JP6773571B2 - Combustion device - Google Patents

Description

The present invention relates to a combustion device including a light and shade burner provided with a frame rod for stopping combustion when oxygen is deficient.

Conventionally, as this type of combustion device, a combustion casing is provided, and a partition plate for partitioning the space inside the combustion chamber into a combustion chamber and an air supply chamber below the combustion chamber is provided in the combustion chamber, and the combustion chamber is shaded. It is known that a plurality of burners are arranged side by side in the horizontal direction so that secondary air is supplied from the air supply chamber to the combustion chamber through a large number of distribution holes formed in the partition plate. The light and light burner is located at the upper end of the light flame port, which is long in the front-rear direction and ejects a light mixture whose fuel concentration is leaner than the stoichiometric air-fuel ratio, and on both outer sides of the light flame port in the lateral direction. It is a burner having a pair of concentrated flame ports that eject a concentrated air-fuel mixture having a higher fuel concentration than the above.

Further, in such a combustion device, a frame rod having a detection rod portion extending in the lateral direction at a position near the end of one of the front and rear ends of some of the specific light and shade burners among the plurality of light and shade burners is provided. It is also known that the combustion is stopped when the frame rod stops detecting the flame by the flame lift at the time of absence.

By the way, when oxygen is deficient, oxygen in the primary air is insufficient, and the combustion speed becomes lower than the ejection speed of the air-fuel mixture, causing a flame lift. In particular, in the light and shade burner, the light flame formed on the light flame mouth lifts before the deep flame formed on the dark flame mouth. In this case, if the frame rod does not lift up to the deep flame, the flame is detected and the combustion is not stopped. Here, when oxygen is deficient, the dense flame formed in the dense flame port spreads outward in search of secondary air. When the amount of secondary air supplied is large, the concentrated flame is turned up from the outside by the secondary air flowing upward along the burner side plate on the outside of the concentrated flame port, and further, the concentrated flame port is opened by the secondary air. As it is cooled and the combustion speed slows down, it becomes easier for the dense flame to lift.

Therefore, according to Patent Document 1, distribution holes are distributed per unit area of the partition plate in the portion of the partition plate through which the secondary air flowing to the portion facing the detection rod portion of the frame rod of the specific light and shade burner (frame rod installation portion) passes. It is known that the hole is formed so that the opening area is larger than that of other parts. In the case described in Patent Document 1, since the amount of secondary air supplied to the frame rod installation portion of the specific light and shade burner is larger than that of the other parts, not only the light flame but also the high flame is generated in the frame rod installation portion. It is said that the frame rod will not detect the flame because it will be lifted in the initial stage of oxygen deficiency.

However, in reality, it was found that the lift of the dense flame at the frame rod installation part does not occur unless the oxygen deficiency progresses to some extent. The reason is as follows. That is, in a combustion device, generally, one end of each light and shade burner and one front and rear end of a light and shade burner adjacent thereto are placed on a positioning frame arranged inside one of the front and rear plates of the combustion casing. A claw piece that is inserted in the upper part of the gap between the and is provided to position each light and shade burner in the lateral direction. Therefore, even if the amount of secondary air supplied to the frame rod installation portion of the specific light and shade burner is increased, the supply of secondary air to one of the front and rear ends of the specific light and shade burner is obstructed by the claw pieces, resulting in a high flame. At one end of the front and back of the mouth, it becomes difficult for the dense flame to lift. Then, the lift of the high flame at the frame rod installation portion is delayed due to the flame holding action by the high flame at one end of the front and rear ends of the high flame port.

Japanese Unexamined Patent Publication No. 2011-252671

In view of the above points, the present invention prevents the delay in lifting the dark flame at the frame rod installation portion by early lifting the dark flame at one end of the front and rear ends of the dark flame port of the specific light and shade burner when oxygen is deficient. The challenge is to provide a combustion device that enables it.

