JP2699128B2 - Measuring system for sewage concentration - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for measuring the concentration of sewage used in a sewage treatment system or the like.

[0002]

2. Description of the Related Art Sewage such as sewage and industrial wastewater is stored in a sedimentation tank, and suspended turbid matter in the water is decomposed by microorganisms and settled, and a relatively clean supernatant layer formed at an upper part and a lower part formed at a lower part. A sewage treatment system that separates and treats sediment that has accumulated is used. In such a sewage treatment system, a segregator is rotated at a low speed of about once every several minutes in a sedimentation tank to settle the sediment to the central part and collect the sediment through a discharge pipe installed in the central part. A configuration for processing is adopted.

In such a sewage treatment system, an operator immerses a concentration sensor, which is connected to a main body by a cable, into sewage and changes the depth of the ultrasonic sensor in order to know the progress of sedimentation in the sedimentation tank. A concentration detecting device is used that detects the concentration distribution of sewage in the depth direction, particularly the concentration distribution of the sedimentary layer, by measuring the magnitude of the light attenuation.

[0004]

In the above-mentioned conventional sewage treatment system, since the worker measures the concentration distribution in the depth direction while changing the depth of the concentration sensor immersed in the sewage, labor and time are required. There is a problem. It is also conceivable to install an automatic mechanism for automatically adjusting the depth of the sensor.However, this requires an automatic winding mechanism for the cable connecting the sensor and the main unit, which makes the measurement system complicated and expensive. Problem.

Further, in order to avoid collision with a scraper rotating in the settling tank, it is necessary to pull up the concentration sensor from the sewage in synchronization with the rotating state of the scraper. However, there is also a problem that the measuring device becomes more complicated and the measuring device becomes more expensive.

[0006]

SUMMARY OF THE INVENTION A system for measuring the concentration of waste liquid according to the present invention comprises a plurality of contaminants rotating or swirling in a sedimentation tank, which are installed at a desired interval in the depth direction in a submerged part of the liquid. A concentration sensor, a slave station device that is installed on the liquid above the collecting device, collects output data of each concentration sensor via a wired signal path, and transmits the data as it is or converts it into a measured value and transmits it as a wireless signal; A master station device installed at an external fixed point and receiving a radio signal from the slave station device.

[0007]

A slave station in which output data of a plurality of concentration sensors installed in a submerged portion of the scraper while maintaining a desired interval in the depth direction is fixed to an upper portion of the scraper via a wired signal path such as a cable. Once collected by the device, it is converted to a radio signal and sent to the master station device installed at a fixed location outside the scraper. Since each concentration sensor is installed on the scraper itself rotating in the sedimentation tank, a mechanism for avoiding collision with the scraper is not required at all. Further, since a plurality of density sensors are installed in accordance with a desired depth to be detected, a depth adjusting mechanism is not required at all.

[0008]

FIG. 1 is a sectional view showing the configuration of a system for measuring the concentration of sewage according to an embodiment of the present invention, together with a related sewage treatment system. First, the configuration and operation of a related wastewater treatment system will be briefly described.

This sewage treatment system includes a substantially cylindrical sedimentation tank 1 buried in the ground, a sediment discharge pipe 2 formed at the center of the bottom of the sedimentation tank 1, maintenance, inspection, measurement, etc. A bridge 3 suspended on the sedimentation tank 1 and a scraper 4 are provided as a passage for an operator. Scraper 4
A rotating shaft 5 rotatably supported at the center of the bridge 3 and rotated by a motor through a gear; a frame structure fixed to the rotation shaft 5; and a plurality of frames fixed to a lower portion of the frame structure. Are provided. The scraping plates 6, 7, 8...
Is attached to the frame structure in a state of being inclined in the circumferential direction, and the sediment deposited on the bottom of the sedimentation tank 1 is scraped to the central portion as the frame structure rotates.

