HK1147125A - Oil quality sensor and oil heater for deep fryers - Google Patents

Description

Oil quality sensor and oil heater for deep fryer

Technical Field

The present invention relates to an oil quality sensor installed in a deep fryer for indicating when cooking oil should be replaced. The present invention also relates to an oil quality sensor disposed in-line with a heater for maintaining cooking oil temperature after draining and filtering the cooking oil to maintain oil quality sensor accuracy.

Background

The oil in a deep fryer deteriorates and loses its cooking ability during use. The periodic temperature increase over the useful life of the oil and the impurities of deep fried foods limit cooking ability.

Other devices have been used to sense oil quality; they have disadvantages. Oil density sensors and oil viscosity sensors are typically placed within the oil stream and are easily clogged with debris. Sensors that sense the magnetism of particulate matter in oil can be expensive.

Thus, there is a need for an oil quality sensor that is installed at multiple locations in a deep fryer that employs LEDs and light sensitive sensors to indicate oil quality and allow an operator to determine when cooking oil should be changed. There is also a need for a heater disposed in-line with the oil quality sensor to maintain oil viscosity and oil quality sensor accuracy.

Disclosure of Invention

The present disclosure provides an oil quality sensor for a deep fryer that employs colored LEDs and a light sensitive sensor to determine a color change of a cooking oil sample. The color change indicates a decrease in oil quality.

The present disclosure also provides an oil quality sensor for a deep fryer that emits light from a colored LED to transmit the light through an oil sample of the deep fryer. The transmitted light is received by a light sensitive sensor and the resulting signal is processed to determine the color change of the oil sample. A color change of the oil sample indicates oil degradation.

The present disclosure also provides an oil quality sensor installed in the recirculation system of a deep fryer so that it can be used for several fryers at the same time.

The present disclosure also provides a plurality of oil quality sensors installed in the deep fryer that measure and compare the color change of the oil from one side of the fryer to the other side of the fryer.

The present disclosure also provides an oil quality sensor for a deep fryer having a first LED coupled to a light-sensitive sensor and a second LED coupled to a light-sensitive sensor, wherein a difference between signals received by the light-sensitive sensors is measured as an indication of the absorption capacity of the oil.

The present disclosure also provides for an oil quality sensor having a blue LED coupled to a first light sensitive sensor and a red LED coupled to a second light sensitive sensor, wherein an operator is notified to change the oil upon detecting that a predetermined difference threshold is reached between the first light sensitive sensor signal and the second light sensitive sensor signal.

The present disclosure also provides an oil quality sensor in a return line of a deep fryer for a deep fryer.

The present disclosure also provides an oil quality sensor and heater disposed in a return line of a recirculation system of a deep fryer.

The present disclosure also provides for an oil quality sensor disposed between a drain valve and a filter pan of a recirculation system of a deep fryer.

The present disclosure also provides an oil quality sensor and heater disposed between a drain valve and a filter pan of a recirculation system of a deep fryer.

A sensor for monitoring oil in a deep fryer system having at least one fryer pot and a conduit for directing oil to the fryer pot has: a first sensor and a second sensor; and a first emitter arranged to emit light such that the light transmits through the oil to the first sensor and a second emitter arranged to emit light such that the light transmits through the oil to the second sensor. The sensor also has a processor for comparing signals received from the first sensor with signals received from the second sensor, wherein a notification is provided when a difference between the signals exceeds a predetermined threshold.

A deep fryer system having an oil quality sensor having: a body for containing oil; a first transmitter disposed proximate the body for transmitting a signal to pass through the oil to the first sensor; a second transmitter disposed proximate the body for transmitting a signal to pass through the oil to the second sensor; and a processor for comparing the signal received from the first sensor with the signal received from the second sensor. A notification is provided when the difference between the signals exceeds a predetermined threshold indicative of low oil quality.

