JP4710470B2 - Exhaust top and hot water supply apparatus provided with the same - Google Patents

Description

  The present invention relates to an exhaust top that is attached to an object from which exhaust gas after combustion is derived, such as a hot water supply device, and that is used to receive the exhaust gas thus derived and exhaust it to the external space, and a hot water supply device including the exhaust top In particular, it relates to measures for exhaust gas drainage.

  Conventionally, exhaust gas drain is generated due to condensation of combustion exhaust gas at an exhaust port that exhausts combustion exhaust gas from the inside of a housing of a combustion apparatus such as a gas water heater. Therefore, in order to discharge the exhaust gas drain to the external space, A device provided with an outlet is known (see, for example, Patent Document 1).

  Also, in recent years, as a hot water supply device, a primary heat exchanger for heat exchange heating by the combustion heat of a combustion burner, and a secondary heat exchanger for recovering latent heat from the combustion exhaust gas after heat exchange heating the primary heat exchanger A so-called condensing type with a heat exchanger is known. And in such a condensing type, it arrange | positions so that the combustion exhaust gas which passed the primary heat exchanger may flow sideways from one side of the secondary heat exchanger to the other side and then be discharged to the external space, An exhaust gas drain generated in the secondary heat exchanger is collected and recovered inside the hot water supply device, neutralized, and discharged outside (for example, see Patent Document 2).

No. 4-5872 JP 2004-198065 A

  By the way, when the combustion exhaust gas after the heat exchange with the heat exchanger is exhausted from the housing of the hot water supply device to the external space, the exposed portion of the wall in the vicinity of the exhaust port, in particular, the opening portion exposed to the external space and cooled. The amount of exhaust gas drain generated tends to increase due to the combustion exhaust gas coming into contact with the walls constituting the.

  In particular, in the above condensing type, the exhaust gas also recovers the latent heat of the exhaust gas, so the exhaust gas temperature is considerably lower than that of the conventional type (eg, 200 ° C.) that does not have a secondary heat exchanger (for example, 200 ° C.). For example, the flow rate of the exhaust gas near the exhaust top becomes slow (for example, about 2/3), and the amount of exhaust gas drain generated tends to increase. That is, in addition to the generation of exhaust gas drain in the secondary heat exchanger case in which the secondary heat exchanger is accommodated, the exhaust gas temperature is low, so that it is flowed to the exhaust top in a higher humidity state and the flow rate is also slow. As a result, the contact time with the wall of the opening becomes longer, so that the amount of exhaust gas drain generated in the exhaust top after exiting the secondary heat exchanger case tends to increase.

  In addition, even if the exhaust gas drain generated in the secondary heat exchanger case is recovered for neutralization, the exhaust gas drain generated in the exhaust top or at the opening of the exhaust port may be scattered outside or flow down. This will cause various inconveniences. That is, since the exhaust gas drain shows strong acidity, discoloration may occur if the exhaust gas drain scatters to the outside and adheres to the outer surface of the housing of the hot water supply device or the outer wall of the building.

  The present invention has been made in view of such circumstances, and the object of the present invention is to suppress / reduce the generation of exhaust gas drain near the exhaust port of the exhaust top, and even if it occurs. It is an object of the present invention to provide an exhaust top that can be treated inside without being spilled to the outside or the like, and a hot water supply device including the exhaust top.

In order to achieve the above object, according to the first aspect of the present invention, the following specific matters are applied to a cylindrical exhaust top in which an exhaust passage extending from one inflow port to another exhaust port is defined. I decided to prepare. That is, the exhaust passage is provided with a preheating portion attached so as to extend at least in a partial region in the inner circumferential direction. And as said preheating part, the outer surface wall which faces external space, the inner surface wall which faces the said exhaust passage and forms the exhaust passage, and the passage space formed between the said outer surface wall and the inner surface wall, and An inlet that opens opposite to the flow direction of the exhaust gas that flows into the exhaust passage and flows through the exhaust passage toward the exhaust port, and introduces the exhaust gas into the passage space. the exhaust gas after passing through the passage space after you with that and a outlet back to the exhaust passage.

