JPH05273032A - Tank contents discharger - Google Patents

Abstract

PURPOSE:To obtain an apparatus which enables the detecting the interface of the contents separated at least into two layers accurately from the inside of a tank to a lower withdrawing port to make it suitable for the automation of a separation process during the discharging. CONSTITUTION:This apparatus contains a first detector 10 to detect an interface utilizing changes in electrostatic capacitance and a second detector 20 which utilizes an ultrasonic wave. The former contains an electrode 11 for measuring an electrostatic capacitance moving vertically within tank, a guide pipe 12 for housing, a measuring section 13 to measure the position of the electrode and an amplification display section 14. The latter has probes 21 and 22 for admitting and detecting ultrasonic waves as arranged on the outer circumference of a lower withdrawing port pipe 2 of the tank, a transmitter 23 and a receiver 24. The detection of an interface III moving with the discharging can be shared among the interface detectors as mentioned above. The first interface detector 10 detects the interface moving downward and thereafter. when the interface part is passing through the withdrawing port pipe, the passage thereof is detected with the second interface detector 20. Operation may be either manual or automatic.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for discharging a content of a tank, and more particularly to detecting the interface of the content in a tank containing the contents forming at least two layers, and accurately extracting the content. The present invention relates to a tank content discharging device.

[0002]

2. Description of the Related Art A device utilizing ultrasonic waves has been proposed as a liquid interface detecting device for detecting a boundary surface in a tank (Japanese Patent Application No. 2-38128). According to this, for example, an ultrasonic pulse incidence probe and an ultrasonic detection probe are provided on the outer circumference of the tank to be measured at two points facing each other across the tank center,
Provide a transmitter for injecting ultrasonic waves from the incident probe and a receiver for measuring the waveform and sound pressure level of the ultrasonic waves received by the detection probe, and set the position of each probe. The interface between the two liquid layers is detected by providing a mechanism for moving the liquid in the vertical direction.

[0003]

In the liquid interface detecting device using ultrasonic waves, it is easy to use a sensor system (an ultrasonic wave incident probe, an ultrasonic wave detection probe) of an external mounting type. However, the boundary surface inside the tank can be detected from outside the tank, but there is still room for improvement when considering the following points. That is, depending on the application, for example, it may be desirable to separate the two-liquid layer of the contents in the tank to the outside of the tank, and in that case, when discharging the contents in the tank to the outside of the tank, the Although the surface moves, in order to accurately detect the movement of the boundary surface, it is necessary to provide a large number of incident probes and detection probes facing the same on the outer circumference of the tank.

Further, it is important that the opposing probes are accurately placed so as to sandwich the center of the tank in order to maximize the performance of the sensor.
From the standpoint of maintaining its performance, maintenance is also required to prevent the displacement (the sensitivity decreases as the relative position deviates), and when many probes need to be installed on the outer circumference of the tank, Therefore, the burden of maintenance will increase accordingly. Further, depending on the kind of the contents of the tank, it is necessary to control at a temperature other than room temperature. For that purpose, it may be necessary to provide a jacket on the outer circumference of the tank for control, but in that case, the heat transfer area is small because the notch is made in the jacket and the probe must be provided directly on the outer wall of the tank. It also affects the efficiency in terms of temperature control.

Further, regarding the case of extracting the contents from the tank, further, a glass gauge is provided in the extraction pipe at the bottom of the tank, and an operator visually monitors the boundary surface of the two liquid layers from there, and extracts the contents separately. When you do
The burden on the operator is heavy, and in the case of such a glass gauge at the bottom of the tank, there is a risk of overlooking the boundary surface, making it difficult to ensure reliability.

On the other hand, as a detection device for knowing, for example, the liquid level in the tank, a device for detecting and instructing the level surface by measuring the electrostatic capacity is known as a level indicating device (Japanese Patent Publication No. 25-25347). Publication). This one is
Basically, an electrode is placed in an insulating pipe inserted in a conductive tank, and the bridge mechanism output that uses the capacitance between the electrode and the tank drives the servo mechanism, which causes the electrode to level. It is intended to follow the surface and give an instruction to detect the level surface. Therefore, such a detecting device measures an insulating guide pipe inserted into a conductive tank, an electrode housed in the guide pipe, which moves up and down as the capacitance changes, and a position of the electrode connected to the electrode. It can be said that the device is composed of a measurement unit and an amplification display unit.