Although not shown because it is not directly related to the gist of the present invention, wastewater to be treated and factory wastewater are injected into the sedimentation tank 1 from a water supply pipe installed above the sedimentation tank. The water is stored to a depth that does not submerge the top of 4. When the sediment accumulates to some extent in the center of the bottom of the sedimentation tank as the sedimentation progresses, a valve (not shown) closing the discharge pipe 2 is opened, and the sediment is separated from the supernatant layer and separated. It is discharged to the outside of the sedimentation tank 1, subjected to appropriate treatment for detoxification, and discarded.

The sewage concentration measuring system according to one embodiment of the present invention comprises six concentration measuring units installed at a desired depth in the underwater portion at the center of one wing of a skeleton structure constituting a scraper. 16 and sensors 11, 12, 13,...
A slave station device 20 installed on the water surface of the scraper, a holding rod 30 for holding a sensor signal group and a wired signal path connecting the sensor group and the slave station device, and a high altitude outside the sedimentation tank 1. A master station device 40 is provided.

Each of the six density sensors 11 to 16 is composed of a pair of light-emitting / light-receiving elements, a pair of acoustic elements, and the like, which are opposed to each other while maintaining a predetermined interval, and propagates in sewage water between the element pairs. The configuration is such that the concentration of sewage is detected by detecting the amount of attenuation of absorption of light waves or sound waves by sewage. In this embodiment, an ultrasonic pulse having a constant amplitude of about 1 MHz is output from the transmitter, and the ultrasonic pulse received by the opposing receiver is held in the holding rod 30 while maintaining watertightness. The signal is transmitted to the slave station device via a wired signal path, and the peak value of the received pulse is detected in the slave station device. Since the configuration and operation of such a concentration sensor utilizing absorption loss on the propagation path of the ultrasonic wave are well known, further description is omitted.

As shown in the block diagram of FIG. 2, the slave station device 20 includes a CPU 21, a transmitter 22, a receiver 23, a timing signal generation circuit 24, switch circuits 25 and 26, a peak hold circuit 27, an A / D converter. Circuit 28, modem 2
9, a wireless transceiver 31, an antenna 32, and a storage battery 33.

The CPU 21 transmits a measurement start command transmitted from the master station device 40 via the antenna 41 to the antenna 3.
2. Upon reception via the transceiver 31 and the modem 29, the timing generation circuit 24 is activated. The activated timing signal generation circuit 24 sends an activation signal having a predetermined period to the transmitter 22 to generate an AC signal having a frequency of about 1 MHz in a pulse form for a short period of about several cycles, and also includes switching circuits 25 and 26. Issue a signal path selection command. The switch circuit 25 transmits an electric pulse output from the transmitter 22 at a predetermined cycle in accordance with the selection command to a transmission signal path T connected to the transmitters of the six density sensors 11 to 16.
1 to T6. In synchronization with the operation of the switch circuit 25, the switch circuit 26 includes six density sensors 1
The electric pulses appearing on the reception signal paths R1 to R6 connected to the receivers 1 to 16 are sequentially supplied to the receiver 23.

The electric pulse supplied to the receiver 23 is amplified while being subjected to waveform equalization and band limitation, becomes a baseband pulse signal, and operates as a baseband pulse signal by a timing signal output from the timing signal generating circuit 24. The signal is supplied to the circuit 27 and converted into the amplitude of the ultrasonic pulse received by the receivers of the density sensors 11 to 16. The amplitude of the ultrasonic pulse is converted into a digital signal by the A / D conversion circuit 28 and supplied to the CPU 21. CPU
1 converts the digital signal received from the A / D conversion circuit 28 into a concentration of sewage, and temporarily stores the concentration in a built-in memory. CP
When the six density data detected by the six density sensors are collected, U1 assembles a data packet of an appropriate format including the data and transfers the data packet to the modulation / demodulation circuit 29. This data packet contains the identification code of the transmission source slave station device as necessary. The modulated data packet is output from the wireless transceiver 31 to the antenna 32 and radiated into the air.

The master station device 40 receives the data packet transmitted from the slave station device 20 via the antenna 41, extracts six measurement data included in the data packet, and displays the data on a screen or prints out the data. Or save until there is an output command.

