JP2603883Y2 - Drum screen type filtration device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filtration device for separating and removing solids such as fibers from raw water to be treated, and more particularly to a filtration device provided with a cylindrical drum screen.

[0002]

2. Description of the Related Art Conventionally, this type of drum screen type filtration apparatus has been used in a filtration step at a stage prior to biological treatment of domestic wastewater or the like, which is schematically shown in FIGS. 5 and 6. It is. In these figures, reference numeral 1 denotes a drum screen.
Is a cylindrical screen formed by arranging a large number of metal wires having a triangular cross section called a wedge wire close to each other, and by inclining the wedge wire with respect to the axial direction. , A bias angle for generating an advancing force in the axial direction when the solid content rolls is set. The drum screen 1 is arranged inside the casing 2 so that its central axis is substantially horizontal, and is held so as to rotate about its central axis. A tapered portion 3 having a small diameter at the distal end is provided at an end portion in a direction in which the solid is advanced, and a screw blade 4 for advancing the solid content is provided on the inner surface thereof. Further, a raw water supply pipe 5 is inserted into the inside of the drum screen 1, and raw water to be treated is supplied from the raw water supply pipe 5 to the inner surface of the drum screen 1 via a supply dam 6. .

Accordingly, when the raw water to be treated is supplied toward the inner surface of the drum screen 1 while rotating the drum screen 1 in the direction of the arrow in FIG. 6, a solid content that does not pass through the screen remains in the inside, and the liquid content mainly flows through the drum screen 1. It penetrates and flows down below. The solid matter 7 remaining inside the drum screen 1 is thus lifted to some extent by the rotation of the drum screen 1 and frictionally rolls along the inner surface of the drum screen 1 while maintaining a predetermined height position. As a result, the solids 7 gradually grow in a snow dalma manner by attaching new solids to the outer periphery thereof, and at the same time, are advanced inside the drum screen 1 by the bias angle of the screen. The solid matter 7 thus grown is discharged to the outside from the open end of the tapered portion 3 by the screw blade 4 formed on the inner surface of the tapered portion 3.

[0004]

In the above-mentioned drum screen type filtration device, clogging occurs similarly to a general filtration device. Therefore, washing is performed by injecting washing water from the outer surface side. If the operation is continued, clogging cannot be eliminated by cleaning by injecting the cleaning water. When such a situation is reached, in the above-mentioned conventional drum screen type filtration device, the raw water to be treated gradually accumulates at the bottom of the drum screen 1, which reaches the tapered portion 3 and increases the amount of water in the solid 7. Or let me
Alternatively, there is a disadvantage that the growth of the solid content 7 is inhibited.

In order to solve such inconvenience, it is conceivable to open the other end of the drum screen 1 completely, but in this case, the raw water to be treated flows outside without being treated. In addition, there is a possibility that a part of the solid content 7 may fall to the outside from the opened end.
Therefore, it is conceivable to further provide a weir at the cylindrical opening of the drum screen 1 so as to protrude inward. However, in such a configuration, when clogging of the drum screen 1 occurs, the raw water to be treated is accumulated inside the drum screen 1 up to the height of the weir, and therefore, the same inconvenience as described above occurs. Since the supply of the raw water to be treated must be stopped before passing over the weir, the clogging state of the drum screen 1 must be constantly monitored, or the supply of the raw water to be treated must be controlled in accordance with the clogged state. There is.

The present invention has been made in view of the above circumstances, and provides a drum screen type filtration device capable of preventing inconveniences such as an increase in the amount of water in solids due to clogging of the drum screen. The purpose is to do so.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides a drum screen having a center axis which is provided with a bias angle which applies a bias angle to a solid component rolling on an inner surface in an axial direction. Are arranged so as to be substantially horizontal and rotate about the center axis thereof, and a tapered portion having a smaller inner diameter at the distal end side is provided at an end in a direction in which the solid content is advanced by the screen mesh, and the tapered portion is provided. In a drum screen type filtration device provided with a screw blade for feeding solid matter to the inner surface of the drum screen, the other end of the drum screen is opened in a cylindrical shape, and the drum screen is provided at the end thereof at the front side in the rotation direction. A plurality of protective walls inclined with respect to the axial direction so as to be separated from the end of the It is characterized in that the raw water receiving for flowing the treated raw water overflowing below the portion where is provided the Mamorukabe from the end of the drum screen is provided.

