Explosion-proof wind speed detector

Abstract

This invention proposes an explosion-proof wind speed detector, comprising: an explosion-proof housing, a laser, an optical probe, a circuit board, and an intrinsically safe battery. The built-in laser and optical probe form a non-contact measurement unit. The laser is precisely projected onto fluid particles through the optical probe and the scattered light signal is captured, thereby measuring the wind speed and eliminating the risk of ignition caused by mechanical friction. Simultaneously, the explosion-proof housing and the internal circuit board, through a protective layer, provide electrical insulation, effectively preventing potential internal electrical sparks from contacting external explosive gases and ensuring stable operation in high-risk environments. Furthermore, the intrinsically safe control circuit integrated into the circuit board limits the current of the constant drive signal below a preset threshold, ensuring that the laser's operating power remains within a safe range. Combined with the intrinsically safe battery, the output energy is strictly constrained within the threshold allowed by explosion-proof standards, eliminating the potential for arcing or heat accumulation at the source.

Description

Technical Field

[0001] This utility model relates to the field of speed measuring equipment technology, and in particular to an explosion-proof wind speed detector. Background Technology

[0002] Wind speed detectors are devices used to measure wind speed. Traditional wind speed detectors mainly rely on mechanical or ultrasonic working principles, but their design flaws can pose serious safety hazards in explosive environments. Mechanical devices typically use rotating parts to sense wind force. During operation, friction between metal parts can easily generate static electricity or electric sparks, and even a small release of energy in an explosive environment can ignite flammable gases or dust. Furthermore, moving parts of mechanical structures exposed to corrosive gases or high humidity environments for extended periods are prone to jamming and wear, leading to measurement drift or even malfunction. While ultrasonic devices have no moving parts, in industrial settings with high dust concentrations and drastic temperature and humidity fluctuations, the sound wave signal is easily affected by suspended particles or changes in medium density, resulting in signal attenuation, reflection path deviation, and measurement errors.

[0003] If the circuit systems of these two types of equipment are not explosion-proof, even a weak electric arc or overheating from the internal electronic components could become an ignition source. More importantly, the casings of traditional equipment are mostly made of ordinary aluminum alloy and lack explosion-proof structural design. Once an electric arc or high temperature occurs inside, the flame could directly ignite the external environment through the gaps. Utility Model Content

[0004] The main purpose of this invention is to propose an explosion-proof wind speed detector, which aims to solve the problems of insufficient explosion-proof performance, low measurement accuracy and poor long-term stability of traditional wind speed detection devices in explosive environments.

[0005] To achieve the above objectives, this application proposes an explosion-proof wind speed detector, comprising:

[0006] The explosion-proof housing has a measuring window at the top.

[0007] A laser, housed within the explosion-proof enclosure, is used to generate laser light;

[0008] An optical probe, disposed within the measurement window and connected to the output end of the laser, is used to incident the laser generated by the laser onto the fluid to be measured and to collect the scattered light scattered by the fluid particles in the fluid to be measured.

[0009] A circuit board is disposed inside the explosion-proof housing. The circuit board is covered with a first wrapping layer and integrates an intrinsically safe control circuit. The control terminal of the intrinsically safe control circuit is connected to the controlled terminal of the laser and is used to drive the laser to output at a constant power. The input terminal of the intrinsically safe control circuit is connected to the optical probe and is used to receive and process the scattered light collected by the optical probe to detect the velocity of the fluid to be measured.

[0010] An intrinsically safe battery is disposed inside the explosion-proof housing, and its output end is connected to the power input end of the laser to provide intrinsically safe power to the laser.

[0011] In one embodiment, the intrinsically safe control circuit includes:

[0012] The intrinsically safe power conversion circuit is used to process the input power supply and limit its output to a second preset power range.

[0013] A laser driving circuit, connected to the laser, is used to dynamically adjust the current / voltage output signal to drive the laser to output at a constant power.

[0014] A photodetector, with its input end connected to the optical probe, is used to convert the scattered light collected by the optical probe into a detection signal output.

[0015] A signal processing circuit, connected to the photodetector, is used to receive and process the detection signal output by the photodetector to obtain the velocity of the fluid to be measured.

[0016] In one embodiment, the optical probe includes:

[0017] An optical circulator has a first port, a second port, and a third port. The first port is connected to the output of the laser, and the third port is connected to the input of the photodetector.

[0018] The lens group, connected to the second port, is used to focus the laser output from the laser onto the fluid to be measured to form a velocity measurement area, and to collect the scattered light scattered by fluid particles within the velocity measurement area;

[0019] The optical circulator is used to transmit laser light unidirectionally from the first port to the second port, and to transmit scattered light unidirectionally from the second port to the third port.

[0020] In one embodiment, the intrinsically safe control circuit further includes:

[0021] An optical fiber amplifier, connected to the output of the laser and the first port of the optical circulator, is used to amplify the laser signal generated by the laser.

[0022] In one embodiment, the circuit board includes a substrate and electronic components disposed on the substrate; the first encapsulation layer includes:

[0023] A sealing frame having an opening, a substrate being embedded in the opening of the sealing frame, and electronic components being disposed on the side of the substrate facing the opening;

[0024] A potting layer is filled and fixed within the encapsulation frame, and the potting layer covers the side of the substrate where electronic components are disposed.

