JP2014029256A - Infrared combustion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an infrared combustion device to fundamentally solve a problem on occurrence of backfire, and stabilize combustion flame.SOLUTION: An infrared combustion device 1 includes a device body 10, and a red-heating radiation plate 20 disposed at a heated object side of the device body 10. The red-heating radiation plate 20 includes a plurality of burner port portions 21 formed with recessed portions 21A, on a surface of the red-heating radiation plate 20. Tips of the through holes 22 penetrating through the red-heating radiation plate 20 in a thickness direction, are communicated with the burner port portions 21, and gas outgoing ports 23A of gas supply paths 23 disposed in the through holes 22, face the burner port portions 21. In the device body 10, a combustion air supply portion 10A communicated with the through holes 22 and fuel gas supply portions 10B communicated with the gas supply paths 23 are independently disposed, and mixing spaces for a fuel gas released from the gas outgoing ports 23A and the combustion air supplied through the through holes, are formed in the recessed portions 21A of the burner port portions 21.

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.

  In such a conventional infrared combustion apparatus, a plurality of the above-mentioned premixed flames are formed on the surface of the combustion plate to cause planar combustion, and at the same time, the combustion plate is heated red by burning the flame. As a result, the object to be heated is heated by heating due to the combustion of the flame and infrared radiation from the red hot combustion plate.

JP 2003-35403 A

  The above-described 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 glow red uniformly. 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, it is an object of the present invention to fundamentally solve the problem of backfire generation, to stabilize the combustion flame, and to continue red heat combustion in a good state.

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

  The infrared combustion apparatus includes an apparatus main body and a red heat radiating plate disposed on a heating target side of the apparatus main body, and the red heat radiating plate includes a plurality of flame holes formed with recesses on the surface of the red heat radiating plate, In the flame hole portion, a tip of a through-hole penetrating the red heat radiation plate in the thickness direction communicates, and a gas outlet of a gas supply path disposed in the through-hole faces the main body of the apparatus. The fuel air supply section communicating with the through hole and the fuel gas supply section communicating with the gas supply path are separately provided, and the fuel discharged from the gas outlet into the recess of the flame hole section. A mixed space of gas and combustion air supplied through the through hole is formed.

  According to the infrared combustion apparatus having such a feature, by adopting a premixing method in which a mixed space of fuel gas and combustion air is formed in the recesses of the flame holes formed on the surface of the red heat radiation plate, The flashback phenomenon, which is a problem with the premixed combustion method, can be fundamentally eliminated. The flame is generated by mixing the fuel gas and combustion air in the recess on the surface of the red heat radiation plate, so that the flame combustion can be stabilized by the recess configuration, and a stable micro flame with a short flame length can be achieved. A plurality of red heat radiation plates can be formed on the surface. Thereby, uniform infrared plane radiation can be obtained from the red heat radiation plate. By forming the air supply path by the through hole of the red heat radiation plate, the components can be simplified.

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing (the figure (a) is a top view, the figure (b) is the XX partial sectional view in the figure (a)) which showed the example of 1 structure 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 rays combustion apparatus which concerns on embodiment of this invention. It is explanatory drawing which shows the air supply path | route of the infrared combustion apparatus which concerns on embodiment of this invention. It is explanatory drawing which shows the air supply path | route of the infrared combustion apparatus which concerns on embodiment of this invention ((a) is X1-X1 sectional drawing in FIG. 3, (b) is X2-X2 sectional drawing in FIG. 3). It is explanatory drawing which shows the other example in the air supply path | route of the infrared combustion apparatus which concerns on embodiment of this invention (X1-X1 sectional drawing in FIG. 3).

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory view showing a configuration example of an infrared combustion apparatus according to an embodiment of the present invention. FIG. 1A is a plan view, and FIG. 1B is a partial cross-sectional view taken along the line XX in FIG.

  The infrared combustion apparatus 1 according to the embodiment of the present invention includes an apparatus main body 10 and a red heat radiation plate 20 disposed on the heating target side of the apparatus main body 10. In the illustrated example, the red heat radiation plate 20 is disposed on the ceiling surface of the apparatus main body 10. However, when the heating direction is directed to the side, the red heat radiation plate 20 is disposed so as to face the heat radiation plate 20.

  The red heat radiating plate 20 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. The red heat radiating plate 20 includes a plurality of flame holes 21 having concave portions 21A formed on the surface thereof. In the illustrated example, the flame holes 21 are arranged in a matrix, but the arrangement is not limited to this. The flame hole portion 21 forms a micro flame with a short flame length in the recess 21A, and the red heat radiation plate 20 is formed by forming a micro flame in each of the plurality of flame hole portions 21 formed on the surface. It is burnt red and flat in a uniform manner.

