CN1080131C - Media Fluidizable Filters for Radial Flow of Fluids - Google Patents

Abstract

A radial flow filter uses non-stationary particulate particles to filter out impurities from an influent stream and the particulate media can be fluidized by a backwash operation to release the impurities trapped therein, in which backwash operation the backwash fluid applies an upward draft to the upper particulate particles to lift them into a backwash chamber to fluidize them. Fluidizing one by one in the same manner; thereby cleaning all of the granular media. After the backwash operation is completed, the particulate matter falls back into the filtration chamber to form a filter bed for the next filtration operation.

Description

Media Fluidizable Filters for Radial Flow of Fluids

Technical Field of the Invention

The present invention generally relates to the following devices:

Equipment for the co-acting of incoming fluid and porous media, equipment for removing impurities, solids, and particulate matter from incoming fluid, especially a fluid that flows radially, and the medium used is non-fixed , and during backwashing, the flow direction of the fluid can be reversed to remove the filtered material, so the filter is regenerated for reuse. Related applications:

This application requires that previous applications be filed,

Provisional application number: 60/018,168 (filed on May 23, 1996)

and all benefits claimed in Application No. 60/023,679 (filed August 17, 1996). The above two applications are still under review.

Background of the invention

There are many types of filters available for removing particulate particulate matter from an incoming fluid. These filters can generally be divided into two categories: fixed media, and non-fixed media. Media-fixed filters use a removable cassette filter element made of woven or non-woven fiber material. The choice of media depends on the porosity determined by the size of the particulate impurities to be removed from the incoming fluid. This kind of media-fixed cassette filter element, when a considerable amount of impurities have accumulated, the filter element must be removed and cleaned, or even the entire element must be replaced. Cassette filters are not easily backwashed, but many cassette filters are radial flow. Such radial flow filters provide the greatest possible contact surface for the fluid to be filtered. Therefore, there is little resistance to fluid flow.

Another category uses non-fixed media such as sand, small glass beads, animal bone meal, or other tiny granular substances through which fluid can pass. This non-fixed medium is generally spherical or other irregularly shaped granular substances. The gap between the particles can effectively filter out the impurity particles in the fluid. An advantage of non-fixed media is that the media can be regenerated by the backwash procedure. The function of backwashing includes floating and fluidizing the medium, so that the impurities trapped in the medium are driven out from the intergranular or particle surface of the medium. However, this filter has a disadvantage: the filter is larger in size, higher in cost, and lower in efficiency. Due to the small surface area available to the fluid, it is often forced to use a medium with larger particles, or to use a higher flow rate (per unit area of the fluid). In other words, it is a non-trivial task to develop a radial flow filter that uses a non-fixed media and the filter bed can be regenerated by backwashing.

Martin discloses a radial flow filter in US Pat. No. 3,415,382. It uses glass beads as the non-fixed medium. Although this type of filter is effective in the filtration function for which it was designed, because the media it uses are beads with larger particles, the filter must be disassembled and the media removed to regenerate the media.

Radial flow filters are used in a wide variety of manufacturing and production industries where impurities or solid matter need to be removed from fluids. FIG. 1 shows the general structure of a basic radial flow filter 10 . The filter comprises two concentric porous tubes 12 and 14 and a porous medium 16 filling an annular space 20 between the two concentric tubes. These filter elements are housed in a filter housing 18 . The porous medium 16 is composed of fine glass spheres of uniform size. The size of the glass spheres is roughly fixed for a particular filter, but can vary widely from filter to filter. The size of the media beads can be submicron, micron, or even the same size as coarse sand. They completely fill the small compartment 20 between the porous tubes 12 and 14 . The holes in the tube are circular, uniform in size, and distributed in a uniform pattern, but the holes may be arranged in other arrangements. This assembly of concentric tubes and porous media (media) is completely encased so that the fluid, during filtration operations, completely encloses the filter assembly. Filtration occurs over the entire axial length of the filter 10 as fluid flows radially into the porous medium 16 through the pores of the outer concentric tube 12 and exits the porous medium 16 through the pores of the inner tube. Impurities in the fluid are captured as the fluid moves laterally through the porous media 16 .

After one or more filtration cycles, the porous media 16 must be cleaned by backwashing. The backwash procedure includes clean fluid rushing radially outward from the inner tube 14 into the porous medium 16 and then flowing out from the outer porous circular tube 12 . Its direction of flow is substantially opposite to that taken during the filtration cycle. Figure 2 shows the operation of such a filter 10 in a conventional backwashing process. The considerable flow rate coupled with the surge created around the glass beads dislodges and flushes away the impurities that have accumulated between and on the beads. These impurities are small enough to pass through the spaces between the glass beads that make up the porous medium 16 . However, not all impurities such as resin residues can be removed. The impurity particles gradually accumulate in the porous medium 16 . Therefore, after a certain number of filtration and backwash cycles, the filter 10 must be removed to replace or maintain the porous media 16 back into good condition.

From the above discussion, it can be seen that there is a need for a radial flow filter using free-flowing media configured to provide backwash capability.

There is also a need for a filter that uses free-flowing media: the porous media is fully regenerated during the backwash cycle, thus eliminating the need to intermittently take the filter apart to clean or replace the porous media. In addition, it is necessary to use non-fixed media and filters that can be backwashed, and the backwashing working pressure should not be too high. There is also a need for a filter that generates high resistance to the backwash fluid at the end of the backwash cycle, with an increase in backwash fluid pressure signaling completion of the backwash operation.

Introduction to the invention

It is an object of the present invention to provide a filter which allows easy fluidization of the filter medium.

Another object of the present invention is to provide a filter which allows the filter media to be fluidized sequentially, ie section by section.

The above objects of the present invention are achieved by the construction of the filter in which the filter medium is supported within an annular post so that fluid can flow radially through the filter medium. The large-area filter media of the annular column can then be used to interact with the fluid.

During regeneration of the filter media, the flow of fluid through the filter is reversed, whereby the filter media is fluidized. This filter has a series of one-way valves that define sections of the filter media so that during regeneration the one-way valves are closed and the regeneration fluid provides lift to the top of the filter media until it fluidizes. Thereafter, each successive portion of the filter media is fluidized by the lift force of the regeneration fluid until substantially all of the filter media is moved from the filter portion to the fluidized portion of the filter. Once fluidized, the filter media has been regenerated so, for example, filtered particulate matter is released from the fluidized particles and removed from the filter.

Once the regeneration cycle is complete, the media particles fall back to the bottom of the filter in the annular column. Filtration or interaction of the fluid with the transition medium can be restarted.

