Liquid level detection optical fiber sensing detection device for external floating roof tank
By combining mechanical linkage and optical signals with fiber optic sensing detection devices, the problems of false alarms and safety hazards of liquid level switches under complex operating conditions are solved, achieving high-precision, stable and safe liquid level detection, and adapting to the flexibility and reliability of storage tanks of different specifications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SINOCHEM ZHOUSHAN XINGHAI CONSTR
- Filing Date
- 2025-10-20
- Publication Date
- 2026-07-21
AI Technical Summary
Existing level switches have a high false alarm rate under complex operating conditions, insufficient detection accuracy, and are susceptible to environmental interference. Traditional electrical connection methods pose safety hazards, affecting the production safety and efficiency of petrochemical enterprises.
The device employs a fiber optic sensing detection system, which combines mechanical linkage with optical signals. It utilizes a spark-proof float and a steel wire rope mechanical triggering mechanism, along with a fiber optic liquid level sensor and a sealed housing design, to avoid electrical interference and environmental influences, ensuring the accuracy and safety of the detection.
It reduced the false alarm rate, improved detection accuracy and system stability, avoided the risks of electromagnetic radiation and lightning current, ensured the safe operation of the tank farm environment, reduced false alarms and missed alarms, and improved production efficiency.
Smart Images
Figure CN224535186U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of liquid level detection, and in particular to an optical fiber sensing detection device for liquid level detection in external floating roof tanks. Background Technology
[0002] As a core line of defense for safe production in petrochemical storage enterprises, the high-level alarm system for storage tanks directly affects the effectiveness of the tank root valve interlock shut-off and pump shutdown functions, thereby improving the safety and stability of the entire production process. Currently, with the rapid development of the petrochemical industry, the scale of storage tanks is constantly expanding, and the stored media are becoming increasingly diversified, placing higher demands on liquid level detection technology. However, many large domestic storage enterprises commonly face the problem of false high-level alarms in practical applications. This not only leads to frequent triggering of interlock shutdowns, reducing production efficiency, but may also cause safety hazards due to false triggering.
[0003] Existing level switches generally have a high false alarm rate under complex operating conditions, insufficient detection accuracy, and are not adaptable to complex conditions such as rain, high temperature, and high viscosity media. They are also susceptible to environmental interference, which can lead to detection failure. Traditional electrical connection methods pose safety hazards in explosion-proof environments. Utility Model Content
[0004] To solve the above-mentioned technical problems, or at least partially solve them, this utility model provides an optical fiber sensing detection device for liquid level detection in external floating roof tanks.
[0005] To achieve the above objectives, this utility model provides the following technical solution: The fiber optic sensing detection device for liquid level detection in external floating roof tanks of this utility model includes: A fixed bracket is fixedly connected to the edge of the external floating roof tank. The limiting threaded rod is inserted and mounted on the fixed bracket, and the inside of the limiting threaded rod is a hollow structure. The fiber optic liquid level sensor has its bottom end connected to the top end of the limiting threaded rod, and a photosensitive port is provided at the bottom end of the fiber optic liquid level sensor. A sealing shell is fixedly connected to the bottom of the fiber optic liquid level sensor, and the sealing shell is fitted onto the photosensitive port. The spring positioning seat is fixedly installed on the inner wall of the sealing shell; The linkage pin is slidably inserted into the spring positioning seat, and a lifting ring is provided at the bottom end of the linkage pin; A light-blocking plate is fixedly connected to the top of the linkage shaft pin and is slidably installed in the sealed housing to control the opening and closing of the photosensitive port. A spring is positioned at the top of the spring positioning seat, with the top of the spring fitting against the bottom of the light-blocking plate. The wire rope is hooked at the top and attached to the lifting ring at the bottom of the linkage shaft pin. The wire rope is also located inside the limit threaded rod. The spark-proof float has a double-ended connector at its top, a hanging ring on the double-ended connector, and a brass contact plate at its bottom.
