EXHAUST ADAPTER

Abstract

An exhaust adapter includes a cylindrical part for connecting an exhaust pipe of a combustion device to a collective exhaust duct; and a backflow prevention structure for preventing backflow of the exhaust from the collective exhaust duct side to the exhaust pipe side. The backflow prevention structure includes: a damper receiving part formed with an opening through which the exhaust from the exhaust pipe passes; an exhaust damper plate that opens the opening by pressure of the exhaust from the exhaust pipe and closes the opening by its own weight when there is no exhaust from the exhaust pipe; a support shaft that rotatably supports the exhaust damper plate; and a bearing part that supports the support shaft. A pair of shaft hole parts of the exhaust damper plate for inserting the support shaft is formed in a long hole shape.

Claims

1. An exhaust adapter comprising: a cylindrical part for connecting an exhaust pipe of a combustion device to a collective exhaust duct for collecting and discharging exhaust of a plurality of the combustion devices; and a backflow prevention structure for preventing backflow of the exhaust from the collective exhaust duct side to the exhaust pipe side, wherein the backflow prevention structure comprises: a damper receiving part formed with an opening through which the exhaust from the exhaust pipe passes; an exhaust damper plate that opens the opening by pressure of the exhaust from the exhaust pipe and closes the opening by its own weight when there is no exhaust from the exhaust pipe; a support shaft that rotatably supports the exhaust damper plate; and a bearing part that supports the support shaft, wherein the exhaust damper plate comprises a pair of shaft hole parts for inserting the support shaft, and the pair of shaft hole parts is formed in a long hole shape that is long in a vertical direction with respect to the support shaft when the exhaust damper plate is in a posture in which the opening is closed.

2. The exhaust adapter according to claim 1, wherein the cylindrical part is formed to have a width equal to a width of the exhaust pipe, the damper receiving part has an outer shape that is formed in a circular shape along an inner circumference of the cylindrical part, and the opening is formed in a shape of a circle with a center eccentric from a center of the circular damper receiving part, or formed in a partial circular shape having a part of this circle.

3. The exhaust adapter according to claim 2, wherein the bearing part is provided in a wide part of the damper receiving part formed by making the opening eccentric.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG. 1 is an illustration view of a hot water supply system having multiple hot water supply devices.

[0018] FIG. 2 is a top view of an exhaust adapter connecting the exhaust pipe of the combustion device and the collective exhaust duct as viewed from the collective exhaust duct side.

[0019] FIG. 3 is a cross-sectional view taken along the line of FIG. 2.

[0020] FIG. 4 is a perspective view of a backflow prevention structure mounted on the exhaust adapter.

[0021] FIG. 5 is an assembly illustration view of the backflow prevention structure.

[0022] FIG. 6 is a top view of the backflow prevention structure as viewed from the collective exhaust duct side.

[0023] FIG. 7 is a cross-sectional view taken along the line VII-VII of FIG. 6.

[0024] FIG. 8 is a top view of another example of the backflow prevention structure as viewed from the collective exhaust duct side.

[0025] FIG. 9 is a cross-sectional view showing a state in which the backflow prevention structure of FIG. 6 has started to open.

[0026] FIG. 10 is an enlarged cross-sectional view of a main part for illustrating the start of opening of the backflow prevention structure of FIG. 9.

[0027] FIG. 11 is a cross-sectional view showing a fully open state of the backflow prevention structure of FIG. 6.

[0028] FIG. 12 is an illustration view of a support shaft and a bearing part of a conventional backflow prevention structure.

DESCRIPTION OF EMBODIMENTS

[0029] Hereinafter, modes for carrying out the disclosure will be described with reference to embodiments.

EMBODIMENT

[0030] First, a hot water supply system 1 will be described.

[0031] As shown in FIG. 1, the hot water supply system 1 is configured by, for example, three hot water supply devices 11a to 11c as multiple hot water supply devices. The hot water supply devices 11a to 11c include corresponding combustion devices 3a to 3c. Exhaust pipes 4a to 4c extending upward from the combustion devices 3a to 3c are connected to a collective exhaust duct 2 above the hot water supply devices 11a to 11c via corresponding exhaust adapters 5a to 5c. Further, the exhaust adapters 5a to 5c may be connected to the exhaust pipes 4a to 4c and the collective exhaust duct 2, respectively, via, for example, a flexible duct, so as to be compatible with various sites (positional relationship between the exhaust pipes 4a to 4c and the collective exhaust duct 2).

[0032] For example, the hot water supply device 11a has a blower fan 6a which is a part for blowing air for combustion, and a burner 7a for burning fuel. A heat exchanger 12a for heating hot water by combustion heat is provided between the burner 7a and the exhaust pipe 4a. The hot water supply device 11a has a control part 14a, and the control part 14a controls the drive of the blower fan 6a and the combustion of the burner 7a to supply hot water heated to a predetermined temperature.

