WO2023147004A1

WO2023147004A1 - Brown grease separator

Info

Publication number: WO2023147004A1
Application number: PCT/US2023/011682
Authority: WO
Inventors: Nicholas D. CLARK; Maruthi Mavinakunte HANUMANTHARAYAPPA; Phaneendra Govindasetty Tirumani; Jamison Kyle MILLS; Tod David USREY
Original assignee: Downey Ridge Environmental Company
Priority date: 2022-01-31
Filing date: 2023-01-27
Publication date: 2023-08-03

Abstract

An assembly to extract rich brown grease including: a containment vessel configured to receive grease trap waste, and a grease skimmer having: a support device; at least one suction strainer mounted to the support device; and at least one float mounted to the support device, wherein the grease skimmer has a buoyancy configured to float on a residual water layer and/or a batter layer in the containment vessel and sink the grease skimmer in a rich brown grease layer in the containment vessel.

Description

BROWN GREASE SEPARATOR RELATED APPLICATION [0001] This application incorporates by reference in its entirety and claims priority to U.S. Provisional Patent Application 63/305,166, filed January 31, 2022. TECHNICAL FIELD [0002] The present invention relates to separation and removal of rich brown grease from grease trap waste. BACKGROUND [0003] Grease traps collect food waste from restaurants and other food processors. The waste from a grease trap includes water, food scraps, grease fats, food solids and other typically organic materials. The grease trap waste is typically loaded into a containment vessel 10 as shown in Figure 1. [0004] FIGURE 1 shows a conventional containment vessel 10 configured to receive grease trap waste. The grease trap waste flows into the containment vessel 10 and is allowed to settle in the vessel as the waste is heated. The waste separates (stratifies) into layers which include layers for: residual water 12, batter 14, rich brown grease 16, and food solids 18. The batter 14 is typically an emulsion of food particles and other organic material. The rich brown grease 16 has a low density and forms in an uppermost layer in the vessel 10. The lowest and most dense layer is the residual water 12. Some food solids 18 collect at the bottom of the vessel. The batter 14 tends to be a thin layer between the layer of rich brown grease 16 and residual water 10. U.S. Patent 8,911,513, discloses a conventional containment vessel for separating rich brown grease from the grease trap waste. [0005] The vessel 10 is heated to promote separation of the layers. Heating also reduces the viscosity of the rich brown grease which promotes extraction of the rich brown grease from the containment vessel. Heating tubes 20 are positioned within the vessel to heat the grease trap waste. A heating fluid circulates through the tubes 20 and a boiler 22 that heats the heating fluid. [0006] A controller 23 determines when to turn on and off the boiler based on the temperature of the heating fluid and the temperature in the containment vessel. The controller ensures that the heating fluid remains below an upper temperature threshold, such as in a range of 180 to 185 degrees Fahrenheit (82 to 85 degrees Celsius). The controller shuts off the boiler to prevent overheating of the heating fluid and the grease trap waste in the containment vessel. If the temperature of the heating fluid drops below a certain temperature, such as 10 degrees Fahrenheit below the upper temperature threshold or in a range of 170 to 175 degrees Fahrenheit (77 to 80 degrees Celsius), the controller restarts the boiler to resume heating the heating fluid. By turning on and off the boiler, the controller ensures that the heating fluid does not exceed the upper temperature threshold while maintaining the heating fluid at a relatively high temperature to heat the grease trap waste in the containment vessel. [0007] After the layers stratify and the grease trap waste is heated, the rich brown grease is extracted from the vessel. Conventionally, a human operator inserts a hose into the vessel and positions an end of the hose in the rich brown grease layer. Suction is applied to the hose to pump out the rich brown grease. The other layers are then drained or pumped to empty the vessel. The manual extraction of rich brown grease is a messy, prone to spillage, prone to inadvertently extracting batter and residual water with the rich brown grease, and requires a human operator to physically handle the hose and attend to the extraction of the rich brown grease. [0008] The empty vessel is ready to receive a new batch of grease trap waste. The batch process of filling a vessel with grease trap waste, heating the waste, stratifying the waste into layers of different composition, and extracting the layers may take a day (24 hours) for a 10,000 gallon vessel 10. [0009] To increase the rate of processing grease trap waste it is known to used twin containment vessels 10. The vessels are heated by a common boiler 22. As one vessel is heated, grease trap waste is pumped into the other vessel and settles to start the stratification process. The controller for the two containment vessels directs hot heating fluid through one of the heating vessels until the grease trap waste in that vessel is heated, stratified, and extracted. [0010] The rich brown grease extracted from the containment vessel may be used as a biofuel, such as in the boiler to heat the heating fluid. The residual water, food solids and batter extracted separately from the vessel may be further processed, such as in a waste water treatment system. BRIEF DESCRIPTION OF THE INVENTION [0011] There is a long felt need to automate the process of treating grease trap waste and extracting rich brown