[0006] Furthermore, the fixed bracket is provided with an internal threaded flange, and the limit threaded rod is threadedly inserted into the internal threaded flange.
[0007] Furthermore, it also includes a telescopic sleeve, which is fixedly connected to the double-ended connector. The telescopic sleeve is slidably inserted into the bottom of the limiting threaded rod and is sleeved on the outside of the wire rope.
[0008] Furthermore, a sealing sleeve is fitted at the bottom of the limiting threaded rod, and the sealing sleeve slides in conjunction with the telescopic sleeve.
[0009] Furthermore, a guide sleeve is fitted at the top of the telescopic sleeve, and the guide sleeve slides and fits against the inner wall of the limiting threaded rod.
[0010] Furthermore, the photosensitive port is provided with a staggered platform for use with a light-blocking plate, and a light-blocking buffer pad is provided on the staggered platform.
[0011] Furthermore, the mounting bracket also includes: The edge of the external floating roof tank is L-shaped and is located at the edge of the external floating roof tank. The U-shaped slot is located on the left end of the fixed bracket. The U-shaped slot is installed on the edge of the external floating roof tank. Two lower set screws are threaded at the bottom of the U-shaped slot, and the top of the lower set screws is close to the outer end face of the edge of the external floating roof tank.
[0012] Furthermore, the fixed support also includes a side stop block, which is set on the inner side of the edge of the external floating roof tank. The top of the side stop block is attached to the bottom of the fixed support. The side stop block is fixedly connected to the fixed support by fastening bolts. A side set screw is installed on the side stop block with a horizontal thread, and the side set screw is tightly fitted to the side wall of the edge of the external floating roof tank.
[0013] In the above technical solution, the fiber optic sensing detection device for liquid level detection in external floating roof tanks provided by this utility model has the following beneficial effects: The front-end detection relies on the combination of mechanical linkage and optical signals, eliminating the circuit noise and electromagnetic interference problems of traditional electrical sensors. It solves the false alarm problems caused by vibration frequency interference in tuning fork switches and electromagnetic coupling in capacitor switches, ensuring stable operation even in tank environments with dense motors and frequency converters. The light-blocking plate achieves rapid reset via spring force, and the sealed shell provides physical protection for the photosensitive port, preventing interference from environmental factors such as rainwater and direct sunlight. Simultaneously, the spark-proof float's triggering mechanism is only sensitive to liquid level changes, unaffected by dynamic interference such as medium fluctuations and tank wall vibrations, reducing the false alarm rate. The optical signal of the fiber optic liquid level sensor... The transmission eliminates the attenuation and drift issues common to traditional electrical signals, allowing for precise identification of the on / off state of the photosensitive port. It avoids the weak signal and trigger delay problems caused by variations in dielectric constant in capacitor switches, ensuring timely interlocking actions. The entire front-end detection process is free of cables, wires, and other conductive components. Metal components such as steel wire ropes and spark-proof floats have no electrical connections, eliminating the risk of lightning current conduction from traditional electrical sensors due to cable conductivity. The sealed housing provides airtight protection for core components such as the photosensitive port and spring positioning seat, preventing oil, gas, and dust from entering the tank. Furthermore, the hollow channel of the limiting threaded rod is solely for steel wire rope installation, eliminating space for oil and gas accumulation and reducing the risk of explosion. Attached Figure Description
[0014] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the embodiments will be briefly described below.
