JP2002177712A - Rotary drum screen for solid/liquid separation, and sludge concentration device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary drum screen for solid/liquid separation, which is capable of surely removing solid substances or foreign matters put between wedge wires, biological slime stuck on the screen surface, and hairs or fibers coiled around wedge wires, always keeping the drum screen free from clogging and markedly reducing the use amount of cleaning water, and to provide a sludge concentration device using the same. SOLUTION: In the sludge concentration device, sludge in raw water is concentrated by feeding the raw water into the rotary drum screen 1 for solid/liquid separation, being rotated, and filtering liquid through gaps 6 between wedge wires 5. In the sludge concentration device a cylindrical drum screen 1 formed by arranging the wedge wires 5, each having a triangular cross section, at a prescribed space 6 in the circumferential direction of the drum screen in a ring-shaped state is used, and a brush 8 for cleaning the screen is provided at least at the inner side of the cylindrical drum screen 1 in parallel to the rotary axis of the drum so that the tip end of the brush is brought into contact with and slides on the surface of the screen.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary drum screen for solid-liquid separation and a sludge concentrator using the same.

[0002]

2. Description of the Related Art A rotary drum type sludge concentrator has a rotary drum screen (hereinafter abbreviated as "drum screen") for solid-liquid separation, which is driven to rotate by a motor or the like, and an object to be processed in the drum screen. A raw water supply pipe for feeding raw water (sludge), a filtrate discharge mechanism that collects the filtrate filtered by the drum screen and discharges it to the outside, and a screw conveyor that collects sludge concentrated by the drum screen and transports it to the outside And a sludge discharge mechanism.

[0003] A drum screen is made by arranging metal wires called wedge wires having a triangular cross section in a cylindrical shape in a direction parallel to the axis of the drum with a slight gap therebetween.
The sludge in the raw water is concentrated by filtering the liquid component in the raw water through a minute gap formed between adjacent wedge wires.

[0004]

However, in the above-mentioned rotary drum type sludge concentrator, the screen surface is clogged as the operation time elapses, and a biofilm by microorganisms is attached. It is necessary to clean the screen surface. In the case of a conventional apparatus, the washing process of the screen surface is performed by injecting washing water at regular intervals toward the screen surface from washing water jet pipes arranged inside and outside the drum screen.

[0005] However, when the cleaning water is injected,
In order to perform sufficient cleaning, a large amount of cleaning water is required.Also, solids and foreign matter caught between the wedge wires, biological films attached to the screen surface, hair and fibers entangled with the wedge wires, etc. are completely removed. It was difficult to remove. For this reason, it is necessary to stop the apparatus periodically and perform a large cleaning of the drum screen, and there is a problem that a great deal of labor, labor and cost are required for the maintenance management of the apparatus.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and includes a solid or foreign matter sandwiched between wedge wires, a biological film attached to a screen surface, and hair or fibers entangled with the wedge wires. Etc. are surely removed,
It is an object of the present invention to provide a rotary drum screen for solid-liquid separation, which can always keep a drum screen in a clog-free state and also greatly reduce the amount of washing water used, and a sludge concentrator using the same. is there.

[0007]

In order to achieve the above object, a solid-liquid separating rotary drum screen of the present invention comprises a cylindrical drum screen formed by arranging wedge wires at a predetermined gap, A screen cleaning brush is disposed at least inside the cylindrical drum screen, and is arranged in parallel with the drum rotation axis such that the brush tip is in sliding contact with the screen surface.

As the solid-liquid separation drum screen, a wedge wire having a triangular cross section is arranged in a ring shape in the circumferential direction of the drum screen with a predetermined gap, and a wedge wire having a triangular cross section is used. Using a wedge wire with a triangular cross section spirally wound in the direction of the rotation axis of the drum screen with a predetermined gap. Can be.

The sludge concentrator according to the present invention is characterized in that raw water to be treated is put into a rotating rotary drum screen for solid-liquid separation, and liquid is filtered from gaps formed between wedge wires. In a sludge concentrator configured to concentrate sludge in raw water, a solid-liquid separation rotary drum screen provided with the above-described screen cleaning brush is used as a solid-liquid separation rotary drum screen.

When the solid-liquid separating rotary drum screen and the sludge concentrating apparatus having the above-mentioned constitutions are used, when the drum screen is washed, it can be washed while the screen surface is scraped off with a screen washing brush. For this reason,
Solids and foreign matter sandwiched between the wedge wires, biological films adhering to the screen surface, hair and fibers entangled with the wedge wires can be easily and reliably removed.

In particular, when a solid-liquid separation rotary drum screen in which wedge wires having a triangular cross section are arranged in a ring shape in the circumferential direction of the drum screen with a predetermined gap therebetween is used, the rotation direction of the screen cleaning brush and the rotation direction are different. Since the direction of the gap formed between the wedge wires matches the direction, the cleaning is performed while rotating while the screen cleaning brush enters the gap of the wedge wire, so the scraping effect by the brush is significantly improved Thus, a better cleaning effect can be obtained.

