A kind of gutter oil rapid detection device based on microwave reflection power difference

Abstract

A kind of gutter oil rapid detection device and method based on microwave reflection power difference.The present application relates to the special design of the structure of non-contact gutter oil rapid online detection measuring head.The ability of both transmitting microwave and simultaneously receiving microwave is integrated in a measuring head body, forming intensive structure.It includes an insulating substrate, a ring-shaped microstrip radiator is arranged on the front surface of the insulating substrate, and a metal back plate is arranged on the back surface of the insulating substrate;A light-transmitting central light hole is arranged at the center position, and a bismuth-sb three-dimensional antenna microwave power meter is arranged at the position of the central light hole.The present application integrates the microwave transmission structure of ring-shaped microstrip radiator in a measuring head body, and a bismuth-sb three-dimensional antenna microwave power meter structure that can only receive the microwave reflected by the oil film uniformly coated on the surface of the mirror-polished metal reflecting substrate is reasonably arranged at the position of the central light hole of the microwave transmission structure, thereby forming the "intensive" integrated structure that can both transmit microwave and simultaneously receive microwave.The present application is convenient to operate and use, and the cost is greatly reduced.

Description

Technical Field

[0001] This utility model belongs to the field of food safety testing technology, specifically a rapid detection device for gutter oil based on microwave reflection power difference. Background Technology

[0002] As an illegally recycled product of catering waste, gutter oil contains potent carcinogens such as aflatoxin and benzo[a]pyrene, posing a serious threat to food safety and public health. Traditional detection methods, such as high-performance liquid chromatography and atomic absorption spectrometry, have limitations such as expensive equipment (the cost of a single instrument can reach 500,000 to 1 million yuan) and complex operation (requiring a professional laboratory environment) (Research on the application of fluorescence spectroscopy in the identification of gutter oil).

[0003] Domestic: Xi'an Jianshang Intelligent obtained a patent for an online microwave heating device for crude oil, leaving a gap in gutter oil detection; US: US20080202982A patent proposes a microwave pyrolysis process for waste oil, but does not involve gutter oil detection; Europe: EP1904222A2 patent also focuses on microwave pyrolysis of waste oil, leaving a gap in gutter oil detection; Japan: JP2018-53921 uses near-infrared spectroscopy detection, but no authorized patent has been found for gutter oil detection technology.

[0004] Therefore, rapid detection of gutter oil (<3 minutes), without complicated sample pretreatment, and capable of portable on-site detection, suitable for market supervision, catering enterprises and other scenarios, has become a technical problem that urgently needs to be solved in this field.

[0005] Therefore, how to design a "comprehensive" measuring head that can integrate the ability to both emit and receive reflected microwaves within a single measuring head body, embed characteristic parameters of the reflected microwave power of authentic edible oil and gutter oil into a minimal data processing system, fit the relationship curve with the known values ​​of authentic edible oil and gutter oil, and directly display the values ​​of authentic edible oil and gutter oil during the rapid online microwave detection process has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] This utility model addresses the above-mentioned technical problems by providing a compact measuring head that integrates the ability to both emit and receive microwaves within a single measuring head body, thereby forming a compact structure for a rapid detection device of microwave reflection power difference in waste cooking oil.

[0007] The technical solution of this utility model is as follows: the measuring head housing includes an insulating substrate, the front side of which is provided with an annular microstrip radiator, and the back side of which is provided with a metal back plate; a central large hole is opened at the center of the insulating substrate, and a bismuth-antimony three-dimensional antenna microwave power meter is provided on the back side of the insulating substrate corresponding to the position of the central large hole.

[0008] Furthermore, a ring-shaped microstrip radiator is used to emit microwaves that are perpendicularly incident; a bismuth-antimony three-dimensional antenna microwave power meter is placed at the central aperture of the ring-shaped microstrip radiator to receive reflected microwave power and convert it into a micro-voltage value.

[0009] Furthermore, the metal reflective substrate has a mirror-polished surface to support the oil film to be tested;

[0010] Furthermore, the minimum data processing system is connected to a bismuth-antimony three-dimensional antenna microwave power meter, and has a built-in calibration curve database and comparison algorithm; wherein, the calibration curve is established through the following steps:

[0011] (a) Coating known gutter oil and genuine edible oil onto a metal reflective substrate to form a uniform oil film;

[0012] (b) Measure the reflected microwave power of the two types of oil films, convert it into micro-voltage values, and generate differentiated standard curves;

[0013] The comparison algorithm compares the micro-voltage value of the unknown oil sample with the calibration curve and outputs the result of the gutter oil determination.

