JP2005069549A - Exhaust stack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of damaging the environment due to noises released from an exhaust stack. <P>SOLUTION: This exhaust stack is provided with a muffling body 3 to the upper part of an exhaust guide port 21 facing an exhaust passage 12, the muffling body 3 being formed by shape-retaining porous granules and powder 31 made of perlite in massive form with maintaining air permeability, and muffling layers 44 are laminated and constructed on the peripheral wall surface of the exhaust passage 12, the muffling layer being formed by shape-retaining porous granules and powder made of perlite in laminar form with maintaining air permeability. The muffling bodies 3 are arranged on a plurality of places in the exhaust gas flow direction inside the exhaust passage 12, and a lower part muffling layer 5 is arranged on the lower part of the exhaust guide port 21, the lower part muffling layer 5 being formed by shape-retaining porous granules and powder made of perlite in laminar form. <P>COPYRIGHT: (C)2005,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 and combustion noise in the machine room, or exhaust that flows through the exhaust passage of the exhaust stack. In other words, there was a situation where these sounds became noise and damaged the environment.

  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.

  In the exhaust pipe according to the present invention, a silencer formed by holding porous powder particles in a lump shape is installed in the exhaust passage above the exhaust inlet facing the exhaust passage, and at least the silencer A sound deadening layer formed by retaining the porous granular material in a layer shape is laminated on the peripheral wall surface of the exhaust passage around the substrate.

  According to this invention, the porous powder and granular material forming the sound deadening body and the sound deadening layer cause irregular reflection of sound waves in the exhaust passage to cause interference, absorb sound waves, and absorb and take in sound waves. By exhibiting the effect of causing irregular reflection and interference within the layer, and by exhibiting the effect of absorbing the acoustic energy by friction of the porous powder and the sound wave, the exhaust from the exhaust pipe outlet The sound emission is suppressed and a high silencing effect is exhibited. 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.

  In the present invention, it is desirable that the silencer is installed in the exhaust passage in a form that causes vibration in contact with the exhaust flow rising in the exhaust passage. By vibrating, the effect of irregularly reflecting the sound wave is improved, thereby improving the silencing effect.

  In the present invention, it is possible to operate a configuration in which the muffler is disposed at a plurality of locations in the exhaust flow direction in the exhaust passage. It is also possible to adopt a configuration in which the muffler is shaped like a bullet.

  In the present invention, a lower sound deadening layer made of the porous granular material may be provided at the lower end of the exhaust passage below the exhaust inlet. According to this, not only does the silencer inside the exhaust passage and the silencer layer on the peripheral wall side of the exhaust passage both exert a silencing action, but the lower silencing layer also exerts a silencing action at the lower end of the exhaust passage. As a result, the silencing effect is more reliably exhibited.

  As described above, according to the present invention, the sound deadening body and the sound deadening layer formed by keeping porous powder particles such as pearlite, glass beads, and alumina bubbles in a certain shape are taken into the exhaust pipe from the outside. The sound emitted from the exhaust stack will be significantly reduced by effectively irregularly reflecting the reflected sound wave and the sound generated in the exhaust stack, or absorbing and reflecting the diffused sound in the layer. The situation where the environment is damaged by noise emitted from the exhaust stack is improved.

  FIG. 1 is a partially longitudinal side view schematically showing an exhaust pipe according to the present invention, FIG. 2 is a detailed sectional view of a location where a sound deadening layer is provided, and FIG. 3 is a partially cutaway front view schematically showing a sound deadening body.

  In FIG. 1, reference numeral 1 denotes an exhaust tube main body. The exhaust tube main body 1 includes an exhaust for building or factory chimney, smoke exhaust duct, air conditioning duct and the like. The exhaust cylinder of the illustrated example is provided with an exhaust introduction port 21 formed by an end opening of an elbow-shaped exhaust introduction pipe 2 attached to the exhaust cylinder body 1, and this exhaust introduction port 21 is provided in the exhaust cylinder body 1. Opening upward at the center of the exhaust passage 12 formed by the internal space of the exhaust passage 12 and facing the exhaust passage 12.

  In this exhaust pipe, the silencer 3 is installed above the exhaust inlet 21 in the exhaust passage 12, and the lining 4 is provided on the peripheral wall surface of the exhaust passage 12 around the silencer 3, that is, on the inner peripheral surface of the exhaust cylinder body 1. Are stacked. Further, a lower sound deadening layer 5 is installed at the lower end of the exhaust passage 12 below the exhaust introduction port 21, and a drain pipe 6 is attached to the lower end of the exhaust passage 12.

  As shown in FIG. 3, the muffler 3 is formed into a lump shape by loading a required amount of porous powder particles 31 into an outer shell 32 having air permeability, and the porous powder particles 31 include pearlite. Is used, the outer shell 32 is made of a perforated stainless steel plate or a stainless mesh excellent in rust resistance.

  The pearlite used as the porous granular material 31 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. is there. Among these, when using perlite pearlite as the porous granular material 31, for example, SiO2 75.0%, Al2 O3 14.0%, Fe2 O3 0.9%, CaO 0.1%: K2 O4.2. %, Na2 03.5% nacreous pearlite 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 muffler 3 shown in FIG. 3 is shaped like a bullet, it may be shaped in other shapes such as a sphere. When the muffler 3 is held in a bullet shape, the major axis length b may be set to about twice the maximum diameter a. Further, the maximum diameter a of the silencer 3 may be set to about 1/3 to 1/5 of the diameter D1 of the lining 4 (see FIG. 1).

