GB1601953A - Burner bar for the combustion of a mixture of air and a gas - Google Patents

Description

(54) BURNER BAR FOR THE COMBUSTION OF A MIXTURE OF AIR AND A GAS (71) We, COVRAD LIMITED, a British Company of Sir Henry Parkes Road, Canley, Coventry CV5 6BN, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a burner bar for the combustion of a mixture of air and a gas and is an improvement in or modification of the invention of our British Patent No.

1,120,766.

That patent described and claimed a burner bar for the combustion of a mixture of air and combustible gas, including a tubular member which is adapted at one end to receive a supply of the gas and air and is closed at the other end, and has a longitudinally-arranged series of pairs of transverse slits in its wall, the portion of the wall between the slits of each pair being depressed to below the inner wall of the tubular member to form a recess with facing slot-like ports at the bottom through which opposed supplies of the mixture are delivered for combustion in a direction substantially perpendicular to the member, the recess acting as a flame holder.

British Patent No. 1,184,844, which is a patent of addition to British Patent No.

1,120,766, describes and claims a modification of or improvement in the burner bar of specification 1,120,766 and in the case where the burner bar includes a tubular member formed from two complementary pressings of which one is provided with flame slits, according to which the slitted pressing is provided on its inner side with a covering of wire mesh which is adapted to absorb heat from a flame which tends to enter the tubular member, whereby to extinguish it.

According to the present invention, there is provided a modification of or improvement in the burner bar for the combustion of a mixture of air and a gas as described and claimed in Claim 1 of British Patent No.

1,120,766, the burner bar being intended for use with natural gas and in which the tubular member is formed from two complementary parts in one of which slits are provided, wherein the slitted part is provided on its inner side with a covering of perforated metal sheet or expanded metal mesh, whereby to assist in providing even flame distribution.

One embodiment of the invention will now be specifically described with reference to the accompanying drawings of which, Figure 1 is a side elevation of a burner bar, Figure 2 is a plan view of the burner bar of Figure 1, Figure 3 is a section on the line Ill-Ill of Figure 1, and Figure 4 is an enlarged view of the expanded metal mesh, before being curved.

Referring to the drawings, the burner bar is made from two sheet-metal channel members 10, 11, having flanges 10a, I la, along their sides and round one end. The flanges 10a, I la, lie against one another, and are secured together by seam welding so as to form a substantially circular-section duct, one end of which is closed and the other end of which receives a supply of gas and air. The upper surface of member 10 is provided with pairs of transverse slits 12, 13, so that the intermediate portion 14 is depressed, with its outer surface below the inner surface of the main body of the member 10. The combustible mixture issues through slits 12, 13, and is ignited outside the member 10, the depressed portion 14 acting as a flame holder.

A grid 15 of expanded stainless steel mesh is shaped to substantially semi-cylindrical form, and is fixed to the underside of member 10 by spot-welding at the positions 16 shown. The grid 15 lies against the inner surfaces of the depressed portions 14, and thus there is a clearance between the grid and the inner surface of member 10 between the depressed portions 14. The apertures in the expanded metal mesh have a major axis and a minor axis, and the latter is preferably parallel to the axis of curvature of the mesh.

Each element of the grid 15 is inclined (as seen looking on Figure 1) so that its inner edge is nearer the closed end of the burner bar than its outer edge. One corner of the grid is clipped off as shown at 17, (Figures 2 and 4) to identify the end of the grid to be positioned nearer the closed end of the burner bar.

It is found that the provision of the expanded metal mesh provides a more even flame distribution; alternatively perforated metal could be used for the grid 15.

WHAT WE CLAIM IS: 1. A burner bar for the combustion of a mixture of air and a gas as described and claimed in claim 1 of British Patent No.

1,120,766, the burner bar being intended for use with natural gas and in which the tubular member is formed from two complementary parts in one of which slits are provided, wherein the slitted part is provided on its inner side with a covering of perforated metal sheet or expanded metal mesh, whereby to assist in providing even flame distribution.

2. A burner bar as claimed in claim 1, wherein the part of the tubular member in which the slits are provided is substantially semi-circular in cross-section, and wherein the covering of expanded metal mesh is also substantially semi-circular in cross-section and fits closely within the slitted part.

3. A burner bar as claimed in claim 2, wherein the covering of expanded metal mesh lies against the inner surfaces of the depressed portions.

4. A burner bar as claimed in any preceding claim in which the apertures in the expanded metal mesh have a major axis and a minor axis and the latter is parallel to the axis of curvature of the mesh.

5. A burner bar substantially as hereinbefore described with reference to and as illustrated in Figures 1 to 4 of the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. the inner surface of member 10 between the depressed portions 14. The apertures in the expanded metal mesh have a major axis and a minor axis, and the latter is preferably parallel to the axis of curvature of the mesh. Each element of the grid 15 is inclined (as seen looking on Figure 1) so that its inner edge is nearer the closed end of the burner bar than its outer edge. One corner of the grid is clipped off as shown at 17, (Figures 2 and 4) to identify the end of the grid to be positioned nearer the closed end of the burner bar. It is found that the provision of the expanded metal mesh provides a more even flame distribution; alternatively perforated metal could be used for the grid 15. WHAT WE CLAIM IS: 1. A burner bar for the combustion of a mixture of air and a gas as described and claimed in claim 1 of British Patent No.

1,120,766, the burner bar being intended for use with natural gas and in which the tubular member is formed from two complementary parts in one of which slits are provided, wherein the slitted part is provided on its inner side with a covering of perforated metal sheet or expanded metal mesh, whereby to assist in providing even flame distribution.

2. A burner bar as claimed in claim 1, wherein the part of the tubular member in which the slits are provided is substantially semi-circular in cross-section, and wherein the covering of expanded metal mesh is also substantially semi-circular in cross-section and fits closely within the slitted part.

3. A burner bar as claimed in claim 2, wherein the covering of expanded metal mesh lies against the inner surfaces of the depressed portions.

4. A burner bar as claimed in any preceding claim in which the apertures in the expanded metal mesh have a major axis and a minor axis and the latter is parallel to the axis of curvature of the mesh.

5. A burner bar substantially as hereinbefore described with reference to and as illustrated in Figures 1 to 4 of the accompanying drawings.