JP2017122559A - Corner vane and silencer using corner vane - Google Patents

Abstract

An object of the present invention is to reduce pressure loss without sacrificing sound reduction performance due to the effect of reflection interference of sound waves at a curved portion of an air passage. A corner vane (10) is provided for installation in a bend (58) of an air passage. At least part of the corner vanes are acoustically transparent and have resistance to airflow passing through the air passage. The corner vane has an outer member 12 which defines a cavity 14 therein. [Selection drawing] Fig. 1

Description

  The present invention relates to a corner vane having sound permeability for installation in a bent portion of a gas passage, and a silencer using the corner vane.

  An air passage (duct) 100 forming a gas passage such as a ventilation duct in a building or a concrete duct for tunnel ventilation may include a bent portion 158 (see FIG. 5). In the bent part 158 of the air path 100, when the gas flows through the bent part 158, the air flow is disturbed and a pressure loss occurs. Therefore, a corner vane (Corner Vane, current transformer plate) 110 may be provided in order to suppress the turbulence of the airflow at the bent portion 158 of the air passage 100 and reduce the pressure loss (see FIGS. 6 and 7).

  A wind path provided with a bent portion has a sound reduction effect due to reflection and interference of sound at the bent portion. In order to further enhance the sound reduction effect, a sound absorbing material 160 may be provided inside the air passage 100 (see FIG. 8).

Japanese Utility Model Publication No. 6-14013 JP 2011-140949 A

  Conventionally, corner vanes have been installed in order to reduce pressure loss at the bends of the air passage, and the shape of the corner vanes has been adapted to make the gas flow smooth.

  Since the sound wave is reflected at the bent portion of the air path, the sound wave interferes with each other due to the phase difference between the inside and the outside of the path, thereby reducing the sound. However, if a corner vane is installed at the bent portion, the sound wave is reflected along the flow direction in the same way as the gas flow, so that the interference effect due to the phase difference is reduced and the sound reduction effect is reduced. When a corner vane having a small size with respect to the wavelength of noise is installed (see, for example, FIG. 7), the reduction of the sound reduction effect is small. On the other hand, when a corner vane having a large size with respect to the wavelength of the noise is installed (see, for example, FIG. 6), the interference effect due to the phase difference caused by the reflection path is reduced, so the sound reduction effect is reduced.

  In Patent Documents 1 and 2, the corner vanes have a splitter structure (see FIG. 9), thereby improving sound reduction performance and reducing pressure loss by rectifying at the same time. However, even if the corner vane has a splitter structure, the interference effect due to the phase difference of the sound wave is reduced, so the sound reduction effect is reduced.

  One object of the present invention is to provide a corner vane that reduces pressure loss without sacrificing sound reduction performance due to the action of reflection / interference of sound waves at the bent part of an air passage.

According to the first aspect of the present invention, there is provided a corner vane for installation at a bent portion of an air passage, and at least a part of the corner vane is acoustically permeable, and , Having a passage resistance to the airflow passing through the air passage, and further, the corner vane has an outer member, and the outer member defines a cavity therein.

  According to the 2nd form of this invention, at least one part of the said outer member is formed from a metal fiber board in the corner vane by a 1st form.

  According to the third aspect of the present invention, in the corner vane according to the first aspect, at least a part of the outer member is formed of punching metal.

  According to the 4th form of this invention, in the corner vane by a 3rd form, a glass cloth is attached to the said cavity side of the said punching metal.

  According to the fifth aspect of the present invention, there is provided a corner vane for installation at a bent portion of an air passage, and at least a part of the corner vane is acoustically permeable and passes through the air passage. The corner vane is formed of a plate-like member.

  According to a sixth aspect of the present invention, in the corner vane according to the fifth aspect, at least a part of the plate-like member is formed from a punching metal or a metal fiber plate.

  According to a seventh aspect of the present invention, in the corner vane according to the sixth aspect, the plate-like member is formed from a punching metal, and a glass cloth is attached to the punching metal.

