AU651480B2 - Improvements in and relating to a flue cap - Google Patents

Description

iii -l~-lll-1 Regulation 3.2

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION 6 8 FOR A STANDARD PATENT

ORIGINAL

C $0 00 Name of Applicant: Actual Inventor: Address for Service: Invention title: Aurelius Alessandro Carbone 22 Aurelius Alessandro Carbone A.Pr Pa 7i4Tradeark4 CPo oxc 772 4delaide 54 6ot C/ ri. J fl'LJ.Im1O U ACUmU"lATDUi) cJ AgSL 00a 0( i--jllII mt e -tt, -u-laiu-e, outh "Improvements In And Relating To A Flue Cap" Details of Associated Provisional Application No: PK 7793 dated 16th August 1991.

The following statement is a full description of this invention, including the best method of performing it known to me.

1 This invention relates to an improved roof air exhaust terminal, and in particular to a flue terminal (or cap) which is suitable for use with industrial heating appliances and equipment. It is also suitable, but to a lesser extent, for use with domestic exhaust flues.

In the applicant's Australian patent specification 564597, there is described an improved flue terminal which is effective in reducing incidence of down draught, and which comprises a plurality of frusto-conical annular deflectors arranged in a vertical array, there being respective air spaces being formed between adjacent deflectors, and interconnecting means extending internally of the flue terminal for securing the deflectors together in said array.

The aforesaid flue terminal is particularly suitable for use with domestic heating appliances such as wood fuel stoves; however, it has been found not to be completely suitable for industrial applications due to its inability to effectively inhibit the ingress of rain. It will of course be appreciated for industrial heating installations e.g. in a foundry, it is important that the flue terminal prevents any ingress of rain into the flue which might otherwise cause undesirable damage oo and corrosion to plant or equipment located below the flue.

It is the main object of the present invention to provide an a improved air dispersion terminal of the general kind described and illustrated in the applicant's aforesaid patent specification 564597, which will be effective in inhibiting I "the entry of rain into a flue, Y,4;it at the same time permitting an adequate and efficient up-draught through the flue.

4841 According to this invention therefore, in improved flue terminal comprises a plurality of deflectors, each deflector aaving sloping side walls which converge in an upwards direction, and retaining means retaining said deflectors in a vertical array with respective air spaces between adjacent deflectors, the upper end of the uppermost deflector comprising a pair of cover plates which have their inner free 2 i; i i ;d"~r edges spaced apart so as to define a central exit opening, the upper end of said upper most deflector being closed apart from said opening, and a watershed channel-forming member supported beneath said opening and coextensive therewith, said watershed member being arranged to collect rain water passing into the flue terminal through the opening and to allow water, thus collected, to flow along the watershed member towards the sloping side wall(s) of said uppermost deflector and drain downwardly through the air space formed between the uppermost deflector and the next to top deflector, the arrangement of the cover plates and the watershed member being effective to inhibit the ingress of rain downwardly through the interior of the terminal.

Preferably, the deflectors are annularly shaped and the exit opening extends diametrically of the uppermost deflector.

Preferably, the watershed member is an elongate V-shaped metal or plastics member, the transverse width of said S: 20 member, at its upper end, being slightly greater than the #0 transverse width of said diametral opening.

.o .I Preferably, the watershed member has its opposite ends fixedly secured e.g. by spot welding or fasteners such as rivets, to diametrically opposed side wall portions of the 0o uppermost deflector, said watershed member sloping downwardly to one end to assist water flow. The watershed member may be designed to slope downwardly from a central region to each of 0 its ends.

The walls of the V-shaped watershed member may be convexly "0 curved.

Preferably, each said cover plate is part-circular and convexly curved (looking downwardly through the terminal) to allow water to run off.

It will be appreciated that the relative positioning and dimensions of the diametral opening in the upper wall of the 3 A~ I__ uppermost deflector and the watershed member are chosen so as to achieve maximum (or nearly s( water run off with minimum resistance to the upward flow of air through the terminal.

