Method for operating a gas hob, and gas hob

Abstract

For operating a gas hob having at least two gas burners which can be operated separately and which each have a nozzle, a dedicated gas valve for adjusting a gas supply to the gas burner is associated with each gas burner. The nozzle of a gas burner has an opening cross-section which is 10% to 30% larger than the opening cross-section which is required for the rated power of the gas burner. During normal operation of the gas burner, the associated gas valve is adjusted to a rated throughput. During operation of the gas burner under excess power with full utilization of the full opening cross-section of the nozzle, the gas valve is opened further and adjusted to an excess power throughput.

Claims

1. A method for operating a gas hob comprising: at least two gas burners which can be actuated and operated separately from each other, wherein each of said gas burners comprises at least one nozzle; and a dedicated gas valve for adjusting a gas supply to each of said gas burners, wherein said nozzle of at least one of said gas burners comprises an opening cross-section being larger than an opening cross-section which is required for a rated power of said gas burner, wherein, during normal operation of said one of said gas burners, an associated gas valve to said one of said gas burners is adjusted to a rated throughput, and, during operation of said one of said gas burners at excess power with full utilization of a full opening cross-section of said nozzle, said gas valve is opened further and adjusted to an excess power throughput, wherein said gas burners of said gas hob are operated in such a way that a sum of momentary powers of all of said operated gas burners does not exceed a sum of rated powers of said operated gas burners, and wherein exactly one gas valve is provided for each gas burner having at least one nozzle.

2. The method according to claim 1, wherein a check is made to determine how many of said gas burners of said gas hob are active, and one said gas burner can be operated at excess power only in an instance in which at least one further of said gas burners is in operation at its rated power.

3. The method according to claim 2, wherein said gas burner is operable at excess power only in an instance in which at least said further gas burner is in operation at a lower power being below its rated power by a difference between said rated power and said excess power in said other gas burner.

4. The method according to claim 1, wherein said gas hob comprises more than two said gas burners and said operating state of all of said gas burners is checked, wherein the number of gas burners which can be operated at excess power is always one less than the number of gas burners which can be operated at all.

5. The method according to claim 4, wherein at least one said gas burner is operated at rated power in order to allow operation of said other gas burners at excess power.

6. The method according to claim 1, wherein operation at least of one said gas burner which is operated at excess power is optically or acoustically indicated.

7. The method according to claim 1, wherein operation of said gas burner at excess power is limited in respect of time.

8. The method according to claim 7, wherein said operation of said gas burner at excess power is a maximum of 10 minutes.

9. The method according to claim 1, wherein said opening cross-sections of said nozzles of said gas burners are 5% to 30% greater than said opening cross-sections as rated throughput for their rated power.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) Exemplary embodiments of the invention are schematically illustrated in the drawings and will be explained in greater detail in the text which follows. In the drawings:

(2) FIG. 1 shows a plan view of a gas hob according to the invention,

(3) FIG. 2 shows a detail of a gas valve with the opening cross-section illustrated, and

(4) FIG. 3 shows a plan view of an extremely enlarged nozzle of a gas burner from FIG. 1.

DETAILED DESCRIPTION

(5) FIG. 1 shows a plan view of an exemplary embodiment according to the invention of an electronically controlled gas hob 100. The figure specifically shows a hob plate 129 with four cooking points 112 to 115 which could also be seen as individual cooking zones, each for one cooking vessel. A cooking vessel 216 is arranged on the cooking point 113, and a cooking vessel 116 is arranged on the cooking point 114. The cooking vessels 116 and 216 each stand on support grids 122 of the cooking points 112 to 115 in this case. Each cooking point has an associated gas burner 117 to 120 in the centre. Furthermore, the gas hob 100 has a plurality of operator control elements 101, an indicator device 102 and also a control unit 103. A central controller 103 which controls and regulates all of the functions of the gas hob 100 is particularly advantageous. Part of the control unit 103 is an electronic gas controller 107, which controls all gas valves of the gas hob 100, the gas valves advantageously being of identical construction.

