JP6300634B2 - Infrared combustion equipment - Google Patents

Description

  The present invention relates to an infrared combustion apparatus that can be used for various uses such as cooking, heating, drying, and heat treatment.

  2. Description of the Related Art Conventionally, as an infrared combustion apparatus, there is known an infrared combustion apparatus that heats up a combustion plate by forming a number of premixed flames on a combustion plate made of a refractory material such as ceramic (see Patent Document 1 below).

  In this prior art, a number of flame holes are provided so as to penetrate the combustion plate, and a premixed gas in which fuel gas and combustion air are mixed in advance is formed on the upstream side of the combustion plate. A premixed flame is formed on a single flame hole or a plurality of flame holes by supplying to the flame holes of the combustion plate.

  Such a conventional infrared combustion apparatus forms a plurality of the above-mentioned premixed flames on the surface of the combustion plate and performs planar combustion, and at the same time, the combustion plate is red hot by burning the flame, thereby heating and red hot by the combustion of the flame. The object to be heated is heated by infrared radiation from the burned plate.

JP 2003-35403 A

  The conventional infrared combustion apparatus uses a premixed flame that can shorten the flame length and can uniformly form a flame on a flat surface in order to make the combustion plate surface uniformly red hot. However, since the plate temperature of the combustion plate in a red hot state becomes 800 ° C. or higher, there is a concern that a backfire may occur depending on the heating operation condition in the conventional infrared combustion apparatus using combustion by the premixed flame. there were.

  Backfire is a phenomenon in which a flame propagates through the premixed gas supply path to the flame hole. Normally, the premixed gas ejection speed is adjusted appropriately to determine the premixed gas ejection speed and the flame combustion speed. By maintaining the balance, the flashback phenomenon is prevented. However, if any malfunction or improper use condition is made, the balance between the jetting speed of the premixed gas and the combustion speed of the flame may be lost, and a flashback phenomenon may occur.

  The flashback phenomenon is a fatal problem in a premixed combustion system combustion apparatus. In general, sufficient countermeasures have been studied. However, if this flashback phenomenon occurs frequently, the premixed gas There is a possibility that it may lead to malfunctions of the apparatus such as damage due to heating of the supply path.

  This invention makes it an example of a subject to cope with such a problem. That is, in the infrared combustion apparatus, the flashback phenomenon, which is a problem in the premixed combustion method, is fundamentally eliminated by adopting a premixing method that forms a mixed space of fuel gas and combustion air at the flame hole. In that case, even if the flame holes are arranged at high density, it is possible to supply a uniform combustion air, to make the combustion flame uniform and stable, and to perform red hot combustion in a good state It is an object of the present invention to be able to continue.

  In order to achieve such an object, an infrared combustion apparatus according to the present invention has at least the following configuration.

  A red heat radiation plate having a flame hole portion that penetrates in the thickness direction and has a flame opening on the front surface side and a through hole on the back surface side, and a gas supply body having a gas supply path for supplying fuel gas, The gas supply body includes a gas emission portion that projects into the through hole and emits fuel gas that has passed through the gas supply path into the flame hole portion, and is provided between the gas supply body and the back side of the red heat radiation plate. An air flow path for supplying combustion air to the flame hole is formed in a gap between the side air flow path formed along the side of the gas supply body and the gas supply body. An infrared combustion apparatus having a transverse air passage formed on the surface of the gas supply body and linearly crossing between the sides of the gas supply body.

  According to the infrared combustion apparatus having such a feature, it becomes a problem in the premixed combustion method by adopting a premixing method in which a mixed space of fuel gas and combustion air is formed in the flame hole portion of the red heat radiation plate. The flashback phenomenon can be basically eliminated. In the flame hole part of the red heat radiation plate, the fuel gas emitted from the gas emission part of the gas supply body and the combustion air are mixed to produce a flame, so that the flame combustion is stabilized by the recess shape of the flame hole part. In addition, a plurality of stable micro flames having a short flame length can be formed on the surface of the red heat radiation plate. Thereby, uniform infrared plane radiation can be obtained from the red heat radiation plate.

