JPH01304322A - Instrument for measuring boundary of suspended matter - Google Patents

Abstract

PURPOSE:To accurately measure the boundary of floatable suspended matters in a liquid by using a measuring device which can directly measure the boundary by means of ultrasonic waves of a frequency of about 400-1,500kHz and their reflected waves. CONSTITUTION:The capacity and depth of a settling reservoir 1 are respectively formed in corresponding to the processing quantity of waste water, sewage, etc., to be processed and 4-5mm in the case of processing waste water and 10m in the case of processing sewage. The bottom of the reservoir 1 is formed to a funnel-like shape and the sucking port of a suction pump 2 is opened at the central part of the bottom of the funnel. In addition, a drain pipe 3 for supernatant liquid is connected with the upper part of the liquid layer in the reservoir 1 and an ultrasonic wave transmitter-receiver dr which transmits ultrasonic waves of 400-1,500kHz in frequency into the liquid is provided above the surface of the liquid in the reservoir 1. When the ultrasonic wave is reflected on the boundary between the liquid and sludge, the reflected wave is received and transmitted to a measuring instrument MS. The instrument MS discriminates boundary signals from the reflected signals and measures the time from the transmission to the reception or the attenuated quantity of the reflected waves. Then the instrument MS calculates the position of the boundary, namely, depth to the boundary between the liquid and sludge based on the time or attenuated quantity.

Description

DETAILED DESCRIPTION OF THE INVENTION A.Objective of the invention (industrial application field)
A device that measures the interface of floating foreign matter suspended in a liquid. Specifically, by selecting an ultrasonic wave of 400 to 1500 KHz and using a measurement unit that measures the depth by discriminating the interface signal from the reflected wave, it is possible to directly receive the reflected wave from the floating suspended foreign object and measure the interface. The present invention relates to an interface measuring device that can reliably perform measurements, and an alarm and control device that operates based on the measurement results.

(Prior Art) Conventionally, as a device for measuring the thickness of a deposited layer of muddy foreign matter etc. deposited on the bottom of water, there has been known a device described in Japanese Patent Application Laid-Open No. 58-218607. It has an ultrasonic receiver placed at a predetermined height, emits ultrasonic waves almost vertically downward and receives the reflected waves, and a flat surface on the lower surface that is suspended by a wire and moves up and down inside the tank.
It consists of a weight with a spherical surface and a means for moving the needle of the same type downward.

(Problem to be Solved by the Invention) The conventional device described above uses ultrasonic waves of 1 to 5 MHz, but it receives reflected waves from the interface of solids deposited on the bottom of the tank and Since it is not possible to measure the depth of This is an indirect measurement method that determines the actual depth of the deposited layer by adding the thickness of the layer. Therefore, mechanical ancillary equipment such as a weight and a means to raise and lower it is required.
This equipment was inconvenient and had problems with portability.

The present invention has been made/made to solve the above-mentioned conventional problems, and it is based on the jX constant of the ultrasonic frequency suitable for detecting the interface of a foreign object suspended in a liquid, and the detection of an interface signal from the reflected wave. This interface measuring device is equipped with a measurement section that discriminates and obtains measured values, allowing it to directly measure the interface, and does not require incidental equipment such as a weight or means for raising and lowering it, making it convenient for equipment and excellent in portability. The purpose of this project is to provide alarms and control devices that utilize this technology.

Structure of the Invention (Means for Solving the Problems) The means of the present invention for achieving the object of the present invention is that floating foreign matter forms an interface and is suspended in a liquid of 400 to 1500 km.
T An interface measuring device for suspended foreign matter is equipped with a measurement unit that measures It is in the configuration of the alarm and control device.