A storage battery 33 for supplying operating power to each unit is built in the slave station device, and a slip ring or the like required when operating power is supplied from outside the slave station device is not required. In order to suppress the consumption of the storage battery 33 as much as possible, the measurement of the concentration is performed after an instruction from the master station device.

As described above, the system for measuring the concentration of waste liquid of the present invention has been described with reference to one embodiment. However, various modified embodiments can be considered within the scope of the present invention. Only the main ones of these modified embodiments are listed below.

A configuration in which a pair of a light emitting element and a light receiving element is used instead of using an ultrasonic sensor as a density sensor.

A configuration in which the main station apparatus 40 is installed on the bridge of the sedimentation tank instead of being installed outside the sedimentation tank 1.

A configuration in which measurement data is transferred between a slave station device installed in each of the scrapers of a plurality of sedimentation tanks and a single master station device. In this case, the data packet transmitted and received between the slave station device and the master station device includes an identification code of the sender slave station device or master station device as necessary.

Instead of sending the density data obtained by processing the output data of the sensor from the slave station apparatus to the master station apparatus, the sensor output data is sent as it is and processed by the master station apparatus to obtain the density data. . Settling tank

The data transmitted from the slave station device to the master station device includes, in addition to the wastewater concentration data, other appropriate data,
For example, a configuration that includes data such as water level of sewage.

A configuration in which the present invention is applied to a wastewater treatment system such as a special factory wastewater instead of being applied to a wastewater treatment system.

[0025]

As described in detail above, the system for measuring the concentration of waste liquid according to the present invention has a structure in which the concentration sensor is installed in the scraper, so that the concentration sensor is used to avoid collision with the scraper. There is no need for a complicated and expensive winding mechanism for pulling out the wastewater from the waste liquid, and the system can be simplified and reduced in cost.

Further, in the system of the present invention, a complicated and expensive winding mechanism for adjusting the depth of the density sensor is not required because a plurality of density sensors are installed in the depth direction.

Further, the system of the present invention wirelessly transmits and receives measurement data between a slave station installed in the liquid above the scraper and a master station installed in a fixed place outside the scraper. The configuration eliminates the need for a slip ring or the like that causes a failure or noise, and enables a highly reliable system to be constructed.

Further, since the system of the present invention has a configuration in which a slave station device and a master station device are connected by a wireless transmission path, a large number of slave station devices can be simply used in a large-scale sewage treatment system having a large number of sedimentation tanks. Since it can be easily connected to one master station, there is also an advantage that the measurement system is highly expandable.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of a sewage concentration measuring system according to an embodiment of the present invention, together with a related sewage treatment system.

FIG. 2 is a block diagram illustrating an example of a configuration of a slave station device in FIG.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 sedimentation tank 4 scraper 11 to 16 concentration sensor group 20 slave station device 30 holding rod holding density sensor group and wire signal path 32 antenna of slave station device 40 master station device 41 antenna of master station device

Claims (3)

(57) [Claims] A sewage treatment system in which a suspended turbid substance in a sewage stored in a sedimentation tank is settled to a central portion by a scraper rotating or rotating in the settling tank while sedimentation, thereby separating the supernatant from the supernatant. A plurality of concentration sensors installed in the submerged portion of the scraper while maintaining a desired interval in a depth direction, and a plurality of concentration sensors installed in the submerged portion of the scraper, The slave station device that collects the output data of each of the concentration sensors via a wired signal path and converts the data as it is or converts it into a measured value and sends it out as a wireless signal, and is installed at a fixed location outside the scraper and the A wastewater concentration measurement system, comprising: a master station device for receiving a radio signal from a slave station device. 2. The wastewater concentration according to claim 1, wherein the slave station device starts collecting output data of each of the concentration sensors and transmitting the data by a radio signal after waiting for a command from the master station device. Measuring system. 3. The apparatus according to claim 1, wherein the master station receives a radio signal from the plurality of slave stations installed for each of a plurality of sedimentation tanks.