Combustion equipment

Abstract

To provide a combustor in which a plurality of longitudinal burners 2 having flame holes 23 for jetting air-fuel mixture to an upper end is provided side by side in a front-rear direction in a combustion housing, where in gaps between the respective burners, a fire spreading plate 19 is arranged in the vicinity of an upper end of a front-rear direction portion matching one end part in a front-rear direction of a flame port formation region of each burner 2 to obstruct rise of secondary air, which can surely prevent deterioration of a fire spreading performance even when a clearance between a side surface of a groove part 27 and a side edge of the fire spreading plate 19 becomes wider due to an error in a breadth of the burner 2 or the fire spreading plate 19.SOLUTION: At a position in a front-rear direction of an outer surface of a burner 2 that matches a fire spread plate 19, at a portion located above the fire spread plate 19, a bulging part 29 is provided that bulges outward in a lateral direction with respect to a portion of a burner outside surface adjacent to the portion in the front-rear direction.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

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

[0003] However, due to the width error of the burner and the flame transfer plate, outer surface If the clearance between the plate and the side edge of the plate becomes wide, secondary air will flow upward through the clearance and blow away the air-fuel mixture remaining directly above the plate, resulting in a deterioration in the plate's flame-transfer performance. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 5-280715 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 reliably prevent deterioration of flame-catching performance. [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 longitudinal in the front-to-rear direction and having a flame port at their upper end for ejecting an air-fuel mixture are arranged side by side with gaps in the horizontal direction in a combustion chamber, and secondary air is supplied into the gaps between each burner from below, and a fire-stop plate for preventing the secondary air from rising is disposed in the gaps between each burner, located near the upper end of a front-to-rear portion that coincides with one of the front and rear ends of the flame port forming area of ​​each burner, and is characterized in that a bulge portion is provided on the outer surface of the burner at a front-to-rear position that coincides with the fire-stop plate and in a portion located above the fire-stop plate, which bulges outward laterally more than the portion of the outer surface of the burner adjacent to the front-to-rear direction of that portion.

[0007] According to the present invention, even if the clearance between the outer surface of the burner and the side edge of the fire-transfer plate becomes somewhat wider due to an error in the width of the burner or the fire-transfer plate, the bulging portion imparts a large lateral component to the flow of secondary air that flows through the clearance toward the upper part of the fire-transfer plate, and the upward momentum of the secondary air is weakened. Therefore, the mixed gas that remains directly above the fire-transfer plate can be effectively prevented from being blown away by the secondary air. Furthermore, in the part that matches the fire-transfer plate, the bulging portion narrows the gap between the flame port of one burner and the flame port of the other burner that are adjacent in the lateral direction, making it easier for the fire to transfer between these flame ports, and this, combined with the fact that the blowing away of the mixed gas that remains directly above the fire-transfer plate by the secondary air can be effectively prevented, ensures that the fire-transfer performance is prevented from deteriorating. In addition, since the part of the outer surface of the burner adjacent to the bulging portion in the front-rear direction does not bulge outward in the lateral direction, sufficient secondary air is supplied to the mixed gas that ejects from the flame port, and the combustibility is not deteriorated. [Brief description of the drawings]

[0008] [Figure 1] 1 is a perspective view of a combustion device according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a cross-sectional side view taken along line II-II in FIG. [Diagram 3]FIG. 3 is a cross-sectional plan view taken along line III-III in FIG. 2. [Figure 4] FIG. 4 is an enlarged cross-sectional view of a main part taken along line IV-IV in FIG. [Diagram 5] FIG. 2 is a perspective view of a burner provided in the combustion device according to the embodiment. [Figure 6] FIG. 6 is a cross-sectional view of the burner taken along line VI-VI in FIG. 5. [Figure 7] FIG. 4 is a perspective view of a burner retainer plate provided in a combustion housing of the combustion device according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] 1 to 3, a combustion device according to an embodiment of the present invention includes a combustion housing 1, a plurality of burners 2 (six in this embodiment) long in the front-rear direction and arranged side by side with horizontal gaps in the lower part of the combustion housing 1, a gas manifold 3 for supplying fuel gas to the burners 2, and a heat exchanger 4 arranged in the upper part of the combustion housing 1 and heated by the combustion gas from the burners 2. An upstream water supply pipe 41 and a downstream hot water outlet pipe 42 are connected to the heat exchanger 4. A valve unit 5 for controlling the supply of fuel gas is connected to the gas manifold 3.