According to the principle and concept of this invention, the present application discloses a radial flow filter using non-fixed media, which can effectively remove impurities or tiny particles by backwashing procedure to regenerate the media. According to a preferred embodiment of the invention, the radial flow filter uses larger media chambers to accommodate granular media beads. During the backwash cycle, the reverse flow of the backwash fluid applies an upward force to the particulate beads, transporting it to the upper part of the backwash chamber, thereby separating the beads and allowing accumulated particulate matter to be dislodged with the belt. Walk. During the filtration cycle, the granular beads settle to the lower part of the media chamber, and the influent fluid passes between the beads, from where the particulate matter is filtered out.

According to a preferred embodiment of the radial flow filter of the present invention, the influent fluid passes through a screen covering the outer porous cylinder and radially passes through the particles of the media. The filtered fluid then passes through an inner porous cylinder covered with a screen. The filtered fluid then passes through a series of check valves housed in a screen-covered inner porous cylinder and flows to the fluid outlet of the filter.

During the backwash cycle, the backwash fluid is forced to pass through the filter in the opposite direction. At this time, the check valve is closed, and the backwash fluid passes through the granular media in the opposite direction. In the reverse washing process, the fluid can generally pass through the granular medium radially and move upward along the axis. The upward force of this backwash fluid causes the check valve to close, thereby allowing most of the fluid to enter the granular media rather than flow upward in the inner porous cylinder. The upward traction force generated by this counter-flow fluid causes the upper media particles to rise into the backwash chamber, where the impurity particles are separated and taken away from the media. The movement and separation process of this granular medium is often referred to as "floating" or "fluidization", which occurs when the traction force of the particles acting on the upper layer (or upper section) of the medium exceeds the buoyant weight ( buoyant weight). Once the uppermost layer of media is fully fluidized, then the lower layer of media is also fluidized, and the granular media in this layer is forced to flow upwards, so that the particles are separated and the fine particles are released. Each lower layer of media is also fluidized in turn, and the entire filter media is thus completely regenerated during backwashing. Because the medium is fluidized in layers, the pressure required for backwashing is significantly reduced, and therefore the required backwashing pumps and other equipment requirements are also reduced.

In a preferred radial flow filter, the backwash chamber is constructed to a volume capable of containing substantially all of the fluidized particulate media. When fully fluidized, the granular media completely fills the mesh-covered inner porous cylinder partway into the backwash chamber. Because there is no easy, or unobstructed, passage between the backwash chamber and the upper portion of the screen-covered inner porous cylinder, the pressure of the backwash fluid increases. This increase in backwash fluid pressure can be used as a signal that the backwash sequence is complete. Once the backwash fluid stops flowing, those granular media fall back down to the lower part of the media chamber, and the next filtration process can start.

Other embodiments of the present invention include other different arrangements, such as o-rings, porous bags and check valves, etc., to facilitate the fluidization process of the medium.

Introduction to the drawings

Some features and advantages of the present invention will become apparent from the following description of preferred and other embodiments of the present invention. In the following description and drawings, the same reference numerals will be used for the same parts, elements and the like.

Figure 1 is a general cross-sectional view of a well known radial flow filter. Shows the operation of the filter during the filter cycle.

Figure 2 is a diagram showing the filter shown in Figure 1 in backwashing operation.

Figures 3 and 4 show schematic construction views of a radial flow filter constructed in accordance with the present invention. The filter is in the filtering operation and the backwashing operation respectively.

Figures 5a-5f are partial schematic cross-sectional views of a radial flow filter showing various stages of fluidization of granular media.

Figure 6a is a partial cross-sectional view of a radial flow filter showing the velocity vector acting on the granular media causing an upward gravitational force to cause fluidization of the granular media.

Figure 7 is a computer generated graphic showing fluid flow during backwashing.

Figure 8 is a cross-sectional view of a radial flow filter having the backwash and fluidization capabilities disclosed in the present invention.

Fig. 9 is a cross-sectional view of a check valve used on an inner porous cylinder in an embodiment of the present invention.

Figure 10 is a plan view of a check valve plate constructed in accordance with a second embodiment of the present invention.

Figures 11 and 12 are cross-sectional views of a check valve used on a filter housing. The check valve is in open or closed state respectively.

13 is a cross-sectional view of various portions of a radial filter constructed in accordance with another embodiment of the present invention.

14a and 14b are schematic cross-sectional views of a radial flow filter constructed in accordance with another embodiment of the present invention, showing a porous flexible member in operation during filtration and backwash cycles, respectively.

15a and 15b are schematic cross-sectional views of a radial flow filter constructed in accordance with yet another embodiment of the present invention, each showing a radial flow filter operating in opposite flow directions.

A detailed description

Figure 3 shows a schematic diagram of a radial flow filter assembly 50 constructed in accordance with the present invention. This radial flow filter assembly 50 uses a novel backwash technique, thereby avoiding the periodic downtime and maintenance costs of loose porous media required by previous filter technologies. While the preferred and other embodiments will be described in terms of an apparatus that uses granular media to filter particulate matter from an incoming fluid, the principles and concepts of the present invention can be used to interact with an incoming fluid (gas or liquid) and a media ( co-acting), where the media must be periodically backwashed to clean or regenerate the media used.

The radial flow filter assembly 50 has a solid cylindrical housing 52 covering the entire length of the filter assembly. A screen covered inner porous cylinder 54 extends the full length of the filter assembly housing 52 . It is not shown that the inner mesh is made on the supporting structure 54 of the perforated cylinder to prevent the collapse of the screen cloth. The space of adorning porous medium 56 is made of two small chambers. During the filtration cycle, the porous media 56 is housed in a first chamber 58 located generally on the lower or bottom of the filter assembly 50 . The first porous media chamber 58 comprises an annular space surrounded by two concentric porous cylinders covered with mesh. Of the two concentric perforated cylinders, one bounds the inner screen 54 and the other bounds the outer screen 60 . Much like the screen-covered inner porous cylinder 54, the outer screen 60 is also supported by a porous cylinder that extends only about half the length of the filter assembly 50 overall. The openings of screen cylinders 54 and 60 are smaller than the typical diameter of porous media 56 . In this way, the mesh can retain the porous media within the filter 50 .

