JP4051260B2 - Filtration device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a filtration device that can perform effective filter cleaning.
[0002]
[Prior art]
Conventionally, various types of filtration devices are used for removing suspended substances in water. There is what is called a screen cylinder type filter, and a cylindrical screen (cylindrical filter having a predetermined hole diameter) is disposed in a cylindrical hermetic housing, thereby performing filtration. That is, raw water is pumped from the inside of the filter, and treated water is obtained outside the filter. And in this screen cylinder type filter, the washing nozzle which can move spirally is located inside the filter, and the discharge way of this washing nozzle is opened intermittently or continuously. By opening the washing nozzle, suction from the washing nozzle is generated by the raw water pressure, and thereby the suspension cake filtered and separated on the filter inner surface is removed from the filter inner surface.
[0003]
In such a screen cylinder type filter, the filter can be cleaned by switching the valve (opening the discharge path of the cleaning nozzle) while the filtration is continued, and the filtrate can be effectively removed.
[0004]
[Problems to be solved by the invention]
However, depending on the amount of the suspension in the raw water and the raw aqueous state, the filter may not be sufficiently cleaned only by suction using the above-described cleaning nozzle. For example, white water in a paper mill contains a large amount of fibrous suspended substances and a large amount of soluble impurities. For this reason, if the filtration is continued, the suspension cake on the inner surface of the filter may not be sufficiently removed, or a backlogging phenomenon may occur in which a part of the suspension adheres and accumulates on the outer surface of the filter.
[0005]
This invention is made | formed in view of the said subject, and aims at providing the filtration apparatus which can perform more effective filter washing | cleaning.
[0006]
[Means for Solving the Problems]
The present invention is a filtration device for filtering raw water containing soluble impurities, a cylindrical filter composed of a wire mesh member , a housing surrounding and sealing the filter, and a raw water chamber inside the filter. Raw water supply means for supplying pressurized raw water, discharge means for discharging filtrate from the filtrate chamber outside the filter, a suction nozzle provided in the raw water chamber and opening at a position facing the filter inner surface, When connected to the suction nozzle and having a mud valve, the washing water discharging means for discharging the washing waste water sucked from the suction nozzle through the mud valve to the outside, and when the raw water chamber is in a pressurized state, A suction control means for performing control for opening the mud valve of the cleaning water discharging means to suck the cleaning waste water from the suction nozzle, a nozzle moving means for moving the suction nozzle along the inner surface of the filter, A backwash nozzle that is disposed in a filtrate chamber and is opposed to the suction nozzle and that discharges backwash water; and when the drainage valve of the wash water discharge means is open, the backwash nozzle Backwashing water supply means for pressurizing backwashing water, and backwashing nozzle moving means for moving the backwashing nozzle in synchronization with the suction nozzle, wherein the suction nozzle and backwash nozzle are By moving in synchronization with both the axial direction and the circumferential direction of the filter, the suspended cake adhering to the inner surface of the filter is sucked and removed by moving spirally with respect to the filter, and the solubility contained in the raw water It is characterized by preventing backlogging caused by the suspension adhering to the filtrate side of the filter due to the impurities .
[0007]
As described above, according to the present invention, the backwash water is jetted from the backwash nozzle in accordance with the suction of the suction nozzle. Accordingly, sufficient cleaning can be performed when the filter cannot be sufficiently cleaned only by suction from the suction nozzle due to the properties of the raw water. That is, it is possible to reliably prevent backlogging where the suspended matter adheres to the filtrate side of the filter. In addition, since the suction nozzle and the backwash nozzle are moved synchronously, effective cleaning can be performed while maintaining the spraying of the backwash water at a sufficient speed and the suction by the suction nozzle.
[0008]
A cleaning step of supplying backwash water to the backwash nozzle when the drainage valve of the cleaning water discharge means is open; and It is preferable to carry out both the washing step in which no backwash water is supplied to the backwash nozzle .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 and 2 are diagrams illustrating an overall configuration of a filtration device according to an embodiment.
[0010]
The device housing 1 is cylindrical and has a structure in which the inside is sealed, and one end side (left side in the figure) has a small diameter part with a small radius, and the other end side (right side in the figure) has a large diameter part with a large radius. Yes. A flange-shaped housing lid 2 is provided at the end of the device housing 1 on the small diameter side (left end in the figure), and the small diameter side end is closed. A raw water inlet 3 is provided in a part of the small diameter portion of the apparatus housing 1. The raw water inflow port 3 has a pipe shape facing outward and has a flange-shaped tip, to which a raw water inflow pipe is connected. Further, a filtrate outlet 4 is provided in a part of the large diameter portion of the apparatus housing 1. The filtrate outlet 4 has a pipe shape facing outward, and its tip has a flange shape, to which a filtrate discharge pipe is connected.
