Abstract:
A cooking oil filtration system for a cooking apparatus wherein organic contaminants suspended in hot cooking oil are separated and trapped in/on a hollow cylindrical filter made of high temperature food grade and/or FDA approved polymer material as the hot cooking oil is pumped through a filter housing fluidly connected to a cooking oil reservoir. A fryer basket with walls and a bottom constructed of fine wire mesh provide surface filtration of organic contaminants suspended in the hot cooking oil before passing through the filter housing.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61/428,739 filed Dec. 30, 2010. 
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not Applicable. 
       THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT 
       [0003]    Not Applicable. 
       REFERENCE TO A SEQUENCE LISTING 
       [0004]    Not Applicable. 
     
    
     BACKGROUND OF THE INVENTION 
       [0005]    1. Field of the Invention 
         [0006]    The present invention generally relates to a system comprising a group of devices for use with a cooking apparatus, including a cooking oil purification or separation means, through which cooking oil is purified or separated and continuously returned and reused by the cooking apparatus. 
         [0007]    2. Description of the Related Art 
         [0008]    Present filtration systems connected to the cooking apparatus, such as a deep fat fryer or vacuum fryer, typically use either a single or multi-stage purification system to purify the cooking oil. In a typical single stage purification system a filter media is used to remove solids suspended in the cooking oil. As disclosed in U.S. Pat. No. 4,068,571 issued to Cunningham, a predetermined amount of filter media, like cotton fiber, is placed within a filter cavity disposed within a flow of cooking oil. The cotton fiber traps solids and eventually creates a filter bed by which further solids are removed from the cooking oil as it passes through. In the multi-stage system, the typical filter comprises a first stage that removes larger solids suspended in the cooking oil and a second stage that removes smaller solids suspended in the cooking oil. U.S. Pat. No. 3,685,433 issued to Cunningham discloses the use of a paper sheet against the inner surface of a foraminous cylindrical shell filled with copper turnings wherein purification is achieved as the cooking oil moves from the interior of the shell through the copper turnings (first stage) and the paper filter (second stage) to the exterior of the shell. Whether a single or multi-stage filter, the use of free filter media such as copper turnings or cotton fiber without a support structure results in compaction and eventually failure of the purification process. 
         [0009]    Other cooking oil purification processes utilize a pre-coat filter. A woven wire cloth typically provides the structure for the buildup of a filter cake. The weave pattern of the wire cloth and the type of filter medium typically determines the effectiveness of the cooking oil purification process. Use of pre-coat wire cloth filter may affect the quality of the cooking oil if the improper wire cloth is used to set up the filter bed. Furthermore, the use of a pre-coat with wire cloth increases the likelihood of contamination of the cooking oil with the filter media. 
         [0010]    The purification processes described above tend to result in increased operating costs, mostly due to the labor required to replace the appropriate amount of filter media. Furthermore, these purification process increase the likelihood of cook oil losses due to improper filter preparation/installation. Finally, the likelihood of personal injuries increase when improper filter preparation/installation occurs. 
       BRIEF SUMMARY OF THE INVENTION 
       [0011]    The present invention is directed to a novel purification process for cooking oil at or near the cooking apparatus wherein heated cooking oil moves from a fine mesh fryer basket substantially immersed in an oil reservoir or vat of the cooking apparatus through high temperature piping to a pump and a cartridge of Food and Drug Administration (FDA approved high temperature polymer to remove and trap solids suspended in cooking oil. The filtered cooking oil passes through high temperature piping back to the oil reservoir or vat. The fryer basket comprises a fine mesh wire screen in which food is fried when the basket is immersed in the cooking oil. The fine wire mesh acts a surface filter to segregate organic material suspended in the cooking oil contained in the oil reservoir. The cartridge of FDA approved high temperature polymer is placed within a high temperature filter housing which can be fixed above, below or at the same level as the positive displacement pump. Both the suction and discharge ends of purification system are located below the surface of the cooking oil contained within the reservoir or vat of the cooking apparatus. 
