JP7168174B1 - premixed burner - Google Patents

Abstract

A premixed burner capable of uniformly mixing fuel gas and air with a relatively simple structure is provided. A premixing burner 1 includes a mixing pipe 2, a blower fan 3 connected to one end of the mixing pipe 2, a burner head 4 connected to the other end of the mixing pipe 2, It has a fuel gas ejection portion 5 and a throttle portion 6 . The fuel gas jetting part 5 is provided on the pipe peripheral wall of the mixing pipe 2 and is configured to be capable of jetting the fuel gas F into the mixing pipe 2 . The throttle section 6 is provided between the blower fan 3 and the fuel gas ejection section 5 and has a throttle hole 61 that throttles the flow rate of the air A sent from the blower fan 3 . In the premixed burner 1 , the air A and the fuel gas F are uniformly mixed by the swirl of the air A generated on the downstream side of the throttle portion 6 . [Selection drawing] Fig. 3

Description

The present invention relates to premixed burners.

Conventionally, a premixed burner that mixes fuel gas and air and burns the generated premixed gas is known. For example, in Patent Document 1, a gas supply pipe is inserted from the side of a mixture flow path into which air from a blower fan is forced and supplied, and a plurality of gas lines are formed in a row along the longitudinal direction of this gas insertion pipe. A technique for ejecting fuel gas from an ejection port into an air flow has been disclosed. In this prior art, a premixed gas is formed by mixing the fuel gas and the air using an air swirl generated by a gas supply pipe arranged in the air-fuel mixture flow path.

JP-A-2001-99410

However, the prior art requires a special gas supply pipe formed with a plurality of gas ejection holes in order to form a uniformly mixed premixed gas. Therefore, the conventional technology tends to have a complicated premixing structure.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems, and an object of the present invention is to provide a premixed burner capable of uniformly mixing fuel gas and air with a relatively simple structure.

One aspect of the present invention is
a mixing pipe;
A blower fan connected to one end of the mixing pipe;
a burner head connected to the other end of the mixing pipe;
a fuel gas ejection part provided on the pipe peripheral wall of the mixing pipe and configured to be able to eject fuel gas into the mixing pipe;
a throttling part provided between the blower fan and the fuel gas ejection part and having a throttle hole for throttling the flow rate of the air sent from the blower fan,
The fuel gas ejection part does not protrude inside the mixing pipe ,
in the premixed burner.

The premixed burner has the configuration described above. In the premixed burner, the air sent from the blower fan passes through the throttle hole of the throttle, thereby generating an air swirl downstream of the throttle. Then, the fuel gas from the fuel gas ejection portion is ejected to the downstream side of the throttle portion. Therefore, according to the above-mentioned premixed burner, even without using a special gas supply pipe as in the prior art, the swirl of air generated on the downstream side of the constricted portion allows the mixture of the air and the gas to the extent that the required combustibility is satisfied. uniformly mixed with the fuel gas.

Therefore, according to the premixed burner, it is possible to uniformly mix the fuel gas and the air with a relatively simple structure.

FIG. 1 is a front view schematically showing a premixed burner of Embodiment 1. FIG. FIG. 2 is a plan view schematically showing the premixed burner of Embodiment 1. FIG. FIG. 3 is a cross-sectional view schematically showing a cross-section taken along line III--III shown in FIG. FIG. 4 is a cross-sectional view schematically showing a cross section taken along line IV-IV shown in FIGS. 1 and 2. FIG. FIG. 5 is a cross-sectional view schematically showing a cross section taken along line VV shown in FIG. 6A and 6B are diagrams schematically showing the throttle portion used in Embodiment 1 together with a modified example. FIG. 7 is a cross-sectional view schematically showing the premixed burner of Embodiment 2 corresponding to FIG.

(Embodiment 1)
A premixed burner of Embodiment 1 will be described with reference to FIGS. 1 to 6. FIG. As illustrated in FIGS. 1 to 6, the premixed burner 1 of the present embodiment includes a mixing pipe 2, a blower fan 3, a burner head portion 4, a fuel gas ejection portion 5, a throttle portion 6, have. This will be explained in detail below.

