JP4512437B2 - tube - Google Patents

Description

  The present invention relates to piping for passing a gas or gas-liquid mixed fluid used in various facilities such as factories, experimental research facilities, and general houses.

  When a gas or gas-liquid mixed fluid flows in the pipe, resonance occurs depending on the pipe diameter and flow velocity (or flow rate per unit time), and the noise level (decibel) increases rapidly. In particular, in the bellows tube, a sound is easily generated when the fluid collides with the irregularities inside the tube, and when this sound resonates, it becomes annoying noise.

As a technique for eliminating such resonance, Patent Document 1 is disclosed. Patent Document 1 describes a configuration for preventing air column resonance vibration generated by Karman vortices formed on the downstream side of an obstacle arranged in a high-temperature gas flow passage. The obstacle assumed in Patent Document 1 is a heat exchanger disposed on the exhaust passage in order to recover the heat of the high-temperature exhaust gas. The air column resonance prevention apparatus of Patent Document 1 is effective as a countermeasure against noise generated in such a special gas passage, but expects an effect of suppressing noise generated inside a widely used pipe. It is not possible.
JP 2002-71101 A

  Then, this invention aims at providing the pipe | tube provided with the noise reduction member which can suppress the noise which generate | occur | produces when letting gas or a gas-liquid mixed fluid pass to the pipe | tube used by various facilities.

The invention of claim 1 for solving the above problems is a tube of a flexible type having an internal muffling member through the gas or gas-liquid mixed fluid, wherein the silencing member is a plurality of extending in the direction of flow of said fluid A surface, an edge formed in the boundary between the adjacent surfaces of the plurality of surfaces and a ridge line extending in a direction in which the fluid flows, an end side extending in the direction in which the fluid flows, and a side crossing the flow path of the pipe are those, of the sides of said surface, said boundary serving ridge fluid is formed Ru extends in the direction of flow side, all end side extending in a direction of fluid flow, in contact inner wall of the tube and those The plurality of surfaces cross the flow path of the tube.

  In the invention of claim 2, in the invention of claim 1, the tube is a bellows tube.

  According to a third aspect of the invention, in the first or second aspect of the invention, the silencing member has a V-shaped cross section.

  According to the first aspect of the present invention, the silencer member having a plurality of surfaces extending in the direction of fluid flow is disposed in the pipe, so that the fluid smoothly flows along the plurality of surfaces and the generation of noise can be suppressed.

  Since at least two sides extending in the direction in which the fluid flows are in contact with the inner wall of the tube among the sides of the plurality of surfaces, the silencing member continues to maintain a stable posture in the tube even when the fluid flows be able to. Furthermore, since at least one surface of the plurality of surfaces crosses the flow path of the tube, it is possible to prevent the fluid from drawing a monotonous spiral along the inner wall of the tube. Therefore, it is possible to satisfactorily suppress the sound generated by the collision of the fluid with the inner wall of the tube from resonating.

  In the invention of claim 2, since the silencer is arranged inside the bellows tube where noise is particularly likely to occur, the effect of reducing the noise level is easy to recognize, and it is good regardless of the flow velocity of the fluid to be passed. Generation of noise can be suppressed.

  In the invention of claim 3, since the cross-section of the silencing member is V-shaped, even if the pipe is bent and the silencing strap 3 does not maintain the V-shaped cross-section, the fluid accumulates inside the silencing strap. A space is not formed, and the flow of fluid is not hindered.

  FIG. 1 is a side view in which a part of a pipe 1 embodying the inventions of claims 1 and 2 is vertically cut. The tube 1 is a bellows tube, and the inner wall 2 is uneven. FIG. 2A is a perspective view of a silencer strap 3 (silencer member) for carrying out the present invention, and FIG. 2B is a front view of the tube 1 in which the silencer strap 3 is inserted.

  As shown in FIGS. 2A and 2B, the silencing strap 3 has a V-shaped cross section and has a surface 7 (back surface 7a) and a surface 8 (back surface 8a). A side 6 is formed at the boundary between the surface 7 and the surface 8. The edge 5 of the surface 7 and the edges 4 and 6 of the surface 8 extend in the longitudinal direction of the muffler strap 3 (fluid flow direction).

  As shown in FIG. 2 (b), the side 11 and the side 12 of the muffler strap 3 are shorter than the inner diameter of the tube 1. Therefore, if the angle 9 between the surface 7a and the surface 8a is made smaller than the state shown in FIG. 2B, the silencing strap 3 can be smoothly inserted into the tube 1. The end side 5, the end side 4, and the side 6 of the muffler strap 3 are in contact with the inner wall 2 (convex portion) of the tube 1 and maintain a stable posture in the tube 1. The surface 7 (back surface 7a) and the surface 8 (back surface 8a) cross the flow path of the tube 1. The fluid flows smoothly along the surface 7 (back surface 7a) and the surface 8 (back surface 8a).

