EP2333418A1 - Oven and gas burner device, in particular for an oven - Google Patents

Abstract

The gas burner device comprises a burner tube (9) having a carrier section and a gas outlet panel (11) which is connected with the carrier section. The holes (13) are provided in the gas outlet panel for gas outlet, where the carrier section (10) is gas-tight connected with the gas outlet panel. An independent claim is also included for a household device with a cooking chamber.

Description

The present invention relates to a gas burner device for heating an interior of a domestic appliance and a household appliance equipped with such a gas burner device, and more particularly to an oven. In this case, the gas burner device comprises at least one burner tube.

Known gas burners are used to heat the interior of a baking oven by the energy released during combustion of gas. Known gas burners have tubular gas burner tubes, in which flame nozzles are provided, through which the gas to be burned emerges.

The EP 0 860 658 B1 discloses a gas-fired oven, wherein the gas burner tube has laterally guided flame nozzles. Various methods are common for the production of the gas burner tubes and the introduction of the flame nozzles in the gas burner tubes.

A problem in the manufacture of burner tubes is the formation of holes with approximately elliptical cross-section at the bending radii of the burner tube. This results in an uneven flame distribution on the circumference of the burner tube, which in turn produces an uneven heat distribution in the oven.

An elliptical cross section occurs when pipes provided with circular holes are bent. The originally circular holes are distorted in the area of the bend and assume an elliptical cross-section.

In order to obtain perfectly round holes as flame nozzles, the holes can be burned in by laser insertion. This process is complicated and expensive. In addition, after the completion of a desired hole, the laser continues to bore and thus may damage underlying material. To prevent this is tedious and requires a lot of technical and time. Mechanical drilling of the holes does not lead to a better economic result, since this method is also complex and also very time consuming.

The object of the invention is therefore to provide a gas burner device for heating an interior of a household appliance and a household appliance equipped therewith, which is or is less expensive to produce. In particular, a uniform combustion behavior should be achievable.

This object is achieved by an inventively designed gas burner device with the features of claim 1. The household appliance according to the invention is the subject of claim 11. Advantageous embodiments of the invention are set forth in the subclaims. Further advantages and features of the invention will become apparent from the embodiment.

The gas burner device according to the invention is used for heating an interior of a household appliance and in particular a baking oven. The gas burner device has at least one burner tube, wherein the burner tube comprises at least one carrier profile and at least one gas outlet plate connected thereto, in which holes are provided for the gas outlet.

This design allows separate production and storage of carrier profile and gas outlet plate. The carrier profile can be designed with a larger sheet thickness than the gas outlet plate, which costs can be saved. A separate production is possible. This saves additional material and costs.

The holes in the gas outlet plate are particularly preferably punched. This makes it possible to inexpensively produce gas outlet plates with a large number of holes with great precision and high production speed. Size and geometry of the holes can also be designed differently on a sheet.

The carrier profile is in particular gas-tightly connected to the at least one gas outlet plate. Gas-tight connections ensure a uniform supply. This connection is preferably made by welding or crimping. A screw connection between the carrier profile and the at least one gas outlet plate is also possible, but may possibly require the use of seals. The connection should remain gas-tight even during the operating temperatures.

The carrier profile is designed in particular as DIN rail, wherein the gas outlet plate is preferably designed as a flat sheet. In the particularly preferred embodiment, the DIN rail is designed as a U-shaped profile having two flat bearing surfaces. The bearing surfaces serve to build or conditioning of the gas outlet plate. By this construction, a simple positioning of the gas outlet plate on the carrier profile is possible, which is particularly important for the production. An implementation of further manufacturing steps is thereby considerably simplified. By the execution of the gas outlet plate as a flat sheet, it is cost effective in procurement. The punching of the holes is considerably facilitated.

The gas outlet plate and the carrier profile advantageously have different sheet thicknesses. The different sheet thicknesses are due to the different thermal and mechanical stress possible and allow cost optimization. The carrier profile has a slightly larger wall thickness and also serves for stabilization, while the gas outlet plate can be very thin.

The gas outlet plate in particular has a thickness of about 0.2 mm to about 1.0 mm. Preferably, the thickness is between 0.3 mm and 0.7 mm. In the particularly preferred embodiment, the gas outlet plate has a thickness of 0.4 mm to 0.6 mm.

A particularly great advantage of the small thickness of the gas outlet plate lies in the fact that the flame pattern is very positively influenced.

The gas outlet plate is adjusted by bending - in sections - the outer contour of the carrier profile.

Even with a thin gas outlet plate, the originally circular holes are distorted at the bends. The previously circular shape of the holes changes slightly to a somewhat non-round shape. The size of the distortion depends on the thickness of the sheet or wall. Due to the considerably smaller thickness of the gas outlet plate, this effect is very small and barely observable.

In contrast to the prior art, in which large wall thicknesses lead to highly elliptical holes, the flame nozzles can be much more uniform in a burner tube according to the invention, so that a uniform flame pattern is made possible.

Heavily elliptical holes have a different gas outlet than circular holes. By elliptical holes, an uneven flame and a non-uniform flame pattern over a circumference of the gas outlet plate may occur. This effect is virtually completely avoided in the variant according to the invention. Conversely, if a finished tube is bent, distortions occur as a result of wall thickness, which are significantly greater.

