JP7385804B2 - Premixing device and combustion device equipped with the same - Google Patents

Description

The present invention relates to a premixing device and a combustion device equipped with the same.
Here, "premixing" is a process of mixing air and fuel gas in advance to generate a combustible mixed gas for the purpose of performing premixing combustion.

A specific example of a premixing device is one described in Patent Document 1.
The premixing device described in this document includes a tubular member (premixing channel forming member) that forms a venturi-shaped premixing channel, and two vertical and horizontal blade sections that are installed inside this tubular member. We are prepared. The intake side of a fan is connected to the downstream side (terminus side) of the premixing channel, and air flows into the premixing channel from the upstream side (starting end side). The blade part is provided with a fuel gas outlet, and when air flows into the premixing channel and negative pressure is generated, the fuel gas flows from the fuel gas outlet to the premixing channel due to the action of this negative pressure. flows out and mixes with air.

However, in the prior art, there is room for improvement as described below.

That is, the premixing device does not use only one type of fuel gas, but generally uses one of two types of fuel gas: natural gas and LP gas. However, since these two types of fuel gases have different components and calorific values, the premixing device needs to be adapted to the type of fuel gas.
Specifically, the premixing device is provided with a fuel gas flow path for guiding the fuel gas from the outside of the premixing flow path forming member to the fuel gas outlet; It must be compatible with the type of gas. When the negative pressure generated in the premixing channel is the same, fuel gas with a lower calorific value flows out from the fuel gas outlet into the premixing channel in a larger amount than fuel gas with a higher calorific value. and the premixing device needs to be so specified.

On the other hand, conventionally, no means to easily and appropriately deal with the above-mentioned problems has been proposed. Conventionally, parts are manufactured and prepared in advance according to the type of fuel gas, and when a different type of fuel gas is used than the planned fuel gas, parts are replaced or new parts are installed. The reality is that countermeasures such as adding parts are being taken.
However, this requires replacement or additional parts, and the number of these parts in stock increases, resulting in high costs. Moreover, parts management becomes troublesome. Furthermore, when parts are replaced, there is a risk that the original replaced parts may be discarded.

Special Publication No. 11-502278

The present invention was devised under the above-mentioned circumstances, and can be applied to multiple types of fuel gas without replacing parts or adding new parts depending on the type of fuel gas. The object of the present invention is to provide a premixing device that can appropriately respond to various situations, and a combustion device equipped with the same.

In order to solve the above problems, the present invention takes the following technical measures.

The premixing device provided by the first aspect of the present invention forms a premixing flow path for causing air to flow from one end side to the other end side and for mixing fuel gas with this air. A premixing flow path forming member, a pipe joint portion for connecting a gas pipe for supplying the fuel gas, a base portion to which the pipe joint portion is attached, and a fuel gas whose terminal end opens into the premixing flow path. A fuel gas flow path formed as an outlet and for guiding the fuel gas supplied to the pipe joint part to the fuel gas outlet; the pipe joint part and the base part include: The premixing device is provided with a joint-side hole and a base-side hole that can face each other and communicate with each other as holes constituting a part of the fuel gas flow path, wherein the pipe joint The part is configured to be able to change the manner in which it is attached to the base part, and by changing the manner in which it is attached, the mutually opposing position and/or opposing area of the joint side hole part and the base side hole part are changed. The fuel gas flow path is characterized in that the flow path resistance of the fuel gas flow path can be changed.
Here, "the manner of attachment to the base can be changed" refers to the case where at least one of the position, direction, angle, or posture of the attachment of the pipe fitting to the base can be changed. do.

