GB2368632A - Drainage system for a chimney - Google Patents

Abstract

A liquid diversion system 10 for a gas exhaust conduit 28. A column 12 is located inside an exhaust gas conduit 28 with helical guide means 14 providing an exhaust gas path A, and also intercepting water falling down the chimney and diverting it to a drainage duct 20 arranged to lead such water to a drain 32. The exhaust gas conduit may be a flue or chimney, for example, and the water may be rain.

Description

LIQUID DIVERSION SYSTEM

This invention to a liquid diversion system. More particularly, but not exclusively, it relates to a liquid diversion system for use in a flue, chimney, or other exhaust gas conduit to prevent the passage of water, typically rainwater, down the conduit whilst allowing exhaust gases to pass out therefrom.

The ingress of water into flues and chimneys can produce a variety of problems. In the case of domestic chimneys water can result in damp problems on internal walls and cause, for example wallpaper to peel.

This problem is exacerbated in houses with central heating as fires are not set regularly as they once were and water can remain in the brickwork for quite some time.

Rainfall can also dislodge soot from chimneys which can fall onto carpets and damage them.

In industrial flues the ingress of water can produce, for example, acid solutions upon chemical reactions with exhaust gases which can attack the fabric of the flue or may enter a combustion chamber and reduce the efficiency thereof.

There are currently a number of available mechanisms for preventing the ingress of water down a chimney or flue. Two such arrangements are shown in Figure 1 and 2.

Referring now to Figure 1, this shows a chimney capping arrangement wherein a conical cap is spaced apart from the top end of the flue by a series of bars. This arrangement is highly effective at preventing rain from entering the flue. It does however have a number of problems

associated with it which include a build up of a back pressure within the flue due to the small gap between the flue and the cap which can produce a backfilling of the chamber or room which is being exhausted. Also, more importantly the escaping gases are directed downward towards the ground. This can be a particular problem for flues used to exhaust noxious gases into the atmosphere as they should be directed upwards, away from the ground, to aid their dispersion.

Referring now to Figure 2, this shows the use of counterbalanced leaves which pivot about a pin mounted centrally over the flue to prevent water ingress. The problem of a build up of back pressure is even more acute in this arrangement than in the capping arrangement as the weight of the counterbalances must be overcome. The problem of directing exhaust gases groundward still exists as the leaves are pivoted from above the flue.

There is also the further problem that this arrangement requires regular maintenance in order to ensure that then leaves are free to pivot and are well lubricated. In the case of industrial exhausts the flues may be mounted high on the side of buildings or may be chimneys many metres tall. Therefore the lubrication of the pivot mechanism can be a costly, time consuming and dangerous exercise.

It is an object of the present invention to provide a liquid diversion system that goes at least some way towards alleviating at least one of the above mentioned disadvantages or problems.

According to a first aspect, this invention provides a liquid diversion system for a gas exhaust conduit comprising guide means arranged to provide a generally helical exhaust gas path and to intercept water falling

axially of that path and divert that water to a drainage duct arranged to lead such water to a drain. A liquid diversion system constructed in accordance with the present invention has the advantage of militating against a flow of water down a flue or chimney.

The guide means may be constituted by a series of discrete, stepped, oblique blades which are angularly displaced from one another about a common axis and down which the water can cascade. Alternatively the guide means may be formed from a continuous or substantially continuous chute. The chute may be stepped but is preferably in the form of a continuous smooth chute. The guide means may be extended from a central axial column which may be solid or hollow.

The conduit may be of circular cross-section. Alternatively the conduit may be square or of any convenient cross-section. The conduit may be a chimney and may have a waisted section. The guide means may be of complementary cross-section to the conduit.

The guide means may be located within the conduit by welding, if the conduit and guide means are made of metal. Alternatively, the guide means may be dependent within the conduit from a spar placed across the conduit which may be located by fixing means such as screws or bolts to the conduit. As a further alternative the guide means may be located within the conduit by frictionally engaging walls of the conduit at a waisted section, by sitting on a shoulder, or it may be formed integrally with or preattached to a section of the conduit.

The drainage duct may be an up-turned lip or channel section on an end of the guide means. The drain may be a hole which passes through a wall of the conduit.

The guide means may extend over at least 4500 of arc with respect to its axis. Preferably the guide means extends over at least 540 of arc with respect to its axis. The pitch of the guide means preferably has an average angle of pitch of between 300 and 600.

