Liquid level alarm device for fire-fighting tank body

Abstract

The invention discloses a liquid level alarm device for a fire-fighting tank, and relates to the technical field of liquid level alarm equipment, the liquid level alarm device comprises a power supply, a hollow shaft and an annular electrifying plate, the power supply is fixedly mounted on one side of the top of the tank, the top of the power supply is electrically connected with a display control panel, and a controller and an alarm are arranged in the display control panel; the three hollow shafts are rotationally installed in the tank body in an annular array mode, the outer sides of the hollow shafts are fixedly connected with oval electrifying feeler levers in a sleeving mode, and meshing transmission parts are connected between the top ends of the multiple hollow shafts and a control handle of the tank body; the annular electrifying plate is fixedly installed in the middle of the top of the tank body, one end of the annular electrifying plate is electrically connected with a power source, and the other end of the annular electrifying plate penetrates through the tank body and is electrically connected with the electrifying feeler levers. According to the invention, whether gas leakage or deflation exists in the tank body is alarmed and prompted, the detection mode is simple and timely, and the precision is high.

Description

Technical Field

[0001] This invention relates to the field of liquid level alarm technology, and in particular to a liquid level alarm device for fire-fighting tanks. Background Technology

[0002] Liquid levels need to be monitored in various industries to make corresponding adjustments. In fire fighting, liquid carbon dioxide is frequently used. During the storage of liquid carbon dioxide, it needs to be placed in a low-temperature and high-pressure tank environment and the tank needs to be sealed. Therefore, in order to prevent the leakage of carbon dioxide due to tank leakage, it is necessary to monitor and warn of the liquid carbon dioxide level.

[0003] Currently, liquid level alarm devices used for storing carbon dioxide tanks generally employ liquid level detection equipment to monitor the liquid level of carbon dioxide in real time and record the initial liquid level height. They then determine whether the tank is leaking or releasing gas based on whether the liquid level has dropped, and then issue an alarm. This method of liquid level alarm is cumbersome to operate, easily affected by external factors, and has low accuracy. Summary of the Invention

[0004] The purpose of this invention is to solve the problems of cumbersome operation, susceptibility to external interference, and low accuracy in the prior art, and to propose a liquid level alarm device for fire tanks.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A liquid level alarm device for fire-fighting tanks includes components installed on the tank:

[0007] The power supply is fixedly installed on the top side of the tank, and a display control panel is electrically connected to the top of the power supply. The display control panel is equipped with a controller and an alarm.

[0008] Hollow shafts, three of which are arranged in a ring array and rotatably installed inside the tank, with elliptical power-conducting contact rods fixedly sleeved on the outside of the hollow shafts, and meshing transmission components connecting the tops of the multiple hollow shafts to the control handle of the tank.

[0009] An annular energizing plate is fixedly installed at the top center of the tank. One end of the annular energizing plate is electrically connected to a power source, and the other end passes through the tank and is electrically connected to multiple energizing contact rods.

[0010] The system includes three floats that slide around the outside of three energized contact rods. Each float has a sensing block attached to the outside of the energized contact rod. The sensing block is ring-shaped, and two conductive contact plates are symmetrically arranged on the inner ring surface of the sensing block. These contact plates are electrically connected to both ends of the energized contact rod and clamp the energized contact rod. Each sensing block has a pressure sensor on its upper surface that is electrically connected to the conductive contact plate. An energized wire connects two adjacent sensing blocks. The controller is electrically connected to the alarm and the pressure sensor.

[0011] Preferably, the meshing transmission component includes a main gear fixedly installed on the top of the infusion pipe of the tank and a driven gear fixedly sleeved on the outside of multiple hollow shafts. The main gear meshes with the multiple driven gears and is the same size. The main gear and the multiple driven gears are also covered by a shell fixed to the top wall of the tank.

[0012] Preferably, the inner ring diameter of the sensing block, the inner diameter of the float, and the major axis of the energized contact rod are all the same.