grease from the waste. The inventions disclosed herein provides automation of the extraction of the rich brown grease, the circulation of the heating fluid through containment vessels and determining the depth of the liquid layers in the containment vessels. [0012] The invention may be embodied as an assembly to extract organic material from a liquid comprising: a containment vessel configured to receive the liquid, and a skimmer including: a support device; at least one suction strainer, and at least one float connected to the suction strainer, wherein the skimmer has a buoyancy configured to float on or above a residual water layer in the containment vessel and sink the at least one suction strainer in a liquid layer containing the organic material in the containment vessel. [0013] The assembly may include a passage extending from the at least one suction strainer to an organic outlet at an upper region of the containment vessel. The passage may include a vertical support tube connected to the at least one suction strainer and the at least one float. The passage may further include an extended conduit having a lower end connected to the vertical support tube and an upper end connected to a swivel joint mounted to the containment vessel. [0014] The assembly may include an inspection cable connected at a first end to a lower region of the extended conduit or the vertical support tube, and connected at a second end to an upper portion of the containment vessel, wherein the inspection cable limits a downward movement of the skimmer within the containment vessel. [0015] The skimmer may further include: a base beam to which is attached the at least one suction strainer; and at least one rod extending substantially vertically up from the base beam, wherein the at least one float is mounted to the at least one rod at an elevation which may be varied by moving the at least one float with respect to the at least one rod. [0016] The at least one rod may include a first rod at a first end region of the base beam and a second rod at a second end region of the base beam, and the at least one float includes a first float mounted to the first rod and a second float mounted to the second rod, wherein the first float and the second float each have a substantially similar mass and density, and wherein the first rod and the second rod are arranged symmetrically about a center of the base beam. [0017] The assembly may further include a first weight mounted to the first rod and a second weight mounted to the second rod, wherein the first weight and second weight each have a density greater than a density of the residual water layer, and the first float and the second float each have a density less than a density of the residual water layer. [0018] The assembly may further include a pump configured to pump the organic material from the containment vessel, into the at least one suction strainer and out of the containment vessel. [0019] The invention may be embodied as an assembly to extract rich brown grease comprising: a containment vessel configured to receive grease trap waste, and a grease skimmer including: a support device; at least one suction strainer mounted to the support device, and at least one float mounted to the support device, wherein the grease skimmer has a buoyancy configured to float on a residual water layer and/or a batter layer in the containment vessel and sink the grease skimmer in a rich brown grease layer in the containment vessel. [0020] The assembly may comprise a passage extending from the at least one suction strainer to a rich brown grease outlet at an upper region of the containment vessel. The passage may include a vertical support tube connected to the at least one suction strainer and the at least one float. The passage may further include an extended conduit having a lower end connected to the vertical support tube and an upper end connected to a swivel joint mounted to the containment vessel. [0021] The assembly may further include an inspection cable connected at a first end to a lower region of the extended conduit or the vertical support tube, and connected at a second end to an upper portion of the containment vessel, wherein the inspection cable limits a downward movement of the grease skimmer within the containment vessel. [0022] The grease skimmer may further include: a base beam to which is attached the at least one suction strainer; and at least one rod extending substantially vertically up from the base beam, wherein the at least one float is mounted to the at least one rod at an elevation which may be varied by moving the at least one float with respect to the at least one rod. The at least one rod may include a first rod at a first end region of the base beam and a second rod at a second end region of the base beam, and the at least one float includes a first float mounted to the first rod and a second float mounted to the second rod, wherein the first float and the second float each have a substantially similar mass and density, and wherein the first rod and the second rod are arranged symmetrically about a center of the base beam. [0023] The assembly may further include a first weight mounted to the first rod and a second weight mounted to the second rod, wherein the first weight and second weight each have a density greater than a density of the residual water layer, and the first float and the second float each have a density less than a density of the residual water layer. [0024] The assembly may further include: a pump configured to pump rich brown grease from the containment vessel, into the at least one suction strainer and out of the containment vessel. [0025] The invention may be embodied