Optical fiber type particle detector and preparation method and application thereof

Abstract

The invention relates to an optical fiber type particle detector and a preparation method and application thereof. The optical fiber type particle detector comprises an image acquisition unit; and the output end of the image transmission unit is coupled with the image acquisition unit. The technical problem to be solved is to transmit internal information of a reaction container to a CMOS (Complementary Metal-Oxide-Semiconductor Transistor) by utilizing an optical fiber total reflection principle to realize digitization so as to realize real-time observation of an internal reaction process of an opaque container.

Description

Technical Field

[0001] The invention belongs to a detection instrument, and in particular relates to an optical fiber particle detector and a preparation method and application thereof. Background Art

[0002] At present, in many fields such as petroleum, chemical industry, rubber, pesticide, dye, medicine, food, etc., a series of chemical processes such as sulfidation, nitration, hydrogenation, hydrocarbonization, polymerization, condensation, and physical processes such as mixing, dispersion, dissolution, crystallization, and extraction are involved. Among them, the specific high-temperature and high-pressure explosive reaction process, high-viscosity polymerization production process, salt and white sugar preparation process, cement clinker particle size online detection and analysis, and engine oil particle detection all have or generate particle products. The external material of the reaction container of this process is opaque, and the reaction progress is regulated by experience and reaction time to achieve the reaction process. It often leads to deviations in the judgment of the reaction process, and requires a large amount of experimental data for summary and induction. The cost is high and the results are easily affected by external conditions, which limits the preparation and production efficiency to a certain extent. In view of the above situation, the key to improving work efficiency is to achieve real-time observation of the reaction process, fully grasp the reaction state of the material at any time, and make corresponding measures and adjustments in time. At present, research on the realization of real-time monitoring of the above chemical and physical processes is relatively rare, and it is impossible to achieve high integration, miniaturization, and high-definition images. Summary of the invention

[0003] In view of this, the main purpose of the present invention is to provide a fiber optic particle detector and its preparation method and application. The technical problem to be solved is to use the principle of total reflection of optical fiber to transmit the internal information of the reaction container to CMOS for digitization, so as to realize real-time observation of the reaction process inside the opaque container.

[0004] The purpose of the present invention and the technical problem to be solved are achieved by adopting the following technical solutions. The present invention proposes an optical fiber particle detector, which comprises:

[0005] Image acquisition unit;

[0006] An image transmission unit has an output end coupled to the image acquisition unit.

[0007] Preferably, in the aforementioned optical fiber particle detector, a metal tube with a thickness of 2-5 mm is embedded in the input end of the image transmission unit, and a fixing glue with a thickness of 2-3 mm is filled between the metal tube and the image transmission unit.

[0008] Preferably, in the aforementioned optical fiber particle detector, the image transmission unit is an image transmission optical fiber bundle 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 more than 200 lp / mm.

[0009] Preferably, in the aforementioned fiber optic particle detector, the image acquisition unit includes a CCD or CMOS camera, and the CCD or CMOS camera is wrapped by a high-temperature resistant metal frame with a thickness of 2-5 mm, and the high-temperature resistant metal frame is provided with a cylindrical high-temperature resistant metal shell with a diameter of 80-100 mm and a height of 100-120 mm.

[0010] Preferably, 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 thereof is provided with an illumination light source 2-8 mm beyond the tail plane of the fiber optic imaging bundle, and the tail surface of the imaging fiber optic bundle is coated with a layer of Teflon coating.

[0011] Preferably, in the aforementioned optical fiber particle detector, the surface of the illumination light source is plated with a layer of Teflon coating.

[0012] Preferably, in the aforementioned optical fiber particle detector, the illumination light source is an LED light source or a halogen light source.

[0013] Preferably, in the aforementioned fiber optic particle detector, the illumination light source includes four light guide rods surrounding the fiber optic image transmission bundle, and a ring-shaped LED lamp arranged at the coupling connection between the image transmission unit and the image acquisition unit.

[0014] Preferably, in the aforementioned optical fiber particle detector, a refractory material is filled between the high temperature resistant metal frame and the high temperature resistant metal shell.

