JP2006064315A - Exhaust pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a situation wherein environment is damaged by noise emitted from an exhaust pipe. <P>SOLUTION: A pipe wall is made to include an innermost steel pipe-like body 44, and a silencing layer 44 wherein porous particulate matter made of pearlite is formed in a layer state with breathability maintained. The pipe-like body 44 has: a small diameter pipe part 41; upper and lower large diameter pipe parts 43, 44 equipped on both the upper and lower sides of the small diameter pipe part 41; upper and lower taper-like pipe parts 45, 46 making the large diameter pipe parts 43, 44 continue to the small diameter pipe part 41; and a tapered-off pipe part 47 continuously formed in an upper end part of the upper-side large diameter pipe part 43. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an exhaust pipe, and more particularly to an exhaust pipe provided with noise reduction measures.

  Depending on the installation location, the exhaust stack including the chimney picks up and emits sound generated outside the exhaust stack, such as machine operation noise in the machine room and combustion noise in the combustion chamber, or exhausts the exhaust passage of the exhaust stack. Since the exhaust sound of the flowing exhaust was released, there was a situation where these sounds became noise and the environment was damaged.

  On the other hand, as a conventional example, a silencer made of a sound absorbing material is provided at the bottom of the chimney main body, and a silencer built-in type in which a taper sound absorber that is expanded upward is provided inside the casing of the silencer so as to be movable up and down. There was a chimney (see Patent Document 1).

JP-A-6-323123

  However, the chimney with built-in silencer described in Patent Document 1 is only intended to adjust the range of sound to be silenced by moving the taper-shaped sound absorber up and down. It has not been possible to sufficiently satisfy the demand for noise reduction inside the exhaust pipe, such as the sound generated outside the exhaust pipe, such as the operation sound of the machine and the combustion sound, and the sound generated inside the exhaust pipe, such as the flow sound of the exhaust.

  The present invention has been made under the above circumstances, and an object thereof is to make it possible to achieve comprehensive silencing of sound emitted from an exhaust stack including a chimney.

  An exhaust pipe according to the present invention is a laminate of a steel cylindrical body whose internal space forms an exhaust passage on a cylindrical wall, and a sound deadening layer composed of a porous granular material layer that is a foamable heat insulating material. In the exhaust cylinder including a portion, the cylindrical body includes a small-diameter cylindrical portion, upper and lower large-diameter cylindrical portions disposed on both upper and lower sides of the small-diameter cylindrical portion, and these large-diameter cylindrical portions are connected to the small-diameter cylindrical portion. The upper and lower tapered cylindrical portions that are continuous with each other and the tapered cylindrical portion that is connected to the upper end portion of the upper large-diameter cylindrical portion are provided, and the silencing layer has a silencing performance. It is desirable that the provided fibrous heat insulating material layers are added and laminated next to each other, and a water stop material is interposed between the fibrous heat insulating material layers and the sound deadening layer.

  According to this invention, the porous granular material forming the sound deadening layer absorbs the sound wave, or exhibits the action of causing the sound wave taken in by absorbing the sound to diffuse and interfere in the layer. In addition, the porous powder and granular materials exhibit an effect of absorbing acoustic energy by friction with sound waves, so that the release of sound from the exhaust pipe outlet is suppressed and only a high silencing effect is exhibited. In the innermost part of the exhaust cylinder, the exhaust gas flowing through the exhaust passage is formed by the shape of the steel cylindrical body formed by the small diameter cylindrical part, the large diameter cylindrical part, the tapered cylindrical part, and the tapered cylindrical part. As the sound is squeezed or released after being squeezed, the silencing action is further promoted, and the silencing action is significantly exhibited as a whole.

  In addition to pearlite, glass beads, alumina bubbles, etc. can be used as the porous granular material. Among these, pearlite is an aggregate of airtight small bubbles and is 1/10 to 1/20 the weight of sand, so it has excellent lightness, fire resistance and chemical resistance, Even if installed in the exhaust stack, not only the strength burden on the exhaust stack can be kept small, but it also shows excellent durability against high-temperature exhaust, and the initial silencing action lasts for a long time. Since it exhibits a chemically stable property with respect to exhaust with uneven values, it exhibits a remarkable effect that the initial silencing action lasts for a long time even in such an exhaust environment.

