JP7022253B1 - Screen device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a screen device having a uniform mesh width even when installed horizontally, increasing the flow rate of a liquid to be treated in contact with a filter body, and being able to be manufactured at low cost. SOLUTION: A screen device 1 has two cylindrical punching metals 2A and 2B in which a plurality of holes h are formed, and a wire rod 6 spirally wound around each of the two punching metals 2A and 2B. It has one coil spring 3A and 3B, two outer cylinders 4A and 4B, two drive devices 5A and 5B, and a control device 20 for controlling two drive devices 5A and 5B. One of the two punching metals 2A and 2B is supplied with the liquid to be treated W1, and the other is connected to the downstream side in the flow direction of the liquid to be treated W1 and has a smaller inner diameter than the other. The control device 20 controls the two drive devices 5A and 5B when the wire rod 6 is clogged, and cuts impurities in each of the two coil springs 3A and 3B. [Selection diagram] Fig. 1

Description

The present invention relates to a screen device that separates a permeate from sludge (a liquid to be treated) such as human waste and concentrates the liquid to be treated.

For example, in sludge treatment in a sewage treatment plant, a screen device using a coil spring as a screen is used to separate impurities contained in a liquid to be treated. For example, Patent Document 1 discloses a screen device that cuts contaminants by controlling the ends of sharp-angled coil springs to come into contact with each other when the gaps in the coil springs are clogged with contaminants. Has been done.

Further, Patent Document 2 discloses a cross-flow filtration device in which a rotation shaft provided with a large number of swinging pieces is arranged inside a filter body as a screen device for eliminating clogging. In the screen device disclosed in Patent Document 2, the rotating shaft is rotated by the liquid to be treated rotating the rotary drive blade, and the swaying piece in contact with the filter body clears the clogging. In addition to this, according to Patent Document 2, since the rotation axis to which a large number of rocking pieces are attached is arranged inside the filter body, the cross-sectional area of the filter body through which the liquid to be treated passes becomes small, and the filter becomes a filter. It is said that the filtration efficiency is improved because the flow rate of the liquid to be treated that comes into contact with the body increases.

Japanese Patent No. 6458962 Japanese Unexamined Patent Publication No. 10-272309

By the way, the screen device disclosed in Patent Document 1 has a simple structure and is inexpensive, but since it is basically intended for vertical placement, when it is installed horizontally, it is a cylinder formed of a coil spring. The shape may be bent like a half moon, the width (eye width) of the opening (gap of the coil spring which is the filter body) may not be uniform, and the function of the screen may be defective. Further, in the screen device disclosed in Patent Document 1, when the screen device is installed horizontally, when the permeated liquid flows out from the opening, the flow velocity in the vicinity of the coil spring becomes slow, so that in the cylindrical filter body, the inside of the filter body is slowed down. The liquid to be treated flowing near the central axis passes through without contacting the filter body, and the filtration efficiency (or the concentration efficiency of the liquid to be treated) may decrease. Therefore, it is conceivable to adopt the technique of Known Document 2 that can increase the flow rate of the liquid to be treated that comes into contact with the filter body, but the structure of the rotation shaft to which a large number of swinging pieces are attached becomes complicated and expensive. ..
Therefore, the present invention provides a screen device that can be manufactured at low cost by increasing the flow rate of the liquid to be treated that has a uniform mesh width and comes into contact with the filter body even when it is installed horizontally. The purpose is.

The screen device of the present invention includes a cylindrical first punching metal in which a plurality of holes are formed and a liquid to be treated is supplied, and a first coil spring in which a wire is spirally wound on the outside of the first punching metal. The first outer cylinder that covers the first coil spring from the outside at intervals from the first coil spring is connected to the downstream side of the first punching metal in the flow direction of the liquid to be treated, and a plurality of holes are formed. A cylindrical second punching metal having an inner diameter smaller than that of the first punching metal, a second coil spring in which a wire is spirally wound around the outside of the second punching metal, and the second coil spring at intervals. A second outer cylinder that covers the second coil spring from the outside, a first drive device that expands and contracts the first coil spring, a second drive device that expands and contracts the second coil spring, the first drive device, and the second drive device. It has a control device for controlling. The first coil spring and the second coil spring include a first surface which is a spiral cylindrical surface and a second surface which is a spiral slope whose angle formed with the first surface is an acute angle, and the control thereof. The device controls the first drive device and the second drive device when contaminants are clogged between the wires, and the ridgeline of the wire having a cutting edge shape between the first surface and the second surface. Cuts the contaminants in each of the first coil spring and the second coil spring.

According to the present invention, there is provided a screen device having a uniform mesh width, a large flow rate of a liquid to be treated that comes into contact with a filter body, and can be manufactured at low cost even when installed horizontally. be able to.

