Premixing device and combustion device comprising a premixing device

Abstract

The present application provides a premixing device and a combustion device including the premixing device. A premixing flow path forming member (4) of a premixing device (A) is provided with a fuel gas flow path adjusting member (8) capable of blocking a portion of a fuel gas flow path (7), and by changing the mounting form of the fuel gas flow path adjusting member (8), the position and / or area at which the fuel gas flow path adjusting member (8) blocks the fuel gas flow path (7) is changed, so that the flow path resistance of the fuel gas flow path (7) can be changed. According to this structure, a premixing device can be provided which can appropriately cope with a plurality of fuel gases without changing parts or adding new parts corresponding to the type of fuel gas.

Description

Technical Field

[0001] This invention relates to a premixing device and a combustion apparatus including the premixing device. Here, "premixing" means the process of mixing air and fuel gas in advance to generate a combustible mixture for the purpose of premixing combustion. Background Technology

[0002] As a specific example of a premixing device, there is the device described in Patent Document 1.

[0003] The premixing device described in the document includes: a tubular component (premixing flow path forming component) forming a venturi-shaped premixing flow path; and two blade sections, longitudinal and transverse, installed within the tubular component. The downstream side (terminal side) of the premixing flow path is connected to the intake side of a fan, and air flows into the premixing flow path from the upstream side (starting side). A fuel gas outlet is provided in the blade section. When air flows in the premixing flow path and generates negative pressure, fuel gas flows out from the fuel gas outlet into the premixing flow path under the action of the negative pressure, thereby mixing with the air.

[0004] However, there is room for improvement in the prior art, as described below.

[0005] That is, there exists a situation where the fuel gas used in the premixing device is, for example, either natural gas (NG) or liquefied petroleum gas (LP). In this case, the two fuel gases have different compositions and calorific values, therefore the premixing device needs to be configured to correspond to the type of fuel gas.

[0006] Specifically, the premixing device includes a fuel gas flow path for guiding fuel gas from the outside of the premixing flow path forming member to the fuel gas outlet. This fuel gas flow path needs to be configured to correspond to the type of fuel gas. Given the same negative pressure generated within the premixing flow path, it must be configured such that the fuel gas with lower calorific value flows out of the fuel gas outlet into the premixing flow path in greater quantities than the fuel gas with higher calorific value. The premixing device needs to be configured to this specification.

[0007] In contrast, no simple and appropriate means to address the aforementioned situation has been previously proposed. Previously, the practice was to pre-fabricate parts corresponding to the type of fuel gas and prepare them. If a different type of fuel gas was used, measures such as replacing or adding new parts were taken. However, this requires replacing or adding parts, increasing the inventory and thus raising costs. Furthermore, parts management becomes cumbersome. Moreover, there is a concern that the original parts being replaced may become unusable.

[0008] [Existing technical documents]

[0009] [Patent Literature]

[0010] [Patent Document 1] Japanese Patent Publication No. 11-502278 Summary of the Invention

[0011] [The problem the invention aims to solve]

[0012] The purpose of this invention is to provide a premixing device and a combustion device including the premixing device, which can appropriately handle a variety of fuel gases without replacing parts or adding new parts corresponding to the type of fuel gas.

[0013] [Technical means to solve the problem]

[0014] To address the aforementioned issues, the following technical means are employed in this invention.

[0015] A premixing apparatus provided by a first aspect of the present invention includes: a premixing flow path forming member for forming a premixing flow path for causing air to flow in a predetermined direction and for mixing fuel gas with the air; a fuel gas flow path having a fuel gas supply port for receiving the fuel gas from the outside and a fuel gas outlet opening into the premixing flow path, and for guiding the fuel gas supplied to the fuel gas supply port to the fuel gas outlet; and a fuel gas flow path adjusting member, directly or indirectly mounted on the premixing flow path forming member, and capable of blocking a portion of the fuel gas flow path; and the mounting configuration of the fuel gas flow path adjusting member can be changed, and by changing the mounting configuration, the position and / or area of ​​the fuel gas flow path being blocked by the fuel gas flow path adjusting member can be changed, thereby changing the flow path resistance of the fuel gas flow path.

[0016] Here, "the installation form of the fuel gas flow path adjustment component can be changed" is equivalent to the situation where at least one of the installation position, direction, angle, or posture of the fuel gas flow path adjustment component can be changed.

[0017] The "Change the area of ​​the blocked fuel gas flow path" also includes the case of changing the area of ​​the blocked fuel gas flow path to zero.

[0018] Preferably, the premixing device of the present invention is configured such that the fuel gas flows out from the fuel gas outlet into the premixing flow path due to the negative pressure generated by the air flow in the premixing flow path.

[0019] As the fuel gas, there are different types of first fuel gas and second fuel gas. Preferably, the premixing device of the present invention further includes a first gas type display unit and a second gas type display unit that respectively represent the first fuel gas and the second fuel gas, and is configured such that: when the fuel gas flow path adjustment member is set to a predetermined first mounting configuration corresponding to the first fuel gas, the second gas type display unit is covered by the fuel gas flow path adjustment member and the first gas type display unit is exposed; on the other hand, when the fuel gas flow path adjustment member is set to a predetermined second mounting configuration corresponding to the second fuel gas, the first gas type display unit is covered by the fuel gas flow path adjustment member and the second gas type display unit is exposed.

[0020] Preferably, the premixing device of the present invention further includes a pipe connector portion having a cylindrical portion with an open front end, the cylindrical portion being used to connect a gas pipe for supplying the fuel gas, the fuel gas supply port being disposed in the inner side wall portion of the cylindrical portion, and the fuel gas flow path adjustment member being inserted into the cylindrical portion from the front end opening portion of the cylindrical portion and being installed in the inner side wall portion using a fastening member.

[0021] Preferably, the portion of the fuel gas flow path near the fuel gas supply port is divided into multiple parallel flow paths, and multiple fuel gas supply ports corresponding to the multiple parallel flow paths are provided as the fuel gas supply ports. The fuel gas flow path adjustment component can change the position and / or number of the multiple fuel gas supply ports that are blocked.

[0022] Preferably, the premixing device of the present invention includes a first parallel flow path and a second parallel flow path with different flow path areas as the plurality of parallel flow paths, and includes a first fuel gas supply port and a second fuel gas supply port corresponding to the first parallel flow path and the second parallel flow path as the plurality of fuel gas supply ports, wherein the fuel gas flow path adjusting member can selectively block one of the first fuel gas supply port and the second fuel gas supply port.

