Fiber-optic particle detector, and preparation method therefor and use thereof

Abstract

The present application relates to a fiber-optic particle detector, and a preparation method therefor and the application thereof. The fiber-optic particle detector comprises: an image collection unit; and an image transmission unit, wherein an output end thereof is coupled and connected to the image collection unit. The technical problem to be solved is to use the principle of total internal reflection of an optical fiber to transmit internal information of a reaction vessel to a CMOS for digitization, so as to realize real-time observation of a reaction process inside an opaque vessel.

Description

Fiber Optic Particle Detector, Its Fabrication Method and Application

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411417843.1, filed on October 11, 2024, entitled "Fiber Optic Particle Detector and its Preparation Method and Application", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application pertains to a detection instrument, specifically relating to a fiber optic particle detector, its preparation method, and its application. Background Technology

[0004] Currently, numerous fields such as petroleum, chemical, rubber, pesticides, dyes, pharmaceuticals, and food involve a series of chemical processes including sulfidation, nitration, hydrogenation, hydrocarbonation, polymerization, and condensation, as well as physical processes such as mixing, dispersion, dissolution, crystallization, and extraction. Specific high-temperature, high-pressure, explosive reactions, high-viscosity polymerization processes, salt and sugar preparation processes, online particle size analysis of cement clinker, and engine oil particulate matter detection all involve or generate particulate products. In these processes, the reaction vessels are often opaque, and the reaction progress is controlled based on experience and reaction time, frequently leading to errors in process judgment. Furthermore, extensive experimental data is required for summarizing and generalizing, resulting in high costs and results easily affected by external conditions, thus limiting production efficiency. To address these issues, improving efficiency hinges on real-time observation of the reaction process, fully understanding the reaction state of materials at any given moment, and taking timely corresponding measures and adjustments. Currently, research on real-time monitoring of these chemical and physical processes is relatively scarce, and high integration, miniaturization, and high-resolution imaging are not yet feasible. Summary of the Invention

[0005] In view of this, the main objective of this application is to provide a fiber optic particle detector, its preparation method and application. The technical problem to be solved is to use the principle of total internal reflection of optical fibers to transmit the information inside the reaction vessel to CMOS for digitization, so as to realize real-time observation of the reaction process inside the opaque container.

[0006] The purpose of this application and the technical problem it solves are achieved by the following technical solution. This application proposes a fiber optic particle detector, which includes:

[0007] Image acquisition unit;

[0008] An image transmission unit, the output of which is coupled to the image acquisition unit.

[0009] Optionally, in the aforementioned fiber optic particle detector, the input end of the image transmission unit is embedded with a metal tube with a thickness of 2-5 mm, and the space between the metal tube and the image transmission unit is filled with a 2-3 mm thick fixing adhesive.

[0010] Optionally, in the aforementioned fiber optic particle detector, the image transmission unit is a bundle of image transmission optical fibers with a length of 20-400 mm and a diameter of 5-15 mm, a wire diameter of 2-6 μm, and a resolution of 200 lp / mm or higher.

[0011] Optionally, in the aforementioned fiber optic particle detector, the image acquisition unit includes a CCD or CMOS camera, which is enclosed by a high-temperature resistant metal frame with a thickness of 2-5mm, and the high-temperature resistant metal frame is surrounded by a cylindrical high-temperature resistant metal shell with a diameter of 80-100mm and a height of 100-120mm.

[0012] Optionally, in the aforementioned fiber optic particle detector, one end of the metal tube is connected to the high-temperature resistant metal frame, and the other end is provided with an illumination source 2-8 mm beyond the tail plane of the fiber optic image bundle. The tail surface of the image bundle is coated with a layer of Teflon.

[0013] Optionally, in the aforementioned fiber optic particle detector, the surface of the illumination source is coated with a Teflon coating.

[0014] Optionally, in the aforementioned fiber optic particle detector, the illumination source is an LED light source or a halogen light source.

[0015] Optionally, in the aforementioned fiber optic particle detector, the illumination source includes four light guides surrounding the fiber optic image bundle, and a ring-shaped LED light disposed at the coupling connection between the image transmission unit and the image acquisition unit.

[0016] Optionally, in the aforementioned fiber optic particle detector, the space between the high-temperature resistant metal frame and the high-temperature resistant metal outer shell is filled with refractory material.

[0017] The purpose of this application and the technical problem it solves are achieved by the following technical solution. This application proposes a method for fabricating a fiber optic particle detector, comprising the following steps: coupling the output end of an image transmission unit to the photosensitive surface of an image acquisition unit.