As can be seen in Figure 3, in accordance with an important feature of the present invention, the radial flow filter assembly 50 includes an upper backwash chamber 62 and a lower porous media chamber 58. The volume of the backwash chamber 62 is preferably the same as that of the medium chamber 58 . As will be described in more detail below, the upper backwash chamber 62 generally has a larger diameter than the lower porous media chamber 58 to facilitate fluidization, separation and agitation of the porous media 56 during the backwash cycle. . A plug 64 secured between the inner porous cylinder 54 and the screen serves to prevent fluid from flowing axially from the upper portion of the screen cylinder to the lower portion of the screen cylinder, or vice versa. There are one or more orifices 66 positioned equidistantly within the inner porous cylinder 54 . The orifices gradually decrease in size so that the backwash fluid is more resisted closer to the plug 64 . As will be described below in the description of the backwash cycle, the orifices 66 force the backwash fluid outwardly into the porous media 56, thereby creating a lift force to fluidize the porous media in a vertical section.

During the filtration cycle, a small part of the incoming fluid enters the top of the inner porous cylinder 54 with suspended particles, passes through the screen along the radial direction, and then enters the backwash chamber 62 in the direction indicated by the arrow 68. upper part. This flow of influent fluid conveys downward any porous media 56 that may have accumulated in the backwash chamber 62 during the backwash cycle. However, most of the incoming fluid will pass through the plurality of ports 70 in the housing 52 and be directed around the outer porous cylinder 60, not shown in FIGS. 3 and 4. The filter assembly 50 is mounted on another housing. , the housing has an inlet and an outlet to connect with other pump equipment. Each port 70 has a check valve which allows fluid to enter the filter assembly 50 but which prevents reverse flow of backwash fluid. After passing through the outer porous cylinder 60 , the incoming fluid passes through the porous medium 56 in a radial direction, where the particulate impurities are trapped in the interstices between the particles of the porous medium 56 or stay on the surface of the medium 56 . Thus, the incoming fluid is filtered. The filtered fluid flows radially through the screen-coated inner porous cylinder 54 through the orifices 66 . Filtered fluid exits the radial flow filter assembly 50 in the direction indicated by arrow 72 .

The porous media may be glass or other types of small beads such as sand, animal bone meal, activated carbon, or any other granular material having the desired properties to remove particles of a specified size and form of impurities. The well known 100 micron nominal diameter beads, when positioned as shown in Figure 3, filter out particulate matter smaller than the beads. Thus, the screens overlying the perforated cylinders 54 and 60 retain media particles, allowing particulate matter to pass through the screens but be retained by the media bed to filter out. Depending on the amount of suspended impurities contained in the influent fluid and the volume of the porous media of the filter bed, the gaps between the media particles will eventually be filled by these granular impurities, and the efficiency of the filter assembly 50 will be reduced, resulting in pump failure. load increases.

In accordance with an important feature of the present invention, the radial flow filter assembly 50 can be effectively backwashed by reversing the direction of fluid flow. The flow path of the backwash fluid is shown in Figure 4. Backwash fluid enters this radial flow filter assembly 50 at the point indicated by arrow 74. This backwash fluid attempts to flow axially along the inner porous cylinder 54, but due to the presence of a series of small holes 66, the fluid is drawn toward The field imports porous medium 56 lis. It can be seen that the check valve at orifice 70 is forced closed during the backwash cycle so that all backwash fluid is directed upwards into filter chamber 58 .

According to another feature of the present invention, as shown in FIG. 4, the upper portion of the porous medium is fluidized first due to the upward pulling force exerted by the backwash fluid. In addition, the orifices 66 at different heights have different opening sizes, allowing different sections of the porous medium 56 to be fluidized sequentially in succession. The uppermost section of the porous medium 56 is the first to be fluidized because the upward force acting on this layer of porous medium and particulate impurities exceeds its buoyant weight. Once the uppermost layer of porous media 56 is fluidized, it is then removed from the lower section of porous media so that the lower section of media can be fluidized. In this way, eventually all the porous media 56 in the filter chamber 58 is fluidized, and almost all of the media is carried by the backwash fluid to the backwash chamber 62 above it. This staged fluidization procedure overcomes the need for high backwash pressures to lift the porous media throughout the annulus. Without considerable backwash pressure, it is difficult to lift the media string.

The backwash chamber 62 has two functions. First, the fluidization of the porous media 56 from the smaller diameter filter chamber 58 is effected by a swirling action into the backwash chamber 62 . This swirling motion agitates the porous media 56, thereby separating the media particles and releasing fine-grained impurities. These contaminant particles are carried by the backwash fluid through the screened inner porous cylinder 54 and out of the filter assembly 50 in the direction indicated by arrow 76 . The upper portion of the filter housing 52 may be perforated to allow larger particles and impurities to be carried away from the filter assembly 50 . According to the volume flow rate of the backwash fluid, the backwash pressure and the particle size and weight of the porous medium, the selection of the size of the orifice 66 is determined, so that the backwash fluid can exert sufficient traction on the porous medium 56 of each layer to lift the medium particles. and transfer it from filter chamber 58 to backwash chamber 62. A second feature of the present invention is that when almost all of the porous media 56 is delivered to the backwash chamber 62, the flow of backwash fluid is subject to accumulation in the screened inner porous cylinder extending into the backwash chamber 62. Part of the resistance of porous media. Thus, when fluidization of porous media 56 is complete, an increase in backwash fluid pressure can be measured. This can be used to indicate that the backwash cycle for filter assembly 50 has ended, and to initiate the start of the next filtration cycle.

When several radial flow filters are used in parallel, the phenomenon of increased backwash fluid described above can be used to advantage. If each radial flow filter assembly 50 uses the same source of backwash fluid, then when one of the filter media becomes fully fluidized to increase backwash fluid through it, the pressure of the backwash fluid can be used by the other filter to facilitate fluidization of its porous media. In other words, once a filter is fluidized, it does not pass a substantial amount of backwash fluid, it significantly prevents the passage of this backwash fluid. This feature becomes especially beneficial when the porous media of one of several filters connected in parallel is so heavily clogged with foreign particles that most of the backwash pressure is required to fluidize its media.