While the height and width of the terminal may vary, it has been found, in practice, that the dispersion of air from the flue terminal is significantly improved when the watershed member is located remote from the flue outlet end.

In order to more fully describe the present invention, two preferred embodiments thereof are described hereunder, with reference to the accompanying drawings in which: Fig 1 is a perspective view of a flue terminal according to a first embodiment of this invention; Fig 2 is a fragmentary sectional view of the terminal shown in Fig 1; and It4, S: 20 Fig 3 is a fragmentary perspective view, showing a terminal o. according to a second embodiment of the invention.

In this embodiment, a flue terminal 10 comprises a plurality of deflectors 11, each deflector 11 being formed from sheet metal and being a hollow conical frustum with its sloping oL walls 12 converging in an upward direction. The deflectors 11 are secured together by interconnecting means (not shown) so as to lie in a vertical array, with annular air passages 13 obeing formed between adjacent deflectors 11, the air passages 30 13 allowing air to flow into and upwardly within the terminal or, where ai. is discharging from the terminal, allowing air to flow downwardly and outwardly therefrom.

The uppermost deflector 11 is provided with an air exit opening 15 which, in this embodiment, is formed between a pair of horizontally aligned approximately semicircular cover plates 16, 17 which are convexly curved (to assist the shedding of water from its surfaces away from the opening), the free inner edges of the cover plate 16, 17 being parallel -4to one another and horizontally spaced apart so as to define the diametral opening 15. The opening 15 has a width proportional to a percentage of the diameter of the flue 21.

Located a short distance from and directly beneath the diametral opening 15 is a V-shaped watershed member 18 which is coextensive with the opening 15 and has its ends 19, fixed, e.g. by riveting or welding, to corresponding opposed wall portions of the sloping side wall 12 of the deflector 11. The watershed member 18 slopes downwardly to one side of the deflector 11 so that water entrapped thereby (or condensation on the lower surface thereof) will run off the lower open end of the member 18, and flow downwardly through passage 13, whereafter it can run downwardly over the outer walls 12 of the lower deflectors 11.

As shown in Fig 2, the transverse width of the watershed member 18 measured between its opposite upper edges slightly exceeds the width of the diametral opening 15. Each of the 20 limbs of the member 18 may be either planar or curved in two planes.

The design configuration of the member 18 is preferably chosen in order to maximise the collection of incoming water, °o 25 e.g. rain, and thereby prevent same from flowing downwardly through the interior of the whilst at the same time providing miniml resista.ce tc air discharge.

To facilitate the securement of the member 18 to the wall 12, integral flange formations may be provided at each end of the member 18 and which bear against inner surface portions of the wall 12, rivets being used to fix the flans, formations in place.

With the member 18 fixed in place, its lower open end edge is spaced from the inner surface of the wall 12 so as to form a gap which allows water to drain from the member 18.

5 In practice, the above watershed arrangement has proven extremely effective to inhibit the entry of water into the interior of the terminal 10 and thereby into the flue, while at the same time minimising resistance to the flow of air upwardly through the terminal.

In the embodiment shown in Fig 3 of the drawings, the watershed member 30 is a shallow approximately U-shaped channel which is designed to cope with and displace a higher volume of water than the member 18 of the first embodiment.

It will be appreciated that in some tropical rainfall locations, the watershed member will need to displace a larger volume of water than in areas of lower rainfall. As in the first embodiment, the member 30 slopes downwardly to one side of the deflector 11 and has its ends secured, near the upper edges thereof, to wall 12, the lower end of the member 30 having its bottom edge spaced from the inner o surface of the wall 12 so as to form a water drainage opening 4 which allows the water collected by the member 30 to run-off, #20 downwardly through the annular air gap 13.

*040 co 0" The arrows 32 illustrate the flow pattern of the air discharging from the terminal.