  According to the 8th form of this invention, the silencer for installing in the bending part of an air path is provided, The said silencer is a silencer main body provided with the bending part corresponding to the bending part of an air path, and the said A corner vane disposed at the bent portion of the silencer body, and the corner vane is any one of the first to seventh embodiments.

1 shows a silencer with a corner vane having sound transparency according to an embodiment of the present invention. FIG. FIG. 3 is a diagram illustrating a silencer comprising a plurality of corner vanes having sound transparency according to an embodiment of the present invention. FIG. 3 is a diagram illustrating a silencer comprising a plurality of corner vanes having sound transparency according to an embodiment of the present invention. It is a figure which shows the silencer by which the sound-absorbing material was internally attached provided with the corner vane which has sound permeability by one Embodiment of this invention. It is a figure which shows air paths, such as a ventilation duct provided with a bending part. It is a figure which shows the air path in which the corner vane which does not have sound permeability was installed. It is a figure which shows the air channel in which the some corner vane which does not have sound permeability was installed. It is a figure which shows the air path in which the sound-absorbing material was installed. It is a figure which shows the silencer of a splitter structure. It is a figure which shows the silencer which has the corner vane which does not have sound permeability, and the sound-absorbing material was stuck inside. It is a graph which shows the sound reduction effect of the silencer shown in Drawing 4, Drawing 8, and Drawing 10. It is a graph which shows the pressure loss of the silencer shown in Drawing 4, Drawing 8, and Drawing 10. It is a figure which shows the silencer provided with the plate-shaped corner vane which has sound permeability by one Embodiment of this invention.

  Hereinafter, embodiments of a corner vane and a silencer using the corner vane according to the present invention will be described with reference to the accompanying drawings. In the accompanying drawings, the same or similar elements are denoted by the same or similar reference numerals, and redundant description of the same or similar elements may be omitted in the description of each embodiment. Further, the features shown in each embodiment can be applied to other embodiments as long as they do not contradict each other.

  FIG. 1 shows a corner vane 10 and a silencer 50 using the corner vane 10 according to an embodiment, and shows a section cut out in a horizontal plane parallel to the airflow passage direction. The silencer 50 is installed in a bent portion of an air passage (duct) such as a ventilation duct in a building or a concrete duct for tunnel ventilation.

  Such a silencer 50 has a hollow silencer body 56 having an inlet 52 and an outlet 54. The silencer main body 56 includes a bent portion 58. In one embodiment, the bend 58 of the silencer body 56 bends at an angle of about 90 degrees. The angle of the bent portion 58 is formed so as to coincide with the bent portion of the installed air passage, and does not necessarily need to be 90 degrees. The silencer 50 has at least one corner vane 10 that is installed at the bend 58. The airflow passing through the air path enters from the inlet portion 52 of the silencer 50, passes through the bent portion 58 of the silencer body 56, and exits from the outlet portion 54.

  In one embodiment, the corner vane 10 shown in FIG. The outer member 12 defines the outer shape of the corner vane 10. The outer member 12 may be formed by combining plate-like members or may be formed as an integral member. The outer member 12 of the corner vane 10 has a shape that reduces the pressure loss of the passing airflow by rectifying the airflow so that the airflow passing through the bent portion 58 of the silencer 50 flows smoothly. Such shapes are known to those skilled in the art and are not specifically described herein. The outer member 12 of the corner vane 10 defines a cavity 14 therein. In one embodiment, at least a portion of the outer member 12 is formed from a metal fiber plate. More specifically, at least a part of the outer member 12 can be formed from an aluminum sintered plate. The metal fiber plate is acoustically permeable and has a passage resistance against the air flow passing through the air path and the silencer 50. Therefore, the corner vane 10 is acoustically permeable as a whole, and has a passage resistance against the airflow passing through the air passage and the silencer 50. The sound transmission of the material forming the outer member 12 is preferably such that the sound transmission loss from one side to the other side is 3 dB or less. As another embodiment, the outer member 12 of the corner vane 10 is formed from a metal perforated plate (punching metal), porous ceramics, foamed concrete, cloth, nonwoven fabric, porous material, rubber, silicone, and any combination thereof. can do. The outer member 12 may be formed of other materials as long as it has sound transparency.