[0015] The purpose of the present invention and the technical problem solved are achieved by adopting the following technical solutions: The present invention proposes a method for preparing an optical fiber particle detector, comprising the following steps: coupling and connecting the output end of the image transmission unit with the photosensitive surface of the image acquisition unit.

[0016] Preferably, in the preparation method of the aforementioned fiber optic particle detector, the image acquisition unit includes a CCD or CMOS camera, and the CCD or CMOS camera is wrapped by a high-temperature resistant metal frame with a thickness of 2-5 mm, and the high-temperature resistant metal frame is provided with a cylindrical high-temperature resistant metal shell with a diameter of 80-100 mm and a height of 100-120 mm.

[0017] Preferably, in the aforementioned preparation method of the fiber optic particle detector, the coupled glue is a UV curing agent, whose composition is 5wt% benzoin ether; 25wt% hydroxyethyl acrylate; 70wt% polyurethane acrylate, with a refractive index of 1.80, a curing UV wavelength of ~320nm, and a visible light transmittance greater than 98%.

[0018] Preferably, in the aforementioned method for preparing the optical fiber particle detector, the thickness of the coupled glue layer is 5-10 μm.

[0019] Preferably, in the aforementioned method for preparing the optical fiber particle detector, the amount of the coupling glue used is 0.2-0.5 ml.

[0020] The purpose of the present invention and the technical problem to be solved are achieved by adopting the following technical solutions. A particle detection method proposed by the present invention comprises the following steps:

[0021] Check the power supply, and turn on the light source and power supply of the fiber optic particle detector and the computer monitor in turn;

[0022] Insert the image acquisition end of the optical fiber particle detector along the reserved hole of the reaction container to be tested, and then wrap a layer of aluminum silicate fiber at the interface position after it is fully inserted;

[0023] During the reaction process, the camera is controlled to capture the particle status in the container and the camera exposure time;

[0024] After the detection is completed, the display, the power supply and the light source of the optical fiber particle detector are turned off in sequence;

[0025] Finally, after taking out the optical fiber particle detector, clean the surface of the image acquisition end and the surface of the light source in time.

[0026] Preferably, in the aforementioned method of using the optical fiber 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.

[0027] Preferably, in the aforementioned method of using the optical fiber particle detector, when the operating environment is greater than 200° C., the light source is a halogen light source or a high temperature resistant LED light source.

[0028] Preferably, in the method of using the aforementioned fiber optic particle detector, when the diameter of the imaging 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 imaging bundle, and an annular LED light is arranged at the coupling position between the two.

[0029] Compared with the prior art, the optical fiber particle detector and its preparation method and application of the present invention have the following beneficial effects:

[0030] The present invention can realize real-time observation of the reaction process inside the opaque container; the internal information of the reaction container is transmitted to CMOS for digitization by utilizing the total reflection principle of optical fiber; the digitized image is recognized and processed by the MATLAB software processing function, so that not only the real-time observation picture can be obtained, but also the particle size, shape and quantity can be calculated based on the digitized image, and finally the particle uniformity and distribution can be obtained.

[0031] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural schematic diagram of the optical fiber particle detector of the present invention;

[0033] Figure 2A It is a schematic diagram of the structure of the metal frame of the camera in the optical fiber particle detector of the present invention;

[0034] Figure 2B It is a schematic structural diagram of a fixing piece of a metal frame of a camera in the optical fiber particle detector of the present invention;

[0035] Figure 3 A diagram of a ring-shaped light guide rod in the optical fiber particle detector of the present invention;

[0036] Figure 4 It is a detection diagram of large particles of reaction products in the reactor of the present invention;

[0037] Figure 5 It is a detection diagram of small particles of reaction products in the reactor of the present invention;

[0038] Figure 6 It is a detection image of asphalt mixing particles in the planetary mixer of the present invention;

[0039] Figure 7 A detection diagram of oil particles in an engine of the present invention;

[0040] Figure 8 This is a detection diagram of salt and white sugar particles of the present invention.

[0041] 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 glue; 9-metal pipe; 10-material entry and exit window; 11-illumination light source; 12-ring LED light; 13-light guide rod; 14-fixing plate reserved slot; 15-fixing plate. DETAILED DESCRIPTION

[0042] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of the fiber-optic particle detector and its preparation method and its specific implementation, structure, features and effects of the application according to the present invention in combination with the preferred embodiments. In the following description, different "one embodiment" or "embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0043] Unless otherwise specified, all reagents used can be purchased on the market, and unless otherwise specified, all methods involved are conventional methods. All components involved are commercially available products well known to those skilled in the art.