In the case of the specific items described above, if the exhaust top is connected to the outlet from which the exhaust gas is derived with respect to the object from which the exhaust gas after combustion such as a hot water supply apparatus is derived, Most of the exhaust gas flowing in from the exhaust passage passes through the exhaust passage and is exhausted from the exhaust port to the external space. On the other hand, a part of the exhaust gas flowing from the inlet port into the exhaust passage enters the passage space through the introduction port. After passing through the space in the inner circumferential direction, it returns to the exhaust passage again from the outlet. Since the introduction ports are opposed to each other in the flow direction of the exhaust gas, a part of the exhaust gas is reliably introduced into the passage space, and both the outer wall and the inner wall are in the passage space while the exhaust gas flows. Preheated by the retained heat of the exhaust gas. As described above, since the inner wall constituting the exhaust passage is preheated, condensation does not easily occur even if the exhaust gas contacts the inner wall when passing through the exhaust passage, thereby preventing the generation of exhaust gas drain. It can be suppressed or reduced. In other words, when there is no preheating part, the outer surface of the wall constituting the exhaust passage is exposed to the external space, so that a large amount of exhaust gas passing through the exhaust passage comes into contact with the wall cooled to the outside air. In the case of the present invention, the inner wall constituting the exhaust passage is self-heated in advance by a part of the exhaust gas, so that the generation of the exhaust gas drain is suppressed as much as possible. Or it can be reduced. In addition, since the preheating also uses a part of the exhaust gas as a heat source, other new heat sources are unnecessary and energy saving can be achieved.

In addition, in the first invention, the preheating unit, and a Rukoto be arranged to form at least part of the opening edge of the exhaust port (claim 1). The part that constitutes the opening edge of the exhaust port is exposed to the external space, that is, it is easy to be cooled by touching the outside air, so that this part is composed of a preheating part and preheated to suppress and reduce the generation of exhaust gas drain Will be effectively achieved.

Incidentally, the inner surface wall, Ru can also be arranged from a downstream end of the exhaust gas outlet side to the inclined state so as to be obliquely descending slope toward the upstream side of the exhaust passage. By doing so, even if exhaust gas drainage is generated due to contact with the inner wall of the preheated state, or the preheated state is preheated on the inner surface side of the outer wall facing the outer space even though it is in the preheated state. Even if exhaust gas is generated due to contact with the exhaust gas for use, the exhaust gas drain flows down to the upstream side along the wall surface of the inner wall, so that it is sure to scatter and flow down from the exhaust port to the outside. To be blocked. For this reason, it is possible to reliably prevent the occurrence of inconvenience such as discoloration due to adhesion to the external wall surface.

In the first invention, the introduction port is formed on the inner wall surface at an intermediate position with respect to the inner circumferential direction of the exhaust passage, while the outlet port is formed from the intermediate position in the inner circumferential direction starting from the intermediate position. (Claim 2 ). By doing in this way, it becomes possible to take in a part of exhaust gas which flows into an exhaust passage, and to flow reliably with respect to the passage space from an inlet to an outlet.

Incidentally, the exhaust port, Ru can opening edge located on the bottom is arranged to be positioned higher than the opening edge located at the bottom of the inlet. By doing so, even if exhaust gas drain is generated in the exhaust passage and the exhaust gas drain is accumulated in the exhaust passage, the accumulated exhaust gas drain may flow down to the inlet side. Thus, it is possible to reliably eliminate the flow down to the external space.

Further, in the first invention, as the inner wall, the surface portion facing the exhaust passage or all the portions may be formed of a neutralizing material that neutralizes the exhaust gas drain by contact (claim). 3 ). By doing in this way, if the exhaust gas drain which generate | occur | produced in the exhaust passage or has flowed down into the exhaust passage contacts the inner surface wall, the exhaust gas drain will be neutralized. As a result, even if the exhaust gas drain leaks from the exhaust port to the outside due to scattering or flowing down, the outer surface of the housing or the like is not discolored. Here, forming the surface portion of the inner wall facing the exhaust passage with the neutralizing material means, for example, forming a coating layer made of the neutralizing material on the surface portion, and all the portions with the neutralizing material. Forming means forming the inner wall itself with a material made of a neutralizing material.

According to a second aspect of the present invention, in the hot water supply apparatus, the exhaust top according to any one of the first to third aspects, a combustion burner, and a heat exchanger that is heat-exchanged and heated based on the combustion of the combustion burner. An inlet of the exhaust top communicates with a communication port that is opened laterally in a heat exchanger case containing the heat exchanger and through which the exhaust gas passes through the heat exchanger. The exhaust top is attached to the heat exchanger case (claim 4 ).

  In the case of this invention, the exhaust gas heat-exchanged and heated by the heat exchanger flows into the inlet of the exhaust top from the communication port of the heat exchanger case, and is discharged from the exhaust port to the external space through the exhaust passage. On the other hand, a part of the exhaust gas is introduced into the passage space from the introduction port of the preheating part to preheat the outer wall and the inner wall. As a result, it is possible to suppress and reduce the generation of exhaust gas drain accompanying the exhaust gas exhaust from the hot water supply device as described above, and to reliably prevent the exhaust gas drain from scattering and flowing into the external space. .

In such a hot water supply apparatus, as the heat exchanger, a primary heat exchanger that is heat-exchanged and heated by the combustion heat of the combustion burner, and a second heat exchanger for recovering latent heat from exhaust gas that has passed through the primary heat exchanger. and a following heat exchanger, it is possible to communication port of the heat exchanger casing it is assumed that the exhaust gas having passed through the secondary heat exchanger described above is derived (claim 5). In this case, the exhaust gas that has become low temperature after the latent heat is recovered after passing through the secondary heat exchanger flows into the exhaust passage of the exhaust top. The action of suppression / reduction is most effectively exhibited.

As described above, according to the exhaust top according to any one of claims 1 to 3 , the exhaust top is attached to a target from which exhaust gas after combustion such as a hot water supply device is derived, so that the inlet to the exhaust passage. While most of the inflowing exhaust gas is exhausted from the exhaust port to the external space, a part of the exhaust gas that has flowed into the exhaust passage from the inflow port is used as a heat source, so that Both can be preheated. Thereby, even when the exhaust gas passes through the exhaust passage and contacts the inner wall, it is possible to make it difficult for condensation to occur, thereby suppressing or reducing the generation of exhaust gas drain. In other words, when there is no preheating part, the outer surface of the wall constituting the exhaust passage is exposed to the external space, so that a large amount of exhaust gas passing through the exhaust passage comes into contact with the wall cooled to the outside air. Exhaust gas drain may be generated, but according to the exhaust top of the present invention, the inner wall constituting the exhaust passage is preheated by a part of the exhaust gas, so that generation of exhaust gas drain is possible. Can be suppressed or reduced. In addition, since the preheating also uses a part of the exhaust gas as a heat source, other new heat sources can be dispensed with and energy saving can be achieved.

In addition, since the portion constituting the opening edge of the exhaust port is exposed to the external space, that is, it is easy to be cooled by touching the outside air, this portion is constituted by the preheating portion so as to be preheated. The suppression and reduction of gas drain generation can be realized more effectively.

According to the second aspect , a part of the exhaust gas flowing in the exhaust passage can be taken in and reliably flowed to the passage space from the inlet to the outlet, thereby reliably preheating the inner wall and the outer wall. Will be able to do.

According to the third aspect , since at least the surface portion of the inner wall facing the exhaust passage is formed of the neutralizing material, the exhaust gas drain generated in the exhaust passage or flowing down into the exhaust passage is formed on the inner wall. If contacted, the exhaust gas drain can be neutralized, thereby preventing discoloration or the like from occurring on the outer surface of the housing or the like even if the exhaust gas drain leaks out of the exhaust port due to scattering or flowing down. can do.

In addition, according to the hot water supply apparatus of claim 4 or 5 , by attaching the exhaust top, it is possible to suppress or reduce the generation of exhaust gas drain due to exhaust gas exhaust from the hot water supply apparatus. In addition, it is possible to reliably prevent the exhaust gas drain from scattering and flowing into the external space.

In particular, according to claim 5 , since the exhaust gas that has passed through the secondary heat exchanger for recovering the latent heat of the exhaust gas and has recovered the latent heat and then cooled down flows into the exhaust passage of the exhaust top, The suppression and reduction of exhaust gas drain generation due to the presence of the preheating portion can be most effectively exhibited.

