KR20120122854A - Self-cleaning filter and method - Google Patents

Abstract

PURPOSE: A self-cleaning filter and a method for filtering fluid containing osmosis fluid and concentrated pollutants are provided to prevent the malfunction of a system and the damage of a driving motor. CONSTITUTION: A self-cleaning filter includes a filter plate and one or more mobile hinge type blades. A hinge type blades includes a scrapping edge(17). The scrapping edge scrapes the perforated part of the filter plate. The hinge type blade includes an elongated frame(13) and a scraping knife(14). The scraping knife is arranged at the scraping knife. The first end part of one elongated frame is connected to the scraping knife using a mobile joint. The hinge type blade includes a solid core rod(11) and a spring(12). The solid core rod includes a first end part to be attached at a main driving shaft and a second end part to be mounted in the second end part of the frame.

Description

Self-Cleaning Filters and Methods {SELF-CLEANING FILTER AND METHOD}

The present invention relates to a self cleaning filter and a corresponding method.

In general, in many industries, including fluid treatment, for example, the concentration of contaminants (particles captured by the filter or other contaminants) can be collected to reuse the osmotic fluid (fluid passing through the filter and residual particles). By making this possible regeneration, filters are widely used to conserve such fluids, which in some cases may be expensive. Therefore, there is an effect that allows manufacturers to reduce some of the production costs.

In order to improve the efficiency of the filters, several self-cleaning filters have been introduced to allow the operator to reduce the unnecessary time required to remove concentrated contaminants during the filtration process. According to one of the existing designs, a plurality of scrapers or blades with sharp edges, which are installed to be driven by a motor inside the closed chamber, are used to remove concentrated contaminants from the filter membrane, thereby Release or collection of material is possible. This method is often used in the textile industry to remove concentrated contaminants, especially lint accumulated in the filters of dyeing machines.

In addition to filters, concentrated contaminants that accumulate on the edges of blades or scrapers have been of interest. If this buildup occurs, the concentrated contaminants can clog the filter, thereby slowing down the process and affecting the fluid pressure, which in turn can lead to system failure. In addition, the drag may increase as the amount of concentrated contaminant between the transfer brush and the filter membrane increases. As a result, reaction forces acting on the scraping blades may cause damage to the connecting parts or even the drive motor.

Various measures have been introduced to prevent mechanical failure due to such problems as described above, for example installing a spring between the end of the blade (s) and the rotating shaft to improve the tolerance. The solution does not solve the problem that some concentrated contaminants still remain on the blade (s) during operation. These residual concentrated contaminants are not directly harmful to machine parts, but result in significant efficiency degradation.

For this reason, development of a new scraping blade configuration in which an arm is connected to a rotating shaft is underway, and a self-cleaning filter capable of cleaning not only the filter but also the cleaning mechanism itself is sometimes required.

The present invention seeks ways to address or mitigate the necessity as described above.

In a first aspect, a filter device as described in claim 1 is provided.

In another aspect, a fluid filtration method as described in claim 14 is provided.

Individual additional aspects and features of the invention are as defined in the appended claims.

In one embodiment of the invention, a filter device for inlet fluid comprising a concentrated contaminant and an osmotic fluid is dropped from a container assembly for an inlet fluid and an inlet assembly, blade (s) for conveying the inlet fluid to the container assembly. A motor-driven shaft connected to an arm having a passage assembly for collecting concentrated contaminants, an outlet assembly for osmotic fluid, and a scraping blade that rotates along the axis of the circular filter, wherein the arm and the blade move freely. A joint is provided, and the blade is moved by a spring provided on the arm.

The inlet fluid is first injected into the vessel through the inlet tube and then flows along a flow path extending in a predetermined direction, during which the concentrated contaminants separate and remain on the inner surface of the filter membrane or filter plate. Some of the concentrated contaminants accumulate in the blade as the blade moves through the circular motion to scrape out some of the concentrated contaminants. As a predetermined weight of concentrated contaminant accumulates on the blade, the blade is flipped downward about the joint, causing the concentrated contaminant to free fall by gravity. Thereafter, the blade returns to its original position within a predetermined time period, thereby repeatedly performing the above-described operation during the entire filtration process.

Hereinafter, another embodiment of the present invention will be described by way of example with reference to the accompanying drawings.

According to the present invention, a self-cleaning filter and a filtration method capable of raising or alleviating the necessity as described above can be obtained.

