JP2014190570A - Latent-heat-collection combustion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a latent-heat-collection combustion device having a structure that can keep an acoustic absorption effect by an acoustic absorbent and can prevent the corroded acoustic absorbent from being discharged to outside, capable of easily achieving the prevention of the corroded acoustic absorbent from being discharged to the outside at low cost, and the like.SOLUTION: A latent-heat-collection combustion device 1 includes: a latent-heat-collection heat exchanger collecting latent heat of exhaust air; an exhaust-air collection cylinder 5 for discharging exhaust air after being subjected to heat exchange by the latent-heat-collection heat exchanger to an outside; and an acoustic absorbent 40 provided within the exhaust-air collection cylinder 5. The exhaust-air collection cylinder 5 includes: a main body case 31; an acoustic-absorbent holding member 41 installed within the main body case 31 with an acoustic-absorbent accommodation space kept vacant. The acoustic absorbent 40 is arranged in the acoustic-absorbent accommodation space, and the acoustic-absorbent holding member 41 is made of punching metal having many small-diameter holes at a diameter of 1 to 3 mm.

Description

  The present invention relates to a latent heat recovery combustion apparatus, and more particularly, to a device having a structure capable of preventing the corroded sound absorbing material from being discharged to the outside even when the sound absorbing material is corroded by drain contained in exhaust gas.

  2. Description of the Related Art Conventionally, a combustion apparatus that combusts a gas has been widely spread as a heat source apparatus such as a hot water supply apparatus and a heating device. This type of combustion apparatus includes a blower fan that takes in combustion air from the outside, a burner unit that mixes and burns combustion air and fuel gas, and heat that heats water by exchanging heat between combustion heat and water. An exchanger part, an exhaust passage part (exhaust gas collection cylinder) for exhausting the exhaust gas after heat exchange to the outside are provided.

  In the combustion apparatus described above, various sound absorbing structures in which an inorganic fiber sound absorbing material such as glass wool or rock wool is attached to the exhaust passage portion have been put into practical use in order to reduce noise due to exhaust after heat exchange. For example, the combustion apparatus disclosed in Patent Document 1 discloses a sound absorbing structure in which a sound absorber is attached to an exhaust passage portion between a heat exchanger and an exhaust port. This sound absorbing structure is composed of a sound absorbing board in which a large number of through holes are formed in a sound absorbing material such as glass wool, and a wire mesh formed so as to cover the surface of the sound absorbing board and the peripheral wall surface of the through holes. According to this sound absorbing structure, it is possible to prevent the sound absorbing effect from being reduced by preventing the sound absorbing material from being peeled off by the wire mesh.

  By the way, in the above-described combustion apparatus, not only those equipped with a sensible heat recovery heat exchanger that uses sensible heat of exhaust gas, but also after heat exchange by a sensible heat recovery heat exchanger in order to improve thermal efficiency. A latent heat recovery type combustion apparatus equipped with a heat exchanger for recovering latent heat using the latent heat of exhaust gas has been put into practical use.

  However, in the case of a latent heat recovery type combustor, the drain (condensed water) generated by the latent heat recovery is strongly acidic, so that the strongly acidic drain adheres to the sound absorbing material made of inorganic fibers such as glass wool, thereby absorbing the sound. There is a problem that the material corrodes. For this reason, in the case of a latent heat recovery type combustion apparatus, a sound absorbing material such as glass wool cannot be installed downstream of the latent heat recovery heat exchanger, and an acid-resistant sound absorbing material needs to be installed. For example, the combustion apparatus disclosed in Patent Document 2 discloses a structure in which an acid-resistant gel-like sound absorber is installed in an exhaust passage portion between a latent heat recovery heat exchanger and an exhaust port.

Japanese Utility Model Publication 2-38209 JP 2006-183912 A

  As described above, by installing a gel-like sound absorber as in Patent Document 2 on the downstream side of the latent heat recovery heat exchanger, the sound absorber is prevented from corroding and the sound absorber is scattered outside. Can be prevented. However, since the gel-like sound absorber is a special member, it may be desired to install a sound absorbing material mainly made of inorganic fibers such as glass wool. As described above, it is difficult to install on the downstream side of the industrial heat exchanger.

