Premixing device and combustion device comprising same

Abstract

Provided are: a premixing device which can easily, quickly and appropriately correspond to the type of fuel gas; and a combustion device which is provided with the premixing device. A premixing device (A) is provided with a fuel gas flow path (8a) in a base part (44) of a premixing flow path forming member (4), and a first wall surface part (S1) of the fuel gas flow path (8a), which is partially open, serves as a part facing a flow path adjusting member (2). The flow path adjustment member (2) has a claw section (23) capable of holding the seal member (7) on a second wall surface section (S2) on the rear surface side of the flow path adjustment member (2), and the pipe joint section (9) can attach the flow path adjustment member (2) to the base section (44) in a sandwiched state so that the seal member (7) is sandwiched between the first wall surface section (S1) and the second wall surface section (S2).

Description

Technical Field

[0001] The present invention relates to a premixing device and a combustion device including the premixing device. Here, the so-called "premixing" is a process of pre-mixing air and fuel gas to generate a combustible mixture gas for the purpose of premixing combustion. Background Art

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

[0003] The premixing device described in this document includes a premixing flow path forming member that forms a premixing flow path for allowing air to flow from one end side to the other end side and mixing fuel gas into the air. A base portion for installing a pipe connection portion for connecting a gas pipe is provided in the premixing flow path forming member. The fuel gas supplied from the gas pipe passes through a prescribed fuel gas flow path to reach the fuel gas outlet at the terminal thereof, and flows out into the premixing flow path. Thus, a mixture of fuel gas and air is generated in the premixing flow path, and the mixture is supplied to the downstream side of the premixing device.

[0004] As the fuel gas, for example, there are two types: natural gas and liquefied petroleum (LP) gas. Since their components and calorific values are different, it is necessary to make the premixing device correspond to the type of fuel gas. That is, when the negative pressure generated in the premixing flow path is the same, it is necessary to set so that the amount of the fuel gas with a lower calorific value flowing out from the fuel gas outlet into the premixing flow path is larger than that of the fuel gas with a higher calorific value.

[0005] Therefore, in Patent Document 1, a prescribed flow path adjusting member is directly or indirectly installed in the premixing flow path forming member, and the flow path resistance of the fuel gas flow path is changed by changing the installation form or the like, so that it can be set to be suitable for the type of fuel gas. According to such a structure, it is possible to appropriately correspond to a variety of fuel gases.

[0006] However, the prior art still has room for improvement as described below.

[0007] That is, it is desired to perform the operation of changing the flow path adjusting member corresponding to the type of fuel gas as easily and quickly as possible. This operation is sometimes carried out at the installation site of a hot water supply device including a premixing device, so this requirement is stronger. Therefore, compared with Patent Document 1, it is desired that the workability for the operation corresponding to the type of fuel gas is better. In addition, of course, it is necessary to pay attention to ensuring proper sealing to prevent improper leakage of fuel gas or the like.

[0008] [Prior Art Documents]

[0009] [Patent Documents]

[0010] [Patent Document 1] Japanese Patent Publication No. 7385804

[0011] [Patent Document 2] Japanese Patent Publication No. 5373671

[0012] [Patent Document 3] Japanese Patent Publication No. 2857352

[0013] [Patent Document 4] Japanese Unexamined Patent Publication No. 52-159434 Summary of the Invention

[0014] [Problems to be Solved by the Invention]

[0015] The present invention has been conceived on the basis of the above-described circumstances, and an object thereof is to provide a premixing device that can easily, quickly, and appropriately correspond to the type of fuel gas, and a combustion device including the premixing device.

[0016] [Technical Means for Solving the Problems]

[0017] To solve the above problems, the present invention takes the following technical means.

[0018] The premixing device provided by the first aspect of the present invention includes: a premixing flow path forming member that forms a premixing flow path for allowing air to flow from one end side to the other end side and mixing fuel gas into the air; a base portion provided on the premixing flow path forming member and for mounting a pipe joint portion to which a gas pipe for supplying the fuel gas is connected; a fuel gas flow path having a fuel gas outlet formed at a terminal portion for allowing the fuel gas to flow out into the premixing flow path and for guiding the fuel gas supplied to the pipe joint portion to the fuel gas outlet; a flow path adjusting member having an opening portion that forms a part of the fuel gas flow path, and the opening portion is set to an opening area corresponding to the type of fuel gas; and a sealing member for sealing the mounting portion of the flow path adjusting member, wherein a first wall surface portion where a part of the fuel gas flow path is opened is provided on the base portion as a portion facing the flow path adjusting member, the flow path adjusting member has a claw portion for holding the sealing member on a second wall surface portion on the rear surface side of the flow path adjusting member, and the pipe joint portion can mount the flow path adjusting member in a sandwiched state on the base portion so that the sealing member is sandwiched between the first wall surface portion and the second wall surface portion.

[0019] According to this structure, by using an opening portion provided with an opening area corresponding to the type of fuel gas as a flow path adjusting member, the flow path resistance of the fuel gas flow path can be made suitable for the fuel gas. In addition to this case, furthermore, the following effects can be obtained.

