Abstract:
An apparatus and method for removing soluble and particulate matter from a liquid. The liquid is introduced into a lower section of the apparatus and develops an upward helical flow. The vertical component of the helical flow is decreased in a conical section. The liquid then passes through fluidized bed media where an interaction between the liquid and the fluidized bed media can occur. The liquid may be passed through a system that removes suspended solids.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    None. 
       BACKGROUND OF THE INVENTION 
       [0002]    In the treatment of water, it is known in the industry to use conical sludge blanket clarifiers (CSBC) for clarification and cold lime softening applications. CSBCs incorporate a cylindrical inlet flow device located at the bottom of an inverted conical vessel. Liquid enters the cylindrical inlet flow device at multiple tangential inlet ports which creates an upward helical liquid flow pattern. In its typical operation, a CSBC contains a sludge blanket of suspended solids within the inverted conical vessel. 
         [0003]    It is also known in the industry to use fluidized bed biological reactors (FBBR) containing sand media to treat wastewater. FBBRs containing sand media having a high specific surface area per unit volume of media (M 2 /m 3 ) which provides for high biomass concentrations, hence high biological loadings. FBBRs have influent distribution systems which must achieve uniform distribution of influent liquid flow across the entire reactor area, prevent plugging and media escape, minimize abrasive wear, and minimize shearing of biomass above the influent distribution manifold. Typical influent distribution systems include a header manifold, lateral pipes branching from the header manifold, and nozzles attached to the lateral pipes pointing down towards the bottom of the reactor. The liquid flow pattern within FBBRs is primarily vertical from the influent distribution systems to the overflow collectors. 
         [0004]    It is also known in the industry to use fluidized bed chemical reactors (FBCR) to remove calcium compounds, such as calcium carbonate, from low magnesium raw waters. FBCRs typically have inverted conical configurations with very steep sidewalls. The fluidized bed media used in FBCRs often consists of fine sand. FBCRs have tangential inlet ports which creates an upward helical liquid flow pattern. 
         [0005]    CSBCs do not provide an ion exchange process, which can further purify and decontaminate liquids. With fluidized bed reactors, any suspended solids contained in the inlet liquid and any suspended solids generated within the reactor will be contained in the outlet liquid. Typically, the suspended solids must be removed in a separate process that follows the fluidized bed reactor. In fluidized bed reactors utilizing ion exchange, high concentrations of non-target ions will often be discharged in the outlet liquid as the fluidized bed becomes saturated with the target ions. 
         [0006]    Accordingly, a need exists for an apparatus and method that can remove suspended solids as well as effecting a fluidized bed media. A need also exists for a fluidized bed reactor that allows for the reduction of non-target ion concentration spikes. A further need exists for a fluidized bed reactor that has enhanced reaction kinetics, which leads to shorter detention times, smaller vessels, and lower costs. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention is directed to a fluidized bed apparatus that provides removal of various contaminants using fluidized bed media in addition to the removal of suspended solids. In accordance with one embodiment of the invention, a fluidized bed reactor includes a lower section effecting a rotational flow component, a generally conical middle section, an upper section containing fluidized bed media, and optionally a means for removing particular matter. A tangential inlet port preferably feeds, liquid into the lower section to assist in developing an upward helical liquid flow pattern in the middle section. The Fluidized bed media may be used to perform an ion exchange process or a variety of other processes for removing contaminants. 
         [0008]    The present invention is also directed to a method of removing soluble and particulate matter from a liquid including the steps of introducing a liquid into a first vessel in a manner creating an upward helical flow of the liquid, discharging the liquid from the first vessel in a generally conical second vessel that overlies the first vessel therefore causing a decrease in the vertical velocity component of the generally helical flow as the liquid moves up through the second vessel, and passing the liquid generally upward through a fluidized bed media that is located above the second vessel and formulated to remove selected contaminants from the liquid. 
