GB2433308A

GB2433308A - Inclined rain guard for a boiler air inlet

Info

Publication number: GB2433308A
Application number: GB0525581A
Authority: GB
Inventors: Ian Sharp
Original assignee: BBT Thermotechnology UK Ltd; Worcester Heat Systems Ltd
Current assignee: Bosch Thermotechnology Ltd
Priority date: 2005-12-16
Filing date: 2005-12-16
Publication date: 2007-06-20
Also published as: GB0525581D0

Abstract

A rain guard adaptor device 10 for adapting a flue and air conduit 42 of a boiler. The conduit 42 comprises a flue gas passageway 44 which has a flue gas inlet into which flue gas discharged from the boiler can enter and a flue gas outlet (52, fig 3) from which the said flue gas is discharged to the ambient environment, and an air passageway 48 which has an air inlet 54 through which ambient air can enter the air passageway 48 and an air outlet (56, fig 3) through which the said ambient air passes as it moves to the boiler. The adaptor device 10 comprises a front edge 14, a rear edge 16, a frustro conical rain directing surface 18 which extends from or substantially from the front edge 14 and towards the rear edge 16, catches 28 for fastening the adaptor device 10 to the flue and air conduit, so that the rain directing surface 18 extends into the air passageway of the conduit from or substantially from the air inlet 54, and a spacer (38, fig 8) by which the rain directing surface 18 is oriented to provide a shallow fall towards the front edge 14 of the adaptor device 10, so that, in use, rain which passes through the air inlet 54 and onto the adaptor device 10 is directed back out of the air inlet 54 by the rain directing surface 18. The adapter has a lip 40, and may be retrofitted to an existing conduit.

Description

RAiN GUARD FOR A BOILER AW INLET This invention relates to a flue and

air conduit for the discharge of flue gas from a boiler and for the intake of air into the boiler, and more specifically to a rain guard which directs rain passing into the conduit back out Combined flue and air conduits for boilers are typically inclined to enable the draining of condensate collected from the flue gas back into the boiler. The recommended minimum standard for inclination is 30 from horizontal The problem of ingress of water, typically rain, into an air passageway of such an inclined flue and air conduit has been considered. For example, Figures 1 and 2 show an arrangement used by Interactive Bouwprodukten by of Postbus 200, 6940, HA, Didam, Nederland. This arrangement provides a cylindrical device 1 which locates coaxially within the air passageway 2 of the inclined conduit 3. The device 1 is provided integrally as part of the flue terminal and has an inwardly reversed rear edge 4.

The device I is positioned in the air passageway 2 of the conduit 3, downstream of the opening of the flue terminal 5.

A problem with the known arrangement is that rain or other water which passes into the air passageway is simply collected by the inwardly reversed rear edge. Once the depth of collected water exceeds the height of the reversed rear edge, water flows into the air passageway and down into the boiler The reversed rear edge thus simply acts as a weir.

Increasing the height of the reversed rear edge is possible, but this then further restricts air flow along the air passageway.

A further problem associated with the known arrangement is that it cannot be installed in existing flue and air conduits. It is thus not retro-fittable The present invention seeks to provide a solution to these problems According to a first aspect of the present invention, there is provided a flue and air conduit for the discharge of flue gas from a boiler to the ambient environment and for the intake of ambient air into the boiler, the conduit comprising a flue gas passageway having a flue gas inlet into which flue gas discharged from the boiler can enter and a flue gas outlet from which the said flue gas is discharged to the ambient environment, an air passageway which has an air inlet through which ambient air can enter the air passageway and an air outlet through which the said ambient air passes as it moves to the boiler, and a rain directing surface which extends into the air passageway from or substantially from the air inlet and which, in use, has a shallow fall towards the air inlet, so that rain which passes through the air inlet and onto the rain directing surface is directed back out of the air inlet.

Preferable and/or optional features of the first aspect of the invention are set forth in claims 2 to 4, inclusive.

According to a second aspect of the invention, there is provided a rain guard adaptor device for adapting a flue and air conduit to provide the flue and air conduit in accordance with the first aspect of the invention, the adaptor device comprising a front edge, a rear edge, a rain directing surface which extends from or substantially from the front edge and towards the rear edge, means for fastening the adaptor device to the flue and air conduit, so that the rain directing surface extends into the air passageway of the conduit from or substantially from the air inlet, and means by which the rain directing surface is oriented to provide a shallow fall towards the front edge of the adaptor device, so that, in use, rain which passes through the air inlet and onto the adaptor device is directed back out of the air inlet by the rain directing surface.

