JPH10235336A - Control apparatus of sludge concentration distribution measuring device and control thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the measuring accuracy of sludge concn. distribution. SOLUTION: A detection part 39 receives a signal oscillated from an oscillator 12 through a receiver 13 to detect sludge concn. distribution. The detected signal is supplied to a concn. detection circuit 14 and a taking-up control unit 15 performing the rising and falling of the detection part 39. The sludge concn. detected by the concn. detection circuit 14 is supplied to a rising and falling speed control apparatus 18 of a microcontroller and, in the rising and falling speed control apparatus 18, the density of the supplied concn. is judged by the density judge part 18a and the judge output is applied to a detection part taking-up speed judge part 18b to obtain a detection part taking-up speed. The taking-up speed judge output obtained in the output of the rising and falling speed control apparatus 18 is applied to the taking-up control unit 15 and the taking-up speed of the detection part 39 of a taking-out apparatus is controlled on the basis of the density of sludge concn.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control of a sludge concentration measuring instrument for controlling the elevation of a detecting portion of a sludge concentration measuring instrument used for a first sedimentation basin, a final sedimentation basin, a thickening tank, etc. in a sewage treatment plant. The present invention relates to an apparatus and a control method thereof.

[0002]

2. Description of the Related Art FIGS. 3 and 4 are plan and sectional views showing a first sedimentation basin, a final sedimentation basin, a concentration tank, and the like in a sewage treatment plant. In FIGS. 3 and 4, the sedimentation basin main body 31 has a circular shape. It is formed and a rectifying cylinder 32 is installed at the center.
A sludge scraping machine 34 having a sludge scraping plate 33 is rotatably disposed on the inner bottom of the sedimentation tank main body 31 around the rectifying cylinder 32. A scum scraping machine 36 having a scum scraping plate 35 is disposed above the flow regulating cylinder 32. Reference numeral 37 denotes a corridor main body. One end of the corridor main body 37 is fixed to an end of the sedimentation basin main body 31, and the other end is a rectifying cylinder 32.
It is fixed to the upper surface of.

In the corridor body 37, a sludge concentration distribution measuring instrument control device housing 38 shown in FIG.
Detection unit 3 of the sludge concentration distribution measuring instrument
9 is suspended by a winding device 51 so as to be able to move up and down freely. The detection unit 39 is controlled to be wound up by the winding device 51 when the sludge scraper 34 approaches, and to be raised from the position where the detection unit 39 is hung. The control operation is performed so that the detection unit 39 is moved down. Reference numeral 40 denotes an inflow pipe, 41 denotes an outflow pipe, 42 denotes a drain pipe, 43 denotes a return sludge pipe, 44 denotes a reduction gear, 45 denotes an overflow plate, and 46 denotes a scum.

[0004] In the sedimentation basin configured as described above,
In order to measure the sludge concentration distribution in the sedimentation tank main body 31, the detection unit 39 of the sludge concentration distribution measuring device is suspended in the sedimentation tank main body 31, and when the sludge scraper 34 approaches, the detection unit 39 is raised while the sludge is raised. The concentration distribution is measured, and when the sludge scraper 34 is separated, the sludge concentration is measured while lowering the detection unit 39.

[0005]

As described above, when the sludge scraper 34 approaches, the detection unit 39 of the sludge concentration distribution measuring device operates the limit switch installed at a predetermined position of the sedimentation tank main body 31. It is configured to electrically detect the approach of the sludge scraper 34. When the approach is detected, the detection signal is used to forcibly raise the detection unit 39 of the sludge concentration distribution measuring device.

Conventionally, since the elevating speed of the detecting unit 39 is constant, in the measurement mode, the distribution state of the sludge concentration cannot be measured unless the elevating / lowering speed is very slow. For this reason, when the sludge scraper 34 approaches, the detection unit 39 is forcibly raised by the winding device 51, so that the rising speed is increased. If the rising speed of the detection unit 39 is increased, it becomes almost impossible to measure the sludge concentration distribution, and there is a problem that the measurement must be temporarily stopped. As a result, conventionally, it was not possible to expect to improve the measurement accuracy of the sludge concentration distribution. Even when the detection unit 39 is located at the bottom of the sedimentation basin body 31 that requires the most measurement accuracy, when the sludge scraper 34 approaches,
Since the detector 39 had to be pulled up, improvement in the measurement accuracy of the sludge concentration distribution at this position could not be expected.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a control device and a control method of a sludge concentration distribution measuring instrument for improving the measurement accuracy of the sludge concentration distribution.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is directed to a first aspect of the present invention, wherein a sludge scraper is rotated to collect sludge concentration in a sedimentation tank when the sludge is being scraped. The sludge concentration device in the sedimentation basin is a device that controls the distribution measuring device to be suspended in the sedimentation basin by a take-up device so that the sludge scraper can be lifted by the take-up device when the sludge scraper approaches the measurement device. A concentration detection circuit that detects the output from the measuring instrument,
A depth detection circuit for detecting the depth of the measuring instrument in the sedimentation basin, a detection output from the depth detection circuit and a concentration detection output from the concentration detection circuit are supplied, and the depth of the measuring instrument in the sedimentation basin is supplied. And a lifting / lowering speed control device for giving an output for controlling the winding speed to the winding device in accordance with the detected concentration in the above.

