FR2839547A1 - BURNER HEAD FOR A GAS COOKING APPLIANCE - Google Patents

Abstract

The burner head has a stack of rings (14) inside a cover (18). The rings have a central flat portion and an outer section angled towards the cover. The angle formed by the peripheral part with respect to the central part is between 15 and 35 degrees.

Description

ignition and a flame control device (16a).

  The present invention relates to a burner head for a gas cooking appliance. This cooking appliance is for example a hob

  with one or more gas burners or a stove.

  A cooktop fitted with gas burners generally has burner pots of different sizes intended to receive burners whose power depends appreciably on the size of the pot and the burner. The burner comprises a burner head constituted by an annular ring pierced with orifices from which flames emerge allowing the heating of a container or the like. A cover closes the annular crown on one side and directs the

  gas mixture towards the orifices where combustion takes place.

  For a given pot size, the variation in power, taking into account the adaptable burners, takes place over a range in a ratio of approximately 1 to 3. This range is relatively limited. Wile forces to plan on the same table

  cooking pots of different sizes.

  Document US-2,235,635 discloses a gas burner for a hob in which the burner head is obtained by superposition of flat rings and wavy rings. It is indicated in this document that this embodiment makes it possible to reduce the cost price of the burner head and allows good combustion to be obtained. Wile also makes it possible to provide a peripheral outer surface of the burner head which, like the annular rings pierced with conventional orifices, presents a series of small orifices aligned in one or more rows. The orifices are no longer circular, but the size and number of the outlet openings of the burner head compared to a conventional burner head vary little. This structure also allows, although not mentioned in this document, to have for a given size a variation of power

  interesting, more important than for the classic burners mentioned above.

  However, this embodiment of a burner head turns out to be quite noisy because turbulence is created at the level of the wavy rings. In addition, the energy efficiency of such a burner is limited because the flames leaving the head are not directed towards the pan, or equivalent, to be heated. In addition, with such celebrations of burner, flame separation is often observed and a draft can blow and extinguish the flame. Finally, the rings, especially the wavy rings, tend to deform when they are subjected to high temperatures. The initial geometric of the burner therefore changes

  over time and the burner performance decreases.

  The object of the present invention is therefore to provide an improved burner head the power of which can vary over a wide range for a given pot size. Advantageously, this burner head will make it possible to obtain a racing and intense flame but will also make it possible to produce a longer and more diffuse flame. Preferably, this burner head will be silent, will have a good energy efficiency, will not deform and will not be sensitive to

Air Currents.

  To this end, the present invention provides a burner head for a gas cooking appliance comprising a stack of rings closed by a cover. According to the invention, the rings have a flat central part and a peripheral part folded towards the cover, the rings being regularly

  spaces by spacing means.

  This embodiment makes it possible to obtain a new burner head for application to a cooking appliance such as, for example, a hob or a stove. Here the outlet openings wind from the peripheral slots of relatively large surface area compared to the outlet openings of the burner parties of the prior art. This new embodiment makes it possible to have rings of relatively low thickness but is still presenting, race with the presence of a fold, a very good thermomechanical resistance. The inclination given to the peripheral part also makes it possible to give a more stable flame and better attached to the burner head (less sensitivity to drafts). In addition, by the inclination given, the flame is oriented towards the container to be heated and allows good energy efficiency. Finally, the fact of having relatively large surface outlets makes it possible to limit the noise of the air / gas mixture leaving the

  burner head by limiting turbulence at the outlet.

  In a burner head according to the invention, the angle formed by the peripheral part with respect to the central part is advantageously between 15 and 35. These values make it possible to obtain good thermomechanical resistance, good attachment of the flame and good efficiency.

energetic without being noisy.

  To maintain a constant space between two neighboring rings, spacers wind for example regularly distributed between these two rings. volslns. In one embodiment, it can be expected that the spacing means between the rings are an integral part of the rings. In this case, each ring has for example stamped bores whose edges have been rolled to each time form a rim of predetermined height. To keep the rings in place with respect to each other, pins may be provided regularly distributed, corresponding bores being then provided in each ring. The bores cooperating with the wind pins preferably entirely made in the flat part of each

1 0 ring.

  The wind rings for example made of steel. In this case, we can provide a ring thickness between 0.6 and 0.9 mm and a spacing

  between two neighboring rings between 0.8 and 1.2 mm.

