Combustion device

Abstract

In a combustion apparatus in which a plurality of longitudinally elongated burners 2 each having a flame port 23 for injecting an air-fuel mixture at an upper end thereof are arranged side by side in a combustion housing 1 with a gap therebetween in a lateral direction, a flame transfer plate is disposed in the gap between the burners 2, 2 so as to be located in the vicinity of an upper end of a longitudinal portion corresponding to one of front and rear end portions of a flame port forming region of each of the burners 2, thereby preventing overheating of front and rear wall surfaces of the combustion housing 1.SOLUTION: As the transfer plates, a first transfer plate 61 disposed in the vicinity of an upper end of a longitudinal portion corresponding to a rear end of a flame port forming region of the burner 2 and a second transfer plate 62 disposed in the vicinity of an upper end of a longitudinal portion corresponding to a front end of the flame port forming region of the burner 2 are mixed in a gap between the burners 2, 2.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a combustion device that includes a combustion housing in which a plurality of burners, each elongated in the front-to-rear direction and having a flame nozzle at the top end for ejecting an air-fuel mixture, are arranged side by side with gaps in the lateral direction, and secondary air for combustion is supplied upward from below into the gaps between each burner. [Background technology]

[0002] Conventionally, in this type of combustion device, a fire-transfer plate that prevents secondary air from rising is arranged in the gap between each burner, near the upper end of the front-to-rear portion that coincides with one of the front and rear ends of the flame port formation region of each burner (see, for example, Patent Document 1). In this device, secondary air is less likely to flow directly above the fire-transfer plate, so that when fire transfers, part of the air-fuel mixture ejected from the flame port of one adjacent burner and part of the air-fuel mixture ejected from the flame port of the other burner through the gap remain directly above the fire-transfer plate, facilitating fire transfer from one burner to the other burner.

[0003] Here, at the end of the flame port formation area that matches the flame transfer plate, the supply of secondary air is blocked by the flame transfer plate, so the flame formed at that end leans toward the wall of the combustion housing in search of secondary air. Conventionally, the front-to-rear portions of the gaps between each burner where the flame transfer plates are located are aligned for all flame transfer plates. Therefore, the flames formed at either the front or rear end of the flame formation area of ​​all burners (the end that matches the flame transfer plate) lean toward either the front or rear wall of the combustion housing, making this wall more susceptible to overheating. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-125685 Summary of the Invention [Problem to be solved by the invention]

[0005] In view of the above, an object of the present invention is to provide a combustion device that can prevent overheating of the front and rear wall surfaces of a combustion housing. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention provides a combustion device comprising a combustion housing in which a plurality of burners elongated in the front-to-rear direction and having flame ports at their upper ends for ejecting an air-fuel mixture are arranged side by side in the combustion chamber with gaps left horizontally, and secondary air for combustion is supplied upward from below into the gaps between each burner, and a fire-transfer plate is disposed in the gap between each burner near the upper end of the front-to-rear portion that coincides with one of the front and rear ends of the flame port formation area of ​​each burner to prevent the secondary air from rising, and the fire-transfer plate is a mixture of a first fire-transfer plate in which one of the front and rear ends is a rear end and a second fire-transfer plate in which one of the front and rear ends is a front end. In addition, "the first fire-transfer plate having one of the front and rear ends as the rear end" means a fire-transfer plate positioned near the upper end of the front-to-rear portion that coincides with the rear end of the flame nozzle forming area of ​​each burner, and "the second fire-transfer plate having one of the front and rear ends as the front end" means a fire-transfer plate positioned near the upper end of the front-to-rear portion that coincides with the front end of the flame nozzle forming area of ​​each burner.

[0007] According to the present invention, since the first and second flame-transfer plates are mixed, the flames formed at either the front or rear end of the flame formation area of ​​all burners do not lean toward either the front or rear wall of the combustion housing, thereby preventing overheating of the front and rear walls of the combustion housing.

