JP2020131073A - Production method of casing for filtration module and casing for filtration module - Google Patents

Abstract

To provide a production method of a casing for a filtration module excellent in abrasion resistance and corrosion resistance without requiring an expensive mold in production.SOLUTION: A production method of a casing 10 for a filtration module having a spiral fin 12 on the peripheral wall of a filter housing camber 16 housing a cylindrical filter 20 whose side wall is a filter material includes: a fin forming step forming the metal spiral fin 12; and a fin insertion step inserting the spiral fin 12 into the filter housing chamber 16 formed with the internal space of a casing body 11 made of a metal circular pipe. In the fin forming step, it is preferable that the spiral fin is formed by winding a belt-like metal plate on a cylindrical body.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for manufacturing a casing containing a cylindrical filtration filter, and more particularly to a method for manufacturing a casing for a filtration module having a spiral passage on the peripheral wall of a cylindrical filtration chamber containing the filtration filter.

Conventionally, a cylindrical filter having a side wall as a filter material is arranged in a columnar filtration chamber extending in the vertical direction, and a liquid to be filtered is passed from the outside to the inside of the filter to filter the filter module. Is widely used.

In such a filtration module, in order to prevent the filter material from adhering to the outer periphery of the filter material, a spiral water passage is provided in the space between the inner wall of the filtration chamber and the side wall of the filter. The inventor also proposed such a module in Patent Document 1, and as a method for manufacturing the casing, a method of cutting out from a resin block by machining or pasting two or three resin members formed by injection molding. We are proposing a method for forming a casing for a filtration module with a complicated shape by combining them.

Japanese Unexamined Patent Publication No. 2018-015693

However, in the method for manufacturing a filtration module of Patent Document 1, the method of machining from a resin block material has a problem that the yield is poor, such as thin and long fins being damaged during processing.
Further, the method of bonding the injection-molded two-piece member or the three-piece member has the following problems. That is, (1) it has been confirmed that a fine pulsating current is generated due to a step generated between the members bonded to each other on the wall of the filtration chamber, and this pulsating current may scrape the resin to open a hole in the casing or a spiral groove. There is a risk that the shape of the circulating water will change and the flow rate and flow velocity of the circulating water will change. (2) The manufacturing cost of a mold for forming a two-piece member or a three-piece member by injection molding is high. (3) The raw water to be filtered is not only fresh water but also various miscellaneous water such as wastewater, wastewater, sewage, and high temperature water. When the casing is made of resin, the temperature of the raw water and particles mixed in it There is a risk of wear and corrosion due to chemicals.
The present invention has been made to solve such a problem, and an object of the present invention is to provide a method for manufacturing a casing for a filtration filter, which can provide a casing having a low manufacturing cost and excellent wear resistance and corrosion resistance.

The invention made to solve the above problems is a method for manufacturing a casing for a filtration module having a spiral fin on the peripheral wall of a filter accommodating chamber accommodating a cylindrical filter for filtering on a side wall, and is a metal spiral. It is characterized by comprising a fin forming step of forming a spiral fin and a fin inserting step of inserting the spiral fin into a filter accommodating chamber formed of an internal space of a casing body made of a metal circular tube.

As described above, in the method for manufacturing a casing for a filtration module of the present invention, since the spiral fins are formed separately from the casing main body and then housed in the filter storage chamber of the casing main body, a lump material such as a bar is used. The filter casing provided with the spiral fins can be easily formed and the material cost can be saved as compared with the case where the spiral fins are carved out. Further, by doing so, it is possible to eliminate the step generated by laminating the two-part or three-part members, so that the occurrence of pulsating flow can be prevented and a spiral flow can be effectively formed on the filter surface.

In the fin forming step, it is preferable to form a spiral fin by winding a strip-shaped metal plate around a cylinder. By doing so, the spiral fin can be easily formed.

The method for manufacturing a casing for a filtration filter of the present invention includes a spiral groove forming step of forming a spiral groove on the inner wall of the filter accommodating chamber, and the spiral fin is inserted into the spiral groove in the fin inserting step. Therefore, it is preferable to insert the spiral fin into the filter accommodating chamber. By doing so, the spiral fin can be easily inserted into the filter housing chamber.

In the fin insertion step, it is preferable to insert the spiral fin into the spiral groove while rotating the fin. By doing so, the spiral filter can be easily inserted into the spiral groove.

