JP4623666B2 - Filtration device - Google Patents

Description

  The present invention relates to a filtration device.

Filter materials such as metal nets and perforated plates are superior to fabric (fiber) in terms of operability, maintainability, durability, and so on. There are pressure filtration devices such as pressure dehydrators. This device has a long history and has a very simple structure, so it features low power, low noise, low cost, etc., and even when applied to a hard-to-dehydrate solid-liquid mixture with a low solid content. Because of its excellent dewatering performance, it is often used in the sewage sludge dewatering field. (For example, see Patent Documents 1 and 2)
However, in a screw press comprising a cylindrical outer filter medium and a screw inserted therein, the liquid to be treated is transferred from the inlet side to the outlet side at a low speed, and at the same time, generated by the tightening force of the screw. Although it is continuously dehydrated by the pressing pressure, the filtrate is squeezed out only from the outer filter medium, so it is difficult to shorten the length of the outer filter medium, and it is difficult to downsize the equipment.
On the other hand, in the rotary pressurization type dehydrator, it is necessary to increase the diameter of the disk or to arrange a plurality of dehydrators in order to improve the throughput of dehydration filtration. It was.
Therefore, in view of such problems, the present inventors provide a concentrically arranged cylindrical or conical inner filter medium and outer filter medium, and a filtration space between these inner filter medium and outer filter medium. A spiral-shaped partition, and feeds the liquid to be treated from one end of the filtration space, discharges the cake from the other end of the filtration space, and passes the filtrate that has passed through the inner and outer filter media. A filtering device configured to discharge to the outside has been proposed in which the inner filter medium and / or the outer filter medium rotate around the axis, and the spiral partition does not rotate (for example, Patent Document 3). .
JP 2001-212697 A JP 2001-113109 A Japanese Patent Application No. 2005-176901

In the above invention, the device itself can be reduced in size and the dewatering performance can be improved. However, when the filter medium is attached to a cylindrical or conical inner frame, it is more reliable with the inner frame. Improvements in adhesion and mounting work efficiency, prevention of deformation and cracking, and the like have been demanded.
Then, the main subject of this invention is to solve the said subject, and is providing the filtration apparatus which aimed at the more reliable adhesion with an inner frame, the improvement of attachment work efficiency, and prevention of a deformation | transformation and a crack. .

The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
The invention according to claim 1 is a concentrically arranged cylindrical or conical inner frame and outer frame, an inner filter medium and an outer filter medium that can be attached to the inner frame and the outer frame, the inner filter medium, and the A spiral partition provided in the filtration space between the outer filter medium, the axial center is vertically oriented, and the device is arranged vertically, and the liquid to be treated is directed upward from below the filtration space. and fed to discharge the cake from the upper side in the filtration space, a filtering device configured to discharge to the outside the filtrate in the process through the inner filter material and said outer filter media, the inner frame and the outer frame Is rotated around the axis, the inner filter medium and the outer filter medium rotate around the axis, and the spiral partition is not rotated, and the cake is caused by frictional force with the rotating filter medium. Raise along the partition and filter Is configured to be discharged from between, on the inner frame, the groove for securing the inner filter material is formed on an outer peripheral portion, the inner filter media, so as to correspond to the inner frame, slightly larger than the inner frame inner diameter When mounting the inner filter medium, the inner filter medium is sandwiched between the groove section and the presser member by pressing the presser member corresponding to the groove section from the outside of the inner filter medium. The filtration device is characterized in that the inner filter medium is attached to the inner frame by fixing the member and the groove.