The mixing pipe 2 is a flow path through which the premixed gas G formed by mixing the fuel gas F and the air A flows. The length of the mixing pipe 2 and the cross-sectional shape of the pipe are not particularly limited. The mixing pipe 2 may have no bends, as exemplified in FIGS. 1-3, or may have one or more bends (not shown). FIGS. 1 to 3 show an example in which the mixing pipe 2 is straight and does not have a bent portion. In this embodiment, for example, the mixing pipe 2 can have a length of 100 mm and a rectangular cross-sectional shape. The mixing pipe 2 can be made of, for example, a metal material such as stainless steel, resin, or the like.

In this embodiment, a flange portion 21 is provided on the other end side (burner head portion 4 side) of the mixing pipe 2 . Specifically, the flange portion 21 is made of a plate-like member, and a hole portion 210 having a size equivalent to the flow passage cross section of the mixing pipe 2 is formed substantially in the center. The flange portion 21 is welded to the other end of the mixing pipe 2 so that the hole portion 210 of the flange portion 21 communicates with the inside of the mixing pipe 2 . The flange portion 21 can be made of, for example, a metal material such as stainless steel, resin, or the like.

In this embodiment, as illustrated in FIGS. 1 and 2, the premixed gas G ejected from the premixed gas ejection holes 43 (described later) formed in the burner head portion 4 is ignited. is attached to the flange portion 21 . A flame rod 92 is attached to the flange portion 21 for detecting flames formed in the burner head portion 4 .

The blower fan 3 is connected to one end of the mixing pipe 2 (the side opposite to the other end of the mixing pipe 2). The blower fan 3 is configured to be able to supply air A for forming the premixed gas G into the mixing pipe 2 from one end of the mixing pipe 2 . A known fan can be used as the blower fan 3 as appropriate.

The burner head part 4 is connected to the other end of the mixing pipe 2 . In this embodiment, the base end portion of the burner head portion 4 is connected to the flange portion 21 provided at the other end portion of the mixing pipe 2 .

In this embodiment, the burner head portion 4 is formed in a cylindrical shape with a bottom, as illustrated in FIG. The burner head portion 4 has an opening 41 on the base end side and is closed by a bottom portion 42 on the tip end side. A plurality of premixed gas ejection holes 43 for ejecting the premixed gas G are formed on the cylinder peripheral surface of the burner head portion 4 . In this embodiment, as exemplified in FIGS. 1 to 3, the cylinder peripheral surface in which the premixed gas ejection holes 43 are formed is covered with a metal fiber portion 40 such as metal knit. According to this configuration, the premixed gas G can be fueled while holding the flame. Further, in this embodiment, for example, the length of the burner head portion 4 can be set to 250 mm, the outer diameter of the burner head portion 4 can be set to 70 mm, and the length of the metal fiber portion 40 can be set to 150 mm. The burner head portion 4 can be made of, for example, a metal material such as stainless steel.

The fuel gas ejection part 5 is provided on the peripheral wall of the mixing pipe 2 and is configured to be able to eject the fuel gas F into the mixing pipe 2 . A fuel pipe from a fuel gas source (not shown) is connected to the fuel gas ejection portion 5 . The fuel gas ejection part 5 can be made of, for example, a metal material such as stainless steel or resin . The fuel gas ejection part 5 does not protrude inside the mixing pipe 2 . Specifically, the fuel gas ejection portion 5 has a set screw 51, a body portion 52, and a communication hole 53, as illustrated in FIG.