     
    
     
       DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0009]    In the accompanying drawings: 
           [0010]      FIG. 1  is a cross-sectional elevational view of the fluid bed apparatus containing a vertical velocity component means for removing particulate matter and a flow collection system in accordance with one embodiment of the present invention; 
           [0011]      FIG. 2  is a cross-sectional elevational view of the fluid bed apparatus containing a flow collection system in accordance with one embodiment of the present invention; 
           [0012]      FIG. 3  is a cross-sectional elevational view of the fluid bed apparatus containing a means for removing particulate matter utilizing a gravity sedimentation device and a flow collection system in accordance with one embodiment of the present invention; 
           [0013]      FIG. 4  is a cross-sectional elevational view of the fluid bed apparatus containing a means for removing particulate matter utilizing a buoyant granular media filter and a flow collection system in accordance with one embodiment of the present invention; and 
           [0014]      FIG. 5  is a cross-sectional elevational view of the fluid bed apparatus containing a means for removing particulate matter utilizing a submerged membrane filtration device in accordance with one embodiment of the present invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0015]    The present invention is directed toward a fluidized bed reactor  10  and method for removing soluble and particulate matter from a liquid. As shown in  FIG. 1 , a fluidized bed reactor  10  constructed according to one embodiment of the invention includes a lower section  12 , a middle section  14 , and an upper section  16 . 
         [0016]    The lower section  12  includes a wall  18 , an upper end  20 , and a lower end  22 . In one embodiment, the lower section wall  18  is generally cylindrical. However, it will be appreciated by those skilled in the art that the lower section wall  18  can alternatively be constructed in other geometries, including a generally conical configuration. Tangential inlet ports  24 ,  26  allow untreated liquid to be fed into the lower section  12 . As illustrated in  FIGS. 1-5 , one inlet port  24  may be larger than another inlet port  26 . However, it will be appreciated by those skilled in the art that the inlet ports  24 ,  26  may also be the same size. While two tangential inlet ports  24 ,  26  are shown in  FIGS. 1-5 , the present invention could include a single inlet port  24  or more than two inlet ports  24 ,  26 . 
         [0017]    The inlet ports  24 ,  26  are positioned tangential to the inner surface of the lower section wall  18 . A tangential positioning of the inlet ports  24 ,  26  in the lower section  12 , along with the removal of liquid from the upper section  16 , serves to develop an upward helical flow of the liquid in the lower section  12  and the middle section  14 . The helical flow may also continue into the upper section  16 . The helical flow results in the liquid traveling in an elongated flow path. 
         [0018]    Flow directing vanes  28  may be provided to be in communication with the inlet ports  24 ,  26 . The flow directing vanes  28  can be adjusted to vary the inlet velocity of liquid into the lower section  12 . As illustrated in  FIGS. 2-5 , the lower section  12  may also include an inlet service nozzle  30 . The inlet service nozzle  30 , which is capable of producing a high velocity liquid flow, can be used to assist the inlet ports  24 ,  26  in re-suspending the fluidized bed media  48  should the fluidized bed media  48  settle into the lower section  12 . Also, as illustrated in  FIGS. 2-5 , the lower section  12  may include an outlet port  32  proximate its lower end  22  that can be used to remove heavy grit. 
         [0019]    The middle section  14  includes a wall  34 , an upper end  36 , and a lower end  38 . In one embodiment, the middle section wall  34  is generally conical and extends upwardly and outwardly from the lower section upper end  20  to the upper section lower end  46 . The primary function of the middle section  14  is to reduce the vertical velocity vector of the upward helical liquid flow. As the liquid rises in its upward helical path through the generally conical middle section  14 , it spreads to fill the increasing cross-sectional area of the middle section  14 . This results in a corresponding decrease in the vertical velocity vector of the liquid traveling through the middle section  14 , while the net flow rate of the liquid through the middle section  14 , as well as the net flow rate of the liquid through the entire reactor  10 , remains constant. 
         [0020]    The vertical velocity of the liquid continues to decrease until it reaches a portion of the reactor  10  having a constant cross-sectional area. Proximate the upper section lower end  46 , the vertical velocity of the liquid is generally equal to the velocity required to keep the fluidized bed media  48  in section  16  suspended. In other words, the lifting force of the liquid and the counteracting gravitational force on the fluidized bed media  48  are in equilibrium. The vertical velocity that is required to keep the fluidized bed media  48  suspended is a function of multiple factors, including the density, shape, and size of the fluidized bed media  48 , as well as the temperature, density, and viscosity of the liquid being treated. 
