GAS BURNER

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority, under 35 U.S.C. §119, of European patent application EP 08 164 454, filed Sep. 16, 2008; the prior application is herewith incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

The invention relates to a gas burner with a fan and a mixing device arranged on the intake side of the fan, said mixing device mixing the air taken in through an intake channel with a gas supplied to the intake channel through a gas inlet to form a gas-air mixture.

A gas burner of the type is described, for instance, in the published German patent application DE 10 2005 041 691 A1. There, the gas burner has a controllable fan and a venturi mixing nozzle, in which the gas supplied through a gas port upstream of the inlet into the fan, is mixed with the intaken air. The outlet of the fan is connected to a flame tube which can be inserted into a combustion chamber of a firing plant which is passed through by the gas-air mixture. To counteract the appearance of whistling noises, the flame tube of the gas burner has a sound suppressor.

German patent DE 197 30 254 C2 also discloses a method for suppressing interfering sound emissions when combusting a gas-air mixture. The gas-air mixture is supplied to a burner with a premixing hood by way of an intake tube provided with an air intake opening, a fan and a premixing path, in which burner the mixture formation of gas and air is perfected. The path from the intake tube to the premix dome is embodied such that the volumes increase, whereby the cross-section-length ratio of the components along the path in the flow direction of the air-gas mixture increases or remains the same.

The prior structural measures for noise reduction are disadvantageous in that these are dependent on the design of the burner and require considerable installation space. The prior art measures also result in an additional pressure loss.

SUMMARY OF THE INVENTION

It is accordingly an object of the invention to provide a gas burner, which overcomes the above-mentioned disadvantages of the heretofore-known devices and methods of this general type and which reduces interfering noises occurring in a mixing system of a gas burner, for example as a result of thermo-acoustic oscillations, in a simple and cost-effective manner; the noise reduction measures should be possible independently of the design of the burner.

With the foregoing and other objects in view there is provided, in accordance with the invention, a gas burner, comprising:

a fan having an suction side;

a mixing device disposed at the suction side of the fan, the mixing device having an intake channel for air and the intake channel for air having a gas inlet, the mixing device mixing air taken in through the intake channel for air with a gas supplied through the gas inlet to form a gas-air mixture; and

the mixing device having a housing with an air inlet formed with cutouts for noise reduction.

In other words, the objects of the invention are achieved by a mixing device that has a housing with an air inlet formed with cutouts for noise reduction. In a preferred embodiment of the invention the air inlet of the mixing device housing is embodied in an annular fashion and the cutouts are provided at regular intervals on the annular circumference of the air inlet for instance. The mixing device housing is preferably formed in one piece with the air inlet. The air inlet can however also be embodied as a separate part which can be connected to the mixing device housing. The intake channel of the mixing device is preferably embodied in the form of a venturi nozzle.

In accordance with an added feature of the invention, the housing of the mixing device has an annular disk configured for connection to the suction side of the fan. In a preferred embodiment, the housing of the mixing device, the annular disk, and the gas inlet are formed in one piece. Finally, there may be provided a sound suppressor to be connected to the air inlet.

A noise reduction through the cutouts provided on the air inlet of the mixing device is possible in a simple and cost-effective fashion and irrespective of the design of the burner. The cutouts do not require any additional installation space, as a result of which the gas burner can be embodied in a very compact manner. Also, no additional pressure loss appears along the gas-air mixing path as a result of the cutouts.

Other features which are considered as characteristic for the invention are set forth in the appended claims.

Although the invention is illustrated and described herein as embodied in a gas burner, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.

The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is a perspective view of an exemplary embodiment of a gas burner according to the invention with a mixing device and fan;

FIG. 2 is a perspective view of an exemplary embodiment of an additional mixing device;

FIGS. 3 and 4 are perspective views of different exemplary embodiments of an air inlet of a mixing device; and

FIG. 5 is a perspective view of a gas burner according to the invention with an additional sound suppressor.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown a perspective view of a controllable fan 1. A mixing device 3 with a housing is disposed at a suction side 2, or intake side 2, of the fan 1. The mixing device housing 3 has an annular disk 11, which is detachably connected to the suction side of the fan 2. The mixing device housing 3 can be fastened to the intake side of the fan 2 in the form of a screw connection 8, 9 for instance. Alternatively, the mixing device 3 can also form an integral part of the fan 1 or a fan part.

The mixing device 3 has an intake channel 4, for example, a venturi nozzle, which is surrounded by the mixing device housing 3. A tubular gas inlet 12 is arranged at right angles to the intake channel 4, to which gas inlet 12 a gas line 40 is connected. The gas inlet 12 is tubular and embodied such that the gas line 40 can be plugged into the gas inlet 12, with the gas line being fastened to the gas inlet 12 by means of a pressure clamp 10.

The mixing device housing 3 has an annular air inlet 5 for instance. Cutouts 6 for noise reduction are provided at regular intervals on the annular circumference of the air inlet 5 for instance. The mixing device housing 3 and the air inlet 5 is preferably formed from one piece, e.g. injection-molded from plastic. The air taken in through the air inlet 5 and the intake channel 4 is mixed with the gas supplied to the intake channel 4 through the gas inlet 12. In this way the cutouts 6 reduce the noises occurring as a result of thermoacoustic oscillations for instance.

The gas-air mixture is supplied to the gas burner through a fan outlet 23, which is surrounded by a fan flange 20. The fan flange 20 has the openings 21 and 22 for connection to a burner flange (not shown here).

FIG. 2 shows a perspective view of a further exemplary embodiment of a mixing device, which differs from the mixing device shown in FIG. 1 only in the form of the cutouts of the air inlet. In this exemplary embodiment the cutouts 7 of the air inlet 5 have a rectangular shape. The cutouts 6, 7 of the air inlet 5 can naturally also comprise a round or oval or otherwise suitable form.

Contrary to the exemplary embodiments shown in FIGS. 1 and 2, the air inlet 5 shown in FIGS. 3 and 4 is embodied as a separate part of the mixing device housing, which is manufactured from plastic using injection-molding technology for instance. The air inlet 5 with the cutouts 6, 7 can be connected to the mixing device housing in the form of a plug-in connection or screw connection for instance. This variant is then particularly advantageous if mixing devices which are already on the market, the housing of which is compatible with the inventive air inlet, are subsequently to be provided with the noise-reducing part 5.

FIG. 5 shows a development of the exemplary embodiment shown in FIG. 1. This differs from the development shown in FIG. 1 only in that a sound suppressor 30 is also connected to the air inlet of the mixing device housing 3. The sound suppressor 30 can be connected to the mixing device housing 3 in the form of a plug-in connection or screw connection for instance.