JPH079409U - Drum screen type filtration device - Google Patents

Abstract

(57) [Summary] [Purpose] When the drum screen is clogged, ensure solid and solid water separation. [Structure] The other end of the drum screen 10 having one end having a tapered portion 25 is opened in a cylindrical shape, and the drum screen 10 is provided at that end at the front side in the rotation direction.
A plurality of protective walls 18 inclined with respect to the axial direction so as to be separated from the end of the drum are provided at regular intervals in the circumferential direction, and the drum is provided below the place where the protective walls 18 are provided. A raw water receiver 21 into which raw water to be treated overflowed from the end of the screen 10 is provided. Therefore, the solid content is prevented from falling from the opening end by the protective wall 18, and the raw water to be treated is quickly discharged from the opening end to the raw water receiver 21 at the time of clogging.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 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 equipped with a cylindrical drum screen.

[0002]

[Prior art]

 Conventionally, this type of drum screen type filtration device has been used in a pre-stage filtration process for biological treatment of domestic wastewater and the like, and it is schematically shown in FIGS. 5 and 6. In these drawings, reference numeral 1 denotes a drum screen, and this drum screen 1 has, for example, a wedge screen formed by arranging a large number of metal wires having a triangular cross section close to each other and forming a cylindrical screen. In addition, by tilting the wedge wire with respect to the axial direction, a bias angle is set to generate a forward force in the axial direction when the solid component rolls. The drum screen 1 is arranged inside the casing 2 so that its central axis line is substantially horizontal, and is held so as to rotate about the central axis line. A taper portion 3 having a small diameter on the tip side is provided at the end portion in the direction of advancing the minute portion, 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 inside the drum screen 1, and the raw water to be treated is supplied from the raw water supply pipe 5 through a supply dam 6 toward the inner surface of the drum screen 1. There is.

Therefore, 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, the solid content that does not pass through the screen remains inside, and the liquid content mainly contains the liquid content. Permeate through and flow down. Thus, the solid content 7 remaining inside the drum screen 1 is 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 position of a predetermined height. As a result, the solid content 7 gradually grows in a snow darma type with new solid content attached to the outer periphery thereof, and at the same time, the interior of the drum screen 1 is advanced by the bias angle of the screen. The solid content 7 thus grown is discharged from the open end of the tapered portion 3 to the outside by the screw blades 4 formed on the inner surface of the tapered portion 3.

[0004]

[Problems to be solved by the device]

 Even in the above-mentioned drum screen type filtering device, as in the case of a general filtering device, clogging occurs, so cleaning water is sprayed from the outer surface side for cleaning, but if the operation is continued for a long time, cleaning water is sprayed. It becomes impossible to clear the clogging by cleaning by doing. When such a situation is reached, in the conventional drum screen type filtration device, the raw water to be treated gradually accumulates at the bottom of the drum screen 1, and this reaches the taper portion 3 to reduce the amount of water in the solid content 7. There is an inconvenience of increasing the amount or inhibiting the growth of the solid content 7.

In order to eliminate such an inconvenience, it is conceivable to completely open the other end of the drum screen 1, but in this case, the raw water to be treated flows to the outside as it is untreated. Not only will it end up, but part of the solid content 7 may fall outside from the open end. Therefore, it is possible to further provide a weir at the cylindrical opening of the drum screen 1 so as to project toward the inner peripheral side. However, in such a configuration, when the drum screen 1 is clogged, the raw water to be treated is stored in the drum screen 1 up to the height of the weir, so that the same inconvenience as described above occurs. Furthermore, since the raw water to be treated must be stopped before passing over the weir, it is necessary to constantly monitor the clogging state of the drum screen 1 or control the feed of the raw water to be treated according to the clogging state. I have a problem.

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 the solid content due to clogging of the drum screen. The purpose is to do.

[0007]

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention provides a drum screen in which a bias angle for axially urging a solid matter rolling on an inner surface is applied to a screen of a drum screen. The wire is arranged so as to be substantially horizontal and rotates about its central axis, and a taper portion having a smaller inner diameter at the tip side is provided at the end in the direction in which the solid content is advanced by the screen mesh. In a drum screen type filtration device provided with screw blades for feeding solids to the inner surface of the taper part, the other end of the drum screen is opened cylindrically, and at the end thereof, the front side in the direction of rotation thereof. A plurality of protective walls inclined with respect to the axial direction so as to be separated from the end of the drum screen are provided at regular intervals in the circumferential direction. It is characterized in that the raw water receiving for flowing the treated raw water overflowing from the end of the drum screen below the locations where the are a protective wall provided is provided.

Further, in this invention, it is possible to provide a cleaning port for injecting the raw water to be treated to the protective wall from the side opposite to the raw water receiver.

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

[0010]

[Action]

 Therefore, in the filtering device of the present invention, the other end of the drum screen is opened in a cylindrical shape, so that when the clogging occurs, the raw water to be treated supplied to the inside of the drum screen is It flows out from the department 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 open end, and this protective wall is directed in the direction opposite to the end where the solid content inside is opened as the drum screen rotates. Since it is provided so as to be inclined with respect to the axial direction so as to be pressed, the solid content is prevented from falling from here.

Further, by injecting the raw water to be treated and the wash water from the cleaning port to the protective wall, the deposits adhering to the protective wall are removed by the raw water to be treated, and the raw water to be treated is discharged from the raw water receiver. It will be returned to the designated place.

[0012] Furthermore, the drum screen is cleaned by injecting the liquid and the pressurized gas from the respective concentric loosely fitted injection pipes provided on the outer periphery of the drum screen, and in this case, the liquid is granulated. In addition, since it is accelerated by the pressurized gas, efficient cleaning is possible.

[0013]

【Example】

 Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing an embodiment of the present invention, in which a filtering device shown here is so arranged that a drum screen 10 is horizontally placed and rotated to separate solids from raw water to be treated. It is configured. That is, the drum screen 10 is formed into a cylindrical shape as a whole by arranging wedge wires in parallel with each other at regular intervals, as in the conventional device described with reference to FIGS. 5 and 6. The wedge wire is set with a predetermined bias angle so as to be inclined with respect to the axial direction of the cylindrical body, and thereby, the solid matter rolling on the inner surface of the drum screen 10 is given an axial propulsive force. ing.

The drum screen 10 is held in a cylindrical shape by attaching annular frames 11 to both ends in the axial direction, and a ring-shaped support rail 12 is fixed to the left frame 11 in FIG. ing. Further, a plurality of rail receiving plates 13 are fixed to the frame 11 on the opposite side over the entire inner circumference thereof at regular intervals, and the tip portions of these rail receiving plates 13 are connected to each other. A ring-shaped support rail 14 is fixed to the. The drum screen 10 is supported substantially horizontally by placing these support rails 12 and 14 on a pair of support rollers 15 provided in front and rear, respectively, and a pair of rear end sides (right side in FIG. 1). By driving the roller 15 via the motor 16 and the chain 17, the roller 15 is configured to rotate about the central axis. The outline of these drive mechanisms is shown in FIG.

Each of the rail receiving plates 13 is bent into the shape shown in FIG. That is, in the portion which is vertically fixed to the frame 11, the tip end side in the rotation direction of the drum screen 10 (the arrow direction in FIG. 3) is gradually separated from the end of the drum screen 10. It is inclined with respect to the axial direction of the screen 10, and this portion serves as a fall-off protection wall 18 for solids. 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 end portion of this rail receiving arm 19. Therefore, the rear end portion (right end portion in FIG. 1) of the drum screen 10 is cylindrically opened, and the space between the rail receiving plates 13 serves as an overflow port 20.

Below the overflow port 20, a raw water receiver 21 for inflowing the raw water to be treated that has overflowed from the drum screen 10 is arranged, and a return pipe 22 is connected to the raw water receiver 21. A filtrate receiver 23 is arranged below the drum screen 10, and a filtrate pipe 24 is connected to the filtrate receiver 23.

Further, at the tip portion (left end portion in FIG. 1) of the drum screen 10, as in the conventional drum screen described with reference to FIGS. 5 and 6, a taper portion having a gradually decreasing diameter on the tip side is formed. 25 is connected, and a screw blade 26 for transporting the solid content is attached to the inner surface thereof. The tip of the taper portion 25 is open, and the drop port 27 is arranged below the open end.

A raw water supply pipe 28 is arranged along the center axis of the drum screen 10 and the taper portion 25, the tip end of the taper portion 25 side is closed and fixed to the casing 29, and after that. An input pipe 30 is connected to the end portion of the raw water tank (not shown) or the like for drawing up and supplying the raw water to be treated. A portion of the raw water supply pipe 28 located inside the drum screen 10 opens upward for a predetermined length, and a supply dam 31 is connected to the opening. Like the conventional one, this supply dam 31 is a container opened upward, and the raw water that has overflowed is treated at its upper end with the inner surface of the drum screen 10, more specifically, the rotation of the drum screen 10. A guide plate 32 is connected to the inner surface of the portion that moves downward in accordance with the above.

A branch pipe 33 having a small diameter is connected to the base end portion (right end portion in FIG. 1) of the raw water supply pipe 28, and a shutter 34 is interposed in the middle portion 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 that opens and closes the shutter 34 is projected to the outside of the casing 29. That is, by opening the shutter 34, the raw water to be treated and the cleaning water are poured onto the rail receiving plate 13 to remove the deposits attached to the rail receiving plate 13.

Further, a wiper 36 fixed to the above-mentioned taper portion 25 is disposed close to a portion of the outer peripheral portion of the raw water supply pipe 28 on the tip side of the supply dam 31, and the wiper 36 is disposed near the raw water supply pipe 28. By rotating along the outer peripheral surface of the supply pipe 28, the deposit adhered to the raw water supply pipe 28 is removed.

On the outer peripheral side of the drum screen 10, a plurality of cleaning nozzles 37 that spray cleaning water toward the outer peripheral surface of the drum screen 10 are arranged. The cleaning noval 37 is for spraying the cleaning water into a mist and spraying it on the drum screen 10. As shown in FIG. 4, a water nozzle 39 connected to the water supply pipe 38 and an air nozzle 41 connected to the air supply pipe 40 are provided. They are concentrically arranged in a loosely-fitted state to make water mist by pressurized air and to increase the injection speed.

Next, the operation of the above-mentioned device will be described. When the raw water to be treated is supplied to the raw water supply pipe 28 while the motor 16 is started to rotate the drum screen 10 in the direction of the arrow in FIG. 2, the raw water to be overflowed from the supply dam 31 passes through the guide plate 32 to the drum 32. It is supplied toward the inner surface of the screen 10. As a result, a solid content larger than the screen mesh remains on the inner surface of the drum screen 10, and a liquid content mainly permeates the dry screen 10 and flows from the filtrate receiver 23 to the filtrate pipe 24, thereby performing solid-liquid separation.

The solid content remaining inside the drum screen 10 is lifted in the rotating direction of the drum screen 10 due to its viscosity due to the rotation of the drum screen 10, but after being lifted to a certain degree, the solid weight remains due to its own weight. It rolls down 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 a bias angle is attached to the screen eye during such rolling, a propulsive force in the axial direction is received, so that the solid content grows and advances in the axial direction. Then, in the taper portion 25, the solid content is conveyed by the screw blades 26 and discharged to the drop port 27.

On the other hand, the rear end portion of the drum screen 10 is opened in a cylindrical shape, and since the drop-off protection wall 18 which is inclined and arranged as described above is provided in this portion, the solid solid material that has grown is formed. The minute portion is pushed back toward the inside of the drum screen 10 by the falling protection wall 18, so that the solid content separated and removed from the raw water to be treated is not discharged from the rear end portion of the drum screen 10.

Water is supplied from the water supply pipe 38 to the cleaning nozzle 37 and the pressurized air is cleaned from the air supply pipe 40 while the filtration is performed as described above or intermittently after a certain period of time. When it is sent to the nozzle 37, the solid content clogging the screen eyes is removed by the mist. The wash water is discharged from the filtrate receiver 23 to the filtrate pipe 24. Even if such a cleaning operation is performed, it may not be possible to remove the deposits adhering to the drum screen 10. In that case, the supply amount of the raw water to be treated becomes excessive with respect to the filtration amount. Since the end portion is opened in a cylindrical shape and the overflow port 20 is formed here, the excess raw water to be treated is discharged from the overflow port 20 to the raw water receiver 21 and from there through the return pipe 22 to a predetermined location. , For example, sent to a raw water tank. Therefore, the raw water to be treated does not accumulate inside the drum screen 10, so that it is possible to prevent the water content of the raw water to be treated from penetrating into the separated solid matter to deteriorate the drainage.