Figures 5a-5f diagrammatically show examples of the continuous sequential fluidization of different sections of the porous medium 56. Shown is a typical radial flow filter with four check valves 90-95 arranged on the inner porous cylinder dividing the porous media 56 into five sections. These check valves are shown in more detail in Figure 9. Figure 5a shows the flow annulus column of particulate filter beads before fluidization begins at the beginning of the backwash cycle. Figure 5b shows that the uppermost portion of the porous media 80 begins to fluidize and is lifted upwards into the backwash chamber 62 by the traction force of the fluid. As mentioned above, this is because the axial traction force acting on the upper part 60 of the porous medium 56 exceeds the buoyant weight (buoyant weight) of the medium itself, so the porous medium is forced to move upward into the backwash chamber 62. As this procedure continues, the porous media of the first section 80 is fully lifted up into the backwash chamber 62 as shown in Figure 5c. In Figure 5c, the next section 82 is beginning to fluidize, and is conveyed upward to the backwash chamber 62 where the particles of the media are separated from each other and also from the filtered particulate matter. At this time, because the buoyant weight of the medium of the first section 80 previously pressed on it has been removed, the medium of the second section 82 is also lifted upwards. In FIG. 5 d , the porous media 56 in a section 84 further below begins to fluidize and is lifted upwards into the backwash chamber 62 . FIG. 5e shows the fluidization of the medium in section 86 . In Fig. 5f, the porous media of the bottommost layer 88 is lifted upwards due to the pulling force of the backwash fluid entering from the inlet 96 at the bottom of the filter assembly.

It is very important that the openings of the check valves 90-94 and 95 are each different. The uppermost check valve 90 has the smallest opening, while the lowermost check valve 95 has the largest opening, and the check valves (92-94) between them also have the opening sizes in between. Inlet 96 preferably does not have real orifice structure, but its opening itself has the effect of orifice, and its size is bigger than orifice 95. The selection of the orifice size of the top check valve 90 depends on the pressure of the backwash fluid entering the inlet 90, and the traction force acting on the porous medium 56 must be sufficient to make the medium in the upper section 80 rise. Once the porous medium 56 in the uppermost section 80 is transmitted upward by the force of the fluid, the backwash fluid can continue to flow through the orifice of the check valve 90 without the resistance of the porous medium 56 . But because the orifice of the check valve 90 is small, the residual force of the backwash fluid flowing through the check valve 92 can give enough traction to the second section 82 to lift the porous medium 56 of this section upward. Utilize the design of the different opening sizes of the orifices of the check valves (90-95), it can be assumed that when the porous medium of the previous section is fluidized and sent to the backwash chamber 62, the traction force that the porous medium 56 of each section receives Both are almost the same size. The selection of these orifice sizes depends on the backwash fluid pressure, the size and weight of the porous media 56 particles, and other parameters determined experimentally. As a further alternative, the radial flow filter section 50 constructed in accordance with the principles of the present invention can be simulated and analyzed using suitable electronic computer software. There is a filter fluid dynamics program called "FLUENT". The radial flow filter disclosed in the present invention is simulated by this program, and its relevant important parameters are determined. The results of the analysis are documented in Miguel Amaya's doctoral thesis "Technical Behavior of a Radial Flow Filter During Backwashing Cycle", presented on August 17, 1996. This paper is hereby incorporated by reference into this patent application.

Above, an important feature of the present invention that allows the porous medium to be fluidized section by section in countercurrent operation is that the inner porous cylinder 54 is provided with a series of equidistant but progressively smaller radius orifices. Figure 6a shows a computer program analysis of a radial flow filter using this orifice design and its effect on the porous media in the annular space between the inner porous cylinder 54 and the outer porous cylinder 60 . A first orifice 90 and a second orifice 92 are shown secured within the inner porous cylinder 54 . In this design, there is a significant region within the inner porous cylinder 54 that is enclosed by the flexible member 100 . This flexible member 100 may be fabricated from a thin sheet of durable, resilient rubber material that is glued or secured to the inner surface of the inner porous cylinder 54 . This pouch 100 covers the orifice and prevents the passage of fluid. A small portion 102 of the opening 104 of the inner porous cylinder 54 located directly below the orifice structures 90 and 90 is uncovered by the flexible member 100 . There is a workaround, instead of the pouch 100, just make the inner perforated cylinder 54 not all perforated. The backwash fluid flows in the direction of arrow 106 within the inner porous cylinder 54 . The arrows shown in the filter chamber 58 are the velocity vectors of the backwash fluid flow.

Orifices 90 and 92 restrict the flow of backwash fluid in inner porous cylinder 54 and cause a drag force on the porous media. Only when this traction force exceeds the buoyancy weight of the porous media, the porous fluid can move up the axial direction during the backwash operation. The value of the fluid velocity loss in the axial direction can determine the area of porous media where the fluid traction force exceeds the buoyancy weight. The flow rate loss 108, shown in Figure 6a, shows the dynamics of the fluid flow and the resulting traction at a certain moment in time. In section 110 of porous media, fluid velocity loss 108 is generally upward. Assuming that the uppermost layer of the porous media is depicted in FIG. 6a, the buoyant weight of the porous media is at a minimum in this region compared to the tractive forces acting on it due to the presence of the orifices 90. The result of the computer analysis is determined: the application selects the appropriate size of the orifice 90, selects the appropriate size and distribution of the orifice 104 on the inner porous cylinder 54, and the size and weight of the porous medium particles can make the traction force acting on the porous medium exceed its buoyancy weight. In this condition, the porous media is lifted upwards and moved from filter chamber 58 to backwash chamber 62 .

In section 112 of filter chamber 58, the fluid flow velocity vector is virtually non-existent at this point and there is no net drag force acting on the porous media. In the section directly above the section 112, the direction of the velocity loss 111 is downward. Therefore, the downward force acting on section 112 prevents the entire porous media string from being lifted upward like a plug. However, when the section of porous media above the orifice 90 is removed, the downward velocity loss ceases to exist, which prepares the section below for fluidization. This arrangement thus promotes a continuous fluidization process of the medium from top to bottom. For the second orifice 92 , the upward traction on the porous media also exists in section 114 . This traction does not exceed the buoyancy weight in section 114 due to the accumulated weight of the porous media above it. When the porous media in section 110 above it is removed and fluidized, the tractive force acting on porous media section 114 exceeds its buoyant weight, so the media particles in this section begin to rise and are transported to the inverse The wash chamber 62 is fluidized. The same hydrodynamic action takes place in the remaining orifice section until the entire annulus 58 is cleared of porous media.

Figure 6b is a partial cross-sectional view of a radial flow filter. This filter is provided with an annular cuff between the outer porous cylinder 60 and the filter assembly housing 52 . It can be seen that each section of porous media 56 has an associated band. This annular cuff, or other similar configuration, is used to direct backwash fluid from the outer annular chamber 118 back into the porous media 56 . This annular band 116 can be integral with the housing of the filter assembly, or with the outer wall of the outer porous cylinder 60 .