According to such a configuration, the following effects can be obtained.
In other words, by changing the manner in which the pipe fitting part is attached to the base part, the fitting side hole provided in the pipe fitting part and the base side hole provided in the base part can be positioned opposite to each other and/or opposite to each other. It is possible to change the area and change the flow path resistance of the fuel gas flow path. For this reason, for example, in the case of fuel gas with a large calorific value, the flow path resistance of the fuel gas flow path is set to be large, and in the case of fuel gas with a low calorific value, the flow path resistance is set to be small. By setting it so that it becomes, it becomes possible to make the mixing ratio of the air and fuel gas in a premixing flow path into an appropriate ratio.
Therefore, according to the present invention, when the type of fuel gas is different from the expected type of fuel gas, there is no need to replace the pipe joint with another pipe joint, and there is no need to replace the pipe joint with another pipe joint. There is no need to add and use additional parts. Therefore, it is possible to eliminate the problem of increasing the number of parts in stock to accommodate different types of fuel gas, reduce costs required for parts inventory, and facilitate parts management. When replacing parts, the original parts may be discarded as unnecessary items, but according to the present invention, there is no such waste.
Furthermore, the pipe joint is a part originally provided in the premixing device as a means for connecting gas pipes. The present invention utilizes such a pipe joint part to correspond to the type of fuel gas, so the configuration is rational, suppresses an increase in the number of parts of the entire premixing device, and reduces costs. It is even more preferable to achieve the following.

In the present invention, preferably, the fuel gas is configured to flow out from the fuel gas outlet into the premixing channel by the action of negative pressure generated due to the airflow in the premixing channel. There is.
The present invention is most suitable for a premixing device having such a configuration.

In the present invention, preferably, the fuel gas includes predetermined first and second fuel gases of different types, and the mounting aspect of the pipe joint portion is such that the facing area corresponds to the first fuel gas. It is possible to selectively set either one of a first mounting mode in which the opposing area is an area corresponding to the second fuel gas, and a second mounting mode in which the opposing area is an area corresponding to the second fuel gas.

According to such a configuration, depending on whether the fuel gas used for premixing is the predetermined first or second fuel gas, the mounting manner of the pipe joint portion is changed between the first and second predetermined fuel gases. It is sufficient to set it on the corresponding side of either one of the mounting modes. Therefore, it is possible to easily and accurately correspond to the type of fuel gas.

In the present invention, preferably, the base portion is provided with first and second gas type display portions indicating the first and second fuel gases, respectively, and the pipe joint portion is preferably provided with first and second gas type display portions indicating the first and second fuel gases, respectively. When the mounting mode is set, the second gas type display section is covered and hidden by the pipe joint section, and the first gas type display section is exposed, while the pipe joint section is When the second mounting mode is set, the first gas type display section is covered by the pipe joint section, and the second gas type display section is exposed. has been done.

According to such a configuration, of the first and second gas type display parts, the gas type display part on the exposed side that is not covered by the pipe joint part is determined according to the mounting mode of the pipe joint part. indicates whether the corresponding fuel gas is the first or second fuel gas. Therefore, it is possible to easily and quickly confirm whether or not the type of fuel gas actually used corresponds to the manner in which the pipe joint is attached. For example, even though a pipe joint is set up in an installation mode compatible with the first fuel gas (first installation mode), it is installed in an installation mode compatible with the second fuel gas (second installation mode). It is also possible to appropriately resolve the erroneous determination that the

In the present invention, preferably, at least two base-side holes having different inner diameters are provided side by side as the base-side holes, and the first attachment mode is preferably one of the two base-side holes. is opposite to the joint-side hole, and the other side is closed by the pipe joint, and the second mounting method is different from the first mounting method in that the pipe joint side hole is closed by the pipe joint. The directions of the base holes are reversed, and one of the two base side holes is closed by the pipe joint, and the other side faces the joint side hole.
Further, in the present invention, unlike the above configuration, at least two joint side holes having different inner diameters are provided side by side as the joint side holes, and the first mounting mode is different from the above structure. One of the joint-side holes faces the base-side hole, and the other is closed by the base, and the second mounting mode is different from the first mounting mode. , the direction of the pipe joint part is reversed, the one of the two joint side holes is closed by the base part, and the other one faces the base side hole part; You can also.

According to such a configuration, by changing the pipe joint from the first attachment mode to the second attachment mode and vice versa, the flow resistance of the fuel gas flow path can be appropriately changed. However, it is possible to appropriately deal with two types of fuel gas. The mounting manner of the pipe joint can be changed by simply reversing the mounting direction of the pipe joint, and the workability is also good.

