JPH07116415A - Rotary drum type filter apparatus - Google Patents

Abstract

PURPOSE:To simply form a precoat layer while miniaturizing a storage tank and the whole of an apparatus by extending a pivot shaft from a filter drum having the precoat layer formed on the peripheral surface part thereof to the storage tank and supporting the shaft so as to freely alter the position thereof to rotationally drive the same. CONSTITUTION:A storage tank 3 storing a liquid 2 to be treated such as sludge and a filter drum 5 having a precoat layer 4 formed on the peripheral surface part thereof are arranged to a rotary drum type filter apparatus 1. A pivot shaft 6 is extended from one side surface of the filter drum 5 to the outside of the side wall of the storage tank 3 and supported by a position altering means 7 so as to be freely altered in its position. Negative pressure is supplied into the filter drum 5 and the filter drum 5 is rotated by a drive means 9 through the pivot shaft 6. The precoat layer 4 is scraped off by the position altering means 7 to be brought to a contact or separation state with respect to a plate. Negative pressure 6 is allowed to act on the filter drum 5 through the suction passage 26 in the pivot shaft 6 and a liquid 2 to be treated is filtered through the precoat layer 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary drum type filtering device, and more particularly to a device for filtering sludge generated during dredging work and for filtering and dehydrating sludge.

[0002]

2. Description of the Related Art As a rotary drum type filtering device of this type, there is known one described in Japanese Patent Publication No. 5-51322 previously proposed by the present applicant. The rotary drum type filtration device described in these publications supports both ends of a filtration drum having a precoat layer supported on one end of a bearing member,
The other end is rotatably supported by the storage tank, and while the rotating drum is rotated by the driving means, the bearing member is moved by the swinging means so that the surface of the precoat layer is brought into contact with or separated from the scraping blade fixed to the storage tank. It is configured to swing in the direction of movement.

[0003]

However, in the rotary drum type filtration device having the structure described in the above publication, a bearing member supporting both ends of the filtration drum and a driving means for rotating the filtration drum (for example, a chain or a sprocket) are used. Etc.) is provided at the shaft end of the filtration drum in the storage tank, so the storage tank must be made considerably larger than the effective width of the filtration drum, which leads to an increase in size of the entire device. There was a problem.

In addition, since the bearing member for supporting both ends of the filtration drum and the driving means for rotationally driving the filtration drum are constantly immersed in the sludge, the solid mass in the sludge (treatment liquid) is the bearing member and It was easy to get caught in the driving means, which could cause early wear or failure, resulting in a problem in durability.

Further, in the rotary drum type filtration device having the structure described in the above publication, when the precoat layer formed on the surface of the filtration drum reaches the usable limit, once the sludge in the storage tank is removed and cleaned, a large size A filter medium for forming a precoat layer is supplied into the storage tank, and the filter medium is adsorbed on the filter drum to form the precoat layer. After that, since the sludge is supplied after removing the filter medium from the storage tank and the filtration is restarted, it takes a lot of time and effort to form the precoat layer,
There was also the problem of low operating efficiency. The present invention has been proposed in view of the above problems, and while the storage tank can be downsized to downsize the entire apparatus, the precoat layer can be easily formed, and the rotation efficiency and durability can be improved. It is an object of the present invention to provide a drum type filtration device.

[0006]

In order to achieve the above object, the rotary drum type filtration device according to the present invention is, firstly, for treating at least a part of a filtration drum having a precoat layer formed on its peripheral surface in a storage tank. A pivot shaft extending from one side of the filtration drum to the outside of the side wall of the storage tank is immersed in the liquid, and is pivotally supported by the side wall of the storage tank through the position changing means, and the pivot shaft can be rotated by the driving means. A suction passage, one end of which is opened in the filtration drum and the other end of which is connected to a negative pressure forming means, is formed on the pivot shaft, and a negative pressure is applied to the filtration drum through the suction passage to form a precoat layer. The treatment liquid is filtered with, and the scraping blade that scrapes off the adsorbed matter adsorbed and retained in the precoat layer is fixed to the storage tank, and the position changing means is driven to move the precoat layer toward and away from the scraping blade. The filter drum is configured to be displaceable It is characterized in.

Secondly, at least the upper end portion of the filtration drum is exposed on the upper surface of the treatment liquid in the storage tank, and a filter medium supply device for supplying a filter medium for forming a precoat layer to the exposed filtration drum is provided. The negative pressure forming means comprises a pressurizing pump for pressurizing the liquid, and a jet pump for injecting the pressurized liquid into the pipe to form a negative pressure in the pipe, and the negative pressure formed by the jet pump. One of the features is that the suction port for acting on is opened inside the rotary drum.