(Function and effect)
By performing filtration and concentration with two surfaces of the inner filter medium and the outer filter medium, it is possible to reduce the size of the equipment as compared with a screw press that performs filtration only with a conventional outer filter medium. In addition, the inner filter medium and / or the outer filter medium rotate around the axis and the spiral partition does not rotate, so that the liquid to be treated fed into the filtration space is spirally installed along the partition. While moving inside, first, filtration and concentration by the two sides of the inner and outer filter media is performed, and then press dewatering is performed, but not only the inner and outer filter media but also the ribbon screw, all of which are configured to be freely rotatable compared to the screw press The filtration device according to the present invention can simplify the structure, reduce the manufacturing cost, and improve the maintainability.
The inner frame has a groove for fixing the inner filter medium in the outer peripheral portion, and the inner filter medium has a cylindrical or conical shape with a slightly larger inner diameter than the inner frame so as to correspond to the inner frame. Yes, when attaching the inner filter medium, press the holding member corresponding to the groove from the outside of the inner filter medium, sandwich the inner filter medium between the groove section and the presser member, and fix the presser member and groove section to fix the inner filter medium. By being configured to be attached to the inner frame, reliable adhesion to the inner frame can be obtained, and the gap between the inner filter medium and the partition can be kept uniformly at a constant interval. Moreover, since there is little possibility that the clearance gap between an inner frame and an inner side filter medium will arise, the to-be-processed liquid and a cake can be prevented from leaking. Furthermore, the inner filter medium can be easily attached to the inner frame, and the attachment time can be shortened.

<Invention of Claim 2>
Invention of Claim 2 is a filtration apparatus of Claim 1 with which the said inner side filter medium was comprised by the cylindrical shape or the cone shape by welding of both ends.

(Function and effect)
When the inner filter medium is fixed to the inner frame by fastening means such as bolts, the inner filter medium is formed into a cylindrical or conical shape by welding, so that the sheet-shaped filter medium is welded into a cylindrical or conical shape without welding. The burden (stress) applied to the bolt hole formed in the filter medium can be reduced rather than being fixed to the inner frame with a bolt or the like in a rolled state. Therefore, deformation and cracking during use can be prevented. Moreover, reliable adhesion with the inner frame can be obtained, and the gap between the inner filter medium and the partition can be kept uniform at a constant interval. In addition, since there is little possibility of a gap between the inner frame and the inner filter medium, leakage of the liquid to be processed and the cake can be prevented. Furthermore, the inner filter medium can be easily attached to the inner frame, and the attachment time can be shortened.

<Invention of Claim 3>
Invention of Claim 3 is a filtration apparatus of Claim 1 or 2 whose surface which contact | abuts the inner side filter medium in the said holding member is circular cross-sectional shape.

(Function and effect)
By making the surface of the presser member in contact with the inner filter medium into a circular arc shape, the stress can be evenly distributed to the inner filter medium with respect to the force that pulls the inner filter medium inward in the groove.

According to the present invention, there are advantages that the apparatus can be downsized and the dewatering performance can be improved.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
<Configuration of filtration device according to the present invention>
As shown in FIGS. 1 and 2, the casing 7 in the filtration device according to the present invention has an inner cylinder rotating shaft to which a driving force is transmitted by a first rotation driving means (not shown) such as a motor. 5, a rotatable cylindrical inner frame 1 having an upper plate 1A connected thereto, a rotatable cylindrical outer frame 2 arranged concentrically with the inner frame 1, an inner frame 1 and an outer frame 2 Both ends are fixed to the inner filter medium 1B and the outer filter medium 2B that can be attached to the upper plate 7A and the bottom plate 7B of the casing 7, and are arranged in the filtration space 4 formed between the inner filter medium 1B and the outer filter medium 2B. And a spiral (ribbon screw-shaped) partition 3. In addition, although the casing 7 is a cylindrical shape in this Embodiment, it is not restricted to this, Shapes, such as a polyhedron, may be sufficient. Further, the arrangement of the inner frame 1 in the casing 7 is not limited to the above, and can be rotatably mounted by various known methods.

As shown in FIGS. 1 and 2, the liquid inlets 10, 11 are formed on the bottom plate 7 </ b> B of the casing 7 where the filtration space 4 is projected, and the liquid inlets 10, 11 are connected to the liquid inlets 10, 11. Treatment liquid is fed. The liquid to be treated is pumped by a pump (not shown), and rises from the bottom to the top of the casing 7 together with this pressure by friction caused by the rotation of the inner filter medium 1B and the outer filter medium 2B . Also the liquid to be treated feed inlet is a two positions in this embodiment, but is not limited thereto.