According to a second aspect of the present invention, the elevation speed control device includes a density judging section for judging the density of the density from a density detection output from a density detecting circuit, and winding in accordance with the density output output from the density judging section. A winding speed determining unit for changing a winding speed of the apparatus.

According to a third aspect of the present invention, the elevating speed control device decreases the elevating speed of the measuring instrument in accordance with the concentration of the sludge in the sedimentation tank when the elevating speed is high, and increases the speed in two stages so as to increase the speed when the lightness is low. It is characterized by being changed.

According to a fourth aspect of the present invention, there is provided a method for measuring a sludge concentration distribution in a sedimentation basin, wherein when the sludge concentration distribution measuring device is raised from a position where the sludge concentration is high in the sedimentation basin to a position where the sludge concentration is low. When there is a measuring device at a position where the sludge concentration is high in the sedimentation tank, raise and lower the speed at a slow speed, and when there is a measuring device at a position where the concentration is light,
It is characterized in that the lifting speed is increased.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention. The same parts as those in FIGS. 3 and 4 are denoted by the same reference numerals. In FIG. 1, reference numeral 11 denotes an ultrasonic oscillation and reception circuit, and this circuit 11 is connected to a detection unit 39 of a sludge concentration distribution measuring instrument. The detecting unit 39 includes the oscillator 1
The receiver 13 receives the signal oscillated from the oscillator 12 and detects the sludge concentration distribution.

The detected signal is supplied to a density control circuit 14 and a winding control device 15 for raising and lowering the detection section 39. The concentration detection circuit 14 detects the sludge concentration, indicates the concentration by the concentration indicator 16, and records the concentration on the recorder 17 via the external output terminal. Reference numeral 18 denotes a sensitivity adjusting unit for adjusting the sensitivity of the density. The sludge concentration detected by the concentration detection circuit 14 is supplied to an elevating speed control device 18 including a microcontroller. In the elevating speed control device 18, the density is determined by the density determining unit 18a from the supplied density.
The determination output is provided to the detection unit winding speed determination unit 18b to obtain the detection unit winding speed.

The winding speed judgment output obtained from the output of the lifting speed control device 18 is supplied to the winding control device 15 so that the winding speed of the detecting section 39 of the winding device 51 is controlled by the density of the sludge. . Winding control device 15
Is supplied to the depth detection circuit 19 of the detection unit, and the depth position of the detection unit 39 in the sedimentation basin is detected. This detection output is supplied to the depth indicator 20 to indicate the depth, and is recorded on the recorder 17 via the external output terminal. Note that the depth position of the detection unit of the depth indicator 20 is also supplied to the elevation speed control device 18.

Next, the operation of the above-described embodiment will be described. Usually, the position where the sludge concentration measurement of the sedimentation basin is to be mainly performed using the sludge concentration distribution measuring device is deeper in the center of the sedimentation basin. Close to the bottom of the part, not the top of the sedimentation basin. It is known that the sludge concentration becomes thinner (lighter) as the upper part of the sedimentation basin approaches the liquid level, and it has been detected as a result of various experiments that the concentration suddenly changes particularly near a certain level. . In order to monitor the process of sewage treatment using this phenomenon, as described above, it is only necessary to change the elevating speed of the detecting unit of the sludge concentration distribution measuring instrument according to the concentration of the sludge.

For this purpose, in the measuring mode of the sludge concentration distribution measuring device, the concentration detecting circuit 14 detects the sludge concentration, and the detection output is inputted to the sludge concentration density judging section 18a of the elevation speed control device 18. The sludge density shading determination unit 18a determines the density of the sludge density, and performs at least two levels of density determination when the sludge density is high and when the sludge density is low. This determination output is input to the winding speed determination unit 18b of the detection unit. In the speed judging unit 18b, when the concentration is high, the detecting unit 39 is located at a relatively deep position of the sedimentation basin (this position is input from the depth indicator 20). Control output winding control device 1
5 to control the operation of the winding device 51. Conversely, when the concentration is low, a control output for moving the detection unit to increase the elevating speed is given to the winding control device 15 to control the operation of the winding device 51. The detecting unit 3
The control related to the ascent and descent of 9 may be performed by a preset program.