The method for manufacturing a casing for a filtration module of the present invention includes a fin welding step of welding the spiral fins to the casing body, and in the fin welding step, for welding that communicates with the spiral groove from the outer wall side of the casing body. It is preferable to provide a recess and weld the spiral fin to the casing body from the welding recess. By doing so, the spiral fin can be easily fixed to the casing body.

In the front fin insertion step, it is preferable to provide at least a part of the lower side of the spiral flow path formed by the spiral fins so as to gradually narrow toward the lower side. The undiluted solution to be filtered flows through the spiral flow path while contacting the surface of the filter, and gradually passes through the filter, so that the flow rate decreases and the mixture stalls. By narrowing the spiral flow path downward, the cross-sectional area of the flow path can be adjusted to the amount of raw water flowing through the spiral flow path, and the flow velocity of the raw water flowing through the spiral flow path can be increased. it can.

The present invention is a casing for a filtration module having a spiral fin on the peripheral wall of a filter accommodating chamber accommodating a cylindrical filter for filtering on a side wall, and comprises a metal circular tube having an internal space as a filter accommodating chamber. The casing for a filtration module includes a casing main body and a metal spiral fin which is formed separately from the casing main body and is attached to an inner wall of the filter accommodating chamber.
The spiral fin is preferably inserted into a spiral groove provided on the peripheral wall of the filter accommodating chamber, and at least a part of the lower side of the spiral flow path formed by the spiral fin is downward. It is preferable that the helix is provided so as to gradually narrow toward.

As described above, according to the manufacturing method of the present invention, it is possible to provide a casing for a filtration module having excellent durability and economy.

It is a vertical sectional view of the filtration module which concerns on one Embodiment of this invention. It is a partial front view which shows the upper appearance of the filtration module shown in FIG. FIG. 5 is a sectional view taken along line XX in FIG. It is explanatory drawing which shows one example of the method of forming a spiral fin, (a) shows the plate material used for forming a spiral fin, (b) is wound the plate material in a spiral shape into a spiral fin. It shows how it is formed. It is a vertical sectional view of the casing body shown in FIG. It is a vertical sectional view of the casing shown in FIG. Regarding the state of welding the spiral fins to the casing main body, (a) is an explanatory view showing a state seen from the outside of the casing main body, and (b) is an explanatory view showing a main part in a vertical cross section. It is a front view which showed by cutting out a part of the filter shown in FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. However, the present invention is not limited to the following embodiments.
FIG. 1 shows a filtration module 100 according to an embodiment of the present invention. The filtration module 100 mainly includes a casing 10 and a filter 20, and also includes a filter cap 3, a filter hold 4, a casing cap 5, and a safety bar 6.

As shown in FIG. 6, the casing 10 has a bottomed tubular shape with an open upper end, a cylindrical casing main body 11, a spiral fin 12 provided on the inner peripheral surface of the casing main body 11, and a casing main body 11. A bottom member 13 made of a disk that closes the bottom, a filter support tube 14 that extends downward from a through hole provided in the center of the bottom member 13, and a through hole that extends downward from a through hole near the periphery of the bottom member 13. It is provided with a raw water discharge port 19. The casing 10 is preferably formed by processing stainless steel throughout, but other metals such as iron and aluminum may be used. By using stainless steel having excellent heat resistance, corrosion resistance, and abrasion resistance, it is possible to treat a wide range of water qualities such as fresh water such as groundwater, industrial wastewater, and industrial wastewater.

The casing main body 11 is made of a metal circular tube such as stainless steel, and as shown in FIG. 5, a spiral groove 15 is provided on the inner peripheral surface by machining (spiral groove forming step), and is radially provided near the upper end. A pair of bar holes 11c and 11c facing each other are provided. In the spiral groove 15, the interval W between adjacent grooves is constant in the upper half, while the interval W in the lower half gradually narrows toward the lower side. Further, on the upper end side of the casing body, slit-shaped viewing windows 11d (see FIG. 2) used for pulling out the filter 20 from the casing 10 are provided at two locations in the circumferential direction (only one location in FIG. 2) as described later. A pair of locking pieces 11e and 11e for locking the lower end of the casing cap 5 are provided.

As shown in FIG. 6, the spiral fin 12 is composed of a single strip formed of a long plate-shaped metal plate such as stainless steel and connected in a spiral shape. In the fin forming step, the spiral fin 12 is a round bar-shaped shaft (columnar column) in which, for example, a long plate member 12A as shown in FIG. 4A is rotated by a lathe or the like as shown in FIG. 2B. Body) Formed by wrapping around A. The spiral fin 12 is inserted into the spiral groove 15 by, for example, inserting the lower end thereof into the upper end of the spiral groove 15 and then rotating the spiral fin 12 (fin insertion step). The spiral groove 15 is provided with a stopper (not shown) for stopping the spiral fin 12 at a predetermined position.
As shown in FIG. 7, the spiral fin 12 has the outer edge in the width direction inserted into the spiral groove 15 so as to intersect the spiral groove 15 from the outer peripheral surface of the casing main body 11 and the spiral groove 15 The ellipse of the two-point chain line indicated by reference numeral 12b in the fin welding process, FIG. 7 is welded from the outside to the casing main body 11 via a groove (welding recess) 11a provided so as to communicate with the fin welding process. The welded part is shown schematically). By fixing the spiral fins 12 to the casing main body 11 in this way, the spiral flow path 17 is formed on the peripheral wall of the filter accommodating chamber 16.

The spiral fin 12 is formed to have a thickness of 1 mm or more and 5 mm or less, a protrusion height from the inner peripheral surface of the casing body 11 of 3 mm or more and 10 mm or less according to the outer diameter of the filter, and the outer diameter of the filter 20 is φ62 mm. If so, for example, the thickness is 2 mm and the protrusion height is 7.5 mm.

As shown in FIG. 6, the spiral fin 12 is provided with a raw water intake portion 121 formed on the upper end side so that the width of the fin gradually increases toward the lower end. By doing so, raw water can be easily taken into the filter accommodating chamber 16 and the spiral flow path 17. Further, the lower half of the spiral fin 12 is provided so that the distance W between adjacent fins is gradually reduced in accordance with the spiral groove 15 so that the spiral flow path 17 is gradually narrowed. .. The raw water flowing through the spiral flow path 17 gradually passes through the filter 20 and the flow rate decreases as it goes downward, so that the flow velocity drops and the cross-flow effect cannot be sufficiently obtained. In this way, the spiral flow path is spiral. By narrowing the flow path 17 downward, the flow velocity of the raw water can be maintained and the decrease in the cross-flow effect can be suppressed.

As shown in FIG. 8, the filter 20 includes an inner core 21, a thread layer 22, and a pair of upper and lower end members 23, 23.

As shown in FIG. 1, the inner core 21 is formed in a cylindrical shape with both upper and lower ends opened from resin or metal, and is a rectangular window-shaped water passage hole 21a composed of a large number of through holes penetrating in the thickness direction of the side wall. Are formed in a grid pattern side by side in the circumferential direction and the axial direction. As shown in FIG. 8, the outer peripheral surface of the inner core 21 is provided with a plurality of suspension protrusions 21b extending in the axial direction (in the illustrated example, two at four locations in the circumferential direction, for a total of eight). There is. The recess 21c, which consists of a valley between two suspension protrusions 21b and 21b arranged in close proximity to each other, is used as a guide when cutting the thread layer 22 with a cutter in order to reuse the inner core 21. ..

The yarn layer 22 is formed by winding twisted yarns such as cotton and polypropylene in multiple layers around the inner core 21. As the twisted yarn used for the yarn layer 22, a known yarn generally used for a yarn winding filter can be appropriately selected and used according to a target filtration amount and filtration accuracy.

In the thread layer 22, adjacent threads are adhered to each other at a plurality of locations (for example, two locations) in the circumferential direction by an adhesive, and are also adhered to the suspension ridges 21b. It is wound around the inner core 21 in a state slightly separated from the outer peripheral surface of the inner core 21.

As shown in FIG. 1, the end member 23 includes a flat tubular inner core fitting portion 231 and a filtered water discharge port 233 with the flange portion 232 interposed therebetween, and the inner core fitting portion 231 is inserted into the inner core 21. The openings at both ends of the inner core 21 are closed. The inner core fitting portion 231 is provided with a bottomed hole 23a on the outer peripheral surface for inserting the safety bar 6 when the filter 20 is pulled out from the casing 10.
As shown in FIG. 2, the bottomed hole 23a is provided slightly below the viewing window 11d when the filter 20 is set in the casing 10, and is a safety bar when the filter 20 is pulled out from the casing 10. The tip of the 6 is inserted into the bottomed hole 23a of the upper end member 23 via the viewing window 11d, and the rear end side is pushed down to lift the filter 20 with the safety bar 6 as a lever with the edge of the viewing window 11d as a fulcrum. To do so.
The outer peripheral surface of the filtered water discharge port 233 is provided with two O-ring grooves 233a and 233a for loading the O-ring 7 that seals the gap between the filter support tube 14 and the inner peripheral surface.

