Gas burner, a cooking hob and a stove

Abstract

The invention relates to a gas burner (1) to burn a combustible gas in a cooking hob (2), comprising a burner housing (4), which can rest on a cooking plate (101) of the cooking hob (2) and / or be fixed to the same, a burner cover (5), which can rest on the burner housing (4), thereby delimiting a distributing chamber (7) between the burner housing (4) and the burner cover (5), a mixing tube (21) communicating the distributing chamber (7) with a mixing section (8) provided next to the burner housing (4) and extending from the mixing tube (21) to mix the combustible gas with a primary air, and wherein the gas burner (1) further comprises a gas injector (10), arranged on the other side of the mixing section (8), provided to inject the combustible gas into a mixing space (12) of the mixing section (8), and the mixing section (8) has at least one primary air inlet (13) giving access into the mixing space (12) to the primary air from the surroundings (14) of the mixing section (8). To guarantee a stable primary air and combustible gas mixture, the mixing space (12) is delimited by a mixing wall (22), where the at least one primary air inlet (13) is arranged, a tube side (23), which is connected with a tube end (24), and an injector side (11) connected with the gas injector (10), and the at least one primary air inlet (13) is bored into the mixing wall (22). Furthermore, the invention relates to a cooking hob (2) with such a gas burner (1), as well as to a gas stove (100) with such a gas burner (1) and / or with such a cooking hob (2).

Description

[0001] Gas burner, a cooking hob and a stove

[0002] The present invention relates to a gas burner, a cooking hob and a stove.

[0003] In gas burners, a Venturi nozzle is used to mix the combustible gas with primary air. To this, the combustible gas is injected into a mixing space of the gas burner by means of a gas injector. Through the openings for primary air, provided next to the mixing space, primary air is drawn in from the surroundings of the gas burner and mixed with the combustible gas.

[0004] JP 3109608 II describes a gas burner having conducting elements, which are configured to conduct primary air towards a combustible gas stream so as to achieve a good mixing of primary air with the combustible gas.

[0005] Considering this background, this invention solves the technical problem relating to providing an improved gas burner.

[0006] Therefore, a gas burner to burn a combustible gas in a cooking hob is provided, comprising a burner housing, which can rest on a cooking plate of the cooking hob and / or be fixed to the same, a burner cover, which can rest on the burner housing, thereby delimiting a distributing chamber between the burner housing and the burner cover, a mixing tube communicating the distributing chamber with a mixing section provided next to the burner housing and extending from the mixing tube to mix the combustible gas with a primary air. Furthermore, the gas burner comprises a gas injector, arranged on the other side of the mixing section, provided to inject the combustible gas into a mixing space of the mixing section, and the mixing section has at least one primary air inlet giving access into the mixing space to the primary air from the surroundings of the mixing section.

[0007] In particular, the mixing space is delimited by a mixing wall, where the at least one primary air inlet is arranged, a tube side, which is connected with a tube end, and an injector side connected with the gas injector, and the primary air inlet is bored into the mixing wall.

[0008] The burner housing is a metal body normally shaped with a substantially circular bottom and whose bottom side rests on the cooking plate of the cooking hob to which it is fixed. A burner cover rests on its top side detachably. Preferably, the burner cover has a plurality of burner nozzles, which are arranged uniformly distributed over a perimeter of the burner cover. In addition, the burner nozzles can be shaped between the burner cover and the top side of the burner housing, or they can be made in a vertical wall of the top side of the gas burner housing as well, while the cover closes this vertical wall entirely from above. The distributing chamber is delimited between the burner cover and the top side of the burner housing, into which the combustible gas and primary air mixture can flow and leave the burner through the burner nozzles when it is combusted. To this, the burner cover is arranged downstream of the mixing space.