4 25 In a variation to the above described embodiments, the eo watershed members 18, 30 may have one of its ends projecting below the plane of the lower opening of the uppermost *r deflector 11. In this instance, it is necessary to provide a horizontal space between the uppermost deflector 11 and the next to top deflector rather than having the upper circular edge of each deflector lying approximately in the horizontal plane of the lower opening of an adjacent deflector as shown in Figs 1 and 3.

A brief consideration of the above-described embodiment will 8how that the invention provides for a very simple flue terminal construction which incorporates an excellent watershed arrangement so that water which enters through the open upper end of the terminal is prevented from passing -6downwardly through the interior of the terminal. By having an opening in the-upper end of the terminal, a vastly improved up-draught is achieved in comparison to prior art flue terminals which normally use a closed conical cover positioned over the upper end of the terminal.

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Claims (8)

1. An improved roof air exhaust terminal for attachment to a flue, comprising a plurality of deflectors, each deflector having sloping side walls which converge in an upwards direction, and retaining means retaining said deflectors in a vertical array with respective air spaces between adjacent deflectors, the uppermost deflector comprising a pair of cover plates having their inner free edges spaced apart so as to define a central exit opening, the upper end of said uppermost deflector being closed apart from said opening, and a watershed channel forming member supported beneath said opening and co-extensive therewith, said watershed member being arranged to collect rain water passing into the flue terminal through the opening and to allow water, thus collected, to flow along the watershed member towards the sloping side wall(s) of said uppermost deflector and drain downwardly through the airspace formed between the uppermost C deflector and the adjacent lower deflector, the arrangement of the cover plates and the watershed member being effective to inhibit the ingress of rain downwardly through the 20 interior of the terminal.

2. A terminal according to claim 1 wherein said watershed S member is either V-shaped or approximately U-shaped in cross-section, the transverse width of said member, measured between its opposite upper edges being slightly greater than the transverse width of said exit opening.

3. A terminal according to either claim 1 or claim 2 wherein said exit opening extends diametrically of the uppermost deflector.

4. A terminal according to any one of the preceding claims wherein said watershed member has its opposite ends fixedly secured to diametrically opposed side wall portions of the uppermost deflector, said watershed member sloping downwardly to one end thereof to assist water flow. 8 A terminal according to any one of the preceding claims wherein each said o~over plate is part circular and convexly curved (when viewed in plan looking downwardly through the terminal).

6. A terminal according to any one of the preceding claims wherein said watershed member has its lower end edges each spaced from the inner surface of the deflector side wall so as to form a gap through which water can arain from the watershed member.

7. A terminal accoraing to any one of the preceding claims wherein said watershed member is housed wholly within the confines of the uppermost deflector.

8. A terminal according to any one of the preceding claims wherein the deflectors are annularly shaped, each deflector, 1 apart from the uppermost deflector, having an upper circular edge lying approximately in the horizontal plane of the lower opening of an adjacent said deflector.

9. A terminal according to any one of the preceding claims when fitted to a flue. a; 10. A roof air exhaust terminal substantially as hereinbefore described with reference to and as illustrated a in Figs 1 and 2 or Fig 3 of the accompanying drawings. a Dated this 5th day of August, 1992. AURELIUS ALESSANDRO CARBONE By his Patent Attorneys A r PaIRN& 7"deiATH& IHo~~j WTN ABSTRACT An improved flue terminal (10) comprising a plurality of frusto-conical annular deflectors (11) arranged in a vertical array, with air spaces (13) formed between adjacent deflectors a top cover comprising a pair of cover plates (16, 17) fitted to the uppermost deflector (11) and a central air exit opening (15) formed between the cover plates (16, 17), and a watershed channel forming member (18) supported beneath the exit opening (15) arranged to collect rainwater passing into the terminal through the opening and allcw water, thus collected, to drain therefrom downwardly through the air space (13) formed between the uppermost deflector (11) and the adjacent lower deflector (11). o .s 9t .0 0 01 0 I H|