DE20001107U1 - Atmospheric gas burner - Google Patents

Description

(18 349)

Atmospheric gas burner

The innovation relates to an atmospheric gas burner according to the preamble of claim 1.

According to DE 197 47 481 Cl, a gas burner is known with a burner body and a base part (gas-air mixing section), which can be easily separated from one another for maintenance work using a quick-release fastener. Since the burner body is exposed to high temperatures due to the combustion of the gas-air mixture, the base part is designed as a cast part.

The aim of the innovation is to reduce the manufacturing and material costs of a burner of the type mentioned above.

According to the innovation, this object is achieved with an atmospheric gas burner of the type mentioned at the outset by the features mentioned in the characterising part of claim 1.

According to the innovation, a gas-air mixing section made of plastic is to be arranged on the gas supply side of the combustion surface and the combustion surface is to be designed in direct connection with at least one cooling channel, i.e. the combustion surface and the cooling channel should be in direct thermal contact, i.e. without any thermal bridges (as before). In this way, it is possible to dissipate sufficiently large amounts of heat from the combustion surface to the cooling water, so that the gas-air mixing section can be made of inexpensive and easy-to-process plastic.

According to DE 195 45 844 A1, a burner with integrated cooling channels made in one piece using the extrusion process is already known. However, the task of this design is to create a gas burner that is as simple and easy to manufacture as possible and has an increased temperature resistance of the burner surface. A separate manufacture of the gas-air mixing section (made of plastic at that) is not suggested for this design, as otherwise the desired simplest possible manufacture would no longer be possible, especially since the mixing chamber of this burner is provided with a flat, wide Venturi channel with a rectangular inlet cross-section, which is particularly easy to manufacture using extrusion.

As mentioned, the material bond between the combustion surface and the cooling channel or channels is best produced by extrusion. However, casting can also produce the desired material bond.

It is further advantageous that the composite body is made of aluminum. This material not only has good heat transfer properties, but is also well suited to the manufacturing processes described above.

With regard to the combustion surface, it is advantageous that the gas outlet openings are designed in the form of slots that are optionally milled or sawn into the composite body. In this way, the gas outlet openings can be introduced cost-effectively into the composite body produced by casting or extrusion.

Depending on the manufacturing method of the composite body, i.e. casting or extrusion, at least one open cross-section is produced. In order to close this, it is planned, for example, to

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A casting process is used to produce a pair of composite bodies that match each other, each with only one open cross-section, which is closed by joining the pair together. In terms of production technology, it is alternatively more economical and therefore advantageous to close the at least one open cross-section of the composite body with a lid.

In order to be able to supply cooling water to the at least one cooling channel arranged on the combustion surface in a simple manner, it is further advantageously provided that supply and return connections are arranged on the at least one cover.

The innovative atmospheric gas burner and its advantageous further developments are explained in more detail below with reference to the drawing of an exemplary embodiment.

It shows Fig . 1 Fig . 2 Fig . 3 Fig . 4 Fig . 5 Fig . 6 Fig . 7 Fig . 8th

perspective view of the combustion surface with several cooling channels in combination;

as a diagram the basic relationship between flow noise and outlet cross-section;
as a diagram the basic relationship between outlet cross-section and risk of kickback;
perspective view of the external view of a closure lid;

perspective view of the inside of a closure lid;

in section the combustion surface with a gas-air mixing section made of plastic;

in side view the gas-air mixing section and
Front view of the gas-air mixing section for a gas distributor with eight gas nozzles.

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Fig. 1 shows an atmospheric gas burner which consists of a combustion surface 1 provided with gas outlet openings 2, to which a total of six water-conducting cooling channels 3 are assigned on the gas supply side, in the region of the gas outlet openings 2.

In front of the combustion surface 1, on the gas supply side, there is a gas-air mixing section 5 (see Fig. 6), which serves to mix the gas coming from a gas line with the required amount of air. This trough-shaped gas-air mixing section 5 is shown in Figs. 6 to 8 from various views. It essentially has three areas, namely firstly a gas-air inlet area 14 with eight inlet openings 13, secondly tubular gas-air mixing areas 15 adjoining thereto and thirdly a chamber 16 which is connected upstream of the combustion surface 1 on the gas supply side, with a gas distributor 17 with eight nozzles 18 being arranged in the gas-air inlet area 14.

