JPS60194317A - Probe for transmitting and receiving ultrasonic wave - Google Patents

Abstract

PURPOSE:To secure the protection of a vibrator from steam leakage by retaining a housing tube as closed between a vibrator housing and a plug in a probe housing with a communicating hole piercing it through the outside air. CONSTITUTION:A housing tube 17 is retained in a probe housing 6 while a vibrator housing 8 is retained airtight in one end of the housing 6 with a housing holder 9, a spacer 10 and an O ring 12 and a spacer 11 is interposed therebetween. In addition, a plug stopper 15 is retained airtight with an O ring 18 interposed. A small-diameter communicating hole 19 is provided running through the wall part of the housing 6 to always keep the probe housing 6 at the atmospheric pressure inside. The probe 4' thus obtained is inserted into a socket of a piping with the end thereof connected to a terminal box and fixed with a gas seal unit, which is provided with a communicating hole running between the inside and outside thereof.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to ultrasonic transmission and reception for measuring the flow rate and flow rate of high temperature, high pressure moisture such as steam flowing inside a pipe using ultrasonic waves. This relates to probes for

[Prior art]

BACKGROUND ART Devices have been developed that measure the flow rate and flow rate of gas inside a pipe by propagating ultrasonic waves through the gas flowing through the pipe and utilizing changes in the propagation speed, and are used in various fields. For example, as shown in Fig. 1, an apparatus for measuring the flow rate and flow rate of steam using ultrasonic waves is a device that uses sockets 2 installed diagonally opposite each other on the circumferential wall of a pipe 1 that conducts steam (as shown in the figure). In this case, one side is omitted) Insert the ultrasonic transmitting/receiving probe 4 which has a terminal box 3 at the end, fix it with a gas seal unit 5, and connect the terminal box 3 to a controller (not shown). It is something that Then, the ultrasonic pulse signals controlled by the controller are alternately repeated and transmitted and received by each probe 4, and the propagation time of the ultrasonic signals propagating through the pipe 1 is measured, and the steam flowing through the pipe 1 is measured. flow velocity,
You can adjust the flow rate.

Conventionally, such a steam probe 4 is shown in FIG.
As shown, a transducer 7 is attached to one end of a cylindrical probe housing 6 with a transducer housing 8 made of a metal material such as titanium, a housing holder 9, and an O-ring 12 to seal the transducer 7 airtightly. A plug 14 is held at the other end of the probe housing 60 by a plug stopper 15, which is connected to the vibrator 7 and connected to a lead wire 13 coated and insulated with a Teflon tube or the like, and which is inserted into the terminal box 3. It is configured.

Reference numeral 16 in FIG. 2 indicates an O-ring interposed between the gas seal unit 5 and the gas seal unit 5.

In such a probe, the seal of the vibrator 7 is attached to the O ring 1.
However, since steam, which is the gas to be measured, has high temperature, pressure, and activity, there is a problem that the O IJ song 2, which is in direct contact with the steam, may become stiff. Even with the most steam-resistant material ever, the temperature is 10% at around 183℃.
There is no material that can withstand steam measurements of about kP/cril -G, and the O cylinder 12 will become sagging in a short period of time, resulting in a seal failure.

If a seal failure occurs, steam will leak into the probe housing 6, resulting in poor insulation of the transducer 7, poor adhesion between the transducer housing 8 and the transducer 7, and heat-resistant plastics (such as polyimide Is this because it causes various problems such as hydrolysis of resin) and makes it impossible to measure flow rate and flow rate with short-term rH5? T-frequently? This probe had to be replaced. Also, plug stopper 15
When the terminal box 3 is hydrolyzed and steam leaks out, the terminal box 3 may also suffer from insulation failure, requiring replacement of the terminal box 3, which poses a problem in reliability as a measuring device.

Reliability is important for industrial measuring instruments such as gas flowmeters, and in particular they are required to operate stably over a long period of time, but as mentioned above, conventional steam probes do not meet these requirements. could not be fulfilled.

[Purpose of the invention]

The present invention solves the disadvantages of the conventional Q IJ song such as early replacement of the probe due to poor sealing and reduced reliability, and ensures protection against steam leakage of the transducer, even if steam leaks inside the probe housing. The purpose of the present invention is to provide a probe for measuring the ultrasonic nodding zone, which allows stable operation for a long period of time without affecting the probe because steam is released into the atmosphere even if it leaks. It is.

Another object of the present invention is to prevent interference of received signals due to reverberation phenomena. There it is.

[Structure of the invention]

The present invention provides an ultrasonic transmitting/receiving probe in which a transducer is built into one end of the probe housing via the transducer housing, and a plug connected to the transducer by an electric wire protrudes from the other end. The housing and the plug are sealed by a housing pipe and held in the probe housing, and a wall of the probe housing is provided with a communication hole with outside air, and further, the housing pipe is It is also characterized by being equipped with reverberation prevention means.

