JPH091176A - Magnetic separation device for activated sludge - Google Patents

Abstract

(57) [Abstract] [Purpose] It is intended to provide a rotation speed control type activated magnetic sludge magnetic separation device capable of performing optimum magnetic adsorption / separation control regardless of fluctuations in the treatment flow rate. [Structure] A part of a rotary drum 3 having a magnet is made to face and rotate in a flow path 1 in which an activated sludge liquid A to which magnetic powder is added flows, and the activated sludge B is magnetically adsorbed by the magnet to activate the activated sludge B. In the apparatus for magnetic separation of activated sludge B for separating and recovering into activated water and treated water C, a curved flow path 1a is formed at the lower part of the rotating drum 3 to cover the outer circumference and the side surface of the lower part of the rotating drum 3, and the rotation thereof. On the outer circumference of the drum 3, the flow path 1
Is provided with a brim-shaped magnetic attraction member 7 for partitioning the right and left sides in the flow direction, and a scraping member 8 for removing the activated sludge B adsorbed by the magnetic attraction member 7 is provided above the rotary drum 3.
A flow rate sensor 41 for detecting the flow rate of the activated sludge liquid A flowing in the flow path 1 on the upstream side of the curved flow path 1a is provided, and the detection value of the flow rate sensor 41 is input, and the peripheral speed and flow of the magnetic adsorption member 7 are input. A rotation speed automatic control device 43 for controlling the rotation of the rotary drum 3 so that the flow velocity of the activated sludge liquid A in the passage 1 becomes the same.
It is characterized by having provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an activated sludge magnetic separator for separating and recovering activated sludge from an activated sludge liquid by using magnetic force.

[0002]

2. Description of the Related Art Conventionally, as a method of separating activated sludge liquid such as sewage into activated sludge and treated water, as disclosed in JP-A-48-42570, instead of natural sedimentation, A method has been proposed in which magnetic powder is added and mixed into the activated sludge liquid and passed through a magnetic field to agglomerate the activated sludge to promote solid-liquid separation of the activated sludge liquid.

However, since this method is also a solid-liquid separation method based on natural sedimentation, there are disadvantages that a vast precipitation separation layer is required, continuous treatment is not possible, and solid-liquid separation takes time. have. Therefore, in Japanese Patent Publication No. 63-59759, as shown in FIG. 9, the activated sludge liquid A containing the magnetic powder is extracted from the aeration tank b to the separation tank c by the slurry pump a or the like, and is rotated in the separation tank c. The magnetic separation roller f provided with the magnet e around the roller d magnetically adsorbs the activated sludge B containing the magnetic powder in the activated sludge liquid A to positively perform solid-liquid separation, and the activity separated by the scraper g. An activated sludge separation device has been proposed in which the sludge B is returned to the inside of the aeration tank b again.

[0004]

By the way, as shown in the figure, in this activated sludge separation device, a magnetic separation roller f for adsorbing and separating the activated sludge B is installed in a box-shaped separation tank c having a flat bottom. A part of the activated sludge liquid A is immersed in the flowing activated sludge liquid A. Therefore, there is a region where the magnetic force from the magnetic separation roller f does not act on the activated sludge B in the separation tank c, so that it is difficult to efficiently adsorb and separate the activated sludge B in the separation tank c.

Therefore, the present applicant has filed Japanese Patent Application No. 6-25057.
No. 0 (Invention name: Activated sludge magnetic separator)
"A part of the rotating drum with a magnet is faced and rotated in the flow path of the activated sludge liquid containing magnetic powder,
In a magnetic separator for activated sludge for magnetically adsorbing activated sludge with the magnet to separate and recover activated sludge and treated water, a curved flow that covers the lower outer periphery and side surface of the rotating drum in the lower part of the rotating drum. A path is formed, and a brim-shaped magnetic adsorption member that divides the flow path into left and right sides is provided on the outer periphery of the rotary drum, and at the top of the rotary drum, the activated sludge adsorbed by the magnetic adsorption member is removed. A magnetic separation device for activated sludge, comprising a scraping member. Was proposed. According to this device, the magnetic force acts evenly in the curved flow path, and good magnetic adsorption / separation can be performed.

However, in the water treatment using this magnetic separator, there is a problem that the fluctuation of the treatment flow rate greatly deteriorates the separation performance.