[0008]

First, a pressure pump for sucking and pressurizing a liquid, for example, while at least part of the filtration drum having the precoat layer immersed in the treatment liquid in the storage tank is rotated by the driving means, When the negative pressure generated by the negative pressure forming means composed of the jet pump for injecting the pressurized liquid into the pipe to form the negative pressure in the pipe is supplied to the filtration drum, the negative pressure causes the treatment of the storage tank. A solid mass (adsorbate) of the liquid is adsorbed on the precoat layer, and only water is sucked into the filtration drum. The solid mass adsorbed and held by the precoat layer is scraped off by a scraping blade as the filtration drum rotates. Thus, the solid mass adsorbed and held on the precoat layer gradually causes the precoat layer to be clogged, the filtration function is lowered, and the negative pressure of the negative pressure forming means is increased. The position changing means is operated in a direction in which the surface of the precoat layer approaches the scraping blade by the driving means by detecting the increase in the negative pressure artificially or automatically, so that the precoat layer in the clogged portion is It is scraped off and the filtration function is restored

The precoat layer is gradually scraped off, and the thickness of the precoat layer reaches the usable limit. However, when forming a new precoat layer, a part of the treatment liquid in the storage tank is drained to lower the liquid surface, and the surface of the precoat layer is operated in a direction away from the scraping blade, and the filtration drum is placed on the liquid surface. Expose. Next, a new precoat layer is formed by supplying the filter material from the filter material supply device to above the filter drum exposed on the liquid surface of the treatment liquid and adsorbing it to a predetermined thickness. When a new precoat layer is formed, the filtration can be restarted by supplying the treatment liquid to the storage tank in a state where at least a part of the precoat layer of the filtration drum is immersed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a rotary drum type filtration device of the present invention will be described below with reference to the drawings. In this embodiment, as shown in FIGS. 1 and 2, the rotary drum type filtration device 1 includes a storage tank 3 for storing a treatment liquid 2 such as sludge, a filtration drum 5 having a precoat layer 4 formed on the peripheral surface thereof, and a filtration drum 5. Positioning means 7 for pivotally supporting the pivot shaft 6 extending from one side surface of the drum 5 to the outside of the side wall 3a of the storage tank 3 and changing its position, and a negative pressure in the filtration drum 5 shown in FIG. The negative pressure forming means 8 for supplying the precoat layer 4, the driving means 9 for rotating the filtration drum 5 via the pivot shaft 6, and the position changing means 7 are operated to operate the precoat layer 4
And a scraping blade 10 that contacts and separates.

The storage tank 3 is formed in a substantially box shape and is shown in FIG.
As shown in FIG. 5, the bottom portion 11 is formed in a substantially “W” shape, and the scraping blade 10 is fixed to the top of the intermediate chevron portion with its tip facing substantially the center of the filtering drum 5. An outlet 12 for the treatment liquid 2 is formed on the lower side of the filtration drum 5 in the rotation direction, and a concentrated liquid or solid mass outlet 13 is formed on the bottom of the upper side of the filtration drum 5 in the rotation direction. . The side wall 3a of the storage tank 3 is provided with a mounting window 15 through which the flange 14 of the filtration drum 5 can be inserted and removed.
Supports the pivot shaft 6 of the filtration drum 5, and the side wall 3 of the storage tank 3.
It is closed by a mounting plate 17 of the support member 16 forming a part of a.

Precoat layer 4 formed on filter drum 5
In this example, the flanges 14 at the left and right ends of the filtration drum 5 are
A screen 18 having a large number of small holes formed between 14 is attached in a cylindrical shape, and diatomaceous earth is relatively thickly adsorbed in a layered manner on the upper surface of the screen 18 by a method described later. Although not shown in the drawing, aggregates are bridged between the flanges 14 on the left and right ends of the filtration drum to form a substantially cylindrical frame, and a so-called “wire” having an inverted triangular cross section is formed on the outer peripheral surface of the frame. "Wedge wire" with a predetermined gap between adjacent edges
It is also possible to form a screen by winding it so as to have a constant width within the range of 0.2 to 0.8 mm, and to form a relatively thick layer of diatomaceous earth on the upper surface of the screen 18 by a method described later. The pivot shaft 6 of the filtration drum 5 is formed of a cylinder extending from one flange 14 to the outside of the side wall 3a of the storage tank 3, and a sprocket 19 is attached to the tip of the pivot shaft 6.

