JPH037781Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention is a vortex flow rate system that more completely removes magnetic powder contained in the fluid to be measured from flowing into the detection section and enables safe operation over a long period of time. Regarding the structure of the meter.

Prior Art The flow in the communication pipe leading from the introduction hole for introducing the dynamic pressure generated upstream of the vortex generator of the Karman vortex flowmeter to the outlet hole that opens on the flow side of the vortex generator is as follows.
The frequency is proportional to the fluctuating pressure caused by the generation of vortices, so by detecting this fluctuating flow, a stable vortex flowmeter can be realized.
This is known in Japanese Patent No. 24492, and also discloses that a solid-liquid separator is attached to remove foreign matter such as dust contained in the fluctuating flow in the communication pipe.

Problems to be Solved by the Present Invention However, in the above-mentioned vortex flowmeter, if there is a lot of dust, if a filter is used as a solid-liquid separator, it will clog immediately, so cleaning and replacing the filter is inconvenient. It was hot. For this reason, if the aperture area of the filter was increased, the dust could not be captured. Particularly when the fluid is a gas, there are many fine iron particles in the piping, but this iron powder cannot be separated and adheres to the detection element, causing the detection element to act like a thermal thermistor. In this case, there were problems with poor response and erroneous transmissions.

Means for Solving the Problems The present invention has been made to solve the above-mentioned problems, and is particularly applicable to cases where magnetic powder such as iron powder is included. That is, the kinetic energy of the magnetic powder is reduced by reducing the flow velocity of the fluid flowing through the communication pipe, and a cavity is arranged in the communication pipe so that it is easily attracted by a magnet in addition to free falling. , a magnet is removably installed.

Embodiment FIG. 1 is a cross-sectional view for explaining one embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line -- in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line -- in FIG. In the figure, 1 is a flow pipe through which the fluid to be measured flows, and 2 is the flow pipe 1.
a vortex generator disposed across the vortex generator 2;
As is well known, a number of vortices proportional to the flow velocity are alternately generated on both sides of the pipe, and by measuring the frequency at which these vortices are generated, the flow velocity of the fluid flowing in the pipe can be detected. To measure the generation frequency of the vortices, generally, pressure fluctuations caused by the vortices or fluid flows caused by the pressure fluctuations are detected. 9 is a detection block disposed on the outer wall of the flow pipe 1; 4 is a dynamic pressure introduction port 3 that opens into the flow pipe 1;
4a is an expansion chamber provided in the middle of the introduction side military passageway 4, and 10 is a magnet removably disposed within the expansion chamber 4a. , 7 is an outlet side flow path 7 that opens in the pipe wall near both sides of the vortex generator 2 of the flow path pipe 1 and derives the vortex fluctuation pressure.
The flow is returned to the flow pipe 1 through the aperture 5, the detector 6, the outlet flow path 7, and the communication hole 8 opened on both sides of the vortex generator 2, and during this time, the frequency of pressure fluctuation is detected by the detector 6. is detected. In the vortex flowmeter described above, if the fluid to be measured contains fine iron powder, especially if the fluid to be measured is a gas and the detector is a heat-sensitive thermistor, the thermistor may contain iron powder. There was a risk that powder, etc. would adhere and the heat capacity would change, resulting in poor response and erroneous transmission. This idea is
This was done in order to prevent deterioration of the sensitivity of the detector due to the adhesion of iron powder, etc. as described above, and as shown in the figure, a magnet 10 that attracts the iron powder as described above is removably installed in the introduction side flow path. This is to prevent iron powder etc. from adhering to the detector 6. In the case of the illustrated example, a part of the introduction side flow path 4 is enlarged, and the enlarged chamber 4 is
A permanent magnet 10 is removably attached to a part of the enlarged chamber 4a using a magnet holder 11, but as shown in FIG. As shown in (b), a cylindrical permanent magnet may be used and fluid is passed through it, or as shown in (b), a bar-shaped magnet may be used and gas is passed around its outer circumference. .