Drawings

Other and further benefits, advantages and features of the present disclosure will be understood by reference to the following description in conjunction with the accompanying drawings; in the drawings, like numbering represents like structural elements.

Fig. 1 illustrates an example deep fryer that houses the sensors and/or sensors and heaters of the present invention;

FIG. 2 illustrates a oil quality sensor according to a first embodiment of the present invention;

FIG. 3 shows a cross-sectional view of the sensor of FIG. 1 along line 3-3;

FIG. 4 shows a cross-sectional view of the sensor of FIG. 1 along line 4-4;

FIG. 5 illustrates a first embodiment of the oil quality sensor of FIG. 2 installed in a recirculation system of an exemplary fryer pot according to a first configuration of the present disclosure;

FIG. 6 illustrates a second embodiment of an oil quality sensor installed in an example fryer pot, according to the present disclosure;

FIGS. 7 and 8 illustrate the oil quality sensor of the second embodiment of FIG. 6 installed in an example fryer pot according to second and third configurations of the present invention;

FIG. 9 illustrates a second configuration of oil quality sensors according to the first sensor embodiment in line with a heater, mounted adjacent to a return valve, according to the present invention;

FIG. 10 illustrates a third configuration of an oil quality sensor according to the first sensor embodiment, mounted proximate a drain valve of an example fryer pot, in accordance with the present invention; and

FIG. 11 illustrates a fourth configuration of an oil quality sensor according to the first sensor embodiment mounted proximate to a drain valve of an example fryer pot in-line with a heater according to the present invention.

Detailed Description

Referring to fig. 1, a diagram of an exemplary deep fryer is shown and generally designated by the numeral 10. Deep fryer 10 has a housing 5, a pair of fryers 15 and a pair of filter pans 40. Each filter disk of the pair of filter disks 40 contains a filter medium 35, such as a debris basket 25 and a filter pad 30, for filtering used cooking oil. Although deep fryer 1 is shown with only two fryers 15, there may be as many as 12 fryers depending on the requirements of a professional food service. The deep fryer 1 also has a controller 20 for monitoring and maintaining the overall operation of the deep fryer 1.

Referring to FIG. 2, a diagram of an oil quality sensor according to a first embodiment of the present invention is shown and generally designated by the reference numeral 50. Sensor 50 has a body 55 with one end of body 55 operatively connected to conduit 60 and the other end operatively connected to a second conduit 65. According to a first embodiment of the invention, shown in FIG. 4, conduits 60 and 65 are located in the piping of fryer 15. The sensor 50 is provided with a seal 70 between the mating parts of the conduits 60 and 65 and the body 55. The seal 70 is a known seal such as a teflon tape.

Sensor 50 has a measurement Light Emitting Diode (LED)75 coupled to a measurement broadband photosensor 80. Sensor 50 has a reference LED85 coupled to a reference broadband photosensor 90. LEDs 75 and 85 are coupled to wires 95 and 100, respectively. Photosensitive sensors 80 and 90 are coupled to lines 105 and 110, respectively. Wires 95, 100, 105, and 110 are bundled in a sleeve 115 and directed to processor 20. The LEDs 75 and 85 and the photosensors 80 and 90 are fixed to the body 55. Insulator 120 is wound around body 55.

Referring to fig. 3 and 4, the sensor 50 is shown in more detail. In fig. 3, a cross-sectional view of the sensor 50 is shown. Sensor 50 has a transparent tube 70 within body 55. The ends of the body 55 and the tube 70 are secured together to prevent any oil from leaking therebetween. Light emitted from the measurement LED 75 is transmitted through the oil 130 in the tube 70 and is measured by the measurement photosensor 80. Similarly, light emitted from reference LED85 is transmitted through oil 130 in tube 75 and measured by reference photosensor 90. The signal from the measuring photosensor 80 is compared with the signal from the reference photosensor 90 to determine the change in transmitted light emitted by the LEDs 75 and 85, respectively, to detect the degree of oil degradation caused by the cooking process. The amount of debris present in the oil 130 will change the manner in which light from the LEDs 75 and 85 is transmitted and received by the respective light sensitive sensors. The greater the amount of debris present in the oil 130, the greater the absorption capacity of the oil and, therefore, the greater the change in the signal received by the photosensors 80 and 90. Depending on the type of LED used and the sensitivity of the light sensitive sensor, temperature compensation may be required. If the signal returned from the light sensitive sensor is not strong, an additional signal is required to alert the user to clean the surface of the tube through which the light is passing.

