JP7514697B2 - Combustion equipment - Google Patents

Description

The present invention relates to a combustion device that includes a combustion chamber that contains multiple burners arranged horizontally inside the combustion chamber, and an air supply chamber below the combustion chamber that is separated from the combustion chamber by a partition plate, the front of the air supply chamber is closed off by a gas manifold that supplies fuel gas to the multiple burners, and air supplied from a fan to the air supply chamber is supplied from the front of the air supply chamber to each burner as primary air for combustion, and is also supplied to the combustion chamber through multiple distribution holes formed in the partition plate as secondary air for combustion.

Conventionally, in this type of combustion device, the air inlet that allows air from the fan to flow into the air supply chamber is generally provided on the bottom surface of the air supply chamber, but there are also known combustion devices in which the air inlet is provided on at least one of the rear wall surface and one lateral side wall surface of the air supply chamber (see, for example, Patent Document 1).

Here, in the latter conventional example, the fan can be placed at a position equal to or higher than the air supply chamber outside the combustion housing. Therefore, compared to the former conventional example, which requires the fan to be placed below the combustion housing, this has the advantage of being able to reduce the height dimension of the entire combustion device, including the fan.

However, in the latter conventional example, the air flows into the air supply chamber from the air inlet with almost no upward directional component, so the air does not flow easily through the distribution holes formed in the part of the partition plate close to the air inlet. As a result, there is a shortage of secondary air in the part of the combustion chamber close to the wall where the air inlet is located, which makes it easy for poor combustion to occur.

JP 2014-59114 A

In view of the above, the present invention aims to provide a combustion device in which an air inlet is provided in at least one of the rear wall surface and one of the lateral side wall surfaces of the air supply chamber, and in which air can easily flow through the distribution holes formed in the part of the partition plate close to the air inlet.

In order to solve the above problems, the present invention provides a combustion device comprising a combustion chamber which houses a plurality of burners lined up horizontally within the combustion chamber, and an air supply chamber below the combustion chamber which is separated from the combustion chamber by a partition plate, the front of the air supply chamber being closed by a gas manifold which supplies fuel gas to the plurality of burners, and air supplied from a fan to the air supply chamber is supplied from the front of the air supply chamber to each burner as primary air for combustion, and is also supplied to the combustion chamber through a number of distribution holes formed in the partition plate, and the air inlet for allowing air from the fan to flow into the air supply chamber is opened in at least one of the rear wall surface and one lateral side wall surface of the air supply chamber, and the present invention is based on the premise that a screen plate is provided in the air supply chamber facing the air inlet for bouncing a portion of the air flowing in from the air inlet towards the air inlet.

According to this premise , part of the air flowing in from the air inlet hits the partition plate and bounces back toward the air inlet, which makes it easier for air to flow through the distribution holes formed in the partition plate near the air inlet. This makes it possible to suppress a shortage of secondary air in the part of the combustion chamber near the wall where the air inlet is opened.

Here, the present invention is characterized in that , when the air inlet is provided in one of the rear wall surface of the air supply chamber and one of the lateral side walls, the partition plate is inclined from the longitudinal center toward each longitudinal end in a plan view so as to approach the wall surface of the air supply chamber in which the air inlet is provided . This makes it easier for air to flow from each end of the partition plate along the wall surface portion of the air supply chamber adjacent to the end of the air inlet, and also makes it easier for air to flow through the distribution holes formed in the part of the partition plate close to this wall surface portion, resulting in a more uniform distribution of secondary air in the combustion chamber.

In addition, when the air inlet is provided on both the rear wall surface and one of the lateral side walls of the air supply chamber, and the air from the fan flows from the air inlet into the air supply chamber with a directional component inclined in the other lateral direction toward the front, the air is difficult to flow near the wall surface adjacent to the front of the front end of the air inlet on one of the lateral side walls of the air supply chamber. Therefore, the present invention is characterized in that in this case, the partition plate has a first plate portion facing the part of the air inlet provided on the rear wall surface of the air supply chamber, and a second plate portion facing the part of the air inlet provided on one of the lateral side walls of the air supply chamber and inclined in one lateral direction toward the front in a plan view . This makes it easier for air to flow from the front end of the second plate portion along the wall surface adjacent to the front of the front end of the air inlet on one of the lateral side walls of the air supply chamber, thereby eliminating the above-mentioned problem.

In addition, when the fan is installed outside the combustion chamber at a position higher than the air supply chamber and air is supplied to the air inlet through a duct located below the fan, the air bounces upward at the underside of the duct near the air inlet and collides with air that has bounced off the screen plate below the part of the partition plate close to the air inlet, creating a vortex. When a vortex is created, the flow of air into the distribution holes formed in the part of the partition plate close to the air inlet is obstructed.

