JPH1038259A - Sound attenuating chamber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attenuate the noise to be generated through suction of the outside air by a blower. SOLUTION: A sound absorbing part 2 and a cavity part 3 are provided in a chamber 1. The sound absorbing material A is filled in the sound absorbing part 2, and the cavity part 3 is a void. The sound absorbing material A is a glass wool cylinder 5, and is densely arranged and filled in the noise absorbing part 2. A duct 10 is connected to the cavity part 3, and an air inlet 12 of a blower 11 is connected to the duct 10. The noise generated in the air inlet 12 through the operation of the blower 11 is passed through the duct 10, and attenuated in the cavity part 3, and absorbed by the sound absorbing part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silencing chamber for noise generated during operation of a blower.

[0002]

2. Description of the Related Art Equipment for blowing air through piping is used in various technical fields. For example, in an incinerator, a blower is used to supply combustion air, and air is blown into the furnace through piping.

[0003] In some incinerator facilities, sufficient measures must be taken against noise.
For example, it is a case where it is installed on the premises of a hospital.
In other words, when designing and constructing a furnace for medical waste incineration to be installed on the premises of a hospital, sufficient consideration must be given to noise as compared to incinerator equipment for other uses that are not particularly restricted. .

[0004] By the way, in pursuit of the noise generation source of the incinerator equipment, the sound of sucking outside air from the suction port of the blower during the operation of the blower provided for supplying the combustion air and for lowering the exhaust gas temperature is the main cause of the noise generation. It turned out to be a factor.

[0005]

There is a muffler as a device for reducing harmful noise from machinery. The silencer is a device that uses the properties of sound diffraction, reflection, absorption, etc. to prevent sound propagation, and uses a perforated plate in part of the tube and fills it with a sound-absorbing material. , "Resonance type" with a resonance chamber, "interference type", "expansion type", "high reactor wave type", etc.

However, the silencer is used mainly for reducing noise generated when steam, gas, and the like are discharged to the atmosphere, and has been almost studied for noise generated due to suction of outside air. It is not the fact. It is not possible to effectively reduce the noise generated at the air inlet of the blower using the existing silencer.

An object of the present invention is to provide a noise reduction chamber that effectively reduces noise generated at a suction port of a blower.

[0008]

In order to achieve the above object, the present invention provides a sound deadening chamber according to the present invention, which has a sound absorbing part and a hollow part in the chamber, wherein the chamber is connected to an air connecting a blower. The pipe is on the suction side of the outside air, and the sound absorbing part is a part formed on the upstream side of the chamber, and has a sound absorbing material.
It is a cylindrical body of porous tissue, is densely arranged and filled in parallel in the sound absorbing part, the hollow part is a space formed on the downstream side of the sound absorbing part, has a duct, and the blower is connected to the duct The air is sucked into the duct from the chamber and blown.

The hollow portion is a portion that expands and attenuates the energy of noise, and the sound absorbing portion is a portion that absorbs the noise attenuated in the hollow portion.

[0010] The cross-sectional area of the cavity of the chamber is sufficiently larger than the cross-sectional area of the duct forming the suction port of the blower.

The total area of all the cylinders and the gaps between the cylinders filled in the sound absorbing portion is larger than the cross-sectional area of the duct forming the suction port of the blower.

The sound absorbing section of the chamber is open to the atmosphere.

Further, the cylinder is a cylinder made of glass wool, and the porosity of the cylinder is formed by gaps between the fibers of the glass wool.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, the sound deadening chamber of the present invention has a sound absorbing part 2 and a hollow part 3 in a chamber 1. In the present embodiment, the chamber 1 is a cylinder having an open upper surface, and has legs 4 on its body, and the legs 4 are fixed to the floor surface. The chamber 1 is divided into two parts at the center of the body, and the upper part is the sound absorbing part 2,
It is on the upstream side, and the lower part is the hollow part 3 and is on the downstream side. A sound absorbing material A is housed in the sound absorbing section 2. The sound absorbing material A is a porous cylinder, specifically a cylinder (glass wool cylinder) 5 formed by laminating glass wool. The glass wool cylinder 5 has a gap between the accumulation of the fibers of the glass wool,
This gap forms a porous structure through the inside and outside of the cylinder.

A wire mesh 7 is held by a stay 6 in the chamber 1, and a plurality of glass wool cylinders 5 are arranged in parallel on the wire mesh 7 and are densely filled in the sound absorbing section 2. As the glass wool cylinder 5, a commercially available material as a heat insulating material for piping can be used as it is. This heat insulating material has, for example, a diameter of 5 mm.
There is a length of 0 mm, which is cut into 700 mm according to the capacity of the sound-absorbing section 2 of the chamber 1 (for example, 550φ in diameter × 700 mm in length), and a total of 21 pieces are arranged in a dense arrangement as shown in FIG. 2 can be filled. A wire mesh 8 is further stretched over the upper opening of the chamber 1 and fixed to the flange 9, and the bundle of the glass wool cylinder 5 is held in the chamber 1 while suppressing the upper surface of the glass wool cylinder 5.