         [0021]    In one embodiment, the middle section wall  34  is inclined at an angle of 40 to 60 degrees from the horizontal to provide for the proper rate of decrease in the vertical velocity of the liquid and to prevent the fluidized bed media from settling and accumulating on the wall  34 . Depending upon the vertical velocity of the liquid, there can be fluidized bed media  48  contained in the middle section  14 , as well as the upper section  16 . As shown in  FIGS. 2-5 , the middle section  14  may also include an access plate  40  through which the reactor  10  can be inspected, maintained, and cleaned. 
         [0022]    The upper section  16  includes a wall  42 , an upper end  44 , and a lower end  46 . In one embodiment, the upper section wall  42  is generally cylindrical. However, it will be appreciated by those skilled in the art that the upper section wall  42  can alternatively be constructed in other geometries, including square, rectangular, or generally conical configurations. When the upper section wall  42  is generally conical, or configured in any other geometry having an increasing cross-sectional area, the vertical velocity of the liquid traveling through the upper section  16  will continue to decrease until it reaches a point where the cross-sectional area of the of the upper section  16  is no longer increasing and becomes constant. 
         [0023]    As illustrated in  FIGS. 2-5 , the upper section contains fluidized bed media  48 . The fluidized bed media  48  may be used to perform an ion exchange process. The fluidized bed media  48  may remove soluble ions, molecules, and/or other compounds from the liquid through biological, physical, or chemical processes. The material of the fluidized bed media  48  may be selected from a group consisting of granular activated carbon, ion exchange resin, sand, combinations thereof, or any other material suitable for use in the present invention now known or hereafter developed. As previously discussed, the fluidized bed media  48  is suspended in the upper section  16  (and in some cases the middle section  14  as well) by the lifting force of the liquid, which counteracts the gravitational force on the fluidized bed media  48 . 
         [0024]    It is desirable to have the ability to replace, regenerate, and/or rejuvenate the fluidized bed media  48  while the reactor  10  is in use. In order to replace, regenerate, and/or rejuvenate the fluidized bed media  48 , the reactor must include a means for removing fluidized bed media and a means for adding fluidized bed media. As shown in  FIGS. 2-5 , the upper section  16  may contain a fluidized bed media outlet port  66  and  68  and a fluidized bed media inlet port  68  and  66 . These ports  66 ,  68  may be located between the upper section upper and lower ends  44 ,  46 . The upper section  16  may also contain a submerged hopper  70  having an upper end  72 , a lower end  74 , an overflow dam  76  proximate the upper end  72 , and a fluidized bed media outlet port  78  proximate the lower end  74 . The submerged hopper  70  provides a location where the fluidized bed media  48  can consolidate prior to removal from the reactor  10 . The overflow dam  76  is located at a height equal to the maximum desirable upper level of the fluidized bed media  48 . The level of the fluidized bed media  48  can be continuously monitored by a level sensor  86 . 
         [0025]    One of the events triggering removal of fluidized bed media  48  from the reactor  10  occurs when the fluidized bed media  48  reaches a level above its maximum desirable upper level. Again, the overflow dam  76  is located at a height equal to the maximum desirable upper level of the fluidized bed media  48 . Once the fluidized bed media  48  reaches a level above the overflow dam  76 , the fluidized bed media  48  can enter the region directly above the hopper  70 . In this region directly above the hopper  70 , the vertical velocity of the liquid is decreased due to the hopper  70  deflecting the upward flow of the liquid. This decrease in vertical velocity results in the liquid having a vertical velocity less than that required to keep the fluidized bed media  48  suspended. In other words, in the region directly above the hopper  70 , the lifting force of the liquid is less than the counteracting gravitational force on the fluidized bed media  48 . Therefore, the fluidized bed media  48  descends into the hopper  70 . Once the fluidized bed media  48  is in the hopper  70 , it can be removed through the hopper&#39;s outlet port  78 . 
         [0026]    As illustrated in  FIGS. 2-5 , the reactor  10  can also contain sample lines  80 . The sample lines  80  have inlet ports  82  and outlet ports  84 . The sample lines  80  are used to obtain samples of fluidized bed media  48 . While two sample lines  80  are shown in  FIGS. 2-5 , the present invention could include a single sample line  80  or more than two sample lines  80 . If the reactor  10  contains two or more sample lines  80 , the sample line inlet ports  82  can be located at multiple elevations within the fluidized bed media  48 , as shown in  FIGS. 2-5 . The sample line outlet ports  84  are located outside of the middle section  14  near ground level for access by a user. 
