Liquid purification or separation – Filter – With pump – gas pressure – or suction source
Reexamination Certificate
2000-05-10
2002-04-02
Lithgow, Thomas M. (Department: 1724)
Liquid purification or separation
Filter
With pump, gas pressure, or suction source
C210S241000, C210S184000, C210S186000, C210S470000
Reexamination Certificate
active
06365046
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates generally to the field of cooking equipment, and, more particularly, to an improved, automated device for effective removal of waste grease from a grease trap, and for the transportation of the waste grease to a storage container for proper disposal.
In the restaurant industry, grill stations used for the preparation of food products typically include holding reservoirs, commonly known as grill grease traps. These grease traps contain used remains from cooking, including in particular waste grease (beef tallow), along with solid particles. The solid particles may include meat, egg, starch, or other food particles, or carbon residue that may have been scraped from the grill cooking surface. Disposal of the waste grease and solid particles that accumulate in the grease traps has been a longstanding problem for restaurants. It is environmentally harmful to dispose of the waste grease into a drain or garbage container. For this reason, rendering containers are used to dispose of the grease. Traditionally, restaurant employees would empty the waste grease in buckets. The employees would then manually carry the buckets to the back parking lot of the restaurant, where the waste grease would be poured into the rendering tank.
Previous devices have been directed to the removal of oil from fryers, usually for recycling, and therefore these devices have not addressed the problem of removing waste grease. One such device, disclosed in U.S. Pat. No. 5,609,193 to Steckler, “Automated Container for Waste Grease,” is directed to the removal of spent fryer grease from a fryer for recycling. Steckler shows a tank 11 (FIG. 2) with liquid level sensors. A stationary filter pump 62 periodically transfers a portion of the spent fryer grease from a fryer 80 to the tank. When the liquid level sensors indicate that the tank has accumulated a predetermined level of spent fryer grease, a truck is coupled to the tank for removal of the grease. The container there disclosed removes the need for a back parking lot rendering tank. However, the device does not replace the manual task of removing and disposing of waste grease from grill station grease traps. For removal and transport of waste grease, the grease trap typically has to be removed from the grill station. Spillage of waste grease is a common problem, resulting in hazardous work conditions, as well as added cleanup time to remove the spilled waste grease. In addition, as waste grease cools, it solidifies, creating additional difficulties for the removal of the grease from the grease trap. A way to more effectively remove waste grease to a waste storage container is desired.
Another prior device directed to removal and recycling of oil is disclosed in U.S. Pat. No. 4,113,623, to Koether et al. Koether et al disclose a filter apparatus using an inlet/outlet hose which transports used oil from a fryer through a two-way pump to a holding tank. When it is desired to return the oil to the fryer, the pump motor is reversed, drawing the used oil through a disposable filter bag that has been submersed in the used cooking oil. The (filtered) oil is returned through the pump and to the fryer. If the filter becomes clogged due, for example, to the hardening of oil or grease that has cooled, the filter must be disconnected and cleaned or replaced.
U.S. Pat. No. 4,702,827, to Wenzel, discloses a portable filter for filtering solid material from a reusable cooking medium (oil) and returning the filtered oil to a fryer. The portable filter uses a reversible pump to draw the oil into a storage container. To return the oil to the fryer, the pump motor is reversed, drawing the return oil through a filter, which removes solid particles from the return oil and delivers the oil to the fryer. If solid oils are present in the return oil, a wrap around heater, present in the return plumbing, may be activated to melt the solids. Because the device disclosed in Wenzel is designed for filtering oil from a fryer, the device requires the use of a holding container, and the device only filters and heats the oil upon returning it to the fryer. Because of this, the portable filter of Wenzel is prone to clogs from waste grease entering the device, and it is difficult to clean.
Accordingly, it is an object of this invention to provide a waste grease removal system that is automatic, and that may be used without removing the grease trap.
A further object of this invention is to provide a waste grease removal system that will draw waste grease from a grease trap and deliver it directly to any storage container, without the need for a temporary container.
A further object of this invention is to provide a waste grease removal system that will prevent waste grease from solidifying as it passes through the system.
A further object of this invention is to provide a waste grease removal system that will prevent solid particles from damaging or causing premature wear on the pump as the pump draws the waste grease.
A further object of this invention is to provide a waste grease removal system that may be cleaned easily and thoroughly, and to provide a system that contributes to a cleaner and less hazardous workplace.
SUMMARY OF THE INVENTION
These and other useful objects are achieved by the present invention, an automated system for removing waste grease from a grease trap. The invention uses an intake assembly, or wand/hose assembly, for insertion into the grease trap. The user manipulates a wand to draw waste grease into the system, while operating an optional strainer/scooper to prevent larger solid particles from entering, the wand. A pump provides the suction for drawing the waste grease through the wand and through the intake assembly. A filter in-line with the intake assembly is employed to remove solid particles that remain in the system and prevent them from entering the pump. The filtered waste grease enters a suction line, passes the pump, and then enters a pressure line to a storage container, of the user's choosing, for removal, without needing to be initially stored in a temporary holding container within the system. To prevent solidification of the waste grease as it is drawn through the system, a heater is provided for the suction line and preferably other components of the system. Typically, the heater is in the form of heat tape, which is attached to the suction line, pump, and pressure line, though other means for heating are possible, such as pad heaters. The pump and heater are operatively coupled to a power supply, and the system may include a power switch for selective operation.
In a typical embodiment of the invention, the pump, suction line and pressure line are housed within an outer container, the outer container being covered so as to protect the inner components of the system and also to conserve heat within the lines and pump. The intake assembly and any desired storage container are connected to couplings located on front and rear walls, respectively, of the outer container. For easy cleaning, the intake assembly may be detachable from the remainder of the system for connection to a sink, or other water source, in order to flush the intake assembly.
The following detailed description of embodiments of the invention, taken in conjunction with the appended claims and accompanying drawings, provide a more complete understanding of the nature and scope of the invention.
REFERENCES:
patent: 2902161 (1959-09-01), Humbert, Jr. et al.
patent: 3279605 (1966-10-01), Shepherd
patent: 3759388 (1973-09-01), Thomason
patent: 3880757 (1975-04-01), Thomason
patent: 3914820 (1975-10-01), Hankel
patent: 4052319 (1977-10-01), Friedman
patent: 4113623 (1978-09-01), Koether et al.
patent: 4282094 (1981-08-01), Mitchell
patent: 4591434 (1986-05-01), Prudhomme
patent: 4702827 (1987-10-01), Wenzel
patent: 4747944 (1988-05-01), George
patent: 4979255 (1990-12-01), Buchnag
patent: 5609193 (1997-03-01), Steckler
patent: 5908551 (1999-06-01), Onken
Johnston R. Blake
Lithgow Thomas M.
Piper Marbury Rudnick & Wolfe
Restaurant Technologies, Inc.
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