  Rock wool and glass wool can be suitably used as the fibrous thermal insulation of the fibrous thermal insulation layer with sound deadening performance, and the fibrous thermal insulation layer employing these fibrous thermal insulations also absorbs sound waves Exhibits noise reduction performance. Therefore, if this fibrous heat insulating material layer is added to the sound deadening layer and laminated, the above sound deadening effect by the sound deadening layer and the sound deadening effect by the fiber heat insulating material layer are synergistically obtained and a remarkable sound deadening effect is obtained. . By the way, when rock wool or glass wool is used for the fibrous heat insulating material of the fibrous heat insulating material layer, since the fibrous heat insulating material has a fine space showing a capillary phenomenon, the cylindrical body and When a porous powder used as a sound deadening layer is placed in the space between the fibrous heat insulating material layer by an appropriate method such as pouring, spraying, troweling, etc., as a binder for the porous powder There is a possibility that the water used may infiltrate the fibrous heat-insulating material which is difficult to dry and significantly reduce the heat insulating performance and the sound deadening performance. However, this point is that the water-stopping material is used by adopting a configuration in which a water-stopping material is interposed between the fibrous heat insulating material layer and the sound deadening layer as in the present invention. This helps prevent water from entering the fibrous insulation and eliminates the situation where water penetrates into the fibrous insulation layer and degrades its thermal insulation and silencing performance. As the water-stopping material, an aluminum foil having a thickness of 0.1 to 200 μm or a thin steel plate having a thickness of 100 to 200 μm can be suitably used. However, when the internal temperature is 250 degrees or less, a resin film or the like can be used. Good. And by applying these water blocking materials, sound insulation and heat insulation are also improved.

  As described above, according to the present invention, the sound deadening layer made of a porous granular material such as pearlite, glass beads, and alumina bubbles can efficiently generate sound waves taken into the exhaust pipe from the outside or generated in the exhaust pipe. Not only does it reflect irregularly or absorbs diffusely into the layer and exhibits a silencing effect, but the shape of the cylindrical body is designed to improve the silencing performance, so the noise emitted from the exhaust stack Is remarkably reduced, and the situation where the environment is damaged by noise emitted from the exhaust stack is improved.

  1 is a partially longitudinal side view schematically showing an exhaust pipe according to the present invention, FIG. 2 is a sectional view of a fibrous heat insulating material layer 5, and FIG. 3 is a partially longitudinal side view showing another configuration of the exhaust pipe. .

  The exhaust pipe 1 shown in FIG. 1 includes an exhaust for a building or factory chimney, a smoke exhaust duct, an air conditioning duct or the like. Further, the exhaust cylinder 1 is provided with an exhaust introduction port 21 formed by an end opening of an elbow-shaped exhaust introduction pipe 2 attached to the cylinder wall, and the exhaust introduction port 21 is provided with the exhaust cylinder body 1. The exhaust passage 12 opens upward at the center in the radial direction and faces the exhaust passage 12.

  In this exhaust cylinder 1, a laminated portion of a cylindrical body 4 whose internal space forms an exhaust passage and a sound deadening layer 6 made of a porous granular material layer that is a foaming heat insulating material is formed on the cylindrical wall. include. Here, “the cylindrical wall includes a laminated portion of the cylindrical body 4 and the sound deadening layer 6” means that part or all of the cylindrical wall is formed by the laminated portion of the cylindrical body 4 and the noise deadening layer 6. It is that it has been. In other words, in the entire height region of the cylindrical wall, when the laminated portion of the cylindrical body 4 and the sound deadening layer 6 exists in a part of the region, the laminated body of the cylindrical body 4 and the noise deadening layer 6 in the entire region. The meaning includes both the case where the portion is present. In addition, in addition to the case where the laminated portion is partially formed in the entire height region of the cylindrical wall, it is meant to include the case where it is formed at a plurality of two or more locations. In the illustrated exhaust cylinder 1, a silencer 3 is installed above the exhaust inlet 21 in the exhaust passage 12, and the tubular body 4 as a buried mold is formed around the silencer 3, and this cylinder The fiber heat insulating material layer 5 provided on the outer side of the shaped body 4 and the space between the tubular body 4 and the fiber heat insulating material layer 5 are provided by an appropriate method such as pouring, spraying, and troweling. The sound deadening layer 6 composed of a layer of the porous granular material thus formed is provided. Although not shown, a lower sound deadening layer is provided at the lower end of the exhaust passage 12 below the exhaust inlet 21, and a drain pipe is attached to the lower end of the exhaust passage 12.

  The cylindrical body 4 is a cylindrical steel plate that hardly rusts, such as a stainless steel plate, but this steel plate may be formed of a corrugated perforated stainless steel plate, such as a punching metal or a wire mesh. However, when this corrugated perforated stainless steel plate is used, if it is too long in the axial direction, the flow resistance (friction resistance) of the fluid becomes too large and the smoke exhausting action of the exhaust stack is impaired. Therefore, the axial length is a length that does not cause such inconvenience, for example, the small diameter cylindrical portion 41 described below, and the upper and lower large diameter cylindrical portions 43 and 44 arranged on both upper and lower sides of the small diameter cylindrical portion 41, Upper and lower tapered cylindrical portions 45, 46 that connect these large diameter cylindrical portions 43, 44 to the small diameter cylindrical portion 41, and a tapered cylindrical portion 47 that is connected to the upper end portion of the upper large diameter cylindrical portion 43. It is desirable to provide only in the vicinity.

  The muffler 3 is shaped like a lump by loading a required amount of porous granular material into a breathable outer shell, whereas perlite is used for the porous granular material, For the outer shell, a perforated stainless steel plate or a stainless steel mesh excellent in rust resistance is used. Perlite used as a porous granule is an aggregate of airtight small bubbles obtained by crushing natural volcanic glass pearlite or pinestone to a predetermined particle size and rapidly heating and expanding it. . Among these, when using perlite pearlite as the porous granular material 31, for example, SiO2 75.0%, Al2O3 14.0%, Fe2O3 0.9%, CaO 0.1%, K2O 4.2%. Pearlite pearlite having a composition of Na2O 3.5% can be preferably used. The pearlite of this composition has a light weight of 1/10 to 1/20 of the unit volume mass of sand, fire resistance that does not melt even at 1200 ° C., and a thermal conductivity of 0.036 to 0.05 kcal / m · Excellent heat insulation at h · ° C., glassy, excellent chemical resistance, neutral pH value of 7 and chemically stable properties. Although the silencer 3 shown in FIG. 3 has a spherical shape, it may be formed in another lump shape, for example, a bullet shape.

  In the exhaust pipe 1 shown in the figure, the silencers 3 and 3 having different sizes are arranged in two places at the top and bottom as shown in FIG. 1, but the size, number, arrangement pattern, etc. of the silencers 3 are limited to those shown in the figure. In addition, the arrangement position of the muffler 3 can be changed within the exhaust passage 12 above the exhaust introduction port 21.

  The same porous material as that used for the silencer 3 is adopted for the porous granular material forming the silencer layer 6, and the silencer layer 6 is composed of the tubular body 4 and the fibrous heat insulating material layer. 5 is a layer of the above-mentioned porous granular material provided in the space between each other.

  FIG. 2 shows the configuration of the fibrous heat insulating material layer 5. The fibrous heat insulating material layer 5 is formed by sandwiching a fibrous heat insulating material 51 such as rock wool or glass wool between an outer steel pipe 52 and an inner water stop material 53. The water-stopping material 53 prevents permeation of water into the fibrous heat insulating material 51 when the sound deadening layer 6 is formed by an appropriate method such as pouring, spraying or troweling using pearlite having an aqueous solution as a binder. In order to prevent this, water is preliminarily interposed between the fibrous heat insulating material 51 and the sound deadening layer 6, so that water can enter the layer of the fibrous heat insulating material 51 which is difficult to dry and its heat insulating performance and sound deadening. The situation of lowering performance will not occur. As the water-stopping material, an aluminum foil having a thickness of 0.1 to 200 μm or a thin steel plate having a thickness of 100 to 200 μm can be suitably used. However, when the internal temperature is 250 degrees or less, a resin film or the like can be used. Well, it has been found that applying these water-stopping materials improves sound insulation and heat insulation.

  According to the exhaust pipe configured as described above, the porous granular material made of pearlite forming the muffler 3 and the muffler layer 6 causes the sound waves to be diffusely reflected in the exhaust passage 12 to interfere with each other. Absorbs or absorbs and absorbs sound waves that are diffusely reflected in the layer and interferes with each other, and the porous granular material absorbs acoustic energy by friction with sound waves. It has been confirmed that by exhibiting the action, the release of sound from the exhaust pipe outlet is suppressed and a high silencing action is exhibited. It has been confirmed that even when the silencer 3 is omitted, a high silencing effect is exhibited.