  The present invention also relates to a burner for a gas cooking appliance, characterized in that it comprises a burner head as described above, as well as a cooking appliance such as a hob, or a gas stove. , characterized in that it comprises at least one burner head

as described above.

  A hob according to the invention is for example a hob comprising a support for pans or the like which has support arms extending radially with respect to each burner head, the rings of each burner head being held at [ using regularly distributed pins, for each burner head the number of pins corresponds to the number of support arms, and the pins facing the

support arms.

  Details and advantages of the present invention will become more apparent from

  the following description, made with reference to the accompanying schematic drawing

  representing two embodiments of a burner head according to the invention and

  in which: FIG. 1 is a sectional view showing a burner fitted with a burner head according to the invention, FIG. 2 is a view correspond to FIG. 1 and showing on an enlarged scale the burner head according to the invention , Figure 3 is a view correspond to Figure 2 for an alternative embodiment of the burner head, Figure 4 is a sectional view of the cover shown in Figures 2 and 3, Figure 5 is a top view of 'a ring shows Figure 2, Figure 6 is a sectional view along the section line VI-VI of Figure 5, Figure 7 is a sectional view along the sectional line VII-VII of Figure 5, La Figure 8 is a top view, on a reduced scale, of the burner of Figure 1, and Figures 9 to 13 show in side view of the flame forms obtained with a burner head according to the invention and different containers to be heated. FIG. 1 shows a burner equipping a gas cooking appliance,

  which is in the present description a hob 2. A gas, the most

  often methane, propane or butane is mixed with air and the

  mixture is sent via a supply line 4 to a burner head 6.

  A skirt 8 connects the burner head 6 to the hob 2. A support, here comprising four support arms 10, is placed on the hob 2 and

  keeps a pan, or similar, above the burner head 6.

  A piezoelectric ignition device 12 is arranged near the head of

  brDieur 6 to control its ignition.

  The present invention relates essentially to the head of burner 6.

  This behind comprises rings 14 empires on pins 16, a diffuser cover 18 as well as a cap 20. Figures 5 to 7 show in detail an embodiment of a ring 14 used for the realization of the burner head represented in FIG. 2. The header 6 of FIG. 2 comprises

  five rings 14 such as that shown in FIG. 5.

  Each ring 14 is made of stainless steel. It has a flat central part 22 and a peripheral part 24 in cli ned connected to the central part 22 by a fold 26. The angle determining the inclination of the part

  peripheral 24 with respect to the flat part 22 is for example 25.

  The central part (FIG. 5) has four tongues 28 extending, in the plane of the central part 22, radially towards the center of the latter. At each tongue, there is a hole 30 provided for the passage of a corresponding pin 16. In the embodiment shown in Figure 2 and Figures 5 to 7, the hole 30 is obtained by stamping. The edge of the hole was then folded over to form around this hole 30 a rim 32 of height h (FIG. 6) predetermined. This height h corresponds to the spacing which it is desired to leave between two neighboring rings 14. The 28 wind tabs provided here

  to be able to move the holes 30 away from the peripheral part 24.

  The peripheral part 24 is of regular width and extends without

  discontinuity around the central part 22.

  As shown in FIG. 1, a support is provided for receiving a pan above the burner head 6. This support comprises four support arms 10 which extend radially around the shredder head 6. The support arms 10 are evenly distributed around the header 6 so that two adjoining support arms 10 make an angle between them of 90. As indicated above, the rings 14 on the head of the 6 wind breaker mounted on four pins 16. These pins are also regularly arranged and oriented 90 from each other with respect to the rings 14. The pins 16 are arranged in order to

  that they are facing the support arms 10.

  To make the head of the burner 6, the pins 16 are fixed on the skirt 8 and the rings 14 are then pressed against each other, each hole 30 receiving a pin 16. The rings 14 are made worse so that the part peri pheriqu e 24 moves away from cooking table 2, or otherwise d it, either

  oriented towards the diffuser cover 18 or the cap 20.

  The diffuser cover 18 is in the form of a disc preferably made in the same material as the rings 14. This disc has in its center a boss 34 attached to a flat part 36 itself surrounded

  a peripheral part 38 identical to the peripheral part 24 of a ring 14.