         [0027]    The upper section  16  can also include a means  50  for removing particulate matter, such as suspended solids, from the liquid. As shown in  FIG. 3 , the means  50  for removing particulate matter  50  can be a gravity sedimentation device  52 . The gravity sedimentation device  52  can include tube settlers. The tube settlers can be positioned parallel to each other and at an incline between 30 and 60 degrees from horizontal. For applications requiring the use of expensive fluidized bed media  48 , tube settlers can be used to minimize the loss of the fluidized bed media  48 . In an alternative embodiment, the gravity sedimentation device  52  can make use of multiple flat sheets that are positioned parallel to each other at an incline between zero and 60 degrees from horizontal. 
         [0028]    As shown in  FIG. 4 , the means for removing particulate matter  50  can include a buoyant granular media filter  54 . The buoyant granular media has a specific gravity less than the specific gravity of the liquid in the reactor  10 . The material of the buoyant granular media may be selected from a group consisting of polyethylene, polystyrene, polypropylene, pumice, combinations thereof, or any other material suitable for use in the present invention now known or hereafter developed. When a buoyant granular media filter  54  is used, the buoyant granular media is retained by an overlying retaining screen  56 . The retaining screen  56  should have openings smaller than the nominal size of the buoyant granular media. 
         [0029]    The buoyant granular media  54  may require occasional backwashing. The backwashing is accomplished by diverting outlet flow from the primary outlet  64  to a secondary outlet  65  and adding air uniformly through an air distribution grid  58  located beneath the granular media filter  54 . 
         [0030]    As shown in  FIG. 5 , the means for removing particulate matter  50  can include a submerged membrane filtration device  60 . The submerged membrane filtration device  60  allows liquid to pass through it but retains particulate matter from passing. The submerged membranes may include hollow fibers having diameters less than ¼ inch. Both ends of the hollow fibers may be connected to the filtration device  60  such that the treated liquid can be collected and passed from the filtration device  60  through the outlet  64 . The submerged membrane filtration device  60  can also include a submerged membrane that is configured in a flat sheet arrangement with a void between two sheets where the clarified liquid can be collected and passed from the filtration device  60  through the outlet  64 . 
         [0031]    The reactor  10  can also include a flow collection system  62  ( FIGS. 1-4 ) proximate the upper section upper end  44 . The flow collection system  62  may collect the liquid passing through the reactor and direct it to a common collection point outside of the reactor  10 . The flow collection system  62  can include a plurality of radial troughs, a plurality of parallel troughs, or a manifold header with a plurality of lateral troughs. 
         [0032]    Several treatment processes can be achieved within the fluidized bed reactor  10  of the present invention, including biological processes, ion exchange processes, physical adsorption processes, and chemical precipitation processes. The biological processes can include the anoxic de-nitrification of waters containing nitrates. The ion exchange processes can include the ion exchange of soluble ions, molecules, or compounds on synthetic or natural ion exchange media. For example, one ion exchange process involves the removal of disinfection by-product precursors from waters. The physical adsorption processes can include the physical adsorption of soluble ions, molecules, or compounds on the surface of adsorbents. For example, one physical adsorption process involves the removal of soluble organic contaminates upon activated carbons. The chemical precipitation processes can include the chemical precipitation upon inert media. For example, one chemical precipitation process involves cold lime softening for the removal of calcium such as calcium carbonate. 
         [0033]    From the foregoing, it will be seen that this invention is one well adapted to attain all the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure. It will be understood that certain features and sub combinations are of utility and may be employed without reference to other features and sub combinations. This is contemplated by and is within the scope of the claims. Since many possible embodiments of the invention may be made without departing from the scope thereof, it is also to be understood that all matters herein set forth or shown in the accompanying drawings are to be interpreted as illustrative and not limiting. 
         [0034]    The constructions described above and illustrated in the drawings are presented by way of example only and are not intended to limit the concepts and principles of the present invention. Thus, there has been shown and described several embodiments of a novel invention. As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. The terms “having” and “including” and similar terms as used in the foregoing specification are used in the sense of “optional” or “may include” and not as “required”. Many changes, modifications, variations and other uses and applications of the present construction will, however, become apparent to those skilled in the art after considering the specification and the accompanying drawings. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow.