JPH0514178Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) This invention relates to a noise attenuator used when measuring flow rate using ultrasonic waves.

(Prior art) In conventional ultrasonic flow meters and eddy current meters that measure using ultrasonic waves, when the fluid to be measured passes through various devices in the flow measurement system, such as pressure reducing valves or flow control valves, fluid vibrations, Ultrasonic waves generated by fluid friction or the like propagate within the pipe and act as a noise component on the ultrasonic measuring means, which is disadvantageous in that high-precision measurements cannot be made. Therefore, a method is used in which a silencer such as a siren is inserted in the pipe line upstream of the flow meter to remove the ultrasonic component.

However, this siren for removing ultrasonic components is extremely expensive, and there is a problem in that the flow system cannot be made inexpensive.

(Purpose of the invention) This invention was made by focusing on the points mentioned above, and a predetermined position is placed in a cylindrical tube with an inlet and an outlet for fluid at a position opposite to the direction of fluid flow. A plurality of blade bodies constituted by a plurality of blades having an inclination angle are arranged at a predetermined interval and each blade of each blade body is arranged so as not to overlap with respect to the flow direction, and the surface of the blade body and the To provide an inexpensive and simple-structured noise attenuator which effectively and reliably removes ultrasonic noise components propagating in a fluid by forming a sound-absorbing surface for absorbing ultrasonic waves on the inner wall of a cylindrical tube body. .

(Example) An example of this invention will be described below with reference to the drawings.

1 is a cylindrical tube having an inlet 2 and an outlet 3 for fluid; 4 is a wing body composed of a plurality of wings having a predetermined inclination angle α with respect to the flow direction. Two or more blade bodies 4 are arranged within the cylindrical tube body 1 at a predetermined interval so that the blades of the blade bodies 4 do not overlap in the flow direction. 5 is a sound absorbing surface provided on the surface of the wing body 4 to absorb ultrasonic waves, and 6 is a sound absorbing surface provided along the entire inner wall of the cylindrical tube 1 to absorb ultrasonic waves.

These sound absorbing surfaces 5 and 6 are made of sponge,
Any material that can absorb ultrasonic waves, such as felt, fibrous material, or nonwoven fabric, may be used.

The operation will be described based on the above configuration.

The cylindrical tubular body 1 is disposed in a conduit of a flow rate measurement system and absorbs and removes noise components directed toward the downstream side of ultrasonic components generated on the upstream side.

That is, the ultrasonic component that has reached the inside of the cylindrical tube body 1 collides with each wing of the wing body 4 and is absorbed and attenuated by the sound absorption surface 5, but some of it is reflected or
The ultrasonic component that has passed between the blades reaches the next blade body 4, where the same ultrasonic absorption action is performed again and the sound pressure energy is attenuated one after another. Furthermore, the ultrasonic components that reach the wall surface of the vessel body 1 are absorbed and attenuated by the sound absorption surface 6 and removed.

Note that when the fluid passes through the blade body 4, the inclination angle α
Other wing bodies 4 that follow sequentially under the rotational action of
Although the swirling action is accelerated by the flow, there is little flow resistance, so it is easy to transfer the fluid.

(Effect of the invention) As described above, in this invention, the fluid exhibits a swirling action by the blade body having an inclination angle, but the ultrasonic component in the fluid is transmitted to the sound absorbing surface of the blade body and the inner wall of the cylindrical tube. Therefore, since sound absorption and attenuation can be carried out continuously, a very efficient sound absorption effect can be obtained, and since the fluid can be transferred easily due to the swirling action, there is an effect that there is no problem in the fluid transfer.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional side view showing an embodiment of the noise attenuator according to the invention, and FIG. 2 is a front view of the wing body. 1... A cylindrical tube with an inlet 2 and an outlet 3 opened, 4... A predetermined inclination angle α with respect to the flow direction
A wing body composed of a plurality of wings having 5, 6... sound absorbing surfaces.

Claims (1)

[Scope of utility model registration request] A plurality of blade bodies each having a plurality of blades having a predetermined inclination angle are disposed in a cylindrical tube having an inlet and an outlet for fluid at a position opposite to the flow direction of the fluid.
A sound absorbing surface for absorbing ultrasonic waves is provided on the surface of the blade body and the inner wall of the cylindrical tube body, the blades of each blade body being arranged at a predetermined interval so as not to overlap with each other in the flow direction. A noise attenuator characterized by forming.