Abstract:
The present invention comprises a gravity draining automatic FOG interceptor with solids removal capability used as a first stage in the treatment of gray water. A preferred embodiment comprises a multi compartment container, the compartments separated by baffles, having a serviceable solids strainer in a first compartment, a second compartment having a cogged belt for FOG removal and collection, a third compartment for collection of clarified effluent, and a fourth compartment for tertiary treatment of the gray water effluent, for example, the introduction of biotechnology. The unique baffle configuration prevents biotechnology backflow migration from the fourth compartment with resulting bacterial contamination of the FOG.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims benefit of provisional U.S. application No. 60/713,462 filed Sep. 1, 2005. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates generally to removal of food preparation contaminants from wastewater and in particular, to removal and collection of wastewater fats, oils, and grease, henceforth referred to as FOG, from food source and food service facilities.  
       BACKGROUND OF THE INVENTION  
       [0003]     Wastewater FOG is produced by, for example, meat fats in food scraps, cooking oil, shortening, lard, butter and margarine, gravy, and food products such as mayonnaise, salad dressings, and sour cream. Wastewater from food source and food service facilities such as restaurants, processing plants, cruise lines and cargo ships, factories, garages, hotels, and casinos are often referred to as “gray water”. When gray water passes through sewer systems. FOG accumulates inside the pipes eventually restricting the flow in the pipes with the potential of causing untreated wastewater to back up into businesses and homes, resulting in high costs for cleanup and restoration, FOG, discharged into septic systems and drain fields can cause malfunctions, resulting in more frequent tank pump-outs and other expenses. Additionally, manholes can overflow into parks, yards, streets, and storm drains, allowing wastewater to contaminate local waters, including drinking water.  
         [0004]     Exposure to untreated wastewater is a public-health hazard. Every year, communities spend significant sums unplugging or replacing grease-blocked pipes, repairing pump stations, and cleaning up costly and illegal wastewater spills. If a blockage can be attributed to a particular business, these communities may charge the business for the repair of the sewer pipes and the spill cleanup. In addition, communities often add a surcharge to wastewater bills if a business exceeds a specified discharge limit. These expenses can be significant.  
         [0005]     In response, businesses attempt to reduce their FOG discharge through the use of, for example, grease traps. However, it is not practical to pump grease traps on a continual basis. Even if a grease trap is pumped on a monthly or weekly basis, in that time, significant portions of the grease will break down and turn septic. Not only does the grease have an offensive smell, but it will sink and pass out of the grease trap adding to the BOD (Biochemical Oxygen Demand) at the local sewer plant or contaminate and foul sand mounds or fields of on lot systems.  
         [0006]     With the ever increasing cost of petroleum based fuel, biodiesel fuel is taking a more prominent role. For purposes of this application, biodiesel fuel refers to a diesel-equivalent processed fuel derived from biological sources such as mono-alkyl esters of long chain fatty acids derived from vegetable oils or animal fats. Biodiesel may be used as a pure fuel or blended with petroleum in any percentage. FOG removed from gray water can serve as an important and easily obtained biological source for the production of biodiesel fuel, thereby reducing dependence on fossil fuels while simultaneously reducing stress on public and private sewage systems. FOG is also used in the manufacture of cosmetics, animal feeds and detergents.  
         [0007]     Known FOG removal systems such as those disclosed in U.S. Pat. Nos. 5,030,357; 4,268,396; and 4,051,024, assigned to Lowe Engineering, Friedens, Pa. and U.S. Pat. Nos. 6,878,270; 6,800,195; and 5,133,881 assigned to Thermaco, Inc., Asheboro, N.C. utilize a polyethylene revolving wheel and a wiper blade with polyethylene scraper blades, to remove FOG, which has an affinity for polyethylene. One significant disadvantage of such systems is that the wheel and blades as taught need continuous maintenance and replacement.  
         [0008]     Accordingly, there is still a continuing need for improved FOG removal and collection system designs. The present invention fulfills this need and further provides related advantages.  
       BRIEF SUMMARY OF THE INVENTION  
       [0009]     The present invention comprises a gravity draining automatic FOG interceptor with solids removal capability used as a first stage in the treatment of gray water. A first embodiment comprises a multi compartment container, the compartments separated by baffles, having a serviceable solids strainer in a first compartment, a second compartment having a FOG collection and removal device, a third compartment for collection of clarified effluent, and a fourth compartment for tertiary treatment of the gray water effluent, for example, the introduction of biotechnology. The unique baffle configuration prevents biotechnology backflow migration from the fourth compartment with resulting bacterial contamination of the FOG.  
