JPH0886673A - Pressure type flowmeter - Google Patents

Abstract

PURPOSE: To enhance the reliability of a pressure type flowmeter. CONSTITUTION: The pressure type flowmeter comprises an L-shaped tube 2 encapsulating an antifreezing solution disposed in an enclosed piping 1 with the cross-section thereof directing perpendicular to the direction of a fluid 7 a diaphragm 8 disposed at the cross-section part of the L-shaped tube 2 in order to separate the fluid 7 from the antifreezing solution 3 and to transmit the dynamic pressure of the fluid 7 to the antifreezing liquid 3, and a short piping 4 coupled with the L-shaped tube 2 in order to lead out the dynamic pressure to the outside of the piping 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure type flow meter device for measuring a flow rate in the industrial field and the public field.

[0002]

2. Description of the Related Art A conventional flow meter device is easily affected by a substance in the case of an electromagnetic type, has a throttle mechanism type such as an orifice or a venturi, and has a long straight pipe length in the case of an ultrasonic type, and also has a gear wheel. There was a problem that the measured values were not linear in the formulas and capacitance formulas.

[0003]

As described above, the measuring method is influenced by the substance and is also influenced by the straight pipe length. Therefore, an object of the present invention is to provide a pressure type flow meter device capable of performing measurement without being affected by a substance and being capable of performing measurement without being significantly affected by a straight pipe length. .

[0004]

A pressure type flow meter device of the present invention is an L-shaped tube provided in a sealed pipe, having a cross section in a direction perpendicular to a fluid, and having an antifreeze liquid sealed therein. A diaphragm provided in the cross section of the L-shaped pipe for separating the fluid and the antifreeze liquid and transmitting the dynamic pressure of the fluid to the antifreeze liquid; a small pipe connected to the L-shaped pipe to draw the dynamic pressure to the outside of the pipe; A take-up boss installed in the pipe penetration part to prevent the fluid from leaking to the outside, a pressure gauge connected to a small pipe to measure the dynamic pressure, and the dynamic pressure measured by the pressure gauge is converted into a flow rate signal. A converter and a signal transmitter for transmitting the flow rate signal converted by the converter are provided. Further, the pressure type flow meter device according to the second aspect is characterized in that the small pipes are connected in parallel to form a plurality of parallel small pipes.
Next, the pressure type flow meter device according to a third aspect of the present invention is characterized in that it is a converter that measures the mass of the fluid and calibrates and converts the dynamic pressure based on the mass value. Further, the pressure type flow meter device according to the fourth aspect is characterized in that the liquid level in the opened water channel is measured and the cross-sectional area of the fluid is calculated to obtain the flow rate signal.

[0005]

In the pressure type flow meter device of the present invention, an L-shaped tube having a cross section perpendicular to the fluid is provided in a sealed pipe, an antifreezing liquid is sealed inside, and a diaphragm is provided in the cross section of the L-shaped pipe. Provided to separate the fluid from the antifreeze liquid, transmit the dynamic pressure of the fluid to the antifreeze liquid, connect a small pipe to the L-shaped pipe to draw the dynamic pressure to the outside of the pipe, and provide a boss for taking the pipe through part of the small pipe. Prevent leakage of fluid to the outside, connect a pressure gauge to a small pipe to measure the dynamic pressure, convert the dynamic pressure measured by the pressure gauge into a flow rate signal with a converter, and convert the flow rate with the converter. It is characterized in that the signal is transmitted by a signal transmitter.
Further, the pressure type flow meter device according to the second aspect is characterized in that the small pipes are connected in parallel to form a plurality of parallel small pipes. Next, the pressure type flow meter device according to a third aspect of the present invention is characterized in that it is a converter that measures the mass of the fluid and calibrates and converts the dynamic pressure based on the mass value. Further, the pressure type flow meter device according to a fourth aspect is characterized in that the liquid level in the opened water channel is measured, the cross-sectional area of the fluid is calculated, and the flow rate signal is obtained.

