JP3021671B2 - Vortex flow meter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vortex flowmeter, and more particularly to a vortex flowmeter excellent in measurement sensitivity.

[0002]

2. Description of the Related Art Conventionally, there is a vortex flow meter as a flow meter for measuring a flow rate. This vortex flowmeter generates a so-called Karman vortex street on the downstream side of the vortex generating column provided in the pipeline,
The flow rate of the fluid flowing in the pipeline is measured based on the generation cycle of the vortex. In addition, this type of vortex flowmeter has
In order to measure the generation cycle of the Karman vortex street, on the downstream side of the vortex generation column, a transmitter that generates ultrasonic waves in a pipeline,
A receiver is provided to receive the ultrasonic waves that have propagated in the fluid flowing through the pipeline, and the change in the propagation time of the ultrasonic waves due to the vortex of the Karman vortex street is detected to calculate the generation period of the vortex of the Karman vortex street. A device for determining a flow rate of a fluid is known.

[0003]

By the way, since the above-mentioned ultrasonic transmitter and receiver are directly attached to the pipeline, the ultrasonic waves transmitted from the transmitter are transmitted to the pipeline. > It wrapped around the receiver, and the wrapped ultrasonic wave was received as a noise component, leading to a decrease in the reliability of received data. For this reason, a noise filter must be provided in the amplifier connected to the receiver, and adjustment must be made so as to find a good balance between the noise filter and the amplification of the amplifier.

The present invention has been made in view of the above circumstances, and an eddy flow meter capable of efficiently transmitting ultrasonic waves transmitted from a transmitter to a receiver side and obtaining highly reliable received data. It is intended to provide.

[0005]

A vortex flowmeter according to the present invention comprises:
A vortex generating column provided in the pipe, and a vortex generating column of the pipe below the vortex generating column;
A transmitter provided on the flow side for transmitting ultrasonic waves, and the conduit
Downstream of the vortex generating column, with the transmitter
A supersonic transmitted from the transmitter, provided to face each other
And a receiver for receiving the waves.
Karma generated by the vortex generating column from the ultrasonic waves
Vortex street and measures flow rate based on the Karman vortex street
Vortex flowmeter, the transmitter to the receiver
Ultrasonic waves are transmitted along the transmission path of ultrasonic waves
Characterized in that a groove is formed to prevent the transmission of the light .

[0006]

According to the vortex flow meter of the present invention, even if the ultrasonic wave transmitted from the transmitter to measure the period of the vortex of the Karman vortex street is to be transmitted to the receiver along the pipeline,
Of the transmission line of the ultrasonic wave along the line from the tube to the receiver
A groove is formed in the groove, and the transmission of the ultrasonic wave is blocked by the groove. Thereby, it is possible to prevent the generation of noise due to the transmission of the ultrasonic waves transmitted from the transmitter through the pipeline and the receiver, and to transmit the ultrasonic waves into the fluid with high efficiency and high reliability. Measurement data can be obtained.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the vortex flowmeter of the present invention will be described below with reference to the drawings. First, a schematic configuration of the vortex flowmeter will be described with reference to FIG. In the figure, reference numeral 1 denotes a pipeline. The pipe 1 is provided with a vortex generating column 2 at a position substantially orthogonal to the direction in which the fluid flows (the direction of arrow A in the figure). Further, a transmitter 3 for transmitting an ultrasonic wave and a receiver 4 for receiving the ultrasonic wave transmitted from the transmitter 3 are located at positions facing each other in the pipeline 1 on the downstream side of the vortex generating column 2. An amplifier 5 is connected to the transmitter 3 and the receiver 4.

Next, the structure for attaching the transmitter 3 and the receiver 4 to the pipeline 1 will be described with reference to FIG. In the figure, reference numeral 11 denotes a holder. A vibrator 13 is provided in a space 12 formed in the holder 11, and a cord 14 connected to the vibrator 13 is formed on a lid 15 attached to the holder 11 to seal the space 12. The hole 15a is drawn out. This holder 11
The flange 11a formed in the holder 11 and the outer peripheral surface of the pipeline 1 are fixed by fitting holes 1a formed in the pipeline 1 with bolts or the like. O-rings 16 and 17 are interposed between the holder 11 and the fitting hole 1a and between the flange portion 11a of the holder 11 and the outer peripheral surface of the pipeline 1, respectively. 1 is secured.

In addition, a groove 18 is formed in the pipe 1 around the holder 11 from the outer circumference of the pipe 1 toward the inner circumference thereof. A gap exists around the outer periphery.

According to the vortex flowmeter having the above structure, when the fluid flows in the direction of arrow A in FIG. 1, vortices are generated alternately downstream from the sides of the vortex generating columns 2 to form a so-called Karman vortex street. Thus, when the Karman vortex street occurs, the propagation time until the ultrasonic wave transmitted from the transmitter 3 reaches the receiver 4 is changed by the vortex of the Karman vortex street. Then, the change in the propagation time is detected by a detection device (not shown) via the amplifier 5, and the generation cycle of the vortex of the Karman vortex street is measured to obtain the flow rate of the fluid.