In order to solve the above problems, the present invention includes a combustion chamber, and a partition plate for partitioning the space inside the combustion chamber into a combustion chamber and an air supply chamber below the combustion chamber is provided in the combustion chamber, and the upper end thereof is provided. A light flame port that is long in the front-rear direction and a light flame port that is long in the front-rear direction that ejects a light air-fuel mixture whose fuel concentration is leaner than the theoretical air-combustion ratio, and a light flame port that is located on both lateral sides of the light flame port, and has a higher fuel concentration than the light mixture. A plurality of light and shade burners having a thick flame port for ejecting a rich air-fuel mixture are arranged side by side in the combustion chamber, and air is supplied from the air supply chamber to the combustion chamber through a large number of distribution holes formed in the partition plate. A frame rod having a detection rod portion that extends laterally at a position near the end of one of the front and rear ends of a part of the specific light and shade burners among the plurality of light and shade burners. It is provided with a positioning frame arranged inside one of the front and rear plate portions of the combustion chamber, and the positioning frame is provided between one front and rear end of each light and shade burner and one front and rear end of an adjacent light and shade burner. In the case where a claw piece that is inserted in the upper part of the gap and is provided to position each light and shade burner in the lateral direction, the specific claw piece that positions the specific light and shade burner is a burner located outside the dark flame port of the specific light and shade burner. A ventilation gap that is located at one end of the side plate portion that is in contact with the laterally curved corner radius portion and allows secondary air to flow from below to above along this corner radius portion. It is characterized in that a notch portion for securing the above is formed.

According to the present invention, secondary air flows from the lower side to the upper side along the corner radius portion of the burner side plate portion of the specific shading burner through the ventilation gap secured by the notch portion formed in the specific claw piece. Then, due to the influence of this secondary air, the concentrated flame is lifted at an early stage when oxygen is deficient at one end of the concentrated flame port of the specific density burner. Therefore, it is possible to prevent the lift of the high flame at the frame rod installation portion from being delayed due to the flame holding action by the high flame at one end of the front and rear ends of the high flame port. As a result, the frame rod does not detect the flame in the initial stage of oxygen deficiency, which is safe.

By the way, the frame rod has a longitudinal shaft portion in the front-rear direction that bends toward one of the front and rear plate portions of the combustion casing at a position above the gap between the specific shading burner and the non-specific shading burner adjacent thereto. are doing. Since this shaft portion is burned by both the high flame of the specific light and shade burner and the high flame of the non-specific light and shade burner, the temperature becomes considerably high. As a result, the shaft portion is oxidized at a high temperature to precipitate oxides, which makes it difficult for current to flow and may impair the function of the frame rod.

Therefore, the second specific claw piece located directly below the shaft portion of the frame rod has a corner radius portion at one end of the burner side plate portion of the specific shade burner and one front / rear portion of the burner side plate portion of the non-specific shade burner. It is desirable that the portion located between the end portion and the corner radius portion is excised over the entire width. According to this, the amount of secondary air flowing toward the shaft portion increases, and the shaft portion is cooled by the secondary air, so that the precipitation of oxides can be suppressed.

By the way, one of the front and rear sides is the front, and at the front end of the partition plate, an upright plate portion extending upward and an upper plate portion that bends forward from the upper end of the upright plate portion to reach the front plate portion of the combustion casing are provided. If a plurality of ventilation holes for flowing cooling air from the air supply chamber along the inner surface of the front plate portion are formed on the upper plate portion at lateral intervals, the following problems may occur. is there. That is, when oxygen is deficient, the concentrated flame at the front end of the concentrated flame port spreads forward in search of secondary air. Then, when the amount of air flowing upward from the ventilation holes is large, the concentrated flame approaches the front plate portion and causes overheating of the front plate portion. Therefore, in order to reduce the amount of air from the ventilation holes, it is desirable that the area of each ventilation hole is smaller than the area of the ventilation gap secured by the notch.

The perspective view of the combustion apparatus of embodiment of this invention. Top view of the combustion apparatus of the embodiment. The cut side view cut by the line III-III of FIG. The cut front view cut by the IV-IV line of FIG. Cross-sectional view of the flame opening part of the burner. FIG. 3 is an enlarged cut plan view of a main part cut along the VI-VI line of FIG.

With reference to FIGS. 1 to 4, the combustion apparatus according to the embodiment of the present invention includes a combustion casing 1. The combustion casing 1 has a front plate portion 11 on the upper front surface, side plate portions 12 and 12 on both sides in the lateral direction, a rear plate portion 13, and a bottom plate portion 14, and further, a heat exchanger for hot water supply or the like is provided at the upper end. It has a connection flange portion 15 for connecting (not shown). Further, the combustion chamber 1 is provided with a partition plate 2 that partitions the space inside the combustion chamber 1 into a combustion chamber 1a and an air supply chamber 1b below the combustion chamber 1a. A combustion fan (not shown) is connected to the bottom surface of the air supply chamber 1b, that is, the bottom plate portion 14. Then, the air supplied from the combustion fan to the air supply chamber 1b is supplied to the combustion chamber 1a as secondary air through a large number of distribution holes 21 formed in the partition plate 2.