  In one embodiment, the outer member 12 can be formed of punched metal. The punching metal here is not a metal fiber plate in which small gaps are formed between metal fibers, but a solid metal plate in which a large number of holes are formed. Depending on the number, size, aperture ratio, etc. of the holes, the sound permeability of the punching metal and the passage resistance against the air flow can be adjusted. When the outer member 12 is formed of punching metal, an airflow sound may be generated when the airflow passes through the hole. Therefore, when forming the outer member 12 with a punching metal, generation | occurrence | production of an airflow sound can be suppressed by attaching a glass cloth to the cavity side. The punching metal can be formed from aluminum, steel, stainless steel material, or the like.

With this configuration, the airflow passing through the ventilation duct enters from the inlet 52 of the silencer 50, is rectified by the corner vane 10 at the bent portion 58 of the silencer main body 56, and then exits from the outlet portion 54. Therefore, the pressure loss is almost equal to that of a corner vane that does not have sound permeability. However, it becomes smaller than an elbow silencer without a corner vane (see, for example, FIG. 5).

  In the case of the corner vane 10 having sound transparency, since most of the sound wave is transmitted through the corner vane, the action of reflection at the bent portion and subsequent interference is larger than that of the corner vane without sound transparency. That is, the sound reduction performance decreases in the order of an elbow silencer without a corner vane, an elbow silencer with a corner vane having sound permeability, and an elbow silencer with a corner vane without sound permeability.

  As a general characteristic of a material having sound transparency, low frequency sound is more easily transmitted than high frequency sound. For this reason, in the silencer 50 according to the embodiment of the present invention, the low-frequency component is transmitted through the corner vane 10 having acoustic transparency, so that it is reduced by the bending portion 58 of the silencer 50 due to the reflection and subsequent interference due to the path difference. Although high-frequency components are not easily transmitted through the corner vanes 10, they are not reduced by the bent portion 58 of the silencer 50, and are reduced compared to an elbow silencer without the corner vanes 10 (see, for example, FIG. 5). Sound effect is reduced. However, as a general characteristic of the silencer, the high frequency component has a higher sound reduction performance than the low frequency component, so the high frequency component is often reduced more than necessary, and the high frequency component has a poor sound reduction performance. However, it is rarely a problem. Further, in the embodiment of the present invention, by installing the corner vane 10, the generation of the air flow accompanying the sudden expansion or contraction of the bent portion in the conventional technology (for example, FIG. 9) in which the corner vane 10 is not provided and the splitter type is used. Since no sound (generally occupying most of the high frequency component) is generated, the reduction in the sound reduction performance of the high frequency component is offset.

  FIG. 13 shows a plate-shaped corner vane 10 having sound transparency according to an embodiment, and a silencer 50 using the corner vane 10. The difference from the corner vane 10 having sound permeability according to the embodiment of FIG. 1 is that the corner vane 10 is formed of a plate-like member 13. Since other configurations can be the same as those in FIG. The plate-like member here refers to a member in which the cavity 14 does not exist inside the member as in the embodiment shown in FIG. The plate-like member 13 can be formed from, for example, a punching metal having acoustic transparency and a metal fiber plate. When the plate-like member 13 is formed of a punching metal, the sound permeability of the punching metal and the passage resistance to the airflow can be adjusted by the number, size, aperture ratio, etc. of the holes formed in the punching metal. Airflow noise may occur when airflow passes through the hole in the punching metal. Therefore, it is possible to suppress the generation of airflow sound by attaching a glass cloth to the surface of the punching metal. The punching metal can be formed from aluminum, steel, stainless steel material, or the like.

  FIG. 2 shows a corner vane 10 having sound transparency according to an embodiment, and a silencer 50 using the corner vane 10. The difference from the corner vane 10 having sound transparency according to the embodiment of FIG. 1 is that a plurality of corner vanes 10 having a smaller size than that of FIG. 1 are provided, and other configurations are the same as those of FIG. Will be omitted. In general, the large corner vane shown in FIG. 1 has a large airflow rectification effect, that is, an effect of reducing pressure loss, but most of the sound wave is transmitted through the corner vane. Is likely to occur, and the sound reduction effect is not reduced. On the other hand, in the small corner vane as in the embodiment shown in FIG. 2, the air flow rectifying effect, that is, the effect of reducing the pressure loss is reduced, but the sound transmission amount is large, so the sound reducing effect is shown in FIG. It is superior to the case of the embodiment.

