AU606078B2

AU606078B2 - Top cap for a flue

Info

Publication number: AU606078B2
Application number: AU79333/87A
Authority: AU
Inventors: Ivor Russell Nyman
Original assignee: FLEXIBLE ELECTRICALS Pty LIMIT
Current assignee: FLEXIBLE ELECTRICALS PTY Ltd
Priority date: 1986-10-02
Filing date: 1987-10-02
Publication date: 1991-01-31
Anticipated expiration: 2007-10-02
Also published as: AU7933387A

Description

Li 1~ r:7T ICGs rATVCN ACCEPTED AND AMENDMENTS

ALLUVYL-

606 78 Form PATENTS ACT 1952 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE Short Title: Int. Cl: Application Number: PG 8283 Lodged: 2nd October, 1986 Complete Specification-Lodged: Accepted: Lapsed: Published: i This document contains the amendments made under liSectk'ni 49 andl is correct for It Printing Priority: ;elated Art: TO BE COMIPLETED BY APPLICANT Name of Applicant'. -POWE RWHERM-(-NSW,) '-PrTY- '--IMI T'ED- ~?L&MI3a C C 14 1- Address of Applicant:- 2 -5--Brodie-Sireet, Ron ~C~ -RYDALM RE 0 4~ Actual Inventor: IVOR RUSSELL NYMAN AdrssforSrvc: F ORD-&-MAXWE-I--- Adres orSevie:Patent Trade Mark Attorneys, Complete Specification fo1tblnentqon enild Z~1 "TOP CAP FOR A FLUE" The following statoert is a full description of this invention, lncludIn6 the best, method of performing it known to n~m4xZx us: Note: The description is to be typed In Iouble spacing, pica type face, In an area not oxcoodIriQ 260 mm In depth and 16f0 mm In width, on tough white paper of good quality and It Is to be Inserted Inside this form.

14166/77-L 141 e/77-LPrinted by C, 3. UIOMPSON, Acting Commonwealth Oovernmcnt Printer, Canberra

II

i(jJmi mum. ml mum .q- -2- This invention relates to solid fuel heaters and more I particularly to flue pipe extensions for use in association with such heaters.

The heating efficiency of an open fireplace is much less than an enclosed heater which normally has some means for controlling the amount of air admitted to the combustion zorne. Thus, the fuel consumption of an open fireplace is V higher than that of a slow combustion enclosed) stove and this had lead to increased popularity of the slow combustion stove.

Both kinds of heaters can and do cause significant local air pollution. As it is possible to restrict the quantity of combustion air with a slow combustion stove ana thereby slow the combustion speed, the potential for emission 1 of air pollutants Is greater- than for an open fireplace.

Improved combustion (and hence less pollution) can be achieved in properly designel and operated slow combustion stoves by the use of additional air ingress to provide for secondary combustion. A catalytic reactor may also be used to promote secondary combustion.

The products of combustion are removed fivom the slow combustion stove by a flue connected to a chimney which allows dispersion of the combustion products to the surrounding atmosphere.

The chimney acts as a pollution control device by dispersing the exhaust gases. The chimney also allows air to AT 0 ,FC A-Eos

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-3be drawn into the f irebox by natural draught. If the emissions from a particular slow combustion stove are large, the local pollution impact will be reduced if the dispersion of the exhaust gases is adequate. Adequate dispersion can only be achieved if the exhaust gases are discharged as high ao possible, as hot as possible and with as high a vertically upward velocity as is possible.

Most modern chimney installations incorporate some form of rain excluder such as a "chinaman's hat" but these devices *10 tend to hinder the vertically upward movement of the hot exhaust gases by initially directing them horizontally or downwards.

In an endeavour to reduce pollution by slow combustion stoves, it has been proposed to replace conventional rain excluders with a concentric extended shrouded rain excluder which consists of a tube of diameter equal to the chimney pipe plus 22mm with its lower edge not less than 150mm below the chimney outlet and which projects upwards not less than 4 times the chimney diameter above the chimney outlet, A disadvantage of the above proposal is that It does not prevent rain entry. Rain can penetrate into the chimney If It falls at an anigle to the axis of the excluder and is deflected by the inner wall of the exclud~er into the chimney.

According to the present invention there is provided a 23 combined chimney extender and rain excluder for a. chimney comprising a substantially tubular body of internal diameter larger than the external diameter of an upper end opening of

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-4said chimney and adapted to be mounted over said upper end opening of said chimney so 'that a lower end of said tubular body extends a predetermined distance below said upper end opening of said chimney and an upper end of said tubular body extends a predetermined distance above said upper end opening of said chimney whereby said tubular body receives exhaust P-lterial from s,-xid chimney and receives atmospheric air from a generally annular gap located between said upper end opening of qaid chimney and said lower end of said tubuilar 0 body; said extender and excluder further including a baffle 0 located entirely with-In and supported by sail tubular body; said baffle located and sized so as to prevent. at least a substantial portion of any rain which enters said extender and excluder and which -'ain is deflected from an inner surface thereof from entering said upper end opening of said chimney; said baffle also located and sized so as not to unduly Impede upward gas flow.

In order that the Invention may be vuore readily understood and put into practical effect, reference will now be made to the accompanying drawings in which:- Fig. I is a schematic view of a chimnciy extender *0 according to one embodiment of the invention, Fig, 2 is a modified form of baffle for the chimney extender shown in Fig. 1, Fig. 3 is a further modified form of the baffle for the chimney extender shown in Fig. 1, Fig. 4 shows an alternative baffle for the chimney extender shown in Fig. 1, and, Fig. 5 is a schematic view of a chimney extender and rain excluder according to another embodiment of the invention.