[0015] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the installation structure of the light-blocking plate; Figure 3 yes Figure 1 Enlarged structural diagram of section A in the middle; Figure 4 yes Figure 1 Enlarged structural diagram of section B; The attached diagram is labeled as follows: 1. Fixed bracket; 2. Limiting threaded rod; 3. Fiber optic liquid level sensor; 4. Sealing shell; 5. Spring positioning seat; 6. Linkage shaft pin; 7. Light blocking plate; 8. Spring; 9. Steel wire rope; 10. Spark-proof float; 11. Double-ended connector; 12. Internal threaded flange; 13. Telescopic sleeve; 14. Sealing sleeve; 15. Guide sleeve; 16. Brass contact plate; 1a. Edge of external floating roof tank; 1b. U-shaped groove; 1c. Lower set screw; 1d. Side stop block; 1e. Fastening bolt; 1f. Side set screw; 31. Light-blocking buffer pad. Detailed Implementation
[0016] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings.
[0017] See Figure 1-4 As shown; The fiber optic sensing detection device for liquid level detection in an external floating roof tank according to an embodiment of this utility model includes: Fixed bracket 1 is fixedly connected to the edge of the external floating roof tank; The limiting threaded rod 2 is inserted and mounted on the fixed bracket 1, and the inside of the limiting threaded rod 2 is a hollow structure. The fiber optic liquid level sensor 3 is connected to the top of the limiting threaded rod 2 at its bottom end, and a photosensitive port is provided at the bottom end of the fiber optic liquid level sensor 3. The sealing shell 4 is fixedly connected to the bottom end of the fiber optic liquid level sensor 3, and the sealing shell 4 is sleeved on the photosensitive port. Spring positioning seat 5 is fixedly installed on the inner side wall of sealing shell 4; The linkage pin 6 is slidably inserted into the spring positioning seat 5, and a lifting ring is provided at the bottom end of the linkage pin 6; The light-blocking plate 7 is fixedly connected to the top of the linkage shaft pin 6 and is slidably disposed in the sealing shell 4 to control the opening and closing of the photosensitive port. Spring 8 is set at the top of spring positioning seat 5, and the top of spring 8 is attached to the bottom of light blocking plate 7. The top hook of the wire rope 9 is set on the lifting ring at the bottom end of the linkage shaft pin 6, and the wire rope 9 is set inside the limit threaded rod 2. A spark-proof float 10 is provided with a double-ended connector 11 at the top of the spark-proof float 10. A hanging ring is provided on the double-ended connector 11. The hanging ring at the top of the double-ended connector 11 is fixedly connected to the bottom end of the steel wire rope 9. A brass contact plate 16 is provided at the bottom end of the spark-proof float 10. Under the gravity of the spark-proof float 10, the linkage pin 6 and the light-blocking plate 7 are pulled downward by the steel wire rope 9. At this time, the spring 8 will be compressed, causing the photosensitive port to open. Once the spark-proof float 10 is lifted by the float or moves upward by buoyancy, the light-blocking plate 7 will lose the gravity of the spark-proof float 10. Under the elastic force of the spring 8, it will immediately slide upward and reset, covering the photosensitive port and thus closing the photosensitive port. The floating roof of an external floating roof tank is a movable cover that floats directly on the surface of the stored liquid. As the liquid level in the tank rises or falls, the floating roof rises or falls accordingly under the action of buoyancy. When the liquid level rises, the buoyancy on the floating roof increases, which lifts the spark-proof floats 10 upwards, causing them to rise with the floating roof. At this time, the brass contact plate 16 contacts the top surface of the floating roof. Brass has good conductivity and relatively soft properties, and it is not easy to generate static sparks during friction, thus effectively avoiding the risk of combustion or explosion of flammable and explosive materials in the tank caused by sparks, ensuring the safe operation of the tank. The spark-proof floats 10 are triggered by the floating roof when the floating roof is operating normally. When the floating roof is jammed, they are driven by buoyancy as the liquid level rises. The triggering function can be ensured in both working conditions, solving the failure problem of the traditional single triggering mode when the floating roof is abnormal.