[0033] Similar to the hot water supply device 11a, the other hot water supply devices 11b and 11c include blower fans 6b and 6c, burners 7b and 7c, heat exchangers 12b and 12c, control parts 14b and 14c, and the like. The hot water supply system 1 has a control unit 16 for hot water supply operation that supplies hot water by the number of operating hot water supply devices according to the amount of hot water supply, and an operation terminal 17 connected to the control part 16. In FIG. 1, the hot water supply devices 11b and 11c are performing hot water supply operation.

[0034] The collective exhaust duct 2 collects the exhaust from the hot water supply system 1 configured by the multiple hot water supply devices 11a to 11c and discharges the exhaust to the outside collectively. The exhaust adapter 5a includes a backflow prevention structure 18a that prevents the exhaust of the other combustion devices 3b and 3c from flowing back through the collective exhaust duct 2 during non-combustion of the connected combustion device 3a. The backflow prevention structure 18a opens by the pressure of the exhaust of the combustion device 3a and closes by its own weight when there is no exhaust of the combustion device 3a to prevent the backflow of the exhaust. The exhaust adapters 5b and 5c are equipped with the same backflow prevention structures 18b and 18c.

[0035] Hereinafter, the exhaust adapter 5a provided with the backflow prevention structure 18a will be described, and the description of the exhaust adapters 5b and 5c having the same configuration will be omitted.

[0036] As shown in FIGS. 1 to 3, the exhaust adapter 5a has a cylindrical part 21 for connecting the exhaust pipe 4a extending upward from the combustion device 3a and the collective exhaust duct 2, and the backflow prevention structure 18a for preventing backflow of the exhaust from the collective exhaust duct 2 side to the exhaust pipe 4a side. The cylindrical part 21 is formed to have a predetermined width equal to that of the exhaust pipe 4a. The backflow prevention structure 18a is provided to close the inside of the cylindrical part 21.

[0037] As shown in FIGS. 4 to 7, the backflow prevention structure 18a is configured by an exhaust damper plate 22, a damper receiving part 23, a support shaft 24, and a bearing part 25. The damper receiving part 23 having a circular outer shape formed along the inner circumference of the cylindrical part 21 is formed with a circular opening 26 through which the exhaust from the exhaust pipe 4a passes. The center C1 of the opening 26 is eccentric with respect to the center C0 of the circular damper receiving part 23. The bearing part 25 is joined to a wide part 23a of the damper receiving part 23 formed by making the opening 26 eccentric to match a pair of positioning protrusions 23b.

[0038] The bearing part 25 has a pair of round holes 25a parallel to the damper receiving part 23 for inserting the support shaft 24 in a direction orthogonal to the straight line connecting the center C1 of the opening 26 and the center C0 of the damper receiving part 23. In the support shaft 24 inserted through the bearing part 25, the movement in the direction orthogonal to the shaft is restricted by the bearing part 25, and the movement in the shaft direction is restricted by deforming both ends of the support shaft 24 or attaching a cap member. As a result, the bearing part 25 supports the support shaft 24 so as not to move.

[0039] The opening 26 is formed inside a cylindrical wall part 23c that protrudes upward (on the collective exhaust duct side) from the damper receiving part 23, and the tip part of the cylindrical wall part 23c is bent inward. The exhaust damper plate 22 formed in a circular shape larger than the opening 26 for closing the opening 26 has a rectangular extension part 22a extending radially outward. A shaft insertion part 22b having a semi-circular part is formed to extend upward from both ends of the extension part 22a parallel to the radial direction in which the extension part 22a extends.

[0040] The shaft insertion part 22b has a pair of shaft hole parts 22c for inserting the support shaft 24. The pair of shaft hole parts 22c is formed in a long hole shape that is long in the vertical direction with respect to the inserted support shaft 24 when the exhaust damper plate 22 is in a posture in which the opening 26 is closed. As a result, the exhaust damper plate 22 is allowed to move in the vertical direction with respect to the support shaft 24 fixed to the damper receiving part 23 via the bearing part 25. Therefore, the machining error and the assembly error of the backflow prevention structure 18a are absorbed by the shaft hole parts 22c in a long hole shape, and the exhaust damper plate 22 easily abuts on the tip part of the cylindrical wall part 23c by its own weight.

[0041] As shown in FIG. 8, for example, in order to increase the opening area, the opening 26 may be formed in a partial circular shape (D shape) having a part of the circle with the center C1 eccentric with respect to the center C0 of the damper receiving part 23. In this case, the exhaust damper plate 22 is formed in a shape that can close the opening 26.