[0020] That is, in the installed state of the flow path adjusting member, the sealing member is sandwiched between a specified first wall surface portion of the base portion and a second wall surface portion on the rear surface side of the flow path adjusting member, and excellent sealing performance is obtained in this portion. Therefore, the reliability of preventing fuel gas leakage can be made high.

[0021] Since the sealing member can be held by the claw portion of the flow path adjusting member, the sealing member and the flow path adjusting member can be processed collectively, and the installation and disassembly operations of these with respect to the pre-mixed flow path forming member become easy.

[0022] The installation of the flow path adjusting member with respect to the pre-mixed flow path forming member can be achieved by sandwiching the flow path adjusting member between them when the pipe joint portion is installed on the base portion of the pre-mixed flow path forming member. Therefore, the installation operation of the flow path adjusting member becomes easier, and similarly, the disassembly operation also becomes easier.

[0023] In the present invention, preferably, the flow path adjusting member includes: a main body member including a cylindrical wall portion whose inner side region constitutes a part of the fuel gas flow path and the claw portion protruding from one end portion side of the cylindrical wall portion; and an auxiliary member overlapping with the one end portion side of the cylindrical wall portion and having the opening portion, the second wall surface portion, and a hole portion or a cut portion through which the claw portion is inserted, and the sealing member overlaps with the second wall surface portion of the auxiliary member in such a manner that the auxiliary member is sandwiched between the main body member, and is engaged with an engaging portion provided on the front end portion side of the claw portion.

[0024] According to this structure, the following effects can be obtained.

[0025] That is, by combining these in a state where the auxiliary member and the sealing member overlap with the main body member of the flow path adjusting member, these can be processed collectively, and the workability of installation or disassembly can be made good. Here, for example, if in an inappropriate combination state where only one of the auxiliary member and the sealing member overlaps with the main body member and the other does not overlap, the one becomes a state of not being fixed to the main body member. Therefore, an operator who performs installation or the like of the flow path adjusting member and the sealing member can easily notice the intention, and for example, the possibility of installing the flow path adjusting member on the base portion in a state where the sealing member is missing can be appropriately eliminated.

[0026] In the present invention, preferably, the flow path adjusting member has the following structure: including a cylindrical wall portion whose inner region forms a part of the fuel gas flow path, and the second wall surface portion and the claw portion provided with the opening portion are integrally formed on the cylindrical wall portion.

[0027] According to this structure, compared with the case where the flow path adjusting member includes, for example, two members, a main member and an auxiliary member, the number of parts of the flow path adjusting member can be reduced. Therefore, in addition to easier handling, a reduction in manufacturing cost can also be achieved.

[0028] In the present invention, preferably, a first concave portion having an open front surface is provided in the base portion, and in the first concave portion, the flow path adjusting member can be set in a state where its rear side portion is inserted, and in a state where the pipe joint portion is detached from the base portion, the front side portion of the flow path adjusting member is configured to protrude toward the front side near the outside of the base portion.

[0029] According to this structure, when the flow path adjusting member is installed on the base portion, the rear side portion of the flow path adjusting member can enter the first concave portion and be supported thereby. Therefore, in this state, it is only necessary to install the pipe joint portion on the base portion, and the installation operations of the flow path adjusting member and the pipe joint portion become easier. In addition, in a state where the flow path adjusting member and the pipe joint portion are installed on the base portion, if the pipe joint portion is detached from the base portion, the front side portion of the flow path adjusting member protrudes toward the front side near the outside of the base portion. Therefore, by grasping the protruding portion, the entire flow path adjusting member can be easily pulled out from the first concave portion.

[0030] In the present invention, preferably, a second concave portion into which the claw portion can enter is provided on the first wall surface portion of the base portion.

[0031] According to this structure, in the installed state of the flow path adjusting member, improper interference between the claw portion and the first wall surface portion of the base portion can be avoided, and it can be easily achieved that the claw portion does not become an obstacle on the basis of bringing the sealing member into contact with the first wall surface portion. In addition, as will be described later, when the sealing member is attached to the first wall surface portion, the second concave portion can also be used as a concave portion for inserting a tool for peeling off the sealing member. Figure 13 As described later, in the case where the sealing member is attached to the first wall surface portion, the second concave portion can also be used as a concave portion for inserting a tool for peeling off the sealing member.

[0032] In the present invention, preferably, a partition wall portion is further included, and the partition wall portion divides the pre-mixing flow path into a first flow path and a second flow path arranged in parallel. The fuel gas flow path branches into a first fuel gas flow path and a second fuel gas flow path, and these first fuel gas flow path and second fuel gas flow path have first fuel gas outlets and second fuel gas outlets that are arranged to enable the fuel gas to flow out to the first flow path and the second flow path as the fuel gas outlets. As the opening portion of the flow path adjusting member, a first opening portion and a second opening portion corresponding to the first fuel gas flow path and the second fuel gas flow path are provided.

[0033] According to such a structure, it is possible to appropriately correspond both the first fuel gas flow path and the second fuel gas flow path for supplying fuel gas to the first flow path and the second flow path of the pre-mixing flow path to the type of fuel gas.

