EP0909207A1 - Filtre fluidisable a ecoulement radial - Google Patents

Filtre fluidisable a ecoulement radial

Info

Publication number
EP0909207A1
EP0909207A1 EP97930996A EP97930996A EP0909207A1 EP 0909207 A1 EP0909207 A1 EP 0909207A1 EP 97930996 A EP97930996 A EP 97930996A EP 97930996 A EP97930996 A EP 97930996A EP 0909207 A1 EP0909207 A1 EP 0909207A1
Authority
EP
European Patent Office
Prior art keywords
media
fluidizing
backwash
filter
flow
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP97930996A
Other languages
German (de)
English (en)
Other versions
EP0909207A4 (fr
Inventor
John D. Martin
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Publication of EP0909207A1 publication Critical patent/EP0909207A1/fr
Publication of EP0909207A4 publication Critical patent/EP0909207A4/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D35/00—Filtering devices having features not specifically covered by groups B01D24/00 - B01D33/00, or for applications not specifically covered by groups B01D24/00 - B01D33/00; Auxiliary devices for filtration; Filter housing constructions
    • B01D35/14—Safety devices specially adapted for filtration; Devices for indicating clogging
    • B01D35/153—Anti-leakage or anti-return valves
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D24/00—Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof
    • B01D24/02—Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof with the filter bed stationary during the filtration
    • B01D24/04—Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof with the filter bed stationary during the filtration the filtering material being clamped between pervious fixed walls
    • B01D24/08—Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof with the filter bed stationary during the filtration the filtering material being clamped between pervious fixed walls the filtering material being supported by at least two pervious coaxial walls
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D24/00—Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof
    • B01D24/38—Feed or discharge devices
    • B01D24/42—Feed or discharge devices for discharging filtrate
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D24/00—Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof
    • B01D24/46—Regenerating the filtering material in the filter
    • B01D24/4631—Counter-current flushing, e.g. by air
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D24/00—Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof
    • B01D24/46—Regenerating the filtering material in the filter
    • B01D24/4668—Regenerating the filtering material in the filter by moving the filtering element
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2201/00—Details relating to filtering apparatus
    • B01D2201/44—Special measures allowing the even or uniform distribution of fluid along the length of a conduit