The sprocket 19 has a chain 24 wound around a sprocket 23 of an output shaft 22 of a drive motor 21 provided on the upper surface of a frame 20 of a storage tank. Two
4 and the driving motor 21 constitute a driving means 9, and the driving means 9 drives the filtration drum 5 to rotate via the pivot shaft 6. A suction pipe 25, which penetrates through the pivot shaft 6 and extends in the vicinity of the other flange 14 of the filtration drum 5, is inserted inside the pivot shaft 6, and a negative pressure is applied to the inside of the suction pipe 25. A suction passage 26 for introducing the negative pressure of the supply means 8 is formed, and a suction port 27 for acting in the filtration drum 5 is opened toward the lower inner surface of the filtration drum 5.

The eccentric cam 2 of the position changing means 7 is provided between the pivot shaft 6 of the filtration drum 5 and the support member 16 supporting the shaft.
8 is interposed. The position changing means 7 is used for the storage tank 3
A cylindrical support cylinder 19 extends from a mounting plate 17 that closes a mounting window 15 formed on one side wall 3a, and water-tightly fits at both ends of the support cylinder 29 so that the rotatable cam member 3 can rotate.
The eccentric cams are formed by connecting the positions displaced from the center of 0.30 with a connecting cylinder 31, and inserting the pivot shaft 6 of the filtration drum 5 into the central portion of the connecting cylinder 31 so as to be rotatable relative to the connecting cylinder 31. 28, and a rotation bracket 32 attached to a side surface of the eccentric cam 28 is attached to a rotation operation mechanism 33.
It is designed to be rotated by.

The rotating operation mechanism 33 of the eccentric cam 28 is shown in FIG.
As shown in FIG.
4, the lower end of the operating rod 36, which is composed of an elevating tube 35 whose lower end is connected to the rotating bracket 31, is pivoted to the upper end of a column 37 standing upright from the upper surface of the frame 20 of the storage tank 3. Support the servomotor 39 via the belt transmission 38.
The rotation bracket 32 connected to the lower end of the up-and-down tube 35 is operated by rotating the up-and-down tube 35 by rotating and controlling the upper end of the screw member 34.
The rotation control of the servomotor 39 is performed when the negative pressure gauge 41 provided in the communication pipe 40 that communicates the negative pressure supply passage 26 and the negative pressure forming means 8 detects that the negative pressure becomes higher than a predetermined value. A rotation drive signal is issued from the control device 42 in response to the detection signal to rotate the servomotor 39 by a predetermined amount.

The negative pressure supply means 8 is a jet pump M.
The jet pump MJP includes a JP and a communication pipe 40 that connects the negative pressure supply port 43 of the jet pump MJP to the suction passage 26.
A pressure pump 47 that sucks and pressurizes the water 45 therein from a water suction port 46, a jet nozzle 49 that jets the pressurized water toward a discharge pipe 48, and a discharge port 50 at the tip of the discharge pipe 48. The generated water is returned to the water storage tank 44. In FIG. 2, reference numeral 51 is a filter material supply device for forming the precoat layer 4 on the peripheral surface of the filtration drum 5, and a lower end portion 53 is attached to a bracket 52 protruding from the side wall of the storage tank 3.
And a filter medium supply pallet 54, which is swingably supported, and whose front end can swing in a direction toward and away from the surface of the filter drum 5 with the lower end 53 as a swing center, and the filter medium supply pallet 5.
4 and a supply nozzle 55 for supplying a filter medium.

The operation of the rotary drum type filtering device 1 constructed as above will be described below. First, at least a part of the filtration drum 5 on which the precoat layer 4 is formed is immersed in the treatment liquid 2 in the storage tank 3 and the negative pressure forming means 8 is driven while the filtration drum 5 is rotated by the driving means 9. . When the jet pump MJP of the negative pressure forming means 8 is driven,
The water 45 in the water storage tank 44 is sucked from the water inlet 46 and pressurized by the pressurizing pump 47. Injection nozzle 4 for pressurized water
When jetted from the nozzle 9 toward the discharge pipe 48 as a jet water flow, the high-pressure jet water flow jetted from the jet nozzle 49 spreads in the discharge pipe 48 as much as possible, and this widened portion is inside the discharge pipe 48 toward the discharge port 50 side. Since it acts like a piston that slides continuously, a negative pressure is formed in the injection nozzle 49 side portion.