  An inner filter medium 1 </ b> B that is a porous plate as a filter medium is stretched on the outer peripheral side of the inner frame 1. The inner frame 1 functions as a reinforcing material that holds the shape of the inner filter medium 1B and the like, and a plurality of holes 1a, 1a,. The inner filter medium rotates around the axis when the inner frame 1 rotates around the axis. Of the liquid to be treated that is fed into the filtration space 4 formed between the inner filter medium 1B and the outer filter medium 2B, a part of the filtrate subjected to solid-liquid separation is put on the bottom plate 7B of the casing 7 in the inner filter medium 1B. It is accumulated and finally discharged from the filtrate outlet 12.

  The outer frame 2 is rotatably attached to the casing 7 by a swiveling wheel (bearing) (not shown) or the like disposed in the casing 7 at a circumferential upper end portion. The upper end portion is not shown, but via a pinion gear (not shown) or the like to an outer rotating shaft (not shown) to which a driving force is transmitted by a second rotation driving means (not shown) such as a motor. The outer filter medium 2B itself is connected and rotated. Although not shown, the inner frame 1 is attached to the casing 7 so as to be rotatable with respect to the casing 7 by a swiveling wheel (bearing) (not shown) disposed in the casing 7 as in the case of the outer frame 2. It can also be set as the structure which transmits a driving force by a 1st rotation drive means.

  The outer filter medium 2B is a perforated plate, like the inner filter medium 1B, and is stretched on the inner peripheral side of the outer frame 2. The outer filter medium 2B rotates around the axis when the outer frame 2 rotates around the axis. Of the liquid to be treated that has been fed into the filtration space 4, a part of the filtrate that has undergone solid-liquid separation is stored in the bottom plate 7B in the portion between the casing 7 and the outer filter medium 2B, and finally the filtrate. It is discharged from the discharge port 13.

  Here, even when the inner filter medium 1B and the outer filter medium 2B are rotated at the same angular velocity (° / sec), a circumferential speed difference (mm / sec) of each radial difference is generated, so that shear force is applied to the cake. As a result, the dehydration efficiency is improved. For example, for the liquid to be treated containing raw sludge having a high fiber content or mixed raw sludge, since this shearing force is more effective, a slight angular velocity difference is given to the inner filter medium 1B and the outer filter medium 2B. It is possible to further improve the dehydration efficiency by rotating. Moreover, when the relative speed of the inner side filter medium 1B and the outer side filter medium 2B is large, the cake in the vicinity of the filtration surface (for example, the filtration surface of the inner filter medium 1B) that rotates rapidly is the other filtration surface (for example, the filtration of the outer filter medium 2B). The effect of moving to the surface) side appears, and the mixing action in the cake occurs, so that the moisture content distribution in the filtration device can be made uniform.

As described above, the shearing force is applied to the cake due to the difference in angular velocity between the filtration surfaces of the inner and outer filter media 1B and 2B, and the dewatering efficiency is improved. However, since this effect depends on the properties of the target cake, the cake is operated in an optimum state. In this case, it is desirable to set the difference between the internal and external angular velocity according to the cake properties. For this reason, in this embodiment, the inner and outer filter media 1B and 2B are provided with rotational drive means such as individual motors so that the angular velocity difference can be easily adjusted.
On the other hand, depending on the cake properties, when a shearing force is applied, the cake may be fluidized, and conversely, the dewaterability may be impaired. In such a case, it is preferable to rotate at the same angular speed. Moreover, about the cake which has the spin-drying | dehydration effect by a shearing force, and a cake property hardly changes throughout the year, you may rotate at the same angular speed, For these object cakes, inner and outer filter media 1B and 2B are used. You may make it rotate at the same angular velocity with one motor .

  As described above, a porous plate is used as the filter medium used for the inner and outer filter media 1B and 2B. As this porous plate, for example, a slit grill, a diamond screen, a raster metal, a round hole, a slit, a herringbone, A punching plate used for dehydrating, separating, concentrating, and classifying solids such as square holes can also be employed. Preferably, it is desirable to employ a plate drilled by laser processing in order to make the hole diameter smaller.

