GAS BURNER DEVICE WITH FLAME ARRESTOR

Description

[0001] The invention relates to a gas burner device according to the preamble of patent claim 1.

[0002] A gas burner device of the type mentioned above is known from document EP 3 751 196 A1. This gas burner device consists of a burner body for combustion of a hydrogen-containing gas mixture, wherein the burner body has an interior space which is pneumatically connected, on the one hand, to a burner surface arranged externally on the burner body and, on the other hand, to a fuel gas supply. A flame arrester device is arranged in the interior space between the burner surface and the fuel gas supply, in this solution in the form of a non-return valve.

[0003] The documents WO 2013 / 178465 A2 and EP 0 628 146 A1 each show gas burner devices according to the preamble of claim 1.

[0004] The invention is based on the object of improving a gas burner device of the type mentioned above. In particular, a particularly reliable flame arrester device is to be created.

[0005] This object is achieved with a gas burner device of the type mentioned at the outset by the features listed in the characterising part of patent claim 1.

[0006] According to the invention, it is therefore provided that the flame arrester device has a plurality of through holes that are always open for the gas mixture.

[0007] In other words, the solution according to the invention is characterized in that the flame arrester is designed as a body with a plurality of through-holes. The body is made of a porous material, and each through-hole is formed as a recess penetrating the body. This body, with its through-holes, ensures that a flame, should it be deflected back into the space between the burner surface and the flame arrester, cannot spread further toward the fuel gas supply, because the flame stabilizes itself at least for a certain period of time due to a quench effect on the flame arrester.

[0008] Other advantageous developments arise from the dependent patent claims.

[0009] The gas burner device according to the invention, including its advantageous developments according to the dependent patent claims, is explained in more detail below with reference to the drawing of a preferred embodiment.

[0010] It shows schematically Figure 1 shows a section through a gas burner device with the flame arrester device according to the invention.

[0011] The Figure 1The gas burner device shown consists, in a known manner, of a burner body 1 for the combustion of a gas mixture consisting of fuel gas and air, wherein the fuel gas contains at least 50%, preferably at least 70%, and most preferably at least 90% hydrogen. The burner body 1 also has an interior space 2 which is pneumatically connected, on the one hand, to a burner surface 3 arranged on the outside of the burner body 1 and, on the other hand, to a fuel gas supply 4. Pneumatically connected is to be understood as meaning that, for example, the aforementioned fuel gas can flow from the fuel gas supply 4 (i.e., an inlet or mixing point for the fuel gas and regularly also for the air, i.e., the gas mixture) through the interior space 2 to the burner surface 3. Furthermore, it is provided that a flame arrester device 5 is arranged in the interior space 2 between the burner surface 3 and the fuel gas supply 4.

[0012] What is essential for the gas burner device according to the invention is that the flame arrester 5 has a plurality of through holes 6 that are always open to the gas mixture. As tests have surprisingly shown, this ensures a reliable flame arrester despite low pressure loss and without moving parts (compare the prior art mentioned above).

[0013] Furthermore, it is particularly preferably provided that a gas mixture receiving volume enclosed between the fuel gas supply 4 and the flame arrester 5 is at least three times, preferably at least five times, particularly preferably at least seven times, as large as a gas mixture receiving volume enclosed between the flame arrester 5 and the burner surface 3.

[0014] Furthermore, it is preferably provided that each orthogonal distance between the burner surface 3 and the flame arrester 5 is at most 10 mm, preferably at most 8 mm, particularly preferably at most 6 mm. Regarding the term "orthogonal," reference is made to the following Wikipedia article for the sake of simplicity: https: / / de.wikipedia.org / w / index.php?title=Orthogonalit%C3%A4t&oldid=210353727. The space between the burner surface 3 and the flame arrester 5 is deliberately kept relatively small or narrow with respect to the thickness of the flame arrester, so that the local displacement of the flame into a space (located in the flame arrester 5, for example, a pore) with a larger surface-to-volume ratio is dampened.The prevention of flame flashback into the fuel gas supply is ensured by the significantly larger surface-to-volume ratio in conjunction with the heat capacity of the flame arrester 5 and the flame quenching. Due to the high heat transfer coefficients, the gas temperature remains at a level below the ignition temperature within the flame arrester 5. Due to the temperature dependence of the so-called quench distance, detection of the flame displacement and stopping of the fuel gas supply are particularly preferred.

[0015] Looking more closely, the above-mentioned surface area refers to the material surface present inside the flame arrester device 5. Furthermore, the above-mentioned volume refers to the entire volume of the flame arrester device 5, i.e., both the material volume and the cavity volume resulting, for example, from porosity.

[0016] It is particularly preferred that a quotient of the aforementioned surface area and the aforementioned volume is at least 1500 m 2 < / m 3 <.

[0017] If the flame arrester device 5 is formed from a porous aluminum body, it is further preferably provided that the quotient of the aforementioned surface and the aforementioned volume is between 1500 m 2< / m 3< and 8000 m 2< / m 3< , preferably between 2000 m 2< / m 3< and 6000 m 2< / m 3< .

[0018] Furthermore, it is particularly preferred that an orthogonal distance between the burner surface 3 and the flame arrester 5 is the same within a predetermined tolerance value at every point between the burner surface 3 and the flame arrester 5. In this way, a quasi-equidistant distance and thus uniform behavior of the entire gas burner device is ensured. Expressed in numbers, it is particularly preferred that the tolerance value be at most 5 mm, preferably less than 3 mm, particularly preferably less than 1 mm.

[0019] Furthermore, the invention provides that the flame arrester 5 consists of a body, and each through-hole 6 is formed as a recess (completely) penetrating the body. The recess preferably has a length of at least 3 mm between its inlet and outlet openings. The body is designed to be correspondingly thick, i.e., the body preferably has a thickness of at least 3 mm.