[0044] like Figure 1-Figure 3 As shown, some embodiments of the present invention provide a fiber optic particle detector, which includes:

[0045] Image acquisition unit;

[0046] An image transmission unit has an output end coupled to the image acquisition unit.

[0047] In the above technical scheme, the present invention needs to consider three factors when coupling the output end of the image acquisition unit and the image transmission unit: 1. The coupling interface must not have defects such as bubbles and moiré fringes; 2. The coupling glue layer must be less than 10 microns to ensure that there is no loss of resolution after coupling; 3. After the CMOS is coupled to the optical fiber image transmission bundle, it can perform detection work in various harsh environments.

[0048] 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 transmission bundle 1; if the thickness of the metal tube 9 is less than 2 mm, the protection effect is poor; if the thickness of the metal tube 9 is greater than 5 mm, the device as a whole is too large; a fixing glue 8 with a thickness of 2-3 mm is filled between the metal tube 9 and the image transmission unit; the fixing glue 8 serves to connect the optical fiber image transmission bundle 1 and the metal tube 9, and 2-3 mm is the gap between the two. When it is less than 2 mm, the gap is too small to be easily assembled, and when it is greater than 3 mm, the gap is too large and the overall device is too large.

[0049] In some embodiments, the CMOS is selected in consideration of the use environment. Optionally, the image transmission unit is 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 more. One of the reasons for the generation of moiré fringes is that the CMOS pixel and the wire diameter of the optical fiber image transmission bundle 1 are not well matched, so the wire diameter of the optical fiber image transmission bundle 1 needs to be adjusted to eliminate the moiré fringes.

[0050] In some embodiments, optionally, the image acquisition unit includes a CCD or CMOS camera 2, and the CCD or CMOS camera 2 is wrapped by a high-temperature resistant metal frame with a thickness of 2-5 mm, and the high-temperature resistant metal frame is provided with a cylindrical high-temperature resistant camera metal shell 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 protective effect is poor; when its thickness is greater than 5 mm, the device as a whole is too large. The size of the cylindrical high-temperature resistant camera metal shell 3 is based on actual use.

[0051] In some embodiments, one end of the metal tube 9 is optionally connected to the high temperature resistant metal frame, and the other end thereof is provided with an illumination light source 11 2-8 mm beyond the tail plane of the optical fiber image transmission bundle 1. The 2-8 mm gap serves as the material inlet and outlet window 10 and is height-adjustable. The gap is for material flow and is adjusted according to actual use. The gap can be reduced when the material viscosity is low, and increased when the viscosity is high (the material refers to the substance being reacted in the reaction container to be detected); the tail surface of the image transmission optical fiber bundle 1 is plated with a layer of Teflon coating to ensure that the material can flow on the surface of the optical fiber image transmission bundle without resistance. The power cords of the camera and the illumination light source 11 are led out from the upper end of the outermost metal shell, and real-time monitoring can be achieved by connecting to a computer. The thickness of the Teflon coating is 20-30 microns; when the thickness is less than 20 microns, it is too thin to meet the requirements, and when the thickness is greater than 30 microns, it is too thick and there is a risk of coating peeling.

[0052] In some embodiments, optionally, a layer of Teflon coating is plated on the surface of the illumination light source 11. The thickness of the Teflon coating is 20-30 microns; when the thickness is less than 20 microns, it is too thin to meet the requirements, and when the thickness is greater than 30 microns, it is too thick and there is a risk of coating peeling.

[0053] In some embodiments, optionally, the illumination light source 11 is an LED light source or a halogen light source. When the ambient temperature is below 85 degrees Celsius, the LED light source is used, and when the ambient temperature is above 85 degrees Celsius, the halogen light source is used.

[0054] In some embodiments, optionally, the illumination light source 11 includes four light guide rods 13 surrounding the optical fiber image transmission bundle 1, and a ring-shaped LED light 12 arranged at the coupling connection between the image transmission unit and the image acquisition unit. Figure 3 .

