JP2001300216A - Disk-shaped strainer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a monolithic structure of a disk-shaped strainer capable of being easily arranged and attached, having a simple structure, capable of uniformly dispersing water and air, hard to generate clogging and capable pf efficiently performing a filtering process and a backward washing process. SOLUTION: In the disk-shaped strainer, the strainer body is formed of a bottom plate part 3, which has an upper male screw part 1 for pressing and fastening a disk and a water and air passing cylindrical water gathering and dispersing part 2 provided in the lower part of the male screw part and is arranged on a filter bed plate 9, and a lower piping 4, which is continued to the bottom plate part and has a male screw passed through the strainer arranging hole provided in the filter bed plate or a sleeve having a female screw, and obtained as a monolithic molded object.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a water supply system, a sewer system,
Wastewater, generally used for water treatment of seawater, etc., and also used when a liquid requires a filtration step, a strainer as a water collecting and distributing device for a filter, or a pressure type using the same,
Or, it relates to a gravity filter. The water collecting and distributing device collects the treated water uniformly when filtering the filter, and evenly distributes the water and air during backwashing, so that it can be collected in the filter material such as sand filled at the top of the water collecting and distributing device. It plays the role of removing and discharging trapped turbidity. Since the water collecting and distributing device is a fundamentally important element technology for the filter, it has been improved with the progress of the filter, and various water collecting and distributing devices have been proposed and put to practical use. TECHNICAL FIELD The present invention relates to a water collecting and distributing device also called a strainer or a nozzle. Strainers have been studied for use in ion exchange devices and various filters since the 1940s to 1950s, and strainers of various shapes have been put to practical use.

[0002]

2. Description of the Related Art There are various types of water collecting and distributing apparatuses having various structures and functions. A perforated pipe system composed of a main pipe (base pipe) and a branch pipe connected to the main pipe and having small holes or slits, and a strainer type in which a strainer having slits is installed on a filter bed plate (perforated plate) (the present invention) Belongs to this method). The above-mentioned “slit” means “gap”, and the slit width is determined so that the treated water passes and the filtering material does not pass at the time of filtration. In addition, during filtration, the structure is such that turbidity and the like are unlikely to enter the slit. Also, if turbidity or fine filter material itself that causes clogging enters the slit, these substances are used. There is a demand for a structure that can apply an effective backwashing method that can easily discharge wastewater.

There are various types of perforated tube systems.
An example is shown below. (1) A small hole of about 6 to 12 mm in diameter (diameter) is drilled in a branch pipe connected to the main pipe, and gravel as a support layer is laminated in the order of large, medium and small sizes, and a filtering material such as sand is placed thereon. Filling method. (2) A method in which the branch pipe having the small holes is covered with a plastic net or a metal net having fine and uniform slits. (3) The so-called perforated pipe method and the strainer method are combined, in which a strainer is directly installed in a branch pipe instead of a small hole. In addition, there are several methods corresponding to the type of the filter medium, the shape of the device, the operation method, and the like.

[0004] The perforated tube method is generally applied when only backwashing with water is mainly performed. This is because the pipe resistance of air is considerably smaller than that of water, and the pipe diameter and small holes for water cannot be used as they are. In order to perform air backwashing properly, an appropriate pipe diameter,
It is necessary to provide a dedicated air backwashing piping system having the hole diameter of the air inlet, and to perform uniform distribution of air. This method is more complicated because it has a double piping system for water and air. Therefore, when the specific gravity of the filter medium is small, air is directly blown into the main pipe to provide an effect similar to "simultaneous washing of water and air". However, in the case of this method, when the filter medium has a large specific gravity, such as sand, it is difficult to uniformly disperse the filter medium. In addition, when there is a support layer or when the filter medium is a multi-layer, it is difficult to apply it because mixing occurs and it is difficult to adjust the layer again after backwashing.

[0005] The strainer method is further described below.
Generally, there are two types. (1) Vertical strainer with vertical slits 1) This method mainly uses plastic materials,
The slit width can be configured quite freely, from 0.1 to 1.0 mm. Further, since it can be manufactured in various shapes, it is widely used. The structure of the slit is usually 0.15 to 0.5 mm outside the slit of the strainer so that clogging is difficult to occur. The inside of the opening immediately opens in a fan shape, and the opening is several times larger than the outside. Width. That is, the distance in the horizontal direction of the slit is extremely short, and turbidity and the like that have passed through the outer slit width do not accumulate in the horizontal direction of the slit, but immediately flow into filtered water or washing wastewater. And clogging hardly occurs.

On the other hand, in the case of backwashing, if there are many turbid substances having a larger particle size than the slit width in the backwashing water, clogging occurs from the inside of the slit and accumulates in the fan-shaped portion. There is a risk that backwashing will not be possible. This phenomenon is
The large turbidity is strongly pressed by the flow rate at the time of the backwash from the inside of the slit to the narrowest slit width, and once the outer slit is clogged, the turbidity having a particle size smaller than the slit width. And the horizontal distance of the slit may be extremely short, and clogging occurs in a short time. Therefore, generally as backwash water,
Backwashing with raw water that contains filtered water and contains turbid and large particles is usually not performed due to the high risk of clogging.

2) Pressure filter φ3000 shown in FIGS.
As shown in the example of (inner diameter: 3000 mm), the filter floor plate 9 is provided with a hole 37 through which the strainer 34 of the vertical slit passes, and the lower pipe 4 having a male screw connected to the vertical slit portion 36 and the bottom plate 3 is inserted. The worker enters under 9 and cooperates with the worker on the filter floor plate to tighten and fix the nut 13 with a locking nut 13. In this installation method, an area below the filter floor plate 9 is given a margin to facilitate installation of manholes where workers enter and exit and work under the filter floor plate 9.