as grease skimmer including: an extended conduit having a first end configured to connect to fluid passage extending externally of a containment vessel adapted to receive grease trap waste; a support device connected to an end of the extended conduit and support device includes: at least one suction strainer mounted to the support device; and at least one float mounted to the support device, wherein the grease skimmer has a buoyancy configured to float on a residual water layer and/or a batter layer in the containment vessel and sink in a rich brown grease layer in the containment vessel. [0026] The extended conduit may include a lower end connected to the support device and an upper end connected to a swivel joint mounted to the containment vessel. [0027] The grease skimmer may include an inspection cable connected at a first end to a lower region of the extended conduit or the vertical support tube, and connected at a second end to an upper portion of the containment vessel, wherein the inspection cable limits a downward movement of the grease skimmer within the containment [0028] The support device may include: a base beam to which is attached at least one suction strainer; and at least one rod extending substantially vertically up from the base beam, wherein the at least one float is mounted to the at least one rod at an elevation which may be varied by moving the at least one float with respect to the at least one rod. [0029] The at least one rod may include a first rod at a first end region of the base beam and a second rod at a second end region of the base beam, and the at least one float includes a first float mounted to the first rod and a second float mounted to the second rod, wherein the first float and the second float each have a substantially similar mass and density, and wherein the first rod and the second rod are arranged symmetrically about a center of the base beam. [0030] The grease skimmer may further include a first weight mounted to the first rod and a second weight mounted to the second rod, wherein the first weight and second weight each have a density greater than a density of the residual water layer, and the first float and the second float each have a density less than a density of the residual water layer. [0031] The invention may be embodied as a method to extract rich brown grease from a containment vessel for grease trap waste, the method comprising: separating the rich brown grease from at residual water in great trap waste held in the containment vessel; positioning a suction skimmer in the containment vessel wherein the suction skimmer is buoyant with respect to the residual water and sinks in rich brown grease, and after the rich brown grease separates from the residual water, sucking the rich brown grease into a conduit connected to the suction skimmer and pumping the rich brown grease out of the containment vessel. [0032] The positioning of the suction skimmer may include pivoting an extended conduit connected to a swivel joint attached to an upper portion of the containment vessel, wherein a lower end of the extended conduit is connected to the suction skimmer. [0033] The method may include adjusting the buoyancy of the suction skimmer by adding or removing floats or weights to suction skimmer. [0034] The method may further include adjusting an elevation of at least one float with respect to the suction skimmer. [0035] The adjusting the elevation of at least one float may position the suction skimmer in a range of two to eight inches from a bottom of a layer of the rich brown grease. BRIEF DESCRIPTION OF THE DRAWINGS [0036] FIGURE 1 is a schematic cross-sectional view of a conventional brown grease separator containment vessel and boiler. [0037] FIGURE 2 is a side view of a brown grease containment vessel with a portion of the sidewall cut- away to show components within the vessel. [0038] FIGURE 3 is an end view of a first end of the containment vessels shown in FIG. 2. [0039] FIGURE 4 is a top down view of the containment vessels shown in FIG. 2. [0040] FIGURE 5 is a perspective view of a grease skimmer assembly. [0041] FIGURE 6 is a side view of the grease skimmer assembly shown in FIG. 5. [0042] FIGURE 7 is a topdown view of the grease skimmer assembly shown in FIG. 7. DETAILED DESCRIPTION OF THE INVENTION [0043] FIGURES 2 to 4 show side, top and end views, respectively of a containment vessel 30 for a grease separator system. The containment vessel 30 may be a 10,000 gallon vessel, a vessel having a capacity of 7,500 to 12,500 gallons, or other capacity selected, for example, based on the supply of grease trap waste. The term grease trap waste means waste from grease traps and/or other sources of food wastes, often referred to as FOG for fat, oil, and grease. [0044] Support legs 32 support the containment vessel on the ground or on a support skid. There may be two or more containment vessels next to each other and connected to the same boiler. [0045] The containment vessel may include an upper fill port 34 into which may be pumped grease trap waste. A lower port(s) 36 may be used to extract some materials, such as residual water, batter and food solids. The lower port may also be used to fill the containment vessel with the grease trap waste. [0046] Grease trap waste fills the containment vessel 30 and separates into layers, as discussed above with respect to Figure 1. Rich brown grease, in layer 16, is ready for extraction from the containment vessel after the layers are formed and the grease trap waste is heated. [0047] Heating tubes 38 may be arranged in a serpentine pattern as shown in Figure 2. The heating tubes are shown with dotted lines in Figure 2 to illustrate that the