In the combustion chamber 1a, a plurality of light and shade burners 3 that are long in the front-rear direction are arranged side by side in the horizontal direction. As shown in FIG. 5, each light and shade burner 3 has a light flame port 31 that is long in the front-rear direction and a light flame port 31 that is laterally long in the front-rear direction that ejects a light mixture having a fuel concentration leaner than the stoichiometric air-fuel ratio at the upper end portion. It is located on the outside and has a pair of dense flame ports 32 and 32 that eject a rich mixture having a higher fuel concentration than the light mixture. A plurality of straightening vanes 311 are mounted in the light flame port 31 at intervals in the lateral direction, and further, return regions 312 in which no air-fuel mixture is ejected are provided on both sides of the light flame port 31. ing. Further, at the lower front end of the burner 3, a first inflow port 33 connected to the light flame port 31 and a second inflow port 34 connected to the deep flame port 32 located above the first inflow port 33 are provided. There is. Further, at each of the front and rear ends of the burner side plate 35 located outside the dark flame port 32, a corner radius portion 35a that curves inward in the lateral direction toward the overlapping flange portion 36 of the front and rear ends of the light and shade burner 3 Is provided.

Further, at the front end of the partition plate 2, an upright plate portion 22 extending upward and an upper plate portion 23 that bends forward from the upper end of the upright plate portion 22 to reach the lower end of the front plate portion 11 of the combustion casing 1 are provided. Has been done. In the present embodiment, the front end of the upper plate portion 23 is bent upward to integrally form the front plate portion 11. The upright plate portion 22 is formed with openings 24, 25 that match the first and second inflow ports 33, 34 of the light and shade burners 3, and further, in front of the upright plate portion 22, the lower portion of the combustion casing 1 is formed. The manifold 4 is mounted so as to close the front surface. Further, in the vicinity of the front end of the upper plate portion 23, a plurality of ventilation holes 26 for flowing cooling air from the air supply chamber 1b along the inner surface of the front plate portion 11 are formed at intervals in the lateral direction. ..

The manifold 4 is provided with first and second gas nozzles 41 and 42 facing the first and second inflow ports 33 and 34 of the light and shade burners 3. Then, fuel gas is supplied from the first and second gas nozzles 41 and 42 to the first and second inflow ports 33 and 34, and between the air supply chamber 1b and the upright plate portion 22 and the manifold 4. Primary air is supplied to the inflow ports 33 and 34 through the voids defined in. Note that the manifold 4 is omitted in FIG.

An ignition electrode 5, a frame rod 6, and a viewing window 7 are arranged on the front plate portion 11 of the combustion casing 1. Further, in the combustion casing 1, a front positioning frame 8 and a rear positioning frame 9 are arranged so as to be located inside the front plate portion 11 and inside the rear plate portion 13. At the upper ends of the positioning frames 8 and 9, the claw pieces 81 inserted into the upper part of the gap between the front and rear ends of the light and shade burners 3 and the front and rear ends of the adjacent light and shade burners 3 A plurality of 91s are formed, and each of the shade burners 3 is positioned in the lateral direction by the claw pieces 81 and 91.

In the front half of the left and right side edges of the claw piece 81 of the positioning frame 8 on the front side, a notch 82 through which air flows from the ventilation hole 26 formed in the upper plate portion 23 of the partition plate 2 is formed. There is. Further, a pair of side plate portions 92, 92 that sandwich the burner arrangement portion from both sides in the lateral direction are curved on both lateral portions of the positioning frame 9 on the rear side. Then, the rear positioning frame 9 is screwed 93 to the front plate portion 11 together with the front positioning frame 8 at the front end portion 921 of each side plate portion 92, and the tongue piece extending to the rear lower end of each side plate portion 92. Screws 94 are fixed to the partition plate 2 at the portion 922. Further, the upper inner surfaces of the front plate portion 11 and the rear plate portion 13 of the combustion casing 1 are covered with the heat shield plates 111 and 131.