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

  FIG. 1 shows a part of a hot water supply apparatus according to an embodiment of the present invention. This hot water supply apparatus is configured in a so-called condensing type latent heat recovery type. That is, this hot water supply apparatus introduces into the housing 1 a combustion burner 2, a primary heat exchanger 3 that is heat-exchanged by the combustion heat of the combustion burner 2, and exhaust gas that has passed through the primary heat exchanger 3. And a secondary heat exchanger 4 that recovers the latent heat of the exhaust gas by heat exchange, and an exhaust top 5 that receives the exhaust gas after passing through the secondary heat exchanger 4 and discharges it to the external space. .

  The combustion burner 2 is built in the burner case 21 and receives the supply of combustion air from the blower fan 22 and the supply of fuel (for example, fuel gas) from the fuel supply pipe 23 toward the upper combustion space. It is supposed to be burned. The primary heat exchanger 3 is housed in a primary heat exchanger case 31 connected to the upper side of the burner case 21, and water after being preheated by passing through the secondary heat exchanger 4 is the primary heat exchanger. 3 is flowed from one end to the other end and is heat-exchanged and heated by the combustion heat of the combustion burner 2 while flowing through the primary heat exchanger 3.

  Between the primary heat exchanger case 31 and the secondary heat exchanger case 41 in which the secondary heat exchanger 4 is housed, the exhaust gas from the upper surface opening of the primary heat exchanger case 31 is subjected to secondary heat. A passage case 6 in which an internal passage 61 is defined so as to be gathered and guided to the rear communication port 42 of the exchanger case 41 is interposed. In the passage case 6, the inner passage 61 spreads over the entire upper surface opening of the primary heat exchanger case 31 on its lower surface to collect exhaust gas from the primary heat exchanger 3, and then gradually toward the rear side upward. The exhaust gas (see the dotted arrow in FIG. 1) is guided to the rear communication port 42 of the secondary heat exchanger case 41.

  As said secondary heat exchanger 4, what is called a thin tube type or a multi-tube type is illustrated in FIG. This is because a large number of thin tubes 43, 43,... Grouped for forward and return are arranged so as to traverse the inside of the secondary heat exchanger case 41. Are passed through a large number of tubules 43, 43,... For return and passed through a plurality of tubules 43, 43,... For return from the folded header, and then passed from the return header to one end side of the primary heat exchanger 3. It comes to supply. And the exhaust gas introduced from the back surface communication port 42 of the secondary heat exchanger case 41 contacts the above-mentioned numerous thin tubes 43, 43,... While passing through the front surface communication port 44, and the latent heat of the exhaust gas. Is absorbed by the water in each narrow tube 43 by heat exchange, and latent heat recovery is performed. Of course, the secondary heat exchanger 4 may be of a type other than the capillary type as described above.

  The secondary heat exchanger case 41 is inclined so that its bottom wall 45 has an oblique downward slope from the rear communication port 42 side to the front communication port 44 side, and a drain is formed at the front end (left end in FIG. 1). The upstream end of the water collecting pipe 71 is opened. Thereby, the exhaust gas drain falling from the secondary heat exchanger 4 or the like onto the upper surface of the bottom wall 45 is guided to the front end side and dropped into the drain water collecting pipe 71 to collect water. The front communication port 44 is set lower than the rear communication port 42. That is, in other words, the lowermost opening edge of the rear surface communication port 42 is lower than the lowermost opening edge of the rear surface communication port 42. In other words, the lowermost opening edge of the rear surface communication port 42 is the front surface communication port. The vertical positional relationship between the two communication ports 44 and 42 is set so as to be higher than the lowest opening edge of 44. As a result, even if a situation occurs in which the drain water collecting pipe 71 is clogged and the exhaust gas drain accumulates on the bottom wall 45 of the secondary heat exchanger case 41, the accumulated exhaust gas drain is communicated with the rear surface. It does not flow over the opening 42 and flow down to the primary heat exchanger 3 or the combustion burner 2 side.

  As shown in detail in FIGS. 2 to 4, the exhaust top 5 is a flange piece attached on the back side to the secondary heat exchanger case 41 with a screw (screw or screw) 512 via a seal member 511. 51, a rectangular tubular outer wall 52 protruding forward from the flange piece 51, a front wall 53 covering the front surface of the outer wall 52, and an upper inner wall connected to the inner side of the upper portion 521 of the outer wall 52 A face wall 54 and a lower inner wall 55 connected to the inner side of the front wall 53 from the inner side of the lower part 522 of the outer surface wall 52 are provided.

  The inside of the outer surface wall 52, that is, the portion surrounded by the flange piece 51 is greatly opened to the back side, and a later-described part of the opening 56a forms an inflow port 56. An exhaust port 57 is formed by opening over the entire width. That is, the opening 56 a is formed to be larger by a predetermined amount in the vertical direction than the front communication port 44 of the secondary heat exchanger case 41, and the lowest part of the opening 56 a is the lowest part of the front communication port 44. The exhaust top 5 is fixed to the secondary heat exchanger case 41 by the flange piece 51 so as to meet at the same level. As a result, the opening 56 a communicates with the inside of the secondary heat exchanger case 41 in a region corresponding to the opening area of the front communication port 44, and the exhaust top 5 side corresponding to the front communication port 44 is connected. The open area constitutes the inflow port 56.

  In the state where the exhaust top 5 is fixed to the secondary heat exchanger case 41 as described above, an exhaust passage 58 that bends in a crank shape from the inlet 56 to the exhaust outlet 57 is provided inside the exhaust top 5. The heat exchanger case 41 is partitioned by the part 411, the lower inner wall 55, and the upper inner wall 54. The lower inner wall 55 is inclined obliquely upward from the inlet 56 side (back side; right side in FIG. 2) toward the front side (left side in FIG. 2) where the exhaust port 57 is provided. The lower side of the passage 58 is partitioned, and the lower end portion of the opening edge of the exhaust port 57 is configured by the upper end portion (see the upper end portion 554 described later). On the other hand, the upper inner wall 54 is inclined so as to be inclined obliquely downward from the front side to the rear side, thereby defining the upper side of the exhaust passage 58, and at the front end portion of the exhaust port 57. It will constitute the upper part of the opening edge.

  A more specific shape setting example will be described. The lower inner surface wall 55 has a lowermost portion 551 positioned at the lowermost position of the inflow port 56 (front communication port 44), and the lowermost portion 551. A curved portion 552 that curves in a concave curve from the top to the top, a rising portion 553 that rises upward from the upper end position of the curved portion 552, and a diagonally upward and forward direction from the upper end position of the rising portion 553 A lower opening edge 571 that is a part of the front wall 53 and forms the opening edge of the exhaust port 57 is overlapped with the upper end part 554 so as to be coupled to the front wall 53. Has been. Further, the upper inner wall 54 is overlapped with the flange piece 51 and joined to a predetermined position to be suspended, and the upper inner wall 54 is bent from the lower end position of the suspended part 541 and is obliquely upward with respect to the front side (left side in FIG. 2). And an upper opening edge 572 that is a part of the outer wall 52 and that forms the opening edge of the exhaust port 57 is overlapped with the inclined portion 542 that extends to the front end portion 543 that is the front end of the inclined portion 542. 52.

  As described above, exhaust gas flowing in the leftward direction in FIG. 2 from the front communication port 44 and the inlet 56 of the secondary heat exchanger case 41 as the exhaust passage 58 first collides with the curved portion 553 of the lower inner wall 55. The direction of the exhaust gas flow is changed upward, and the exhaust gas flowing upward collides with the upper inner wall 54, whereby the direction of the exhaust gas flow is changed to the left and obliquely upward in FIG. A passage is formed in which the flow direction of the exhaust gas flowing in from the inflow port 56 is bent in a crank shape and then discharged from the exhaust port 57 so as to be discharged from the exhaust port 57 to the outside.

  On the other hand, the space between the upper inner wall 54 and the upper portion 521 of the outer wall 52 along the opening edge of the exhaust port 57 is the left-right direction (the direction perpendicular to the paper surface of FIG. 2, the oblique left-right direction of FIG. 3). That is, a passage space 59 extending in the inner peripheral direction of the opening edge is defined. One or a plurality of slit holes extending in the left-right direction across both portions 541 and 542 as exhaust gas inlets 543 are formed at the boundary between the suspended portion 541 and the inclined portion 542 of the upper inner wall 54 (see FIG. 3). Are formed in three examples). These inlets 543 are arranged at the intermediate position in the left-right direction, and the flow of exhaust gas that flows upward and collides with the upper inner wall 54 out of the flow of exhaust gas in the exhaust passage 58 described above. Since the openings are opposed to each other in the direction, a part of the exhaust gas that collides is surely pushed and introduced into the passage space 59 from the introduction port 543. The left and right ends of the upper inner wall 54 are opened to the space of the exhaust passage 58 so as to be orthogonal to the flow direction of the exhaust gas, and these exhaust ports 544 for exhaust gas from the passage space 59 are opened. 544 (see FIG. 3). The preheating unit 50 is configured by the upper portion 521 of the outer wall 52, the upper inner wall 54, the passage space 59, the introduction port 543 for introducing exhaust gas into the passage space 59, and the outlet port 544 for leading out. ing.

  In the preheating unit 50, the exhaust gas introduced into the passage space 59 from the introduction ports 543, 543,... Passes through the passage space 59 and is led out from the outlet port 544, and the exhaust gas in the passage space 59 The outer wall 52 and the inner wall 54 are heated by this contact. As a result, the inner wall 54 facing the exhaust passage 58 and in direct contact with the exhaust gas is preheated using the exhaust gas itself as a heat source, and even if the exhaust gas comes into contact with the inner wall 54, it is difficult for condensation to occur. Generation can be suppressed and the generation amount can be drastically reduced. On the other hand, even if exhaust gas drain is generated by the exhaust gas flowing in the passage space 59 coming into contact with the inner surface of the outer wall 52, the exhaust gas drain flows down to the inlet 543 due to the downward slope of the inner wall 52, It falls onto the side inner wall 55 and is finally led into the secondary heat exchanger case 41 through a notch 513 and a through hole 412 described later. Therefore, the exhaust gas drain generated in the passage space 59 is not scattered outside.

  Also, a gap space 531 extending in the left-right direction is defined between the lower inner wall 55, the lower portion 522 of the outer wall 52, and the front wall 53, as in the case of the preheating portion 50. A sound absorbing material (for example, glass wool or the like) S is fitted in the gap space 531 between the front wall 53 and the lower inner wall 55 so as to be filled therewith. Then, an intermediate portion in the left-right direction of the sound-absorbing material S is cut out, and a laterally relatively small opening 532 is formed through the inside and outside at the lowest position of the front wall 53 corresponding to the cut-out portion S1. . Further, the lower sides of the lower inner wall 55 are cut off at the left and right end portions to form a cutout portion 555, and a cutout portion 513 is formed in the seal member 511 so as to face the cutout portion 555. A through hole 412 (see FIG. 2) is formed in the secondary heat exchanger case 41 at the lower position so as to communicate with the notch 513. In addition, the lower portion 522 of the outer surface wall 52 is set to be inclined obliquely downward from the front wall 53 side toward the flange piece 51 side, that is, from the front surface side toward the rear surface side.

  One notch portion 555 serves as an inlet for introducing exhaust gas into the gap space 531, and the other notch portion 555 serves as a lead-out port for extracting exhaust gas that has passed through the gap space 531. Therefore, the lower portion 522 of the outer wall 52, the front wall 53 (a kind of outer wall facing the hearing space), the lower inner wall 55, the gap space 531 and the both notch portions 555 described above. 555 also constitutes a preheating part. Here, the one notch portion 555 serving as the introduction port is formed so as to open opposite to the flow direction of the exhaust gas flowing in from the inflow port 56, and thus is similar to the upper introduction port 543. In addition, a part of the exhaust gas can be reliably introduced into the internal gap space 531 from the cutout portion 555 to preheat the lower inner wall 55 and the like. Further, a flow of exhaust gas that flows into the gap space 531 from the cutout portion 555 and is discharged to the outside through the opening 532 is also generated. The opening 532 is formed so that the opening edge protrudes inward by burring processing from the outside to the inside, and the exhaust gas drain generated in the gap space 532 is hardly scattered from the opening 532.

  Further, the exhaust top 5 protrudes from the front opening of the front cover 1a of the housing 1, and the exhaust cover 8 (see FIG. 1) is installed so as to cover the entire front wall 53 including the exhaust port 57 of the protruding exhaust top 5. In this case, the front end piece 82 (see FIG. 2 or FIG. 4) of the lower partition plate 81 is inserted into the opening 532. Thus, the exhaust gas drain generated in the exhaust cover 8 is guided to the tip piece 82 and flows into the gap space 531 from the opening 532, and the cutout portion 555 is formed along the inner upper surface of the lower portion 522 of the outer surface wall 52. Then, it flows down into the secondary heat exchanger case 41 through the notch 513 and the through hole 412, and can be recovered from the drain water collecting pipe 71 (see FIG. 1) for neutralization. Further, since the tip piece 82 is inserted into the opening 532, the positioning reference when the exhaust cover 8 is mounted, in other words, the opening 532 can also function as a positioning hole.

  In addition, when the drain water collecting pipe 71 is clogged, and the exhaust gas drain accumulates in the secondary heat exchanger case 41 along with this, when the exhaust gas drain exceeds the position of the opening 532 due to the rise of the water level, The exhaust gas drain accumulated in the secondary heat exchanger case 41 overflows to the exhaust cover 8 side through the front communication port 44, the cutout portion 555 and the opening 532, and is discharged to the drain hole 83 (FIG. 2). Will be discharged to the outside. That is, since the lowermost opening edge of the front communication port 44 is set to be located below the lowermost opening edge of the rear communication port 42, the drain collecting pipe 71 may be clogged. Even if this occurs, it is possible to reliably prevent the accumulated exhaust gas drain from flowing down to the primary heat exchanger 3 or the combustion burner 2 side.

  On the other hand, in the exhaust passage 58, the lower inflow port 56 and the upper exhaust port 57 are offset to the upper and lower positions so as to flow from the lower inflow port 56 to the upper exhaust port 57. Since the middle is bent in the shape of a crank, the exhaust passage length can be secured longer with a compact front and rear width, and for example, noise from the inside of the secondary heat exchanger case 41 is hardly transmitted to the outside. It can contribute to noise reduction. Further, the noise absorbing material S transmitted so as to advance from the front surface communication port 44 of the secondary heat exchanger case 41 and collide with the lower inner surface wall 55 by bending it in a crank shape with an offset arrangement as described above. The transmission direction can be cut off, and the noise absorbing material S absorbs and blocks the noise so that it is difficult to transmit to the outside. This can also reduce noise. In addition, the opening area of the exhaust port 57 is narrower than the inflow port 56 having an opening area equivalent to that of the front communication port 44 of the secondary heat exchanger case 41, and the exhaust passage from the inside of the secondary heat exchanger case 41. The exhaust gas that has flowed into 58 is gradually throttled from the inlet 56 to the exhaust outlet 57, and is squeezed to the maximum at the exhaust outlet 57, leaving the exhaust outlet 57 and released at once. Thereby, coupled with the smooth curved shape of the lower inner wall 55, the flow of exhaust gas can be smoothly guided and rectified, and the occurrence of wind noise and the like can be suppressed and prevented. The noise can be reduced by contributing to the attenuation of the noise.

<Other embodiments>
In addition, this invention is not limited to the said embodiment, Various other embodiments are included. That is, in the above-described embodiment, the inlet 56 of the exhaust top 5 is communicated with the front communication port 44 of the secondary heat exchanger case 41, and the exhaust gas after passing through the secondary heat exchanger 4 is discharged by the exhaust top 5. However, the present invention is not limited to this, and an exhaust top may be attached so that the exhaust gas discharged from the primary heat exchanger case 31 flows into the inlet 56 and is discharged. In short, the exhaust top 5 may be attached to a hot water supply device that is not a condensing type hot water supply device but only a primary heat exchanger that does not include a secondary heat exchanger.

  In the above-described embodiment, the preheating unit 50 is provided on the upper portion of the opening edge of the exhaust port 57. However, the present invention is not limited to this, and the preheating unit 50 may be provided on substantially the entire periphery of the opening edge.