In the present invention, a washing port for injecting the raw water to be treated from the side opposite to the raw water receiver to the protective wall can be provided.

Further, according to the present invention, the cleaning nozzle in which the injection pipe of the cleaning liquid and the injection pipe of the pressurized gas are loosely fitted concentrically can be arranged on the outer peripheral side of the drum screen toward the center thereof. .

[0010]

Therefore, in the filtering device of the present invention, since the other end of the drum screen is opened in a cylindrical shape, when clogging occurs, the raw water to be treated supplied to the inside of the drum screen is From this end, it flows out to the raw water receiver and is returned to the raw water tank. In addition, a plurality of protective walls are provided at regular intervals at the opened end, and the protective wall is arranged in a direction opposite to the open end of the solid content inside the drum screen as the drum screen rotates. Since it is provided inclined with respect to the axial direction so as to press,
Solids are prevented from dropping from here to the outside.

[0011] Further, by spraying raw water to be treated and cleaning water from the cleaning port to the protective wall, sediment adhering to the protective wall is removed by the raw water to be treated. Returned to a predetermined location.

Further, the liquid screen and the pressurized gas are jetted from each of the concentrically loosely inserted jet pipes provided on the outer periphery of the drum screen, whereby the drum screen is washed.
In this case, since the liquid is granulated and accelerated by the pressurized gas, it is possible to efficiently clean the liquid.

[0013]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing one embodiment of the present invention. The filtration device shown here is configured to separate a solid content from raw water to be treated by rotating a drum screen 10 in a so-called horizontal manner. ing. That is, the drum screen 10 is formed in a cylindrical shape as a whole by arranging wedge wires in parallel with each other at regular intervals, similarly to the conventional apparatus described with reference to FIGS. 5 and 6. A predetermined bias angle is set so that the wedge wire is inclined with respect to the axial direction of the cylindrical body, thereby giving an axial driving force to the solid content rolling on the inner surface of the drum screen 10. .

The drum screen 10 is held in a cylindrical shape by attaching annular frames 11 to both ends in the axial direction thereof.
, A ring-shaped support rail 12 is fixed. A plurality of rail receiving plates 13 are fixed at regular intervals over the entire inner periphery of the frame 11 on the opposite side, and a ring is connected so as to connect the distal ends of these rail receiving plates 13. The support rail 14 is fixed. The drum screen 10 connects these support rails 12 and 14 to each other.
The pair of rollers 15 on the rear end side (the right side in FIG. 1) are supported substantially horizontally by being placed on the support rollers 15 provided one by one in the front and the rear, respectively.
By driving through the center 7, it is configured to rotate around a central axis. FIG. 2 schematically shows these drive mechanisms.

Each of the rail receiving plates 13 is bent into the shape shown in FIG. In other words, the portion fixed vertically to the frame 11 is such that the tip side in the rotation direction (the direction of the arrow in FIG. 3) of the drum screen 10 gradually moves away from the end of the drum screen 10. This portion is inclined with respect to the axial direction, and this portion serves as a solid content falling protection wall 18. The portion following this extends in the axial direction of the drum screen 10, and this portion serves as a rail receiving arm 19, and the support rail 14 is fixed to the tip of the rail receiving arm 19. Therefore, the rear end portion (right end portion in FIG. 1) of the drum screen 10 is opened in a cylindrical shape, and an overflow port 20 is formed between the respective rail receiving plates 13.

A raw water receiver 21 through which the raw water to be processed overflows from the drum screen 10 is disposed below the overflow port 20, and a return pipe 22 is connected to the raw water receiver 21. A filtrate receiver 23 is disposed below the drum screen 10.
A filtrate tube 24 is connected to the filtrate receiver 23.

Further, the tip of the drum screen 10 (FIG. 1)
5 is connected to a tapered portion 25 having a gradually decreasing diameter on the distal end side, as in the conventional drum screen described with reference to FIGS. 5 and 6. Screw blade 26 is attached. The distal end of the tapered portion 25 is open, and a drop port 27 is arranged below this open end.

A raw water supply pipe 28 is arranged along the center axis of the drum screen 10 and the tapered portion 25, and the tip on the tapered portion 25 side is closed and fixed to the casing 29. An input pipe 30 is connected to the end of the feed pipe 30 for drawing and supplying raw water to be treated from a raw water tank (not shown). This raw water supply pipe 2
A portion of the drum 8 located inside the drum screen 10 is opened upward over a predetermined length, and a supply dam 31 is connected to the opening. This supply dam 31
Is a container that is opened upward, as in the prior art, and has an upper end portion on which the raw water that has overflowed is filled with the inner surface of the drum screen 10, more specifically, downward as the drum screen 10 rotates. A guide plate 32 that supplies the inner surface of the moving portion is connected.