[0018] Optionally, in the aforementioned method for preparing a fiber optic particle detector, the image acquisition unit includes a CCD or CMOS camera, the CCD or CMOS camera is encased in a high-temperature resistant metal frame with a thickness of 2-5 mm, and the high-temperature resistant metal frame is surrounded by a cylindrical high-temperature resistant metal shell with a diameter of 80-100 mm and a height of 100-120 mm.

[0019] Optionally, in the aforementioned method for preparing the fiber optic particle detector, the coupling adhesive is an ultraviolet curing agent, which consists of 5 wt% benzoin ether, 25 wt% hydroxyethyl acrylate, and 70 wt% polyurethane acrylate, with a refractive index of 1.80, a curing ultraviolet wavelength of ~320 nm, and a visible light transmittance greater than 98%.

[0020] Optionally, in the aforementioned method for fabricating a fiber optic particle detector, the thickness of the coupled adhesive layer is 5-10 μm.

[0021] Optionally, in the aforementioned method for preparing the fiber optic particle detector, the amount of adhesive used for coupling is 0.2-0.5 ml.

[0022] The purpose of this application and the technical problem it solves are achieved by the following technical solution. This application proposes a particle detection method, comprising the following steps:

[0023] Check the power supply, and turn on the light source and power supply of the fiber optic particle detector and the computer monitor in sequence.

[0024] Insert the image acquisition end of the fiber optic particle detector along the reserved hole of the reaction vessel to be tested, and after it is fully inserted, wrap a layer of aluminum silicate fiber at the interface.

[0025] During the reaction process, the camera is used to capture the state of the particles inside the container and the camera exposure time is controlled.

[0026] Once the test is complete, turn off the power to the display, the fiber optic particle detector, and the light source in sequence.

[0027] Finally, after removing the fiber optic particle detector, clean the surface of the image acquisition end and the surface of the light source promptly.

[0028] Optionally, in the aforementioned method of using the fiber optic particle detector, when the operating environment is below 200°C and the material transmittance is less than 20%, the light source is an LED light source.

[0029] Optionally, in the aforementioned method of using the fiber optic particle detector, when operating in an environment with a temperature greater than 200°C, the light source is a halogen light source or a high-temperature resistant LED light source.

[0030] Optionally, in the aforementioned method of using the fiber optic particle detector, when the diameter of the image transmission bundle is less than 10 mm and the transmittance of the material being measured is greater than 80%, the light source includes four light guide rods surrounding the fiber optic image transmission bundle, and a ring-shaped LED light is arranged at the coupling position between the two.

[0031] Compared with existing technologies, the fiber optic particle detector, its fabrication method, and its application have the following advantages:

[0032] This application enables real-time observation of the reaction process inside an opaque container; by utilizing the principle of total internal reflection of optical fibers, the information inside the reaction container is transmitted to CMOS for digitization, and the digitized image is recognized and processed by MATLAB software. This not only provides real-time observation images, but also allows for the calculation of particle size, shape, and quantity based on the digitized images, ultimately yielding particle uniformity and distribution.

[0033] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, the preferred embodiments of this application are described in detail below. Attached Figure Description

[0034] Figure 1 is a schematic diagram of the structure of the fiber optic particle detector of this application;

[0035] Figure 2A is a schematic diagram of the camera metal frame in the fiber optic particle detector of this application;

[0036] Figure 2B is a schematic diagram of the structure of the fixing piece of the camera metal frame in the fiber optic particle detector of this application.

[0037] Figure 3 shows the annular light guide rod in the fiber optic particle detector of this application;

[0038] Figure 4 shows the detection of large particles of reaction products inside the reactor of this application;

[0039] Figure 5 is a detection diagram of small particles of reaction products inside the reactor of this application;

[0040] Figure 6 is a detection diagram of the asphalt mixing particles inside the planetary mixer of this application;

[0041] Figure 7 is a detection diagram of oil particles inside the engine according to this application;

[0042] Figure 8 shows the detection patterns of salt and sugar granules in this application.