[0034] In the present invention, preferably, the flow path adjusting member includes a cylindrical wall portion whose inner region forms a part of the fuel gas flow path. As the opening portion of the flow path adjusting member, a third opening portion located upstream of the first opening portion and the second opening portion in the fuel gas flow direction is provided, and it is configured such that the fuel gas passing through the third opening portion travels toward the first opening portion and the second opening portion.

[0035] According to such a structure, it is possible to control the flow path resistance of each of the first flow path and the second flow path not only by using the first opening portion and the second opening portion of the flow path adjusting member but also by using the third opening portion, and thus the control accuracy can be improved.

[0036] The combustion device provided by the second aspect of the present invention includes the pre-mixing device provided by the first aspect of the present invention.

[0037] According to the description of the embodiments of the invention given below with reference to the accompanying drawings, other features and advantages of the present invention will be further clarified. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic explanatory view showing an example of a combustion device including the pre-mixing device of the present invention.

[0039] Figure 2 is Figure 1 the external perspective view of the pre-mixing device.

[0040] Figure 3 is Figure 2 the exploded perspective view.

[0041] Figure 4A is Figure 2 the front sectional view of the pre-mixing device shown, Figure 4BIt is the exploded sectional view.

[0042] Figure 5A It is Figure 2 the plan sectional view of the main part of the premixing device shown, Figure 5B and it is the exploded sectional view.

[0043] Figure 6A It is Figure 2 the sectional view of different parts of the premixing device shown in Figure 4A , Figure 6B It is Figure 6A the VIb-VIb sectional view of

[0044] Figure 7A It is Figure 2 the plan view of the premixing flow path forming member of the premixing device shown, Figure 7B and it is the enlarged view of its main part, Figure 7C It is Figure 7A the plan sectional view of

[0045] Figure 8A It shows Figure 2 the perspective view of the assembly of the flow path adjusting member and the sealing member of the premixing device shown, Figure 8B It is Figure 8A the exploded perspective view of

[0046] Figure 9A It is the perspective view from different directions of the assembly shown in Figure 8A , Figure 9B It is Figure 9A the exploded perspective view of

[0047] Figure 10A It is Figure 8A , Figure 8B and Figure 9A , Figure 9B the plan sectional views of the assembly shown, Figure 10B It is Figure 10A the exploded sectional view of

[0048] Figure 11A It is Figure 8A , Figure 8B and Figure 9A , Figure 9B the longitudinal sectional views of the assembly shown, Figure 11B It is Figure 11A the exploded sectional view of

[0049] Figure 12A It shows Figure 2 and Figure 3 the schematic front view of the base part and the pipe joint part of the premixing flow path forming member shown, Figure 12B , Figure 12CIt is a schematic front view showing the state where the pipe joint part is installed on the base part.

[0050] Figure 13 It is showing Figure 2 and Figure 3 A main part sectional view of an example of countermeasures when a sealing member is attached to the base part of the pre - mixing flow path forming member shown.

[0051] Figure 14A It is a plan sectional view showing another example of an assembly of the flow path adjusting member and the sealing member of the pre - mixing device. Figure 14B It is Figure 14A longitudinal sectional view.

[0052] Figure 15 It is an exploded perspective view showing another example of the flow path adjusting member and the sealing member of the pre - mixing device.

[0053] [Explanation of symbols]

[0054] A: Pre - mixing device

[0055] B: Combustion device

[0056] S1, S2: First wall surface part and second wall surface part

[0057] 2, 2A, 2B: Flow path adjusting members

[0058] 2a: Main body member (of the flow path adjusting member)

[0059] 2b: Auxiliary member (of the flow path adjusting member)

[0060] 22a~22c: First opening part, second opening part and third opening part (of the flow path adjusting member)

[0061] 23: Claw part

[0062] 23a: Engaging part (of the claw part)

[0063] 26: Hole part (of the auxiliary member)

[0064] 26a: Cut - out part (of the auxiliary member)

[0065] 3: Pre - mixing flow path

[0066] 3a, 3b: First flow path and second flow path

[0067] 4: Pre - mixing flow path forming member

[0068] 44: Base part (of the pre - mixing flow path forming member)

[0069] 45a, 45b: First concave part and second concave part

[0070] 7: Sealing member

[0071] 76: Hole portion (of the sealing member)

[0072] 76a: Notch portion (of the sealing member)

[0073] 8: Fuel gas flow path

[0074] 8a, 8b: First fuel gas flow path and second fuel gas flow path (fuel gas flow path)

[0075] 80a, 80b: First fuel gas outlet and second fuel gas outlet (fuel gas outlet)

[0076] 9: Pipe joint portion

[0077] 99: Gas pipe Detailed implementation mode

[0078] Hereinafter, with reference to the drawings, the preferred implementation modes of the present invention will be specifically described.

[0079] Figure 1 The hot water device WH is shown. The hot water device WH is a hot water supply device, including a premixing device A, a combustion device B (premixed combustion device), and a heat exchanger 11. The combustion device B is composed of a blower 1 and a burner part 12 combined in the premixing device A. The blower 1 is variable in speed (variable in air volume).