It is a partial sectional side view of the screen apparatus of embodiment. It is an enlarged view of the X part of FIG. 1, (a) is a figure for explaining the state in which a coil spring is extended, and (b) is a figure for explaining the state in which a coil spring is compressed. FIG. 1 is a cross-sectional view taken along the line YY in FIG. It is a partial cross-sectional perspective view of the punching metal and the coil spring provided in the screen apparatus of a modification. It is a partial cross-sectional perspective view of the punching metal and the coil spring provided in the screen apparatus of another modification.

Hereinafter, the screen apparatus of the embodiment will be described with reference to the drawings. The configurations shown below are merely examples, and there is no intention to exclude various modifications or applications of technology that are not specified. The configurations and the like shown below can be variously modified and implemented without departing from the essential constituent requirements and the gist of the present invention.

[1. Constitution]
FIG. 1 is a diagram for explaining the screen device 1 according to the embodiment. The screen device 1 is a device that can be installed horizontally, and sludge, human waste, or a mixed solution thereof (hereinafter, these are collectively referred to as "processed liquid W1") is referred to as a permeated liquid PW. It is separated from the concentrate W2 containing the contaminant T.
The term "horizontal placement" as used herein includes not only the direction in which the axis L (described later) of the screen device 1 coincides with the horizontal direction but also the direction in which the screen device 1 is tilted. For example, when the angle α of the axis L with respect to the horizontal direction is set in the range of 0 ° ≦ α <75 ° so that the upstream side is higher than the downstream side when viewed from the flow of the liquid W1 to be treated, here, “horizontal”. Call it "place". In addition, "the angle β of the axis L with respect to the horizontal direction is set in the range of 75 ° ≤ β ≤ 90 °" is referred to as "vertical installation" here.
The screen device 1 may be installed in a "vertical" position, but may be installed in a "horizontal" position to appropriately perform solid-liquid separation or concentration.

The screen device 1 is formed from a liquid W1 to be treated flowing inside a cylindrical screen (filter body) formed of a punching metal 2 and a coil spring 3, which will be described later, into a permeation liquid PW and a concentrated liquid W2 containing impurities T. To separate. By controlling the size (eye width) of the opening of the coil spring 3, solid-liquid separation and classification can be performed according to the purpose.
Further, in the screen device 1, when the screen is clogged, the function of cutting the contaminants T and clearing the clogging is performed by controlling the size (mesh width) of the opening of the coil spring 3 to be small. Have.
Hereinafter, the configuration of the screen device 1 will be described in detail.

The screen device 1 has a cylindrical punching metal 2 in which a plurality of holes h are formed, and a portion concentric with the punching metal 2 and radially outside the punching metal 2 in which the holes h of the punching metal 2 are formed. It has at least two units 10 including a coil spring 3 for covering, an outer cylinder 4 for covering the coil spring 3 from the outside, and a driving device 5 for expanding and contracting the coil spring 3. One unit has three drive devices 5 as shown in FIG. 3 described later, but in FIG. 1, only one drive device 5 is shown in one unit for the sake of simplification of the figure.
In the present embodiment, the horizontal screen device 1 provided with the three units 10 is exemplified, but the number of the units 10 may be two or four or more. Further, the screen device 1 has a control device 20 that controls the drive device 5 of each unit 10.
The outer diameter of the punching metal 2 and the inner diameter of the coil spring 3 included in one unit 10 are substantially the same, but the inner diameter of the coil spring 3 is slightly larger than the outer diameter of the punching metal 2.

The three units 10 are arranged in series along the flow direction of the liquid to be treated W1. Hereinafter, when the three units 10 are distinguished, they are referred to as the first unit 10A, the second unit 10B, and the third unit 10C in order from the upstream side in the flow direction. Further, when distinguishing the punching metal 2, the coil spring 3, the outer cylinder 4, and the drive device 5 included in each of the three units 10, the units 10 having the elements 2 to 5 are matched (in order from the upstream side). , Add "first" to "third" at the beginning of the element name and add A to C at the end of the code.

The three punching metals 2 included in each of the three units 10 have a cylindrical shape, but each has a different inner diameter. The three punching metals 2 are arranged in series, but the inner diameter of the punching metal 2 arranged upstream in terms of the flow of the liquid to be treated is larger than the inner diameter of the punching metal 2 arranged downstream thereof. Be placed. In other words, the inner diameter of the punching metal 2 arranged downstream in terms of the flow of the liquid to be treated is smaller than the inner diameter of the punching metal 2 arranged upstream thereof.
The three punching metals 2 are arranged coaxially and in series so that their central axes are aligned with the axis L and become a straight line. The liquid to be treated W1 is supplied to the inside of the first punching metal 2A located on the most upstream side.
Adjacent punching metals 2 are connected to each other by a truncated cone-shaped connecting pipe (12A or 12B) whose inner diameter decreases from upstream to downstream when viewed from the flow of the liquid to be treated.
Specifically, the downstream end of the first punching metal 2A and the upstream end of the second punching metal 2B are connected by the first connecting pipe 12A, and the downstream end of the second punching metal 2B and the upstream end of the third punching metal 2C are connected. Is connected by the second connecting pipe 12B.