[0043] Among them: 1-Image transmission fiber bundle; 2-CCD / CMOS camera; 3-Camera metal shell; 4-Refractory material; 5-Outermost metal shell; 6-Light source power cord; 7-Camera power cord; 8-Fixing adhesive; 9-Metal tube; 10-Material inlet / outlet window; 11-Light source; 12-Ring LED light; 13-Light guide rod; 14-Pre-reserved slot for fixing plate; 15-Fixing plate. Detailed Implementation

[0044] To further illustrate the technical means and effects adopted by this application to achieve its intended purpose, the following detailed description, in conjunction with preferred embodiments, provides a detailed explanation of the specific implementation methods, structures, features, and effects of the fiber optic particle detector, its preparation method, and its application based on this application. In the following description, different "embodiments" or "embodiments" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable manner.

[0045] Unless otherwise specified, all reagents used are commercially available, and all methods used are conventional. All components are commercially available products well-known to those skilled in the art.

[0046] As shown in Figures 1-3, some embodiments of this application provide a fiber optic particle detector, which includes:

[0047] Image acquisition unit;

[0048] An image transmission unit, the output of which is coupled to the image acquisition unit.

[0049] In the above technical solution, the coupling connection between the output end of the image acquisition unit and the image transmission unit needs to consider three factors: 1. The coupling interface must not have defects such as bubbles or moiré fringes; 2. The coupling adhesive layer must be less than 10 micrometers to ensure that the resolution is not lost after coupling; 3. After CMOS is coupled to the fiber optic image transmission bundle, it can perform detection work in various harsh environments.

[0050] In some embodiments, optionally, a metal tube 9 with a thickness of 2-5 mm is embedded in the input end of the image transmission unit to protect the optical fiber image bundle 1; if the thickness of the metal tube 9 is less than 2 mm, the protection effect is not good; if the thickness of the metal tube 9 is greater than 5 mm, the overall device is too large; a 2-3 mm thick fixing adhesive 8 is filled between the metal tube 9 and the image transmission unit; the fixing adhesive 8 serves to connect the optical fiber image bundle 1 and the metal tube 9, and 2-3 mm is the gap between the two. If the gap is less than 2 mm, it is too small and difficult to assemble; if it is greater than 3 mm, the gap is too large and the overall device is too large.

[0051] In some embodiments, considering the CMOS selected for the operating environment, the image transmission unit may optionally be an image transmission fiber bundle 1 with a length of 20-400 mm and a diameter of 5-15 mm, a wire diameter of 2-6 μm, and a resolution of 200 lp / mm or higher. One of the causes of moiré fringes is poor matching between the CMOS pixel and the wire diameter of the fiber image transmission bundle 1; therefore, the wire diameter of the fiber image transmission bundle 1 needs to be adjusted to eliminate moiré fringes.

[0052] In some embodiments, optionally, the image acquisition unit includes a CCD or CMOS camera 2, which is enclosed by a high-temperature resistant metal frame with a thickness of 2-5 mm. The high-temperature resistant metal frame is surrounded by a cylindrical high-temperature resistant camera metal housing 3 with a diameter of 80-100 mm and a height of 100-120 mm. The high-temperature resistant metal frame protects the CCD or CMOS camera 2; when its thickness is less than 2 mm, the protection is inadequate; when its thickness is greater than 5 mm, the overall device becomes too large. The dimensions of the cylindrical high-temperature resistant camera metal housing 3 are determined based on actual application.

[0053] In some embodiments, optionally, one end of the metal tube 9 is connected to the high-temperature resistant metal frame, and the other end is provided with an illumination source 11 2-8 mm beyond the tail plane of the optical fiber image bundle 1. This 2-8 mm gap serves as a material entry / exit window 10 with adjustable height, allowing material flow. The gap is adjusted according to actual usage; the gap can be reduced for low-viscosity materials and increased for high-viscosity materials (materials refer to substances reacting in the reaction vessel to be detected). The tail surface of the image fiber bundle 1 is coated with a Teflon layer to ensure that materials can flow freely on the surface of the optical fiber image bundle. The power cords of the camera and illumination source 11 are led out from the top of the outermost metal shell and connected to a computer for real-time monitoring. The thickness of the Teflon coating is 20-30 micrometers; a thickness less than 20 micrometers is too thin to meet requirements, while a thickness greater than 30 micrometers is too thick and poses a risk of coating peeling.

[0054] In some embodiments, optionally, the surface of the lighting source 11 is coated with a Teflon coating. The thickness of the Teflon coating is 20-30 micrometers; a thickness less than 20 micrometers is too thin to meet the requirements, while a thickness greater than 30 micrometers is too thick and poses a risk of coating peeling.

[0055] In some embodiments, the lighting source 11 may optionally be an LED light source or a halogen light source. An LED light source is used when the ambient temperature is below 85 degrees Celsius, and a halogen light source is used when the ambient temperature is above 85 degrees Celsius.