[0010] 5 and 6, the burner 2 includes 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 burner body 21 from both lateral sides. At the upper end of the burner 2, a main flame port 23a located between the upper ends of the both side plates 21a, 21a of the burner body 21 and a sleeve flame port 23b defined between the upper ends of each side plate 21a of the burner body 21 and the upper ends of each side plate 22a of the burner cap 22 are provided as a flame port 23 for ejecting the mixture. The main flame port 23a is formed in a plurality of positions at intervals in the front-rear direction on the upper plate portion 21b connecting the upper ends of the both side plates 21a, 21a of the burner body 21.

[0011] The burner body 21 is 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-rear direction from the rear end of the mixing tube section 24. A mixture of fuel gas and primary air flowing in from the inlet 24a is guided to the main flame port 23a via the mixing tube section 24 and the main mixture passage 25.

[0012] Between each side plate 21a of the burner body 21 and each side plate 22a of the burner cap 22, a sleeve fire mixture passage 26 connected to the sleeve fire port 23b is provided. In addition, each side plate 21a of the burner body 21 is located above the overlapping portion of the lower parts of the side plates 22a of the burner cap 22, and a plurality of vent holes 26a communicating the main mixture passage 25 and the sleeve fire mixture passage 26 are formed at intervals in the front-rear direction. Then, the mixture diverted from the main mixture passage 25 through these vent holes 26a is supplied to the sleeve fire port 23b through the sleeve fire mixture passage 26, and the main flame formed on the main flame port 23a is maintained by the sleeve fire formed on the sleeve fire port 23b.

[0013] In addition, grooves 27 recessed laterally inward are formed in each side plate 22a of the burner cap 22, positioned above the vent hole 26a. This allows the mixture flowing from the vent hole 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 port 23b. The burner cap 22 has bridges 22b connecting the upper ends of both side plates 22a, 22a at multiple points in the front-rear direction.

[0014] 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, side plates 12, 12 on both lateral sides, a rear side plate 13, and a bottom plate 14. Heat shield plates 15, 16, 17 are provided so as to face the inner surfaces of the front, lateral, and rear side plates 11, 12, 13. Furthermore, an electrode part 7 having an ignition electrode 71 for igniting the burner 2 and a flame rod 72 for detecting the flame of the burner 2 is attached to the front side plate 11.

[0015] 7 is disposed on the inside of the rear side plate 13. The burner pressing plate 18 has a pressing piece 181 at the lower end that engages with a recess 28 formed in the lower rear edge of the burner body 21. In order to position each burner 2, the pressing piece 181 has a number of slit-like notches 182 formed corresponding to the number of burners 2 into which the rear edge portion of the burner body 21 recessed forward by the recess 28 is inserted.

[0016] The front part of the bottom plate 14 is formed with an upright plate part 141 rising upward at a rear position of the gas manifold 3, and an upper plate part 142 bending forward from the upper end of the upright plate part 141 to reach the front side plate 11. The upright plate part 141 is provided with an opening part 143 facing the inlet 24a of each burner 2. In addition, a ventilation adjustment plate 6 is arranged in front of the upright plate part 141. The ventilation adjustment plate 6 has a plurality of opening parts 61 facing the inlet 24a of each burner 2, through which the fuel gas and primary air pass, corresponding to the plurality of burners 2. The ventilation adjustment plate 6 is fixed to the upright plate part 141 with a screw 62 at the upper end part of its lateral center part.