(6) The desired cooking stages for the associated cooking points 112 to 115 or the gas burners 117 to 120 thereof can be set by means of the operator control elements 101. The desired cooking stage of a cooking point 112 to 115 is transmitted from the associated operator control element 101 to the controller 103, in particular to the gas controller 107. The gas controller then controls, for example for the third cooking point 114, the gas valve 104 such that a burner power which corresponds to the desired cooking stage is set for the associated burner 119. The gas supply is illustrated using the example of cooking points 114 and 113. Gas is supplied to the cooking point 114 comprising the gas burner 119 and, respectively, to the cooking point 113 comprising the gas burner 118 via a gas supply line 105 and, respectively, 205, the gas valve 104 and, respectively, 204 and the gas feed line 106 and, respectively, 206. The other gas valves are not illustrated but are connected in the same way.

(7) Furthermore, a nozzle 118 of the gas burner 118 and also a nozzle 119 of the gas burner 119 are illustrated using dotted lines. The nozzles are of conventional design and are covered by corresponding removable covers of the gas burners. A plan view of a nozzle 118 of this kind with a central nozzle hole 118 is illustrated in FIG. 3. The round opening cross-section can be seen at the nozzle hole, wherein a diameter lies in the abovementioned range and is at most 2 or 3 mm, advantageously between 1 mm and 1.5 mm.

(8) FIG. 2 illustrates a gas valve 204 for the cooking point 113 and, respectively, the gas burner 118 in section and in plan view, as is known per se from the abovementioned document DE 102009047914 A1. The gas valve 204 has a rotor disc 11 with a toothed ring 14 on the outside. The rotor disc 11 is rotatably mounted on a shaft 23 by means of a disc hub 17 and is driven by an electric motor, preferably by a stepper motor, by virtue of a pinion at the top left. A region 15 does not have any openings, whereas, on the right-hand side, an opening 12, together with an output opening 26 and a ring seal 27 around it, defines a gas throughput or opening cross-section of the gas valve 204. Reference is made to DE 102009047914 A1 in respect of the importance of the special shape of the opening 12.

(9) In order to now design the gas valve 204 for excess power operation, provision can be made, for normal operation of the gas burner 118, for the rotor disc 11 to be located in the position which is rotated somewhat further in the anticlockwise direction and which is illustrated using dashed lines for the opening 12. It is clear that there is now a narrower region of the elongate opening 12 above the output opening 26 and an opening cross-section is smaller. This can also be the maximum open or end position for rated operation of the gas burner 118, even if there is still a form of power reserve available. The rated power at the gas burner 118 which is supplied by the gas valve 204 is 3 kW in this case. By further rotation of the rotor disc 11 in the clockwise direction into the position which is illustrated using solid lines, more gas is passed for an excess power throughput and the excess power of 3.7 kW is generated at the gas burner 118 and, respectively, the nozzle 118. In this case, this excess power throughput can be matched precisely to the opening cross-section of the associated gas burner 118 and, respectively, of the nozzle 118, for example by as much gas being passed in this case as can flow out of the nozzle 118 at most. Further opening of the gas valve 204 would not generate any higher power at the gas burner 118 and, respectively, at the nozzle 118 either.

(10) The gas valve 104 for the gas burner 119 can also be designed in a corresponding manner. However, since the power of the gas valve during rated operation is intended to be, by way of example, only 2 kW and therefore considerably less than the 3 kW of the gas burner 118 of the cooking point 113, an end position of the rotor disc according to FIG. 2 can produce an even smaller passage cross-section. In this case, an excess power of at most 2.5 kW can be generated by somewhat further rotation of the rotor disc. However, the controller 103 ensures that the condition of the sum of all the powers being at most the sum of the rated powers of the operated burners is always complied with.

(11) The indicator device 102 or the LED indicators 108 to 111 of the indicator device indicate whether a cooking point 112 to 115 is being operated at excess power, for example by flashing or extra-bright illumination. The reduction in power of a cooking point can likewise be indicated, this occurring because another cooking point is intended to be operated at excess power.