Patent Application
20120022694
This disclosure relates to the determination of physical and chemical degradation of oils, more particularly to sensor designs and sensing schemes for simultaneously detecting physical and chemical degradation in oil caused by heating, oxidation and suspended matter.
This section provides background information related to the present disclosure which is not necessarily prior art.
Different kinds of oils are used daily for different applications. For example, cooking oils are used in frying various types of food items, such as french fries, chicken, and fish, etc. Similarly, different grades of oils are used in many engineering applications for various purposes, such as lubrication and cooling, etc.
Irrespective of the applications as well as grades, all the oils undergo physical and chemical degradation during their usage. Chemical changes pertain to oxidation, hydrolysis and polymerization, etc., whereas physical degradation pertains to suspended foreign matters, such as metal debris, food particulates, water, corrosive materials (e.g.: KOH, soot), antifreeze, gasoline, glycol and dust, etc.
Physical as well as chemical degradation of oils can lead to inefficient performance of the oils during their services. For example, degraded cooking oils can result in less tasty and fatty food which may not be a healthy diet. On the other hand, the oils used in many engineering applications lose their lubrication and thermal capacity due to degradation in the quality.
Therefore, monitoring of oil quality on a regular basis is vital either for filtering or adding preservatives in order to enhance the performance. In addition, it is also necessary to monitor the degradation of oils in service in order to replace with the new oils.
There are different types of oil sensors available in the market. For example, they can sense the overall quality of the oils through the changes in dielectric properties or electrical properties or viscosity or color variations. However, they cannot distinguish the effect of physical degradation due to the contaminants or foreign materials from the chemical degradation.
Recently, the optical properties of oils have been exploited to determine the quality and thereby different sensing methods have been proposed [REFERENCES 1-4]; yet, they lack the differentiating capability between chemical and physical degradation simultaneously.
The change in transmission behavior of light through oils can happen either because of absorption or scattering phenomena, and thereby it is imperative to distinguish the effect of both the physical and chemical degradation on the absorption and scattering events in order to determine the quality of the oils.
A schematic transmission behavior of light in the range 200-800 nm wavelength through fresh and used oils is shown in
This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.
A sensing scheme to distinguish the chemical degradation from the physical degradation and thereby corresponding sensor designs are disclosed.
The sensing scheme comprises the determination of absolute shift or change in the cut off wavelength of the radiation being transmitted due to the chemical degradation and subtraction of associated absolute change in transmission above the cut off wavelength using established correlations from the overall transmission above the cut off wavelength of the radiation, resulting in the transmission behavior that is associated with the physical degradation. Thus, it enables simultaneous detection of chemical and physical degradation in the oils.
The chemical degradation levels are determined by detecting the absolute change/shift in cut off wavelength of the transmitted radiation while transmitting different wavelengths of the light/radiation through the oil. It can be achieved using multi-color bulbs or multi color LEDs or multi wavelength light or radiation emitter in the UV-Visible-Infrared range coupled with a photoresistor and/or photodetector with a provision in between to store/flow the oil or to place a transparent (to the UV-Visible-Infrared light) container with oil inside so that the radiation could transmit through the oil before falling on the photoresistor or photodetector and then detect the extent of transmission of the radiation passed through the oil sample while varying the wavelength of the radiation and thereby observing the variation in the resistance value of the photoresistor and/or photodetector; then with the help of a microprocessor physical degradation can be detected by subtracting the absolute change/reduction in the transmission above the cut off wavelength of the radiation due to the chemical degradation from the observed transmission above the cut off wavelength of the radiation using prior established correlations between the absolute change/shift in the cut off wavelength of the radiation and the absolute change/reduction in transmission above the cut off wavelength of the radiation.
Further applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
The figures and drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.
Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.
The present invention provides a process and a sensor for sensing oil degradation. As such, the present invention has use as a sensor.
The process includes irradiating a quantity of used oil with different wavelengths of electromagnetic radiation at a given intensity such that a first subset of wavelengths does not pass through the quantity of used oil and a second subset of wavelengths does pass through the quantity of used oil. In addition, a maximum wavelength of the first subset of wavelengths that does not transmit through the quantity of used oil and/or an amount of the electromagnetic radiation from the second set of wavelengths that is transmitted through the quantity of used oil is determined. Thereafter, a comparison is made between the maximum wavelength of the first subset of wavelengths and/or the amount of transmitted electromagnetic radiation from the second subset of wavelengths is made to a standard maximum wavelength and/or a standard amount of transmitted electromagnetic radiation, respectively.