The combustion device provided by the second aspect of the invention is characterized in that it comprises the premixing device provided by the first aspect of the invention.

According to such a configuration, effects similar to those described for the premixing device provided by the first aspect of the present invention can be obtained.

Other features and advantages of the present invention will become more apparent from the following description of embodiments of the invention with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram showing an example of a combustion device including a premixing device according to the present invention and a water heater using the same. FIG. 2 is a sectional view taken along line II-II in FIG. 1; (a) is a perspective view of the premixing device shown in FIGS. 1 and 2, and (b) is an exploded perspective view of (a). FIG. 4 is a perspective view from the inner surface of the pipe joint portion of the premixing device shown in FIG. 3; 3(a) is a front view of FIG. 3(a), and FIG. 3(b) is a sectional view taken along line VV in FIG. 3(a). FIG. 5B is an exploded cross-sectional view of FIG. 5(b). 5(a) is a front view of the pipe joint section set in a different manner from FIG. 5(a), and FIG. 5(b) is a sectional view taken along line VII-VII of FIG. 5(a). FIG. 6 is a perspective view showing another example of the premixing device according to the present invention. FIG. 9 is an exploded front view of a main part of the premixing channel shown in FIG. 8; 9 is a sectional view taken along line XX in FIG. 8. FIG. FIG. 11 is a cross-sectional view of the pipe joint section set in a different manner from FIG. 10; It is a sectional view showing other examples of the premixing device concerning the present invention. FIG. 7 is an exploded cross-sectional view showing another example of the premixing channel according to the present invention.

Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

FIG. 1 shows a premixing device A, a combustion device B (premixing combustion device) configured by combining the premixing device A with a fan 1 and a combustion plate 2, and a combustion device B (premixing combustion device) configured by combining the combustion device B with a heat exchanger 11. The configured water heater WH is shown.

The details of the premixing device A will be described later, but the premixing device A is used to generate a mixed gas of air and fuel gas (combustible mixed gas), and this mixed gas is passed through the fan 1. and is discharged toward the combustion plate 2. The combustion plate 2 is a porous plate having a plurality of ventilation holes 20, and is housed in the case 10, and the mixed gas passes through the combustion plate 2 and burns below it. The combustion gas generated thereby acts on the heat exchanger 11, and hot water passing through the heat exchanger 11 is heated. As a result, hot water is generated, and this hot water is supplied to a desired hot water supply destination.

The premixing device A includes a premixing channel forming member 4 having a tubular portion 41 forming a premixing channel 40, a housing member 5 surrounding the premixing channel forming member 4, and a fuel gas outlet 74. A fuel tube including each blade part 6, a pipe joint part 8 for connecting a gas pipe 9 (including a hose) for supplying fuel gas, a base part 55 to which this pipe joint part 8 is attached, and a fuel gas outlet 74. A gas flow path 7 is provided.

The premixing channel 40 is connected to the intake side of the fan 1, and when the fan 1 is driven, external air flows into the premixing channel 40 from an opening at one end thereof. The premixing channel 40 has an upstream region in the gas flow direction that is a tapered region whose inner diameter gradually decreases toward the downstream side in the gas flow direction, and a region downstream of this tapered region whose inner diameter gradually decreases toward the downstream side. It has a venturi shape with an expanding tapered region.

Each blade portion 6 is a portion that serves as a nozzle for causing fuel gas to flow out from the fuel gas outlet 74 into the premixing flow path 40, and as shown in FIG. It has a bridge shape with both ends connected, and is located within the premixing channel 40. The pair of blade portions 6 are arranged substantially parallel to each other at appropriate intervals in the thickness direction (left-right direction in FIG. 1).

Inside each blade portion 6 is a cavity 73 forming a part of the fuel gas passage 7, and a fuel gas outlet 74 communicates with this cavity 73. On the other hand, the air flow in the premixing channel 40 generates negative pressure near the fuel gas outlet 74. Due to the effect of this negative pressure, the fuel gas flows out from the fuel gas outlet 74 into the premixing channel 40, and air and fuel gas are mixed.
Note that the number of blade portions 6 is not limited to two, and a configuration in which only one blade portion 6 is provided, or three or more blade portions may be provided.