tubes are within the containment vessel. In Figure 2, a center portion of the containment vessel is cut away to illustrate the heating tubes 38 and a grease skimmer assembly 60. The grease skimmer assembly in Fig. 2 is rotated 90 degrees for purposes of illustration to show a top-down view of the assembly. [0048] Heating fluid circulates between the heating tubes 38 and a boiler 22. The heating tubes have an inlet 42 on the containment vessel and an outlet 40, both of which are connected to pipes connected to the boiler. An air vent 44 coupled to the heating tubes allows air to be purged from the heating liquid. A drain 46 allows heating liquid to be drained from the tubes 38. [0049] Temperature sensors 48 measures the temperature of liquid within the containment vessel at various levels in the vessel such as upper, middle and bottom levels. Another temperature sensor 50 (Fig. 4) measures the temperature of the heating fluid exiting the heating tubes 38 in the containment vessel. A fluid level monitor 52 detects a lower level of the rich brown grease layer. The controller uses data from the fluid level monitor to calculate the depth (thickness) of the rich brown grease layer. A controller 54 receives measurement signals from the temperature sensors and fluid level monitors. The controller may include a computer processor and digital memory to store the measurement signals, settings of the containment vessel and boiler, and computer programs with instructions for operating the containment vessel. The controller may determine when the boiler is heating the heating fluid, when to pump the heating fluid through the heating tubes, when a pump extracts rich brown grease and when to pump remaining liquids from the containment vessel. These determinations may be based on the measurement signals from the temperature sensors and rich brown grease monitor. [0050] A grease skimmer assembly 60 in the containment vessel extracts rich brown grease. The grease skimmer assembly floats within the containment vessel on the batter 14 layer or the residual water 12 layer. For example, if there is no batter layer, the grease skimmer assembly floats on the upper level of the residual water layer. The grease skimmer assembly 60 sinks in the rich brown grease 16 layer. Rich brown grease is sucked into the skimmer assembly and pumped from the containment vessel. [0051] The grease skimmer assembly 60 is accessible within the containment vessel through an upper opening 62 in the containment vessel. The opening may be covered by a riser housing 64. The opening allows the grease skimmer assembly to be inserted and removed from the containment vessel. The opening 62 also allows access to the grease skimmer assembly to, for example, adjust the height of floats on the grease skimmer assembly. [0052] The opening 62 allows an extended conduit 66 to exit the containment vessel and connect to a pump 68 which pumps rich brown grease to provide suction to draw the rich brown grease into the grease skimmer assembly. The rich brown grease is sucked into the grease skimmer assembly, is pumped through the extended conduit 66 by the pump 68, through a grease strainer and/or filter 70 and to an outlet 72 of a fluid passage for the rich brown grease. The rich brown grease may be output to a collection tanker for processing as a biofuel or to provide fuel to be burned in the boiler 22. A flow meter 73 (Fig. 4) measures a flow rate of the rich brown grease being pumped from the containment vessel. [0053] A cover 74 for the riser housing 64 shields the opening 62 from debris falling into the containment vessel and suppresses odors from escaping the containment vessel and entering the atmosphere. An air filter 76 may be integrated into the cover 74 to reduce the odors and allow ventilation of the containment vessel. [0054] FIGURES 5, 6 and 7 are perspective, top down and side views, respectively, of the grease skimmer assembly 60. The grease skimmer assembly 60 includes suction strainers 84 which may be positioned slightly above, such as in a range of two to eight inches (5 to 20 cm), above the interface between the rich brown grease and batter layers. The suction strainers 84 are inlets to a series of pipes that form a passage from the suction strainers to the rich brown grease outlet 72. [0055] The grease skimmer assembly 60 includes floats 82 that float on the surface of the batter layer 14 and/or the residual water layer 12. The floats and the rest of the grease skimmer assembly 60 sink into the rich brown grease of layer 16 and floats on either or both the batter in layer 14 and the residual water in layer 12. [0056] The components of the grease skimmer assembly 60 includes the floats 82, suction strainers 84, a base beam 86, a vertical support tube 88 and conduits 90 supporting the suction strainers. The base beam 86 supports the floats and the vertical support shaft, which itself supports the conduits 90 and suction strainers 84. These components may be formed of materials, such as aluminum, stainless steel or plastic that may be denser than water. [0057] The floats 82 may be hollow with sealed air-filled chambers. The floats may be less dense than the rich brown grease. Weights 92, such as iron discs, may be added to reduce the buoyancy of the grease skimmer assembly and cause the skimmer assembly to skink through the rich brown grease and float on the batter and/or residual water. The floats and weights are mounted to threaded rods 94 that extend substantially vertically upward from the base beam. [0058] The grease skimmer assembly 60 floats on the residual water layer but may or may not float on the batter layer. The density of the batter layer is greater than the