Definitions

  • the present invention relates in general to a device for coacting a porous media with an influent, or for removing impurities, solids or particulate matter from an influent, and more particularly to a radial-flow type of filter having a nonbonded filter media, and in which the flow of the fluids can be reversed in a backwash operation to remove the filtered matter and thus regenerate the filter for reuse
  • a bonded media filter includes a removable cartridge element constructed of a fibrous woven or nonwoven material The material can be selected with a given porosity so that particulate matter of a given size can be removed from the influent When the bonded cartridge filter element has a sufficient accumulation of filtered matter thereon, it is simply removed and cleaned, or replaced
  • the cartridge type filters are not easily backwashed
  • many cartridge-type filters are of the radial-flow type, whereby a maximum surface area is provided for filtering, thereby allowing a reduced resistance to the flow of the influent
  • Another family of filters contains a nonbonded media, such as sand, glass beads, diatomaceous earth and other granules or particles through which the influent flows
  • the nonbonded media is generally of a granular type of material, circular, rounded or irregular in shape so that the spacing between the particles is effective to filter the particulate matter
  • the advantage of utilizing a nonbonded media filter is that it can be backwashed to regenerate the media Backwashing can include the fluidizing of the media which allows the fluid to dislodge the entrapped contaminants from both the interstices between the grains of the media, as well as from the surface of each grain itself
  • the primary disadvantage of such type of filter is the size requirements and costs, as well as filter inefficiencies, in that they have little surface area of the filter exposed to the incoming flow, and thus are forced to utilize larger media grains and higher flow rates per unit area exposed to the incoming flow In other words, the development of a radial-flow, nonbonded media filter that can be regenerated by backwashing is not a
  • FIG. 1 A generalized diagram of a basic radial-flow filter 10 is shown in Figure 1
  • the filter consists of two concentric perforated pipes 12 and 14 and a porous filter media 16 filling the annular space 20 between the two pipes, all housed within a filter case 18
  • the porous media 16 is composed of tiny glass spheres which are of uniform size for a particular filter but can range widely in size for different filters
  • the spheres can be submicron sized, micron sized or as large as coarse sand, and completely fill the compartment 20 between the perforated pipes 12 and 14
  • the perforations in the pipes are circular, of uniform size
  • the radial-flow filter utilizing a nonbonded media and which can be efficiently backwashed to dislodge the impurities and particulate matter to thereby regenerate the filter media
  • the radial-flow filter includes an over-sized filter media chamber for the granular filter beads During a backwash cycle, the reverse flow of the backwash liquid provides an upward lifting force on the granular beads and transfers the beads into an upper portion of the chamber, thereby separating the beads and allowing accumulated particulate matter to be dislodged and carried away During the filtration cycle, the granular beads settle to the bottom of the filter media chamber so that the influent flows between the beads to filter the particulate matter therefrom
  • the influent passes through the screen mesh covering the outer perforated cylinder and radially through the filter granules
  • the filtered influent then passes through an inner screen mesh-covered perforated cylinder
  • the filtered influent then passes through a series of open check valves located within the mesh-covered inner perforated cylinder, and then to the outlet port of the filter
  • the backwash liquid is forced through the filter in a reverse direction, whereby the check valves are closed and the backwash liquid is directed in a reverse direction through the granular media
  • the liquid may generally through the granular filter media in a radial direction, and in an upward axial direction
  • the upward force of the backwash liquid causes the check valves to close thereby forcing a majority of the liquid into the granular filter media rather than upwardly through the inner perforated cylinder
  • the upward or drag force of the backwash liquid causes an upper section of the granules to be lifted into a backwash chamber where the particulate matter is separated therefrom and carried out of the filter This movement and separation of the granular media is sometimes denoted herein as "fluidization,” and occurs when the drag force exceeds the buoyant weight of the upper layer or section of the granular media
  • the backwash chamber is constructed with a volume to hold substantially all of the fluidized granular media
  • the granular media completely covers the portion of the mesh- covered inner perforated pipe that extends into the backwash chamber
  • the pressure of the backwash liquid increases because there is no easy or unrestricted flow path from the backwash chamber into the upper portion of the mesh-covered inner perforated cylinder
  • This increase in the liquid pressure can be used as a signal that the backwash operation has been completed
  • the granular media falls back into the bottom part of the media chamber so that a filtration operation can commence
  • FIG 1 is a generalized cross-sectional view of a radial-flow filter well known in the prior art, showing the liquid flow during a filtration cycle
  • FIG 2 illustrates the radial-flow filter of FIG 1, but during a backwash cycle
  • FIGS 3 and 4 illustrate in generalized form the structural features of the radial- flow filter assembly constructed in accordance with the invention, during a respective filtration cycle and during a backwash cycle,