[0014] Furthermore, the operating frequency of the annular microstrip radiator is 2450MHz, and its radiation direction is perpendicular to the surface of the metal reflective substrate.

[0015] Furthermore, the bismuth-antimony three-dimensional antenna microwave power meter consists of three bismuth-antimony thermocouple half-wave dipole microwave power probes, which are specifically designed to receive microwave power reflected by the surface of the metal reflective substrate and convert it into a micro-voltage value.

[0016] Furthermore, the metal reflective substrate is made of stainless steel or aluminum alloy.

[0017] Furthermore, the data processing minimum system comparison algorithm performs the following operations:

[0018] Calculate the difference ΔV between the micro-voltage value of the unknown oil sample and the reference voltage of authentic edible oil;

[0019] If ΔV exceeds the preset threshold, it is determined to be gutter oil;

[0020] The threshold is determined by the discrete range of microvoltages from statistical samples of waste cooking oil.

[0021] Furthermore, the measuring head housing is encapsulated in a cylindrical metal cavity, and a polytetrafluoroethylene heat shield is provided on the top of the cavity.

[0022] Furthermore, the bismuth-antimony three-dimensional antenna microwave power meter includes an insulating ceramic substrate, three bismuth-antimony thermocouple half-wave dipoles, and an output structure. The insulating ceramic substrate has three layers of orthogonal grooves and a central through-hole. The three bismuth-antimony thermocouple half-wave dipoles are fixed in the grooves and through-hole along the X / Y / Z axes, respectively. The output structure has all bismuth wires connected together as the negative electrode, and all antimony wires connected in parallel as the positive electrode, outputting a micro-voltage value proportional to the temperature rise. The insulating ceramic substrate is made of alumina or aluminum nitride with a thickness of 0.5~1mm, and the center-to-center spacing of the dipoles is less than or equal to 4.2mm. The diameters of the bismuth and antimony wires in the thermocouples are both 0.2~0.3mm, and the hot spot solder joint size is less than or equal to 0.5mm. The bismuth-antimony three-dimensional antenna microwave power meter further includes a temperature compensation module for calibrating the cold junction ambient temperature drift.

[0023] Furthermore, the outer surface of the metal backplate is provided with an insulating layer, on which a cable interface is fixedly provided. The cable interface has a shielding layer and a core wire. A conductive bridge passes through the insulating layer, the metal backplate, and the insulating substrate, and conductively connects the core wire to the annular microstrip radiator. The conductive bridge is insulated from the metal backplate.

[0024] Furthermore, a measuring head bottom shell is provided, which is circular and has a receiving groove for housing the housing. The bottom shell is also provided with a coaxial cable interface shielding layer and core wire adapted to the annular microstrip radiator. One end of the shielding layer and core wire of the coaxial cable conductor is electrically connected to the coaxial cable interface shielding layer and core wire fixed on the insulation layer inside the housing, and the other end of the shielding layer and core wire of the coaxial cable conductor is electrically connected to the coaxial cable interface shielding layer and core wire fixed on the bottom shell.

[0025] Furthermore, the coaxial cable interface shielding layer and core wire fixed on the bottom shell are electrically connected to the metal shell of the microwave signal generator and the microstrip impedance converter of the microwave signal generator outside the shell through coupling capacitors.

[0026] Furthermore, the bottom shell is provided with mounting holes, and a connector is installed through the mounting holes. One end of the connector is electrically connected to the positive and negative terminals of the output structure inside the shell, and the other end of the connector is connected to the data processing minimum system of the shell.

[0027] Furthermore, this method involves uniformly coating a known film of gutter oil and genuine edible oil onto the surface of a mirror-polished metal reflective substrate. The characteristic parameters of the reflected microwave power are fitted with the known values ​​of genuine edible oil or gutter oil, and this curve is used as a calibration curve for rapid online microwave detection of genuine edible oil or gutter oil.