The negative pressure thus formed by operating the jet pump MJP is taken out from the negative pressure supply port 43, and acts on the inside of the filtration drum 5 via the communication pipe 40, the suction pipe 25, the suction passage 26 and the suction port 27. Let Then, the treatment liquid 2 is sucked from the surface of the precoat layer 4 which is in contact with the treatment liquid 2 in the storage tank 3 due to the negative pressure in the filtration drum 5, and only the water and the extremely small solid lumps cause the precoat layer 4 to be absorbed. After passing, the solid mass is adsorbed on the surface of the precoat layer 4. The moisture sucked into the filtration drum 5 and the fine solid mass that has permeated the precoat layer 4 are sucked from the suction port 27 to the jet pump MJP via the suction passage 26, the suction pipe 25, and the communication pipe 40, and the jet pump MJP. Is discharged from the discharge port 50 into the water storage tank 44.

Next, the solid mass adsorbed and held on the surface of the precoat layer 4 is scraped off by the scraping blade 10 by the rotation of the rotary drum 5. The precoat layer 4 above the scraping blade 10 is in the atmosphere. When it is exposed to the inside, it is sufficiently dehydrated before reaching the scraping blade 10 and is scraped off from the scraping blade 10 in the form of a cake. Further, in the case where the entire filtration drum 5 is immersed in the treatment liquid, the solid mass scraped off by the scraping blade 10 gradually concentrates the portion on the upstream side of the rotation direction of the filtration drum 5. The cake-like solid mass scraped off by the scraping blade 10 and the concentrated treatment liquid are taken out from the concentrated liquid or solid mass extraction port 13 at the bottom and processed.

The precoat layer 4 of the filtration drum 5 is gradually clogged by the solid mass adsorbed and held there, and the filtration function is deteriorated. However, when the filtration function is deteriorated, the negative pressure of the negative pressure supply means 8 is reduced. Therefore, the negative pressure gauge 41 of the communication filtration drum 40 detects the increase in the negative pressure, and the servomotor 39 is rotated by a predetermined amount by the rotation drive signal from the control device 42, and the screw member is passed through the belt transmission device 38. 34 is rotated and the hoisting pipe 35 is extended downward. When the hoisting pipe 35 extends downward, the rotating bracket 32 is swung from the position shown by the solid line in FIG. 3 in the direction indicated by the alternate long and short dash line. Accordingly, the eccentric cam 28 swings and the filter drum 5 also goes downward. Then, the portion of the precoat layer 4 that has been clogged is scraped off by the scraping blade 10, the clogging is eliminated, and filtration can be continued. Then, when the clogged precoat layer 4 portion is cut by the scraping blade 10 and the rotary bracket 32 reaches the position indicated by the chain double-dashed line in FIG. 3, the thickness of the precoat layer 4 reaches the use limit.

When the precoat layer 4 which has reached the use limit is regenerated to a predetermined thickness, a part of the processing liquid 2 in the storage tank 3 is drained to lower the liquid level, and the surface of the precoat layer 4 is scraped off. The filter drum 5 is exposed above the liquid surface by operating the position away from the position shown by the solid line in FIG. Then, the filter medium supply pallet 54 of the filter medium supply device 51 is swung so that the tip of the filter medium supply pallet 54 comes into contact with the precoat layer 4 which has reached the use limit, and the filter medium is supplied from the supply nozzle 55 to be adsorbed to a predetermined thickness. That is, the precoat layer 4 is formed. When the new precoat layer 4 is formed in this way, the filtration can be restarted by supplying the treatment liquid 2 to the storage tank 3 in a state where at least a part of the precoat layer 4 of the filtration drum 5 is immersed.

In the above embodiment, the jet pump MJP of the negative pressure forming means is used to inject water pressurized by the pressure pump from the injection nozzle toward the discharge pipe as a jet water flow,
Although a negative pressure is formed in the discharge pipe, as shown in FIG. 5, the jet water flow jetted from the jet nozzle 49 to the air mixing pipe 51 causes the air mixing pipe 51 and the jet nozzle 4 to move.
9, a negative pressure is generated, and the negative pressure mixes the air sucked from the intake pipe 52 with the jet water flow to form a mixed air jet flow, and the mixed air jet flow is discharged from the air mixing pipe 51. It is needless to say that the air-fuel mixture jet pump MJP which is made to inject into the pipe 48 to form a negative pressure in the discharge pipe 48 can be used, and the present invention constitutes a negative pressure forming means by a vacuum pump. It does not exclude things.