In some known exhaust ducting arrangements a plurality of relatively narrow bore ducts for example up to 220mm in diameter feed into a larger conduit where they are located by a baffle plate through which they pass.

The invention is of particular value in protecting such a baffle plate against corrosion due to the presence of standing water possibly mixed with chemical effluent.

The conduit may have a wire mesh over the top thereof in order to prevent animals or birds nesting therein. The mesh may have a plurality of holes of up to 40 mm diameter therethrough.

The conduit and/or the guide means may be made of steel sheeting and may be galvanised and/or may be powder coated or may be made of stainless steel. Alternatively, the conduit and/or the guide means may be of a synthetic resin. As a further alternative the conduit and/or the guide means may be made of terracotta. The conduit and guide means may be formed of an integral clay moulding and form a chimney pot.

The invention extends to a flue or a chimney incorporating a liquid diversion system as herein defined.

The invention will now be described, by way of example only, with reference to the accompanying drawings in which : Figure 1 is a schematic representation of a prior arrangement of capped flue; Figure 2 is a schematic representation of a prior art arrangement of a counterbalanced leaved flue cover; Figure 3 is a perspective view of a liquid diversion system according to the present invention; Figure 3a is a perspective view of a second embodiment of a liquid diversion system according to the present invention.

Figure 4 is a perspective view of part of the liquid diversion system of Figure 3; Figure 5 is a schematic sectional view of the liquid diversion system of Figure 3 mounted in a flue, Figure 5a is a schematic sectional view of the liquid diversion system of Figure 3a mounted in a flue; and Figure 6 is a schematic sectional view of a third embodiment of a liquid diversion system according to the present invention.

As shown in Figure 3 a liquid diversion system 10 includes a central, solid, plain cylindrical column 12 of circular cross-section and a helical chute 14 which projects laterally therefrom. The chute 14 is inclined at an angle with respect to the longitudinal axis of the column 12 so as to

define an inclined channel 16 therebetween. The chute 14 extends over one and a half revolutions of the column 12. Figure 4 shows a lower end section 18 of the liquid diversion system 10 of which a terminal end 19 of the chute 14 has a channel 20 formed therein. The channel 20 has a rectangular base 22 and an upstanding wall 24 projecting therefrom. The channel 20 is downwardly inclined away from a lower end 26 of the column 12.

Figure 5 shows the liquid diversion system 10, mounted in a hollow cylindrical flue (or chimney) 28 of circular cross-section, having a mesh 29 over a free upper end 28a end thereof. The column 12 and the flue 28 are concentric. An outer edge 30 of the chute 14 is in intimate contact with a wall 31 of the flue 28.

The liquid diversion system 10 is mounted within the flue 28 such that the channel 20 is aligned, and in communication, with a drain opening 32 through the wall 31.

In use, exhaust gases (or smoke) pass up the flue 28, as indicated by the arrow A in Figure 5. The gases strike the underside of the chute 14 and follow a helical trajectory on their egress from the flue 28, thereby 'rifling'out of the flue 28. This rifling effect aids the passage of the exhaust gases higher into the atmosphere that would otherwise be the case and improves their dispersion into the atmosphere.

Conversely, rain water entering the flue 28 via its open upper end 28a as shown by the arrow B in Figure 5 is collected by the liquid diversion system 10 as it will land on the upper surface of the chute 14 and run down the inclined channel 16.

The rain water will flow around the column 12 in the channel 16 until it reaches the channel 20 whereupon it will be diverted by the base 22 and the wall 24, through the drain opening 32 in the wall 31 and onto the external surface of the flue 28.

It is envisaged that in this embodiment that the chute 14 and flue 28 are metallic and the edge 30 of the chute 14 will be welded the flue 28 once channel 20 and opening 32 are in alignment.

Figure 3a shows a second embodiment of a liquid diversion system 10 in which the helical chute 14a is downwardly inclined away from the column 12.

Figure 5a shows the liquid diversion system of Figure 3a installed in a flue 28. Rain water entering the flue 28 via end 28a is intercepted by the chute 14a and will run off the chute 14a to the junction of the chute 14a and the wall 31. The water will then flow down the chute 14a and pass out of the flue 28 via the drain opening 32. A wall 24a extends along the lower free edge of the chute 14a between the column 12 and the wall 31 in order to prevent water flowing over the end of the chute 14a and down the body of the flue 28.