[0023] The premixing apparatus provided by a second aspect of the present invention includes: a premixing flow path forming member for forming a premixing flow path for causing air to flow in a predetermined direction and for mixing fuel gas with the air; a pipe connector for connecting a gas pipe for supplying the fuel gas; a base for mounting the pipe connector; and a fuel gas flow path, the terminal portion of which is formed as a fuel gas outlet opening into the premixing flow path and for guiding fuel gas supplied to the pipe connector to the fuel gas outlet; and wherein the pipe connector and the base are provided with a connector-side hole and a base-side hole that are mutually facing and communicating as holes constituting part of the fuel gas flow path, the pipe connector being able to change its mounting configuration relative to the base, and by changing the mounting configuration, changing the mutually facing position and / or facing area of ​​the connector-side hole and the base-side hole, thereby changing the flow path resistance of the fuel gas flow path.

[0024] Here, "able to change the mounting configuration of the base" is equivalent to the situation where at least one of the following can be changed: the position, direction, angle, or posture of the pipe fitting relative to the base.

[0025] As the fuel gas, there are different types of first fuel gas and second fuel gas. Preferably, the premixing device of the present invention further includes a first gas type display section and a second gas type display section that respectively represent the first fuel gas and the second fuel gas, and is configured such that: when the pipe joint is set to a predetermined first mounting configuration corresponding to the first fuel gas, the second gas type display section is covered by the pipe joint and the first gas type display section is exposed; on the other hand, when the pipe joint is set to a predetermined second mounting configuration corresponding to the second fuel gas, the first gas type display section is covered by the pipe joint and the second gas type display section is exposed.

[0026] Preferably, in the premixing device of the present invention, at least two base side holes with different inner diameters are arranged as the base side holes. The first installation configuration is that one of the two base side holes faces the connector side hole, and the other is blocked by the connector. Compared with the first installation configuration, the second installation configuration is that the direction of the connector is reversed, one of the two base side holes is blocked by the connector, and the other faces the connector side hole.

[0027] Preferably, in the premixing device of the present invention, at least two connector side holes with different inner diameters are arranged as the connector side holes. The first installation configuration is that one of the two connector side holes faces the base side hole, and the other is blocked by the base. Compared with the first installation configuration, the second installation configuration is that the direction of the pipe connector is reversed, one of the two connector side holes is blocked by the base, and the other faces the base side hole.

[0028] The combustion apparatus provided by a third aspect of the invention includes the premixing apparatus provided by a first or second aspect of the invention.

[0029] Other features and advantages of the invention become clearer from the following description of embodiments of the invention with reference to the accompanying drawings. Attached Figure Description

[0030] Figure 1 This is an explanatory diagram illustrating an example of a combustion apparatus including the premixing device of the present invention and a hot water supply device utilizing the same.

[0031] Figure 2 yes Figure 1 Section II-II.

[0032] Figure 3 yes Figure 1 and Figure 2 The diagram shows a perspective view of the premixing device.

[0033] Figure 4A yes Figure 3 Section IV-IV Figure 4B yes Figure 4A Anatomical diagram.

[0034] Figure 5 yes Figure 4A VV cross-section diagram.

[0035] Figure 6 yes Figure 3 Front view of the main part of the premixing device shown.

[0036] Figure 7 yes Figure 6 The main parts are broken down into frontal views.

[0037] Figure 8 This indicates that the fuel gas flow path adjustment component is set to be consistent with... Figure 6 Front view of the main part of different morphological examples.

[0038] Figure 9A and Figure 9B express Figures 1 to 8The fuel gas flow path adjustment component used in the premixing device shown, Figure 9A This is a three-dimensional view taken from the outside. Figure 9B This is a three-dimensional view taken from the inside side.

[0039] Figure 10 This is a perspective view showing another example of the premixing apparatus of the present invention.

[0040] Figure 11A yes Figure 10 XI-XI cross-section view, Figure 11B yes Figure 11A Anatomical diagram of the main parts.

[0041] Figure 12 yes Figure 10 Front view of the main part of the premixing device shown.

[0042] Figure 13 yes Figure 12 The main parts are broken down into frontal views.

[0043] Figure 14 This indicates that the fuel gas flow path adjustment component is set to be consistent with... Figure 12 Front view of the main part of different morphological examples.

[0044] Figure 15 It means Figures 10-14 A perspective view of the fuel gas flow path adjustment component used in the premixing device, viewed from the inside side.

[0045] Figure 16 This is a front view of the main part showing other examples of the premixing apparatus of the present invention.

[0046] Figure 17A yes Figure 16 XVII-XVII cross-sections, Figure 17B yes Figure 17A Anatomical diagram of the main parts.

[0047] Figure 18 yes Figure 16 The main parts are broken down into frontal views.

[0048] Figure 19 This indicates that the fuel gas flow path adjustment component is set to be consistent with... Figure 16 Front view of the main part of different morphological examples.

[0049] Figure 20 This is an exploded front view showing other examples of the premixing apparatus of the present invention.

[0050] Figure 21A and Figure 21B It means in Figure 20 The diagram shows a front view of the main part of the structure with the fuel gas flow path adjustment component installed.

[0051] Figure 22 This is a front view of the main part showing other examples of the premixing apparatus of the present invention.

[0052] Figure 23 yes Figure 22 Cross-sectional view of the main parts of XXIII-XXIII.

[0053] Figure 24 yes Figure 22 The main parts are broken down into frontal views.

[0054] Figure 25A and Figure 25B This indicates that the fuel gas flow path adjustment component is set to be consistent with... Figure 22 Examples of different forms, Figure 25A This is a front view of the main part. Figure 25B yes Figure 25A XXV-XXV cross-sectional view.

[0055] Figure 26A and Figure 26B Other examples illustrating the premixing apparatus of the present invention, Figure 26A This is a front view of the main part. Figure 26B yes Figure 26A XXVI-XXVI cross-sectional view.

[0056] Figure 27 yes Figure 26A The main parts are broken down into frontal views.

[0057] Figure 28A and Figure 28B This indicates that the fuel gas flow path adjustment component is set to be consistent with... Figure 26A and Figure 26B Examples of different forms, Figure 28A This is a front view of the main part. Figure 28B yes Figure 28A XXVIII-XXVIII cross-section.

[0058] Figure 29 This is a partial anatomical view showing other examples of the premixing apparatus of the present invention.

[0059] Figure 30A This is a perspective view showing other examples of the premixing apparatus of the present invention. Figure 30B yes Figure 30A An exploded 3D diagram.

[0060] Figure 31 yes Figure 30A and Figure 30BA perspective view of the pipe fitting of the premixing device as seen from the inside.

[0061] Figure 32A yes Figure 30A Front view, Figure 32B yes Figure 32A Sectional view of XXXII-XXXII.