In use, the sensor 50 operates by: colored LEDs 75 and 85 and light sensitive sensors 80 and 90 are used to determine a color change of oil 130, the color change of oil 130 indicating a degradation of oil quality. The processor periodically transmits signals from the LEDs 75 and 85 and receives signals from the light sensitive sensors 80 and 90, respectively, to monitor oil quality. Sensor 50 employs blue light emitted by LED85 and red light emitted by LED 25. Blue light provides a greater degree of wavelength change after passing through the oil 130 than red light does after passing through the oil 130. Thus, the red light emitted by the LED85 is used as a reference LED, while the blue light emitting LED 75 is used as a measurement LED. Similarly, the photosensor 80 is a measurement photosensor, and the photosensor 90 is a reference photosensor. As the oil 130 ages and changes color, its absorption capacity changes. As the absorption capacity changes, the colored LEDs 75 and 85 will transmit differently through the oil 130 and the light received by the respective photosensors 80 and 90 will change accordingly. The signals received by the light sensitive sensors 80 and 90 determine the parameters of the predetermined threshold. When the difference between the parameters associated with light sensitive sensors 80 and 90 exceeds a predetermined threshold, the operator is notified to change oil 130. Notification may be accomplished by any known mechanism such as a bell or light.

In a first configuration, as shown in fig. 5, a first embodiment of oil sensor 50 is located in the recirculation system of fryer 15 of fryer 5. Sensor 50 is positioned to sample the filtered oil before it re-enters fryer 15. By being located in the recirculation system of fryer 5, a single sensor 50 may be used for several fryers 15, as they share a recirculation system.

In fig. 6, a sensor according to a second embodiment of the invention is shown and indicated by reference numeral 140. The sensor 140 is configured to measure the oil mass in the fryer 15 for the entire volume of oil 130. Thus, the sensor 140 is modified as compared to the sensor 50 of the previous embodiment. Rather than being tubular in construction, the sensor 140 has two separate components. One of the two components contains a sensor and the other of the two components contains an LED. In this embodiment, the oil sensor 140 has a reference LED145 and a measurement LED 150 on one side of the fryer 15 and a reference photosensor 155 and a measurement photosensor 160 on the other side of the fryer. The LED145 is coupled to the reference photosensor 155 and the LED145 is coupled to the measurement photosensor 155.

As shown in fig. 7, the sensor 140 according to the second embodiment of the sensor of the present invention has a third configuration. Sensor 140 is configured to measure the oil mass in fryer 15 for the span of fryer 15. Sensor 140 has a reference LED145 and a measurement LED 150. The LED145 is coupled to a reference photosensor 155 and the LED 150 is coupled to a measurement photosensor 160. Wires associated with the respective LEDs and light sensitive sensors are strapped under the fryer 15 and directed to the processor for measuring the difference between the signals sensed by the reference light sensitive sensor 155 and the measurement light sensitive sensor 160. After the difference between the reference light sensor 155 and the measured light sensor 160 reaches a predetermined threshold, the operator is notified to change the oil in the fryer 15.

