BURNER UNIT

Description

[0001] The present invention relates to a burner unit for burning an air-fuel mixture. The burner unit is, for example, part of a heater for heating air or a liquid, e.g., water. The fuel is, for example, diesel, gasoline, or a flammable gas (e.g., propane).

[0002] DE 295 11 384 U1 describes a burner unit with an outer and an inner tube. The inner tube is located inside the outer tube and allows combustion air to be supplied via slots. The fuel is introduced into the outer tube. The resulting mixture of air and fuel is burned in a flame tube. The design of a combustion chamber can also be found in DE 633 304, DE 44 42 425 B4, DE 44 47 986 B4, DE 195 29 994 A1, or DE 10 2013 109 184 A1.

[0003] For combustion to be as complete and low in emissions as possible, the best possible mixing of air and fuel is required.

[0004] The object underlying the invention is therefore to propose a burner unit that allows the best possible combustion of the air-fuel mixture.

[0005] The invention solves the problem by means of a burner unit for burning an air-fuel mixture, comprising a combustion chamber, a combustion air guide dome and a fuel supply, wherein the combustion air guide dome is located in the combustion chamber and has recesses, wherein the fuel supply opens into the combustion chamber, and wherein the recesses on an inside of the combustion air guide dome have a greater width than on an outside of the air supply dome.

[0006] The openings in the combustion dome, through which the (combustion) air from the dome's interior enters the combustion chamber, do not have a constant width, but rather narrow from the inside out. This is viewed in a plane perpendicular to a longitudinal axis of the dome and / or the burner unit. The dome can alternatively be described as an inner tube or inner cylinder. Fuel, such as diesel, enters the combustion chamber via a fuel supply. It has been shown that the narrowing of the openings improves mixing. This results, for example, in a more homogeneous velocity distribution within the combustion chamber. Furthermore, pressure losses can be avoided.

[0007] The recesses are designed, for example, as slots along the longitudinal axis. Air enters the interior of the dome via a blower and from there into the combustion chamber surrounding the air supply dome. In one configuration, the burner unit is part of a heating system.

[0008] One design feature is that the recesses taper conically from the inside to the outside. The side walls of the recesses, for example, have a smooth profile with a constant slope.

[0009] One embodiment provides that the recesses are designed in such a way that they create a nozzle effect for air directed out of the combustion air guide dome.

[0010] One embodiment involves the recesses having a substantially consistent shape along a longitudinal axis of the air supply dome. These recesses are, for example, axially oriented slots. An alternative embodiment provides for the recesses to change their shape along a longitudinal axis of the air supply dome.

[0011] The longitudinal axis of the combustion air guide dome is perpendicular to the direction in which the recesses narrow from the inside out.

[0012] One embodiment involves the combustion air guide dome having a substantially circular cylindrical shape. The combustion air guide dome can be closed or open at the end face.

[0013] One embodiment provides that the recesses along a longitudinal axis of the air supply dome have different heights. In this embodiment, the recesses have different lengths or extensions in the axial direction. An alternative embodiment consists of the recesses along a longitudinal axis of the air supply dome having a common height. In this embodiment, the recesses have a common or identical axial extension along the longitudinal axis.

[0014] In detail, there are numerous possibilities for designing and further developing the burner unit according to the invention. Reference is made, on the one hand, to the claims subordinate to claim 1, and on the other hand, to the following description of exemplary embodiments in conjunction with the drawing. The drawing shows: Fig. 1 shows a section through a schematic representation of the burner unit along the longitudinal axis and Fig. 2 shows a section through the burner unit perpendicular to the longitudinal axis.

[0015] The Fig. 1The figure schematically shows a burner unit 1, which is, for example, part of a heating system. In the combustion chamber 2, a mixture of fuel, e.g., gas or diesel, and combustion air is burned. Thorough mixing is necessary for the most efficient combustion possible, which also produces as few pollutants as possible. The combustion air enters the combustion chamber 2 through the openings 4 in the combustion air guide dome 3. Here, the openings 4 are designed as slots that extend from the inner end face of the combustion air guide dome 3 and along the longitudinal axis 6 of the burner unit 1 and also of the combustion air guide dome 3. The shape of the openings 4 is therefore constant in the axial direction, and the openings 4 run parallel to each other. In the illustrated configuration, the openings 4 also have a common height, i.e., a common, i.e., identical, axial extent.The combustion air guide dome 4 is a cylinder with a circular base. The fuel enters the combustion chamber 2 via a fuel supply 5.

[0016] The Fig. 2 Figure 1 shows a section along the longitudinal axis 6 through the combustion air guide dome 3. Visible are the recesses 4, which extend from the inner side 30 to the outer side 31 and become narrower from the inside out. The width of the recesses 4 is therefore greater on the inner side 30 than on the outer side 31. This creates the effect of a nozzle. Reference symbol list

[0017] 1 burner unit 2 combustion chamber 3 Combustion air guide dome 4 recess 5 Fuel supply 6 Longitudinal axis of the combustion air guide dome 30 Inside of the combustion air guide dome 31 Outside of the combustion air guide dome

Claims

1. A burner unit (1) for combusting an air-fuel mixture, comprising a combustion space (2), a combustion air guide dome (3) and a fuel inlet (5), wherein the combustion air guide dome (3) is located in the combustion space (2) and has recesses (4), wherein the fuel inlet (5) opens into the combustion space (2), characterized in that the recesses (4) have a larger width on an inside (30) of the combustion air guide dome (3) than on an outside (31) of the air supply dome (3).

2. The burner unit (1) according to claim 1, wherein the recesses (4) taper from the inside (30) to the outside (31).

3. The burner unit (1) according to claim 1 or 2, wherein the recesses (4) are configured such that they produce a nozzle effect for air directed out of the combustion air guide dome (3).

4. The burner unit (1) according to any of claims 1 to 3, wherein the recesses (4) have a constant profile along a longitudinal axis (6) of the air supply dome (3).

5. The burner unit (1) according to any of claims 1 to 4, wherein the combustion air guide dome (3) has a circular cylindrical shape.

6. The burner unit (1) according to any of claims 1 to 5, wherein the recesses (4) have a common height along a longitudinal axis (6) of the air supply dome (3).