There are several methods for attaching the inner filter medium 1B to the inner frame 1.
As shown in FIGS. 9 and 10, the first method is a method of bending one end of each sheet-like inner filter medium 1 </ b> B in advance to form one side surface of a groove 1 </ b> C formed in the outer peripheral portion of the inner frame 1. One of the bent portions of the inner filter medium 1B is brought into contact with the other side, the other side of the inner filter medium 1B is brought into contact with the other side surface of the groove portion of the inner frame 1, and each bent portion and the side surface of the groove portion are connected to the bolt 50. , 50 or the like.
However, in this method, in order to make it closely contact with the inner frame 1, if the folding positions of both ends of the inner filter medium 1 </ b> B are not accurate, a gap is generated at the boundary between the groove 1 </ b> C and the outer peripheral portion of the inner frame 1. Therefore, it is necessary to adjust the gap (error) between the inner frame 1 and the inner filter medium 1B with a liner (not shown) or the like, and the work efficiency is not good including the installation effort. Further, when the inner filter medium 1B is not in close contact with the inner frame 1, the liquid to be treated and the cake leak from the gap, or the load (stress) due to the cake pressure concentrates on the loose part of the inner filter medium 1B, and the inner filter medium There is a risk of 1B breaking.

In the second method, as shown in FIGS. 11 and 12, both ends of one sheet-like inner filter medium 1B are bolted to bolts 52, 52 in advance in a substantially wedge-shaped presser member 51 extending in the vertical direction in advance. In a state where the inner filter medium 1B is fixed in a cylindrical shape, the pressing member 51 corresponding to the groove 1C is fixed with a bolt 53 or the like while being pushed into the groove 1C of the inner frame 1. In order to eliminate the step between the presser member 51 and the outer peripheral surface of the inner filter medium 1B, an attachment member (not shown) is attached to the presser member 51 with a bolt or the like, and the presser member 51 and the partition 3 or the scraper 16 are placed between them. What is necessary is just to block the gap which arises.
In this second method, adhesion is obtained as compared with the first method, but in the bolt hole of the inner filter medium 1B for fixing the bolts 52, 52 against the force of pulling the inner filter medium 1B inward in the groove 1C. There is a risk that the load is concentrated, the hole is deformed, and cracks occur during use.

Therefore, in order to solve the problems of the first and second methods, the present inventors can easily attach and attach in close contact with the inner frame 1 to reduce the local load concentration of the inner filter medium 1B. A reduced third method was found. In the third method, as shown in FIG. 13, a cylindrical inner filter medium 1B having a slightly larger inner diameter than the inner frame 1 is pressed with a pressing member 54 corresponding to the groove section 1C, and the inner filter medium 1B is pressed with the groove section 1C. It is fixed to the groove portion 1C with a bolt 55 or the like while being pushed into the groove portion 1C of the inner frame 1 so as to be sandwiched between the members 54.
Thereby, compared with a 2nd method, concentration of the load to the bolt hole of the inner side filter medium 1B can be avoided, and the deformation | transformation and crack in use can be prevented. Moreover, reliable adhesion with the inner frame 1 can be obtained, and leakage of the liquid to be processed and cake can be prevented. The inner filter medium 1B can be easily attached to the inner frame 1, and the attachment time can be shortened. Furthermore, the load (stress) can be dispersed by adopting a configuration in which the presser member 54 is configured to have substantially the same length as the axial direction of the filtration surface of the inner filter medium 1B, and the inner filter medium 1B is pressed by the entire length of the presser member 54. , Deformation and cracking during use can be prevented.

  The inner filter medium 1B can be manufactured in a cylindrical shape by welding a single sheet at both ends. Further, the surface (part) of the presser member 54 that contacts the inner filter medium 1B has an arc-shaped cross section (more preferably a semicircular shape), and the inner filter medium 1B is subjected to a force that pulls the inner filter medium 1B inward in the groove 1C. It is preferable to apply stress evenly. Thereby, the deformation | transformation and crack of the inner side filter medium 1B can further be reduced. Moreover, when using the inner side filter medium 1B manufactured by the cylinder shape by welding, it is preferable to form a bolt hole in the position which removed the welding part. As for the elimination of the step between the presser member 54 and the outer peripheral surface of the inner filter medium 1B, an attachment member (not shown) is attached to the presser member 54 with a bolt or the like in the same manner as in the second method described above. You can close it.