Therefore, an object of the present invention is to provide a rotational speed control type activated sludge magnetic separation apparatus which can perform optimum magnetic adsorption / separation control regardless of fluctuations in the treatment flow rate.

[0008]

In order to achieve the above object, the invention of claim 1 is such that a part of a rotary drum having a magnet is faced with a flow path of an activated sludge liquid to which magnetic powder is added and the rotary drum is rotated. Then, in the activated sludge magnetic separation device for magnetically adsorbing the activated sludge with the magnet to separate and recover the activated sludge and the treated water, the lower outer periphery and the side surface of the lower rotating drum are attached to the lower portion of the rotating drum. Forming a curved flow path to cover,
A brim-shaped magnetic attraction member is provided on the outer circumference of the rotary drum to partition the flow passage into left and right directions, and a scraping member for removing the activated sludge adsorbed by the magnetic attraction member is provided above the rotary drum. Providing a flow rate sensor for detecting the flow rate of the activated sludge liquid flowing in the flow path on the upstream side of the curved flow path,
A detection value of the flow rate sensor is input, and an automatic rotation number control device is provided to control the rotation of the rotating drum so that the peripheral speed of the magnetic adsorption member and the flow velocity of the activated sludge liquid in the flow path become the same. is there.

According to the second aspect of the present invention, an activated sludge sensor for detecting activated sludge in the treated water is provided on the downstream side of the curved flow path, and the rotation speed automatic detection is performed based on the detection value of the activated sludge sensor. The control unit controls the maximum number of rotations of the rotary drum.

[0010]

According to the present invention having the above-mentioned structure, the magnetic force of the magnetic adsorption member for partitioning the flow path is surely applied to the activated sludge liquid by flowing the activated sludge liquid containing the magnetic powder in the flow path. Therefore, the activated sludge is effectively adsorbed on the magnetic adsorption member,
The scraping member continuously separates and collects from the magnetic attraction member.

In this magnetic adsorption / separation, the flow path has
The flow rate sensor detects the flow rate of the activated sludge liquid flowing in the curved flow path, and the rotational speed of the rotary drum is controlled so that the flow velocity of the activated sludge liquid and the peripheral speed of the magnetic adsorption member are the same, thereby making the magnetic adsorption member The flow of the activated sludge in the flow path that is adsorbed by the is not disturbed, and the adsorption by the magnetic force of the magnetic adsorption member can be effectively performed. Further, the activated sludge sensor detects the residual activated sludge in the treated water and appropriately controls the rotation of the rotary drum, so that it is possible to operate at almost the maximum treatment capacity.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

First, the outline of the magnetic separation device will be described with reference to FIG.

FIG. 8 shows an example of a conventional sewage treatment process, and this sewage treatment process 11 is mainly composed of a water treatment system 12 and a sludge treatment system 13.

In the water treatment system 12, the sewage pumped by the pump 14 passes through a sand basin 15, a settling basin 16, an aeration tank (aeration tank) 17 and a magnetic separator 18,
It is recycled through the tertiary treatment facility 19 or discharged through the sterilization layer 21. In the aeration tank 17, the sludge liquid reacts with microorganisms to be organically decomposed, and aeration air is sent from the aeration blower 22 to further accelerate the decomposition. Further, magnetic powder is added and mixed in the aeration tank 17 in order to facilitate solid-liquid separation of the activated sludge liquid. The excess sludge discharged from the settling tank 16 and the magnetic separation device 18 via the pump 23 is the sludge treatment system 13.
In order to carry out sludge treatment, the sludge treatment system 13 includes a sludge concentrator 24, a sludge centrifugal concentrator 25, and a sludge digestion tank 2.
6, a gas holder 27, a belt press 28, a centrifugal dehydrator 29, a sludge incinerator 31 and the like are installed.

The magnetic separator 18 is disclosed in Japanese Patent Application No. 6-250.
The device proposed in No. 570 will be described with reference to FIGS.

FIG. 2 is a partially cutaway side view showing the magnetic separation device 18 of this prior application, FIG. 3 is its plan view, and FIG. 4 is D- in FIG.
It is a D line arrow line view.

