JPH09113324A - Vortex flowmeter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a vortex flowmeter by which a flow rate can be measured precisely without being influenced by a disturbance vibration. SOLUTION: A vortex generating body 3 is installed inside a flow passage 2. Heat ray sensors 4, 5 are attached to the downstream side of the vortex generating body 3. The heat ray sensors 4, 5 are attached laterally symmetrically. The heat ray sensors 4, 5 are connected to a computing part 6. Karman's vortex which is generated by the vortex generating body 3 is detected as a change in the quantity of radiation heat of the heat ray sensors 4, 5.

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 capable of accurately measuring the number of vortices generated by a flow. As is well known, the vortex flowmeter,
The Karman vortex number generated when a fluid passes through the vortex generator provided in the flow path is detected, and the fluid flow velocity or the passing flow rate is converted.

[0002]

2. Description of the Related Art As a conventional vortex type flow meter, for example, Japanese Patent Laid-Open No.
The one disclosed in Japanese Laid-Open Patent Publication No. 34417/1994 was used. This is because a vibration sensor as a vortex detecting means is attached to the upper part of the vortex generator, and a hot wire type flow sensor is attached to the front part of the vortex generator so that the vortex generated by the vortex generator is normal when the flow rate is normal. The number is measured by the vibration sensor and the flow rate is measured by the hot wire type flow sensor when the flow rate is very small.

[0003]

SUMMARY OF THE INVENTION In the above prior art,
It is possible to measure even a minute flow rate and widen the rangeability as a flow meter, but it is possible to accurately detect the number of vortices under the influence of vibration due to disturbance of the device with the flow meter attached. Therefore, there is a problem that the flow rate cannot be accurately measured.

A flow meter is usually mounted in a pipe through which a fluid to be measured flows down, and vibrations from the pipe itself or vibrations transmitted from various devices connected to the pipe are easily transmitted. In many cases, the vibration sensor as the vortex detecting means makes an erroneous detection.

Therefore, a technical object of the present invention is to obtain a vortex flowmeter capable of measuring a flow rate with high accuracy even if the vortex flowmeter is attached to a place where vibration as a disturbance is easily transmitted.

[0006]

The technical means of the vortex flowmeter of the present invention is to provide a vortex generator and a vortex detecting means in the flow path of a measurement fluid to measure the flow rate passing through the flow path. A heat ray sensor as a vortex detecting means is attached on the downstream side of the vortex generator, and a calculation unit for calculating the flow rate from the vortex number is detected by detecting the number of vortices generated in the flow path by the signal from the heat ray sensor. It is provided.

[0007]

The operation of the above technical means is as follows.
The vortex generated by the vortex generator reaches the downstream heat ray sensor, and the vortex is detected by changing the amount of heat radiated from the heat ray sensor. Heat ray sensor with vortex number attached downstream
By detecting with, it is possible to detect the number of vortices without being affected by vibration due to disturbance, as in the conventional example of detecting with a vibration sensor.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment showing a specific example of the above technical means will be described. The flow path 2 is formed in the flowmeter main body 1, and the vortex generator 3 is provided in the central portion. In FIG. 1, the fluid flows from the front of the drawing to the rear surface through the vortex generator 3. The vortex generator 3 is an isosceles triangular prism having a bottom surface on the upstream side. On the downstream side of the vortex generator 3, that is, on the rear surface, heat ray sensors 4 and 5 as vortex detecting means are attached. The heat wire sensors 4 and 5 have thin heat transfer wires in a rectangular shape and are attached to the left and right sides of the central axis of the vortex generator 3.

An arithmetic unit 6 is arranged on the upper part of the main body 1, and signals from the heat ray sensors 4, 5 are converted into a flow rate conversion unit via an unillustrated comparison unit, amplification unit, voltage / current conversion unit and the like in the arithmetic unit 6. Connecting.

Next, the operation will be described. When the fluid flows down in the flow path 2, a Karman vortex is generated on the downstream side of the vortex generator 3, and the radiated heat amount of the heat ray sensors 4 and 5 changes, so that the vortex number is detected. The calculation unit 6 converts the flow rate of the passage from the number of vortices, the cross-sectional area of the flow path 2 and the specific weight of the fluid, and displays the converted flow rate.

[0011]

As described above, according to the present invention, since the vortex is detected by the heat ray sensor, it is not affected by the vibration due to the disturbance. Therefore, the vortex number can be accurately detected and the flow rate can be accurately measured. Can be measured.

[Brief description of the drawings]

FIG. 1 is an external view of an embodiment of a vortex flowmeter of the present invention.

[Explanation of symbols]

 1 Flowmeter main body 2 Flow path 3 Vortex generator 4,5 Heat ray sensor-6 Calculation unit

Claims (1)

[Claims] 1. A vortex generator and a vortex detecting means are provided in a flow path of a measurement fluid to measure a flow rate passing through the flow path, wherein a heat ray sensor as a vortex detecting means is provided downstream of the vortex generator. A vortex flowmeter provided with an arithmetic unit that is attached and detects the number of vortices generated in the flow path by a signal from the heat ray sensor and calculates the flow rate from the number of vortices.