[0055] In some embodiments, optionally, a refractory material 4 (filling rate is 100%) is filled between the high temperature resistant metal frame and the camera metal housing 3 to protect the camera from high temperature and ensure that the operating temperature of the camera is not higher than 40° C. The refractory material 4 is commercially available aluminum silicate refractory fiber.

[0056] Some embodiments of the present invention further provide a method for preparing an optical fiber particle detector, comprising the following steps: coupling and connecting an output end of an image transmission unit to a photosensitive surface of an image acquisition unit.

[0057] In some embodiments, optionally, the method specifically comprises the following steps:

[0058] S1 Preparation of image transmission optical fiber bundle; using the rod-tube combination method to combine a high-refractive-index glass rod and a low-refractive-index glass tube together, and then drawing them into a single filament (with a diameter of 2.6-2.7 mm) at 550-850°C; arranging the drawn single filament and a light absorbing filament (with a diameter of 0.4-0.6 mm) for absorbing stray light into a hexagonal shape, and then drawing them into a primary multifilament (with a diameter of 1.3-1.5 mm) at 550-850°C; arranging the primary multifilament into a hexagonal shape again and drawing (at 550-850°C) into a secondary multifilament (with a diameter of 2-2.2 mm), at which time the diameter of the internal unit filament is only 2-2.5 μm, and the theoretical resolution exceeds 200 lp / mm; the refractive index of the high-refractive-index glass rod is 1.7-1.8, and its composition in terms of mass percentage is: SiO2 63-65%; B2O3 4.2-4.5%; Al2O3 4.5-4.8%; Na2O 6.6~7%; La2O3 4.7~5%; BaO

[0059] The low-refractive-index glass tube has a refractive index of 1.4-1.5, and its composition by mass percentage is: 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%.

[0060] The image output end of the S2 image transmission fiber bundle is coupled with the photosensitive surface; the coupling glue is a UV curing agent with a refractive index of 1.80, a curing UV wavelength of less than 400nm, and a visible light transmittance of more than 98%. The glue can be quickly cured by direct irradiation with 254-400nm UV light for 30-60 seconds. First, turn on the CCD / CMOS power supply, observe the coupling process in real time, and place it on a high-precision displacement platform. Its movement accuracy and repeat positioning accuracy can reach 1μm and below. Combined with the high-definition image when coupling the CMOS optical fiber image transmission bundle, the center position can be identified, and coupling at a specific position can also be achieved as needed. Fix the optical fiber image transmission bundle perpendicular to the CCD / CMOS surface on the coupling bracket, drop 0.2-0.5ml of UV curing glue on the center of the photosensitive surface of the CCD / CMOS, and fix the optical fiber image transmission bundle perpendicular to the CCD / CMOS surface on the coupling bracket to ensure horizontal coupling between the two. During the coupling process, observe the quality of the captured image. After complete coupling, turn on the UV light source. The UV light passes through the homogenizing glass to emit uniform UV light, which is irradiated to the UV curing glue through the image transmission fiber bundle to achieve rapid curing. At this time, the thickness of the coupling glue layer is 5-10μm. If the UV curing glue is less than 0.2ml, the coupling failure rate is high, and the glue layer is too thin and the bonding strength is too weak; if the UV curing glue is higher than 0.5ml, the coupling glue layer is too thick, affecting the coupling resolution. If the coupling glue layer is less than 5 microns, the glue layer is too thin and the bonding strength is too weak; if the coupling glue layer is greater than 10 microns, the coupling glue layer is too thick, affecting the coupling resolution.