In the example shown in FIG. 7, the vertical slit portion 36, the bottom plate 3 and the lower pipe 4 following the vertical slit portion 36 are integrally formed. An air backwash pipe 5 having an air inlet 15 and an air outlet 16 is inserted into the lower pipe 4 and fixed with an adhesive or the like to form an integral structure as a whole. Although the thickness of the filter plate varies depending on the tower diameter of the filter, the thickness is about 9 to 32 mm even when a rubber lining component is added to the iron material.

3) In the case of the gravity type having a generally large filtration area, the number of strainers to be installed also increases. FIG. 8 shows an installation example. FIG. 8 shows an example of only one strainer,
Other strainers are installed as well. Since the filtration area is large, the thickness L7 of the filter bed plate 9 is set to 100 to 2 when newly installing the apparatus so as to sufficiently withstand the pressure during operation, particularly when backwashing.
00 mm, usually about 150 mm thick, firstly, preliminary work to fix the sleeve 22 vertically, further reinforcement work to insert a reinforcing bar, work to inject mortar and the like as a fixing agent, and support work for filter floor plates, etc., are particularly important. Be careful. This work requires a lot of trouble because of the large number of strainers and the like. For this reason, improvements and improvements in the structure and strength of the strainer are still required at the present time in order to facilitate the work inspection at the time of periodic inspections or abnormalities, along with the improvement of the construction method in the installation work of the sleeve. ing.

4) However, in FIG. 8 showing an example of an improved vertical strainer in recent years, almost the same as the examples of FIGS. A semicircular slit 38 having the same structure and a diameter of about 70 mm, a bottom plate 3 for increasing the strength for fixing, and a lower pipe 4 having a male thread are formed integrally with the slit 38. Further, the air backwashing pipe 5 inserted and fixed in the lower pipe 4 is also integrally formed as a whole. This integrated structure is screwed into the sleeve from above the filter floor plate 9 and tightened to fix it. With this configuration, it is easy to remove the filter floor plate 9 from the filter floor plate 9 again at the time of periodic inspection and when necessary, thereby facilitating the installation and inspection work of the strainer. Also, as shown in FIGS.
The work of tightening the lower nut has been eliminated.

However, torque management when tightening and fixing is important, and care is taken not to overtighten. The basic structures of the integrated structures of the examples shown in FIGS. 6 to 7 and 8 are almost the same except for the method of fixing to the filter floor plate 9.
Further, the air inlet 15, air outlets 16, 21 and the like provided on the air backwashing pipe 5 of the integrated structure are formed in the post-processing so that they have the same hole diameter and position as other strainers. And uniform dispersion during backwashing is achieved. And water backwash, air backwash water backwash, "simultaneous backwash of water and air"
And so on, if necessary.

(2) Disk-type strainer in which disks are stacked and slits are provided in the horizontal direction. A conventional example of FIGS. 9 and 10 will be described below. 1) When the disk structures are devised and laminated, a slit, which is a gap, having a width of about 0.15 to 0.5 mm is formed on the outside 51 of the outer peripheral portion 49 between the disks. In the case of a vertical slit, as described above, the outside that is the inflow side during filtration and the outlet side during backwashing is, for example,
If the width is 0.25 to 0.3 mm, the inside which is the outlet side during filtration and the inlet side during backwashing has a large fan-like opening with a width of 1 to 2 mm. The length of this fan-shaped part is 2-3mm
About short. On the other hand, in the disk type, if the outer (outer peripheral) slit has a width of 0.25 to 0.3 mm, the inner side immediately opens horizontally to a width of 0.7 to 1.2 mm, and the length L11 is 8 to 1 depending on the disc structure
It is about 2 mm.

The width and length of the horizontal portion and the structure thereof are important for preventing clogging due to turbidity. The width is as large as possible, and the length L11 is preferably as short as possible. Even if the width and length of this horizontal portion are increased to about 20 mm, the shape is uneven, and the desired slit width is obtained, and a large number of holes of about 2 to 3 mm are arranged so that there is no problem in strength. However, there is a structural example in which the suspended matter or the like that has entered the horizontal portion is devised so as to be discharged.

2) FIG. 9 shows an example of the overall structure, and FIG. 10 shows an example of the structure of the disk used in FIG. In FIG. 9, the strainer body 39 also serves as a sleeve. Bolt hole 4 in the center of the disc in FIG.
A support 40 is provided for supporting and fixing bolts 42 passing through the bolts 8. Then, the disk 41 is passed through the bolt 42 and is stacked on the upper part of the main body 39. Then, the holding plate 44,
The nut 43 is doubled and tightened, and the laminated body of the disk 41 is pressed and fixed. Further, since the main body 39 also serves as a sleeve, the main body 39 is fixed in the filter floor plate.
5 are provided. 9 and 10 show an example of the use, which is as follows.

In the strainer shown in FIG. 9, the lower end 46 of the pipe in the figure is connected to a branch pipe of a perforated pipe type (welding or the like).
Use a mortar or the like to slightly lower the disk 41, that is, L
The part 10 and all the branch pipes and main pipes below it are embedded and fixed. In this case, an opening 47 having a hole diameter of 9 to 10 mm is provided at the center of the lower end 46 of the pipe. In such a method of use, the backwashing with water is considered to be fairly uniform. However, with the hole diameter of the opening 47 at the lower end 46 of the pipe, the resistance to air backwashing is too small, and uniform backwashing cannot be performed. In addition, since the main body, branch pipe and main pipe are buried with mortar, subsequent inspections can be performed only at the upper part of the strainer.If any problems occur at the connection with the branch pipe, take appropriate measures. Becomes extremely difficult.