(Function) When measuring the interface of sludge that is suspended in the liquid of a settling tank and forms an interface, the interface measuring device of the present invention configured as described above can be used on the surface of the liquid or in the liquid. If you install a sound wave transmitter/receiver and transmit an ultrasonic wave of, for example, 100 OK T-Tz into the liquid, the ultrasonic wave will travel through the liquid and reach the interface or bottom of the tank, where the density is different from that of the liquid. It is reflected by the receiver and received by the receiver. Then, the measurement unit amplifies and analyzes the reflected waves, distinguishes the reflected signal from the surrounding object world IW1 from other reflected signals, and determines the time from transmission to reception of this signal, or the time of reflection and reception. The depth of the interface is calculated based on the degree of attenuation and displayed on the display, and if a recorder is also placed on this display, the display will be recorded one by one. In addition, if an alarm is placed on the measuring part that is activated when the sludge interface exceeds the reference position and reaches a dangerous level, there is a danger that the interface, soil, and clear liquid will come close to being discharged and flow into the river. When this condition is detected, an alarm is issued, and the administrator is forced to stop the operation of the withdrawal pump (/i2L) and take artificial measures to prevent sludge from flowing into the river.

In addition, if the above-mentioned measuring unit is combined with a controller that operates when the sludge interface exceeds the reference position and reaches a dangerous position, the sludge interface will approach the supernatant discharge port, causing a dangerous situation where it will flow into the river. When this happens, the controller operates the sludge extraction pump to pull out the sludge, and when the interface drops to the standard level, the pump is stopped, and then the raw water supply pump is operated to compensate for the drop in the raw water level due to the sludge extraction. and measures to prevent sludge from flowing into rivers can be automatically taken.

(Example) Experimental examples and examples of the apparatus according to the present invention will be described below.

(Experiment example) As shown in Figure 1 of the drawing, a 300φ, 3m acrylic test tank was manufactured, and a liquid in which five types of floating sludge were suspended as shown in Attached Table 1 was placed in this test tank. A signal of 2001 (Hz, 600
KHz, 1000KHz, 2000K) (Z)4 types of ultrasonic waves are emitted, each reflected wave is received by the receiver, and the measurement unit amplifies this signal to distinguish the interface signal from other signals. Calculate based on reflection time and degree of attenuation,
A test was conducted to measure the interface position (depth). The results are shown in the same table. At 200 KHz, the ultrasonic waves would pass through the sludge no matter what kind of sludge it was in, so no counterwave could be obtained, so it was not possible to measure the interface, but at 600 KHz, the interface could not be measured.
At Hz, reflected waves can be obtained for sewage sludge, paper manufacturing sludge, and milk sludge, and the interface can be measured. Since the field 1fh-i could not be measured, at 1000 KHz, the reflection from the interface was obtained due to the sludge G with a total of ゛C, and the interface could be measured. However, 2
At 000 KHz, the ultrasonic wave is attenuated and a strong reflected wave cannot be obtained, so it is impossible to measure the interface. Based on these results, the ultrasonic wave that can be used to measure the sludge interface as described above is 1000 KHz. is the peak, and from this = 1
-Several 100 KI-■Z degree, i.e. 400-1500
It has been demonstrated that frequencies in the range I(I-Iz) are suitable.

In this experimental example and the examples described later, in order to directly measure the interface using the weak signal reflected from the sludge interface, the weak signal must be amplified to the required magnitude and only the interface signal can be extracted from the reflected signal. This requires a high-precision measurement device that separates and extracts the signal from other noise signals, tank bottom signals, etc., and calculates the depth of the interface based on the reflection time and degree of attenuation. There are two methods as shown in the block diagrams of FIGS. 2 and 3. The one shown in the block diagram not shown in FIG. 2 is a measurement cycle clock generation circuit.

Timing generation circuit, single pulse case 1 ~ generation circuit,
Live circuit to transducer 1, transducer (transmission/reception section), amplification/detection circuit, reception wave gate circuit.

Amplifier circuit, AGC circuit, STC circuit, counter star 1, sub I ~ tube gate circuit, counter, CPU (
Central processing unit) 1 memory, 2 or more input/output circuits, 1 display section, alarm section.

A control section is provided, and a clock generation circuit sets the period for one measurement, and a timing generation circuit determines the pulse width applied to the vibrator and the timing of the measurement star 1 and step 1.