[0006]

Next, an embodiment of the pressure type flow meter device of the present invention will be described. 1 is an explanatory view showing an embodiment of the present invention, and FIG. 2 is a sectional view of FIG. In FIGS. 1 and 2, an L-shaped pipe 2 is an internal pipe provided in a sealed pipe 1 and having a cross section perpendicular to a fluid 7 and an antifreeze liquid 3 sealed therein. The diaphragm 8 is a film provided in the cross section of the L-shaped tube 2 to separate the fluid 7 from the antifreeze liquid 3 and to transmit the dynamic pressure of the fluid 7 to the antifreeze liquid 3. Small pipe 4 is L-shaped pipe 2
It is a connection pipe connected to and drawing dynamic pressure to the outside of the pipe 1. The take-up boss 5 is a packing that is provided in the pipe penetrating portion of the small pipe 4 and that prevents the fluid 7 from leaking to the outside. The pressure gauge 6 is a measuring instrument that is connected to the small pipe 4 to measure the dynamic pressure. The converter 9 is a signal converter that converts the dynamic pressure measured by the pressure gauge 6 into a flow rate signal. The signal transmitter 10 is connected to the converter 9 and transmits the flow rate signal converted by the converter 9.

Further, the small pipes 4 are connected in parallel to form a plurality of parallel small pipes, the mass of the fluid 7 is measured, and the dynamic pressure is calibrated and converted by the mass value. It is also possible to obtain the flow rate signal by measuring the liquid level and calculating the cross-sectional area of the fluid.

That is, in this embodiment, the measuring method is to measure the flow rate by changing the dynamic pressure value flowing in the pipe, and the above-mentioned means can be expressed by the following mathematical formula.

F = (S ₁ / S ₂ ) × (P / m) where F is the flow rate, S ₁ is the pipe cross-sectional area (fixed value), S ₂
Is a dynamic pressure extraction area (fixed value), P is a fluid dynamic pressure, and m is a fluid mass (fixed value).

Then, a small pipe 4 for removing the dynamic pressure from the pipe 1 is attached.

The dynamic pressure transmitted from the small pipe 4 is measured by the pressure gauge 6.

Then, the flow rate F can be obtained by substituting the measured dynamic pressure P into the above formula of action.

As described above, in the conventional flowmeter, the turbulent flow becomes a serious problem, and therefore the influence of the turbulent flow can be reduced by providing the small pipe 4 for extracting the dynamic pressure.

The selection of the dynamic pressure measuring device is determined from the mass and diameter of the fluid and the flow rate (maximum flow rate).

If the fluid is water (1 g / cm ³ ), the aperture is 800 mm, and the maximum flow rate is 3000 m ³ / h, the maximum flow velocity can be calculated by the following formula.

First, the pipe cross-sectional area is 800 × 800 ×
3.14 / 4 = 0.5 (m ² ) Then the flow velocity is 0.8 /
It becomes 0.5 = 1.6 (m / s).

Next, assuming that the area of the inlet of the dynamic pressure extraction small pipe is 0.01 cm ² , the maximum dynamic pressure is 1600 g /
cm ² · s (156905.6 Pa / s), and it suffices to select an item that can measure it.

[0018]

According to the present invention, the reliability of the pressure type flow meter device can be improved.

[Brief description of drawings]

FIG. 1 is an explanatory view of a pressure type flow rate device showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of FIG.

[Explanation of symbols]

 2 L-shaped tube 3 Antifreeze 4 Small piping 8 Diaphragm

Claims (4)

[Claims] 1. An L-shaped pipe provided in a sealed pipe and having a cross section in a direction perpendicular to the fluid, and an antifreeze liquid enclosed therein, and the fluid provided in the cross-sectional portion of the L-shaped pipe. A diaphragm for separating the dynamic pressure of the fluid to the antifreeze liquid, a small pipe connected to the L-shaped pipe for drawing the dynamic pressure to the outside of the pipe, and the pipe penetrating the small pipe. A boss provided in the portion for preventing the fluid from leaking to the outside, a pressure gauge connected to the small pipe for measuring the dynamic pressure, and the dynamic pressure measured by the pressure gauge converted into a flow rate signal. And a signal transmitter that transmits the flow rate signal converted by the converter. 2. The pressure type flow meter device according to claim 1, wherein the small pipes are connected in parallel to form a plurality of parallel small pipes. 3. The pressure type flow meter device according to claim 1, wherein the pressure type flow meter device is a converter for measuring the mass of the fluid and calibrating and converting the dynamic pressure based on the mass value. 4. A pressure type flow meter device, characterized in that a liquid level in an open water channel is measured and a cross-sectional area of the fluid is calculated to obtain a flow rate signal.