[0062] Figure 33 yes Figure 32B Anatomical diagram.

[0063] Figure 34A It is to set the pipe fitting part to be with Figure 32A Front views of different forms and states. Figure 34B yes Figure 34A Sectional view of XXXIV-XXXIV.

[0064] Figure 35 This is a perspective view showing another example of the premixing apparatus of the present invention.

[0065] Figure 36 yes Figure 35 An exploded front view of the main parts of the premixing device shown.

[0066] Figure 37 yes Figure 35 Sectional view of XXXVII-XXXVII.

[0067] Figure 38 It is to set the pipe fitting part to be with Figure 37 Cross-sectional views of different states.

[0068] Figure 39 This is a cross-sectional view showing another example of the premixing apparatus of the present invention.

[0069] Figure 40 This is a cutaway view illustrating other examples of the premixing apparatus of the present invention. Detailed Implementation

[0070] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0071] Figure 1 The diagram shows a premixing device A, a combustion device B (premixed combustion device) consisting of a fan 1 and a combustion plate 2 combined in the premixing device A, and a hot water supply device WH consisting of a heat exchanger 11 combined in the combustion device B.

[0072] Details regarding the premixing device A will be described below. The premixing device A generates a mixture of air and fuel gas (combustible mixture), which is then ejected towards the combustion plate 2 via a fan 1. The combustion plate 2 is a porous plate with multiple vent holes 20 and is housed within a housing 10. The mixture passes through the combustion plate 2 and burns below it. The resulting combustion gases act on a heat exchanger 11, heating the hot and cold water passing through it. This generates warm water, which is supplied to the desired hot water supply destination.

[0073] Premixing device A includes: a premixing flow path forming member 4 having a tubular portion 41 forming a premixing flow path 40; a housing member 5 mounted on the premixing flow path forming member 4; blade portions 6 each having a fuel gas outlet 74; a fuel gas flow path 7 having a fuel gas outlet 74; and Figures 3 to 9B The fuel gas flow path adjustment component 8 is shown.

[0074] The premixing flow path forming component 4 is connected to the intake side of the fan 1. When the fan 1 is driven, external air flows into the premixing flow path 40 from one end opening. The premixing flow path 40 is venturi-shaped as follows: the upstream region in the gas flow direction is a cone-shaped region with an inner diameter that gradually decreases towards the downstream side in the gas flow direction, and the region further downstream than the cone-shaped region is a cone-shaped region with an inner diameter that gradually increases towards the downstream side.

[0075] Each blade section 6 is a nozzle that directs fuel gas from the fuel gas outlet 74 into the premixed flow path 40. Figure 2 As shown, it is configured as a bridge-like structure with both ends connected to the peripheral wall of the tubular portion 41, located within the premixing flow path 40. A pair of blade portions 6 are positioned in their thickness direction ( Figure 1 Arranged roughly parallel to each other at appropriate intervals in the left and right directions.

[0076] The interior of each blade section 6 is a cavity section 73 that forms part of the fuel gas flow path 7, and the fuel gas outlet 74 communicates with the cavity section 73. On the other hand, the airflow in the premixing flow path 40 generates a negative pressure near the fuel gas outlet 74. Under the action of this negative pressure, fuel gas flows out from the fuel gas outlet 74 into the premixing flow path 40, thereby achieving mixing of air and fuel gas.

[0077] The number of blade sections 6 is not limited to two; it can also be set to only one or more than three.

[0078] The housing component 5 includes a cylindrical housing body 50, a pipe fitting portion 51 integrally or separately disposed with the housing body 50, and a flange portion 53 having a bolt insertion hole 52. The flange portion 53 facilitates easy and proper connection of the premixing device A to the desired location.

[0079] The stepped portions 42a and 42b, which are embedded on the outer periphery of the premixed flow path forming member 4, surround the premixed flow path forming member 4 in a state of airtight sealing achieved by the sealing ring 49. The area 72 between the premixed flow path forming member 4 and the housing body 50 constitutes part of the fuel gas flow path 7.

[0080] The connector 51 is the part where the gas pipe 9 (including a hose) for supplying fuel gas is connected, and the fuel gas supplied from the gas pipe 9 to the connector 51 flows into the area 72. Figure 2 As shown, the premixed flow path forming member 4 has an opening 43 that communicates with the cavity 73 in each blade section 6. Fuel gas flowing into the region 72 flows into each blade section 6 through the opening 43 and flows out from the fuel gas outlet 74 as described above.

[0081] The pipe connector portion 51 is described in more detail. The pipe connector portion 51 includes a cylindrical portion 51a with an open front end, and an inner wall portion 51b with a fuel gas supply port 70 is provided deep inside the cylindrical portion 51a.

[0082] Fuel gas flow path 7 is a flow path that guides fuel gas from fuel gas supply port 70 to fuel gas outlet 74. For example, Figures 4A to 8 As shown, a first parallel flow path 71A and a second parallel flow path 71B, which form part of the fuel gas flow path 7, are arranged at appropriate intervals in the pipe joint portion 51, and a first fuel gas supply port 70a and a second fuel gas supply port 70b are provided as their openings.

[0083] like Figure 4A and Figure 4B As shown, the inner diameters Da and Db of the first parallel flow path 71A and the second parallel flow path 71B are different, and Da < Db. The inner diameter Da is the flow path inner diameter suitable for using LP gas as the fuel gas. The inner diameter Db is the flow path inner diameter suitable for using natural gas as the fuel gas.

[0084] The inner diameter Dc of the portion into which the sealing convex part 83 of the fuel gas flow path adjustment component 8 (the portion near the first fuel gas supply port 70a and the second fuel gas supply port 70b) is embedded is larger than the inner diameters Da and Db, and they are made to be the same size.

[0085] like Figure 7 As shown, a first gas type display section Ia and a second gas type display section Ib, as well as two threaded holes 59, are also provided on the inner wall section 51b of the pipe connector section 51. The first gas type display section Ia and the second gas type display section Ib are positioned near the upper or lower side of the first fuel gas supply port 70a and the second fuel gas supply port 70b, respectively, and indicate that the first fuel gas supply port 70a and the second fuel gas supply port 70b correspond to LP gas and natural gas, respectively. For example, they are set as the characters "LP" and "NG". However, different display forms are also possible.

