JP3388062B2 - Transducer for interface measurement of suspended foreign matter - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention emits ultrasonic waves toward the interface of precipitates in a settling tank for wastewater treatment, sewage treatment, etc. and other foreign matter suspended in a liquid to measure the position of the interface. The transmitter / receiver for doing.

[0002]

2. Description of the Related Art FIG. 7 shows an outline of a conventional interface measuring apparatus equipped with this type of transducer. This interface measuring device is disclosed in Japanese Patent Application Laid-Open No. 1-304322.

In FIG. 7, the settling tank 101 is set so that its volume corresponds to the amount of liquid such as waste water and sewage to be treated, the bottom is formed in a funnel shape, and the drawing pump 102 is provided at the center of the bottom. A continuous suction port is opened, and a discharge pipe 103 for discharging the supernatant is connected to the upper part.

The wave transmitter / receiver 105 is arranged so that the lower half of the wave is immersed in the liquid 106 in the settling tank 101 (may be completely submerged in the liquid), for example, 400 to 1500.
(KHz) ultrasonic waves are transmitted downward. And
Various reflected waves including reflected waves reflected by the interface 109 between the sludge 108 and the liquid 106, which are sediments, are received and the received signal is transmitted to the measuring device 110.

The measuring device 110 discriminates the signal related to the interface from the received signal, measures the time from the transmission to the reception, the degree of attenuation, etc., and based on these measured values, the interface 109.
Calculate the position of.

[0006]

The above-mentioned conventional wave transmitter / receiver 105 is apt to be corroded when the acidity of the liquid 106 in which it is soaked is large and the repair / replacement must be carried out relatively frequently. For liquids with particularly strong corrosiveness, the installation has been postponed despite the need to measure the position of the interface, and the versatility is poor.

The interface position is measured for the purpose of effective operation of the precipitation tank 101. That is, the settling tank 10
When the amount of sludge 108 in 1 becomes too large, it becomes difficult to sufficiently purify the liquid 106, and more seriously, the accumulation of sludge 108 further advances and the wastewater containing the sludge itself flows out through the discharge pipe 103 to the outside. there's a possibility that. In order to avoid these situations, the position of the interface is managed, and the extraction pump 102 is appropriately operated to operate the sludge 10
The amount of sludge is controlled so that the amount of sludge is always below the regulation.

In recent years, as environmental problems such as pollution of rivers are being questioned, industrial enterprises having settling tanks and the like aim to prevent the above situation, but it is difficult to install a wave transmitter / receiver. As for the treatment of liquids, a negative compromise is compelled, and a solution to this point is strongly desired.

On the other hand, the above-mentioned wave transmitter / receiver 105 is installed so as not to move downward from a predetermined position in the settling tank 101. Therefore, when a large amount of sludge 108 is extracted by the extraction pump 102 and the position of the liquid level is greatly lowered, the whole is leaked out of the liquid, and the ultrasonic waves emitted may not be transmitted to the liquid 106 and measurement may be impossible. is there.

Further, since the wave transmitter / receiver 105 has a dead zone (measurable band) of, for example, about 50 (cm) from the wave transmitting / receiving surface for transmitting / receiving ultrasonic waves, it is impossible to measure near the liquid surface. Has become.

[0011]

The present invention has been made in view of the above-mentioned drawbacks of the prior art. Even if the change in the liquid surface position is large, the measurement can be continued without exposing the wave transmitting / receiving surface in the air, and
It is an object of the present invention to provide a wave transmitter / receiver capable of removing the dead zone even at a position very close to the liquid surface for measurement, and also to provide a wave transmitter / receiver capable of producing other effects.

[0013]

In order to achieve the above-mentioned object, the wave transmitter / receiver according to the present invention has the following constructions. It is configured to include a transducer main body for transmitting and receiving ultrasonic waves, and a longitudinal case that is airtight and holds the transducer main body inside one end in the longitudinal direction and is open at the other end. . A transducer main body for transmitting and receiving ultrasonic waves, an airtight longitudinal case that holds the main body of the transducer inside one end in the longitudinal direction and is open at the other end, and an open end at the other end of the case And a lid for opening and closing. A transducer main body for transmitting and receiving ultrasonic waves, a longitudinal case holding the transducer main body inside one end in the longitudinal direction, and a physical case having substantially the same physical properties as the liquid to be measured are filled in the case. And a medium for transmitting sound waves, the medium for transmitting sound waves is adapted to expand the amplitude of ultrasonic waves.

