JP2001205016A - Microstrainer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a microstrainer constituted by improving a rotary type microstrainer and characterized in that the treatment amount of a raw liquid is increased by expanding the filtering surface of a drum and a metal screen having good releasability is used to be combined with a filter medium according to the properties of a raw liquid to be treated to enable precise filtering. SOLUTION: In the microstrainer wherein a raw liquid is supplied in the drum 4 arranged in a treatment tank 1 in a freely rotatable manner and a filtrate is discharged from the filtering surface of the peripheral part of the drum 4 to be subjected to solid-liquid separation treatment, the outer peripheral surface 18 of the drum 4 is formed into an uneven shape and the metal screen 19 is provided on the outer peripheral surface 18 under tension to expand the filtering area of the peripheral surface of the drum 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a rotary type microstrainer for removing SS from intake water of working water, sewage inflow water, etc., plankton and algae.

[0002]

2. Description of the Related Art Conventionally, a micro-strainer that introduces raw water into a cylindrical drum installed in a filtration tank, discharges filtrate from an outer filtration surface of the drum while rotating the drum, and performs solid-liquid separation is known. It is well known. An apparatus in which a filter cloth having a nap filter layer formed on a reinforcing net made of stainless steel or the like is stretched over a strainer and a cover net is wound around the outside of the filter cloth is described in, for example, Japanese Patent Publication No. 4-9081. As is known. Further, as a filter medium, a cylindrical rotary drum in which a fine mesh filter net and a reinforcing pilot net are stretched around its periphery is also known as described in, for example, Japanese Patent Publication No. 63-86.

[0003]

SUMMARY OF THE INVENTION S contained in the treated water
In the case of a stock solution containing small particles such as S, plankton, bacteria, or algae, it is necessary to use a filter medium having a very fine opening. The above-mentioned apparatus using a filter cloth as the conventional filter medium enables fine filtration. However, fine particles accumulate on the fiber surface of the filter cloth and cause clogging. Removal of clogging was difficult and durability was short. In addition, even in a device using a conventional filtration network, fine particles are removed from the eyes of the screen and the recovery is extremely poor. There is a risk of damage due to fluctuations, and the conventional apparatus has a limit on the throughput of the stock solution. The present invention has the strength of reducing the size of the screen by enlarging the filtration surface of the drum to increase the processing amount of the undiluted solution, using a metal screen with good releasability, combining filter media with the properties of the undiluted solution, and reducing the size of the screen. An object of the present invention is to provide a filter medium and a micro-strainer that eliminates clogging.

[0004]

SUMMARY OF THE INVENTION The gist of the present invention is to supply a stock solution inside a drum rotatably disposed in a processing tank,
In a strainer for discharging a filtrate from a filtration surface at a peripheral portion of a drum to perform solid-liquid separation, an outer peripheral surface of the drum is formed in an irregular shape, and a metal filter medium is stretched over the outer peripheral surface to form a drum peripheral surface. This is an enlarged filtration area. The convex portion on the outer peripheral surface of the drum may be formed in a pyramid shape or a trapezoidal shape. And the metal filter medium stretched on the drum is made of multiple metal screens, the mesh of the superposed metal screen is made finer as the inner surface layer, the mesh of the superimposed screen becomes finer,
Fine particles in the stock solution are also trapped, enabling microfiltration and, at the same time, increasing the strength of the filter medium.