[0086] The fuel gas flow path adjustment component 8 is used to selectively block either the first fuel gas supply port 70a or the second fuel gas supply port 70b according to the type of fuel gas. For example... Figure 9A and Figure 9B As shown, the fuel gas flow path adjustment component 8 has the following structure: it includes a semi-circular plate-shaped main body 80, and the main body 80 is provided with a pinching part 81, a threaded body insertion hole 82, and a sealing convex part 83. Figure 4A , Figure 4B and Figure 5 As shown, the sealing O-ring 84 is externally fitted onto the sealing convex portion 83.

[0087] like Figures 4A to 6 As shown, the fuel gas flow path adjustment member 8 is installed on the inner wall portion 51b of the pipe connector portion 51 in a form that blocks the first fuel gas supply port 70a (first installation form). This installation is performed using a threaded body 98 (fastening member) such as a screw that engages with the threaded hole 59. In the first installation form, the sealing protrusion 83 is inserted into the first fuel gas supply port 70a, and the second gas type display portion Ib is covered by the fuel gas flow path adjustment member 8. The first gas type display portion Ia is exposed on the front of the pipe connector portion 51 without being covered by the fuel gas flow path adjustment member 8.

[0088] Regarding the fuel gas flow path adjustment component 8, as in its mounting configuration relative to the inner wall portion 51b of the pipe connector portion 51, such as... Figure 8As shown, it can also be configured to block the second fuel gas supply port 70b (second installation configuration). The change from the first installation configuration to the second installation configuration can be performed as follows: loosen the fastening of the threaded body 98, temporarily remove the fuel gas flow path adjusting member 8 from the inner wall portion 51b, and then reinstall the fuel gas flow path adjusting member 8 in its reversed position using the threaded body 98 back onto the inner wall portion 51b. In the second installation configuration, unlike the first installation configuration, the sealing protrusion 83 is embedded in the second fuel gas supply port 70b. Furthermore, the first gas type display portion Ia is covered by the fuel gas flow path adjusting member 8, while the second gas type display portion Ib is exposed on the front of the pipe connector portion 51.

[0089] Next, the function of the premixing device A will be explained.

[0090] First, regarding the environment in which premixing device A is used, in the case where the fuel gas is, for example, natural gas, Figures 3-6 As shown, the fuel gas flow path adjustment member 8 is pre-configured in a first installation configuration. Consequently, the first parallel flow path 71A is blocked by the fuel gas flow path adjustment member 8, and the second parallel flow path 71B becomes an effective flow path constituting part of the fuel gas flow path 7. As described above, the inner diameter Db of the second parallel flow path 71B corresponds to that of natural gas. Natural gas has a lower calorific value than LP gas, therefore, compared to the case of using LP gas, a greater amount of gas relative to air is required. This necessity can be appropriately addressed according to the first installation configuration. That is, the inner diameter of the second parallel flow path 71B is larger than that of the first parallel flow path 71A, which reduces the flow resistance of the fuel gas flow path 7. Therefore, through the negative pressure effect caused by the airflow in the premixed flow path 40, more natural gas can flow out from the fuel gas outlet 74.

[0091] Unlike the above, when the fuel gas is LP gas, it only needs to be changed to Figure 8 The second mounting configuration shown is acceptable. As described above, the change from the first mounting configuration to the second mounting configuration can be easily and quickly performed by loosening the threaded body 98, etc. In the second mounting configuration, unlike the first mounting configuration, the second parallel flow path 71B is closed, and the first parallel flow path 71A becomes an effective flow path constituting part of the fuel gas flow path 7. As described above, the inner diameter Da of the first parallel flow path 71A corresponds to LP gas. LP gas has a higher calorific value than natural gas, therefore it is necessary to reduce the amount of gas relative to air; this situation can be appropriately addressed according to the second mounting configuration.

[0092] As described above, according to this embodiment, even if the fuel gas is either natural gas or LP gas, there is no need to replace parts or install new parts. Simply changing the installation configuration of the fuel gas flow path adjustment component 8 is sufficient to accommodate different types of fuel gases. Therefore, there is no problem such as an increased inventory of parts to accommodate different types of fuel gases, reducing the cost of parts inventory. In addition, component management becomes easier.

[0093] Furthermore, according to this embodiment, when the fuel gas flow path adjustment member 8 is installed in the first mounting configuration, the second gas type display section Ib is covered, but the character "NG" in the first gas type display section Ia remains exposed. Conversely, when the fuel gas flow path adjustment member 8 is installed in the second mounting configuration, the first gas type display section Ia is covered, and the character "LP" in the second gas type display section Ib is exposed. Therefore, by checking this display, it is possible to easily and accurately determine whether the mounting configuration of the fuel gas flow path adjustment member 8 is an appropriate mounting configuration corresponding to the actual type of fuel gas.

[0094] Furthermore, the fuel gas flow path adjustment component 8 is formed in the shape of a small piece and is installed inside the pipe joint portion 51. Therefore, the fuel gas flow path adjustment component 8 does not have a large volume, and the large size of the premixing device A can also be suppressed.

[0095] Figures 10-40 Other embodiments of the invention are illustrated. In these figures, elements that are the same as or similar to those in the described embodiments are labeled with the same symbols as in the described embodiments, and repeated descriptions are omitted.

[0096] exist Figures 10-14 In the premixing device Aa shown, a plurality of (e.g., four) parallel flow paths 71 are provided on the inner wall portion 51b of the pipe connector portion 51, and a plurality of fuel gas supply ports 70, which serve as their openings, are arranged concentrically. A threaded hole 59 is provided in the center of the inner wall portion 51b, and a plurality of positioning recesses 58 are provided around it.

[0097] like Figure 15 As shown, the fuel gas flow path adjustment member 8A has the following structure: a circular plate-shaped main body 80 has a number of elongated openings 85, the same number as the fuel gas supply port 70, and multiple positioning protrusions 86 protrude from the inner surface of the main body 80. The multiple positioning protrusions 86 are positioned such that, when the fuel gas flow path adjustment member 8A is set in the first and second mounting configurations described later, they are embedded in the multiple recesses 58 to achieve positioning of the fuel gas flow path adjustment member 8A.

[0098] like Figures 10-12As shown, the premixing device Aa in this embodiment is configured as follows: a fuel gas flow path adjustment member 8A is installed on the inner wall portion 51b of the pipe joint portion 51 using a threaded body 98. Wherein, when the fuel gas is natural gas, the fuel gas flow path adjustment member 8A is configured as follows: Figure 12 The first installation configuration is shown. In the first installation configuration, the plurality of openings 85 overlap with the plurality of fuel gas supply ports 70, and the effective opening area of ​​the plurality of fuel gas supply ports 70 is equal to the total area of ​​the plurality of openings 85.