  In this embodiment, as shown in FIG. 1, the cylindrical body 4 has a small-diameter cylindrical portion 41, upper and lower large-diameter cylindrical portions 43 and 44 arranged on both upper and lower sides of the small-diameter cylindrical portion 41, and the diameters thereof. The upper and lower tapered cylindrical portions 45 and 46 that make the large cylindrical portions 43 and 44 continuous with the small diameter cylindrical portion 41 and the tapered cylindrical portion 47 that is connected to the upper end portion of the upper large diameter cylindrical portion 43 are provided. ing. The upper and lower mufflers 3 are arranged in a space surrounded by the upper and lower large cylindrical portions 43 and 44. The shape of the internal space of the cylindrical body 4 configured in this way is similar to the shape of the internal space of the muffler cylinder provided in the exhaust pipe of the automobile, and the muffling property is reduced by the feature of the shape surface. Demonstrate. Therefore, in addition to the silencing action by the silencing body 3 and the silencing layer 6, the silencing action is also obtained by the shape characteristics of the tubular body 4, and the noise emitted from the exhaust pipe is remarkably reduced. The situation where the environment is damaged by the noise emitted from the cylinder is improved. In the example shown in the figure, the cylindrical body 4 has a silencing region with one large diameter cylindrical portion 43 and 44, one small diameter cylindrical portion 41, and upper and lower tapered cylindrical portions 45 and 46 as one unit. Although an example in which only one stage is provided has been shown, this point can also be provided with the unit of the above-mentioned silence area over two or more stages.

  By the way, in this embodiment, the silencer 3 is swingably attached to the support rod 13 attached to the cylindrical body 4 as can be inferred in FIG. If it does in this way, since the silencer 3 will contact the exhaust flow which raises the inside of the exhaust passage 12, and will vibrate, the effect | action which diffuses the sound wave by the silencer 3 will improve, and a silencing effect will improve further. .

  In the present invention, the sound deadening layer 6 is desirably provided at least around the sound deadening body 3 and does not necessarily need to be provided at the entire height portion of the exhaust stack main body 1.

  In this embodiment, pearlite is employed as the porous powder, but glass beads, alumina bubbles, or the like can also be employed as the porous powder.

  FIG. 3 shows a laminated structure of cylindrical walls in another embodiment. In this embodiment, a fiber chamber heat insulating material 51 is provided outside the tubular body 4 with a water blocking material 53 interposed on the outer surface, a sound deadening layer 6 similar to the above is provided on the outside, and a concrete layer is provided on the outermost side. 8 is formed. When the exhaust temperature is low, it can be configured as in this embodiment. However, in such a case, it is considered that it may not be possible to satisfactorily ensure the strength against the external pressure generated when the concrete layer 8 is cast and formed only by the sound deadening layer 6. Therefore, in this embodiment, the spiral steel pipe 7 is provided on the outer surface of the sound deadening layer 6, and the strength against the external pressure when the concrete layer 8 is cast and formed by the spiral steel pipe 7 is secured. It is also possible to provide a spiral steel pipe on the inner surface of the sound deadening layer 6 to ensure the necessary strength against external pressure.

1 is a partially longitudinal side view schematically showing an exhaust pipe according to the present invention. It is sectional drawing of a fibrous heat insulating material layer. It is the partial vertical side view which showed the other structure of the cylinder wall of an exhaust pipe.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 Silencer 4 Cylindrical body 5 Fiber insulation layer 6 Silencer layer 12 Exhaust passage 21 Exhaust introduction port 41 Diameter small cylinder part 43, 44 Diameter large cylinder part 45, 46 Tapered cylinder part 47 Tapered cylinder part 51 Fiber Insulation material 52 Steel pipe 53 Water stop material

Claims (2)

In the exhaust pipe including a laminated portion of a steel tubular body whose inner space forms an exhaust passage and a silencer layer formed of a porous granular material that is a foamable heat insulating material on the cylindrical wall,
The cylindrical body has a small-diameter cylindrical portion, upper and lower large-diameter cylindrical portions disposed on both upper and lower sides of the small-diameter cylindrical portion, and an upper and lower taper that continues the large-diameter cylindrical portion to the small-diameter cylindrical portion. An exhaust tube comprising a cylindrical tube portion and a tapered tube portion provided continuously with an upper end portion of the upper large-diameter tube portion. A fiber heat insulating material layer having a sound deadening performance is added and laminated adjacent to the sound deadening layer, and a water stop material is interposed between the fiber heat insulating material layer and the sound deadening layer. The exhaust pipe described in 1.

Images