Although not shown in the drawing, as the porous plate of the inner filter medium 1B and / or the outer filter medium 2B, filtration concentration is mainly performed in the lower part of the filtration space 4 having a low solid content and a large amount of liquid to be treated. In order to achieve this, a large pore diameter (opening) is used, and on the other hand, the filtration space 4 having a small pore diameter is mainly used in the upper part of the filtration space 4 having a large moisture content in the cake. It is also possible to adopt a configuration in which the hole diameter gradually decreases from the lower part to the upper part. That is, if the hole diameter at the upper part of the filtration space 4 is reduced, a high pressure is generated on the cake discharge port side, so that it is difficult for the cake portion to flow out of the filter medium, and the effect of improving the SS recovery rate (%) occurs. is there.
As a modified example, the same hole diameter is formed from the lower part of the filtration space 4 to the upper part. However, the opening ratio may be gradually reduced from the lower part to the upper part of the filtration space 4. it can.

  Although not shown, a filter medium subjected to a high friction treatment can be used as the filter medium of the inner filter medium 1B and / or the outer filter medium 2B. The cake and the liquid to be treated are conveyed in the circumferential direction of the inner and outer filter media 1B and 2B by friction with the rotating filter media, and interfere with the partition 3 to rotate in the axial direction while rotating around the axis. Since it moves and is finally discharged | emitted from the cake discharge port 14, conveyance property can be improved by performing a high friction process to a filter medium. High friction treatment means using a material having a high frictional resistance (friction coefficient), processing with a high frictional resistance by surface treatment such as unevenness, or attaching a member subjected to such processing to the surface. It shall be said. As this high friction treatment, for example, a perforated plate having irregularities formed on the surface thereof such as a diamond screen or a slit grill can be considered. The surface unevenness increases the contact area with the cake and the liquid to be treated, and the frictional resistance increases, thereby improving the transportability.

  In particular, by using a filter medium that has been subjected to at least a high friction treatment in the upper part of the filtration space 4 having a large amount of cake having a reduced moisture content, it is possible to increase the frictional force with the filter medium and facilitate the transport of the cake. Moreover, even if it uses for the lower part of the filtration space 4 with many to-be-processed liquids with low solid content concentration and fluidity | liquidity, stirring efficiency can be improved.

  As shown in FIGS. 1 and 4, the partition 3 has a spiral shape (ribbon screw shape), and is disposed in an annular filtration space 4 formed between the inner filter medium 1B and the outer filter medium 2B. . Since the partition 3 is fixed to the upper plate 7A and the bottom plate 7B of the casing 7, the partition 3 does not rotate around the axis. As a result, the filtration device according to the present invention can simplify the structure, reduce the manufacturing cost, and improve the maintainability, compared to a screw press that can rotate not only the inner and outer filter media but also the ribbon screw. Can be achieved.

  The inner peripheral edge and the outer peripheral edge of the partition 3 are configured to be close to or in contact with the filtration surfaces of the inner filter medium 1B and the outer filter medium 2B, respectively. With this configuration, the cake adhered to the filtration surfaces of the inner and outer filter media 1 and 2 can be easily scraped off, the efficiency of filtration and concentration can be maintained, and the treatment object fed from the treatment liquid inlets 10 and 11 can be maintained. The liquid can be raised spirally along the partition 3. Since the lower part of the filtration space 4, that is, the vicinity of the processed liquid inlets 10 and 11 side is mainly subjected to filtration and concentration by solid-liquid separation action, at least the inner peripheral edge and the outer peripheral edge of the partition 3 are at least of the processed liquid. What is necessary is just a structure in which the vicinity of the inlets 10 and 11 approaches or contacts the inner and outer filter media 1B and 2B, respectively.

  Further, as shown in FIG. 4, by attaching a scraper 16 formed of rubber or the like to the inner and outer peripheral edges of the partition 3, the inner filter medium 1B and the outer filter medium 2B rotate around the axis, and the partition 3 rotates. Due to the non-configuration, the cake captured on the filtration surface can be scraped off by the scraper 16. Note that, as described above, the lower part of the filtration space 4, that is, the vicinity of the liquid inlets 10 and 11 to be processed mainly concentrates by filtration through solid-liquid separation. The scraper should just be attached to 11 side vicinity.

