The present invention relates to a gas burner, a gas burner arrangement with a gas burner and a gas stove with a gas burner.

Usually, gas stoves may comprise a top sheet and a gas burner. The top sheet can comprise a through-hole at which the gas burner can be arranged. The gas burner may comprise a gas valve for providing combustible gas from below the top sheet. The combustible gas may be mixed with primary air for providing an inflammable combustion mixture. This may occur in a mixing chamber arranged in the area below the top sheet. The gas burner may comprise gas outlet openings for providing flames by means of the mixture. For facilitating combustion, secondary air may be provided at the gas outlet openings.

EP 3 591 289 A1 discloses a dual circuit burner comprising a burner body having inner gas outlet openings for providing circularly arranged inner flames, at least one secondary air outlet for providing secondary air at the inner gas outlet openings, and a secondary air chamber which is fluidly connected to the at least one secondary air outlet.

It is one object of the present invention to provide an improved gas burner.

According to a first aspect, a gas burner is provided. The gas burner comprises: gas outlet openings arranged in a ring for providing flames directed towards an interior of the ring; and at least one lower secondary air outlet located below the gas outlet openings for providing secondary air along an interior side of the flames.

The secondary air provided by the at least one lower secondary air outlet facilitates combustion and improves the reliability of the gas burner. In particular, enough secondary air is provided on the interior side of the flames to prevent the flames from extinguishing while the gas burner is being used and/or to provide balanced flames. Preventing that the flames extinguish is further advantageous in improving the safety of the gas burner because a gas flow without burning flames can be avoided. Further, by ensuring a proper combustion, a carbon monoxide level can be kept small. The gas burner may be a single or double circuit burner. The gas burner may be a single or a multicrown burner. The ring including the gas outlet openings can be part of a gas burner body. The ring can have a circular shape, oval shape, rectangular shape, square shape, hexagonal shape, octagonal shape, elliptical shape, or any closed shape, in particular when viewed from above. "When viewed from above" and all other directions used herein relates to a state and orientation of the gas burner in which the gas burner is arranged at or on the plate, in particular top sheet, of the gas stove for normal use of the gas burner.

In particular, the gas burner body may comprise several parts which are configured to be assembled together or a one-piece body. For example, the gas burner body can be produced by means of injection molding. In particular, the gas burner body or parts thereof may be made of a metal or a ceramic.

As used herein, "primary air" is the air which is to be mixed with the gas for providing the combustible mixture before the combustion. In particular, such a mixing may be carried out below a plate, in particular top sheet, of the gas stove. The primary air and the gas may be mixed in a Venturi tube. As used herein, "secondary air" is the air which is provided during combustion for maintaining the combustion. A deficiency of secondary air may lead to a lapse of the flames. Secondary air may allow getting the desired chemical combustion reaction.

The gas outlet openings can be arranged along the entire circumference of the ring, for example in an evenly distributed manner. Flames can be provided by combustion of the combustible mixture at the gas outlet openings. The combustible mixture can comprise a fuel gas. In particular, the combustible mixture can be a mixture of a fuel gas, such as acetylene, natural gas or propane, with an oxidizer, such as ambient air, supplied oxygen or the like.

The gas outlet openings can be directed towards the interior of the ring, i.e. they can face radially inwards. The interior of the ring can be a center of the ring. In particular, the flames are directed towards the interior of the ring as they leave the gas outlet openings.

The flames can have a circular arc shape or a substantially circular arc shape so that they extend horizontally near the gas outlet openings and more and more vertically as a distance to the gas outlet openings increases. After the vertical position, the flames can slightly fold back towards the exterior of the gas burner. The flames can be referred to as interior flames or volcano flames.

The at least one lower secondary air outlet is also referred to as "the lower secondary air outlet" in the following. The lower secondary air outlet can be an opening in the ring, a passage in the ring or the like through which secondary air exits. The lower secondary air outlet can be an opening facing the interior (in particular, the center) of the ring, i.e. it can face radially inwards. The lower secondary air outlet can also be directed toward a top of the gas burner. The lower secondary air outlet being below the gas outlet openings relates to a state and orientation of the gas burner in which the gas burner is arranged at or on the plate, in particular top sheet, of the gas stove for normal use of the gas burner.

The lower secondary air outlet emits secondary air along a lower secondary air path that is along the interior side of the flames. The interior side of the flames can be a side that is facing the interior (in particular, the center) of the ring. The lower secondary air path can extend in parallel to the flames, on an interior side thereof.

At the lower secondary air outlet facing radially inwards, the secondary air can be emitted substantially horizontally (inwards). The secondary air from the lower secondary air outlet then follows a circular arc shape or a substantially circular arc shape and flows more and more vertically. After the vertical position, the secondary air path can slightly fold back towards the exterior of the gas burner. Alternatively, at the lower secondary air outlet facing upwards, the secondary air can be emitted substantially vertically upwards.

According to an embodiment, the gas burner further comprises at least one upper secondary air outlet located above the gas outlet openings for providing secondary air along an exterior side of the flames, the exterior side of the flames being a side that is facing the gas outlet openings.

The at least one upper secondary air outlet is also referred to as "the upper secondary air outlet" in the following. The upper secondary air outlet can be an opening in the ring, a passage in the ring or the like through which secondary air exits. The upper secondary air outlet can be an opening facing the interior (in particular, the center) of the ring, i.e. it can face radially inwards. The upper secondary air outlet being above the gas outlet openings relates to a state and orientation of the gas burner in which the gas burner is arranged at or on the plate, in particular top sheet, of the gas stove for normal use of the gas burner. The upper secondary air outlet emits secondary air along an upper secondary air path that is along the exterior side of the flames. The exterior side of the flames can be a side that is facing an exterior of the ring. The upper secondary air path can extend in parallel to the flames, on an exterior side thereof. In particular, the upper secondary air (from the upper secondary air outlet) flows along a side of the flames that is opposite to the side of the flames on which the lower secondary air (from the lower secondary air outlet) flows. The flames can be between the upper secondary air flow and the lower secondary air flow.

At the upper secondary air outlet, the secondary air is emitted substantially horizontally (inwards). The secondary air from the upper secondary air outlet then follows a substantially circular arc shape or a circular arc shape and flows more and more vertically. After the vertical position, the secondary air path can slightly fold back towards the exterior of the gas burner.

The secondary air provided by the upper secondary air outlet facilitates combustion and improves the reliability of the gas burner even further. Balanced flames can be achieved with the secondary air. In particular, enough secondary air is provided on the exterior side of the flames to prevent the flames from extinguishing while the gas burner is being used.

According to a further embodiment, the gas burner comprises multiple lower secondary air outlets and/or multiple upper secondary air outlets.

The multiple lower secondary air outlets and/or multiple upper secondary air outlets can have the same properties as the lower secondary air outlet and/or the upper secondary air outlet described above. For example, the number of lower secondary air outlets and/or of upper secondary air outlets is the same as the number of gas outlet openings. The lower secondary air outlets and/or upper secondary air outlets can be arranged below or above a corresponding gas outlet opening. One lower secondary air outlet and/or one upper secondary air outlet can be provided for multiple gas outlet openings. There can be the same number of lower secondary air outlets and/or upper secondary air outlets. For example, there are two, three, four, five or six lower secondary air outlets and/or upper secondary air outlets. According to a further embodiment, the multiple lower secondary air outlets and/or the multiple upper secondary air outlets are arranged evenly along a circumference of the ring.

Evenly arranged in particular means that distances between neighboring lower secondary air outlets and/or upper secondary air outlets are identical over the entire circumference of the ring. Thereby, enough secondary air is provided for all flames.

According to a further embodiment, the gas burner further comprises a gas burner body in which the gas outlet openings are arranged; wherein the at least one lower secondary air outlet and/or the at least one upper secondary air outlet is formed as a through-hole in the gas burner body which is fluidly connected with an exterior of the gas burner, in particular with a region that is radially around the gas burner body.

The through-hole can be a passage for the secondary air. Providing the lower secondary air outlet and/or the upper secondary air outlet as through-holes in the gas burner body allows forming the lower secondary air outlet and/or the upper secondary air outlet in one piece with the gas burner body, which reduces the number of components of the gas burner and facilitates its manufacture. The exterior of the gas burner can designate a region that is radially around the gas burner body.

According to a further embodiment, the gas outlet openings, the at least one lower secondary air outlet and/or the at least one upper secondary air outlet are facing the interior (in particular the center) of the ring.

In other words, the gas outlet openings, the at least one lower secondary air outlet and/or the at least one upper secondary air outlet are directed radially inwards.

According to a further embodiment, the gas burner further comprises a lower secondary air channel which extends along a radial direction from an exterior of the gas burner to the lower secondary air outlet below the ring, the lower secondary air channel being configured to guide secondary air from the exterior of the gas burner to the lower secondary air outlet.