  By forming an air flow path for supplying combustion air to the flame hole in the gap between the gas supply body and the back side of the red heat radiation plate, the components can be simplified. Further, the air flow path is formed on the side of the gas supply body, and the transverse air flow path is formed on the surface of the gas supply body and linearly crosses between the sides of the gas supply body. Therefore, even when the arrangement density of the flame holes is increased, or when the area of the gas supply body and the red heat radiation plate is increased, the combustion air can be surely sent into each flame hole. Uniform plane radiation of infrared rays can be obtained.

It is explanatory drawing (plan view) which showed the example of 1 structure of the infrared combustion apparatus which concerns on embodiment of this invention. It is explanatory drawing (XX sectional drawing in FIG. 1) which showed the example of 1 structure of the infrared combustion apparatus which concerns on embodiment of this invention. It is explanatory drawing (YY partial sectional drawing in FIG. 2) which showed the example of 1 structure of the infrared combustion apparatus which concerns on embodiment of this invention. It is explanatory drawing (ZZ sectional drawing in FIG. 2) which showed one structural example of the infrared combustion apparatus which concerns on embodiment of this invention. It is explanatory drawing which showed the characteristic of the flame hole part of the infrared combustion apparatus which concerns on embodiment of this invention ((a) shows the state of combustion in a flame hole part, (b) is the 1st taper of a flame hole part. A graph showing the relationship between the angle θ1 and the blow-off limit air ratio λ is shown).

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1-4 is explanatory drawing which showed the example of 1 structure of the infrared rays combustion apparatus which concerns on embodiment of this invention. 1 is a plan view, FIG. 2 is a sectional view taken along line XX in FIG. 1, FIG. 3 is a partial sectional view taken along line YY in FIG. 2, and FIG.

  The infrared combustion apparatus 1 according to the embodiment of the present invention includes at least a red heat radiation plate 10 having a flame hole portion 11 and a gas supply body 20 having a gas supply passage 21 for supplying fuel gas. Further, in the illustrated example, a base body 30 having a gas chamber 31 communicating with a fuel gas supply source is provided, and a gas supply body 20 is provided on the base body 30 so as to cover the gas chamber 31. A red heat radiation plate 10 is provided on the base 30 so as to cover the surface.

  The red heat radiating plate 10 is formed of, for example, a refractory material such as ceramic, and radiates infrared rays as radiant heat by red heat combustion. In the example shown in the figure, it is constituted by a flat plate having a predetermined plate thickness. This red heat radiation plate 10 has a flame hole portion 11 that penetrates in the thickness direction and has a flame opening 11A on the front surface side and an opening 11B on the back surface side. In the illustrated example, a plurality of flame holes 11 are arranged in a staggered pattern on the plane, but the arrangement form and the number thereof are not limited to this.

  The flame hole portion 11 forms a micro flame with a short flame length in the flame opening 11A. The red heat radiation plate 10 is formed by forming a micro flame in each of the plurality of flame hole portions 11 formed on the surface. Is burned red hot in a flat and uniform manner. As shown in the figure, if the flame holes 11 are arranged in a staggered pattern in the vertical and horizontal directions, the flame holes 11 can be arranged at high density, and the amount of heat generated by the red heat radiation plate 10 can be increased.

  The gas supply body 20 includes a gas emission portion 22 that protrudes into the through-hole 11 </ b> B of the red heat radiation plate 10 and emits the fuel gas that has passed through the gas supply path 21 into the flame hole portion 11. A gap G is formed between the gas supply body 20 and the back surface side of the red heat radiation plate 10, and this gap G forms an air flow path Ga for supplying combustion air to the flame hole portion 11.

  The air flow path Ga is formed on the surface of the gas supply body 20 and the side air flow path Gb formed along the side edge of the gas supply body 20 and crosses linearly across the side of the gas supply body 20. It has an air flow path Gc. The side air flow path Gb is formed between the side surface of the gas supply body 20 and the inner side surface of the red heat radiation plate 10 so as to surround the gas supply body 20. The side air flow path Gb communicates with an air inlet 12 that opens to the side of the red heat radiation plate 10. Then, both ends of the transverse air flow path Gc communicate with the side air flow path Gb. Further, the side air flow path Gb and the transverse air flow path Gc communicate with the air flow path Ga in the flame hole portion 11.