[0061] S3 camera protection; the size of CCD / CMOS camera 2 is 45*45*20mm. Prepare a camera metal shell 3 with the same shape as the camera and a thickness of 3mm. Reserve a circular hole with a diameter of 20-30mm at the bottom. The camera metal shell 3 is divided into two symmetrical parts along the XOZ plane, such as Figure 2A , Figure 2B As shown, the camera metal housing 3 is provided with a fixed plate reserved groove 14; first place the CCD / CMOS camera 2 in one half of the metal housing, and then fix the other half of the metal housing to the previous metal housing as a whole through the fixed plate 15. After fixing, install the bottom of the camera metal housing 3, and reserve a circular hole with a diameter of 20-30mm at the bottom, the size of which is designed according to the metal tube. After the bottom is installed, a hollow cylindrical metal frame with a diameter of 20-30mm and a thickness of 2mm is sleeved on the outside of the image transmission fiber bundle 1, and connected to the reserved hole of the camera metal frame by bolts. The space between the camera metal housing 3 and the outermost metal shell 5 is filled with refractory material 4, and the outermost metal shell 5 is also made into a split structure and connected by screws for easy assembly. Two holes with a diameter of 3mm are reserved at the top of the outermost metal shell 5 for leading out the light source power line 6 and the camera power line 7.

[0062] S4 optical fiber image transmission bundle image collection end; a 20-30 micron Teflon coating is plated on the image collection end of the optical fiber image transmission bundle 1, and the coating has excellent waterproof, oil-proof, high temperature resistant, wear-resistant and other properties, ensuring that the material can flow without resistance on the end face of the image transmission bundle, and will not leave traces on the surface to affect the observation effect. In addition, a light source with a diameter of 10-18 mm can be set at 4-8 mm from the end face of the optical fiber image transmission bundle 1 as an illumination light source 11, and a 20-30 micron Teflon coating is also plated on the surface of the illumination light source 11 to ensure that the light intensity is stable during the observation process.

[0063] S5 Light source selection: According to the usage scenario, LED light source can be selected in a normal temperature operating environment and when the material transparency is low (transmittance is less than 20%); if it is operated in a high temperature environment, such as above 200°C, halogen light source or high temperature resistant LED light source can be used, and the temperature resistance range is -20°C to 700°C; in addition, for scenarios where the image bundle diameter is less than 10mm and the transmittance of the measured material is greater than 80%, 4 light guide rods 13 can be selected to surround the optical fiber image bundle 1, and a ring LED lamp 12 is set at the coupling position to provide light source for the light guide rod 13, adopting a ring lighting method.

[0064] Some embodiments of the present invention further provide a particle detection method, comprising the following steps:

[0065] Select the appropriate light source type according to application needs. In a low temperature (below 200°C) operating environment, and when the material transparency is low (transmittance is less than 20%), an LED light source can be selected; if it is operated in a high temperature environment, such as above 200°C, a halogen light source or a high temperature resistant LED light source can be used; in addition, for scenes where the image transmission bundle diameter is less than 10mm and the transmittance of the measured material is higher than 80%, the light source can be selected: Use 4 light guide rods 13 around the optical fiber image transmission bundle 1, and set a ring LED lamp 12 at the coupling position of the two to provide light source for the light guide rod 13, and adopt a ring lighting method.

[0066] Check the power supply, and turn on the light source and power supply of the fiber optic particle detector and the computer monitor in turn;

[0067] Slowly insert the image acquisition end along the reserved hole of the reaction container to be tested, and wrap a layer of aluminum silicate fiber at the interface position after it is fully inserted to prevent the temperature inside the reaction container from fluctuating. During the reaction process, the camera can be controlled to capture the state of the particles in the container, and the camera exposure time can be controlled.

[0068] After the detection is completed, turn off the display, the power supply and the light source of the fiber optic particle detector in turn. Finally, take out the particle detector and clean the image acquisition end face and the light source surface in time.

[0069] The present invention will be further described below with reference to the embodiments.

[0070] Example 1: Preparation of particle detector for low temperature and low transmittance environment

[0071] Preparation of S1 image transmission fiber bundle; using the rod-tube combination method to combine a high-refractive-index glass rod and a low-refractive-index glass tube together, and then drawing them at 850°C into a single filament with a diameter of 2.6mm; arranging the drawn single filament and a light-absorbing filament with a diameter of 0.5mm for absorbing stray light into a hexagonal shape, and then drawing them at 850°C into a primary multifilament with a diameter of 1.4mm; arranging the primary multifilament into a hexagonal shape again and drawing (850°C) into a secondary multifilament with a diameter of 2.1mm, at which time the diameter of the internal unit filament is only 2.5μm, and the theoretical resolution is 230lp / mm; the refractive index of the high-refractive-index glass rod is 1.8, and its composition in 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 refractive index of the low-refractive-index glass tube is 1.5, and its composition by mass percentage is: SiO2 64%; B2O3 4.5%; Al2O33.5%; Na2O 5.5%; K2O 5.4%; BaO 7.5%; CaO5.6%; ZrO2 2.7%; Bi2O3 1.3%.