As shown, this magnetic separation device 18
The rotating drum body 3 is rotatably supported by the frame body 2 in which the flow path 1 through which the activated sludge liquid A flows is formed.
A drive motor 6 is attached to the rotary shaft 4 via a coupling 5.
Are connected, and the rotary drum body 3 is driven to rotate clockwise in FIG. In addition, the flow path 1 is formed in a gutter-like shape and has a U-shaped cross section. Further, a curved flow curved in a concentric arc shape along the outer periphery of the rotary drum body 3 in a portion facing the rotary drum body 3. The path 1a is formed. Further, a flange-shaped magnetic attraction member 7 protruding outward in the radial direction of the rotary drum body 3 is formed at the center of the outer circumference of the rotary drum body 3, and as shown in FIG. The activated sludge B in the activated sludge liquid A flowing through the curved flow path 1a is adsorbed on both sides thereof.

The magnetic attraction member 7 is a collar portion 7b formed integrally with the rotary drum 3 by injection molding with a thermoplastic resin or the like.
As shown in FIG. 1, for example, a cylindrical magnet body 7a is arranged in the circumferential direction of the rotary drum body 3, and as shown in FIG. 4, each magnetic pole (NS pole) is a side surface of the rotary drum body 3, that is, The magnetic poles are continuously arranged so as to be positioned on the curved flow paths 1a, 1a, and the magnetic force is exerted effectively by allowing the magnetic pole portions having the strongest magnetic force to face the curved flow paths 1a, 1a. It is like this.

Further, a pair of scraping members 8, 8 are provided on the upper part of the rotary drum 3 so as to sandwich the magnetic attraction member 7 from the left and right. As shown in the drawing, the scraping members 8 and 8 are gutter-shaped members formed in a U-shaped cross section and fixed to the frame body 2 by inclining them, and the activated sludge B adsorbed to the magnetic adsorption member 7 is removed. It is scraped and returned to the aeration tank 17 side.

The magnetic separation by the magnetic separation device 18 will be described.

As shown in FIGS. 2 and 3, the activated sludge liquid A
Is flowed through the flow path 1 and then flows toward the curved flow path 1a. In the curved flow path 1a, the magnetic adsorption member 7 faces along the curved flow path 1a, and the activated sludge B in the activated sludge liquid A is attracted to the magnet body 7a of the magnetic adsorption member 7, as shown in FIGS. As shown in FIG. 5, it is separated and adsorbed from the activated sludge liquid A. At this time, since the rotary drum 3 is driven to rotate clockwise in the figure, the activated sludge B adsorbed on the magnetic adsorption member 7 is separated from the activated sludge liquid A by the rotation of the rotary drum 3.

The activated sludge liquid A from which the activated sludge B has been separated becomes treated water C, and the activated sludge B adsorbed on one of the magnetic adsorption members 7 is brought into contact with both sides of the magnetic adsorption member 7. The scraping members 8, 8 are continuously scraped from the magnetic attraction member 7.

Next, examples of the present invention will be described in detail.

FIG. 1 shows an embodiment of the present invention. FIG. 1 (A) is a schematic view and FIG. 1 (B) is FIG.
FIG. 1C is a view taken along the line EE in FIG.
FIG. 1D is a view taken along the line FF in FIG.
The GG line arrow line view in (C) is shown.

In FIG. 1 (A), a flow rate sensor 41 for detecting the flow rate of the activated sludge liquid A is provided at the inlet of the flow passage 1 before and after the curved flow passage 1a covering the lower portion of the rotary drum 3 having the magnetic attraction member 7. And an activated sludge sensor 42 for detecting residual activated sludge (or magnetic powder) in the treated water C is disposed at the outlet.

The rotary drum 3 is driven by a rotary shaft 4 through a drive motor.
The rotary motor 6 is connected to the motor 6 and is rotated by the drive motor 6 in the same direction as the flow of the activated sludge liquid A as shown by the arrow in the figure. The speed is controlled to be variable.

The detection value of the activated sludge sensor 42 is input to the rotation speed automatic control device 43 so that the maximum rotation speed of the rotary drum 3 is controlled.

The flow rate of the activated sludge liquid A flowing into the channel 1 is detected by the flow rate sensor 41 arranged at the inlet of the channel 1. The detected data is fed forward to the rotation speed automatic control device 43, and the rotation speed automatic control device 43 controls the drive motor 6, so that the peripheral speed of the magnetic adsorption member 7 is activated sludge. The flow rate of the liquid A is controlled to be the same.

The operation of this embodiment will be described.