The ultrasonic waves that hit the transducer are converted into electrical signals, but because they are weak voltages, they are amplified by an amplifier circuit. Since this signal contains high frequencies, it is amplified at high frequencies. In addition, the amplifier is equipped with a gain control terminal so that the gain can be varied using the signals from the A, GC, and ST''C circuits.Furthermore, it is equipped with a gain function to transmit signals to the oscillator. When adding a signal, I close the cables 1~ to prevent it from being amplified.

The counter circuit generates a measurement start signal from the measurement cycle clock, resets the flip-flop, and waits for the °C reflection signal to arrive. When a reflected wave arrives, it closes the gate I and notifies the CPU that a reflected wave has arrived.The CPU operates based on this notification, distinguishes the interface signal from the reflected signal, and detects the reflected wave. The depth of the interface is calculated based on the arrival time or the degree of attenuation, and is displayed on the display unit and is also transmitted to the alarm unit and control unit.

The block diagram shown in FIG. 3 includes a timing generation circuit, a single pulse generation circuit, a vibrator drive circuit, a vibrator, and an A/T converter.

Detection amplifier circuit, STC circuit, CPU, memory, input/output circuit, output circuit 4 display section, alarm section.

It is equipped with a control unit and is operated by a CPU (Central Processing Unit) or a program in memory, and a timing generation circuit controls the pulse width, s'-r, applied to the ultrasonic transducer.
The timing of the start of c amplification, etc. and the timing of sw. Since the ultrasonic transducer is a transmitter/receiver type (a type exclusively for transmitter and receiver is also possible), the ultrasonic wave that enters the transducer is converted into an analog electric signal, but it is weak and therefore ST
The signal is amplified and detected by an amplifier and a detector whose gain is controlled by the C circuit. The analog signal is converted into a gain signal using an A/D converter, and the operation of storing the data in memory under control of the CPU is repeated 2 to 5 times to accumulate data.Based on this accumulated data, the interface signal is converted into a gain signal. The depth of the interface is measured based on the reflection time and the degree of attenuation of the signal, and is displayed on the display unit, and the measurement results are also transmitted to the alarm unit and control unit.

Examples of sludge interface measurement using these measuring devices will be described below, with the entire measuring device being represented as MS and the transceiver (oscillator) being represented as dl-.

In the embodiment shown in Figure 4 of the drawings, the sedimentation tank 1 is formed to have a volume commensurate with the amount of wastewater 1 to be treated, such as sewage, etc., and a depth of 4 to 5 m for wastewater treatment; In the case of a tank 1, it should be formed to a length of 10 m, and its lower part should be shaped like a leak, and the suction port of the drawing pump 2 should be opened in the center of the bottom, and the second part of the liquid layer in the tank 1 should be filled with two clear liquid. The ultrasonic transmitter/receiver dr is placed on the liquid surface (or even on the liquid surface) of the above-mentioned sedimentation tank, and the ultrasonic wave transmitter/receiver is heated at 0 to 1500 K.
An ultrasonic wave of I(z is transmitted into the liquid, and when this ultrasonic wave is reflected at the interface between the liquid and sludge, it is received and transmitted to the measurement device MS.The measurement bag WMS then detects the interface signal from the reflected signal. The time from transmission to reception is determined, and the degree of attenuation of the reflected wave is measured.Based on this, the position of the sludge interface, that is, the depth from the liquid surface, is calculated and measured.

The results of measuring the sludge interface in the treatment of wastewater and sewage according to the above example are shown in Attached Table 2. In this case, the tests were omitted for paper manufacturing wastewater and milk wastewater, but the results for other wastewaters were as follows. In this case, the same results as in the experiment using the test tank described above were obtained, and it was demonstrated that ①-IZ is appropriate for the ultrasonic frequency of 400 to 1500.