For ovens, a defined and reproducible flame pattern is important, as with an undefined flame pattern incomplete combustion can occur, which can even produce toxic carbon monoxide.

The gas burner tube according to the invention is preferably designed as a particular closed ring, which may preferably be designed substantially rectangular. This embodiment is preferred because the cross sections of most ovens have a square or rectangular shape. Alternatively, it is also possible to make gas burner tubes as a ring, which has a substantially circular or elliptical shape.

The gas burner device has holes in the gas outlet plate. These holes are preferably arranged in rows on the gas outlet plate. In a particularly preferred embodiment, two rows are executed parallel to each other.

The holes in the gas outlet plate have predefined dimensions. The holes have approximately the same dimensions in terms of manufacturing accuracy. The holes of a lower row have a smaller diameter than the holes of an upper row. The holes with the smaller diameters contribute to an ignition of the flame to ensure a Flammenrundlauf. In addition, they ensure a quick re-ignition of the upper flame when extinguishing an upper flame.

The holes of the lower row are preferably arranged vertically displaced from the holes of the upper row. This arrangement has been made to permit flame ignition of the gas leaving the top holes with the smaller holes.

For the gas burner device, a central gas supply is provided. This gas supply supplies the gas burner tube with gas. The gas burner device may have, in addition to an ignition device, a device for temperature control of the flame and a gas outlet sensor. The gas leakage sensor emits in particular an optical and an acoustic alarm, if escaping gas is not burned. The combined alarm is very beneficial for use in kitchens that are also used by people with sensory disabilities such as poor vision or hearing. If required, this sensor can also be equipped with radio monitoring for alarm signaling. This is important if the user can not stay in the kitchen during the entire cooking time.

The household appliance according to the invention serves in particular as an oven and has at least one interior to be heated. At least one gas burner device is provided for heating the at least one interior space. The or at least one gas burner device comprises at least one burner tube, wherein the burner tube has at least one carrier profile and at least one gas outlet plate connected thereto. In the gas outlet plate holes are provided for gas outlet.

In preferred developments, the gas burner device is designed according to at least one development described above.

With reference to the following figures, a particularly preferred embodiment of the invention will be described.

• Fig. 1: einen Küchenherd mit geöffnetem Garraum,
• Fig. 2: den geöffneten Garraum mit eingeschobener Gasbrennervorrichtung,
• Fig. 3: eine eingebaute Gasbrennereinrichtung in Draufsicht, und
• Fig. 4: eine eingebaute Gasbrennervorrichtung in Seitenansicht.

In the figures show:

• Fig. 1 : a kitchen stove with open cooking space,
• Fig. 2 : the open cooking chamber with inserted gas burner device,
• Fig. 3 a built-in gas burner device in plan view, and
• Fig. 4 : a built-in gas burner device in side view.

FIG. 1 shows a household appliance designed here as Hherd 1 with an open Garrraum 2. The bottom surface 3 of the cooking chamber has an approximately rectangular cross-section. Below the bottom surface 3 is - not visible in this illustration - a gas burner device according to the invention. The back 4 of the cooking chamber has a circulating air fan 5. On the top four separate gas-operated hobs 16 are provided here. In other embodiments, radiant panels or induction hobs may also be provided. On a control panel arranged control buttons 17 are used to set the hobs 16 and setting the temperature in the cooking chamber. 2

FIG. 2 shows the stove 1 highly schematized with built-in gas burner device 6 in an exploded view. The bottom surface 3 of the cooking chamber 2 was shown on the front side 7 in section. Clearly visible is a line 8 for the central gas supply and the burner tube 9. The burner tube 9 has a carrier profile 10 and a base profile and a gas outlet plate 11 on. In the rear wall 12 of the cooking chamber 2, a circulating air blower 5 is installed, which transports heated air from the region of the gas burner tube 11 in the region of the cooking chamber 2 as circulating air.

The gas outlet plate 11 has holes 13, which are also referred to as flame nozzles. The holes 13 are preferably produced by punching. The carrier profile 10 is connected to at least the gas outlet plate 11 and in particular welded here. This construction facilitates an execution of burner tubes 9 even with complex geometry with simple production.

The carrier profile 10 is made in the particularly preferred embodiment as DIN rail, wherein the gas outlet plate 11 is designed as a flat sheet. The combination of hat rail and flat plate is also for the production of the combustion tube 9 of advantage, since it greatly facilitates the fixation of the gas outlet plate 11 on the support section 10. The gas outlet plate 11 and the carrier profile 10 are preferably connected by welding or flanging gas-tight together.

FIG. 3 shows a built-in oven 2 gas burner device 6 in a plan view in section. The burner tube 9 has a substantially rectangular shape with rounded corners and is designed as a closed ring. The gas is supplied centrally via the line 8. The illustration clearly shows that, for example, in the inner region 14 of the burner tube 9, a further burner tube 9 could be placed. This option could be interesting for use in commercial kitchens, as it is also the speed in the foreground.