3) The example of the disk structure shown in FIG. 10 is viewed from above. Circular convex portions 50 are provided on the outer peripheral portion 49 on the front and back sides of the disk, and when the disks are stacked and fastened and fixed, for example, a target slit width of 0.3 mm can be obtained. In this example, a uniform slit width is obtained because there are four connecting portions 54 between the disk center portion 55 and the outer peripheral portion 49 and four openings 53, respectively, and these are uniformly laminated without displacement. It is at the time of the state. However, this lamination state is disordered, that is,
It is known that when a random lamination state is obtained, the initial 0.3 mm width fluctuates to about 0.24 to 0.37 mm, resulting in an uneven slit width.

This phenomenon is caused by the hole 4 in the center of the disk.
8 is circular, and since the bolt 42 serving as a disk holder is cylindrical, the disk 41 gradually moves due to the repetitive load at the time of filtration or backwashing for long-term operation, etc. Due to randomness. Then, due to the fluctuation of the slit width, when the process shifts to the cleaning step after the backwashing, the filtering material and the like easily enter the slit. In addition, there is a problem that the resistance at the time of backwashing due to a random lamination state increases.

4) As in the case of the vertical strainer, a method of fixing the disk type with a nut below the filter plate is generally used. However, air backwash, "simultaneous washing of water and air"
For example, as shown in FIG. 1 of the present invention, an air backwash pipe having an air inlet 15, an air outlet 16, and an opening 18 serving as an inlet and an outlet of water below the filter plate 9. 5 are limited. With a disk type other than such a structure, for example, the conventional example of FIG. 9, backwashing becomes insufficient as described above.

5) It is conceivable to apply the examples of FIGS. 9 and 10 to a gravity filter. In this case, the thickness of the filter plate 9 is L10. Opening 47 provided at lower end 46 of pipe
With the hole diameter φ9 to 10 mm, as described above,
Although water backwashing can be performed, air backwashing is uneven and has little effect. To perform air backwashing, "simultaneous washing of water and air", etc., an example of the present invention is to provide an air backwashing pipe as shown in FIG. It is necessary to have a function as shown in FIG. In the conventional example shown in FIG. 9, in order to uniformly perform the air backwashing, the lower end 46 of the pipe is connected (welded) to the above-described perforated pipe type branch pipe, and then mortar or the like is embedded to a slightly lower portion of the disk. In that case, it is necessary to provide a separate air backwashing piping system.

[0020]

SUMMARY OF THE INVENTION The present invention has been made to solve the following problems in order to enable a disk type strainer to be used also as a pressure type filter and a gravity type filter, and to sufficiently fulfill its object. With the goal. That is, 1) To provide a simple structure having a low height from the upper surface of the filter plate to the disk so as to minimize dead space on the upper surface of the filter plate. 2) An integrated structure that can uniformly disperse water and air and that does not easily cause clogging. 3) In the gravity type filter, the above-mentioned object is solved, and the integrated structure is further taken out from the filter floor plate, and the disk type strainer can be recharged and fixed. Makes the work during periodic inspections easier. 4) In addition, air backwashing and "simultaneous backwashing of water and air" can be applied as well as water backwashing so that the filtration step and backwashing step can be performed efficiently.

[0021]

The present inventors have conducted intensive studies to solve the above-mentioned problems. As a result, a strainer having a basic structure shown in FIGS. 1 to 5 is preferable, and the above-mentioned various problems can be solved. And found the present invention. The basic structure example is the example of FIG. 1 of a pressure filter having a thin filter plate,
The following description will be made in accordance with the example shown in FIG. 2 for a gravity filter having a thick filter bed plate and the example shown in FIG. 3 in which the strainer of the present invention is installed in a perforated pipe type branch pipe. FIG. 1A is a plan view showing a partial cross-sectional view of a strainer for a pressure filter of the present invention, and FIG. 1B is a longitudinal sectional view of the strainer of the present invention. FIG. 2 is a longitudinal sectional view of the strainer of the present invention for a gravity filter. FIG. 3 is a longitudinal sectional view of the strainer of the present invention for a perforated tube system. FIG. 4A is a plan view of a disc as an example of the strainer of the present invention, and FIG. 4B is a cross-sectional view of a water collecting and dispersing part adapted to the disc. FIG. 5 (c) is a plan view of another disk for the strainer of the present invention, and FIG. 5 (d) is a cross-sectional view of a water collecting and dispersing part adapted to the disk.

Hereinafter, the structure of the strainer of the present invention will be described in detail with reference to the drawings. (1) As shown in FIG. 1 (b), the strainer main body has an upper male screw part 1 for holding and tightening the disk 7, and a water collecting and dispersing part 2 for passing cylindrical water and air thereunder. The lower part thereof comprises a bottom part 3 for installing a strainer on the filter floor plate 9, and a lower pipe 4 having a male screw passing through a strainer installation hole (not shown) provided on the filter floor plate 9. These are integrally formed and have a simple structure.

(2) A disk 7 shown in FIGS. 4 and 5 used in the present invention is laminated on the upper surface of the bottom plate 3 and around the side surface of the water collecting and dispersing portion 2 having a cylindrical shape. 12,
The nuts 11 and 10 are passed through the upper male screw portion 1 having a rod shape of about M12 to M20, and the nuts 11 and 10 are tightened and fixed. At this time, it is preferable that the nut 10 has a loosening prevention function. This is because the nut 10 tends to loosen after a long time. The loosening of the nuts 10 and 11 means that the lamination state of the disk 7 is loosened, the width of the slit becomes large at the time of backwashing, etc., and not only the uneven dispersion at the time of backwashing but also the filtration and washing from the backwashing. At the time of transfer, turbidity and filter media may enter the inside of the slit and cause clogging. It is also important that the upper surface and the side surface of the cylindrical water collecting and dispersing portion 2 serving as the contact surface with the presser plate 12 have as few gaps as possible and eliminate the blind spot.