[0028] This invention integrates a microwave transmitting structure with a ring-shaped microstrip radiator onto a measuring head housing. Simultaneously, a bismuth-antimony three-dimensional antenna microwave power meter, capable only of receiving microwave power reflected from the surface of a metal reflective substrate, is strategically placed at the central large aperture of the microwave transmitting structure. This results in a "compressed" integrated structure that can both transmit and receive microwaves. This makes operation convenient and significantly reduces costs. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of the measuring head body in this utility model.

[0030] Figure 2 yes Figure 1 The right side of the image,

[0031] Figure 3 This is a structural diagram of the bottom surface of the measuring head body.

[0032] Figure 4 This is a schematic diagram of the working principle of this utility model.

[0033] Figure 5 This is a schematic diagram of the structure of the bismuth-antimony three-dimensional antenna microwave power meter of this utility model.

[0034] Figure 1 In this diagram, 1 is the measuring head body, 10 is the insulating substrate, 11 is the ring microstrip radiator, 111 is the conductive bridge, 112 is the coaxial cable interface shielding layer, 1121 is the coaxial cable interface core wire, 12 is the metal backplate, 13 is the insulating layer, 14 is the central large hole, 15 is the bismuth-antimony three-dimensional antenna microwave power meter, and 16 is the positive and negative terminals of the output voltage of the output structure.

[0035] Figure 3 In the diagram, 2 represents the base of the measuring head body, 21 represents the receiving slot, 201 represents the first coaxial cable interface connection hole, and 202 represents the second connector connection hole.

[0036] Figure 4 In the diagram, 3 represents the ring microstrip radiator, the hollow arrow 301 indicates the microwave emission direction of the ring microstrip radiator, the double-dotted elliptical area represents the 2450MHz microwave emission area, 4 represents the oil film being uniformly coated on the mirror-polished metal reflective substrate surface, the hollow arrow 401 indicates the microwave reflection direction reflected by the surface of the metal reflective substrate, the three-dotted elliptical area represents the 2450MHz microwave effect area, and 5 represents the bismuth-antimony three-dimensional antenna microwave power meter set at the large hole in the center of the ring microstrip radiator. It is specifically used to receive the microwave power reflected by the surface of the metal reflective substrate and outputs a micro-voltage value proportional to the temperature rise via a bismuth-antimony thermocouple.

[0037] Figure 5In the diagram, 15 is a bismuth-antimony three-dimensional antenna microwave power meter, 150 is an insulating ceramic substrate, 151, 152, and 153 are three bismuth-antimony thermocouple half-wave dipoles set along the X / Y / Z axes, 154 is the positive terminal of the output structure, and 155 is the negative terminal of the output structure. Detailed Implementation

[0038] The following is in conjunction with the appendix Figure 1-5 Further explanation of this utility model.

[0039] The measuring head body 1 of this utility model includes a polytetrafluoroethylene glass fiber insulating substrate 10, a ring microstrip radiator 11, a conductive bridge 111, a coaxial cable interface shielding layer 112, a coaxial cable interface core wire 1121, a metal backplate 12, an insulating layer 13, a central large hole 14, a bismuth-antimony three-dimensional antenna microwave power meter 15, and the positive and negative terminals of the output voltage of the output structure 16.

[0040] In this implementation, the outer annular metal patch radius of the ring microstrip radiator 11 is 14±0.5mm, and the inner annular metal patch radius is 12.8±0.5mm. The ring microstrip radiator 11 can radiate 2450MHz microwaves along its central axis. For example... Figure 4 As shown.

[0041] Furthermore, at the central aperture of the annular microstrip radiator 11, a bismuth-antimony three-dimensional antenna microwave power meter is set up, consisting of three bismuth-antimony thermocouple half-wave dipoles arranged in a spatially orthogonal configuration, with bismuth and antimony wires each having a diameter of 0.2~0.3mm and a total length of 12mm. This power meter is specifically designed to receive microwave power reflected from the surface of the metal reflective substrate and outputs a micro-voltage value proportional to the temperature rise from the bismuth-antimony thermocouples. This voltage is then compared with the calibration curve of gutter oil or authentic edible oil embedded in the minimum data processing system outside the housing. The measured gutter oil or authentic edible oil value is displayed in real time on the monitor.

[0042] Furthermore, the coaxial cable interface core wire 1121 is electrically connected to the microstrip impedance transformer inside the microwave signal generator outside the measuring head body through a coupling capacitor; the coaxial cable interface shielding layer 112 is connected to the metal shell of the microwave signal generator outside the measuring head body. The microwave signal generator generates a 2450MHz microwave signal, which is provided to the ring microstrip radiator 11 for microwave emission.