Although the clogging of the precoat layer can be detected and the clogged precoat layer can be automatically cut, the invention is not limited to this, and the filtration drum is manually moved up and down. Of course you can. Further, in the above embodiment, the position changing means controls the rotation of the screw member by the servo motor to move the hoisting pipe up and down, thereby turning the eccentric cam through the turning bracket connected to the lower end of the hoisting pipe. However, it is of course possible to directly rotate the eccentric cam by forming a tooth profile on the peripheral surface of the cam member of the eccentric cam and attaching a worm gear meshing with the tooth profile to the output shaft of the servo motor. Is.

[0024]

As described above, according to the rotary drum type filtration device of the present invention, the pivot support extending from the one side surface of the filtration drum having the precoat layer formed on the peripheral surface to the outside of the side wall of the storage tank. Since the shaft is pivotally supported on the side wall of the storage tank through the position changing means and the pivot shaft is configured to be rotatable by the driving means, the storage tank is small enough to accommodate the width of the precoat layer of the filtration drum. Therefore, there is an advantage that the rotary drum type filtration device can be significantly downsized.

In addition, since the bearing member and the drive means for rotating the filter drum are provided on the pivot shaft of the filter drum extending outside the side wall of the storage tank, it must be immersed in sludge as usual. It is said that the solid mass in the sludge caused by the fact that it is not caught in the bearing member and the driving means, does not wear early, greatly improves the durability, and makes inspection and repair convenient. There are also advantages.

Further, when the precoat layer is formed on the filter drum which has reached the limit of use, the filter drum is exposed on the liquid surface, and the filter material is supplied from the filter material supply device to the filter drum exposed on the liquid surface of the treatment liquid. Since a new precoat layer is formed by supplying it upward and adsorbing it to a predetermined thickness, it is possible to easily form the precoat layer within a short time, and to perform the filtration for forming the precoat layer. There is also an advantage that the down time of the device can be shortened and the operating efficiency thereof can be improved.

In addition, the negative pressure forming means comprises a pressurizing pump for pressurizing the liquid and a jet pump for injecting the pressurized liquid to form the negative pressure. The negative pressure formed by the jet pump is used. With a suction port that opens the inside of the rotating drum that acts on the negative pressure acting space, even if the liquid sucked under negative pressure contains a minute solid mass that has permeated the precoat layer, this Therefore, there is also an advantage that the negative pressure forming means such as a jet pump is not worn or the performance is not deteriorated, and the durability of the negative pressure forming means can be improved.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing a schematic structure of a rotary drum type filtration device.

FIG. 2 is a vertical side view of a rotary drum type filtration device.

FIG. 3 is an explanatory diagram of a rotation operation mechanism of an eccentric cam.

FIG. 4 is an explanatory diagram of a jet pump that constitutes negative pressure supply means.

FIG. 5 is an explanatory diagram of a modified example of a jet pump that constitutes negative pressure supply means.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Rotating drum type filtration device 2 ... Treatment liquid 3 ... Reservoir 4 ... Precoat layer 5 ... Filtration drum 6 ... Pivot shaft 7 ... Position changing means 10 ...・ Scraping blade 26 ・ ・ ・ Suction path 51 ・ ・ ・ Filter material supply device MJP ・ ・ ・ Jet pump

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B01D 37/02 E 7305-4D C02F 11/12 D 7446-4D

Claims (3)

[Claims] 1. A pivot shaft extending from one side surface of the filtration drum to the outside of a side wall of the storage tank is positioned by immersing at least a part of a filtration drum having a filtration surface on its peripheral surface in the treatment liquid of the storage tank. A suction passage which is rotatably supported on the side wall of the storage tank through the changing means, the pivot shaft is configured to be rotatable by the driving means, one end of which is opened in the filtration drum, and the other end of which is connected to the negative pressure forming means. Is formed in the pivot shaft, negative pressure is applied to the filtration drum through the suction passage to filter the treatment liquid in the precoat layer, and the scraping blade that scrapes off the adsorbed matter adsorbed and retained in the precoat layer is stored. A rotary drum type filtration device characterized in that the filtration drum is displaceable in a direction in which the precoat layer is scraped off by moving the position changing means while being fixed to the tank, and being moved toward and away from the blade. 2. A filter material supply device for exposing at least the upper end of the filter drum onto the upper surface of the treatment liquid in the storage tank and supplying a filter material for forming a precoat layer to the exposed filter drum. The rotary drum type filtration device according to claim 1. 3. The negative pressure forming means comprises a pressurizing pump for pressurizing the liquid, and a jet pump for injecting the pressurized liquid into the pipe to form a negative pressure in the pipe, which is formed by the jet pump. The rotary drum type filtration device according to claim 1, wherein a suction port for applying a negative pressure is opened inside the rotary drum.