(3) Further, in the present invention, the disk 7 is reliably prevented from laterally moving due to repeated loads such as long-term operation and backwashing, so that non-uniform lamination does not occur. Two to four movement prevention bridges 24 are provided for each disk. 4 and 5 are provided at four places,
The concave portion 25 or the convex portion 33-1 at the tip of the movement prevention bridge 24
As shown in FIGS. 4 (b) and 5 (b), they enter each other into the convex portion 30 or the concave portion 33-2 provided on the side of the water collecting and dispersing portion 2 on the strainer main body side, and the disc is moved sideways. I try not to move. The vertical length of the convex portion 30 or the concave portion 33 of the water collecting and dispersing portion 2 may be approximately equal to the height L1 (see FIG. 1B) of the number of stacked disks. With such a structure, in the example of FIG. 4, the lamination and removal of the disks 7 are performed from the top of the water collecting and dispersing unit 2 by combining the disk 7 with the concave portions 25 and the convex portions 30 of the water collecting and dispersing unit 2. You can do it freely.

When the movement preventing bridges 24 are provided at four places as in the examples of FIGS. 1 to 5, the openings 6 of the water collecting and dispersing unit 2 are provided at four places. During backwashing from the inner diameter 31 of the water collecting and dispersing portion 2, the width increases from the four inner openings 6 to the outer opening 32, and further toward the wide opening 23 of the disk, and finally the outer periphery of the disk. From the slit width formed on the outer side 28 of the part 26, for example, 0.3 mm width, it goes out horizontally to the outside of the strainer and performs water backwashing. The same applies to air backwashing.

(4) In FIGS. 1 to 3, not only water backwashing but also air backwashing and simultaneous backwashing of water and air can be freely performed. Therefore, as shown in FIG. 1 (b), the air below the filter plate plate is removed as much as possible during the air backwashing after air backwashing or after “simultaneous washing of water and air”. In order to discharge quickly, the air backwash pipe 5 provided with the air discharge ports 16 and 21 is inserted into the inside of the lower pipe 4 and fixed, thereby forming an integral structure as a whole. In addition, filter floor plate 9
In order to discharge air such as a gap between a hole (not shown) of the lower pipe 4 and the lower pipe 4 from the air discharge port 16, a vertical groove 8 is formed in the lower pipe 4.
Is provided. In this way, the strainer formed as an integral structure is inserted into a hole (not shown) of the filter plate 9 via the packing 20, and the nut 13, 14 is used under the filter plate 9 to double the male screw of the lower pipe 4. Use to secure firmly.
It is preferable that the nut 14 has a function of preventing loosening similarly to the nut 10 described above. In this way, the height from the upper surface of the filter floor plate 9 to the disk 7 is increased by the packing 20 and the bottom plate 3, but is extremely low, such as about 7 mm at the lowermost part of the disk and about 25 mm at the uppermost part of the disk. The height from the upper surface of the filter plate 9 to the disk 7 is the same as that in FIG.

(5) FIG. 2 shows a case where the filter bed plate 9 of the gravity filter is thick. The basic structure is almost the same as FIG.
Since the filter plate 9 is thick, the strainer having the integral structure can be easily inserted into, fixed to, or removed from the filter plate 9 from the filter plate 9. For this purpose, a sleeve 22 having a female thread for inserting and fixing the lower pipe 4 having the male thread of the strainer body is provided. Sleeve 22
The length of the female thread portion allows the lower pipe 4 having the male thread to be absorbed, and the lower pipe 4 of the strainer body is screwed in and fixed. For this reason, it narrows down with an appropriate torque using the two projections 19 of the bottom part 3. Sleeve 22
Is made substantially the same as the thickness L7 of the filter floor plate 9. The sleeve 22 must be fixed vertically, and it is particularly important to construct the filter plate 9 to which the sleeve 22 is fixed before installing the strainer.

(6) FIG. 3 shows an example of a method of installing the strainer of the present invention on a branch pipe or main pipe of a perforated pipe system. A sleeve 22 having a female thread is attached to a circular branch pipe shown in the lower part of FIG. 3 by welding or the like. Then, mortar or the like is poured into the lower surface of the bottom portion 3 of the strainer,
2. Embed the branch pipe and main pipe, make the sleeve vertical and smooth the mortar surface where the strainer is installed. And
As in FIG. 2, the integral structure of the strainer is
Screw it into 2 and tighten it. At this time, the air inlet 15 and the water inlet / outlet opening 18 are located inside the branch pipe. In this case, the height from the upper surface of the filter floor plate 9 to the disk 7 becomes the same as in FIGS.

(7) In the present invention, the strainer body is formed as an integral body, and the water collecting and dispersing section 2 has a cylindrical shape.
By devising the shape of the disk 7, laminating the disk 7,
Removal work etc. can be done easily. In addition, even during long-term operation, the disk 7 does not move laterally and the slit width does not fluctuate, so that the initial stacking state of the slits can be maintained. In addition, the air backwashing pipe also has a simple structure as a whole as an integral structure. And pressure filter (thin filter plate), gravity filter (thick filter plate),
And when installed and used in a perforated pipe type branch pipe,
Although the method of attaching the strainer is different, both have a strainer structure that can be shared, thereby solving the above-mentioned problem.