[0056] In some embodiments, optionally, the illumination source 11 includes four light guide rods 13 surrounding the optical fiber image bundle 1, and a ring-shaped LED light 12 disposed at the coupling connection between the image transmission unit and the image acquisition unit, as shown in Figure 3.

[0057] In some embodiments, optionally, a refractory material 4 (100% filling rate) is filled between the high-temperature resistant metal frame and the camera metal housing 3 to protect the camera from high temperatures and ensure that the camera's operating temperature does not exceed 40°C. The refractory material 4 is commercially available aluminosilicate refractory fiber.

[0058] Some embodiments of this application also provide a method for fabricating a fiber optic particle detector, including the following steps: coupling the output end of an image transmission unit to the photosensitive surface of an image acquisition unit.

[0059] In some embodiments, optionally, the method specifically includes the following steps:

[0060] Fabrication of S1 image transmission fiber bundle: A high-refractive-index glass rod and a low-refractive-index glass tube are combined using a rod-tube combination method and drawn into a single filament (diameter 2.6-2.7 mm) at 550-850℃. The drawn single filament and a light-absorbing filament (diameter 0.4-0.6 mm) for absorbing stray light are arranged into a hexagonal shape and drawn into a primary complex filament (diameter 1.3-1.5 mm) at 550-850℃. The primary complex filament is then arranged into a hexagonal shape again and drawn (at 550-850℃) into a secondary complex filament (diameter 2-2.2 mm). At this point, the diameter of the internal unit filament is only 2-2.5 μm, with a theoretical resolution exceeding 200 lp / mm. The high-refractive-index glass rod has a refractive index of 1.7-1.8, and its composition by mass percentage is: SiO2 63-65%; B2O3 4.2-4.5%; Al2O3 4.5-4.8%; Na2O The low-refractive-index glass tube has a refractive index of 1.4-1.5 and its composition by mass percentage is as follows: SiO2 63-65%; B2O3 4.5-4.8%; Al2O3 3.5-4%; Na2O 5.5-6%; K2O 5.3-5.5%; BaO 7.5-7.8%; CaO 5.5-6%; ZrO2 2.7-3%; Bi2O3 1-1.5%.

[0061] The S2 image transmission fiber bundle's image output end is coupled to the photosensitive surface. The coupling adhesive is a UV-curing agent with a refractive index of 1.80, a curing UV wavelength less than 400nm, and a visible light transmittance greater than 98%. This adhesive can achieve rapid curing after direct irradiation with 254-400nm UV light for 30-60 seconds. First, the CCD / CMOS power is turned on, and the coupling process is observed in real time. It is placed on a high-precision displacement platform with a movement accuracy and repeatability of 1μm or less. Combined with the high-definition image of the CMOS coupled fiber transmission bundle, the center position can be identified, and coupling at specific positions can also be achieved as needed. The fiber transmission bundle is fixed perpendicularly to the CCD / CMOS surface on the coupling bracket. 0.2-0.5ml of UV-curing adhesive is applied to the center of the CCD / CMOS photosensitive surface. The fiber transmission bundle is then fixed perpendicularly to the CCD / CMOS surface on the coupling bracket, ensuring horizontal coupling between the two. During coupling, the quality of the captured image is observed. After complete coupling, the ultraviolet light source is turned on. The ultraviolet light passes through the homogenizing glass to emit uniform ultraviolet light, which is then irradiated onto the ultraviolet curing adhesive through the image transmission fiber bundle to achieve rapid curing. At this time, the thickness of the coupling adhesive layer is 5-10 μm. If the ultraviolet curing adhesive is less than 0.2 ml, the coupling failure rate is high, and the adhesive layer is too thin, resulting in weak bonding strength. If the ultraviolet curing adhesive is more than 0.5 ml, the coupling adhesive layer is too thick, affecting the coupling resolution. If the coupling adhesive layer is less than 5 μm, the adhesive layer is too thin, resulting in weak bonding strength. If the coupling adhesive layer is greater than 10 μm, the coupling adhesive layer is too thick, affecting the coupling resolution.