A small-diameter branch pipe 33 is connected to the base end (right end in FIG. 1) of the raw water supply pipe 28, and a shutter 34 is interposed in the middle of the branch pipe 33. The branch pipe 33 extends to a position facing the raw water receiver 21 with the rail receiving plate 13 interposed therebetween. A lever 35 for opening and closing the shutter 34 is projected outside the casing 29. That is, by opening the shutter 34, the raw water to be treated and the washing water are poured on the rail receiving plate 13 to remove deposits attached to the rail receiving plate 13.

Further, a wiper 36 fixed to the tapered portion 25 is disposed close to a portion of the outer peripheral portion of the raw water supply pipe 28 which is closer to the distal end than the supply dam 31, and the wiper 36 is connected to the raw water supply pipe. By rotating along the outer peripheral surface of the pipe 28, the deposits attached to the raw water supply pipe 28 are removed.

On the outer peripheral side of the drum screen 10, a plurality of cleaning nozzles 37 for spraying cleaning water toward the outer peripheral surface of the drum screen 10 are arranged. The cleaning nobal 37 is for forming mist of cleaning water and spraying the mist onto the drum screen 10. As shown in FIG. 4, a water nozzle 39 connected to a water supply pipe 38 and an air nozzle 41 connected to an air supply pipe 40 are formed. They are arranged concentrically in a loose fit so that water is mist-formed by pressurized air and the injection speed is increased.

Next, the operation of the above-described device will be described. The motor 16 is started to move the drum screen 10 as shown in FIG.
When the raw water is supplied to the raw water supply pipe 28 while being rotated in the direction of the arrow, the raw water that has overflowed from the supply dam 31 is supplied toward the inner surface of the drum screen 10 via the guide plate 32. As a result, a solid content larger than that of the screen remains on the inner surface of the drum screen 10, and the liquid content mainly passes through the dorascreen 10 and flows from the filtrate receiver 23 to the filtrate tube 24, thereby performing solid-liquid separation.

The solid matter remaining inside the drum screen 10 is lifted in the rotation direction of the drum screen 10 due to the viscosity of the drum screen 10 due to the rotation of the drum screen 10, but after being lifted to some extent, the weight of the drum screen 10 is reduced by its own weight. It rolls and falls along the inner surface of 10. That is, the solid content continues to roll at a position slightly higher than the lowermost portion of the drum screen 10, and such an operation causes the solid content to further adhere to the outer periphery and gradually increase. In addition, since the screen is provided with a bias angle at the time of such rolling, it receives an axial driving force, so that the solid content grows and advances in the axial direction. And, in the tapered portion 25, the screw blade 2
The solids are conveyed by 6 and discharged to the drop port 27.

On the other hand, the rear end of the drum screen 10 has a cylindrical opening, and since the drop-off protection wall 18 which is arranged at an inclination as described above is provided at this portion, the solid content Is pushed back toward the inside of the drum screen 10 by the falling-off protection wall 18, so that solid matter separated and removed from the raw water to be treated is not discharged from the rear end of the drum screen 10.

During the filtration as described above,
Alternatively, when water is intermittently supplied from the water supply pipe 38 to the cleaning nozzle 37 after a certain period of time, and pressurized air is supplied from the air supply pipe 40 to the cleaning nozzle 37, the solid matter clogged in the screen becomes mist. Removed by
The washing water is discharged from the filtrate receiver 23 to the filtrate tube 24. Even if such a washing operation is performed, the drum screen 1
In some cases, the amount of the raw water to be treated becomes excessive with respect to the amount of filtration, but the rear end of the drum screen 10 is opened in a cylindrical shape. Since the overflow port 20 is formed, excess raw water to be treated is discharged from the overflow port 20 to the raw water receiver 21, from which the raw water is sent through a return pipe 22 to a predetermined location, for example, a raw water tank. Therefore, since the raw water to be treated does not accumulate inside the drum screen 10, it is possible to prevent a situation in which the water of the raw water to be treated permeates into the separated solid content and the drainage is deteriorated.