[0008] In addition, in the present invention, it is desirable to alternately arrange one first and one second fire-transfer plates within a predetermined lateral range within the combustion housing. Here, within the range where one first and one second fire-transfer plates are alternately arranged, secondary air is supplied from the gap between the burners opposite the first fire-transfer plate to the air-fuel mixture ejected from the rear end of the flame formation region of each burner, and secondary air is supplied from the gap between the burners opposite the second fire-transfer plate to the air-fuel mixture ejected from the front end of the flame formation region of each burner, thereby suppressing the forward and rearward tilt of the flames formed at the front and rear ends of the burner hole formation region. This effectively suppresses overheating of the front and rear wall surfaces of the combustion housing. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view of a combustion device according to an embodiment of the present invention; [Figure 2] FIG. 2 is a plan view of the combustion device according to the embodiment. [Figure 3] FIG. 3 is a cross-sectional side view taken along line III-III in FIG. 2. [Figure 4] FIG. 4 is an enlarged cross-sectional view taken along line IV-IV in FIG. 2. [Figure 5] FIG. 2 is a perspective view of a burner provided in the combustion device according to the embodiment. [Figure 6] Cross-sectional view taken along line VI-VI in Figure 5. [Figure 7] FIG. 2 is a perspective view showing the layout of the first and second flame-transfer plates in the combustion device according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] 1 to 3, a combustion apparatus according to an embodiment of the present invention includes a combustion housing 1 with an open top, a plurality of burners 2 longitudinal in the front-to-rear direction that are arranged side by side with gaps in the lateral direction at the bottom of the combustion housing 1, and a gas manifold 3 (not shown in FIG. 1) that supplies fuel gas to the burners 2 from the front. An object to be heated, such as a heat exchanger, is placed on top of the combustion housing 1 and is heated by combustion gas generated by combustion of the air-fuel mixture ejected from the burners 2. Although not shown, the combustion gas that has passed through the object to be heated is discharged to the outside by an exhaust fan.

[0011] 5 and 6, the burner 2 comprises a burner body 21 having a pair of side plates 21a, 21a facing each other in the lateral direction, and a burner cap 22 having a pair of side plates 22a, 22a covering the outside of both lateral sides of the burner body 21. At the upper end of the burner 2, there are provided flame ports 23 for ejecting the air-fuel mixture, which include a plurality of main flame ports 23a formed at intervals in the front-to-rear direction on an upper plate 21b connecting the upper ends of the side plates 21a, 21a of the burner body 21, and sleeve flame ports 23b defined between each side plate 21a of the burner body 21 and each side plate 22a of the burner cap 22.

[0012] The burner body 21 is also provided with a lower mixing tube section 24 extending rearward from an inlet 24a at the front end, and a main mixture passage 25 extending upward while widening in the front-to-rear direction from the rear end of the mixing tube section 24. The gas manifold 3 is provided with a plurality of nozzles 31 corresponding to the plurality of burners 2, each of which injects fuel gas from the front toward the inlet 24a of each burner 2 (see FIG. 3). The mixture of fuel gas flowing in from the inlet 24a and primary air flowing in from the inlet 24a by the suction force of the exhaust fan is guided to the main flame port 23a via the mixing tube section 24 and the main mixture passage 25. The side plates 21a, 21a and the top plate 21b of the burner body 21 are formed by bending a single plate.

[0013] Between each side plate 21a of the burner body 21 and each side plate 22a of the burner cap 22, a sleeve-fired mixture passage 26 communicating with the sleeve flame nozzle 23b is provided. Furthermore, each side plate 21a of the burner body 21 is formed with a plurality of vent holes 26a spaced apart in the front-to-rear direction, positioned above the portion where the lower parts of the side plates 22a of the burner cap 22 overlap. The mixed gas diverted from the main mixture passage 25 via these vent holes 26a is supplied to the sleeve flame nozzle 23b via the sleeve-fired mixture passage 26, and the main flame formed on the main flame nozzle 23a is stabilized by the sleeve flame formed on the sleeve flame nozzle 23b.

[0014] Furthermore, grooves 27 recessed laterally inward are formed in each side plate 22a of the burner cap 22, positioned above the vent holes 26a. This allows the mixture flowing from the vent holes 26a into the sleeve-fire mixture passage 26 to be distributed in the front-rear direction below the grooves 27, ensuring uniformity in the front-rear distribution of the mixture ejected from the sleeve flame ports 23b. The burner cap 22 also has bridge portions 22b connecting the upper ends of both side plates 22a, 22a at multiple locations in the front and rear. A recess 28 is formed in the lower rear end of the burner body 21, into which the burner retainer plate 15, described later, engages.

[0015] The combustion housing 1 is composed of a front side plate 11 that covers the front portion of the combustion housing 1 located above the gas manifold 3, a rear side plate 12, side plates 13, 13 on both lateral sides, and a bottom plate 14. Heat shield plates 111, 121, 131 are provided so as to face the inner surfaces of the front, rear, and lateral side plates 11, 12, 13. The height of the upper ends of the front and rear heat shield plates 111, 121 is low, and the inner surfaces of the front and rear side plates 11, 12 above these heat shield plates 111, 121 are covered with heat insulating materials 112, 122.

