Abstract:
A separator provides improvements for better separation of an effluent into constituent parts and greater ease of use. A tapered basket provides improved flow and better filtration. A baffle directs effluent into the basket with greater force. An asymmetrical flange prevents mis-orientation the basket and baffle. An improved oil valve provides a locking mechanism to prevent dislodging of the valve during cleaning. An alternative valve uses a sensor to sense an oil/water interface and close the oil valve appropriately. A top seal prevents leakage of effluent at connection points with the lid of the housing. An underground unit allows below floor level installation of the separator. A bidirectional unit can be reversed to provide flow in either direction. A dual purpose tank can be used to store both separated oil and oil from operations for common removal.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of the filing date of now abandoned provisional application U.S. Ser. No. 60/556,832, filed Mar. 26, 2004, entitled “IMPROVED SEPARATOR FOR IMMISCIBLE LIQUIDS” and U.S. Ser. No. 60/582,993, filed Jun. 25, 2004, entitled “IMPROVED SEPARATOR FOR IMMISCIBLE LIQUIDS”. 
    
    
     STATEMENT OF FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
    
    
     BACKGROUND OF THE INVENTION 
     1. Technical Field 
     This invention relates in general to a liquid separation devices and, more particularly, to a device for separating oils and/or grease from water. 
     2. Description of the Related Art 
     In several industries, and in particular the food industry, there is a need to separate liquid greases, fats and oils from waste water prior to passing the water to the sewage system. The waste water could be, for example, discharge from a washing device for cleaning dinnerware and cooking utensils. If the greases and fats solidify in the sewage system, a blockage can occur which is expensive to remediate. 
     Additionally, there is a movement in many localities to recycle grease and oils. 
     A commercially available separation device of the type described in European Patent EP 890381 B1 is shown generally in  FIGS. 1   a  and  1   b .  FIG. 1   a  illustrates an exterior perspective view of the separation device  10 . Effluent (containing two or more immiscible liquids of different densities, typically water entrained with oil, grease dissolved fats and other particles) is received at inlet  12  providing a passage into housing  14  (including removable lid  15 ). Effluent is heated using a probe-type heater  16 , which is coupled to an electrical connection. As described below, the immiscible liquids separate within housing  14 , and the less dense material (e.g., grease and oils) empties into container  18 . The more dense liquid (e.g., water) is discharged from water outlet  20 . Silt may accumulate at the bottom of housing  14 . The silt may be periodically discharged through silt outlet  22 . 
     Operation of the separation device  10  is described in greater detail in connection with  FIG. 1   b .  FIG. 1   b  illustrates a cross-sectional side view of the separation device  10 . A coarse filtration chamber  24  is defined between the housing  14  and control plate  25 , which extends the full width of the housing. As effluent enters the coarse filtration chamber  24  through inlet  12 , it passes through a filtering basket  26  (shown in greater detail in connection with  FIG. 2 ), which filters out solid particles, such as undissolved fat and other food particles. 
     After passing through the basket  26 , the effluent enters the separation chamber  28 , defined by control plate  25 , control plate  30  (which extends the full width of the housing), top plate  32  and the bottom of housing  14 . There are two exits from the separation chamber: (1) through floating ball valve  34  and through passage  36 , disposed between the bottom of control plate  30  and the bottom of the housing  14 . Top plate  32  is angled upward from the bottom portion of control plate  25  towards control plate  30 . 
     Weir plate  38 , which extends the full width of the housing, defines a water (high density liquid) release chamber  40 , along with control plate  30  and the housing  14 . Outlet  20  is disposed through the housing. 
     In operation, as the effluent enters the separation chamber  28 , the lower density liquid (grease/oil) rises. The flow through the separation chamber  28  is set at a rate that allows the lower density liquid to separate from the water and float upwards to the surface of the water, where it is contained below the sloping top plate  32 . 
     The sloping top plate  32  forces the lower density liquid to accumulate at the entry to floating ball valve  34 . Floating ball valve  34  is shown in greater detail in connection with  FIG. 4 . Floating ball valve  34  uses a ball that floats at the interface between the high density liquid and the low density liquid. When the high density liquid reaches a predetermined height, the ball rises to a height which stops flow from the separation chamber  28  to the container  18 . 