[0025] In one embodiment, the intrinsically safe battery includes:

[0026] The battery casing is externally encapsulated with a second wrapping layer;

[0027] The intrinsically safe protection circuit is integrated into the battery casing and is used to limit the output power of the intrinsically safe battery within a first preset range.

[0028] The battery cell is disposed inside the battery casing, and the battery cell is connected to the intrinsically safe control circuit through the intrinsically safe protection circuit.

[0029] In one embodiment, the explosion-proof housing includes:

[0030] The outer casing has a mounting port on the back, and the outer casing is made of explosion-proof material;

[0031] The rear cover fits onto the mounting opening of the outer shell to form an explosion-proof cavity.

[0032] In one embodiment, it further includes:

[0033] A first positioning frame is disposed outside the laser, and a first limiter is disposed inside the explosion-proof cavity to match the first positioning frame. The laser is fixed in the explosion-proof cavity by the first positioning frame and the first limiter.

[0034] In one embodiment, it further includes:

[0035] The second positioning frame is set on the side of the first wrapping layer facing away from the outer shell. The intrinsically safe battery is set inside the second positioning frame. The explosion-proof cavity is provided with a second limiter that matches the second positioning frame. The intrinsically safe battery is fixed to the bottom of the explosion-proof cavity by the second positioning frame and the second limiter.

[0036] In one embodiment, the housing has a display screen mounting hole and a button mounting hole. The explosion-proof wind speed detector also includes a display screen and a button. The display screen is disposed in the display screen mounting hole, and the button is disposed in the button mounting hole. The display screen and the button are connected to the intrinsically safe control circuit.

[0037] This application proposes an explosion-proof wind speed detector. A non-contact measurement unit is formed by an internal laser and optical probe. The laser is precisely projected onto fluid particles through the optical probe, capturing the scattered light signal to measure the wind speed, thus eliminating the risk of ignition caused by mechanical friction. Simultaneously, the device employs an explosion-proof housing, and the internal circuit board is electrically insulated through a protective layer, effectively preventing potential internal electrical sparks from contacting external explosive gases, ensuring stable operation in high-risk environments. Furthermore, the intrinsically safe control circuit integrated into the circuit board limits the current of the constant drive signal below a preset threshold, ensuring that the laser's operating power remains within a safe range. Combined with an intrinsically safe battery, the output energy is strictly constrained within the threshold allowed by explosion-proof standards, eliminating the risk of arcing or heat accumulation at the source. This approach ensures the inherent safety of equipment operation in explosive environments while avoiding the wear and contamination problems of traditional mechanical structures, improving long-term stability and environmental adaptability. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0039] Figure 1 This is a structural diagram of an embodiment of the explosion-proof wind speed detector of this utility model;

[0040] Figure 2 This is a structural diagram of one embodiment of the explosion-proof wind speed detector of this utility model;

[0041] Figure 3 This is an intrinsically safe power conversion circuit diagram of an embodiment of the explosion-proof wind speed detector of this utility model;

[0042] Figure 4 This is a cross-sectional view of an embodiment of the explosion-proof wind speed detector of this utility model.

[0043] Reference numerals: Explosion-proof housing 01, outer shell 11, rear cover 12, first positioning frame 13, second positioning frame 14, optical probe 02, laser 03, circuit board 04, first wrapping layer 41, intrinsically safe battery 05, intrinsically safe control circuit 06, intrinsically safe power conversion circuit 61, laser drive circuit 62, photodetector 63, signal processing circuit 64.

[0044] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0045] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0046] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0047] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, if the word "and / or" appears throughout the text, it means including three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0048] To achieve the above objectives, this application proposes an explosion-proof wind speed detector, referring to... Figure 1 , Figure 2 and Figure 4 ,include:

[0049] An explosion-proof housing 01 has a measurement window at its top; a laser 03 is disposed inside the explosion-proof housing 01 and is used to generate laser light; an optical probe 02 is disposed inside the measurement window and is connected to the output end of the laser 03, and is used to incident the laser light generated by the laser 03 onto the fluid to be measured and collect the scattered light scattered by the fluid particles in the fluid to be measured.

[0050] Circuit board 04 is disposed inside the explosion-proof housing 01. The circuit board 04 is covered by a first wrapping layer 41, and the circuit board 04 integrates an intrinsically safe control circuit 06. The control terminal of the intrinsically safe control circuit 06 is connected to the controlled terminal of the laser 03, and is used to drive the laser 03 to output constant power. The input terminal of the intrinsically safe control circuit 06 is connected to the optical probe 02, and is used to receive and process the scattered light collected by the optical probe 02 to detect the velocity of the fluid under test. Intrinsically safe battery 05 is disposed inside the explosion-proof housing 01, and its output terminal is connected to the power input terminal of the laser 03, and is used to provide intrinsically safe power to the laser 03.