Further, the upstream end of the first punching metal 2A is fixed to the inlet pipe 11 for introducing the liquid to be treated W1 into the screen device 1, and the downstream end of the third punching metal 2C is a concentrated liquid separated from the liquid to be treated W1. It is fixed to the outlet pipe 13 that discharges W2. The inlet pipe 11, the first connecting pipe 12A, the second connecting pipe 12B, and the outlet pipe 13 all have a cylindrical shape in which the liquid W1 to be treated can flow, and are arranged substantially concentrically with the axis L of the punching metal 2. Will be done.
A circular flange portion 17 is arranged and fixed on the outer surface on the upstream side of the first connecting pipe 12A, the second connecting pipe 12B, and the outlet pipe 13 so as to project radially from the outer surface and around the axis L.

As will be described later, the control device 20 can expand and contract the coil spring 3, but the inlet pipe 11, the first punching metal 2A, the first connecting pipe 12A, the second punching metal 2B, the second connecting pipe 12B, and the third punching. Since the metal 2C and the outlet pipe 13 both have a constant length, the length from the inlet pipe 11 to the outlet pipe 13 does not change regardless of the expansion / contraction state of the coil spring 3.

As shown in FIG. 2A, the diameter of the plurality of holes h formed in each punching metal 2 is set to be larger than the opening of the coil spring 3 arranged on the outside of each punching metal 2. The size of the opening of the coil spring 3 is basically set to a size that does not allow impurities T to pass through.
Therefore, the screen device 1 separates the permeated liquid PW from the liquid W1 flowing inside the punching metal 2 from the inside to the outside in the radial direction of the cylindrical punching metal 2 and the coil spring 3, and the liquid W1 to be treated. The permeate PW is removed from the permeate, and the concentrate W2 containing the contaminant T is discharged in the L direction along the axis.

As described above, the inner diameters of the three punching metals 2 are set smaller as they are located downstream. That is, as shown in FIG. 1, the inner diameter D2 of the second punching metal 2B is set smaller than the inner diameter D1 of the first punching metal 2A, and the inner diameter D3 of the third punching metal 2C is smaller than the inner diameter D2 of the second punching metal 2B. Is also set small. That is, there is a relationship of D1> D2> D3.

The liquid to be treated W1 introduced from the inlet pipe 11 is supplied to the inside of the first punching metal 2A. After that, the liquid to be treated W1 flows through the insides of the first punching metal 2A, the first connecting pipe 12A, the second punching metal 2B, the second connecting pipe 12B, and the third punching metal 2C in order, and the permeated liquid in each unit 10. The PW is separated and discharged from the outlet pipe 13 as the concentrated liquid W2. In FIGS. 1 and 2, the permeate PW is indicated by a white arrow.

The coil spring 3 included in each of the three units 10 is composed of a wire rod 6 spirally wound so as to be substantially concentric with the axis L. The inner diameter of the coil spring 3 included in one unit is substantially the same as the outer diameter of the punching metal 2 arranged inside the coil spring 3, and is slightly larger than the outer diameter.
The thickness, cross-sectional shape, and the like of the wire rod 6 constituting the coil spring 3 of each unit 10 do not necessarily have to be the same in all the units 10.

As shown in FIG. 2, each coil spring 3 formed by winding the wire rod 6 is a spiral slope in which the angle θ formed by the first surface 61, which is a spiral cylindrical surface, is an acute angle. It has a second surface 62.
Here, as shown in FIGS. 2A and 2B, a wire rod 6 having a triangular cross section is formed by a first surface 61 facing inward in the radial direction and a pair of second surfaces 62 facing outward in the radial direction. Illustrate. The angle θ formed by the first surface 61 and the second surface 62 is preferably 30 ° to 70 °, but is not limited to this as long as it is an acute angle.

The first surface 61 of the wire rods 6 adjacent to each other in the axis L direction (flow direction of the liquid to be treated W1) is formed so as to be an inner wall of a cylinder having the same inner diameter. The second surface 62 is formed so that the second surfaces 62 of the wire rods 6 adjacent to each other in the L direction of the axis are separated from each other as the second surfaces 62 are radially outward.

