ES2676621T3 - Gas burner device with flame monitoring electrode - Google Patents

Abstract

Gas burner device (10) having: - a burner body (20) with a number of adjacent gas outlet holes (25), - an ignition electrode (30), - a flame monitoring electrode ( 40), and - a common electrical electrode connection (60) for the electrodes (30, 40) to a control device (70) of the gas burner device (10), - where the ignition electrode (30) is connects at least one explosor (35) with the electrode connection (60) and the flame monitoring electrode (40) connects directly with the electrode connection (60), - and where the ignition electrode (30) and The flame monitoring electrode (40) are arranged adjacent to the burner body (20) and in such a way that the ignition electrode (30) has a lower breaking voltage to the burner body (20) than the electrode of the flame monitoring (40) - where the ignition electrode (30) has a different electrode tip qu e the flame monitoring electrode (40) to achieve the lowest breaking voltage of the ignition electrode (30).

Description

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Gas burner device with flame monitoring electrode

[0001] The invention relates to a gas burner device as well as an arrangement of the gas burner with such a gas burner device.

[0002] A gas burner device is known for example from DE 10107190 C1.

Such gas burner devices can be used for example as a heat source for cooking or roasting devices such as stoves or ovens.

[0003] Normal gas burner devices feature a burner body with a number of gas outlet holes adjacent to each other, from which flammable gas exits during operation of the gas burner device.

While previously the gas was usually manually ignited, current gas burner devices typically have an ignition electrode, to which a voltage can be applied to create a voltage arc.

Through this voltaic arc, the outgoing gas can be ignited.

[0004] In the automatic ignition of gas burner devices, however, the previous usual manual control of whether a flame actually expands through all the gas outlet orifices is suppressed.

Just in installation situations with difficult visibility conditions, for example in ovens, this can be problematic.

When, for example, objects such as parts of a food or kitchen utensils fall on the burner body, then some of the gas outlet holes can be covered with them.

This can prevent a flame burning in the ignition electrode from expanding through all gas outlet holes.

This is therefore particularly problematic because in this case the gas outlets in which the flame has not expanded comes out of gas that does not burn.

This gas in any case is not desired and in the best case is annoying, but this can also lead to a considerable risk of explosion and fire.

[0005] In the state of the art it is known how to monitor the correct expansion of the flame through the gas outlet orifices by means of a thermoelement, which is in front of the burner body of the ignition electrode.

If the flame does not expand correctly, this thermoelement detects a temperature that is too low.

In this case, for example, a control can interrupt the continued gas supply.

Because of the heat that also emanates from a flame that has only partially expanded, this type of arrangement however is not very reliable.

[0006] Furthermore, in the state of the art it is known to measure the generation of a flame by measuring a current flow from the ignition electrode over the flame to the burner body, where the burner body in this case is normally made of a conductive material and also with earth connection.

Although this allows a more reliable detection of whether a flame had been ignited, however it causes the problem that in this case the measurement can be performed only on the ignition electrode.

With this, it is not possible to detect if a flame has also in fact expanded through all the gas outlet holes.

[0007] It would be conceivable to provide an additional flame monitoring electrode that is disposed in a position away from the ignition electrode and that is connected to a separate monitoring circuit that monitors the correct expansion of the flame.

Such an embodiment would, however, have the disadvantage that an additional supervision circuit would be necessary, which for example in existing systems would mean that it has to be engaged in the electronics already present.

This would entail a considerable development cost and also the need for a new device approval.

[0008] From US 3,574,496 a gas burner device with an ignition device and two flame sensors is known.

A flame sensor reacts to ultraviolet light to detect a spark of ignition.

The other flame sensor detects a flame itself.

In addition the ignition circuit contains an explosor.

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[0009] From US 5,127,823 another gas burner device with a control device for a gas oven is known.

Here we explain in more detail how an ignition spark is generated by a transformer.

[0010] From EP 0 088 412 A1 a new gas burner device is known which has an ignition electrode.

The ignition electrode with an adjacent part of the gas burner forms an explosor, which is connected in parallel with a secondary winding of an ignition transmitter.