[0051] More specifically, intrinsic safety is an explosion-proof technology design concept. Its core objective is to strictly limit the energy of electrical equipment to ensure that the equipment, whether in normal or faulty conditions, cannot release sufficient energy to ignite an explosive atmosphere. It is one of the core methods for the safe design of electrical equipment in explosive hazardous locations. The three core principles of intrinsic safety are: limiting the maximum current, voltage, and energy storage capacity of the circuit through hardware design to ensure that even in the event of a short circuit, open circuit, or component failure, the released energy remains below the minimum threshold for igniting an explosive mixture; employing a multi-level protection mechanism so that even if a single protection fails, other redundant measures can still maintain the system within a safe range; and in the event of a fault, the circuit can quickly cut off or limit energy output to prevent energy accumulation from exceeding safe limits. The standard for intrinsic safety is the international standard: IEC 60079 series (General Standards for Equipment in Explosive Atmospheres).

[0052] Traditional wind speed detection devices are key equipment used for real-time monitoring of gas flow velocity. Their technical principles and structural design directly affect their reliability and safety in complex industrial scenarios. In explosive hazardous environments, conventional equipment has multiple safety hazards due to inherent design flaws: mechanical devices rely on the interaction between rotating parts such as impellers and propellers and the airflow. When metal parts rotate at high speeds, static electricity accumulation or tiny electric sparks can easily be generated due to friction. However, the minimum ignition energy of combustible gases such as methane and hydrogen or coal dust in explosive environments is extremely low. The unavoidable mechanical contact measurement method of such devices during operation essentially constitutes a continuous ignition risk source.

[0053] Meanwhile, metal moving parts exposed to corrosive media such as hydrogen sulfide and salt spray for extended periods are prone to oxidation and corrosion, leading to increased rotational resistance. This not only accelerates mechanical wear and reduces measurement accuracy but can also cause localized overheating due to jamming. Although ultrasonic devices achieve non-contact measurement through the time difference of sound wave transmission, their effectiveness is limited when dust concentration exceeds 200 g / m³. 3Under certain operating conditions, suspended particles will significantly attenuate the intensity of the acoustic signal, and the drastic fluctuations in medium density with temperature and humidity will cause the acoustic refraction path to deviate. These factors together cause the signal-to-noise ratio of the echo signal to deteriorate, making the measurement error exceed the allowable range under operating conditions.

[0054] The explosion-proof performance of the equipment's circuit system also poses a significant challenge. Traditional devices often lack intrinsically safe PCB designs, making it difficult to completely eliminate potential ignition sources such as transient arcs generated during power device switching and spike pulses from capacitor charging and discharging in conventional circuit layouts. More seriously, the equipment casing 11 is generally made of ordinary die-cast aluminum alloy, lacking explosion-proof joint structures at its seams, and its protection level only meets IP65 dust and water resistance requirements. When an internal short circuit or component overheating occurs, the flame propagation path lacks an effective blocking mechanism, making it highly susceptible to igniting external explosive mixtures through casing gaps. Current industry-standard improvements include applying antistatic coatings to the surface of mechanical devices and adding dust filters to ultrasonic probes; however, these measures only partially mitigate specific risks and cannot systematically address the inherent safety issues of energy management and structural sealing in explosive environments.

[0055] To address the aforementioned technical challenges, intrinsically safe laser velocimetry technology exhibits significant advantages. By employing the laser Doppler frequency shift principle, it utilizes the scattering effect of fluid-carried particles on the incident laser to achieve non-contact measurement, completely eliminating rotating parts and mechanical contact points, and fundamentally eliminating the risks of frictional heat generation and static electricity accumulation. Therefore, this application proposes an explosion-proof anemometer, comprising: an explosion-proof housing 01, a laser 03, an optical probe 02, a circuit board 04, and an intrinsically safe battery 05.

[0056] The explosion-proof housing 01 serves as the first line of safety for the equipment. It is constructed from a special explosion-proof material with high strength, impact resistance, and excellent thermal insulation properties. Furthermore, the housing seams are sealed to ensure complete physical isolation between the internal cavity and the external explosive environment. The structural strength and sealing performance of the housing effectively suppress the outward diffusion of electric arcs or high temperatures generated during internal circuit malfunctions, while also preventing the infiltration of external flammable gases into the internal cavity. A measurement window is located at the top of the explosion-proof housing 01 for laser transmission. It is noteworthy that this measurement window must ensure both efficient laser beam transmission and resistance to external dust or corrosive media.

[0057] Laser 03, housed within the explosion-proof housing 01, generates laser light. Laser 03 employs a semiconductor laser module, producing a collimated laser beam of a specific wavelength through electroluminescence. Its output light path is shaped by a lens group within the optical probe 02, converting the divergent light into a focused spot, precisely projected onto the fluid region to be measured. Optical probe 02, located within the measurement window and connected to the output of laser 03, directs the laser light generated by laser 03 onto the fluid to be measured and collects the scattered light from fluid particles within the fluid. Optical probe 02 integrates a beam splitter prism and a reflector group, utilizing optical path deflection technology to control the interaction area between the incident laser and moving particles in the fluid within a preset measurement cross-section. The probe simultaneously collects the laser signal scattered by the particles and converts the light intensity change into an electrical signal through a subsequent photodetector 63, achieving non-contact flow velocity sensing. The entire optical system is completely enclosed within the explosion-proof housing 01, avoiding the physical contact risks associated with traditional mechanical sensors.

