JPS6193914A - Method and device for ultrasonic measurement of fluid flow rate - Google Patents

Abstract

PURPOSE:To make possible the measurement of the flow rate of not only fluid of a low temp. (ordinary temp.) but also high-temp. fluid with good accuracy by connecting an auxiliary bar for ultrasonic oscillation to the oscillation plane of an oscillator. CONSTITUTION:The auxiliary bar 5 is supported nearly concentrically with a dustproof socket 2 by an annular supporting member 6 made of an acoustic insulating material provided in the socket 2. A material such as aluminum, Mg, Ti or fluororesin which is strong to the heat received from the high-temp. fluid and has a good transmission characteristic of an ultrasonic wave is used for the bar 5. The ultrasonic wave from the oscillator 41 on the transmission side in such constitution propagates in the auxiliary bar 5 for ultrasonic oscillation connected to said oscillator, flows from the top end thereof into the fluid in a conduit, from which the wave passes the top end of the bar 5 connected to the oscillator on the reception side and arrives at the oscillator on the reception side by passing through the inside thereof. More specifically the flow rate of the high-temp. fluid is measured with good accuracy simply by adding the auxiliary bar to the probe of a commercially marketed device.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to an ultrasonic fluid flow measuring method and device capable of measuring not only low-temperature fluid but also high-temperature body flow.

(b) Combustion exhaust gas from sintering, blast furnaces or converters in conventional technology steel works, etc.
It is often necessary to measure the flow rate of high-temperature fluids, such as reactive twin substances in petrochemical plants. Traditionally, orifice, gas flowmeters, venturi flowmeters, etc. have been used to measure the flow rate of these temperature fluids, but they suffer from high pressure loss and are unfavorable in terms of power savings, and venturi flowmeters have the problem of high equipment costs. .

In recent years, ultrasonic type Jc meter has become widely used for measuring fluids in relatively low temperature range (room temperature) due to its advantages such as low installation cost and low pressure loss. The measurement method is to place a pair of ultrasonic transducers, that is, probes a, on the peripheral wall of a fluid conduit, as shown in FIG. 5, but conventionally used probes are As shown in FIG. 6, an insulating body d is installed on the inner periphery of the probe case C, and a vibrator e having a tilted plate f bonded to both sides of the vibrator is disposed therein. A protective film 1 in which an electrode plate at the front end of the probe case C is provided at the front end of the probe case C.
Since the structure is simply cut out and bonded via adhesive Ag, the temperature at 150°C to 18°C is due to the following reasons.
It was not suitable for measuring high temperature fluids of 0°C or higher.

■A thin plate of Teflon, SUS, Ti, etc. as a protective film.
However, with current adhesives and bonding technology, 15
At temperatures of about 0° C. to 180° C., the adhesive peels off, and the attenuation of ultrasonic waves increases, making it unusable.

■The transmission characteristics of ultrasonic transmitting elements also deteriorate in high-temperature atmospheres.

■The high-temperature fluid flowing inside the pipe generally has a temperature distribution as shown in Figure 7, with a temperature boundary layer y occurring at the part where it contacts the pipe wall, and a temperature gradient increasing near it. However, in conventional measurement methods, the probe is either aligned with the inner surface of the tube wall or retracted to the outside.

Before the ultrasonic waves emitted from the glove reach the probe on the opposite side, they must pass through the temperature boundary layer yya' with a large temperature gradient, and due to reflection, refraction, scattering, etc. due to the temperature of the fluid, density LIΣ, etc. As shown in CA), the attenuation of the ultrasonic waves is large and the reception sensitivity of the receiving glove is not sufficient, making measurement impossible.

p-+ Problem to be solved by the invention The problem to be solved by the invention is to provide an ultrasonic fluid flow rate that can accurately measure the flow rate of not only low-temperature (room-temperature) fluids but also high-temperature fluids.
11 and a measuring method 7 using the device.

B) Means for solving the problem The first technical means for solving the above problem is to arrange a pair of vibrators on the peripheral wall of the fluid conveying conduit so as to face each other and to be separated from the fluid flow area. The ultrasonic fluid flow rate measuring device is constructed by connecting an ultrasonic vibration auxiliary rod to the oscillation surface of the vibrator.

The second technical means is an ultrasonic fluid flow rate ♂11 determination method in which a pair of vibrators are disposed on the peripheral wall of a fluid conveying conduit so as to face each other and to be separated from the fluid flow area. An ultrasonic vibration auxiliary rod is connected to the oscillation surface of the child, and the tip 7 of the ultrasonic vibration auxiliary rod is projected to the uniform temperature zone of the fluid, and the ultrasonic wave is transmitted between the ultrasonic vibration auxiliary rod and the temperature uniform zone. Configured to propagate.