[0014]

[0015]

In the wave transmitter / receiver having the above-described structure, if the liquid to be measured at the interface position is filled in the longitudinal case and attached so that one end side of the case projects above the liquid level, the position of the liquid level changes greatly. Even if the whole body of the transmitter / receiver is always immersed in the liquid, the transmission of ultrasonic waves is not interrupted. Further, in this state, the wave transmitter / receiver body is located above the liquid surface.

[0016] Furthermore, in the transducer having the above-described structure, substantially the same as this, in which the liquid for which the interface position is to be measured or the acoustic wave transmission medium having substantially the same physical properties is filled in the longitudinal case. If it is installed so that one end side protrudes above the liquid surface, even if the position of the liquid surface changes significantly, the whole body of the transducer will be kept in the state of being immersed in the liquid or the medium for transmitting the ultrasonic wave and transmitting the ultrasonic wave. I can't refuse. Further, in this state, the wave transmitter / receiver body is located above the liquid surface.

Similarly, in the transducer having the above-mentioned structure, the ultrasonic wave is transmitted by the ultrasonic wave even when the position of the liquid surface is largely changed by mounting the longitudinal case so that one end side thereof projects above the liquid surface. Reliable transmission between working medium and liquid. Further, in this state, the wave transmitter / receiver body is located above the liquid surface. In addition, the amplitude of ultrasonic waves is expanded by the sound wave transmission medium.

[0018]

Embodiments of the present invention will now be described with reference to the accompanying drawings.

FIGS. 1 to 3 show a transmitter / receiver for measuring the interface of suspended foreign matter and an interface measuring apparatus equipped with the same as a first embodiment of the present invention.

As shown in FIGS. 1 and 3, a transducer 1 according to the present invention includes a transducer main body 3 that transmits an ultrasonic wave and receives a reflected wave thereof, and the transducer main body 3. It has a longitudinal case 5 surrounding it.

As shown in FIG. 3, the case 5 has a top plate 5 at the upper and lower opening portions of a cylindrical body 5a, for example.
The bottom plate 5c and the bottom plate 5c are fixed by welding, bolting, or the like to be closed, have liquid tightness, and have a space inside. The body 5a, the top plate 5b, and the bottom plate 5c are made of, for example, stainless steel (corresponding to SUS316), and have sufficient corrosion resistance against acids and the like. The wave transmitter / receiver main body 3 is fixed to the bottom plate 5c on the wave transmission / reception surface 3a side via a silicone grease 6.

The case 5 has a predetermined thickness as the material of the body 5a, the top plate 5b and the bottom plate 5c so that the case 5 can sufficiently withstand the external pressure applied from the liquid 8 as the subject of measuring the interface position. To be done. However, the thickness of the bottom plate 5b is determined in consideration of the influence on the transmission / reception of the transducer main body 3. Specifically, the length L and the diameter D of the case 5 are, for example, 1500 (mm) and 500 (m), respectively.
m), the thickness of the bottom plate 5c is about 1
(Mm), and the thicknesses of the body 5a and the top plate 5b are set equal to or more than this.

The length L of the case 5 is set with a sufficiently large margin with respect to the dimension indicated by the symbol S in FIG. 3, that is, the amount of change in the position of the liquid surface. The length L is set to 1500 (mm) as described above when the variation S is estimated to be approximately 800 (mm).

The transducer main body 3 is composed of one oscillator, and this oscillator can transmit and receive ultrasonic waves of two or more different frequencies. This utilizes the characteristics of the vibrator, and for example, the basic 350 (K
The frequency is three times higher than that of the ultrasonic wave having a frequency (fundamental frequency) of 1
Ultrasonic waves having a frequency of 050 (KHz) can be transmitted and received at the same time.

It should be noted that although it is possible to transmit / receive any frequency that is an odd multiple of the fundamental frequency (350 KHz), that is, 1, 3, 5, ..., The reason is that the amplitude decreases as the frequency increases. Therefore, it is practically preferable to use up to three times. Here, the current accuracy is ± about 1.0%. The selection of the basic frequency is not limited to this, and any frequency can be selected, but in this embodiment, the frequency serving as the measurement point is about 400 (KHz) to 1 M (KHz). Therefore, it is set so as to include these frequencies.