[0058] Circuit board 04 is housed within the explosion-proof housing 01. The circuit board 04 is externally encapsulated by a first covering layer 41, which is treated with epoxy resin potting to effectively prevent any electrical sparks generated by the internal circuit board 04 from contacting external explosive gases, ensuring stable operation in high-risk environments. Circuit board 04 integrates an intrinsically safe control circuit 06. The control terminal of the intrinsically safe control circuit 06 is connected to the controlled terminal of the laser 03, used to drive the laser 03 to output constant power. The output terminal of the intrinsically safe control circuit 06 is connected to the drive input terminal of the laser 03, and adjusts the output current / voltage through closed-loop feedback to maintain a constant power output of the laser 03 within its rated operating range. Simultaneously, the circuit incorporates a hardware current limiting module, a transient energy absorption unit, and a redundant fault protection mechanism to ensure that the electrical parameters of the laser's output power remain below the intrinsically safe threshold specified in the IEC 60079-11 standard under abnormal operating conditions such as short circuits, open circuits, or control failures, preventing the release of dangerous energy. The intrinsically safe control circuit 06 is connected to the optical probe 02 at its input terminal. It receives and processes the scattered light collected by the optical probe 02 to detect the velocity of the fluid under test. Essentially, the intrinsically safe control circuit 06 monitors the operating current of the laser 03 in real time via constant current drive, and uses a negative feedback mechanism to strictly limit the peak value of the drive signal within a preset safety threshold, ensuring that the laser power is always below the critical ignition energy value of the flammable medium. Simultaneously, it performs time-frequency analysis on the scattered light signal input from the optical probe 02, detects the velocity of fluid particles using a Doppler frequency shift calculation algorithm, and finally outputs linearized wind speed data.

[0059] The intrinsically safe battery 05, housed within the explosion-proof housing 01, has its output end connected to the power input terminal of the laser 03, providing intrinsically safe power to the laser 03. The intrinsically safe battery 05 employs an integrated design of a lithium-ion battery pack and multiple safety circuits, confining the total output energy within the intrinsically safe power standard range. Even in the event of an internal short circuit or overload fault, the instantaneous energy can be diverted and dissipated through the fusible protective layer and the discharge resistor. A bidirectional isolation circuit is provided between the battery output terminal and the laser 03 power supply, ensuring power supply stability while blocking reverse current surges. During system operation, the intrinsically safe battery 05 works in conjunction with the control circuit, dynamically adjusting the power supply pulse width and voltage amplitude to achieve a precise balance between energy supply and safety thresholds. Furthermore, this application incorporates the intrinsically safe battery 05, optimizing the device structure while ensuring performance, resulting in a compact size and lightweight design, facilitating installation and mobile measurement in different areas of explosive environments, and improving the flexibility and convenience of detection.

[0060] This application proposes an explosion-proof wind speed detector. A non-contact measurement unit is formed by a built-in laser 03 and an optical probe 02. The laser is precisely projected onto fluid particles through the optical probe 02, capturing the scattered light signal to measure the wind speed, thus eliminating the risk of ignition caused by mechanical friction. Simultaneously, the external casing 01 of this application is explosion-proof, and the internal circuit board 04 is electrically insulated through a protective layer, effectively preventing potential internal electrical sparks from contacting external explosive gases, ensuring stable operation in high-risk environments. Furthermore, the intrinsically safe control circuit 06 integrated into the circuit board 04 limits the current of the constant drive signal below a preset threshold, ensuring that the laser 03's operating power is always within a safe range. Combined with an intrinsically safe battery 05, the output energy is strictly constrained within the threshold allowed by explosion-proof standards, eliminating the risk of arcing or heat accumulation at the source. This ensures the inherent safety of equipment operation in explosive environments while avoiding the wear and contamination problems of traditional mechanical structures, improving long-term stability and environmental adaptability.

[0061] In one embodiment, reference is made to Figure 2 The intrinsically safe control circuit 06 includes:

[0062] The intrinsically safe power conversion circuit 61 processes the input power and limits its output to a second preset power range. The intrinsically safe power conversion circuit 61 converts external input power into intrinsically safe electrical energy through a multi-level energy limiting mechanism. Its core lies in dynamically adjusting the coupling relationship between voltage and current, utilizing current-limiting resistors and fast-response protection chips to construct an energy limiting network. The circuit monitors the input power spectral density in real time and ensures that the output power remains below the critical value for igniting an explosive medium through feedback adjustment of the switching power supply topology. Even in the event of a short circuit or overload fault, its internal multiple composite protection mechanisms can instantly cut off the energy transmission path and simultaneously discharge residual charge, completely eliminating the conditions for the generation of electrical sparks or high-temperature thermal effects. The second preset power range refers to the output power limit that meets intrinsically safe standards and is not specified here.