[0080] Details of the premixing device A will be described later. A mixture of air and fuel gas (flammable mixture) is generated by the premixing device A, and the mixture is supplied to the burner part 12 via the blower 1. The burner part 12 includes a porous plate 12a having a plurality of ventilation holes 12b (flame holes), and is housed in a housing 10. An ignition spark plug or a flame detection sensor (not shown) is attached to the burner part 12. The mixture passes through the plurality of ventilation holes 12b and burns below the porous plate 12a. The combustion gas generated by the burner part 12 acts on the heat exchanger 11, and the hot water in the heat exchanger 11 is heated. Thereby, hot water is generated, and the hot water is supplied to a desired hot water supply destination.

[0081] As Figures 2 to 6B In detail, the premixing device A includes a device main body part A0, and a baffle 5, a flow path adjusting member 2, and a sealing member 7 assembled in the device main body part A0.

[0082] In the figure, the x-direction and the y-direction are mutually intersecting directions, and both are directions intersecting with the air flow direction (upward) in the premixing flow path 3 described later.

[0083] The apparatus main body A0 includes a premixing flow path forming member 4 and a pipe connection head 9.

[0084] The premixing flow path forming member 4 includes a cylindrical portion 49 in which a venturi-shaped premixing flow path 3 is formed inside, a mounting flange portion 48 connected to the upper end of the cylindrical portion 49, a base portion 44, and a fuel gas flow path 8.

[0085] The pipe connection head 9 is a portion that is connected to a gas pipe 99 (refer to Figure 1 ) and receives the supply of fuel gas. The pipe connection head 9 includes a cylindrical portion 94 in which a cavity portion serving as the starting end portion of the fuel gas flow path 8 is formed inside, and a mounting flange portion 95 connected to the base end portion of the cylindrical portion 94.

[0086] The base portion 44 is a portion for mounting the pipe connection head 9, and is in a pedestal shape or a similar shape integrally provided on the outer peripheral surface of the cylindrical portion 49, and includes a flange portion 44a corresponding to the flange portion 95 of the pipe connection head 9. The pipe connection head 9 is mounted on the base portion 44 by fastening these in a state where the flange portion 95 and the flange portion 44a face each other and are in contact with each other using a screw member 90 such as a small screw.

[0087] On the flange portion 44a of the base portion 44, there are provided a gas type display portion 98a and a gas type display portion 98b indicating the type of fuel gas supplied to the premixing device A. The gas type display portion 98a and the gas type display portion 98b are respectively characters such as "NG" and "LP", with the former indicating natural gas and the latter indicating LP gas.

[0088] The flange portion 95 of the pipe connection head 9 has a non-circular shape when viewed from the front, and as described below, can be set to selectively hide either the gas type display portion 98a or the gas type display portion 98b and not hide the other.

[0089] That is, the pipe connection head 9 and the base portion 44 have a structure as Figure 12A shown when viewed from the front. When the pipe connection head 9 is mounted on the base portion 44 in the orientation as Figure 12A shown, as Figure 12B shown, the character "LP" of the gas type display portion 98b is hidden by the pipe connection head 9, and the character "NG" of the gas type display portion 98a is not hidden. In the case where the fuel gas is natural gas, it is only necessary to set this state. In contrast, when the pipe connection head 9 is in the orientation reversed from the above, as Figure 12C shown, the character "NG" of the gas type display portion 98a is hidden by the pipe connection head 9, and the character "LP" of the gas type display portion 98b is not hidden. In the case where the fuel gas is LP gas, it is only necessary to set this state.

[0090] As shown Figure 1 in FIG. 1, in the premixing device A, the pipe joint portion 9 is connected to the gas pipe 99, and fuel gas is supplied from a fuel gas supply source (not shown) via the pressure equalizing valve (zero pressure valve) V1. On the other hand, the premixing device A is directly or indirectly connected to the intake side of the blower 1 by means of the flange portion 48. When the blower 1 is driven, outside air flows into the premixing flow path forming member 4 (the premixing flow path 3 in the cylindrical portion 49). Due to the negative pressure generated by the flow of the air, the fuel gas flows out from the first fuel gas outlet 80a and the second fuel gas outlet 80b described later, and a mixture of the fuel gas and the air is generated. The mixture is supplied to the burner portion 12 via the blower 1.

[0091] As shown Figure 6A in FIG. 2 Figures 7A to 7C in detail, a partition wall portion 40 extending along the air flow direction and in the vertical height direction is provided in the premixing flow path 3. Thereby, a part of the premixing flow path 3 is partitioned by the partition wall portion 40 into a first flow path 3a and a second flow path 3b arranged in the y direction.