rich brown grease and less than the residual water. Regardless of whether the grease skimmer floats on the batter layer or the residual water layer, the floats and weights position the suction strainers 84 in the layer of rich brown grease, such as at a level in the rich brown grease two to eight inches (5 to 20cm) above the batter layer. [0059] The density of water is 1 g/cm³, which is representative of the density of the residual water in the containment vessel. The density of rich brown grease (or other organic liquid mixture, such as organic, non- petroleum mixture) which is less than the density of the residual water and typically in a range of 0.86 g/cm³ to 0.93 g/cm³, as reported in “Are You Aware Of Grease Trap Science”, Grease Guardian®, Frontline Engineering; Automatic Grease Trap Manufacturers (July 20, 2018). The grease skimmer assembly 60 should have an average density in a range of 0.99 g/cm³ to 0.93 g/cm^3, or to 0.865 gm/cm³. [0060] The mass and density of the floats 82 should be sufficient to provide buoyancy for the entire grease skimmer assembly 60. The density of the floats may be less than that of the rich brown grease layer to compensate for the higher density of other components in the skimmer assembly, such as the base beam, suction skimmers, support shaft and to compensate for the mass of the extended conduit 66. The density of the floats must be less than that of residual water to ensure that the skimmer assembly does not sink into the residual water. [0061] Because the grease skimmer assembly 60 floats on the surface of the residual water or batter layer, the grease skimmer assembly moves up or down within the containment vessel as the volume of residual water and batter changes in the vessel. The volume of residual water or batter varies depending on the composition of the grease trap waste. Because the volume may vary, the elevation of the surface of the residual water or batter layer may change within the containment vessel from one batch of grease trap waste to another. Floating the grease skimmer assembly on the residual water or batter allows the grease skimmer assembly to automatically position the suction strainers 84 within the rich brown grease layer, such as near the bottom of the rich brown grease layer and within a few inches, e.g., two to eight inches, of the batter layer. [0062] The grease skimmer assembly 60 may be positioned within the containment vessels between columns of the heating tubes 38. The heating tubes may be arranged in a serpentine pattern in which the tubes extend horizontally across the length of the containment vessel and extend back through the length of the vessel. The heating tubes 38 may form vertical columns along left and right regions of the containment vessel. A horizontal gap 96 (Fig. 3) between the vertical columns of tubes may receive the grease skimmer assembly 60. Positioning the grease skimmer assembly in the gap 96 allows the heating tubes to be positioned in the upper elevations of the containment vessel and, particularly in the rich brown grease layer. Positioning the heating tubes in upper, middle and lower elevations in the containment vessels assists in uniformly heating the great trap waste and separating the waste into layers within the containment vessel. [0063] The base beam 86 may be oriented horizontally and provides a support for the floats 82 and a vertical support tube 88. Threaded rods 94 are mounted to opposite ends of the base beam and extend upward, e.g., vertically. The treaded rods may be at equal distances from a center of the base beam. The vertical support tube 88 may be attached to the center of the base beam. [0064] Multiple floats 82 may be mounted to each of the threaded rods. Also weights 92 may be mounted to the treaded rods in a manner similar to the mounting of the floats to the threaded rods. The mass, density and number of floats and weights are selected to achieve a buoyance of the skimmer that floats the grease skimmer on the batter layer and/or residual water and sinks the skimmer in the rich brown grease. [0065] The mass, density and number of floats and weights may be selected by first measuring the densities of the rich brown grease, batter and residual water. Alternatively, known density values for rich brown grease, batter and residual water may be selected as the densities of these layers. [0066] The mass, density and/or number of floats and weights are selected to achieve a buoyancy of the grease skimmer that is less than the density of the batter or the residual water and greater than the density of the rich brown grease layer. The selection may be based on calculations of the buoyance of the grease skimmer with various types and/or numbers of floats and weights. Alternatively, the selection may be based by experimenting to determine the types and/or numbers of floats or weights needed to make the grease skimmer skin in the rich brown grease layer and float on the residual water and/or batter. [0067] Once a desired buoyancy of the grease skimmer assembly 60 is achieved such as by calculations and/or experimentation, the elevations of the floats and weights on the treaded rods are adjusted to position the suction strainers 84 within the rich brown grease layer, such as two to eight inches above the batter layer. [0068] The threaded rods 94 each receive one, two or more floats 82 and weights 92 (or no weights). The floats and weights may include nuts or other threaded holes to engage the threaded rods. The elevation of the floats and weights with respect to the base beam is determined by the engagement of the floats and the threaded rod. Turning the floats or the nuts associated with the floats positions the