         [0012]    The present invention of a cartridge form of filter media comprising food grade high temperature polyester eliminates the purification problems associated with loose form filter media and pre-coat filters. The cartridge filter form also reduces the time to replace filter media and the likelihood of contamination and loss of cooking oil. Finally, the cartridge form of filter media provides consistent and repeatable filter characteristics to be utilized or changed in the present novel cooking oil filtration system. Likewise, the use of the fine wire mesh fryer basket allows any type of pump (positive displacement or otherwise) to be used to continuously circulate the cooking oil at frying temperature through the filter. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0013]      FIG. 1  is a schematic of the novel cooking oil filtration system  10  depicting a fryer basket  70  with a fine wire mesh  73  immersed in cooking oil  05  held in a cooking oil reservoir  03  of a cooking apparatus  01 , a filter housing  11 , pump  20 , pump suction line  30 , shut off valve  35 , pump discharge line  40 , Y-valve  45 , return line  50 , and discharge line  60 . Organic contaminants  07  are suspended in cooking oil  05 . 
           [0014]      FIG. 2  is a overhead view of an embodiment of the filter housing  11 . 
           [0015]      FIG. 3  is a cross sectional plan view of an embodiment of the novel cooking oil filtration system  10  depicting the FDA approved high temperature polymer  15  in the form of yarn wound into a hollow cylindrical form about a foraminous core  17 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0016]    The present invention of a cooking oil filtration system  10  contemplates the use of a pump  20  fluidly connected by a pump suction line  30  to a cooking oil reservoir  03  of a cooking apparatus  01 . See  FIG. 1 . In a preferred embodiment, the cooking apparatus  01  is a deep fat fryer. In another embodiment, the cooking apparatus  01  is a vacuum fryer. The cooking oil reservoir  03  holds a pre-determined volume of cooking oil, fat or lard  09 . Food is placed within a fryer basket  70  and immersed in the heated cooking oil  09 . The fry basket  70  comprises a fine wire mesh  73  with a mesh size ranging between approximately 50 to approximately 250 such that the micron rating is between approximately 360 microns to approximately 60 microns. Suspended in the cooking oil, fat or lard  09  are unwanted organic contaminants  07  which are the byproduct of frying food in the fryer basket  70 . The unwanted organic contaminants  07  can be solids such breading, vegetable or meat as well as organic acids, such as free fatty acids, and organic alcohols suspended in the cooking oil, fat or lard  09 . Any one or combination of the above listed organic contaminants  07  can alter the flavor and useful life of the cooking oil, fat or lard  09 . It is the main purpose of this invention to remove or at least reduce the concentration of these organic contaminants  07  through the use of filtration while the cooking oil, fat or lard  09  is at a frying temperature but not to exceed 400 degrees Fahrenheit. The temperature of the cooking oil  05  is maintained by the cooking apparatus  01 . 
         [0017]    The fryer basket  70  comprises a handle  71  attached to a basket  73  with at least sides and a bottom made of fine wire mesh. While holding food, the fine wire mesh basket  73  is immersed in the cooking oil  05  which is at the desired cooking temperature. The fine wire mesh basket  73  acts a surface filter to at least reduce the spread of organic contaminants  07  from the food in the fine wire mesh basket  73  into the oil reservoir  03 . The fryer basket  73  is constructed from fine wire mesh, preferably stainless steel, but can be any FDA approved material rated for use at high temperatures not to exceed 400 degrees Fahrenheit. It is contemplated that the wire mesh would be a mesh size between approximately 50 to approximately 250 such that the micron rating is between approximately 360 microns to approximately 60 microns. The fryer basket  70  described above used in conjunction with the filter described below, operates as a two stage cooking oil filtration system  10 . 