[0062] S3 Camera Protection: The CCD / CMOS camera 2 measures 45*45*20mm. Prepare a 3mm thick metal housing 3 with the same shape as the camera, with a pre-drilled 20-30mm diameter hole at the bottom. The metal housing 3 is divided into two symmetrical halves along the XOZ plane, as shown in Figures 2A and 2B. The metal housing 3 has a pre-drilled slot 14 for a fixing piece. First, place the CCD / CMOS camera 2 into one half of the metal housing. Then, use the fixing piece 15 to fix the other half of the metal housing to the first half. After fixing, install the bottom of the metal housing 3, with a pre-drilled 20-30mm diameter hole at the bottom, the size of which depends on the metal tube design. After the bottom is installed, fit a 20-30mm diameter, 2mm thick hollow cylindrical metal frame over the image transmission fiber bundle 1 and connect it to the pre-drilled hole in the camera metal frame using bolts. The space between the camera's metal housing 3 and the outermost metal housing 5 is filled with refractory material 4. The outermost metal housing 5 is also made of a split structure and connected by screws for easy assembly. Two 3mm diameter holes are pre-drilled at the top of the outermost metal housing 5 for leading out the light source power cable 6 and the camera power cable 7.

[0063] The image collection end of the S4 fiber optic image bundle 1 is coated with a 20-30 micrometer Teflon coating. This coating possesses excellent waterproof, oil-proof, high-temperature resistance, and wear resistance properties, ensuring that materials can flow freely on the end face of the image bundle without leaving marks on the surface, thus affecting the observation results. Furthermore, a light source with a diameter of 10-18 mm can be placed 4-8 mm away from the end face of the fiber optic image bundle 1 as an illumination source 11. Similarly, a 20-30 micrometer Teflon coating is deposited on the surface of this illumination source 11 to ensure stable light intensity during observation.

[0064] S5 Light Source Selection: Depending on the application scenario, LED light sources can be selected when the material has low transparency (transmittance less than 20%) in a normal operating environment; halogen light sources or high-temperature resistant LED light sources can be used in high-temperature environments, such as those exceeding 200℃, with a temperature range of -20℃ to 700℃; additionally, for scenarios where the image transmission bundle diameter is less than 10mm and the transmittance of the measured material is greater than 80%, four light guide rods 13 can be used to surround the optical fiber image transmission bundle 1, and a ring LED light 12 can be set at the coupling position to provide light source to the light guide rods 13, adopting a ring lighting method.

[0065] Some embodiments of this application also provide a particle detection method, including the following steps:

[0066] Select the appropriate light source type according to the application requirements. In low-temperature (below 200℃) operating environments where the material transparency is low (transmittance less than 20%), an LED light source can be selected. In high-temperature environments, such as those above 200℃, a halogen light source or a high-temperature resistant LED light source can be used. Additionally, for scenarios where the image bundle diameter is less than 10mm and the measured material has a high transmittance greater than 80%, the light source can be selected as follows: four light guide rods 13 surround the optical fiber image bundle 1, and a ring-shaped LED light 12 is placed at the coupling point between the two to provide light to the light guide rods 13, adopting a ring lighting method.

[0067] Check the power supply, and turn on the light source and power supply of the fiber optic particle detector and the computer monitor in sequence.

[0068] Slowly insert the image acquisition device along the pre-drilled hole in the reaction vessel under test. Once fully inserted, wrap a layer of aluminum silicate fiber around the interface to prevent temperature fluctuations inside the reaction vessel. During the reaction, the camera can be controlled to capture the state of the particles inside the vessel, and the camera exposure time can also be controlled.

[0069] After the test is complete, turn off the power to the monitor, the fiber optic particle detector, and the light source in sequence. Finally, remove the particle detector and clean the image acquisition end face and the surface of the light source promptly.

[0070] The present application will be further described below with reference to the embodiments.

[0071] Example 1: Fabrication of a particle detector for use in low-temperature, low-transparency environments

[0072] Fabrication of S1 image transmission fiber bundle: A high-refractive-index glass rod and a low-refractive-index glass tube are combined using a rod-tube combination method and drawn into a single filament with a diameter of 2.6 mm at 850℃. The drawn single filament and a 0.5 mm diameter light-absorbing filament for absorbing stray light are arranged into a hexagonal shape and drawn into a primary complex filament with a diameter of 1.4 mm at 850℃. The primary complex filament is then arranged into a hexagonal shape again and drawn (at 850℃) into a secondary complex filament with a diameter of 2.1 mm. At this point, the diameter of the internal unit filament is only 2.5 μm, and the theoretical resolution is 230 lp / mm. The high-refractive-index glass rod has a refractive index of 1.8 and its composition by mass percentage is: SiO2 63%; B2O3 4.3%; Al2O3 4.6%; Na2O 6.8%; La2O3 5%; BaO 7.3%; CaO 6%; ZrO2 2%; Bi2O3 1%; the low-refractive-index glass tube has a refractive index of 1.5 and its composition by mass percentage is: SiO2 64%; B2O3 4.5%; Al2O3 3.5%; Na2O 5.5%; K2O 5.4%; BaO 7.5%; CaO 5.6%; ZrO2 2.7%; Bi2O3 1.3%.