[0099] In contrast, when the fuel gas is LP gas, the fuel gas flow path adjustment component 8A is set to... Figure 14 The second mounting configuration is shown. In this second mounting configuration, a portion of each of the plurality of openings 85 overlaps with a portion that is not a fuel gas supply port 70, but the entire plurality of openings 85 does not overlap with the plurality of fuel gas supply ports 70. Therefore, in this second mounting configuration, [the following is a description of the second mounting configuration, which is not directly related to the second mounting configuration]. Figure 12 Compared to the first installation configuration shown, the effective opening area of ​​the fuel gas supply port 70 is reduced to better accommodate the high calorific value of LP gas.

[0100] From Figure 12 The first installation configuration shown has been changed to Figure 14 In the second installation configuration shown, simply loosen the threaded body 98 to rotate the fuel gas flow path adjusting member 8A by an appropriate angle. Furthermore, at this time, simply set the angle of the fuel gas flow path adjusting member 8A to the position where the multiple protrusions 86 and recesses 58 for positioning engage. Therefore, changing the installation configuration is also easy.

[0101] exist Figures 16-19 In the premixing device Ab shown, a plurality of parallel flow paths 71 are provided on the inner sidewall 51b of the connector portion 51, and a plurality of fuel gas supply ports 70, which are their openings, are arranged on the same circle. The parallel flow paths 71 and fuel gas supply ports 70 are provided with a smaller area than those of the premixing device Aa in the previous embodiment, and the number of such parallel flow paths 71 and fuel gas supply ports 70 is increased. The fuel gas flow path adjustment member 8B has the following structure: it is provided with the same number of openings 85 as the fuel gas supply ports 70, and the openings are approximately the same shape and size as the fuel gas supply ports 70. In addition, it also includes a plurality of protrusions 86 that can engage with a plurality of positioning recesses 58 provided on the connector portion 51.

[0102] In the premixing device Ab of this embodiment, when the fuel gas is natural gas, the fuel gas flow path adjustment member 8B is set to... Figure 16The first installation configuration is shown. In this configuration, the plurality of openings 85 overlap with the plurality of fuel gas supply ports 70, and the plurality of fuel gas supply ports 70 are in a wide-open state. Therefore, it is suitable for natural gas with low calorific value.

[0103] In contrast, when the fuel gas is LP gas, the fuel gas flow path adjustment component 8B is set to... Figure 19 The second installation configuration is shown. In this configuration, the fuel gas supply ports 70 and openings 85 do not overlap perfectly, and a portion of each fuel gas supply port 70 is blocked. Therefore, it is suitable for LP gas with high calorific value.

[0104] In this embodiment, the change in the mounting configuration of the fuel gas flow path adjustment member 8B is the same as that of the premixing device Aa described previously; simply loosening the threaded body 98 allows the fuel gas flow path adjustment member 8B to rotate, making the operation easy. Furthermore, by engaging the multiple protrusions 86 with the recesses 58, the rotation angle of the fuel gas flow path adjustment member 8B can be precisely determined, thus providing convenience.

[0105] exist Figures 20-21B In the premixing device Ac shown, a plurality of parallel flow paths 71 are provided on the inner sidewall 51b of the pipe connector 51, and a plurality of fuel gas supply ports 70 are provided as their openings. The plurality of fuel gas supply ports 70 are arranged on the same circle, but they are not equally spaced, but have unequally spaced portions 70' (slightly wider areas where no fuel gas supply ports 70 are provided).

[0106] The fuel gas flow path adjustment component 8C includes multiple openings 85 that are substantially the same in shape, size, and configuration as the multiple fuel gas supply ports 70.

[0107] In the premixing device Ac, when the fuel gas is natural gas, the fuel gas flow path adjustment member 8C is set as follows: Figure 21A The first installation configuration is shown. In this configuration, all of the multiple fuel gas supply ports 70 overlap with the opening 85, creating a wide-open state. In contrast, when the fuel gas is LP gas, the fuel gas flow path adjustment member 8C is set as... Figure 21BThe second installation configuration is shown. In this configuration, an opening 85 is located at unequal intervals 70', and one of the multiple fuel gas supply ports 70 is blocked by the fuel gas flow path adjusting member 8C. Therefore, in this embodiment, it is feasible to handle situations where the fuel gas is either natural gas or LP gas. Regarding changes to the installation configuration of the fuel gas flow path adjusting member 8C, it is simply a matter of loosening the threaded body 98 to rotate the fuel gas flow path adjusting member 8C, thus the operation remains easy.

[0108] exist Figures 22-25B In the premixing device Ad shown, instead of multiple parallel flow paths, a single orifice 71C is provided in the pipe connector portion 51, forming part of the fuel gas flow path 7. The opening of the orifice 71C is a fuel gas supply port 70. The fuel gas supply port 70 is positioned offset in one direction (to the right in the drawing) relative to the center of the inner wall portion 51b of the pipe connector portion 51. On the other hand, the fuel gas flow path adjustment member 8D has the following structure: two openings 85a and 85b of different diameters and two threaded insertion holes 82 are provided in the circular plate-shaped main body portion 80.

[0109] Figure 22 and Figure 23 A first mounting configuration of the fuel gas flow path adjustment member 8D is shown. In this first mounting configuration, the opening 85a on the large-diameter side of the fuel gas flow path adjustment member 8D overlaps with the fuel gas supply port 70. In contrast, Figure 25A and Figure 25B A second mounting configuration of the fuel gas flow path adjustment member 8D is shown. In this second mounting configuration, the small-diameter opening 85b of the fuel gas flow path adjustment member 8D overlaps with the fuel gas supply port 70.

[0110] The effective opening area of ​​the fuel gas supply port 70 is larger in the first installation configuration and smaller in the second installation configuration, thus achieving the intended effect of the present invention. Switching between the first and second installation configurations is easy; simply loosen the threaded body 98, temporarily remove the fuel gas flow path adjustment component 8D, reverse it, and reinstall it.

[0111] According to this embodiment, there is no need to set up multiple parallel flow paths, thus simplifying the fuel gas flow path 7.

[0112] exist Figures 26A to 28BIn the premixing device Ae shown, a hole 71D forming part of the fuel gas flow path 7 is provided at the pipe joint 51. The hole 71D is elongated and its opening is the fuel gas supply port 70. On the other hand, the fuel gas flow path adjustment member 8E has the following structure: a circular opening 85 is provided at a position off-center from the center of the circular plate-shaped main body 80.

[0113] Figure 26A and Figure 26B A first installation configuration of the fuel gas flow path adjustment member 8E is shown. In this first installation configuration, the fuel gas supply port 70 is blocked by the fuel gas flow path adjustment member 8E such that the opening 85 of the fuel gas flow path adjustment member 8E faces a portion of the fuel gas supply port 70.

