Gas burner and domestic cooking appliance

Abstract

A gas burner for a household appliance includes a burner housing having a mixing chamber for mixing fuel gas with primary air, a gas nozzle accommodated in the burner housing and configured to inject the fuel gas into the mixing chamber, and an annular first primary air inlet provided between the gas nozzle and the mixing chamber for drawing in the primary air. The gas nozzle has a second primary air inlet which is guided through the nozzle for drawing in the primary air. The second primary air inlet is configured in a direction of flow of the primary air through the second primary air inlet to taper at least once and to widen out again. The gas nozzle has an annular fuel gas outlet opening which opens directly into the second primary air inlet.

Claims

1. A gas burner for a household appliance, said gas burner comprising: a burner housing having a mixing chamber for mixing fuel gas with primary air, a gas nozzle accommodated in the burner housing and configured to inject the fuel gas into the mixing chamber, and an annular first primary air inlet provided between the gas nozzle and the mixing chamber for drawing in the primary air, said gas nozzle having: a second primary air inlet which is guided through the nozzle for drawing in the primary air, said second primary air inlet being configured in a direction of flow of the primary air through the second primary air inlet to taper at least once and to widen out again, an annular fuel gas outlet opening which opens directly into the second primary air inlet, an annular fuel gas distribution channel configured to taper in a direction of the annular fuel gas outlet opening, and a connecting channel connecting the annular fuel gas distribution channel with the annular fuel gas outlet opening, the connecting channel being curved in a shape of an arc.

2. The gas burner of claim 1, wherein the fuel gas outlet opening breaks through an outer wall of the second primary air inlet.

3. The gas burner of claim 1, wherein the second primary air inlet includes an inlet section tapering conically in the direction of flow of the primary air, an outlet section widening out conically in the direction of flow of the primary air and facing towards the mixing chamber, and a cylindrical intermediate section arranged between the inlet section and the outlet section.

4. The gas burner of claim 3, wherein the fuel gas outlet opening opens into the second primary air inlet between the intermediate section and the outlet section.

5. The gas burner of claim 1, wherein the gas nozzle is configured rotationally symmetrical to a central axis of the gas burner, said second primary air inlet being configured rotationally symmetrical to the central axis.

6. The gas burner of claim 1, wherein the burner housing includes a lower burner part which houses the mixing chamber, and a nozzle holder which is connected to the lower burner part and accommodates the gas nozzle.

7. The gas burner of claim 6, wherein the nozzle holder includes a fuel gas channel for supplying the fuel gas to the gas nozzle.

8. The gas burner of claim 6, wherein the second primary air inlet is configured at least in part in the nozzle holder.

9. A household appliance, comprising a gas burner, said gas burner comprising a burner housing having a mixing chamber for mixing fuel gas with primary air, a gas nozzle accommodated in the burner housing and configured to inject the fuel gas into the mixing chamber, and an annular first primary air inlet provided between the gas nozzle and the mixing chamber for drawing in the primary air, said gas nozzle having a second primary air inlet which is guided through the nozzle for drawing in the primary air, said second primary air inlet being configured in a direction of flow of the primary air through the second primary air inlet to taper at least once and to widen out again, said gas nozzle having: an annular fuel gas outlet opening which opens directly into the second primary air inlet, an annular fuel gas distribution channel configured to taper in a direction of the annular fuel gas outlet opening, and a connecting channel connecting the annular fuel gas distribution channel with the annular fuel gas outlet opening, the connecting channel being curved in a shape of an arc.

10. The household appliance of claim 9, constructed in the form of a gas stove.

11. The household appliance of claim 9, wherein the fuel gas outlet opening breaks through an outer wall of the second primary air inlet.

12. The household appliance of claim 9, wherein the second primary air inlet includes an inlet section tapering conically in the direction of flow of the primary air, an outlet section widening out conically in the direction of flow of the primary air and facing towards the mixing chamber, and a cylindrical intermediate section arranged between the inlet section and the outlet section.

13. The household appliance of claim 12, wherein the fuel gas outlet opening opens into the second primary air inlet between the intermediate section and the outlet section.

14. The household appliance of claim 9, wherein the gas nozzle is configured rotationally symmetrical to a central axis of the gas burner, said second primary air inlet being configured rotationally symmetrical to the central axis.