  As shown in FIG. 1, in the illustrated exhaust stack, a large silencer 3 is provided above the exhaust inlet 21, and a plurality of small silencers 3 are provided above the exhaust silencer 3. The height h1 up to the installation location is set to about three times the diameter D2 of the exhaust inlet 21 and the height h2 from the large silencer 3 to the small silencer 3 is set to about 1500 mm. The diameter D2 of the exhaust inlet 21 However, the size, number, arrangement pattern, etc. of the silencer 3 are not limited to the illustrated example, and the arrangement position of the silencer 3 is not limited to that of the exhaust passage 2. Any change can be made in the exhaust passage 12 above the inlet 21.

  The lining 4 has an outer layer 41 in which a heat insulating layer 42 such as rock wool is sandwiched between non-woven fabrics 43, 43 and is laminated inside the outer layer 41, and a non-woven fabric 46 is placed inside the porous granular material layer 45. A sound deadening layer 44 is provided as an inner layer in which an inner shell 47 having air permeability is provided. For the porous granular material layer 45, pearlite similar to that used in the muffler 3 is employed. Further, the inner shell 47 is made of a perforated stainless steel plate or a stainless steel mesh (metal mesh) excellent in rust resistance. When a perforated stainless steel plate is used for the inner shell 47, it is possible to suitably use a corrugated inner shell 47. When such a corrugated inner shell 47 is used, a silencing effect described later is used. (This point will be described later). In the sound deadening layer 44, the nonwoven fabric 46 and the inner shell 47 prevent the pearlite from falling off or losing its shape. In addition, the lining 4 of this structure is used for the exhaust pipe intended for normal temperature exhaust, and in the case of the exhaust pipe intended for high-temperature exhaust, instead of the above-described nonwoven fabrics 43 and 46, It is necessary to employ a material having heat resistance, such as a glass cloth or a ceramic cloth.

  The lower sound deadening layer 5 is formed by retaining porous powder particles in a predetermined shape, and the same pearlite is used for the porous powder particles, and for retaining the shape, a perforated stainless steel plate or stainless steel is used. Mesh or non-woven fabric is used.

  According to the exhaust pipe configured as described above, the porous granular material made of pearlite forming the muffler 3 and the sound deadening layer 44 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. In particular, when a corrugated perforated stainless steel plate is used for the inner shell 47 of the sound deadening layer 44, the inner shell 47 irregularly reflects sound waves, thus further enhancing the noise reduction effect. However, when a corrugated perforated stainless steel plate is used for the inner shell 47, if the axial length is too long, the flow resistance (friction resistance) of the fluid becomes too large and the smoke exhausting action of the exhaust stack may be impaired. Therefore, it is desirable to suppress the axial length to a length that does not cause such inconvenience. The lower sound deadening layer 5 also exhibits the same sound deadening action.

  Moreover, since the pearlite used as the porous granular material is used, the light weight reduces the burden on the strength applied to the exhaust stack, and its chemical stability stabilizes the initial silencing effect over a long period of time. It is confirmed that it will last.

  By the way, in this embodiment, the muffler 3 is swingably attached to the support rod 13 attached to the exhaust tube main body 1 as can be analogized 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 44 only needs to be stacked on at least the peripheral wall surface of the exhaust passage 12 around the sound deadening body 3, and does not necessarily need to be provided at the entire height portion of the exhaust pipe body 1. For example, the silencing layer 44 has a height that combines the height h1 from the exhaust inlet 21 shown in FIG. 1 to the installation location of the large silencing body 3 and the height h2 from the large silencing body 3 to the small silencing body 3. It may be set in a range or may be stacked in a range where the height range is extended upward by h3 (h3 is about 2000 mm, for example). Further, if the axial length of the sound deadening layer 44 is about this level, even if the inner shell 44 is corrugated as described above, a situation in which the fluid flow resistance (friction resistance) becomes too large does not occur. Further, in the range H in which the sound deadening layer 44 is not laminated, by taking a measure of including a porous granular material such as pearlite in the refractory heat insulating material itself which is a constituent material of the peripheral wall 1a of the exhaust passage, The peripheral wall surface exhibits a silencing effect. That is, as the refractory heat insulating material which is a constituent material of the peripheral wall 1a of the exhaust passage, there are, for example, zonolite-based calcium silicate and castable. When the peripheral wall 1a is formed by mixing the required amount of porous powder particles, the peripheral wall 1a itself exerts a silencing action.

  In addition, the lower sound deadening layer 5 can be installed as needed.

1 is a partially longitudinal side view schematically showing an exhaust pipe according to the present invention. It is a detailed sectional view of a sound deadening layer deployment place. It is the partially broken front view which showed the silencer roughly.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 Silencer 5 Lower silencer layer 12 Exhaust passage 21 Exhaust inlet 31 Porous granular material 44 Silent layer 45 Porous granular material layer

Claims (5)

A silencer formed by holding porous powder particles in a lump shape is installed in the exhaust passage above the exhaust introduction port facing the exhaust passage, and at least around the exhaust passage around the silencer. An exhaust pipe characterized in that a sound deadening layer formed by laminating the porous granular material in a layer shape is laminated on a wall surface. The exhaust pipe according to claim 1, wherein the silencer is installed in the exhaust passage in a form that causes vibration by contacting with an exhaust flow rising in the exhaust passage. The exhaust pipe according to claim 1 or 2, wherein the muffler is disposed at a plurality of locations in the exhaust flow direction in the exhaust passage. The exhaust pipe according to any one of claims 1 to 3, wherein the silencer is formed in a bullet shape. The exhaust pipe according to any one of claims 1 to 4, wherein a lower sound deadening layer made of the porous granular material is provided at a lower end portion of the exhaust passage below the exhaust introduction port.

Images