The cavity 3 is a space formed in the lower part of the chamber 1. The body 3 of the chamber 1 has a cavity 3
The duct 10 that leads to the space inside is installed, and the duct 10
Is connected to the intake port 12 of the blower 11. This blower 11 is for supplying combustion gas when the blower pipe 13 is an incinerator facility.

In this embodiment, when the blower 11 is operated, the vibration that causes the noise generated at the intake port 12 of the blower 11 due to the suction of the outside air from the intake port 12 passes through the duct 10 and passes through the chamber 10. 1 enters the hollow portion 3 and is released to the outside air through the sound absorbing portion 2, but in the present invention, the hollow portion 3 is smaller than the cross-sectional area of the duct 10.
Is large, the vibration energy is attenuated by the difference between the two cross-sectional areas, and each glass wool cylinder 5 of the sound absorbing section 2 functions as a sound absorbing duct, and the noise attenuated in the hollow section 3 is further reduced by the sound absorbing section. The sound is absorbed by the second glass wool cylinder 5.

The bundle of glass wool cylinders 5 also functions as an "aperture" against noise vibration. That is, the noise attenuated in the hollow portion 3 is dispersed and flows into each glass wool cylinder 5 or the gap between the glass wool cylinders 5, is narrowed by the decrease in cross-sectional area, and flows out of the chamber 1. The sound expands and attenuates and is muted.

In the embodiment described above, the example in which the glass wool cylinder 5 is used as the sound absorbing material has been described, but the sound absorbing material simply converts incident energy of the sound into thermal energy in the material and eliminates it. Therefore,
If it has the same effect, besides glass wool, porous materials such as rock wool, and materials having a porous structure such as a foam material such as soft urethane foam can be used.
Glass wool is particularly excellent in sound deadening effect, and the glass wool cylinder 5 is advantageous because a commercially available heat insulating material for piping can be directly used as a sound absorbing material.

[0020]

As described above, the present invention divides the interior of the chamber into a cavity and a sound absorbing section, introduces noise generated by the suction of outside air from the blower into the chamber, and attenuates the noise in the space of the cavity. Furthermore, noise can be effectively silenced by making the porous cylinder filled in the sound absorbing portion absorb sound.

Further, according to the present invention, since the total area of all the porous cylinders filled in the sound absorbing portion and the gap between the cylinders is larger than the sectional area of the duct serving as the suction port of the blower,
No excessive load is applied to the blower.

According to the present invention, a chamber having a simple structure and a large noise reduction effect can be obtained without using a special material, and is not limited to the noise reduction of a combustion air supply blower of an incinerator installed on a hospital premises. This has the effect that it can be widely used as a silencer for equipment in which noise on the intake side of the blower is a problem.

[Brief description of the drawings]

FIG. 1 is a front view of a muffling chamber showing one embodiment of the present invention.

FIG. 2 is a plan view of the same.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Chamber 2 Sound absorption part 3 Cavity part 4 Leg 5 Glass wool cylinder 6 Stay 7, 8 Wire mesh 9 Flange 10 Duct 11 Blower 12 Intake port 13 Blower piping

Claims (6)

[Claims] 1. A sound-absorbing chamber having a sound-absorbing part and a hollow part in a chamber, wherein the chamber is an air pipe connecting a blower, and serves as a suction side for outside air, and the sound-absorbing part is located upstream of the chamber. The sound absorbing material is a cylindrical body having a porous structure, and is densely arranged in parallel in the sound absorbing portion, and the hollow portion is provided on the downstream side of the sound absorbing portion. A silencing chamber, which is a formed space and has a duct, wherein the blower is connected to the duct, and sucks air into the duct from inside the chamber to blow air. 2. The silencing device according to claim 1, wherein the cavity is a portion that expands and attenuates noise energy, and the sound absorbing portion is a portion that absorbs the noise attenuated in the cavity. Chamber. 3. The silencing chamber according to claim 1, wherein a cross-sectional area of the cavity of the chamber is sufficiently larger than a cross-sectional area of a duct forming a suction port of the blower. . 4. The apparatus according to claim 1, wherein the total area of all the cylinders and the gaps between the cylinders filled in the sound absorbing portion is larger than a cross-sectional area of a duct forming a suction port of the blower. The described silencing chamber. 5. The sound deadening chamber according to claim 1, wherein the sound absorbing part side of the chamber is open to the atmosphere. 6. The muffler according to claim 1, wherein the cylinder is a cylinder processed from glass wool, and the porosity of the cylinder is formed by gaps between fibers of the glass wool. Chamber.