[0017] The bottom plate 14 has a plurality of upward recesses 144 that sandwich the lower edge of each burner 2 from both sides in the lateral direction, and also has a number of small holes 145. A second upright plate portion 146 that rises along the inner surface of the front side plate 11 is formed at the front end of the upper plate portion 142. A plurality of claw portions 147 are bent at the upper end of the second upright plate portion 146 and are inserted into the gap between the front ends of adjacent burners 2, 2 to position the front ends of the burners 2 in the lateral direction.

[0018] An exhaust fan 8 is connected to the upper end of the combustion box 1 via an exhaust hood 81. A fan motor 82 is attached to the exhaust fan 8. The combustion gas that has passed through the heat exchanger 4 is sucked into the exhaust fan 8, and the combustion gas is discharged to the outside through an exhaust pipe (not shown) connected to an outlet 83 of the exhaust fan 8. In addition, combustion air is supplied to each burner 2 by the suction force of the exhaust fan 8. That is, air sucked from the inlet 24a through each opening 61 of the ventilation adjustment plate 6 and each opening 143 of the standing plate portion 141 is supplied to each burner 2 as primary air for combustion, and air sucked from the small hole 145 is supplied to the gap between each burner 2, 2 from below as secondary air for combustion.

[0019] Incidentally, when combustion starts, it is necessary to transfer the flame from the burner 2 facing the ignition electrode 71 to the other burner 2. Therefore, a flame transfer plate 19 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-rear direction part that coincides with the rear end of the flame port forming area of ​​each burner 2. With this, since it becomes difficult for the secondary air to flow directly above the flame transfer plate 19, at the time of flame transfer, a part of the mixture gas ejected from the flame port 23 of one adjacent burner 2 and a part of the mixture gas ejected from the flame port 23 of the other burner 2 remain directly above the flame transfer plate 19, and the flame transfer from one burner 2 to the other burner 2 is promoted.

[0020] 4, the side edge of the fire-transfer plate 19 is inserted into the groove 27 formed in the vertical position that matches the fire-transfer plate 19 of each side plate 22a of the burner cap 22, which is the outer surface of the burner 2. With this, even if the clearance between the side of the groove 27 and the side edge of the fire-transfer plate 19 becomes somewhat wider due to an error in the width of the burner 2 or the fire-transfer plate 19, the flow path of the secondary air from below to above the fire-transfer plate 19 through the clearance is bent laterally in the groove 27, so that the air flow resistance increases and the flow rate of the secondary air flowing above the fire-transfer plate 19 does not increase significantly.

[0021] In addition, a tongue portion 19a extending diagonally forward and downward is provided at the front end of the flame-transfer plate 19. The reason for providing the tongue portion 19a is as follows. Near the front end of the flame-transfer plate 19, a vortex occurs in the flow of secondary air going upward. When this vortex reaches the upper end of the burner 2, the influence of the vortex adversely affects the combustibility of the burner 2. When the tongue portion 19a is provided, a vortex occurs near the front end of the tongue portion 19a in the flow of secondary air going upward. Therefore, the position where the vortex occurs is shifted downward, making it difficult for the vortex to reach the upper end of the burner 2, and it is possible to prevent the combustibility of the burner 2 from being deteriorated due to the influence of the vortex. In addition, in order to extend the tongue portion 19a below the groove portion 27, the width of the side edge portion of the flame-transfer plate 19 is narrower than the main body portion of the flame-transfer plate 19 inserted into the groove portion 27.

[0022] However, the recess depth of the groove 27 in the lateral direction cannot be made too deep in order to prevent the ventilation resistance of the secondary air-fuel mixture passage 26 from becoming excessively large. Therefore, it is difficult to sufficiently increase the ventilation resistance of the secondary air in the groove 27.

