Oil quality sensor and adapter for deep fryers

Abstract

A system for measuring the state of degradation of cooking oil or fat includes at least one fryer pot. A conduit is fluidly connected to the fryer pot for transporting cooking oil from the fryer pot and returning the cooking oil back to the fryer pot. A pump is provided for re-circulating cooking oil to and from the fryer pot. A sensor is disposed in fluid communication with the conduit and measures an electrical property of the cooking oil as the cooking oil flows past the sensor and is returned to the at least one fryer pot.

What is claimed is: 
     
         1 . A system for measuring the state of degradation of deep fryer cooking oils or fats in a deep fryer comprising:
 at least one fryer pot;   at least one conduit in fluid communication with said at least one fryer pot for transporting said deep fryer cooking oil from said at least one fryer pot and/or returning said deep fryer cooking oil back to said at least one fryer pot; and   an oil quality sensor that is in fluid communication with said conduit to measure an electrical property of said deep fryer cooking oil when it is external to said at least one fryer pot and as said deep fryer cooking oil flows past or comes into contact with said oil quality sensor.   
     
     
         2 . The system of  claim 1 , wherein said oil quality sensor is a capacitance sensor, a coaxial sensor, a conductivity sensor or a resonant sensor. 
     
     
         3 . The system of  claim 1 , further comprising a filtration unit, wherein said filtration unit is disposed in-line with said conduit. 
     
     
         4 . The system of  claim 1 , wherein said conduit comprises a single pipe that drains said deep fryer cooking oil from said at least one fryer pot and returns said deep fryer cooking oil to said at least one fryer pot via said single pipe. 
     
     
         5 . The system of  claim 1 , wherein said sensor is disposed in an adapter that is connected to either said return pipe or said drain pipe. 
     
     
         6 . The system of  claim 1 , further comprising at least one pump for re-circulating said deep fryer cooking oil from and to said at least one fryer pot, and wherein said pump is disposed either upstream or downstream of said sensor and said at least one fryer pot to pump said cooking oil past said sensor to said at least one fryer pot. 
     
     
         7 . The system of  claim 5 , wherein said oil quality sensor is disposed on a support surface contained within said adapter. 
     
     
         8 . The system of  claim 5 , further comprising a connector in electrical communication with said oil quality sensor that extends from said adapter for connection to a controller and measurement electronics. 
     
     
         9 . The system of  claim 1 , further comprising an indicator operatively connected to said oil quality sensor to provide an indication when said electrical property of said deep fryer cooking oil exceeds a predetermined threshold, and, optionally, wherein said indicator is a display or an alarm. 
     
     
         10 . The system of  claim 9 , wherein said alarm is an audible or visible alarm. 
     
     
         11 . The system of  claim 9 , wherein said display is on a display panel and shows measurements relating to degradation of said cooking oil. 
     
     
         12 . The system of  claim 10 , wherein said visible alarm is color-coded to indicate a level of acceptability of said electrical property of said cooking oil. 
     
     
         13 . The system of  claim 12 , wherein a color provided by said visible alarm indicates when said cooking oil needs replacement. 
     
     
         14 . The system of  claim 9 , wherein said alarm comprises a staged alarm according to different values of degradation of said cooking oil. 
     
     
         15 . A system for measuring the state of degradation of deep fryer cooking oil in a deep fryer comprising:
 at least one fryer pot;   at least one conduit in fluid communication with said at least one fryer pot for carrying deep fryer cooking oil from said at least one fryer pot through a filtration unit back to said at least one fryer pot; and   an oil quality sensor disposed between said filtration unit and said at least one fryer pot for measuring said deep fryer cooking oil when it is external to said at least one fryer pot and after said deep fryer cooking oil has been filtered by said filtration unit, said oil quality sensor being in fluid communication with said at least one conduit for measuring an electrical property of said deep fryer cooking oil, after said deep fryer cooking oil is pumped through said filtration unit.   
     
     
         16 . The system of  claim 15 , wherein said oil quality sensor is disposed in an adapter that is connected to said conduit. 
     
     
         17 . The system of  claim 15 , further comprising a pump, wherein said pump is disposed between said oil quality sensor and said at least one fryer pot to pump said cooking oil from said filtration unit to said at least one fryer pot. 
     
     
         18 . A device for installation in a deep fryer for measuring the state of degradation of deep fryer cooking oil in at least one fryer pot comprising:
 an oil quality sensor disposed in a conduit with flowing deep fryer cooking oil to measure and sample an electrical property of said deep fryer cooking oil that is indicative of total polar materials of said deep fryer cooking oil; and   a controller and measurement electronics operatively connected to said oil quality sensor to provide measurements and to calculate and average values of said total polar materials during return of said deep fryer cooking oil to said at least one fryer pot.   
     
     
         19 . The device of  claim 18 , wherein said oil quality sensor is at least one selected from the group consisting of: a capacitance sensor, a coaxial sensor, a conductive sensor, and a resonant sensor. 
     
     
         20 . A system for measuring the state of degradation of deep fryer cooking oils in a deep fryer comprising:
 a plurality of fryer pots,   a filtration loop comprising a filter pan and drain plumbing that collects said deep fryer cooking oil that has been used for frying from said plurality of fryer pots and a return conduit that returns said deep fryer cooking oil to each of said plurality of fryer pots after said deep fryer cooking oil has been filtered;   a pump for re-circulating said deep fryer cooking oil through said filtration loop to and from said plurality of fryer pots; and   an oil quality sensor external to said plurality of fryer pots and disposed in fluid communication with said deep fryer cooking oil to measure an electrical property that is indicative of total polar materials of said deep fryer cooking oil as said deep fryer cooking oil flows past said oil quality sensor and is returned to said plurality of fryer pots,   wherein said drain plumbing comprises at least one drain pipe associated with each of said fryer pots, wherein said drain pipe transports said deep fryer cooking oil from said plurality of fryer pots, and wherein said return conduit returns said deep fryer cooking oil to each of said plurality of fryer pots, and   wherein said oil quality sensor is disposed in said return pipe between said filter pan and a return valve and measures said electrical property of said deep fryer cooking oil before said deep fryer cooking oil is returned to said plurality of fryer pots.