  Therefore, in order to make the mesh of the metal mesh finer when adopting a structure in which the periphery of the sound absorber is covered with a metal mesh as in Patent Document 1 so that the sound absorber made of inorganic fiber is not discharged to the outside even if it corrodes. Constructing a wire mesh with a thin wire will deteriorate the corrosion resistance of the wire mesh.On the other hand, if a wire mesh is formed with a thick wire, the mesh of the wire mesh will increase, so that the corroded sound absorbing material will be scattered outside. The problem arises that it cannot be effectively prevented. Moreover, since it is necessary to process a metal mesh according to the shape of a sound-absorbing material, it takes time and costs are increased.

  An object of the present invention is to provide a latent heat recovery type combustion apparatus having a structure capable of maintaining the sound absorbing effect of the sound absorbing material and preventing the corroded sound absorbing material from being discharged to the outside. An object of the present invention is to provide a device that can easily prevent discharge at a low cost.

  A latent heat recovery type combustion apparatus according to claim 1 is a latent heat recovery heat exchanger that recovers the latent heat of exhaust, an exhaust gas collection cylinder for discharging the exhaust after heat exchange by the latent heat recovery heat exchanger, In the latent heat recovery type combustion apparatus provided with a sound absorbing material provided inside the exhaust collecting cylinder, the exhaust collecting cylinder includes a main body case and a sound absorbing material installed with a sound absorbing material accommodation space inside the main body case. The sound absorbing material is disposed in the sound absorbing material accommodation space, and the sound absorbing material holding member is made of a punching metal having a plurality of small-diameter holes having a diameter of 1 to 3 mm. It is said.

  A latent heat recovery combustion apparatus according to a second aspect is the invention according to the first aspect, wherein the sound absorbing material is disposed on a top plate side sound absorbing material disposed on the top plate side of the main body case and on a rear plate side of the main body case. The top plate side sound absorbing material of the sound absorbing material is mainly composed of glass wool, and an acid-resistant solidifying material is applied to at least the surface of the glass wool in contact with the exhaust. It is characterized by.

  According to the first aspect of the present invention, the exhaust collecting cylinder includes a main body case and a sound absorbing material holding member installed inside the main body case with a sound absorbing material accommodating space, and the sound absorbing material is provided in the sound absorbing material accommodating space. Since the sound absorbing material holding member is made of a punching metal having a large number of small-diameter holes having a diameter of 1 to 3 mm, the sound absorbing material is exhausted by the sound absorbing material holding member made of an existing punching metal. Can be easily held inside.

  Therefore, even when the sound absorbing material is peeled off due to corrosion by strong acid drain or aging deterioration, it is possible to prevent the sound absorbing material from being discharged to the outside by the punching metal as much as possible. Since the punching metal has high openability due to a large number of small-diameter holes, the reduction of the sound absorbing effect of the sound absorbing material can be suppressed as much as possible. By using the punched metal which is an off-the-shelf product, it is possible to prevent scattering of the corroded sound absorbing material with a low-cost and easy structure.

  According to the invention of claim 2, the top plate side sound absorbing material of the sound absorbing material is mainly composed of glass wool, and the acid-resistant solidifying material is applied to at least the surface of the glass wool in contact with the exhaust. The solidifying material can prevent the sound absorbing material from being corroded by the drain, and can improve the durability of the sound absorbing material.

It is a schematic block diagram of the latent heat recovery type combustion apparatus which concerns on the Example of this invention. It is a perspective view of a latent heat recovery type combustion apparatus. It is a perspective sectional view of the upper structure of a latent heat recovery type combustion device. It is a longitudinal cross-sectional view of the upper structure of a latent heat recovery type combustion apparatus. It is a perspective view of the exhaust gas collection cylinder of the state which removed the top plate part. It is a top view of the exhaust gas collection cylinder of the state which removed the top plate part. It is a perspective view from the back surface side of the top plate part of the exhaust collecting cylinder, the sound absorbing material holding member, and the sound absorbing material. It is a perspective view of an upper heat exchange can body and a base plate of a latent heat recovery type combustion device. It is a top view of the upper side heat exchange can body and base plate of a latent heat recovery type combustion apparatus. FIG. 10 is a sectional view taken along line XX in FIG. 9.

  Hereinafter, embodiments of the present invention will be described based on examples.