[0030]

Embodiments of the present invention will be described with reference to the drawings. (1) FIGS. 1, 4 and 5 showing examples of the basic structure for a pressure type filter having a thin filter plate will be described in more detail. 1) The upper male screw portion 1 having the male screw, the water collecting and dispersing portion 2, the bottom plate portion 3, and the lower pipe 4 having the male screw are integrally formed. The same material is preferable, and the selection is determined by the place of use. For example, when seawater, chlorine resistance, ozone resistance, etc. are required, for example, a hard vinyl chloride resin (HPVC) is suitable as the material. However, the material is not only the place of use, but also various manufacturing requirements (for example,
Dimensional accuracy, etc.) is also determined in consideration.

Further, as shown in FIG. 1 (b), the integrally formed body is tightened by screws of nuts 13 and 14 below the filter plate 9 and fixed. As for the tightening method, a fastener is fixed to the projection 19 of the bottom plate 3 from above the filter floor plate 9 and tightened. The tightening torque is required to be 500 to 1000 Nm, and the strength of the strainer that can withstand this force, particularly the strength of the joint between the bottom plate 3 and the lower pipe 4 is sufficiently considered.
Determine the dimensions. For example, the thickness of the bottom part 3 may be about 4 to 6 mm made of HPVC. 2) In FIG. 1, six discs 7 are stacked on the bottom plate 3 from above the water collecting and dispersing section 2 having a cylindrical shape. At this time, for example, the protrusions 30 of the water collecting and dispersing portion 2 shown in FIG. 4B are stacked so as to enter the concave portions 25 at the tip of the movement prevention bridge 24 of the disk 7 shown in FIG. Go. The concave portion 25 is slightly larger in size than the convex portion 30,
It is preferable that the lamination and unloading operations are facilitated.

The number of bridges 24 for preventing movement of the disk 7 may be two to four per disk. Four points are preferable in consideration of the structure of water collection and dispersion of water and air from the cylindrical water collection and dispersion part 2 and the strength of the water collection and dispersion part. After lamination, the holding plate 12 is set to M12 to M20, preferably M12 to M20.
The thread is passed through approximately 16 upper male threads 1 and tightened with a nut 11 at a torque of 500 to 1000 Nm and fixed. The nut 10 is further similarly tightened and fixed to prevent loosening.
Further, the nut 10 may be provided with a physical locking function, or the same material as the upper male screw portion 1, by pouring an adhesive at three to four places on the upper part of the nut 10 to have a locking function. . One nut, for example, nut 11
When tightening with only the strainer, the height of the strainer is also reduced, and it becomes more compact. However, in this case, it is essential to have a firm locking function.

The number of stacked disks 7 is determined according to the installation pitch. In the example of FIG.
The number 6 is six, corresponding to about 80 mm, a slit width of 0.3 mm, and an installation pitch of 200 to 240 mm.
The disc 7 is moved by the holding plate 12 and the nuts 11 and 10.
When they are firmly narrowed down and laminated, and the desired slit width is obtained, the lamination height is L1. The height of L1 is
For example, the length of the water collecting and dispersing portion 2 is set to be slightly lower than the vertical length of the convex portion 30 in FIG. 4 so that a gap is not generated as much as possible between the holding plate 12 and the upper surface of the stacked disks. Is also an idea. In the case where the strainer is designed with seven discs to be stacked, if there are six effective discs, one dummy disc is added and the total number of discs is seven.

3) After the disk laminating operation, the lower piping 4 is inserted through the packing 20 in the center of the hole (not shown) of the filter floor plate 9.
, And tighten the nut from below the filter floor plate 9 with the nut 13 at a torque of about 500 to 1000 Nm. Alternatively, the nut 13 may be held down, and the nut 13 may be tightened from above the floor plate 9 using the projection 30 of the bottom plate 3. The nut 14 is used to prevent loosening, and it is preferable that the nut 14 has a function of, for example, a physical method, or a function of preventing loosening using an adhesive, like the above-described nut 10 after being tightened. The packing 20 is required to have a thickness of 2 to 3 mm, to maintain the tightness of the filter floor plate 9 and the bottom plate 3, to absorb slight irregularities on the lower surface of the filter floor plate 9, and to install the strainer horizontally.

No packing is required between the lower surface of the filter floor plate 9 and the nut 13. The air under the filter plate 9 has a hole diameter of 1.5 to 2 mm.
An air discharge groove (not shown) is provided on the upper surface of the nut 13 so that the air can be easily discharged from one or two air discharge ports 16. A vertical air discharge groove 8 is also provided in the male thread portion of the lower pipe 4. At the time of water backwash after air backwash,
The ability to smoothly discharge air is an important function for eliminating turbulence of air in a filtration layer (not shown) and adjusting the filtration layer. 4) In FIG. 1, the thickness L2 of the filter floor plate 9 is usually about 9 to 26 mm. 15-32mm when rubber-lined
About. L3 is the length of the lower pipe 8 and may be any length as long as it is between the nuts 13 and 14, and is 60 to 80 m.
m is sufficient. From the lower surface of the filter plate 9 to the air inlet 15
The length L4 is required to be equal to or longer than the diameter of the air inflow pipe to the lower part of the apparatus filter floor plate.

The length L5 from the air inlet 15 of the air backwash pipe 5 to the water inlet / outlet opening 18 varies depending on the equipment conditions. In particular, the determination is made in consideration of a decrease in the water level from the air inlet 15 due to the air backwash condition. But,
The total length is preferably shorter in consideration of the swing and vibration caused by the backwashing operation or the like. The anti-sway groove 17 at the lower portion of the air backwash tube 5 is provided for preventing the above-mentioned run-out, vibration, and disturbance of the water surface below the filter plate 9 during backwashing. Its size is a vertical groove of about 2 × 20 mm, and its position may be near the opening 18 or continue to the opening 18.
In FIG. 1, two convex portions 19 of the bottom plate 3 are provided to fix the upper portions of the filter floor plate 9 so as not to rotate together when the nuts 13 and 14 are tightened when the strainer is installed. Further, it is provided to confirm the tightening torque on the upper surface of the filter floor plate 9.