The setscrew 51 has a through hole 510 passing through in the axial direction (screw axial direction). The set screw 51 can be configured by forming a through hole 510 in the axial direction of a commercially available set screw with a hexagonal hole, as illustrated in FIGS. 4 and 5, for example. According to this configuration, the setscrew 51 can be prepared relatively easily using a general-purpose item. The body portion 52 has a hole portion 520 into which the set screw 51 is screwed. An inner wall surface of the hole portion 520 is formed with a female thread portion 521 into which a male thread portion 511 formed on the outer peripheral surface of the set screw 51 can be screwed. Specifically, FIGS. 3 and 4 show an example in which the set screw 51 can be screwed into the inner wall surface of the hole 520 of the main body 52 formed in a tubular shape. Note that the main body portion 52 may be formed in other shapes such as a block body in which the hole portion 520 is formed. The communication hole 53 is formed in the pipe peripheral wall portion of the mixing pipe 2 with which the tip of the hole portion 520 of the main body portion 52 is in contact. The communication hole 53 allows the inside of the hole portion 520 of the main body portion 52 and the inside of the mixing pipe 2 to communicate with each other. The fuel gas F is jetted into the mixing pipe 2 from this communication hole 53 . In this embodiment, the hole diameter of the communication hole 53 is made smaller than the outer diameter of the set screw 51 . Specifically, the hole diameter of the communication hole 53 can be set to, for example, 3.2 mm, and the outer diameter of the set screw 51 can be set to 10 mm.

In this embodiment, as exemplified in FIGS. 3 and 4, in the fuel gas ejection portion 5, the body portion 52 protrudes from the peripheral wall of the mixing pipe 2 in a direction perpendicular to the peripheral wall of the mixing pipe 2. are placed. Therefore, in this embodiment, the ejection direction of the fuel gas F ejected from the fuel gas ejection portion 5 into the mixing pipe 2 is set to be perpendicular to the peripheral wall of the mixing pipe 2 .

The throttle section 6 is provided between the blower fan 3 and the fuel gas ejection section 5 . The throttling part 6 has a throttling hole 61 for throttling the flow rate of the air A sent from the blower fan 3 . The constricted portion 6 can be made of, for example, a metal material such as stainless steel or resin. Specifically, in this embodiment, as illustrated in FIG. According to this configuration, the throttle portion 6 can be provided relatively easily as a separate member between the blower fan 3 and the fuel gas ejection portion 5 . Therefore, according to this configuration, the manufacturability of the premixed burner 1 is good. Moreover, according to this configuration, the structure of the mixing pipe 2 can be simplified as compared with, for example, the case where the throttle portion 6 is provided in the mixing pipe 2 . Specifically, in FIGS. 1 to 3, there is an example in which the throttle portion 6 is sandwiched between the pipe opening 20 on the one end side of the mixing pipe 2 and the blower port 30 of the blower fan 3. It is shown.

In the present embodiment, the throttle portion 6 is made of a plate-like member having a plurality of throttle holes 61 penetrating in the plate thickness direction, as illustrated in FIGS. 4 and 6(a). there is In this case, the throttle part 6 made of a plate-like member may be fixed to the mixing pipe 2, to the blower fan 3, or to both. Although not shown, the throttle portion 6 can also be configured by a plate-like member having a plurality of throttle holes 61 penetrating in a direction intersecting with the plate surface direction.

Note that the throttling portion 6 can be provided inside the mixing pipe 2 or inside the blower fan 3 if the flow rate of the air A sent from the blower fan 3 can be throttled on the upstream side of the fuel gas ejection portion 5 .

In this embodiment, the throttle portion 6 has four throttle holes 61 as illustrated in FIGS. 4 and 6(a). In addition, the number of throttle holes 61 can be 2 or more and 26 or less, for example, as shown in FIGS. 6(b) to 6(f). The number of throttle holes 61 is preferably 2 or more and 6 or less from the viewpoint of facilitating formation of the throttle portion 6, easiness of generating a vortex by the air A, and the like.

In this embodiment, as shown in FIG. 4, each throttle hole 61 has a hole diameter of the communication hole 53 in the ejection direction of the fuel gas F ejected into the mixing pipe 2 from the fuel gas ejection part 5. When a virtual space (not shown) formed by extending to the central axis of is projected onto the diaphragm portion 6, it is arranged so as not to overlap the projection area 7. As shown in FIG.

Next, the effects of the premixed burner 1 of this embodiment will be described.

In the premixed burner 1 of the present embodiment, the air A sent from the blower fan 3 passes through the throttle hole 61 of the throttle portion 6 to generate a vortex V of the air A downstream of the throttle portion 6 . The fuel gas F from the fuel gas ejection portion 5 is ejected to the downstream side of the throttle portion 6 . Therefore, according to the premixed burner 1 of the present embodiment, the required combustibility is achieved by the vortex V of the air A generated on the downstream side of the throttle portion 6 without using a special gas supply pipe as in the prior art. The air A and the fuel gas F are uniformly mixed to the extent that Therefore, according to the premixed burner 1 of this embodiment, it is possible to uniformly mix the fuel gas F and the air A with a relatively simple structure.

