CN110832253A

CN110832253A - Premix gas burner

Info

Publication number: CN110832253A
Application number: CN201880044544.4A
Authority: CN
Inventors: R·范祖特费恩特; G·福克斯; D·霍尔特洛普; R·博尔; D·欧斯特拉
Original assignee: Bekaert Combustion Technology BV
Current assignee: Bekaert Combustion Technology BV
Priority date: 2017-07-13
Filing date: 2018-07-04
Publication date: 2020-02-21
Also published as: WO2019011741A1; US20200200437A1; EP3652484A1

Abstract

The premixed gas burner includes a metal plate structure, a burner deck, and a shaped distributor plate. A metal plate structure is provided for mounting the premix gas burner to a heating appliance. The burner deck includes a woven wire mesh over the outer surface of which the premixed gas is combusted after it has flowed through the woven wire mesh. The shaped distributor plate includes perforations. When the burner is in use, the premixed gas flows through the perforations of the shaped distributor plate before flowing through the woven wire mesh. One or more slot or notch shaped openings are provided in the shaped distributor plate. The woven wire mesh includes a circumferential edge that includes at least one tab. The tab or tabs are inserted through an opening in the shape of a slot or notch in the shaped dispenser plate.

Description

Premix gas burner

Technical Field

The present invention relates to the field of premixed gas burners, more particularly to surface stabilized premixed gas burners comprising a woven wire mesh as the burner platform.

Background

Surface-stabilized premix gas burners with woven wire burner platforms are known.

US5474443A discloses a premix gas burner with a hemispherical burner deck made of woven wire mesh.

US2005/172915 shows a premix gas burner with a woven wire mesh combustion surface comprising rigid ribs.

Disclosure of Invention

A first aspect of the invention is a premix gas burner comprising a metal plate structure, a burner deck and a shaped distributor plate for mounting the premix gas burner in a heating appliance (e.g. in a condensing boiler). The burner deck comprises and preferably consists of a woven wire mesh over the outer surface of which the premixed gas is combusted after it has flowed through the woven wire mesh. The shaped distributor plate includes perforations. When the burner is in use, the premixed gas flows through the perforations of the shaped distributor plate before flowing through the woven wire mesh. One or more slot or notch shaped openings are provided in the shaped distributor plate. The woven wire mesh includes a circumferential edge. The peripheral edge of the woven wire mesh comprises at least one tab. Preferably, the peripheral edge of the woven wire mesh comprises a plurality of tabs. The tab or tabs are each inserted through an opening in the shape of a slot or notch in the shaped dispenser plate.

Woven wire mesh burner platforms of surface stabilized premixed gas burners become hot when the burner is in use. Woven wire mesh combustor platforms need to be able to handle the stresses caused by thermal expansion associated with high temperatures when the combustor is in use and the stresses caused by shrinkage when the combustor is not in use. If this is not the case, early mechanical failure of the combustor platform may occur. Due to the provision of one or more tabs at the periphery of the woven wire burner, which tab or tabs are inserted through a slot or notch-shaped opening in the forming distributor plate, a certain amount of movement of the woven wire relative to the forming distributor plate is possible when the woven wire expands when heated or contracts when cooled. It is therefore surprising that the premix gas burner of the invention is very well adapted to withstand thermal expansion and contraction, resulting in a long life of the premix gas burner.

Preferably the tab has a maximum width of between 4mm and 20mm, more preferably between 6mm and 12 mm. Preferably the tab has a maximum width of between 3mm and 6 mm.

Preferably, the woven wire mesh has a thickness between 0.6mm and 1.3 mm. As an example, a woven wire mesh of 0.9mm thickness may be advantageously used in the present invention.

In a preferred embodiment, the shaped distributor plate and the metal plate structure are welded to each other.

In a preferred embodiment, the shaped distributor plate and the metal plate structure are fixed to each other by mechanical connection means; for example by means of bolts, rivets or by means of a slot-tongue connection.

Preferably, at least one tab is bent such that an angle of less than 180 ° is provided between the tab inserted through the slot or notch and the portion of the woven wire mesh on the other side of the slot or notch. Preferably, all the tabs are bent such that an included angle of less than 180 ° is provided between the tab passing through the slot or notch and the portion of the woven wire on the other side of the slot or notch. More preferably, the included angle is less than 150 °, even more preferably less than 120 °. Preferably, the included angle is greater than 30 °, even more preferably greater than 60 °, even more preferably greater than 90 °. The embodiment wherein at least one tab is bent ensures that the woven wire mesh is better held in place in applications where the burner is used with the burner deck facing down; and helps to achieve a longer life of the combustor platform and the combustor.