FIG. 2 shows a measurement time chart B of the measuring instrument according to the embodiment of the present invention and a measurement time chart A of the measuring instrument according to the conventional method. It can be seen from the time chart of FIG. 2 that the operability of the sewage treatment operation according to the embodiment of the present invention is improved. Note that in FIG.
Indicates a measurement position in a relatively low concentration place (upper part of the sedimentation basin) in the sedimentation basin, and measurement 2 indicates a measurement position in a relatively high concentration place (bottom part of the sedimentation basin).

Also, in the measurement of the sludge concentration distribution, there is an advantage that the accuracy of the measured concentration at the place where the measurement is desired is increased because the speed of elevation of the detecting unit 39 at the position where the sludge concentration is high is slow.

[0019]

As described above, according to the present invention,
Slowing speed of the detector at the position where measurement accuracy of sludge concentration is required is slowed, and at a position where the measurement accuracy is relatively low, the speed is high, so the measurement accuracy is improved at important points for measurement. Because the relationship between the rise and fall of the detecting part of the sludge concentration distribution measuring instrument and the operation of the sludge scraper is controlled by a program, the measurement may be interrupted due to an inadvertent rise of the detecting part or the sludge scraper may be forcibly stopped. It is possible to remove the impact on the machine body, and it is possible to obtain advantages that smoothness of process measurement and operability of sewage treatment operation can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an embodiment of the present invention.

FIG. 2 is a measurement time chart of a sludge concentration distribution measuring device according to a conventional system and a system according to the present invention.

Fig. 3 First settling tank, last settling tank in sewage treatment plant,
The top view which shows a concentration tank.

Fig. 4 First sedimentation basin, final sedimentation basin in sewage treatment plant,
Sectional drawing which shows a concentration tank.

FIG. 5 is a configuration explanatory view of a sludge concentration distribution measuring instrument control device housing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Ultrasonic oscillation and reception circuit 12 ... Oscillator 13 ... Receiver 14 ... Density detection circuit 15 ... Winding control device 18 ... Elevation speed control device 18a ... Shading determination part 18b ... Winding speed determination part 19 ... Depth detection circuit 34: Sludge scraper 39: Detector 51: Winding device

Claims (4)

[Claims] When a sludge scraper is rotated to scrape sludge in a sedimentation basin, a sludge concentration distribution measuring device is suspended in the sedimentation basin by a winding device so as to be able to move up and down freely in the sedimentation basin. When approaching the measuring instrument,
In a device for controlling a measuring device to be lifted by a winding device, a concentration detecting circuit for detecting a sludge concentration in a sedimentation basin by an output from the measuring device, and a depth for detecting a depth of the measuring device in the sedimentation basin. A detection circuit, a detection output from the depth detection circuit and a concentration detection output from the concentration detection circuit are supplied, and the winding speed is adjusted by the winding device according to the detected concentration at the depth of the measuring instrument in the sedimentation tank. A control device for a sludge concentration distribution measuring device, comprising a lifting speed control device for giving an output to be controlled. 2. The apparatus according to claim 1, wherein the raising / lowering speed control device includes a density determining unit that determines the density of the density from a density detection output from a density detection circuit, and a winding device that winds the winding device in accordance with the density output output from the density determination unit. 2. The control device for a sludge concentration distribution measuring device according to claim 1, further comprising a winding speed determining unit that changes a winding speed. 3. The elevating speed control device changes the speed in two stages according to the concentration of sludge in the sedimentation basin such that the speed is reduced when the elevating speed of the measuring device is high, and the speed is increased when the speed is low. The control device for a sludge concentration distribution measuring instrument according to claim 1, characterized in that: 4. A method for measuring a sludge concentration distribution in a sedimentation basin, wherein when the sludge concentration distribution measuring device is raised from a position where the sludge concentration is high in the sedimentation basin to a position where the sludge concentration is low, the elevation speed of the measuring device is increased. When there is a measuring instrument at a position where the sludge concentration is high in the sedimentation basin, it is moved up and down at a slow speed, and when there is a measuring instrument at a position where the concentration is light, the ascending and descending speed is increased. Control method.