The adjacent wire rods 6 approach or separate from each other according to the expansion and contraction of the coil spring 3 in the axis L direction. FIG. 2A is a cross-sectional view of the wire rod 6 when the coil spring 3 is extended by the control device 20, and FIG. 2B is a cross-sectional view of the wire rod 6 when the coil spring 3 is compressed by the control device 20. It is a figure.
As shown in FIG. 2A, when the coil spring 3 is extended, the wire rods 6 adjacent to each other in the axis L direction are separated from each other, and a gap G is formed between them. The contaminant T contained in the liquid to be treated W1 is basically designed so as not to pass through the gap G of the coil spring 3, but the permeate PW containing no contaminant T or a small contaminant that passes through the gap G. The permeate PW containing only T flows out from the gap G between the wire rods 6 in the radial direction of the coil spring 3.
On the other hand, when a part of the large contaminant T is caught in the gap G of the coil spring 3 and causes clogging, the coil spring 3 is compressed by the control device 20 as shown in FIG. 2 (b), and the first The ridge line R between the surface 61 and the second surface 62 is in line contact with the adjacent wire rods 6. As a result, the contaminant T that causes the clogging is cut at the two ridge lines R that are in contact with the line, and the clogging is cleared.

As shown in FIG. 1, the upstream end of the first coil spring 3A is fixed to the inlet pipe 11, the upstream end of the second coil spring 3B is fixed to the first connection pipe 12A, and the upstream end of the third coil spring 3C is the second connection. It is fixed to the tube 12B.

The downstream end of each coil spring 3 is located substantially concentrically with the axis L and is fixed to the inner cylinder 7 that slides on the punching metal 2 in the axis L direction.
The inner cylinder 7 includes a cylindrical cylindrical portion 71 and a plate portion 72 protruding outward in the radial direction from a part of the outer peripheral surface of the cylindrical portion 71 (a portion downstream of the fixed portion of the coil spring 3). In other words, the plate portion 72 is fixed to the outer peripheral surface of the cylindrical portion 71.
The cylindrical portion 71 has an inner diameter equal to or slightly larger than the outer diameter of the punching metal 2 arranged inside each coil spring 3, and a pipe (first connecting pipe 12A) to which the downstream end of the punching metal 2 is fixed. , The outer diameter is equal to or smaller than the inner diameter of the upstream end of the second connecting pipe 12B or the outlet pipe 13).
The downstream end of the cylindrical portion 71 is slidably inserted into the gap between the punching metal 2 and the pipe. The plate portion 72 is a portion connected to the rod of the drive device 5, and, for example, as shown in FIG. 3, has a triangular shape with rounded corners when viewed from the direction of the axis L. A rod (which can be pushed out and pulled in) of the drive device 5 is fixed to each corner of the plate portion 72.

The outer cylinder 4 has a main cylindrical portion 41 arranged substantially concentrically with the axis L at a distance outward from the coil spring 3 in the radial direction, and an annular upstream end face portion 42 attached to an opening on the upstream side of the main cylindrical portion 41. And an annular downstream end face portion 43 attached to the downstream opening of the main cylindrical portion 41.
The upstream end surface portion 42 of the outer cylinder 4 of each unit 10 has an annular inner peripheral end surface fixed to a pipe for fixing the upstream end of each coil spring 3. Specifically, the upstream end face portion 42 of the first outer cylinder 4A is fixed to the inlet pipe 11, the upstream end face portion 42 of the second outer cylinder 4B is fixed to the first connecting pipe 12A, and the third outer cylinder 4C. The upstream end face portion 42 of the above is fixed to the second connecting pipe 12B. Further, in the downstream end surface portion 43 of the outer cylinder 4, the annular inner peripheral end surface is brought into contact with the outer peripheral surface of the inner cylinder 7 via a sealing member such as an oil seal. As a result, the outer cylinder 4 covers the coil spring 3 from the outside, and a space (permeate side space) is formed between the coil spring 3 and the outer cylinder 4.

A permeation liquid discharge pipe 14 for discharging the permeate PW is connected to the lower outer surface of the main cylinder portion 41 of the outer cylinder 4. The permeate discharge pipe 14 includes a plurality of branch pipes 14a connected to each of the main cylindrical portions 41 of the outer cylinder 4 of each unit 10 on the upstream side and the lower side, and one end on the downstream side of each branch pipe 14a. It is provided with a merging pipe 14b for connecting the portions.
An opening is formed in the main cylindrical portion 41 of each outer cylinder 4, and the other end of each branch pipe 14a is provided in a communicating state at the position of the opening. The permeate PW passes through the branch pipe 14a from the space between the coil spring 3 and the outer cylinder 4, merges at the confluence pipe 14b, and is sent to, for example, a permeation liquid storage tank (not shown).