In a preferred embodiment, the burner deck is arranged in a convex shape. This means that the flame of the burner is anchored on the convex side of the burner deck when the burner is in operation. More preferably, the entire surface of the burner deck is provided in a convex shape; meaning that the flame of the burner deck has a convex shape over the entire surface of its side that is anchored when the burner is in operation.

Preferably, the burner deck has a double curved surface. When a surface is doubly curved at one point of the surface, there is no direction at that point where the radius of curvature is infinite. As an example, a cylindrical burner is a burner with a single curved surface.

Preferably, all areas of the shaped distributor plate where perforations are provided are spaced a distance from the woven wire. This means that no perforations can be in contact with the woven wire, but the perforations are located at a distance from the woven wire. The ability of such embodiments facilitates production of burners having long lifetimes.

In a preferred embodiment, the periphery of the burner deck has a rectangular shape, wherein the two short sides are rounded. More preferably, the short sides of the rectangle are rounded continuously. Preferably, the tabs are provided only along the two long sides of the rectangular shape of the perimeter of the burner deck. Meaning that no tab is provided along the short side, which may be continuously rounded. The burner according to this embodiment is even better suited for long life use, since the absence of tabs along the short sides allows for better thermal expansion of the woven wire in its length direction.

In a preferred embodiment, wherein the periphery of the burner deck has a rectangular shape, the two short sides of which are rounded, the metal plate structure comprises upstanding ridges at the two short sides of the rectangular burner deck. The distance between the upstanding ridges at the two short sides and the burner deck is at least 0.5mm when the burner is cold. Preferably, the distance is at least 1mm, more preferably at least 1.2mm, and for example 1.35 mm. The presence of the upstanding ridges synergistically increases to achieve a burner with a longer life. The upstanding ridge has been shown to provide a barrier to prevent flames from flashing back into the burner.

Preferably, the metal plate structure has a central opening. The burner deck and the shaped distributor plate are configured to be inserted through and extend through the central opening. More preferably, the metal plate structure comprises an upstanding ridge surrounding the central opening. The ridge extends in a direction in which the burner deck extends through the central opening of the metal plate structure. The presence of the upstanding ridges synergistically increases to achieve a burner with a longer life. The upstanding ridge has been shown to provide a barrier to prevent flames from flashing back into the burner.

In a preferred embodiment, wherein the upstanding ridges are provided along two long sides of the burner deck, the distance between the upstanding ridges at the two long sides and the burner deck is less than 0.5 mm.

In a preferred embodiment, wherein the upstanding ridges are provided along the entire circumference of the burner deck, the distance between the upstanding ridges at both long sides and the burner deck is less than 0.5 mm.

In a preferred embodiment, the woven wire mesh comprises neither ribs nor protrusions.

In a preferred embodiment, the woven wire mesh comprises ribs and/or protrusions.

A second aspect of the invention is a condensing boiler comprising said premix gas burner according to any embodiment of the first aspect of the invention.

Drawings

Fig. 1-4 show a premix gas burner according to the invention.

Detailed Description

Fig. 1 shows a view 100 of a burner deck of a premix gas burner according to the invention. Fig. 2 shows a bottom view 200 of the premix gas burner of fig. 1. Fig. 3 shows a view 300 of the premix gas burner of fig. 1 in a cross section III-III. Fig. 4 shows a view 400 of the premix gas burner of fig. 1 in a cross-section along IV-IV.

The premixed gas burner includes: a metal plate structure 102 for mounting the premixed gas burner in a heating apparatus (e.g., in a condensing boiler); a combustor platform 104; and a shaped distributor plate 106. The shaped distributor plate 106 is shown in fig. 2-4; perforations 108 forming the distributor plate are visible in fig. 1 through the combustor platform 104. The burner deck and the shaped distributor plate are configured to be inserted into and extend through a central opening in the metal plate structure.

The entire surface of the burner deck is convex in shape. The burner 104 deck is comprised of a woven wire mesh through the outer surface of which the premixed gas is combusted after flowing. In this example, the woven wire mesh has a thickness of 0.9 mm. The shaped distributor plate includes perforations 108. When the burner is in use, the premixed gas flows through the perforations of the shaped distributor plate before flowing through the woven wire mesh.

