JP4499245B2 - Gas measuring device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas measuring device, and more particularly to a gas measuring device in which dust contained in a gas pipe is removed in front of a flow rate measuring unit such as an ultrasonic sensor to improve flow rate measurement accuracy.
[0002]
[Prior art]
In recent years, studies using an ultrasonic sensor to measure the amount of gas used at an instantaneous flow rate have begun to be studied.
[0003]
A gas measuring device using a conventional ultrasonic sensor will be described with reference to FIG. A shutoff valve 12 is provided in the gas passage 11 in the measuring device. The shutoff valve 12 is configured to shut off gas by pressing against a valve seat 13 provided in the gas passage 11, and the gas passage 11 below the shutoff valve 12 is formed in a shape along the shutoff valve 12. There are no depressions or the like. An ultrasonic sensor 15 that measures the instantaneous flow rate is disposed downstream of the shutoff valve 12 in the gas passage 11.
[0004]
[Problems to be solved by the invention]
However, there has been a problem in that measurement accuracy may be affected when dust such as chips from the gas pipe remaining in the gas pipe reaches the portion of the gas passage 11 where the ultrasonic sensor 15 is disposed.
[0005]
An object of the present invention is to provide a gas measuring device in which dust contained in a gas pipe is removed in front of a flow rate measuring unit to improve flow rate measurement accuracy in view of the above-described conventional problems.
[0006]
[Means for Solving the Problems]
The gas measuring device of the present invention includes an upstream downward passage and a horizontal passage communicating with the downward passage through a crank-shaped bent portion formed in the middle of the downward passage and a downstream upward passage in the measurement device. A gas passage arranged in a substantially U shape, a flow rate measurement unit that measures the flow rate of gas that is arranged in the horizontal passage and flows through the gas passage, a valve seat provided in the bent portion, and In the gas measuring device having a shut-off valve for opening and closing the valve seat, the valve seat is formed at a tip of the projecting portion to the downward passage, and a dust receiving portion is provided in the downward passage below the projecting portion. Therefore, the measurement accuracy can be improved by removing the dust in the gas passage before the gas containing the dust passes through the flow rate measuring unit.
[0007]
In addition, if the dust receiving part provided in the gas passage is formed in a shape that makes it difficult to disturb the gas flow downstream of the valve seat of the shut-off valve, the dust receiving part can regulate the gas flow toward the flow rate measuring part. Measurement accuracy can be improved.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the gas measuring device of each embodiment of the present invention will be described with reference to the drawings.
[0011]
(First embodiment)
The gas measuring device of this embodiment is demonstrated with reference to FIG. The gas passage 1 in the measuring apparatus is arranged in a substantially U shape having an upstream downward passage 1a, an intermediate horizontal passage 1b, and a downstream upward passage 1c, and is formed in the upstream downward passage 1a. A shut-off valve 2 is disposed on the crank-shaped bent portion 1d. That is, the shutoff valve 2 is configured to shut off the gas by pressing the valve body 2a from the upstream side to the valve seat 3 provided in the bent portion 1d of the gas passage 1. A dust receiving portion 4 that collects dust is provided at a lower portion on the upstream side of the valve seat 3 of the shutoff valve 2 in the bent portion 1 d of the gas passage 1. An ultrasonic sensor 5 that measures the instantaneous gas flow rate is disposed in the horizontal passage 1 b of the gas passage 1.
[0012]
According to the above configuration, before the gas containing dust reaches the horizontal passage 1b where the ultrasonic sensor 5 is disposed, the gas is provided in the lower portion on the upstream side of the valve seat 3 in the downstream downward passage 1a. The dust can be removed by the dust receiving portion 4, and the dust does not adversely affect the measurement of the ultrasonic sensor 5, and the measurement accuracy of the ultrasonic sensor 5 that is easily affected by the dust can be improved.
[0013]
(Second Embodiment)
Next, the gas measuring device of this embodiment will be described with reference to FIG. Note that the same components as those in the first embodiment are denoted by the same reference numerals, description thereof is omitted, and only differences are described.
[0014]
In this embodiment, while providing the dust receiving part 4, the shape of the part which faces the gas passage 1 in the downstream of the valve seat 3 in this dust receiving part 4 is made into the shape which does not disturb a gas flow easily, and the rectification part 6 is made. Provided.
[0015]
According to this configuration, the turbulence of the gas flow flowing out from the shutoff valve 2 can be suppressed by the rectifying unit 6, dust is removed upstream of the ultrasonic sensor 5, and the gas passes through the shutoff valve 2. The influence on the gas flow rate measurement due to the turbulence of the generated flow can be suppressed, and accurate measurement can be performed.
[0016]
(Third embodiment)
Next, the gas measuring device of this embodiment will be described with reference to FIG. Note that the same constituent elements as those in the second embodiment are denoted by the same reference numerals, description thereof is omitted, and only differences are described.
[0017]
In the present embodiment, a dust receiver 4 is provided, and an adsorbent 7 that adsorbs dust to the dust receiver 4 is provided. The adsorbent 7 can be configured by applying, for example, an adhesive or a pressure-sensitive adhesive having an adsorbing action to the entire inner surface of the dust receiving portion 4 or arranging a porous adsorbing member.
[0018]
According to this configuration, more dust can be removed on the upstream side of the ultrasonic sensor 5, and the collected dust does not flow out again, thereby suppressing the influence of dust on measurement when measuring the gas flow rate. And accurate measurement can be performed.
[0019]
【The invention's effect】
According to the gas measuring device of the present invention, as apparent from the above description, the dust receiving portion is provided in the lower portion of the upstream side of the valve seat of the shut-off valve in the gas passage, so that the gas containing dust flows into the flow measuring portion. The measurement accuracy can be improved by removing dust in the gas passage before passing through.
[0020]
In addition, if the dust receiving part provided in the gas passage is formed in a shape that makes it difficult for the gas flow downstream of the valve seat of the shut-off valve to be disturbed, the dust receiving part can regulate the gas flow, further improving the measurement accuracy. it can.
[0021]
Further, if a dust adsorbing material is disposed in the dust receiving portion, dust can be removed more reliably.
[0022]
Further, when the flow rate measuring unit measures the instantaneous flow rate with an ultrasonic sensor, it is easily affected by dust, and thus the above-described effect is more remarkably exhibited.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a gas measurement device according to a first embodiment of the present invention.
FIG. 2 is a configuration diagram of a gas measuring device according to a second embodiment of the present invention.
FIG. 3 is a configuration diagram of a gas measuring device according to a third embodiment of the present invention.
FIG. 4 is a configuration diagram of a conventional gas measuring device.
[Explanation of symbols]
1 Gas passage 2 Shut-off valve 3 Valve seat 4 Dust receiver 5 Ultrasonic sensor 6 Rectifier 7 Adsorbent

Claims (2)

In the measuring device,
An upstream downward passage and a horizontal passage communicating with the downward passage through a crank-shaped bent portion formed in the middle of the downward passage and a downstream upward passage are arranged in a substantially U shape. A gas passage,
A flow rate measuring unit that is disposed in the horizontal passage and measures a flow rate of gas flowing through the gas passage;
A valve seat provided in the bent portion;
In the gas measuring device comprising a shut-off valve for opening and closing the valve seat ,
The valve seat is formed at the tip of the protrusion to the downward passage,
A gas measuring device , wherein a dust receiving portion is provided in the downward passage below the protruding portion .   2. The gas measuring device according to claim 1, wherein the dust receiving portion provided in the gas passage is formed in a shape that makes it difficult to disturb the gas flow on the downstream side of the valve seat of the shut-off valve.

Images