  • FIGS 5a-5f are generalized sectional views of a portion of a radial-flow filter showing the different stages of the fluidization of the granular filter media
  • FIG 6a is a partial cross-sectional view of a portion of a radial-flow filter showing velocity vectors that act upon the granular filter media to produce an upward drag force to thereby cause fluidization of the granular media,
  • FIG 6b is a partial cross-sectional view of a radial flow filter equipped with o- ⁇ ngs between the housing and the outer perforated cylinder, with velocity vectors showing the drag forces on the filter media
  • FIG 7 is a computer generated drawing of the liquid flow pattern during a backwash operation
  • FIG 8 is a cross-sectional view of one embodiment of a radial-flow filter provided with the backwash and fluidizing capabilities of the invention
  • FIG 9 is a cross-sectional view of a check valve of one embodiment employed in the inner perforated cylinder
  • FIG 10 is a top view of a check value plate constructed in accordance with a second embodiment
  • FIGS 1 1 and 12 are cross-sectional views of a check valve in respective closed and open positions, as utilized in the case that houses the filter assembly
  • FIG 13 is a cross-sectional view through different portions of a radial-flow filter constructed in accordance with another embodiment of the invention
  • FIGS 14a and 14b are generalized cross-sectional views of a radial flow filter constructed in accordance with another embodiment of the invention, illustiatmg a perforated bladder in a filter cycle and in a backwash cycle
  • FIGS 1 1 and 12 are cross-sectional views of a check valve in respective closed and open positions, as utilized in the case that houses the filter assembly
  • FIG 13 is a cross-sectional view through different portions of a radial-flow filter constructed in accordance with another embodiment of the invention
  • FIGS 14a and 14b are generalized cross-sectional views of a radial flow filter constructed in accordance with another embodiment of the invention, illustiatmg a perforated bladder in a filter cycle and
  • FIGS 15a and 15b are generalized cross-sectional views of a radial flow filter constructed in accordance with yet another embodiment of the invention, showing a radial flow filter operating in an inverted manner
  • FIG 3 illustrates in a generalized diagrammatic form, the radial-flow filter assembly 50 constructed in accordance with the invention
  • the radial-flow filter assembly 50 employs a new backwashing technique, thereby avoiding the downtime and expense of reconditioning the nonbonded porous media, as was periodically required by the prior art filters While the preferred and other embodiments will be described in connection with a device using a granular filter media for filtering particulate matter from an influent, the principles and concepts of the invention can be utilized for coacting a media with an influent, a gas or liquid, where the media periodically requires backwashing to cleanse or regenerate the media
  • the radial-flow filter assembly 50 is constructed with a rigid cylindrical housing 52 that extends the entire length of the filter assembly
  • An inner perforated cylinder 54 with a screen mesh extends the entire length of the filter housing 52 While not shown, the inner screen mesh is formed onto the perforated cylindrical support structure 54 for preventing collapse of the screen mesh.
  • the volume in which the porous media 56 is contained includes two chambers During the filtration cycle, the porous media 56 is situated in a first chamber 58 situated generally in the lower or bottom part of the filter assembly 50
  • the first porous media chamber 58 comprises an annular area bounded by concentric screen mesh cylinders, one defining the inner screen mesh 54 and the other defining an outer cylindrical screen mesh 60 Much like the inner screen mesh cylinder
  • the outer screen mesh 60 is supported by a perforated cylindrical pipe that extends axially only about halfway through the filter assembly 50
  • the size of the pores in the screen mesh cylinders 54 and 60 is smaller than the general diametric size of the porous media 56 In this manner, the screen mesh contains the porous media within the filter 50
  • the radial flow filter assembly 50 includes an upper backwash chamber 62 of a volume that is preferabk about the same as that of the lower chamber 58.
  • the general diameter of the top backwash chamber 62 is greater than that of the bottom porous media chamber 58 to facilitate fluidizing, separation and agitation of the porous media 56 during the backwash cycle
  • Fixed within the inner perforated cylinder 54 and screen mesh is a plug 64 that prevents the passage of the influent axially from the top portion of the screen mesh cylinder to the bottom portion of the screen mesh cylinder and vice versa
  • One or more orifices, one shown as reference numeral 66 are fixed at spaced-apart locations within the inner perforated cylinder 54 The size of each spaced-apart orifice is smaller so that the backwash flow of liquid therethrough toward the plug 64 becomes more restricted As will be described below in conjunction with the backwash cycle, the orifices 66 force the backwash liquid outwardly into
  • the porous media may be glass or other types of beads, sand, diatomaceous earth, activated carbon, anthracite coal or any other granular media that has the desired characteristics for removing particulate matter of a specified size or impurities of specified type
  • beads of a nominal diameter of 100 microns when tightly settled together as shown in FIG 3, can filter particulate matter much smaller than the size of the beads
  • the mesh screen covering the perforated cylinders 54 and 60 contains the beads, but allows the particulate matter to flow therethrough and become lodged and filtered by the media bed
  • the interstices thereof eventually become full of the particulate matter, thereby reducing the efficiency of the filter assembly 50 and increasing the load on the pump