Objective and solution

[0011] It is an object of the invention to create a gas burner device in which with the smallest possible change or even none of the existing control components it is possible to reliably monitor the expansion of the flame through all the outlet orifices of gas.

It is also an object of the invention to create a gas burner arrangement with such a gas burner device.

[0012] This objective is achieved by a gas burner device with the features of claim 1 or 3 as well as by an arrangement of the gas burner with the features of claim 12. Advantageous as well as preferred configurations of the invention are object of the other claims and are explained in more detail below.

This describes some of the features only for the gas burner device or only for the gas burner arrangement.

However, they must independently be valid independently for both the gas burner device and the gas burner arrangement.

[0013] The gas burner device according to the invention has a burner body with a number of adjacent gas outlet holes, an ignition electrode, a flame monitoring electrode, and a common electrical electrode connection for the electrodes. in a control device of the gas burner device.

The ignition electrode is connected to at least one explosor with the electrode connection, and the flame monitoring electrode is directly connected to the electrode connection.

The ignition electrode and the flame monitoring electrode are arranged adjacent to the burner body in such a way that the ignition electrode has lower breaking voltage to the burner body than the flame monitoring electrode or the breaking voltage The burner body is larger in the flame monitoring electrode.

[0014] By means of the gas burner device according to the invention it is possible to provide using only one electrode connection both the functionality of the automatic ignition and also the functionality of the supervision of the correct expansion of the flame through all the gas outlet orifices. .

An additional connection with its corresponding electronics can be dispensed with.

[0015] The operation of the gas burner arrangement according to the invention is briefly outlined below.

[0016] In an explosor it is usually a component that only becomes conductive when an applied voltage is greater than a disruptive voltage of the explosor.

Such a sufficiently large voltage normally leads to the ionization of a gas located between two electrodes in a discharge chamber.

This becomes conductive and the explosor is short-circuited in this way in fractions of a microsecond.

In the present case the explosor particularly meets the objective of short-circuiting a voltage applied to the electrode connection only to the ignition electrode when an ignition is attempted.

A corresponding high voltage is normally applied at a power up.

If only a voltage lower than the disruptive voltage is applied, then this voltage normally serves the measurement and is separated through the ignition electrode explosor.

A current flowing due to the flame showing a flame that has expanded properly can therefore flow only through the flame monitoring electrode.

More explosors can also be connected in series, advantageously two explosors.

Their tensions of rupture are then added to a tension of total rupture.

[0017] The forecast of the explosor alone however would not be sufficient to ensure that the ignition takes place at the ignition electrode.

This is achieved through the second measure provided according to the invention, that is to say that the ignition electrode has a lower breaking voltage to the burner body than the flame monitoring electrode.

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With this, it is achieved that, when adjusting the ignition voltage with correctly chosen voltage or height, a spark from the ignition electrode jumps to the burner body, even if no spark from the flame monitoring electrode jumps to the burner body.

The configuration according to the invention allows in other words to choose an ignition voltage in which only in the ignition electrode, but not in the flame monitoring electrode, a spark jumps to the burner body.

Preferably, the ignition voltage is therefore found in the area between the rupture voltage of the ignition electrode and the rupture voltage of the flame monitoring electrode, namely the burner body respectively.

[0018] To reach the lower breaking voltage, the ignition electrode according to an independent aspect of the invention has an electrode tip shaped differently from the flame monitoring electrode, preferably a sharper electrode tip.

This is a possibility to lower the breaking voltage.

Alternatively, the ignition electrode according to another aspect of the invention may be arranged at a lower distance from the burner body than the flame monitoring electrode to achieve the lower breaking voltage of the ignition electrode.

This is based on the knowledge that the breaking voltage increases with the distance of a corresponding electrode to the burner body.

By increasing the distance therefore also the breaking voltage can be increased.

Here, distance is defined as the minimum path between an electrode and the burner body, that is, the path in which the rupture takes place.

[0019] The ignition electrode preferably has a distance of 3 mm to 5 mm, preferably approximately 4 mm, from the burner body.