As shown in FIGS. 1 and 3, the wave transmitter / receiver 1 having the above-described structure is attached so that the lower half of the liquid 8 in the settling tank is immersed. In this state, the transmitter / receiver body 3
From, the two types of ultrasonic waves of 350 (KHz) and 1050 (KHz) are transmitted downward. Then, it receives various reflected waves including the reflected waves reflected at the interface 11 between the sludge 10 which is a sediment and the liquid 8, and outputs a reception signal.

As shown in FIG. 2, the received signal transmitted from the transmitter / receiver main body 3 is the frequency automatic selection switcher 1.
3 is output via the connection cable 12 and via the receiving circuits 14 and 15.

The connection cable 12 is shown in FIGS.
Is also shown. As shown in FIG. 3, the connection cable 12
Is led out of the case 5 through a hole formed in the top plate 5b of the case 5. However, a packing 9 is provided in the hole to maintain liquid tightness in the case.

The receiving circuit 14 is composed of a filter or the like, and receives a relatively low frequency, in this case, a frequency of 350 (KHz), which is the basic frequency, and directs it to the automatic frequency selection switch 13 or switching means. Output. The receiving circuit 15 has a frequency that is three times the fundamental frequency.
It receives a frequency of 50 (KHz) and outputs it to the automatic frequency selection switch 13. The automatic frequency selection switch 13 inputs a signal having both frequencies to the signal processing arithmetic circuit 16 based on the switching signal S output from the signal processing arithmetic circuit 16 as the arithmetic control circuit. Signal processing arithmetic circuit 1
6 is composed of a microcomputer and the like, and 35
The signal of 0 (KHz) or the frequency of 1050 (KHz) is discriminated as the optimum interface signal, and the optimum interface signal determines the time from the transmission to the reception or the attenuation of the reflected wave. Is calculated, and the position of the sludge interface, that is, the depth from the liquid surface is calculated based on this.

The transmitting circuit 17 shown in FIG. 2 is a circuit for transmitting ultrasonic waves at a basic frequency of 350 (KHz).

With the above structure, 1
It is possible to transmit and receive two or more types of frequencies using one transducer body 3, and even if two or more transducers have to be prepared conventionally, one transducer body can handle can do.

As is apparent from the above, in the wave transmitter / receiver 1 having the above structure, the wave transmitter / receiver main body 3 for transmitting and receiving ultrasonic waves is surrounded by the case 5 having liquid tightness. According to this configuration, the liquid 8 which is the object of interface position measurement is prevented from entering the case 5 and the transducer main body 3 does not get wet. Therefore, even if the liquid 8 is corrosive, by making the case 5 corrosion resistant, the transducer main body 3 is protected for a long period of time, and during that time, complicated maintenance such as repair is not particularly required. . Therefore, it is useful because it can be used for all purposes regardless of the properties of the target liquid, such as having strong acidity.

Next, a transmitter / receiver as a second embodiment of the present invention will be described with reference to FIG.

The wave transmitter / receiver 21 as the second embodiment is
The interface measuring device shown in FIGS. 1 and 2 can be used in place of the transducer 1 included in the interface measuring device.

The wave transmitter / receiver 21 has the same structure as that of the wave transmitter / receiver 1 as the first embodiment shown in FIGS. 1 and 3, except for the portions described below. The description of the operation will be omitted because it is redundant, and only the description of the essential parts will be given.

Further, in the following description and in FIG.
The same components as those of the wave transmitter / receiver 1 of the first embodiment are designated by the same reference numerals.

The same applies to the transducers of the third and subsequent embodiments, which will be described later.

In FIG. 4, the transmitter / receiver 21 includes a transmitter / receiver main body 3 for transmitting and receiving ultrasonic waves, and the transmitter / receiver main body 3
Is held inside one end in the longitudinal direction, and a longitudinal case 23 opened at the other end is provided.

The case 23 is composed of, for example, a cylindrical body 23a and a top plate 23b fixed by welding or the like so as to close the upper end opening of the body 23a, and is airtight. . The body 23a and the top plate 23b are made of, for example, stainless steel (equivalent to SUS316), and have corrosion resistance. The wave transmitter / receiver main body 3 is fixed to the top plate 23b on the side opposite to the wave transmitting / receiving surface 3a via a silicone grease 6.

The thicknesses of the body 23a and the top plate 23b are selected so that they can withstand the use of the transducer 21 under the worst possible conditions.