[0011]
A coarse screen cylinder 9 is disposed concentrically with the apparatus housing in the small diameter portion of the apparatus housing 1. This coarse screen cylinder 9 is for separating coarse solids, and is formed of punching metal or the like, and separates and removes coarse solids in raw water on its outer surface. The outer side of the coarse screen cylinder 9 in the small diameter portion of the apparatus housing 1 is the raw water chamber 5, but in this embodiment, the filtrate of the coarse screen cylinder 9 is the raw water of the fine screen cylinder 10 in the next stage, and is fine clean. The inner chamber of the cylinder 10 is the raw water chamber 5. Further, the outer space of the coarse screen cylinder 9 in the raw water chamber 5 is partitioned on the right side (large-diameter portion side) in the figure by a thin screen cylinder shielding plate 25, while the left side (apparatus housing lid 2) in the raw water chamber 5 in the figure. Side) is partitioned by the raw water inflow chamber shielding plate 26. On the large-diameter side of the device housing 1, a thin screen cylinder 10 having substantially the same diameter as the coarse screen 9 is provided, and the right end of the thin screen cylinder 10 in the figure is closed by a water stop flange 7. The thin screen cylinder 10 is formed of a wire mesh member, and the mesh opening is about 10 to 500 μm (about 600 to 30 mesh). The material is, for example, stainless steel.
[0012]
Accordingly, the raw water supplied under pressure from the raw water inlet 3 passes through the coarse screen cylinder 9 from the outside to the inside, and then reaches the inside of the fine screen cylinder 10 and exits from the inside to the outside. Then, when the coarse screen cylinder 9 is removed from the outside toward the inside, primary filtration is performed to remove a large suspended matter. Thereafter, when the fine screen cylinder 10 is removed from the inside toward the outside, the fine screen cylinder 10 is removed. Secondary filtration is performed. Then, the filtrate is discharged as treated water from the filtrate outlet 4.
[0013]
At the center of the coarse screen cylinder 9 and the fine screen cylinder 10, a pipe-shaped suction scanner 20 that extends from the water stop flange 7 to the entire region and penetrates the raw water inflow chamber shielding plate 26 is provided. The suction scanner 20 is closed at its end on the water stop flange side, and a suction nozzle 23 that extends in the radial direction and opens near the inner surface of the thin screen cylinder 10 is provided on a part of the peripheral surface thereof. In this example, the suction nozzle 23 extends in a radial direction 180 degrees different from the suction nozzle 23 at a position corresponding to the axial center of the thin screen cylinder 10 of the suction scanner 20 in the vicinity of the inner surface of the thin screen cylinder 10. Another suction nozzle 23 that opens is provided. That is, the suction nozzle 23 is connected to the suction scanner 20 in a state where the suction nozzle 23 communicates with the suction scanner 20 at a position that differs by 180 degrees in the radial direction and differs by about ½ of the axial length of the thin screen cylinder 10 in the axial direction. An end portion of the suction scanner 20 on the apparatus housing lid 2 side is opened at a position (a little ahead) penetrating the raw water inflow chamber shielding plate 26.
[0014]
A space partitioned by the apparatus housing lid 2 where the suction scanner 20 opens and the raw water inflow chamber shielding plate 26 is a flushing chamber 8. In the flushing chamber 8, a cylindrical screen having substantially the same diameter as the coarse screen cylinder 9 and the fine screen cylinder 10 is disposed. The diameter of the opening of this cylindrical screen is larger than the opening of the coarse screen cylinder 9. The apparatus housing 1 of the flushing chamber 8 is provided with a mud discharge port 27, and an automatic mud discharge valve 28 is connected to the mud discharge port 27 via a mud pipe. The automatic mud discharge valve 28 is connected to a mud drain pipe (not shown).
[0015]
Therefore, when the raw water chamber 5 is in a pressurized state, the suspension cake attached to the inner surface of the fine screen cylinder 10 is sucked into the suction nozzle 23 by opening the mud valve 28, and this is the suction scanner 20, It is discharged through the flushing chamber 8 and the automatic mud valve 28.
