Abstract:
A casing defines a cavity having a top, a bottom and front and rear ends. The casing is configured to conduct a liquid along a flow path through the cavity from the front end to the rear end. A holding structure, in the cavity, defines a chamber that can be filled with coalescing media. The holding structure has a top passageway through which the liquid can flow downwardly into the chamber and a rear passageway through which the liquid can flow rearwardly out of the chamber. Blocking structures constrain the flow path to extend through the top passageway into the chamber.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a division of U.S. application Ser. No. 10/614,156, filed Jul. 7, 2003, incorporated herein by reference, which claims the benefit of U.S. Provisional Application No. 60/448,326, filed Feb. 19, 2003. 
     
    
     TECHNICAL FIELD  
       [0002]     The present invention relates to water clarification and oil-water separators.  
       BACKGROUND  
       [0003]     A water clarification system can be an oil-water separator used to separate contaminants from water. The water is typically rain runoff from a parking lot. The contaminants are typically oil, sludge and gravel. The separator may be buried in the ground. In operation, a mixture of the water and the contaminants enters the separator. The water exits the separator, while the contaminants are retained by and in the separator. The contaminants may be manually removed from the separator by way of manholes located along the top of the separator.  
       SUMMARY  
       [0004]     An apparatus comprises a casing defining a cavity having a top, a bottom and front and rear ends. The casing is configured to conduct a liquid along a flow path through the cavity from the front end to the rear end. A holding structure, in the cavity, defines a chamber that can be filled with coalescing media. The holding structure has a top passageway through which the liquid can flow downwardly into the chamber and a rear passageway through which the liquid can flow rearwardly out of the chamber. Blocking structures constrain the flow path to extend through the top passageway into the chamber.  
         [0005]     Preferably, the blocking structures include a lower blocking structure extending from a front end of the top passageway down to the bottom of the cavity. The blocking structures further include an upper blocking structure extending upward from a rear end of the top passageway. Liquid can bypass the chamber through a bypass passageway in the cavity only when the liquid is above a predetermined level. The holding structure includes a frame connected to the casing and a porous basket extending downward from the frame.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]      FIG. 1  is a perspective view of an embodiment of the present invention;  
         [0007]      FIG. 2  is a side sectional view of the embodiment of  FIG. 1 ;  
         [0008]      FIG. 3  is a perspective view of a part shown in  FIG. 1 ;  
         [0009]      FIG. 4A  is a sectional view of other parts shown in  FIG. 1 ;  
         [0010]      FIG. 4B  is a sectional view taken at line  4 B- 4 B of  FIG. 4A ;  
         [0011]      FIG. 5  is a perspective view of yet other parts shown in  FIG. 1 ; and  
         [0012]      FIG. 6  is a perspective view of a part shown in  FIG. 5 . 
     
    
     DESCRIPTION  
       [0013]     The apparatus  10  shown in  FIG. 1  has parts which, as described below, are examples of the elements recited in the claims.  
         [0014]     The apparatus  10  is a water-contaminant separator. The separator  10  is used to separate contaminants from a liquid. In this example, the liquid is water, such as rain runoff from a parking lot. The contaminants can be buoyant, such as oil and styrofoam debris, or sedimentary, such as sludge and gravel. The separator  10  includes a cylindrical casing  14 . In operation, a mixture of the water and the contaminants enters the casing  14  through an inlet structure  22 . The contaminants are initially either floating at the top of the water, settled at the bottom, or suspended in-between. A plate coalescer  26  and a media coalecser  30  within the casing  14  promote floating of the initially-suspended buoyant contaminants and settling of the initially-suspended sedimentary contaminants. As the water exits the tank structure  14  through an outlet structure  34 , baffles  38  of various types within the casing  14  retain the floating and settled contaminants in the casing  14 . The contaminants may be manually removed from the casing  14  through manways  41 ,  42  and  43  located along the top of the chamber  14 .  