floats at a selected elevation on the threaded rods. It may be sufficient to only have the lower most float or weight to have a nut to engage the threaded rod. [0069] The floats and weights may be arranged symmetrically on the base beam to apply a substantially vertical upward force, e.g., at least a 90 percent vertical force, on the beam and the vertical support tube. The symmetrical arrangement of the floats and weights avoids applying a moment that twists the beam and vertical support tube about a horizontal axis. A symmetrical arrangement of floats and weights may be achieved by each suction strainer sucks in the rich brown grease in the upper layer 16 of the containment vessel. The pore side of the perforations is selected to allow the rich brown grease to enter the suction strainer and to filter out, e.g., prevent entrance, of solid maters than may be in the rich brown grease layer. [0070] Each suction strainer 84 includes an inner chamber into which the rich brown grease initially collects. The top of each suction strainer may be perforated to allow the rich brown grease to enter the inner chamber in the suction strainer. The size of the perforations may be large enough to allow passage of the rich brown grease but small enough to prevent passage of food solids or other large particles. The bottom of each suction strainer may be a solid panel lacking openings. Avoiding openings in the bottoms of the suction strainers reduces the risk that batter is sucked into the suction strainers. [0071] An outlet port of each of the suction strainers is connected to a conduit 90 that is in fluid communication with the hollow vertical support tube 88. The conduit 90 may also provide structural support for the suction strainer. A pair of conduits may form a T-shaped arrangement to support a pair of the suction strainers. The conduits may position the suction strainers at a uniform elevation with respect to the vertical support tube and base beam. [0072] The vertical support tube 88 may have an upper end with a flange that connects to a first rotatable swivel joint 100. The first swivel joint allows the vertical support tube to hang vertically in the rich brown grease. [0073] The first swivel joint connects to the extended conduit 66, e.g., five to 20 feet in length. The extended conduit has an upper end connected to a second swivel joint 102 mounted on or near an interior surface of the containment vessel. The lower end of the extended conduit moves up and down within the containment vessel as the upper end pivots about the second swivel joint. The up and down movement of the lower end of the extended conduit has a corresponding up and down movement of the floats, weights, suction strainer, base beam and vertical support tube. [0074] The amount of rotation of the first and/or the second swivel joints may be limited to 45 degrees or a range of 30 degrees to 75 degrees, 15 degrees to 45 degrees, or 20 degrees to 40 degrees. Limiting the degrees of rotation of the swivel joints may be used to prevent the grease skimmer assembly from dropping to low in the containment vessel, especially when the liquids are removed from the vessel. [0075] An inspection cable 104 may be attached to a lower end region of the extended conduit 66 or the vertical support tube 88 and to an upper region of the containment vessel. The inspection cable prevents the grease skimmer assembly from dropping to low in the containment vessel, especially when the liquids are removed from the vessel. The inspection cable may also be used to raise the grease skimmer assembly in the inspection vessel, such as when liquids are removed from the vessel. A winch 106 on top of the containment vessel may be used to pull up the inspection cable and raise the grease skimmer assembly 60. [0076] An internal passage for rich brown grease extends from the suction strainers 84, through the vertical support tube 88, the first swivel joint 100, the extended conduit 66, the second swivel joint 102 and through the piping external to the containment vessel. [0077] The invention may be applied in separation system used to extract organic material from a liquid or a mixture of liquids, e.g., an emulsion. The organic material may be non-petroleum material such as fats, oils and/or grease (FOG), grease waste trap materials, agricultural wastes and cooking oil including used cooking oil (UCO). The separation systems may be in wastewater treatment plants, used by service providers that pump waste from grease traps and used by other processors needing to separate organic material from a liquid(s). [0078] The reference numbers in the Figures corresponds to the following components of the embodiment disclosed herein: [0079] containment vessel 10 [0080] Residual water 12 [0081] Food solids 14 [0082] Rich brown grease 16 [0083] Batter 18 [0084] Heating tubes 20 [0085] boiler 22 [0086] Containment vessel 30 [0087] Support legs 32 [0088] Upper fill port 34 [0089] Lower port for extraction 36 [0090] Heating tubes 38 [0091] Outlet of heating tube 40 [0092] Inlet of heating tube 42 [0093] Air vent 44 [0094] Drain for heating fluid 46 [0095] Temp sensor 48 [0096] Temp sensor 50 [0097] Fluid level monitor 52 [0098] Controller 54 [0099] Grease skimmer assembly 60 [00100] Opening 62 [00101] Riser housing 64 [00102] Conduit 66 [00103] Pump 68 [00104] filter 70 [00105] Outlet 72 [00106] Flow meter 73 [00107] cover 74 [00108] Air filter 76 [00109] Float 82 [00110] strainer 84 [00111] Base beam 86 [00112] Support tube 88 [00113] Conduit 90 [00114] weights 92 [00115] Rods 94 [00116] Swivel joint 100 [00117] Swivel joint 102 [00118] Inspection cable 104 [00119] While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