[0013] Preferably, the bottom ends of the float are connected to the top ends of the sensing block by connecting ropes, and the buoyancy of the float in the tank is greater than the sum of the weights of the float and the sensing block in the solution in the tank, so that the float is always on the liquid surface.

[0014] Preferably, both ends of the long shaft of the energized contact rod are provided with contact heads for conducting electricity, and the contact heads at both ends of the energized contact rod rotate with the hollow shaft and contact the two pressing conductive contact pieces.

[0015] Preferably, the clamping conductive contact is slidably disposed in the inner ring of the sensing block, and both sides of the end of the clamping conductive contact located inside the sensing block have protrusions extending outward, and a rebound member is provided between the end of the clamping conductive contact located inside the sensing block and the inner wall of the outer ring of the sensing block.

[0016] Preferably, the rebound component includes a spring and a guide post, wherein the guide post is perpendicular to the clamping conductive contact and fixed on the inner wall of the outer ring of the sensing block, the spring is sleeved on the outside of the guide post, and the two ends of the spring abut against the surface of the clamping conductive contact and the inner wall of the sensing block, respectively.

[0017] Preferably, the inside of the sensing block is provided with a resistance wire reel on one side of one of the rebounding elements. The inside of the resistance wire reel is provided with a winding shaft, on which a resistance wire is wound. One end of the resistance wire passes through the resistance wire reel and is connected to a current-carrying wire, and the other end of the resistance wire is connected to a pressing conductive contact via the winding shaft.

[0018] Preferably, the surface of the display control panel is provided with a power indicator light that is electrically connected to a power source and induction indicator lights that are respectively connected to multiple energized wires.

[0019] Preferably, the controller within the display control panel is also electrically connected to multiple sensor-activated light bulbs.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] This invention utilizes a hollow shaft, an energized contact rod, a float, a conductive contact plate, a sensing block, and a meshing transmission component installed inside a tank. A power supply and a display control panel with an alarm are installed outside the tank. During use, the energized contact rod is energized by the tank handle, making contact with the conductive contact plate inside the sensing block. This fixes the sensing block to the surface of the energized contact rod, while the float floats on the liquid surface. When carbon dioxide leaks from the tank, the carbon dioxide level gradually drops, causing the float to fall onto the surface of the sensing block and touch the pressure sensor. The controller then activates the alarm, providing a simple, timely, and highly accurate detection method for detecting leaks or releases within the tank. Furthermore, during the process of draining liquid from the tank, the float and sensing block are connected by the short shaft of the energized contact rod and the conductive contact plate inside the sensing block. The conductive contacts correspond to each other, allowing both the float and the sensing block to slide on the surface of the energized contact rod. This, combined with the liquid discharge from the tank, enables subsequent detection and alarm at any liquid level within the tank, making detection more convenient. Furthermore, multiple floats and sensing blocks are configured with their circuits connected in parallel. This avoids the problem of detection failure due to a malfunction of the pressure sensor in any single sensing block. Simultaneously, when the liquid level in the tank fluctuates, the stationary position of the float causes a change in the length of the resistance wire pulled by the energized conductor, resulting in different brightness levels of the sensing lights. This allows for real-time assessment of the liquid condition within the tank. When the float and sensing block work together to detect and alarm for leaks in the liquid within the tank, interference from tank movement is avoided, improving detection accuracy. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of a liquid level alarm device for fire-fighting tanks proposed in this invention;

[0023] Figure 2 This is a cross-sectional view of a liquid level alarm device for fire-fighting tanks proposed in this invention;

[0024] Figure 3 This is a cross-sectional view of another perspective of the liquid level alarm device for fire tanks proposed in this invention.