1 is a view schematically showing a filter according to an embodiment of the present invention.
2 is an exploded view schematically showing the hinged blade assembly.
3A is a schematic representation of the angle between the plane of rotation of the blade assembly and the hinge and scraping knife.
3B schematically illustrates the interaction between the scraping knife and the filter.
4 shows the chamfered space between the scraping knife and the elongated sheath.
5 is a view showing the configuration of a (curved) filter plate and a movable scraping blade moving correspondingly according to a modification.
6 is a view showing the configuration of a (planar) filter plate and a scraping blade moving correspondingly according to a modification.
7 is a flowchart of a filtration method according to an embodiment of the present invention.

Self-cleaning filters and methods are disclosed. In the following description, numerous specific details are provided to assist in a thorough understanding of the embodiments of the present invention. However, it will be apparent to one skilled in the art that these specific details are not necessarily employed in the practice of the invention. Conversely, specific details that are known to those skilled in the art will be omitted where appropriate for clarity.

The invention described herein is suitable for application in the textile industry, although not limited thereto. Therefore, for the sake of clarity, the following discussion relates to dyeing practice and focuses on the application where the main concentrated contaminant to be filtered is a fluid containing baffles. However, it will be appreciated that the disclosure of the self-cleaning filter of the present invention is not limited to this application only.

In the embodiment shown in FIG. 1, the filter comprises a hollow container 1 comprising various components described below. The vessel is generally cylindrical and installed in a vertical direction, provided with a fluid inlet 2a and a pressurized gas inlet 2b on the upper side thereof, and an osmotic liquid outlet 3a on the side wall. The inlet and outlet are designed to be connected to the pipe network of the dyeing machine, whereby some of the circulating dye solution is carried through the filter. The dye solution is injected into the chamber through the inlet, filled into the chamber during filtration, and then passed through the filter into the other volume 4. The volume is a portion surrounded by the filter plate 5 and the inner wall of the container 1, where the dye solution is sent to the outlet. A passage outlet is provided at the bottom of the container and is connected to the concentrated pollutant outlet 3b through which the concentrated pollutant is ejected after the filtration process is completed.

The shaft 6 is mounted coaxially with the cylindrical vessel. A waterproof seal is provided that covers the space between the component parts of the assembly, which serves to prevent the dye solution from flowing out of the system at undesirable processing capacities during operation. A motor 7 or similar drive system is connected to one end of the shaft for rotation of the shaft.

A cylindrical filter plate 5 is also arranged coaxially with the shaft such that the shaft rotates in the center of the filter plate. The filter plate is provided with a plurality of perforations 8 (only partially shown in FIG. 1), allowing the dye solution to pass through the filter plate, leaving only concentrated contaminants inside the filter. The filter plate is formed in a mold so that it can be removed from the top of the container for maintenance and / or cleaning purposes if necessary. In this case, an opening may be provided, such as a lid 9, on top of the container for installation and removal of the filter plate.

In operation, the dye solution containing the baffles is sent to the inlet at the top of the vessel. In this state, the osmosis liquid outlet 3a is open while the outlet is closed by a valve. The container is filled with dyeing solution during filtration. Thus, the concentrated contaminants remaining inside the volume portion surrounded by the filter vessel accumulate at the bottom of the vessel near the outlet. On the other hand, some of the concentrated contaminants may remain on top of the moving blade (s) as the fluid flows from top to bottom. During the filtration process, provided that the outlet is sealed, the dye liquor is pushed out only through the outlet of the system. However, concentrated contaminants, such as baffles, are too large to pass through the perforations, so they are sent to the inner surface or upstream of the filter plate and remain there. At this time, the blade (s) is used to scrape the perforated area of the filter plate to remove the baffle from the filter plate surface, so that the baffle accumulates on the surface of the moving blade (s) or is surrounded by the filter plate and the passage outlet inside the chamber. It will flow along the turbulence generated by the blade (s) until settling in or settling somewhere again in the filter wall.

In the system described above, one or a plurality of blades are connected to the shaft. When a plurality of blades are installed, these blades may be arranged at uniform intervals in each direction on the shaft for improved efficiency, but of course not limited to this configuration.