[0092] As shown Figures 4A to 7C in FIG. 3 Figure 7A in detail, a first blade portion 41a and a second blade portion 41b (the dot pattern portions in FIGS. 4 and 5) are provided in the first flow path 3a and the second flow path 3b. The first fuel gas outlet 80a and the second fuel gas outlet 80b are provided in an upwardly opening manner on the upper surface portions of the first blade portion 41a and the second blade portion 41b facing the downstream side in the air flow direction. Figure 7C in FIGS. 4 and 5

[0093] The first blade portion 41a and the second blade portion 41b extend in the y direction so as to cross the first flow path 3a and the second flow path 3b in the horizontal direction, and one end portion thereof is connected to the inner surface portion of the peripheral wall of the premixing flow path 3 (the inner surface portion of the peripheral wall of the cylindrical portion 49), and the other end portions thereof are connected to each other via the partition wall portion 40.

[0094] As shown Figures 7A to 7C in FIG. 4

[0095] The fuel gas flow path 8 is a flow path that starts from the inside of the cylindrical portion 94 of the pipe connection portion 9 and ends at the first fuel gas outlet 80a and the second fuel gas outlet 80b. Among them, in the fuel gas flow path 8, with the first opening 22a and the second opening 22b (described later) of the flow path adjustment member 2 as branch points, the portion on the more downstream side branches into a first fuel gas flow path 8a and a second fuel gas flow path 8b. These first fuel gas flow path 8a and second fuel gas flow path 8b are formed inside the base portion 44 and inside the first blade portion 41a and the second blade portion 41b.

[0096] The fuel gas supplied to the pipe connection portion 9 is guided to the first fuel gas outlet 80a and the second fuel gas outlet 80b through the first opening 22a and the second opening 22b of the flow path adjustment member 2, and the first fuel gas flow path 8a and the second fuel gas flow path 8b.

[0097] An air inlet portion 3c and an air outlet portion 3d communicating with the first flow path 3a and the second flow path 3b are formed in the lower part and the upper part inside the cylindrical portion 49. When the blower 1 is driven, external air can branch and flow into the first flow path 3a and the second flow path 3b after flowing into the air inlet portion 3c. Due to the negative pressure generated by the air flow in the first flow path 3a and the second flow path 3b, the fuel gas flows out from the first fuel gas outlet 80a and the second fuel gas outlet 80b to generate a mixture of air and fuel gas. The mixture flows out from the air outlet portion 3d to the outside of the cylindrical portion 49.

[0098] As Figures 4A to 6B shown, the baffle 5 can simultaneously open and close the first flow path 3a (a pair of regions 3a') and the first fuel gas outlet 80a. The baffle 5 is, for example, a resin molded product, and its base end portion is supported by a support portion 52 using a shaft body 61 and can swing in the vertical height direction around its center line CL. As Figure 3 shown in detail, the shaft body 61 is a portion supported by a pair of auxiliary members 60 having support holes 60a. The pair of auxiliary members 60 are installed in a step portion 43 separately provided in the first flow path 3a using screw members 92 or the like.

[0099] The baffle 5 swings using its own weight as the downward force and the air flow traveling upward in the first flow path 3a as the upward force. When the air flow rate in the premixing flow path 3 is small, the opening degree is smaller than when the air flow rate is large. In the case where the air flow rate is small, the baffle 5 topples due to its own weight and becomes a closed state. When the air flow rate increases, the baffle 5 is lifted by the upward air flow and becomes an open state. A pair of fins 55 are appropriately protruded on the baffle 5, and the pair of fins 55 are present in a manner that separates the first blade portion 41a when the baffle 5 is in the closed state.

[0100] The flow path adjusting member 2 is a member for controlling the flow path resistance of each of the first fuel gas flow path 8a and the second fuel gas flow path 8b, and controlling the flow rate of the fuel gas toward the first fuel gas outlet 80a and the second fuel gas outlet 80b to a flow rate corresponding to the type of the fuel gas.

[0101] As Figures 8A to 11B As shown in detail, the flow path adjusting member 2 is formed by combining a main body member 2a and an auxiliary member 2b.

[0102] The main body member 2a includes: a cylindrical wall portion 20a, the inner region of which forms a part of the fuel gas flow path 8; a third opening portion 22c provided in the front wall portion 20b of the cylindrical wall portion 20a; and a pair of claw portions 23 protruding from one end portion (rear wall portion side) of the cylindrical wall portion 20a. The front end portion of each claw portion 23 is in a hook shape or a shape close to a hook shape, and is a engaging portion 23a for holding the sealing member 7.

[0103] The auxiliary member 2b includes: cylindrical portions 24a and 24b, which have a first opening portion 22a and a second opening portion 22b and are of short dimensions; and a plate-like portion 25 connecting these cylindrical portions 24a and 24b. The rear surface portion of the plate-like portion 25 is a second wall surface portion S2 corresponding to a first wall surface portion S1 of the base portion 44 described later. A pair of hole portions 26 for inserting the pair of claw portions 23 are also provided in the plate-like portion 25.

[0104] The first opening portion 22a and the second opening portion 22b of the auxiliary member 2b are portions for individually controlling the flow path resistance of each of the first fuel gas flow path 8a and the second fuel gas flow path 8b. In contrast, the third opening portion 22c is a portion located upstream of these first opening portion 22a and second opening portion 22b and for controlling the total flow path resistance of the first fuel gas flow path 8a and the second fuel gas flow path 8b. Considering that the opening areas of the first opening portion 22a to the third opening portion 22c are all set to areas appropriately corresponding to the type of the fuel gas supplied to the premixing device A, the flow rate of the fuel gas passing through these opening portions 22a to 22c becomes a reasonable flow rate.