     As the water flows through the separator  10 , it must rise above the top of weir  38  in order to exit. Accordingly, the water in separation chamber  28  attempts to rise to approximately the same height. Since the top of the separation chamber  28  is below the top of weir plate  38 , the hydrostatic pressure of the upward force of the water will push the separated grease/oil at the top of the separation chamber  28  through valve  34 . The water, however, cannot pass through the valve  34 , because the floating valve will stop its passage. Hence, once all the separated grease/oil is forced out of the separation chamber, the valve will remain closed until more grease/oil accumulates. 
     The separated water passes through passage  36 , over weir plate  38  and out outlet  20 . Silt in the water tends to accumulate at the bottom of housing  14 , unable to rise over weir plate  38 . Silt valve  22 , located at the bottom of housing  14 , can be opened periodically, and the flow of water out of the valve will flush out the silt. 
     In many fields of use for the separator  10 , and in particular the food industry, it can be assumed that the employees who will operate and maintain the separator will be relatively transient between employers. Accordingly, aspects of the operation and maintenance of the separator must allow for unfamiliarity with details. Matters such as periodic cleaning of various components of the separator, such as the floating ball valve, if performed incorrectly, can lead to unwanted consequences, such as allowing water to exit into the oil/grease container or oil/grease flowing out of the outlet  20 . 
     Also, it would be beneficial to improve the flow of liquids through the separation chamber, since oil and grease are by their nature sticky and tend to accumulate on hard surfaces. 
     Accordingly, there is a need in the industry for an improved separator. 
     BRIEF SUMMARY OF THE INVENTION 
     In one aspect of the present invention, a separator includes a tank having an inlet, an inlet chamber, a separation chamber and an outlet chamber, with the inlet feeding effluent into the inlet chamber, the inlet chamber being in communication with the separation chamber through a first passage and the separation chamber in being communication with the outlet chamber through a second passage. A basket having at least one tapered side disposed in the inlet chamber below the inlet, such that the one tapered side is disposed at an angle relative to an adjacent sidewall of the inlet chamber. 
     In another aspect of the present invention a baffle directs effluent into the basket with greater force. 
     In another aspect of the present invention, an asymmetrical flange prevents mis-orientation the basket and baffle. 
     In another aspect of the present invention the continuous seating and continuous flange on the basket prevents floatable solids bypassing the basket and floating up with the oil to interfere with the oil valve ball seating. 
     In another aspect of the present invention a self closing silt valve eliminates the chance of the silt valve being left open, which may cause the heater to overheat, burn out and cause smoking of the oil. 
     In another aspect of the present invention, an improved oil valve provides a locking mechanism to prevent dislodging of the valve during cleaning. 
     In another aspect of the present invention, a valve uses a sensor to sense an oil/water interface and close the oil valve appropriately. 
     In another aspect of the present invention, a top seal allows the incoming effluent to surcharge in the inlet chamber without leaking over connection points on with the lid of the housing. 
     In another aspect of the present invention, an underground unit allows below floor level installation of the separator. 
     In another aspect of the present invention, a bidirectional unit can be installed in such a way to allow flow in either direction, thus eliminating the need to manufacture and inventory units that flow either left-to-right or right-to-left. 
     In another aspect of the present invention, a dual purpose tank can be used to store both separated oil and oil from operations for common removal. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: 
         FIGS. 1   a  and  1   b  illustrate a perspective view and a cross-sectional view of a prior art separation device; 
         FIG. 2  illustrates a prior art filtration basket used in the device of  FIGS. 1   a  and  1   b;    
         FIGS. 3   a  through  3   d  respectively illustrate perspective, top, cross-sectional front, and cross-sectional side views of an improved basket; 
         FIG. 4  illustrates a prior art floating ball valve used in the separation device of  FIGS. 1   a  and  1   b;    
         FIG. 5   a  illustrates a cross-sectional view of an improved floating ball valve; 
         FIG. 5   b  illustrates a perspective view of a housing for an improved floating ball valve; 
         FIG. 5   c  illustrates a top view of the improved floating ball valve; 
         FIG. 6   a  illustrate a block diagram of an improved valve for replacing the ball valve of  FIG. 4 ; 
         FIGS. 6   b  through  6   d  illustrate cross-sectional view of butterfly, gate and ball valves, respectively; 
         FIGS. 7   a  through  7   c  illustrates an improved separation device with low friction surfaces, improved heating and silt removal, and leakage prevention; 
         FIG. 8  illustrates an improved separation device that can be used in an in-ground installation; 
         FIG. 9  illustrates a tool for cleaning the separation device of  FIG. 8 ; 
         FIG. 10  illustrates a separation device combined with a large capacity storage container for unified grease control; 
         FIG. 11  illustrates a bi-directional separation device; 
         FIG. 12  illustrates an embodiment using a breather tube for eliminating trapped air in the separation chamber; 
         FIGS. 13   a  and  13   b  illustrate a cross-sectional side view and a top view, respectively, of an embodiment of a ball valve with an integral breather tube; and 
         FIG. 14  illustrates another embodiment of an in-ground separator  200 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention is best understood in relation to  FIGS. 1-11  of the drawings, like numerals being used for like elements of the various drawings. 
       FIG. 2  illustrates a prior art filtration basket  26 . The basket has a front side (facing the housing at inlet  12 ) and a back side (facing control plate  25 ) that is perforated with holes  50 , as is the bottom of the basket. Since the front side is relatively flush with housing  14  and the back side is relatively flush with control plate  25 , and the ends are not perforated, almost all of the effluent flow is through the holes in the bottom of the basket. Over time, food particles will accumulate on the bottom of the basket  26 , severely limiting flow into the separation chamber  28 . 
     Other problems concern removal and replacement of the basket  26 . The prior art uses a handle  52  which terminates through holes on either side of the basket. The basket  26  has flanges  54  on either side; flanges  54  normally rest on support clips  56  formed on either side of the housing in the coarse filtration chamber  24 . In order to accommodate the exposed ends of the handle  52  when the basket is removed or replaced, slots  58  are formed in support clips  56  through which the ends of the handle may pass. 
     During operation, the slots  58  prevent a complete seal between flanges  54  and support clips  56 . Some of food particle in the effluent may pass through the slots  58 , bypassing basket  26 . Food particles may also pass through the narrow gap between the front edge of the basket and the outer body  14  and the rear edge of the basket and the control plate  25 . Excessive food particles entering the separation chamber  28  can clog the floating ball valve  34 , resulting in water passing into the oil collection chamber  18 . 
       FIGS. 3   a  through  3   d  illustrate perspective, top, cross-sectional front and cross-sectional side views of an improved basket  60 . The improved basket increases efficient effluent flow, eliminates solid particles in the effluent from bypassing the filtration mechanism of the basket, and enhances effluent separation in the separation chamber  28 . 
     As distinguished from the vertical sides of basket  26 , tapered basket  60  has tapered sides that angle away from housing  14  and control plate  25 . Further, all four sides are perforated. Accordingly, a larger surface area of the basket is separated from a constricting wall for more efficient flow through the basket  60 . Since there is more area for holes  62 , the holes  62  can have a smaller diameter, without affecting flow of effluent through the basket. In the prior art, holes  50  had a diameter of approximately 11/64 inches, while holes  62  can have a diameter of approximately 1/16 inches (0.15875 cm). This allows smaller particles to be trapped by the basket  60  for more effective coarse filtering. Further, more debris may be collected before the basket needs to be emptied, since the basket will continue to efficiently filter the effluent even when the bottom is covered. 
     An additional improvement is the addition of inclined baffle plate  64  to the basket  60 . Baffle plate  64  deflects water from inlet  12  towards the bottom of the basket  60 . A cut-out  64   a  in the baffle plate  64  faces inlet  12 . As effluent enters the coarse filtering chamber  24 , the baffle directs the effluent downwards to help drive oils and grease under the control plate  25 . Further, as effluent-hits the baffle plate  64 , it is driven through a layer of oil, which helps to saturate the chemical emulsions, causing the emulsions to release the oil. 
     The handle  68  of basket  60  is attached to the top of the baffle plate  64 . Because the handle does not protrude from the sides of the basket  60 , the slots  58 , shown in  FIG. 2  are no longer necessary. 