Further, an opening for introducing the cleaning liquid CW into the screen device 1 is formed on the upper outer surface of the main cylindrical portion 41 of the outer cylinder 4, and one end of the cleaning liquid introduction pipe 15 is provided in a communicating state at the position of this opening. .. The other end of the cleaning liquid introduction pipe 15 connected to the main cylindrical portion 41 of each outer cylinder 4 is connected to the cleaning liquid supply device 30.
The cleaning liquid supply device 30 is controlled by the control device 20, and when the coil spring 3 is clogged, the cleaning liquid CW is supplied to the space between the coil spring 3 and the outer cylinder 4 through the cleaning liquid introduction pipe 15 to perform backwashing. To carry out. As the cleaning liquid CW introduced from the cleaning liquid introduction pipe 15, for example, the permeation liquid PW stored in the above-mentioned permeation liquid storage tank can be used.
When another liquid is used as the cleaning liquid CW without using the permeation liquid PW stored in the permeation liquid storage tank, the cleaning liquid CW of each unit 10 is used to prevent the other liquid from entering the permeation liquid storage tank. It is desirable to discharge the cleaning liquid CW used for backwashing to the outside of the system by a three-way valve (not shown) arranged in the pipe after the merging into the merging pipe 14b and before flowing into the permeation liquid storage tank.
In each unit 10, the opening to which the permeate discharge pipe 14 is connected is provided near the upstream end of the main cylindrical portion 41, and the opening to which the cleaning liquid introduction pipe 15 is connected is provided near the downstream end of the main cylindrical portion 41. However, the position of the opening to which the permeate discharge pipe 14 and the cleaning liquid introduction pipe 15 are connected is not limited to this.

As shown in FIGS. 1 and 3, the downstream end surface portion 43 of the outer cylinder 4 has an extending portion 43a extending radially outward from the outer peripheral surface of the main cylindrical portion 41. The drive device 5 is fixed to the surface facing the downstream side of the extension portion 43a. The extension portion 43a stays on the flange portion 17 provided in the pipe (first connection pipe 12A, second connection pipe 12B or outlet pipe 13) for fixing the downstream end of the punching metal 2 of one unit 10. It is fixed via the portion 73. In other words, one end of the rod-shaped stay portion 73 is fixed to the extending portion 43a, and the other end of the stay portion 73 is fixed to the flange portion 17. Thereby, the expansion / contraction distance of the rod included in the drive device 5 can be stably controlled.

As the drive device 5, a device such as an air cylinder having a cylinder having a piston inside and a rod provided integrally with the piston can be adopted. The tip of the rod is fixed to the plate portion 72. Therefore, the drive device 5 can slide the inner cylinder 7 so as to be pushed out or pulled in the axis L direction (flow direction of the liquid to be processed W1) by pushing out or pulling in the rod by the cylinder. That is, under the control of the control device 20, the drive device 5 can extend or contract the coil spring 3 fixed to the inner cylinder 7.
Here, as shown in FIG. 3, three drive devices 5 are provided for each unit 10, but the number of drive devices 5 is not limited to this, and one for each unit 10 depending on the design. It suffices to provide one or more drive devices 5.

A flow meter 23 that measures the flow rate of the permeate PW passing through the permeate discharge pipe 14 and transmits it to the control device 20 is installed in the permeate discharge pipe 14. In the screen device 1 shown in FIG. 1, among the confluence pipes 14b of the permeate discharge pipes 14 connected to the three outer cylinders 4, all the permeate PWs discharged from the three units 10 merge and circulate. A flow meter 23 is installed.
Further, in the screen device 1, the first pressure sensor 21A, which is arranged inside the first punching metal 2A, detects the pressure of the liquid to be treated and transmits it to the first pressure gauge 21, and the first pressure sensor 21A. The first pressure sensor 21 that calculates the received pressure information and transmits the first pressure value P1 (measured value) to the control device 20 is arranged outside the first coil spring 3A and inside the first outer cylinder 4A. The second pressure sensor 22A that detects the pressure of the permeate and sends it to the second pressure sensor 22 and the pressure information received from the second pressure sensor 22A are calculated and the second pressure value P2 (measured value) is controlled by the control device 20. A second pressure sensor 22 to transmit to is installed.

The control device 20 controls each drive device 5 so that the mesh width (gap G) of the coil spring 3 of each unit 10 becomes constant during normal operation in which the punching metal 2 and the coil spring 3 are not clogged. As a result, the screen device 1 carries out the treatment (solid-liquid separation or concentration) of the liquid to be treated W1 according to the purpose.

Further, in the control device 20, when the flow rate measured by the flow meter 23 is less than the first threshold value Q, or the second pressure measured by the second pressure gauge 22 from the first pressure value P1 measured by the first pressure gauge 21. When the differential pressure ΔP (= P1-P2) obtained by subtracting the value P2 is equal to or higher than the second threshold value P, it is determined that the coil spring 3 is more clogged, and the contaminant T is cut.
That is, when the flow rate of the permeate PW is smaller than the first threshold value Q, or the pressure inside the first punching metal 2A is second than the pressure outside the first coil spring 3A and inside the first outer cylinder 4A. When the threshold value P or more is larger, the contaminant T that is caught between the wire rods 6 of the coil spring 3 and is clogged is cut.