[0018] By adopting the above technical solution, when the liquid level in the storage tank does not reach the high-high alarm threshold, the spark-proof float 10 hangs naturally due to its own gravity. The double-ended connector 11 at the top pulls the wire rope 9, generating a stable tension. This tension is transmitted to the linkage pin 6 through the hollow channel inside the limiting threaded rod 2, causing the linkage pin to slide downwards along the spring positioning seat 5. The light-blocking plate 7, fixedly connected to the top of the linkage pin, moves downwards accordingly, simultaneously compressing the spring 8 sleeved on the outside of the linkage pin, causing the photosensitive port at the bottom of the fiber optic liquid level sensor 3 to fully open. At this time, the optical path of the fiber optic liquid level sensor remains unobstructed, and the optical signal can be transmitted normally to the back-end photoelectric control unit. The system determines that the liquid level is within a safe range. The system remains in standby mode. When the tank level rises to the high-high alarm threshold, the spark-proof float 10 contacts and is subjected to the buoyancy of the floating top. The buoyancy gradually counteracts the float's own weight. As the buoyancy increases, the tension of the wire rope 9 gradually decreases until it disappears. The compressed spring 8 releases its elastic potential energy, pushing the light-blocking plate 7 to slide rapidly upward along the inner side of the sealing shell 4. When the light-blocking plate completely covers the light-sensing port of the fiber optic level sensor 3, the light path is precisely blocked. The fiber optic level sensor immediately transmits the interrupted optical signal to the back-end photoelectric control unit via optical cable. The photoelectric control unit converts the optical signal into a digital electrical signal and transmits it to the storage and transportation process automatic control system (DCS), triggering emergency actions such as tank root valve interlock shut-off and oil pump shutdown. Simultaneously, an audible and visual alarm is issued, completing the detection and safety interlock response for high liquid levels. When the tank liquid level drops, the buoyancy of the spark-proof float 10 decreases, and its own weight again exceeds the buoyancy. The steel wire rope 9 pulls the linkage pin 6 and the light-blocking plate 7 down again, the spring 8 is compressed again, the photosensitive port reopens, and the system returns to standby mode, achieving automatic mechanical reset. The front-end detection relies on the coordination of mechanical linkage and optical signals, eliminating the circuit noise and electromagnetic radiation interference problems of traditional electrical sensors. It solves the false alarms caused by the vibration frequency interference of tuning fork switches and the electromagnetic coupling of capacitor switches, and can still work stably in tank area environments with dense motors and frequency converters. The light-blocking plate 7 achieves rapid reset through the elasticity of the spring 8, and the sealing shell 4 provides protection against the light-blocking plate. The optical port forms physical protection to avoid interference from environmental factors such as rainwater adhesion and direct sunlight on the optical path. At the same time, the triggering mechanism of the spark-proof float 10 is only sensitive to changes in liquid level and is not affected by dynamic interference such as medium fluctuations and tank wall vibration, thus reducing the false alarm rate. The optical signal transmission of the fiber optic liquid level sensor 3 does not have the attenuation and drift problems of traditional electrical signals. The on / off state of the photosensitive port can be accurately identified. There are no weak signals or trigger delays caused by changes in dielectric constant of capacitor switches, ensuring the timeliness of interlocking actions. There are no conductive parts such as cables or wires in the entire front-end detection process. Metal parts such as the steel wire rope 9 and spark-proof float 10 have no electrical connections, solving the risk of lightning current introduction caused by the conductivity of cables in traditional electrical sensors.The sealing shell 4 provides airtight protection for core components such as the photosensitive port and spring positioning seat 5, preventing oil, gas, and dust from entering the tank. Furthermore, the hollow channel of the limiting threaded rod 2 is solely for the installation of the wire rope, leaving no space for oil or gas accumulation and reducing the risk of explosion.