Figure 7 shows the flow of backwash fluid during the backwash process. The porous media in the uppermost section has been transported away by fluidization. Shown in vertical section is a filter with an inner porous cylinder fitted with five orifices of decreasing radius. Where the line on the graph is thicker and the color is darker, it shows a larger flow of backwash fluid, while individual undulating lines show that the flow of backwash fluid in this area decreases. It can be seen from the figure that the porous medium 56 in the upper section has been fluidized, but the media in the lower section has not been subjected to a traction force exceeding the buoyant weight of the accumulated medium above it, so fluidization has not yet started. It can thus be seen that radial flow filters can be constructed in such a manner as to provide fluidization capability to porous media without requiring excessive backwash pressures which would reduce the efficiency of filter operation.

As mentioned above, the various structural elements of the radial flow filter affect the capacity and efficiency of the fluidization process. Among the many variables that must be considered in the design of fluidization of porous media, the magnitude of the flow velocity and the influence of the flow velocity on the radial traction force and pressure drop are greater than the influence of many other variables. Using computer analysis, it was found that increasing the flow rate of the filter increases the traction of media particles, but this comes at the expense of increased pressure drop. The nature and characteristics of the porous medium affect its reaction more than the pattern of the orifice arrangement of the inner porous cylinder. For example, reducing the size of the porous media particles increases the pressure by an average of 5955 Pa, which is nine times the result of changing the percent open area of the inner porous cylinder 54 . The traction force increases with respect to the percent open area. For radial filter designs, this shows that the orifice pattern variation is less important when the media uses smaller particles. Also note that changing the percent open area has the opposite effect on the amount of traction. For example, the average effect of increasing the percent open area is to decrease traction, whereas increasing the orifice size results in increased traction. According to computer analysis results, when the percentage of opening area is large, the large openings of the inner porous cylinder 54 will reduce the traction force; but if the percentage of opening area is small, the use of large openings will increase the traction force. Increasing the percent open area and opening size simultaneously results in a comparable pressure drop across the radial fluid filter. Note also that the flow rate of the backwash liquid and the particle diameter of the porous media have been found to have a large effect on the draw force and pressure drop of the filter. The orifice pattern of the inner porous cylinder does not have much to do with the effect of traction and pressure drop when using higher flow rates and smaller particle sizes.

An embodiment of the present invention is analyzed with computer program "FLUENT" (V4.31), Fluid Flow Modeling (Fluid Flow Modeling 1995, FLUENT, INC., Centerra Resource park, 10 Cavendish Court, NH 03766). This filter was constructed as follows: 5 orifices with radii between 0.645 cm (0.254 in) and 2.66 cm (1.047 in) were used. The particles of the medium generally have a diameter of 44-840 microns and a specific gravity of 2.5, which is similar to sand. The orifices in the inner porous cylinder 54 have a radius of 1.9 cm (0.75 inches), and the orifices have an open area of 66 percent. The size of the annular filter chamber containing the porous media is 2.0 cm (0.80 o'clock) (radial) x 57.47 cm (22.625 inches) (axial), and the flow rate is 11.3-106.0 liters (3-28 gallons) per minute. The range of backwash pressure is 0.5-10kPa. It is expected that with filters so constructed, the porous media can be successfully fluidized and thus completely removed from impurities, saving the downtime that would otherwise be required in order to disassemble the filter assembly to replace the media.

Figure 8 shows a cross-sectional view of a radial filter incorporating many of the features described above. The filter 120 has a base 122 and a removable housing 124 connected to each other by bolts and clips 126 . The casing 124 and the base 122 are sealed with elastic rubber or other types of adhesives. Base 122 has an inlet connection 128 for connection to an incoming fluid supply. Fluid is pumped in the direction indicated by arrow 130 . The incoming fluid includes fluid and granular impurities to be separated by the filter bed in the casing 124 . Once the impurities are removed, the effluent liquid is discharged from the filter through the outlet joint 132 along the direction shown by the arrow 134. During the backwashing operation, the backwashing fluid is introduced into the filter 120 through the joint 132, and is filtered out from the joint 128 with the suspended impurities. device. For those familiar with the process of removing a filter from a pumping system and connecting it to a backwash system, there are a variety of valve installations and control systems available.

Radial flow filter assembly 136 is secured within housing 124 . The filter assembly 136 has an enclosed case 138 to accommodate and support the filter assembly. This case 138 includes a cylinder 140 secured between an upper top cover 142 and a bottom cover 144 . The interior space of the box 138, except for one or several openings 70 in the cylinder 140, is fluid-tight. The fluid is connected to the filter 120 by an inlet connection 128 . Each of the aforementioned openings 70 has a check valve that allows fluid to enter the tank 138, but does not allow fluid to flow in the opposite direction. This box 138 can be made of plastics or metal, to suit the special needs of each filtration system, will filter out impurities from water or similar liquids, and the box can be made of PVC or polyethylene plastic material under low pressure situation. In this case, the upper and lower end caps 142 and 144 may be fixed to the cylinder by bonding, welding or other methods. When using higher pressure or corrosive liquids (such as chemicals), the box 138 can be made of stainless steel or other kinds of materials and joined by welding.

Inside the box 138 of the filter assembly 136, there are a pair of perforated cylinders. The inner porous cylinder 54 is supported in the openings of the top cover 142 and the bottom cover 144 . In addition, the inner porous cylinder 54 is also supported by the bottom cover 146 of the filter chamber. These elements may be glued, bolted or otherwise secured for permanent or removable mounting. The outer periphery of the inner porous cylinder 54 is covered with a screen 148 . This screen can be made of synthetic or metallic material with a mesh small enough to prevent the passage of particles of the filter bed or porous media. There is also a plug 64 inside the inner porous cylinder 54 to prevent the liquid from passing through the inner porous cylinder 54 in the axial direction.

As an alternative to the orifice arrangement 66 described above in relation to FIGS. 3 and 4 , the FIG. 8 design includes the use of several check valves 150 . We expect a check valve with an orifice to be a better construction. The check valve 150 includes a valve seat, and a ball made of synthetic material that floats in the liquid. The check valve 150 also has one or more orifices, which will be described in more detail below. While the check valve 150 is open during filtration operation, it is generally closed during backwash operation except for small orifices. Due to this design, restrictions on fluid flow during filtration operations are eliminated.