  The muffler strap 3 is formed of a material (for example, synthetic rubber, natural rubber, fluorine resin, etc.) having the same degree of flexibility as the bellows-like tube 1. Therefore, when the tube 1 is bent or bent, the muffler strap 3 follows and deforms so as not to damage the inner wall 2 of the tube 1.

  When the tube 1 is bent, the muffler strap 3 does not maintain the V-shaped cross-section and is kidnapped, but the muffler strap 3 is not circular, so that fluid accumulates inside the muffler strap 3. A space is not formed, and the flow of fluid is not hindered.

  Movement in the radial direction of the fluid in the pipe 1 in which the silencing strap 3 formed in this way is inserted is restricted by the silencing strap 3 in the radial direction, and as shown by an arrow 10 in FIG. 7a) and flows smoothly along the surface 8 (back surface 8a). Therefore, the amount of fluid flowing along the uneven inner wall 2 is reduced, and the sound generated by colliding with the unevenness of the inner wall 2 is reduced. In addition, the fluid whose movement in the radial direction is restricted by the muffler strap 3 does not draw a spiral while flowing in the direction indicated by the arrow 10 in the tube 1, so that resonance hardly occurs at any flow rate.

  FIG. 7A is a graph showing the relationship between the flow velocity (L / min) of the fluid flowing in the pipe 1 and the noise level (db). FIG. 7B is a graph showing the relationship between the flow velocity (L / min) of the fluid flowing in the pipe 1 and the pressure loss (KPa). A solid line graph indicated by reference numeral 15 in FIG. 7A indicates the noise level (db) measured in a state where nothing is put in the tube 1. In this case, the noise level (db) is high in a relatively slow region where the flow velocity is 20 to 100 (L / min).

  On the other hand, in FIG. 7A, a solid line graph denoted by reference numeral 16 indicates a noise level (db) measured in a state where the muffler strap 3 is arranged in the tube 1. When the muffler strap 3 is arranged in the pipe 1, the noise level (db) is low even in the region of the flow velocity of 20 to 100 (L / min). When the flow velocity exceeds 100 (L / min), the flow in the pipe 1 is more occupied by the turbulent flow than the laminar flow, so the influence of the unevenness of the inner wall 2 is reduced, and the noise level (db) is reduced. It is thought to decrease.

  In FIG. 7B, a solid line graph indicated by reference numeral 15 indicates a pressure loss (KPa) that is a differential pressure between the inlet and the outlet of the tube 1 measured without the silencer strap 3 being inserted. Moreover, the solid line graph shown by the code | symbol 16 has shown the pressure loss (KPa) of the pipe | tube 1 measured in the state which has arrange | positioned the silencer strap 3 in the pipe | tube 1. FIG. In FIG. 7B, when both graphs indicated by reference numerals 15 and 16 are compared, the pressure loss due to the arrangement of the muffler strap 3 in the pipe 1 is insignificant, and the performance degradation of the pipe 1 through which fluid flows is little. It turns out that it is not recognized.

  7A and 7B, graphs of noise level (db) and pressure loss (KPa) measured by arranging a strap having a circular cross section and a strap having a decagonal cross section in the tube 1 are shown. These are indicated by reference numerals 17 (broken lines with a short pitch) and 18 (broken lines with a long pitch), respectively. The cross-sectional area of the strap having a circular cross section and the strap having a decagonal cross section disposed in the tube 1 was set to have the same area.

  When a strap having a circular cross section and a strap having a decagonal cross section are arranged in the pipe 1, the noise level (db) is high at a flow rate of 20 (L / min) to 60 (L / min). It can be read from FIG. 7 (a) that a relatively low value is obtained in a flow velocity range of 60 (L / min) or more.

  However, as shown in FIG. 7B, when a strap having a circular cross section and a strap having a decagonal cross section are arranged in the pipe 1, the pressure loss (KPa) increases, and the basic of the pipe 1 that allows fluid to pass therethrough. Performance will be degraded.

  From the above results, it can be seen that if the strap has a flat surface or a gentle curved surface, a silencing effect can be achieved. In addition, although it is conceivable to form a curved surface or a flat surface on the side surface of a strap having a circular cross section or a polygonal cross section (verified by a decagonal shape as an example), the cross-sectional area of the flow path in the tube 1 is reduced. Therefore, it is a problem in practical use. Moreover, although not graphed, in the hollow cylindrical strap, when the tube 1 is bent, the tube 1 is bent and the inside is closed, and as a result, the flow path cross-sectional area of the tube 1 is reduced. After all it is not practical.