The flame monitoring electrode preferably has a distance of 5 mm to 7 mm, preferably approximately 6 mm, from the burner body.

These values have proven advantageous in practice in gas burners, such as those used primarily in gas ovens.

It is especially preferable that the flame monitoring electrode has a distance that is approximately 30% to 70% greater than the distance of the ignition electrode from the burner body.

[0020] According to one embodiment, an explosor is formed as a gas-filled discharge chamber between a first explosive electrode and a second explosive electrode, where the first explosive electrode is connected to the ignition electrode and the second explosive electrode is connect with electrode connection.

In this case both explosion electrodes have a defined distance from each other.

Alternatively, for this purpose the explosor can also be formed as a component.

If several or advantageously two explosors are provided, then they can be configured differently, for example one with explosion electrodes and one as an electronic component.

However, they are advantageously configured identically.

[0021] The ignition electrode and the flame monitoring electrode are preferably fixed to the burner body.

This allows a compact and easy-to-use form of construction.

Furthermore, the distances of the electrodes to the burner body can be defined very well, precisely and relatively easily.

[0022] The ignition electrode and the flame monitoring electrode have positions with respect to the burner body preferably very far apart from each other or even in particular preferably opposite positions.

Advantageously, its distance is at least 50% of the burner body length.

Especially advantageous can be positions in the distant extreme regions respectively in the burner body, especially the ignition electrode is advantageously arranged in an extreme region.

This allows the ignition electrode to ignite the flame on one side of the burner body, and the flame monitoring electrode can then reliably detect a flame, when the flame has expanded correctly through all the exit holes of the gas to the other end.

[0023] Preferably the explosor has a disruptive voltage of 250 V up to 450 V open, preferably 400 V. These values have proven to be advantageous in practice.

[0024] Preferably the flame monitoring electrode is arranged so that its tip is within a flame, when the flame burns in the gas burner device.

This allows reliable detection of a flame by means of a current flow over the flame monitoring electrode to the burner body.

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[0025] The invention further relates to a gas burner system having a gas burner device according to the invention described above and a control device with an outlet, which is configured to connect the electrode connection of the burner device. Of gas.

The control device is configured to emit an ignition pulse at the output with an ignition voltage that is greater than the rupture voltage of the ignition electrode to the burner body and less than the rupture voltage of the flame monitoring electrode at burner body

In this case the control device is configured to emit a measuring voltage at the output to detect a flame burning in the gas burner device, which is less than the explosive voltage of the explosor.

Through the arrangement of the gas burner according to the invention, the advantages described above with reference to the gas burner device according to the invention can be used for an arrangement of the gas burner. As for the gas burner device, all the variants and embodiments described above can be used.

The advantages explained apply accordingly.

[0026] The control device may, for example, have a microprocessor, a microcontroller, a specific application integrated circuit (ASIC), a programmable logic controller (SPS) or another programmable unit for performing control functions.

Especially the arrangement of the gas burner can have processor means and storage means, whereby the program code that controls the behavior of the gas burner arrangement in this embodiment is stored on storage media through the processor media

A flame can be ignited in the gas burner device by emitting an ignition pulse.

By measuring the voltage, it can be detected if the flame has expanded correctly through all the gas outlet holes of the gas burner device.

The control device can therefore control both functions of the gas burner device in an advantageous manner and thereby allows autonomous operation of the gas burner device.

[0027] The ignition voltage is preferable between 8 kV and 12 kV, preferably 10 kV. More preferable is that the ignition voltage is less than the breaking voltage of the flame monitoring electrode.

The measuring voltage is preferably between 200 V and 260 V, especially preferably 230 V, where these values are effective values and the measuring voltage is alternating voltage, so that the maximum value is 325 V. These values have proved advantageous in the practice.

[0028] According to a preferred embodiment, the control device is configured to emit the ignition pulse with a certain period of time to ignite the gas burner device and then emit the measuring voltage, and thereby monitor a burning flame. in the gas burner device. This allows an advantageous configuration of the control device for autonomous commissioning of the gas burner arrangement, whereby manual controls can be waived without exposing the risk of unburned gas leakage.