[0019] As a preferred embodiment of the above technical solution, such as Figure 1 As shown, the fixed bracket 1 is provided with an internal threaded flange 12, and the limiting threaded rod 2 is threadedly inserted into the internal threaded flange 12. In this embodiment, based on the actual liquid level detection requirements of the storage tank and the floating range of the spark-proof float 10, the operator can adjust the insertion depth of the limiting threaded rod 2 into the internal threaded flange 12 by rotating it. When the limiting threaded rod 2 is rotated, its height position relative to the fixed bracket 1 changes, thereby changing the initial detection position of the fiber optic liquid level sensor 3. This allows the device to adapt to storage tanks of different specifications and liquid levels, improving the device's versatility and flexibility. During device operation, the limiting threaded rod 2 is tightly fitted with the internal threaded flange 12 through a threaded connection, ensuring its stability under complex working conditions such as storage tank vibration and medium fluctuations. The threaded connection has a self-locking function, which can effectively prevent the limiting threaded rod 2 from loosening or falling off due to external forces during operation, ensuring the long-term reliable operation of the device.
[0020] As a preferred embodiment of the above technical solution, such as Figure 1 As shown, it also includes a telescopic sleeve 13, which is fixedly connected to the double-headed connector 11. The telescopic sleeve 13 is slidably inserted into the bottom of the limiting threaded rod 2, and the telescopic sleeve 13 is sleeved on the outside of the wire rope 9. In this embodiment, when the liquid level in the storage tank rises, the spark-proof float 10 moves upward under the action of buoyancy, causing the double-ended connector 11 and the telescopic sleeve 13 to move upward synchronously. The telescopic sleeve 13 slides at the bottom of the limiting threaded rod 2, and its length is automatically adjusted according to the liquid level change, always maintaining the wrapping and protection of the wire rope 9. When the liquid level in the storage tank drops, the spark-proof float 10 loses its buoyancy and moves downward under the action of gravity, causing the double-ended connector 11 and the telescopic sleeve 13 to move downward synchronously. The telescopic sleeve 13 slides at the bottom of the limiting threaded rod 2, and its length shortens, continuing to maintain the wrapping and protection of the wire rope 9. The telescopic sleeve 13 is fitted over the outside of the wire rope 9, effectively preventing the wire rope 9 from being directly exposed to the harsh storage tank environment. Through the wrapping effect of the telescopic sleeve 13, the wear and corrosion of the wire rope 9 are reduced, its service life is extended, and maintenance costs are reduced. The telescopic sleeve 13 provides stable guidance and support for the wire rope 9, preventing it from swaying or shifting during liquid level changes and under the action of external wind.
[0021] As a preferred embodiment of the above technical solution, such as Figure 3As shown, a sealing sleeve 14 is fitted at the bottom end of the limiting threaded rod 2, and the sealing sleeve 14 slides in conjunction with the telescopic sleeve 13. In this embodiment, the sliding fit design of the sealing sleeve 14 and the telescopic sleeve 13 effectively blocks the path of external medium entering the device through the gap, avoiding problems such as corrosion of the wire rope 9, jamming of the spring 8, or failure of the fiber optic liquid level sensor 3 caused by medium intrusion; it improves the reliability of the device under harsh working conditions and reduces false alarms or equipment damage caused by seal failure; through the mechanical seal design of the sealing sleeve 14 and the telescopic sleeve 13, it completely avoids contact between electrical components and external medium, eliminates the possibility of electric sparks, and enhances the explosion-proof performance of the device.
[0022] As a preferred embodiment of the above technical solution, such as Figure 3 As shown, a guide sleeve 15 is fitted at the top of the telescopic sleeve 13, and the guide sleeve 15 slides against the inner wall of the limiting threaded rod 2. In this embodiment, the guiding function of the guide sleeve 15 ensures the axial movement accuracy of the telescopic sleeve 13, avoids uneven force on the wire rope 9 due to swaying or jamming, and thus prevents the light-blocking plate 7 from delaying or failing; it also reduces the probability of false alarms caused by mechanical transmission failure and improves the accuracy of liquid level detection.