[0063] More specifically, refer to Figure 3 The intrinsically safe power conversion circuit 61 includes a first conversion circuit and a second conversion circuit. The first conversion circuit focuses on power density limiting, while the second conversion circuit emphasizes dynamic current cutting protection. Together, they ensure that the final output voltage, current, and instantaneous power are always below the critical values ​​for igniting an explosive mixture, achieving intrinsically safe output.

[0064] The laser drive circuit 62, connected to the laser 03, dynamically adjusts the current / voltage output signal to drive the laser 03 to output constant power. This circuit employs a constant current source architecture and pulse width modulation technology, dynamically adjusting the operating current of the laser 03 through a precision current negative feedback loop. The laser drive circuit 62 provides stable operating conditions for the laser by dynamically adjusting the current / voltage output signal, ensuring its output power remains constant. It is noteworthy that intrinsically safe design requires the laser's maximum power (including power during faults) to always be below the safety limits specified in intrinsically safe standards. Therefore, both the current and voltage signals must drive the laser to achieve constant power output within the limits specified in intrinsically safe standards. In constant current mode, the circuit dynamically adjusts the output voltage by monitoring the laser's operating current in real time to compensate for the effects of laser impedance changes or external environmental fluctuations. In constant voltage mode, the circuit stabilizes the output voltage, but a reasonable current-limiting protection must be designed based on the laser's volt-ampere characteristics to prevent thermal runaway caused by overcurrent. To ensure intrinsic safety, this type of circuit also needs to integrate multiple protection mechanisms. At the hardware level, passive components such as current-limiting resistors and Zener diodes form the first line of defense, directly clamping the maximum current or voltage when the control loop fails; the capacity of energy storage components is strictly limited to prevent the storage of excessive energy during faults. At the software level, overcurrent, overtemperature, and short-circuit protection algorithms monitor key parameters in real time, and immediately shut down the output or switch to a safe mode once an abnormality is detected.

[0065] A photodetector 63, with its input end connected to the optical probe 02, converts the scattered light collected by the optical probe 02 into a detection signal output. The detector employs an avalanche photodiode or photomultiplier tube structure, converting the scattered light signal into a micro-current signal through the photoelectric effect. It integrates a low-noise preamplifier and utilizes common-mode rejection technology to eliminate environmental electromagnetic interference. The detector surface is covered with an anti-saturation protective layer, which automatically activates a dynamic compression function when encountering sudden strong light to prevent device overload damage. The quantum efficiency of the photosensitive element is strictly matched to the laser wavelength to ensure efficient capture and conversion of weak scattered light.

[0066] A signal processing circuit 64, connected to the photodetector 63, receives and processes the detection signal output by the photodetector 63 to obtain the velocity of the fluid under test. The signal processing circuit 64 includes a high-speed analog-to-digital converter (ADC) that digitizes the analog signal. A digital signal processor then executes a Doppler frequency shift calculation algorithm to extract particle velocity information through time-frequency analysis. Adaptive threshold detection and motion compensation techniques are incorporated into the processing to effectively overcome signal distortion caused by fluid turbulence. Finally, standardized flow velocity data is output through a digital isolator, ensuring that the signal transmission process meets intrinsically safe isolation requirements.

[0067] The power conversion circuit establishes a safety boundary from the energy source, the laser drive and photoelectric detection realize safe optical-electric interaction, and the signal processing completes the accurate extraction and safe transmission of information, together constructing a complete measurement system that meets the requirements of explosive environments.

[0068] In one embodiment, the optical probe 02 includes:

[0069] An optical circulator has a first port, a second port, and a third port. The first port is connected to the output of the laser 03, and the third port is connected to the input of the photodetector 63. A lens group is connected to the second port and is used to focus the laser output by the laser 03 onto the fluid to be measured to form a velocity measurement area, and to collect scattered light scattered by fluid particles in the velocity measurement area. The optical circulator is used to transmit the laser unidirectionally from the first port to the second port and to transmit the scattered light unidirectionally from the second port to the third port.

[0070] This can be understood as follows: the optical circulator achieves unidirectional transmission of optical signals through its non-reciprocal optical properties. The original laser emitted by laser 03 enters the optical circulator from the first port and propagates unidirectionally to the second port along a specific path, but cannot propagate back to the third port. When the scattered light returns from the second port, the optical circulator, through a combination of an internal Faraday rotator and a polarization beam splitter, forces a change in its transmission path, ensuring that it can only propagate directionally to the third port and cannot return to the first port. This unidirectional transmission characteristic effectively isolates the optical paths of the laser source and the detector, preventing back-reflected light from interfering with the operation of laser 03, while ensuring that the scattered light signal is transmitted to the photodetector 63 without loss.

[0071] The lens group focuses the laser beam output from the second port to form a high-energy-density velocities measurement region. Simultaneously, it captures multi-angle scattered light generated by fluid particles within this region, collimates it, and couples it back to the second port of the optical circulator. The optical surfaces of the lens group are typically coated with an anti-reflection film to reduce interface reflection losses, and aberrations are corrected through aspherical design to ensure efficient optical signal transmission and high signal-to-noise ratio acquisition. The entire system, through the optical path isolation of the optical circulator and the dual focusing and collecting functions of the lens group, forms a closed-loop optical path of "emission-scattering-reception," ensuring both directional utilization of laser energy and accurate extraction of weak scattered light, providing a reliable optical foundation for flow velocity measurement.