FIG. 4 shows in the left part of a lateral section through the burner tube 9 and a front view of the gas outlet plate 11 in the right part. The carrier profile 10 is designed as a hat profile. The hat profile has contact surfaces 15 at the upper and at the lower edge. The contact surfaces 15 allow for the welding process a quick and easy fixation of the gas outlet plate 11 on or on the support section 10, for example with a screw clamp. In the side view, the carrier profile 10 and the gas outlet plate 11 are shown separated from each other. This representation was chosen in order to be able to represent the shape of the carrier profile 10 and of the gas outlet plate 11 in a defined manner.

The gas outlet plate 11 and the carrier profile 10 are made in different sheet thicknesses. In this case, the gas outlet plate 11 has a thickness of 0.2 mm to 1.0 mm. In the most preferred embodiment, the gas exit plate 11 has a thickness between about 0.3 mm and about 0.7 mm.

One advantage is that the carrier profile 10 can be designed to be somewhat more stable for carrying, while the gas outlet plate 11 can be optimized for a homogeneous gas outlet and a homogeneous flame pattern. While the carrier profile 10 is exposed to a combined, predominantly thermomechanical load, the load of the gas outlet plate 11 1 is predominantly on the thermal component.

On the gas outlet plate 11, the holes 13 are arranged. The holes 13 are preferably provided in two rows on the gas outlet plate 11. In a particularly preferred embodiment, the rows are arranged parallel to one another. The holes 13 have predefined same dimensions. The holes 13 are preferably circular in shape and have a defined diameter, with the holes 13 of a lower row having a smaller radius than the holes 13 of an upper row.

Alternative to the representation in FIG. 4 Gas outlet plates are also executable with three or more rows of holes. In these constructions, preferably - analogously to FIG. 2 - The bottom row of holes on the holes 13 with the smallest diameter.

The holes 13 of the lower row are here arranged vertically shifted to the holes 13 of the upper row.

The holes 13 with the smaller radii in the lower row serve firstly as a backup row to ensure a flame run-up during ignition. Second, in the case of extinction of the upper flame, the series serves to quickly reignite it.

The small sheet thickness of the gas outlet plate 11 already described above proves to be a great advantage in curved sections of the burner tube 9. As a result of deformation by bending, holes in thick sheets in the bends take on an approximately elliptical shape. The expression of the elliptical shape depends on the sheet thickness and a radius of curvature. Due to the very small thicknesses of the gas outlet plate 11, the effect described above is hardly noticeable here.

The geometry of the holes 13 of the gas exit plate 11 plays an important role in the local flame formation. If the originally circular holes 13 change their shape to an elliptical shape, this may possibly result in an uneven flame and an uneven flame pattern. A defined flame pattern is important, among other things, for uniform heating and complete combustion.

LIST OF REFERENCE NUMBERS

1

stove

2

oven

3

floor area

4

back

5

circulation fan

6

Gas fire

7

front

8th

management

9

burner tube

10

Carrier profile / basic profile

11

Gas outlet plate

12

rear wall

13

Holes, flame nozzles

14

interior

15

contact surface

16

heating position

17

control knob

Claims (13)

Gas burner device (6) for heating an interior of a domestic appliance, in particular a cooking chamber 2 of a baking oven or stove (1) with at least one burner tube (9), wherein the burner tube (9) at least one carrier profile and at least one associated gas outlet plate (11) , in which holes (13) are provided for the gas outlet. Gas burner device (6) for an oven or hearth (2) according to claim 1, characterized in that the holes (13) are punched. Gas burner device (6) according to one of the preceding claims, characterized in that the carrier profile (10) with the at least one gas outlet plate (11) is connected in a gastight manner. Gas burner device according to one of the preceding claims, characterized in that the carrier profile (10) is designed in particular as Hutschine, wherein the gas outlet plate (11) is preferably designed as a flat sheet. Gas burner device (6) according to one of the preceding claims, characterized in that the gas outlet plate (11) and the carrier profile (10) have different sheet thicknesses. Gas burner device (6) according to one of the preceding claims, characterized in that the gas outlet plate (11) has a thickness of 0.2 mm to 1.0 mm, in particular between 0.3 mm and 0.7 mm. Gas burner device (6) according to one of the preceding claims, characterized in that the gas burner tube (9) is designed as a closed ring and preferably substantially rectangular. Gas burner device (6) according to one of the preceding claims, characterized in that the holes (13) are arranged in particular in two rows on the gas outlet plate (11). Gas burner device (6) according to one of the preceding claims, characterized in that the holes (13) have predefined same dimensions. Gas burner device (6) according to one of the preceding claims, characterized in that the holes (13) are preferably designed circular and each have a defined Diameter, wherein the holes (13) of a lower row have a smaller radius than the holes of an upper row. Gas burner device (6) according to one of the preceding claims, characterized in that the holes (13) of the lower row are preferably arranged vertically displaced relative to the holes (13) of the upper row. Gas burner device (6) according to one of the preceding claims, characterized in that a central gas supply (8) is provided. Domestic appliance and in particular oven or stove with a cooking chamber and with at least one gas burner device for heating the cooking chamber according to at least one of the preceding claims.

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