  In the example shown in FIG. 3, the transverse air flow paths Gc are formed along an oblique linear array of the gas emission portions 22 arranged in a zigzag pattern. By forming the transverse air flow path Gc in this way, it is possible to reliably supply combustion air to the entire flame hole portions 11 arranged in a staggered pattern in the vertical and horizontal directions. The crossing air flow path Gc may be a groove (concave part) formed on the surface of the gas supply body 20, or between the diagonal linear arrangements of the gas emission parts 22 arranged linearly along the crossing air flow path Gc. You may form between the wall parts which bury.

  As described above, the base 30 includes the gas chamber 31 therein. The gas chamber 31 is provided with a gas inlet 32 communicating with a fuel gas supply source. The fuel gas that has flowed into the gas chamber 31 passes through the gas supply path 21 of the gas supply body 20 and exits from the exit of the gas exit 22 into the flame hole 11. On the other hand, the combustion air flowing in from the air inlet 12 flows along the surface of the transverse air flow path Gc and the gas supply body 20 from the side air flow path Gb, and is arranged facing the gas supply body 20. The red heat radiation plate 10 is supplied into the flame hole 11 from the through hole 11B. A mixing space for mixing the supplied fuel gas and combustion air is formed in the flame hole portion 11.

  The gas supply body 20 is a plate-like body integrally formed with the gas emission part 22, and a plurality of flame hole parts 11 of the red heat radiation plate 10 are arranged on a plane, and the gas emission part 22 of the gas supply body 20 is a flame hole part. A plurality of 11 are arranged. Then, by arranging the red heat radiation plate 10 on the gas supply body 20 which is a plate-like body, the gap G formed between the front surface side of the gas supply body 20 and the rear surface side of the red heat radiation plate 10 is flat. Air flow path Ga. The gas emission part 22 which becomes the convex part on the gas supply body 20 and the transverse air flow path Gc which becomes the concave part can be formed by integral molding with a mold.

  The infrared combustion apparatus 1 can form a micro flame in the flame mouth 11A of the flame hole portion 11 formed in the red heat radiation plate 10 by the premixing method by providing the above-described configuration. As a result, a combustion mixture is not formed on the upstream side of the flame hole 11, and the combustion of the flame occurs only in the flame port 11 </ b> A of the flame hole 11. As a result, the flashback phenomenon that becomes a problem in the premixed combustion method can be fundamentally eliminated. Further, by providing a plurality of flame holes 11 on the surface of the red heat radiation plate 10, it is possible to form a plurality of short flame length micro flames on the surface of the red heat radiation plate 10 and to perform planar combustion. Can be efficiently and uniformly heated. When the flame holes 11 are arranged in a staggered pattern in the vertical and horizontal directions, sufficient combustion air is formed in all the flame holes 11 by forming the transverse air flow paths Gc on the gas supply body 20. Even when the area of the red heat radiation plate 10 is increased, uniform heating can be realized.

  FIG. 5 is an explanatory diagram showing the characteristics of the flame hole portion of the infrared combustion apparatus according to the embodiment of the present invention. In the example shown in FIG. 5A, the flame hole portion 11 gradually widens the first taper angle θ1 that gradually widens the flame opening 11A toward the surface side and the through-hole 11B toward the gas supply body 20 side. A second taper angle θ2 is provided. Further, the gas emission part 22 protruding into the through-hole 11B has a truncated cone shape corresponding to the second taper angle θ2.

  A micro flame Mf as shown is formed in the space above and above the flame port 11A having the first taper angle θ1. Here, the combustion stability of the micro flame Mf can be improved by appropriately setting the first taper angle θ1.

  FIG. 5B shows the value of the blow-off limit air ratio λ when the first taper angle θ1 of the flame hole portion 11 is changed. The air ratio is defined by the ratio (λ = B ÷ A) of the minimum required theoretical air amount A for completely burning the fuel gas and the actually supplied air amount B. Combustion with an air ratio close to 1 is ideal, but even when the air ratio λ is increased, the combustion stability can be evaluated by the fact that no flame blows out. As is apparent from FIG. 5B, when the first taper angle θ1 of the flame hole 11 is changed, the limit air ratio at which blow-off occurs (blow-off limit air ratio) changes, and the first taper angle θ1 is set to 20%. By setting the range to -40 °, more preferably 25 to 35 °, the blow-off limit air ratio can be maximized. That is, the stability of the micro flame can be improved by setting the first taper angle θ1 of the flame hole portion 11 to a range of 20 to 40 ° (preferably 25 to 35 °).