The housing member 5 includes a cylindrical housing main body part 50, a pipe joint part 8 configured separately from the housing main body part 50, and a flange part 53 having a bolt insertion hole 52. This flange portion 53 serves to easily and appropriately connect the premixing device A to a desired site.

The housing main body portion 50 is fitted onto the step portions 42a and 42b provided on the outer periphery of the premixing flow path forming member 4, and the premixing flow path forming member 4 is sealed in an airtight manner by the sealing ring 49. surrounding. A region 72 between the premixing flow path forming member 4 and the housing main body portion 50 forms a part of the fuel gas flow path 7 . The pipe joint part 8 is a part to which a gas pipe 9 for supplying fuel gas is connected, and the fuel gas supplied from the gas pipe 9 to the pipe joint part 8 flows into the above-described region 72. As shown in FIG. 2, the premixing flow path forming member 4 is formed with an opening 43 that communicates with the cavity 73 in each blade portion 6. As shown in FIG. The fuel gas that has flowed into the above-described region 72 passes through the opening 43, flows into each blade portion 6, and flows out from the fuel gas outlet 74 as described above.

As clearly shown in FIGS. 3 and 6, the base portion 55 is a portion for attaching the pipe joint portion 8 to the housing member 5, and is provided on the outer surface of the housing member 5. The base portion 55 has a flat front surface suitable for mounting the pipe joint portion 8, and also has two holes 71A and 71B (base side hole 71A, 71B), a pair of left and right screw holes 59, a packing groove 56 into which a sealing packing 94 is mounted, and first and second gas type display sections 3a, 3b.
The first gas type display section 3a is a display section indicating that the fuel gas is LP gas, and displays, for example, the characters "LP". The second gas type display section 3b is a display section that indicates that the fuel gas is natural gas, and displays, for example, the characters "NG".

As shown in FIG. 6, the two base side holes 71A and 71B have different inner diameters Da and Db, and have a relationship of Da<Db. The inner diameter Da is a flow path inner diameter suitable for using LP gas as the fuel gas. The inner diameter Db is a flow path inner diameter suitable for using natural gas as the fuel gas.
However, the inner diameter Dc of the portion 70 into which the later-described sealing convex portion 83 of the pipe joint portion 8 is fitted (the portion 70 closer to the pipe joint portion 8 among the base side holes 71A and 71B) is the inner diameter Dc described above. The dimensions are larger than Da and Db, and the dimensions are the same.

The pipe joint part 8 includes a cylindrical part 80 with an open end, a plate part 81 connected to the base end of the cylindrical part 80, and an inner wall part 85 provided deep inside the cylindrical part 80. ing. The inner wall portion 85 is provided with a hole 77 (joint side hole 77) that forms part of the fuel gas flow path 7, and is provided with a protruding convex portion 83 for sealing (see also FIG. 4). ). A sealing O-ring 84 is attached to the sealing convex portion 83. The joint side hole 77 and the sealing convex portion 83 are arranged to correspond to the two base side holes 71A and 71B.

The pipe joint portion 8 is attached to the base portion 55 such that the plate portion 81 is in face-to-face contact with the front surface of the base portion 55 . As this attachment means, for example, a screw body 98 such as a screw that is inserted into a pair of screw body insertion holes 82 provided in the plate portion 81 is inserted into the screw hole 55 of the base portion 55.
9 is used to fasten the plate portion 81. The sealing packing 94 is compressed while being sandwiched between the pipe joint part 8 and the base part 55, and serves to prevent leakage of fuel gas. The sealing packing 94 and the packing groove 56 have a loop shape surrounding the two base side holes 71A and 71B.

The manner in which the pipe joint portion 8 is attached to the base portion 55 can be selectively set to either the first or second attachment manner described below.
In the first mounting mode, as shown in FIGS. 3 and 5, one of the two base-side holes 71A and 71B, one of which is connected to the joint-side hole 77, faces the joint-side hole 77. There is. The other base side hole 71B is in a state where a sealing convex portion 83 is fitted and closed.