[0073] The S2 image transmission fiber bundle's image output end is coupled to the photosensitive surface. The coupling adhesive is a UV-curing agent, composed by weight percentage of benzoin ether (5wt%), hydroxyethyl acrylate (25wt%), and polyurethane acrylate (70wt%), with a refractive index of 1.80. It cures at a UV wavelength of ~400nm and has a visible light transmittance greater than 98%. This adhesive can achieve rapid curing after 30 seconds of direct irradiation with 254-400nm UV light. First, the CCD / CMOS power supply is turned on, and the coupling process is observed in real time. It is placed on a high-precision displacement platform, achieving a movement accuracy and repeatability of 1μm. Combined with the high-definition image of the CMOS coupled fiber transmission bundle, the center position is identified. The fiber transmission bundle is fixed perpendicularly to the CCD / CMOS surface on the coupling bracket. 0.3ml of UV-curing adhesive is dropped into the center of the CCD / CMOS photosensitive surface. The fiber transmission bundle is then fixed perpendicularly to the CCD / CMOS surface on the coupling bracket, ensuring horizontal coupling. During coupling, the quality of the captured image was observed. After complete coupling, the ultraviolet light source was turned on, and the ultraviolet light emitted uniformly through the homogenizing glass was directed onto the ultraviolet curing adhesive via the image transmission fiber bundle to achieve rapid curing. At this point, the thickness of the coupling adhesive layer was 7 μm.

[0074] S3 Camera Protection: The CCD / CMOS camera measures 45*45*20mm. Prepare a 3mm thick metal casing with the same shape as the camera, and pre-drill a 30mm diameter hole at the bottom. The metal casing is divided into two symmetrical halves along the XOZ plane, as shown in Figure 3. Place the camera in one half and secure the other half of the metal casing with bolts. After securing, install the bottom of the metal casing, pre-drilling a 30mm diameter hole at the bottom, the size of which is designed according to the metal tube. After installing the bottom, fit a 30mm diameter, 2mm thick hollow cylindrical metal frame over the image transmission fiber rod and connect it to the pre-drilled hole in the camera's metal frame with bolts. The space between the camera's metal casing 3 and the outermost metal casing 5 is filled with refractory material 4. The outermost metal casing 5 is also made into a split structure and connected with screws for easy assembly.

[0075] S4 fiber optic image bundle image collection end; a 30-micron Teflon coating is deposited on the fiber optic image bundle image collection end; since this embodiment is a low temperature (50°C) operating environment and the material transparency is 20%, an LED with a diameter of 15mm is set at 5mm away from the end face of the image bundle as an illumination source 11, and a 30-micron Teflon coating is also deposited on the surface of the illumination source 11.

[0076] Example 2: Fabrication of a particle detector for use in a low-temperature, high-transmittance environment (50°C, 80% transmittance).

[0077] The difference between this embodiment and embodiment 1 is that this embodiment uses four light guide rods 13 around the optical fiber image bundle 1 as supplementary light sources (the light guide rods 13 are respectively set in the four directions of the optical fiber image bundle 1, and the end face of the light guide rod is kept horizontal with the optical fiber image bundle), adopts a ring illumination method, and at the same time, a 30-micron Teflon coating is formed on the surface of each light guide rod 13, and steps S1, S2, and S3 are the same as in embodiment 1.

[0078] Example 3: Fabrication of a particle detector for high-temperature environments (200℃)

[0079] The difference between this embodiment and Embodiment 1 is that this embodiment uses a halogen light source or a specially made high-temperature resistant LED light source as the supplementary light source, adopts a ring lighting method, and at the same time, a 30-micron Teflon coating is formed on the surface of the high-temperature resistant halogen lamp (its temperature range is -20℃ to 700℃), and steps S1, S2, and S3 are the same as in Embodiment 1.