Specifically, the control device 20 controls the drive device 5 to pull in the rod and slide the inner cylinder 7 to the upstream side of the liquid W1 to be processed to compress the coil spring 3. More specifically, the control device 20 controls each of the first drive device 5A, the second drive device 5B, and the third drive device 5C, and controls each of the first coil spring 3A, the second coil spring 3B, and the third coil spring 3C. Compress. As a result, the contaminants T are cut at each of the first coil spring 3A, the second coil spring 3B, and the third coil spring 3C by the ridge line R forming the cutting edge shape between the first surface 61 and the second surface 62 of the wire rod 6. The control device 20 may repeatedly expand and contract the coil spring 3 to cut the contaminant T.
After the cutting operation of the contaminant T is completed, the control device 20 returns the coil spring 3 to the state before cutting. That is, each drive device 5 is controlled to push out the rod, and the coil spring 3 is extended so that the mesh width of the coil spring 3 of each unit 10 becomes constant.
The control device 20 may perform a backwash operation of supplying the cleaning liquid CW from the cleaning liquid supply device 30 after the cutting operation of the contaminant T.

The control device 20 may perform backwashing when only one of the determination using the measured value of the flow meter 23 and the determination using the measured values of the two pressure gauges 21 and 22 shows clogging. However, backwashing may be performed when both determinations indicate clogging. In the former case, the flow meter 23 or the pressure gauges 21 and 22 not used for the determination can be omitted.
Here, in the first unit 10A located at the most upstream, two pressure sensors (first pressure sensor 21A, second pressure sensor 22A) and corresponding pressure gauges (first pressure gauge 21, second pressure gauge 22) are added. ) Was arranged to control the expansion and contraction of the coil springs 3 of all the units 10 connected in series. However, two similar pressure sensors and corresponding pressure gauges are arranged in each of the plurality or all units 10, and the control device 20 expands and contracts the coil spring 3 of the unit 10 in which the pressure sensors and the pressure gauges are installed. May be individually controlled according to the measured pressure value.

[2. Action and effect]
According to the screen device 1, when the contaminant T is clogged between the wire 6 of the coil spring 3, the contaminant T is cut by the ridge line R of the wire 6 having the cutting edge shape between the first surface 61 and the second surface 62. Therefore, the clogging of the coil spring 3 can be effectively cleared.

Further, even when the screen device 1 is installed horizontally, since the punching metal 2 is provided inside the coil spring 3, the punching metal 2 acts as a mandrel and the coil spring 3 does not bend. Therefore, the mesh width of the coil spring 3 can be controlled to be constant. The same effect can be obtained even when the axis L of the screen device 1 is tilted at an angle α with respect to the horizontal direction.

Further, in the screen device 1, since the punching metal 2 having a large inner diameter and the punching metal 2 having a small inner diameter are sequentially connected from upstream to downstream of the liquid W1 to be treated, the punching metal through which the liquid W1 to be treated passes. The cross-sectional area of 2 (the area of the cross-section orthogonal to the axis L) gradually decreases in the flow direction. As a result, in the unit 10 on the upstream side (for example, the first unit 10A), the liquid to be treated W1 flowing near the axis L that has passed through without contacting the wall surface of the punching metal 2 has a cross-sectional area larger than that of the punching metal 2 on the upstream side. It is possible to make it easier to contact the wall surface of the punching metal 2 on the downstream side where the size is small. Therefore, the filtration efficiency can be improved.

In addition, the screen device 1 can be manufactured at low cost because the above effect is realized without providing a rotation shaft provided with a large number of swinging pieces as in the prior art.
Therefore, according to the screen device 1, the flow rate of the liquid to be treated W1 that has a uniform mesh width and is in contact with the wall surface of the punching metal 2 that is a filter body is increased even when the screen device 1 is installed horizontally. At the same time, the device can be manufactured at low cost.

The control device 20 determines that the flow rate measured by the flow meter 23 is less than the first threshold value Q, or the differential pressure ΔP obtained by subtracting the second pressure value P2 from the first pressure value P1 is equal to or higher than the second threshold value P. Each drive device 5 is controlled to cut the clogged contaminant T. In this way, by determining the degree of clogging of the coil spring 3 using the flow meter 23 or the pressure gauges 21 and 22, the clogging of the coil spring 3 can be reliably and inexpensively cleared.

[3. Modification example]
The screen device 1 described above is an example, and its configuration is not limited to that described above.
FIG. 4 is a partial cross-sectional perspective view of the punching metal 2 and the coil spring 3 included in the screen device 1'of the modified example. The screen device 1'is different from the screen device 1 in that at least one of the units 10 is provided with a rotating device 8 for increasing the flow rate of the liquid to be processed W1 in contact with the punching metal 2. The composition of is similar.