15. The household appliance of claim 9, wherein the burner housing includes a lower burner part which houses the mixing chamber, and a nozzle holder which is connected to the lower burner part and accommodates the gas nozzle, wherein the nozzle holder includes: a drawing-in section tapering in the direction of flow of the primary air, and a supply section in communication with the second primary air inlet of the gas nozzle, the supply section connecting the drawing-in section to the second primary air inlet of the gas nozzle.

16. The household appliance of claim 9, further comprising: a cooktop, wherein a part of the burner housing is on the cooktop, and wherein the second primary air inlet includes an inlet section tapering conically in the direction of flow of the primary air, an outlet section widening out conically in the direction of flow of the primary air, and a cylindrical intermediate section arranged between the inlet section and the outlet section and immediately before the outlet section, the outlet section facing towards the mixing chamber and opening directly into the annular first primary air inlet, wherein the annular fuel gas outlet opening opens into the second primary air inlet between the intermediate section and the outlet section and immediately before the outlet section.

17. A household appliance comprising: a cooktop; a gas burner having a burner housing at least partially disposed on the cooktop, wherein the burner housing includes: a lower burner part having a mixing chamber for mixing fuel gas with primary air, and a gas distribution chamber configured to distribute a primary air/fuel gas mixture formed in the mixing chamber to a plurality of gas outlet openings of the gas burner; a nozzle holder below the cooktop; a gas nozzle supported by the nozzle holder, the gas nozzle configured to inject the fuel gas into the mixing chamber for mixing the fuel gas with the primary air; and an annular first primary air inlet provided between the gas nozzle and the mixing chamber for drawing in the primary air, wherein the gas nozzle includes: a second primary air inlet extending through a body of the gas nozzle for drawing in the primary air, said second primary air inlet being configured in a direction of flow of the primary air through the second primary air inlet to taper at least once and to widen out again, an annular fuel gas outlet opening which opens directly into the second primary air inlet, and an annular fuel gas distribution channel in communication with the annular fuel gas outlet opening, the annular fuel gas distribution channel configured to taper in a direction of the fuel gas outlet opening; and wherein the nozzle holder includes: a drawing-in section tapering in the direction of flow of the primary air, a supply section in communication with the second primary air inlet of the gas nozzle, the supply section connecting the drawing-in section to the second primary air inlet of the gas nozzle, a fuel gas channel for supplying the fuel gas to the gas nozzle, the fuel gas channel of the nozzle holder being in communication with the annular fuel gas distribution channel of the gas nozzle, and a connecting channel connecting the annular fuel gas distribution channel with the annular fuel gas outlet opening, the connecting channel being curved in a shape of an arc.

18. The household appliance of claim 17, wherein the supply section is a cylindrical supply section.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantageous embodiments and aspects of the gas burner and/or of the household cooking appliance are the subject matter of the subclaims as well as the exemplary embodiments of the gas burner and/or of the household cooking appliance described below. The gas burner and/or of the household cooking appliance will be explained in greater detail below with reference to the enclosed figures.

(2) FIG. 1 shows a schematic view of a form of embodiment of a household cooking appliance;

(3) FIG. 2 shows a schematic sectional view of a form of embodiment of a gas burner for the household cooking appliance as depicted in FIG. 1;

(4) FIG. 3 shows a further schematic sectional view of the gas burner as depicted in FIG. 2;

(5) FIG. 4 shows a schematic perspective part sectional view of a form of embodiment of a gas nozzle for the gas burner as depicted in FIG. 2; and

(6) FIG. 5 shows a schematic sectional view of the gas nozzle as depicted in FIG. 4.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE PRESENT INVENTION

(7) Elements that are the same or that function in the same way have been labeled with the same reference characters, unless stated otherwise.

(8) FIG. 1 shows a schematic view of a form of embodiment of a household cooking appliance 1. The household cooking appliance 1 is in particular a gas stove or household gas stove. The household cooking appliance 1 can be a built-in appliance or a freestanding appliance. The household cooking appliance 1 comprises a number of gas burners 2. There can be any given number of gas burners 2. For example four gas burners 2 can be provided. Each gas burner 2 is assigned a gas control valve or gas regulation valve 3, with the aid of which a fuel gas flow supplied to the respective gas burner 2 can be optionally switched on, switched off and can be regulated, in particular steplessly.

