JP2010096411A - Premix burner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the deterioration of a combustion state and the occurrence of a backfire failure caused by the leakage of premixed gas from a burner plate lateral face caused by the drop etc. of a burner plate and part of a heat insulating material around the burner plate. <P>SOLUTION: In this premix burner, the disc burner plate 7 is provided near a tip of a cylindrical burner body 1. The upstream side of the burner body 1 from the burner plate 7 serves as a mixing part and the downstream side from the burner plate 7 as a combustion part. Premixed gas obtained by mixing fuel gas and combustion air in the mixing part is injected toward the tip of the burner plate, and combustion is performed at the downstream side of the burner plate. A metallic pressing ring 2 for pressing the peripheral edge of the burner plate 7 is provided at the combustion part side of the burner plate 7. The pressing ring 2 formed by notching part of an arc is used. A through hole is bored on the lateral wall near the burner body tip and a fixing tool 6 is penetrated through the through hole so as to fix the pressing ring 2 to sandwich it between the fixing tool 6 and the burner plate 7. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a premix burner in which a burner plate is installed at the tip of a burner body and combustion is performed by injecting a premix gas toward the front side of the burner plate.

  A disc-shaped burner plate is installed near the tip of the cylindrical burner body, and the upstream side of the burner plate of the burner body is set as the mixing section, and the downstream side of the burner plate is set as the combustion section. There is a premixed burner that injects a premixed gas mixed with air toward the front side of the burner plate and performs combustion on the downstream side of the burner plate. In the invention described in Japanese Patent Publication No. 2-19368, the fixing of the burner plate with the premixed burner is fixed by using the fastening bracket 14. The clamp 14 in Japanese Examined Patent Publication No. 2-19368 has an L-shaped cross section, and one surface is fixed outside the casing member, and is a claw that is parallel to the surface of the burner plate (combustor 1). The burner plate is fixed at the part. When the combustion is started and stopped by this burner, expansion and contraction due to heat occur in the clamp 14 and the clamp 14 is fixed outside the casing member. The claw portion that fixes the plate moves up and down. The thermal stress due to the fastener 14 is applied in the thickness direction of the burner plate, and the burner plate may be damaged by the repeated stress. Therefore, in the invention of Japanese Patent Publication No. 2-19368, a disk-shaped heat insulating material (second heat insulating material 12) is sandwiched between the fastening fitting 14 and the burner plate, and the heat is absorbed by the heat insulating material.

If it does as mentioned above, a heat insulating material becomes a cushion and it can reduce the stress with respect to a burner plate. However, the heat insulating material is a superposition of fiber materials. When the premixed gas deteriorates due to the influence of the flow when the premixed gas is ejected from the burner plate or the on / off operation of combustion, a part of the tissue is It sometimes collapsed. When the structure of the heat insulating material collapses and falls off, the first heat insulating material installed between the burner plate and the casing member also drops off, and a gap is formed between the burner plate and the casing member. The burner plate has a large number of fine holes to inject the premixed gas toward the front side of the burner plate. If a gap is formed between the burner plate and the burner body, a part of the premixed gas is injected. Will leak around the burner plate. When the premixed gas leaks from the side surface of the burner plate, the combustion state deteriorates and a backfire failure occurs.
Japanese Patent Publication No. 2-19368

  The problem to be solved by the present invention is that the burner plate and a part of the heat insulating material around the burner plate fall off, and the premixed gas leaks from the side surface of the burner plate, thereby causing deterioration of the combustion state and backfire failure. It is to prevent that.

  According to the first aspect of the present invention, a disc-shaped burner plate is provided near the tip of the cylindrical burner body, and the upstream side of the burner plate of the burner body is set as the mixing portion, and the downstream side of the burner plate is set as the combustion portion. In the premixing burner in which the premixed gas in which the fuel gas and the combustion air are mixed in the mixing section is injected toward the front side of the burner plate and burned on the downstream side of the burner plate, the burner is disposed on the burning section side of the burner plate. There is a metal retaining ring that presses against the peripheral edge of the plate. The retaining ring uses a notched part of the arc, and a through hole is formed in the side wall near the tip of the burner body to fix it to the through hole. The presser ring is fixed so as to be sandwiched between the fixture and the burner plate.

  According to a second aspect of the present invention, in the premixed burner, a fastening member that has a short arc shape and covers the notch portion of the retaining ring is installed in the notch portion of the retaining ring, and the retaining member is pressed by the retaining member. It is characterized by blocking the notch of the ring.

  By making the holding ring made of metal, the holding ring will not partly fall out and fall off, and the holding ring is notched, so even if the holding ring expands or contracts due to heat, the holding ring Phenomenon such as floating from the burner plate surface does not occur. For this reason, it is possible to eliminate the occurrence of a gap around the burner plate and leakage of the premixed gas from the surroundings, and it is possible to prevent the deterioration of the combustion state and the occurrence of a backfire failure. And about the notch part of a press ring, since the clamping metal fitting is installed so that a notch part may be covered, it can also prevent that the heat insulating material of a notch part falls off. In addition, since the retaining ring is fixed by being sandwiched by screws that penetrate the side wall of the burner body, there is no stress applied to the burner plate due to the expansion and contraction of the fixing tool, and the burner plate by the fixing tool Can also be prevented.

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an assembly diagram of a premixing burner embodying the present invention, and FIG. 2 is a cross-sectional view of a premixed burner with its tip portion extracted. The burner body 1 has a cylindrical shape and burns downward. A disc-shaped burner plate 7 made of ceramic is provided near the tip of the burner body 1, and the inside of the burner body 1 hitting the upstream side of the burner plate 7 is a mixing unit 9 for mixing combustion air and fuel gas, and a burner plate The downstream side is the combustion section 10. A wind box (not shown) for rectifying combustion air and a fuel gas supply means (not shown) are provided on the former side of the burner body 1 so as to supply combustion air and fuel gas to the mixing unit 9. Keep it.

  The burner mixes combustion air and fuel gas in the mixing section 9 and injects the premixed gas toward the front side of the burner plate. The burner plate 7 has a large number of small jets for injecting the premixed gas. A hole is made. Around the burner plate 7, the heated expansion mat 5 is wound around the burner plate 7 in order to prevent a gap from being formed between the burner plate 1 and the wall surface of the burner body 1. If the burner plate 7 wound with a mat that is fireproof and expands when heated is placed in the burner body 1, the heated expansion mat 5 expands when heated once, so the burner plate 7 and the burner body 1 The gap can be eliminated. However, since the heating expansion mat 5 has a property of being easily broken and dropped compared to the burner plate 7, a metal pressing ring 2 that presses the peripheral portions of the heating expansion mat 5 and the burner plate 7 from the lower side is provided. The holding ring 2 is a plate-like ring in which a part of the arc is cut out, and a screw hole 8 for preventing misalignment is provided at a location away from the cutout portion of the holding ring 2.

  The burner body 1 has a plurality of through holes in the side wall near the tip, and the fixing ring 6 made of screws and nuts is passed through the through holes in the wall surface so that the presser ring 2 and the burner plate 7 do not fall off. Secure to. The position of the retaining ring 2 is determined by aligning the position of the screw hole 8 for preventing displacement of the retaining ring 2 with a specific through hole, and the wall surface of the burner body and the screw hole 8 for preventing displacement are penetrated by the fixture 6. The burner body 1 and the holding ring 2 are fixed. By passing the fixing tool 6 through the other through-holes, the tip of the fixing tool 6 protrudes below the burner plate 7 in the burner body 1, and the holding ring 2 is fixed to the fixing tool 6 and the burner plate 7. The presser ring 2 is fixed by sandwiching the pin. The holding ring 2 is also fixed by a fastening metal fitting 3 having a short arc shape and having a screw hole. The arc-shaped fastening fitting 3 is installed so as to cover the notch 4 of the pressing ring 2, and the fastening fitting 3 is also fixed by a fixture 6 that penetrates the wall surface of the burner body. Since the position of the notch 4 is determined by providing a screw hole 8 for preventing misalignment in the holding ring 2 and fixing the position of the screw hole 8 for preventing misalignment, the position of the notch 4 is determined. The fastening bracket 3 is installed.

  When the burner is burned, the metal pressing ring 2 expands, but the pressing ring 2 is provided with the notch portion 4, so that the thermal stress can be released. If the cutout portion 4 is provided, the holding ring 2 is not provided at that portion, so that the heating expansion mat 5 cannot be pressed by the presser ring 2, but a small arc-shaped fastening metal fitting 3 that covers the cutout portion 4. By providing the, the heated expansion mat 5 at the notch portion 4 can be pressed by the fastening fitting 3.

Assembly drawing of a premix burner embodying the present invention Sectional drawing which extracted the front-end | tip part of the pre-mixing burner of this invention

Explanation of symbols

1 Burner body
2 Presser ring
3 Fastening bracket
4 Notch
5 Heating expansion mat
6 Fixing tool
7 Burner plate
8 Misalignment prevention screw holes
9 Mixing section
10 Combustion section

Claims (2)

  A disc-shaped burner plate is installed near the tip of the cylindrical burner body, and the upstream side of the burner plate of the burner body is set as the mixing section, and the downstream side of the burner plate is set as the combustion section. In a premixed burner that injects premixed gas mixed with air toward the front side of the burner plate and burns on the downstream side of the burner plate, it is made of metal that presses the peripheral edge of the burner plate against the burning part side of the burner plate A presser ring is used, and a presser ring with a part of a circular arc cut out is used. A through hole is formed in the side wall near the tip of the burner body, and a fixing tool is passed through the through hole. A premix burner characterized in that it is fixed so as to be sandwiched between a fixture and a burner plate.   2. The premix burner according to claim 1, wherein a fastening member having a short arc shape and covering the notch portion of the pressing ring is provided at a notch portion of the pressing ring, and the notching portion of the pressing ring is provided by the fastening bracket. Premixed burner characterized by blocking

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