[0005] More specifically, a metal screen is formed by laying a coarse screen on the lower surface, interposing a medium screen on the intermediate layer above the fine screen, and stretching a fine screen on the surface layer. The lower the lower layer of the screen, the larger the mesh of the screen, so that the filtrate passing through the filter medium of the surface layer is discharged well, the solid matter trapped on the outer filtration surface is washed away, and the clogged matter is also removed from the outer periphery of the drum. It can be easily washed from the surface. In addition, depending on the properties of the undiluted solution to be filtered and the clarity of the required filtrate, the intermediate screen interposed in the intermediate layer may be used as the fine screen, or the coarse screen laid on the lower surface may be used as the intermediate screen. Things. In addition, the outer peripheral surface of the drum with the metal screen stretched is a wedge wire, and the slit side of the wedge wire is used as the support surface of the metal screen, and the filter media strength of the metal screen supported by the surface of the wedge wire increases. Since it is expanded toward the outer surface, the drainage of the filtrate is improved.
And, in order to increase the strength of the drum, the outer peripheral surface of the drum may be constituted by a punching metal of a support plate and a wedge wire of a support floor disposed therein.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The apparatus according to the present invention is configured as described above. When the drum is rotated while supplying the undiluted solution to be filtered to the inside of the drum, the unevenness of the drum due to the liquid level difference between the inside and outside of the drum. The filtrate is discharged from the metal screen on the filtration surface, and solid matter such as SS is captured by the metal screen and transferred upward by rotation of the drum. Then, the washing water is sprayed from above the drum, and the solid matter caught by the drum falls into the washing drainage receiver above the inside of the drum, and the solid matter is discharged out of the drum together with the washing wastewater.
The permeate of the laminated metal screen becomes larger at the outer periphery, so the filtrate that has passed through the surface layer filter medium is discharged well. Since the filter medium is a metal screen, clogging can be easily done from the back. It can be washed. The microstrainer of the present invention has a filtration area that is approximately twice as large as that of a conventional strainer, increases the throughput, and combines a plurality of metal screens according to the properties of the stock solution. The strength can be increased, the screen can be made finer, and small particles can be captured to increase the recovery rate.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The microstrainer according to the present invention will be described in detail with reference to the drawings. First, in FIG. 1, reference numeral 1 denotes a treatment tank, and the treatment tank 1 is composed of a raw water tank 3 provided with a raw water inlet 2. A filtrate tank 5 provided with a drum 4 for supplying a stock solution from the stock water tank 3 and performing solid-liquid separation therein;
And a discharge tank 7 for allowing the filtrate in the filtrate tank 5 to overflow from the discharge weir 6. A part of the drum 4 is immersed in the filtrate tank 5, and as shown in FIGS. 2 and 3, a side plate 8 having an opening 8 a for inflow of the undiluted solution in a peripheral portion, and a side plate 9 having a closed side surface. The side plate 8 is fitted around the drum 4.
Bearings 10 and 11 fitted in 9 are inserted through a central shaft 12 provided at the axis of the drum. Annular frames 13, 14 having an opening 13a for inflow of the undiluted solution and an opening 14a for outflow of the filtrate in the inner peripheral portion are respectively provided upright in front of and behind the filtrate tank 5, and the center shaft 12 is located in front and rear. Frame 13, 1
The drum 4 is rotatably supported by a shaft 4.

A worm wheel 15 is fitted to a side plate 8 at one end of the drum 4, and a pinion 17 of a driving device 16 is meshed with the worm wheel 15. The undiluted solution of the raw water tank 3 overflowing from the opening 13a of the thirteen flows into the inside of the drum 4 through the opening 8a of the side plate 8, and the outer periphery of the drum 4 is filtered by the difference in water level between the undiluted solution of the raw water tank 3 and the filtrate of the filtrate tank 5. The filtrate is separated from the surface. The drum 4 arranged in the filtrate tank 5
The outer peripheral surface 18 is formed in an uneven shape, and FIGS.
In the embodiment shown in FIG. 5, the convex portion is formed in a pyramid shape, and a metal screen 19 is stretched on the surface thereof, so that the filtration area is doubled as compared with a conventional cylindrical drum. Note that, as shown in FIG. 1, the bottom surface of the concave portion of the outer peripheral surface 18 may be covered with a flat plate due to a problem in strength. However, as shown in FIG. If this is the case, the filtration area will be further expanded. The undiluted solution flowing into the inside of the drum 4 is discharged from the outer peripheral metal screen 19 to the filtrate tank 5, and solids such as SS captured by the metal screen 19 are transferred upward with the rotation of the drum 4. is there.

As shown in FIG. 1, a washing water pipe 20 is opposed to the uneven outer peripheral surface 18 of the drum 4 and
The solids adhered to the inside of the drum 4 and transported upward by the washing water sprayed from the washing nozzle 20a of No. 0 are peeled off and dropped into the washing drainage receiver 21 connected to the upper end of the central shaft 12 inside the drum 4. It is like that. And the central axis 12
Water is supplied from a pressure water pipe 22 connected to the rear end of the tank, and the solid matter collected on the central shaft 12 is washed away and discharged from a washing drain pipe 23. As shown in FIG.
If the convex portion of the outer peripheral surface 18 of the drum 4 is formed in a trapezoidal shape,
The outer peripheral surface 18 can be easily cleaned. In the embodiment of FIG. 5, the outer peripheral surface 18 of the drum 4 is
a metal screen 19 is stretched using the slit side of the wedge wire 18a as a support surface, and the wedge-shaped tip of the wedge wire 18a is provided on the outer peripheral side, so that the cleaning water is spread. Thus, the supply of the washing water and the discharge of the filtrate are preferably performed through the through hole of the wedge wire 18a.