In the above configuration, the ultrasonic wave from the oscillating side transducer is transmitted through the ultrasonic vibration auxiliary rod connected to the oscillator, flows from its tip into the fluid in the conduit, and from there the receiving side vibration is transmitted. The ultrasonic vibration auxiliary rod connected to the transducer passes through the tip of the rod and reaches the receiving transducer.

(f) Example Embodiments of the present invention will be described below with reference to the drawings.

Fig. 1 shows a unit 1 of an embodiment of the ultrasonic fluid flow rate measuring device (hereinafter simply referred to as measuring device) according to the present invention. The units are installed in holes 2 and diametrically opposite each other in the same manner as conventional devices, and only the structure of one unit will be explained.

The unit 1 consists of a long tubular dust-proof socket 2 made of SUS, ceramic, etc. with an open end, a cover 3 fixed to the rear end of the dust-proof socket 2, and a cover 3 with an open end.
3. A probe 4 that is provided to protrude into the dust-proof socket 2 through the heat, and an ultrasonic vibration auxiliary rod (hereinafter simply referred to as the auxiliary rod) that is connected to the tip of the probe 4 and extends almost its entire length inside the dust-proof socket 2. 5.

The probe 4 may have a conventional structure in which a vibrator 41 is provided within a probe case 40. Therefore, detailed explanation of its structure will be omitted.

The auxiliary rod 5 is supported substantially concentrically with the dustproof socket by a ring-shaped support member 6 made of an acoustic insulator provided inside the dustproof socket. A cooling plate 7 is attached to the outer periphery of the joint between the probe 4 and the auxiliary rod 5.

The cover 3 is connected to an inlet pipe 31 and an outlet pipe 32 for cooling air, and introduces cooling air into a space defined by the dustproof socket 2, cover 3, and support member 6, and connects the probe 4 and the auxiliary rod. 5 can be cooled.

The auxiliary rod 5 is preferably made of aluminum, 1Vfq, Tj, fluororesin, or the like, which is resistant to heat received from high-temperature fluid and has good ultrasonic transmission characteristics.

The method of connecting the probe 4, more specifically, the vibrator 41 in the probe 4 and the auxiliary rod 5, is as shown in FIG. It may be bonded to the protective film 42α via an adhesive 46α such as epoxy resin, or the adhesive 4 may be bonded directly to the electrode plate 43b on the front surface of the vibrator 41b as shown in FIG.
Alternatively, as shown in FIG. 2 [C], an auxiliary rod 5f may be attached to the front end of the probe case 40C.
A fluid ultrasonic vibration medium 47C'l such as 7 recon oil, water, or grease may be enclosed within the space between the vibrator 41C and the auxiliary rod 5C by Y-junction. In addition, this place! It is also possible to provide a means for attaching inlet/outlet piping to the joint enclosure section to communicate with the medium, or a means for attaching a header for the medium to prevent expansion, contraction, and inclusion of air bubbles due to heat, and to suppress the temperature rise of the vibrator. .

Similar to conventional devices, the unit with the above configuration has two auxiliary rods attached to the pipe wall of the conduit, with the auxiliary rods facing each other in a straight line.
Install as a set. When measuring the flow rate of high-temperature fluid, the tip of the auxiliary rod 5 is made to protrude into the uniform temperature zone of the fluid, as shown in FIG. 8 (B). Cooling air is also introduced into the space C through the introduction pipe 31 to cool the probe 4 and the connecting portion between the probe 4 and the auxiliary rod 5. And the ultrasonic waves are sent from the transducer of the glove of one unit and the transducer of the probe of the other unit? and measure the flow rate. In this case, since the ultrasonic waves are transmitted from the auxiliary rod 5 to the temperature uniform zone and from the temperature uniform zone to the auxiliary rod 5, accurate measurement can be performed without being affected by the temperature gradient.

In the embodiment shown in Figure 1, the support member 6 for the auxiliary rod 5 is attached to the rear (cover side) of the dustproof socket. However, it may be attached to the front as shown in FIG.

