GB2184532A

GB2184532A - Flame effect burner

Info

Publication number: GB2184532A
Application number: GB08630022A
Authority: GB
Inventors: Michael Cafferty
Original assignee: Geo Bray and Co Ltd
Current assignee: Geo Bray and Co Ltd
Priority date: 1985-12-17
Filing date: 1986-12-16
Publication date: 1987-06-24
Anticipated expiration: 2006-12-16
Also published as: GB2184532B; GB8530988D0; GB8630022D0

Abstract

In order to reduce the cost of providing a flame effect in a gas burner and to reduce the overall depth of the burner, an auxiliary burner is formed of two generally flat sheets 6,7 of steel, or a single sheet folded, in face to face relationship, at least one of the sheets being formed with a channel for an inlet part to an outlet part and the other sheet provides a cover the the channel. The channels may be branched and if the channel in one sheet crosses a channel in the other sheet an intermediate flat sheet element is sandwiched between the first and second sheet to form covers for both channels at the crossing. <IMAGE>

Description

SPECIFICATION Flame effect burner The invention relates to means defining passages for the conveyance of streams of fuel gases.

In the construction of gas fire units having an elongate main burner, it is common to provide a "flame" effect by arranging forthe localised inpinge ment of an auxiliary gas stream, at each of several spaced locations along the length ofthe main burner, with the main gas stream issuing from the main burner. In the past the provision of auxiliary stream has required the use of separate pipes or tubes which has added considerably to the cost of production and to the physical size of the unit. One of the objects of the invention is to provide for the pas sage of the auxiliary streams with the minimum cost and without unduly increasing the depth of the unit.

According to the invention there is provided a gas burner comprising means defining passages for the conveyance of gas streams from at least one inlet porttoa plurality of outlet ports, said meanscom- prising first and second sheets of material generally in face to face contact, each sheet being generally flat but at least one sheet having a channel formed therein and terminating at its ends to define said ports at an edge or edges of the sheet, portions of onesheetformingcoversforthechannelsoftheor each other sheet. Preferably the cover portions are flat along at least most of the length of the channels.

The channel or channels may be branched. If the channel in one sheet crosses a channel in the other sheet, an intermediate flat sheet element is sandwiched between the first and second sheets to form covers for both channels at the crossing.

Possiblythe channels areflatand shallowatthe ends defining outlet ports. The sheets may be perforated nearthe inlet ports to allow ingress of air.

The sheets may be secured together by folding one over the other along straight edges, or bywelding. The sheets may be integral with one another, being formed from a single blank by folding along a straight edge.

The channels may be of semi-circular or other suit- able cross-section, and the sheet otherwise forming a flat coverforthe channel in the other sheet may itself be formed with a corresponding semi-circular channel towards the inlet port so as to define, with the first mentioned channel, a circular inlet.

Embodiments ofthe invention will now be described by way of example, with reference to the accompanying drawings ofwhich:- Figure 1 shows a gas burner effect unit in side elevation; Figure 2 shows the unit of Figure 1 in plan.

In the embodiment shown in the figures, aflame effect auxiliary burner comprises two shaped pieces of stainless steel sheet of substantially similar general!y rectangular shape and of only slightly different dimensions. The sheets, pressed to a form to be described below, are arranged face to face and in register, and are secured together by folding projecting edges of the larger shape overthe smaller along longitudinal edge 1, transverse edge 2 and recessed edges 3, and by spot welds at closely spaced posi tions 4 around the remainder ofthe periphery with the exception of the inlet and outlet ports to be des cribed below.

In a pressing operation each piece is formed with a branched channel of semi-circular cross-section.

Thus sheet 5 is formed with a channel 7 which extends the length of the rectangle, terminates at edge 8, curves upwardly at 9to terminate at edge 10 and branches at 11 to terminate at edge 12. The other sheet, 6, of which only the folded over edges are seen in Figure 1, is formed with a channel 13 of sim ilar cross-sectional shape and running parallel to channel 7. Channel 13 also terminates at edge 8, at its other end bends upwardly at 1 4to terminate at edge 15and branchesatl6toterminateatedgel7.

As will be seen from Figure 2 the sheets are piaced together in such a way that the channel in each sheet extends away from the other sheet, and for most of the length of the channel 7 the sheet 6 forms a flat cover to the channel, the channel and cover together defining an elongate passageway. Similarly sheet 5 forms a flat cover to channel 13 over most of its length, and defines a second passageway. As the channels approach the respective edges 10, 12, 15 and 17they become somewhat narrower and shal- lower and terminate in substantially flat flame ports 18,19,20and21 as shown in Figure 2.

In normal operation, with the auxiliary burner positioned alongside a main burner (not shown), gas entering the passageways can exit freely at the flame ports to provide a flame effect in the main burner as known in the art, and the pressureofthe gas inthe passageways is consequently very low so that provided the sheets are substantially flat where not chan- nelled there is little risk of leakage of gas from the passageways. However, itwill be seen thatthe channel 7 between its branching at 11 and its exit at edge 12 overlies a portion ofthe channel 13 in the other sheet and it is therefore necessary to introduce an internal mask 22 ofthin sheet steel to act as a cover four both channels in the overlapping region.

One or each of the sheets 5,6 may be slightly recessed, if required, to accommodate the mask.

Whilst in the embodiment described the channels are semi-circular in section, other shapes may be used provided that the cross-sectional area of the passage defined between the channel of one sheet and the adjacentflatsurface ofthe other sheet is sufficientto allow the passage ofthe required stream of gas without excessive surface drag. Where the channel 7 of sheetS terminates at edge 8, the other sheet 6 is pressed into a channel 24 of similar dimensions at the edge itself but reducing rapidly to zero depth as itextends away from the edge. Similarly sheet5 is provided with a short tapered channel 23 opposed to the channel 13 in the sheet6towards edgeS. Thus, the passageways have substantially circular cross-section where they terminate at edge 8 to provide inlet ports suitableforconnection to gas suppiy pipes. It is within the scope of the invention to providethatthe portions of one sheet forming a cover for a channel in the other sheet are themselves formed as channels along at least the greater part of their length.

Adjacentthe inlet ports the sheets are perforated at 25 to allow ingress of air into the passageways.

Claims

1. A gas burner comprising means defining pas sagesfortheconveyance of gas streams from at least one inlet port to a plurality of outlet ports, said means comprising first and second sheets of material generally in face to face contact, each sheet being generally flat but at least one sheet having a channel formed therein and terminating at its ends to define said ports at an edge or edges of the sheet, portions of one sheet forming covers forthe channels of the or each other sheet.

2. A gas burner according to Claim 1 wherein the cover portions are flat along at least most ofthe length of the channels.

3. A gas burner according to Claim 1 or Claim 2 wherein the channel is or channels are branched.

4. Agas burneraccording to any one of preceding claims wherein a channel in one sheet crosses a channel in the other sheet and an intermediate flat sheet element is sandwiched betweenthe first and second sheets to form covers for both channels at the crossing.

5. A gas burner according to any one of the preceding claimswhereinthe sheet otherwise forming a flat coverforthe channel in the other sheet is itself formed with a corresponding semi-circular channel towardsthe inlet port so asto define, with thefirst mentioned channel, a circular inlet.

6. A gas burner according to any one of the preceding claims wherein the sheets are integral with one another, being formed from a single blank byfolding along a straight edge.

7. A gas burner substantially as described with reference to the accompanying drawings.