[0023] Therefore, in this embodiment, a bulging portion 29 is provided on each side plate 22a of the burner cap 22, which is the outer surface of the burner 2, at a front-rear position that matches the flame-transfer plate 19 and above the groove portion 27, i.e., at a portion located above the flame-transfer plate 19, which bulges outward in the lateral direction from the portion of the outer surface of the burner adjacent to the front-rear direction of the said portion. This provides a large lateral component to the flow of secondary air toward the upper side of the flame-transfer plate 19 by the bulging portion 29, thereby weakening the upward momentum of the secondary air. Therefore, even if the ventilation resistance of the secondary air in the groove portion 27 cannot be sufficiently increased, the mixed gas remaining directly above the flame-transfer plate 19 can be effectively prevented from being blown away by the secondary air. Furthermore, in the portion that meets the flame transfer plate 19, the gap between the sleeve flame nozzle 23b of one burner 2 and the sleeve flame nozzle 23b of the other burner 2 that are adjacent in the horizontal direction is narrowed by the bulge 29, making it easier for flame to transfer between these sleeve flame nozzles 23b, 23b. This, combined with the fact that the blowing away of the air-fuel mixture that remains directly above the flame transfer plate 19 by the secondary air can be effectively suppressed, reliably prevents deterioration of flame transfer performance.

[0024] In addition, since the part of the outer surface of the burner adjacent to the bulging part 29 in the front-rear direction does not bulge outward in the lateral direction, the secondary air is sufficiently supplied to the mixture gas ejected from the flame port 23, and the combustibility is not deteriorated. In addition, in this embodiment, as shown in FIG. 7, the flame transfer plate 19 is integrally formed at the upper end of the burner pressing plate 18. This allows the number of parts to be reduced, thereby reducing costs. Furthermore, in this embodiment, a pair of bulging parts 29 is formed symmetrically in the front-rear direction on each side plate 22a of the burner cap 22. As a result, even if the burner cap 22 is attached to the burner body 21 in the front-rear direction inverted, the bulging part 29 exists in the front-rear direction part that matches the flame transfer plate 19. Therefore, the burner cap 22 can be attached to the burner body 21 without worrying about the front-rear direction, and the assembling workability of the burner cap 22 is improved.

[0025] Although the embodiment of the present invention has been described above with reference to the drawings, the present invention is not limited thereto. For example, the above embodiment is an application of the present invention to a combustion device in which secondary air is supplied from below to the gaps between the burners 2, 2 by the suction force of the exhaust fan 8, but the present invention can also be applied to a combustion device in which an air supply chamber to which air is supplied from a fan is provided below the bottom plate 14 of the combustion housing 1, and secondary air is supplied from below to the gaps between the burners 2, 2 through the air supply chamber.

[0026] It is also possible for the burner 2 not to have the burner cap 22. In this case, a bulging portion that bulges outward in the lateral direction from the part of the burner outer surface adjacent to the part in the front-rear direction of the side plate 21a of the burner body 21, which is the outer surface of the burner 2, may be provided at a front-rear position that matches the fire-transfer plate 19 and is located above the fire-transfer plate 19. Furthermore, the fire-transfer plate 19 may be disposed in the gap between the burners 2, 2, in the vicinity of the upper end of the front-rear portion that matches the front end of the flame port formation region of each burner 2. [Explanation of symbols]

[0027] 1...combustion box, 19...fire transfer plate, 2...burner, 23...flame mouth, 29...bulge.

Claims

[Claim 1] A combustion device comprising a combustion housing, in which a plurality of burners each having a flame port at an upper end for ejecting an air-fuel mixture and elongated in the front-rear direction are arranged side by side with gaps in the lateral direction, and secondary air is supplied 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 region of each burner, and prevents the secondary air from rising, A combustion device characterized in that a bulging portion is provided on the outer surface of a burner at a front-to-rear position that coincides with a flame-transfer plate and is located above the flame-transfer plate, the bulging portion bulging outward laterally more than the portion of the outer surface of the burner adjacent to the front-to-rear position of the burner.

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