In the premixed burner 1, when the throttle portion 6 is composed of a plate-like member having a plurality of throttle holes 61 penetrating in the plate thickness direction, the plate-like member is subjected to a plurality of hole drilling processes to obtain a comparison. The constricted portion 6 can be formed in a relatively simple manner. Further, in this case, it becomes easier to implement a configuration in which the throttle portion 6 is sandwiched between the mixing pipe 2 and the blower fan 3 .

The premixed burner 1 has the following advantages because the fuel gas ejection portion 5 does not protrude into the mixing pipe 2 . When a gas supply pipe having a gas ejection hole as used in the prior art projects into the mixing pipe 2, the direction of the gas ejection hole is precisely aligned and the gas supply pipe is inserted into the mixing pipe 2. difficult to do. Further, in the conventional technology, the degree of insertion of the gas supply pipe tends to vary. On the other hand, according to the above configuration, such alignment or the like becomes unnecessary. Therefore , according to the said structure, the premixed burner 1 excellent in manufacturability is obtained.

In the premixed burner 1, when the fuel gas ejection portion 5 has the set screw 51, the body portion 52, and the communication hole 53, by appropriately adjusting the hole diameter of the through hole 510 in the set screw 51, The ejection amount of the fuel gas F can be adjusted relatively easily. Therefore, according to the above configuration, by preparing the setscrew 51 having the through hole 510 having a predetermined hole diameter, the premixed burner 1 can be appropriately adjusted according to the model and capacity of the equipment to which the premixed burner 1 is applied. A premixed burner 1 in which the ejection amount of the fuel gas F can be easily adjusted can be obtained. Moreover, since the set screw 51 can be prepared by drilling a general-purpose set screw so as to have a required hole diameter, the cost of the premixed burner 1 can be reduced.

In the premixed burner 1, when the hole diameter of the communication hole 53 is smaller than the outer diameter of the set screw 51, the following advantages are obtained. In this case, when the set screw 51 is screwed all the way into the main body 52, the tip of the set screw 51 hits the outer peripheral edge of the communication hole 53 in the pipe peripheral wall of the mixing pipe 2, and the set screw 51 is pushed further inward. It will not progress. Therefore, in the above case, the set screw 51 does not fall off into the mixing pipe 2, and the screw mounter can easily screw the set screw 51 in with peace of mind. Further, in the above case, since the set screw 51 can be fixed at a predetermined position, the set screw 51 can be mounted so that the communication hole 53 is positioned at the correct position and angle.

In the premixing burner 1, a virtual space formed by extending the hole diameter of the communication hole 53 to the central axis of the mixing pipe 2 in the direction in which the fuel gas F jetted from the fuel gas jetting portion 5 into the mixing pipe 2 is narrowed. When the aperture 61 is arranged so as not to overlap the projection area 7 when projected onto the portion 6, the following advantages are obtained. In the premixed burner 1 , the fuel gas F is jetted into the mixing pipe 2 from the communication hole 53 . In the above case, the fuel gas F ejected from the communication hole 53 can easily reach the central axis of the mixing pipe 2 without being affected by the air A coming from the upstream side. Therefore, in the above case, the fuel gas F can be brought into contact with the swirl V of the air A generated by the constricted portion 6, and the fuel gas F and the air A can be mixed even in the relatively narrow mixing pipe 2. can be easily mixed evenly. From the viewpoint of uniform mixing of the fuel gas F and the air A, the fuel gas ejection part 5 is preferably configured to be capable of ejecting the fuel gas F toward the approximate center position of the vortex V.

In the premixed burner 1, when the ejection direction of the fuel gas F ejected into the mixing pipe 2 from the fuel gas ejection portion 5 is perpendicular to the peripheral wall of the mixing pipe 2, the fuel gas ejection portion It is easier to improve the manufacturing accuracy of the fuel gas ejection portion 5 compared to the case where the portion 5 is inclined.