[0114] Figure 28A and Figure 28B A second mounting configuration of the fuel gas flow path adjustment member 8E is shown. In this second mounting configuration, the fuel gas supply port 70 is blocked by the fuel gas flow path adjustment member 8E so that only a portion of the opening 85 of the fuel gas flow path adjustment member 8E faces a portion of the fuel gas supply port 70.

[0115] In this embodiment, similar to the previous embodiment, the effective opening area of ​​the fuel gas supply port 70 is larger in the first installation configuration and smaller in the second installation configuration. The first installation configuration is suitable for natural gas, and the second installation configuration is suitable for LP gas. Furthermore, similar to the premixing device Ad, multiple parallel flow paths are not required, simplifying the fuel gas flow path 7.

[0116] exist Figure 29 In the premixing device Af shown, the premixing flow path forming member 4F is constructed using a first tubular portion 4b and a second tubular portion 4c. An air inlet 40a is provided at the base end of the first tubular portion 4b, and the first tubular portion 4b and the second tubular portion 4c form a premixing flow path 40. A fuel gas outlet 74a, serving as a gap, is provided between the front end of the first tubular portion 4b and the base end of the second tubular portion 4c, opening into the premixing flow path 40. Fuel gas supplied to the connector portion 51 passes through the region 72 provided between the first tubular portion 4b and the second tubular portion 4c and the housing member 5F, and reaches the fuel gas outlet 74a.

[0117] A pipe connector portion 51 is provided in the housing member 5F, but the pipe connector portion 51 is provided with, for example, a... Figure 4A and Figure 4BThe two parallel flow paths 71A and 71B shown are identical. In addition, either of the two fuel gas supply ports 70 (70a and 70b) that serve as the openings of the parallel flow paths 71A and 71B can be selectively blocked by the fuel gas flow path adjustment member 8.

[0118] In this embodiment, a negative pressure is generated near the fuel gas outlet 74a due to the air flowing in the venturi-shaped premixing flow path 40, causing the fuel gas to flow out from the fuel gas outlet 74a into the premixing flow path 40. Unlike the previously described embodiment, the blade portion 6 with the fuel gas outlet 74 is not used, but a suitable mixture of air and fuel gas can still be generated. The premixing flow path and the premixing flow path forming member in this invention can also be configured as in this embodiment.

[0119] exist Figure 30A and Figure 30B In the premixing device Ag shown, with Figures 1 to 29 The described implementation methods differ, including the pipe connector 3, and by changing the installation configuration of the pipe connector 3, the flow resistance of the fuel gas flow path 7 can be changed.

[0120] Specifically, in the premixing device Ag, a base portion 55 is provided in the housing component 5, and a pipe connector portion 3 for connecting the gas pipe 9 is installed on the outer surface of the base portion 55.

[0121] In addition to having a flat front portion suitable for mounting the pipe fitting portion 3, the base portion 55 also includes two holes 75A and 75B (base side holes 75A and 75B) that form part of the fuel gas flow path 7, a pair of threaded holes 59 on the left and right, a gasket groove 56 for assembling the sealing gasket 94, and a first gas type display portion Ic and a second gas type display portion Id.

[0122] Furthermore, the first gas type display unit Ic differs from the previous first gas type display unit Ia, and is set to display the character "LP" indicating that the fuel gas is LP gas. The second gas type display unit Id differs from the previous second gas type display unit Ib, and is set to display the character "NG" indicating that the fuel gas is natural gas.

[0123] like Figure 33As shown, the inner diameters De and Df of the two base side holes 75A and 75B are different, with De < Df. The inner diameter De is the flow path inner diameter suitable for using LP gas as fuel gas. The inner diameter Df is the flow path inner diameter suitable for using natural gas as fuel gas. Specifically, the inner diameter Dg of the portion 76 (the portion 76 of the base side holes 75A and 75B closest to the pipe connector 3) into which the sealing protrusion 33 of the supply pipe connector 3 (described later) is embedded is larger than the inner diameters De and Df, and they are made to be the same size.

[0124] The pipe fitting portion 3 includes a cylindrical portion 30 with an open front end, a plate portion 31 connected to the base end of the cylindrical portion 30, and an inner wall portion 35 disposed deep within the cylindrical portion 30. The inner wall portion 35 has a hole portion 77 (fitting-side hole portion 77) that forms part of the fuel gas flow path 7, and also has a protruding sealing convex portion 33 (see also...). Figure 31 A sealing O-ring 34 is fitted onto the sealing convex portion 33. The connector side hole portion 77 and the sealing convex portion 33 are configured to correspond to the two base side holes portions 75A and 75B.

[0125] The pipe fitting portion 3 is mounted to the base portion 55 such that the front surfaces of the plate portion 31 and the base portion 55 are in face-to-face contact. As a mounting method, for example, the plate portion 31 can be fastened by screwing a threaded body 97, such as a screw, into a pair of threaded insertion holes 32 provided in the plate portion 31, into a threaded hole 59 in the base portion 55. A sealing washer 94 is sandwiched between the pipe fitting portion 3 and the base portion 55 and compressed, which helps to prevent fuel gas leakage. The sealing washer 94 and the washer groove 56 are annular, surrounding the two base side holes 75A and 75B.

[0126] The mounting configuration of the pipe fitting portion 3 relative to the base portion 55 can be selectively set to either the first mounting configuration or the second mounting configuration described below.

[0127] In the first installation configuration of the pipe fitting portion 3, such as Figure 30A , Figure 30B , Figure 32A and Figure 32B As shown, one of the two base side holes 75A and 75B, 75A, faces and communicates with the connector side hole 77. The other base side hole 75B is in a state where the sealing protrusion 33 is embedded and blocked.

[0128] A narrow and wide slit 31a is provided at one end of the plate portion 31 of the pipe connector portion 3. In the first mounting configuration, the slit 31a of the plate portion 31 exposes the character "LP" for the first gas type display unit Ic. On the other hand, the character "NG" for the second gas type display unit Id is covered by the plate portion 31.

[0129] In the second mounting configuration of the pipe fitting portion 3, such as Figure 34A and Figure 34B As shown, the connector portion 3 is mounted on the base portion 55 in a direction reversed from the first mounting configuration. In the second mounting configuration, the base side hole portion 75B faces and communicates with the connector side hole portion 77. Furthermore, the base side hole portion 75A is in a state where the sealing protrusion 33 is embedded and blocked. The position of the cutout portion 31a of the plate portion 31 is reversed from the first mounting configuration, thus the character "NG" for the second gas type display portion Id is exposed, while the character "LP" for the first gas type display portion Ic is covered by the plate portion 31.