  Each flame hole portion 21 communicates with a tip of a through hole 22 that penetrates the red heat radiation plate 20 in the thickness direction. Each flame hole 21 faces a gas outlet 23A of a gas supply path 23 disposed in the through hole 22.

  The apparatus main body 10 includes a combustion air supply unit 10A and a fuel gas supply unit 10B. The combustion air supply unit 10 </ b> A and the combustion gas supply unit 10 </ b> B are separated and arranged in the apparatus main body 10. This prevents combustion air and fuel gas from mixing in the apparatus main body 10.

  In the illustrated example, the combustion air supply unit 10 </ b> A includes an air chamber 11, and the fuel gas supply unit 10 </ b> B includes a gas chamber 12. The air chamber 11 communicates with the outside of the apparatus main body 10 through an air inflow path 11A. The gas chamber 12 communicates with a fuel gas supply source via a combustion gas introduction path 12A.

  The above-described through-hole 22 of the red heat radiation plate 20 communicates with the combustion air supply unit 10A, and serves as a flow path for air supplied from the combustion air supply unit 10A. Thus, by using the through-hole 22 of the red heat radiation plate 20 as an air flow path, the number of parts can be reduced and the components can be simplified. The gas supply path 23 disposed in the through hole 22 communicates with the fuel gas supply unit 10B, and serves as a supply path for fuel gas supplied from the fuel gas supply unit 10B.

  In the illustrated example, the through hole 22 communicates with the air chamber 11, and the gas supply path 23 communicates with the gas chamber 12. Moreover, the air chamber 11 and the gas chamber 12 are airtightly separated by the partition plate 13, and the gas supply path 23 passes through the air chamber 11, passes through the partition plate 13, and communicates with the gas chamber 12.

  The infrared combustion apparatus 1 can form a micro flame in the flame hole portion 21 formed on the surface of the red heat radiation plate 20 by the premixing method by providing the above-described configuration. That is, the fuel gas discharged from the gas outlet 23A of the gas supply passage 23 is supplied into the recess 21A of the flame hole portion 21, and further combusted from the through hole 22 serving as a supply path for combustion air into the recess 21A. Supply air is supplied. As a result, a mixed space of fuel gas and combustion air is formed in the recess 21 </ b> A of the flame hole 21.

  As described above, the infrared combustion apparatus 1 according to the embodiment of the present invention has a structure in which a combustion mixture is not formed on the upstream side of the flame hole 21, and the combustion of the flame is performed only in the recess 21 </ b> A of the flame hole 21. Will occur. 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 21 on the surface of the red heat radiation plate 20, it is possible to form a plurality of short flame length micro flames on the surface of the red heat radiation plate 20 and perform planar combustion, and the surface of the red heat radiation plate 20. Can be efficiently and uniformly heated.

  FIG. 2 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. 2A, the flame hole portion 21 is provided with a taper angle θ on the inner surface of the concave portion 21A that gradually widens the flame hole portion 21 upward. According to the flame hole portion 21 having such a configuration, a micro flame Mf as illustrated is formed in the space inside and above the recess 21A. And the combustion stability of the micro flame Mf can be improved by setting taper angle (theta) appropriately.

  FIG. 2B shows the value of the blow-off limit air ratio λ when the taper angle θ of the flame hole 21 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 apparent from FIG. 2B, when the taper angle θ of the flame hole 21 is changed, the limit air ratio at which blow-off occurs (blow-off limit air ratio) changes, and the taper angle θ is set to 20 to 40 °. More preferably, the blow-off limit air ratio can be maximized by setting the range to 25 to 35 °. That is, the stability of the micro flame can be improved by setting the taper angle θ of the flame hole portion 21 to a range of 20 to 40 ° (preferably 25 to 35 °).

  3 and 4 are explanatory views showing an air supply path of the infrared combustion apparatus according to the embodiment of the present invention. 4A shows a cross-sectional view along X1-X1 in FIG. 3, and FIG. 4B shows a cross-sectional view along X2-X2 in FIG. Portions that overlap with the above description are given the same reference numerals and redundant description is omitted.

  In the infrared combustion apparatus 1A in which the area of the red heat radiating plate 20 is relatively large, in order to perform uniform combustion over the entire red heat radiating plate 20, the plurality of flame holes 21 arranged on the surface of the red heat radiating plate 20 are uniform. Is required to supply air. As an air supply path for this purpose, in the example shown in FIG. 3, an air inflow path 11A is formed in the apparatus body 10 so as to surround the air chamber 11, and the air inflow path 11A and the air chamber 11 are connected to each other. The air chamber 11 communicates with each other through an air outlet 11A1 arranged at a predetermined interval. According to such an infrared combustion apparatus 1A, air is supplied to the air chamber 11 via the air outlets 11A1 arranged around the air chamber 11 at a predetermined interval.