Next, the frame rod 6 will be described in detail. With reference to FIG. 2, the frame rod 6 has a detection rod portion 61 extending laterally above the portion of the plurality of shade burners 3 adjacent to each other near the front end portions of the two adjacent specific shade burners 3A, 3A. A shaft portion 62 that is long in the front-rear direction and bends toward the front plate portion 11 at a position above the gap between one specific light and shade burner 3A and the non-specific light and shade burner 3 adjacent thereto. At 62, it is pierced and supported by the front plate portion 11 via an insulator. Then, when the frame rod 6 does not detect the flame by the flame lift at the time of oxygen deficiency, that is, the frame current flowing through the flame between the frame rod 6 and the specific light and shade burner 3A moves upward from the frame rod 6. When the flame lift drops below a predetermined threshold value, the gas supply to the light and shade burner 3 is stopped.

By the way, in the light and shade burner 3, the light flame formed on the light flame port 31 at the time of oxygen deficiency is lifted before the deep flame formed on the dark flame port 32. In this case, the frame rod 6 detects the flame unless the deep flame is lifted. Here, the concentrated flame spreads outward in search of secondary air when oxygen is deficient. Then, the concentrated flame is turned up from the outside by the secondary air flowing upward along the burner side plate portion 35 on the outside of the concentrated flame port 32, and further, the concentrated flame port 32 is cooled by the secondary air and the combustion speed is slowed down. Therefore, the deep flame lifts.

However, at the front and rear ends of each light and shade burner 3, the supply of secondary air is obstructed by the claw pieces 81 and 91 provided on the positioning frames 8 and 9, and the front and rear ends of the dark flame port 32 when oxygen is deficient. It becomes difficult for the deep flame to lift in the part. Then, when it becomes difficult for the dark flame to lift at the front end of the dark flame port 32 of the specific light and shade burner 3A, the frame rod installation portion (detection rod portion 61) near the front end of the specific light and shade burner 3A is affected by the flame holding action of the dark flame. The lift of the deep flame at the facing part) is delayed.

Therefore, in the present embodiment, as shown in FIG. 6, the specific claw piece 81A for positioning the specific light and shade burner 3A among the claw pieces 81 of the front positioning frame 8 is attached to the front end of the burner side plate portion 35 of the specific light and shade burner 3A. A notch 83 is formed so as to be located at a portion in contact with the corner round portion 35a and to secure a ventilation gap 83a that allows secondary air to flow from the lower side to the upper side along the corner round portion 35a. .. The specific claw piece 81A has a contact portion 84 that contacts the burner side plate portion 35 of the specific light and shade burner 3 at the bending base end portion on the rear side of the corner radius portion 35a at the front end.

According to the present embodiment, there are two from the bottom to the top along the corner radius portion 35a at the front end of the burner side plate portion 35 of the specific shade burner 3A through the ventilation gap 83a secured by the notch portion 83 formed in the specific claw piece 81A. Next air flows. Then, due to the influence of this secondary air, the concentrated flame is lifted at an early stage at the front end of the concentrated flame port 32 of the specific shade burner 3A when oxygen is deficient. Therefore, it is possible to prevent the lift of the high flame at the frame rod installation portion from being delayed due to the flame holding action of the high flame at the front end of the high flame port 32. As a result, the frame rod 6 does not detect the flame at the initial stage of oxygen deficiency, which is safe.

Further, since the shaft portion 62 of the frame rod 6 is burned by both the high flame of the specific light and shade burner 3A and the high flame of the non-specific light and shade burner 3 adjacent thereto, the temperature becomes considerably high. As a result, the shaft portion 62 is oxidized at a high temperature to precipitate oxides, which makes it difficult for current to flow and may impair the function of the frame rod 6.

Therefore, in the present embodiment, the second specific claw piece 81B located immediately below the shaft portion 62 of the frame rod 6 is the corner radius portion 35a of the burner side plate portion 35 of the specific shade burner 3A and the burner of the non-specific shade burner 3. The portion of the side plate portion 35 located between the corner round portion 35a and the corner round portion 35a is cut off over the entire width, and there is no portion such as the contact portion 84 of the specific claw piece 81A. According to this, the amount of secondary air flowing toward the shaft portion 62 increases, and the shaft portion 62 is cooled by the secondary air, so that the precipitation of oxides can be suppressed.