(9) FIGS. 2 and 3 respectively show a schematic sectional view of a form of embodiment of a gas burner 2 for the household cooking appliance 1. The gas burner 2 comprises a burner housing 4. The burner housing 4 is preferably made of an aluminum or magnesium alloy. The burner housing 4 comprises a lower burner part 5, which rests on a cooktop or top sheet 6. The cooktop can also be referred to as the top sheet 6. The top sheet 6 is for example a metal sheet or a glass ceramic sheet. All gas burners 2 of the household appliance 1 are fastened to the top sheet 6. This means that a common top sheet 6 is allocated to all gas burners 2.

(10) The lower burner part 5 is embodied rotationally symmetrical to a central axis or an axis of symmetry M.sub.2 of the gas burner 2. A tubular mixing chamber 7 is provided centrally in the lower burner part 5. The mixing chamber 7 is likewise embodied rotationally symmetrical to the central axis M.sub.2. The mixing chamber 7 is configured to mix fuel gas B, for example natural gas, with fresh air or primary air L. Laid on top of the lower burner part 5 is a burner cover 8.

(11) A gas distribution chamber 9 is formed between the burner cover 8 and the lower burner part 5 for evenly distributing a primary air/fuel gas mixture formed in the mixing chamber 7 to a plurality of gas outlet openings 10 provided on the edge of the burner cover 8. There can be any number of gas outlet openings 10. The gas outlet openings 10 are arranged distributed evenly around a circumference of the burner cover 8. The burner cover 8 is likewise embodied rotationally symmetrical to the central axis M.sub.2.

(12) With the aid of the gas distribution chamber 9 the primary air/fuel gas mixture created in the mixing chamber 7 is able to be distributed evenly to the gas outlet openings 10. In addition the mixing of the primary air L with the fuel gas B can be further improved in the gas distribution chamber 9. This means that there can be a premixing of the fuel gas B and primary air L in the mixing chamber 7 and the full mixing can be continued in the gas distribution chamber 9.

(13) The burner housing 4 furthermore comprises a nozzle holder 11. The nozzle holder 11 is arranged below the top sheet 6. For example the top sheet 6 can be fixed by a clamp between the lower part of the burner 5 and the nozzle holder 11. To this end a breakthrough can be provided in the top plate 6. The nozzle holder 11 has an annular fastening section 12, which is connected permanently to the lower part of the burner 5. An outer thread can be provided for this purpose for example on the outside of the mixing chamber 7, which is screwed into a corresponding inner thread of the fastening section 12.

(14) The nozzle holder 11 furthermore comprises a nozzle receiving section 13, which is connected via a web section 14 in one piece to the fastening section 12. In particular the fastening section 12, the nozzle receiving section 13 and the web section 14 are embodied as one piece of material. The nozzle holder 11, the lower part of the burner 5 and the burner cover 8 can for example be embodied as aluminum die cast components. This enables the gas burner 2 to be manufactured at low cost in large volumes.

(15) The nozzle holder 11 furthermore comprises a fuel gas channel 15 provided in the nozzle receiving section 13 for supplying the fuel gas B to a gas nozzle 16 of the gas burner 2. With the aid of the gas nozzle 16 the fuel gas B can be injected into the mixing chamber 7. An annular, circumferential first primary air inlet 17 is provided between the gas nozzle 16 and the mixing chamber 7. The gas nozzle 16 is arranged spaced apart from the lower edge 18 of the mixing chamber 7. This means that the gas nozzle 16 is positioned entirely outside the mixing chamber 7. During injection of the fuel gas B with the aid of the gas nozzle 16 into the mixing chamber 7, primary air L is drawn in at the side via the first primary air inlet 17. The gas nozzle 16 thus causes a Venturi effect.

(16) A form of embodiment of the gas nozzle 16 is shown in FIGS. 4 and 5. The gas nozzle 16 is likewise embodied rotationally symmetrical to the central axis M2. The gas nozzle 16 comprises a cylindrical base body 19, which is preferably made of a metal material. In particular the base body 19 can be made of brass. The base body 19 has an optional chamfer 20 facing towards the mixing chamber 7. The chamfer 20 can make an angle of 45° with the central axis M2 for example. The chamfer 20 makes it easier for the primary air L to flow past the gas nozzle 16 into the mixing chamber 7.

(17) The gas nozzle 16 further comprises a second primary air inlet 21 guided centrally through said nozzle. Primary air L is likewise drawn in through the second primary air inlet 21 and supplied to the mixing chamber 7. The second primary air inlet 21 is a hole provided in the center of the base body 19. The second primary air inlet 21 tapers in a direction of flow R of the primary air L at least once and subsequently widens out again in the direction of flow R. In particular the second primary air inlet 21 comprises a conical inlet section 22 tapering in the direction of flow R of the primary air L, a conical outlet section 23 widening out in the direction of flow R, which faces towards the mixing chamber 7, and a cylindrical intermediate section 24 arranged between the inlet section 22 and the outlet section 23.