(2) Examples of the basic structure for a gravity type filter having a thick filter plate, that is, FIGS. 2, 4 and 5 will be described in more detail as follows. 1) The basic structure of the strainer is almost the same as FIG. The difference is that the strainer is fixed with nuts 13 and 14 below the filter plate 9 in FIG. On the other hand, in FIG. 2, the thickness L7 of the filter floor plate 9 is 100 to 200 mm, usually 1
Since it is as thick as about 50 mm, the sleeve 22 having a female thread is vertically fixed in the filter floor plate 9, and the lower pipe 4 having a male screw is screwed and fixed in the female thread portion. At the time of this fixing, screwing and tightening operations are performed while controlling the torque using the two projections 19 of the bottom plate 3. 500 ~
The torque is about 1000 Nm. The outer shape of the sleeve 22 may be the example shown in FIG. 2, but may be any shape that can be easily fixed to the filter floor plate 9. The length of the female thread portion in the sleeve 22 is approximately
The length is set to about 60 to 80 mm in accordance with the length of the lower pipe 4.

2) In FIG. 2, an air discharge port 21 having a hole diameter of 1.5 to 2 mm is further provided in the air backwash pipe 5 immediately below the filter bed plate 9 in order to smoothly discharge air below the filter plate plate 9. Has been added. L8 corresponds to L4 in FIG. 1 and has a length larger than the diameter of the air inflow pipe (not shown). Other structures are the same as those in FIG. (3) FIG. 3 shows an example in which the strainer of the present invention is installed in a perforated branch pipe or main pipe. The lower pipe 4 having the male screw of the strainer as an integral structure shown in FIGS. 1 and 2 is inserted into the inside of the sleeve 22 indicated by the hatched portion in the figure and having a female thread as in FIG.

At this time, the length of the air backwash pipe 5 is adjusted (cut), and the lower end of the air backwash pipe 5 is inserted as much as possible into the lower circular branch pipe in FIG. It is important to locate the inlet 15. The vertical groove 17 of the steady rest may be lowered to the opening 18 for inflow and discharge of water at the lower end. Further, in order to increase the installation strength of the air backwash pipe 5 in the branch pipe, the opening 18 may be extended to the lowermost part of the branch pipe to have a role of both support and opening. In this method, since the material of the strainer is often plastic, the sleeve, the branch pipe, and the main pipe are usually made of hard vinyl chloride resin (HPVC) or the like. In the example of FIG.
After installing the strainer of the present invention in a perforated pipe system, mortar or the like is injected up to the lower surface of the bottom portion 3 of the strainer, and the sleeve 2
2. Both branch pipe and main pipe are embedded and fixed.

The sleeve is fixed vertically so that the bottom plate 3 of the strainer is horizontal when the strainer is installed. In this way, air backwashing, water backwashing, simultaneous washing of water and air, and the like can be performed. In the example of FIG. 3, the diameter of the branch pipe is φ75 mm or more, preferably the air inlet 15,
Considering the positional relationship of the lower end of the air backwash tube 5, φ100
mm or more is preferable. This is because, when the diameter of the branch pipe is increased, the speed of air dispersion into each branch pipe of the perforated pipe system decreases, and the amount of air flowing into each branch pipe acts in a direction of uniformity.

(4) Structural Examples of Disk 7 and Water Collection and Dispersion Section 1 1) FIGS. 4 and 5 show an example in which four anti-migration bridges 24 are provided on the disk 7. FIGS. 4A and 5C show the disk 7 viewed from above. An outer peripheral portion 26 of the disc, and teardrop-shaped projections 27 are provided in the outer peripheral portion 26 at the same position, the same height, and the same shape on the back and front. And disk 7
Are stacked so that the teardrop-shaped projection 27 and the movement prevention bridge 24 are located at the same position. In this way, the teardrop-shaped projections 27 overlap, and the outer peripheral portion 2
8, a desired slit width, for example, 0.3 mm width can be formed.

The detailed dimensions of the disk are determined in consideration of the strength of the disk itself so that the width (height direction) of the inner peripheral portion 29 is, for example, about 0.5 to 1.0 mm. The horizontal distance L9 of the outer peripheral portion 26 is 8 to 12 mm.
However, a smaller value is preferable for preventing turbid discharge and accumulation. 2) Although the number of the teardrop-shaped projections 27 is 12 in FIGS. 4 and 5, the portion at the movement prevention bridge 24 may be omitted and may be eight. In the present invention, the teardrop-shaped projections 27 are surely overlapped when stacked. Therefore, the desired slit width can be reliably obtained,
It may be 4 to 6 pieces. The shorter the distance L9 in the horizontal direction of the outer peripheral portion 26 is, the better the turbidity is discharged, and the less the turbidity is accumulated. Therefore, the size of the teardrop-shaped projection 27 may be reduced. Further, the shape of the teardrop-shaped projection 27 may be a shape opposite to the shape shown in FIGS. 4 and 5. The teardrop shape has a lower hydrodynamic resistance than the circular shape shown in FIG.
It is preferable for discharging suspended matter. When circular discs are stacked, circular projections may be used as long as the circular projections surely overlap and the number of circular projections can be reduced and reduced. By taking such measures, it is possible to prevent turbidity from being mixed into the disk and clogging. Conversely, since the slit width can always be kept uniform and constant, uniform dispersion and collection of water and air are achieved.