         [0010]     A second preferred embodiment incorporates an additional FOG collection compartment.  
         [0011]     The present invention also contemplates a method of removing and collecting FOG utilizing the novel interceptor.  
         [0012]     One advantage of the present invention is that it requires far less maintenance than known technology.  
         [0013]     A second advantage of the present invention is that the novel baffle and/or modular configuration allows for early introduction of tertiary treatment such as biotechnology resulting in an effluent which places significantly less stress on both public and private sewer systems.  
         [0014]     Yet another advantage of the novel configuration is that biotechnology free FOG is collected which may then be used in the manufacture of biodiesel.  
         [0015]     Yet another advantage is the cost savings to both public and private entities that result from such cleaner effluent.  
         [0016]     Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]      FIG. 1  is a side view of the first embodiment.  
         [0018]      FIG. 2  is a top view of the first embodiment.  
         [0019]      FIG. 3  is a side view of a cogged belt skimmer attached to the second compartment.  
         [0020]      FIGS. 4, 6  and  7  are top views of various arrangements of the five compartments of the second embodiment.  
         [0021]      FIG. 5  is a side view of the second embodiment depicted in  FIG. 4 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0022]     Referring now to  FIGS. 1 through 3 , in a first preferred embodiment, the present invention comprises a container  2  having a plurality of compartments  4  separated by baffles  6 . Bold arrows  11  in  FIG. 3  depict effluent flow patterns. Interior of container  2  and baffles  6  are manufactured from any liquid impervious, biotechnology static material. As used herein, “bio-technology static material” refers to any material that does not allow growth and migration of biologic material, described in more detail below.  
         [0023]     Baffles  6  are mounted, for example, soldered or welded at an L fold  9 , within container  2 , forming liquid impervious barriers. Preferably, container  2  is a four compartment stainless steel square or rectangular tank, each compartment  4  separated from one another by a stainless steel baffle  6 . As used herein, the term “weir baffle” refers to a baffle which allows liquid to overflow the top of the baffle upon reaching a predetermined pool depth.  
         [0024]     Waste effluent and solids from, for example, a sink drain, floor drain, steamer or dishwasher, enter first compartment  8  through inlet  10 , located on container first end wall  7  such that waste effluent and solids must pass through solid material collector  12  before entering second compartment  14 . Solid material collector  11  is contained within first compartment  8  and has an effluent porous geometry to effectuate collection and disposal of effluent gross solid material  20 . It is preferably removable, for example, a removable strainer basket, most preferably a removable polypropylene or aluminum strainer basket.  
         [0025]     First weir baffle  16  forms a dividing wall to separate first  8  and second  14  compartments. It is positioned such that incoming waste effluent forms waste effluent pool  18  in first compartment  8 . Waste effluent pool  18  effectuates settling out of waste effluent gross solid material  20  into solid material collector  12  for subsequent operator removal. The resulting gross solid material free FOG effluent  22  overflows first weir baffle  16  into second compartment  14 . Preferably, solid material collector  12  extends above first weir baffle  16 , so that if it becomes clogged it acts as a weir, thereby maintaining effective flow patterns for FOG separation, described in detail below.  
         [0026]     Second compartment  14 , used to contain and collect gross solid material free FOG effluent  22 , is formed by first weir baffle  16  at its inflow end and containment baffle  24  at its outflow end. First weir baffle  16  and second weir baffle  26  create FOG effluent pool  28  within second compartment  14 , allowing FOG  30  to gravity-separate from heavier clarified non-FOG effluent  32 . Optionally, liquid heating element  49  is positioned and affixed within second compartment  14  in conventional fashion to promote FOG  30  separation. Devices to heat a liquid bath, their attachment within a bath and their electrical connection are well known and need not be described in detail herein. Containment baffle  24  does not extended to container floor  34  thereby permitting clarified non-FOG effluent  36  to pass into third compartment  38  while containing separated FOG  30  within second compartment  14 .  
         [0027]     Referring to  FIG. 3 , at least one skimmer  40 , for example, a cogged belt skimmer wheel skimmer, rope skimmer, drum skimmer or combinations thereof, extends below first weir baffle  16  to automatically, remove separated FOG  30 . In a preferred embodiment, cogged belt skimmer  40  of known design having fixed tail pulley  42 , cogged pulley  44 , cogged belt  46  and motor assembly  48 , such as the Mini-Skimmer manufactured by Wayne Products, Inc., Frazer, Pa., is mounted in known fashion, for example, using an L bracket within second compartment  14 .  
