Atmospheric gas burner

(42) Date of commencement of the patent: 15. 3.1994 (45) Date of issue: 25.11.1994

<td>(56) Documents:</td><td>(73) Patent owner:</td>

<td>AT-PS 181403</td><td>VAILLANT SOCIETY MBH A-1233 VIENNA (AT).</td>

<td></td><td></td>

(54) ATMOSPHERIC GAS BURNER (57) Atmospheric gas burner for a boiler with a burner chamber (1), the interior of which is fed with a gas / primary air mixture via a plurality of mixing tubes (6) arranged below the burner chamber, each with a gas nozzle (8), wherein the mixing tubes (6) are approximately perpendicular and at its burner chamber (1) facing away from the inlet side (7) with the gas nozzle (8) are provided and that gas-primary air mixture at the top (2) of the burner chamber (1) in the region of mixture outlet openings (3, 4) where flames form, exit. These are equipped to equalize the flame height in the region of the projection of the mixing tubes (6) on the top (2) of the burner chamber (1) with a smaller cross section than in the other areas.

CQ

AT 398 339

<img file="AT398339B_D0001.tif" />

DTOoraeiB

AT 398 339 Β

The present invention relates to an atmospheric gas burner with at least one burner chamber, the interior of which is fed with at least one arranged below the burner chamber provided with a gas nozzle nearly vertical mixing tube with a gas-air mixture, wherein the gas nozzle is assigned to the Eineißseite facing away from the burner chamber of the mixing tube and wherein the gas-primary air mixture from arranged at the top of the burner chamber mixture outlet openings, where flames form, exit.

Such burners are known. It occurs in these burners the difficulty that at a constant over the entire surface of the burner chamber arrangement of the mixture outlet openings are formed on these flames, which are larger in the region of the extensions of the mixing tubes ais in the other areas, and due to the fact in that the gas primary air jet from the mixing tube is present here at higher pressure directly at the mixture outlet openings.

In a gas burner described in the AT-PS 181 403, the burner tube is roofed above the mouth of the mixing tube with a cap whose inlets are arranged laterally of the projection of the mixing tube. The cap is provided with mixture outlet openings, which form flames. These mixture outlet openings correspond in size and distance to those of the rest of the burner tube; The disadvantage here in addition to the complicated structure - especially in connection with gas tightness between the cap and burner tube - especially the formation of the flames on the cap and the burner tube in different height ranges.

The object of the present invention is to equalize the burner flame height over the entire surface of the burner chamber.

To achieve the object, the invention provides that the outlet cross section of each mixture outlet opening and the total cross section of the mixture outlet openings in the region of the projection of the mixing tubes on the upper side of the burner chamber is smaller than in the remaining area.

By this configuration, one achieves the advantage that the outlet resistance for the gas-primary air mixture in the extension of the axes of the mixing tubes is increased, so that here less gas-primary air mixture exits than in the other areas that are not directly hit by the gas primary air jet. In this way, a homogenization of the flame image over the entire surface of the burner chamber succeeds.

In an embodiment of the invention, it is proposed that the projection of the mixing tubes associated surface of the top of the burner chamber is provided with holes designed as circular cross-section fuel mixture outlet openings, the other area, however, with shooters with approximately rectangular cross-section.

This gives the advantage that the homogenization of the flame image even better.

Further embodiments and particularly advantageous developments of the invention will become apparent from the following description, which explains an embodiment of the invention with reference to Figures 1 to 4 of the drawing.

Show it:

1 is a side view of an atmospheric gas burner,

Fig. 2 is a plan view of a burner chamber and the

Figures 3 and 4 Details of the top of the burner chamber.

In all four figures, like reference numerals indicate the same details.

An atmospheric gas burner for a boiler has a burner chamber 1, which has approximately upright prismatic shape. On its upper side 2, the burner chamber has a plurality of mixture outlet openings in the form of shooters 3 and holes 4. Below the burner chamber, a mixing tube unit 5 is arranged, which has individual mixing tubes 6, wherein the mixing tubes are each embossed in half in two sheet metal shells. The inlets 7 of the mixing tubes are facing gas nozzles 8 aligned, all gas nozzles 8 are fed from a gas line, not shown, with LPG. From a gap 9 between the gas nozzle 8 and inlet 7 air is entrained under the injection effect of the gas jet, so that forms a gas-primary air mixture inside the mixing tubes 6, which is the bottom 10 of the burner chamber and thus the interior of the burner chamber supplied.

2 shows that three hole areas 11 and four contactor areas 12 result. In each case a hole area is arranged where the projection of a mixing tube 6 results on the top 2 of the burner chamber 1, optionally with a more or less enlarged environment. From Fig.2 it can be seen because in one area the top 2 is cut away. This is also understandable that the three lying in a plane mixing tubes 6 according to Figure 1 opposite three hole areas 11 as shown in FIG 2. In the hole areas 11, the outlet of the gas-primary air mixture is greatly decelerated by the upper side 2 of the burner chamber 1, thus due to the relatively small diameter of the holes, only a small amount of gas-primary air mixture passes through the top of the burner chamber, as a result of2

AT 398 339 Β burns the gas-air mixture here with a relatively small flame. In the slot regions 12, the on-resistance for the gas-air mixture is considerably smaller, On the other hand, these areas are not directly in the blow-out area of ​​the individual mixing tubes, so that here the gas primary air pressure is smaller, due to the enlarged outlet cross-sections of the mixture outlet opening, however, flames then form at a height here, which is equal to the height, as they occur directly in the extension of the axes 13 of the mixing tubes at the reduced there mixture outlet openings.

At the same time you get the advantage that the flames that arise in the area 11 of the holes 4, as

Serve detention flames.

3 shows a detail of the upper side 2 of the burner chamber 1 is shown. It can be seen that the

Slot 3 is in the region of a survey 14, which protrudes beyond the other surface of the top 2.