Device and method for cooktop fire mitigation

Abstract

A device for limiting the temperature of cookware on a cooktop to a threshold level that corresponds to an oil ignition temperature. The device includes a temperature sensor that is positioned adjacent a bottom of the cookware on the cooktop. A control device in combination with each of the temperature sensor and the cooktop monitors the temperature and adjusts a heating element of the cooktop as needed to avoid cooking oil ignition. The temperature sensor can be a spring loaded temperature sensor to ensure and/or absorb contact with the cookware.

What is claimed is: 
     
         1 . A device for limiting a temperature of a cookware on a cooktop to a threshold level that corresponds to an oil ignition temperature, the device comprising:
 a temperature sensor adjacent a bottom of the cookware on the cooktop; and   a control device in combination with each of the temperature sensor and the cooktop, wherein the control device modifies a heating element of the cooktop in response to a signal from the temperature sensor to maintain a temperature of the bottom of the cookware below a predetermined oil ignition temperature and above a cooking temperature.   
     
     
         2 . A device in accordance with  claim 1 , wherein the temperature sensor comprises a spring loaded temperature sensor. 
     
     
         3 . A device in accordance with  claim 1 , wherein the temperature sensor comprises a thermistor or a resistance temperature detector. 
     
     
         4 . A device in accordance with  claim 1 , wherein the temperature sensor comprises a convex cover that maintains cookware contact during cookware use on the cooktop. 
     
     
         5 . A device in accordance with  claim 1 , further comprising an algorithm executed by the control device that relies on both temperature and rate of change of temperature to ensure that the cookware does not exceed the oil ignition temperature. 
     
     
         6 . A device in accordance with  claim 1 , wherein the cooktop is an electric coil cooktop including a source of electric power and an electric resistance heating element that has thermal inertia such that the cookware temperature can continue to rise even after the power to the element has been reduced or removed, the temperature sensor is in direct contact with the bottom of the cookware, and the control device is in controlling combination with an electric relay of the source of electric power to reduce power in order that the cookware bottom temperature remains below the oil ignition temperature and above temperatures required for standard cooking techniques. 
     
     
         7 . A device in accordance with  claim 1 , wherein the cooktop is an electric coil cooktop including a source of electric power and an electric resistance heating element that has thermal inertia such that the cookware temperature can continue to rise even after the power to the element has been reduced or removed, the temperature sensor is in direct contact with the bottom of the cookware, and the control device is in controlling combination with an electric infinite valve of the cooktop to reduce power in order that the cookware bottom temperature remains below the oil ignition temperature and above temperatures required for standard cooking techniques. 
     
     
         8 . A device in accordance with  claim 1 , wherein the cooktop is a gas fired cooktop including a source of gaseous fuel, a gas-fired burner, and a gas flow line containing a gas flow of the gaseous fuel to the gas-fired burner, the temperature sensor is in direct contact with the bottom of the cookware, and the control device is in controlling combination with the gas flow line to reduce the gas flow in order that the cookware bottom temperature remains below the oil ignition temperature and above temperatures required for standard cooking techniques. 
     
     
         9 . A device in accordance with  claim 8 , wherein the control device lowers the gas flow to a set input rate that does not turn a cooktop flame off entirely when controlling the cookware temperature to a threshold level to avoid oil ignition. 
     
     
         10 . A device in accordance with  claim 8 , wherein the control device is in controlling combination with a valve of the gas flow line. 
     
     
         11 . A device in accordance with  claim 10 , wherein the valve directs the gas flow to a bypass line with a defined diameter. 
     
     
         12 . A device in accordance with  claim 1 , wherein the cooktop is a smoothtop electric cooktop including a source of power, a glass ceramic cooktop surface with thermal inertia such that the cookware temperature can continue to rise even after power to the element has been reduced or removed, and an electric heat source below the cooktop surface, the temperature sensor is mounted to an under surface of the glass ceramic cooktop surface in proximity to the heating element, and the control device controls power to the electric heat source in order that the cookware bottom temperature remains below the oil ignition temperature and above temperatures required for standard cooking techniques. 
     
     
         13 . A device in accordance with  claim 12 , further comprising an algorithm of the control device that controls the power as a function of both a sensed temperature and rate of change of the sensed temperature, to ensure that the cookware does not exceed an oil ignition temperature. 
     
     
         14 . A device in accordance with  claim 12 , further comprising an algorithm of the control device that controls the power as a function of each of a sensed temperature, a rate of change of the sensed temperature, and a change in a slope of the temperature/time curve, to ensure that the cookware does not exceed an oil ignition temperature. 
     
     
         15 . A method for limiting a temperature of a cookware on a cooktop to a threshold level that corresponds to an oil ignition temperature, the device comprising:
 sensing a temperature at a bottom of the cookware; and   automatically controlling a heat input rate of the cooktop in response to a detection of a predetermined temperature and/or rate of temperature increase.   
     
     
         16 . A method in accordance with  claim 15 , further comprising automatically controlling the heat input rate of the cooktop as a function of a predetermined temperature, a rate of temperature increase, a change in a slope of the temperature/time curve, or combinations thereof.