In this embodiment, as shown in Fig. 1, a pair of blades is used, and these blades are arranged at even intervals in each direction, that is, at intervals of 180 ° from each other. Further, as the blades are formed to be inclined at a predetermined angle, each blade is formed to cover a circular region (ie, a cylindrical region) of the filter having a predetermined height. As such, when using a plurality of scraping knives, the vertical spacing between the blades must be adjusted to match the angle of inclination of the blades so that all the blades can sweep the entire punched area. In the embodiment as shown in FIG. 1, it is preferred that there is no area not included in the operating range of the vertical space between the two circular swept areas, where the vertical direction of the perforated area is indicated by the arrow A. FIG. The range is indicated.

Referring to FIG. 2, one embodiment of a hinged concentrated contaminant scraping blade 10 (or hereinafter simply referred to as a 'blade') is shown in an exploded view. The blade comprises a solid rod 11, a spring 12, an elongate (and typically tubular) sheath 13 and a scraping knife 14. One end of the solid rod is fastened to the shaft and the other end is covered by the sheath. The spring is inserted between the solid rod and the elongated sheath to provide the opposite forces continuously to these members, such that the end portions of the blades consisting of the sheath and the scraping knife are pushed towards the inner wall of the filter plate. Studs 15 are fitted in openings 16 provided in both the elongated sheath and solid rod, in order to limit the extent of expansion or contraction of the blades. As will be apparent to those skilled in the art, the position of the opening along the sheath may be adjusted such that the blade assembly 10 contacts the inner surface of the filter plate and scrapes the inner surface.

In one embodiment of the invention, the scraping edge 17 of the knife is formed to coincide with the surface of the filter. In addition, the knife is fixed at an angle of approximately 30 ° with respect to the plane of rotation of the corresponding blade (see FIG. 3). While the blade is in operation, the lateral end of the scraping knife located above is in the direction of rotation. For example, in FIG. 1, the surface of the knife extends inclined so that the counterclockwise direction is upwards (when viewed from above), thereby rotating along that direction. Depending on the configuration of the knife and the filter, the angle between the knife surface and the plane of rotation can be changed, where appropriate, such that, for example, the vertical extent of the scraping edge of the knife is substantially similar to the extent of the perforations of the filter. Likewise, the shape of the scraping knife can be changed if necessary.

As the fluff begins to accumulate on the blades while the system is operating, the spring is squeezed towards the center of rotation. As this compressive force acts as a tolerance to allow the scraping knife to move in the opposite direction from the container wall, there is an effect that the interference forces generated by the fluff between the knife and the filter wall are alleviated.

However, as the amount of accumulation of baffles increases, the limiting action of the stud and aperture set configuration leads to a level at which the spring can no longer be compressed. However, as long as the compression spring serves to maintain the speed of rotation and to minimize the undesirable shear stresses applied to the shaft and components, the motor can still operate normally. In particular, in this state the blades are covered with a bundle of baffles, and the scraping edges can no longer remove concentrated contaminants that accumulate in the filter. In this case the blade may be considered inoperable.

Thus, a hinge joint is added between the scraping knife and the elongated sheath in order to allow the knife to move freely within a predetermined angle range. However, the angular range can be modified as the contact area between the knife and the sheath changes. 4 illustrates an embodiment of a method of limiting the moving range of a scraping knife within a predetermined angle range about an axis of an elongated sheath.

The elongate sheath and the scraping knife are each perforated with holes concentric with each other in the hinge joint area where they are connected to each other. When these holes are concentrically aligned with each other to form an elbow joint, a screw 18 and a set of nuts that fit to the size of these holes are fastened through the holes so that the scraping knife is formed by the center of the joint. It can rotate on a plane orthogonal to the axis, in which case the axis forms a center of rotation. However, instead of using screws, various other connecting means may also be employed to construct the movable joint.

The circular block 19 is extruded from the scraping knife in order to limit the up and down operation of the blade, also known as flipping operation range. As the circular surface of this extruded portion collides with the outer wall 20 of the elongated sheath, a chamfer is formed at an angle of 30 ° in the lower half of the outer wall, for example, as shown in FIG. As a result, each side of the scraping knife (shaded in FIG. 4) is disturbed whenever a physical collision occurs, thus the flipping operating range as defined herein is theoretically shown in FIG. 4. Same as the chamfer angle. As can be clearly seen, the shape and thickness of the extruded portion on the scraping knife as well as the angle of the chamfer of the elongate sheath are, for example, a predetermined angle within which the movable joint is within the range of 1 ° to 90 °. Modifications can be made within the preferred range to allow movement downward.