When oxygen is deficient, the concentrated flame at the front end of the concentrated flame port 32 spreads forward in search of secondary air. Then, when the amount of air flowing upward from the ventilation hole 26 of the upper plate portion 23 of the partition plate 2 is large, the concentrated flame approaches the front plate portion 11 and causes the front plate portion 11 to overheat. Therefore, in the present embodiment, in order to reduce the amount of air from the ventilation holes 26, the area of each ventilation hole 26 is made smaller than the area of the ventilation gap 83a.

Although the embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited thereto. For example, in the above embodiment, the detection rod portion 61 of the frame rod 6 faces above the portion near the front end of the specific shade burner 3A, but is detected above the portion near the rear end of the specific shade burner 3A. It is also possible to face the rod part. In this case, of the claw pieces 91 of the rear positioning frame 9, the specific claw piece for positioning the specific light and shade burner 3A is ventilated between the corner radius portion 35a at the rear end of the burner side plate portion 35 of the specific light and shade burner 3A. A notch may be formed to secure a gap.

1 ... Combustion box, 1a ... Combustion chamber, 1b ... Air supply chamber, 11 ... Front plate (one of the front and rear plates), 2 ... Partition plate, 21 ... Distribution hole, 3 ... Light and shade burner, 3A ... Specific light and shade burner, 31 ... Light flame port, 32 ... Dark flame port, 35 ... Burner side plate part, 35a ... Corner radius part, 6 ... Frame rod, 61 ... Detection rod part, 62 ... Shaft part, 8 ... Positioning frame, 81 ... Claw piece, 81A ... Specific nail piece, 81B ... Second specific nail piece, 83 ... Notch, 83a ... Ventilation gap.

Claims (3)

A combustion chamber is provided, and a partition plate is provided inside the combustion chamber to divide the space inside the combustion chamber into a combustion chamber and an air supply chamber below the combustion chamber. At the upper end, the fuel concentration is thinner than the theoretical air-fuel ratio. It has a light flame port that is long in the front-rear direction to eject the light mixture and a rich flame port that is located on both lateral sides of the light flame port and ejects a rich mixture having a higher fuel concentration than the light mixture. It is a combustion device in which a plurality of light and shade burners are arranged side by side in the combustion chamber, and secondary air is supplied to the combustion chamber from the air supply chamber through a large number of distribution holes formed in the partition plate. ,
Inside a frame rod having a detection rod portion that extends laterally at a position near the end of one of the front and rear ends of a part of the plurality of light and shade burners, and inside one of the front and rear plates of the combustion casing. A positioning frame to be arranged is provided, and each light and shade burner is inserted into the positioning frame above the gap between one front and rear end of each light and shade burner and one front and rear end of an adjacent light and shade burner. In the case where a claw piece is provided to position the rod in the lateral direction.
Positioned on the specific claw piece that positions the specific shade burner, at the portion in contact with the corner radius portion that curves inward in the lateral direction provided at one of the front and rear ends of the burner side plate portion located outside the dark flame port of the specific shade burner. A combustion device characterized in that a notch portion is formed to secure a ventilation gap that allows secondary air to flow from the lower side to the upper side along the corner radius portion. The combustion apparatus according to claim 1, wherein the frame rod is located above a gap between the specific light and shade burner and a non-specific light and shade burner adjacent thereto, and is directed toward one of the front and rear plates of the combustion casing. In a device having a longitudinal shaft portion in the front-rear direction of bending, the second specific claw piece located immediately below the shaft portion of the claw pieces is a corner radius at one end of the front and rear ends of the burner side plate portion of the specific light and shade burner. A combustion device characterized in that a portion located between a portion and a corner radius portion at one of the front and rear ends of a burner side plate portion of a non-specific shade burner is cut over the entire width. The combustion apparatus according to claim 1 or 2, wherein one of the front and rear sides is the front, and the upright plate portion extending upward and the combustion casing bent forward from the upper end of the upright plate portion at the front end of the partition plate. An upper plate portion that reaches the front plate portion of the above plate is provided, and vent holes for flowing cooling air from the air supply chamber along the inner surface of the front plate portion are laterally spaced in the upper plate portion. A combustion device characterized in that the area of each vent is smaller than the area of the vent gap secured by the notch in a plurality of formed ones.

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