  When air is supplied from the periphery of the air chamber 11 that communicates with each flame hole 21 via the through hole 22, sufficient air is also supplied to the flame hole 21 in the center of the red heat radiation plate 20 having a relatively large area. In order to supply the air, it is necessary to increase the jet flow velocity into the air chamber 11 from the air supply path. The infrared combustion apparatus 1 </ b> A is provided with the air jet port 11 </ b> A <b> 1 described above, thereby increasing the jet flow velocity into the air chamber 11 and supplying sufficient air to the flame hole portion 21 in the central portion of the red heat radiation plate 20.

  FIG. 5 shows another example of the air supply path of the infrared combustion apparatus according to the embodiment of the present invention. In the example shown in FIG. 5, similarly to the examples shown in FIGS. 3 and 4, an air inflow path 11 </ b> A is formed in the apparatus main body 10 so as to surround the air chamber 11. The air chamber 11 communicates with the periphery of the air chamber 11 via an air jet port 11A1 arranged at a predetermined interval. In this example, the air outlets 11 </ b> A <b> 1 that are arranged to face each other are arranged so as to be shifted to positions where the air ejection direction into the air chamber 11 does not collide.

  In the example shown in FIG. 5, the air flowing into the air chamber 11 from the air outlets 11 </ b> A <b> 1 that face each other collides with each other near the center, and in the flame hole portion 21 that exists near the center of the red heat radiation plate 20. It is possible to suppress the excessive supply of air. Thereby, it is possible to make the air supply amount uniform to each of the flame hole portions 21 arranged in the red heat radiation plate 20.

  As described above, the infrared combustion apparatus 1 according to the embodiment of the present invention generates backfire by mixing the fuel gas and the combustion air in the flame hole portion 21 formed on the surface of the red heat radiation plate 20. This problem can be fundamentally solved. In addition, by appropriately setting the shape of the flame hole portion 21, in particular, by providing the flame hole portion 21 with a taper angle θ and setting the taper angle in a range of 20 to 40 °, the combustion flame is stabilized. It is possible to continue the red hot combustion in a good state. Thus, safe and good infrared combustion can be realized, and uniform infrared plane radiation can be obtained from the red heat radiation plate 20.

  In addition, in the infrared combustion apparatus 1A having the red heat radiation plate 20 having a relatively large area, the air supplied to each flame hole portion 21 of the red heat radiation plate 20 can be uniformly supplied. Since the combustion air ratio of each flame hole portion 21 becomes uniform and combustion is possible at an appropriate set air-fuel ratio, stable combustion with reduced exhaust CO becomes possible.

  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, 1A: Infrared combustion device,
10: apparatus main body, 10A: combustion air supply unit, 10B: fuel gas supply unit,
11: Air chamber, 11A: Air inflow path, 11A1: Air outlet
12: Gas chamber, 12A: Combustion gas introduction path, 13: Partition plate,
20: Red heat radiation plate, 21: Flame hole part, 21A: Recessed part, 22: Through hole,
23: Gas supply path, 23A: Gas outlet, θ: Taper angle

Claims (7)

Comprising a device main body and a red heat radiation plate arranged on the heating target side of the device main body,
The red heat radiating plate includes a plurality of flame holes formed with recesses on the surface of the red heat radiating plate,
The flame hole portion communicates with a tip of a through hole penetrating the red heat radiation plate in a thickness direction, and a gas outlet of a gas supply path arranged in the through hole faces,
The apparatus main body is separately provided with a combustion air supply part communicating with the through hole and a fuel gas supply part communicating with the gas supply path,
An infrared combustion apparatus, wherein a mixed space of fuel gas discharged from the gas outlet and combustion air supplied through the through hole is formed in the recess of the flame hole.   The infrared combustion apparatus according to claim 1, wherein a taper angle that gradually expands the flame hole portion upward is provided on an inner surface of the concave portion.   3. The infrared combustion apparatus according to claim 2, wherein the taper angle is set to 20 to 40 [deg.] With respect to a vertical axis.   The said combustion air supply part is provided with the air chamber connected to the exterior of an apparatus main body, The said fuel gas supply part is provided with the gas chamber connected to a fuel gas supply source in any one of Claims 1-3 characterized by the above-mentioned. The infrared combustion apparatus described.   5. The air chamber and the gas chamber are separated by a partition plate, and the gas supply path passes through the air chamber, passes through the partition plate, and communicates with the gas chamber. Infrared combustion device.   6. The infrared combustion apparatus according to claim 4, wherein air is supplied to the air chamber via an air jet port disposed around the air chamber at a predetermined interval.   The infrared combustion apparatus according to claim 6, wherein the air jet outlets arranged to face each other are arranged to be shifted to a position where the jet direction of the air into the air chamber does not collide.

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