Under normal operating conditions without load, the blades are held in a movable top position, that is, due to the rotational inertia, the circular surface of the extrusion remains in contact with the upper outer wall located at the end of the elongated sheath. In this position, the scraping edge comes into contact with the filter, which is defined as the original position in the description below.

In addition to the rotational inertia, depending on the angle of the blade in the fluid and the relative speed of movement of the fluid relative to the blade, the interaction of the blade with the fluid may further generate a lift force that pushes the blade to the uppermost position.

Since there is no external support to prevent the free fall of the scraping knife, the rotational speed, the fluid pressure inside the chamber, as well as the weight of the scraping knife must be well balanced to achieve the above requirements.

Once the concentrated contaminants accumulate on the knife, the spring is contracted or stretched by the concentrated contaminants until the joints that enable the flipping operation as described above cannot withstand the weight of the concentrated contaminants. The scraping knife is then flipped downward at an angle by the joint, so that a gap is formed between the scraping edge 17 and the surface of the filter wall. As a result, concentrated contaminants can slide along the slope of the blade and fall.

In other words, when concentrated contaminants accumulate on the scraping edge between the scraping edge and the filter, the spring may be retracted to accommodate the presence of the concentrated contaminants. In such circumstances, concentrated contaminants may fall along the filter bottom through the gaps provided as described above, or may continue to accumulate until the spring contracts to the maximum range allowed by the studs and openings. However, in some cases and / or when additional concentrated contaminants accumulate in other parts of the knife, at one point the mass of the concentrated contaminant and / or the drag of the concentrated contaminant are combined so that the hinged blade falls from its top position. This may facilitate the dropping of concentrated contaminants from the knife. Thus, the mass and / or drag of the concentrated contaminants may cause the knife to be flipped (i.e. drooped downward, descended or otherwise articulated downward through the hinge actuation). It will be appreciated that forces that counteract rotational inertia and / or lift forces occur.

For example, as the concentrated contaminants accumulate on top of the knife, the knife may be stretched downward by providing a force by gravity that acts downward against the rotational inertia and lift force of the knife. Likewise, as the concentrated contaminants accumulate on the knife's scraping edges, the edges of the knife are slowly moved downwards by frictional and / or hydrodynamic drag against the filter, thereby directly directing the rotational inertia and lift generated by the knife. On the other hand, the edge of the knife can be drooped.

The limit value of the amount of concentrated contaminant required for the knife to flip in this manner can be expressed as a function of the properties of the concentrated contaminant, the angle and rotational force of the knife, the flow rate of the fluid inside the filter and other factors. The limit value may be determined empirically and is simply a proxy change of one of the aforementioned factors, for example, but not limited to, knife rotational speed or knife mass without load applied. May be adjusted.

In one embodiment of the present invention, as described above, the scraping knife is disposed at an angle of 30 ° with respect to the horizontal direction, or is arranged to have another suitable inclination with respect to a predetermined filter configuration, but in addition, the hinge It is arranged to be inclined at an angle of 15 ° with respect to the horizontal direction, or more generally, to have a smaller balanced inclination with respect to the scraping knife as shown in FIG. 3. The edge of the scraping knife is formed in the shape of a half moon and there is a slight gap between the scraping edge and the surface of the filter wall depending on the three factors mentioned above, namely the knife angle, the hinge angle and the knife shape. The surface is not parallel to the axis of the hinge joint. The gap is maximized at each end of the scraping edge as shown in FIG. 3B.

Thus, in an embodiment of the present invention, the blade can move in additional degrees of freedom with respect to the radial compressive force provided by the spring. In the case of the hinged knife which is disposed at an angle with the rotational plane at an angle, the concentrated contaminants accumulated on the surface of the knife can be easily removed.

Once the compressed spring is restored after removal of the concentrated contaminants, the blade can also return to its extended position, in which the knife and its scraping edges are substantially free of baffles. Thus, advantageously, the filtration efficiency can be recovered and the thus obtained filtration efficiency can be maintained throughout the entire filtration process.

Once the filtration process is complete, the osmotic outlet is closed and the concentrated contaminant outlet is opened while no more fluid is flowing through the fluid inlet 2a. Instead, pressurized gas is injected through the inlet 2b into the chamber. The pressurized gas is applied to the remaining fluid in the chamber to discharge through the concentrated pollutant outlet. The outlet is the only outlet of the system, in which concentrated contaminants that had previously precipitated near the outlet are ejected from the filter system along with the remaining fluid.