The metal clean 19 stretched over the wedge wire 18a can be used in plurals depending on the slurry to be filtered. The fine screen of the screen becomes fine, and fine filtration can be performed without missing fine particles. In the embodiment shown in FIG. 6, a coarse screen 19a is laid on the upper surface of the wedge wire 18a, a medium screen 19b is interposed in the intermediate layer above the coarse screen 19a, and the fine screen 1 is formed on the surface layer.
9c is stretched. The combination of the metal screens 19 can determine the configuration depending on the properties of the slurry to be filtered and the clarity of the required filtrate, and the intermediate screen 19b interposed in the intermediate layer can be used as the fine screen 19c, or , Coarse screen 19a laid on the lower surface
May be used as the middle screen 19b. When the outer peripheral surface needs to be reinforced by increasing the size of the drum 4, a punching metal 18 b is provided on the outer peripheral portion of the wedge wire 18 a, and the punching metal 18 b
May be used as a support plate for the wedge wire 18a. Reference numeral 24 denotes a filtrate outlet of the discharge tank 7, and reference numeral 25 denotes a connecting rod that connects and fixes the front and rear frames 13, 14.

[0011]

As described above, in the microstrainer of the present invention, since the outer peripheral filtration surface of the drum is formed in an uneven shape, the filtration area is enlarged as compared with the conventional cylindrical drum. The filtrate passage on the support floor of the filter medium is also expanded,
This improves the supply of the washing water and the discharge of the filtrate. And, due to the properties of the slurry to be filtered, if a metal screen with a finer grain is placed on the upper surface layer, the mesh of the screen becomes finer, compared to the conventional metal filter medium used alone,
Fine filtration becomes possible, and the filter medium strength is also increased. Further, the mesh of the screen becomes larger in the lower surface layer of the metal screen, the filtrate passing through the filter material of the surface layer is discharged well, and the clogged material can be easily washed from the outside of the drum.

[Brief description of the drawings]

FIG. 1 is a partial longitudinal side view of a microstrainer according to the present invention.

FIG. 2 is a vertical sectional side view of a drum provided in a filtrate tank according to the present invention.

FIG. 3 is a front view of a frame supporting the drum.

FIG. 4 is a vertical sectional side view of another embodiment of the drum.

FIG. 5 is a partial longitudinal side view of a drum having a metal screen stretched over a wedge wire.

FIG. 6 is a conceptual diagram when a plurality of metal screens are stretched on the outer peripheral filtration surface of the drum.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Processing tank 4 Drum 18 Outer peripheral surface 18a Wedge wire 18b Punched metal 19 Metal screen 19a, 19b, 19c Metal screen

Claims (9)

[Claims] An undiluted solution is supplied to a drum (4) rotatably disposed in a treatment tank (1), and a filtrate is discharged from a filtration surface on a peripheral portion of the drum (4) to perform solid-liquid separation. A micro-strainer according to claim 1, wherein the outer peripheral surface (18) of the drum (4) is formed in an uneven shape, and a metal screen (19) is stretched over the outer peripheral surface (18). 2. The micro-strainer according to claim 1, wherein the convex portion on the outer peripheral surface of the drum is formed in a pyramid shape. 3. The micro-strainer according to claim 1, wherein the convex portion of the outer peripheral surface of the drum is formed in a trapezoidal shape. 4. A metal screen (19) stretched over said drum (4), comprising a plurality of metal screens (19).
4. The microstrainer according to claim 1, wherein the metal screens (19a, 19b, 19c) are made finer toward the inner surface layer. 5. The metal screen (19) has a coarse screen (19a) laid on the lower surface, a medium screen (19b) on the upper intermediate layer, and a fine screen (19c) on the surface layer. The micro-strainer according to claim 4, wherein the micro-strainer is stretched. 6. The microstrainer according to claim 5, wherein the middle screen (19b) interposed in the intermediate layer is a fine screen (19c). 7. A coarse screen (1) laid on the lower surface.
6. The microstrainer according to claim 5, wherein 9a) is a medium screen (19b). 8. An outer peripheral surface (18) of the drum (4) is
8. The microstrainer according to claim 1, wherein the wedge wire (18a) has a slit side of the wedge wire (18a) as a support surface of the metal screen (19). 9. The outer peripheral surface (18) of the drum (4)
8. The micro-strainer according to claim 1, wherein the micro-strainer comprises a punching metal (18b) of a support plate and a wedge wire (18a) of a support floor disposed therein.