[0025] Figure 4 This is a schematic diagram of the meshing transmission component of a liquid level alarm device for fire tanks proposed in this invention;

[0026] Figure 5 This is a schematic diagram of the outer shell structure of a liquid level alarm device for fire tanks proposed in this invention;

[0027] Figure 6 This is a schematic diagram of the structure of a liquid level alarm device for fire tanks according to the present invention when multiple sensing blocks are connected;

[0028] Figure 7 This is a rear-view sectional view of a liquid level alarm device for fire-fighting tanks proposed in this invention.

[0029] Figure 8 This is a top view after cross-section of the sensing block of a liquid level alarm device for fire tanks proposed in this invention;

[0030] Figure 9 This invention proposes a liquid level alarm device for fire-fighting tanks. Figure 8 Enlarged view of point A in the middle;

[0031] Figure 10 This is a circuit connection diagram of a liquid level alarm device for fire-fighting tanks proposed in this invention;

[0032] Figure 11 This is a front view after cross-section of a liquid level alarm device for fire-fighting tanks proposed in this invention;

[0033] Figure 12 This is a circuit diagram of a liquid level alarm device for fire tanks proposed in this invention.

[0034] In the diagram: 1. Tank; 2. Power supply; 3. Display control panel; 301. Power indicator light; 302. Induction indicator light; 4. Annular energized plate; 5. Hollow shaft; 6. Meshing transmission component; 61. Main gear; 62. Driven gear; 63. Outer shell; 7. Energized contact rod; 701. Contact head; 8. Float; 9. Induction block; 10. Energized wire; 11. Connecting rope; 12. Tightening conductive contact piece; 13. Pressure sensor; 14. Spring; 15. Resistance wire reel; 16. Winding shaft; 17. Resistance wire. Detailed Implementation

[0035] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0036] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0037] Currently, conventional liquid level alarm devices are mainly used to warn of liquid level changes, thus determining whether the required liquid level has been reached. However, this method of liquid level alarm cannot provide a warning function when applied to fire-fighting tanks, especially when the liquid level changes due to air leakage within the tank. Conventional liquid level detection methods first record the initial liquid level, then record the liquid level after a leak, and use the change in liquid level, along with the alarm device, to determine if the fire-fighting tank is leaking. This method requires data transmission, and the material of the tank itself can affect data transmission, thus affecting the accuracy of the detection. Furthermore, the swaying of the liquid level within the tank can also affect the detection results. Therefore, existing liquid level alarm devices are not very effective and have low accuracy in detecting leaks in fire-fighting tanks.

[0038] Reference Figures 1-4 A liquid level alarm device for fire-fighting tanks includes: a power supply 2, hollow shafts 5, an annular energized plate 4, and a float 8, all installed on the tank body 1. The power supply 2 is fixedly installed on the top side of the tank body 1 and is rechargeable. A display control panel 3 is electrically connected to the top of the power supply 2, providing power to the display control panel 3. The display control panel 3 contains a controller and an alarm, which can provide both voice and visual alarms. Three hollow shafts 5 are arranged in a circular array and rotatably installed inside the tank body 1. The hollow shafts 5 can rotate vertically inside the tank body 1. An elliptical energized contact rod 7 is fixedly sleeved on the outer side of the hollow shafts 5. Engaging transmission components 6 connect the tops of the multiple hollow shafts 5 to the control handle of the tank body 1. An annular energizing plate 4 is fixedly installed at the top center of the tank 1. One end of the annular energizing plate 4 is electrically connected to the power supply 2, and the other end passes through the tank 1 and is electrically connected to multiple energizing contact rods 7, so that the power supply 2 supplies power to the energizing contact rods 7 through the annular energizing plate 4 and the hollow shaft 5. There are three floats 8, which are slidably sleeved on the outside of the three energizing contact rods 7. According to the height of the liquid level, the floats 8 slide on the energizing contact rods 7. Each float 8 is connected to a sensing block 9 sleeved on the outside of the energizing contact rod 7. The sensing block 9 is annular, and two symmetrically arranged on the inner annular surface of the sensing block 9 are electrically connected to and clamp the two ends of the energizing contact rod 7. The conductive contact plate 12 is pressed against the electric contact rod 7. During detection, the sensing block 9 is clamped to the energized contact rod 7 and energized. When not detecting, the sensing block 9 slides on the energized contact rod 7 and is de-energized. Each sensing block 9 has a pressure sensor 13 that is electrically connected to the conductive contact plate 12 on its upper surface. When the float 8 contacts the upper surface of the sensing block 9, it will touch the pressure sensor 13, thereby triggering a detection alarm. An energized wire 10 is connected between two adjacent sensing blocks 9. The energized wire 10 can prevent multiple sensing blocks 9 from rotating with each energized contact rod 7. The controller is electrically connected to the alarm and the pressure sensor 13.