[0072] The image output end of the S2 image transmission fiber bundle is coupled with the photosensitive surface; the coupling glue selects an ultraviolet curing agent, which is composed of benzoin ether (5wt%), hydroxyethyl acrylate (25wt%) and polyurethane acrylate (70wt%) by mass percentage, with a refractive index of 1.80, a curing ultraviolet wavelength of ~400nm, and a visible light transmittance of more than 98%. The glue can be quickly cured by direct irradiation of 254-400nm ultraviolet light for 30 seconds. First, turn on the CCD / CMOS power supply, observe the coupling process in real time, and place it on a high-precision displacement platform. Its movement accuracy and repeatability can reach 1μm. Combined with the high-definition image when coupling the CMOS optical fiber image transmission bundle, the center position can be identified. The optical fiber image transmission bundle is fixed on the coupling bracket perpendicular to the CCD / CMOS surface, 0.3ml of ultraviolet curing glue is dripped on the center of the photosensitive surface of the CCD / CMOS, and the optical fiber image transmission bundle is fixed on the coupling bracket perpendicular to the CCD / CMOS surface to ensure horizontal coupling between the two. During the coupling process, the quality of the captured image is observed. After complete coupling, the UV light source is turned on, and the UV light is emitted uniformly through the homogenizing glass, and irradiated to the UV curing glue through the image transmission fiber bundle to achieve rapid curing. At this time, the thickness of the coupling glue layer is 7μm.

[0073] S3 camera protection: The size of the CCD / CMOS camera is 45*45*20mm. Prepare a metal shell with the same shape as the camera and a thickness of 3mm. Reserve a circular hole with a diameter of 30mm at the bottom. The metal shell is divided into two symmetrical parts along the XOZ plane, such as Figure 3 As shown, place the camera in it and fix the other half of the metal shell with bolts. After fixing, install the bottom of the metal shell, and reserve a circular hole with a diameter of 30mm at the bottom, the size of which is designed according to the metal tube. After the bottom is installed, a hollow cylindrical metal frame with a diameter of 30mm and a thickness of 2mm is put on the outside of the image transmission optical fiber rod, and connected to the reserved hole of the camera metal frame by bolts. The space between the camera metal shell 3 and the outermost metal shell 5 is filled with refractory material 4, and the outermost metal shell 5 is also made into a split structure, which is connected by screws for easy assembly.

[0074] S4 optical fiber imaging bundle image collecting end; a 30-micron Teflon coating is plated on the image collecting end of the optical fiber imaging bundle; since this embodiment is a low-temperature (50°C) operating environment and the material transparency is 20%, a 15mm diameter LED is set 5mm away from the end face of the imaging bundle as an illumination light source 11, and a 30-micron Teflon coating is also plated on the surface of the illumination light source 11.

[0075] Example 2: Preparation of particle detector for low temperature and high transmittance environment (50°C, transmittance 80%)

[0076] 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 a fill light source (the light guide rods 13 are respectively arranged in four directions of the optical fiber image bundle 1, and the end faces of the light guide rods are kept horizontal with the optical fiber image bundle), adopts an annular lighting method, and at the same time, a 30-micron Teflon coating is made on the surface of each light guide rod 13, and steps S1, S2, and S3 are the same as in embodiment 1.

[0077] Example 3: Preparation of particle detector for high temperature environment (200°C)

[0078] 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 a fill light source, adopts a ring lighting method, and at the same time, a 30-micron Teflon coating is made on the surface of the high-temperature resistant halogen lamp (whose temperature resistance range is -20°C to 700°C), and steps S1, S2, and S3 are the same as in embodiment 1.