[0042] When the exhaust from the combustion device 3a passes through the exhaust adapter 5a and flows into the collective exhaust duct 2, the exhaust damper plate 22 is pushed up by the pressure of the exhaust as shown in FIG. 9, and the backflow prevention structure 18a starts to open. At this time, as shown in FIG. 10, the exhaust damper plate 22 starts to rotate so as to open the opening 26 with the tip part of the cylindrical wall part 23c as a fulcrum on the support shaft 24 side, and the extension part 22a and the shaft insertion part 22b are lowered. Since the shaft hole parts 22c have a long hole shape, the extension part 22a and the shaft insertion part 22b are lowered until the backflow prevention structure 18a is opened to some extent and the upper edge parts of the shaft hole parts 22c abut on the support shaft 24. As a result, even when the pressure of the exhaust is not strong, the weight of the exhaust damper plate 22 pushed up by the exhaust when the backflow prevention structure 18a in the closed state is opened is reduced, so that the backflow prevention structure 18a can be easily opened. When the upper edge parts of the shaft hole parts 22c abut on the support shaft 24, the exhaust damper plate 22 including the extension part 22a and the shaft insertion part 22b rotates around the support shaft 24, and the backflow prevention structure 18a opens to a greater extent.

[0043] As shown in FIG. 11, the bearing part 25 is equipped with a rotation restricting part 25b that receives the rotation of the exhaust damper plate 22 at a predetermined position. The rotation restricting part 25b prevents the backflow prevention structure 18a from opening too much due to the pressure of the exhaust and not being closed by the weight of the exhaust damper plate 22. When the exhaust is stopped, the exhaust damper plate 22 rotates by its own weight and abuts on the tip part of the cylindrical wall part 23c, and the exhaust damper plate 22 closes the opening 26. The closed backflow prevention structure 18a prevents the exhaust of the other combustion devices 3b and 3c from flowing back through the collective exhaust duct 2 (see FIG. 1).

[0044] The operation and effect of the exhaust adapter 5a provided with the backflow prevention structure 18a will be described.

[0045] The exhaust adapter 5a connects the exhaust pipe 4a of the combustion device 3a to the collective exhaust duct 2. The backflow prevention structure 18a of the exhaust adapter 5a opens the opening 26 formed in the damper receiving part 23 by rotating the exhaust damper plate 22 by the pressure of the exhaust from the exhaust pipe 4a. On the other hand, when there is no exhaust from the exhaust pipe 4a, the exhaust damper plate 22 closes the opening 26 by its own weight to prevent the backflow of the exhaust from the collective exhaust duct 2.

[0046] The support shaft 24 supported by the bearing part 25 for rotatably supporting the exhaust damper plate 22 is inserted into the pair of shaft hole parts 22c provided in the exhaust damper plate 22. Since the support shaft 24 is supported by the bearing part 25 and does not incline, the rotation of the exhaust damper plate 22 is not hindered by the inclination of the support shaft 24.

[0047] The pair of shaft hole parts 22c is formed in a long hole shape that is long in the vertical direction with respect to the support shaft 24 when the exhaust damper plate 22 is in a posture in which the opening 26 is closed. Since the pair of shaft hole parts 22c allows the exhaust damper plate 22 to move in the vertical direction in a posture in which the opening 26 is closed with respect to the support shaft 24, the exhaust damper plate 22 can be made to abut on the damper receiving part 23 so as to close the opening 26 of the damper receiving part 23 by its own weight. Therefore, it is possible to prevent the formation of a gap between the damper receiving part 23 and the exhaust damper plate 22 to prevent the backflow of the exhaust, and since the rotation of the exhaust damper plate 22 is not hindered, it is possible to prevent the backflow prevention function from deteriorating.

[0048] Since the damper receiving part 23 has the outer shape that is formed in the shape of a circle along the inner circumference of the cylindrical part 21 of the exhaust adapter 5a, the exhaust adapter 5a provided with the backflow prevention structure 18a can be formed in the cylindrical part 21 having the same width as the exhaust pipe 4a. The opening 26 through which the exhaust passes is formed in a shape of a circle with the center C1 eccentric from the center C0 of the circular damper receiving part 23, or formed in a partial circular shape having a part of this circle. The support shaft 24 of the exhaust damper plate 22 that opens and closes the opening 26 and the bearing part 25 thereof can be accommodated in the cylindrical part 21 while increasing the opening area by the eccentric circular shape or partially circular shape of the opening 26.

[0049] By making the opening 26 eccentric with respect to the damper receiving part 23, the wide part 23a is formed in the damper receiving part 23, and the bearing part 25 is provided in the wide part 23a. Therefore, since the bearing part 25 of the support shaft 24 that rotatably supports the exhaust damper plate 22 is provided in the wide part 23a outside the opening 26, the exhaust adapter 5a having a constant width may be formed without expanding the diameter of the cylindrical part 21. Therefore, when the exhaust adapter 5a is covered with the heat insulating material, it can be easily covered because there are no parts having different widths.

[0050] In addition, a person skilled in the art can carry out the embodiments in forms in which various modifications are added to the above embodiments without departing from the spirit of the disclosure, and the disclosure includes such modified embodiments.