  The partition 3 may have a uniform spiral pitch throughout the filtration space 4, but in order to eliminate the unevenness (distribution) of the moisture content of the cake discharged, as shown in FIG. 1 and FIG. It is preferable that the pitch of the partition 3 is shortened from the bottom plate 7B side of the casing 7 to the top plate 7A side. Specifically, the spiral pitch is set at the upper portion of the filtration space 4. It is preferable to shorten the length of the cake discharge route to enhance the squeezing effect. On the other hand, as shown in FIGS. 5 to 8, which will be described later, when the radius difference between the inner and outer filter media 1 and 2 is reduced in order to improve the dewatering efficiency in the upper part of the filtration space 4, although not shown, You may comprise the partition 3 so that the pitch may become long as it goes from the bottom plate 7B side of the casing 7 to the upper plate 7A side.

  Although not shown, a hole through which the cake can pass can be formed in a part of the spiral partition 3 to promote stirring and mixing of the cake. Furthermore, the lower part of the partition 3 is provided apart from the bottom plate 7B of the casing 7 in the lower part of the filtration space 4, that is, in the vicinity of the liquid inlets 10 and 11 to be processed (the lower part of the spiral partition 3 is cut). In this case, the partition 3 and the bottom plate 7B of the casing 7 may be fixed via an arbitrary support member (for example, a columnar member).

  As shown in FIGS. 1 and 4, the scraper 16 attaches the upper plate 7 </ b> A and the bottom plate 7 </ b> B of the casing 7 as both ends in the axial direction of the casing 7 along the inner and outer peripheral edges of the partition 3. Can be considered. Although this scraper 16 is attached to each of the inner peripheral edge and the outer peripheral edge in FIG. 4, it may be attached to a plurality of positions. As a modification, the scraper 16 may be attached only to the lower part of the filtration space 4 where solid-liquid separation is mainly performed. As a mounting method in this case, although not shown, it may be installed only on the bottom plate 7B of the casing 7, or may be installed so as to connect the bottom plate 7B of the casing 7 and the partition 3, or in the axial direction. You may install so that the periphery of the adjacent partition 3 may be bridged and connected. In addition, the scraper 16 is not attached in parallel to the axial direction but is not shown, but the scraper 16 may be attached to the respective leading ends along the inner and outer peripheral edges of the partition 3.

  As described above, the scraper itself may be made of rubber, resin, or the like that can be pressed against the filtration surface by elastic force. However, as a modification, a spring is attached to the tip of the scraper. A blade having a function of allowing the blade to move in the radial direction of the inner filter medium 1B and the outer filter medium 2B by using a spring or the like can be used.

  Below, the relationship with the inner side filter medium 1B, the outer side filter medium 2B, and the partition 3 is demonstrated. The liquid to be processed fed from the liquid inlets 10 and 11 to be processed formed on the bottom plate 7B of the casing 7 to be described later has a low solid content and fluidity, and in the lower part of the filtration space 4, Filtration concentration occurs through the openings of the cylindrical filter media in the inner filter media 1B and the outer filter media 2B. In the lower part of the filtration space 4, filtration concentration by solid-liquid separation action is an important function. However, when the filtration concentration progresses to some extent, the concentrated cake adheres to the filtration surface and the filtration efficiency decreases. Therefore, in order to maintain the concentration efficiency, the scraper 16 is attached to the partition 3, and the surface of the filter medium in the inner filter medium 1B and the outer filter medium 2B is scraped at a high frequency to scrape the cake adhered to the surface.

  Moreover, since the cake which lost fluidity | liquidity by the concentration effect | action produces a frictional force with a filter medium, it is conveyed by the rotating filter medium in the circumferential direction of the inner and outer filter media 1,2. However, a spiral (ribbon screw-shaped) partition 3 is arranged in the filtration space 4, and the cake rotating along the inner and outer filter media 1 and 2 interferes with the partition 3, thereby centering the axis. And move in the axial direction. While being concentrated by filtration, the cake is finally discharged from the cake outlet 14 formed in the upper part of the filtration space 4. In addition, although mentioned later, the back pressure plate 15 which suppresses discharge | emission of a cake is attached to the cake discharge port 14, and a cake is consolidated in the filtration space 4 by forcibly suppressing discharge | emission amount, The moisture content can be reduced.