[0130] Next, the function of the premixing device Ag will be explained.

[0131] First, regarding the environment in which the premixing device Ag is used, in the case where the fuel gas is, for example, LP gas, such as Figure 30A , Figure 30B , Figure 32A and Figure 32B As shown, the pipe fitting portion 3 is pre-configured as the first mounting configuration. In the first mounting configuration, as... Figure 30A , Figure 30B , Figure 32A and Figure 32B As shown, the base side hole 75B is blocked by the pipe connector 3, and the base side hole 75A faces and communicates with the connector side hole 77. The inner diameter De of the base side hole 75A is small, thus increasing the flow resistance of the fuel gas flow path 7. Here, since LP gas has a higher calorific value than natural gas, the amount of gas relative to air needs to be reduced compared to using natural gas. According to the first installation configuration, the flow resistance of the fuel gas flow path 7 increases, thus creating a setting suitable for LP gas.

[0132] On the other hand, when the fuel gas is natural gas, it is changed to Figure 34A and Figure 34B The second mounting configuration is shown. The change from the first mounting configuration to the second mounting configuration is simple: just loosen the threaded body 97, change the orientation of the pipe fitting portion 3, and reinstall it on the base portion 55. Therefore, the operation can be performed easily and quickly.

[0133] In the second installation configuration, opposite to the first configuration, the base side hole 75A is blocked by the pipe connector 3, and the base side hole 75B faces and communicates with the connector side hole 77. The base side hole 75B has a large inner diameter Df, which reduces the flow resistance of the fuel gas flow path 7. Since the calorific value of natural gas is less than that of LP gas, it is necessary to reduce the flow resistance and increase the amount of gas relative to air. The second installation configuration can appropriately address this situation.

[0134] As described above, according to this embodiment, even if the fuel gas is either LP gas or natural gas, there is no need to replace parts or add new parts. Simply changing the installation configuration of the connector 3 is sufficient to accommodate both fuel gases. Therefore, similar to the premixing devices A, Aa to Af described previously, there is no issue of increased inventory of parts for handling two types of fuel gases, reducing inventory costs. Furthermore, component management becomes easier. The connector 3 is a part originally included in the premixing device Ag; in this embodiment, it is configured to handle various types of fuel gases, making its structure reasonable and more preferable in terms of avoiding an increase in the number of parts or overall enlargement.

[0135] Furthermore, according to this embodiment, when the connector portion 3 is configured in the first mounting configuration, it becomes such that the second gas type display Id is covered by the connector portion 3, and the character "LP" for the first gas type display Ic is exposed. Conversely, when the connector portion 3 is configured in the second mounting configuration, it becomes such that the first gas type display Ic is covered, and the character "NG" for the second gas type display Id is exposed. Therefore, by checking this display, it is possible to easily and accurately determine whether the mounting configuration of the connector portion 3 is an appropriate mounting configuration corresponding to the actual type of fuel gas.

[0136] exist Figures 35-38 In the premixing device Ah shown, two connector side holes 77A and 77B are provided in the pipe connector section 3, and only one base side hole 75 is provided in the base section 55. The inner diameters D1 and D2 of the two connector side holes 77A and 77B are different, for example, D1 < D2.

[0137] In the premixing device Ah, regarding the first mounting configuration of the pipe fitting portion 3, as follows: Figure 35 and Figure 37 As shown, it can be set to the following state: the connector side hole 77A and the base side hole 75 face each other and are connected, while the connector side hole 77B is not connected to the base side hole 75. The inner diameter D1 of the connector side hole 77A is a small diameter, so according to the first installation configuration, the flow resistance of the fuel gas flow path 7 can be increased, which is suitable for LP gas.

[0138] On the other hand, regarding the second mounting configuration of the pipe fitting portion 3, such as Figure 38 As shown, conversely, it can also be configured as follows: the connector-side hole 77B faces and communicates with the base-side hole 75, while the connector-side hole 77A is not communicated with the base-side hole 75. According to the second installation configuration, the inner diameter D2 of the connector-side hole 77B is a large diameter, which reduces the flow resistance of the fuel gas flow path 7, thus making it suitable for natural gas.

[0139] In the premixing apparatus Ah of this embodiment, when with Figures 30A to 34B Compared to the premixing device Ag of the previous embodiment shown, the relationship between the base side hole portion 75 (75A, 75B) provided in the base portion 55 and the connector side hole portion 77 (77A, 77B) provided in the connector portion 3 is reversed, but the same function as the premixing device Ag of the previous embodiment can be obtained.

[0140] exist Figures 36-38 In this structure, the gasket 94A, which serves as a seal between the base portion 55 and the pipe connector portion 3, includes a portion that includes a straight portion 94b positioned between the two connector side holes 77A and 77B, in addition to an annular portion 94a that surrounds the opposing areas of the two connector side holes 77A and 77B. This structure effectively prevents fuel gas leakage between the two connector side holes 77A and 77B.

[0141] exist Figure 39 In the premixing device Ai shown, a connector-side hole 77 is formed in the connector portion 3 in a so-called conical shape. The inner diameter or width of the connector-side hole 77 becomes narrower as it moves from the front end side of the connector portion 3 towards the base end side. Figure 39 The diagram shows the state in which the connector side hole 77 and the base side hole 75B face each other and are connected. However, when the pipe connector 3 is set to the installation state after left and right reversal, the connector side hole 77 and the base side hole 75A face each other and are connected.

[0142] According to this embodiment, fuel gas supplied from gas pipe 9 to pipe connector 3 can smoothly flow from connector side hole 77 to base side hole 75A, 75B. This is preferable in terms of stabilizing the supply of fuel gas to premixed flow path 40.

[0143] exist Figure 40 In the premixing device Aj shown, the premixing flow path forming component 4F is configured to be... Figure 29 The premixed flow path forming member 4F shown has the same structure. On the other hand, a base portion 55 is provided on the housing member 5G. The base portion 55 is, for example, similar to... Figure 32B and Figure 33The base portion 55 shown has the same structure and has two base side holes 75A and 75B. The pipe fitting portion 3 can be installed in the base portion 55.

[0144] In this embodiment, based on and Figure 29 The same principle applies to the illustrated embodiment, enabling the appropriate generation of a mixture of air and fuel gas within the premixing flow path 40. Furthermore, by changing the mounting configuration of the connector 3 relative to the base 55, the intended effects of the present invention can be appropriately achieved.

[0145] This invention is not limited to the embodiments described herein. Various design changes can be freely made to the specific structures of the premixing device and combustion device of this invention within the scope of the invention's intent.

