JPS5841451B2 - Impeller type high-sensitivity gas flow meter - Google Patents

Description

[Detailed Description of the Invention] Conventional impeller type gas flowmeters are designed so that the impellers are relatively light and the frictional resistance of the bearings is small.
Even so, the frictional resistance cannot be reduced to zero, so the impeller will not rotate at low flow rates, but will rotate normally when the flow rate exceeds a certain level.

As mentioned above, in a mechanism that supports the impeller with a bearing, there is always frictional resistance, so in order to eliminate this friction, in the present invention, a float is attached to the impeller, and the impeller is supported by the float floating in the liquid. , the static friction force is reduced to zero, making it possible to accurately measure the flow rate over a wide measurement range regardless of the size of the flow rate.

As shown in the drawings, the present invention includes a cylindrical liquid container 4 having an open upper surface, such as a bowl shape, placed in the center of a cylindrical conduit 1 having an inlet 2 at the bottom and an outlet 3 at the top. .

This container 4 is installed so as to form an annular gas passage 5 between it and the inner surface of the cylindrical pipe 1.

The center part of the impeller 6 is attached to the upper part of the float 7, and a small steel ball 8 is attached to the lower part of the float.

The float 7 is floated on top of the liquid in the container 1 with the steel balls 8 facing downward, and a magnet 9 is provided at the center of the lower part of the container 4 at a spacing sufficient to lightly attract the steel balls 8.

In this way, the float 7 floating on the liquid in the container 4
This relates to a vane wheel type highly sensitive gas flowmeter characterized in that the airflow meter is located approximately in the center of the airflow meter.

Note that the container 4 is used by filling Newtonian fluid (for example, water, petroleum, mercury, etc.).

The flow meter of the present invention is installed vertically, allows gas to be measured to flow in from the lower part 2 of a cylindrical pipe 1, and measures the flow rate.

According to the present invention, the float 7 attached to the center of the impeller 6 floats on the liquid in the container 4, and the steel ball 8 attached to the lower part of the float is attached to the magnet 9 provided at the center of the lower part of the container 4. By being pulled lightly, the float 7 floats approximately at the center of the liquid surface, and the impeller 6 rotates horizontally together with the float 7 in accordance with the flow of gas to be measured.

When the flow rate increases, the rotation of the impeller 6 becomes faster, a swirling flow is generated in the liquid, and the float 7 rotates without leaving the center of the liquid surface even if the attraction force of the magnet 9 to the steel ball 8 is slight.

Furthermore, since Newtonian fluid is placed in the container 4 and the float 7 is floated, the static friction force against the rotational force is theoretically zero, so the impeller 6) rotates even at a small flow rate, making it possible to measure minute flow rates. It becomes possible.

This is a distinct advantage of the flowmeter of the present invention.

Since the rotation of the impeller 6 is directly proportional to the magnitude of the flow rate, the flow rate can be determined from the rotation speed of the impeller 6.

Since the rotation of the impeller must be detected without contact, the light emitted from the light source 10 is received by the photoelectric element 11 as pulsed light by the blades of the impeller 6, converted into an electrical pulse signal, and this is used for counting and calculation. The circuit digitally displays the flow rate per unit time.

12 is an electronic circuit including a counting and arithmetic circuit, and 13 is a flow rate indicator.

[Brief explanation of drawings]

The drawings are cross-sectional views showing embodiments of the present invention. 1... Cylindrical pipe line, 2... Lower inlet of the cylindrical pipe line, 3... Upper outlet of the same, 4...
... Cylindrical container for liquid, 5 ... Gas passage, 6
...Wing wheel, 7...Float, 8...
・Steel ball, 9...! magnet.

Claims (1)

[Claims] 1. A fluid container with an open top is installed in the center of a cylindrical pipe with an inlet at the bottom and an outlet at the top, and a gas passage is created between this container and the inner surface of the cylindrical pipe. An annular gap is provided so as to form an annular gap, the center of the impeller is attached to the top of the float, a small steel ball is attached to the bottom of the float, and the float is floated on top of the liquid in the container with the steel ball facing down. A blade wheel type high-sensitivity gas flow meter characterized by a magnet installed in the center of the lower part of the container to lightly attract the float so that the float floats approximately in the center of the container.