According to a further embodiment, the gas burner further comprises: a shield element having a ring shape with a radius that is equal to or larger than a radius of the ring comprising the gas outlet openings; wherein the shield element extends above the ring; and wherein the at least one upper secondary air outlet is formed as an opening in the shield element located above the gas outlet openings.

The shield element can be made of enameled stamped, welded and/or screwed steel. Other materials such as brass (machining process), aluminum (machining process), cast iron or the like can also be used.

The shield element can be arranged concentrically to the ring. At least part of the shield element can extend above the ring, in particular above the gas outlet openings. The portion of the shield element extending above the gas outlet openings includes the upper secondary air outlet. The upper secondary air outlet can be formed as an opening cut out of the shield element. In particular, the opening is located in a lateral side of the shield element, the lateral side extending vertically or substantially vertically. The opening can have a rectangular or substantially rectangular (without rounded edges or the like) shape.

The shield element can be an element that is separate from the gas burner body. This is advantageous in that an upper secondary air outlet can be added to an existing gas burner to upgrade the existing gas burner.

According to a further embodiment, the shield element is integrally formed with the gas burner body in which the gas outlet openings are arranged and/or with a pot support configured to hold cooking pots.

The shield element being formed integrally with the gas burner body in particular reduces the number of parts of the gas burner to be manufactured and assembled, thereby facilitating an assembly of the gas burner. The shield element can include arms directed radially inwards on an upper end thereof, the arms being for holding a cooking pot. The arms can be integrally formed with the shield element. The arms are an example of a pot support, but other implementations of the pot support are also realizable. For example, the pot support can be formed by the upper edge of the shield element, on which the cooking pot can be directly placed. The pot support can also be formed by narrow pot holding extensions extending upward from the upper edge of the shield element. According to a further embodiment, the at least one lower secondary air outlet is formed or connected to a further opening in the shield element located below the gas outlet openings.

In particular, the shield element also includes a further opening below the gas outlet openings which allows intaking the secondary air from the exterior of the gas burner and leading it to the lower secondary air outlet. This further opening can be formed as an opening cut out of the shield element. In particular, the further opening is located in the lateral side of the shield element. The further opening can be located along a lower edge of the shield element. The further opening can have a rectangular or substantially rectangular (without rounded edges or the like) shape.

According to a further embodiment, the shield element further comprises a combustion opening located above the upper secondary air outlet for ejecting combustion products from the combustion of the gas.

The combustion opening can be formed as an opening cut out of the shield element. In particular, the combustion opening is located in the lateral side of the shield element. The combustion opening can be located along an upper edge of the shield element. For example, the combustion element is formed by the openings between neighboring narrow pot holding extensions. The combustion opening can have a rectangular or substantially rectangular (without rounded edges or the like) shape.

According to a further embodiment, the at least one lower secondary air outlet has a height between 1 and 20 mm and/or the at least one upper secondary air outlet has a height between 1 and 20 mm.

The height of the lower and/or upper secondary air outlet is a height along a vertical direction, in particular a maximal height along a vertical direction.

According to a second aspect, a gas burner arrangement, in particular for a gas stove, is provided. The gas burner arrangement comprises a gas burner according to the first aspect or according to an embodiment thereof, and a plate having an upper surface on which the gas burner is mounted, wherein the at least one lower secondary air outlet and/or the at least one upper secondary air outlet is arranged above the upper surface of the plate. The plate can be the top sheet of the gas stove. The plate can comprise a through-hole at which the gas burner can be arranged. The gas burner may comprise a gas valve for providing combustible gas from below the top sheet. The combustible gas may be mixed with primary air for providing an inflammable combustion mixture. This may occur in a mixing chamber arranged in the area below the top sheet. The gas burner may comprise gas outlet openings for providing flames by means of the mixture.

The embodiments and features described with reference to the gas burner of the first aspect or an embodiment thereof apply mutatis mutandis to the gas burner arrangement of the second aspect.

According to a third aspect a gas stove having a gas burner according to the first aspect or an embodiment thereof or a gas burner arrangement according to the second aspect is provided.

The embodiments and features described with reference to the gas burner of the first aspect or an embodiment thereof and the gas burner arrangement of the second aspect apply mutatis mutandis to the gas stove of the third aspect.

Further possible implementations or alternative solutions of the invention also encompass combinations - that are not explicitly mentioned herein - of features described above or below with regard to the embodiments. The person skilled in the art may also add individual or isolated aspects and features to the most basic form of the invention.