[0079] Example 4: Detection of large particles of reaction products in a reactor

[0080] The material in the reactor has a relatively high transparency (transmittance of 80%), but the temperature is also high (temperature is 500°C), and it is corrosive. The light source is a high-temperature resistant halogen lamp or a special LED lamp. The preparation process is as described in steps S1-S4 of Example 3. According to the usage 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 resistant halogen lamp (its temperature resistance range is -20°C to 700°C). The main body of the fiber-optic particle detector prepared in Example 3 of the present invention (a cylindrical high-temperature resistant metal shell with a diameter of 80mm and a height of 100mm) is placed on the top of the container furnace of the reactor. The signal acquisition end of the image acquisition unit passes through the top plate of the reactor and inserts into the material from top to bottom. The fiber-optic particle detector of the present invention revolves around the center axis of the furnace with the top plate as a whole, and the image data and power supply of its CMOS circuit substrate and chip are connected to the computer display through a rotary conversion joint. Figure 4 The size of the particles can be observed in real time. Figure 4 It can be seen that the particle size and shape during the reaction inside the reactor can be used to control the reaction process and estimate the remaining reaction time.

[0081] Example 5: Detection of small particles of reaction products in a reactor

[0082] The difference between this embodiment and embodiment 1 is that the fiber image transmission bundle of this embodiment has a diameter of 3 microns and a resolution of 192 lp / mm. The main body of the fiber optic particle detector of embodiment 3 of the present invention (a cylindrical high temperature resistant metal shell with a diameter of 80 mm and a height of 100 mm) is placed on the top of the container furnace of the reactor, and 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, and the image data and power supply of the CMOS circuit substrate and chip are connected to the computer display and the external display system and power supply are connected. Figure 5 The size of the particles can be observed in real time. Figure 5 Individual small particles can be clearly observed.

[0083] Example 6: Detection of asphalt mixing particles in a planetary mixer

[0084] The planetary mixer can be used for mixing and stirring asphalt (its composition is: 95wt% sand and gravel; 5wt% asphalt mud) (2000rpm). During the stirring process, the viscosity of the material is high, the ambient temperature is high (200℃), and the transparency of the material is low (30%). The main part of the fiber optic particle detector of Example 3 of the present invention (a cylindrical high-temperature resistant metal shell with a diameter of 80mm and a height of 100mm) is placed on top of the asphalt stirring container. The signal acquisition end of the image acquisition unit passes through the top plate of the planetary mixer and is inserted into the material from top to bottom. The fiber optic particle detector of the present invention revolves around the center axis of the furnace as a whole with the top plate. The image data and power supply of the CMOS circuit substrate and chip are connected to the computer display through a rotary conversion joint. During the high-speed stirring process of 2000rpm, the size of the particles can be observed in real time, such as Figure 6 As shown. Figure 6 It can be seen that during the stirring process, it can be observed that the material does not stick to the surface of the collection end, and the particle morphology and size can be clearly seen.

[0085] Example 7: Used for detecting oil particles in an engine

[0086] The oil particle detection in the engine can be carried out at room temperature, and the detection physical transparency is relatively high (the transmittance is 80%). The main body of the fiber optic particle detector of Example 1 of the present invention (a cylindrical high-temperature resistant metal shell with a diameter of 80 mm and a height of 100 mm) is placed on the engine, and the signal acquisition end of the image acquisition unit is inserted into the material from top to bottom through the top plate. The fiber optic particle detector of Example 1 of the present invention revolves around the center axis of the furnace as a whole with the top plate of the reactor, and the image data and power supply of the CMOS circuit substrate and chip are connected through a computer monitor. Figure 7 The size of the particles can be observed in real time. Figure 7 It can be seen that under the illumination of the light guide rod, the morphology and size of the particles inside the engine can still be clearly seen.

[0087] Example 8: Detection of salt and sugar particles

[0088] During the crystallization preparation process of salt and white sugar particles, the ambient temperature is relatively low (40°C), and the physical transparency of the detection is high (transmittance is 80%). A ring-shaped light guide rod can be used as an illumination light source, and the signal acquisition end of the image acquisition unit passes through the top plate from the top to the bottom of the main body and is inserted into the material. The entire fiber-optic particle detector of Example 2 of the present invention revolves around the center axis of the furnace with the top plate, and the image data and power supply of the CMOS circuit substrate and chip are connected through a computer monitor. Figure 8 The size of the particles can be observed in real time. Figure 8 It can be seen that under the illumination of the light guide rod, the morphology and size of the particles during the preparation process of salt and white sugar can still be clearly seen.