The embodiment shown in FIG. 5 shows an embodiment of an interface measuring device suitable for continuous treatment of wastewater and sewage.
- It is basically the same as the embodiment shown in the figure, but the discharge port of the raw water supply pump 4 is opened above the tank, so that the raw water is continuously supplied. Ultrasonic transmitter/receivers d and r are placed above the liquid level (or even in the liquid) of the sedimentation tank 1, and from this, 400-1500 KHz ultrasonic waves are emitted into the liquid, and these ultrasonic waves cause the interaction between the liquid and sludge. When reflected at the interface, the measuring device MS receives it, discriminates the interface signal, and calculates the position (depth) of the sludge interface based on the time from transmission to reception or the degree of attenuation of the reflected wave. , is displayed on the display and transmitted to the controller, and the result is the same as in the previous embodiment. In this embodiment, when the depth of the interface rises above the reference value and reaches the critical value, By operating the controller, the extraction pump is operated to extract the sludge, and when the water level drops due to this, the raw water supply pump is operated to replenish the water level, which is effective in automatically preventing the sludge from flowing into the river.

Figure 6 shows an example used for batch treatment of wastewater 2 sewage, where the volume of sediment 1HIj; and the depth is 4 to 5 m for wastewater treatment.
In the case of sewage treatment, the bottom of the funnel is 10 m long, the bottom of which is the bottom of the funnel, the suction port of the drawing pump 2 is opened on one side of the bottom, and the suction pipe of the drainage pump 5 is connected to the liquid printing part in the tank 1-'. As shown in the figure, a plurality of suction tubes 6 of different lengths are arranged side by side, and these can be selectively used by selective operation of the valve 7. Although the drawing is omitted, - The suction pipe 6 is moved up and down to change the suction position of the liquid, and an aeration pipe 8 is inserted into the sludge layer to aerate the sludge, and this sedimentation Similarly to the embodiment shown in FIG.
S is used to constantly measure and monitor the sludge interface, and when an abnormal rise occurs in the interface, the sludge is automatically pulled out to suppress the rise in the interface and prevent the sludge from flowing into rivers due to this. be.

C. Effects of the Invention The device of the present invention configured as described above uses ultrasonic waves of an appropriate frequency and a measuring device that can directly measure an interface using the reflected waves of the ultrasonic waves, thereby detecting suspended foreign particles in a liquid. Since the interface can be accurately measured, the sludge interface can be monitored based on this measured value to prevent sludge from flowing out due to a rise in the interface and maintain the water quality of the effluent.

Using a device that can directly measure the interface of a foreign object using reflected waves eliminates the need for conventionally used incidental equipment such as a weight and means for raising and lowering it, making it convenient for equipment and excellent in portability.

Since ultrasonic waves are used, measurement errors do not occur even when measuring the interface of floating sludge in colored wastewater.

Depending on the frequency selected, it can be widely used for various types of wastewater treatment, for sediment phase detection in sewage treatment facilities, and for various interface measurement devices.

Using the output of the measurement results, an alarm is issued when the interface rises, and based on this, the sludge is pulled out manually, making it possible to artificially prevent sludge from flowing out.

The output of the measurement results can be used to operate a controller to automatically prevent sludge withdrawal.

It has the following unique effects.

[Brief explanation of the drawing]

FIG. 1 is a front view of an experimental apparatus related to the present invention. Second
3 and 3 are block diagrams of a measuring device used in the device of the present invention. 4 to 6 are schematic configuration diagrams showing each embodiment of the present invention. FIG. 4 shows the basic form, FIG. 5 shows the continuous processing type, and FIG. 6 shows the batch processing type. In the figure, 1 and 1' are sedimentation tanks, d and r are ultrasonic transmitters and receivers,
MS is a measuring device. = 16- JP-A-1-, 304.322 (6), d, r

Claims (2)

[Claims] (1) Floating foreign matter forms an interface and is suspended in a liquid40
A transmitting part that emits ultrasonic waves of 0 to 1500 kHz, a receiving part that receives the reflected waves, and the received signal is amplified and the interface signal is discriminated, and the depth of the interface is determined based on the reflection time, degree of attenuation, etc. What is claimed is: 1. An interface measuring device for suspended foreign matter, comprising: a measuring section for measuring . (2) The interface measuring device for suspended foreign matter according to claim 1,
An alarm and control device characterized by a combination of an alarm, a controller, etc. that operate based on the measured value.