FIG. 5 is a sectional view showing another embodiment of the present invention;
FIG. 6 is a cross-sectional view taken along the line -- in FIG. ₁ , aperture 5
₁ , detector 6 ₁ , outlet hole 8 ₁ through the outlet side flow path 7 ₁
and a second channel that communicates with the outlet hole 8 2 through the introduction hole 3 , the introduction-side channels 4 and 4 ₂ , the aperture 5 ₂ , the detector 6 ₂ , and the outlet-side channel _{7 2 .} are provided in parallel, each flow path is provided with a magnet for adsorbing iron powder as described above, and a stop valve is provided with the magnet and detector in between. That is, in the first flow path, stop valves 20 1 and 21 1 are provided with the magnet portion 10 ₁ and the detection portion 6 ₁ in between, and in the second flow path, the stop valves 20 ₁ and 21 ₁ are provided with the magnet portion 10 1 and the detection portion 6 ₁ in between.
The stop valves 20 ₂ and 2 are sandwiched between the detection part 6 ₂ and the detection part 6 2
1 ₂ are provided so that when repairing or cleaning one detector and/or magnet, the other detector can be used. For example, when you want to remove iron powder etc. attached to the permanent magnet 10 ₁ in the first flow path, or when you want to repair the detector 6 ₂ ,
When the stop valves 20 ₁ and 21 ₁ are tightened, the permanent magnet 10 ₁ and the detector 6 ₁ are completely separated from the fluid to be measured, and the magnet 10 ₁ and the detector 6 ₂ can be easily removed. Measurement can be performed using the detector ₆₂ . On the contrary, magnet 1
When cleaning or repairing the detector 6 ₂ or the detector 6 ₂ , the stop valves 20 ₂ and 21 ₂ are tightened and removed, while measurements can be taken with the detector 6 ₁ .

Effects As is clear from the above explanation, according to the present invention, since the fluid to be measured is made to flow to the detector after removing iron powder etc. mixed in the fluid to be measured, it is particularly effective for the thermistor. When measuring the flow rate of gas using such a heat-sensitive detector, responsiveness is not impaired, and accurate measurement can be performed.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line -- in FIG. 1, FIG. 3 is a cross-sectional view taken along the line -- in FIG. FIG. 5 is a cross-sectional view showing another embodiment of the present invention, and FIG. 6 is a cross-sectional view taken along the line -- in FIG. 5. DESCRIPTION OF SYMBOLS 1... Channel pipe, 2... Vortex generator, 3... Dynamic pressure inlet, 4, 4 ₁ , 4 ₂ ... Introducing side channel, 4a, 4
a ₁ , 4a ₂ ... expansion chamber, 5, 5 ₁ , 5 ₂ ... aperture,
6, _{6 1} , 6 ₂ ... Detector, 7, _{7 1} , 7 ₂ ... Derivation side channel, 8, 8 ₁ , 8 ₂ ... Derivation hole, 10, 10 ₁ ,
10 ₂ ... Permanent magnet, 11, 11 ₁ , 11 ₂ ... Magnet holder, 20 ₁ , 20 ₂ , 21 ₁ , 21 ₂ ... Stop valve.

Claims (1)

[Scope of utility model registration request] An introduction side flow path that introduces the dynamic pressure flow of a vortex generator disposed opposite to the flow inside the flow path pipe to the outside of the flow path pipe, and a flow path that introduces the vortex fluctuating pressure generated on both sides of the vortex generator to the outside of the flow path pipe. In a vortex flowmeter that communicates with an outlet flow path leading outside the tube and has a built-in detector that detects the flow flowing in the outlet flow path according to the vortex fluctuation pressure, an enlarged chamber is provided in the introduction side flow path. 1. A vortex flowmeter characterized in that a magnet is detachably disposed within the expansion chamber.