  Although the filtration space 4 which concerns on embodiment has shown the cyclic | annular inner frame 1 and the outer frame 2 which have the same cross section from the top to the bottom, the lower part of the filtration space 4 is large in order to ensure a processing amount. It is preferable to narrow the difference in radius between the inner frame and the outer frames 1 and 2 in order to increase the volume of the filtration chamber and to improve the dewatering efficiency in the upper part of the filtration space 4. Specifically, as shown in FIG. 5, the shape of the outer frame remains the same, and the radial direction of the inner frame 1 is continuous from the liquid feed inlets 10 and 11 side toward the cake outlet 14 side. It is possible to propose a shape that expands in the shape of a circle (substantially conical shape) or a shape that expands in a staircase shape (multi-stage cylindrical shape) as shown in FIG. Further, as shown in FIG. 7, the inner frame 1 remains in the same shape, and the radial direction of the outer frame 2 is continuously reduced from the liquid inlets 10 and 11 to the cake outlet 14 side. You can also suggest a shape to go. In this case, the inner filter medium or the like may be formed in a conical shape by welding at both ends. Further, it is possible to propose a shape that shrinks stepwise as shown in FIG.

  As shown in FIGS. 1 and 2, the inner cleaning pipe 8 is provided along the inner peripheral surface of the inner filter medium 1B, and a plurality of cleaning nozzles 8A, 8A,. The inner cleaning tube 8 is attached so as to face the peripheral surface. Similarly, the outer cleaning pipe 9 is provided along the outer peripheral surface of the outer filter medium 2B, and the outer cleaning pipe 9A, 9A,... Faces the outer peripheral surface of the outer filter medium 2B. 9 is attached. Then, while rotating the inner filter medium 1B and the outer filter medium 2B around the axis, the cleaning liquid is sprayed from the plurality of cleaning nozzles 8A, 8A,..., 9A, 9A,. The filtration surface is cleaned. The cleaning liquid sprayed at the time of cleaning is stored as cleaning waste liquid on the bottom plate 7B of the casing 7 in the inner filter medium 1B and the bottom plate 7B between the casing 7 and the outer filter medium 2B together with the filtrate. The filtrate discharge ports 12 and 13 are configured to discharge the filtrate.

  Here, the inner and outer filter media 1B and 2B are cleaned by spraying a high-pressure cleaning liquid, but it is preferable that the cleaning is performed by spraying an alkaline chemical as the cleaning liquid. In addition, it is more preferable to install an ultrasonic transmitter on the filtration surfaces of the inner and outer filter media 1B and 2B and vibrate and wash the filter media itself, since the cleaning power is improved.

  In addition, the installation positions of the inner and outer cleaning pipes 8 and 9 and the cleaning nozzles 8A and 9A are not limited to the above, and are installed in the filtration space 4, and a cleaning nozzle (not shown) is attached to the partition 3 and the like, so that the filtration space The cleaning liquid may be sprayed from within 4. Further, a plurality of inner and outer cleaning tubes 8 and 9 may be installed.

  As shown in FIG. 3, the cake discharge port 14 is formed in the part which projected the filtration space 4 in the upper plate 7A of the casing 7, From this, the dehydrated cake is discharged | emitted. A back pressure plate 15 is attached to the cake discharge port 14. The back pressure plate 15 generates discharge resistance and adjusts the amount of discharged sludge to further squeeze the cake and lower the moisture content. Thus, the volume can be reduced.