[0016]
Further, an opening connected to the suction side of the filtrate injection electric pump 29 is provided in the left portion (portion close to the small diameter portion) of the filtrate chamber 6 in the apparatus housing 1. The discharge side of the filtrate injection electric pump 29 is connected to a sealed backwash filtrate chamber 22 provided outside the right end wall of the apparatus housing 1. The washing filtrate chamber 22 is connected to a backwash nozzle 24 via a backwash pipe. The backwash nozzle 24 is provided at a position facing the suction nozzle 23 described above with the fine screen cylinder 10 interposed therebetween. That is, the two backwash nozzles are provided at positions that differ by 180 degrees in the radial direction and differ by about ½ of the axial length of the thin screen cylinder 10 in the axial direction.
[0017]
In addition, there are two pipes from the washing filtrate chamber 22 to the backwash nozzle 24, each of which enters the filtrate chamber 6 from the opposite side (position different by 180 degrees) at the center side portion, and then radially outward. Is connected to the backwash nozzle 24 at a predetermined position outside the thin screen cylinder 10 by extending in the axial direction. Moreover, while the front-end | tip part (left side part) of piping closes, it connects with the piping extended in the circumferential direction. As a result, the pressures at the two backwash nozzles 24 are equalized and the strength is sufficient.
[0018]
Further, the end portion (right end portion) of the suction scanner 20 on the thin screen cylinder 10 side is closed, and a connecting shaft 14 is connected to this end portion, and this passes through the washing filtrate chamber 22. And extends to the right. The connecting shaft 14 is located at the center of the apparatus housing 1 in the axial direction. Moreover, the part which penetrates the water stop flange 7 of the connection shaft 14 is sealed by the sealing material, so that raw water does not leak from here.
[0019]
The drive shaft 12 of the electric gear motor 11 is coupled to the right end portion of the coupling shaft 14. Therefore, the drive shaft 12 and the connecting shaft 14 are rotated by driving the electric gear motor 11. Further, a limit switch disk 13 is provided in the vicinity of the connection portion between the drive shaft 12 and the connecting shaft 14, and a pair of limit switches 15 are provided at a predetermined position outside the limit switch disk 13. . In other words, the pair of limit switches 15 are installed at predetermined points A (left) and B (right) in the axial direction of the connecting shaft 14, and the limit switch disk 13 moves in the axial direction. If you do come in contact. Therefore, when the connecting shaft 14 is moved in the axial direction, the limit switch disk 13 comes into contact with the pair of limit switches 15 so that the movement of the distance corresponding to the interval between the limit switches 15 can be detected.
[0020]
The drive shaft 12 is a screw shaft having a screw formed around it. The drive shaft 12 passes through a fixed nut 30 in the vicinity of the electric gear motor 11. Therefore, the drive shaft 12 moves in the left-right direction according to the rotation. The drive shaft 12 and the nut 30 are preferably ball screws.
[0021]
As described above, the drive shaft 12 is fixed to the end of the suction scanner 20 via the connecting shaft 14. Therefore, the suction scanner 20 moves in the axial direction while rotating by the rotation of the electric gear motor 12. Therefore, the suction nozzle moves spirally along the inner surface of the thin screen cylinder 10. By moving in this axial direction, it can be detected that the limit switch disk 13 has moved to point A and point B, so that the drive shaft can be moved between point A and point B. When the limit switch disk 13 is positioned at point A, the left suction nozzle 23 is positioned at the left end of the thin screen cylinder 10, and when the limit switch disk 13 is positioned at point B, the right suction nozzle 23 is positioned. Is located at the right end of the thin screen cylinder 10. As a result, the pair of suction nozzles 23 can be moved along the entire inner surface of the thin screen cylinder 10.