In the embodiment of the present invention, when filter plates of various configurations are used in various situations, the configuration of the hinged scraping blade is not limited to the scraping edge layout and the flipping angle as described above.

For example, a modification of the filter device is shown in cross section in FIG. 5. In this configuration, the filter plate 5 is disposed across the fluid flow path, and both ends of the filter are connected to the container wall portions 1a and 1b. The direction of movement of the blade and the hinged scraping knife is indicated by arrows B and C, respectively. The plate is formed in a curved shape with a concave shape of the fluid inflow surface. The shaft 6 is arranged coaxially with the plate and is connected to one or more blades (in this example only one blade is used) in which the scraping edge is in contact with the filter wall. Instead of rotating along the entire circular path, the shaft rotates back and forth in a predetermined angular range so that the blade (s) can repeatedly sweep the punctured area on the filter plate. As in the above embodiment, when no hinge is employed, concentrated contaminants may accumulate on the blades. Thus, the addition of elbow joints can reduce the likelihood that concentrated contaminants will cover the scraping edges during blade operation.

FIG. 6 shows another embodiment in which the filter wall is straight and arranged across the flow path formed by the container wall portions 1a, 1b. Rail 21 is used to guide the blade to move parallel to the filter surface. In the embodiment shown in FIGS. 5 and 6, it will be appreciated that a motor or other suitable drive mechanism is further provided to perform angular or linear movement of the blade (s).

In addition, the connection configuration is not limited to only physical contact between components. For example, a hydraulic or pneumatic assembly suitable for forming a joint and / or replacing a spring that performs the same performance may be used.

In summary, in an embodiment of the invention, the filter device is one or more movable hinges having a scraping edge 17 arranged to perform sweeping across the perforations 8 of the filter plate 5. The blade 10. The hinged blade may again comprise an elongate sheath 13 and a scraping knife 14 provided with the scraping edge 17. The first end of the elongate sheath is connected to the scraping knife by a movable joint. The hinged blade may also comprise a solid rod 11 and a spring 12 having a first end attachable to the main drive shaft 6, the second end of the solid rod being elongated. It is mounted inside the second end of the sheath.

According to such a hinged blade, the first end of the elongate sheath may be formed such that it can be moved downward by a joint movable up to a predetermined angle in the range of 1 ° to 90 °. On the other hand, the main surface of the scraping knife of the hinged blade may be mounted so as not to be in parallel with the axis of the hinged joint. Likewise, the major surface of the scraping knife may be arranged inclined with respect to the rotating surface of the hinged blade.

In operation, the hinged blade is arranged to pivot upward to a position having a predetermined distance from the filter plate in response to the force applied. However, if the amount of concentrated contaminants accumulated on the hinged blades exceeds the limit value, the hinged blades are also arranged to pivot downward in response to the force additionally applied to the blades during operation.

Such hinged blades may include, for example, a container 1 containing the filter plate 5, a fluid inlet 2a for conveying the inlet fluid, an outlet 3a for discharging the osmotic fluid and concentrated contamination. It can be used in a filter device comprising an outlet 3b for discharging material. Typically, the filter plate 5 is tubular and the outlet for discharging concentrated contaminants comprises a funnel with a narrowing cross section located at the bottom of the vessel.

In the case of a tubular filter, the filter arrangement typically comprises a shaft 6 which is coaxially arranged with respect to the filter plate and to which one or more movable hinged blades are attached, thereby in operation, the rotation of the hinged blades by the rotational force of the shaft. The scraping edge 17 is moved across the perforation of the filter plate.

Such a filter device may be installed to form part of a dyeing machine.

Referring to FIG. 7, a corresponding method for filtering a fluid comprising osmotic fluid and concentrated contaminants,

A first step (s10) of conveying the inflow fluid to the filter;

A second step (s20) of applying a force for pivoting the hinged blade to the blade to move the blade to a position where the scraping edge of the blade moves across the perforated area of the filter; And

A third step (s30) of collecting the concentrated contaminants removed by the blade at the filter outlet outlet

It includes.

Use of the filter device may include a filtration step and a maintenance or cleaning step. Thus, the method relates to the filtration step, opening the osmotic outlet and closing the concentrated contaminant outlet, and in connection with the maintenance step, closing the osmotic outlet and opening the concentrated contaminant outlet and reducing the gas pressure. And applying force to the concentrated contaminant to cause the concentrated contaminant to pass through the concentrated contaminant outlet.