         [0015]     The separator  10  is configured to operate in an installed orientation shown in  FIG. 2 , typically buried in the ground. The various features of the separator  10  are described as follows with reference to the installed orientation.  
         [0016]     The cylindrical casing  14  is centered on a horizontal axis  45 . The casing  14  has an inner surface  46  that surrounds the axis  45  to define a cavity  47 . In this example, the casing  14  comprises a cylindrical inner liner  50  surrounded by a corrugated wall  52  with circumferentially-extending corrugations  54 . The inner liner  50  defines the inner surface  46  of the casing  14 . Front and rear walls  56  and  58  cap the casing  14  at axially front and rear ends  66  and  68  of the cavity  47 .  
         [0017]     The cavity  47  has a top  70 , a bottom  72  and two opposite sides  74  and  76 . As indicated by arrows  79 , the chamber  14  is configured to conduct the mixture of the water and the contaminants rearward through the cavity  47  from the inlet structure  22  to the outlet structure  34 .  
         [0018]     The cavity  47  is divided by the baffles  38  into first, second, third and fourth compartments  81 ,  82 ,  83  and  84 , as shown in  FIG. 2 . In each compartment  81 ,  82 ,  83  and  84 , a portion of the initially-suspended contaminants rises upward or settles downward. The resulting floating and settled contaminants are inhibited by the baffles  38  from progressing along with water from one compartment  81 ,  82 ,  83  and  84  to the next.  
         [0019]     The outlet structure  34  comprises a horizontal tube  90  and a vertical tube  92  joined at an elbow junction  94 . The vertical tube  92  has an intake opening  96  within the fourth compartment  84 . The vertical tube  92  extends from the intake opening  96  upward to the junction  94 . The horizontal tube  90 , in turn, extends from the junction  94  axially rearward through the rear wall  58 .  
         [0020]     The horizontal tube  90  has a horizontal channel  97 . A bottom  99  of the horizontal channel  97  defines a nominal water line  101  within the cavity  47 . The nominal water line  101  corresponds to the surface of the water in a normal flow condition of the separator  10 . In this example, the nominal water line  101  coincides with the central axis  45  of the casing  14 . The intake opening  96  is located midway between the nominal water line  101  and the bottom  72  of the cavity  47 . This helps prevent both the floating and settled contaminants from exiting the cavity  47  through the intake opening  96 .  
         [0021]     Like the outlet structure  34 , the inlet structure  22  comprises a horizontal tube  110  and a vertical tube  112  joined at an elbow junction  114 . The horizontal tube  110  of the inlet structure  22  extends axially rearward through the front wall  56  to the elbow junction  114  within the first chamber  81 . The vertical tube  112  extends downward from the junction  114  and has a discharge opening  116  within the first compartment  81 .  
         [0022]     The horizontal tube  110  has a horizontal inlet channel  117  through which water flows rearward toward the junction  114 . The horizontal inlet channel  117  has a top  118  and a bottom  119 , both located above the nominal water line  101 . This impedes the water from draining out of the cavity  47  by way of the inlet structure  22 .  
         [0023]     The discharge opening  116  of the inlet structure  22  is submerged below the nominal water line  101 . Accordingly, the water spilling down from the horizontal inlet channel  117  hits the nominal water lines  101  inside the vertical inlet tube  112 . Most of the resulting turbulence is thus confined to within the vertical tube  112 , which reduces turbulence elsewhere within the cavity  47 . This is beneficial, because turbulence detrimentally impedes rising and settling of the contaminants.  
         [0024]     One of the baffles  38  is a transversely-extending (with respect to the axis  45 ) perforated weir  120 . The weir  120  is located rearward of the inlet structure  22  and separates the first compartment  81  from the second compartment  82 . As shown in  FIG. 3 , the weir  120  extends from the bottom  72  of the cavity  47  up to a horizontal top edge  122  of the weir  120 . The top edge  122  extends transversely and horizontally from one side  74  of the casing  14  to the other side  76 . The weir  120  thus defines a barrier to water flow bounded by the top edge  122  and the casing  14 .  