Therefore, the present invention is characterized in that, when the fan is provided outside the combustion housing at a position higher than the air supply chamber and air is supplied to the air inlet through a duct arranged below the fan, a eaves portion is provided that protrudes inward from at least a part of the upper edge of the air inlet into the air supply chamber. With this, air that bounces upward at the lower surface of the duct near the air inlet hits the eaves portion and does not collide with air that bounces off the screen plate and heads upward from the eaves portion. As a result, the generation of vortexes below the part of the partition plate near the air inlet is suppressed, and air flows smoothly into the distribution holes formed in the part of the partition plate near the air inlet.

In addition, when the air inlet is opened on both the rear wall surface and one of the side walls in the lateral direction of the air supply chamber, and air from the fan flows from the air inlet into the air supply chamber forward with a directional component inclined in the other lateral direction, and the fan is installed outside the combustion chamber at a position higher than the air supply chamber, and air is supplied to the air inlet through a duct installed below the fan, the air will bounce upwards significantly at the bottom of the duct in the other lateral half of the air inlet opened on the rear wall surface of the air supply chamber. Therefore, in this case, it is sufficient to provide a visor that protrudes inward into the air supply chamber from the upper edge of at least the other lateral half of the air inlet opened on the rear wall surface of the air supply chamber.

The length of the eaves portion that extends inward from the air supply chamber is preferably set so that at least the distribution hole closest to the upper edge of the air inlet where the eaves portion is provided overlaps with the eaves portion when viewed from below. This can reliably prevent the occurrence of vortexes below the distribution hole closest to the upper edge of the air inlet from impeding the flow of air into that distribution hole.

1 is a perspective view of a combustion device according to a first embodiment of the present invention, as viewed obliquely from above and in the front; 1 is a perspective view of a combustion device according to a first embodiment of the present invention, as viewed obliquely from above and behind; 1 is a plan view of a combustion apparatus according to a first embodiment of the present invention; FIG. 4 is a cross-sectional side view taken along line IV-IV in FIG. 3 . 5 is a cross-sectional bottom view taken along line VV in FIG. 4 . FIG. 6 is a cross-sectional front view taken along line VI-VI in FIG. 4 . FIG. 6 is a cutaway bottom view corresponding to FIG. 5 of a second embodiment of the present invention;

Referring to Figures 1 to 4, the combustion device according to the embodiment of the present invention includes a combustion housing 1. The top of the combustion housing 1 is open, and a hot water heat exchanger (not shown) is installed on top of the combustion housing 1 as an object to be heated. Inside the combustion housing 1, there is a combustion chamber 2 and an air supply chamber 3 below the combustion chamber 2. The air supply chamber 3 is separated from the combustion chamber 2 by a partition plate 4.

The combustion chamber 2 contains multiple burners 5, each long in the front-to-rear direction, arranged side by side. Each burner 5 has multiple slit-shaped flame holes 51 at the top end spaced apart in the front-to-rear direction, and a mixing tube section 53 at the bottom extending rearward from an inlet 52 at the front end. The mixture (a mixture of fuel gas and primary air for combustion) generated in the mixing tube section 53 is ejected from the flame holes 51 and combusted. A flame rod 13 and an ignition electrode 14 are respectively arranged on the front plate section 11 and one side plate section 12 in the lateral direction of the combustion box 1.

Air is supplied to the air supply chamber 3 from the fan 6. The fan 6 is composed of a sirocco fan having an impeller driven by a motor 62 inside a fan casing 61. A part of the air supplied to the air supply chamber 3 is supplied to the combustion chamber 2 as secondary air for combustion through a number of distribution holes 41 formed in the partition plate 4. In addition, at the front end of the partition plate 4, an upwardly bending upright plate portion 42 and an upper plate portion 43 that bends forward from the upper end of the upright plate portion 42 and reaches the front plate portion 11 of the combustion box 1 are provided, and the front portion 31 of the air supply chamber 3 rises upward in front of the upright plate portion 42. The front surface of the air supply chamber 3 is closed by a gas manifold 7. In addition, the upright plate portion 42 has each opening 44 facing the inlet 52 of each burner 5, and the gas manifold 7 has each nozzle 71 facing each opening 44. Fuel gas is supplied from each nozzle 71 to the inlet 52 of each burner 5, and a portion of the air supplied to the air supply chamber 3 is supplied from the front part 31 of the air supply chamber 3 to the inlet 52 of each burner 5 as primary air for combustion.

In addition, an air inlet 34 for allowing air from the fan 6 to flow into the air supply chamber 3 is provided on at least one of the rear wall surface 32 and the side wall surface 33 on one side of the horizontal direction (left side in FIG. 5) of the air supply chamber 3. In this embodiment, the air inlet 34 is provided on both the rear wall surface 32 and the side wall surface 33 on one side of the horizontal direction of the air supply chamber 3. The fan 6 is provided on the outside of the combustion case 1 on one side of the horizontal direction and at a position higher than the air supply chamber 3. A duct 8 is provided below the fan 6, extending from the outside of the side wall surface 33 on one side of the horizontal direction of the air supply chamber 3 to the outside of the rear wall surface 32 of the air supply chamber 3. Referring to FIG. 5, a connection port 81 for the fan 6 is provided on the upper surface of the duct 8, positioned on the rear side on one side of the horizontal direction. As shown by arrow a in Figure 5, the air from the fan 6 flows into the air supply chamber 3 toward the front (upward in Figure 5) with a directional component that is inclined to the other side (to the right in Figure 5).

In the air supply chamber 3, a partition plate 35 is provided facing the air inlet 34, which bounces a portion of the air flowing in from the air inlet 34 toward the air inlet 34, as shown by the arrow b in FIG. 4. This makes it easier for air to flow through the distribution holes 41 formed in the part of the partition plate 4 close to the air inlet 34 due to the influence of the air bouncing off the partition plate 35 toward the air inlet 34. Therefore, it is possible to suppress a shortage of secondary air in the part of the combustion chamber 2 close to the wall surface where the air inlet 34 is opened, that is, the part close to the rear wall surface and one side wall surface in the lateral direction of the combustion chamber 2. The upper edge of the partition plate 35 is located at a height equal to or higher than the height of the vertical center of the air inlet 34 so that the air flowing in from the air inlet 34 can be effectively bounced back toward the air inlet 34.

The partition plate 35 has a first plate portion 351 facing the portion of the air inlet 34 opened on the rear wall surface 32 of the air supply chamber 3, and a second plate portion 352 facing the portion of the air inlet 34 opened on one lateral side wall surface 33 of the air supply chamber 3. The other lateral end (right side in FIG. 5) of the first plate portion 351 is located on the other lateral side of the other lateral end of the portion of the air inlet 34 opened on the rear wall surface 32 of the air supply chamber 3, and the front end of the second plate portion 352 is located forward of the front end of the portion of the air inlet 34 opened on one lateral side wall surface 33 of the air supply chamber 3.

However, air has a very hard time flowing near the wall surface adjacent to the front end of the air inlet 34 on one lateral side wall surface 33 of the air supply chamber 3. Therefore, the second plate portion 352 is inclined in one lateral direction (leftward in FIG. 5) toward the front (upward in FIG. 5) in a plan view. This makes it easier for air to flow from the front end of the second plate portion 352 along the wall surface adjacent to the front end of the air inlet 34 on one lateral side wall surface 33 of the air supply chamber 3, as shown by arrow c in FIG. 5. Therefore, air also easily flows into the distribution holes 41 formed in the part of the partition plate 4 close to this wall surface, making the distribution of secondary air in the combustion chamber 2 more uniform.

The front end of the second plate portion 352 is located forward of the front end of the air inlet 34 on one lateral side wall surface 33 of the air supply chamber 3, so that air flows more easily along the wall surface portion adjacent to the front of the front end of the air inlet 34. In addition, the first plate portion 351 of the partition plate 35 has a portion 351a that extends from the rear end of the second plate portion 352 toward the other lateral direction (to the right in FIG. 5) at an incline forward, and a portion 351b that extends from the other lateral end of the portion 351a in the other lateral direction. However, it is also possible to omit the portion 351a and form the first plate portion 351 so that it extends from the front end of the second plate portion 352 of the partition plate 35 in the other lateral direction as shown by the imaginary line in FIG. 5.

In addition, when the fan 6 is installed outside the combustion chamber 1 at a position higher than the air supply chamber 3 and air is supplied to the air inlet 34 through the duct 8 arranged below the fan 6, the air bounces upward at the underside of the duct 8 near the air inlet 34 and collides with air that has bounced back from the screen 35 below the part of the partition plate 4 close to the air inlet 34, creating a vortex. When a vortex is created, the flow of air into the distribution holes 41 formed in the part of the partition plate 4 close to the air inlet 34 is obstructed. In particular, as in this embodiment, when the air inlet 34 is opened across both the rear wall surface 32 and one lateral side wall surface 33 of the air supply chamber 3, and the air from the fan 6 flows forward from the air inlet 34 into the air supply chamber 3 with a directional component inclined in the other lateral direction, the air tends to bounce upward as shown by arrow d in Figure 4 on the underside of the duct 8 near the air inlet 34 in the half of the air inlet 34 opened on the rear wall surface 32 of the air supply chamber 3 that is closer to the other lateral direction.