As shown in FIG. 4, the wave transmitter / receiver 21 having the above-mentioned structure is attached so that the lower half of the liquid 8 in the settling tank is dipped, that is, the upper end side of the liquid 8 projects above the liquid surface. In addition, the case 8 is filled with the liquid 8. In this state, ultrasonic waves are transmitted downward from the transducer main body 3. And sludge 10 (Fig.
(Refer to FIG. 1) and the liquid 8 and the reflected wave reflected by the interface 11 (see FIG. 1) is received to generate a reception signal.

In the above-mentioned wave transmitter / receiver 21, if the position of the liquid surface is largely changed (indicated by the symbol S), the wave transmitter / receiver main body 3 has its wave receiving / transmitting surface 3a as a whole if it is attached as described above. Is always kept submerged in the liquid. Therefore, the measurement can be continued without interrupting the transmission of ultrasonic waves.

Further, in the above-mentioned mounted state, the transmitter / receiver main body 3
Since is located above the liquid surface, even if the interface is very close to the liquid surface, it is out of the dead zone and measurement is possible.

Further, in the wave transmitter / receiver 21, the one end side of the longitudinal case 23, that is, the wave transmitter / receiver main body 3
A communication hole 25 for communicating the inside and outside of the case is formed on the mounting side of, and a cap 26 as an opening / closing means for opening and closing the communication hole 25 is provided. With this configuration, when the liquid is filled in the longitudinal case 23 as described above,
While removing the cap 26 and opening the communication hole 25 to remove air, the entire transducer 21 is submerged in the liquid substantially vertically,
It suffices to close the communication hole 25 again. As another method of filling the liquid 8 in the case 23, the transducer 2
It is conceivable to invert 1 in the liquid, but the transducer 2
If 1 is large, this work is difficult. With the above configuration, it is not necessary to invert the wave transmitter / receiver 21, and the work is easy.

When draining the liquid from the case 23,
The cap 26 is removed, the communication hole 25 is opened, air is introduced into the case 23, and the entire transducer 21 is lifted.
It can be pulled out of the liquid. In this method, the lifting force may be large enough to weigh the transducer 21.

Incidentally, in the case of lifting without introducing air from the communication hole 25 in this way, the liquid 8 exists in the case 23 until the lower open end of the case 23 comes out of the liquid surface, and its weight is also added. It requires a great deal of power.

Next, a transmitter / receiver as a third embodiment of the present invention will be described with reference to FIG.

As shown in the figure, the wave transmitter / receiver 31 of the third embodiment has a wave transmitter / receiver main body 3 for transmitting and receiving ultrasonic waves, and a wave receiver / transmitter main body 3 for holding the wave transmitter / receiver body 3 inside one end in the longitudinal direction and the other end. It is provided with a longitudinal case 33 that is open at the side and a lid body 35 that opens and closes the other end opening portion of the case 33.

The case 33 is composed of, for example, a cylindrical body 33a and a top plate 33b fixed by welding or the like so as to close the upper end opening of the body 33a, and is airtight. . The wave transmitter / receiver main body 3 is fixed to the top plate 33b on the side opposite to the wave transmitting / receiving surface 3a via silicon grease 6.

The lid 35 is swingably attached to the case 33 by a hinge 36. Although not shown, the lower end opening of the case 33 and the lid 35
A packing for maintaining the airtightness is interposed between and.

A lock mechanism (not shown) for fixing the lid 35 at the closed position is provided.

The body 33a, the top plate 33b and the lid 35
Is made of, for example, stainless steel (SUS316
(Corresponding) is selected and has sufficient corrosion resistance.

The body 33a, the top plate 33b and the lid 35
Is selected such that the transducer 31 is not destroyed even if used under the worst possible conditions.

As shown in FIG. 5, the wave transmitter / receiver 31 having the above-mentioned structure is mounted so that the lower half of the liquid 8 in the precipitate layer is immersed, that is, the upper end side of the liquid 8 projects above the liquid surface. In addition, the case 8 is filled with the liquid 8. In this state, ultrasonic waves are transmitted downward from the transducer main body 3. And sludge 10 (Fig.
(Refer to FIG. 1) and the liquid 8 and the reflected wave reflected by the interface 11 (see FIG. 1) is received to generate a reception signal.

