JPS61204014A - Method and device for intaking supernatant water - Google Patents

Abstract

PURPOSE:To separate supernatant water effectively by installing a small type optical fiber photoelectric switch to a water collecting device moving vertically in accordance with variation of water level and controlling the water intaking operation by the electric signal emitted when the photosensing part contacts with sludge zone. CONSTITUTION:A pair of optical fiber 1, 2 is suspended from the bottom of a water collecting trough 6, and sensors 3, 4 are fixed at the top ends of the optical fibers. When water-intake is commenced by opening a treating water valve 15, the water collecting trough 6 sinks as the supernatant water decreases. When the sensors 3, 4 are thrusted into the sludge zone 19, light is shielded by dense sludge becoming nontransmissive. So the switch is turned OFF and the treating water valve 15 is closed, the water intake by the water collecting trough 6 is interrupted, and the sludge zone 19 is sucked up and elevating trough 6 is interrupted, and the sludge zone 19 is sucked up and elevated by the water intake preventing carrying over of the sludge.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is mainly concerned with batch-type sewage treatment, and also relates to cross-section treatment and solid-liquid separation operations.

[Conventional technology]

Conventionally, in coagulation and sedimentation treatment operations, ultrasonic devices have been used to measure the amount of sludge that settles and accumulates. In some cases, a photoelectric zone detector is installed to predict carryover.

Separately, in activated sludge treatment, in order to measure the distance from the water surface of the sedimentation tank to the surface of the settled sludge, it is a special practice to immerse the sensor of a dissolved oxygen meter under the water surface and measure the indicated concentration at each depth. It is described in Publication No. 58-8309.

[Problem that the invention seeks to solve]

As mentioned above, various methods have been proposed and implemented in order to determine the state of sludge in settling tanks, but the first problem is that the detection device itself is very expensive; They often cost up to 1.5 million yen, and the accuracy of the sensor is poor.For example, the ultrasonic method has poor sensitivity and lacks reliability when measuring sewage sludge (1%wt), and the light transmission method requires a light source lamp. Since the light-receiving part and other parts were submerged in water, the sensor was not only large in size, but also had to be completely watertight, making the structure complex, and despite the many ideas it had, its practical effects were poor.

Particularly in batch-type sewage treatment equipment, where aeration treatment and precipitated supernatant water intake after treatment are carried out in one tank, a sludge zone detection mechanism is absolutely necessary for the functionality of the equipment. There are many dissatisfaction with the above-mentioned detection devices in terms of scale and cost.

[Means for solving problems]

This invention aims to solve the above problems.

It is small, especially the sensor is extremely small.

In addition, it uses a transmission type optical fiber type photoelectric switch with a lens whose length and position can be adjusted arbitrarily. This device uses a red diode as the light source, a phototransistor as the light receiving part, and the light sink part is an optical fiber, so it does not require special watertightness, and even an amateur can use the fiber made of plastic. It also offers the convenience of being easily changeable. And the amplifier (
The light source, light receiver, amplification) and control unit are extremely small and are not subject to space or weight restrictions when mounted on a water collection device, and the distance between the light source and light receiver can be approximately 10 ai for models with lenses. Therefore, maintenance such as cleaning is easy.

In terms of cost, the objective can be achieved with costs ranging from 1130 to 115 that of the conventional device.

[Effect]

As shown in Fig. 1, an optical fiber 1 with a diameter of about inn
, 2 are placed facing each other at a distance of 70 m so that the light beam passing through one fiber 1 can be received by the other fiber 2 across a space.
...ON, non-transparent...OFF types were used to test the switching effect. First, it was transmitted through the atmosphere, and then the sensors 3 and 4 were submerged in water 5 of an aquarium.

Sludge concentration mg/Q Switching effect O
(Clear water) ON 665 (very turbid water) 0N820
0 F F1080
0 F F1430
0 F F14500 O
FF Normally, the suspended concentration of sludge in treated water (supernatant water) in the activated sludge treatment method is 50 mg/Q or less, and the suspended concentration in the sludge zone itself (sooo ~ 15000 mg/Q)
) can be clearly distinguished from the others, and it has been found that certainty can be obtained.