[0023] As a preferred embodiment of the above technical solution, such as Figure 2 As shown, the photosensitive port is provided with a staggered platform for cooperating with the light-blocking plate 7, and a light-blocking buffer pad is provided on the staggered platform; In this embodiment, the precise cooperation between the light-blocking plate 7 and the misalignment ensures that the photosensitive port is completely blocked in the alarm state, avoiding light leakage caused by the offset or tilt of the light-blocking plate 7, and improving the threshold accuracy of liquid level detection. The elastic deformation of the light-blocking buffer pad absorbs the impact force when the light-blocking plate 7 is reset, reducing the damage of mechanical vibration to the sensor and the fixed bracket 1, avoiding loosening or deformation of components due to long-term hard collisions, extending the service life of the misalignment and the light-blocking plate 7, and reducing the maintenance frequency.
[0024] As a preferred embodiment of the above technical solution, such as Figure 4 As shown, the fixed bracket 1 also includes: The edge 1a of the external floating roof tank is L-shaped and is located at the edge of the external floating roof tank. U-shaped slot 1b is located at the left end of fixed bracket 1. U-shaped slot 1b is snapped onto the edge 1a of the external floating roof tank. Two lower set screws 1c are threaded into the bottom of U-shaped slot 1b. The top of the lower set screws 1c is in close contact with the outer end face of the edge 1a of the external floating roof tank. In this embodiment, the edge 1a of the external floating roof tank has an L-shaped structure, extending laterally to the outside of the tank to form a stable installation reference surface. During installation, the U-shaped groove 1b at the left end of the fixed bracket 1 is first aligned horizontally with the horizontal section of the L-shaped tank edge, so that the horizontal part of the tank edge 1a is completely embedded in the groove of the U-shaped groove. At this time, the two side walls of the U-shaped groove are located on the upper and lower surfaces of the tank edge, forming a lateral limit, initially restricting the displacement of the fixed bracket in the direction perpendicular to the tank wall. After the U-shaped groove 1b is horizontally engaged, it is tightened by rotating the two lower set screws 1c inserted into the bottom thread of the U-shaped groove. The thread adjustment design of the lower set screws 1c allows the installation and disassembly of the bracket to be completed without special tools, and can be completed by a single person, significantly shortening the on-site construction time and reducing labor costs. The dimensions of the L-shaped edge 1a and the U-shaped groove 1b are standardized, which can be adapted to external floating roof tanks of different specifications, reducing the need for customized design and reducing the production cost of the device.
[0025] As a preferred embodiment of the above technical solution, such as Figure 4 As shown, the fixed support 1 also includes a side block 1d, which is disposed inside the edge 1a of the external floating roof tank. The top of the side block 1d is attached to the bottom of the fixed support 1. The side block 1d is fixedly connected to the fixed support 1 by a fastening bolt 1e. A side set screw 1f is installed on the side block 1d with a horizontal thread, and the side set screw 1f is tightly fitted to the side wall of the edge 1a of the external floating roof tank. In this embodiment, after the U-shaped slot 1b is laterally engaged with the edge 1a of the external floating roof tank, the side block 1d is placed on the inner side of the edge 1a of the tank, close to the tank wall, so that the top of the side block is completely in contact with the bottom of the fixed bracket 1, and the side wall of the side block is aligned with the inner side wall of the edge 1a of the tank. This step provides an inner support point for the fixed bracket through physical contact, balances the support force of the U-shaped slot 1b on the outer side of the tank edge, and avoids the bracket from tilting due to unilateral force. The side screw 1f of the side block 1d and the lower screw 1c of the U-shaped slot 1b form a bidirectional clamping force. The side screw restricts the bracket from moving out of the tank from the inside, and the lower screw restricts the bracket from moving inward from the outside. The bidirectional clamping force can offset the lateral impact force generated by vibration, ensure the long-term stability of the liquid level detection threshold, and avoid false alarms or missed alarms caused by displacement.
[0026] The above are all preferred embodiments of this utility model, and are not intended to limit the scope of protection of this utility model. Therefore, all equivalent changes made to the structure, shape and principle of this utility model should be covered within the scope of protection of this utility model.
