Combustion device

Abstract

The present application provides a kind of combustion device, with: multiple burners (2) in the lower part of combustion shell (1) and side by side arrangement, manifold (3) is supplied with fuel gas to these burners (2), heat exchanger (4) is heated using the combustion gas from burner (2), and for attracting the fan of combustion gas after passing through heat exchanger (4);Manifold (3) is composed of manifold body (3a) and cover (3b), wherein, on manifold body, multiple towards the flow inlet (22) of mixed pipe portion (21) of each burner 2 Nozzle (31) is projected and arranged, distribution chamber (32) of fuel gas is divided between cover and manifold body (3a), so that the cost reduction of manifold can be realized.Manifold body (3a) is formed by the stamping processing of sheet material, the projection height of nozzle (31) is set to: the height that can be drawn into shape by 1 time stamping processing.

Description

Technical Field

[0001] The present invention relates to a combustion device comprising: a combustion housing, a plurality of burners arranged side by side in the lower part of the combustion housing, a manifold for supplying fuel gas to the plurality of burners, and a heat exchanger disposed in the upper part of the combustion housing and heated by combustion gas from the burners. Background Technology

[0002] Conventionally, in such combustion devices, an air intake chamber is typically located below the burner housing of the combustion casing, and a fan is connected to the air intake chamber. Air from the fan is supplied as combustion air to multiple burners via the air intake chamber (see, for example, Patent Document 1). Additionally, a primary air chamber, which communicates with the inlet of the mixing tube of each burner and extends upwards, is located at the front of the air intake chamber. Furthermore, a manifold is installed to seal the front surface of the primary air chamber.

[0003] In this combustion device, the manifold consists of a manifold body and a cover. The manifold body, corresponding to multiple burners, has multiple nozzles that spray fuel gas through inlets facing the mixing pipes of each burner. A fuel gas distribution chamber is defined between the cover and the manifold body. Since the manifold body functions as a cover sealing the front surface of the primary air chamber, its flatness must be ensured. Therefore, conventionally, the manifold body was made of die-cast material, and its flatness had to be ensured.

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-2594 Summary of the Invention

[0006] However, the combustion device is equipped with a fan for drawing in the combustion gases after passing through the heat exchanger, and the fan's suction force supplies combustion air to each burner. In such a combustion device with exhaust suction, it is not necessary to seal the front surface of the primary air chamber by the manifold body. Therefore, it is not necessary to ensure the flatness of the manifold body.

[0007] In view of the above-mentioned problems, the objective of the present invention is to provide a combustion device with an exhaust suction method that can reduce costs by not manufacturing the manifold body as a die-cast part.

[0008] To solve the above-mentioned problems, the combustion apparatus of the present invention comprises: a combustion shell, a plurality of burners arranged side by side in the lower part of the combustion shell, a manifold for supplying fuel gas to the burners, a heat exchanger disposed in the upper part of the combustion shell and heated by the combustion gas from the burners, and a fan for drawing the combustion gas after passing through the heat exchanger; combustion air is supplied to each burner by the suction force of the fan, the manifold is composed of a manifold body and a cover, wherein, on the manifold body, a plurality of nozzles are provided protruding corresponding to the plurality of burners, which spray fuel gas toward the inlet of the mixing tube of each burner, and a fuel gas distribution chamber is divided between the cover and the manifold body, characterized in that the manifold body is formed by stamping a sheet metal, and the protrusion height of each nozzle is set to a height that can be drawn into shape by one stamping process.

[0009] According to the present invention, the manifold body is formed by stamping sheet metal, thereby reducing costs compared to the conventional method of using a die-cast manifold body. Furthermore, in the present invention, the nozzle protrusion height is set to a height that can be drawn into shape in a single stamping operation, thereby reducing the number of stamping operations and minimizing costs.

[0010] Furthermore, when forming the manifold body using sheet metal stamping, it is difficult to ensure the flatness of the manifold body. However, since the present invention pertains to an exhaust suction combustion device, no adverse effects will occur even if the flatness of the manifold body cannot be ensured.

[0011] However, during the distribution of combustion devices, improper handling during transport can sometimes cause them to fall off. Even if the fall causes internal damage, the exposed parts may remain intact and undeformed, allowing the combustion device to continue to be used.

[0012] Here, the manifold typically has a fixed portion fixed to the combustion chamber and a fuel gas inlet located lower than the combustion chamber. If the combustion unit falls, the manifold will be subjected to a force (impact force) in the direction of the fixed portion and the inlet. Therefore, it is preferable to form a defect in the manifold that acts as a stress concentration point, where shear stress is concentrated due to the force applied to the manifold in the direction of the fixed portion and the inlet. Accordingly, if the combustion unit falls, the manifold is prone to deformation and breakage due to the defect. This prompts caution against continuing to use the combustion unit under such conditions.

[0013] Furthermore, preferably, the direction in which the multiple burners are arranged side by side is transverse, the fixing part is provided at at least on both transverse ends of the manifold, and the defect part is provided at a position closer to the transverse ends than the transverse center of the manifold. Accordingly, the downward force applied to the fixing part by the burner falling will easily cause stress concentration in the defect part, thereby increasing the reliability of the defect part in terms of deformation and breakage upon falling.

[0014] Furthermore, it is even more preferable that the fixing part is only provided at the ends of the two lateral sides of the manifold, and the inflow part is provided at the lateral center of the manifold. Accordingly, since the combustion device is more likely to cause stress concentration in the defective part when it falls, the reliability of the defective part in terms of deformation and fracture when it falls is further increased. Attached Figure Description

[0015] Figure 1 This is a perspective view of a combustion device according to an embodiment of the present invention.

[0016] Figure 2 It is along Figure 1 A sectional side view obtained by cutting along line II-II.

[0017] Figure 3 This is a perspective view of the combustion device manifold of the embodiment, viewed from a slightly downward angle, showing the manifold separated.

[0018] Figure 4 This is a perspective view of the manifold of the combustion device in the embodiment, viewed from a rear-facing angle.

[0019] Figure 5 This is a perspective view of the combustion device of the embodiment, viewed from the oblique front, showing the manifold body and the cover separated.

[0020] Figure 6 It is along Figure 4 Enlarged cross-sectional view of the nozzle section obtained by wire cutting VI-VI.

[0021] Explanation of symbols in attached drawings

[0022] 1…combustion shell; 2…burner; 21…mixing pipe section; 22…inlet; 3…manifold; 3a…manifold body; 3b…shroud; 31…nozzle; 32…distribution chamber; 33…inlet (flow section); 34…fixed section; 35…deficiency section; 4…heat exchanger; 7…fan. Detailed Implementation

[0023] Below, refer to Figure 1 , Figure 2The combustion apparatus according to an embodiment of the present invention includes: a combustion housing 1, a plurality of burners 2 arranged side by side in the lower part of the combustion housing 1, a manifold 3 for supplying fuel gas to the burners 2, and a heat exchanger 4 disposed in the upper part of the combustion housing 1 and heated by the combustion gas from the burners 2.

[0024] With the burners 2 arranged side-by-side in a transverse direction, each burner 2 is a flat burner with a flame nozzle at its upper end, and this flame nozzle is elongated in the horizontal direction orthogonal to the transverse direction, i.e., the front-to-back direction. A mixing tube section 21 is provided at the lower part of each burner 2. An inlet 22 that is open at the front end is provided at the front end of the mixing tube section 21. Furthermore, fuel gas ejected from each nozzle 31 (described from the rear of the manifold 3) flows into the inlet 22 of each burner 2, and primary air flows into the inlet 22, generating a mixture of fuel gas and primary air in the mixing tube section 21. This mixture is ejected from the flame nozzle of the burner 2 and combusted.

[0025] Reference Figure 3 A stepped portion 111 is formed at the front of the bottom plate 11 of the combustion casing 1, rising upwards. An opening 112 is provided at the opening of this stepped portion 111, facing the inlet 22 of the mixing tube 21 of each burner 2. In this embodiment, since six burners 2 are arranged side-by-side, six openings 112 are also arranged side-by-side in the transverse direction. Furthermore, a plurality of recesses 113 are formed on the bottom plate 11, sandwiching the lower edges of each burner 2 from both transverse sides and facing upwards. Additionally, an electrode device 5 is mounted on the front plate 12 of the combustion casing 1. This electrode device 5 has an ignition electrode 51 for igniting the burners 2 and a flame rod 52 for monitoring the flame of the burners 2.

[0026] The heat exchanger 4 is a finned tube heat exchanger and has multiple heat-absorbing fins 41 stacked in the transverse direction and multiple heat-absorbing tubes 42 penetrating these heat-absorbing fins 41. These heat-absorbing tubes 42 are connected in series by multiple U-shaped connecting pipes 43 on the upper outer surface of the combustion shell 1. Furthermore, a water supply pipe 44 is connected to the upstream heat-absorbing tube 42, and a hot water discharge pipe 45 is connected to the downstream heat-absorbing tube 42.

[0027] A fan 7 is connected to the upper end of the combustion chamber 1 via an exhaust shroud 6. A fan motor 71 is attached to the fan 7. Combustion gases after passing through the heat exchanger 4 are drawn in by the fan 7. The combustion gases drawn in by the fan 7 are discharged to the outside through an exhaust pipe (not shown) connected to the outlet 72 of the fan 7. Additionally, as... Figure 3As shown, a plurality of small holes 114 are formed on the bottom plate 11 of the combustion casing 1. Moreover, combustion air is supplied to each burner 2 by the suction force of the fan 7. That is, air drawn from the inlet 22 through each opening 112 is supplied to each burner 2 as primary air for combustion, and air drawn from the small holes 114 is supplied to each burner 2 as secondary air for combustion.

[0028] The lower front end of the side plates 13 on both sides of the combustion casing 1 is provided with a tongue portion 131 that protrudes further forward than the stepped portion 111 of the base plate 11. Furthermore, the manifold 3 is fixed to the tongue portion 131 by screws 34a at the fixing portions 34 provided at the ends on both sides of the combustion casing 1.

[0029] Reference Figures 4 to 6 The manifold 3 consists of a manifold body 3a and a cover 3b. The manifold body 3a has a plurality of nozzles 31 (six in this embodiment) that correspond to the plurality of burners 2 and spray fuel gas towards the inlet 22 of the mixing tube section 21 of each burner 2. A fuel gas distribution chamber 32 is divided between the cover 3b and the manifold body 3a. The cover 3b is welded to the manifold body 3a at its periphery. The manifold 3 also has a fuel gas inlet section 33 located below the combustion shell 1. The aforementioned fixing part 34 and the inlet 33 are provided in the manifold body 3a. Fuel gas flows into the inlet 33 via a valve unit 8 connected to the inlet 33. Furthermore, the fuel gas flowing in from the inlet 33 is distributed to each nozzle 31 via the distribution chamber 32 and sprayed from each nozzle 31 towards the inlet 22 of the mixing tube section 21 of each burner 2.

[0030] Here, as described in this embodiment, the exhaust suction combustion device includes a fan 7 for drawing combustion gases after passing through the heat exchanger 4. In this exhaust suction combustion device, it is not necessary to ensure the flatness of the manifold body 3a as described above. Therefore, in this embodiment, the manifold body 3a is formed by stamping a sheet metal such as stainless steel. Accordingly, compared to the conventional example where the manifold body 3a is a die-cast part, cost reduction can be achieved. Furthermore, in this embodiment, the cover 3b is formed by stamping a sheet metal thinner than the material of the manifold body 3a.

[0031] Furthermore, in this embodiment, the protrusion height H of the nozzle 31 (refer to...) Figure 6The height is set to be such that it can be drawn into shape in a single stamping process. For example, if the material of the manifold body 3a, i.e., the sheet metal, is a 1.2mm thick stainless steel sheet (SUS304), and the protrusion height H of the nozzle 31 is 4mm, then the nozzle 31 can be drawn into shape in a single stamping process. Moreover, by stamping the nozzle 31 in a single stamping process, the cost can be reduced as much as possible.

[0032] Here, as Figure 6 As shown, each nozzle 31 includes a cylindrical nozzle body 311 with an internal space 311a into which fuel gas flows from the distribution chamber 32, and an end wall portion 312 located on the side opposite to the fuel gas inflow side, i.e., the base end of the nozzle body 311. A nozzle hole 313 is formed in the end wall portion 312 for the fuel gas flowing into the internal space 311a of the nozzle body 311 to be ejected. When the protrusion height H of the nozzle 31 is set to a relatively small value that can be drawn in one stamping process, the flow of combustion gas in the internal space 311a of the nozzle body 311 is not sufficiently rectified, which can easily lead to unstable combustion performance or undesirable conditions such as buzzing sounds. Therefore, in this embodiment, a tapered portion 313a that gradually expands in diameter toward the internal space 311a of the nozzle body 311 is provided at the base of the nozzle hole 313 located on the side of the internal space 311a of the nozzle body 311. Accordingly, even if the flow of fuel gas is not fully rectified in the internal space 311a of the nozzle body 311, the flow of fuel gas is adjusted by the conical portion 313a of the nozzle orifice 313, thereby stabilizing combustion performance and suppressing the generation of buzzing noise.

[0033] However, during the distribution of combustion devices, improper handling during transport can sometimes cause them to fall off. Even if the fall causes internal damage, the exposed parts may remain intact and undeformed, allowing the combustion device to continue to be used.

[0034] Here, if the combustion device falls, the manifold 3 will be subjected to a force (impact force) in the direction of the fixing part 34 and the inlet 33. Therefore, in this embodiment, a defect 35 is formed in the manifold 3, which becomes a stress concentration point. That is, this stress concentration point causes shear stress to concentrate when the manifold 3 is subjected to a force in the direction of the fixing part 34 and the inlet 33. Accordingly, if the combustion device falls, the manifold 3 is prone to deformation and breakage due to the defect 35. Therefore, it is advisable to avoid continuing to use the combustion device under such circumstances.

[0035] Furthermore, preferably, when the fixing part 34 is provided at least on both lateral ends of the manifold 3, the defect part 35 is provided at a position closer to the lateral ends than the lateral center of the manifold 3. Accordingly, the downward force applied to the fixing part 34 due to the combustion device falling will easily cause stress concentration in the defect part 35, thereby increasing the reliability of the defect part 35 in terms of deformation and breakage upon falling. In particular, in this embodiment, the fixing part 34 is only provided at the lateral ends of the manifold body 3a, and the inflow part 33 is provided at the lateral center of the manifold body 3a. Moreover, a pair of defect parts 35 are formed at a position closer to the lateral ends than the lateral center of the manifold body 3a. Accordingly, since the combustion device is more likely to cause stress concentration in the defect part 35 upon falling, the reliability of the defect part 35 in terms of deformation and breakage upon falling is further increased.

[0036] While embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited thereto. For example, in the above embodiments, although the fixing portion 34 provided in the manifold body 3a extends laterally outward from the cover 3b, fixing portions overlapping with the fixing portion 34 provided in the manifold body 3a may also be provided at the ends of both lateral sides of the cover 3b. In this case, it is sufficient to form a defect portion 35 near the ends of both lateral sides on both the manifold body 3a and the cover 3b.

Claims

1. A combustion apparatus comprising: a combustion housing; a plurality of burners arranged side-by-side in the lower part of the combustion housing; a manifold for supplying fuel gas to the burners; a heat exchanger disposed in the upper part of the combustion housing and heated by combustion gas from the burners; and a fan for drawing combustion gas after passing through the heat exchanger. Combustion air is supplied to each burner by the suction force of a fan. The manifold consists of a manifold body and a cover, wherein, On the manifold body, corresponding to multiple burners, there are multiple nozzles that spray fuel gas toward the inlet of the mixing tube of each burner, and a fuel gas distribution chamber is divided between the shroud and the manifold body. Its features are, The main body of the manifold is formed by stamping sheet metal. The protrusion height of each nozzle is set to the height that can be drawn into shape through a single stamping process. The manifold includes: a fixing part fixed to the combustion shell, and a fuel gas inlet located below the combustion shell. The manifold has a defect that becomes a stress concentration point. This stress concentration point is subjected to a force in the direction of the fixed part and the inflow part that is close to each other, causing shear stress concentration to occur.

2. The combustion device according to claim 1, characterized in that, With the side-by-side arrangement of the plurality of burners as the transverse direction, the fixing part is provided at the ends of at least the transverse sides of the manifold, and the defective part is provided at a position closer to the ends of the manifold than the transverse center.

3. The combustion device according to claim 2, characterized in that, The fixing part is only provided at the ends of the two sides of the manifold in the lateral direction, and the inflow part is provided at the center of the manifold in the lateral direction.

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