[0016] A burner holding plate 15 is provided along the lower inner surface of the rear side plate 12. Referring to Figure 7, the lower end of the burner holding plate 15 is formed with a forward bent portion 151 that engages with the recessed portion 28 of each burner 2. The upper end of the burner holding plate 15 is also bent with a plurality of positioning claws 152 that are inserted from behind into the upper portions of the gaps between the burners 2, 2.

[0017] The bottom plate 14 is formed with a plurality of raised portions 141 that sandwich the lower edge of each burner 2 from both sides in the lateral direction, and also has a large number of small holes 142 that face the gaps between the burners 2, 2. Then, secondary air for combustion is supplied upward from below through the small holes 142 into the gaps between the burners 2, 2 by the suction force of the exhaust fan.

[0018] An upright plate portion 143 is formed at the front of the bottom plate 14, rising upward at a position rearward of the gas manifold 3. The upright plate portion 143 has openings 144 facing the inlets 24a of each burner 2. Furthermore, a ventilation adjustment plate 4 is disposed in front of the upright plate portion 143, facing each opening 144 and having openings 41 through which fuel gas and primary air pass. An upper plate portion 145 is formed at the upper end of the upright plate portion 143, bending forward to reach the lower end of the front side plate 11 of the combustion housing 1, and a second upright plate portion 146 is formed, rising upward from the front end of the upper plate portion 145 along the inner surface of the front side plate 11. Referring to FIG. 7, a plurality of positioning claws 147 are bent at the upper end of the second upright plate portion 146, and are inserted from the front into the upper portions of the gaps between the burners 2, 2.

[0019] An electrode part 5 having an ignition electrode 51 for igniting the burner 2, a ground electrode 52 facing the ignition electrode 51, and a flame rod 53 for detecting the flame of the burner 2 is attached to the front side plate 11 of the combustion housing 1.

[0020] Incidentally, when combustion starts, it is necessary to transfer the fire from the burner 2 facing the ignition electrode 51 and the ground electrode 52 to the other burner 2. Therefore, a fire transfer plate that prevents the secondary air from rising is provided in the gap between each burner 2, 2, located near the upper end of the front-to-rear portion that coincides with one of the front and rear ends of the flame port formation area of ​​each burner 2. This makes it difficult for secondary air to flow directly above the fire transfer plate, so that when the fire transfers, part of the air-fuel mixture ejected from the flame port 23 of one adjacent burner 2 and part of the air-fuel mixture ejected from the flame port 23 of the other burner 2 through the gap remain directly above the fire transfer plate, facilitating the transfer of the fire from one burner 2 to the other burner 2.

[0021] Here, if the front-to-rear portions of the gaps between each burner 2, 2 where the fire transfer plates are placed are aligned for all fire transfer plates, the flames formed at either the front or rear end of the flame formation area of ​​all burners 2 (the end that coincides with the fire transfer plate) will seek secondary air and lean toward either the front or rear wall of the combustion housing 1, i.e., toward one of the front heat shield plates 111 or the rear heat shield plate 121, making it more likely that this heat shield plate will overheat.

[0022] Therefore, in this embodiment, a first fire-transfer plate 61 is disposed in the gap between the burners 2, 2, near the upper end of the front-rear direction portion that coincides with the rear end of the flame port formation region of the burner 2, and a second fire-transfer plate 62 is disposed in the gap between the burners 2, 2, near the upper end of the front-rear direction portion that coincides with the front end of the flame port formation region of the burner 2. The first fire-transfer plate 61 protrudes forward from the rear positioning claw portion 152, and the second fire-transfer plate 62 protrudes rearward from the front positioning claw portion 147. The side edges of the first and second fire-transfer plates 61, 62 are inserted into the grooves 27 formed in the side plates 22a of the burner cap 22 (see FIG. 4).