     With the addition of the baffle plate  64 , it is important that the basket  60  is oriented correctly (such that the baffle plate deflects effluent downward, not upward). A careless replacement of the basket  60  could thus cause problems with the operation of the separator  10 . To prevent an errant replacement, the basket  60  has asymmetric flanges  54   a  and  54   b . As shown in  FIGS. 3   a - d , flange  54   a  is wider than  54   b , and support clip  56   a  is wider than  56   b . If the basket  60  is replaced in the reverse orientation, the mismatch between the support clips  56   a - b  and flanges  54   a - b  will not allow the basket to seat properly (and the lid will not be able to close). This will notify the operator that the basket needs to be reversed. Front and back flanges  54   c  and  54   d  provide an integral lip that completely surrounds the basket  60  for a complete seal. 
       FIG. 4  illustrates a type of floating ball valve  34  used in the prior art. Floating ball valve  34  includes a ball  70  within housing  72 . Ball  70  is held within housing  72  by a grid  74 . Insert  76  includes a mating portion  78  for mating with the housing  72  above the ball  70  and an outlet portion  79  for communicating with the oil/grease container  18 . A passage  80  is formed in insert  76  through the mating portion  78  and outlet portion  79 , with a tapered opening  82  at the end of the passage  80 . Passage  80  is coupled to outlet  84 . O-ring  86  seals mating portion  78  and housing  72 . As described above, the ball  70  is designed to float at the interface between two immiscible liquids (e.g., water and oil/grease). As the water rises, the oil/grease is pushed into passage  80 , where it exits to the oil/grease container  18  via outlet  84 . Once all of the lower density liquid (oil/grease) has been pushed into the passage  80 , the ball  70  presses against the tapered opening  82 , thereby closing the passage. In this way, only the lower density liquid can pass through the passage  80 . 
     Since the oils and grease will pass through the passages  80  and  84  to the oil/grease container  18 , the passages  80  and  84  need to be cleaned periodically to remove congealed substances. To do so, a brush is inserted into the passage  80  from above or passage  84  from the side and an up and down scrubbing motion is used to dislodge the congealed oil/grease within the passage  80 . During the cleaning process, the mating portion  78  can easily become dislodged from the housing  72 , causing failure of the valve  34 . 
     In  FIG. 5   a  illustrates a cross-sectional side view of an improved floating ball valve  90 , which can be used in place of floating ball valve  34 . Floating ball valve  90  includes a mating portion  78 , with two protruding locking pins  92 . Housing  72  includes two vertical channels  94  forming L-shapes with respective horizontal channels  96  (see  FIG. 5   b ) to accept pins  92 . The mating portion  78  is engaged within housing  72  by aligning the pin  92  with vertical channel  94 , inserting the mating portion  78  into the housing  72  until pin  92  reaches the end of the vertical channel  94 , then rotating the pin within the horizontal channel  96  to lock the mating portion within the housing  72 . 
       FIG. 5   b  shows a perspective view of housing  72 , illustrating the vertical channel  94  and horizontal channel  96 .  FIG. 5   c  illustrates the insert  76  in a locked position within housing  72 . 
     Another problem associated with floating ball valve  34  is the problems which can occur if the ball  70  sticks to the mating portion  82 . This is possible because of the oil/grease that will coat both surfaces during normal operation of the separator  10 . 
       FIG. 6   a  illustrates a schematic of an alternative embodiment of a valve which can be used to eliminate the need for a floating ball. In  FIG. 6   a , a sensor  100  senses the location of the interface between the two immiscible liquids. When the interface has reached a predetermined level, the sensor sets a control signal to actuator  102 . Responsive to the control signal, the actuator closes a valve  104  which controls flow between an oil/grease inlet  106  and an oil/grease outlet  108 . 
       FIGS. 6   b  through  6   d  illustrate three types of valves that could used implement valve  104  (other valve types could be used as well).  FIG. 6   b  illustrates a cross-sectional side view of a butterfly valve  110 . The butterfly valve operates by rotating a disk  114  within cylindrical housing  112 . When surface the disk  114  is aligned parallel to the axis of the cylindrical housing, the valve  110  is in an open state; when the surface of the disk  114  is perpendicular to the axis of the cylindrical housing  112 , the valve  110  is in a closed state. 