         [0025]     The top edge  122  of the weir  120  is located above the nominal water line, indicated in  FIG. 3  axially by the dashed line  101  and transversely by dashed line  127 . This prevents the mixture from floating over, and thus bypassing, the weir  120  under normal flow conditions. However, the top edge  122  is spaced below the top  70  of the cavity  47 , and, preferably, even lower than the top  118  of the horizontal inlet channel  117  ( FIG. 2 ). This provides an open section between the top edge  122  of the weir  120  and the top  70  of the cavity  47  through which the water can quickly flow, and bypass the weir  120 , during abnormally high flow conditions.  
         [0026]     The weir  120  consists of a perforated upper section  124  and a non-perforated lower section  126 . The perforated upper section  124  has two horizontal rows  128  of holes  129  located below the nominal water line  101 . The rows  128  are vertically overlapping. The holes  129  are separated from each other, with the holes  129  of one row  128  horizontally offset from adjacent holes  129  of the other row  129 . Accordingly, the holes  129  of one row  128  are interleaved with, and staggered relative to, the holes  129  of the other row  128 . This enables compact packing of the holes  129 . The holes  129  are fluid flow apertures configured to pass water but not debris larger than the holes  129 . The perforated upper section  124  thus filters out larger contaminants from the water to retain them in the first compartment  81 , shown in  FIG. 2 .  
         [0027]     The lower section  126  is non-perforated to prevent even small sediment from passing from the first compartment  81  to the second compartment  82 . To this end, the weir  120  is free of fluid flow apertures  129  below a first level L 1  located vertically halfway between the bottom  72  of the cavity  47  and the top edge  122 . The weir  120  is also free of fluid flow apertures  129  below a second level L 2  vertically halfway between the bottom  72  of the cavity  47  and the nominal water line  127 .  
         [0028]     The plate coalescer  26 , as shown in  FIG. 2 , is located rearward of the weir  120  between the second and third compartments  82  and  83 . As shown in  FIGS. 4A and 4B , the plate coalescer  26  comprises an inclined stack of corrugated plates  130 . Each plate  130  extends from a bottom edge  132  of the plate  130  rearward and upward to a top edge  134  of the plate  130 . The bottom edge  132  is spaced from the bottom  72  of the cavity  47 , and the top edge  134  is located below the nominal water line  101 . This configuration enables the water to enter the coalescer  26  from below, to flow rearward and rearward in-between the plates  130 , and to exit the coalescer  26  from above.  
         [0029]     Each plate  130  is corrugated, with corrugations  136  extending rearward and upward fully from the bottom edge  132  to the top edge  134 . The corrugations  136  are thus aligned along the direction of the water flow between the plates  130 , as indicated by the arrows  79 . As shown in  FIG. 4B , each corrugation  136  of each plate  130  is positioned directly above a corrugation  136  of the plate  130  just below it. Each plate  130  has two opposite side edges  138  received in respective grooves (not shown) in two opposite plate retainers  139 .  
         [0030]     Flow of the mixture rearwardly upward in-between the plates  130  shown in  FIG. 4A  promotes coalescing of the initially-suspended particles and droplets into agglomerates. Relative to the suspended particles and droplets, the agglomerates have more buoyancy for floating upward or more weight for settling downward. The floating agglomerates can flow out the top of the coalescer  26  into the third compartment  83  where they can float at the water surface  101 . Similarly, the sedimentary agglomerates can be swept by the water out the top of the coalescer  26  and settle as sediment at the bottom of the third compartment  83 . Alternatively, the sedimentary agglomerates can slide down the plates  130  to settle as sediment at the bottom  72  of the second compartment  82 .  