[0009] The mixing tube is arranged in the bottom side of the burner communicating the distributing chamber with the mixing space and causing a Venturi effect in the combustible gas and primary air mixture when flowing towards the distributing chamber from the mixing space. When the burner is mounted in the cooking hob on the cooking plate, the cooking plate has an opening through which the mixing tube can access the opposite side of the cooking plate. The cooking hob is fed with combustible gas from a combustible gas network pipe up to the burner base. The injector has a connecting part to the burner base acting as an injector support and the burner base has an internal channelling conducting the combustible gas from the gas network pipe to the gas injector. The burner base remains fixed in the cooking hob to the cooking plate and supports the housing bottom part of the burner housing. The gas injector has a gas passage opening towards the mixing space. The mixing space is delimited by a mixing wall, a tube side, which is connected with the tube end projecting from the bottom side of the burner, and an injector side to which the injector is connected. In the mixing wall there is at least one primary air inlet communicating the mixing space with the surroundings of the burner. Preferably, the mixing wall is tightly connected to the tube end and / or to the injector side. This configuration makes the mixing space be a space closed to the primary air inflow, except through the at least one primary air inlet. In this manner, the ratio of the combustible gas with primary air mixture is stable. In this way, the amount of primary air flowing into the mixing section and being mixed with the combustible gas stream injected by the gas injector can be controlled better. Furthermore, a proper swirling of the primary air with the combustible gas is so achieved. When primary air flows through the at least one primary air inlet bored into the mixing wall, it collides with the combustible gas injected by the injector. Thereby, they mix in a proper and required amount. In this manner, a good combustion of the primary aircombustible gas mixture is guaranteed having a suitable mixture. With this, the amount of undesired residues from combustion is reduced. This occurs due to the fact that the ratio of the section of the at least one primary air inlet to the flow of the injected combustible gas stream is determined according to the heating power of the gas burner. The higher the power of the cooking hob is, the higher the combustible gas flow injectable by the injector and the bigger the section of the at least one primary air inlet in the mixing wall of the mixing section will be. Furthermore, since a suitable ratio of the section of the at least one primary air inlet to the flow of the injected combustible gas stream is ensured, the mixing space can be reduced compared to the known gas burners.

[0010] In an embodiment of the invention, the primary air inlet is made as a plurality of orifices with a diameter ranging from 0.1 mm to 1 mm. Although the section of the orifices may be irregular, even a polygonal section, it is preferred that the section of the orifices is circular, since a stable primary air flow is guaranteed. Furthermore, it is desirable that the plurality of the orifices is arranged uniformly distributed over the mixing wall. In this case, it is ensured even more that the primary air flows into the mixing space in a uniform manner. In an embodiment of the invention, the ratio of the orifices in the mixing wall amounts to 8 to 22 orifices per burner power kW, depending on their diameter.

[0011] Although the mixing section and the burner housing are tightly connected to each other, they may be made in several pieces. In that case, there is a sealing gasket between the tube side of the mixing section and the tube end to guarantee a tight connection. In this case, the mixing section and the burner housing are an independent component. Here, the mixing section may be, for example, screwed, caulked or otherwise fixedly connected with the tube end of the burner housing.

[0012] According to another embodiment, the gas injector points towards a distributing chamber of the gas burner, wherein the distributing chamber is configured to distribute a combustible gas-primary air mixture among burner nozzles of the gas burner.

[0013] In this manner, the combustible gas stream does not need to be deviated.

[0014] Like above, the mixing wall is tightly connected with the injector with a sealing gasket through its injector side or it may be even made in one piece with the injector side or even in one piece with the injector. In this way, the construction of such a set is advantageous for the construction of the appliance and it can be attached to the burner housing in a simplified manner.

[0015] In an alternative embodiment, the mixing wall could be made in one piece with the tube end of the mixing tube through the tube side of the mixing space having the above- mentioned advantages for the case of a one-piece construction of the mixing wall through the injector side with the injector.

[0016] In a preferred embodiment, at least a part of the mixing wall is tubular with a polygonal or preferably circular section of the outer surface and of the inner surface. In that case, both the injector side and the tube side have a corresponding, polygonal or circular, outer perimeter. If the outer surface of the mixing wall is polygonal, for example hexagonal, it can be fitted with a tool, for example an adjustable wrench, to be screwed to the tube end and / or to the injector side.

[0017] If the injector side is preferably polygonal or circular, the gas injector is positioned in the centre of the injector side pointing towards the centre of the mixing space, the combustible gas stream remaining thereby at a distance to the inner surface of the mixing wall in a stable manner.

[0018] This gas burner construction is particularly advantageous when the combustible gas contains hydrogen at least in part, preferably more than 80% by volume, more preferably more than 95% by volume and, in a particularly advantageous manner, when the combustible gas is 100% hydrogen by volume, since the ratio of the amount of hydrogen to primary air is essential for a suitable combustion. With this construction, the combustible gas being hydrogen, the flame backfire and the gas self-ignition inside the appliance are avoided.

[0019] Furthermore, a cooking hob with such a gas burner is proposed.

[0020] The cooking hob is a gas cooking hob and can be a part of a household appliance.

[0021] In addition, a stove with such a gas burner and / or with such a cooking hob is proposed.

[0022] The stove is a gas stove and in particular a household appliance.

[0023] Other advantageous configurations and aspects of the invention are the object of the secondary claims as well as of the exemplary embodiments of the invention subsequently described. The invention is explained below in more detail by means of preferred embodiments, making reference to the attached figures.