  • the radial-flow filter assembly 50 can be efficiently backwashed by reversing the flow of liquid therethrough
  • the flow of the backwash liquid is shown in FIG 4
  • the backwash liquid enters the radial-flow filter assembly 50 at the location shown by arrow 74
  • the backwash liquid attempts to flow through the inner perforated cylinder 54 in an axial direction, but due to the series of smaller orifices 66, the flow is directed outwardly into the porous media 56
  • the check valve at the port 70 is forced closed during the backwash operation, thereby directing all of the backwash liquid upwardly in the filtration chamber 58
  • an upper portion of the porous media 56 is first fluidized, as shown in FIG 4, due to the uplifting drag force exerted thereon by the backwash liquid
  • the size of the different orifices 66 allow sections or stages of the porous medium 56 to be fluidized in a sequential manner It is noted that the top portion of the porous media 56
  • FIGS 5a-5f picto ⁇ ally illustrate an example of the sequential fluidizing of the different stages of the porous media 56 Shown is an exemplary radial-flow filter having four check valves 90-95 disposed in the inner perforated cylinder, thus creating five sections or stages of the porous media 56 The check
  • FIG 5c the subsequent section 82 begins to fluidize and become transported upwardly to the backwash chamber 62 where it separates from itself, as well as from the filtered particulate matter
  • the second media section 82 is lifted at this time in the backwash cycle because the buoyant weight of the first or upper section 80 has been removed
  • a subsequent section 84 of the porous media 56 begins to fluidize and be lifted upwardly to the backwash chamber 62
  • FIG 5e shows the fluidizing of the media section 86
  • the bottom-most section 88 of the porous media is lifted due to the drag forces exerted thereon by the backwash liquid entering the bottom inlet 96 of the filter assembly
  • the check valves 90-94 and 95 each have orifices of a different size
  • the top orifice in the check valve 90 has the smallest opening therein, the bottom orifice 95 has the largest opening, while the middle orifices of check valves 92 and 94 have intermediate-size openings
  • the inlet 96 preferably has no actual orifice
  • FIG 6a Shown in FIG 6a is a drawing of the computer analysis of a radial-flow filter structure utilizing such type of orifices and the effect thereof on the porous media located in the annular area between the inner perforated cylinder 54 and the outer perforated cylinder 60
  • a first orifice structure 90 and a second orifice structure 92 are shown fixed within the inner perforated cylinder 54
  • the inner perforated cylinder 54 has a major internal area thereof covered by a bladder 100
  • the bladder 100 can be a durable sheet-like elastome ⁇ c material bonded or otherwise adhered to the inner surface of the perforated cylinder 54
  • the bladder 100 covers the perforations and obstructs the flow of liquid therethrough
  • the orifices 90 and 92 restrict the flow of the backwash liquid m the inner perforated cylinder 54 and give rise to drag forces on the porous media It can be appreciated that the porous media can be displaced axially upwardly during the backwashing operation, only if the drag forces are greater than the buoyant weight of the porous media itself
  • the magnitude of the axial components of the liquid velocities identify the regions where the drag forces can exceed the buoyant weight of the porous media
  • the velocity vectors 108 of FIG 6a illustrate the dynamics of the fluid flow and drag forces at one instant of time In the porous media generally shown in media section
  • the velocity vectors 108 are directed generally in an upward direction Assuming that the top of the porous media is as shown in FIG 6a, then the buoyant weight of the porous media is the least at this location, with respect to the drag forces produced thereon as a result of the orifice 90
  • the drag forces can be made to exceed the buoyant weight of the porous material
  • the porous material is lifted upwardly and removed from the filtration chamber 58 to the backwash chamber 62
  • the velocity vectors 1 1 1 just above the region 1 12 are directed downwardly This downward force on region 1 12 prevents the entire column of the media from being lifted as a plug
  • the velocity vectors 1 1 1 just above the region 1 12 are directed downwardly This downward force on region 1 12 prevents the entire column of the media from being lifted as a plug
  • FIG 6b is a partial cross-sectional view of the radial flow filter equipped with an annular band 1 16, or the like, between the outer perforated cylinder 60 and the housing 52 of the filter assembly
  • annular band 1 16 can be constructed integral with the inside wall of the filter assembly housing 52, or integral with the outer sidewall of the outer perforated cylinder 60
  • FIG 7 illustrates the flow of the liquid stream during the backwash operation
  • the porous media of the top section has already been transported by fluidizing
  • a vertical cross-section of the filter is illustrated, where the inner perforated cylinder is equipped with five orifices with decreasing radii
  • the heavy and darkened areas illustrate the heavy flow of the backwash liquid, while the individual wavy lines show areas of reduced flow of the backwash liquid
  • the upper section of the porous media 56 has been fluidized, while the lower sections of the porous media bed are exposed to drag forces that are less than the buoyant weight of the overlying media, whereby no fluidization is yet occurring
  • a radial-flow filter can be structured to provide fluidization of the porous material without requiring excessively high pressures or otherwise compromising the efficiency of the filtration operation
  • the filter was structured as follows Five orifices were employed, with radii ranging from 0 254 inches to 1 047 inches