         [0031]     An upper coalescer baffle  140 , which is one of the baffles  38  mentioned above, extends from a front one of the coalescer plates  130  upward to the casing  14 . The upper coalescer baffle  140  prevents any floating contaminants in the second compartment  82  from migrating to the third compartment  83 . The upper coalescer baffle  140  also prevents the mixture from flowing rearwardly over, and thus bypassing, the coalescer  26  under normal flow conditions when the water is below a predetermined level L 3 . A bypass flow opening  141  in the upper baffle  140  allows the mixture to bypass the plate coalescer  26  under high flow conditions when the water rises above the predetermined level L 3 .  
         [0032]     A lower coalescer baffle  142  extends from a rear one of the plates  130  downward to the casing  14 . The lower coalescer baffle  142  prevents the water from flowing rearwardly under, and thus bypassing, the coalescer  26 . The lower coalescer baffle  142  also prevents any sediment in the second compartment  82  from migrating to the third compartment  83 . In this manner, the lower baffle  142 , along with the upper baffle  140  and the plates  130 , separates the second compartment  82  from the third compartment  83 .  
         [0033]     The media coalecser  30 , as shown in  FIG. 2 , is located rearward of the coalescer  26 , in front of the outlet structure  34 , and between the third and fourth compartments  83  and  84 . As shown in  FIG. 5 , the media coalecser  30  comprises a frame  150 , two porous baskets  152 , and coalescing media  154 . When in use, the media  154  is contained in the baskets  152 .  
         [0034]     A porous bag  155  is used to contain the media  154  during transport to and from each basket  152 . To fill the basket  152 , the media  154  is first transported to the basket  152  while encased in the porous bag  155 . The media  154  is placed in the basket  152  along with the bag  155  and remains encased in the bag  155  while in use. While in use, the bag  155  prevents the water from sweeping the media  154  out of the basket  152 . The media  154  is removed from the basket  152  by simply lifting the bag  155  out of the basket  152 .  
         [0035]     The frame  150  is located below the nominal water line  101 . The frame  150  comprises a nonporous plate  156  extending horizontally from one side  74  ( FIG. 1 ) of the casing  14  to the other side  76 . The plate  156  has two side-by-side rectangular openings  157 . From the two openings  157 , two nonporous rectangular tubes  158  extend downward to two bottom openings  159 .  
         [0036]     The two porous baskets  152  hang down from the two tubes  158 . Each basket  152  consists of a screen  160  extending downward from a top opening  161  of the basket  152 . This top opening  161  coincides with the bottom opening  159  of the respective tube  158 . The screen  160  passes the water while retaining the coalescing media  154 . As shown in  FIG. 6 , the basket  152  is trough-shaped, with a porous bottom wall  171 , porous opposite side walls  172  and  173 , and porous front and rear walls  174  and  175 .  
         [0037]     The water flows by force of gravity into the basket  152  vertically downward through the top opening  161 , as shown in  FIG. 6 . The water then flows through the coalescing media  154  ( FIG. 5 ) in the basket  52 . The water flows, further, out of the basket  152  in several directions. Specifically, the water can flow downward through the bottom wall  171 . This flow is in a first direction  181  extending vertically downward through the top opening  161 , perpendicular to the axis  45  of the casing  14  ( FIG. 2 ). The water can flow out of the basket  152  also through the side walls  172  and  173 . These flows are in horizontal second and third directions  182  and  183  that are opposite each other, perpendicular to the first direction  181  and perpendicular to axis  45  of the casing  14 . The water can flow out of the basket  152  also through the front and rear walls  174  and  175 . These flows are in a horizontal frontward fourth direction  184  and a horizontal rearward fifth direction  185 . These directions  184  and  185  are opposite each other, perpendicular to the first, second and third directions  181 ,  182  and  183 , and parallel with the axis  45  of the casing  14 . So as not to obstruct the water outflow in these directions  181 ,  182 ,  183 ,  184  and  185 , the porous walls  171 ,  172 ,  173 ,  174  and  175  are all spaced from the casing  14 .  