       FIG. 6   c  illustrates a cross-sectional side view of a gate valve  120 . In a gate valve, a gate  122  is positioned within tube  124  to prevent flow and withdrawn from tube  124  to allow flow. 
       FIG. 6   d  illustrates a cross-sectional side view of a ball valve  130  (not to be confused with the floating ball valve  34 ). The ball valve incorporates a sphere  132  with a cylindrical bore  134  disposed through the center of the sphere. When the bore is aligned with the inlet  136  and outlet  138 , liquid can pass from inlet to outlet. When the bore  134  is rotated to a position where it does not communicate between inlet  136  and outlet  138 , liquid can no longer pass through the valve. 
     The ball valve  130  is a preferred embodiment for the present invention, because the operation of the valve rotating between opened and closed positions tends to scrape away congealed oil/grease at the inlet and outlet. Therefore, this valve is somewhat self-cleaning. 
       FIG. 7   a  illustrates improvements made to the separator  10  to improve flow of the liquids (and silt) inside the separation chamber for improved operation. First, the inside of housing  14  and surfaces of control plate  25 , top plate  32 , control plate  30  and weir  38  can be coated with a Teflon layer  39 , or another non-stick coating layer  39 , in improve flow and reduce friction and adhesion between the oil/grease/silt and these surfaces. 
     Additionally,  FIG. 7   a  illustrates improvements made to heating of the liquids, particularly in the separation chamber  28 . In the prior art, a probe-type heating element has been used. This presents several problems. First, the heater is mounted to the outside of the unit, where it can be inadvertently hit by employees, and knocked loose. Second, the surface area of the heater is relatively small and, therefore, the heat is localized. 
     In  FIG. 7   a , several alternatives are shown for heating the liquids in the separation chamber  28 . These alternatives could be used separately or combined. The first alternative uses a heating blanket  140  disposed on the bottom of housing  14 . This eliminates any protruding housing for the heater and heats a larger surface area, keeping the temperatures relative constant across the separation chamber  28 . 
     A second alternative uses induction heating to heat the top plate  32  and/or valve  34 . Since the top plate  32  and valve  34  are in nearly constant contact with the oil/grease, these elements can be heated by induction to most effectively provide heat for keeping the oil/grease as liquid as possible. The induction heating of the top plate  32  and/or valve  34  could be used in conjunction with the heat blanket  140 . 
     Additionally, in  FIG. 7   a , a self-closing valve  147  is used as the silt valve. The valve  147  is held open manually long enough (generally about ten seconds) for the silt to be forced out by the pressure of water in the chamber and will close immediately the operator&#39;s hand is removed from the valve handle. This protects the device from being operated with the silt valve open, which could allow effluent to pass directly out the silt valve; this could cause the heater to overheat and to burn out and/or cause the oil to overheat and smoke. 
       FIGS. 7   a ,  7   b  and  7   c  illustrate top and bottom seals used in the improved separator. A top seal  142  is formed on the perimeter of the housing  14  and on the tops of control plates  25  and  30 , providing a continuous seal. In the preferred embodiment, the seal  142  is mechanically attached to the housing  14  and control plates in the manner shown in  FIG. 7   c . In  FIG. 7   c , the seal material, preferably in the form of a hollow neoprene tube or similar flexible hollow tubing, is affixed to an edge of the housing  14  and control plates  25  and  30  using a mechanical gripping mechanism  144 . In the illustrated embodiment, the mechanical gripping mechanism includes teeth  146  which, when pushed onto the housing edges, will grab the edges to form a strong mechanical bond. Any gaps between strips of materials should be filled with a sealing compound. 
     In operation, the top seal  142  can withstand considerable water pressure with just the weight of the lid  15  maintaining contact with the seal  142 . Thus, if an surge of water is received through inlet  20 , water is maintained within the housing  14 , and is kept from overflowing from either the coarse filtration chamber  24  or the water release chamber  40  into the interior chamber  148  of the housing  14 , where it can become rancid. 
     Prior art mechanisms use a compressive foam that is affixed to the lower edge of the lid by means of a self adhesive strip, and a seal is created by the use of lid clamps to hold the lid to the body. The claims make the user access to the unit difficult. Also, the clamped lid discourages the operators from properly maintaining the unit. 
     An additional bottom seal  149  is affixed around the bottom edge of the housing  14 . Once again, the bottom seal  149  is preferably in the form of a hollow neoprene tube affixed to the edges of the housing  14  using a mechanical gripping mechanism  144  as shown in  FIG. 7   c.    
     Prior art methods for sealing the separator to a floor, such as by caulking, have adhesion problems, particularly in the grout lines. Since units will often be retrofit to existing restaurants, the grease embedded in the grout resists adhesion, allowing water from floor cleaning to seep under the unit. Also, caulking complicates moving of the unit. Placing the unit on legs such that the floor can be cleaned under the unit can add height to the unit, reducing the positive fall of the effluent from sink and dishwasher drains. 
     The bottom seal  149  has been shown to effectively seal the unit to the floor, and is particularly effective in sealing the grout lines, since the weight of the unit holds the bottom seal  149  firmly within the grout lines. 
       FIG. 8  illustrates an embodiment of a separator  150  which has the advantage that it can be used in an in-ground embodiment. For illustration purposes, separator  150  is shown with the prior art heater  16  and floating ball valve  34 , it being understood that the other improvements described herein could be used in the place of these elements. 
     In  FIG. 8 , basket  60  performs coarse filtering on effluent received through inlet  12 . Control plate  25  has an angled portion  152  to provide an improved flow through basket  60  (this improvement can be used in other configurations as well). A downward sloping bottom control plate  154  has a V-shape (or channel) to catch silt, and is preferably Teflon coated. The V-shape bottom control plate transitions into weir  156 , maintaining a V-shape which is slanted upwards to the desired predetermined height to provide hydrostatic pressure on the separated oil at valve  34 . Control plate  158 , is coupled to the top of housing  14  and provides a channel  160  through which the separated water flows. Control plate  158  includes an enlarged portion  162 . Heater  16  is disposed through top plate  32 , within compartment  164 . Apart from compartment  164 , the area above top plate  32  can be used as a sump  166  to store oil/grease from oil/grease valve  34 , preferably in a removable container. Access to the tapered basket  60 , sump  166 , compartment  164  and oil valve  34  can be made by removing one or more lids (not shown) on the top of housing  14 . If silt is to be separate from the water, a water outlet  168  is placed above a silt valve  170 . Alternatively, a single outlet can be provided, which disposes of both water and silt. A mesh screen  172  is positioned in front of water outlet  168  to filter out silt. 
     In operation, silt from the effluent will gather at the bottom plate  154 , and will be drawn towards the lowest portion of the “V” shaped plate  154  at the interface with the weir  156 . The flow of water through channel  160  will push the silt up the channel  160 . The enlarged portion  162  of the channel will create turbulence and additional suction to pull silt up and over the top of weir  156 . Silt will fall to silt valve  170 , which can be periodically opened to a silt outlet or collected separately in a container coupled to the silt valve  170 . The remainder of the water flows out of water outlet  168  into the sewage system. 
     Over time, some silt may collect on weir  156 .  FIG. 9  illustrates a scraper which matches the profile of weir  156  to remove this silt. 
     Preferably, all inside surfaces of separator  150  are Teflon coated to decrease resistance and improve flow. 
       FIG. 10  illustrates a diagram of a separator with a large grease container for containing both grease/oil separated from the effluent and for containing used grease/oil from operations, such as from frying machines. In this embodiment, an underground separator  150  (an above ground separator of the type shown in  FIGS. 1-7   a - c  could also be used) is coupled to a storage tank  170  which is large enough to hold all the discard oil/grease from effluent and operations. Pipe  173  couples the valve  34  to the storage tank  170 . Opening  174  allows workers to pour the oil/grease into the storage tank from an oil caddy, for example. Alternatively, the oil/grease from operations could be pumped directly to the tank  170 . Heater  176  heats the contained oil so that it does not solidify. Valve  178 , typically a quick disconnect valve, provides a suitable connection to an oil pump used to pump oil/grease from the tank  170  for reclamation. Pipe  180  is disposed between valve  178  and the bottom of the tank  170 . 
     In operation, the embodiment shown in  FIG. 10  allows a business to consolidate all oil/grease waste for removal by a collection company, typically an outside contractor or municipality. The unified design allows the collection company to collect all of the used oil/grease from a restaurant. By using the underground configuration, oil drums/dumpsters could be eliminated from the back of the restaurant, or other business. 
       FIG. 11  illustrates an embodiment for an above-ground bidirectional separator  182  (with lid  15  removed), i.e., the valve  34  and heater  16  can be located on either side of the housing  14 . The housing  14  includes two oil valve housings  72 , one of which will receive a valve  34  and the other of which will have a plug installed. Container  18  is mounted through opening  186  on the side of the valve  34 , the other opening  186  is closed with a blank. The holes  186  have slotted holes adjacent to them to enable either the container  18  or support or blank plate to be mounted. Threaded connections  188  are made on either side of the housing  14  for receiving the heater  16 ; the side not receiving the heater is closed with a threaded plug. 
     The embodiment shown in  FIG. 11  allows the separator  182  to be installed in either flow direction, which reduces the cost of inventory that must be maintained and allows the most efficient installation within a business. Further, the direction of the separator  182  can be switched if a kitchen is remodeled (on average, a commercial kitchen is remodeled every five years) to accommodate a change in flow through the pipes. 
       FIG. 12  illustrates an embodiment for eliminating trapped air in the separation chamber  28 . In certain circumstances, such as startup, a rush of effluent with entrained air bubbles into separation chamber  28  can cause the ball  70  to stick against tapered opening  82  (see  FIG. 5   a ). As the entrained air bubbles separate from the effluent, they can hold the ball  70  against the tapered opening  82  causes the valve to remain closed. Daily cleaning of the valve has been found to reduce the problem, but as the entrapped air in the separation chamber  28  escapes through the valve, it propels the oil/grease in the valve at the person cleaning the valve. 
     In  FIG. 12 , a breather tube  190  is in communication with the separation chamber  28  (in the illustrated embodiment, the breather tube  190  is disposed through the unused valve housing  72 , however it could be disposed through any suitable part of top plate  32 ). The breather tube  190  extends to near the lid  15 , such that hydrostatic pressure cannot force oil/grease out of the breather tube  190 . Alternatively, the breather tube  190  could feed into the ball valve, such that any oil/grease emitted from the breather tube  190  would be fed into the container  18 . 
     In operation, since the breather tube communicates directly with the separation chamber  28 , without a ball valve to interrupt communication, air can always pass out of the separation chamber through the breather tube  190  and therefore, the air will not cause the ball valve to close improperly. 
     It should be noted that animal fats may solidify in the breather tube  190 . Accordingly, the breather tube  190  should be kept hot by electrical trace and insulation, or by other methods. 
       FIGS. 13   a  and  13   b  illustrate a cross-sectional side view and a top view, respectively, of an embodiment of a ball valve  34  with an integral breather tube  190 . In this embodiment, a breather tube hole  191  is formed through mating portion  78 , with the tube  190  extending upwards from hole  191  to a level near lid  15 , or other level that will ensure that hydrostatic pressure will not force oil/grease out of the breather tube  190 . Additionally,  FIGS. 13   a  and  13   b  illustrate outlet  84  as a trough, rather than a pipe. A trough configuration is generally easier to clean, and uses less material. 
       FIG. 14  illustrates another embodiment of an in-ground separator  200 . This embodiment is similar to the embodiment of  FIG. 8 , with the container  18  locate above top plate  32 , such that it can be accessed by removing lid  15 . Heater  16  is located below top plate  32  and has extended portions  16   a  to provide additional surface area for heating the effluent. The operation of the separator  200  is the same as described above. 
     This embodiment provides an in-ground separator that can be used, for example, inside a restaurant work area. The container can be easily accessed and removed for transporting the oil/grease to a storage container. 
     Although the Detailed Description of the invention has been directed to certain exemplary embodiments, various modifications of these embodiments, as well as alternative embodiments, will be suggested to those skilled in the art. The invention encompasses any modifications or alternative embodiments that fall within the scope of the claims.