         [0028]     Separated FOG  30  is carried by cogged belt  46  out of second compartment  14 , removed from cogged belt  46  using blade  47  in known fashion, and deposited onto FOG discharge chute  50  for transfer to FOG collection container  52 . Preferably, cogged belt  46  extends at least six inches below first weir baffle  16 . FOG  30  may be deposited directly from discharge chute  50  into collection container  52 , or it may be transferred for example, via a hose (not shown) into a remotely located collection container  52 . In a preferred embodiment, cogged belt is fabricated from a material having an affinity to collect FOG  30 , for example, a steel reinforced polyurethane belt or a stainless steel belt.  
         [0029]     Motor assembly  48  is powered by conventionally electrical connection. Optional timer  54  bay be placed in conventional electrical connection between motor assembly  48  and the power source to allow for predetermined intermittent FOG removal. Optionally, switch  55 , for example, a float switch is located in FOG collection container  52 , operatively connected to skimmer  40  in known fashion to turn skimmer  40  off when FOG collection container  52  becomes full.  
         [0030]     Third compartmental  38  is formed by containment baffle  24  at its inflow end and second weir baffle  26  at its outflow end. Second weir baffle  26  creates FOG effluent pool  28  within third compartment  38  and serves as a barrier to prevent migration of biotechnology contained within fourth compartment  56  into other compartments Preferbly, top of second weir baffle  26  is lower than top of first weir baffle  16  (depicted in  FIG. 5 ). The height differentiation between the weir baffles  16 ,  26  creates a stronger eddy effect in second compartment  14  yielding more effective separation of FOG.  
         [0031]     Forth compartment  56  is formed by second weir baffle  26  at its inflow end and container second end wall  58  at its outflow end. Outlet  60  is positioned on container second end wall  58  below inlet  10  to create positive gravity drainage of clarified effluent and at the same time create tertiary, for example, biotechnology, treatment pool  62 . Outlet  60  connects in conventional manner to sewage wastewater piping (not shown) for transfer of clarified effluent for final public or private waste water treatment. The one-way effluent gravity flow from the higher entry of inlet  10  into first compartment  8  from the lower exit of outlet  60  from fourth compartment  56  prevents biotechnology back-flow and contamination of the entire system.  
         [0032]     Inlet  10  and outlet  60  are sized to effectuate a flow rate such that tertiary treatment pool  62  remains below the top of second weir baffle  26  to prevent migration of biotechnology. Optional flow restrictor  62 , for example, a gate valve or ball valve, is placed upstream of inlet  10  to further control flow rate. As described earlier, second weir baffle  26  is manufactured from biotechnology static material, for example, stainless steel. Prevention of biotechnology migration from fourth compartment  56  to other compartments is important so that reclaimed FOG  30  remains free of biotechnology, particularly important when reclaimed FOG  30  is to be used as a biological source for biodiesel.  
         [0033]     Biotechnology of the tertiary treatment comprises, for example, introduction of known bacterial microbes that reduce the BOD demand at the final public or private treatment facility. Such microbes include for example, facultative microbes and enzymes such as those produced by Bio-Solutions, Inc. of Hattiesburg, Miss. Cover  66  is removably mounted to container  2  in, for example, the “shoebox” manner displayed in  FIG. 5 .  
         [0034]     In a second preferred embodiment, FOG collection compartment  70  is incorporated into container  2  utilizing containment barrier  72 . Unlike containment baffle  24 , containment barrier  72  is affixed to container floor  34  and rises to a height sufficient to completely block effluent passage. In all other respects, the second embodiment incorporates the features described in the first embodiment.  
         [0035]      FIGS. 4 through 7  display examples of differing physical arrangements of compartments  8 ,  14 ,  38 ,  56 . and  70  of the second embodiment. FOG collection compartment  70  may directly receive removed FOG  30  from FOG discharge chute  50  as depicted in  FIGS. 6 and 7 , or it may be utilized to hold FOG collection container  52 , as depicted in  FIGS. 4 and 5 .  
         [0036]     Although the present invention has been described in connection with specific examples and embodiments, those skilled in the art will recognize that the present invention is capable of other variations and modifications within its scope. These examples and embodiments are intended as typical of, rather than in any way limiting on, the scope of the present invention as presented in the appended claims.