[0020] In addition, the invention provides that the body is formed from a (preferably irregularly) porous material.

[0021] According to a first alternative, it is preferably provided that the body is formed from a cast material, preferably cast aluminum. According to a second alternative, it is preferably provided that the body is formed from a ceramic material. Furthermore, even if this does not fall within the scope of protection of the patent claims, it can be provided that the body is optionally formed from a fiber material, a knitted material, or a (particularly wire) woven material.

[0022] According to an alternative embodiment, which is not separately shown and does not fall within the scope of the patent claims, it is further preferably provided that the body is formed from a stack of or from metallic plates, each of which has an opening for introducing the gas mixture into the body and in which the through-holes 6 leading to the burner surface 3 are connected to the openings and formed with the aid of spacers arranged between them (between the plates). The spacers can be designed as knobs, for example. It is also possible for the plates themselves to be corrugated and in this way form the through-holes 6.This solution, in which the gas mixture flows particularly centrally through the openings into the body and then reaches the inside of the burner surface 3 via the through holes 6, can be produced particularly easily and inexpensively, which is of course advantageous.

[0023] As from Figure 1 Furthermore, to ensure the flame arrester function particularly reliably, it is preferably provided that each area of ​​the burner surface 3 is assigned a section of the flame arrester device 5. In other words: there is no burner surface 3 that is not protected by a flame arrester device 5.

[0024] As continues from Figure 1Finally, it is also preferably provided that both the burner surface 3 and the flame arrester 5 are cylindrical. The gas burner device for the combustion of hydrogen-rich fuel gas is therefore preferably a so-called cylindrical burner. Alternatively, however, a flat burner (axial gas outlet) or a combination of a cylindrical and flat burner (i.e., radial and axial gas outlet) can also be provided.

[0025] The gas burner device according to the invention functions as follows: The gas mixture enters the space enclosed by the flame arrester 5, which forms part of the interior 2, via the fuel gas supply 4. From there, the gas mixture flows through the through holes 6 into the space formed between the flame arrester 5 and the burner surface 3, which also forms part of the interior 2. From there, the gas mixture finally flows through corresponding openings to the burner surface and burns there.

[0026] Should, as explained at the outset, a flashback occur undesirably, as can occur relatively easily, particularly during the combustion of hydrogen, the flame arrester device 5 designed according to the invention prevents further spread of the flame into the aforementioned partial space between the fuel gas supply 4 and the flame arrester device 5. Since the effect of the flame arrester device 5, as already mentioned above, is only present for a certain time, it is particularly preferably provided that the gas burner device additionally has a flashback detection device which, upon appropriate detection, prevents the supply of fuel gas.This flashback detection device preferably comprises either a suitable sensor arranged between the burner surface 3 and the flame arrester 5 or, assuming suitable data evaluation, the flame monitoring device already arranged on the outside of the burner surface 3 is used to detect flame formation in this area. In terms of the method, it is therefore particularly preferred that, upon detection of a flame in the space between the burner surface 3 and the flame arrester 5, the supply of the combustible part of the gas mixture to the interior 2 is shut off. List of reference symbols

[0027] 1Burner body 2Interior 3Burner surface 4Fuel gas supply 5Flame arrester 6Through hole

Claims

1. A gas burner device, comprising a burner body (1) for the combustion of a gas mixture containing hydrogen, wherein burner body (1) comprises an interior (2), which is formed pneumatically connected on the one hand to a burner surface (3) arranged on the outside of the burner body (1) and on the other hand to a fuel gas supply (4), wherein a flame arresting device (5) is arranged in the interior (2) between the burner surface (3) and the fuel gas supply (4), wherein the flame arresting device (5) comprises a plurality of through-holes (6) which are always open for the gas mixture, wherein the flame arresting device (5) consists of a body and each through-hole (6) is formed as a recess penetrating the body, characterised in that the body is formed from a porous material.

2. The gas burner device according to claim 1, characterised in that a gas mixture holding volume enclosed between the fuel gas supply (4) and flame arresting device (5) is at least three times as large as a gas mixture holding volume enclosed between the flame arresting device (5) and burner surface (3).

3. The gas burner device according to claim 1 or 2, characterised in that each orthogonal distance between the burner surface (3) and the flame arresting device (5) amounts to at most 10 mm.

4. The gas burner device according to any one of claims 1 to 3, characterised in that an orthogonal distance between the burner surface (3) and the flame arresting device (5) is equal, within a given tolerance value, at each point between burner surface (3) and flame arresting device (5).

5. The gas burner device according to claim 4, characterised in that the tolerance value amounts to a maximum of 5 mm, preferably less than 3 mm, particularly preferably less than 1 mm.

6. The gas burner device according to one of claims 1 to 5, characterised in that the body is formed from a cast material.

7. The gas burner device according to one of claims 1 to 5, characterised in that the body is formed from a ceramic material.

8. The gas burner device according to one of claims 1 to 7, characterised in that both the burner surface (3) and the flame arresting device (5) are designed cylindrical.

9. The gas burner device according to one of claims 1 to 8, characterised in that the latter comprises a flashback detection device.

10. The gas burner device according to one of claims 1 to 9, characterised in that a quotient of an inner area of the flame arresting device (5) and a total volume of the flame arresting device (5) amounts to at least 1500 m2 / m3.

11. A method for the operation of a gas burner device according to any one of claims 1 to 10, wherein, when a flame is detected in the space between the burner surface (3) and the flame arresting device (5), a supply of the combustible part of the gas mixture into the interior (2) is at all events switched off.