The filter cap 3 is formed in a covered cylindrical shape from an elastic soft resin such as polypropylene, and is configured to close the filtered water discharge port 233 of the upper end member 23. The filter hold 4 includes a lidded tubular grip portion 41, a convex portion 42 protruding upward from the grip portion 41, a crosspiece 43 extending radially from the lower edge of the grip portion 41 in a plan view, and a crosspiece 43. It is supported by the outer end and includes an outer peripheral portion 44 that abuts on the inner peripheral surface of the casing main body 11. The casing cap 5 has a flat covered cylindrical shape, the top plate is formed of a punching board having a large number of through holes 5a, and bar holes 5c and 5c through which the safety bar 6 is inserted are formed in the side wall. By covering the casing 10 with the casing cap 5 and inserting the safety bar 6 into the bar holes 5c and 11c, the filter hold 4 is fixed by pressing the convex portion 42, and the casing cap 5 is prevented from being attached or detached. Will be done.
Reference numerals 61 and 62 are stoppers and bars for preventing the safety bar 6 from falling off, respectively, and 61a and 61b are chains for preventing loss of the safety bar 6 and the bar 62.

As shown in FIG. 1, the filter 20 is housed in the filter storage chamber 16 of the casing 10 so that the filtered water discharge port 233 of the lower end member 23 is inserted into the filter support pipe 14. At this time, the positions of the viewing window 11d and the bottomed hole 23a are matched. The thread layer 22 is surrounded by the spiral fins 12 with a slight gap 18 interposed therebetween, and the upper end member 23 is surrounded by the raw water intake portion 121 of the spiral fins 12.

When performing filtration using the filtration module 100, for example, the filtration module 100 is erected at the bottom of a raw water storage tank (not shown) for storing the raw water to be filtered, and the filtration module 100 is placed in the raw water storage tank. The raw water is stored until the upper end of the container is submerged, and the raw water is poured into the filter accommodating chamber 16 through the through hole of the casing cap 5. Large contaminants in the raw water are prevented from flowing into the filtration module 100 by the punching metal of the casing cap 5.

The raw water that has flowed into the filter accommodating chamber 16 flows into the spiral flow path 17 and the gap 18 between the spiral fin 12 and the thread layer 22. Since the spiral fin 12 includes a raw water intake portion 121 in which the width of the fin gradually widens toward the upper end portion, the raw water flowing into the filter accommodating chamber 16 is short-cut along the gap 18. It can be suppressed and smoothly taken into the spiral flow path 17.

A part of the raw water flowing through the spiral flow path 17 and the gap 18 passes through the thread layer 22 of the filter 20 and the inner core 21, becomes filtered water, flows into the internal space 8 of the inner core 21, and flows into the inner core 21. It is discharged from the filtered water discharge port 233 at the lower end of 21 and sent to an appropriate next-process device such as a tank for storing the filtered water.

Further, the raw water flowing into the filter accommodating chamber 16 flows down while swirling around the spiral flow path 17, so that contaminants such as solids in the raw water are separated from the filtration surface by centrifugal force. In addition, the spirally swirling water flow, the Taylor vortex or Dean vortex generated by the spiral vortex, and the water flow vertically flowing down the gap 18 along the thread layer 22 are combined to generate various types on the surface of the thread layer 22. Since the cross-flow effect can be enhanced by the water flow, the filter slag adhering to the yarn layer 22 can be efficiently removed.
In the present embodiment, since the spiral fin 12 is made of stainless steel, the edge can be formed at an acute angle, so that a Dean vortex and a Taylor vortex can be effectively generated, and the spiral fin 12 is slippery as compared with the resin one. Since the property is improved, the flow of raw water becomes smooth and the effects of centrifugal force and cross flow are enhanced.

The raw water flowing through the spiral flow path 17 gradually passes through the thread layer 22 of the filter 20 and flows into the internal space 8 of the filter 20, so that the amount of water decreases and the flow velocity decreases as it goes downward. In the present embodiment, since the spiral flow path 17 is gradually narrowed as it goes downward, the attenuation of the flow velocity can be suppressed, and thus the attenuation of the cross flow effect can be suppressed.

Since the casing main body 11 is formed of a pipe material, there is no step in the circumferential direction on the inner peripheral surface, and the generation of pulsating current due to such a step can be suppressed. Further, since the casing main body 11 is entirely made of stainless steel, it has excellent chemical resistance and abrasion resistance, and various liquids can be filtered.

The raw water that has flowed down the spiral flow path 17 to the lower end without passing through the filter 20 is discharged from the raw water discharge port 19 that opens at the lower end of the spiral flow path 17, is returned to the raw water storage tank, and is filtered again. Processed by module 100.