Figure 6 shows a third embodiment of a liquid delivery system which includes a plurality of part conical baffles 42 which are vertically and angularly displaced relative to one another.

The baffles 42 extend inwardly from the wall 31 of the flue 28 beyond the central axis of the flue 28 and are inclined towards the open end 28a, away from the wall 31. The lower edge of the baffles 42 is joined to, and extends around, at least half of the inner periphery of the wall 31.

A drain opening 44 is provided through the wall 31 adjacent a junction region 46 between each baffle 42 and the wall 31. The opening 44 may extend about substantially all of the region 46 or alternatively the baffles 42 may be sloped with its lowest point corresponding to the opening 44.

In the embodiment of Figure 6 the baffles 42 are alternatively angularly displaced by 180 with respect of each other. It will be appreciated that if more baffles were utilised this angle and the extent of baffles about the periphery of the wall 31 may be varied.

In use, exhaust gases pass up the flue 28, as indicated by the arrow A in Figure 6. Conversely, rain water entering the flue 28 via its open upper end 28a, as shown by the arrow B in Figure 6 will land on the upper surface of one of the baffles 42 and run down the surface, through the drain opening 32 in the wall 31 and onto the external surface of the flue 28.

It will be appreciated that the flue and the liquid diversion system need not be circular in cross-section but may be of any mutually complementary shape.

The diversion system need not be welded to the flue but may depend from a spar mounted over the upper end of this flue which is tied in position once the diversion system and flue are suitably aligned as here in before described. Alternatively, the diversion system may be held in frictional engagement with a waisted section of the flue The flue may have an adapter plate fitted at a lower end thereof to allow outlet pipes of a suitable diameter to be affixed thereto.

It will further be appreciated that the flue need not be metallic but may be of any suitable material, for example brick, clay or terracotta.

It is advantageous, but not essential, for the chute to extend about the inner periphery of the flue for a least one and a half times the extent of the periphery in order to provide no direct path for rain water to bypass the diversion system.

The diversion system may be employed in extraction units such as dust and air extraction units, household chimneys, vents or flues from industrial premises/furnaces.

Claims (19)

1. A liquid diversion system for a gas exhaust conduit comprising guide means arranged to provide a generally helical exhaust gas path and to intercept water falling axially of that path and divert that water to a drainage duct arranged to lead such water to a drain.

2. A system according claim 1 wherein the guide means is formed from a continuous or substantially continuous chute.

3. A system according to claim 2 wherein the chute is provided in the form of a continuous smooth chute.

4. A system according to claim 2 wherein the chute is stepped.

5. A system according to claim 1 wherein the guide means are constituted by a series of discrete, stepped, oblique blades which are angularly displaced from one another about a common axis.

6. A system according to any previous claim wherein the guide means extends over at least 4500 ouf arc with respect to a longitudinal axis thereof.

7. A system according to any previous claim wherein the guide extends over at least 5400 ouf arc with respect to a longitudinal axis thereof.

8. A system according to any previous claim wherein the pitch of the guide means has an average angle of pitch of between 300 and 600.

9. A system according to any previous claim wherein the guide means extend from a central axial column.

10. A system according to any previous claim wherein the guide means are of complementary cross-section to the conduit.

11. A system according to any previous claim wherein the conduit and guide means are formed of an integral clay moulding and form a chimney pot.

12. A system according any one of claims 1 to 10 wherein to the guide means are located within the conduit by welding.

13. A system according to any one of claims 1 to 10 wherein the guide means depend within the conduit from a spar extending across the conduit.

14. A system according to any one of claims 1 to 10 wherein the guide means are located within the conduit by frictionally engaging walls of the conduit

15. A system according to claim 14 wherein the guide means frictionally engage the walls of the conduit at a waisted section thereof.

16. A system according to any one of claims 1 to 11 wherein the guide means are formed integrally with, or preattached to, a section of the conduit.

17. A system according to any previous claim wherein the drainage duct is an up-turned lip or channel section on an end of the guide means.

18. A system according to any previous claim wherein the drain is a hole which passes through a wall of the conduit.

19. A liquid diversion system for a gas exhaust conduit substantially as hereinbefore described with reference to the accompanying drawings.