Further, the cleaning water sprayed on the screen surface may include solids and foreign matters after being scraped off by a brush,
It is sufficient to have enough water to wash away biofilms, hair and fibers. Therefore, it is not necessary to clean the screen surface using a large amount of cleaning water as in the conventional apparatus, and the amount of cleaning water used can be greatly reduced. In addition, by reducing the amount of washing water, the concentration of solids separated by solid-liquid separation and the concentration of concentrated sludge can be kept high without being diluted with the washing water.

Furthermore, since the drum screen can be reliably removed even if the drum screen is clogged as in the conventional apparatus, it is possible to operate the apparatus without maintenance until the time for replacing the screen cleaning brush comes without stopping the apparatus. Become.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show an embodiment of a sludge concentrating device constituted by using the rotary drum screen for solid-liquid separation according to the present invention. 1 is a schematic sectional view of a sludge concentrator, FIG. 2 is a schematic sectional view taken along line II-II in FIG. 1, FIG. 3 is a structural explanatory view of a rotary drum screen for solid-liquid separation, and FIG. It is a schematic perspective view of a trough structure.

In FIG. 1 and FIG. 2, reference numeral 1 denotes a rotary drum screen (hereinafter abbreviated as "drum screen") for solid-liquid separation which is driven to rotate by a driving means such as a motor 2. Inside, a raw water supply pipe 3 for transporting raw water (sludge) to be treated into the drum screen 1 is provided. At the end of the raw water supply pipe 3, a trough 4 for sludge input for allowing the conveyed raw water to fall naturally without stagnating toward the screen surface of the drum screen 1 (see FIG. 4).
Are formed.

As shown schematically in FIG. 3, a part of the drum screen 1 is enlarged and a wedge wire 5 having a triangular cross section is provided with a predetermined width g of about 0.3 mm to 4.0 mm. By arranging in a ring shape in the circumferential direction while leaving a gap 6, a cylindrical drum screen 1 is formed. A minute gap 6 formed between adjacent wedge wires 5 allows a liquid component in raw water to be separated. It is to be filtered. On the inner wall surface of the drum screen 1, a fin-shaped sludge transfer blade 7 (FIG. 1) for sending out the concentrated sludge after the liquid component is filtered toward a concentrated sludge recovery chute 12 described later. , FIG. 2) are provided with a desired inclination angle.

Inside the drum screen 1, a screen cleaning brush 8 whose upper end is slidably in contact with the inner surface of the screen is rotatably disposed in parallel with the drum rotation axis, located above the raw water supply pipe 3. . The screen cleaning brush 8 is configured to be driven to rotate in a direction opposite to the rotation direction of the drum screen 1 by a driving means such as a motor 9. Is considered so that it can be effectively cleaned.

The screen-cleaning brush 8 may be made of, for example, a brush made of synthetic resin brush bristles, a brush made of metal brush bristles, or the like, the material of the wedge wire 5 to be in sliding contact with, or the material to be processed. The most suitable material is selected and used according to the type of solid matter and foreign matter contained in the water.

On the other hand, on the lower side of the drum screen 1,
A filtrate collecting chute 10 for collecting and collecting the filtrate filtered by the drum screen 1, a drain pipe 11 for discharging the collected filtrate to the outside, and a lower part of the opening end side of the drum screen 1 (the left end in FIG. 1) On the lower side), a concentrated sludge collecting chute 12 for collecting and collecting the concentrated sludge after the liquid component is filtered by the drum screen 1 and a driving means such as a motor 13 for transporting the collected concentrated sludge to the outside are provided. A screw conveyor 14 that is driven to rotate is arranged.

At appropriate positions inside and outside the drum screen 1, a washing water spray pipe 15 a for spraying washing water onto the inside and outside surfaces of the drum screen 1 to wash the screen surface.
And 15b are provided respectively.

Next, the sludge concentration process and the screen cleaning process in the above-described sludge concentration device will be described. First, prior to the start of the sludge concentration process, the motor 2 is driven to rotate the drum screen 1 in the direction of the arrow (a) in FIG. 2, and the raw water (sludge) to be treated is supplied to the raw water supply pipe 3. Through the sludge concentrator. The fed raw water is discharged from the trough 4 at the end of the raw water supply pipe into the rotating drum screen 1, and is sent toward the concentrated sludge recovery chute 12 by the sludge transfer blade 7 while the wedge wire is being fed. The liquid is filtered by the gap 11 between the five, and the sludge is concentrated.

The filtrate filtered by the drum screen 1 is collected by a filtrate collecting chute 10 arranged below the drum screen 1 and discharged to the outside through a drain pipe 11.

On the other hand, the concentrated sludge after the liquid is filtered is
As the drum screen 1 rotates, it is gradually fed to the concentrated sludge collection chute 12 by the action of the sludge transfer blade 7, and finally from the left end opening (in FIG. 1) of the drum screen 1. It falls into the inside. The collected concentrated sludge is transported outside by the screw conveyor 14.

When the sludge concentration process is performed as described above, solids and foreign matters are trapped in the gaps 6 between the wedge wires 5 of the drum screen 1 with the passage of time, and hair and fibers are entangled with the sludge. In addition, there is a possibility that a biofilm due to microorganisms adheres and the screen surface is clogged.

Therefore, at a certain time or every certain period,
Screen cleaning brush 8 and cleaning water injection pipes 15a, 15
b is operated to clean the screen surface as follows.

That is, in the cleaning process, the motor 9
Is driven to rotate the screen cleaning brush 8 in the direction of the arrow (b) in FIG. 2 opposite to the rotation direction of the drum screen 1, and a water pressure pump (not shown) is driven to drive the cleaning water injection pipe 15 a, The cleaning water is pumped to 15b, and the cleaning water is jetted from each jet pipe toward the inner and outer surfaces of the drum screen 1.

When the screen cleaning brush 8 is started to rotate, the screen cleaning brush 8 rotates while the brush tip slides on the inner surface of the drum screen 1 rotating in the direction opposite to the brush. In addition, since the rotating direction of the screen cleaning brush 8 and the direction of the gap 6 formed between the wedge wires 5 match, the tip of the screen cleaning brush 8 enters the gap 6 of the wedge wire 5. It rotates in a state. For this reason, the inner surface of the drum screen 1 is brush-cleaned by being scraped off by the screen-cleaning brush 5. Therefore, it is possible to surely remove solids and foreign matters sandwiched in the gaps 6 between the wedge wires 5, biofilms attached to the screen surface, hair and fibers entangled with the wedge wires 5, and the like.

While the screen cleaning brush 8 is scraping the screen surface to perform the brush cleaning as described above, the cleaning water is sprayed from the cleaning water injection pipes 15a and 15b toward the screen surface, and the screen is cleaned. The solids and foreign matter, biological film, hair, fibers and the like scraped off by the cleaning brush 8 are washed off the screen surface, and the screen surface is restored to a clear state.

As is apparent from the above-described cleaning operation, in the case of the present invention, the cleaning water jetted toward the screen surface is a solid or foreign matter, a biological film, or hair after being scraped off by the screen cleaning brush 8. The amount of water enough to wash away fibers and fibers is sufficient. Therefore, it is not necessary to clean the screen surface using a large amount of cleaning water as in the conventional apparatus, and the amount of cleaning water used can be significantly reduced. Further, even if the drum screen is clogged as in the conventional apparatus, the drum screen can be reliably removed, so that the apparatus can be operated without maintenance without stopping the apparatus until it is time to replace the screen cleaning brush.

In the above-described embodiment, the case where the screen cleaning brush 8 is provided only inside the drum screen 1 has been described as an example. However, as shown by a dotted line in FIG. A pair of screen cleaning brushes 8 ′ may be provided on the outside to clean the screen surface from inside and outside of the drum screen 1. If the inner and outer surfaces are scraped off with a brush as described above, a more excellent cleaning effect can be exhibited.

In the above embodiment, the washing water injected from the washing water injection pipes 15a and 15b is introduced from outside the apparatus. Instead, the filtrate discharged from the drain pipe 11 is stored in the filtrate storage tank. Alternatively, the stored filtrate may be pumped up and pumped to the washing water injection pipes 15a and 15b to be used as washing water. In the case of such a configuration, it is not necessary to draw the cleaning water from the outside, so that the apparatus can be simplified and the cost can be reduced.

When the filtrate collected as described above is reused as washing water, the nozzle may be clogged by fine solids contained in the filtrate.
It is desirable to use a self-cleaning nozzle having a large diameter as a and 15b.

FIGS. 5 and 6 show a second embodiment of the drum screen. In the drum screen 1 according to the second embodiment, a wedge wire 5 having a triangular cross section is formed by ringing the wedge wire 5 in the circumferential direction of the drum screen while leaving a predetermined gap 6 having a mesh width g of about 0.3 mm to 4.0 mm. By arranging the drum screen in a cylindrical shape, a cylindrical drum screen 1 is obtained. Except for the difference in the arrangement of the wedge wires 5, all have the same structure as that of the above-described first embodiment, and thus the same portions are denoted by the same reference numerals and detailed description thereof will be omitted.

In order to construct a sludge concentrating apparatus using the drum screen 1 according to the second embodiment, the drum screen 1 in the sludge concentrating apparatus shown in FIGS. Drum screen 1 of FIG.
And other mechanisms can be used as they are.

