JP2001225058A - Sensor retaining device in liquid treating tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sensor retaining device in a liquid treating tank, capable of facilitating the automation of lifting and lowering, of reducing the labor for lifting and lowering work, and of allowing the measurement of high accuracy. SOLUTION: This sensor retaining device in the liquid treating tank is provided with guide parts (11 and 12) projecting to inside and obliquely downward respectively from the internal surface of the liquid treating tank to fix the movement path of sensor (S), a sensor retaining means disposed on the tip end of the guide parts (11, 12) to retain the sensor (S) in the liquid, and a lifting/ lowering means (13) to lift and lower the sensor (S) along the guide parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a holding device such as an ultrasonic sensor used in a sewage treatment system or the like, and in particular, reduces the labor for installation in a liquid and recovery work outside the liquid. And a sensor holding device with improved measurement accuracy.

[0002]

2. Description of the Related Art Conventionally, in a sludge treatment tank of a sewage treatment system, sludge floating in sewage is decomposed by bacteria and the like to form a sedimentary layer, and the sludge is discharged from the bottom of the sludge treatment tank to the outside of the tank. . Simultaneously with the formation of this sludge settling layer, a layer of supernatant water is formed thereon. The progress of such sludge treatment has been grasped by detecting the position of the interface between the supernatant water and the sedimentary layer of sludge, the concentration of sludge in the layer of sedimentation sludge, and the like.

Conventionally, the depth of the interface between the supernatant water and the sludge settling tank has been detected using an ultrasonic range finder. That is, an ultrasonic wave is transmitted directly below from the ultrasonic sensor installed in the liquid, a reflected wave generated at the interface between the lower supernatant water and the settled sludge layer is received, and an elapsed time from the transmission to the reception to the interface. The propagation time of the ultrasonic wave is detected, and the depth of the interface is detected from the propagation time.

That is, as shown in FIG. 3, a sludge treatment tank A having a circular cross section is filled with sewage B to be treated, and a sludge scraping mechanism D is disposed near the bottom of the treatment tank A.
A scum scraping mechanism E is arranged near the surface C of the sewage. Sludge scraping mechanism D and scum scraping mechanism E
Is disposed at the center of the tank and is attached to a rotating rod F that is rotated by a motor, whereby the processing tank is rotated in a horizontal plane inside the processing tank. The sludge scraped by the sludge scraping mechanism D to the center of the bottom of the treatment tank is discharged to the outside of the tank through a sludge discharge pipe attached to the center. The scum swept by the scum sweeping mechanism E near the periphery of the water surface of the tank is discharged to the outside of the tank through the scum discharge pipe G.

[0005] In order to measure the depth of the interface between the sedimentation sludge tank formed by the above treatment and the supernatant water, an ultrasonic sensor S is installed in the wastewater. The ultrasonic sensor S is attached to the tip of a holding rod 2 held on a holding table 1 installed on the upper outer peripheral portion of the processing tank. In order to supply power to the sensor S and to input and output a transmission signal and a reception signal, a cable T connected to the sensor S is pulled out. In order to eliminate the influence of the reflected wave from the sludge scraping mechanism D, transmission and reception of ultrasonic waves by the ultrasonic sensor 1 are performed at a timing when the sludge scraping mechanism D does not exist immediately below,
An abnormal reflected wave component which is considered as a reflected wave from the scraping mechanism D is discarded, or the scraping mechanism D is formed sufficiently below the interface so that the influence of the reflected wave by the scraping mechanism D can be separated.

[0006]

In the conventional ultrasonic sensor shown in FIG. 3, the diameter of the ultrasonic beam is reduced as much as possible by the interface sensor using ultrasonic waves, but the peripheral portion of the beam is located on the inner wall surface of the processing tank. Incident and generates a reflected wave from it. The reflected wave generated on the inner wall surface of the tank interferes with the reflected wave from the interface of the target sludge, and lowers the measurement accuracy of the interface depth. In order to avoid such a reflected wave from the inner wall surface of the tank, it is necessary to install the ultrasonic sensor S as far as possible from the inner wall surface of the tank, that is, close to the center of the tank. However, as is apparent from FIG. 3, since the scum sweeping mechanism E exists near the water surface, the ultrasonic sensor S cannot be moved to the center of the tank, and the measurement accuracy due to the interference of the reflected wave from the inner wall surface. There is a problem that it is impossible to avoid a decrease in the number.

The ultrasonic sensor used in the sewage treatment tank needs to be taken out to the outside at a certain frequency in order to clean the ultrasonic wave transmitting / receiving surface. However, the ultrasonic sensor holding device having the structure shown in FIG. 3 has a problem in that it is difficult to automate the operation, and it is necessary to manually take the work out to the outside. Accordingly, it is an object of the present invention to provide an ultrasonic sensor holding device capable of avoiding interference of reflected waves from an inner wall surface. It is another object of the present invention to provide a sensor holding device that can easily be moved up and down easily and save labor.