In such a wave transmitter / receiver 31, if it is attached as described above, the whole of the wave transmitter / receiver main body 3 is always immersed in the liquid even if the position of the liquid surface is largely changed (indicated by symbol S). Be maintained in a closed state. Therefore, the measurement can be continued without interrupting the transmission of ultrasonic waves.

Further, in the above mounted state, the transmitter / receiver main body 3
Since is located above the liquid surface, even if the interface is close to the liquid surface, it is out of the dead zone and can be measured.

In this transmitter / receiver 31, what is filled in the longitudinal case 33 is the liquid 8 at the measurement site as described above.
Alternatively, a medium for transmitting sound waves, such as castor oil or pure water, whose physical properties such as the speed of sound are substantially the same as that of the liquid 8 may be filled in advance. The point which can be selected in this way is different from the transceiver 21 of the second embodiment. However, when the liquid 8 at the measurement site is filled, the lid 35 may be opened or closed, and when the castor oil or the like is filled, the lid 35 is closed so as not to leak.

Further, in the wave transmitter / receiver 31 of the third embodiment, the inside and outside of the case are communicated with the one end side of the longitudinal case 33, that is, the mounting side of the wave transmitter / receiver main body 3 and the lid 35. Communication holes 38, 39 are formed, and the communication holes 3
Cap 4 as opening / closing means for opening / closing 8, 39
1, 42 are provided. With this configuration, when it is desired to fill the interior of the longitudinal case 33 with the liquid 8 at the measurement site as described above, the lid 35 is opened, and the communication hole 3 on the upper end side is further opened.
8 may be opened and the transmitter / receiver 31 may be submerged in the liquid. In this way, air is released through the communication hole 38,
The liquid 8 easily enters from the lower end open portion of the case 33.
According to this method, the work is easier than the method of inverting the entire transducer in the liquid and filling the case with the liquid.

When the liquid 8 in the case 33 is drained, the communication hole 38 on the upper end side is opened and air is introduced into the case 33 to lift the whole of the wave transmitter / receiver 31 and pull it out of the liquid. However, when the lid 35 is closed, the communication hole 39 provided in the lid 35 is also opened to allow the liquid 8 to flow out. According to this method, it suffices to lift the weight of the transducer 31 itself. If the liquid is lifted up without introducing air into the case 33 in this way, the liquid 8 remains in the case 33 and its weight is added, and a large force is required.

FIG. 6 shows a transmitter / receiver 51 as a fourth embodiment of the present invention.

As shown in the figure, the wave transmitter / receiver 51 includes a wave transmitter / receiver main body 3 for transmitting / receiving ultrasonic waves, and the wave transmitter / receiver main body 3.
Is provided inside one end in the longitudinal direction, and a castor oil 54 filled in the case 53 as a sound wave transmission medium is provided, which is an integral mold type as a whole.

The case 53 has, for example, a top plate 53b and a bottom plate 5 at the upper and lower openings of a cylindrical body 53a.
3c is fixed by welding or the like to be closed and has liquid tightness. These body 53a, top plate 53b and bottom plate 53c
For example, stainless steel (corresponding to SUS316) is selected as the material, and has sufficient corrosion resistance against acid and the like. The wave transmitter / receiver main body 3 is fixed to the top plate 53c through a silicone grease 6 on the side opposite to the wave transmitting / receiving surface 3a.

Further, the thicknesses of the body 53a, the top plate 53b and the bottom plate 53c are selected so as to be able to withstand even when the transducer 51 is used under the worst possible conditions.

As shown in FIG. 6, the wave transmitter / receiver 51 having the above-mentioned structure is mounted so that the lower half of the liquid 8 in the settling tank is immersed, that is, the upper end side of the liquid 8 projects above the liquid surface. To be In this state, ultrasonic waves are transmitted downward from the transducer main body 3. Then, an interface 11 (see FIG. 1) between the sludge 10 (see FIG. 1), which is a precipitate, and the liquid 8.
The reflected wave reflected by is received and a reception signal is emitted.

In the wave transmitter / receiver 51, if the ultrasonic wave is attached as described above, ultrasonic waves are generated between the castor oil 54 and the liquid to be measured 8 even if the position of the liquid surface is largely changed (indicated by symbol S). Can be transmitted reliably and measurement can be continued.

Further, in this state, since the transducer main body 3 is located above the liquid surface, even if the interface is extremely close to the liquid surface, it can be measured out of the dead zone.