[0105] The sealing member 7 is a sheet-like gasket having appropriate elasticity. Among them, hole portions 74a and 74b for inserting the cylindrical portions 24a and 24b of the auxiliary member 2b and a pair of hole portions 76 for inserting the pair of claw portions 23 are provided in the sealing member 7.

[0106] When the flow path adjustment member 2 is assembled in a state where the auxiliary member 2b is overlapped on one end side of the main body member 2a and the sealing member 7 is further overlapped on the rear surface portion of the auxiliary member 2b, that is, on the second wall surface portion S2 side, the engaging portion 23a of the pair of claw portions 23 is engaged with the peripheral portion of the hole portion 76 of the sealing member 7. Thus, the assembled state of the main body member 2a, the auxiliary member 2b, and the sealing member 7 of the flow path adjustment member 2 is maintained, and an assembled product AS for flow path adjustment formed by unitizing these can be produced.

[0107] As Figure 4A , Figure 4B and Figure 5A , Figure 5B shown in detail, a first recess 45a having an open front surface (open on the left side in Figure 4A , Figure 4B , Figure 5A , Figure 5B ) is provided in the base portion 44 of the premixing flow path forming member 4. The first recess 45a is a portion for embedding the rear side portion of the assembled product AS for flow path adjustment. The wall surface portion on the inner side of the first recess 45a (the wall surface portion on the center side of the premixing flow path forming member 4) is the first wall surface portion S1 that comes into contact with the sealing member 7 when the assembled product AS is embedded in the first recess 45a. As Figure 5B shown in detail, a pair of second recesses 45b into which the pair of claw portions 23 can enter are provided in the first wall surface portion S1, so that improper interference between each claw portion 23 and the first wall surface portion S1 can be avoided.

[0108] In a state where the rear side portion of the assembled product AS for flow path adjustment is embedded in the first recess 45a, the front side portion of the assembled product AS protrudes forward of the first recess 45a. In contrast, the pipe connection head 9 has a third recess 9a into which the front side portion of the assembled product AS can be embedded. In a state where the pipe connection head 9 is mounted on the base portion 44, as Figure 4A , Figure 5A shown in detail, the assembled product AS for flow path adjustment is fixedly mounted on the base portion 44 in a manner of being sandwiched between the pipe connection head 9 and the base portion 44. In the mounted state, the third opening portion 22c communicates with the inside of the pipe connection head 9. In addition, the cylindrical portions 24a and 24b forming the first opening portion 22a and the second opening portion 22b are in a state of being the front end opening portions entering the first fuel gas flow path 8a and the second fuel gas flow path 8b. The sealing member 7 is sandwiched between the mutually facing first wall surface portion S1 and second wall surface portion S2.

[0109] Next, the operations of the premixing device A and the combustion device B including the premixing device A will be described.

[0110] In the premixing device A, there is an assembled product AS for flow path adjustment in which a flow path adjustment member 2 and a sealing member 7 are assembled. The first opening 22a to the third opening 22c of the assembled product AS are set to an opening area corresponding to the type of fuel gas actually supplied to the premixing device A. Therefore, the flow path resistance of the fuel gas flow paths 8 (the first fuel gas flow path 8a and the second fuel gas flow path 8b) can be controlled so that the fuel gas flow rate in the fuel gas flow paths 8 is suitable for the type of fuel gas. Therefore, the air-fuel ratio of the mixed gas can be made a suitable ratio corresponding to the type of fuel gas, and the combustibility of the burner unit 12 can be made good. In addition to such an effect, furthermore, the following effects can be obtained.

[0111] That is, in the installed state of the assembled product AS for flow path adjustment, the sealing member 7 is clamped between the first wall surface portion S1 of the base portion 44 and the second wall surface portion S2 of the flow path adjustment member 2, and excellent sealing performance can be obtained in this portion. Therefore, in terms of preventing fuel gas leakage, the reliability can be made high.

[0112] The flow path adjustment member 2 and the sealing member 7 can be processed in a unitized state as the assembled product AS for flow path adjustment, and the installation operation or disassembly operation of the premixing flow path forming member 4 to the base portion 44 can be performed together. Different from this embodiment, for example, if the flow path adjustment member 2 and the sealing member 7 are kept in a separated state, it is necessary to install these on the base portion 44 etc. in sequence, and the operation becomes complicated. In contrast, according to this embodiment, there is no such complication and it is convenient.

[0113] In order to assemble the flow path adjustment member 2 and the sealing member 7 into the assembled product AS, it is only necessary to overlap the main body member 2a, the auxiliary member 2b, and the sealing member 7 of the flow path adjustment member 2, and the operation is also easy. When overlapping the three, it is necessary to insert a pair of claw portions 23 through the hole portion 26 of the auxiliary member 2b and the hole portion 76 of the sealing member 7 respectively, but such an operation is also easy. In addition, when such an operation is performed, the engaging portion 23a of the pair of claw portions 23 automatically engages with the sealing member 7, and the assembled state of the three can be maintained. Since the three are not easily separated, the handleability of the assembled product AS can be made better.