[0080] Example 4: Detection of large particles of reaction products inside a reactor

[0081] The material inside the reactor has relatively high transparency (80% transmittance), but also high temperature (500℃) and is corrosive. A high-temperature halogen lamp or a specially designed LED lamp is selected as the light source. The preparation process is as described in steps S1-S4 of Example 3. Depending on the application scenario, the diameter of the image transmission fiber bundle is 10mm, the wire diameter is 6μm, and the resolution is 96lp / mm. The light source is replaced with a high-temperature halogen lamp (its temperature range is -20℃ to 700℃). The main body of the fiber optic particle detector prepared in Example 3 of this application (a cylindrical high-temperature resistant metal shell with a diameter of 80mm and a height of 100mm) is placed on top of the reactor vessel. The signal acquisition end of the image acquisition unit is inserted into the material from top to bottom through the top plate of the reactor. The entire fiber optic particle detector revolves around the central axis of the furnace along with the top plate. The image data and power supply of its CMOS circuit board and chip are connected to a computer monitor through a rotary converter. Figure 4 shows that the particle size can be observed in real time. As can be seen from Figure 4, the particle size and shape during the reaction process inside the reactor can be used to control the reaction process and estimate the remaining reaction time.

[0082] Example 5: Detection of small particles of reaction products inside a reactor

[0083] The difference between this embodiment and Embodiment 1 is that the fiber optic image bundle diameter in this embodiment is 3 micrometers, and the resolution is 192 lp / mm. The main body of the fiber optic particle detector of Embodiment 3 (a cylindrical high-temperature resistant metal shell with a diameter of 80 mm and a height of 100 mm) is placed on top of the reactor vessel. The signal acquisition end of the image acquisition unit is inserted into the material from top to bottom through the top plate of the reactor. The image data and power supply of its CMOS circuit board and chip are connected to an external display system and power supply via a computer monitor. Figure 5 shows the particle size can be observed in real time. Individual small particles can be clearly observed from Figure 5.

[0084] Example 6: Detection of Asphalt Mixing Particles in a Planetary Mixer

[0085] The planetary mixer can be used for mixing asphalt (composed of 95wt% sand and gravel and 5wt% asphalt mud) at 2000 rpm. This material has high viscosity, high ambient temperature (200℃), and low transparency (30%) during mixing. The main body of the fiber optic particle detector (a cylindrical high-temperature resistant metal shell with a diameter of 80mm and a height of 100mm) of Embodiment 3 of this application is placed on top of the asphalt mixing container. The signal acquisition end of the image acquisition unit is inserted into the material from top to bottom through the top plate of the planetary mixer. The fiber optic particle detector of this application revolves around the central axis of the furnace along with the top plate. The image data and power supply of the CMOS circuit board and chip are connected to a computer monitor through a rotary converter. During the high-speed mixing process of 2000 rpm, the particle size can be observed in real time, as shown in Figure 6. As can be seen from Figure 6, during the mixing process, the material does not stick to the surface of the acquisition end, and the particle morphology and size can be clearly seen.

[0086] Example 7: Detection tool for detecting oil particles inside an engine

[0087] Oil particle detection inside the engine can be performed at room temperature with high physical transparency (80% transmittance). The main body of the fiber optic particle detector in Embodiment 1 of this application (a cylindrical high-temperature resistant metal shell with a diameter of 80mm and a height of 100mm) is placed on top of the engine. The signal acquisition end of the image acquisition unit is inserted into the material from top to bottom through the top plate. The entire fiber optic particle detector of Embodiment 1 of this application revolves around the central axis of the furnace along with the top plate of the reactor. The image data and power supply of the CMOS circuit board and chip are connected through a computer monitor. Figure 7 shows that the particle size can be observed in real time. As can be seen from Figure 7, the morphology and size of the particles inside the engine can still be clearly seen under the illumination of the light guide rod.

[0088] Example 8: Detection of Salt and Sugar Particles

[0089] During the crystallization process of salt and white sugar granules, the ambient temperature is relatively low (40℃), and the physical transparency of the detector is high (transmittance is 80%). A ring-shaped light guide rod can be used as the illumination source. The signal acquisition end of the image acquisition unit passes through the top plate and is inserted into the material from top to bottom of the main body. The fiber optic particle detector of Embodiment 2 of this application revolves around the central axis of the furnace along with the top plate. The image data and power supply of the CMOS circuit board and chip are connected through a computer monitor. Figure 8 shows that the particle size can be observed in real time. As can be seen from Figure 8, even under the illumination of the light guide rod, the morphology and size of the particles during the preparation of salt and white sugar can still be clearly seen.