The rail receiving plate 13 that defines the overflow port 20 may come into contact with the untreated raw water that overflows, so that a deposit may be generated on the rail receiving plate 13. When the shutter 34 is opened by the lever 35, the raw water to be treated and the washing water flow down through the branch pipe 33 toward the rail receiving plate 13, so that the deposits on the rail receiving plate 13 are removed by the raw water to be treated. . That is, it is possible to prevent the overflow port 20 from being blocked.

On the other hand, as the drum screen 10 rotates, the wiper 36 connected to the inner surface of the taper portion 25 rotates along the outer circumference of the raw water supply pipe 28, so that the deposits attached to the raw water supply pipe 28. Can be removed by this wiper 36.

Note that the present invention is not limited to the above-described embodiments, and the present invention can be applied to a filtering device in which a drum screen is composed of a member other than a wedge wire. The means for supplying the raw water to be treated to 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 of the drum screen, it is possible to use a device other than the constitution shown in the above-mentioned embodiment.

[0029]

[Effect of device]

 As described above, according to the present invention, one end of a horizontally held drum screen is opened in a cylindrical shape, and protective walls inclined toward the inside of the drum screen are provided at regular intervals at the open end. Therefore, when the drum screen is clogged, the raw water to be treated is discharged from the space between the protective walls to the outside of the drum screen, and is sent to the specified place from the raw water receiver located below it. Therefore, in the present invention, since the raw water to be treated does not accumulate inside the drum screen, water once again permeates into the solids once separated, and the drainage of the solids becomes worse. This can be prevented in advance, and the solid wall can prevent the solid content from falling through the opening. Even if the raw water to be treated is continuously supplied with the drum screen clogged, the raw water to be treated can be collected through the raw water receiver from the opening end on the protective wall side of the drum screen. It is not essential to continuously monitor the clogging state of the screen and to quickly stop the supply of the raw water to be treated when it is clogged, and thus the maintenance and management of the operation becomes easy.

Further, by providing a cleaning port for injecting the raw water to be treated toward the protective wall, it is possible to easily and easily prevent the portion where the raw water to be overflowed from the inside of the drum screen from being clogged with sediment. can do.

Further, as a nozzle for injecting the cleaning liquid toward the drum screen, a structure in which a liquid nozzle and a gas nozzle are loosely fitted in concentric circles is used, so that the ability to remove deposits adhering to the drum screen is enhanced. However, it is possible to keep the frequency of clogging of the drum screen lower than ever before.

[Brief description of 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 diagram showing a rail receiving plate.

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

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

FIG. 6 is a schematic side view thereof.

[Explanation of symbols]

10 ... Drum screen, 13 ... Rail support plate, 1
8 ... Fall protection wall, 20 ... Overflow port, 21 ...
Raw water receiver, 25 ... Tapered portion, 26 ... Screw blade, 28 ... Raw water supply pipe, 33 ... Branch pipe, 34 ... Shutter, 37 ... Wash nozzle, 39 ... Water nozzle,
41 ... Air nozzle.

Claims (3)

[Scope of utility model registration request] 1. A drum screen provided with a screen having a bias angle for urging the solid content rolling on the inner surface in the axial direction is arranged so that its central axis becomes substantially horizontal and rotates about the central axis. Further, a drum screen filtration in which a taper portion having a small inner diameter is provided on the tip side at the end portion in the direction in which the solid content is advanced by the screen mesh and screw blades for delivering the solid content are provided on the inner surface of the taper portion. In the device, the other end of the drum screen is opened in a cylindrical shape, and a plurality of ends of the drum screen are 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. The protective wall of the drum screen is provided at regular intervals in the circumferential direction, and the end of the drum screen is provided below the place 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 filtration device according to claim 1, wherein a cleaning port for injecting the raw water to be treated is provided to the protective wall from the side opposite to the raw water receiver. 3. A cleaning nozzle, in which a cleaning liquid injection pipe and a pressurized gas injection pipe are concentrically fitted, is arranged on the outer peripheral side of the drum screen toward the center thereof. The drum screen type filtration device according to claim 1.