Claims
1. A fiber optic sensing detection device for liquid level detection in an external floating roof tank, characterized in that, include: A fixed bracket is fixedly connected to the edge of the external floating roof tank; A limiting threaded rod is inserted and mounted on the fixed bracket, and the inside of the limiting threaded rod is set to a hollow structure. A fiber optic liquid level sensor, wherein the bottom end of the fiber optic liquid level sensor is connected to the top end of the limiting threaded rod, and a photosensitive port is provided at the bottom end of the fiber optic liquid level sensor; A sealing shell is fixedly connected to the bottom end of the fiber optic liquid level sensor, and the sealing shell is sleeved on the photosensitive port. A spring positioning seat is fixedly installed on the inner side wall of the sealing shell; A linkage pin is slidably inserted into the spring positioning seat, and a lifting ring is provided at the bottom end of the linkage pin; A light-blocking plate is fixedly connected to the top of the linkage shaft pin and is slidably disposed in the sealing shell to control the opening and closing of the photosensitive port. A spring is disposed at the top of the spring positioning seat, and the top of the spring is in contact with the bottom end of the light-blocking plate; The steel wire rope is hooked at the top and attached to the lifting ring at the bottom end of the linkage shaft pin. The steel wire rope is located inside the limiting threaded rod. A spark-proof float is provided with a double-ended connector at its top, a hanging ring on the double-ended connector, and the hanging ring at the top of the double-ended connector is fixedly connected to the bottom end of the wire rope. A brass contact plate is provided at the bottom end of the spark-proof float.
2. The fiber optic sensing detection device for liquid level detection in an external floating roof tank as described in claim 1, characterized in that, The fixed bracket is provided with an internal threaded flange, and the limiting threaded rod is threadedly inserted into the internal threaded flange.
3. The fiber optic sensing detection device for liquid level detection in an external floating roof tank as described in claim 1, characterized in that, It also includes a telescopic sleeve, which is fixedly connected to the double-ended connector. The telescopic sleeve is slidably inserted into the bottom of the limiting threaded rod and is sleeved on the outside of the wire rope.
4. The fiber optic sensing detection device for liquid level detection in an external floating roof tank as described in claim 3, characterized in that, A sealing sleeve is fitted at the bottom end of the limiting threaded rod, and the sealing sleeve slides in conjunction with the telescopic sleeve.
5. The fiber optic sensing detection device for liquid level detection in an external floating roof tank as described in claim 3, characterized in that, A guide sleeve is fitted at the top of the telescopic sleeve, and the guide sleeve slides against the inner wall of the limiting threaded rod.
6. The fiber optic sensing detection device for liquid level detection in an external floating roof tank as described in claim 1, characterized in that, The photosensitive port is provided with a staggered platform for cooperating with the light-blocking plate, and a light-blocking buffer pad is provided on the staggered platform.
7. The fiber optic sensing detection device for liquid level detection in an external floating roof tank as described in claim 1, characterized in that, The fixed bracket also includes: The edge of the external floating roof tank is L-shaped and is located at the edge of the external floating roof tank. The U-shaped slot is located at the left end of the fixed bracket and is fitted onto the edge of the external floating roof tank. Two lower set screws are threaded into the bottom of the U-shaped slot, and the top of the lower set screws is in close contact with the outer end face of the edge of the external floating roof tank.
8. The fiber optic sensing detection device for liquid level detection in an external floating roof tank as described in claim 7, characterized in that, The fixed support also includes a side stop block, which is disposed on the inner side of the edge of the external floating roof tank. The top end of the side stop block is attached to the bottom end of the fixed support. The side stop block is fixedly connected to the fixed support by fastening bolts. A side set screw is installed on the side stop block with a horizontal thread, and the side set screw is tightly fitted to the side wall of the edge of the external floating roof tank.