[0090] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0091] The numerical range described in this application includes all numerical values ​​within this range, and also includes any range value composed of any two numerical values ​​within this range. Different numerical values ​​of the same indicator appearing in all embodiments of this application can be arbitrarily combined to form a range value.

[0092] The technical features in the claims and / or specification of this application can be combined, and the combination is not limited to the combinations obtained through reference in the claims. Technical solutions obtained by combining the technical features in the claims and / or specification are also within the scope of protection of this application.

[0093] The above description is merely a preferred embodiment of this application and is not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A fiber optic particle detector, characterized in that, It includes: Image acquisition unit; An image transmission unit, the output of which is coupled to the image acquisition unit.

2. The fiber optic particle detector as described in claim 1, characterized in that, The input end of the image transmission unit is embedded with a metal tube with a thickness of 2-5mm, and the space between the metal tube and the image transmission unit is filled with a 2-3mm thick fixing adhesive.

3. The fiber optic particle detector as described in claim 1, characterized in that, The image transmission unit is a bundle of image transmission optical fibers with a length of 20-400mm and a diameter of 5-15mm, a wire diameter of 2-6μm, and a resolution of 200lp / mm or higher.

4. The fiber optic particle detector as described in claim 2, characterized in that, One end of the metal tube is connected to a high-temperature resistant metal frame, and the other end is provided with an illumination source 2-8mm beyond the tail plane of the optical fiber image bundle. The tail surface of the image fiber bundle is coated with a layer of Teflon.

5. The fiber optic particle detector as described in claim 4, characterized in that, The surface of the lighting source is coated with a Teflon coating.

6. The fiber optic particle detector as described in claim 4, characterized in that, The lighting source is an LED light source or a halogen light source.

7. The fiber optic particle detector as described in claim 4, characterized in that, The illumination source includes four light guides surrounding the optical fiber image bundle, and a ring-shaped LED light located at the coupling connection between the image transmission unit and the image acquisition unit.

8. The fiber optic particle detector as described in claim 1, characterized in that, The image acquisition unit includes a CCD or CMOS camera, which is enclosed by a high-temperature resistant metal frame with a thickness of 2-5mm. The high-temperature resistant metal frame is surrounded by a cylindrical high-temperature resistant metal shell with a diameter of 80-100mm and a height of 100-120mm.

9. The fiber optic particle detector as described in claim 8, characterized in that, The space between the high-temperature resistant metal frame and the high-temperature resistant metal outer shell is filled with refractory material.

10. A method for fabricating a fiber optic particle detector, characterized in that, Includes the following steps: The output of the image transmission unit is coupled to the photosensitive surface of the image acquisition unit.

11. The method for fabricating the fiber optic particle detector as described in claim 10, characterized in that, The coupling adhesive is a UV curing agent, composed of 5 wt% benzoin ether, 25 wt% hydroxyethyl acrylate, and 70 wt% polyurethane acrylate, with a refractive index of 1.80, a curing UV wavelength of ~320 nm, and a visible light transmittance greater than 98%.

12. The method for fabricating the fiber optic particle detector as described in claim 10, characterized in that, The thickness of the coupling adhesive layer is 5-10 μm; the amount of coupling adhesive used is 0.2-0.5 ml.

13. A particle detection method, characterized in that, Includes the following steps: Check the power supply, and turn on the light source and power supply of the fiber optic particle detector and the computer monitor in sequence. Insert the image acquisition end of the fiber optic particle detector along the reserved hole of the reaction vessel to be tested, and after it is fully inserted, wrap a layer of aluminum silicate fiber at the interface. During the reaction process, the camera is used to capture the state of the particles inside the container and the camera exposure time is controlled. Once the test is complete, turn off the power to the display, the fiber optic particle detector, and the light source in sequence. Finally, after removing the fiber optic particle detector, clean the surface of the image acquisition end and the surface of the light source promptly.

14. The method of using the fiber optic particle detector as described in claim 13, characterized in that, When the operating environment is below 200°C and the material transmittance is less than 20%, the light source is an LED light source.

15. The method of using the fiber optic particle detector as described in claim 13, characterized in that, In an operating environment with a temperature greater than 200°C, the light source is a halogen light source or a high-temperature resistant LED light source.

16. The method of using the fiber optic particle detector as described in claim 13, characterized in that, When the diameter of the image transmission bundle is less than 10 mm and the transmittance of the material being measured is greater than 80%, the light source includes four light guide rods that surround the optical fiber image transmission bundle, and a ring-shaped LED light is arranged at the coupling position between the two.

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