[0024] Fig.1 shows a perspective view of a gas cooking appliance of the invention with four gas cooking hobs of the invention;

[0025] Fig. 2 shows a perspective view of a schematic section of an embodiment of a gas burner;

[0026] Fig. 3 shows a detail of the mixing section of the burner from figure 2;

[0027] Fig. 4 shows a perspective section of the gas injector with a mixing wall of the burner from figure 2; and

[0028] Fig.5 shows a perspective view of the injector with a mixing wall from figure 4. In the figures, the same elements or having the same function are provided with the same reference numerals, unless otherwise indicated.

[0029] Figure 1 shows a perspective schematic view of a gas cooking appliance 100. The gas cooking appliance 100 is in particular a gas hob and has a cooking or covering plate 101 , on which there are four cooking hobs 2, and an appliance housing 102 having a window through which the end of the gas pipe projects, through which gas flows in coming from the external gas network up to the cooking hobs 2. Each cooking hob 2 has a gas burner 1 with its corresponding burner cover 5.

[0030] Figure 2 shows an embodiment of the gas burner 1 of the invention, which can be assigned to a cooking hob 2, in particular to a gas cooking hob, of a stove 100, in particular of a gas stove.

[0031] The gas burner 1 features a burner housing 4 and a burner cover 5 resting on the top side of the burner housing 4. The bottom side 9 of the burner housing 4 can rest on a cooking field plate and / or be fixed to the same. The burner housing 4 and the burner cover 5 are preferably made as metal components, for example as shaped aluminium or steel components. A plurality of burner nozzles 6 is provided in a vertical wall of the top side of the burner housing 4 next to the burner cover 5. The burner nozzles 6 are preferably arranged uniformly over a perimeter of the top side of the burner housing 4.

[0032] The distributing chamber 7 is delimited between the burner cover 5 and the top side of the burner housing 4, into which the combustible gas and primary air mixture can flow and leave the gas burner 1 through the burner nozzles 6 and be combusted. Furthermore, the distributing chamber 7 uniformly distributes the combustible gasprimary air mixture among the burner nozzles 6.

[0033] The mixing tube 21 communicating the distributing chamber 7 with the mixing section 8 is arranged in the bottom side 9 of the burner housing 9. The mixing section 8 is a sole body formed by the injector 10, which is integrated into the injector side 11 from which the mixing wall 22 stands and which ends at its free end at the tube side 23, which is connected with the tube end 24 of the mixing tube 21 projecting from the bottom side 9 of the burner housing 4. The mixing section 8 forms inside itself the mixing space 12 delimited by the mixing wall 22 and the injector side 11 up to the tube side 23. There is a sealing gasket 25 between the tube side 23 and the tube end 24. In the mixing wall 22 there is a plurality of orifices 13 that form the primary air inlet 13 communicating the mixing space 12 with the surroundings 14 of the gas burner 1 , so that primary air A can flow into the mixing space 12. The mixing section 8 has a gas injector 10 mounted on the burner base 17. The burner base 17 is an element of the gas burner 1 and has an internal channelling through which the combustible gas flows from the gas pipe 3 to the gas injector 10. The burner base 17 remains installed in the cooking hob 2 under the cooking plate 101 and the bottom part of the burner housing 2 is detachably connected to the same.

[0034] Figure 3 shows a detail of the mixing section 8 from figure 2. The mixing section 8 is cylindrical and connected with the tube end 24 of the mixing tube 21 extending from the bottom side 9 of the burner housing 4. The mixing section 8 is made in one material piece with the injector 10, the injector side 11 and the mixing wall 22. In this case, the mixing section 8 is press-fitted with the tube end 24 through its tube side 23, a sealing gasket 25 being arranged between them. The mixing wall 22 features a plurality of orifices 13 through which primary air A can flow from the surroundings 14 of the gas burner 1 into the mixing space 12.

[0035] Figure 4 shows a section of the mixing section 8 from figure 3 decoupled from the burner body and made in one piece. The sealing gasket 25 is positioned on its tube side 23. Figure 5 shows the same mixing section 8 in an entire perspective and this time with no sealing gasket.

[0036] Figures 2 to 5 show the injector 10 as a one-piece component part of the mixing section 8, but it could be a standard injector to be mounted screwed to the injector side 11 of the mixing section 8. The injector 10 is composed of a part of a calibrated injection orifice 16, through which the suitable amount of combustible gas flows, and a connecting part

[0037] 15 to be connected to the gas pipe 3. The diameter of the part of an injection orifice 16 in an injector 10 is always the key to determine the gas injection speed inside the mixing space 12 and the outflow speed of the combustible gas and primary air mixture through the burner nozzles 6. Therefore, the bigger the diameter of the part of an injection orifice

[0038] 16 is, the higher the amount of gas flowing into the mixing space 12 and the higher the number of orifices 13 in the mixing wall 22 to take more primary air A from the surroundings 14 will be. The final power of the gas burner 1 is determined by varying the diameter of the part of an injection orifice 16 and the number of orifices 13. In an embodiment of the invention, the ratio of the orifices 13 in the mixing wall 22 amounts to 8 to 22 orifices per burner power kW, depending on their diameter, which may range from 0.1 mm to 1 mm.