[0089] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0090] The numerical range described in the present invention includes all the numerical values ​​within the range, and includes the range value formed by any two numerical values ​​within the range. Different numerical values ​​of the same indicator appearing in all embodiments of the present invention can be arbitrarily combined to form a range value.

[0091] The technical features in the claims and / or the specification of the present invention may be combined, and the combination is not limited to the combination obtained by reference in the claims. The technical solution obtained by combining the technical features in the claims and / or the specification is also within the protection scope of the present invention.

[0092] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. An optical fiber particle detector, characterized in that: It includes: Image acquisition unit; An image transmission unit has an output end coupled to the image acquisition unit.

2. The optical fiber particle detector according to claim 1, characterized in that: A metal tube with a thickness of 2-5 mm is embedded in the input end of the image transmission unit, and a fixing glue with a thickness of 2-3 mm is filled between the metal tube and the image transmission unit.

3. The optical fiber particle detector according to claim 1, characterized in that: The image transmission unit is an image transmission optical fiber bundle 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 more than 200 lp / mm.

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

5. The optical fiber particle detector according to claim 4, characterized in that: The surface of the lighting source is plated with a layer of Teflon coating.

6. The optical fiber particle detector according to claim 4, characterized in that: The lighting light source is an LED light source or a halogen light source.

7. The optical fiber particle detector according to claim 4, characterized in that: The illumination light source comprises four light guide rods surrounding the optical fiber image transmission bundle, and a ring-shaped LED lamp arranged at the coupling connection between the image transmission unit and the image acquisition unit.

8. The optical fiber particle detector according to claim 1, characterized in that: The image acquisition unit comprises a CCD or CMOS camera, which is wrapped by a high temperature resistant metal frame with a thickness of 2-5 mm, and the high temperature resistant metal frame is provided with a cylindrical high temperature resistant metal shell with a diameter of 80-100 mm and a height of 100-120 mm.

9. The optical fiber particle detector according to claim 8, characterized in that: The space between the high temperature resistant metal frame and the high temperature resistant metal shell is filled with refractory material.

10. A method for preparing an optical fiber particle detector, characterized in that: The following steps are involved: The output end of the image transmission unit is coupled to the photosensitive surface of the image acquisition unit.

11. The method for preparing the optical fiber particle detector according to claim 10, characterized in that: The coupled glue is an ultraviolet curing agent, which is composed of 5wt% benzoin ether, 25wt% hydroxyethyl acrylate, and 70wt% polyurethane acrylate, with a refractive index of 1.80, a curing ultraviolet wavelength of 320nm, and a visible light transmittance of more than 98%.

12. The method for preparing the optical fiber particle detector according to claim 10, characterized in that: The thickness of the coupling glue layer is 5-10 μm; the amount of the coupling glue is 0.2-0.5 ml.

13. A particle detection method, characterized in that: The following steps are involved: Check the power supply, and turn on the light source and power supply of the fiber optic particle detector and the computer monitor in turn; Insert the image acquisition end of the optical fiber particle detector along the reserved hole of the reaction container to be tested, and then wrap a layer of aluminum silicate fiber at the interface position after it is fully inserted; During the reaction process, the camera is controlled to capture the particle status in the container and the camera exposure time; After the detection is completed, the display, the power supply and the light source of the optical fiber particle detector are turned off in sequence; Finally, after taking out the optical fiber particle detector, clean the surface of the image acquisition end and the surface of the light source in time.

14. The method for using the optical fiber particle detector according to claim 13, characterized in that: In an operating environment below 200° C. and when the material transmittance is less than 20%, the light source is an LED light source.

15. The method for using the optical fiber particle detector according to claim 13, characterized in that: When the operating environment is greater than 200° C., the light source is a halogen light source or a high-temperature resistant LED light source.

16. The method for using the optical fiber particle detector according to claim 13, characterized in that: When the diameter of the image transmission bundle is less than 10 mm and the transmittance of the material to be measured is greater than 80%, the light source includes four light guide rods surrounding the optical fiber image transmission bundle, and a ring-shaped LED lamp is arranged at the coupling position of the two.

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