A notch 81a is provided at one end of the plate portion 81 of the pipe joint portion 8, and the notch 81a of the plate portion 81 is provided with a narrow width at the one end. , the letters "LP" which are the first gas type display section 3a are exposed. On the other hand, the character "NG" on the second gas type display section 3b is covered up by the plate section 81.

In the second attachment mode, as shown in FIG. 7, the pipe joint portion 8 is attached to the base portion 55 in a direction that is left and right reversed from that of the first attachment mode described above. In this second attachment mode, the base side hole 71B faces and communicates with the joint side hole 77. Further, the base side hole 71A is in a state where the sealing convex portion 83 is fitted and closed.
Since the position of the notch part 81a of the plate part 81 is horizontally reversed from that in the first mounting mode, the character "NG" which is the second gas type display part 3b is exposed, and the first gas type display part 3b is exposed. The characters “LP” which is the seed display portion 3a are covered by the plate portion 81.

Next, the operation of the premixing device A described above will be explained.

First, in the environment in which the premixing device A is used, when the fuel gas is, for example, LP gas, the pipe joint portion 8 is set in the first mounting mode as shown in FIGS. 3 and 5. In this first attachment mode, as shown in FIGS. 3 and 5, the base side hole 71B is closed by the pipe joint 8, and the base side hole 71A is opposed to the joint side hole 77. However, since the base side hole portion 71A has a small inner diameter Da, the flow resistance of the fuel gas flow path 7 becomes large. Here, since LP gas has a higher calorific value than natural gas, it is necessary to reduce the amount of gas relative to the air than when natural gas is used, but according to the first installation mode, the fuel gas flow Since the flow path resistance of the path 7 becomes large, the setting state becomes suitable for LP gas.

On the other hand, when the fuel gas is natural gas, it is sufficient to change to the second mounting mode as shown in FIG. To change from the first mounting mode to the second mounting mode, it is only necessary to loosen the screw body 98, change the direction of the pipe joint section 8, and reattach it to the base section 55, so the work can be done easily and quickly. Is possible.
In the second attachment mode, contrary to the first attachment mode, the base side hole 71A is closed by the pipe joint 8, and the base side hole 71B faces and communicates with the joint side hole 77. The inner diameter Db of the base side hole 71B is large, so that the flow resistance of the fuel gas flow path 7 can be reduced. Since natural gas has a lower calorific value than LP gas, it is necessary to reduce the flow path resistance and increase the amount of gas relative to the air, but the second installation method can appropriately accommodate such issues. It is possible.

As described above, according to the present embodiment, regardless of whether the fuel gas is LP gas or natural gas, there is no need to replace parts or add and install new parts, and the pipe joint It is possible to appropriately deal with the above two types of fuel gas by simply changing the mounting manner of 8. Therefore, there is no problem such as an increase in the number of parts in stock to cope with the presence of two types of fuel gas, and the cost required for stocking parts can be reduced. Also, parts management becomes easier.
The pipe joint part 8 is a part originally included in the premixing device A, and in this embodiment, the pipe joint part 8 is used to adapt to the type of fuel gas. The configuration is rational and is more preferable in terms of avoiding an increase in the number of parts and an increase in the size of the whole.

Further, according to the present embodiment, when the pipe joint part 8 is set in the first attachment mode, the second gas type display part 3b is covered and hidden by the pipe joint part 8, and the first gas type display part 3a, the letters "LP" are exposed. On the contrary, when the pipe joint part 8 is set in the second mounting mode, the first gas type display part 3a is covered and the second gas type display part 3b with the letters "NG" becomes exposed. Therefore, by checking such a display, it is possible to easily and accurately judge whether or not the mounting manner of the pipe joint 8 is appropriate for the actual type of fuel gas. It is possible.

8-13 illustrate other embodiments of the invention. In these figures, elements that are the same as or similar to those of the embodiment described above are given the same reference numerals as those of the embodiment described above, and redundant explanation will be omitted.