Further embodiments, features and advantages of the present invention will become apparent from the subsequent description and dependent claims, taken in conjunction with the accompanying drawings, in which:

Fig. 1 shows a side view of a gas stove;

Fig. 2 shows a side view of a gas burner arrangement for the gas stove of Fig. 1 ;

Fig. 3 shows a perspective view of a gas burner according to a first embodiment;

Fig. 4 shows a cross-sectional view V-V from Fig. 3; Fig. 5 shows a perspective view of a gas burner according to a second embodiment;

Fig. 6 shows a cross-sectional view W-W from Fig. 5;

Fig. 7 shows a front view of Fig. 6; and

Fig. 8 shows a cross-sectional view X-X from Fig. 6.

In the Figures, like reference numerals designate like or functionally equivalent elements, unless otherwise indicated.

Fig. 1 shows schematically a side view of a gas stove 1. The gas stove 1 comprises a plate 2, in particular a top sheet. The plate 2 is made of glass or glass ceramics. The gas stove 1 further comprises gas burners 3 and 4. The burners 3 are arranged on the plate 2. The gas burners 3, 4 are configured to heat cookware. Each gas burner 3, 4 and the plate 2 form a gas burner arrangement 5.

Fig. 2 shows schematically the gas burner arrangement 5 from Fig. 1. The plate 2 comprises an upper surface 6. The plate 2 further comprises an insertion opening 8. The gas burner 3 is mounted on the upper surface 6 of the plate 2. Further, the gas burner 3 comprises a circular portion 9 which is inserted into the insertion opening 8. The circular portion 9 is adapted to the insertion opening 8 such that a form fit is provided between the gas burner 3 and the plate 2. A diameter D of the insertion opening 8 is preferably between 80 and 110 mm, 90 and 92 mm or exactly 90.9 mm. An outer contour 7 of the circular portion 9 is adapted to the diameter D.

Fig. 3 shows a perspective view of a gas burner 3 according to a first embodiment. The gas burner 3 includes a gas burner body 16 having a ring shape. On an interior side of the burner body 16, which faces an interior 12 of the gas burner 3, a ring 11 of gas outlet openings 10 is formed. The gas outlet openings 10 are for providing circularly arranged inner flames 14. The ring 11 is a circular ring when looking from above.

The gas outlet openings 10 are arranged such that the flames 14 are directed towards the interior 12 of the ring 11. As shown in Fig. 3, the flames 14 are directed radially inwards Rl at the gas outlet opening 10. Fig. 3 only shows one flame 14 but all other gas outlet openings 10 are configured to provide a similar flame 14 directed inwards.

Below the gas outlet openings 10, the burner body 16 comprises eight lower secondary air outlets 15, which have rectangular cross sections. The lower secondary air outlets 15 are arranged evenly around the circumference of the burner body 16. A height H1 of the lower secondary air outlets 15 (along an axial direction A) is between 2 and 15 mm. The lower secondary air outlets 15 are arranged such as to face the interior 12 of the gas burner 3. The lower secondary air outlets 15 are located below the gas outlet openings 10.

The lower secondary air outlets 15 are connected to respective lower exterior openings 24 in the burner body 16 by means of through holes 18 (lower secondary air channel). The through holes 18 connect the interior 12 of the gas burner 3 with the exterior 13 thereof. Secondary air enters the lower exterior openings 24, passes through the through holes 18 and exits the burner body 16 on an interior side thereof through the lower secondary air outlets 15.

Fig. 4 shows a cross-sectional view V-V from Fig. 3. Fig. 4 shows the flow of secondary air 17 leaving the lower secondary air outlets 15. Namely, the secondary air 17 leaves the lower secondary air outlet 15 horizontally or nearly horizontally radially inwards Rl. The secondary air 17 is then deflected upwards. The secondary air 17 follows the direction of the flame 14, wherein the secondary air 17 always flows along an interior side 19 of the flame 14, which is located towards the interior 12. In the example of Fig. 3 and 4, no secondary air is provided on an exterior side 20 of the flame 14, which is located towards the exterior 13.

Fig. 5 shows a perspective view of a gas burner 4 according to a second embodiment. Fig. 6 shows a cross-sectional view W-W from Fig. 5. Fig. 7 shows a front view of Fig. 6. Fig. 8 shows a cross-sectional view X-X from Fig. 6.

Fig. 5 to 8 will be described jointly in the following. The gas burner 4 mostly resembles the gas burner 3 described previously, so that identical elements will not be described again and that we will focus on differences in the following.

