System and method for sensing oil quality

• US 10,178,927 B2
• Filed: 01/05/2018
• Issued: 01/15/2019
• Est. Priority Date: 06/30/2014
• Status: Active Grant

• Current Assignee: Pitco Frialator Inc. (Middleby Corporation)
• Original Assignee: Pitco Frialator Inc. (Middleby Corporation)
• Inventors: McGhee, Owen R., Bassoul, Selim A., Finnie, Jason D., Perkins, Jared, Lambert, Nathaniel A., Fecteau, Michael T.
• Primary Examiner(s): LAFLAME JR, MICHAEL A
• Application Number:
  US15/863,197
• Publication Number:
  US 20180125299A1
• Time in Patent Office: 375 Days
• Field of Search: 99403-418, 324600, 324649, 324691, 324693
• CPC Class Codes: A47J 37/1266 Control devices, e.g. to control temperature, level or quality of the frying liquid
• CPC Class Codes: G01N 33/03 Edible oils or edible fats

Abstract

A system for measuring the state of degradation of cooking oil in a deep fryer is provided. The system includes at least one fryer pot and a loop of piping fluidly connected thereto for selectively allowing flow of oil from the at least one fryer pot into the loop and for selectively allowing the cooking oil to return to said at least one fryer pot from the loop. A pump urges the flow of cooking oil through the loop of piping and selectively to urge oil to return to the at least one fryer pot. The loop further comprises a return portion that extends from a discharge of the pump toward a suction of the pump. A sensor is disposed in the return portion of the loop and adapted to measure an electrical property that is indicative of total polar materials of said cooking oil.

Claims

1. A system for measuring the state of degradation of cooking oil in a deep fryer comprising:

at least one fryer pot, comprising an oil inlet and an oil outlet;

a loop of piping connected to said at least one fryer pot for selectively allowing flow of oil from the at least one fryer pot through the oil outlet into the loop and for selectively allowing the cooking oil to return to said at least one fryer pot through the oil inlet from the loop;

a pump for urging the flow of cooking oil through the loop and selectively to urge oil to return to the at least one fryer pot through the oil inlet,

the loop further comprising a first valve that is positionable in an isolated position to prevent oil flow from returning to the at least one fryer pot through the oil inlet, and is positionable in a second position to allow oil to return to flow the at least one fryer pot through the oil inlet,

the loop further comprises a recirculation portion that extends from a discharge of the pump toward a suction of the pump, wherein the recirculation portion extends from a first portion that selectively receives oil flow from the discharge of the pump to a second portion that is fluidly connected with a suction of the pump;

a sensor disposed in the recirculation portion and adapted to measure an electrical property that is indicative of the quality of the cooking oil within the loop of piping,

wherein the recirculation portion is configured to allow oil to flow past the sensor as urged by the pump with the first valve in the isolated position,

wherein the sensor is configured to measure an electrical property that is indicative of the total polar materials of the cooking oil and is configured to measure the electrical property of the cooking oil when the cooking oil flows past the sensor, and

further comprising a display or an alarm in electrical communication with said sensor for indicating a parameter of the oil that is representative of the measured electrical property of the oil.

2. The system of claim 1, wherein the sensor is configured to measure the electrical property of the cooking oil when the cooking oil flows past the sensor and when the cooking oil is relatively stationary next to the sensor.

3. The system of claim 1, wherein said sensor is selected from a capacitance sensor, a voltage sensor, a resistance sensor, a dielectric sensor, a conductivity sensor, or a conductance sensor.

4. The system of claim 1, wherein said sensor is a coaxial sensor.

5. The system of claim 1, further comprising an oil filtration system that is disposed in fluid communication with the loop and with the second end portion of the recirculation portion such that oil flowing through the recirculation portion and past the sensor reaches the oil filtration system, wherein the suction of the pump is fluidly connected with the oil filtration system.

6. The system of claim 1, wherein the first valve is located downstream from the discharge of the pump.

7. The system of claim 1, wherein the sensor is configured to measure two or more of capacitance, voltage, resistance, dielectric, conductivity, or conductance of oil that contacts the sensor.

8. The system of claim 1, wherein the sensor is disposed upstream of the suction of the pump.

9. The system of claim 1, wherein the loop includes a second valve that is positionable to selectively prevent or allow flow through the recirculation portion, wherein the second valve is disposed between the discharge of the pump and the sensor.

10. The system of claim 9, further comprising a controller that receives a signal from the sensor indicative of the measured electrical property of the oil.

11. The system of claim 10, wherein the first and second valves are remotely operable by the controller, and the controller is configured to selectively operate one or both of the first and second valves based upon the measured electrical property of the oil.

12. The system of claim 11, wherein the loop is fluidly connected to a source of replacement oil, and wherein the loop further comprises a drain, wherein the controller is configured to selectively open the drain to allow cooking oil within the loop to drain from the loop and to selectively allow replacement oil to flow into the loop, wherein the controller selectively allows the cooking oil to drain from the loop and allows replacement oil to flow into the loop based upon the measured electrical property of the oil.

13. The system of claim 9, further comprising a third valve positioned within the recirculation portion and located between the sensor and an oil filtration system, wherein the third valve is downstream of the sensor and the second valve, such that oil flowing through the recirculation portion flows through the sensor, then through the third valve, and then into the oil filtration system.

14. The system of claim 13, wherein the third valve is operable by a controller, wherein the third valve is opened when the second valve is opened by the controller, and the third valve is closed when the second valve is closed by the controller.

15. The system of claim 1, wherein the first valve is a three way valve that is disposed between the discharge of the pump and the oil inlet of the frypot and the first valve is additionally connected with the recirculation portion, and wherein when the first valve is positioned in the second position the three way valve is aligned to direct oil flowing therethrough into the oil inlet of the frypot, and when the first valve is positioned in the isolated position the three way valve is aligned to direct oil flowing therethrough into the recirculation portion of the loop.

16. The system of claim 1, wherein the first valve is closed when in the isolated position.

17. The system of claim 1, wherein the first valve is aligned to direct flow from the pump discharge to the recirculation portion when in the isolated position.