In the premixing device Aa shown in FIGS. 8 to 11, the pipe joint part 8 is provided with two joint-side holes 77A, 77B, and the base part 55 is provided with only one base-side hole 71. It is being The inner diameters D1 and D2 of the two joint side holes 77A and 77B are different, for example, D1<D2.

In this premixing device Aa, as shown in FIGS. 8 and 10, as a first attachment mode of the pipe joint portion 8, the joint side hole portion 77A is made to face and communicate with the base side hole portion 71, and the joint side hole portion 77A is made to face and communicate with the base side hole portion 71. The side hole portion 77B can be set in a state where it does not communicate with the base side hole portion 71. Since the joint side hole portion 77A has a small inner diameter D1, according to this first attachment mode, it is possible to increase the flow resistance of the fuel gas flow path 7, and it is suitable for LP gas. .

On the other hand, as a second attachment mode of the pipe joint 8, as shown in FIG. 11, contrary to the above, the joint side hole 77B is made to face and communicate with the base side hole 71, and It is also possible to set the hole 77A so that it does not communicate with the base side hole 71. According to this second attachment mode, the inner diameter D2 of the joint side hole 77B is large, and the flow resistance of the fuel gas flow path 7 can be reduced, so that it is suitable for natural gas.

In the premixing device Aa of this embodiment, compared to the premixing device A of the previous embodiment shown in FIGS. 1 to 7, the base side hole portions 71 (71A, 71B) provided in the base portion 55 Although the relationship with the joint side holes 77 (77A, 77B) provided in the pipe joint part 8 is reversed, it is possible to obtain the same effect as the premixing device A of the previous embodiment.

9 to 11, a sealing packing 94A interposed between the base portion 55 and the pipe joint portion 8 is shown as a loop-shaped packing 94A that surrounds the entire opposing region of the two joint side holes 77A and 77B. In addition to the portion 94a, a straight portion 94b is used which is arranged between the two joint side holes 77A and 77B. According to such a configuration, it is possible to appropriately prevent leakage of fuel gas between the two joint side holes 77A and 77B.

In the premixing device Ab shown in FIG. 12, a fitting side hole 77 is formed in the pipe fitting part 8 in a so-called tapered hole shape, and as it progresses from the distal end side to the proximal end side of the pipe fitting part 8, The inner diameter or width of the hole 77 is narrow. In FIG. 12, the joint-side hole 77 is shown facing and communicating with the base-side hole 71B, but if the pipe joint 8 is set in a mounting manner in which the left and right sides are reversed, the joint-side hole 77 The portion 77 faces and communicates with the base side hole portion 71A.
According to this embodiment, the fuel gas supplied from the gas pipe 9 into the pipe joint 8 can smoothly flow from the joint side hole 77 to the base side holes 71A, 71B. This is preferable in order to stabilize the supply of fuel gas to the premixing channel 40.

In the premixing device Ac shown in FIG. 13, a premixing flow path forming member 4C is configured using first and second tubular portions 4b and 4c. An opening 40a for air inflow is provided at the base end of the first tubular portion 4b, and a premixing flow path 40 is formed inside the first and second tubular portions 4b and 4c. A fuel gas outlet 74a serving as a gap opening into the premixing flow path 40 is provided between the distal end of the first tubular portion 4b and the base end of the second tubular portion 4c. The fuel gas supplied to the pipe joint part 8 passes through a region 72 provided between the first and second tubular parts 4b and 4c and the housing member 5C, and reaches the fuel gas outlet 74a. .
The housing member 5C is provided with a base portion 55 having two base side holes 71A and 71B, for example similar to that shown in FIG. 6, and the pipe fitting portion 8 can be attached to the base portion 55. It is said that

In this embodiment, due to air flowing through the venturi-shaped premixing channel 40, negative pressure is generated near the fuel gas outlet 74a, and the air flows from the fuel gas outlet 74a into the premixing channel 40. Fuel gas leaks. Unlike the embodiment described above, the blade portion 6 provided with the fuel gas outlet 74 is not used, but it is possible to appropriately generate a mixture of air and fuel gas. The premixing channel and the premixing channel forming member in the present invention can also be configured as in this embodiment.