[0039] Reference Figures 4-5The meshing transmission component 6 includes a main gear 61 fixedly installed on the top of the infusion pipe of the tank body 1 and a driven gear 62 fixedly sleeved on the outside of multiple hollow shafts 5. The main gear 61 meshes with the multiple driven gears 62 and are the same size, so that when the main gear 61 rotates, the driven gears 62 rotate synchronously and at the same speed. The main gear 61 and the multiple driven gears 62 are also covered by a shell 63 fixed to the top wall of the tank body 1 to protect the internal gears. When using the tank body 1, the infusion pipe is rotated first, and then the liquid is sprayed.

[0040] The inner ring diameter of the sensing block 9, the inner diameter of the float 8, and the long axis of the energized contact rod 7 are all the same, so as to ensure that the sensing block 9 and the float 8 can slide on the energized contact rod 7.

[0041] Reference Figure 6 Connecting ropes 11 are connected to both ends of the bottom of the float 8 and both ends of the top surface of the sensing block 9, so that the float 8 slides up and down with the sensing block 9. The buoyancy of the float 8 in the tank 1 is greater than the sum of the weights of the float 8 and the sensing block 9 in the solution in the tank 1, so that the float 8 is always on the liquid surface. When the float 8 is always on the liquid surface, the sensing block 9 sinks into the liquid surface, so that the sensing block 9 and the float 8 are at the same height within the connecting rope 11. Thus, after the sensing block 9 is fixed, the liquid level drops slightly, and the float 8 begins to fall freely onto the sensing block 9 to realize the sensing alarm.

[0042] Reference Figures 6-10 The long shaft of the energized contact rod 7 is provided with contact heads 701 for conducting electricity at both ends. The contact heads 701 at both ends of the energized contact rod 7 rotate with the hollow shaft 5 and contact the two clamping conductive contact pieces 12, so that the power supply 2 supplies power to the whole circuit. The clamping conductive contact piece 12 is slidably disposed in the inner ring of the sensing block 9. Both sides of the end of the clamping conductive contact piece 12 located inside the sensing block 9 have protrusions extending outward, so that the clamping conductive contact piece 12 is partially stuck inside the sensing block 9. A rebound member is provided between the end of the clamping conductive contact piece 12 located inside the sensing block 9 and the inner wall of the outer ring of the sensing block 9, so that the clamping conductive contact piece 12 can rebound and return to its original state after being squeezed by the contact head 701. The rebound component includes a spring 14 and a guide post. The guide post is perpendicular to the clamping conductive contact 12 and fixed to the inner wall of the outer ring of the sensing block 9. The spring 14 is sleeved on the outside of the guide post, which guides the spring 14, causing it to be compressed and rebound on the guide post. Both ends of the spring 14 abut against the surface of the clamping conductive contact 12 and the inner wall of the sensing block 9, respectively. Figure 9 As shown, the protrusions at both ends of the conductive contact 12 are in the energized part, while the part connected to the spring 14 is not energized. The two protrusions are respectively connected to the pressure sensor 13, the energized wire 10, or the resistance wire 17.