[0114] Furthermore, if the three components do not overlap properly due to operator error, such as when the sealing member 7 does not overlap properly, the assembly AS of the flow path adjustment member 2 cannot be properly produced, and only the main member 2a and the auxiliary member 2b of the flow path adjustment member 2 are close together in an offset state. In other words, if the three components are not in a properly assembled state, they will not be completely overlapped. Therefore, the operator can easily detect this situation, and the possibility of the flow path adjustment member 2 or the sealing member 7 being installed in an improper state, such as with the sealing member 7 missing, on the base portion 44, can be eliminated.

[0115] When the flow path adjustment assembly AS is mounted on the base portion 44 of the premixing flow path forming member 4, it is not necessary to screw these assemblies AS individually to the base portion 44. The assembly AS can be installed simultaneously with the installation of the pipe joint portion 9 on the base portion 44. Therefore, the installation and removal of the flow path adjustment assembly AS from the base portion 44 can be performed more efficiently.

[0116] When installing the assembly AS on the base 44, simply fit the rear portion of the assembly AS into the first recess 45a and temporarily hold it there, then install the pipe joint 9 on the base 44. This makes the installation easier. Furthermore, when removing the assembly AS from the base 44, the front portion of the assembly AS protrudes forward from the first recess 45a of the base 44 when the pipe joint 9 is removed from the base 44. This protruding portion can be grasped to easily remove the assembly AS from the first recess 45a.

[0117] During actual use of the premixing device A, the type of fuel gas may be changed to a fuel gas different from the originally intended fuel gas. In such a case, for example, at the installation site of the premixing device A, the flow path regulating member 2 may need to be replaced with another flow path regulating member corresponding to the changed fuel gas. In contrast, as already described, the present embodiment facilitates installation and removal of the flow path regulating member 2 and is therefore also suitable for such situations.

[0118] The sealing member 7 is a member that is strongly pressed against the first wall surface S1 of the base portion 44. Figure 13 As shown, even if the main member 2a or auxiliary member 2b of the flow path adjustment member 2 is removed from the base portion 44, the sealing member 7 may sometimes remain in close contact with the first wall surface portion S1. In this case, the following operation is performed: the tool 87 for peeling the sealing member 7 is inserted through the hole portion 76 into the second recessed portion 45b, and a portion of the tool 87 is brought into contact with the opening peripheral edge portion on the rear side of the hole portion 76 of the sealing member 7, thereby peeling the sealing member 7. The second recessed portion 45b can also be used for this purpose.

[0119] In the pre-mixing device A, when the driving speed of the blower 1 is low and the air flow rate in the pre-mixing flow path 3 is small, as Figure 4A , Figure 4B shown, the baffle 5 is in a closed state, and air flows into the second flow path 3b when the first flow path 3a is blocked. Therefore, the air flow in the second flow path 3b can be made faster, a strong negative pressure acts on the second fuel gas outlet 80b, and an appropriate amount of fuel gas corresponding to the air flow rate flows out into the second flow path 3b. On the other hand, when the driving speed of the blower 1 is high, the baffle 5 is in an open state, and air flows sufficiently in both the first flow path 3a and the second flow path 3b, and an appropriate amount of fuel gas corresponding to the air flow rate can flow out from both the first fuel gas outlet 80a and the second fuel gas outlet 80b. According to this situation, the regulation ratio can be improved.

[0120] Figure 14A , Figure 14B and Figure 15 show another embodiment of the present invention. In these figures, components that are the same as or similar to those in the above embodiment are labeled with the same reference numerals as in the above embodiment, and repeated descriptions are omitted.

[0121] Figure 14A , Figure 14B In the embodiment shown, the flow path adjusting member 2A includes a cylindrical wall portion 20a whose inner region forms a part of the fuel gas flow path 8, and a third opening 22c is provided in the front wall portion 20b of the cylindrical wall portion 20a. In addition, a cylindrical portion 24a and a cylindrical portion 24b that form a first opening 22a and a second opening 22b are provided in the rear wall portion 25a of the cylindrical wall portion 20a, and a flange portion 25b having a second wall surface portion S2 is provided. In addition, a pair of claw portions 23 are also provided in the flow path adjusting member 2.

[0122] The flow path adjusting member 2A of the present embodiment is equivalent to a structure in which the main body member 2a and the auxiliary member 2b of the flow path adjusting member 2 of the above embodiment are integrated.

[0123] According to this structure, since the total number of parts is reduced, cost reduction can be achieved. In addition, the processability can be made better.

[0124] Figure 15 In the flow path adjusting member 2B shown, a cutout portion 26a is provided in the auxiliary member 2b, and the claw portion 23 can be inserted through the cutout portion 26a. For the sealing member 7, a cutout portion 76a through which the claw portion 23 can be inserted is also provided.