A difference between the maximum wavelength of the first subset of wavelengths and the standard maximum wavelength can be a function of chemical degradation of the oil, the chemical degradation of the used oil can be a function of oxidation of the oil, hydrolysis of the oil, polymerization of the oil, heating of the oil, color change of the oil, disassociation of fats within the oil, disassociation of glycerides in the oil, formation of polar molecules in the oil, formation of alcohols in the oil, formation of aldehydes in the oil, and/or formation of ketones in the oil.
A difference between the amount of transmitted electromagnetic radiation from the second subset of wavelengths and the standard amount of transmitted electromagnetic radiation can be a function of physical degradation of the used oil, the physical degradation of the used oil being a function of solid particles, extraneous liquid and/or extraneous gas within the used oil.
In some instances, the different wavelengths of electromagnetic radiation range from wavelengths greater than 200 nanometers to wavelengths of at least 700 nanometers. In other instances, the different wavelengths of electromagnetic radiation range from wavelengths greater than 300 nanometers to wavelengths of at least 700 nanometers.
The process can further include determining when the used oil should be filtered and/or replaced as a function of the maximum wavelength of the first subset of wavelengths and/or the transmitted electromagnetic radiation from the second subset of wavelengths and their comparison to the standard maximum wavelength and the standard amount of transmitted electromagnetic radiation, respectively. In addition, the process can include determining when to add antioxidants to the used oil and/or the amount of free fatty acids remaining in the used oil.
The sensor can include a multi-wavelength electromagnetic radiation source that is operable to emit electromagnetic radiation having different wavelengths. In addition, the sensor can include a multi-wavelength electromagnetic radiation detector spaced apart from the radiation source with a transmission space between the source and the detector that is dimensioned for a quantity of oil to be located therebetween. A microprocessor can be in electronic communication with the multi-wavelength electromagnetic radiation detector and be operable to determine a minimum wavelength of electromagnetic radiation that has been emitted from the multi-wavelength electromagnetic radiation source and detected by the detector and/or a total amount of the electromagnetic radiation transmitted through the quantity of oil and detected by the detector. In addition, the microprocessor can compare the minimum wavelength to a standard wavelength and/or the total amount of electromagnetic radiation transmitted through the quantity of oil to a standard amount of electromagnetic radiation. In some instances, the standard wavelength and the standard amount of electromagnetic radiation can be established by transmitting different wavelengths of electromagnetic radiation through a quantity of unused oil.
In some instances, the multi-wavelength electromagnetic radiation source can emit radiation with wavelengths between 200 and 800 nanometers. In addition, the radiation source and the radiation detector can be sealed off from oil being tested.
The microprocessor can provide an alert signal that can alert an individual to change the oil that has been tested, filter the oil that has been tested, and/or add an antioxidant to the oil being tested. In addition, the sensor can be part of a handheld device and may or may not be dimensioned to be dipped into a quantity of oil to be tested. In the alternative, the sensor can be part of an inline device such that the sensor is located at least partially within a piece of tubing that has oil therein, the oil therein being tested by the sensor.
The sensor can include an alarm that is in electronic communication with the microprocessor, the alarm operable to provide an audible alarm and/or a visual alarm. Finally, the sensor can further include an automated oil replenishment system that is in electronic control with the microprocessor and is operable to filter the oil being tested, replace the oil being tested, and/or add an antioxidant to the oil being tested.
Non-limiting embodiments will now be described more fully with reference to the accompanying drawings.
Further, as shown in
As shown in
The distinctive transmission behavior of light as illustrated above can be employed in an exemplary sensor design as illustrated in
Similarly, the sensing scheme can be implemented in an inline sensor as shown in
The described methods, techniques, approaches, analogies, apparatus, measurements, data, designs, geometries, illustrations, components and the sensors are example only. The details presented are understood by those skilled as examples only. Therefore, the methods, apparatus and designs and sensors for monitoring and determining the quality of oils qualitatively as well as quantitatively on a reference scale or user defined scale or on an absolute scale have been described with reference to preferred embodiments. Also, the unforeseen or unanticipated changes or alternatives, modifications, improvements and variations of the current teachings therein may be subsequently appreciated or made by those skilled in the art without departing from the scope of the invention are also intended to be encompassed by the following claims.
The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a”, “an” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises”, “comprising”, “including”, and “having” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
When an element or layer is referred to as being “on”, “engaged to”, “connected to” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on”, “directly engaged to”, “directly connected to” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between”, “adjacent” versus “directly adjacent”, etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first”, “second”, and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.
Spatially relative terms, such as “inner”, “outer”, “beneath”, “below”, “lower”, “above”, “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
This application claims the benefit of U.S. Provisional Patent Application No. 61/366,646, filed on Jul. 22, 2010. The entire disclosures of the above application are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61366646 | Jul 2010 | US |