Therefore, it is conceivable to use the above technique for detecting the interface between the contents of different layers. When the device for detecting the interface by such a change in capacitance is used, it is advantageous in that it follows the movement of the interface, does not need to be provided with a large number of electrodes, and does not adversely affect the temperature control of the tank. However, there is a drawback that it cannot be extended to the bottom outlet of the tank. That is, when the boundary surface comes to the lower part of the tank due to the discharge of the contents of the tank, there is a problem that it cannot follow any more. Therefore, the movement of the interface at the time of discharging the contents is accurately detected to the extraction part at the bottom of the tank. I can't expect such a function.

The object of the present invention is to solve the above-mentioned problems and to accurately detect the interface of the contents in the tank, and also to accurately detect the movement of the interface when the contents are discharged to the extraction part at the bottom of the tank. To provide a tank content discharging device that can accurately discharge the tank contents that should be discharged, and a tank content discharging device that can respond to this even when automating the separation process and that is suitable for automation. is there.

[0009]

According to the present invention, the following tank content discharging device is provided. An interface detection device utilizing a change in electrostatic capacity, wherein an insulating guide pipe is inserted into a conductive tank containing a content forming a different layer so as to extend over the different layer, and the inside of the guide pipe. The electrode includes a stored electrode and a measuring unit which is connected to the electrode, measures the electrostatic capacitance between the electrode and the tank, and moves the electrode up and down in the guide pipe according to the change in the measured electrostatic capacitance. A first interface detection device for detecting the position of the interface of the contents based on the position, and an interface detection device using ultrasonic waves,
An ultrasonic wave incident probe and an ultrasonic wave detection probe provided to face the outer circumference of the content extraction section at the bottom of the tank, and a transmitter and a receiver respectively connected to these probes, It is a tank content discharge device including a second interface detection device that detects an interface based on a change in received output.

[0010]

Therefore, even when the contents are discharged, the detection of the interfaces that move with the discharge can be shared by the detection devices, and the first interface detection device detects the interfaces that are moving in the tank, and then the interface portion contains the contents. The second interface detection device can detect when the object is about to pass through the extraction portion, and it is possible to appropriately detect the movement of the interface even when discharging the object. In that case, the control device and the tank contents discharging mechanism as described in claim 2 may be provided to give an operation instruction to the discharging mechanism. Further, the weight detection described in claim 3 is also taken into consideration to make the detection more accurate, and the control according to claim 4 realizes automation of discharging the contents, and the automatic detection as described in claim 5. A valve can be used to make the automation even easier.

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows an embodiment of the tank contents discharging device of the present invention. In the figure, the reference numeral 1 indicates a conductive tank for storing contents to which the interface detection by the device of this embodiment can be applied. The tank 1 is for accommodating contents forming a different layer, and is provided with a contents outlet pipe 2 connected to an outlet at the bottom of the tank. The pipe 2 allows the discharged contents to pass through the pipe when the contents are discharged when the contents in the tank are extracted.

Here, forming a different layer with respect to the above-mentioned contents means that the contents form at least two layers that are substantially immiscible with each other. Specifically, it is a substance that is substantially immiscible and has fluidity. For example, it means that after mixing, the mixture is allowed to stand and separated over time with the difference in specific gravities to form at least two layers. The form of such a substance is liquid, powder, granules, etc., and the different layer is formed by a combination thereof. However, the number of layers is not limited to two and may be three or more. In the case shown, the contents I and II are the interfaces.
Illustrated is a state in which the upper and lower layers are separated by III (boundary surface).

As described above, the boundary surface of the contents of the tank, which is separated into two layers such as the contents I in the upper layer and the contents II in the lower layer, can be accurately detected even in the range from the inside of the tank to the outlet of the tank. In order to do so, the interface detection device applied to the tank 1 includes a first interface detection device 10 and a second interface detection device 20. The first interface detection device 10 constitutes a capacitance type detection means for detecting the interface by measuring the capacitance by utilizing the change of the capacitance, and basically, it is installed in the tank. The interface is detected by the capacitance measuring electrode in the inserted guide pipe. The second interface detection device 20 constitutes an ultrasonic detection device that detects the interface using ultrasonic waves, and detects the interface by ultrasonic waves at the outlet portion at the bottom of the tank.

