JP3755148B2 - Screening method and screening device for screen residue - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rotary screen used for removing residue and floating substances such as industrial wastewater, industrial water, or sewage, and more particularly, to a method for scraping a residue screen and improvement of the apparatus.
[0002]
[Prior art]
Conventionally, a metal net is stretched over a drum immersed in the treated water tank, raw water is introduced into the drum, the treated water is passed through the metal net due to the liquid level difference inside and outside the filtration drum, and the drum is rotated to filter the surface A solid-liquid separation device that discharges a solid content such as a residue collected in a trough inside the drum is well known. As a means for dropping the solid content captured by the filtration drum to the trough, a rotary screen having a recovery spray disposed on the upstream side in the rotation direction of the drum and a cleaning spray on the downstream side is, for example, It is known as described in Japanese Patent No. 4-6807.
[0003]
[Problems to be solved by the invention]
However, although the above-mentioned conventional apparatus provided with sprays on the inner and outer surfaces of the drum is an effective means for removing the captured solid content, it is difficult to remove the fibrous solid content entangled with the filter medium surface, and the washing water Also needed a lot. The present invention provides a scraping device for a residue screen that can regenerate the filter medium surface while removing fibers entangled with the filter medium surface, and can also wash residual matter adhering to the filter medium surface with a small amount of washing water. provide.
[0004]
[Means for Solving the Problems]
The gist of the present invention is that a drum in which a filter medium is stretched in a treated water tank is rotatably arranged, raw water is supplied to the inside of the drum, the separated liquid is discharged into the treated water tank, trapped on the surface of the filter medium, etc. In the rotary screen that transports the solid content together with the drum, drops the captured solid content onto a trough provided inside the drum, and discharges it to the outside, a scraper that is in sliding contact with the inner peripheral surface of the drum is used as a driving means. It is a method of scraping off residue on a rotary screen by connecting and rotating a scraper at a speed higher than that of the drum in the same direction as the drum and scraping the collected solid material from the surface of the drum and dropping it on the trough. .
[0005]
A scraping device for carrying out the residue scraping method has a drum supported by a treatment water tank and a cleaning drain pipe connected to the trough, and a scraper abutted on the inner peripheral surface of the drum is supported by the cleaning drain pipe. At the same time, the drum and scraper are connected to the drive means, and the scraper is rotated at a speed higher than that of the drum in the same direction as the drum. The scraper is captured by the filter medium surface of the drum and moves upward together with the drum. The solid content is moved upwards of the drum while being scraped from the surface of the filter medium at a higher speed than the drum with a scraper that is in sliding contact with the inner peripheral surface of the drum, and the accumulated solid content is dropped onto the trough. At the same time, the fibers entangled with the filter medium of the drum, which cannot be removed by washing water, are scraped off to regenerate the filter medium surface.
[0006]
A specific support mechanism for the drum and scraper connects the drum drive ring to one end of the drum, and the drum drive ring is supported by a caster that is pivotally supported on the treatment water tank, and the other end of the drum is pivotally supported by the washing drain pipe. The scraper that is in sliding contact with the filter medium surface of the drum is supported on the washing drain pipe, and the scraper driving ring that is pivotally supported on the washing drain pipe on the inflow side is connected to the drum driving ring and the scraper driving ring. The scraper drive ring rotates in the same direction faster than the drum drive ring in conjunction with the drive machine, and the scraper rotates in the same direction as the drum, scraping solids from the filter medium surface with a slight differential speed. Since it is dropped, the wear of the filter medium stretched on the drum is reduced.
[0007]
The specific means of differential speed rotation is that an annular rack is fitted to the outer periphery of the drum drive ring and the scraper drive ring, a pinion for driving the drum is engaged with the outer periphery of the drum drive ring, and the scraper drive ring A scraper driving pinion is meshed with the outer peripheral portion, and the meshing ratio of the drum driving ring and the drum driving pinion is made larger than the meshing ratio of the scraper driving ring and the scraper driving pinion. In the case of a small rotary screen, a chain is fitted on the outer periphery of the drum drive ring and the scraper drive ring, and a drum drive sprocket is engaged with the outer periphery of the drum drive ring. A sprocket for driving a scraper may be engaged with the part. Then, the pinion or sprocket of the drum drive ring and the pinion or sprocket of the scraper drive ring are respectively fitted to the driven shafts arranged in parallel, and the intermediate sprocket fitted to the driven shaft is connected, and further the driven that is fitted to the driven shaft. The sprocket is linked to the drive machine.