As shown in FIG. 4, the rotating device 8 may be arranged inside the punching metal 2 of any unit 10 or may be arranged inside the punching metal 2 of all the units 10. The rotating device 8 includes a rotating shaft 81 concentric with the axis L, and a balloon-shaped rotating body 82 formed so as to narrow toward the upstream side and having a rounded downstream end.

The rotary shaft 81 is coaxially arranged with the axis L of the punching metal 2, and is rotatably supported by, for example, a support member (not shown) fixed inside the punching metal 2. The support member may have a function of sliding the rotating shaft 81 along the direction of the axis L. An upstream end (tip portion 83, which will be described later) of the rotating body 82 is fixed to the downstream end of the rotating shaft 81. Further, a motor (motor) 87 may be provided on the upstream side of the rotating shaft 81.

The rotating body 82 includes an intermediate portion 85 formed in a substantially cylindrical shape, and a tip portion 83 having a divergent shape that gradually expands in the radial direction from the upstream to the downstream of the liquid to be treated W1 on the upstream side of the intermediate portion 85. It is roughly classified into a terminal portion 84 having a shape that gradually narrows (the radial dimension becomes smaller) from the upstream side to the downstream side of the liquid W1 to be treated on the downstream side of the intermediate portion 85. The outer diameter of the intermediate portion 85 is smaller than the inner diameter of the punching metal 2.
The liquid W1 to be treated flows from the tip portion 83 of the rotating body 82 to the intermediate portion 85, enters the narrow flow path between the intermediate portion 85 and the punching metal 2, and efficiently contacts the wall surface of the punching metal 2. .. Therefore, the filtration efficiency of the punching metal 2 and the coil spring 3 which are the filters is improved.
On the outer peripheral surface of the intermediate portion 85, four spiral-shaped rectifying blades 86 extending over the entire flow direction of the liquid to be treated W1 are fixed.

The liquid W1 to be treated supplied to the screen device 1'flows in the space between the intermediate portion 85 and the punching metal 2. At this time, a force that rotates around the axis L acts on the rectifying blade 86, whereby the rotating device 8 rotates. That is, the rotating device 8 rotates around the axis L without power due to the flow of the liquid to be processed W1.

As the rotating device 8 rotates, the liquid to be treated is agitated, and the liquid to be treated can be effectively brought into contact with the wall surface of the punching metal 2. Further, the liquid to be treated flowing around the rectifying blade 86 is pushed out by the rectifying blade 86 toward the space outside in the radial direction through the hole h of the punching metal 2. As a result, the separation of the liquid to be treated W1 by the coil spring 3 is promoted, and the filtration efficiency is further improved.

The rotation speed may be adjusted by applying a regenerative brake to the motor 87 installed on the upstream side of the rotation shaft 81. Thereby, the separation of the liquid to be treated W1 can be carried out more appropriately. By using the electric power generated by the regenerative brake as the electric power of the lighting provided outside the screen device 1', it is possible to contribute to the power saving of the equipment provided with the screen device 1'. The rotating device 8 may have a function of adjusting the filtration efficiency by sliding the rotating shaft 81 along the axis L.

A plurality of uneven shapes may be formed on the outer peripheral surface of the tip portion 83 to make the liquid to be treated turbulent. Due to the uneven shape, it is possible to prevent the liquid to be treated flowing in the vicinity of the axis L from passing through without contacting the punching metal 2, so that the filtration efficiency can be further improved.

According to the screen device 1'of the modified example, the rotating device 8 having a simple configuration consisting of the rotating shaft 81 concentric with the punching metal 2 and the rotating body 82 having the rectifying blade 86 is to be processed in contact with the wall surface of the punching metal 2. The flow rate of the liquid W1 can be increased. That is, the flow rate of the liquid to be treated W1 in contact with the wall surface of the punching metal 2 can be increased without adopting a complicated configuration in which a large number of swinging pieces are provided on the rotating shaft as in Patent Document 2, so that the product can be manufactured at low cost. A possible screen device 1'can be provided.
Further, since the rotating device 8 rotates around the axis L without power due to the flow of the liquid to be processed W1 even without the motor 87, it is not necessary to provide a device for rotating the rotating device 8. It is also possible to omit the step of arranging the device. This also makes it possible to provide a screen device 1'that can be manufactured at low cost.