When backwashing the filter 20, the washing water is pressurized by a backwashing pump (not shown), and the washing water passes through the inner core 21 and the thread layer 22 from the internal space 8 of the filter 20 to the outside. Let me. This also makes it possible to remove the filter slag accumulated in the thread layer 22. In the present embodiment, the outer peripheral surface of the inner core 21 is slightly separated from the outer peripheral surface of the inner core 21 by the suspension ridge 21b so that the filter yarn of the thread layer 22 is slightly separated from the outer peripheral surface of the inner core 21 at least in the vicinity of the suspension ridge 21b. The filter thread easily vibrates during washing, and the filter slag can be removed efficiently.

Since the raw water becomes thicker as it goes down the spiral flow path 17, the amount of slag increases in the thread layer 22 as it goes down. In the present embodiment, since the end members 23 having the filtered water discharge ports 233 are provided above and below the filter 20, the filter 20 can be used until the entire thread layer is evenly soiled by exchanging the upper and lower parts as appropriate. The life of the product can be greatly extended.

The present invention is not limited to the above embodiment, and the spiral fins may be attached to the casing body without providing the spiral groove on the inner surface of the casing body. For example, a spiral fin may be inserted into a casing body having no spiral groove, and only both ends thereof may be fixed by welding. The spiral fin may be fixed to the casing body by a method other than welding. The spiral fin may be formed by cutting a metal circular tube into a spiral shape by machining. The spiral fin may not be provided with a raw water intake portion, and the width W between the fins may be constant over the entire length.

The filter is not limited to the thread winding filter, and a known cylindrical filter having a side wall as a filter material, such as a ceramic filter or a non-woven fabric filter, can be appropriately used. The inner core does not have to be provided with suspension ridges, or may be assembled by dividing the inner core into a plurality of parts in the longitudinal direction.

The filtration module may be a pressure type, a casing storage type, or other non-immersion type filtration module instead of the immersion type filtration module. The water passage hole of the inner core is not limited to a rectangle, but may have a square shape, a circular shape, or any other appropriate shape.

100 Filtration module 10 Casing 11 Casing body 11a Welding recess 12 Spiral fin 15 Spiral groove 16 Filter storage chamber 17 Spiral flow path 20 Filter cylinder A
Interval W

Claims (9)

A method for manufacturing a casing for a filtration module having spiral fins on the peripheral wall of a filter accommodating chamber for accommodating a cylindrical filter for filtration on a side wall.
Fin forming process to form metal spiral fins,
A method for manufacturing a casing for a filtration module, which comprises a fin insertion step of inserting the spiral fin into a filter accommodating chamber formed of an internal space of a casing main body made of a metal circular tube. The method for manufacturing a casing for a filtration module according to claim 1, wherein a spiral fin is formed by winding a strip-shaped metal plate around a cylinder in the fin forming step. A spiral groove forming step for forming a spiral groove on the inner wall of the filter accommodating chamber is provided.
The method for manufacturing a casing for a filtration module according to claim 1, wherein in the fin insertion step, the spiral fin is inserted into the spiral groove and the spiral fin is inserted into the filter accommodating chamber. The method for manufacturing a casing for a filtration module according to claim 3, wherein in the fin insertion step, the spiral fin is inserted into the spiral groove while rotating. A fin welding process for welding the spiral fin to the casing body is provided.
The filtration module according to claim 3, wherein in the fin welding step, a welding recess that communicates with the spiral groove is provided from the outer wall side of the casing body, and the spiral fin is welded to the casing body from the welding recess. How to manufacture the casing. According to any one of claims 1 to 5, in the fin insertion step, at least a part of the lower side of the spiral flow path formed by the spiral fins is provided so as to be gradually narrowed toward the lower side. The method for manufacturing a casing for a filtration module according to the description. A casing for a filtration module having spiral fins on the peripheral wall of a filter storage chamber that houses a cylindrical filter that filters on the side wall.
A casing body made of a metal circular tube whose internal space is the filter storage chamber,
A casing for a filtration module, which is configured separately from the casing main body and includes a metal spiral fin attached to an inner wall of the filter accommodating chamber. The casing for a filtration module according to claim 7, wherein the spiral fin is inserted into a spiral groove provided on a peripheral wall of the filter accommodating chamber. The casing for a filtration module according to claim 7, wherein at least a part of the lower side of the spiral fin is provided so that the interval gradually becomes narrower toward the lower side.

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