Since the raw water that overflows may come into contact with the rail receiving plate 13 that defines the overflow port 20, deposits may be generated on the rail receiving plate 13. Lever 3
5, the raw water to be treated and the washing water are supplied to the branch pipe 3
3, the sediment on the rail receiving plate 13 is removed by the raw water to be treated. That is, blockage of the overflow port 20 can be prevented.

On the other hand, as the drum screen 10 rotates, the wiper 3 connected to the inner surface of the tapered portion 25
Since the pipe 6 rotates along the outer periphery of the raw water supply pipe 28, the deposit attached to the raw water supply pipe 28 can be removed by the wiper 36.

Note that the present invention is not limited to the above-described embodiment, and the present invention can be applied to a filtering device in which a drum screen is constituted by members other than wedge wires. The means for supplying the raw water to be treated into the inside of the drum screen may be means other than the supply dam described above. Further, as the supporting device and the driving device for the drum screen, a device other than the configuration shown in the above embodiment can be used.

[0029]

[Effect of the invention] As described above, according to the invention,
In the case where the drum screen is clogged because one end of the horizontally held drum screen is opened in a cylindrical shape, and at the opening end, protective walls inclined toward the inside of the drum screen are provided at regular intervals. In the present invention, the raw water to be treated is discharged to the outside of the drum screen from between the protective walls and sent to a predetermined location from a raw water receiver disposed below the raw water.
Because the raw water to be treated does not accumulate inside the drum screen, it is possible to prevent inconveniences such as the infiltration of water into the solids once separated and the drainage of the solids to be deteriorated, and the solids The protective wall can prevent the minute from falling from the opening. Further, even if the raw water to be treated is continuously supplied in a state where the drum screen is clogged, the raw water to be treated can be recovered through the raw water receiver from the opening end of the drum screen on the protection wall side. It is not essential to control the continuous monitoring of the clogging state and to promptly stop the supply of the raw water to be treated when the clogging occurs, so that the maintenance and management of the operation become easy.

By providing a washing port for spraying the raw water to be treated toward the protective wall, it is possible to easily and easily prevent the place where the raw water to be processed overflows from the inside of the drum screen from being clogged with the sediment. Can be.

Further, by using a nozzle having a configuration in which a liquid nozzle and a gas nozzle are loosely fitted concentrically as a nozzle for spraying a cleaning liquid toward the drum screen, the ability to remove deposits attached to the drum screen is enhanced. And
The clogging frequency of the drum screen can be suppressed lower than ever.

[Brief description of the drawings]

FIG. 1 is a vertical sectional front view showing an embodiment of the present invention.

FIG. 2 is a side view thereof.

FIG. 3 is a view showing a rail receiving plate.

FIG. 4 is a partially broken view showing a configuration of a cleaning nozzle.

FIG. 5 is a schematic front view of a conventional drum screen type filtration device.

FIG. 6 is a schematic side view thereof.

[Explanation of symbols]

10 ... Drum screen, 13 ... Rail receiving plate, 1
8: fall-off protection wall, 20: overflow port, 21 ...
Raw water receiver, 25 taper section, 26 screw blade, 28 raw water supply pipe, 33 branch pipe, 34 shutter, 37 cleaning nozzle, 39 water nozzle,
41 ... air nozzle.

Claims (3)

(57) [Scope of request for utility model registration] 1. A drum screen in which a bias angle for urging a solid content rolling on an inner surface in an axial direction to a screen is arranged so that a center axis thereof is substantially horizontal and rotates about the center axis. A drum screen type filtration provided with a tapered portion having a smaller inner diameter on the tip side at an end portion in a direction in which the solid content is advanced by the screen mesh, and a screw blade for feeding solid content on an inner surface of the tapered portion. In the apparatus, the other end of the drum screen is opened in a cylindrical shape, and the end of the drum screen is inclined with respect to the axial direction so as to be separated from the end of the drum screen on the front side in the rotation direction. Are provided at regular intervals in the circumferential direction, and the end of the drum screen is provided below the portion where the protective wall is provided. Drum Screen filtration apparatus characterized by raw water receiving for flowing the treated raw water overflowing is provided from. 2. The drum screen type filtering device according to claim 1, wherein a washing port for jetting the raw water to be treated is provided from a side opposite to the raw water receiver to the protection wall. 3. A cleaning nozzle in which a cleaning liquid injection pipe and a pressurized gas injection pipe are loosely fitted concentrically around an outer peripheral side of the drum screen toward the center thereof. The drum screen type filtration device according to claim 1.