Therefore, in this embodiment, a eaves portion 36 is provided that protrudes inwardly into the air supply chamber 3 from the upper edge of the other lateral half of the air inlet 34 portion opened in the rear wall surface 32 of the air supply chamber 34. The portion of the upper edge of the air inlet 34 where the eaves portion 36 is provided is located lower than the other portion. Also, referring to FIG. 5, the length of the eaves portion 36 protruding inwardly into the air supply chamber 3 is set so that, among the distribution holes 41 formed in the partition plate 4, at least the distribution hole #1 41 closest to the upper edge portion of the air inlet 34 where the eaves portion 36 is provided overlaps with the eaves portion 36 when viewed from below. In this embodiment, in addition to the distribution hole #1 41, the distribution hole #2 41 second closest to the upper edge portion is also made to overlap with the eaves portion 36 when viewed from below.

As a result, as shown in FIG. 4, the air that bounces upward as indicated by arrow d at the underside of the duct 8 near the air inlet 34 hits the eaves 36 and does not collide with the air that bounces off the screen 35 as indicated by arrow b and heads upward toward the eaves 36. As a result, the generation of vortexes at the lower position of the part of the partition plate 4 close to the air inlet 34 is suppressed, and air flows smoothly into the distribution holes 41 of #1 and #2 formed in the part of the partition plate 4 close to the air inlet 34, making the distribution of secondary air in the combustion chamber 3 even more uniform.

It is also possible to form the eaves 36 on a portion of the air inlet 34 opened on the rear wall surface 32 of the air supply chamber 34 that is located to one side in the lateral direction rather than the other half of the portion on the other side in the lateral direction. However, this would cause the eaves 36 to be too close to the rear end of the second plate portion 352 of the partition plate 35, increasing the air flow resistance. Therefore, in this embodiment, the eaves 36 is formed only on the other half of the air inlet 34 opened on the rear wall surface 32 of the air supply chamber 34 that is located to the other side in the lateral direction.

Next, the second embodiment shown in FIG. 7 will be described. The basic structure of the second embodiment is not particularly different from that of the first embodiment, and the same members and parts as those of the first embodiment are given the same reference numerals as those of the first embodiment. The main difference between the second embodiment and the first embodiment is that the air inlet 34 is opened only on the rear wall surface 32 of the air supply chamber 3. In addition, the air supply chamber 3 is provided with a horizontally long partition plate 35 facing the air inlet 34, which bounces back a part of the air flowing in from the air inlet 34 toward the air inlet 34. Although not shown, the upper edge of this partition plate 35 is located at a height equal to or higher than the height of the vertical center of the air inlet 34, as in the first embodiment. In addition, the partition plate 35 is inclined from the longitudinal center toward each longitudinal end in a plan view so as to approach the rear wall surface 32, which is the wall surface of the air supply chamber 3 where the air inlet 34 is opened, that is, inclined backward. This allows air to flow easily along the rear wall surface 32 of the air supply chamber 3 adjacent to each lateral end of the air inlet 34, and also allows air to flow easily through the distribution holes 41 formed in the partition plate 4 close to the rear wall surface 32. In the second embodiment, the rearward inclination angle of the partition plate 35 from the longitudinal center to the longitudinal end is constant, but the partition plate 35 may be curved so that the rearward inclination angle gradually increases as it approaches the longitudinal end.

In addition, a eaves portion 36 is provided that extends inward from the upper edge of a predetermined range including the center of the air inlet 34. The length of extension of the eaves portion 36 inward from the air supply chamber 3 is set, as in the first embodiment, so that at least the #1 distribution hole 41 closest to the upper edge of the air inlet 34 where the eaves portion 36 is provided and the #2 distribution hole 41 that is the second closest among the distribution holes 41 formed in the partition plate 4 overlap with the eaves portion 36 when viewed from below. Therefore, as in the first embodiment, air that bounces upward at the lower surface portion of the duct 8 near the air inlet 34 hits the eaves portion 36 and does not hit the air that bounces off the screen plate 35 and heads upward from the eaves portion 36. As a result, the generation of vortexes at the lower position of the part of the partition plate 4 close to the air inlet 34 is suppressed, and air flows smoothly into the #1 and #2 distribution holes 41 formed in the part of the partition plate 4 close to the air inlet 34.

Although an embodiment of the present invention has been described above with reference to the drawings, the present invention is not limited to this. For example, it is possible to form a recess or an opening in part of the partition plate 35 so that sufficient air can flow in front of the partition plate 35. The present invention can also be applied in the same way when the air inlet 34 is opened only on one lateral side wall surface 33 of the air supply chamber 3.

1...combustion box, 2...combustion chamber, 3...air supply chamber, 31...front part of air supply chamber, 32...rear wall surface of air supply chamber, 33...one lateral side wall surface of air supply chamber, 34...air inlet, 35...screen plate, 351...first plate portion, 352...second plate portion, 36...eaves portion, 4...partition plate, 41...distribution plate, 5...burner, 6...fan, 7...gas manifold, 8...duct.

Claims (5)

A combustion device comprising: a combustion chamber housing in which a plurality of burners are arranged horizontally; and an air supply chamber below the combustion chamber, separated from the combustion chamber by a partition plate; the front of the air supply chamber is closed by a gas manifold which supplies fuel gas to the plurality of burners; and air supplied from a fan to the air supply chamber is supplied from the front of the air supply chamber to each burner as primary air for combustion, and is also supplied to the combustion chamber through a number of distribution holes formed in the partition plate,
In the case where an air inlet for introducing air from a fan into an air supply chamber is provided in one of the rear wall surface and one of the lateral side wall surfaces of the air supply chamber,
A combustion device characterized in that a partition plate is provided in the air supply chamber facing the air inlet, which bounces a portion of the air flowing in from the air inlet back toward the air inlet , and the partition plate is inclined, when viewed in a plane, from the longitudinal center toward each longitudinal end so as to approach the wall surface of the air supply chamber in which the air inlet is opened . A combustion device comprising: a combustion chamber housing in which a plurality of burners are arranged horizontally; and an air supply chamber below the combustion chamber, separated from the combustion chamber by a partition plate; the front of the air supply chamber is closed by a gas manifold which supplies fuel gas to the plurality of burners; and air supplied from a fan to the air supply chamber is supplied from the front of the air supply chamber to each burner as primary air for combustion, and is also supplied to the combustion chamber through a number of distribution holes formed in the partition plate ,
An air inlet for introducing air from a fan into an air supply chamber is provided across both a rear wall surface and one lateral side wall surface of the air supply chamber , and the air from the fan flows forward from the air inlet into the air supply chamber with a directional component inclined in the other lateral direction,
A combustion device characterized in that a partition plate is provided in the air supply chamber facing the air inlet, which bounces back a portion of the air flowing in from the air inlet toward the air inlet, and the partition plate has a first plate portion facing the air inlet portion opened in the rear wall surface of the air supply chamber, and a second plate portion facing the air inlet portion opened in one lateral side wall surface of the air supply chamber and inclined in one lateral direction toward the front in a plan view. A combustion device comprising: a combustion chamber housing in which a plurality of burners are arranged horizontally; and an air supply chamber below the combustion chamber, separated from the combustion chamber by a partition plate; the front of the air supply chamber is closed by a gas manifold which supplies fuel gas to the plurality of burners; and air supplied from a fan to the air supply chamber is supplied from the front of the air supply chamber to each burner as primary air for combustion, and is also supplied to the combustion chamber through a number of distribution holes formed in the partition plate ,
An air inlet for introducing air from a fan into the air supply chamber is provided in at least one of a rear wall surface and one lateral side wall surface of the air supply chamber, the fan is provided outside the combustion case at a position higher than the air supply chamber , and air is supplied to the air inlet through a duct provided below the fan,
This combustion device is characterized in that a partition plate is provided in the air supply chamber opposite the air inlet for bouncing a portion of the air flowing in from the air inlet toward the air inlet, and a eaves portion is provided extending inward from the upper edge of at least a portion of the air inlet into the air supply chamber. 3. The combustion apparatus according to claim 2 , wherein the fan is provided outside the combustion housing at a position higher than the air supply chamber, and air is supplied to the air inlet through a duct provided below the fan;
A combustion apparatus characterized in that a visor portion is provided extending inwardly from an upper edge of at least the other lateral half of the air inlet portion opened in the rear wall surface of the air supply chamber. 5. A combustion apparatus according to claim 3, wherein the length by which the eaves portion extends inwardly into the air supply chamber is set so that at least one of the distribution holes closest to an upper edge portion of the air inlet where the eaves portion is provided overlaps with the eaves portion when viewed from below.

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