Preferable and/or optional features of the second aspect of the invention are set forth in claims 6 to 14, inclusive.

IS According to a third aspect of the invention, there is provided a method of adapting a flue and air conduit having a flue gas passageway for the discharge of flue gas from a boiler and an air passageway for the intake of air into the boiler, the method comprising the step of fastening a rain guard adaptor device in accordance with the second aspect of the invention to an air inlet of the air passageway, so that the rain directing surface of the adaptor device is oriented to provide a shallow fall towards the front edge of the adaptor Preferable and/or optional features of the third aspect of the invention are set forth in claim 17 and claim 18.

The invention will now be more particularly described, by way of example only, with reference to the accompanying drawings, in which Figure 1 is a vertical cross-sectional view of a known flue and air conduit for a boiler, Figure 2 is an enlarged view of the flue terminal shown in Figure 1; Figure 3 is a vertical cross-sectional view of a flue and air conduit, in accordance with the first aspect of the invention, and having a rain guard adaptor device, in accordance with the second aspect of the invention; Figure 4 is an enlarged view of the flue terminal shown in Figure 3; Figure 5 is a perspective view into the front of the flue terminal shown in Figure 4; Figure 6 is an enlarged perspective view out of the front of the flue terminal shown in Figure 4; Figure 7 is a perspective view from a front edge of the adaptor device, and Figure 8 shows the adaptor device inverted.

Referring now to Figures 3 to 8, there is shown a rain guard adaptor device 10 which is typically formed from plastics or metal material. The adaptor device 10 comprises a, generally U shaped, channel body 12 having an arcuate front edge 14, an arcuate rear edge 16, and a rain directing surface 18 which extends from the front edge 14 to the rear edge 16. The rain directing surface 18 is formed as part frusto-conical, and thus the front edge 14 has a greater radius than the rear edge 16 Upper free edges 20 of the channel body 12 include an angled portion 22 which is angled downwardly to meet the rear edge 16. This limits the obstruction to air flow over the adaptor device 10 The adaptor device 10 further comprises a longitudinal slot 24 formed perpendicularly to the front and rear edges 14,16, and which bisects the front and rear edges 14, 16. The adaptor device 10 includes a front edge connector portion 26 which extends slightly beyond the front edge 14 and which interconnects the two portions I 2a and 12b of the channel body 12 bisected by the slot 24. The slot 24 has a lateral extent suitable for receiving an edge of a wall of an air passageway of the conduit as a close fit.

As can be seen in Figure 7, the adaptor device 10 also includes at least one, and in this case two, catch elements 28 formed on opposing edges. The catch elements 28 are wedge-shaped or substantially wedge-shaped to promote sliding in a rear-to-front edge direction, but to prevent or inhibit undesirable sliding in a front-to-rear edge direction.

Two outwardly extending spaced-apart abutment elements 30, best shown in Figures 5 and 7, are provided on the front edge 14 of the channel body 12, and spaced from the catch elements 28 These abutment elements 30 cooperate with the catch elements 28 to hold the adaptor device 10 in place.

As best appreciated from Figures 6 to 8, the slot 24 is defined by longitudinal opposing parallel waIls 32 which are spaced-apart Each wall 32 upstands from the rain directing surface 18, and depends from a lower surface 34 opposite the rain directing surface 18. Due to the part frusto-conical rain directing surface 18, each wall 32 extends along the lower surface 34 of the channel body 12 in the front-to-rear edge direction in a diverging manner, thus forming a wedge-shape. These wedge-shaped portions 36 of the walls 32 act as a spacer element 38, as will be understood hereinafter.

The rear edge 16 of the channel body 12 also includes an inwardly upturned lip to prevent excessive water from spilling over the adaptor device 10.

In use, a flue and air conduit 42 of an installed boiler comprises a flue gas passageway 44 which extends from the flue exhaust of the boiler and through an exterior wall 46 of a building, and a separate air intake passageway 48 within which the flue gas passageway 44 is received. The flue and air conduit 42 typically includes at least a 30 incline from the boiler to the exterior wall 46, to provide for the run back of condensate collected from the discharging flue gas.