  The second taper angle θ <b> 2 at the through-hole 11 </ b> B of the flame hole portion 11 can be appropriately set according to the cone angle of the gas emission portion 22 of the gas supply body 20. By providing such a second taper angle θ2, it is possible to ensure a sufficient combustion air inflow area for the frustoconical gas outlet 22.

  As described above, the infrared combustion apparatus 1 according to the embodiment of the present invention mixes fuel gas and combustion air in the flame hole portion 11 formed in the red heat radiation plate 10, thereby causing a problem of backfire. Can be fundamentally solved. Moreover, the form of the flame hole part 11 is set appropriately, in particular, the first taper angle θ1 is provided in the flame hole 11A of the flame hole part 11, and the first taper angle θ1 is set in a range of 20 to 40 °. Thus, the combustion flame can be stabilized and the red-hot combustion in a good state can be continued. Thereby, safe and good infrared combustion can be realized, and uniform infrared plane radiation can be obtained from the red heat radiation plate 10.

  In addition, the gas supply body 20 can be easily formed by integral press molding by forming the gas supply body 20 into a plate-like body integrally including the truncated cone-shaped gas emission portion 22. This gas supply body 20 is in a form that can be mass-produced with ceramic parts, for example. And by providing 2nd taper angle (theta) 2 in the through-hole 11B formed in the back surface side of the red heat radiation board 10 with respect to the gas emission part 22 of a truncated cone shape, the inner surface of the flame hole part 11 and the gas emission part 22 are provided. A sufficient area of the air channel Ga formed in the gap between the outer surface can be secured. As a result, sufficient air for combustion can be supplied to each flame hole portion 11 without increasing the pressure loss of the combustion air supply system, and stable combustion and proper adjustment of the combustion load are possible. become.

  As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and the design can be changed without departing from the scope of the present invention. Is included in the present invention. In addition, the above-described embodiments can be combined by utilizing each other's technology as long as there is no particular contradiction or problem in the purpose and configuration.

1: Infrared combustion device,
10: Red heat radiation plate, 11: Flame hole part, 11A: Flame port, 11B: Through-hole,
12: Air inlet,
20: Gas supply body, 21: Gas supply path, 22: Gas emission part,
30: Base, 31: Gas chamber, 32: Gas inlet,
G: gap, Ga: air flow path, Gb: side air flow path, Gc: transverse air flow path,
θ1: first taper angle, θ2: second taper angle

Claims (8)

A red heat radiation plate having a flame hole portion penetrating in the thickness direction and having a flame opening on the front surface side and a through hole opening on the back surface side;
A gas supply body having a gas supply path for supplying fuel gas,
The gas supply body includes a gas emission part that projects into the through hole and emits fuel gas that has passed through the gas supply path into the flame hole part,
Forming an air flow path for supplying combustion air to the flame hole in the gap between the gas supply body and the back side of the red heat radiation plate;
The air flow path is formed on the surface of the gas supply body and the side air flow path formed along the side edge of the gas supply body, and the transverse air that linearly crosses between the side edges of the gas supply body. An infrared combustion apparatus having a flow path.   The infrared combustion apparatus according to claim 1, wherein the crossing air flow path is formed along an oblique linear array of the gas emission portions arranged in a zigzag pattern.   The infrared combustion apparatus according to claim 1, wherein the transverse air flow path is a groove formed on a surface of the gas supply body.   3. The infrared combustion apparatus according to claim 2, wherein the transverse air flow path is formed between walls that fill a space between the oblique linear arrays of the gas emission portions.   The infrared combustion apparatus according to any one of claims 1 to 4, wherein the gas supply body is a plate-like body integrally formed with the gas emission portion. The flame hole portion has a first taper angle that gradually widens the flame mouth toward the surface side and a second taper angle that gradually widens the through-hole toward the gas supply body side,
The infrared combustion apparatus according to claim 1, wherein the gas emission unit has a truncated cone shape corresponding to the second taper angle.   The infrared combustion apparatus according to claim 6, wherein the first taper angle is set to 20 to 40 degrees with respect to a vertical axis. A substrate having a gas chamber in communication with a fuel gas supply source;
The gas supply body is disposed on the base so as to cover the gas chamber,
The infrared combustion apparatus according to claim 1, wherein the red heat radiation plate is disposed on the base so as to cover the gas supply body.

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