         [0038]     Accordingly, the water can flow outward through of the basket  152  in multiple, mutually opposite or perpendicular, directions  181 ,  182 ,  183 ,  184  and  185 , and those directions  181 ,  182 ,  183 ,  184  and  185  include both vertical and horizontal directions. These features beneficially decrease resistance to water flow. They also improve coalescing efficacy by reducing turbulence. For this purpose, a depth D of the basket  152  is preferably at least as large as the narrowest width W of the top opening  161 . Additionally, the porous wall  160  extends downward sufficiently such that the surface area of the porous wall  160  is at least double the area encircled by the top opening  161 . In this example, the area encircled by the top opening  161  equals the length L of the opening  161  times the width W of the opening  161 .  
         [0039]     The coalescing media  154  in this example, shown schematically in  FIG. 5 , is in the form of balls  200  known in the art. Examples of such balls  200  are Jaeger Tri-Packs® sold by Jaeger Products, Inc. of Houston, Tex. Each ball  200  comprises a network of plastic ribs (not shown). The network of ribs promotes coalescing of the initially-suspended particles and droplets into agglomerates that have sufficient buoyancy to float upward or sufficient weight to settle downward. Alternatively, the agglomerates can have sufficient size and adhesion to be caught or adhered by the rib network itself. When the balls  200  are first piled into the basket  152 , each ball  200  can roll about the pile due to its round shape, until pile is compactly packed. The media  154  fills each basket  152  and extends upward into each tube  158 . This ensures that the water flowing into the basket  152  through the top opening  161  and outward through the basket  152  must flow through the media  154 .  
         [0040]     A lower media coalecser baffle  210 , shown in  FIGS. 2 and 5 , is one of the baffles  38  mentioned above. It is located in front of the basket  152  and extends vertically from a front end  212  of the frame  150  downward to the casing  14 . The lower baffle  210  also extends upward from the front end  212  almost to the nominal water line  101 . The lower media coalecser baffle  210  prevents the mixture from bypassing the top opening  161  from the side or from below. The lower media coalecser baffle  210  also prevents sediment in the third compartment  83  from migrating to the fourth compartment  84 .  
         [0041]     An upper media coalecser baffle  214  is located rearward of the basket  152  and extends vertically from a rear end  215  of the plate  156  upward to the casing  14 . The upper baffle  214  also extends downward from the rear end  215  of the plate  156  without reaching the bottom  72  of the cavity  47 . The upper baffle  214  prevents floating contaminants in the third compartment  83  from migrating to the fourth compartment  84 . The upper baffle  214  also prevents the water from bypassing the basket  152  from above under normal flow conditions, when the water is below the predetermined level L 3 . A bypass flow opening  217  in the upper baffle  214  allows the water to bypass the media coalescer  30  under high flow conditions, when the water rises above the predetermined level L 3 .  
         [0042]     Thus, the upper baffle  214 , the lower baffle  210  and the non-porous frame  150  together constrain the water flowing through the cavity  47  from the front end  66  to the rear end  68  to flow through the top opening  161  into the basket  152  under normal flow conditions. Consequently, the upper baffle  214 , the lower baffle  210  and the media coalecser  30  separate the third compartment  83  from the fourth compartment  84 .  
         [0043]     The manways  41 ,  42  and  43 , shown in  FIG. 2 , are designated first, second and third manways  41 ,  42  and  43 . They are spaced axially along the casing  14  and extend upward from the top  70  of the cavity  47 . The manways  41 ,  42  and  43  provide access to the various compartments  81 ,  82 ,  83  and  84  for manually removing the floating and settled contaminants that are retained in those respective compartments  81 ,  82 ,  83  and  84 . Specifically, the first manway  41  is located above the weir  120  for removing the contaminants retained in the first and second compartment  81  and  82 . The second manway  42  is located above the third compartment  83  for removing the contaminants retained in the third compartment  83 , and also for removing the baskets  152  and the coalescing media  154 . The third manway  43  is located above the fourth compartment  84  for removing the contaminants retained in the fourth compartment  84 .  
         [0044]     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to make and use the invention. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.