[0008]
The filter medium stretched on the drum is composed of a wedge wire, the slits of this wedge wire are arranged in the circumferential direction of the drum, and the slit surface with a reduced opening is provided on the inner peripheral surface of the drum. A slit of the wedge wire is provided, and the captured solid content is scraped off along the slit of the wedge wire and discharged without being pushed into the eyes of the slit. If a washing water pipe is installed on the upper side of the drum rotation upward toward the trough, the solid matter scraped off by the scraper is also removed from the fiber material entangled with the filter medium surface. Residues adhering to the surface can be cleaned and the filter medium surface can be regenerated.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The apparatus according to the present invention is configured as described above. When the stock solution to be filtered is supplied to the inside of the drum, the separated water is separated from the wedge wire stretched on the drum by the difference in water level between the raw water side and the separated water side of the drum and the treatment water tank. Is discharged, and solid content such as residue is captured on the inner peripheral surface of the drum. Solid matter is placed on the slit surface of the wedge wire that moves on the water surface with the rotation of the drum, and a scraper that rotates slightly faster than the drum slides the filter media along the slit of the wedge wire to remove the solid matter. Ascending to collect solids. The scraper scrapes off fibers and the like entangled in the slit to regenerate the filter medium surface, and the accumulated material that has moved above the drum falls into the trough by its own weight. Residue adhering to the drum is separated by washing water sprayed from above the drum, and fine solids adhering between the slits of the wedge wire are also washed away. The drum from which the solid content such as residue is peeled is lowered and submerged in the treated water tank, and again the solid content such as residue is separated from the raw water.
[0010]
【Example】
The residue screen scraping device according to the present invention will be described in detail with reference to the drawings. First, FIG. 1 is a longitudinal side view of a rotary screen, and an inflow plate 2 and an overflow plate 2 standing on a treated water tank 1 from the tank bottom. The raw water chamber 5 divided by the flow plate 3 and connected to the raw solution supply pipe 4 is divided into the treated water chamber 7 connected to the treated water pipe 6, and the central portion between the inflow plate 2 and the overflow plate 3 is separated into the separation chamber 8. It is as. A washing drain pipe 9 is supported on the front wall on the inflow side of the treatment water tank 1 and the overflow plate 3 standing in the treatment water tank 1, and the washing drain pipe 9 is inserted into the cylindrical drum 10. is there. The inflow side of the drum 10 is open, and an annular drum drive ring 11 having a U-shaped cross section is fitted on the outer peripheral side surface of the open end of the drum. A seal felt 13 extending annularly in the direction of the drum drive ring 11 is fixed to the inflow plate 2 erected in the treated water tank 1, and the seal felt 13 is a U-shaped inner peripheral surface of the drum drive ring 11. The raw water chamber 5 and the separation chamber 8 are sealed. A cutout communicating with the inside of the drum 10 is provided in the upper part of the inflow plate 2 so that the raw water supplied from the raw water supply pipe 4 to the raw water chamber 5 flows into the drum 10.
[0011]
As shown in FIG. 2, casters 16, 16 are placed on mounting bases 15, 15 fixed to cart supports 14, 14 extending from both side walls of the upper part of the treatment water tank 1. An inner peripheral surface of a drum drive ring 11 connected to the motor 10 is supported. As shown in FIG. 1, the outflow side of the drum 10 is closed by a drum boss 17, the central portion of the drum boss 17 is pivotally supported by a cleaning drain pipe 9, and the drum 10 is rotated by the treated water tank 1 and the cleaning drain pipe 9. It is supported as possible. A scraper 18 is disposed inside the drum 10, and a support arm 19 of the scraper 18 is pivotally supported on the cleaning drain pipe 9. An annular scraper drive ring 20 is pivotally supported on the washing drain pipe 9 and disposed in the raw water chamber 5. As shown in FIG. 2, a scraper drive ring 20 is supported by a plurality of ring arms 22 on a sleeve 21 at the center, and a support arm 19 of the scraper 18 on the inflow side and a sleeve 21 of the scraper drive ring 20 are A plurality of supports 23 are connected. As shown in FIG. 3, the scraper 18 and the scraper drive ring 20 are supported on the washing drain pipe 9 and rotate together to bring the inner peripheral surface of the drum 10 into sliding contact.
[0012]
FIG. 4 shows a drum and scraper drive device, which is a drum drive driven shaft 26 and a scraper drive driven shaft 27 supported by a pair of bearings 25 and 25 on a pedestal 24 spanning the upper part of the treatment water tank 1. Are arranged in parallel in the front-rear direction of the treated water tank 1, and a chain 30 is wound around a pair of intermediate sprockets 28, 29 fitted to the driven shafts 26, 27, and the driven shaft 26 for driving the drum and the driven for driving the scraper. The shaft 27 is rotated in the same direction. An annular rack 31 is fitted on the periphery of the drum drive ring 11, and a pinion 32 fitted on the driven shaft 26 is engaged with the rack 31. An annular rack 33 is also fitted to the peripheral portion of the scraper drive ring 20, and a pinion 34 fitted to the driven shaft 27 is engaged with the rack 33. In the case of a small rotary screen, the drive device for the drum 10 and the scraper 18 has a chain 35 fitted around the drum drive ring 11 as shown in FIG. A sprocket 36 fitted into the shaft 26 is engaged. Further, a chain 37 is also fitted to the peripheral portion of the scraper drive ring 20, and if a sprocket 38 fitted to the driven shaft 27 is engaged with the chain 37, a drive device having a simple structure is obtained.
[0013]
As shown in FIG. 4, a chain 41 is wound around a driven sprocket 40 fitted on a driven shaft 26 for driving a drum by a driving machine 39 disposed in the upper part of the treated water tank 1, and the driving force of the driving machine 39 is driven. This is transmitted to the drum drive ring 11 and the scraper drive ring 20 via the shafts 26 and 27, and the drum 10 and the scraper 18 are rotated in the same direction. In the embodiment of the present invention, the outer diameters of the drum drive ring 11 and the scraper drive ring 20 are made equal, the scraper drive pinion 34 is made larger than the drum drive pinion 32, and the rotation of the scraper drive ring 20 is changed to the drum. It is faster than the rotation of the drive ring 11. The scraper 18 that is in sliding contact with the inner peripheral surface of the drum 10 is rotated at a slightly higher speed in the same direction as the rotation of the drum 10, and the speed of the scraper that rotates at a differential speed is slow, so that the wear of the filter medium is reduced. Is. Even if the outer diameter of the drum drive ring 11 is larger than the outer diameter of the scraper drive ring 20, the intermediate sprocket 28 fitted into the driven shaft 26 for driving the drum is fitted into the driven shaft 27 for driving the scraper. Even if it is larger than the intermediate sprocket 29, differential speed rotation is possible in the same direction.
[0014]
As shown in FIG. 1, a wedge wire 42 is stretched on the circumferential surface of the drum 10, and slits of the wedge wire 42 are arranged in the circumferential direction of the drum 10 and a slit surface having a reduced opening is formed inside the drum 10. Is provided. Solid matter such as residue collected by the wedge wire 42 is scraped up by the scraper 18 along the slit to reduce frictional resistance so that the residue is not pushed into the slit. is there. In addition, even if the filter medium stretched on the drum 10 is a punching metal, it is a metal filter medium and has good peelability. A trough 43 disposed above the inside of the drum 10 is connected to the cleaning drain pipe 9, and is collected by scraping up with the scraper 18, and solids such as residue are dropped on the trough 43 and discharged to the cleaning drain pipe 9. I am trying to make it.
[0015]
A washing water pipe 44 is provided on the upper side of the drum 10 so as to face the trough 43, and the residue adhering to the drum 10 after the solid content is dropped on the trough 43 is sprayed from above the drum 10. The fine solid content adhering between the slits of the wedge wire 42 is washed away by washing water. A water injection nozzle 45 is branched from the washing water pipe 44 and connected to the rear end of the washing drain pipe 9, and the solids discharged to the washing drain pipe 9 are swept away by the water flow and pushed outside the treatment water tank 1. It is. This discharge means may be provided with a screw conveyor in the washing drain pipe 9. The overflow plate 46 is provided on the overflow plate 3 that supports the rear end portion of the washing drain pipe 9, and the difference in the water level between the raw water chamber 5 and the separation chamber 8 is adjusted and supplied to the raw water chamber 5 from the raw water supply pipe 4. The raw water is introduced into the drum 10, the separated water is discharged due to the difference in water level between the drum 10 and the separation chamber 8, the overflow plate 46 of the overflow plate 3 is overflowed, and the separated water is treated from the separation chamber 8. It is sent out to the chamber 7 and extracted from the treated water pipe 6.
[0016]
【The invention's effect】
As described above, according to the rotary screen of the present invention, the scraping screen scraping method and scraping device are arranged in the same direction as the drum at a speed faster than the rotation of the drum. The filter is rotated at a differential speed and scraped off from the filter medium surface of the drum to accumulate solids. The filter medium surface can be regenerated while removing the fibers entangled with the filter medium surface. In other words, the conventional apparatus provided with the cleaning pipe on the inner and outer surfaces of the drum is difficult to peel off the fibrous solid matter entangled with the filter medium surface and requires a large amount of cleaning water. In this case, the drum is supported by the treatment water tank and the cleaning drain pipe connected to the trough, and the scraper that is in contact with the inner peripheral surface of the drum is supported by the cleaning drain pipe so that the scraper is driven at a higher speed than the drum. The filter media cannot be removed by washing water by moving it up the drum while scraping off the solid content such as residue from the filter media surface of the drum by scraping with a scraper. The fiber entangled on the surface is scraped off to regenerate the filter medium surface.
[0017]
The drum drive ring connected to the drum and the scraper drive ring connected to the scraper are linked to the drive machine to rotate the scraper drive ring in the same direction faster than the drum drive ring. The scraper rotates in the same direction as the drum. In addition, the solid content can be scraped off from the filter medium surface at a rotational speed difference. This differential speed rotation means makes the meshing ratio between the drum drive ring and the drum drive gear larger than the meshing ratio between the scraper drive ring and the scraper drive gear, and rotates the differential speed. The scraper rotates at a low speed in the same direction as the drum. However, since the solid content is scraped off from the filter medium surface at a slight rotational speed difference, wear of the filter medium stretched on the drum is reduced.
[0018]
The wedge wire slits stretched around the drum are arranged in the circumferential direction of the drum, so the captured solids are scraped along the slits of the wedge wire and discharged without being pushed into the slits. is there. In addition, since a washing water pipe is installed on the upper side of the drum's rotation upward toward the trough, the residue remaining on the filter medium surface can be cleaned with a small amount of washing water, and the filter medium surface can be regenerated. is there.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view of a rotary screen provided with a screen screen scraping device according to the present invention.
2 is a front view of a drum drive ring cut along a line AA in FIG. 1; FIG.
FIG. 3 is a front view of the scraper slidably contacted with the drum cut along the line BB in FIG. 1;
FIG. 4 is a plan view of a drum and scraper driving device according to the present invention.
FIG. 5 is a plan view of another embodiment of the driving device.