The periphery of the burner deck is rectangular in shape, the two short sides of which are continuously rounded.

A plurality of slots 110 are provided in the shaped distributor plate. The peripheral edge of the woven wire mesh includes a plurality of tabs 112. Tab 112 is inserted through slot 110. Tabs 112 are provided only along the two long sides of the rectangular shape of the perimeter of the combustor platform; no tabs are provided along the continuously rounded short sides.

In the exemplary gas premix burner, the shaped distributor plate 106 and the metal plate structure 102 are secured to one another by rivets 114 that pass through holes 116 in the metal plate structure and the shaped distributor plate.

In fig. 2 and 3, tab 112 is shown after insertion into slot 110 fig. 4 shows tab 112 after tab 112 is bent the tab is bent such that an included angle α of less than 180 ° is provided between the tab inserted through the slot and the portion of the woven wire mesh on the other side of the slot.

The metal plate structure 102 includes an upstanding ridge 118 along the entire perimeter of the combustor platform. In the exemplary burner, the distance a between the upstanding ridges at the two short sides and the burner deck is 1.35mm when the burner is cold. The distance B between the upstanding ridges along both long sides and the burner deck is less than 0.35 mm.

Claims

1. A premixed gas burner comprising

-a metal plate structure for mounting the premix gas burner in a heating appliance;

-a burner deck, wherein the burner deck comprises, and preferably consists of, a woven wire mesh over the outer surface of which the premixed gas is combusted after it has flowed through the woven wire mesh; and

-a shaped distributor plate, wherein the shaped distributor plate comprises perforations, wherein the premixed gas flows through the perforations of the shaped distributor plate before the premixed gas flows through the woven wire mesh when the burner is in use;

wherein one or more slot or notch shaped openings are provided in the shaped distributor plate;

wherein the woven wire mesh comprises a circumferential edge;

wherein the circumferential edge of the woven wire mesh comprises at least one tab, and preferably a plurality of tabs;

wherein the tab or tabs are inserted through a slot or notch-shaped opening in the shaped distributor plate.

2. The premix gas burner of claim 1, wherein the shaped distributor plate and the metal plate structure are welded to each other.

3. The premix gas burner as in claim 1, wherein said shaped distributor plate and said metal plate structure are fixed to each other by mechanical connection means, such as by bolts, rivets, or by slot-tongue connection.

4. The premix gas burner as in any of the preceding claims, wherein the burner deck has a double curved surface.

5. The premix gas burner as in any of the preceding claims, wherein at least one tab, preferably all tabs, is bent such that between the tab inserted through the slot or notch and the portion of the woven wire on the other side of the slot or notch, an angle of less than 180 ° is provided.

6. The premix gas burner as in any of the preceding claims, wherein said burner deck is provided in a convex shape; preferably wherein the burner deck is provided in a convex shape over the entire surface of the burner deck.

7. The premix gas burner as in any of the preceding claims, wherein all areas on the shaped distributor plate where perforations are provided are at a distance from the woven wire mesh.

8. The premix gas burner as in any of the preceding claims, wherein a perimeter of said burner deck has said rectangular shape, wherein two short sides are rounded, preferably continuously rounded.

9. The premix gas burner of claim 8, wherein tabs are provided only along two long sides of the rectangular shape of the perimeter of the burner deck.

10. The premix gas burner as in claim 8 or 9,

wherein the metal plate structure comprises upstanding ridges at the two short sides of a rectangular burner deck;

wherein the distance between the upstanding ridges at the two short sides and the burner deck is at least 0.5mm when the burner is cold.

11. The premix gas burner as in any of the preceding claims,

wherein the metal plate structure has a central opening;

wherein the combustor platform and the shaped distributor plate are inserted through and extend through the central opening.

12. The premix gas burner as in claim 11,

wherein the metal plate structure comprises an upstanding ridge surrounding the central opening;

wherein the ridge extends in a direction in which the burner deck extends through the central opening of the metal plate structure.

13. The premix gas burner as in claims 8 to 10 and 12,

wherein the distance between the upstanding ridges at the two long sides and the burner deck is less than 0.5 mm.

14. Condensation boiler comprising a premix gas burner according to any of the preceding claims.