CLAIMS: The invention is: 1. An assembly to extract organic material from a liquid mixture comprising: a containment vessel (30) configured to receive the liquid mixture, and a skimmer (60) including: a suction strainer (84), and a float (82) connected to the suction strainer, wherein the skimmer has a buoyancy configured to float on or above a water layer (12) in the containment vessel and sink the suction strainer in a liquid layer (16) containing the organic material in the containment vessel.

2. The assembly of claim 1, further comprising a passage (90, 66) extending from the suction strainer to an organic outlet (72) above or at an upper region of the containment vessel.

3. The assembly of claim 2, wherein the passage includes a vertical support tube (90) connected to the suction strainer and the float.

4. The assembly of claim 3, wherein the passage further includes an extended conduit (66) having a lower end connected to the vertical support tube and an upper end connected to a swivel joint (102) mounted to the containment vessel.

5. The assembly of claim 4, further comprising: an inspection cable (104) connected at a first end to a lower region of the extended conduit or the vertical support tube, and connected at a second end to an upper portion of the containment vessel, wherein the inspection cable limits a downward movement of the skimmer within the containment vessel.

6. The assembly of any one of claims 1 to 5, wherein the skimmer further includes: a base beam (86) to which is attached the suction strainer; and a rod (64) extending substantially vertically up from the base beam, wherein the float is mounted to the rod at an elevation which may be varied by moving the float with respect to the rod.

7. The assembly of claim 6, wherein the rod is a first rod (64) at a first end region of the base beam and the assembly includes a second rod (64) at a second end region of the base beam, and wherein the float is a first float (82) mounted to the first rod; wherein the assembly includes a second float (82) mounted to the second rod, wherein the first float and the second float each have a substantially similar mass and density, and wherein the first rod and the second rod are arranged symmetrically about a center of the base beam.

8. The assembly of any one of claims 6 and 7, further comprising a first weight (82) mounted to the first rod and a second weight mounted (82) to the second rod, wherein the first weight and second weight each have a density greater than a density of the water layer, and the first float and the second float each have a density less than a density of the water layer.

9. The assembly of any one of claims 1 to 8, further comprising: a pump (68) configured to pump the organic material from the containment vessel, into the at least one suction strainer and out of the containment vessel.

10. An assembly to extract organic grease comprising: a containment vessel configured to receive grease trap waste or other organic waste, and a grease skimmer including: a support device; at least one suction strainer mounted to the support device, and at least one float mounted to the support device, wherein the grease skimmer has a buoyancy configured to float on a residual water layer and/or a batter layer in the containment vessel and sink the grease skimmer in a rich brown grease layer in the containment vessel.

11. The assembly of claim 10, further comprising a passage extending from the at least one suction strainer to a grease outlet at an upper region of the containment vessel.

12. The assembly of claim 11, wherein the passage includes a vertical support tube connected to the at least one suction strainer and the at least one float.