[0125] The cut portions 26a and 76a replace the holes 26 and 76 provided in the auxiliary member 2b and the sealing member 7 of the above-described embodiment. In the present invention, the structure as in the present embodiment can also be adopted.

[0126] The present invention is not limited to the content of the above-described embodiment. Various design changes can be freely made to the specific structures of the respective parts of the premixing device and the combustion device of the present invention within the scope intended by the present invention.

[0127] In the above-described embodiment, the premixing flow path is divided into a first flow path and a second flow path, and a baffle is provided in the first flow path. However, the present invention is not limited thereto. In the present invention, for example, as shown in Patent Document 1, it is also possible to configure a premixing device of a type that does not include a baffle and in which the premixing flow path is not divided into a plurality of flow paths.

[0128] The specific shape, size, material, etc. of the flow path adjusting member can be variously changed. The claw portions do not have to be a pair, and may be configured to have only one or three or more. In addition, at least one opening (corresponding to the first opening to the third opening) corresponding to the type of fuel gas in the fuel gas flow path is sufficient. The opening area of the flow path adjusting member is set to an opening area corresponding to the type of fuel gas, but its specific value is not limited.

[0129] As representative examples of the type of fuel gas, natural gas and LP gas can be cited, but it is not limited thereto, and other types of fuel gas can also be the application target.

[0130] The combustion device of the present invention is not limited to being used for a hot water supply device. For example, it can also be used as a combustion device for heating or incineration or other purposes. In addition, it is not limited to the type in which the combustion gas travels downward, and it can also be configured to be a type in which the combustion gas travels upward, for example.

Claims

1. A premixing device, comprising: A premixing flow path forming member that forms a premixing flow path for allowing air to flow from one end side to the other end side and mixing fuel gas into the air; A base portion provided on the premixing flow path forming member and used for mounting a pipe joint portion connected to a gas pipe for supplying the fuel gas; A fuel gas flow path, the terminal portion of which is formed as a fuel gas outlet for allowing the fuel gas to flow out into the premixing flow path, and is used for guiding the fuel gas supplied to the pipe joint portion to the fuel gas outlet; A flow path adjusting member having an opening portion that forms a part of the fuel gas flow path, and the opening area of the opening portion is set corresponding to the type of the fuel gas; And A sealing member for sealing the installation portion of the flow path adjusting member. The premixing device is characterized in that A first wall surface portion with an opening of a part of the fuel gas flow path is provided on the base portion as a portion facing the flow path adjusting member, The flow path adjusting member has a claw portion for holding the sealing member on a second wall surface portion on the rear surface side of the flow path adjusting member, The pipe joint portion can mount the flow path adjusting member in a sandwiched state on the base portion so that the sealing member is sandwiched between the first wall surface portion and the second wall surface portion.

2. The premixing device according to claim 1, wherein The flow path adjusting member includes: A main body member including a cylindrical wall portion whose inner side region forms a part of the fuel gas flow path and the claw portion protruding from one end side of the cylindrical wall portion; and An auxiliary member overlapping with the one end side of the cylindrical wall portion and having the opening portion, the second wall surface portion, and a hole portion or a cut portion through which the claw portion is inserted, The sealing member overlaps with the second wall surface portion of the auxiliary member in such a manner that the auxiliary member is sandwiched between the main body member and engages with an engaging portion provided on the front end side of the claw portion.

3. The premixing device according to claim 1, wherein The flow path adjusting member has the following structure: including a cylindrical wall portion whose inner side region forms a part of the fuel gas flow path, and the second wall surface portion provided with the opening portion and the claw portion are integrally formed on the cylindrical wall portion.

4. The premixing device according to claim 1, wherein A first concave portion with an open front surface is provided on the base portion, and in the first concave portion, the flow path adjusting member can be set in a state where its rear side portion is embedded, In a state where the pipe joint portion is detached from the base portion, the front side portion of the flow path adjusting member is configured to protrude forward near the outside of the base portion.

5. The premixing device according to claim 1, wherein A second concave portion into which the claw portion can enter is provided on the first wall surface portion of the base portion.

6. The premixing device according to claim 1, further comprising a partition wall portion, The partition wall portion divides the premixing flow path into a first flow path and a second flow path arranged in parallel, The fuel gas flow path branches into a first fuel gas flow path and a second fuel gas flow path, and the first fuel gas flow path and the second fuel gas flow path have a first fuel gas outlet and a second fuel gas outlet that are arranged to allow the fuel gas to flow out to the first flow path and the second flow path as the fuel gas outlet. The opening portion, which is the flow path adjusting member, is provided with a first opening portion and a second opening portion corresponding to the first fuel gas flow path and the second fuel gas flow path.

7. The premixing device according to claim 6, wherein The flow path adjusting member includes a cylindrical wall portion whose inner region forms a part of the fuel gas flow path. The opening portion, which is the flow path adjusting member, is provided with a third opening portion located upstream of the first opening portion and the second opening portion in the fuel gas flow direction, and is configured such that the fuel gas passing through the third opening portion travels toward the first opening portion and the second opening portion.

8. A combustion device, characterized in that, Comprising the premixing device according to any one of claims 1 to 7.

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