The first interface detecting device 10 includes an electrode 11 housed in an insulating guide pipe 12 inserted in a tank.
And a measuring unit 13 that is connected to the electrode 11 and measures the electrostatic capacitance between the electrode and the tank, moves the electrode up and down according to the change in the electrostatic capacitance, and measures the position of the interface from the position of the electrode.
And an amplification display unit 14. The electrode 11 and the guide pipe 12 form a sensor unit arranged in the tank. Measuring unit 13
Is installed in the upper part of the tank, for example, in the manhole part. The display unit 14 constitutes an instruction unit that indicates the level of the measurement target interface with the position of the electrode 11 according to the measurement by the measurement unit 13. In the first interface detecting device 10, as shown in the drawing, the guide pipe 12 is inserted into the tank 1 toward the lower part within a predetermined range, but the guide containing the electrode 11 of the first interface detecting device 10 is inserted. The pipe 12 must be inserted across different layers of the tank contents. This is because in the case of two layers, even if the guide pipe is inserted in only one layer, the boundary surface cannot be detected.

In this example, the contents are in two layers, the first and the second.
On the side of the interface detection device 10 of, the guide pipe 12
I and the contents II are inserted, and the electrode 11 is housed in the guide pipe 12 so that it moves up and down by the tuning relationship of the detection bridge circuit in the measurement unit 13 and the amplification display unit 14 as the capacitance changes. There is. Such a detection device detects the liquid surface by the change in the electrostatic capacitance between the electrode and the tank, which has been conventionally known, and moves the electrode up and down so that the electrode automatically follows the detected liquid surface. The device can be used. At that time, it is better to select a material that can follow the normal interface even if the content adheres to and remains on the guide pipe. Further, as described above, a high-frequency absorption automatic equilibrium tracking type continuous level indication type may be used to continuously read and automate, or may be manual.

On the other hand, the second interface detection device 20 is a detection device in which the sensor system is externally mounted and has no contact with the contents, and a pair of ultrasonic wave incident probes (ultrasonic pulse incident light) are used. Probe) 21, an ultrasonic detecting probe 22, a transmitter 23 and a receiver 24. First interface detection device 10
The second interface detection device 20, which shares and takes charge of interface detection in combination with the above, is a non-wetted type if the object contents I and II are liquids, and further moves it vertically with respect to the probe. It is a device that does not need a mechanism. In the illustrated example, on the side of the second interface detection device 20, the ultrasonic wave incident probe 21 and the ultrasonic wave detection probe 22 are placed on the outer circumference of the outlet pipe 2 at the lower part of the tank and the center of the pipe. It is provided facing each other. Transducers 21 and 22 are transmitters 23 and
Connected to the receiver 24. The transmitter 23 is a transmitter used to make an ultrasonic wave incident from the incident probe 21, and
It is assumed that the receiver 24 can measure the waveform, sound pressure level, and speed of sound of the ultrasonic wave received by the ultrasonic wave detecting probe 22.

In the above structure, the interface detection can be performed as follows. As will be described below with reference to FIGS. 2 and 3, for example, in the step of washing and extracting a water-soluble substance contained in an oily substance with water, a suspension of water and oil in a tank is used. After leaving it to stand and separating it, perform the operation of extracting separately. At this time, if it is possible to know where the boundary surface of the two liquid layers is in the tank and to confirm the respective liquid volumes, it is possible to perform proper separation, and to know the boundary surface of the contents in the tank. In this interface detection device, this is performed as follows.

First, in the above example, when the water-soluble substance contained in the oily substance is washed and extracted with water, water is added to the oily substance in the tank 1 and the mixture is mixed and stirred. , FIG. 1, and each of FIGS. 4 and 6 described later, the mixing and stirring device is not shown). FIG. 2 shows the state of the interface at the time of completion of the separation detected by the first detection device 10, that is, the position of the interface ready to be discharged, as the stirring is stopped and stopped and the time passes.

In FIG. 2, the vertical axis indicates the change in capacitance from the tank 1
The value of the boundary surface converted to the height of is shown. In Fig. 2, when stirring is stopped, it is in the form of emulsion, so in this case it is regarded as a water layer with a large electrostatic capacity, and its indication indicates the top of the tank contents (before t ₁ ). .. Separation into two layers was started with the passage of time, and it was shown that the tank contents were completely separated when the indicated change became zero (t ₂ ). That is, the first interface detection device 10 simultaneously detects the time when the contents are completely separated and the interface at that time. When the contents are completely separated,
Lower part of the bottom of the tank from the outlet pipe 2 (contents
II) is drained. In that case, since the interface III is lowered, it is not shown in FIG. 2, but since the electrode 11 follows it, the indicator curve is lowered again. In such a process, the first interface detection device 10 takes charge of the detection.