First, the overall configuration of the latent heat recovery combustion apparatus 1 will be briefly described.
As shown in FIG. 1, the latent heat recovery combustion apparatus 1 is applied as a heat source device such as a hot water supply device or a heating device, and uses sensible heat and latent heat contained in exhaust gas by burning a fuel gas. It constitutes a gas water heater that heats hot water.

  That is, as shown in FIG. 1, the latent heat recovery combustion apparatus 1 includes a blower fan 2 for supplying combustion air, a burner unit 3 for burning fuel gas, and between the combustion heat generated by the burner unit 3 and hot water. A heat exchanger section 4 for exchanging heat, an exhaust collecting cylinder 5 for discharging the exhaust gas after heat exchange by the heat exchanger section 4 forward, various pipes such as a water inlet pipe 6a, a hot water outlet pipe 6b, and a drain pipe 6c. It has.

  The burner unit 3 includes, for example, ten burners 3 a that mix and burn fuel gas and combustion air, a burner can body 3 b that accommodates these burners, and the like. The blower fan 2 is provided in the lower end part of the burner can body 3b. The heat exchanger unit 4 includes a sensible heat recovery unit 8 and a latent heat recovery unit 9 disposed on the sensible heat recovery unit 8. An exhaust collecting cylinder 5 is provided at the upper end of the latent heat recovery unit 9.

  As shown in FIGS. 1 to 4, the sensible heat recovery unit 8 includes a sensible heat recovery heat exchanger 11 that mainly recovers sensible heat of the exhaust, and a lower heat exchange canister that houses the sensible heat recovery heat exchanger 11. The latent heat recovery unit 9 includes a body 12 and the like, and a latent heat recovery heat exchanger 13 that mainly recovers latent heat of exhaust after sensible heat recovery, an upper heat exchange can body 14 that accommodates the latent heat recovery heat exchanger 13, and the like. It has. The upper end portion of the burner can body 3b, the lower end portion of the lower heat exchange can body 12, the upper end portion of the lower heat exchange can body 12, and the lower end portion of the upper heat exchange can body 14 are joined by caulking or screw fastening, respectively. ing.

  In the latent heat recovery combustion apparatus 1, the incoming water supplied from the inlet pipe 6a is heated by the latent heat of the exhaust in the latent heat recovery heat exchanger 13, and then supplied to the sensible heat recovery heat exchanger 11, where the sensible heat recovery is performed. After being heated by the heat exchanger 11, the hot water supply pipe 6b is supplied. A tray 6d that receives drain (condensed water) generated by the latent heat recovery is provided immediately below the latent heat recovery heat exchanger 13, and the drain recovered in the tray 6d passes through the drain pipe 6c and is neutralized (illustrated). After being neutralized by being sent to (Omitted), it is discharged out of the instrument.

Next, the upper heat exchange can body 14 in which the latent heat recovery heat exchanger 13 is housed will be described.
As shown in FIGS. 2 to 4, the upper heat exchange can body 14 is configured as a box-like body from a front side plate 16, a rear side plate 17, a left side plate 18, a right side plate 19, a top side plate 21, and a bottom side plate 22. . The front plate 16 is formed with an inflating portion 16a that protrudes forward so as to extend in the left-right direction. The expansion portion 16a expands the space inside the upper heat exchange can body 14, thereby smoothing the flow of exhaust gas and improving the efficiency of latent heat recovery by the latent heat recovery heat exchanger 13.

  The top plate 21 is formed with a stepped portion 21a that is stepped downward. The stepped portion 21a is formed in a rectangular shape that is slightly longer in the left-right direction in plan view. The peripheral wall portion of the paragraph portion 21a is formed in an inclined shape that is gently inclined toward the center. An exhaust port 23 of the latent heat recovery heat exchanger 13 is formed at the bottom of the front portion of the paragraph portion 21a. The exhaust port 23 is formed in a substantially rectangular shape that opens upward and extends in the left-right direction. A base plate 25 for fixing the exhaust collecting cylinder 5 is provided on the top surface of the top side plate 21. The specific structure of the base plate 25 will be described later.

  In the rear portion of the bottom plate 22, an introduction port 24 is formed through which exhaust gas after sensible heat recovery by the sensible heat recovery heat exchanger 11 is introduced. The tray 6d described above is formed in the front portion of the bottom side plate 22 of the upper heat exchange can body 14, and the drain pipe 6c is connected to the tray 6d.