[0008]

A sensor holding device according to the present invention, which solves the above-mentioned problems of the prior art, projects from the inner wall surface of a liquid processing tank into the inside of the processing tank and obliquely downwards, and moves the sensor along the path. A guide portion for defining the sensor portion, a sensor holding means for holding the sensor in the liquid at the tip portion of the guide portion, and an elevating means for raising and lowering the sensor along the guide portion of the sensor holding means. It is configured to facilitate installation of the sensor in the liquid and recovery operation from the liquid, and also to facilitate automation using a motor or the like.

[0009]

According to a preferred embodiment of the present invention, the liquid is sewage treated in a sewage treatment tank having an upper scum sweeping mechanism and a lower sludge scraping mechanism, By disposing the tip of the guide portion between the upper sweeping mechanism and the lower scraping mechanism, the ultrasonic sensor disposed at the tip of the guide portion is sufficiently separated from the inner wall surface of the processing tank. In addition, it is configured to effectively avoid a decrease in measurement accuracy due to interference of a reflected wave from the inner wall surface.

According to another preferred embodiment of the present invention,
The elevating means includes a winding means for winding a cable drawn from the sensor by an electric motor, and is configured to be able to be automatically installed and collected without relying on humans.

[0011]

FIG. 1 is a view showing a configuration of a holding mechanism of an ultrasonic sensor according to an embodiment of the present invention, together with a relation between a sewage treatment tank for treating sewage to be measured and an associated mechanism. In this figure,
The sewage treatment tanks denoted by reference numerals A to G and the associated mechanisms are the same components as those already described with reference to FIG. A is a sewage treatment tank, B is sewage to be treated, C is the surface of sewage, D is a sludge sweeping mechanism, E is a scum sweeping mechanism, F is a rotating rod, G is a scum discharge pipe, and S is an ultrasonic sensor. , T are cables.

The holding mechanism of the ultrasonic sensor according to this embodiment includes a root side guide portion 11, a front side guide portion 12,
A lifting unit 13; The root-side guide portion 11 is fixed to an inner wall surface of the processing tank by a stopper. A distal guide 12 is attached to the lower end of the root guide 11, and the ultrasonic sensor S is held at the distal end of the distal guide 12.

The details of the holding mechanism shown in FIG. 1 are shown in a side view (A) and a front view (B) of FIG. The root-side guide section 11 includes a guide rail 11a and an L-shaped metal 11b. The tip side guide portion 12 is a guide rail 12
a and a stopper 12b. The lifting unit 13
It includes a horizontal bar 13a, a circular stopper 13b, a hanging bracket 13c, a wire stopper 13d, and a cable winding drum 13e (FIG. 1).

Guide rail 11a of root side guide portion 11
Has an upward U-shape. This guide rail 1
1a is 1 attached to the left and right side surfaces by screwing.
It is screwed to the inner wall surface of the processing tank via a pair of L-axis fittings 11b. Guide rail 11a of the base side guide portion 11
The guide rails 12a having an upward U-shape are fixed on both side surfaces of the lower portion of the front side guide portion 12 by screws. The guide rail 12 projects from the wall surface of the processing tank toward the center of the processing tank in a downwardly inclined state. The guide rail 12 which is inclined forward and downward
A stopper 12b is formed at the distal end of a.

The horizontal bar 13a of the elevating unit 13 is placed on the upper surface of the guide rail 12a and slides on the upper surface of the guide rail 12a. Disc-shaped stoppers 13b are fixed to both ends of the horizontal bar 13a, and the horizontal bar 13a deviates from the upper surface of the guide rail 12a.
Is prevented by The hanging bracket 13 is attached to the horizontal bar 13a.
c is rotatably mounted in the vertical plane, and the ultrasonic sensor S is hung at the tip of the hanger 13c.

Guide rail 11a of root side guide portion 11
A wire stopper 13d is attached to the wire. To the ultrasonic sensor S, the tip of a cable T representing a power supply line and a signal line as a single line is connected.
As shown in FIG. 2B, the other end of the wire is passed through the inside of the guide rails 11a and 12a and below the horizontal bar of the wire stopper 13d, and as shown in FIG. And then wound up by a cable winding drum 13e. When installing the ultrasonic sensor S in sewage, the cable T is paid out by rotating the cable winding drum 13e manually or by an electric motor.

The ultrasonic sensor S is suspended by the weight of the ultrasonic sensor S attached to the distal end of the cable T, the horizontal bar 13a, the hanging bracket 13c, and the like. First,
After the ultrasonic sensor S is suspended vertically downward along the guide rail 11a, it descends obliquely downward along the guide rail 12a. Finally, the lowering is stopped by the horizontal bar 13a engaging with the stopper 12b formed at the tip of the guide rail 12a, and the ultrasonic sensor S is positioned at a predetermined position in the waste water.