In addition, in the wave transmitter / receiver 51, the castor oil 54 as the sound wave transmitting medium enlarges the amplitude of the ultrasonic wave. Specifically, the length L and the diameter D of the longitudinal case 53 filled with the castor oil 54.
Is set appropriately. As a result, even if the transmitter / receiver main body 3 has a small output, it can be reliably measured.

In the wave transmitter / receiver 51 of the fourth embodiment, castor oil 54 is filled as a sound wave transmission medium, which has substantially the same physical properties as the liquid 8 as the interface position measurement object. , The speed of sound, for example, the castor oil 54
Will be selected if In addition to this, the sound wave transmission medium to be filled may be pure water, or in some cases, a solid such as metal or a gel.

[0069]

As described above, in the first embodiment of the transducer according to the present invention, the body of the transducer, which transmits and receives ultrasonic waves, is surrounded by the liquid-tight case. According to this configuration, the penetration of the liquid, which is the object of interface position measurement, into the case is prevented, and the transducer main body does not get wet. Therefore, even if the liquid is corrosive,
By making the case corrosion resistant, the main body of the transceiver is protected for a long period of time, and during that time, complicated maintenance such as repair is not particularly required. Therefore, it is useful because it can be used for all purposes regardless of the properties of the target liquid, such as having strong acidity. Further, in the second embodiment of the wave transmitter / receiver according to the present invention, the wave transmitter / receiver main body is mounted inside one end in the longitudinal direction of the airtight longitudinal case, and the other end side of the case is opened. In the transducer of this structure, if the liquid to be measured at the interface position is filled in the longitudinal case and attached so that one end side of the case protrudes above the liquid surface, the transducer can be changed even if the position of the liquid surface changes greatly. The entire body of the main body is always kept in a state in which the wave transmission / reception surface is always immersed in the liquid. Therefore, the measurement can be continued without interrupting the transmission of ultrasonic waves. Further, in the above mounted state, the transducer main body is located above the liquid surface,
Even if the interface is very close to the liquid surface, it will be out of the dead zone,
It is possible to measure. Further, in the wave transmitter / receiver of the second example, a communication hole for communicating the inside and the outside of the case is formed at the one end side of the longitudinal case, that is, the mounting side of the wave transmitter / receiver body, and the communication hole is opened and closed. An opening / closing means is provided. In this configuration, when it is attempted to fill the liquid in the longitudinal case as described above, the communication hole is opened and air is evacuated, and the entire transducer is submerged in the liquid substantially vertically, and the communication hole is opened again. Just close it. As another method of filling the liquid in the case, it is conceivable to invert the transducer in the liquid, but if the transducer is large, this work is difficult. With the above configuration, it is not necessary to invert the wave transmitter / receiver, and the work is easy. When draining the liquid from the case, the communication hole may be opened and air may be introduced into the case while lifting the entire wave transmitter / receiver and pulling it out of the liquid. In this method, the lifting force may be large enough to weigh the transducer. Incidentally, when lifting without introducing air from the communication hole in this way, liquid is present in the case until the open end of the case comes out of the liquid surface,
The weight is also added, and a large amount of force is required.
Next, in the wave transmitter / receiver of the third example according to the present invention, the wave transmitter / receiver main body is mounted inside one end in the longitudinal direction of the airtight longitudinal case, the other end side of the case is opened, and the other end open portion is formed. A lid for opening and closing is provided. The wave transmitter / receiver of this configuration is almost the same as the wave transmitter / receiver of the second example, and a liquid for which the interface position is to be measured or a sound wave transmitting medium such as castor oil having substantially the same physical properties is placed in the longitudinal case. If the case is mounted so that one end side of the case projects above the liquid surface, the whole body of the transducer is always kept in the liquid or the medium for transmitting sound waves even if the position of the liquid surface changes greatly. . Therefore, the ultrasonic wave transmission is not interrupted and the measurement can be continued. Further, in the above mounted state, since the transducer main body is located above the liquid surface, even if the interface is close to the liquid surface, it will fall out of the dead zone,
It is measurable. In the wave transmitter / receiver of the third example, a liquid at the measurement site may be used to fill the longitudinal case, or castor oil or the like may be filled in advance. The point which can be selected in this way is different from the transceiver of the second example.
However, when the measurement site is filled with the liquid, the lid may be opened or closed, and when the castor oil or the like is filled, the lid is closed so as not to leak. Further, in the transducer of the third example, the one end side of the longitudinal case,
That is, a communication hole that communicates the inside and outside of the case is formed in the mounting side of the wave transmitter / receiver main body and the lid, and an opening / closing means for opening and closing the communication hole is provided. In this configuration, when trying to fill the inside of the longitudinal case with the liquid at the measurement site as described above, if the lid is opened and the communication hole on the upper end side is further opened, the transducer is immersed in the liquid. Good. By doing so, air is released through the communication hole, and the liquid easily enters from the lower end opening portion of the case. According to this method, the work is easier than the method of reversing the entire transducer in the liquid and filling the case with the liquid as described above. Also, when draining the liquid from the case, open the communication hole on the upper end side and lift the entire transducer while introducing air into the case.
It can be pulled out of the liquid. However, when the lid is closed, the communication hole provided in the lid is also opened to allow the liquid to flow out. According to this method, it suffices to lift the weight of the transducer itself. If the case is lifted without introducing air in this way, the liquid remains in the case and its weight is added, and a large force is required. Subsequently, in the mold type transducer of the fourth example according to the present invention, the transducer main body is mounted inside one end of the longitudinal case in the longitudinal direction, and the physical properties of the transducer are substantially the same as those of the liquid to be measured. Is filled with a sound wave transmission medium such as castor oil. Also in the wave transmitter / receiver having this configuration, like the wave transmitter / receiver of the second and third examples, by mounting so that the one end side of the longitudinal case, that is, the mounting side of the wave transmitter / receiver main body protrudes above the liquid surface, Even if the position of the liquid surface greatly changes, the ultrasonic wave is reliably transmitted between the sound wave transmitting medium and the liquid, and the measurement can be continued. Further, in this state, since the transducer main body is located above the liquid surface, even if the interface is very close to the liquid surface, it can be measured out of the dead zone. In addition, in the transmitter / receiver, the sound wave transmission medium expands the amplitude of ultrasonic waves. Therefore, even if the transducer main body has a small output, it can be reliably measured.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a main part of an interface measuring device including a wave transmitter / receiver for measuring a suspended foreign matter interface as a first embodiment of the present invention, and a water surface, an interface, a bottom surface, and the like.