Next, the transmitted sound pressure level of the ultrasonic pulse is measured by the second interface detecting device 20 having the sensor system for the content extraction pipe 2 at the bottom of the tank.
The curve shown in is obtained. In Fig. 3, the vertical axis represents sound pressure level and the horizontal axis represents time. In Fig. 3, it can be seen that the interface III approaches when the sound pressure level begins to drop.
Since the interface III is in the emulsion state, the sound pressure level is diffused and the sound pressure level becomes a minimum, and when it becomes oil, the sound pressure level rises, but the sound pressure level is lower than that of the first water. Furthermore,
It is also possible to determine the difference between the upper layer portion and the lower layer portion by detecting the difference in the transmission time of the ultrasonic pulse, that is, the difference in the propagation time of the ultrasonic pulse in the content extraction port hype 2 below the tank. Here, by combining both the sound pressure level and the transmission time, it becomes possible to detect the interface more accurately. When measuring only the sound pressure level, if the interface III layer is large (thick), part of the interface III may flow out first due to the effect of turbulence of the lower layer liquid near the extraction pipe,
This is because the sound pressure level suddenly drops and may cause a false detection. Thus, the first interface detection device
After exiting from the detection by 10, the second interface detection device 20 takes charge of the detection, and the passage of the interface III portion can be detected. As described above, the detection can be shared by the first interface detection device 10 and the second interface detection device 20. Thus, while accurately detecting the boundary surface III in the tank 1 in which the contents forming the substantially immiscible two layers are contained,
It is possible to accurately detect the movement of the boundary surface caused by discharging at least one layer out of the tank. Furthermore, the first interface detection device
It is also possible to implement by providing a control device 40 which takes in the interface signal obtained by 10 and the second interface detection device 20 as an input, and a tank content discharging mechanism 50 which is instructed to operate by the control device 40. Therefore, it may be manual or automatic, and the tank contents can be accurately discharged based on the accurate detection of the movement of the boundary surface.

FIG. 4 shows another embodiment of the tank contents discharging apparatus of the present invention. In this embodiment, the first interface detection device 10
In addition to the second interface detection device 20 and a weight detection device
30 is provided to make the detection more accurate, and at the same time, the control device 40 is further provided to automate the discharge of the contents. In FIG. 4, a load cell 31 is a load cell that constitutes the weight detection device 30, is provided so as to support the tank 1, and is connected to a weight indicator 32. Load cell 31
Usually, two or more are installed. The control device 40 includes a first interface detection device 10, a second interface detection device 20, and a weight detection device 30.
Also, it has a function of being connected to the discharge mechanism 50 and fetching an interface discrimination signal or the like from each device and sending a signal for opening / closing the discharge mechanism 50.

The control contents of the control device 40 here may be as follows, for example. That is, the interface discrimination signal is taken in from the first interface detection device 10 and the tank content discharge mechanism 50
The opening / closing instruction to take in the weight signal from the weight detection device 30, and the second interface detection device from both of it and the interface signal.
The operation of 20 is instructed, the interface discrimination signal is taken in from the second interface detection device 20, and the tank content discharge mechanism 50 is instructed to open and close.

Further, referring to FIG. 5, an example will be described.
The device according to FIG. 4 can be used as follows. tank
When the weight detection device 30 and the control device 40 are provided in 1, the weight of the oily substance including the water-soluble substance in the tank, the weight of the added water and the shape of the tank in the case of the target contents of the above-mentioned example As shown in FIG. 5 (t _{11 to} t ₁₃ ), the change in weight due to the discharge of the lower layer (contents II) is obtained from the weight detecting device 30 and is calculated from the first interface detecting device 10. The control device 40 can automatically instruct the operation of the second interface detection device 20 in combination with the interface signal. Then, in response to the interface signal from the second interface detection device 20, the control device 40 outputs a signal for opening / closing to the tank content discharging mechanism 50.

According to the present embodiment, as in the previous embodiment, the interface in the tank containing the contents forming the two layers is quickly and accurately detected, and the contents are discharged from the tank. Can accurately detect the movement of the interface, eject each layer more accurately, and further automate the ejection.

FIG. 6 shows still another embodiment of the interface detecting device of the present invention. In this embodiment, as the discharge mechanism in the second embodiment, specifically, a three-way automatic valve 51 and a two-way automatic valve 52 are used.
By adopting, it becomes easier to automate the discharge of contents. The 3-way automatic valve 51 uses the flow paths 53, 5
4 branches, and the 2-way automatic valve 52
53, can be provided.