[0043]

The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples.

Embodiment 1 (1) With respect to the basic structure example of the present invention shown in FIGS. 1 and 2, various specifications such as main dimensions and materials will be described. 1) Strainer installation pitch; 200 to 230mm 2) Disk 7; φ80mmOD × φ69mm ID number, 5 to 7, 5 layers, layer height about 19mm, slit width, 0.3mm 3) Dimension of water collecting and dispersing part 2; φ23mmID × 28mmH (including bottom part) 4) Material: All hard vinyl chloride resin (HPVC) 5) Other dimensions Upper male thread part 1: M16 equivalent screw Lower piping part 4: M36 equivalent product Air backwash pipe 5; φ36mmOD × φ23mmID × 340mmH (total length) Air inlet 15; φ5 to 5.8mm Air outlet 16; φ2.0mm × 2 Air outlet 21; φ2.0mm × 1

(2) The gravity filter was filtered and backwashed under the following conditions. 1) 25 strainers are installed at a pitch of 200 mm for filtration of 1 m square x 2.7 mH 2) Number of discs: 5 3) Filter floor plate: 150 mm thick reinforced mortar 4) Filter material: 0.6 mm sand x Gravel filling of 600 mmH, 70 mmH at the bottom and particle size of 2 to 5 mm 5) Filtration speed: 5 to 10 m / H, non-chemical filtration 6) Raw water: Seawater (fish rearing water), turbidity 0.5 to 5 degrees, Water temperature 18 ° C 7) Air backwashing; 1.0m / min, 8 minutes 8) Water backwashing; 0.6m / H, 10 minutes Result: 1) Filtration is good and turbidity of filtered water is 0.5 ~ 1.
It was 0 degrees. 2) Observation from the viewing window showed that the sand of the filter medium was flowing uniformly and the turbid matter was discharged well during backwashing with water. 3) Simultaneous washing of water and air was performed under the following conditions, but there was no problem in terms of equipment. (Water, 0.2-0.3m
/ Min + air, 0.8m / min for 10 minutes)

(3) Pressure type filter (thin filter plate) Using a filter of φ2000 × 1600H, LV10m /
H. 1) Raw water; Raw water same as the above (2) Water temperature 18 ° C 2) 70 strainers with 6 disks were installed. 3) Filter bed plate; 3 mm rubber lining was applied to 19 mm SGP. 4) Filter material: 0.6 mm sand × 600 mmH, 2 mm to 5 mm gravel filled at the bottom at 70 mmH 5) Filtration speed: 10 m / H, non-chemical filtration 6) Air backwashing: 1.0 m / min for 8 minutes 7 ) Water backwashing; 0.6m / H for 10 minutes Result: 1) Filtration is good and turbidity of filtered water is 0.5 to 1.
It was 0. 2) Observation from the viewing window showed that the sand of the filter medium was flowing uniformly and the turbid matter was discharged well during backwashing with water. 3) Simultaneous washing of water and air was performed under the following conditions, but there was no problem in terms of equipment. (Water, 0.2-0.3
m / min + air, 0.8m / min for 10 minutes)

(4) Test of a filter equipped with the strainer of the present invention in a perforated tube method Using a filter of φ2000 × 1600H, LV15m /
H. 1) Raw water; river water, turbidity 1 to 8 ° C, water temperature 10 to 20 ° C 2) Number of disks: 6 3) Filter floor plate: The main pipe of a porous pipe made of hard polyvinyl chloride resin is φ200, and the branch pipes are φ75 and 8 Sixty-six strainers with six discs were placed on the book through a sleeve having the shape shown in FIG. The length of the air backwash pipe 5 was adjusted so as to be 65 mm in the branch pipe, and the sleeve 22 and the branch pipe were welded. Then, the mortar was poured under the bottom part 3 of the strainer, the branch pipe, the main pipe, and the sleeve were fixed, and the surface was smoothed. 4) Filtration material; sand having an average particle size of 0.6 mm x 600 mmH, and a bottom filled with gravel having an average particle size of 2 to 5 mm at 70 mmH 5) Filtration speed: 10 m / H, coagulant PAC 10 mg / liter coagulation filtration 6) Air backwashing; 1.0 m / min, 6 minutes 7) Water backwashing: 0.6 m / H, 10 minutes

Results: 1) Filtration was good and turbidity of filtered water was 0.5 ° or less. 2) Observation from the viewing window showed that, at the time of backwashing with water, the sand of the filter medium was flowing uniformly and the turbid matter was discharged well. 3) Simultaneous washing of water and air was performed under the following conditions, but there was no problem in terms of equipment. (Water, 0.2-0.3m /
min + air, 0.8m / min for 10 minutes)

[0049]

According to the present invention, the upper male screw portion, the cylindrical water collecting and dispersing portion, the bottom plate and the lower pipe are integrally formed as a strainer main body, so that the cylindrical water collecting and dispersing portion is particularly formed. By having the part, the disk can be firmly fixed, the lateral movement of the disk and the fluctuation of the slit width can be eliminated, and the slit width can be stably maintained over a long period of time. S
S) is suppressed, the turbidity of the filtered water does not increase, the backwashing is easy, and the number of times of the washing may be small. This disk-type strainer can solve the problems of the conventional disk-type strainer with a simple structure, and can be commonly used for a pressure filter and a gravity filter. Also,
In the gravity type, since the inspection of the strainer can be performed from above the filter bed plate in the same manner as the pressure type, the workability is improved and it contributes greatly to the operation of the filter.

[Brief description of the drawings]

FIG. 1 shows a basic structure of a strainer of the present invention for a pressure filter, where (a) is a plan view of a partial cross section and (b) is a longitudinal cross section.