[0022]
The connecting shaft 14 is provided with a first backwash nozzle driving gear 16. The first backwash nozzle driving gear 16 includes a central gear fixed to the connecting shaft 14 and a pair of peripheral gears engaged with the periphery of the central gear. For this reason, a center gear rotates by rotation of the connection shaft 14, and a peripheral gear rotates further. A pair of backwash nozzle drive gear shafts 17 extending in parallel with the connecting shaft 14 are fixed to the peripheral gear of the first backwash nozzle drive gear 16, and the pair of backwash nozzle drive gear shafts 17. A second backwash nozzle driving gear 18 is connected to the second backwash nozzle. The second backwash nozzle driving gear 18 has a pair of peripheral gears connected to the pair of backwash nozzle driving gear shafts 17 and a central gear meshing with the peripheral gears. A backwash nozzle spindle 19 is fixed to the central gear. The backwash nozzle spindle 19 has a hollow pipe shape, extends in the left direction, passes through the backwash filtrate chamber 22, and reaches the left end in the filtrate chamber 6 of the apparatus housing 1. And the backwash water piping connected to a pair of backwash nozzle 24 is connected to the left end part, and the communicating path for connecting this backwash water piping and the filtrate chamber 19 for backwashing is formed in an inside Has been. Therefore, the filtrate from the filtrate injection electric pump 29 reaches the backwash nozzle 24 from the backwash filtrate chamber 22 once through the passage and the drawing pipe in the backwash nozzle spindle.
[0023]
Further, in the hollow portion of the backwash nozzle spindle 19, a backwash nozzle spindle fixing shaft 21 having a left end fixed to the water stop flange 7 and a right end disk-shaped is disposed. The left end disk of the backwash nozzle spindle fixing shaft 21 is fixed to a fixed frame extending rightward from the right end of the apparatus housing 1.
[0024]
Therefore, the rotation of the connecting shaft 14 is transmitted to the first backwash nozzle drive gear 16, the backwash nozzle drive gear shaft 17, the second backwash gear drive gear 18, and the backwash nozzle spindle 19. Therefore, by making the constituent gears of the first and second backwash nozzle drive gears 16 the same, the rotational speeds of both gears are the same, and the backwash nozzle spindle 19 rotates at the same rotational speed as the rotation of the connecting shaft. Further, since the central gear of the first backwash nozzle drive gear 16 is fixed to the connecting shaft 14, the first backwash nozzle drive gear 16 moves in the axial direction together with the connecting shaft 14. Therefore, the backwash nozzle 24 performs exactly the same spiral movement as the suction nozzle 23.
[0025]
FIGS. 3 and 4 are diagrams corresponding to FIGS. 1 and 2, respectively. The drive shaft 12, the connecting shaft 14, the suction scanner 20, the suction nozzle 23, the first backwash nozzle driving gear 16, and the backwash. The nozzle drive gear shaft 17, the second backwash nozzle drive gear 18, the backwash nozzle spindle 19, and the backwash nozzle 24 are shown moving rightward.
[0026]
In such an apparatus, raw water is supplied to the raw water inlet 3 by a raw water pump (not shown). Therefore, the raw water passes from the raw water chamber 5 through the coarse screen cylinder 9 to the inside, and then moves to the right, passes through the fine screen cylinder 10 from the inside to the outside, and reaches the filtrate chamber 6. Then, it is discharged from the filtrate chamber 6 through the filtrate outlet 4. By continuing such processing, the suspended matter is collected and deposited on the inner surface of the fine screen cylinder 10. As a result, the pressure loss in the fine screen cylinder 10 increases.
[0027]
For this reason, when the pressure loss of the fine screen cylinder 10 exceeds a certain level, the fine screen cylinder 10 is cleaned. In addition, although the pressure loss should just measure the pressure in front and back (inside and outside) of the thin screen cylinder 10, it is good also by measuring the pressure of the inflow raw | natural water and the pressure of the discharged filtrate.
[0028]
In the cleaning process, the automatic mud valve 28 is opened, the filtrate injection electric pump 29 is driven, and the electric gear motor 11 is driven. Thereby, while the filtrate is jetted from the backwash nozzle 24, the mud from the suction nozzle 23 is discharged, and the backwash nozzle and the suction nozzle 23 move spirally.
[0029]
As a result, both the suction mud from the inner surface side of the fine screen cylinder 10 and the cleaning by the filtrate injection from the outer side are performed, and the fine screen cylinder 10 is effectively cleaned.
[0030]
This washing process is completed in several tens of seconds and returns to the filtration process. In the cleaning process, the movement from the point A to the point B may be performed only one way in the axial direction, but it may be one or several reciprocations.
[0031]
As described above, according to the present embodiment, the backwash water is sprayed from the backwash nozzle 24 in accordance with the suction of the suction nozzle 23. Accordingly, sufficient cleaning can be performed when the filter cannot be sufficiently cleaned only by suction from the suction nozzle due to the properties of the raw water. That is, it is possible to reliably prevent backlogging where the suspended matter adheres to the filtrate chamber 6 side of the fine screen cylinder 10. Further, since the suction nozzle 23 and the backwash nozzle 24 are moved in synchronization, the backwash water can be jetted at a sufficient speed and the suspension cake can be sucked. Therefore, it can be effectively applied to white water of a paper mill containing a relatively high concentration of suspended solids.
[0032]
In the above description, some descriptions of the seal and the guide are omitted, but a seal that does not leak water, a guide for ensuring axial movement, and the like need to be provided as appropriate.
[0033]
Further, the size of the mesh of the fine screen cylinder 10 or the like may be appropriately selected according to the properties of raw water. Further, instead of the pressure loss of the fine screen cylinder 10, cleaning may be performed periodically by a timer.
[0034]
Furthermore, the properties of the filtrate may be deteriorated in the washing step. Thus, in the washing step, the filtrate can be returned to the raw water side.
[0035]
Further, the number of suction nozzles 23 and backwash nozzles 24 may be one, or three or more. Further, the injection from the backwash nozzle 24 does not have to be performed every time in the cleaning process, and a cleaning process for performing only suction may be provided.
[0036]
Further, only one filtration may be performed without providing the coarse screen cylinder 9. Furthermore, the moving mechanism of the backwash nozzle 24 and the suction nozzle 23 is not necessarily limited to the configuration of the present embodiment.
[0037]
【The invention's effect】
As described above, according to the present invention, the backwash water is sprayed from the backwash nozzle in accordance with the suction of the suction nozzle. Accordingly, sufficient cleaning can be performed when the filter cannot be sufficiently cleaned only by suction from the suction nozzle due to the properties of the raw water. That is, it is possible to reliably prevent backlogging where the suspended matter adheres to the filtrate side of the filter. In addition, since the suction nozzle and the backwash nozzle are moved synchronously, effective cleaning can be performed while maintaining the spraying of the backwash water at a sufficient speed and the suction by the suction nozzle.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a left side portion of a filtration device according to an embodiment.
FIG. 2 is a diagram illustrating a configuration of a right side portion of the filtration device according to the embodiment.
FIG. 3 is a diagram of a left side portion corresponding to FIG. 1 and shows a state in which a nozzle has moved to the left side.
4 is a diagram of a right side portion corresponding to FIG. 2 and shows a state in which a nozzle has moved to the left side.
[Explanation of symbols]
1 equipment housing, 3 raw water inlet, 4 filtrate outlet, 5 raw water chamber, 6 filtrate chamber, 10 fine screen cylinder, 11 electric gear motor, 14 connecting shaft, 23 suction nozzle, 24 backwash nozzle, 28 automatic mud Valve, 29 Filtrate injection electric pump.

Claims (2)

A filtration device for filtering raw water containing soluble impurities,
A cylindrical filter composed of a wire mesh member ;
A housing surrounding and sealing the filter;
Raw water supply means for supplying pressurized raw water to the raw water chamber inside the filter;
Discharging means for discharging the filtrate from the filtrate chamber outside the filter;
A suction nozzle provided in the raw water chamber and opening at a position facing the inner surface of the filter;
Wash water discharge means connected to the suction nozzle and having a mud valve, for discharging the washing waste water sucked from the suction nozzle through the mud valve to the outside,
When the raw water chamber is in a pressurized state, a suction control means for performing control for opening the mud valve of the cleaning water discharging means and sucking the cleaning waste water from the suction nozzle;
Nozzle moving means for moving the suction nozzle along the inner surface of the filter;
A backwash nozzle that is in the filtrate chamber and is disposed at a position facing the suction nozzle, and discharges backwash water;
Backwash water supply means for pressurizing and supplying backwash water to the backwash nozzle when the mud valve of the wash water discharge means is open;
Backwash nozzle moving means for moving the backwash nozzle in synchronization with the suction nozzle;
Have
The suction nozzle and the backwash nozzle move in synchronization with both the axial direction and the circumferential direction of the filter to move spirally with respect to the filter, thereby sucking the suspension cake adhering to the filter inner surface. A filtration device that removes and prevents backlogging due to a suspended impurity adhering to the filtrate side of the filter due to soluble impurities contained in raw water . The filtration device according to claim 1,
A cleaning step of supplying backwash water to the backwash nozzle when the drainage valve of the washwater discharge means is open, and the backwashing when the drainage valve of the washwater discharge means is open. A filtration apparatus characterized by performing both of a washing step in which no backwash water is supplied to the nozzle.

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