As will be apparent to one of ordinary skill in the art, variations of the foregoing methods, which correspond to the operation of various embodiments of the apparatus as described above and as claimed herein, can be implemented within the scope of the present invention, and only Although not limited to, it includes features as described below:

The first end of the elongate sheath is shaped to allow the movable joint of the hinged blade to move downward to a predetermined angle in the range of 1 ° to 90 °;

The major surface of the scraping knife of the hinged blade is arranged inclined with respect to the axis of the hinge joint;

The major surface of the scraping knife of the hinged blade is arranged inclined with respect to the plane of rotation of the hinged blade;

The hinged blade is pivoted to a position of a predetermined distance from the filter plate in response to the force applied to the blade during operation;

If the amount of concentrated contaminants accumulated on the hinged blade exceeds the limit value, the hinged blade is pivoted downward in response to the force applied to the blade during operation;

A filter device with one or more hinged blades is incorporated inside the dyeing machine.

5: filter plate 6: shaft
8: perforation 10: blade
11: solid rod 12: spring
13: elongated exterior 14: scraping knife
17: scraping edge

Claims (15)

A filter device for an inlet fluid containing osmotic fluid and concentrated contaminants,
Filter plate 5; And
One or more movable hinged blade (s) 10 with scraping edges 17 arranged to perform a sweeping operation across the perforations 8 of the filter plate in operation.
Filter device comprising a. The method of claim 1, wherein the hinged blade,
An elongated sheath 13; And
A scraping knife 14 with a scraping edge 17,
And the first end of the elongate sheath is connected to the scraping knife by a movable joint. The method of claim 2, wherein the hinged blade,
A solid rod (11) having a first end attachable to the main drive shaft (6); And
A spring 12,
And the second end of the solid rod is mounted via a spring within the second end of the elongated sheath. 4. The filter device according to claim 2 or 3, wherein the first end of the elongate sheath is formed in a shape that allows the movable joint to move downward to a predetermined angle in the range of 1 ° to 90 °. . 5. Filter device according to any of the preceding claims, characterized in that the major surface of the scraping knife of the hinged blade is not parallel to the axis of the hinge joint. 6. Filter device according to any one of the preceding claims, wherein the major surface of the scraping knife of the hinged blade is inclined with respect to the plane of rotation of the hinged blade. The filter device according to claim 1, wherein the hinged blade is arranged to pivot to a position of a predetermined distance from the filter plate in response to a force applied to the blade during operation. . 8. The hinged blade of claim 7, wherein in operation, when the amount of concentrated contaminants accumulated on the hinged blade exceeds a limit value, the hinged blade moves downward in response to a force applied to the blade during operation. Filter device, characterized in that arranged to. 9. A container (1) for accommodating the filter plate (5), a fluid inlet port (2a) for conveying inlet fluid, and an outlet port for discharging osmotic liquid (10) according to any one of claims 1 to 8. 3a) and an outlet (3b) for discharging concentrated contaminants. 10. The filter apparatus of claim 9, wherein the outlet for discharging the concentrated contaminants comprises a funnel having a narrowing cross section located at the bottom of the vessel. 11. Filter device according to claim 9 or 10, characterized in that the filter plate (5) is tubular. Further comprising a shaft (6) disposed coaxially with respect to said filter plate,
One or more movable hinged blades are attached to the shaft;
In operation, the filter device, characterized in that the scraping edge (17) of the hinged blade is moved across the perforations of the filter plate by the rotation of the shaft. A dyeing machine comprising the filter device according to any one of claims 1 to 12. A method for filtering a fluid comprising osmotic fluid and concentrated contaminants,
Conveying the incoming fluid to the filter;
Applying a force to pivot the blade to the hinged blade to move the blade to a position where the scraping edge of the blade crosses the punctured area of the filter; And
Collecting concentrated contaminants removed by the blade at the filter outlet outlet
≪ / RTI > 15. The method of claim 14,
In the filtration step, opening the osmotic fluid outlet and closing the concentrated contaminant outlet; And
In the maintenance step, further comprising closing the osmotic outlet and opening the concentrated pollutant outlet and using a gas pressure to force the concentrated pollutant to pass through the concentrated pollutant outlet. How to feature.

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