[0039] Furthermore, in spite of not being shown in the figures, the mixing section 8 could be made in several independent pieces or the mixing wall 22 could be made in one piece with the tube end 24 and the gas injector 10 could be screwed to the injector side 11 with an intermediate sealing gasket 25.

[0040] Although the present invention has been described by means of exemplary embodiments, it can be modified diversely.

[0041] Reference numerals

[0042] 100 gas stove

[0043] 101 cooking plate

[0044] 102 appliance housing

[0045] 1 gas burner

[0046] 2 cooking hob

[0047] 3 gas pipe

[0048] 4 burner housing

[0049] 5 burner cover

[0050] 6 burner nozzle

[0051] 7 distributing chamber

[0052] 8 mixing section

[0053] 9 bottom side

[0054] 10 gas injector

[0055] 11 injector side

[0056] 12 mixing space

[0057] 13 primary air inlet

[0058] 14 surroundings

[0059] 15 connecting part

[0060] 16 injection orifice

[0061] 17 burner base

[0062] 21 mixing tube

[0063] 22 mixing wall

[0064] 23 tube side

[0065] 24 tube end

[0066] 25 sealing gasket

[0067] A primary air

Claims

CLAIMS1. A gas burner (1) to burn a combustible gas in a cooking hob (2) of a gas stove (100), comprising a burner housing (4), which can rest on a cooking plate (101) of the cooking hob (2) and / or be fixed to the same, a burner cover (5), which can rest on the burner housing (4), thereby delimiting a distributing chamber (7) between the burner housing (4) and the burner cover (5), a mixing tube (21) communicating the distributing chamber (7) with a mixing section (8) provided next to the burner housing (4) and extending from the mixing tube (21) to mix the combustible gas with a primary air, and wherein the gas burner (1) further comprises a gas injector (10), arranged on the other side of the mixing section (8), provided to inject the combustible gas into a mixing space (12) of the mixing section (8), and the mixing section (8) has at least one primary air inlet (13) giving access into the mixing space (12) to the primary air from the surroundings (14) of the mixing section (8), characterised in that the mixing space (12) is delimited by a mixing wall (22), where the at least one primary air inlet (13) is arranged, a tube side (23), which is connected with a tube end (24), and an injector side (11) connected with the gas injector (10), and in that the at least one primary air inlet (13) is bored into the mixing wall (22).

2. The gas burner according to claim 1 , characterised in that the at least one primary air inlet (13) is made as a plurality of orifices with a diameter ranging from 0.1 mm to 1 mm made in the mixing wall (22).

3. The gas burner according to claim 1 or 2, characterised in that the mixing wall (22) is tightly connected to the tube end (24).

4. The gas burner according to any of claims 1 to 3, characterised in that the gas injector (10) points towards the distributing chamber (7), which is configured to distribute a combustible gas-primary air mixture among burner nozzles (6) of the gas burner (1).

5. The gas burner according to any of claims 1 to 4, characterised in that the mixing wall (22) is tightly connected with the gas injector (10) through its injector side6. The gas burner according to any of claims 2 to 5, characterised in that the orifices (13) are arranged uniformly distributed over the mixing wall (22).

7. The gas burner according to any of claims 1 to 6, characterised in that the section of the injector side (11) is a regular polygon or a circumference and the gas injector (10) is positioned in the centre of the injector side (11) to inject the combustible gas towards a centre of the mixing space (12).

8. The gas burner according to any of claims 1 to 7, characterised in that the mixing wall (22) and the injector side (11) are made in one piece with the gas injector (10).

9. The gas burner according to any of claims 1 to 8, characterised in that there is a sealing gasket (25) between the tube side (23) and the tube end (24).

10. The gas burner according to any of claims 1 to 8, characterised in that the mixing wall (22) is made in one piece with the mixing tube (21).

11. The gas burner according to any of the preceding claims, characterised in that at least a part of the section of the outer surface and / or of the inner surface of the mixing wall (22) is polygonal or cylindrical.

12. The gas burner according to any of the preceding claims, characterised in that the burner cover (5) is arranged downstream of the mixing space (12).

13. The gas burner according to any of claims 1 to 11 , characterised in that the combustible gas contains hydrogen at least in part, preferably more than 80% by volume, more preferably more than 95% by volume.

14. A cooking hob (2) with a gas burner (1) according to any of claims 1 to 13.

15. A gas stove (100) with a gas burner (1) according to any of claims 1 to 13 and / or with a cooking hob (2) according to claim 14.

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