[Embodiment 1] As shown in FIG. 2, this is an example in which the water collection trough 6 is of a float type in a single batch sewage treatment apparatus. In other words, the water collection trough 6 has floating chambers 10 and 11 arranged unevenly at both ends of a long groove material 9 with an H-shaped cross section, in which the bottom surfaces of the groove materials 7 and 8 are arranged above and below, and a large number of floating chambers 10 and 11 are provided on both sides of the upper channel material 7. Water intake holes 12 are installed in a row,
A freely expandable serpentine discharge pipe 1 at the supernatant water discharge port 13 in the center
4 is connected, and a treated water valve 15 is provided at the point where this pipe 14 is drawn out of the tank. The sensors 3 and 4 at the tips are fixed facing each other so that their relative positions do not move. And optical fiber 1, 2
If a control unit 16 is installed above and connected to a power source (not shown), aeration is completed in the sewage treatment operation, and the activated sludge settles to the bottom of the tank 17.
Since a sludge zone 19 is generated below the supernatant water portion 18, the treated water valve 15 is opened at this point to start water intake. At this time, water entering from the water intake hole 12 of the water collection trough 6 is discharged through the discharge pipe 14, so the water collection trough 6 sinks due to the decrease in supernatant water, but the optical fiber 1
While the sensors 3 and 4 of ゜2 are still in the supernatant water section 18, the light beam is in a transmitted state, and as the water collection trough 6 continues to sink, the sections of the sensors 3 and 4 enter the sludge zone 19. The light rays are blocked by the presence of dense sludge,
Since the water is not permeable, the switch performs the FF operation and closes the treated water valve 15. As a result, water intake by the water collection trough 6 is stopped, and it is possible to prevent the sludge zone 19 from being sucked up by the water intake and rising, thereby preventing sludge from carrying over.

[Example 2] The water intake method in Example 1 uses a float-type water collection trough, but in this example, like the conventional snorkel water intake method, the treated water discharge pipe is used as an arm 20 mechanically. This is a case where the water collection trough 21 is raised and lowered. Motomo sensor 3, 4
The installation method is the same as in Embodiment 1, and when the sensor 3.4 enters the sludge zone 19, the power switch stops the movement of the arm 20 and mechanically fixes the position of the water collection trough 21. Then, water intake will be stopped. In this case, even if the water collection trough 21 stops above the water surface, the suspended sensors 3 and 4 can maintain a certain length so that the detection parts can be placed underwater, so that the attached sludge will not dry. Therefore, contamination of the transmission surface can be avoided.

[Embodiment 3] In this example, a water intake device 2 having a water collection hole 23 is constructed using a float 22.
4 floating on the surface of the supernatant water is the same as in Example 1, but the water intake pump 25 is directly connected to the water intake device 24 in this example, and the operation of this pump 25 raises the supernatant water to a high temperature. On the one hand, the sludge zone 19 is easily pulled up due to the suction action, so the sensor 3.4 is suspended and the pump operation is controlled while knowing the distance to this zone 19.

〔Effect of the invention〕

Since this invention is to be carried out like a savior,
The device is small and low-cost, and can be very easily integrated into the overall system.It also has good sensing accuracy, and can withstand changes in fiber processing capacity due to on-site conditions or seasonal changes in processing capacity. The length can be set to any desired length, and if the sensor becomes contaminated, it can be safely stopped and the sensor is suspended, so it can be easily pulled up and washed with fresh water. It is particularly effective for use in relatively small facilities.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an experimental mode of the method of this invention.
FIGS. 2 to 4 are schematic diagrams of each embodiment. In the figure, 1.2 optical fiber 3.4 sensor 6.21 water collection trough 16 control unit 17 tank 18 supernatant water portion 19 sludge zone. Patent applicant Suido Kiko Co., Ltd. Figure 1 Figure 3

Claims (2)

[Claims] (1) In a water intake method in which supernatant water above the settled sludge zone is collected using a water collection trough equipped with a supernatant water discharge pipe,
A small fiber-optic photoelectric switch is carried on a water collection device that moves up and down in response to water level fluctuations, and the electric signal generated when the photosensitive detection part of the suspended optical fiber comes into contact with the sludge zone allows water to be collected from the top of this zone. A supernatant water intake method characterized by controlling the water intake operation by sensing the distance from the trough. (2) A water collection trough equipped with a supernatant water discharge pipe is provided above the settled sludge zone, in which a water collection device that moves up and down in response to water level fluctuations and a photosensitive detection unit are suspended toward the sludge zone. A supernatant water intake device mainly consisting of a small fiber-type photoelectric switch that includes an optical fiber and is carried by the water collection device.