[0072] In one embodiment, the intrinsically safe control circuit 06 further includes:

[0073] An optical fiber amplifier, connected to the output of laser 03 and the first port of the optical circulator, amplifies the laser signal generated by laser 03. When the initial beam output from the laser driving circuit 62 enters the doped fiber, the pre-injected pump light excites erbium ions to a high-energy state, resulting in population inversion. When the signal light passes through the activated region, the excited-state ions release energy to generate photons of the same frequency and phase, achieving passive gain of the optical signal. Electrical signal intervention is completely avoided during amplification, fundamentally eliminating the risk of electrical sparks and meeting the energy isolation requirements of intrinsically safe systems. More specifically, a closed-loop power monitoring system can be placed inside the amplifier to sample the output optical power in real time via a beam splitter. When the detected power approaches a critical threshold, the feedback circuit immediately adjusts the driving current of the pump source, causing the gain coefficient to dynamically decrease. This adaptive adjustment mechanism ensures that the output light intensity is always below the energy limit for igniting an explosive mixture. The pump module adopts a distributed multi-level structure, with each level's pump power individually limited, forming a graded energy suppression barrier.

[0074] In one embodiment, the circuit board 04 includes a substrate and electronic components disposed on the substrate; the first encapsulation layer 41 includes: a sealing frame having an opening, the substrate being embedded in the opening of the sealing frame, and the electronic components being disposed on the side of the substrate facing the opening; and a potting layer filling and fixing within the sealing frame, the potting layer encapsulating the side of the substrate on which the electronic components are disposed.

[0075] This can be understood as follows: the encapsulation frame opening, through size matching, embeds and fixes the substrate, forming a stable mounting plane. Once the substrate is embedded in the opening, the sidewalls of the encapsulation frame and the edge of the substrate form a continuous physical barrier, effectively isolating the circuit board 04 from the external environment. The frame is made of insulating material, capable of withstanding mechanical impact and preventing dust, liquids, and other contaminants from entering from the side. Its opening depth is designed to create a safe gap between the electronic components on the substrate surface and the upper edge of the frame, facilitating the flow and filling of the encapsulation material while preventing direct contact between component leads and the frame. The encapsulation layer, as a functional encapsulation medium, uses epoxy resin to fill the entire interior of the encapsulation frame. Before curing, the liquid encapsulant penetrates the gaps between electronic components, encapsulating solder joints and leads, forming a dense insulating protective layer after curing. This layer completely covers the circuit surface, eliminating air gaps between exposed conductors and preventing arc discharge or electric sparks. The cured encapsulation layer has stress-buffering properties, absorbing vibration energy, and, through the hydrophobicity and chemical corrosion resistance of the material itself, blocks moisture and corrosive gases from eroding the circuit. The sealing frame provides basic structural positioning and lateral protection, restricting the flow range of the potting material, while the potting layer completes the three-dimensional encapsulation, achieving electrical isolation and environmental sealing.

[0076] In one embodiment, the intrinsically safe battery 05 includes:

[0077] The battery casing has a second encapsulating layer on the outside. The casing itself consists of an A-shell and a B-shell, secured with snap-fit ​​components, and is made of fire-resistant material. The second encapsulating layer covers the casing surface using a silicone encapsulation process, forming a seamless insulating protective layer. This layer not only blocks the intrusion of external moisture and corrosive gases but also absorbs mechanical impact energy through the material's high elasticity, preventing the risk of internal short circuits caused by casing rupture.

[0078] An intrinsically safe protection circuit, integrated within the battery casing, limits the output power of the intrinsically safe battery 05 to a first preset range. The battery cell, housed within the battery casing, is connected to the intrinsically safe control circuit 06 via the intrinsically safe protection circuit. When the intrinsically safe protection circuit detects overcurrent, overvoltage, or short circuit in the battery cell, it responds in three stages: the primary response triggers soft current limiting, the secondary response initiates voltage clamping, and the final response directly disconnects the physical relay. Furthermore, the circuit integrates an energy integration module that continuously accumulates the output energy value, and when it approaches the first preset range threshold, it prematurely enters a power reduction mode. The first preset range refers to the output power limit that meets intrinsically safe standards and is not specified here.

[0079] The entire system, through casing protection and circuit regulation, ensures that the battery's output power is strictly limited to a preset safe range even under extreme conditions, achieving intrinsically safe control throughout the entire process from energy storage to release. Furthermore, the intrinsically safe battery 05 design optimizes the device structure while maintaining performance, making it compact and lightweight, facilitating installation and mobile measurement in different areas of explosive environments, thus improving the flexibility and convenience of testing.