When the ultrasonic sensor S in the sewage is pulled out of the treatment tank, the cable T is wound by rotating the cable winding drum 131e in a direction opposite to the direction when the cable winding drum 131e is installed in the water. The cable T pulled vertically upward from the ultrasonic sensor S suspended from the tip of the hanging bracket 13c is bent by the horizontal bar 13a, and is pulled obliquely upward to the right in FIG. And is pulled up again.
As a result, the ultrasonic sensor S is pulled upward diagonally right along the guide rail 12a, then pulled vertically upward along the guide rail 11a, and collected outside the processing tank.

In the above, the sensor holding device of the present invention has been described by taking as an example the case where the sensor to be held is an ultrasonic sensor for measuring the depth of the interface. However, the holding device of the present invention can be applied to an ultrasonic sensor in which the sensor to be held measures the concentration distribution of sludge near the interface from the intensity of the reflected wave. Further, the holding device of the present invention can be applied to a case where the sensor to be held is an optical sensor or the like that measures the density from the amount of light propagation attenuation.

Also, the case where the sensor holding device of the present invention is installed in sewage in a sewage treatment tank is exemplified, but the sensor holding device of the present invention is installed in a liquid processing tank such as a manufacturing factory or a chemical treatment plant. Can be installed.

[0021]

As described above in detail, the sensor holding device according to the present invention has a guide portion which is projected inside the processing tank and obliquely downward to define a movement path of the sensor. The sensor includes a sensor holding unit that holds the sensor in the liquid at the tip and a lifting unit that moves the sensor up and down along the guide portion of the sensor holding unit. In addition, the operation of recovering from the liquid is facilitated, and the installation and recovery operation using a motor and the like are easily automated.

The sensor holding device according to one embodiment of the present invention has a configuration in which the tip of the guide portion is disposed in the middle of the upper and lower scraping mechanisms in the sewage treatment tank, and the ultrasonic sensor is disposed here. In addition, the ultrasonic sensor can be installed at a distance from the inner wall surface of the processing tank, and the measurement accuracy can be increased by avoiding interference due to reflected waves from the inner wall surface.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an ultrasonic sensor holding device according to an embodiment of the present invention, together with the relationship between a sewage treatment tank to be installed and associated equipment.

2A and 2B are a side view and a plan view, respectively, showing the configuration of the ultrasonic sensor holding device of FIG. 1 in detail.

FIG. 3 is a cross-sectional view showing the ultrasonic sensor holding device according to the related art, together with the relationship between a sewage treatment tank to be installed and associated equipment.

[Explanation of symbols]

 A Sewage treatment tank D Sludge scraping mechanism E Scum sweeping mechanism S Ultrasonic sensor T Cable 11 Root side guide section 12 Tip side guide section 13 Elevating section 13e Cable winding drum

Claims (6)

[Claims] A guide portion for projecting from the inner wall surface of the liquid processing tank into the processing tank and obliquely downward to define a movement path of the sensor, and holding the sensor in the liquid at a tip portion of the guide portion. A sensor holding device in a liquid processing tank, comprising: a sensor holding unit configured to move the sensor along the guide portion of the sensor holding unit. 2. The liquid is sewage treated in a sewage treatment tank having an upper scum sweeping mechanism and a lower sludge sweeping mechanism, and a tip of the guide portion is connected to the upper sweeping mechanism and the lower sludge sweeping mechanism. A sensor holding device in a liquid processing tank, which is arranged at an intermediate position with a scraping mechanism. 3. A sensor holding device in a liquid processing tank according to claim 1, wherein said lifting means includes winding means for winding a cable drawn from said sensor by an electric motor. 4. The sensor according to claim 1, wherein the sensor transmits an ultrasonic wave into a lower liquid to receive a reflected wave from a lower interface, and the sensor transmits the ultrasonic wave to the lower liquid based on a time from transmission to reception. A sensor holding device in a liquid processing tank, which is an ultrasonic sensor of an ultrasonic interferometer for measuring the depth of a liquid. 5. The sensor according to claim 1, wherein the sensor transmits an ultrasonic wave into a lower liquid to receive a reflected wave from the vicinity of a lower interface, and a magnitude of a reception level of the reflected wave. A sensor holding device in a liquid processing tank, which is an ultrasonic sensor of an ultrasonic densitometer for measuring the concentration in the vicinity of the interface. 6. The optical sensor according to claim 1, wherein the sensor is an optical sensor including a pair of a light emitting element and a light receiving element arranged opposite to each other, and detecting the transparency of the liquid from the propagation loss of the light wave. A sensor holding device in a liquid processing tank.