What is essential for this burner is that the gas-air mixture section 5 is made of plastic and that the combustion surface 1 and the six cooling channels 3 form a material composite body 4 which consists of a material with good heat conduction.

The composite body 4 shown in Fig. 1 is designed as an extruded body. It consists of cooling channels 3 that extend in the extrusion direction, are drop-shaped in cross section and have internal ribs, at the narrow ends of which the individual segments of the combustion surface 1 with their gas outlet openings 2 are arranged. The transition region 11 between the combustion surface 1 and the cooling channels 3 ensures effective heat transfer.

For good heat transfer, it is also advantageous that the composite body 4 is made of aluminum.

The gas outlet openings 2 are designed in the form of slots 8 that are optionally milled or sawn into the composite body 4.

With this composite body construction, due to its good thermal conductivity properties, it is possible to exclude flashback despite large gas outlet openings 2. The diagrams in Fig. 2 and 3 illustrate the basic relationships:

Fig. 2 shows that the frequently disturbing flow noises decrease with increasing exit cross-section. In contrast, however, the risk of flashback increases with increasing exit cross-section (see Fig. 3). However, the lower the temperature at the combustion surface 1, the lower the risk of flashback. The optimal configuration is therefore one in which large exit cross-sections are provided to avoid flow noises and the flame or the gas-air mixture is cooled down sufficiently by effective cooling as it passes through the combustion surface 1 that flashback can be ruled out.

The open cross sections on the composite body 4 resulting from extrusion or casting are closed with a cover 7. Such a cover 7, produced by casting, is shown in Fig. 4 and 5 in external and internal views. It is attached to the composite body 1 by means of a special aluminum soldering process. In order to supply the cooling water to the cooling channels 3 in a simple manner,

7 flow and return connections 9 are arranged, to which corresponding connecting pipes (not shown) are connected.

Finally, an advantageous further development consists in that the gas-air mixing section 5 is fastened to the composite body 4 by means of a snap closure 12, wherein a sealing means excludes gas leakage in the transition region from the gas-air mixing section 5 to the composite body 4.

Claims (8)

1. Atmospheric gas burner, consisting of a combustion surface (1) provided with gas outlet openings (2), to which at least one water-carrying cooling channel (3) is assigned on the gas supply side in the region of the gas outlet openings (2), wherein a gas-air mixing section (5) is arranged on the combustion surface (1) on the gas supply side, which is designed like a trough and essentially has three areas, namely firstly a gas-air inlet area (14) having several inlet openings (13), secondly tubular gas-air mixing areas (15) adjoining thereto and thirdly a chamber (16) which is arranged upstream of the combustion surface (1) on the gas supply side, wherein a gas distributor (17) is arranged in the gas-air inlet area (14), characterized in that the gas-air mixing section (5) is made of plastic and that the combustion surface (1) and the at least one cooling channel (3) form a material composite body (4) which is made of well made of heat-conducting material. 2. Atmospheric gas burner according to claim 1, characterized in that the composite body (4) is designed optionally as an extruded body or as a cast body. 3. Atmospheric gas burner according to claim 1 or 2, characterized in that the composite body (4) consists of aluminum. 4. Atmospheric gas burner according to one of claims 1 to 3, characterized in that the gas outlet openings (2) are designed in the form of slots (8) optionally milled or sawn into the composite body (4). 5. Atmospheric gas burner according to one of claims 2 to 4, characterized in that the at least one open cross section of the composite body (4) is closed with a cover (7). 6. Atmospheric gas burner according to claim 5, characterized in that the cover (7) is integrally connected to the composite body (4). 7. Atmospheric gas burner according to claim 5 or 6, characterized in that supply and return connections (9) are arranged on the cover (7). 8. Atmospheric gas burner according to one of claims 1 to 7, characterized in that the gas-air mixing section (5) is fastened to the composite body (4) by a snap closure (12).