[0029] It is understood that the control device can assume even more functions, especially the control of a gas supply to the burner body.

This can increase the ease of handling the gas burner arrangement and further automate the commissioning.

Especially the control device can be configured to interrupt the supply of gas to the burner body when the flame monitoring electrode does not detect a flame within a certain period of time after the end of the ignition pulse.

This indicates that the flame has not expanded properly through all the gas outlet holes and therefore there is unburned gas leakage.

Alternatively or additionally, the control device may, for example, also make a warning to a user, for example, optically or acoustically.

[0030] These and other characteristics are deduced in addition to the claims, also of the description and of the drawings made, whereby the individual characteristics can be realized by themselves or several in the form of sub-combinations in an embodiment of the invention and in other areas and may represent advantageous as well as protectable embodiments for which protection is claimed herein.

The subdivision of the application into provisional titles and individual sections does not limit the statements made in their general validity.

Brief description of the drawing

[0031] Other advantages and aspects of the invention result from the claims and the successive description of preferred embodiments of the invention which are explained below by Fig. 1.

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In this case, Fig. 1 shows an arrangement of the gas burner with a gas burner device according to the invention.

Detailed description of the embodiment example

[0032] Fig. 1 shows an arrangement of the gas burner 5 according to the invention with a gas burner device 10 according to the invention. The gas burner device 10 has a burner body 20.

The burner body 20 has a gas inlet 22 and multiple gas outlet holes 25 adjacent to each other.

In the gas inlet 22 flammable gas can be introduced in a certain amount and pressure controlled by a gas valve in a known manner.

The gas leaves the gas outlet orifices 25 to ignite and burn.

With the flammable gas, the gas burner device 10 can be used to heat, for example, a cooking pot or oven, alternatively also for a water heater or the like. The burner body 20 is made of a conductive metal and is also grounded as a kind of ground connection, so that a current can flow through it.

[0033] For ignition of the outgoing gas of the gas outlet orifices 20 an ignition electrode 30 is provided.

To monitor the correct expansion of a burning flame, a flame monitoring electrode 40 is also provided.

As shown, the flame monitoring electrode 40 has a distance from d to the burner body 30 and therefore is further away than the ignition electrode 30 with a distance from d to the burner body 30. However, it is understood that it is a schematic view in the representation of Fig. 1 only.

But in any case the distance D is greater than the distance d, the difference can be at least 10% or 30%, and in circumstances up to 100% or 200%.

[0034] Both electrodes 30, 40 are arranged so that the respective tips of the electrodes 30, 40 are in the flame in the operation of the gas burner device 10, that is, essentially when a flame burns through the gas outlet holes 25.

The flame monitoring electrode 40 is connected to an electrode connection 60 directly, that is, without intermediate connection of any electrical or electronic component.

The ignition electrode 30 is also connected to the electrode connection 60.

Between the ignition electrode 30 and the electrode connection 60 is, however, an explosor 35. The explosor 35 has a first explosion electrode 36, a second explosion electrode 38 and a discharge chamber 37 filled with gas arranged in the middle.

This could also be ambient air.

The first explosion electrode 36 is connected to the ignition electrode 30.

The second explosion electrode 38 is connected to the electrode connection 60.

The gas between the explosion electrodes 36, 38 takes care that in the case of adjacent voltages, which are less than a disruptive voltage of the explosor 35, a flow of current between the explosion electrodes 36, 38 is prevented.

Neither will an adjacent voltage be transmitted.

Therefore, in this case, the ignition electrode 30 remains without current and without voltage.

Only when the adjacent voltage is greater than the disruptive voltage does the gas ionize and the explosor 35 becomes conductive.

It could also be planned, as mentioned above, several explosors.

[0035] The arrangement of the gas burner 5 also has a control device 70 with an outlet 75. As shown, the electrode connection 60 of the gas burner device 10 is connected to the outlet 75 of the control device 70.

[0036] The control device 70 has no processor means and storage means represented in more detail, whereby the program code is stored in the storage media, which can be carried out by the processor means.

Thus, the control device for the functions described below can be carried out.