[0023] 7, the half portions 6a of the first and second fire-transfer plates 61, 62 near the tips are made slightly narrower so that the side edges do not fit into the grooves 27. The half portions 6a of the first and second fire-transfer plates 61, 62 near the tips are tilted downward. This allows secondary air to swirl and diffuse from the gaps between the burners 2, 2 adjacent to the tip edges of the fire-transfer plates 61, 62 into the space above the half portions 6a of the fire-transfer plates 61, 62 near the tips, and this secondary air contributes to the combustion of the air-fuel mixture ejected from the flame ports 23 in the burner hole formation areas that coincide with the half portions 6a of the first and second fire-transfer plates 61, 62 near the tips. Therefore, even if the input to the burner 2 is increased, the combustion state of the air-fuel mixture ejected from the flame ports 23 present in the part of the burner hole formation area that matches each of the fire-transfer plates 61, 62 does not deteriorate significantly, and an increase in the carbon monoxide concentration in the combustion gas can be suppressed. Furthermore, because secondary air does not rise directly from below into the space above the half 6a near the tip of each of the fire-transfer plates 61, 62, the air-fuel mixture tends to stagnate in this upper space as well, and this, combined with the fact that the air-fuel mixture ejected from the flame ports 23 present in the part of the burner hole formation area that matches the half of the fire-transfer plates near the base end of each of the fire-transfer plates 61, 62 is reliably retained in the space above the half of the fire-transfer plates near the base end of each of the fire-transfer plates 61, 62, ensures good fire-transfer performance.

[0024] Furthermore, as described above, if the first and second fire-transfer plates 61 and 62 are mixed as fire-transfer plates, the flames formed at either the front or rear end of the flame formation area of ​​all burners 2 will not lean toward either the front or rear wall surface of the combustion housing 1. Therefore, overheating of the front and rear wall surfaces of the combustion housing 1, i.e., the front and rear heat shield plates 111, 121, can be suppressed.

[0025] Furthermore, in this embodiment, one first flame-transfer plate 61 and one second flame-transfer plate 62 are alternately arranged within a predetermined range within the lateral direction of the combustion housing 1, excluding the vicinity of the burner 2 where the flame is detected by the flame rod 53. With this, within the predetermined range, secondary air is supplied from the inter-burner gap opposite the first flame-transfer plate 61 to the air-fuel mixture ejected from the rear end of the flame formation region of each burner 2, and secondary air is supplied from the inter-burner gap opposite the second flame-transfer plate 62 to the air-fuel mixture ejected from the front end of the flame formation region of each burner 2, thereby suppressing the front-to-rear tilt of the flames formed at the front and rear ends of the burner hole formation region of each burner 2. Therefore, overheating of the front and rear heat shield plates 111, 121 of the combustion housing 1 can be effectively suppressed.

[0026] The flame transfer plate arranged in one lateral inter-burner gap of the burner 2 where the flame is detected by the flame rod 53 and the flame transfer plate arranged in the other lateral inter-burner gap are both first flame transfer plates 61, and no flame transfer plates are arranged on either side of the front end of the burner 2 facing the flame rod 53. This allows the air-fuel mixture to burn normally in the area facing the flame rod 53 without causing a shortage of secondary air, ensuring the reliability of flame detection.

[0027] Although the above describes an embodiment of the present invention with reference to the drawings, the present invention is not limited thereto. For example, in the above embodiment, secondary air is supplied upward from below into the gap between each burner 2, 2 by the suction force of an exhaust fan. However, an air supply chamber that supplies air from an air supply fan may be provided below the bottom plate 14 of the combustion chamber 1, so that secondary air is supplied downward, i.e., upward from the air supply chamber, into the gap between each burner 2, 2. It is also possible to alternately arrange multiple first and second fire-transfer plates 61 and 62, for example, two each. However, to prevent the flame formed at the front and rear ends of the burner hole formation area of ​​each burner 2 from tilting forward and backward, it is preferable to alternately arrange one first and one second fire-transfer plate 61 and one second fire-transfer plate 62, as in the above embodiment. Furthermore, in the above embodiment, the first and second fire-transfer plates 61, 62 are all the same length, but the lengths of these fire-transfer plates 61, 62 may be different. It is also possible for the burner 2 not to have the burner cap 22 . [Explanation of symbols]

[0028] 1...combustion box, 2...burner, 23...flame mouth, 61...first fire transfer plate, 62...second fire transfer plate.

Claims

1. A combustion device comprising a combustion housing, in which a plurality of burners elongated in the front-rear direction and having flame ports at the upper ends for ejecting an air-fuel mixture are arranged side by side with gaps in the lateral direction, and secondary air for combustion is supplied upward from below into the gaps between each burner, In the case where a flame-transfer plate is disposed in the gap between each burner near the upper end of the front-rear direction portion that coincides with one of the front and rear ends of the flame port forming area of ​​each burner, to prevent the secondary air from rising, A combustion device characterized in that, as a fire transfer plate, a first fire transfer plate in which one of the front and rear ends is a rear end and a second fire transfer plate in which one of the front and rear ends is a front end are mixed.

2. 2. The combustion device according to claim 1, wherein the first fire-transfer plates and the second fire-transfer plates are arranged alternately one by one within a predetermined lateral range within the combustion housing.

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