The bottom of an outer perforated cylinder 60 is secured to the filter chamber top 146 . Its upper end is fixed on the annular small piece 152 of filter assembly box 140 inner surface. Much like the inner porous cylinder structure 54, the outer porous cylinder 60 has a screen 154 attached to its inner surface. Screen 154 serves the same purpose as screen 148 . The annular space between the outer porous cylinder 60 and the inner porous cylinder 54 is the so-called filter chamber 156 . Filter chamber 156 is filled with a porous medium, such as a particulate material, for removing impurities from the incoming fluid. Above filter chamber 156 is backwash chamber 62 . The volume of the backwash chamber is preferably the same as that of filter chamber 156, although it could be larger. As can be seen in Figure 8, the radial dimension of the backwash chamber 62 is larger than that of the filter chamber. This difference in radial dimension imparts a swirling motion to the media particles 58 as they are lifted from the filter chamber 156 into the backwash chamber 62 . This swirling motion agitates the media particles and facilitates particle-to-particle separation to release impurities therefrom. Without this difference in radial dimension, backwash flow has a tendency to lift the entire media string like a plug.

During filtering operation, incoming fluid is directed to flow in the following manner. After entering inlet connection 128 , incoming fluid is forced into space 160 surrounding filter assembly housing 138 . The fluid is then forced into port 70 via a check valve on the inside wall of the filter assembly housing. Once the fluid is forced through check valve orifice 70, it fills annular space 162 and encases the outer surface of outer porous cylinder 60 entirely. The fluid then passes through the porous medium 58 in a radial direction, where impurities in the fluid are removed. The filtered fluid then passes through the pores in the inner porous cylinder 54 and into the space 164 within the inner porous cylinder. The filtered fluid then exits the bottom of the filter 120 through the open check valve 150 and into the outlet fitting 132 . This radial flow feature allows the porous medium 58 to have a large surface area presented to the incoming fluid. This filtering procedure continues until the pressure at the inlet connection of the filter 120 rises, indicating that the porous media 58 has accumulated such an amount of impurities that the filtering operation has lost its efficiency.

Once it is determined that backwash operation must be performed, the opening or closing of some valves is adjusted appropriately to force backwash fluid into connection 132 . The flow path of the backwash fluid is effective to remove impurities from the porous medium 58 and to carry the impurities along with the backwash fluid out of the filter through the connection 128 . Backwash fluid is forced into junction 132 and flows upward into central portion 164 inside inner porous cylinder 54 . At this point, check valve 150 is closed except for a small orifice formed therein. The backwash fluid encounters a series of orifices of progressively decreasing size, thereby promoting fluidization of the media particles, as previously described. The porous media 58 within the filter chamber 156 is fluidized section by section and carried upward into the backwash chamber 62 . In the backwash chamber 62, the swirling and agitating motion of the fluid on the media particles releases impurities from the media. These impurities follow the backwash fluid from the backwash chamber 62 into the central region 166 of the inner porous cylinder 54 and out through the end point 168. It can be seen that the check valve closes the orifice 70 on the filter assembly housing 138 during fluidization, thus preventing substantial backwash fluid from passing radially outwardly through the outer porous cylinder 60 . In any case, the impurities carried out by the backwash fluid are introduced from the top 168 of the inner porous cylinder 54 into the outer annular region 160 and from there into the joint 128 .

FIG. 9 shows a design of a check valve 150 secured within the inner porous cylinder 54 . The check valve 150 consists of a flat plate 170 with a main orifice 172 in the plate. Orifice 172 may be plugged with a ball 174 made of plastic or other similar buoyant material. The buoyant weight of each check valve ball can vary. Not shown in the diagram, but those familiar with the art of check valve design would prefer a cage or similar design to prevent the check valve ball from falling downwards and inadvertently sealing the main orifice of the check valve beneath it. Also on the plate 170, there are one or more orifices 176 which are not blocked by the check valve ball 174 mentioned above. These orifices 176 serve the same purpose as the orifices designated 66 previously mentioned in relation to FIG. 3 . Furthermore, the percent open area of each orifice 176 in one check valve plate 170 is preferably different from the percent open area of the orifices in the other check valve plates secured within inner porous cylinder 58 .

FIG. 10 shows another design of check valve plate 180 that may be secured within inner porous cylinder 58 . Unlike the check valve plate 176 shown in FIG. 9, the opening of the check valve plate 180 of FIG. The unevenly open valve seat 182 on this check valve plate 180 allows liquid to flow therethrough even if the ball 174 falls in the middle of the orifice of the plate 180 .

11 and 12 show a check valve that may be used on wall 140 of filter assembly housing 138, particularly in connection with orifice 70 in FIG. This check valve has a plug 184 made of rubber material. The plug has a flat portion 186 and a stem 188 . There is a conical or enlarged head on the top of the rod. When installing, the rod head can be firmly pressed into the anchor hole 183 in one direction, but it is not easy to take off after being installed. FIG. 11 also shows fluid flow in the direction of arrow 192 , causing the orifice 70 to be closed by the plate portion 186 of the plug, thus preventing fluid flow through the filter assembly housing 140 . In FIG. 12 , fluid flows in the direction of arrow 194 through orifice 70 . Thus, influent fluid can pass through the orifice 70 into the space 162 surrounding the outer porous cylinder (FIG. 8) 60 during the filtration cycle. Although only 2 orifices 70 are shown, the design can use more orifices as long as they can be covered by the plate 186 of the resilient check valve. For other types of check valves, one end of the elastic plate can be fixed on the inner wall of the filter assembly housing 140, and the plate can be opened or closed according to the direction of fluid flow, so its function is the same as that of the check valve. Those skilled in the art may use other types of mechanically operated or electrically operated inlet check valves, and inner porous cylinder check valves associated with filter 120, according to their preference.

Figure 13 shows another radial filter constructed in accordance with the principles and concepts of the present invention. The structural characteristics of this filter assembly 200 are similar to those shown in FIG. 8 . Between the outer porous cylinder 60 of this filter assembly 200 and the cylindrical housing 204, there are several o-rings 202 made of rubber. Although in the design of Figure 13, only four o-rings are shown, any number of o-rings can be used. Each o-ring creates a seal between the outer porous cylinder 60 and the inner wall of the housing 204 . Therefore, the function of the o-ring 202 is to change the flow direction of the fluid in the porous medium 56 . A considerable part of fluid passing through porous media changes from radial flow to axial flow. In addition, additional axial forces are generated inside the porous media. The use of o-rings 202 may alter the number of check valves 150 required and may also require a leak hole 206 in the wall of housing 204 . This leak hole may be provided between each adjacent o-ring to allow fluid to flow in or out of the porous media of each section. As we can know, the number of O-rings and the orifice size of the check valve 150, as well as the determination of the axial length of each section of the porous medium, must be able to ensure that there is an appropriate axial force on the porous medium during the backwash cycle. on the particles.