The premixed burner 1 of the present embodiment described above can be suitably used, for example, in kitchen appliances such as steam convection ovens, various gas appliances, and the like. Further, the premixed burner 1 of the present embodiment described above can be suitably used for applications such as steam generators, hot water generators, hot air generators, etc., in which combustion is performed in a relatively narrow space and heat is exchanged.

(Embodiment 2)
A premixed burner of Embodiment 2 will be described with reference to FIG. It should be noted that, of the reference numerals used in the second and subsequent embodiments, the same reference numerals as those used in the previously described embodiments represent the same components and the like as those in the previously described embodiments, unless otherwise specified.

As exemplified in FIG. 7, in the fuel gas ejection portion 5 of the premixing burner 1 of the present embodiment, the fuel gas is directed from the pipe peripheral wall of the mixing pipe 2 to the blower fan 3 side in the direction perpendicular to the pipe peripheral wall of the mixing pipe 2 . A body portion 52 is arranged so as to protrude at an angle. Therefore, in the present embodiment, the ejection direction of the fuel gas F ejected from the fuel gas ejection portion 5 into the mixing pipe 2 is an oblique direction toward the downstream side of the air flow with respect to the direction perpendicular to the peripheral wall of the mixing pipe 2. It is said that The communication hole 53 is formed so as to be inclined in the same direction as the ejection direction of the fuel gas F.

According to the premixed burner 1 of this embodiment, the area for premixing the fuel gas F and the air A can be increased compared to the premixed burner 1 of the first embodiment. Therefore, the premixed burner 1 of the present embodiment can premix more fuel gas F and air A than the premixed burner 1 of the first embodiment, and burner combustion with a high combustion load can be achieved. It has the advantage of being easily adaptable to Other configurations and effects are the same as those of the first embodiment.

The present invention is not limited to the above-described embodiments and experimental examples, and various modifications can be made without departing from the scope of the invention. Moreover, each configuration shown in each embodiment can be combined arbitrarily.

1 Premixed burner 2 Mixing pipe 3 Blower fan 4 Burner head part 5 Fuel gas ejection part 6 Throttle part 61 Throttle hole F Fuel gas A Air G Premixed gas

Claims (7)

a mixing pipe;
A blower fan connected to one end of the mixing pipe;
a burner head connected to the other end of the mixing pipe;
a fuel gas ejection part provided on the pipe peripheral wall of the mixing pipe and configured to be able to eject fuel gas into the mixing pipe;
a throttling part provided between the blower fan and the fuel gas ejection part and having a throttle hole for throttling the flow rate of the air sent from the blower fan,
The fuel gas ejection part does not protrude inside the mixing pipe ,
premixed burner. The narrowed portion is composed of a plate-like member having a plurality of narrowed holes penetrating in the plate thickness direction,
A premixed burner according to claim 1. The fuel gas ejection part is
A set screw provided with a through hole penetrating in the axial direction, a body portion provided with a hole into which the set screw is screwed, and a pipe peripheral wall portion of the mixing pipe in contact with the tip of the hole, the hole a communication hole that communicates the inside of the unit and the inside of the mixing pipe,
A premixed burner according to claim 1 or claim 2 . The hole diameter of the communication hole is smaller than the outer diameter of the set screw,
A premixed burner according to claim 3 . A virtual space formed by extending the hole diameter of the communication hole to the central axis of the mixing pipe in the ejection direction of the fuel gas ejected from the fuel gas ejection portion into the mixing pipe is projected onto the constricted portion. When the aperture is arranged so as not to overlap the projection area,
A premixed burner according to claim 3 or 4 . 6. The method according to any one of claims 1 to 5 , wherein the direction of ejection of the fuel gas ejected from the fuel gas ejection portion into the mixing pipe is a direction perpendicular to the pipe peripheral wall of the mixing pipe. Premixed burner as described. The direction in which the fuel gas jetted from the fuel gas jetting portion into the mixing pipe is slanted toward the downstream side of the air flow with respect to the direction perpendicular to the peripheral wall of the mixing pipe. A premixed burner according to any one of claims 1 to 5 .

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