In the embodiment shown in FIG. 2, a corner vane in which a part or all of the plurality of corner vanes 10 is formed of a plate-like punching metal shown in FIG. 13 may be used.

  In the present invention, the desired pressure loss and sound reduction effect can be obtained by adjusting the type, size, and number of corner vanes 10 to be installed. That is, the pressure loss decreases in the order of an elbow silencer without a corner vane, a corner vane having sound transmission in FIG. 2, and a corner vane having sound transmission in FIG. The sound reduction performance increases in the order of the corner vane having sound permeability in FIG. 1, the corner vane having sound permeability in FIG. 2, and the elbow silencer without the corner vane.

  FIG. 3 shows a corner vane 10 having sound transparency according to an embodiment, and a silencer 50 using the corner vane 10. In such an embodiment, the plurality of corner vanes 10 are installed in the silencer 50, and the corner vanes 10 having larger dimensions are arranged toward the outside of the bent portion 58 of the silencer 50. Since other configurations can be the same as those in the embodiment of FIG. 2, description thereof will be omitted. As shown in FIG. 3, by increasing the corner vane 10 toward the outside, the pressure loss can be ideally reduced, and the sound reduction performance can be similar to that of an elbow silencer without a corner vane. . In the embodiment shown in FIG. 3, a corner vane formed by the plate-like member 13 shown in FIG. 13 may be used for some or all of the plurality of corner vanes 10.

  FIG. 4 shows a corner vane 10 having sound transparency according to an embodiment, and a silencer 50 using the corner vane 10. In the silencer 50, the sound absorbing material 60 is installed inside the silencer body 56. Other configurations can be the same as those in FIG. In FIG. 4, since the sound absorbing material 60 is installed, the sound reduction effect is greater than in the case where the sound absorbing material 60 is not installed. In particular, it is possible to supplementarily reduce high-frequency components that are less likely to be reduced by the installation of the corner vanes 10. In the embodiment of FIG. 4, only one large corner vane 10 is installed, but a plurality of small corner vanes 10 can be installed as in the embodiment of FIG. 2, and the implementation of FIG. As in the embodiment, a plurality of corner vanes 10 having different dimensions may be installed. In the embodiment shown in FIG. 4, a corner vane formed by the plate-like member 13 shown in FIG. 13 may be used for some or all of the plurality of corner vanes 10.

  FIG. 10 is a view showing a silencer having a corner vane 110 that does not have sound permeability and having a sound absorbing material attached thereto. The silencer of FIG. 10 can have the same configuration as the silencer shown in FIG. 4 except that the corner vane 110 does not have sound permeability.

  Next, the results of experiments confirming the sound reduction effect and pressure loss reduction effect of the silencer shown in FIGS. 4, 8, and 10 will be described. FIG. 11 is a graph showing the sound reduction effect in the silencer of FIGS. 4, 8, and 10. 4 and 10 show the silencer of FIG. 8 with a sound-absorbing material attached inside, in which a corner vane 10 (FIG. 4) having sound permeability and a corner vane 110 (FIG. 10) having no sound permeability are installed. It is. In this graph, the horizontal axis represents frequency (Hz) and the vertical axis represents insertion loss (dB). The insertion loss is a value representing the sound reduction effect of the silencer. The greater the insertion loss, the higher the sound reduction effect. In addition, the silencer which installed the sound absorbing material of FIG. 8 inside and the corner vane 110 which does not have sound permeability of FIG. 10 is a form of the conventional silencer. The material used for the corner vane 10 having sound permeability used in this experiment is a metal fiber plate (specifically, an aluminum sintered plate), and the material used for the corner vane 110 having no sound permeability is 0.8. mm steel plate.