  The diffuser cover has bores 40 whose position corresponds to the position of the holes 30 in the rings 14 so that the diffuser cover 18 can be stacked above the rings 14, the bores 40 then each receiving a pin 16. When the diffuser cover 18 is in place above the rings 14, its boss 34 extends towards the inside of the rings 14 while its peripheral part 38 is parallel to the peripheral parts 24 of the

rings 14.

  The cap 20 rests on the diffuser cover 18 and has here

  essentially a role of hubcap.

  In the embodiment shown in Figure 3, the rings 14 are slightly different. We find an identical structure with a central part 22, a peripheral part 24, tongues 28 and corresponding holes 30. The difference here resides in that the holes 30 wind obtained by per, cage and not by stamping. There are therefore no edges 32 at the level of the holes 30. When the rings 14 wind then worsen on each other using the pins 16, washers 42 are arranged between two neighboring rings at each hole 30 of way to serve as a spacer

  to maintain a constant spacing between two neighboring rings 14.

  The operation of this burner head is shown below.

  An air / gas mixture is sent via the supply line 4 towards the interior of the burner head 6. The air / gas mixture moves towards the diffuser cover 18, that is to say axially with respect to the rings 14. The boss 34 of the diffuser cover 18 aims to help the air / gas mixture to pass between the rings 14, that is to say to rotate at right angles to move in a plane substantially parallel to the central parts 22 of the rings 14. The air / gas mixture then diffuses radially with respect to the rings 14 and is then guided by the peripheral parts 24 outside the head of the burner 6, where combustion occurs. Combustion is initially started by the piezoelectric ignition device 12. Thereafter, combustion is maintained by the arrival of

fresh air / gas mixture.

  Figure 8 shows a burner head 6 and the four support arms 10 (in part) seen from above. A first line 44 in dots represents the outline of a flame of falble power. A second dotted line 46 represents the contour of a higher power flame. Here we see that at the level of the support arms 10, the flame of higher power at the outlet of the burner is recessed. This is due to the presence of pins 16 or more

  precisely the flanges 32 or the washers 42 (depending on the embodiment).

  This removal of the flames makes it possible to limit the heating of the support arms 10 and thus to increase the lifetime of the latter. At low power, the flame spreads regularly around the head of the burner. The presence of pins 16 does not

not disturb.

  The fold 26 produced at the level of the rings between the central part 22 and the peripheral part 24 has several functions. First of all, it makes it possible to increase the thermomechanical stiffness of the corresponding ring 14. Thus, the deformations caused by the heating of the rings 14 are strongly limited. For the same variation in temperature and the same thermomechanical resistance, a ring 14 having a fold 26 will have a thickness less than a fully planar ring. When the wind rings made of stainless steel, a thickness of 0.6 to 0.9 mm gives satisfactory results from a point of view

thermomechanical resistance.

  The inclination of the peripheral part 24 also makes it possible to orient the

  flame produced around the burner head 6 towards the container to be heated.

  The inclination given to the peripheral part of the rings 14 makes it possible to give the flame at the outlet of the burner head a tulip shape as illustrated in FIGS. 9 and 10. In FIG. 9, the power of the flame is at its maximum while that in Figure 10 it is close to the minimum. The inclination given to the air / gas mixture at the outlet of the burner head allows the flame to return to the center of the burner. As illustrated in FIGS. 11 to 13, the flame then comes to properly heat the container placed on the support arms 10. In FIG. 11, a Dutch oven 48 of large diameter is shown. The flame then comes to heat the bottom of this Dutch oven well. On figure 12, a "wok pan" 50 has been represented. Such a container is of almost hemispherical shape. It is also noted here that the flame heats the wall of this container well. FIG. 13 illustrates the heating of a coffee maker 52 of small diameter. Here too, thanks to the tulip shape of the flame, only the bottom of the coffee maker is heated and the energy of the flame is not dissipated

to heat the surrounding air.

  All these examples show that the energy efficiency of a head

  burner according to the invention is improved compared to a burner of the prior art.

  The inclination of the peripheral parts 24 of the rings 14 also makes it possible to achieve better attachment of flames. In fact, the flames heat the end of the ring located above them, thus creating a hot zone favoring the attachment and stabilization of the flame. This hot zone is located at the edge identified by the reference 54 (see Figures 2 and 3). We find such a hot zone also at the peripheral part 38 of the diffuser cover 18. The flame thus created around the head

  brdieur 6 is much less sensitive to a draft.

  To avoid any risk of catching the flame on the skirt 8, this

  behind is preferably set back relative to the periphery of the rings 14.