[0043] The working principle of this utility model is as follows: Figure 4As shown, the annular microstrip radiator 11 inside the measuring head body can output microwaves forward along the central axis after the microwave signal generator is turned on. The microwaves are perpendicularly incident on the surface of the mirror-polished metal reflective substrate, which is uniformly coated with an oil film. The bismuth-antimony three-dimensional antenna microwave power meter 15, located at the large hole in the center, receives the microwave power reflected by the surface of the metal reflective substrate and converts it into a micro voltage value in the area of ​​action.

[0044] This utility model features a compact, single measuring head that is portable, small in size, and easy to use, thereby improving efficiency and reducing equipment costs.

[0045] This utility model is not limited to the above embodiments. Based on the technical solutions disclosed in this invention, those skilled in the art can make some substitutions and modifications to some of the technical features without creative labor, and these substitutions and modifications are all within the protection scope of this invention.

Claims

1. A rapid detection device for waste cooking oil based on microwave reflection power difference, characterized in that, The device includes a measuring head body, comprising: an insulating substrate with a ring-shaped microstrip radiator on its front side and a metal backplate on its back side; a large central hole at the center of the insulating substrate, and a bismuth-antimony three-dimensional antenna microwave power meter positioned on the back side of the insulating substrate corresponding to the large central hole; the radiation direction of the ring-shaped microstrip radiator being perpendicular to the surface of the metal reflective substrate; the surface of the metal reflective substrate being mirror-polished to support the oil film to be measured; the bismuth-antimony three-dimensional antenna microwave power meter receiving microwave power reflected by the oil film on the surface of the metal reflective substrate and converting it into a micro-voltage value; and a minimum data processing system connected to the bismuth-antimony three-dimensional antenna microwave power meter for processing the micro-voltage value and outputting a judgment result.

2. The rapid detection device for waste cooking oil based on microwave reflection power difference according to claim 1, characterized in that: The operating frequency of the ring microstrip radiator is 2450MHz.

3. The rapid detection device for waste cooking oil based on microwave reflection power difference according to claim 1, characterized in that: The bismuth-antimony three-dimensional antenna microwave power meter consists of three bismuth-antimony thermocouple half-wave dipole microwave power probes, which are specifically designed to receive microwave power reflected by the oil film on the surface of the metal reflective substrate and convert it into a micro voltage value.

4. The rapid detection device for waste cooking oil based on microwave reflection power difference according to claim 1, characterized in that: The metal reflective substrate is made of stainless steel or aluminum alloy and has a mirror-polished surface.

5. The rapid detection device for waste cooking oil based on microwave reflection power difference according to claim 1, characterized in that: The measuring head body also includes a measuring head bottom shell, which is a circular cover and has a receiving groove for placing the insulating substrate.

6. The rapid detection device for waste cooking oil based on microwave reflection power difference according to claim 5, characterized in that: The measuring head body is encapsulated in a cylindrical metal cavity, and a polytetrafluoroethylene heat shield is provided on the top of the cavity.

7. The rapid detection device for waste cooking oil based on microwave reflection power difference according to claim 3, characterized in that: The bismuth-antimony three-dimensional antenna microwave power meter includes an insulating ceramic substrate, three bismuth-antimony thermocouple half-wave dipoles, and an output structure. The insulating ceramic substrate has three layers of orthogonal grooves and a central through hole. The three bismuth-antimony thermocouple half-wave dipoles are fixed in the grooves and through hole along the X / Y / Z axes, respectively. The output structure has all bismuth wires connected together as the negative electrode and all antimony wires connected in parallel as the positive electrode, outputting a micro voltage value proportional to the temperature rise.

8. The rapid detection device for waste cooking oil based on microwave reflection power difference according to claim 7, characterized in that: The insulating ceramic substrate is made of alumina or aluminum nitride with a thickness of 0.5–1 mm, and the center-to-center spacing of the oscillators is less than or equal to 4.2 mm; the diameter of the bismuth wire and the antimony wire of the bismuth-antimony thermocouple is 0.2–0.3 mm, and the hot spot solder joint size is less than or equal to 0.5 mm; the bismuth-antimony three-dimensional antenna microwave power meter also includes a temperature compensation module for calibrating the cold junction ambient temperature drift.

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