The flow rate of the activated sludge liquid A depends on the time, weather,
Since there is a difference between the peripheral speed of the magnetic adsorbing member 7 and the flow velocity of the activated sludge liquid A due to variations depending on the season,
A vortex H is generated in the separation flow path 44 between the activated sludge liquid A and the magnetic adsorption member 7 shown in (B) and (C). This vortex H
For example, when the peripheral speed of the magnetic adsorption member 7 is faster than the flow velocity of the activated sludge liquid A, the activated sludge liquid A around the magnetic adsorption member 7 is
Since the magnetic attraction member 7 flows so as to be dragged by the rotation of the magnetic attraction member 7, the flow velocity of the activated sludge liquid A around the magnetic attraction member 7 becomes faster than the flow velocity in the central portion of the separation flow channel 44, and the flow direction of the separation flow channel 44 is left and right. , It occurs because of the difference in the flow velocity.

As shown in FIG. 1 (D), the vortex H generated in this manner not only worsens the magnetic adsorption of the activated sludge B by the magnetic adsorption member 7, but also the activated sludge B magnetically adsorbed.
Is separated from the magnetic adsorption member 7 and the activated sludge B is caused to flow into the treated water C.

Therefore, in this embodiment, the flow rate sensor 41 detects the flow rate and inputs it to the rotation speed automatic control device 43. The rotation speed automatic control device 43 calculates the flow velocity of the activated sludge liquid A flowing in the curved channel 1a from the flow rate of the activated sludge liquid A,
By controlling the number of rotations of the rotary drum 3 so that this flow velocity and the peripheral speed of the magnetic adsorption member 7 are the same, the generation of the vortex H in the separation flow path 44 is prevented, and the activated sludge of the magnetic separation device is thereby prevented. The magnetic adsorption efficiency of B is increased, and the outflow of activated sludge B can be reduced.

The treated water C from which the activated sludge B has been removed is shown in FIG.
It is recycled through the tertiary treatment equipment 19 shown in FIG.

Further, instead of controlling the flow rate sensor 41,
The rotation speed of the rotary drum 3 may be controlled by the feedback of the activated sludge sensor 42. In this case, the rotation speed of the drive motor 6 is controlled by the rotation speed automatic control device 43 so that the amount of residual activated sludge in the treated water C detected by the activated sludge sensor 42 is reduced.

Further, instead of controlling both sensors 41 and 42 independently, both sensors 41 and 42 may be controlled simultaneously.

That is, the flow rate sensor 41 detects the flow rate of the activated sludge liquid A and controls the rotational speed of the rotary drum 3 so that the peripheral speed of the magnetic adsorption member 7 becomes the same as the flow velocity of the activated sludge liquid A. When the flow rate increases, the amount of residual activated sludge is detected by the activated sludge sensor 42 in addition to the detection by the flow rate sensor 41, and the detected data is the rotation speed automatic control device 4
Feed back to 3. By controlling the maximum rotation speed of the drive motor 6 by the rotation speed automatic control device 43, the flow velocity and the peripheral speed of the magnetic adsorption member 7 become the same while flowing the activated sludge liquid A at an appropriate flow rate. Allows optimum control.

Next, another embodiment of the present invention will be described.

FIG. 6 shows a modified example of the rotary drum 3 of FIG.

In FIG. 5, the magnet body 7a is arranged in the circumferential direction of the collar portion 7b of the rotary drum 3 and its magnetic poles (NS).
Is the side surface of the magnetic attraction member 7, that is, the curved flow path 1
Although the magnetic attraction members 7 are arranged by being continuously arranged so as to be located on the sides a and 1a, in the present example, the magnetic attraction members 7 in the rotary drum 3 are formed of thin discs as shown in FIG. A disk 40 is formed by inserting the drum plate 50, which is also formed of a thin disk, on both sides so that the disk 40 is sandwiched between the rotary drum 3 and the magnetic attraction member 7. .

As described above, by independently forming the magnetic attraction members 7 in the rotary drum 3, the structure of the device is simplified, and when a plurality of disks 40 are arranged in parallel to the left and right in the flow direction of the flow path 1. The device can be easily formed.

FIG. 7 shows a further modified example of FIG.
An example in which the rotating drum 3 is configured by providing the disks 40 and the drum plates 50 in multiple stages is shown.

In this example, when the number of magnetic attraction members 7 formed on the disk 40 is plural and arranged in parallel to the left and right in the flow direction of the flow path 1, the activated sludge liquid per unit area of the magnetic attraction members 7 is formed. Since the volume of A becomes smaller, the removal efficiency of activated sludge B becomes better, and the cross-sectional area of the flow path can be made larger, so that the amount of activated sludge treated can be increased.