The filter assembly 200 shown also includes the flexible member 100 . This flexible member 100 can be used in combination with a check valve 150 , with or without a port, and an o-ring 202 . The function of the flexible member 100 is to concentrate almost all of the backwash fluid flowing into the inner porous cylinder 54 into the area directly below each check valve 150 . This flexible member 100 maximizes the axial flow that exists in each porous media section. The figure shows that during the filtering cycle, the outer wall surface of the flexible member 100 is deformed to be concaved inwardly under the pressure of the liquid.

Finally, the filter assembly 200 includes a backwash outlet check valve 210 . This outlet check valve 210 is located in the unperforated portion of the inner porous cylinder 54, preferably near the bottom of the filter assembly 200. This outlet check valve 210 provides a path for fluid to travel from the interior space of the inner porous cylinder 54 to the annular space 162 between the housing 204 and the outer porous cylinder 60 when forced open by the pressure of the backwash fluid. path. Outlet check valve 210 allows backwash fluid to exit from the level below the filter chamber and flow directly into outer annulus 162 without first passing through porous media 56 . Once the backwash fluid enters the outer annular space 162, it may exit through the leak hole 206, or exit through the porous media 56 and flow into the upper backwash chamber 62.

The outlet check valve 210 is also used to close the inlet check valve 184 during the backwash cycle. This is beneficial where small particles of porous media 56 are laden with contaminants, allowing a small amount of backwash fluid to reach the outer annulus 162 . In addition, outlet check valve 210 provides backwash fluid to outer annulus 162 , and o-ring 202 directs additional fluid into porous media 56 to aid fluidization of porous media 56 . It also provides a fluid scrubbing action to the outer annulus 162, thereby significantly reducing the flow rate of backwash fluid required to remove impurities from the porous media 56. This is because the impurities with larger particles trapped on the screen are directly flushed out from the leakage hole 206 instead of being brought back into the porous medium 56 to flow out from the backwash chamber 62 . Impurities with larger particles are directly discharged from the leakage hole 206, and those particles that are too large to pass through the screen covering the outer porous cylinder 60 are completely removed.

One alternative is to remove all leak holes 206 except the top one, and add a vertical channel to each o-ring 202 to allow backwash fluid to flow up and around each o-ring. Additionally, one skilled in the art can devise alternatives to check valve 150 that include forming the orifice in flexible member 100 itself and allowing a portion of the flexible member to block the vertical passage within inner porous cylinder 54 . We can see that the filter assembly 200 in FIG. 13 also provides some other features. These features may be considered optional, but may be required in certain circumstances. Those who are familiar with this process technology can find that the various features of these designs can be properly selected for different situations to produce the best filtration and backwashing effects. Also, while the foregoing has generally only referred to porous media 56 as being relevant to the removal of particulate matter or impurities, other types of media can be selected to remove dissolved solids from liquids, to allow solids to interact with liquids, to provide bonding capabilities, and even to The liquid supplied to the filter provides the catalytic action. However, a filter constructed in accordance with the principles and concepts disclosed in this invention, whether used as a filter or not, provides increased surface area for liquid flowing radially through the media, and it provides effective backwashing Operating capacity to fluidize media.

Figures 14a and 14b show another design of radial flow filter 220 incorporating a perforated flexible member 222. The pouch is preferably made of a flexible rubber material constructed to withstand the pressures that may be encountered within the filter and the type of fluid to be filtered and backwashed through the filter 220. The flexible member 222 can be made into a tube shape. The fixed plate 224 acts as a baffle in the inner porous cylinder 54 to prevent liquid from flowing upward.

The flexible member 222 is ported with a pattern of small holes 226, rather than a ported check valve or the previously mentioned porting configuration. Small holes 226 are formed in the flexible member, near the uppermost portion of the media 56, to allow it to be fluidized during the backwash cycle. The small holes 226 may be distributed annularly in the uppermost section of the flexible member 222 . Subsequent sets of apertures 230-236 are formed on the flexible member. The diameter of each set of orifices numbered 230-236 increases with distance from the baffle 224 . In this arrangement, the function of these groups of orifices is very similar to that of the orifice structures described above in relation to Figures 3 and 4. The variation of the open area of the orifices of each group can be achieved in different ways. For example, the uppermost set of orifices 226 may include a predetermined number of openings of small holes of a first diameter. The second set of orifices 228 may consist of the same number of small holes of slightly larger diameter. Each subsequent set of orifices 230-236 may consist of small holes of progressively larger diameter. One of the alternative methods is to use small holes with the same diameter for each group of holes, but the number of small holes is a small number for the hole 226, and the number of small holes varies according to the distance from the hole to the baffle 224. big. Those skilled in the art can devise many other arrangements to obtain a pore structure that promotes fluidization of porous media.

It is important to mention that each set of orifices 226-236 must be fabricated to align with corresponding apertures on inner porous cylinder 54. In this way, the backwash fluid can flow through the orifices on the flexible member 222 and the small holes on the inner porous cylinder, and enter the porous medium 56 . As for the lowermost set of orifices 236, the openings are sufficiently large that filtered liquid passes therethrough without a detectable pressure differential.

Figure 14a shows the operation of the radial flow filter assembly 220 during a filtration cycle. During this cycle, influent fluid enters the filter assembly 220 in the direction indicated by arrow 240 and enters the top of the porous media 56 column. However, most of the fluid will flow radially through the various regions of the porous media 56 through the open check valve 184 . Each zone is separated by a respective o-ring 202 to facilitate the fluidization process of the backwash cycle. Due to the pressure of the fluid to be filtered that flows radially through the media 56, the side walls of the flexible member are forced to bend inwardly. As shown in Figure 14a. During a filtration cycle, although some filtered fluid passes through each set of orifices, the majority of the fluid will pass through the most open set of orifices 236 and exit the filter assembly as indicated by arrows 232 .

Figure 14b shows the operation of the filter assembly 220 during a backwash cycle. During a backwash cycle, backwash fluid enters the filter assembly in the direction of arrow 244 . The backwash fluid enters the interior space of the flexible member 222 , thereby pressurizing the inner surface of the inner porous cylinder 54 . Backwash fluid is forced through that set of orifices, as indicated by arrows 246 . The backwash fluid then flows into the porous media 56 to fluidize the media in the manner previously mentioned. During the backwash cycle, check valve 184 is closed to facilitate continuous segmented fluidization of the sections of porous media 56 . Finally, the backwash fluid is discharged from the filter assembly 220 in the direction indicated by arrow 248 with impurities and released fine particulate matter.