The chimney extender shown in Fig. 1 consists of a i tubular body 10 the diameter of which is larger than the diameter of the chimney 11. The lower end 12 of the extender 10 projects below the top 13 of the chimney 11 and the top end 14 of the extender 10 extends above the top 13 of the chimney 11 by a distance approximately equal to four times the chimney diameter. Mounted above the top 13 of the 5 chimney 11 is a baffle 15 arranged to prevent rain from v entering into the open end 13 of the chimney 11. Rain which enters the top 14 of the extender 10 at an angle to the axis of the extender (as shown by arrows A) is deflected by the walls of the extender 10 towards the top of the chimney 13 in the direction of arrows B.

The purpose of the baffle 15 is to prevent rain which has been deflected in the direction of arrows B from entering the top of the chimney 13. The baffle 15 can be of any convenient shape or configuration and in the present instance includes a conical base portion 16 arranged to deflect the smoke 17 in an upward direction. The baffle 15 may be secured to the extender 10 in any convenient way.

h I Modifications of the baffle are shown in Figs. 2, 3 and i L L 4. In each case they have a conical base portion 16, The baffle shown in Fig. 2 has a hollow top 20 and combined rain gutters an~k supports 21 by means of which the baffle is secitred the extender The baffle shown in Fig. 3 has a flat top 22 which has an overhanging shroud 23. Attached to the central portion of the top 22 are support straps 24 for securing the baffle to the extender 5 The baffle shown in Fig. 4 has a conical top 25 which 610 has an overhanging portion 26. Other configurations and shapes of baffle could be used.

Although the embodiments of the invention show-i in the drawings include a conical base, it is to be understood that such a base is not an essential feature of the invention.

Irdeed, a flat baffle without a conical base does not adversely effect the upward flow of combustion gases.

'.44 A flat baffle or ain deflector is present 4i the embodi-mntrt of the invehtion shown in Fig. 5. In this 0 051 Instance, the chimney consists of an active flue pipe 30 and an outer liner 31. The exteander 32 is larger in diameter than the flue 30 and its lower end extends below the top of the elue 30. The baffl(e 33 a flat plate that has a downwardly extending skirt 34, The baffle $3 is positioned above the flue outlet by a distance not less than the diameter of the flue 30, A weather cone 35 is located over the top of the outer liner 31.

Various modifications in details of design and construction may be made without departing front the scope and ambit of the invention.

Claims

1. A combined chimney extenider and rain excluder for a chimney comprising a substantially tubular body of internal diameter larger than the external diameter of an upper end opening of a chimney and adapted to be mounted over said upper end opening of said chintney so that a lower end of said tubular bod3y extends a predetermined distance below said upper end opening of said chimney and Rn upper end of said tubular body extends a predetermined distance above said **upper end opening of said chimney whereby said tubular bod7 0 receives exhaust material 4from said chimney and receives 0 0 atmospheric air from a generally annular gap located between said upper end opening of said chimney and said lower end of said tub~ilar body; said extender and excluder further if including a baffle located entir'ely within and supported by said -ubular body; said baffle located and sized so as to prevent at least a substantial portion of any rain which enters said extender and excluder and which rain is deflected from an inner suz".-ce thereof from entering sAid upper end '1 opening 'f said chimney; said baffle also located and sized so as not to unduly impede upward gas flow.

2. The combinped chimney extender and rain excluder of claim I wherein said baffle is located Within said tubular body at least one chimney diameter above said upper end opening of said chimney, L.

3. The combined extender and excluder of any previous claim wherein said predetermined distance above said upper end opening of said tubular body i-s approximately four times the diameter of said chimney.

4. The combined extender and excluder of any previous claim wherein said baffle is located within said tubular body closer to said lower end of paid tubular body than to said upper end of said tubular body.

5. The combined chimney extender and rain excluder of any previous claim wherein said baffle comprises a, substantially flat disc, a. The combined chimnney extender and rain excluder of any one of claims 1 to 13 wherein said baffle comprises a substantially upright cone. 0 7. The combined chimney extender and rain, excluder of any one of claims I to 13 wherein said baffle aoMprises a substantially Inverted cone,

8. The combined chimney extender and rain excluder, 0 of any one of claims I to 1s wherein said baffle comprises a substantially upright cone mounted on top of a substantially Inverted cone,

9. The combined chimney extender and rain excluder of any one of claims 5 to 6 wherein said baffle Includes a downwardly extending rim extending from the widest perimeter portion, of said baffle, The combined chimney extender and rain exctuder of any previous claim wherein said chimney comprises an active flue type shrouded by an cOUter liner. -9-

11. The combined chimney extender and rain excluder of claim 10 incorporating a weather cone shrouding the top of said outer liner.

12. A combined chimney extender and rain excluder substantially as hereinbefore particularly described with reference to Fig. I.

13. A combined chimney extender and rain excluder j a S• substantially as hereinbefore particularly described with reference to Fig. I 14. A combined chb 4 mney extender and rain excluder I substantially as hereinbefore particularly described with reference to FIg- 1 as modified by any one of Figs 2, 3 or 4. J DATED this 27th day of September, 1990. FLEXIBLE ELEOTRICALS PTY. LIMITED Patent Attorneys for the Applicant; PETER MAXWELL ASSOCIATES. /comi/871