<The filtration method according to the present invention>
The filtration method using the filtration apparatus according to the present invention will be described below.
First, the liquid to be processed is pumped to the liquid inlets 10 and 11, and the liquid to be processed is fed into the filtration space 4. The liquid to be treated fed into the filtration space 4 is subjected to two-side filtration by the inner filter medium 1B and the outer filter medium 2B while rising spirally along the partition 3. The inner filter medium 1B and the outer filter medium 2B are rotated by first and second rotation driving means (not shown) such as a motor, respectively. At this time, if necessary, the inner filter medium 1B and the outer filter medium 2B are rotated in the same direction with a speed difference .
The liquid to be treated rises along the partition 3 due to the pumping pressure and rotational frictional force, but solid-liquid separation is performed in the lower part of the filtration space 4 between the inner filter medium 1B and the outer filter medium 2B. In the upper part, dewatering is performed and finally a cake discharge port 14 is formed, from which the dehydrated cake is discharged.
By rotating the inner filter medium 1B and the outer filter medium 2B and preventing the partition 3 from rotating, the scraper 16 scrapes off the cake accumulated on the respective filtration surfaces.
A cake having a high water content after solid-liquid separation rises in the upper part of the filtration space 4, and this cake is caused by rotational friction between the inner filter medium 1 </ b> B and the outer filter medium 2 </ b> B and discharged by the back pressure plate 15. Squeezing is promoted by the resistance, the moisture content is reduced and the volume is reduced, and the cake is discharged from the cake outlet 14.

It is a longitudinal cross-sectional view of the filtration apparatus which concerns on this invention. It is the II sectional drawing (transverse sectional view). FIG. It is the schematic for demonstrating the relationship between a partition and a scraper. It is a longitudinal cross-sectional view which shows the outline of the other Example of a filtration apparatus. It is a longitudinal cross-sectional view which shows the outline of the other Example of a filtration apparatus. It is a longitudinal cross-sectional view which shows the outline of the other Example of a filtration apparatus. It is a longitudinal cross-sectional view which shows the outline of the other Example of a filtration apparatus. It is a cross-sectional view which shows the outline of the 1st attachment method to the inner frame of an inner side filter medium. It is an expanded sectional view of the groove part. It is a cross-sectional view which shows the outline of the 2nd attachment method to the inner frame of an inner side filter medium. It is an expanded sectional view of the groove part. It is an expanded sectional view of a groove part showing the outline of the 3rd attachment method to the inner frame of an inner side filter medium.

  DESCRIPTION OF SYMBOLS 1 ... Inner frame, 1A ... Upper plate, 1B ... Inner filter medium, 1C ... Groove part, 1a ... Hole, 2 ... Outer filter medium, 2B ... Outer filter medium, 3 ... Partition, 4 ... Filtration space, 5 ... Inner cylinder rotating shaft, 7 ... casing, 7A ... upper plate, 7B ... bottom plate, 8 ... inner washing tube, 9 ... outer washing tube, 10 ... treated liquid inlet, 11 ... treated liquid inlet, 12 ... filtrate outlet, 13 ... filtered Liquid discharge port, 14 ... cake discharge port, 15 ... back pressure plate, 16 ... scraper, 50 ... bolt, 51 ... presser member, 52 ... bolt, 53 ... bolt, 54 ... presser member, 55 ... bolt.

Claims (3)

Concentrically arranged cylindrical or conical inner and outer frames;
An inner filter medium and an outer filter medium that can be attached to the inner frame and the outer frame;
A spiral partition provided in a filtration space between the inner filter medium and the outer filter medium,
The axis is vertically oriented and the device is placed vertically,
And fed the treated liquid from the bottom to the top of the filtration space, to discharge the cake from the upper side in the filtration space, to discharge the filtrate in the process to the outside through the inner filter material and said outer filter media A filtration device of the composition,
When the inner frame and the outer frame rotate around the axis, the inner filter medium and the outer filter medium rotate around the axis,
And the spiral partition is configured not to rotate,
The cake is configured to rise along the partition by a frictional force with the rotating filter medium, and to be discharged from the filtration space,
In the inner frame, a groove for fixing the inner filter medium is formed on the outer peripheral portion,
The inner filter medium is cylindrical or conical with a slightly larger inner diameter than the inner frame so as to correspond to the inner frame,
When attaching the inner filter medium, by pressing the presser member corresponding to the groove part from the outside of the inner filter medium, the inner filter medium is sandwiched between the groove part and the presser member,
The inner filter medium was attached to the inner frame by fixing the presser member and the groove,
A filtration device characterized by that.   The filtration device according to claim 1, wherein the inner filter medium is formed in a cylindrical shape or a conical shape by welding at both ends.   The filtration device according to claim 1 or 2, wherein a surface of the presser member that contacts the inner filter medium has a circular arc shape in cross section.

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