Here, the ultrasonic wave transmitted from the transmitter 3 is propagated to the receiver 4 via the fluid,
Is transmitted to the receiver 4 from the side surface of the housing 11 through the pipe 1.
However, since a groove 18 is formed on the outer periphery of the holder 11 in the conduit 1 which is a transmission path of the ultrasonic wave , the groove 18
The transmission of the ultrasonic wave is blocked by the gap consisting of. That is, the ultrasonic wave transmitted from the transmitter 3 passes through the pipe 1
Receiver without going around to 4, since it is propagated to reliably and efficiently fluid, it is possible to prevent the generation of noise at the receiver 4, it is possible to obtain a highly reliable reception data.

Next, the structure of the transmitter and the receiver in the vortex flowmeter provided with a lining layer on the inner surface of the pipeline 1 will be described with reference to FIG.

As shown in the figure, a lining layer 21 is formed on the inner surface of the conduit 1 of the vortex flowmeter. The lining layer 21 is made of, for example, polyfluoroalkyl vinyl resin (PFA) or polytetrafluoroethylene resin (PT
According to the vortex flow meter provided with the lining layer 21, it is used particularly for measuring the flow rate of a clean fluid or corrosive fluid such as ultrapure water, food, or a chemical. It is preferred. The holder 11 is fitted into the fitting hole 1a formed in the conduit 1 of the vortex flowmeter via the lining layer 21 in the same manner as in the above-described embodiment.
It is fixed with bolts and the like. In the lining layer 21 on the outer periphery of the holder 11, a groove 18 is formed on the outer periphery of the holder 11 as in the above embodiment. Since the groove 18 is formed on the outer periphery of the holder 11, the transmission of the ultrasonic wave to the pipe line 1 is prevented and the ultrasonic wave transmitted by the Via Road 1
Prevents sneaking into the receiver 4 and allows the fluid to flow extremely well
Ultrasonic waves can be transmitted to the receiver 4 only through the
Extremely reliable measurement data can be obtained.

As described above, according to the vortex flowmeter of the above embodiment, highly reliable measurement data can be obtained by transmitting an ultrasonic wave only to a fluid very efficiently.
In order to remove the noise component of the data transmitted from
It is not necessary to provide a noise filter or the like in the amplifier 5, and as a result, the cost of the vortex flowmeter itself can be reduced.

In the above embodiment, the groove 18 is formed as a gap. However, the groove 18 may be filled with a material that absorbs ultrasonic waves and blocks transmission. Further, in the above embodiment, both the transmitter 3 and the receiver 4 are provided with the groove 1 around the periphery thereof.
Although the pipe 8 is formed in the conduit 1, the groove 18 may be provided only around one of the pipes. Further, the specific structure (for example, the shape of the vortex generation column) of the vortex flowmeter of the above embodiment is not limited to the embodiment.

[0016]

As described above, according to the vortex flowmeter of the present invention, the following effects can be obtained.

Ultrasonic waves transmitted from the transmitter to measure the generation period of the vortex of the Karman vortex street are transmitted to the receiver along the conduit.
To be transmitted to the
The transmission of the ultrasonic wave is blocked by the gap formed.
This allows the ultrasonic waves transmitted from the transmitter to travel along the pipeline.
To prevent sneaking into the receiver
Noise can be prevented by
Propagation of ultrasonic waves to the receiver through the fluid with high efficiency for reliability
High measurement data can be obtained. Therefore, it is not necessary to provide a noise filter or the like in order to remove a noise component of data transmitted from the receiver. As a result, the cost of the vortex flowmeter itself can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view illustrating the configuration of a vortex flowmeter according to the present invention.

FIG. 2 is a sectional view of a mounting portion of a transmitter and a receiver.

FIG. 3 is a cross-sectional view of a portion where a transmitter and a receiver of a vortex flowmeter provided with a lining layer are attached.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pipeline 2 Vortex generating column 3 Transmitter 4 Receiver 18 Groove

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01F 1/32

Claims (1)

(57) [Claims] 1. A vortex generating column provided in a pipe, and provided on a downstream side of the vortex generating column in the pipe, and emits ultrasonic waves.
A transmitter that communicates with the vortex-generating column downstream of the pipe with the pipe interposed therebetween.
The transmitter is provided to face the transmitter, and the
And a receiver for receiving the received ultrasonic waves. The ultrasonic wave received by the receiver comprises:
The Karman vortex street generated by the raw pillars is detected,
In a vortex flowmeter that measures a flow rate based on a Mann's vortex street, transmission is performed along the pipe from the transmitter to the receiver.
In the ultrasonic transmission path, a groove to block the transmission of ultrasonic waves
A vortex flowmeter characterized by being formed .