  The exhaust top 5 in the above embodiment is a portion that can be seen from the outside, and is formed of a stainless material in principle from an aesthetic point of view. However, a portion where exhaust gas drain is generated is neutralized by contact with the exhaust gas drain. You may make it form with the neutralization material which exhibits an effect | action. In the above embodiment, the outer wall 52, the inner walls 54 and 55, the front wall 53, and the like are targeted. For example, as shown in FIG. 5 using the lower inner wall 55 as an example, the lower inner wall 55 itself is formed of a neutralized material such as an aluminized steel plate (aluminized stainless steel), an aluminum plate, or an alumina plate (FIG. 5). (See (a)), with the lower inner wall 55 formed on the inner surface side and / or outer surface side of the substrate 55a with coating layers 55b, 55b made of neutralizing material by spraying (evaporation) of alumina or aluminum plating. (See FIG. 5B).

  In the above embodiment, the outer surface wall 52 is formed in a rectangular tube shape so that the overall shape of the exhaust top is a rectangular tube shape, but is not limited thereto, and may be a cylindrical shape or a polygonal cylindrical shape. Regardless of the shape of the wall or the exhaust top, any form of cylinder may be used.

It is a section explanatory view showing an embodiment of a hot-water supply device to which the exhaust top of the present invention is applied. It is expansion sectional explanatory drawing of an exhaust top. It is the perspective view which looked at the exhaust top from the back side. It is the perspective view which looked at the exhaust top from the front side. FIG. 5A is an enlarged view of part A in FIG. 2, FIG. 5A shows a case where the neutralizing material itself is formed, and FIG. 5B shows a case where a coating layer made of the neutralizing material is formed.

Explanation of symbols

2 Combustion burner 3 Primary heat exchanger 4 Secondary heat exchanger 5 Exhaust top 31 Primary heat exchanger case 41 Secondary heat exchanger case 44 Front communication port (communication port)
50 Preheating part 52 Outer wall 53 Front wall (outer wall)
54, 55 Inner wall 56 Inlet 57 Exhaust port 58 Exhaust passage 59 Passage space 543 Inlet port 544 Outlet port

Claims (5)

A cylindrical exhaust top in which an exhaust passage extending from an inlet on one side to an exhaust port on the other side is partitioned,
The exhaust passage includes a preheating portion attached so as to extend to at least a partial region in the inner circumferential direction,
The preheating portion includes an outer wall facing the outer space, an inner wall facing the exhaust passage and defining the exhaust passage, a passage space defined between the outer wall and the inner wall, and An inlet that opens in opposition to the flow direction of the exhaust gas that flows in from the inlet and flows in the exhaust passage toward the exhaust outlet, and introduces the exhaust gas into the passage space, and after being introduced from the inlet A discharge port for returning the exhaust gas after passing through the passage space to the exhaust passage, and
The preheater section, that are arranged to form at least part of the opening edge of the exhaust port,
Exhaust top, characterized in that. The exhaust top according to claim 1 ,
The introduction port is formed in the inner wall of the intermediate position with respect to the inner circumferential direction of the exhaust passage, while the outlet port is opened from the end position in the inner circumferential direction starting from the intermediate position in the inner circumferential direction. The exhaust top is formed. The exhaust top according to claim 1 or 2 ,
The exhaust top, wherein the inner surface wall is formed of a neutralizing material that neutralizes exhaust gas drainage by contact with the surface portion or all the portions facing the exhaust passage. An exhaust top according to any one of claims 1 to 3 , a combustion burner, and a heat exchanger heated by heat exchange based on the combustion of the combustion burner,
The inflow port of the exhaust top communicates with the communication port that is opened laterally in the heat exchanger case containing the heat exchanger and through which the exhaust gas is led out after passing through the heat exchanger. A hot water supply apparatus in which an exhaust top is attached to the heat exchanger case. The hot water supply apparatus according to claim 4 ,
As the heat exchanger, a primary heat exchanger that is heat exchange-heated by the combustion heat of the combustion burner, and a secondary heat exchanger for recovering latent heat from the exhaust gas that has passed through the primary heat exchanger. The hot water supply apparatus is provided with exhaust gas after the communication port of the heat exchanger case has passed through the secondary heat exchanger.

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