FIG. 5 is a partial cross-sectional perspective view of the punching metal 2 and the coil spring 3 included in the screen device 1 ″ of another modification. This screen device 1 ″ is a rotating device 8 with respect to the screen device 1 ′ of FIG. Only the shape of the rotating body 82 is different. Since the other configurations of the screen device 1 ″ are the same as those of the screen device 1 ′, the description thereof will be omitted.
As shown in FIG. 5, the rotary device 8'is a bullet having a rotary shaft 81'similar to the rotary shaft 81 included in the rotary device 8 of FIG. 4, and an intermediate portion 85 having a tip portion 83 and a rectifying blade 86. It is provided with a rotating body 82'in shape. The rotating body 82'has no portion corresponding to the end portion 84 of the rotating body 82. Even in the rotating device 8'with such a shape, the same effect as the above-mentioned rotating device 8 can be obtained.

1, 1', 1 ″ screen device 2 punching metal 2A 1st punching metal 2B 2nd punching metal 2C 3rd punching metal 3 coil spring 3A 1st coil spring 3B 2nd coil spring 3C 3rd coil spring 4 outer cylinder 4A 1st outer cylinder 4B 2nd outer cylinder 4C 3rd outer cylinder 5 drive device 5A 1st drive device 5B 2nd drive device 5C 3rd drive device 6 wire rod 7 inner cylinder 8, 8'rotating device 10 unit 10A 1st unit 10B 2nd unit 10C 1st Three units 11 Inlet pipe 12A First connection pipe 12B Second connection pipe 13 Outlet pipe 14 Permeate discharge pipe 14a Branch pipe 14b Confluence pipe 15 Cleaning liquid introduction pipe 17 Flange part 20 Control device 21 First pressure sensor 21A First pressure sensor 22 Second pressure sensor 22A Second pressure sensor 23 Flow meter 30 Cleaning liquid supply device 41 Main cylindrical part 42 Upstream side end face part 43 Downstream side end face part 43a Extension part 61 First side 62 Second side 71 Inner cylinder part 72 Plate part 73 Stay part 81, 81 ′ Rotating shaft 82, 82 ′ Rotating body 83 Tip part 84 End part 85 Middle part 86 Rectification blade 87 Motor h hole D1 Inner diameter of first punching metal D2 Inner diameter of second punching metal D3 Third punching metal Inner diameter L Axis P 2nd threshold P1 1st pressure value P2 2nd pressure value Q 1st threshold W1 Processed liquid W2 Concentrate PW Permeate CW Cleaning liquid T Contaminating matter α, β Angle of axis with respect to horizontal direction θ First surface The corner between the second side

Claims (5)

A cylindrical first punching metal in which multiple holes are formed and a liquid to be treated is supplied.
A first coil spring in which a wire is spirally wound around the outside of the first punching metal, and
A first outer cylinder that covers the first coil spring from the outside at a distance from the first coil spring,
A cylindrical second punching metal that is connected to the downstream side of the first punching metal in the flow direction of the liquid to be treated, has a plurality of holes, and has an inner diameter smaller than that of the first punching metal.
A second coil spring in which a wire is spirally wound around the outside of the second punching metal, and
A second outer cylinder that covers the second coil spring from the outside at a distance from the second coil spring,
The first drive device that expands and contracts the first coil spring,
The second drive device that expands and contracts the second coil spring,
It has the first drive device and the control device that controls the second drive device.
The first coil spring and the second coil spring include a first surface which is a spiral cylindrical surface and a second surface which is a spiral slope whose angle formed with the first surface is an acute angle.
The control device controls the first drive device and the second drive device when contaminants are clogged between the wires, and the wire rod having a cutting edge shape on the first surface and the second surface. A screen device that cuts the contaminants in each of the first coil spring and the second coil spring by the ridgeline of the above. A permeation liquid discharge pipe connected to the first outer cylinder and the second outer cylinder to discharge the permeate,
A flow meter installed in the permeate discharge pipe and measuring the flow rate of the permeate discharged from the permeate discharge pipe, or a first pressure value which is the pressure inside the first punching metal is measured. It further has a pressure gauge and a second pressure gauge that measures a second pressure value, which is the pressure outside the first coil spring and inside the first outer cylinder.
When the flow rate measured by the flow meter is less than the first threshold value,
or,
When the differential pressure obtained by subtracting the second pressure value from the first pressure value is equal to or more than the second threshold value.
The screen device according to claim 1, wherein the control device controls the first drive device and the second drive device to cut the contaminants. It further comprises a rotating shaft concentric with the first punching metal or the second punching metal, a rectifying blade that receives the flow of the liquid to be treated, and a rotating device that rotates around the rotating shaft.
The screen device according to claim 2, wherein the rotating device rotates to increase the flow rate of the liquid to be processed that comes into contact with the first punching metal or the second punching metal. The tip of the rotating device has a divergent shape that gradually expands in the radial direction from the upstream to the downstream of the liquid to be treated.
The tip is fixed to the rotating shaft and
The screen device according to claim 3, wherein the rotating device rotates without power when the rectifying blade receives the liquid to be processed. The screen device according to claim 4, wherein an uneven shape that makes the liquid to be treated turbulent is formed on the tip portion.

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