When a plurality of magnetic attraction members 7 are arranged in parallel to the left and right in the flow direction of the flow path 1, if the magnetic attraction members 7 of the rotary drum 3 are formed separately, as shown in FIG. -Since the mutual relationship with the drum 50 is a structure in which the disc 40 is sandwiched between the drum plates 50, that is, a sandwich-like structure,
Compared with integrally forming the rotary drum 3 and the magnetic attraction member 7, the configuration of the device is simpler and the magnetic attraction members 7 can be easily made plural.

Further, when a plurality of disks 40 are arranged in parallel to the left and right in the flow direction of the flow path 1, as shown in FIG. 7, the magnetic poles M are curved by arranging the same magnetic poles of the magnet body 7a so as to face each other. The activated sludge B can be effectively magnetically adsorbed because the magnetic field extends over the entire curved channel 1a and reaches the entire channel 1a.

In the above-described embodiment, the rotary drum 3 having one or two magnetic attraction members 7 has been described as an example. However, as shown in FIG. By disposing a large number or providing two or more in one flow path along the flow direction, it is possible to greatly increase the sludge separation treatment capacity in a short time.

[0047]

In summary, according to the present invention, Japanese Patent Application No.
-250570, by arranging a flow rate sensor and an activated sludge sensor in the flow passages before and after the curved flow passage covering the lower part of the rotating drum of the magnetic separation device, the flow rate sensor first detects the flow rate flowing in the curved flow passage. By controlling the rotary drum so that the flow velocity of the activated sludge liquid and the peripheral speed of the magnetic adsorption member are the same, the flow of the activated sludge in the flow passage adsorbed by the magnetic adsorption member is not disturbed, The magnetic attraction of the magnetic attraction member can be effectively performed. Further, the activated sludge sensor can detect the residual activated sludge in the treated water and appropriately control the rotation of the rotary drum, thereby exhibiting an excellent effect that it can be operated at almost the maximum treatment capacity. .

[Brief description of the drawings]

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

FIG. 2 is a partially cutaway side view showing an embodiment of a magnetic separation device.

FIG. 3 is a plan view showing an embodiment of a magnetic separation device.

FIG. 4 is a view taken along the line DD in FIG.

5 is a partially enlarged view of FIG.

FIG. 6 is a view showing an example in which the rotary drum of FIG. 5 is modified.

FIG. 7 is a diagram showing a modified example of the embodiment of FIG.

FIG. 8 is a bird's-eye view showing an example of a sewage treatment process.

FIG. 9 is an explanatory diagram showing a conventional magnetic separation device.

[Explanation of symbols]

 1 flow path 1a curved flow path 3 rotating drum 7 magnetic adsorption member 8 scraping member 41 flow rate sensor 42 activated sludge sensor 43 rotation speed automatic control device A activated sludge liquid B activated sludge C treated water

Claims (2)

[Claims] 1. A part of a rotary drum having a magnet is made to face and rotate in a flow path in which an activated sludge liquid added with magnetic powder flows, and the activated sludge is magnetically adsorbed by the magnet to activate the activated sludge and the treated water. In the apparatus for magnetic separation of activated sludge for separating and recovering into and from, a curved flow path is formed in the lower part of the rotary drum to cover the lower outer circumference and side surfaces of the rotary drum, and the flow path is formed on the outer circumference of the rotary drum. Is provided with a brim-shaped magnetic attraction member for partitioning the flow direction into the left and right sides, and a scraping member for removing activated sludge adsorbed by the magnetic attraction member is provided above the rotary drum, and the flow on the upstream side of the curved flow path is provided. A flow rate sensor for detecting the flow rate of the activated sludge liquid flowing through the passage is provided, and the detected value of the flow sensor is input, and the rotation is performed so that the peripheral speed of the magnetic adsorption member and the flow velocity of the activated sludge liquid in the flow passage become the same. Control the rotation of the drum A magnetic separator for activated sludge, characterized by being equipped with an automatic rotation speed control device. 2. An activated sludge sensor for detecting activated sludge in the treated water is provided on the downstream side of the curved flow path, and the above-mentioned automatic rotation speed controller in the rotational speed automatic control device is based on a detection value of the activated sludge sensor. The activated sludge magnetic separator according to claim 1, wherein the maximum number of revolutions of the rotating drum is controlled.