[0080] In one embodiment, reference is made to Figure 1 The explosion-proof housing 01 includes:

[0081] The outer casing 11 has a mounting opening on its back and is made of explosion-proof material. As the main protective layer, the outer casing 11 uses a special composite material to form a rigid barrier. Its high strength can withstand external mechanical impacts and instantaneous pressure waves generated by internal explosions, preventing the casing from rupturing and causing danger to spread. The inherent thermal insulation properties of the material effectively block the conduction of abnormal heat generated by internal circuitry to the external flammable environment, preventing high temperatures from becoming an ignition source. The outer casing 11 has a thickness of 3mm or more, and the back opening is for mounting the encapsulated circuit board 04 and its battery.

[0082] The rear cover 12 fits over the mounting opening of the outer shell 11 to form an explosion-proof cavity. Within the explosion-proof cavity enclosed by the outer shell 11 and the rear cover 12, a potting material completely encapsulates the circuit board 04 and the battery. This curing encapsulation isolates the electronic components from the air, eliminating flammable media. Specifically, the internal layout of the cavity follows a partitioning principle; insulating partitions can be installed between the battery module and the power circuit to block heat conduction paths; critical contacts can be embedded to prevent protruding structures from generating frictional sparks under impact. When an internal electrical fault occurs, the shell physically confines the explosion energy within the sealed space, while utilizing the material's heat dissipation characteristics to control the temperature gradient below the ignition threshold, achieving intrinsic safety protection.

[0083] In one embodiment, it further includes:

[0084] The first positioning frame 13 is disposed outside the laser 03. The explosion-proof cavity is provided with a first limiter that matches the first positioning frame 13. The laser 03 is fixed in the explosion-proof cavity by the first positioning frame 13 and the first limiter.

[0085] In this embodiment, the explosion-proof housing 01 achieves precise fixation and physical isolation of key components through a multi-level positioning and encapsulation structure. The first positioning frame 13 encapsulates the outside of the laser 03 and has a ring-shaped frame with a clasp. It forms an initial fixation through an interference fit with the outer shell 11 of the laser 03. The first limiting position on the inner wall of the explosion-proof cavity is a boss. The first limiting position divides the explosion-proof cavity into an upper part and a lower part. When the laser 03 assembly is installed into the cavity, the positioning frame is locked on the first limiting position, thereby fixing the laser 03 in the upper part of the explosion-proof cavity.

[0086] In one embodiment, it further includes:

[0087] The second positioning frame 14 is disposed on the side of the first wrapping layer 41 facing away from the outer shell 11. The intrinsically safe battery 05 is disposed within the second positioning frame 14. A second limiting device matching the second positioning frame 14 is provided within the explosion-proof cavity. The intrinsically safe battery 05 is fixed to the bottom of the explosion-proof cavity by the second positioning frame 14 and the second limiting device. The second positioning frame 14 serves as a dedicated support structure for the battery, and its inner wall is adapted to the contour of the battery shell 11. When the battery is embedded in the positioning frame, the sidewall generates a uniform wrapping force through compression deformation, eliminating the gap between the battery and the frame. The second limiting device at the bottom of the explosion-proof cavity is used to fix the second positioning frame 14 and the intrinsically safe battery 05.

[0088] The second positioning frame 14, positioned outside the first wrapping layer 41, forms a physical isolation zone. The cured flame-retardant material of the first wrapping layer 41 serves as a primary protective layer, absorbing the heat energy generated by abnormal battery heating. The air gap formed by the positioning frame and the limiting structure constitutes a secondary buffer space, attenuating the mechanical shock wave that may be generated during battery failure through the gas expansion effect. The first limiting structure divides the explosion-proof cavity into an upper and lower part. The laser 03 is fixed in the upper part of the explosion-proof cavity, while the intrinsically safe battery 05 and circuit board 04 are fixed in the lower part, optimizing the center of gravity distribution of the equipment. At the same time, the rigid support characteristics of the second limiting structure are used to directly transmit the vibration energy of the battery during operation to the main structure of the casing for dissipation, avoiding the risk of resonance in other components inside the cavity.

[0089] In one embodiment, the outer casing 11 has a display screen mounting hole and a button mounting hole. The explosion-proof wind speed detector also includes a display screen and a button. The display screen is disposed in the display screen mounting hole, and the button is disposed in the button mounting hole. The display screen and the button are connected to the intrinsically safe control circuit 06. In the explosion-proof wind speed detector, the display screen is embedded in the mounting hole of the outer casing 11. Its outer layer is composed of explosion-proof glass and a sealing ring to form a composite protective interface: the explosion-proof glass resists external impact through a micro-crack self-healing layer, and the sealing ring is compressed by the casing to form an annular sealed band, blocking the transmission path of internal explosion pressure to the screen area. The inner layer of the display screen is connected to the intrinsically safe control circuit 06 through a flexible conductive strip. The control circuit converts the wind speed signal collected by the laser 03 into digital waveforms and numerical information, driving the screen to display real-time data in a low refresh rate mode. This low-power display mechanism not only meets the energy limitation requirements of explosive environments but also adapts to the visibility requirements in dim conditions through dynamic backlight adjustment.