Figures 15a and 15b show another radial flow filter design which operates in the opposite manner. This design is especially suitable for applications where the media particles used are larger or generally lighter in weight. During the filtration cycle, a liquid (preferably not the inflow fluid) which sinks the porous media is pumped into the filter assembly 250 in the direction of arrow 252 as shown in FIG. 15a. The traction exerted by this fluid on the porous media 56 lifts the media beads up to the top of the filter chamber. Each of the check valves 150 fixed in the inner porous cylinder 54 in the backwash chamber 62 is closed, while the check valves 150 in the filter chamber 150 are all open. Once all of the porous media 56 has been lifted into the filter chamber by the sinking liquid, adjustment of a valve system (not shown) can begin to allow the incoming fluid to enter the filter assembly 250 as indicated by arrow 252 . Also, this incoming fluid can pass through open inlet check valve 184 in the direction indicated by arrow 254 . The incoming liquid passes through the medium 56 radially, and then enters the inner space of the inner porous cylinder 54 through the open check valve 150 . Finally, filtered incoming fluid exits filter assembly 250 in the direction indicated by arrow 256 .

Figure 15b shows the operation of such a reverse filter assembly 259 during a backwash cycle. During the backwash cycle, the porous media 56 is only allowed to settle by gravity into the lower filter chamber of the filter assembly. As the filter media 56 moves from the upper filter chamber to the lower backwash chamber, the particles of the media are separated from each other and impurities are removed therebetween. Particulate matter and impurities pass through the open check valve located below the inner porous cylinder 54 and are carried out of the filter assembly 250 by the backwash fluid in the direction of arrow 260 . Under the condition that the column of porous media 56 does not move down due to gravity, the backwash fluid enters the filter assembly 250 from the direction of arrow 262 to produce the previously mentioned continuous fluidization phenomenon of the media segment by segment.

Although we have only disclosed the relevant, preferred and other designs and components of the present invention for a particular radial flow filter, it must be understood that some design and construction details must be based on engineering considerations without violating the rights of As regards the spirit and scope of the invention as defined in the claims, mutatis mutandis. Indeed, those skilled in the art may prefer to utilize only some of the disclosed features of the present invention, or to utilize individual features in many different embodiments, to their individual or combined advantages.

Claims (23)

1. device with medium fluidization, it comprises:

A kind of medium that acts on mutually with the influent stream fluid;

One defines first Room is used for holding above-mentioned medium, so that fluid can be radially

By this medium, and interactional with it therein supporting construction;

A kind of direct fluid is to medium and make its import of radially flowing through this medium knot

Structure;

A fluidisation chamber, it is different from the first above-mentioned Room, and nearly all medium is at stream

All be brought to this chamber in the body process, there is enough big volume this fluidisation chamber, makes Jie

Matter can be separated into particle one by one after first Room is taken this fluidisation chamber to, and

And this chamber have have the residue that allows the fragmentation that is filtered off by but the particle of medium not

The end of the aperture that can pass through.

2. according to the device of claim 1, it is characterized in that: the aspect ratio medium of fluidisation chamber residing height when medium and the interactive operation of fluid is big.

3. according to the device of claim 1, it is characterized in that: the volume of fluidisation chamber is approximately identical with the volume size of first Room that holds described medium when medium and the fluid reciprocation.

4. according to the device of claim 1, it is characterized in that: its structure is to make above-mentioned medium in axial direction be taken to described fluidisation chamber in the fluidisation operating process.

5. according to the device of claim 1, it is characterized in that: supporting construction comprise a pair of concentric supporting construction and the inner supporting structure that is fixed therein on one or several orifice structures with restriction influent stream fluid flowing in described inner supporting structure.

6. according to the device of claim 5, it is characterized in that: orifice structure is drilled with aperture by a slice flat board and constitutes.

7. according to the device of claim 5, it is characterized in that: orifice structure is made up of a kind of check-valves.

8. according to the device of claim 5, it is characterized in that: the effective vent area of first orifice structure and the aperture area of other orifice structure are unequal.

9. device according to Claim 8 is characterized in that: the effective vent area of every group of orifice structure reduces gradually by the order of the aperture from fluid inlet to the fluidisation chamber.

10. according to the device of claim 5, it is characterized in that: comprise also that in addition a baffle plate that is fixed within the said inner supporting structure flows through vertically to stop the fluidisation fluid, thereby make fluid pass through medium from inner supporting structure.

11. device according to claim 1, it is characterized in that: supporting construction comprises a pair of concentric structure, and the structure of this device will make the influent stream fluid during itself and medium interact, axially inwardly by that supporting construction of outside in those two concentric supporting constructions, and in fluidisation operating period, fluidised fluid can not pass through said based on external supporting structure continuously.

12. device according to claim 3, it is characterized in that: medium is in the annulus that is contained between the dwell of cam of said two concentric supporting constructions therein, this annulus has a radial dimension, and its space that is characterized as of fluidisation chamber is the bigger annular space of radial dimension.

13. the device according to right 1 is characterized in that: described device comprises a filter, and described medium comprises granular particle.

14. the device according to claim 13 is characterized in that: said fluidisation chamber comprises a back washing chamber.

15. one kind makes medium and fluid interaction and makes the method for medium fluidization, the method comprises following step:

Medium is supported in first space;

Make the influent stream fluid radially flow through medium;

With influent stream fluid and medium interaction;

Medium is sent to second space, makes medium be separated into particle there, therefore make Jie

Matter is by fluidisation;

In the fluidisation process, the broken material that filters out is taken out of from said second space,

But stop medium to pass through from this second space.

16. the method according to claim 15 is characterized in that: also comprise make medium in the fluidisation process along axially-movable.

17. the method according to claim 16 is characterized in that: comprise also medium is sent to a fluidisation chamber that this fluidisation chamber and said first space are inequality.

18. the method according to claim 15 is characterized in that: also comprise by medium being sent to said second space with this medium fluidization.

19. the method according to claim 18 is characterized in that: also be included in the different time periods, the medium of different piece fluidisation continuously successively.

20. the method according to claim 19 is characterized in that: also be included in the said continuous fluid program, the particle of the medium of every part is bestowed much at one tractive force.

21. the method according to claim 18 is characterized in that: also comprise the flow velocity that reduces fluidisation liquid because of the whole fluidised results of medium.

22. the method according to claim 21 is characterized in that: also comprise by making fluidised medium productive set reduce the flow velocity of fluidisation fluid at a fluidisation fluid outlet area.

23. method according to claim 19, it is characterized in that: also comprise medium is contained within first space that two concentric interior perforated cylinders and outer perforated cylinder defined, said outer perforated cylinder is wrapped in the columnar housing, and be isolated in the annular region that limits between said outer perforated cylinder and the cylindrical shell by one or more zero shape rings.

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