In fig. 8, a fourth configuration of a sensor 140 according to a second embodiment of the present invention is shown. The sensor 140 measures oil quality for a small portion of the fryer 15. Sensor 140 has a reference LED145 and a measurement LED 150. The LED145 is coupled to a reference photosensor 155 and the LED 150 is coupled to a measurement photosensor 160. Sensors 155 and 160 are at a 45 angle to the surface of fryer pot 15. Similarly, LEDs 145 and 150 are also at a 45 angle to the surface of the fryer to ensure that transmitted light is received by the appropriate light sensitive sensor. When a predetermined threshold difference is detected between the signals received from the reference light sensor 155 and the measurement light sensor 160, the operator is notified to change the oil in the fryer 15.

Fig. 9 shows a second configuration of the first embodiment of the sensor 50. Similar to the first configuration of FIG. 5, the second configuration includes sensor 50 in fryer pot 15 positioned proximate to return valve 170. However, after filtering the cooking oil, heaters 180 are placed in-line or in-line before sensor 50. After filtration, the temperature of cooking is reduced, thereby reducing the oil viscosity. The reduction in oil temperature causes a reduction in viscosity and any remaining food particles may separate from the oil, thereby resulting in inaccurate measurements and possibly clogging the sensor. The benefit of providing the heater 180 after the filter media 35, such as shown in fig. 1, having the debris basket 25 and filter mat 30 is that: temperature drop during recirculation filtration and any possible clogging of the sensor can be minimized. By minimizing temperature drop, more accurate oil quality measurements can be achieved.

Fig. 10 shows a third configuration employing a sensor 50 according to the first embodiment of the present invention. Sensor 50 is disposed between fryer pot 15 and filter media 35 such as shown in FIG. 1. By placing the sensor 50 before the filter media 35, the speed of the oil circulation disturbs any food particles that may collect in the sensor 50. The velocity of the cooking oil allows for more accurate oil quality measurements by removing food particles to clean the sensor 50.

According to a fourth configuration of the present invention, as shown in FIG. 11, heater 180 and sensor 50 according to the first embodiment are disposed between fryer pot 15 and filter medium 35. Also, heating the cooking oil with heater 180 minimizes the possibility of any food particles separating from the cooking oil, thereby preventing any possible clogging and inaccurate sensor measurements.

Having thus described the invention with particular reference to the preferred forms thereof, it will be obvious that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (38)

1. A sensor for monitoring oil in a deep fryer system having at least one fryer pot and a conduit directing oil to the fryer pot, comprising:

a first sensor and a second sensor;

a first emitter arranged to emit light so as to transmit light through the oil to the first sensor; a second emitter arranged to emit light so as to transmit light through the oil to the second sensor; and

a processor for comparing signals received from the first sensor with signals received from the second sensor,

wherein a notification is provided when the difference between the signals exceeds a predetermined threshold.

2. The sensor of claim 1, wherein the notification indicates a high oil absorption capacity.

3. The sensor of claim 1, wherein one of the first sensor and the second sensor is a reference sensor and the other of the first sensor and the second sensor is a measurement sensor.

4. The sensor of claim 1, wherein one of the first and second emitters is a reference emitter and the other of the first and second emitters is a measurement emitter.

5. The sensor of claim 4, wherein light emitted by the reference emitter is received by the reference sensor to determine a parameter of the predetermined threshold.

6. The sensor of claim 4, wherein light emitted by the measurement emitter is received by the measurement sensor to determine a parameter of the predetermined threshold.

7. The sensor of claim 1, wherein the signal received from the first sensor and the signal received from the second sensor are signals indicative of oil absorption capacity.

8. The sensor of claim 1, wherein the monitored oil is disposed in a tubular conduit of the deep fryer system.

9. The sensor of claim 8, further comprising a tube housed within the tubular member.

10. The sensor of claim 9, wherein the tube is a transparent tube member.

11. The sensor of claim 8, wherein the first sensor is diametrically opposed to the first emitter and the second sensor is diametrically opposed to the second emitter.

12. The sensor of claim 1, wherein the monitored oil is in a deep fryer pot.

13. The sensor of claim 12, wherein the first transmitter is disposed on an opposite side of the deep fryer pot from the first sensor and the second transmitter is disposed on an opposite side of the deep fryer pot from the second sensor.