In FIG. 4, one of the other embodiments of the measuring device
-1d is shown. In this embodiment, the auxiliary rod 5
A flange 51d is formed at the rear end of d, and the auxiliary rod 5d and probe 4d are fitted onto the outer side of the connector sleeve 9d''r so as to be surrounded by the flange 51d and the flob 4d' with a spring 8d'l provided on one side of the flange. Set screw 10Li,
and the end face of the rod 5d and the probe 4c.
7. A 0'J seal 11d and a heat-resistant grease (or adhesive) 1'2dY are interposed between the end face of the

A plurality of rings 6d made of fireproof material are fixed to the inner periphery of the dust-proof socket 2d at intervals in the axial direction.

Further, a fixing ring 52d made of a refractory material is provided at the tip of the auxiliary rod 5d to engage with a ring 6d at the tip. Further, the cooling air inlet pipe 31d and the exhaust pipe 31d are joined to a joint flange member 21d, which is connected to a dustproof socket.
A hole 22d is formed in the dustproof socket through which a portion of the cooling air can flow out.

Next, a test injection example will be described in which combustion exhaust gas is supplied at 300°C through a conduit having an inner diameter of 850φ.

As a confirmation of the method of the present invention, an aluminum auxiliary rod with a diameter of 60 mm and a length of 80 mm was brought into contact with the oscillation surface of the probe of a commercially available ultrasonic flow rate establishing device via heat-resistant grease (Example 1). , Glue the above auxiliary rod (epoxy 1 phantom resin)
In the case of fixation (Example 2), the amount of protrusion of the tip of the auxiliary rod from the inner wall of the pipe was changed to 10 mm, 20 mm, and 30 mm, the oscillation was made into a sine wave, and the level of 1 wave was changed to Example 1.
The basic setting was set so that the protrusion amount in the intraosseous direction was IV at 30, and the received values were investigated, and the results were as shown in Table 1 (instantaneous pulse applied voltage 1500 V).

On the other hand, the conventional method uses the same probe as used in the above-mentioned method of the present invention, only has a wear-resistant T-bond attached to the oscillation surface, there is no auxiliary rod, and the oscillation tip position is the same as the inner wall of the pipe. I fixed it so that

The probe should be installed so that its axis line is 60 mm with the axis of the conduit.
It was made to form an angle of °.

In the above table, the lowest received value in the case of 10 throats is 10-
It is thought that this is because the tip of the auxiliary rod cannot protrude to the uniform temperature zone of the fluid just by protruding, and ends up within the temperature boundary layer.

Note that when the non-uniform temperature region within the conduit is wide, a mixing device may be installed in the upstream piping and the device of the present invention described above may be used in combination. Further, as the auxiliary rod, the cooling effect and the acoustic effect can be increased by compositely joining suitable materials that differ depending on the III constant conditions.

The device of the present invention can also be used to measure the flow rate of fluid at room temperature, and in that case there is no particular restriction on the position of the end door of the auxiliary rod.

(g) Effects As is clear from the above description, according to the present invention, the flow rate of high-temperature fluid can be accurately measured simply by adding an auxiliary rod to the probe of a commercially available ultrasonic flow rate measuring device.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing one unit of the ultrasonic fluid test amount measuring device according to the present invention, Fig. 2 is a view showing how to connect the vibrator in the probe, and Fig. 3 is a support in the dust-proof socket. FIG. 4 is a diagram showing a modified example of the position of the members.
1. A diagram showing a cross section of one unit of another embodiment of the 1.1 constant device, 5. FIG. 7 is a diagram showing the temperature distribution in a special pipe during high-temperature fluid transportation, and FIG. 8 is a diagram comparing the principles of the conventional measurement method and the method of the present invention. l: Units 4.4a, 41', 4d Niger lobe 41.41cL, 411!1, 41d: Oscillator 5.5a
, 5b, 5d: Auxiliary rod patent applicant: Sumitomo Metal Industries, Ltd. (5 others) Figure 4'32d

Claims (1)

[Claims] 1. In an ultrasonic fluid flow rate measuring device comprising a pair of vibrators disposed on the circumferential wall of a fluid conveying conduit facing each other and separated from a fluid flow area, the oscillation of the vibrators is provided. An ultrasonic fluid flow rate measurement device characterized by an ultrasonic vibration auxiliary rod connected to the surface. 2. In an ultrasonic fluid flow rate measuring method in which a pair of vibrators are disposed on the circumferential wall of a fluid conveying conduit facing each other and separated from a fluid flow area, ultrasonic vibration assistance is applied to the oscillation surface of the vibrator. An ultrasonic wave characterized by connecting rods, protruding the tip of the ultrasonic vibration auxiliary rod to a uniform temperature zone of the fluid, and propagating ultrasonic waves between the ultrasonic vibration auxiliary rod and the temperature uniform zone. Fluid flow measurement method.