The flue gas passageway 44 has a flue gas inlet 50 through which exhaust flue gas from the boiler passes, and a flue gas outlet 52 through which the flue gas discharges to the ambient environment. The air intake passageway 48 has an air inlet 54 through which ambient air is drawn, and an air outlet 56 through which the ambient air passes to enter the boiler As will be understood from Figures 3 and 4, the flue gas passageway 44 typically projects through and beyond the air inlet 54 of the air intake passageway 48 To simplify installation, the flue and air conduit 42 typically includes a flue terminal 58 which is connected to the end of the flue gas passageway 44 to extend the flue gas passageway 44 beyond the air inlet 54 of the air intake passageway 48 The flue terminal 58 can conveniently be provided with a seal 60 to allow blending of the flue and air conduit 42 to an exterior surface 62 of the exterior wall 46. The flue terminal 58 is typically a push snap-fit engagement with the remaining part of the flue and air conduit 42.

Referring to Figures 5 and 6, the flue terminal 58 includes generally vertical and horizontal brace elements 64 in the air inlet 54 of the air intake passageway 48 and which support the flue gas passageway 44 in the air intake passageway 48 The rain guard adaptor device 10 is offered up to the air inlet 54 of the air intake passageway 48 so that the vertical brace element 64 enters the slot 24 adjacent to the rear edge 16 of the adaptor device 10. The vertical brace element 64 slides along the slot 24, as the adaptor device 10 is fed into the air intake passageway 48, until the connector portion 26 of the channel body 12 of the adaptor device 10 and the two abutment elements 30 abut the edge 68 of the air inlet 54, and the catch elements 28 engage rear faces 70 of the horizontal brace elements 64. The adaptor device 10 is thus held securely in the air intake passageway 48, and projects slightly through the air inlet 54.

The spacer element 38 formed by the walls 32 defining the slot 24, due to the wedge shape, supports the channel body 12 so that, despite the incline of the flue and air conduit 42 from the boiler, the rain directing surface 18 has a shallow fall which is towards the front edge 14 of the channel body 12.

Since the front edge 14 of the channel body 12 is at the edge 68 of the air inlet 54, and the rain directing surface 18 extends into the air intake passageway 48 from the front edge 14 of the channel body 12, as rain passes through the air inlet 54 of the air intake passageway 48 and falls onto the rain directing surface 18, it is directed back out of the air inlet 54 due to the fall and the action of gravity The upturned lip 40 at the rear edge 16 of the adaptor device 10 acts as a dam to prevent, in the case of excessive rain entry, overspill from the rain directing surface 1 8 into and down the remaining portion of the air intake passageway 48.

If necessary, the rain guard adaptor device 10 can be unclipped from the flue and air conduit 42, for example for cleaning or replacement To suit different types of flue and conduits, which perhaps do not have the generally vertical brace element, any other suitable means for fastening the adaptor device to the flue and air conduit can be considered. It is preferable that the fastening means allows the adaptor device to he directly fastened to the flue and air conduit at least retrospectively following installation of the flue and air conduit, and without dismantling or partial dismantling of the flue and air conduit, such as removal of the flue terminal Although the adaptor device has a channel-shaped body, the adaptor device can have a circular or substantially circular cross-section, allowing the adaptor device to extend fully or substantially fully around the interior of the air intake passageway In this case, the rain directing surface is preferably frusto-conical.

The adaptor device can be attached to the flue and air conduit at any time, either prior to installation of the flue and air conduit, during installation, or after installation The rain directing surface can be included as an integral part of the flue terminal, rather than as a separate adaptor device. For example, the rain directing surface can be formed engaged with the flue passageway so that, as the flue terminal is attached, the rain directing surface enters the air passageway.

The flue and air conduit can include the rain directing surface, integrally formed as part of the air passageway Tt is thus possible to provide a rain directing surface at the air inlet of a conduit for a boiler which has a shallow fall towards the air inlet to redirect rain or other water entering the air passageway back out of the air inlet. It is also possible to provide an adaptor device with a rain directing surface which can be fitted at any point to the conduit, either prior to, during, or after installation. Retro-fitting of the adaptor to an existing flue and air conduit thus simple and cost-effective.