2 is a block diagram showing a detection circuit of the interface measuring apparatus shown in FIG.

FIG. 3 is a vertical cross-sectional view of a wave transceiver according to a first embodiment of the present invention.

FIG. 4 is a vertical cross-sectional view of a transceiver according to a second embodiment of the present invention.

FIG. 5 is a vertical cross-sectional view of a wave transceiver according to a third embodiment of the present invention.

FIG. 6 is a vertical cross-sectional view of a wave transceiver according to a fourth embodiment of the present invention.

FIG. 7 is a schematic view showing an interface measuring device including a conventional transducer.

[Explanation of symbols]

1,21,31,51 Transceiver 3 Transducer body 5 cases 6 Silicon grease 8 Liquid to be measured 10 sludge 11 Interface 23,33,53 Longitudinal case 25, 38, 39 communication holes 26,41,42 Cap (opening and closing means) 35 Lid 54 Castor oil (medium for transmitting sound waves)

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01F 23 / H04R

Claims (5)

(57) [Claims] 1. A transducer main body for transmitting and receiving ultrasonic waves,
A wave transmitter / receiver having an airtightness and holding the main body of the wave transmitter / receiver inside one end in the longitudinal direction and opening the other end side. 2. A communication hole for communicating the inside and outside of the case is formed on the one end side of the case, and an opening / closing means for opening / closing the communication hole is provided.
The listed transducer. 3. A transducer main body for transmitting and receiving ultrasonic waves,
The present invention is characterized by comprising a longitudinal case that is airtight and holds the main body of the transducer inside one end in the longitudinal direction and is open at the other end side, and a lid body that opens and closes the other end opening part of the case. And a transducer. 4. A communication hole for communicating the inside and outside of the case is formed in the one end side of the case and the lid, and an opening / closing means for opening / closing the communication hole is provided. The transducer according to item 3. 5. The acoustic wave transmission medium having substantially the same physical properties as the liquid to be measured is filled in the case with the lid closed, and the acoustic wave transmission medium has an ultrasonic wave amplitude. The transmitter / receiver according to claim 3 or 4, wherein the transmitter / receiver is expanded.