〔Example〕

An embodiment of the present invention will be described with reference to FIG.
The vibrator 7 is housed in a vibrator housing 8 made of a metal material such as titanium, and a lead wire 13 connected to the vibrator 7 and insulated with a Teflon tube or the like is connected to the vibrator housing 8. The connected plug] 4 is housed in a metal housing tube 17, one end of the housing tube 17 is screwed to the transducer housing 8, and the other end is fixed with a plug 15.
The oscillator 7 is sealed by screwing into the oscillator 7.

Such a housing tube 17 is held within the probe housing 6, and the transducer housing 8 is held airtight within one end of the probe housing 6 by the housing holder 9 and the slider 10, and the oscillator housing 8 is held at the same time. A spacer 11 is interposed between the probe housing 6 and the housing tube 17. Further, the plug stopper 15 is held airtight at the other end within the probe housing 6 with an O ring 18 interposed therebetween.

Furthermore, a small-diameter communication hole 19 that communicates with the outside air is formed in the wall of the probe housing 6 .
Always maintain atmospheric pressure inside.

As the heat-resistant plastic used for the heat shields 10 and 11 and the plug stopper 15, polyether ether ketone resin (PEEK) or the like is used in consideration of steam resistance.

Further, although the various parts of the housing tube 17 can be connected by welding, it is preferable to use screw connection or flange connection as described above to facilitate assembly and disassembly.

To use the probe 4' configured in this way,
As shown in the fourth example, the end of the probe 4' is connected to the terminal box 3, inserted into the socket 2 of the piping 1, and fixed with the gas seal unit 5'. A communication hole 19' is provided for communication between the two. In such a case, even if steam leaks into the probe housing 6 due to a seal failure during use, the vibrator 7 will remain in the housing tube 1.
At the same time, the steam is released into the atmosphere from the communication holes 19 and 19', so the transducer 7 is not adversely affected at all, and the ultrasonic transmitting and receiving function is always maintained reliably. .

Furthermore, by sealing and protecting the sensor 7 with the housing tube 17 as described above, attenuated imaging remains in the housing tube 17 when transmitting ultrasonic waves, which becomes reverberation during reception and interferes with the received signal. Sometimes. In order to prevent this, the housing tube 17 itself may be molded with damping material such as vibration-proof metal or plastic, appropriate parts of the housing tube 17 may be covered with damping material, or the entire housing tube 17 may be covered with damping material. Reverberation can be prevented by changing the acoustic impedance by coating with a damping material such as heat-shrinkable Teflon, or by changing the wall thickness of the housing tube 17 in steps as shown in the fifth example. .

[Effects of the Invention] As described above, even if steam leaks, the ultrasonic transmitting/receiving probe according to the present invention protects the function of the probe by releasing it into the atmosphere, allowing stable operation over a long period of time. This has extremely beneficial effects in that it can guarantee reliability as a measuring device, and can also prevent reverberation and eliminate interference with received signals.

[Brief explanation of drawings]

9th "1M1-ji 2 units 1 Otsun Tsuta-Pr1! 6\l sub-yolk mouth" 4 pieces 9-, 4; A cutaway side view of the probe and FIG. 3 are various external views of one tube showing an embodiment of the probe of the present invention. 1...Piping, 2...Socket, 3...
...Terminal box, 4.4'...Probe, 5.
5'...Gas seal unit, 6...
・Probe housing, 7... Camera element, 8...
... Vibrator housing, 9 ... Housing holder, io, it ... Sweeter, 12, 16° 18 ... 0 ring, 13 ... REIT 9
Electric wire, 14...Plug, 15...Plug stop, 17...Housing tube, 19.19'
・・・・・・Communication hole. Patent applicant Masayuki Takagi, agent of Kaiyo Denki Co., Ltd., patent attorney

Claims (1)

[Claims] 1. Ultrasonic transmitting/receiving device in which a transducer is built into one end of the probe housing via an imager housing, and a plug connected to the transducer by an electric AT is protruded from the other end. In the probe, the transducer housing and the plug are sealed with a housing tube, and the inside of the probe housing is sealed.
1. A probe for transmitting and receiving ultrasonic waves, characterized in that a wall of the probe housing is held and a communication hole with outside air is penetrated through the wall of the probe housing. 2. An ultrasonic transmitting/receiving probe in which a transducer is built into one end of the probe housing via the transducer housing, and a plug connected to the transducer by an electric wire protrudes from the other end, wherein the transducer housing and the plug are connected to each other. An ultrasonic transmitting/receiving probe characterized in that the probe housing is held in the probe housing by sealing the space between the housing tubes with a housing tube equipped with a reverberation prevention means, and the probe housing has a wall through which a hole communicates with the outside air. 3. The probe according to claim 2, wherein the reverberation prevention means is made of a damping material made of the material of the housing tube. 4. The probe according to claim 2, wherein the reverberation prevention means includes a damping material attached to the housing tube. 5. The probe according to claim 2, wherein the reverberation prevention means is obtained by partially changing the wall thickness of the housing tube.