  • the general diameter of the granular particles were between 44-840 microns, with a specific gravity of 2 5, which is very similar to that of sand
  • the radius of the inner perforated cylinder 54 was 0 75 inches, with perforations comprising an open area of 66 percent
  • the annular dimensions of the filtration chamber containing the porous media was 0 80 inches (radial) by 22 625 inches (axial)
  • the flow rate or pressure of the liquid media was between 3 gpm to 28 gpm
  • the backwash pressure was in the range of 0 5 kPa to 10 0 kPa With a filter constructed as such, it is contemplated that the porous media can
  • the filter assembly 136 includes an enclosed case 138 for containing and supporting therein the filter parts and components
  • the case 138 includes a cylindrical sidewall 140 fixed between a top end cap 142 and a bottom end cap 144
  • the internal volume of the case 138 is sealed to the influent that is coupled to the filter 120 by way of inlet connection 128, except for one or more ports 70 formed in the sidewall 140 thereof
  • Each port 70 includes a check valve for allowing the influent to enter into the case 138, but prevents liquid from passing in the reverse direction
  • the case 138 can be constructed of different types of plastics or metals to suit the particular needs of the filtration system For filtering impurities from water and similar liquids, under low-pressure conditions, the case 138 can be constructed with a PVC or polyethylene plastic In this event, the end caps 142 and 144 can be bonded, welded or otherwise secured to the cylindrical sidewall 140 Where higher pressures or caustic liquids are employed, such as chemicals to be filtered, the case
  • a pair of perforated cylinders An inner perforated cylinder 54 is supported within respective holes formed in the top end cap 142 and the bottom end cap 144 Moreover, the inner perforated cylinder 54 is supported by a bottom filter chamber end cap 146
  • the parts can be bonded, threaded or otherwise fixed together for permanent or removable attachment
  • Secured around the outer circumference of the inner perforated cylinder 54 is a screen mesh 148
  • the screen mesh can be of a synthetic or metallic material having a porosity sufficiently small to prevent passage therethrough of the granular particles comprising the porous media or filter bed
  • Fixed within the inner perforated cylinder 54 is a plug 64 to provide an obstruction so as to prevent liquid passage axially along the inner perforated cylinder 54
  • FIG 8 includes plural check valves, one shown as reference character 150 It is contemplated that check valves with orifices will be the preferable structure
  • the check valves 150 each include a seat, and a ball constructed of a synthetic material so as to be buoyant on the liquids
  • the check valve 150 includes one or more orifices, and will be described in more detail below Nevertheless, the check valves 150 are open during the filtration operation, but are generally closed, except for the orifice formed therein during the backwash operation In this manner, the restriction to the fluid flow during the filtration operation is eliminated
  • An outer perforated cylinder 60 is fastened at a bottom end thereof to the filter chamber end cap 146 At the upper end, the outer perforated cylinder 60 is fixed to an annular-shaped piece 152 and bonded or otherwise fastened to the internal surface of the filter assembly case 140
  • the outer perforated cylinder 60 has attached to the inside surface thereof a screen mesh 154 that serves the same function as the screen mesh 148
  • the annular space between the outer perforated cylinder 60 and the inner perforated cylinder 54 defines a filtration chamber 156
  • the filtration chamber 156 is filled with a porous media, such as granular particles for removing impurities from an influent Located above the filtration chamber 156 is the backwash chamber 62
  • the backwash chamber is about the same volume as the filtration chambei 156 although it may be of a larger volume
  • the backwash chamber 62 has a larger radial dimension than the filtration chamber 156 This difference in radial dimensions is believed to impart a
  • the influent is directed in the following path From the inlet connection 128, the influent is forced into the space 160 that surrounds the filter assembly case 138 The influent is then forced into the port 70 via the check valve in the sidewall of the filter assembly case 138 Once the influent is forced through the check valve port 70, it fills the annular chamber 162 and completely surrounds the outer surface of the outer perforated cylinder 60 The influent then passes radially through the porous filter media 58 where the impurities are removed The filtered influent then passes through the perforations of the inner perforated cylinder 54 and into the internal volume 164 of the inner perforated cylinder 54 The filtered influent then passes through the opened check valves 150 and exits at the bottom of the filter 120 to the outlet connection 132 The radial flow aspect allows a large surface area of the porous media 58 to be exposed to the influent This process continues until the pressure rises at the inlet of the filter 120, denoting that the porous media 58 has accumulated a sufficient amount of impurities that the filtration
  • the approp ⁇ ate valves are activated, whereby a backwash liquid is forced into the connection 132
  • the flow path of the liquid is effective to remove the impurities from the porous material 58 and carry the impurities with the backwash liquid out of the filter via the connection 128
  • the backwash liquid is forced into the connection 132 and up into the central part 164 of the inner perforated cylinder 54 I he check valves 150 close, except for the small orifices formed therein In this manner, the flow of the backwash liquid encounters successively smaller orifices, thereby facilitating the fluidizing of the granular particles, as described above
  • Each section of the porous media 58 in the filtration chamber I 56 becomes fluidized and carried up into the backwash chamber 62 In the backwash chamber 62 the swirling and agitation action imparted to the granular particles 58 frees the impurities therefrom
  • the impurities flow from the backwash chamber 62 into the central area 166 of the inner perforated
  • FIG 9 illustrates one embodiment of the check valves 150 fixed within the inner perforated cylinder 54
  • the check valve 150 is constructed with a plate 170 having a primary hole 172 that can be plugged with a spherical-shaped ball 174
  • the ball 174 is preferably constructed of a plastic or similar material that is buoyant
  • the individual check valve balls may be of different buoyant weights While not shown, those skilled in the art may prefer to maintain the ball 174 within a wire cage, or the like, to prevent the ball from falling downwardly and inadvertently stopping the hole in the check valve plate located therebelow
  • Also formed within the plate 170 are one or more orifices 176 that are not plugged or otherwise stopped by the check valve ball 174
  • the orifices 176 function much like those noted above in connection with FIG 3 and identified as reference numeral 66 Again, the cumulative open area of each of the orifices 176 of one check valve plate 170 are preferably different from that of the other check valve plates fixed within the inner perfor
  • FIG 10 illustrates another embodiment of a check valve plate 180 that can be fixed within the inner perforated cylinder 58 Rather than having the apertures 176 shown in FIG 9, the check valve plate 180 of FIG 10 includes a roughened or serrated edge 182 to prevent the ball 174 from seating m a sealed manner to the plate 180
  • the irregular-shaped seat 182 of the plate 180 allows liquid to pass therethrough even when the ball 174 is forced within the hole of the plate 180
  • FIGS 1 1 and 12 illustrate a check valve that can be employed within sidewall
  • This check valve includes an elastomeric stopper 184 having a planar portion 186 and a stem portion 188 formed at the end of the stem 188 is a conical or enlarged end 190 that can be pressed through the anchor hole 183 in one direction during installation, but cannot be easily removed
  • fluid flow in the direction of arrow 192 causes the port holes 70 to be closed by the stopper flap 186, thereby preventing liquid flow through the filter assembly case 140.
  • FIG 13 illustrates another embodiment of the radial-flow filter constructed in accordance with the principles and concepts of the invention
  • the filter assembly 200 has structural features similar to that shown in FIG 8 With the construction of filter assembly 200, there are shown plural elastomeric O-rings 202 located between the outer perforated cylinder 60 and a cylindrical case 204 While four O-rings are shown in the embodiment of FIG 13, any number of O-rings may be utilized Each O-ring 202 provides a seal between the outer perforated cylinder 60 and the inner surface of the case 204.
  • the O-rings 202 function to change or modify the direction of the liquid flow inside the porous media 56 A substantial amount of the radial flow through the porous media 56 is changed to axial flow.
  • the filter assembly 200 is also shown to include the bladder 100
  • the bladder 100 can be used in combination, with or without the orifices in the check valve 150, as well as the O-rings 202
  • the bladder 100 functions to concentrate substantially all of the backwash liquid flow in the inner perforated cylinder 54 is directed to that area located directly beneath each check valve 150
  • the bladder 100 maximizes the amount of axial flow that exists in each porous media section
  • the bladder 100 is shown with the sidewall deformed inwardly in a concave shape, due to the fluid pressure exerted on the outer surface thereof during a filtration cycle
  • the filter assembly 200 includes a backwash outlet check valve 210
  • the outlet check valve 210 is placed in an unperforated portion of the inner cylinder 54, preferably near the bottom of the filter assembly 200
  • the outlet check valve 210 provides a flow path from the internal volume of the inner cylinder 54 to the annular volume 162 that exists between the case 204 and the outer perforated cylinder 60
  • the outlet check valve 210 allows for the backwash liquid to exit below the filtration chamber and be carried directly to the outside annular volume 162 without first having to pass through the porous media 56 Once entering the outside annular volume 162, the backwash liquid exits through either the leak holes 206 or out into the top backwash chamber 62 via the porous media 56
  • the outlet check valve 210 also functions to seal the inlet check valves 184 closed during backwashing This is helpful in situations where very small granular porous media 56 becomes packed with contaminants and allows small amounts of the backwash liquid to reach the outside annular volume 162
  • the outlet check valve 210 provides backwash liquid to the outside annular volume 162 and assists in the fluidization of the porous media 56 by the additional liquid diverted inwardly by the O- rings 202 into the porous media 56 It also produces a water scour to the outside annular volume 162 and significantly reduces the amount of backwash liquid required to remove the impurities from the porous media 56 This is because the larger impurities lodged in the screen mesh are flushed directly out of the leak holes 206, rather than being carried back into the porous media 56 and out through the backwash chamber 62 By discharging the larger impurities directly out of the leak holes 206, the particulate matter that would otherwise be too large to enter through the outer screen mesh covering the outer perforated cylinder 60 is completely removed As an alternative, all
  • the filter assembly 200 of FIG 13 provides additional features which may be considered optional, and in some circumstances may be necessary Those skilled in the art may find that in various situations, various individual features of the embodiments may be selected so as to produce optimum filtering and backwash results
  • the filter media 56 has been desc ⁇ bed above generally in connection with the removal of particulate matter or impurities, other types of media can be selected so as to remove dissolved solids, provide coaction between solids and fluids, provide coalescing capabilities and even provide a catalyst to the influent supplied to the filter
  • the filter constructed according to the principles and concepts of the invention provides an increased surface area for the radial flow of fluids through the media, whether or not it is used for filtering purposes, and provides for an efficient backwash for fluidizing the media
  • FIGS 14a and 14b illustrate another embodiment of the radial flow filter 220, incorporating a perforated bladder 222
  • the bladder is preferably made of a flexible elastomeric material suitably constructed to withstand the pressures encountered within the filter, as well as the type of influent and backwash fluids passed through the filter 220
  • the bladder 222 may be constructed as a tubular member
  • a rigid plate 224 functions as the blocking obstruction within the inner perforated cylinder 54
  • the bladder 222 includes a pattern of perforations 226 functioning as orifices 1 he orifices 226 formed in the bladder 222 adjacent a top section 80 of the filter media 56 functions to enable fluidization during a backwash cycle
  • the orifices 226 can be located annularly around the upper section of the bladder 222 Associated with a second section 82 of the porous media 56, are an additional set of orifices 228 formed in the bladder 222 Associated with a second section 82 of the porous media 56, are an additional set of orifices 228 formed in the bladder 222 Associated with a second section 82 of the porous media 56, are an additional set of orifices 228 formed in the bladder 222 Subsequent sets 230-236 of orifices are formed in the bladder 222
  • the open area of each set 226-236 of orifices is larger, as a function of distance away from the plate 224 As such, the sets of orifices function very much like that described above in conjunction with the or
  • FIG 14a illustrates the radial flow filter assembly 220 during the filter cycle
  • the influent enters the assembly 220 in the direction of arrow 240 and enters the column of the porous media 56 at the top thereof
  • a majority of the influent passes through the opened check valves 184 and flows radially through the respective sections of the porous media 56
  • Each section is separated by a respective o- ring 202 for facilitating fluidization during the backwash cycle
  • the sidewall of the bladder 222 is forced inwardly, as shown in FIG. 14a While some of the filtered influent passes through the various sets of orifices during the filtration cycle, a majority of the influent passes through the set of large orifices 236 and out of the filter assembly, shown by arrow 242.
  • FIG. 14a While some of the filtered influent passes through the various sets of orifices during the filtration cycle, a majority of the influent passes through the set of large orifices 236 and out of the filter assembly, shown by arrow 242.
  • FIGS. 14b illustrates the filter assembly 220 during a backwash cycle
  • the backwash fluid enters the assembly in the direction of arrow 244.
  • the backwash liquid enters the inner volume of the bladder 222, thus pressing it against the inside surface of the inner perforated cylinder 54.
  • the backwash liquid is forced through the sets of orifices, as noted by arrows 246.
  • the backwash fluid then flows into the porous media 66 for fluidization thereof in the manner noted above
  • the check valves 184 are closed during the backwash cycle for facilitating sequential fluidization of the various sections of the porous media 56.
  • the backwash fluid carries the impurities and the released particles out of the filter assembly 220 in the direction noted by arrow 248.
  • FIG 15a and 15b illustrate another embodiment of the radial-flow filter that operates in an inverted manner This embodiment is particularly well suited for use with granular beads that are either large or generally lightweight.
  • a porous media setting liquid which is preferably not the influent, is pumped into the filter assembly 250 in the direction of arrow 252
  • the drag forces imparted from the setting fluid to the porous media 56 caused the beads to be lifted upwardly into the top portion of the filter chamber.
  • Each check valve 150 fixed withing the inner perforated cylinder 54 in the backwash chamber 62 is closed, while the check valves 150 situated in the filtration chamber are opened
  • a valving arrangement (not shown) is actuated to thereby allow the influent to pass into the filter assembly 250 in the direction noted by arrow 252.
  • the influent is allowed to pass through the open inlet check valves 184 in the direction of arrows 254.
  • the influent passes radially through the media 56 and into the internal volume of the inner perforated cylinder 54, via the opened check valves 150.
  • the filtered influent then exits the assembly 250 in the direction noted by arrow 256.
  • FIG 15b illustrates the inverted filter assembly 250 during a backwash cycle
  • the porous media 56 is simply allowed to settle bv w av of gravity into the filter chamber located at the bottom of the assembly
  • the granular particles are separated and the impurities are removed therefrom
  • the particulate matter and impurities pass through the opened check valves within the lower portion of the inner perforated cylinder 54 and are carried out of the assembly 250 by the backwash liquid, in the direction of arrow 260.
  • the backwash liquid entering the assembly 250 in the direction of arrow 262 causes sequential fluidization of the sections in the manner described above.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Filtration Of Liquid (AREA)
  • Infusion, Injection, And Reservoir Apparatuses (AREA)
  • External Artificial Organs (AREA)