         [0018]    A pre-determined amount of food grade and/or FDA approved high temperature polymer material  15  is shaped into a hollow cylinder. See  FIG. 3 . In one embodiment, the food grade and/or FDA approved high temperature polymer material  15  is in the form of a yarn that is spun into the hollow cylinder shape. In another embodiment, the food grade and/or FDA approved high temperature polymer material  15  is in the form of a plurality of microfibers thermally bonded into a one piece cordless hollow cylinder shape. In either one of these embodiments, it is further contemplated as yet another embodiment, that the food grade and/or FDA approved high temperature polymer material is fixed to the exterior surface of a foraminous core  17 . See  FIG. 3 . The porosity of the filter  15  can be varied at different depths within the food grade and/or FDA approved high temperature polymer material by changing the density of the yarn or the microfibers. Likewise, the porosity of the filter  15  can be varied by changing the movement and speed of the yarn as it is spun into the hollow cylinder shape or the heat required to thermally bond the plurality of microfibers into a one piece cordless hollow cylinder shape. Furthermore, these techniques can be combined to create filter  15  with a hybrid construction of thermal bonded microfibers and spun yarn food grade and/or FDA approved high temperature polymer material. Regardless of the construction method, filter  15  would range in length from approximately 10 inches to approximately 20 inches; outside diameter ranging from approximately 1 inch to approximately 4 inches; and inside diameter ranging from approximately 1 inch to approximately 2 inches. 
         [0019]    The filter  15  is fixed within a cavity  13  formed within a filter housing  11 . In a preferred embodiment, the filter housing  11  and cavity  13  are formed from stainless steel. In another embodiment, the filter housing  11  and cavity  13  are constructed from a pre-determined amount of food grade and/or FDA approved high temperature polymer material. The filter housing  11  can be re-sealable by traditional means known to those skilled in the art so that filter  15  can be replaced without the need of replacing the filter housing  11 ; otherwise both filter housing  11  and filter  15  must be replaced as a single unit. If filter  15  and filter housing  11  are consider a single unit, then in a preferred embodiment, food grade and/or FDA approved high temperature quick disconnect couplers known to those skilled in the art are used between the pump discharge line  40 , return line  50  and filter housing  11 . 
         [0020]    The filter housing  11  can be fixed in any position from vertical to horizontal and any position in between. In a preferred embodiment, the filter housing  11  is fixed above the pump  20 . In another embodiment, the filter housing  11  is fixed generally at the same elevation as the pump  20 . And in yet another embodiment, the filter housing  11  is fixed at a position below the pump  20 . Importantly, the end of the return line  50 , submerged below the surface of the cooking oil, fat or lard  05  should not be above the highest point on the filter housing  11 , unless a siphon break known to those in the art is fitted in the return line to prevent back siphoning when the filter housing  11  is opened or removed from the cooking oil filtration system  10 . 
         [0021]    It is contemplated that the lines which fluidly connect the various components of the cooking oil filtration system  10  can be constructed of any material that is of food grade and capable of withstanding high temperatures not exceeding 400 degrees Fahrenheit. In a preferred embodiment, pump suction line  30 , pump discharge line  40 , return line  50  and disposal line  60  are fabricated from stainless steel tubing used in the food industry. In another embodiment, these lines are fabricated from flexible tubing or hose used in the food industry with high temperatures. 
         [0022]    The pump  20  used in the cooking oil filtration system  10  can be a rotary or reciprocating positive displacement pump or a centrifugal pump. In a preferred embodiment, the pump is a positive displacement pump  20 . In another embodiment, the pump  20  is a centrifugal piston or diaphragm pump. It is contemplated that the pump  20  can be mounted above, below or generally at the same level as the surface level of the cooking oil  05  within the cooking oil reservoir  03 . In a preferred embodiment, the pump  20  must be of sufficient capacity to produce at least 20 psi. It is contemplated that the operation of the pump  20  would be handled through conventional control means known to those skilled in the art, such a manual control on/off switch or an automated control system based on well known temperature and pressure sensors. Regardless of the control means, the present invention contemplates continuous filtration while the cooking oil  05  is at cooking temperature. 
         [0023]    Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the claims set forth below.