In the case of the present embodiment, if automatic valves 51 and 52 as shown in FIG. 6 are used, the lower layer liquid (content II) and the upper layer liquid (content I) are separated into separate flow paths 53. , 54 can be automatically discharged.

The present apparatus utilizes the advantages of the previously proposed ultrasonic method and the electrostatic capacity method, while compensating for each difficulty, while moving the interface in the tank. It can be properly detected, and further, the layers of the contents can be separately and accurately discharged out of the tank automatically, which is suitable for automating various separation processes, and therefore various chemicals can be used. Wide application is expected in the fields of industry, especially petrochemical industry, food industry, cosmetics industry and the like.

Although the present invention has been described with reference to particular embodiments, it is not limited thereto. For example, the first
In a mode in which the interface detection device including the interface detection device and the second interface detection device is provided with a weight detection device including a load cell for indicating a tank and a weight indicator connected to the load cell. Can be implemented.

[0029]

According to the present invention, the boundary surface in the tank in which the contents forming at least two layers that are substantially immiscible are contained is detected quickly and accurately, and the contents are removed from the tank. It is possible to accurately detect the movement of the boundary surface at the time of discharging and to discharge each layer separately and accurately, which is suitable for automating the discharging.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a tank contents discharging device of the present invention.

FIG. 2 is a diagram showing an example of progress of a separation interface detected by a first interface detection device in the apparatus of the embodiment.

FIG. 3 is a diagram similarly showing an example of an outflow situation of the contents detected by the second interface detection device to the outside of the tank.

FIG. 4 is a diagram showing a configuration according to another exemplary embodiment of the present invention.

FIG. 5 is a diagram showing an example of an outflow situation of the contents detected by a weight detection device in the device of the same example to the outside of the tank.

FIG. 6 is a diagram showing a configuration according to still another exemplary embodiment of the present invention.

[Explanation of symbols]

 1 Tank 2 Content extraction pipe 10 First interface detection device 11 Electrode 12 Guide pipe 13 Measurement part 14 Amplification display part 20 Second interface detection device 21 Ultrasonic wave incident probe 22 Ultrasonic wave detection probe 23 Transmitter 24 Receiver 30 Weight detection device 31 Load cell 32 Weight indicator 40 Control device 50 Discharge mechanism 51 3-way automatic valve 52 2-way automatic valve 53,54 Flow path I, II Contents III interface

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yoshimasa Ishii 1-14-1 Minami-Biery Place, Yokohama-shi, Kanagawa JGC Corporation Yokohama Works (72) Inventor Itsuo Chosa, Minami-Biery Place, Yokohama City, Kanagawa 14 No. 1 JGC Corporation Yokohama Office

Claims (5)

[Claims] 1. An interface detecting device utilizing a change in electrostatic capacity, which is an insulating guide pipe inserted over a different layer in a conductive tank containing contents forming the different layer, An electrode housed in the guide pipe, connected to the electrode, and measuring the capacitance between the electrode and the tank,
A first interface detection device that includes a measurement unit that moves an electrode up and down in a guide pipe according to a change in the measured capacitance, and detects the position of the interface of the contents based on the electrode position, and ultrasonic waves are used. An interface detector, which is provided with an ultrasonic wave incident probe and an ultrasonic wave detection probe that are provided so as to face the outer periphery of the content extraction section at the bottom of the tank, and transmitters connected to these probes, respectively. And a second interface detection device that includes a receiver and detects an interface based on a change in a reception output thereof. 2. A control device for taking in an interface signal obtained by the first interface detection device and the second interface detection device as an input,
The tank content discharging device according to claim 1, further comprising a tank content discharging mechanism that is instructed to operate by the control device. 3. One or more rollers supporting the tank.
The tank content discharging device according to claim 1 or 2, further comprising a weight detecting device including a docel and a weight indicator connected to the load cell. 4. A control device is provided which receives as input the interface signal obtained by the first interface detection device and the interface signal obtained by the second interface detection device and the weight signal from the weight detection device. Taking in an interface signal from the detection device, instructing the operation of the tank content discharging mechanism, taking in the weight signal from the weight detection device, and operating the second interface detection device from both of it and the interface signal of the first interface detection device. 4. The tank contents discharging device according to claim 3, wherein the tank contents discharging mechanism is controlled according to an interface signal obtained from the operating second interface detecting device. 5. The tank contents discharging device according to claim 4, wherein the tank contents discharging mechanism is an automatic valve.