Abstract

Filtre à écoulement radial (120) utilisant des particules granulées non liées (56) pour filtrer un influent et en éliminer les impuretés; le filtre peut être nettoyé à contre-courant par fluidisation des particules granulées (56) pour en éliminer les impuretés. Lors du nettoyage à contre-courant, un liquide de lavage à contre-courant exerce une force de traînée dirigée vers le haut sur une portion supérieure des particules granulées (56), ce qui fait remonter ces dernières dans la chambre de lavage à contre-courant (62), où elles sont fluidisées. Dès que la portion supérieure des particules granulées (56) du lit de filtrage a été fluidisée, le liquide de lavage à contre-courant exerce une force dirigée vers le haut sur la portion suivante du lit fluidisé, ce qui a pour effet de fluidiser les particules granulées (56) dans la chambre de lavage à contre-courant (62). On fluidise les sections suivantes du lit granulé de manière semblable afin de nettoyer complètement les particules granulées (56). Après le lavage à contre-courant, les particules granulées (56) retombent dans la chambre de filtrage (156) pour former un lit filtrant utilisé dans l'opération de filtrage.
EP97930996A 1996-05-23 1997-05-23 Filtre fluidisable a ecoulement radial Withdrawn EP0909207A4 (fr)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
US1816896P 1996-05-23 1996-05-23
US18168P 1996-05-23
US2367996P 1996-08-17 1996-08-17
US23679P 1996-08-19
PCT/US1997/008942 WO1997044111A1 (fr) 1996-05-23 1997-05-23 Filtre fluidisable a ecoulement radial

Publications (2)

Publication Number Publication Date
EP0909207A1 true EP0909207A1 (fr) 1999-04-21
EP0909207A4 EP0909207A4 (fr) 2000-10-04

Family

ID=26690813

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Application Number Title Priority Date Filing Date
EP97930996A Withdrawn EP0909207A4 (fr) 1996-05-23 1997-05-23 Filtre fluidisable a ecoulement radial

Country Status (7)

Country Link
EP (1) EP0909207A4 (fr)
CN (1) CN1080131C (fr)
AU (1) AU715029B2 (fr)
CA (1) CA2256385C (fr)
HK (1) HK1022114A1 (fr)
MX (1) MXPA98010890A (fr)
WO (1) WO1997044111A1 (fr)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6852232B2 (en) * 1996-05-23 2005-02-08 John D. Martin Down flow radial flow filter
US9718004B2 (en) 2011-10-03 2017-08-01 Ishigaki Company Limited Filter medium layer and filter device provided with same
NL1041872B1 (nl) * 2016-05-18 2017-11-30 Waterslag B V Inrichting en werkwijze voor het filteren van een verontreiniging uit een vloeistof, tevens werkwijze voor het regenereren van zo een inrichting
IT201700103653A1 (it) * 2017-09-15 2019-03-15 Filippo Bussinelli Apparecchiatura di filtraggio per la filtrazione di liquidi
CA3075447A1 (fr) * 2017-09-15 2019-03-21 Filippo Bussinelli Appareil pour le filtrage de liquides
CN114570109B (zh) * 2022-05-09 2022-07-19 北京市一滴水环保科技有限公司 复合滤芯组件、沉淀过滤池及复合滤芯组件的反洗方法

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4019985A (en) * 1975-07-30 1977-04-26 Texaco Inc. Methods for fluidizing a filter media
US4643836A (en) * 1985-10-01 1987-02-17 Schmid Lawrence A Radial flow filter having air fluidizing backwash means

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL17673C (fr) * 1924-10-01
US4021339A (en) * 1973-05-24 1977-05-03 Patrick Foody Water filter
US4185466A (en) * 1978-05-22 1980-01-29 Grumman Aerospace Corporation Partial pressure condensation pump

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4019985A (en) * 1975-07-30 1977-04-26 Texaco Inc. Methods for fluidizing a filter media
US4643836A (en) * 1985-10-01 1987-02-17 Schmid Lawrence A Radial flow filter having air fluidizing backwash means

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of WO9744111A1 *

Also Published As

Publication number Publication date
AU715029B2 (en) 2000-01-13
AU3473997A (en) 1997-12-09
CN1226182A (zh) 1999-08-18
MXPA98010890A (es) 2004-05-21
EP0909207A4 (fr) 2000-10-04
CN1080131C (zh) 2002-03-06
CA2256385C (fr) 2005-12-06
HK1022114A1 (en) 2000-07-28
WO1997044111A1 (fr) 1997-11-27
CA2256385A1 (fr) 1997-11-27

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