The present invention is not limited to the content of the embodiments described above. The specific configuration of each part of the premixing device and combustion device according to the present invention can be variously modified within the intended scope of the present invention.

In the above-described embodiment, the housing members 5, 5C as attachment members attached to the premixing flow path forming members 4, 4C are provided with the base portion 55 for attaching the pipe joint portion. is not limited to this. For example, it is also possible to adopt a configuration in which the premixing flow path forming member is provided with a base portion, and the pipe joint portion is directly attached to the premixing flow path forming member.
The fuel gas is not limited to natural gas and LP gas, and the present invention can also be applied to other types of fuel gas.
The combustion device according to the present invention is not limited to use in a water heater, but can also be used as a combustion device for other uses such as heating or incineration. In addition, it is not limited to the type in which the combustion gas travels downward, but may also be a type in which the fuel gas travels upward, for example.

A, Aa to Ac Premixing device B Combustion device 3a, 3b First and second gas type display sections 4, 4C Premixing channel forming member 40 Premixing channel 5, 5C Housing member 55 Base part 7 Fuel gas flow Paths 71, 71A, 71B Base side holes 74, 74a Fuel gas outlet 77, 77A, 77B Joint side hole 8 Pipe joint 80 Cylindrical part (of the pipe joint)
81 Plate part (pipe joint part)
9 Gas pipe

Claims (7)

A premixing channel forming member forming a premixing channel for causing air to flow from one end side to the other end side and for mixing fuel gas with the air;
a pipe joint for connecting a gas pipe that supplies the fuel gas;
A base part to which this pipe joint part is attached,
a fuel gas passage whose terminal end is formed as a fuel gas outlet opening into the premixing passage, and which guides the fuel gas supplied to the pipe joint part to the fuel gas outlet;
It is equipped with
The pipe joint part and the base part are provided with a joint-side hole part and a base-side hole part, which can be made to face each other and communicate with each other, as holes forming a part of the fuel gas flow path. , a premixing device,
The pipe joint part is configured to be able to change the manner in which it is attached to the base part, and by changing the manner in which it is attached, the joint side hole part and the base side hole part are located in opposing positions and/or opposite to each other. A premixing device characterized in that the area is changed and the flow path resistance of the fuel gas flow path can be changed. The premixing device according to claim 1,
The premixing device is configured such that the fuel gas flows out from the fuel gas outlet into the premixing channel by the action of negative pressure generated due to airflow in the premixing channel. The premixing device according to claim 1 or 2,
The fuel gas includes predetermined first and second fuel gases of different types,
As the mounting mode of the pipe joint part, a first mounting mode in which the opposing area is an area corresponding to the first fuel gas, and a second mounting mode in which the opposing area is an area corresponding to the second fuel gas. A premixing device that can selectively set the installation mode of and either one of. The premixing device according to claim 3,
The base portion is provided with first and second gas type display portions indicating the first and second fuel gases, respectively;
When the pipe joint part is set in the first mounting mode, the second gas type display part is covered and hidden by the pipe joint part, and the first gas type display part is exposed. On the other hand, when the pipe joint section is set to the second mounting mode, the first gas type display section is covered by the pipe joint section, and the second gas type display section A premixing device configured such that it is exposed. The premixing device according to claim 3 or 4,
As the base side hole, at least two base side holes having different inner diameters are provided side by side,
The first attachment mode is such that one of the two base-side holes faces the joint-side hole, and the other is closed by the pipe joint,
In the second attachment mode, the direction of the pipe joint is reversed compared to the first attachment mode, and the one of the two base side holes is closed by the pipe joint. , and the other side faces the joint side hole. The premixing device according to claim 3 or 4,
As the joint side hole, at least two joint side holes having different inner diameters are provided side by side,
The first attachment mode is such that one of the two joint-side holes faces the base-side hole, and the other is closed by the base,
In the second mounting mode, compared to the first mounting mode, the direction of the pipe joint portion is reversed, and the one of the two joint side holes is closed by the base portion, The premixing device is configured such that the other side faces the base side hole. A combustion device comprising the premixing device according to any one of claims 1 to 6.

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