[0090] The button assembly adopts a pressure-triggered explosion-proof structure. When the button plunger passes through the mounting hole, the outer button silicone sleeve fits snugly against the housing hole wall. The inner multi-stage spring assembly provides segmented pressing feedback, ensuring that a signal is triggered only when the operating force exceeds a safety threshold. When the user presses the button, the plunger compresses the spring, pushing the magnet to move. The Hall sensor detects the change in magnetic field and sends a pulse signal to the control circuit. The control circuit interprets instructions according to a preset protocol, such as switching display modes, starting data logging, or triggering device self-tests. At the same time, a current limiting module ensures that the energy during signal transmission remains below the ignition threshold.

[0091] The above embodiments are merely preferred embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the content of this utility model specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. An explosion-proof anemometer, characterized in that, Comprising: An explosion-proof housing with a measurement window provided at the top; A laser, disposed within the explosion-proof housing, for generating laser light; An optical probe, disposed within the measurement window and connected to the output end of the laser, for incident the laser light generated by the laser onto the fluid to be measured and collecting the scattered light scattered by the fluid particles within the fluid to be measured; A circuit board, disposed within the explosion-proof housing, the exterior of the circuit board being coated with a first wrapping layer, and the circuit board integrating an intrinsically safe control circuit, the control end of the intrinsically safe control circuit being connected to the controlled end of the laser, for driving the laser to output at a constant power; The input end of the intrinsically safe control circuit is connected to the optical probe, for receiving and processing the scattered light collected by the optical probe to detect the velocity of the fluid to be measured; An intrinsically safe battery, disposed within the explosion-proof housing, the output end being connected to the power input end of the laser, for providing an intrinsically safe power supply to the laser.

2. The explosion-proof wind speed detector as described in claim 1, characterized in that, The intrinsically safe control circuit includes: An intrinsically safe power conversion circuit, for performing power processing on the accessed power supply and outputting it within a second preset power range; A laser driving circuit, connected to the laser, for dynamically adjusting the current / voltage output signal to drive the laser to output at a constant power; A photodetector, the input end being connected to the optical probe, for converting the scattered light collected by the optical probe into a detection signal and outputting it; A signal processing circuit, connected to the photodetector, for receiving and processing the detection signal output by the photodetector to obtain the velocity of the fluid to be measured.

3. The explosion-proof wind speed detector as described in claim 2, characterized in that, The optical probe includes: An optical circulator, having a first port, a second port and a third port, the first port being connected to the output end of the laser, and the third port being connected to the input end of the photodetector; A lens group, connected to the second port, for focusing the laser light output by the laser onto the fluid to be measured to form a velocity measurement area and collecting the scattered light scattered by the fluid particles within the velocity measurement area; Wherein, the optical circulator is used for unidirectionally transmitting the laser light from the first port to the second port and unidirectionally transmitting the scattered light from the second port to the third port.

4. The explosion-proof wind speed detector as described in claim 3, characterized in that, The intrinsically safe control circuit further includes: An optical fiber amplifier, connected to the output end of the laser and the first port of the optical circulator, for amplifying the laser signal generated by the laser.

5. The explosion-proof wind speed detector as described in claim 1, characterized in that, The circuit board includes a substrate and electronic components provided on the substrate; the first wrapping layer includes: A sealing frame, the sealing frame having an opening, the substrate being embedded within the opening of the sealing frame, and the electronic components being provided on the side of the substrate facing the opening; A casting sealing layer, filled and fixed within the sealing frame, the casting sealing layer wrapping the side of the substrate provided with the electronic components.

6. The explosion-proof wind speed detector as described in claim 1, characterized in that, The intrinsically safe battery includes: A battery housing, externally cast with a second wrapping layer; An intrinsically safe protection circuit, integrated within the battery housing, for limiting the output power of the intrinsically safe battery within a first preset range; A battery core, disposed within the battery housing, the battery core being connected to the intrinsically safe control circuit through the intrinsically safe protection circuit.

7. The explosion-proof wind speed detector as described in any one of claims 1-6, characterized in that, The explosion-proof housing includes: The outer casing has a mounting port on the back, and the outer casing is made of explosion-proof material; The rear cover fits onto the mounting opening of the outer shell to form an explosion-proof cavity.

8. The explosion-proof wind speed detector as described in claim 7, characterized in that, Also includes: A first positioning frame is disposed outside the laser, and a first limiter is disposed inside the explosion-proof cavity to match the first positioning frame. The laser is fixed in the explosion-proof cavity by the first positioning frame and the first limiter.

9. The explosion-proof wind speed detector as described in claim 7, characterized in that, Also includes: The second positioning frame is set on the side of the first wrapping layer facing away from the outer shell. The intrinsically safe battery is set inside the second positioning frame. The explosion-proof cavity is provided with a second limiter that matches the second positioning frame. The intrinsically safe battery is fixed to the bottom of the explosion-proof cavity by the second positioning frame and the second limiter.

10. The explosion-proof wind speed detector as described in claim 7, characterized in that, The outer casing has a display screen mounting hole and a button mounting hole. The explosion-proof wind speed detector also includes a display screen and a button. The display screen is disposed in the display screen mounting hole, and the button is disposed in the button mounting hole. The display screen and the button are connected to the intrinsically safe control circuit.

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