13. The assembly of claim 12, wherein the passage further includes an extended conduit having a lower end connected to the vertical support tube and an upper end connected to a swivel joint mounted to the containment vessel.

14. The assembly of claim 13, further comprising an inspection cable connected at a first end to a lower region of the extended conduit or the vertical support tube, and connected at a second end to an upper portion of the containment vessel, wherein the inspection cable limits a downward movement of the grease skimmer within the containment vessel.

15. The assembly of any one of claims 10 to 14, wherein the grease skimmer further includes: a base beam to which is attached the at least one suction strainer; and at least one rod extending substantially vertically up from the base beam, wherein the at least one float is mounted to the at least one rod at an elevation which may be varied by moving the at least one float with respect to the at least one rod.

16. The assembly of claim 15, wherein the at least one rod includes a first rod at a first end region of the base beam and a second rod at a second end region of the base beam, and the at least one float includes a first float mounted to the first rod and a second float mounted to the second rod, wherein the first float and the second float each have a substantially similar mass and density, and wherein the first rod and the second rod are arranged symmetrically about a center of the base beam.

17. The assembly of any one of claims 15 and 16, further comprising a first weight mounted to the first rod and a second weight mounted to the second rod, wherein the first weight and second weight each have a density greater than a density of the residual water layer, and the first float and the second float each have a density less than a density of the residual water layer.

18. The assembly of any one of claims 10 to 17, further comprising: a pump configured to pump the grease from the containment vessel, into the at least one suction strainer and out of the containment vessel.

19. A grease skimmer including: an extended conduit having a first end configured to connect to fluid passage extending externally of a containment vessel adapted to receive grease trap waste; a support device connected to an end of the extended conduit and support device includes: at least one suction strainer mounted to the support device; and at least one float mounted to the support device, wherein the grease skimmer has a buoyancy configured to float on a residual water layer and/or a batter layer in the containment vessel and sink in a rich brown grease layer in the containment vessel.

20. The grease skimmer of claim 19, wherein the extended conduit includes a lower end connected to the support device and an upper end connected to a swivel joint mounted to the containment vessel.

21. The grease skimmer of claim 19 or 20, further comprising an inspection cable connected at a first end to a lower region of the extended conduit or the vertical support tube, and connected at a second end to an upper portion of the containment vessel, wherein the inspection cable limits a downward movement of the grease skimmer within the containment vessel.

22. The grease skimmer of any one of claims 19 to 21, wherein the support device further includes: a base beam to which is attached the at least one suction strainer; and at least one rod extending substantially vertically up from the base beam, wherein the at least one float is mounted to the at least one rod at an elevation which may be varied by moving the at least one float with respect to the at least one rod.

23. The grease skimmer of claim 22, wherein: the at least one rod includes a first rod at a first end region of the base beam and a second rod at a second end region of the base beam, and the at least one float includes a first float mounted to the first rod and a second float mounted to the second rod, wherein the first float and the second float each have a substantially similar mass and density, and wherein the first rod and the second rod are arranged symmetrically about a center of the base beam.

24. The grease skimmer of claim 22 or 23, further comprising a first weight mounted to the first rod and a second weight mounted to the second rod, wherein the first weight and second weight each have a density greater than a density of the residual water layer, and the first float and the second float each have a density less than a density of the residual water layer.

25. A method to extract rich brown grease from a containment vessel for grease trap waste, the method comprising: separating the rich brown grease from at residual water in great trap waste held in the containment vessel; positioning a suction skimmer in the containment vessel wherein the suction skimmer is buoyant with respect to the residual water and sinks in rich brown grease, and after the rich brown grease separates from the residual water, sucking the rich brown grease into a conduit connected to the suction skimmer and pumping the rich brown grease out of the containment vessel.

26. The method of claim 25, wherein the positioning of the suction skimmer includes pivoting an extended conduit connected to a swivel joint attached to an upper portion of the containment vessel, wherein a lower end of the extended conduit is connected to the suction skimmer.

27. The method of claim 25 or 26, further comprising adjusting the buoyancy of the suction skimmer by adding or removing floats or weights to suction skimmer.

28. The method of any one of claims 25 to 27, further comprising adjusting an elevation of at least one float with respect to the suction skimmer.

29. The method of claim 28, wherein the step of adjusting the elevation of the at least one float positions the suction skimmer in a range of two to eight inches from a bottom of a layer of the rich brown grease.