  Inside the upper heat exchange can 14, vertical rectifying plates 26 a, 26 b, and 26 c are attached to the vicinity of the introduction port 24, the vicinity of the exhaust port 23, and the like. The exhaust gas flowing in from the introduction port 24 is heat-exchanged by the rectifying plates 26a, 26b, and 26c while passing through the latent heat recovery heat exchanger 13, and the exhaust gas after the latent heat recovery by the latent heat recovery heat exchanger 13 is performed at the exhaust port. 23 flows into the exhaust collecting cylinder 5.

  As shown in FIGS. 2 to 4, the latent heat recovery combustion apparatus 1 includes a lower end portion of a front end of the exhaust collecting cylinder 5 and a sensible heat recovery heat exchanger so as to straddle the upper heat exchange can body 14 in the vertical direction. 11 is provided with a reinforcing member 27 that connects the upper flange portion at the front end of the lower heat exchange can body 12 that houses the housing 11.

Next, a specific structure of the exhaust collecting cylinder 5 unique to the present application will be described.
As shown in FIGS. 1 to 7, the exhaust collecting cylinder 5 is disposed on the downstream side of the latent heat recovery heat exchanger 13 and on the upper end side of the upper heat exchange can body 14, and is formed by the latent heat recovery heat exchanger 13. The exhaust after the latent heat recovery is collected and discharged from the front of the latent heat recovery combustion apparatus 1 into the atmosphere.

  The exhaust collecting cylinder 5 is configured as a rectangular parallelepiped box-shaped body made of a stainless steel plate, and a main body case 31 that forms an exhaust passage 32 for exhaust gas rising through the latent heat recovery heat exchanger 13, and the main body case 31. The exhaust top 33 is mainly configured to exhaust the exhaust gas flowing through the exhaust passage 32 to the outside. A sound absorbing material holding member 41 for holding the sound absorbing material 40 is provided inside the main body case 31.

  The main body case 31 includes a front plate portion 34, a rear plate portion 35, a left plate portion 36, a right plate portion 37, a top plate portion 38, and a bottom plate portion 39, and is configured as a flat box-shaped body. A discharge port 34a is formed in the front plate portion 34 of the main body case 31 so as to extend in the left-right direction, and an exhaust top 33 projecting forward and having an open central portion is attached to a peripheral portion of the discharge port 34a. . The main body case 31 is configured to protrude forward from the front end portion of the latent heat recovery heat exchanger 13 and to protrude rearward from the rear end portion of the latent heat recovery heat exchanger 13.

  Lower end flange portions 35a, 36a, and 37a are provided at the lower end portions outside the rear plate portion 35 and the left and right plate portions 36 and 37, respectively, so as to extend in the longitudinal direction. The exhaust collecting cylinder 5 is attached to the upper end portion of the upper heat exchange can body 14 by fixing the three lower end flange portions 35 a, 36 a, 37 a to the base plate 25 with a plurality of screws 42. A specific fixing structure 50 of the exhaust collecting cylinder 5 will be described later.

  The bottom plate portion 39 is formed with a rectangular exhaust introduction port 43 connected to the exhaust port 23 of the latent heat recovery heat exchanger 13. The exhaust introduction port 43 is for introducing exhaust gas from the exhaust port 23 to the exhaust passage 32 in the exhaust collecting cylinder 5. The outer peripheral edge of the exhaust introduction port 43 is formed with a collecting cylinder side paragraph 43a stepped downward. A burring edge 43b is formed on the inner peripheral side of the collecting cylinder side paragraph 43a so as to extend downwardly toward the center of the opening.

  The exhaust introduction port 43 is provided with a rectangular plate-shaped dividing member 45 for dividing the exhaust introduced from the exhaust port 23 into an exhaust flow toward the front of the exhaust collecting cylinder 5 and an exhaust flow toward the rear. Yes. Flange portions 45a bent upward are integrally formed at both left and right ends of the dividing member 45, respectively. The split member 45 is fixed to the inside of the left and right plate portions 36 and 37 of the main body case 31 via a pair of flange portions 45a so as to partially close the exhaust introduction port 43.