[0043] Reference Figures 9-10Inside the sensing block 9, on one side of one of the rebounding elements, there is a resistance wire reel 15. Inside the resistance wire reel 15, there is a winding shaft 16. A resistance wire 17 is wound on the winding shaft 16. One end of the resistance wire 17 passes through the resistance wire reel 15 and is connected to the energized wire 10. The other end of the resistance wire 17 is connected to the clamping conductive contact 12 via the winding shaft 16. At the same time, the clamping conductive contact 12 connected to the resistance wire reel 15 is also connected to the pressure sensor 13, so that the resistance wire 17, the energized wire 10, and the pressure sensor 13 in one resistance wire reel 15 form a series circuit.

[0044] Reference Figures 10-12 The surface of the display control panel 3 is equipped with a power indicator 301 electrically connected to the power supply 2 and multiple sensing indicator lights 302 respectively connected to multiple energized wires 10. The controller within the display control panel 3 is also electrically connected to the multiple sensing indicator lights 302, so that the power indicator 301 indicates whether the entire circuit is energized, while each sensing indicator light 302 only detects the status of its respective series circuit, and changes accordingly when the resistance wire 17 changes. Simultaneously, the sensing indicator lights 302 can also detect and display whether their respective series circuits are energized. Figure 12 The power switch is formed by the contact head 701 of the power-on contact rod 7 contacting the conductive contact piece 12. When the contact head 701 of the power-on contact rod 7 contacts the conductive contact piece 12, the power switch is energized, that is, the entire circuit is energized.

[0045] Working principle: Refer to Figures 1-12 When the tank 1 is placed, the contact head 701 of the energized contact rod 7 contacts the clamping conductive contact piece 12 inside the sensing block 9. Power is supplied to the clamping conductive contact piece 12 by the power source 2 through the annular energized plate 4, the hollow shaft 5, and the energized contact rod 7. At the same time, the contact head 701 squeezes the clamping conductive contact piece 12, which compresses the spring 14. Under the rebound of the spring 14, the clamping conductive contact piece 12 is pressed tightly against the contact head 701, fixing the sensing block 9 to the energized contact rod 7. At the same time, multiple pressure sensors 13 are all energized. Each energized wire 10 is connected to a resistance wire 17 and a sensing change lamp 302 to form a parallel circuit. The sensing change lamp 302 senses the change in the length of the resistance wire 17 and transmits it to the controller in the display control panel 3.

[0046] When tank 1 is in a static state, the liquid surface inside tank 1 is calm, the multiple floats 8 are at the same height, and the lengths of the energized wires 10 and resistance wires 17 between two adjacent floats 8 remain unchanged, so that the brightness of the multiple sensing lights 302 does not change. If the liquid inside tank 1 begins to drop, the floats 8 will slowly drop with the liquid surface until the floats 8 contact the fixed sensing block 9 and touch the pressure sensor 13 inside the sensing block 9. After the controller receives the signal from the pressure sensor 13, the alarm in the control panel 3 will start to sound, indicating that tank 1 is in a state of leakage or venting.

[0047] If the tank 1 is shaking, the liquid level inside the tank 1 will fluctuate. Multiple floats 8 will follow the fluctuations of the liquid level. Since the sensing block 9 is fixedly attached to the energized contact rod 7, and the floats 8 are in contact with the sensing block 9 via the connecting rope 11, the fluctuating liquid level will cause the floats 8 to be in a normal state due to being stretched and pulled when the liquid level is higher than the floats 8. When the liquid level is lower than the floats 8, the floats 8 will begin to descend, and the distance between two adjacent floats 8 will increase. The energized wire 10 will start to pull the resistance wire 17 in the resistance wire reel 15 to start to release the wire. The length of the resistance wire 17 extending out of the resistance wire reel 15 will increase, resulting in an increase in the resistance in the entire circuit. This will cause the sensing light 302 in the circuit to dim. The controller will receive the brightness change data of the sensing light 302. If the float 8 touches the pressure sensor 13 at this time, the controller will no longer alarm until the sensing light 302 returns to its initial state and remains constant. Then the controller will detect the pressure sensor 13 again.