[0146] exist Figures 1 to 29 In the illustrated embodiment, the fuel gas flow path adjustment members 8, 8A to 8E are indirectly mounted on the premixed flow path forming members 4, 4F via the partition housing members 5 and 5F, but the present invention is not limited thereto. For example, if the premixed flow path forming member is provided with a pipe connector for connecting a gas pipe, the structure may also be configured such that the fuel gas flow path adjustment member is mounted on the aforementioned portion (i.e., the structure in which the fuel gas flow path adjustment member is directly mounted on the premixed flow path forming member).

[0147] exist Figures 30A to 40 In the illustrated embodiment, the housing members 5 and 5G, which are mounting members installed on the premixed flow path forming members 4 and 4F, are provided with base portions 55 for mounting pipe fittings, but the present invention is not limited to this. For example, it is also possible to configure the structure such that the base portion is provided on the premixed flow path forming member, and the pipe fitting is directly mounted on the premixed flow path forming member.

[0148] There are no restrictions on the specific shape, size, or material of the fuel gas flow path adjustment components.

[0149] The fuel gas is not limited to natural gas and LP gas; other types of fuel gases may also be applicable to this invention. The combustion device of this invention is not limited to hot water supply devices; for example, it may be used for heating or combustion purposes. Furthermore, it is not limited to a type that directs the combustion gas downwards; it may also be a type that directs the combustion gas upwards, for example.

Claims

1. A premixing device, comprising: A premixed flow path forming component forms a premixed flow path for causing air to flow in a specified direction and for mixing fuel gas with the air; A fuel gas flow path has a fuel gas supply port for receiving fuel gas from the outside and a fuel gas outlet for opening into the premixed flow path, and is used to guide the fuel gas supplied to the fuel gas supply port to the fuel gas outlet; and A fuel gas flow path adjustment component is directly or indirectly installed on the premixed flow path forming component and is capable of blocking a portion of the fuel gas flow path; and The installation configuration of the fuel gas flow path adjustment component can be changed, and by changing the installation configuration, the position where the fuel gas flow path adjustment component blocks the fuel gas flow path can be changed, thereby changing the flow resistance of the fuel gas flow path. As the fuel gas, there are different types of first fuel gas and second fuel gas. The premixing device further includes a first gas type display unit and a second gas type display unit respectively representing the first fuel gas and the second fuel gas, and The configuration is such that, when the fuel gas flow path adjustment member is set to a predetermined first installation configuration corresponding to the first fuel gas, the second gas type display unit is covered by the fuel gas flow path adjustment member, and the first gas type display unit is exposed; on the other hand, when the fuel gas flow path adjustment member is set to a predetermined second installation configuration corresponding to the second fuel gas, the first gas type display unit is covered by the fuel gas flow path adjustment member, and the second gas type display unit is exposed.

2. The premixing device according to claim 1, wherein, The portion of the fuel gas flow path near the fuel gas supply port is divided into multiple parallel flow paths, and multiple fuel gas supply ports corresponding to these parallel flow paths are provided as fuel gas supply ports. The fuel gas flow path adjustment component can change the position of the multiple fuel gas supply ports that are blocked.

3. A premixing device, comprising: A premixed flow path forming component forms a premixed flow path for causing air to flow in a specified direction and for mixing fuel gas with the air; A pipe fitting is used to connect a gas pipe that supplies the fuel gas. Base portion, for mounting the pipe fitting portion; and The fuel gas flow path has a terminal portion formed as a fuel gas outlet opening into the premixed flow path, and is used to guide fuel gas supplied to the pipe fitting portion to the fuel gas outlet; and In the pipe joint portion and the base portion, there are joint-side holes and base-side holes that face each other and communicate with each other, forming part of the fuel gas flow path. The pipe fitting can change its mounting configuration relative to the base, and by changing the mounting configuration, the relative facing positions of the fitting side hole and the base side hole can be changed, thereby changing the flow resistance of the fuel gas flow path. As the fuel gas, there are different types of first fuel gas and second fuel gas. The premixing device further includes a first gas type display unit and a second gas type display unit respectively representing the first fuel gas and the second fuel gas, and The configuration is such that, when the pipe connector is set to a predetermined first installation configuration corresponding to the first fuel gas, the second gas type display is covered by the pipe connector and the first gas type display is exposed; on the other hand, when the pipe connector is set to a predetermined second installation configuration corresponding to the second fuel gas, the first gas type display is covered by the pipe connector and the second gas type display is exposed.

4. The premixing device according to claim 3, wherein, The connector side holes are arranged with at least two different inner diameters. The first installation configuration is one in which one of the two connector side holes faces the base side hole, and the other is blocked by the base. Compared with the first installation configuration, the second installation configuration is characterized by the reversal of the direction of the pipe connector portion, one of the two connector side holes being blocked by the base portion, and the other being opposite to the base side hole portion.

5. A premixing device, comprising: A premixed flow path forming component forms a premixed flow path for causing air to flow in a specified direction and for mixing fuel gas with the air; A pipe fitting is used to connect a gas pipe that supplies the fuel gas. Base portion, for mounting the pipe fitting portion; and The fuel gas flow path has a terminal portion formed as a fuel gas outlet opening into the premixed flow path, and is used to guide fuel gas supplied to the pipe fitting portion to the fuel gas outlet; and In the pipe joint portion and the base portion, there are joint-side holes and base-side holes that face each other and communicate with each other, forming part of the fuel gas flow path. The pipe fitting can change its mounting configuration relative to the base, and by changing the mounting configuration, the relative facing positions of the fitting side hole and the base side hole can be changed, thereby changing the flow resistance of the fuel gas flow path. As the fuel gas, there are different types of first fuel gas and second fuel gas. The premixing device further includes a first gas type display unit and a second gas type display unit respectively representing the first fuel gas and the second fuel gas, and The configuration is such that, when the pipe connector is set to a predetermined first mounting configuration corresponding to the first fuel gas, the second gas type display is covered by the pipe connector, and the first gas type display is exposed; conversely, when the pipe connector is set to a predetermined second mounting configuration corresponding to the second fuel gas, the first gas type display is covered by the pipe connector, and the second gas type display is exposed. The base side holes are arranged with at least two different inner diameters. The first installation configuration is characterized by the first base side hole of the two base side holes facing the connector side hole, and the second base side hole of the two base side holes being blocked by the pipe connector. The second installation configuration is a configuration in which the first base side hole of the two base side holes is blocked by the pipe joint, and the second base side hole faces the pipe joint side hole.

6. A combustion device, comprising: The premixing apparatus as described in any one of claims 1 to 5.

Images