided within the filter 110 as previously described. The larger (side) inlet 114 is orientated away from the fluid flow through the pipeline, represented by arrow 146. In this way, debris in the fluid is less likely to proceed through the largest inlet (the side inlet 114), and cause blockage problems downstream. In FIG. 7a the inlet 114 is orientated at 90 degrees to the fluid flow 146, in FIG. 7b it is orientated at 180 degrees i.e. opposite the fluid flow. Nevertheless the full bore access of the side inlet 114 maintains flow rate and pressure to the nozzle 150.

[0131] The filter 110 is positioned within the T-piece connector 142 such that the end of the tube 112 is slightly below the concentric flowpath of the pipeline 140, or alternatively, just below the longitudinal axis of the pipeline 140. In this manner, the entrapment area for debris flowing in the pipeline is maximised in the T-piece connector 142 arrangement of the pipeline 140 in the region between the slots 120 and the pipeline 140.

[0132] An indicator arrow 148 is provided on the outer face of the bush 122 which corresponds with the orientation of the side inlet 114. Accordingly a user fitting the nozzle 150 and filter 110, will know the rotational position of the side inlet 114 from the indicator arrow 148, and can position relative to the flow direction.

[0133] FIG. 8 illustrates the filter 110 is provided in an elbow adapter 242 of a pipeline 240. The nozzle 150 is provided within the filter 110 as previously described. The larger (side) inlet 114 is orientated at ninety degrees to the fluid flow through the pipeline, represented by arrow 246. A smaller end inlet 118 is provided at an end of the tube 112. Debris in the fluid is less likely to proceed through the largest inlet (the side inlet 114), and cause blockage problems downstream because the debris flows between the slots 120 and the inner face of the elbow adaptor 242. Even when debris is present in this region, the side inlet 114 maintains flow rate and pressure to the nozzle 150.

[0134] Furthermore, deposits such as scale and marine growth build up concentrically within the pipeline, and may inhibit flow along the pipeline. The deposits may eventually break off and flow within the pipeline towards the filter 110. Typically, any debris flow toward the slots and the debris is less likely to flow through the side inlet 114.

[0135] The filter is positioned within the elbow connector such that the end of the tube 112 is slightly above the centre of the pipeline, or alternatively, positioned just above the longitudinal axis of the pipe.

[0136] In FIG. 9, the filter 110 is provided in a weld let adaptor 342 of a pipeline. A nozzle 150 is provided within the filter 110 as previously described, and its second inlet 118 slightly below the central axis of the pipe 342.

[0137] Depending on the dimensions of the pipeline, and the nozzle, a variety of couplings, and reducing bushes may or may not be used, as required, to fit the nozzle to the pipeline. Certain embodiments use the filter without a nozzle such as between individual pipe joins in a pipeline.

[0138] Following from the above description, it should be apparent to those of ordinary skill in the art that, while the methods and apparatuses herein described constitute exemplary embodiments of the present invention, the invention described herein is not limited to any precise embodiment and that changes may be made to such embodiments without departing from the scope of the invention as defined by the claims. Additionally, it is to be understood that the invention is defined by the claims and it is not intended that any limitations or elements describing the exemplary embodiments set forth herein are to be incorporated into the interpretation of any claim element unless such limitation or element is explicitly stated. Likewise, it is to be understood that it is not necessary to meet any or all of the identified advantages or objects of the invention disclosed herein in order to fall within the scope of any claims, since the invention is defined by the claims and since inherent and/or unforeseen advantages of the present invention may exist even though they may not have been explicitly discussed herein.