  The flexible type pipe 1 provided with the muffler strap 3 can be employed in, for example, a pipe constituting a refrigeration circuit for flowing a refrigerant. In this case, the refrigerant (gas) and the lubricating oil (liquid) are allowed to pass through the pipe 1 (refrigeration circuit), but noise can be suppressed satisfactorily by the silencing strap 3. The tube 1 provided with the muffler strap 3 can be employed in a semiconductor testing apparatus that requires temperature adjustment.

  3 to 6 show modifications of the silencer strap 3 (silencer member). In each of FIGS. 3 to 6, (a) shows a perspective view of the muffler strap, and (b) shows a front view in a state of being inserted into the tube 1.

  3 has sides 21a to 21d and a surface 21e (back surface 21f). As shown in FIG. 3B, the sides 21 a to 21 d are in contact with the inner wall 2, and the silencing strap 21 maintains a stable posture in the tube 1. Further, the surface 21e (back surface 21f) crosses the flow path of the tube 1, and the movement of the fluid in the radial direction in the tube 1 is restricted by the surface 21e (back surface 21f), along the surface 21e (back surface 21f). The fluid flows smoothly.

  4 has a flat surface 23a (back surface 23b) and a curved surface 23c (back surface 23d). The silencing effect is higher when the curved surface is separated from the inner wall 2 than along the inner wall 2. Accordingly, the curved surfaces 23c and 23d are preferably formed so that the radius of curvature is substantially planar.

  The silencing strap 24 of FIG. 5 has a curved surface 24a (back surface 24b) and a curved surface 24c (back surface 24d). 6 has a curved surface 25a (back surface 25b) and a curved surface 25c (back surface 25d). The curved surface 24a (the back surface 24b), the curved surface 24c (the back surface 24d), the curved surface 25a (the back surface 25b), and the curved surface 25c (the back surface 25d) all have large radii of curvature, and the fluid flows smoothly along these curved surfaces. Occurrence is well suppressed.

  In each example described above, an example in which all sides (or end sides) of the muffler strap are in contact with the inner wall 2 of the tube 1 is shown. However, if the muffler strap can maintain a stable posture in the tube 1. Even if there is a side that does not contact the inner wall 2, there is no problem.

It is the side view which cut through part of the pipe | tube 1 which implemented invention of Claim 1 and 2. (A) is a perspective view of a silencing strap (silencer member). (B) is a front view of a state in which the muffler strap of (a) is inserted into a pipe. (A) is a perspective view of a silencing strap (a silencing member) different from FIG. 2. (B) is a front view of a state in which the muffler strap of (a) is inserted into a pipe. (A) is a perspective view of a silencing strap (a silencing member) different from FIG. 2 to FIG. 3. (B) is a front view of a state in which the muffler strap of (a) is inserted into a pipe. (A) is a perspective view of a silencing strap (a silencing member) different from FIG. 2 to FIG. 4. (B) is a front view of a state in which the muffler strap of (a) is inserted into a pipe. (A) is a perspective view of a silencing strap (a silencing member) different from FIG. 2 to FIG. 5. (B) is a front view of a state in which the muffler strap of (a) is inserted into a pipe. (A) is a graph which shows the relationship between a flow velocity and a noise level. (B) is a graph which shows the relationship between a flow velocity and a pressure loss.

1 Pipe 2 Inner wall 3 Silencer strap (silencer)
4, 5 End sides extending in the direction of fluid flow of the silencer strap 6 Sides of the silencer strap extending in the direction of fluid flow 7, 8 Surface of the silencer strap 11, arrows 11, 12 indicating the direction of fluid flow, orthogonal to the direction of fluid flow Sides 21-25 of the muffler strap extending in the direction Muffler strap (silencer member)

Claims (3)

A flexible pipe having a silencing member inside for passing a gas or gas-liquid mixed fluid, wherein the silencing member includes a plurality of surfaces extending in a direction in which the fluid flows, and adjacent surfaces and surfaces among the plurality of surfaces. The side formed as a ridge line extending in the direction in which the fluid flows in the boundary, the end side extending in the direction in which the fluid flows, and the side crossing the flow path of the pipe, and forming fluid is serving ridge Ru extending in the direction of flow side, all end side extending in a direction of fluid flow, the inner wall of the tube and abuts, and, said plurality of surfaces, the flow path of the tube A tube characterized by traversing.   The tube according to claim 1, wherein the tube is a bellows tube.   The pipe according to claim 1 or 2, wherein a cross section of the silencing member is V-shaped.

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