In the graph of FIG. 11, the solid line indicates the insertion loss of the silencer of FIG. 8 that does not have a corner vane, and the broken line indicates the insertion loss of the silencer (FIG. 4) in which the corner vane 10 having sound permeability is installed. A dotted line shows the insertion loss of the silencer (FIG. 10) in which the corner vane 110 having no sound permeability is installed. As FIG. 11 shows, when the corner vane 110 which does not have sound permeability is installed, the sound reduction effect is low at 250 Hz to 8000 Hz compared with the case where there is no corner vane. On the other hand, when the corner vane 10 having sound transparency is installed, the sound reduction effect is almost the same as when the corner vane is not installed at 250 Hz to 2000 Hz. The sound reduction effect is higher than when the vane 110 is installed.

  FIG. 12 is a graph showing the pressure loss of the same silencer as that shown in FIG. In this graph, the horizontal axis indicates dynamic pressure (Pa), and the vertical axis indicates pressure loss (Pa). In the graph, the solid line indicates the pressure loss of the silencer of FIG. 8 without the corner vane, the broken line indicates the pressure loss of the silencer (FIG. 4) provided with the corner vane 10 having sound permeability, and the dotted line indicates the sound. The pressure loss of the silencer (FIG. 10) which installed the corner vane 110 which does not have permeability is shown. As in the experiment for confirming the sound reduction effect described in FIG. 11, the silencer having the sound absorbing material shown in FIG. 8 and the corner vane 110 having no sound transmission shown in FIG. It is a form of a silencer.

  As shown in FIG. 12, the configuration in which corner vanes 10 and 110 are installed has a smaller pressure loss than the configuration in which corner vanes are not installed.

  From the results of the above experiments, the silencer with a corner vane with sound transmission exhibits sound reduction performance equivalent to a conventional silencer without corner vanes without a corner vane and has sound transmission. A configuration in which a corner vane without conventional sound permeability is installed, which has higher sound reduction performance than a configuration with no corner vane installed and can reduce pressure loss compared to a silencer without a conventional corner vane. It was found that the pressure loss can be reduced almost equivalently. Therefore, it was confirmed that the expected effect can be obtained by using the sound transmitting material for the corner vane. The material of the corner vane 10 having sound permeability is not limited to the metal fiber plate, and may be the above-described material or other materials.

  Although the embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment. The features of the above-described embodiments can be combined or exchanged as long as they do not contradict each other.

10 Corner vane (having sound transmission)
12 Outer member 13 Plate-like member 14 Cavity 50 Silencer 52 Inlet portion 54 Outlet portion 56 Silencer body 58 Bending portion 60 Sound absorbing material 100 Air passage 158 Bending portion 110 Corner vane (without sound transmission)
160 Sound absorbing material

Claims (8)

A corner vane to be installed at the bend of the airway,
At least a portion of the corner vane is acoustically permeable and has a passage resistance to an airflow passing through the air passage;
The corner vane has an outer member;
A corner vane, wherein the outer member defines a cavity therein. A corner vane according to claim 1,
A corner vane, wherein at least a portion of the outer member is formed from a metal fiber plate. A corner vane according to claim 1,
A corner vane, wherein at least a portion of the outer member is formed from punched metal. A corner vane according to claim 3,
A corner vane in which a glass cloth is attached to the hollow side of the punching metal. A corner vane to be installed at the bend of the airway,
At least a portion of the corner vane is acoustically permeable and has a passage resistance to an airflow passing through the air passage;
A corner vane, wherein at least a part of the corner vane is formed of a plate-like member. A corner vane according to claim 5,
At least a part of the plate-like member is a corner vane formed from a punching metal or a metal fiber plate. A corner vane according to claim 6,
The plate-like member is formed from punching metal,
A corner vane in which a glass cloth is attached to the punching metal. A silencer for installing in a bent portion of an air passage, wherein the silencer is
A silencer body with a bend corresponding to the bend of the air passage;
A corner vane disposed at the bent portion of the silencer body,
The muffler, wherein the corner vane is a corner vane according to any one of claims 1 to 7.

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