Next, the sound absorbing material 40 will be described.
As shown in FIGS. 3, 4, and 7, the sound absorbing material 40 is disposed in a sound absorbing material accommodation space that is partitioned from the main body case 31 and the sound absorbing material holding member 41 into an L shape in a side view. Specifically, the sound absorbing material 40 includes a top plate side sound absorbing material 40a accommodated in a horizontal region of the sound absorbing material accommodation space, and a rear plate side sound absorbing material 40b accommodated in a vertical region of the sound absorbing material accommodation space. In this way, by covering a part of the exhaust passage 32 (the rear plate portion 35 side and the top plate portion 38 side) with the sound absorbing material 40, a sound absorbing effect can be achieved.

  The top plate-side sound absorbing material 40a is mainly composed of glass wool, and an acid-resistant solidifying material 40c is applied to at least the lower end surface of the glass wool that is in contact with the exhaust (see FIGS. 3 and 4). Although acid-resistant silicon is used for the solidifying material 40c, it is not particularly limited to silicon, and various materials can be applied as long as they are acid-resistant. Since the lower end surface of the top plate-side sound absorbing material 40a is the portion most susceptible to the influence of drain contained in the exhaust gas, by applying an acid-resistant solidifying material 40c to this lower end surface, the top plate-side sound absorbing material 40a Durability can be significantly improved.

  The rear plate side sound absorbing material 40b is mainly composed of rock wool. The rear plate side sound absorbing material 40b has a front and rear width larger than (for example, about four times) the vertical width of the top plate side sound absorbing material 40a. Since the rear plate side sound absorbing material 40b is arranged behind the inside of the exhaust collecting cylinder 5, the rear plate side sound absorbing material 40b which is hardly affected by the drain and peeled off by the flow of exhaust gas is difficult to be discharged to the outside. There is no need to apply an acid-resistant solidifying material, and the overall cost of the sound absorbing material 40 can be reduced.

Next, the sound absorbing material holding member 41 will be described.
As shown in FIGS. 3, 4, and 7, the sound absorbing material holding member 41 is installed inside the main body case 31 with a sound absorbing material accommodation space therebetween. Specifically, the sound absorbing material holding member 41 is formed in an inverted L shape when viewed from the side, and is installed in a horizontal position so as to be parallel to the top plate portion 38 in the vicinity of the top plate portion 38. 41a, a rear plate side holding member 41b installed in a vertical posture so as to be parallel to the rear plate portion 35 is provided in the vicinity of the rear plate portion 35.

  The top plate side holding member 41a and the rear plate side holding member 41b are each configured by a punching metal 47 having a rectangular shape in plan view. These punching metals 47 are provided with a large number of small diameter holes 47a having a diameter of 1 to 3 mm formed in a plurality of rows and a plurality of columns (for example, a pitch of about 3 mm).

  Three flange portions 41c bent upward are formed at the left and right ends extending from the front end of the top plate side holding member 41a, and two bent backwards are formed at the left and right ends of the rear plate side holding member 41b. A flange portion 41d is formed, and the sound absorbing material holding member 41 is fixed to the main body case 31 via the plurality of flange portions 41c and 41d.

Next, the fixing structure 50 of the exhaust collecting cylinder 5 will be described.
As shown in FIGS. 8 to 10, the fixing structure 50 is affixed to the base plate 25 for fixing the latent heat recovery heat exchanger 13 and the exhaust collecting cylinder 5, and the upper and lower surfaces of the base plate 25. An elastically deformable seal packing 52, a seal member 53, a plurality of screws 55 (for example, tapping screws) and the like are provided, and the exhaust collecting cylinder 5 covers the upper surface side of the top side plate 21 and its front and rear side portions via the base plate 25. Is attached.

  The base plate 25 is formed in a rectangular plate shape in plan view, and a rectangular opening 51 is formed in the center of the base plate 25 so as to communicate with the exhaust port 23 of the latent heat recovery heat exchanger 13. A bent portion 25 a bent downward is formed at the front end portion of the base plate 25. The bent portion 25a is formed with a pair of elongated holes 25b extending in the left-right direction, and the upper end portion of the reinforcing member 27 is engaged with the pair of elongated holes 25b.

  At the outer peripheral edge portion of the opening portion 51 of the base plate 25, an annular paragraph portion 51a stepped downward is formed (see FIG. 10). An annular seal packing 52 is affixed to the surface side of the annular paragraph 51a. The seal packing 52 includes a plurality of holes 52a that are formed according to the mounting positions of the plurality of screws 55 and that can accommodate the head portions 55a of the plurality of screws 55. An annular seal member 53 is affixed to the back side of the annular paragraph 51a. The seal member 53 includes a plurality of insertion portions 53a that are formed according to the attachment positions of the plurality of screws 55 and into which the screw portions 55b of the screws 55 can be inserted.

  When the exhaust collecting cylinder 5 is attached to the upper end of the upper heat exchange can body 14, first, the upper heat exchange can body is sandwiched between the annular stage portion 51a of the base plate 25 so as to sandwich the seal member 53 attached to the back side thereof. The base plate 25 is fixed to the upper heat exchange can body 14 with a plurality of screws 55. Next, a seal packing 52 having a plurality of holes 52 a for accommodating the heads 55 a of the plurality of screws 55 is affixed to the surface side of the annular stage portion 51 a of the base plate 25.

  Next, in a state where the opening 51 of the base plate 25 and the exhaust inlet 43 of the exhaust collecting cylinder 5 are aligned, the base plate 25 is sandwiched between the bottom plate 39 of the exhaust collecting cylinder 5 and the seal packing 52 sandwiched therebetween. Placed on. By fastening and fixing the three lower end flange portions 35a, 36a, 37a of the exhaust collecting cylinder 5 and the outer peripheral portion of the base plate 25 with a plurality of screws 42 via the seal packing 52, the exhaust collecting cylinder 5 is fixed to the upper heat exchange can. Secure to body 14.

  At this time, the seal packing 52 and the seal member 53 are pressed downward by the collecting cylinder side stage 43a of the bottom plate portion 39 of the exhaust collecting cylinder 5, and project toward the latent heat recovery heat exchanger 13 side of the bottom plate portion 39. Since the inner periphery of the seal packing 52 is pressed by the burring edge 43b, the seal packing 52 and the seal member 53 are compressed, so that the space between the exhaust collecting cylinder 5 and the upper heat exchange can body 14 is airtight. In addition to sealing, the seal packing 52 reliably covers the heads 55a of the plurality of screws 55, so that the plurality of screws 55 can be reliably protected from exhaust.

Next, the operation and effect of the latent heat recovery combustion apparatus 1 of the present invention will be described.
First, the exhaust that rises after the sensible heat and latent heat are recovered via the sensible heat recovery heat exchanger 11 and the latent heat recovery heat exchanger 13 is the exhaust port 23 of the latent heat recovery heat exchanger 13. Then, it flows into the exhaust passage 32 through the exhaust inlet 43 of the exhaust collecting cylinder 5.

  Next, the exhaust gas flowing into the exhaust passage 32 is divided into a front exhaust flow toward the front portion of the exhaust collecting cylinder 5 and a rear exhaust flow toward the rear portion. The exhaust of the front exhaust flow and the rear exhaust flow is merged and mixed on the front side inside the main body case 31. When the exhaust gas is mixed, the exhaust sound of the front exhaust flow and the exhaust sound of the rear exhaust flow cancel each other out due to the canceling action, and the mixed exhaust is discharged from the exhaust top 33 to the outside of the exhaust collecting cylinder 5.

  By the way, the rear exhaust flow is reversed on the front side of the rear plate side holding member 41b and flows forward, so that the drain may adhere to the rear plate side sound absorbing material 40b and the rear plate side sound absorbing material 40b may corrode. In this case, it is possible to prevent the rear plate side sound absorbing material 40b corroded by the rear plate side holding member 41b from being discharged to the outside. The rear plate-side sound absorbing material 40b has a structure that hardly scatters to the outside even if it corrodes due to the structure that forms a flow path in which the rear exhaust flow is reversed on the front side of the rear plate-side holding member 41b.

  Further, since the backward exhaust flow flows forward along the lower end surface of the top plate side holding member 41a, there is a high possibility that the drain adheres to the top plate side sound absorbing material 40a, but it comes into contact with the exhaust of the top plate side sound absorbing material 40a. Corrosion of the top plate-side sound absorbing material 40a can be prevented by the acid-resistant solidifying material 40c applied to the surface. Even when the top plate side sound absorbing material 40a is corroded by the drain, the top plate side sound absorbing material 40a can be prevented from being discharged to the outside by the top plate side holding member 41a.