When a sludge concentrator is constructed using the drum screen 1 according to the second embodiment, the direction of the gap 6 between the wedge wires 5 is determined by the screen cleaning brush 8.
The direction of rotation is orthogonal to the direction of rotation, so that the brush scraping effect is slightly inferior to that of the first embodiment. However, except for this point, the configuration and operation of the sludge concentrator are basically the same. Are the same as in the first embodiment described above. Therefore, the illustration of the overall configuration of the sludge concentrator using the drum screen 1 according to the second embodiment in FIGS. 5 and 6 is omitted.

FIG. 7 shows a third embodiment of the drum screen. The drum screen 1 according to the third embodiment has a cylindrical drum screen by arranging wedge wires having a triangular cross section in parallel with the rotation axis direction of the drum screen while leaving a predetermined gap. is there. The screen cleaning brushes 8 and 8 'are not shown.

To construct a sludge concentrator using the drum screen 1 according to the third embodiment, the drum screen 1 in FIG. 7 is used instead of the drum screen 1 in the sludge concentrator shown in FIGS. The drum screen 1 may be used, and other mechanisms can be used as they are.

When a sludge concentrator is constructed using the drum screen 1 according to the third embodiment, the direction of the gap 6 between the wedge wires 5 is oblique to the rotation direction of the screen cleaning brushes 8, 8 '. Since they intersect with each other, the effect of scraping off by the brush is approximately intermediate between the first embodiment and the second embodiment. The configuration and operation of the sludge concentrator are basically the same as those in the first embodiment. Accordingly, the overall configuration diagram of the sludge concentrator using the drum screen 1 according to the third embodiment in FIG. 7 is not shown.

[0039]

As described above, according to the present invention, since the screen cleaning brush for cleaning the screen surface by slidably contacting the screen surface is provided at least inside the rotary drum screen for solid-liquid separation. The surface can be effectively cleaned, and solid objects and foreign substances caught between the wedge wires, biofilms attached to the screen surface, hair and fibers entangled with the wedge wires, etc. are reliably removed, and the drum screen is always cleaned. It can be maintained without clogging.

Further, since the clogging of the screen surface can be surely removed by the screen cleaning brush, the amount of cleaning water used can be greatly reduced.

Further, even if the drum screen is clogged as in the conventional apparatus, the drum screen can be reliably removed, so that it is possible to operate the apparatus without maintenance without stopping the apparatus until it is time to replace the screen cleaning brush. Become.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an embodiment of a sludge concentrating device according to the present invention.

FIG. 2 is a schematic sectional view taken along line II-II in FIG.

FIG. 3 is a structural explanatory view of a rotary drum screen for solid-liquid separation.

FIG. 4 is a schematic perspective view of a trough structure of a raw water supply pipe.

FIG. 5 is a schematic sectional view showing a second embodiment of the rotary drum screen for solid-liquid separation.

FIG. 6 is a schematic sectional view taken along line VI-VI in FIG. 5;

FIG. 7 is a schematic sectional view showing a third embodiment of a rotary drum screen for solid-liquid separation.

[Explanation of symbols]

 Reference Signs List 1 drum screen 2 motor 3 raw water supply pipe 4 trough 5 wedge wire 6 gap between wedge wires 7 sludge transfer blade 8, 8 'screen cleaning brush 9 motor 10 filtrate collection chute 11 drain pipe 12 concentrated sludge collection chute 13 motor 14 Screw conveyor 15a, b Wash water injection pipe

Claims (5)

[Claims] 1. A cylindrical drum screen is formed by arranging wedge wires at a predetermined gap, and a screen cleaning brush is positioned at least inside the cylindrical drum screen. A rotating drum screen for solid-liquid separation, wherein the rotating drum screen is disposed in parallel with the drum rotating shaft so as to slide on the screen surface. 2. A cylindrical drum screen is formed by arranging wedge wires having a triangular cross section in a ring shape in the circumferential direction of the drum screen with a predetermined gap therebetween. Rotary drum screen for solid-liquid separation. 3. A cylindrical drum screen is formed by arranging wedge wires having a triangular cross section in parallel with the rotation axis direction of the drum screen with a predetermined gap therebetween. Rotary drum screen for solid-liquid separation. 4. A cylindrical drum screen is formed by spirally winding a wedge wire having a triangular cross section in the rotation axis direction of the drum screen with a predetermined gap therebetween. Rotary drum screen for solid-liquid separation. 5. A method of concentrating sludge in raw water by introducing raw water to be treated into a rotating rotary drum screen for solid-liquid separation and filtering liquid through gaps formed between wedge wires. The sludge concentrator according to claim 1, wherein the rotary drum screen for solid-liquid separation is as described above.
4. A sludge concentrator using the rotary drum screen for solid-liquid separation according to any one of 4.