The embodiments described above are given by way of examples only, and further modifications will be apparent to persons skilled in the art without departing from the scope of the invention as defined by the appended claims For example, although the rain directing surface is smoothly arcuate, it could be single-or multi-faceted, or planar, as long as the shallow fall is provided; a further surface can be provided between the rain directing surface and the rear edge of the adaptor device; and further or alternative catch element(s) can be provided in the slot to engage with the vertical brace element

Claims

CLAIMS

1. A flue and air conduit for the discharge of flue gas from a boiler to the ambient environment and for the intake of ambient air into the boiler, the conduit comprising a flue gas passageway having a flue gas inlet into which flue gas discharged from the boiler can enter and a flue gas outlet from which the said flue gas is discharged to the ambient environment, an air passageway which has an air inlet through which ambient air can enter the air passageway and an air outlet through which the said ambient air passes as it moves to the boiler, and a rain directing surface which extends into the air passageway from or substantially from the air inlet and which, in use, has a shallow fall towards the air inlet, so that rain which passes through the air inlet and onto the rain directing surface is directed back out of the air inlet
2. A conduit as claimed in claim I, wherein the flue and air conduit includes a flue terminal on which the rain directing surface is provided.

3 A conduit as claimed in claim 1, wherein the flue and air conduit is or forms part of an air intake and flue exhaust system which is attached or attachable directly or indirectly to a boiler.

4. A conduit as claimed in claim 1, wherein the rain directing surface is integrally formed as part of the air passageway.

5. A rain guard adaptor device for adapting a flue and air conduit to provide the flue and air conduit as claimed in claim 1, the adaptor device comprising a front edge, a rear edge, a rain directing surface which extends from or substantially from the front edge and towards the rear edge, means for fastening the adaptor device to the flue and air conduit, so that the rain directing surface extends into the air passageway of the conduit from or substantially from the air inlet, and means by which the rain directing surface is oriented to provide a shallow fall towards the front edge of the adaptor device, so that, in use, rain which passes through the air inlet and onto the adaptor device is directed back out of the air inlet by the rain directing surface 6 An adaptor device as claimed in claim 5, wherein the fall means comprises a spacer element which, in use, bears against the interior surface of the air passageway and which imparts the shallow fall to the rain directing surface.

7. An adaptor device as claimed in claim 6, wherein the spacer element is wedge shaped.

8. An adaptor device as claimed in any one of claims 5 to 7, wherein the liquid directing surface is at least part frusto-conical 9. An adaptor device as claimed in any one of claims 5 to 8, wherein the adaptor device is channel-shaped.

10. An adaptor device as claimed in any one of claims 5 to 9, wherein the front and rear edges are arcuate, the front edge having a larger radius than the rear edge.

11 An adaptor device as claimed in any one of claims 5 to 10, wherein the fastening means includes a snap-fit arrangement for snap-fittably engaging the adaptor device with the flue and air conduit.

12 An adaptor device as claimed in claim 11, wherein the snap-fit arrangement includes a slot for receiving a wall of the air passageway 13 An adaptor device as claimed in claim 12, wherein the in use snap-fit arrangement engages the adaptor device with the or another wall of the air passageway.

14 An adaptor device as claimed in any one of claims 5 to 13, wherein the fastening means is releasable, so that the adaptor device can be directly removed from the flue and air conduit without dismantling or partial dismantling of the flue and air conduit.

15. An adaptor device substantially as hereinbefore described with reference to the accompanying drawings 16 A method of adapting a flue and air conduit having a flue gas passageway for discharge of flue gas from a boiler and an air passageway for intake of air into the boiler, the method comprising the step of fastening a rain guard adaptor device as claimed in any one of claims 5 to 15 to an air inlet of the air passageway, so that the rain directing surface of the adaptor device is oriented to provide a shallow fall towards the front edge of the adaptor 17 A method as claimed in claim 16, wherein the rain guard adaptor device is fastened to the flue and air conduit prior to, during, or after installation of the flue and air conduit 18 A method as claimed in claim 16 or claim 17, wherein the flue and air conduit is a flue terminal, and the rain guard is fastened to the flue terminal.

19 A rain guard adaptor device for adapting a flue and air conduit of a boiler, the conduit comprising a flue gas passageway having a flue gas inlet into which flue gas discharged from the boiler can enter and a flue gas outlet from which the said flue gas is discharged to the ambient environment, and an air passageway which has an air inlet through which ambient air can enter the air passageway and an air outlet through which the said ambient air passes as it moves to the boiler, the adaptor device comprising a front edge, a rear edge, a rain directing surface which extends from or substantially from the front edge and towards the rear edge, means for fastening the adaptor device to the flue and air conduit, so that the rain directing surface extends into the air passageway of the conduit from or substantially from the air inlet, and means by which the rain directing surface is oriented to provide a shallow fall towards the front edge of the adaptor device, so that, in use, rain which passes through the air inlet and onto the adaptor device is directed back out of the air inlet by the rain directing surface.