(18) The inlet section 22 tapering in a conical shape in the direction of flow R of the primary air L is to be understood as a cross-section or a cross-sectional surface of the inlet section 22 becoming smaller in the direction of flow R. The outlet section 23 widening out in a conical shape in the direction of flow R is to be understood as a cross-section or a cross-sectional surface respectively of the outlet section 23 becoming larger in the direction of flow R. The intermediate section 24 is preferably cylindrical with a circular basic surface.

(19) The inlet section 22, the outlet section 23 and the intermediate section 24 form an outer wall 25 of the second primary air inlet 21. The second primary air inlet 21 can be embodied, as shown in FIGS. 2 and 3, at least partly in the nozzle holder 11. For example a drawing-in section 26 tapering in the direction of flow R of the primary air L is provided in the nozzle receiving section 13 of the nozzle holder 11, which opens into a cylindrical supply section 27. With the aid of the supply section 27 the primary air L is supplied to the gas nozzle 16. The supply section 27 is arranged in this case between the inlet section 22 and the drawing-in section 26.

(20) The gas nozzle 16 furthermore has an annular fuel gas outlet opening 28. Annular is to be understood as the fuel gas outlet opening 28 running completely around the central axis M.sub.2. The fuel gas outlet opening 28 is in the shape of a slot. The fuel gas outlet opening 28 opens directly into the second primary air inlet 21. In doing so the fuel gas outlet opening 28 breaks through the outer wall 25 of the second primary air inlet 21.

(21) Also provided in the base body 19 of the gas nozzle 16 is an annular fuel gas distribution channel 29 running completely around the central axis M.sub.2 and embodied rotationally symmetrical to said axis, for even distribution of the fuel gas B. The fuel gas distribution channel 29 tapers in the direction of the fuel gas outlet opening 28. This means that the fuel gas distribution channel 29 has a larger cross-section than the fuel gas outlet opening 28. Provided between the fuel gas outlet opening 28 and the fuel gas distribution channel 29 is a connecting channel 30 curved in the shape of an arc.

(22) The fuel gas outlet opening 28 opens into the second primary air inlet 21 immediately after the intermediate section 24 of the primary air inlet 21. In particular the fuel gas outlet opening 28 opens into the second primary air inlet 21 between the intermediate section 24 and the outlet section 23.

(23) As FIGS. 2 and 3 show, the fuel gas channel 15 provided in the nozzle receiving section 13 comprises an annular fuel gas distribution channel 31 running around the supply section 27 and the drawing-in section 26, with the aid of which the fuel gas B is supplied to the fuel gas distribution channel 29 of the gas nozzle 16. To this end a connecting channel or a number of connecting channels 32 can be provided in the nozzle receiving section 13. The connecting channels 32 can be embodied as holes.

(24) The functionality of the gas burner will be explained below. In operation of the gas burner 2 fuel gas B is supplied to said burner via the fuel gas channel 15. The fuel gas B flows through the fuel gas outlet opening 28 in an annular shape into the second primary air inlet 21. Through this primary air L is drawn in via the drawing-in section 26 into the gas nozzle 16 and in particular into the second primary air inlet 21. The fact that the second primary air inlet 21 tapers in the direction of flow R of the primary air L means that the primary air L is accelerated and still mixes in the gas nozzle 16 at least partly with the fuel gas B. On exit of the primary air/fuel gas mixture from the gas nozzle 16, further primary air L is drawn into the mixing chamber 7 from the side via the first primary air inlet 17. In the mixing chamber 7 there is a further full mixing of the fuel gas B with the primary air L.

(25) By two primary air inlets 17, 21 being provided, by comparison with known gas burners, an increased amount of primary air L can be drawn in. This also enables a larger amount of fuel gas B to be burned and thus the performance of the gas burner 2 to be enhanced by comparison with known gas burners. The premixing of the primary air L with the fuel gas B can already take place in the gas nozzle 16 in a very restricted space. This enables the gas burner 2 to be constructed lower by comparison with known gas burners. The combustion of the fuel gas B is improved since the mixing of the fuel gas B with the primary air L is more homogeneous. The output of emissions is reduced and the efficiency of the gas burner 2 is enhanced.