The gas burner 4 has an inclined portion 31 which is ring-shaped and on which the gas outlet openings 10 are arranged. The gas outlet openings 10 are directed partly radially inwards Rl, partly upwards along the axial direction A. The burner body 16 of Fig. 5 - 8 has a slightly more complex shape than that of Fig. 3 and 4. The burner body 16 of Fig. 5 - 8 has a circular ring shape and is integrally formed. An upper surface 32 of the burner body is also slightly inclined inwards.

The upper surface 32 has four pot supports 28 formed integrally therewith. The pot supports 28 are portions of the burner body 16 protruding upwards from the upper surface 32. The vertical height H3 of the pot supports 28 from the upper surface 32 is between 5 and 15 mm. The pot supports 28 are arranged evenly along the circumference of the gas burner 4.

Within the burner body 16, a venturi tube 29 is provided to mix the gas and the primary air 30 to obtain a combustible mixture, which is lead to the gas outlet openings 10 to generate flames 14. The primary air 30 enters the burner body 16 from below.

In Fig. 5 - 8, there are only four lower secondary air outlets 15. These are formed between legs 26 protruding downwards from a lower surface 35 of the burner body 16. In other words, the lower secondary air outlets 15 and the through-holes 18 are formed between recessed portions of the lower surface 35 of the burner body 16 and the plate 2.

In addition to the four lower secondary air outlets 15, the burner body 16 of Fig. 5 - 8 includes four upper secondary air outlets 21. The upper secondary air outlets 21 have substantially rectangular cross sections. The upper secondary air outlets 21 are arranged evenly around the circumference of the burner body 16. A height H2 of the upper secondary air outlets 21 (along an axial direction A) is between 2 and 15 mm. The upper secondary air outlets 21 are arranged such as to face the interior 12 of the gas burner 3. The upper secondary air outlets 21 are located above the gas outlet openings 10.

The upper secondary air outlets 21 are connected to respective upper exterior openings 25 in the burner body 16 by means of through holes 22. The through holes 22 connect the interior 12 of the gas burner 4 with the exterior 13 thereof. Secondary air 23 enters the upper exterior openings 25, passes through the through holes 22 and exits the burner body 16 on an interior side thereof through the upper secondary air outlets 21.

Fig. 8 shows the flow of secondary air 17, 23 leaving the lower secondary air outlets 15 (identical to the flow of secondary air 17 described in view of Fig. 4) and the upper secondary air outlets 21. Namely, the secondary air 23 leaves the upper secondary air outlet 21 horizontally or nearly horizontally radially inwards Rl. The secondary air 23 is then deflected upwards. The secondary air 23 follows the direction of the flame 14, wherein the secondary air 23 always flows along the exterior side 20 of the flame 14, which is located towards the exterior 13. The secondary air 17, 23 ensures a good combustion and that the flame is maintained.

When a pot is placed on the pot supports 28, a vertical combustion opening 33 is formed between the upper surface 32 of the burner body 16 and the pot. The combustion opening 33 allows evacuating combustion products 34 in a horizontal direction (radially outwards).

In the figures described above, the burner body 16 or at least part thereof can be considered as a shield element 27. In detail, the shield element 27 is a portion of the burner body 16 that extends above the gas outlet openings 10 in which the upper secondary air outlets 21 are located. In Fig. 3 - 8, the shield element 27 is an integral part of the burner body 16.

However, in other embodiments (not shown), the shield element 27 can be an element that is separate from the burner body 16. Such a shield element 27 can have a cylindrical shape and be placed around the burner body 16, preferably concentrically to the burner body 16. Such a shield element 27 can be added to an existing gas burner 3, 4. The shield element can include the upper secondary air outlets 21 and/or the lower secondary air outlets 15.

Although the present invention has been described in accordance with preferred embodiments, it is obvious for the person skilled in the art that modifications are possible in all embodiments.

Reference Numerals:

1 gas stove

2 plate

3, 4 gas burner

5 gas burner arrangement

6 upper surface

7 outer contour 8 insertion opening

9 circular portion

10 gas outlet opening

11 ring

12 interior

13 exterior

14 flame

15 lower secondary air outlet

16 gas burner body

17 secondary air

18 through-hole

19 interior side of the flame

20 exterior side of the flame

21 upper secondary air outlet

22 through-hole

23 secondary air

24 lower exterior opening

25 upper exterior opening

26 leg

27 shield element

28 pot support

29 venturi tube

30 primary air

31 inclined portion

32 upper surface

33 combustion opening

34 combustion product

35 lower surface

A axial direction

D diameter

H1 height

H2 height

H3 height

Rl radially inwards