14. The sensor of claim 12, wherein the first transmitter is disposed on a side of the deep fryer pot adjacent the first sensor and the second transmitter is disposed on a side of the deep fryer pot adjacent the second sensor.

15. The sensor of claim 1, wherein the first and second emitters are first and second LEDs.

16. The sensor of claim 1, wherein the first sensor is a first light sensitive sensor and the second sensor is a second light sensitive sensor.

17. The sensor of claim 1, wherein the notification is one of a visual notification and an audible notification.

18. A deep fryer system having at least one fryer pot and a filter medium, comprising:

a body for containing oil;

a first transmitter disposed proximate the body for transmitting a signal to pass through the oil to a first sensor;

a second transmitter disposed proximate the body for transmitting a signal to pass through the oil to a second sensor; and

a processor for comparing signals received from the first sensor with signals received from the second sensor,

wherein a notification is provided when the difference between the signals exceeds a predetermined threshold, the threshold indicating a low oil quality.

19. The deep fryer system according to claim 18, wherein said first transmitter and said second transmitter periodically send signals to said first sensor and said second sensor.

20. The deep fryer system according to claim 18, wherein one of said first transmitter and said second transmitter is a reference transmitter and the other of said first transmitter and said second transmitter is a measurement transmitter.

21. The deep fryer system according to claim 20, wherein one of said first sensor and said second sensor is a reference sensor and the other of said first sensor and said second sensor is a measurement sensor.

22. The deep fryer system according to claim 21, wherein light emitted by said reference emitter is received by said reference sensor to determine a parameter of said predetermined threshold.

23. The deep fryer system according to claim 21, wherein light emitted by said measurement emitter is received by said measurement sensor to determine a parameter of said predetermined threshold.

24. The deep fryer system according to claim 18, wherein said body comprises a tubular member operatively associated with said at least one fryer pot and a conduit of said deep fryer system, said fryer pot having a drain valve and an inlet valve.

25. The deep fryer system according to claim 24, wherein said tubular member is disposed between an inlet valve of said at least one fryer pot of said deep fryer system and said filter medium.

26. The deep fryer system according to claim 24, wherein said tubular member is disposed between said drain valve and said filter medium.

27. The deep fryer system according to claim 24, further comprising a tube housed within said tubular member.

28. The deep fryer system according to claim 27, wherein said tube is a transparent tube member.

29. The deep fryer system according to claim 27, further comprising a heater disposed in-line with said conduit of said deep fryer.

30. The deep fryer system according to claim 29, wherein said tubular member is disposed between an inlet of said at least one fryer pot and said heater.

31. The deep fryer system according to claim 29, wherein said heater is disposed between a drain valve of said at least one fryer pot and a filter medium, and said tubular member is disposed between said heater and said filter medium.

32. The deep fryer system according to claim 23, wherein said first sensor is diametrically opposed to said first transmitter and said second sensor is diametrically opposed to said second transmitter.

33. The deep fryer system according to claim 18, wherein said body comprises a deep fryer pot.

34. The deep fryer system according to claim 29, wherein said first transmitter is disposed on a side of said deep fryer pot opposite said first sensor and said second transmitter is disposed on a side of said deep fryer pot opposite said second sensor.

35. The deep fryer system according to claim 29, wherein said first transmitter and said first sensor are disposed on joined sides of said deep fryer pot and said second transmitter and said second sensor are disposed on adjacent sides of said deep fryer pot.

36. The deep fryer system according to claim 18, wherein said first transmitter and said second transmitter are a first LED and a second LED.

37. The deep fryer system according to claim 18, wherein said first sensor and said second sensor are a first light sensitive sensor and a second light sensitive sensor.

38. The deep fryer system according to claim 20, wherein said reference emitter emits red light and said measurement emitter emits blue light.