  As described above, the exhaust collecting cylinder 5 includes the main body case 31 and the sound absorbing material holding member 41 that is installed inside the main body case 31 with a sound absorbing material accommodating space therebetween, and the sound absorbing material 40 accommodates the sound absorbing material. Since the sound-absorbing material holding member 41 is arranged in a space and is constituted by the punching metal 47 having a large number of small-diameter holes 47a having a diameter of 1 to 3 mm, the sound-absorbing material holding member 41 constituted by the existing punching metal 47 is used. Thus, the sound absorbing material 40 can be easily held inside the exhaust collecting cylinder 5.

  Therefore, even when the sound absorbing material 40 is peeled off due to corrosion by strong acid drain or aging deterioration, the punching metal 47 can prevent the sound absorbing material 40 from being discharged to the outside as much as possible. Since the punching metal 47 has a high openability due to the large number of small diameter holes 47a, the reduction of the sound absorbing effect of the sound absorbing material 40 can be suppressed as much as possible. By using the punched metal 47 that is an off-the-shelf product, it is possible to prevent scattering of the corroded sound absorbing material 40 with a low-cost and easy structure.

  Moreover, the top plate side sound absorbing material 40a of the sound absorbing material 40 is mainly composed of glass wool, and the acid-resistant solidifying material 40c is applied to at least the surface of the glass wool in contact with the exhaust gas. Thus, the durability of the sound absorbing material 40 can be improved, and corrosion of the sound absorbing material 40 due to drain can be prevented.

An example in which the embodiment is partially changed will be described.
[1] In the above embodiment, the top plate-side sound absorbing material 40a is mainly composed of glass wool, and the acid-resistant solidifying material 40c is applied to the surface in contact with the exhaust. However, it is necessary to limit to the top plate-side sound absorbing material 40a. Alternatively, the rear-plate-side sound absorbing material 40b may be mainly composed of glass wool, and the solidifying material 40c may be applied to the surface in contact with the exhaust. Further, the material of the sound absorbing material 40 and the application location of the solidifying material 40c can be changed as appropriate.

[2] In addition, those skilled in the art can implement the present invention by adding various modifications without departing from the spirit of the present invention, and the present invention includes such modifications. It is.

DESCRIPTION OF SYMBOLS 1 Latent heat recovery type combustion apparatus 5 Exhaust gas collection tube 13 Latent heat recovery heat exchanger 14 Upper heat exchange can body 23 Exhaust port 25 Base plate 31 Main body case 39 Bottom plate part 40 Sound absorbing material 40a Top plate side sound absorbing material 40b Rear plate side sound absorbing material 41 Sound absorbing material holding member 41a Top plate side holding member 41b Rear plate side holding member 43 Exhaust inlet 43b Burring edge 47 Punching metal 47a Small diameter hole 50 Exhaust tube fixing structure 51 Opening 52 Seal packing 52a Hole 53 Sealing member 55 Screw 55a Head

Claims (2)

A latent heat recovery heat exchanger that recovers the latent heat of the exhaust, an exhaust collect cylinder for exhausting the exhaust after the heat exchange by the latent heat recovery heat exchanger, and a sound absorption provided inside the exhaust collect cylinder In the latent heat recovery type combustion device provided with a material,
The exhaust collecting cylinder includes a main body case, and a sound absorbing material holding member installed with a sound absorbing material accommodation space inside the main body case,
The sound absorbing material is disposed in the sound absorbing material accommodation space, and the sound absorbing material holding member is composed of a punching metal having a large number of small diameter holes having a diameter of 1 to 3 mm. . The sound absorbing material includes a top plate side sound absorbing material arranged on the top plate side of the main body case, and a rear plate side sound absorbing material arranged on the rear plate side of the main body case,
2. The latent heat according to claim 1, wherein the top plate side sound absorbing material of the sound absorbing material is mainly composed of glass wool, and an acid-resistant solidifying material is applied to at least a surface of the glass wool in contact with the exhaust. Recovery type combustion device.