[Explanation of symbols]
1 treated water tank 9 washing drain pipe 10 drum 11 drum drive ring 16 caster 18 scraper 20 scraper drive ring 26, 27 driven shaft 28, 29 intermediate sprocket 31, 33 rack 32, 34 pinion 35, 37 chain 36, 38 sprocket 39 drive machine 40 Driven sprocket 42 Wedge wire 43 Trough 44 Washing water pipe

Claims (8)

A drum (10) with a filter medium stretched in the treated water tank (1) is rotatably arranged, raw water is supplied into the drum (10), and the separated liquid is discharged into the treated water tank (1). In the rotary screen, the solid content such as the collected residue is transferred upward together with the drum (10), and the captured solid content is dropped on the trough (43) provided inside the drum (10) and taken out to the outside. The scraper (18) slidably in contact with the inner peripheral surface of (10) is connected to the driving means, and the scraper (18) is rotated at a higher speed than the drum (10) in the same direction as the drum (10). A method for scraping a residue screen, characterized in that solid matter scraped from the filter medium surface of the drum (10) is dropped onto a trough (43). A drum (10) with a filter medium stretched in the treated water tank (1) is rotatably arranged, raw water is supplied into the drum (10), and the separated liquid is discharged into the treated water tank (1). In the rotary screen, the solid content such as the collected residue is transferred upward together with the drum (10), and the captured solid content is dropped on the trough (43) provided inside the drum (10) and taken out to the outside. (10) is supported by the treated water tank (1) and the washing drain pipe (9) connected to the trough (43), and the scraper (18) brought into contact with the inner peripheral surface of the drum (10) is washed with the washing drain pipe ( 9) and the drum (10) and the scraper (18) are connected to the driving means, and the scraper (18) is rotated at a speed higher than the drum (10) in the same direction as the drum (10). Shigashi characterized by Clean the cleaning device. A drum drive ring (11) is connected to one end of the drum (10), and the drum drive ring (11) is supported by a caster (16) pivotally supported on the treated water tank (1). The scraper (18), whose end is pivotally supported on the washing drain pipe (9) and slidably contacted with the inner peripheral surface of the drum (10), is supported on the washing drain pipe (9), and the washing drain pipe ( The scraper drive ring (20) pivotally supported on 9) is connected to the scraper (18), and the drum drive ring (11) and the scraper drive ring (20) are linked to the drive machine (39). The scraping device for a residue screen according to claim 2. An annular rack (31, 33) is fitted to the outer periphery of the drum drive ring (11) and the scraper drive ring (20), and a drum drive pinion (32) is attached to the outer periphery of the drum drive ring (11). ), The scraper drive pinion (34) is engaged with the outer periphery of the scraper drive ring (20), and the engagement ratio between the drum drive ring (11) and the drum drive pinion (32) is determined by the scraper drive. The scraping screen scraping device according to claim 3, wherein the scraping screen scraper driving pinion (34) has a meshing ratio larger than that of the ring (20). The chain (35, 37) is fitted to the outer periphery of the drum drive ring (11) and the scraper drive ring (20), and the drum drive sprocket (36) is engaged with the outer periphery of the drum drive ring (11). The scraper driving sprocket (38) is meshed with the outer periphery of the scraper driving ring (20), and the meshing ratio of the drum driving ring (11) and the drum driving sprocket (36) is determined by the scraper driving ring (20). And the scraper drive sprocket (38) is larger than the meshing ratio of the scraper screen scraping device according to claim 3. The pinion (32) or sprocket (36) of the drum drive ring (11) and the pinion (34) or sprocket (38) of the scraper drive ring (20) are fitted to the driven shafts (26, 27) arranged in parallel, respectively. The intermediate sprocket (28, 29) fitted to the driven shaft (26, 27) is connected, and the driven sprocket (40) fitted to the driven shaft (26) is linked to the driving machine (39). A scraping device for a screen residue according to claim 3 or 5. The filter medium stretched on the drum (10) is constituted by a wedge wire (42), the slits of the wedge wire (42) are arranged in the circumferential direction of the drum (10), and the slit surface having the reduced opening is formed on the drum ( The scraper for scraping screen according to any one of claims 3 to 6, wherein the scraper is provided on the inner peripheral surface of 10). The screen of any one of claims 2 to 7, characterized in that a washing water pipe (44) is provided facing the trough (43) above the rotation rising side of the drum (10). Scraping device.

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