[0037] When the arrangement of the gas burner 5 must be put into operation, the control device 70 firstly worries that flammable gas does not flow into the valves represented in more detail at the inlet 22 of the burner body 20, of so that it exits the gas outlet holes 25.

Then the control device 70 places an ignition voltage of 10 kV at the output 75.

This voltage is much greater than the disruptive voltage of the explosor 35 which in the present example is 400 V, whereby the ignition voltage reaches the ignition electrode 30.

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This ignition voltage is also greater than a breakdown voltage of the ignition electrode 30 to the burner body 20, so that a voltage arc arises between the ignition electrode 30 and the burner body 20.

The ignition voltage is, however, less than a breaking voltage between the flame monitoring electrode 40 and the burner body 20, so that no voltage arc arises in the flame monitoring electrode 40.

[0038] Through the voltaic arc already described between the ignition electrode 30 and the burner body 20, the outgoing gas of the gas outlet orifices 25 is ignited.

The control device 70 connects after a certain period of time the voltage applied to the output 75 with the ignition voltage applied, so that then only a measuring voltage of 230 V is applied as an alternating voltage to the output 75.

This measuring voltage, with a maximum value of approximately 325 V, is less than the disruptive voltage of the explosor 35, which can be advantageously simply 400 V, so that the ignition electrode 30 of the measuring voltage is not reached.

The measuring voltage therefore reaches exclusively the flame monitoring electrode 40.

[0039] When the flame ignited on the ignition electrode 30 expands through the gas outlet holes 25 out to the opposite end of the ignition electrode 30 of the burner body 20, then the flame also reaches the flame monitoring electrode 40. In this case it flows due to the measuring voltage adjacent to the flame monitoring electrode 40 through the flame, which contains a high concentration of ionized particles and therefore conductive, a current on the burner body 20 according to mass. This current can be detected by the control device 70 to detect that the flame has expanded correctly through the entire burner body 20, that is, especially through all the gas outlet orifices 25.

In this case the gas burner device 10 continues to operate.

If instead an undesirable object is found on the burner body 20 that blocks a number of gas outlet holes 25, for example food debris, then the flame cannot be expanded to the monitoring electrode of flame 40.

In this case, the ionized particles already described between the burner body 20 and the flame monitoring electrode 40 would be missing, so that no current flows through the flame monitoring electrode 40.

This can be detected by the control device 70.

[0040] The control device 70 is configured to wait for a certain period of time after switching the ignition voltage to the measurement voltage, and then to check if a current above a predetermined threshold value flows through the electrode flame monitoring 40.

When this is the case then the control device 70 detects that the flame was lit correctly and that it has expanded through all the gas outlet orifices 25.

In the event that the current, however, did not exceed the predetermined threshold value, then the control device 70 would detect that the flame has not expanded properly or eventually did not even ignite.

In this case, the control device 70 disconnects the gas supply to the gas inlet 22 of the burner body 20 for safety reasons.

[0041] The control device 70 can also be programmed so that in this case it makes a second attempt to ignite, that is, for a certain period of time it applies the ignition voltage to the output 75.

Then it can be checked again if the flame was lit and expanded accordingly. In addition, a warning can be given to a user.

[0042] The arrangement of the gas burner 5 according to the invention can therefore function autonomously reliably, so that a manual check of whether the flame has been ignited and has been correctly expanded can be dispensed with.

There is no risk that uncontrolled flammable gas will escape from an ignition fault or a flame expansion block from the gas outlet orifices 25, which can accumulate and lead to a risk of fire and explosion or alternatively also It can simply cause a false power generation.