FIG. 2 shows the basic structure of the strainer of the present invention for a gravity filter, and shows a longitudinal sectional view thereof.

FIG. 3 shows a basic structure of a strainer of the present invention for a perforated tube system, and shows a longitudinal sectional view thereof.

FIGS. 4A and 4B show a disk used in the present invention and a shape example 1 of a water collecting and dispersing part, wherein FIG.
(B) shows a cross-sectional view of the water collecting and dispersing section.

FIGS. 5A and 5B show a disk used in the present invention and a shape example 2 of a water collecting and dispersing part, wherein FIG. 5C is a plan view of the disk and FIG. 5D is a cross-sectional view of the water collecting and dispersing part.

FIG. 6 is an explanatory view showing an example of installation of a conventional vertical slit strainer on a pressure filter.

7 is an explanatory view showing an installation structure of a vertical slit strainer with respect to a filter bed plate in the pressure filter of FIG.

FIG. 8 is a longitudinal sectional view showing an example of installation of a conventional vertical slit strainer on a gravity filter.

FIG. 9 is a vertical cross-sectional view showing how a conventional disk-type slit strainer is installed in a gravity filter.

FIG. 10 is a plan view of a disk used in the conventional disk-type slit strainer of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Upper thread part 2 Water collecting and dispersing part 3 Bottom part 4 Lower piping 5 Air backwashing pipe 6 Opening of water collecting and dispersing part 7 Disk 8 Vertical groove 9 Filter floor plate 10 Nut (for preventing loosening) 11 Nut (disk fixed) 12) Holding plate (for fixing disk) 13 Nut for fixing 14 Nut for fixing 15 Air inlet 16 Air outlet 17 Vertical groove for preventing steadying 18 Lower end opening of air backwashing pipe 19 Bottom projection 20 Packing 21 Air outlet 22 Sleeve 23 Disk opening 24 Anti-migration bridge 25 Depression at the end of anti-migration bridge 26 Disk outer periphery 27 Tear-shaped protrusion 28 Outer periphery outer 29 Inner periphery inside 30 Convex portion of water collecting / dispersing portion 31 Inner diameter of water collecting and dispersing part 32 Opening of water collecting and dispersing part 33-1 Convex part of bridge tip for preventing movement 33-2 Concave part of bridge tip for preventing movement 34 Conventional vertical slit Strainer 35 Lower water storage part of pressure filter 36 Conventional vertical slit 37 Strainer installation hole of thin filter floor plate 38 Conventional vertical semicircular spherical slit part 39 Conventional disk-type main body 40 Bolt support 41 Conventional Disc shape example 42 Bot 43 Nut 44 Holding plate 45 Conventional disk shape example steady rest 46 Piping lower end of conventional disc shape example 47 Opening of pipe lower end 48 Bolt hole at the center of conventional disk 49 Peripheral portion of conventional disk Reference Signs List 50 circular convex 51 outer peripheral part 52 outer peripheral part inner part 53 disk opening 54 connecting part 55 disk center L1 disk stacking height L2 pressure filter floor plate thickness L3 lower piping length L4 filter Length from the bottom surface of the floor plate to the air inlet (more than the diameter of the backwash air inlet pipe) L5 Air inflow from the backwash air pipe Length from mouth to lower end opening L6 Disk diameter L7 Thickness of gravity filter filter plate L8 Length from bottom of filter plate of gravity filter to air inlet L9 Horizontal distance of disk outer periphery L10 Conventional Length from bottom surface of bottom of disk-type strainer to bottom of pipe L11 Horizontal distance of outer circumference of conventional disk

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B01D 35/16 B01D 29/38 520A 540 (72) Inventor Katsunobu Yamaguchi 11-1 Haneda Asahimachi, Ota-ku, Tokyo No. within the Ebara Works Co., Ltd. (72) Keiichi Akagi, Inventor Keiichi Akagi 11-1, Haneda Asahimachi, Ota-ku, Tokyo Inside the Ebara Works Co., Ltd. (72) Fumihiro Otsubo 11-1, Haneda Asahi-cho, Ota-ku, Tokyo Ebara Co., Ltd. In the factory (72) Inventor Yutaka Kofujita 11-1 Haneda Asahimachi, Ota-ku, Tokyo Ebara Denden Co., Ltd.

Claims (5)

[Claims] 1. A bottom plate having an upper male screw portion for holding and tightening a disk, and a cylindrical water collecting and dispersing portion thereunder that allows water and air to pass therethrough. A disc type strainer, wherein a main body of the strainer is formed by a portion and a lower pipe having a strainer installation hole or a male screw provided on the filter floor plate, and the main body is formed as an integral molded body. 2. A disk is stacked on the bottom portion and around the cylindrical shape of the water collecting and dispersing portion, and the disk is held down using a pusher plate and a nut by using an upper male screw portion of the strainer body. The strainer according to claim 1, wherein the strainer is fixed by tightening. 3. In order to prevent lateral movement of the disk and random stacking of the disks, two or four cylindrical portions of the water collecting and dispersing portion are provided with convex portions or concave portions in the vertical direction, On the other hand, on the disk side, a movement prevention bridge
3. A structure in which four parts are provided and the tip part is a concave part or a convex part, and these are configured to enter the cylindrical convex part or the concave part of the water collecting and dispersing part. Strainer. 4. An air inlet, wherein:
An air backwash pipe having an air outlet, a water inlet, a water outlet, and the like is inserted and fixed inside a lower pipe of the strainer main body to form an integrated structure.
The strainer according to claim 3. 5. A water collecting and distributing device for a filter as claimed in claim 1.
A filter to which the disk-type strainer according to any one of claims 4 is attached.