  We can for example predict, as shown for example in Figure 2, that the entire peripheral portion 24 of the rings 14 is projecting from the

skirt 8.

  The angle of inclination oc of the peripheral part 24 with respect to the central part 22 of the ring, to obtain the advantages described above, is

preferably between 15 and 35.

  To limit the noise at the level of the head of burner 6 it is preferable to have between the rings 14 a flow of the air / gas mixture laminar or quasi-laminar. To obtain such a flow, two parameters are taken into account: on the one hand the shape of the boss 34 of the diffuser cover 18 and on the other hand

  the spacing between the rings 14. This last parameter is the most important.

  It has been found that a spacing of between 0.8 and 1.2 mm gives good results for a domestic hob burner. The boss 34 of the diffuser cover 18 makes it possible to facilitate the introduction of the mixture

air / gas between the rings 14.

  The pins 16 and therefore the edges 32 (or the washers 42) are preferably moved away from the outside edge of the burner head. Indeed, at the edges 32 (or washers 42) turbulence can appear. To limit the noise generated by these turbulences, it is preferable for the air / gas mixture having a turbulent regime to come out of the burner head with a laminar regime. For this, the turbulence zone must be far enough from the outlet of the burner head. Preferably, the peripheral part 24 of the rings 14 does not present any obstacle. Thus a laminar regime can be established between the fold 26 and the exit

  from the head of brDieur 6, in the event that wind turbulence appeared upstream.

  A burner as described above allows modulation of the power in a ratio of 1 to 8. In addition, higher powers are obtained than with "conventional" burner parties. For example, the power of a burner head according to the invention with a diameter of 60 mm can be modulated from 0.5 kW to 4.2 kW while a conventional burner head of a domestic cooktop with a diameter of 110 mm has a maximum power of

around 3.5 kW.

  The power of the burner depends of course on the number of rings

  used and of the surface of the air / gas mixture outlets of the burner head 6.

  With a burner according to the invention, it is possible to modulate the power at the output of the burner head between 0.6 W / mm2 to 5.0 W / mm2. Such power modulation is not possible with parties of prior art burners. The present invention is not limited to the embodiments described above by way of nonlimiting example. Wile also concerns all the variants within the reach of those skilled in the art in the context of

claims below.

Claims (12)

  1. Breader head (6) for a gas cooking appliance comprising a stack of rings (14) closed by a cover (18), characterized in that the rings (14) have a central central part (22) which is flat and a peripheral part (24) folded towards the cover (18), the rings (14) being regularly spaced by spacing means (32; 42). 2. burner head (6) according to claim 1, characterized in that the angle (oc) formed by the peripheral part (24) relative to the central part (22) is between 15 and 35.   3. Burner head (6) according to one of claims 1 or 2,   characterized in that spacers (32; 42) are regularly distributed between two neighboring rings (14).   4. burner head (6) according to one of claims 1 or 2,   characterized in that the spacing means (32) between the rings (14) make integral part of the rings.   5. burner head (6) according to claim 4, characterized in that each ring (14) has bores (30) stamped whose edges have been   rollers to form each time a rim (32) of predetermined height (h).   6. BrDieur head (6) according to one of claims 1 to 5, characterized   in that the rings (14) are maintained by means of pins (16) regularly distributed, corresponding bores (30) being provided in each ring (14).   7. BrGieur head (6) according to claim 6, characterized in that the bores (30) cooperating with the pins (16) are entirely produced in   the flat part (22) of each ring (14).   8. Burner head according to one of claims 1 to 7, characterized in   what the rings (14) are made of steel.   9. Burner head according to claim 8, characterized in that the thickness of the rings (14) is between 0.6 and 0.9 mm, and in that   The spacing between two neighboring rings (14) is between 0.8 and 1.2 mm.   10. BrDieur for gas cooking appliance, characterized in that it   comprises a header (6) according to claims 1 to 9.   11. Cooking appliance, characterized in that it comprises at least one   burner head (6) according to one of claims 1 to 9.   12. Cooktop according to claim 11, characterized in that it comprises a support for pots and the like having support arms (10) extending radially with respect to each burner head (6), in that the rings ( 14) of each burner head (6) wind maintained by means of pins (16) regularly distributed, in that for each burner head (6) the number of pins (16) corresponds to the number of support arms (10 ), and in that the