Claims (15)

5 10 fifteen twenty 25 30 35 40 Four. Five fifty 55 60 65 1. Gas burner device (10) presenting: - a burner body (20) with a number of adjacent gas outlet holes (25), - an ignition electrode (30), - a flame monitoring electrode (40), and - a common electrical electrode connection (60) for the electrodes (30, 40) to a control device (70) of the gas burner device (10), - where the ignition electrode (30) is connected on at least one explosor (35) with the electrode connection (60) and the flame monitoring electrode (40) is connected directly with the electrode connection (60), - and where the ignition electrode (30) and the flame monitoring electrode (40) are arranged adjacent to the burner body (20) and in such a way that the ignition electrode (30) has a lower breaking voltage to the burner body (20) that the flame monitoring electrode (40) - where the ignition electrode (30) has a different electrode tip than the flame monitoring electrode (40) to achieve the lower breaking voltage of the ignition electrode (30). 2. Gas burner device (10) according to claim 1 characterized in that the ignition electrode (30) has a sharper electrode tip than the flame monitoring electrode (40). 3. Gas burner device (10) presenting: - a burner body (20) with a number of adjacent gas outlet holes (25), - an ignition electrode (30), - a flame monitoring electrode (40), and - a common electrical electrode connection (60) for the electrodes (30, 40) to a control device (70) of the gas burner device (10), - where the ignition electrode (30) is connected on at least one explosor (35) with the electrode connection (60) and the flame monitoring electrode (40) is connected directly with the electrode connection (60), - and where the ignition electrode (30) and the flame monitoring electrode (40) are arranged adjacent to the burner body (20) and in such a way that the ignition electrode (30) has a lower breaking voltage to the burner body (20) that the flame monitoring electrode - where the ignition electrode (30) is arranged at a lower distance from the burner body (20) than the flame monitoring electrode (40) to achieve the lower breaking voltage of the ignition electrode (30). 4. Gas burner device (10) according to any of the preceding claims characterized in that the ignition electrode (30) has a distance of 3 mm to 5 mm from the burner body (20), preferably 4 mm. 5. Gas burner device (10) according to any of the preceding claims characterized in that the flame monitoring electrode (40) has a distance of 5 mm to 7 mm from the burner body (20), preferably 6 mm 6. Gas burner device (10) according to any of the preceding claims characterized in that an explosor (35) is configured as a discharge chamber (37) filled with gas between a first explosive electrode (36) and a second explosion electrode (38), where the first explosion electrode (36) is connected to the ignition electrode (30) and the second explosion electrode (38) is connected to the electrode connection (60). 7. Gas burner device (10) according to one of claims 1 to 5 characterized in that an explosor (35) is configured as an electronic component. 8. Gas burner device (10) according to any of the preceding claims characterized in that the ignition electrode (30) and the flame monitoring electrode (40) are fixed to the burner body (20). 9. Gas burner device (10) according to any of the preceding claims characterized in that the ignition electrode (30) and the flame monitoring electrode (40) have opposite positions and / or positions located in respective areas remote ends in the burner body (20). 10. Gas burner device (10) according to any of the preceding claims characterized in that the explosor (35) has a disruptive voltage of 250 V to 450 V. 5 10 fifteen twenty 25 11. Gas burner device (10) according to any of the preceding claims characterized in that the flame monitoring electrode (40) is arranged so that its tip is placed within a flame when the flame burns in the gas burner device (10). 12. Provision of the gas burner (5) that presents: - a gas burner device (10) according to any of the preceding claims, - where the control device (70) has an output (75), which is configured to connect the electrode connection (60) of the gas burner device (10), where the control device (70) is configured to emit at the output (75) an ignition pulse with an ignition voltage, which is greater than the breakdown voltage of the ignition electrode (30) to the burner body (20) and less than the breaking voltage of the flame monitoring electrode (40) to the burner body, and where the control device (70) is configured to emit at the output (75) a measuring voltage to detect a flame ignited in the gas burner device (10) that is less than the disruptive voltage of the explosor (35). 13. The gas burner arrangement (5) according to claim 12 characterized in that the ignition voltage is between 8 kV and 12 kV, preferably 10 kV. 14. Gas burner arrangement (5) according to claim 12 or 13 characterized in that the measuring voltage is between 200 V and 260 V, preferably 230 V. 15. Arrangement of the gas burner (5) according to one of claims 12 to 14 characterized in that the control device (70) is configured to emit the ignition pulse with a certain period of time to turn on the device gas burner (10) and then emit the measuring voltage and with it monitor a burning flame in the gas burner device (10).