[0048] When tank 1 is put into use, the infusion tube of tank 1 is rotated. The infusion tube rotates 90°, and the hollow shaft 5 is rotated 90° by the main gear 61 and the driven gear 62. The hollow shaft 5 drives the energized contact rod 7 to rotate 90°. The short shaft of the energized contact rod 7 begins to align with the top conductive contact piece 12, so that the energized contact rod 7 is no longer clamped to the sensing block 9. That is, the internal components of the sensing block 9 are de-energized. At this time, tank 1 is used, and the liquid level continues to drop. The float 8 and the sensing block 9 also drop with the liquid level until the use ends and the tank is placed back in its place. The alarm device continues to monitor.

[0049] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A liquid level alarm device for fire-fighting tanks, characterized in that, Including those installed on the tank (1): Power supply (2), the power supply (2) is fixedly installed on the top side of the tank (1), and the top of the power supply (2) is electrically connected to a display control panel (3), which is equipped with a controller and an alarm. Hollow shaft (5), three hollow shafts (5) are provided and rotated inside the tank body (1) in a ring array. An elliptical power contact rod (7) is fixedly sleeved on the outside of the hollow shaft (5). A meshing transmission component (6) is connected between the top of the multiple hollow shafts (5) and the control handle of the tank body (1). The annular energizing plate (4) is fixedly installed in the middle of the top of the tank (1). One end of the annular energizing plate (4) is electrically connected to the power supply (2), and the other end passes through the tank (1) and is electrically connected to multiple energizing contact rods (7). The float (8) has three floats that are slidably fitted on the outside of three energized contact rods (7). Each float (8) has a sensing block (9) fitted on the outside of the energized contact rod (7) below it. The sensing block (9) is ring-shaped. Two clamping conductive contact pieces (12) are symmetrically arranged on the inner ring surface of the sensing block (9) and are electrically connected to both ends of the energized contact rod (7) and clamp the energized contact rod (7). Each sensing block (9) has a pressure sensor (13) that is electrically connected to the clamping conductive contact piece (12) on its upper surface. An energized wire (10) is connected between two adjacent sensing blocks (9). The controller is electrically connected to the alarm and the pressure sensor (13).

2. The liquid level alarm device for fire-fighting tanks according to claim 1, characterized in that, The meshing transmission component (6) includes a main gear (61) fixedly installed on the top of the infusion pipe of the tank (1) and a driven gear (62) fixedly sleeved on the outside of multiple hollow shafts (5). The main gear (61) meshes with multiple driven gears (62) and is the same size. The outer side of the main gear (61) and multiple driven gears (62) is also covered by a shell (63) fixed to the top wall of the tank (1).

3. The liquid level alarm device for fire-fighting tanks according to claim 1, characterized in that, The inner ring diameter of the sensing block (9), the inner diameter of the float (8), and the long axis of the energized contact rod (7) are all the same.

4. A liquid level alarm device for fire-fighting tanks according to claim 1, characterized in that, The bottom ends of the float (8) are connected to the top ends of the sensing block (9) by connecting ropes (11), and the buoyancy of the float (8) in the tank (1) is greater than the sum of the weights of the float (8) and the sensing block (9) in the solution in the tank (1), so that the float (8) is always on the liquid surface.

5. A liquid level alarm device for fire-fighting tanks according to claim 1, characterized in that, The long shaft of the energized contact rod (7) is provided with contact heads (701) for conducting electricity at both ends, and the contact heads (701) at both ends of the energized contact rod (7) rotate with the hollow shaft (5) and contact the two pressing conductive contact pieces (12).

6. A liquid level alarm device for fire-fighting tanks according to claim 5, characterized in that, The clamping conductive contact (12) is slidably disposed in the inner ring of the sensing block (9). Both sides of the clamping conductive contact (12) located inside the sensing block (9) have protrusions extending outward. A rebound member is provided between the end of the clamping conductive contact (12) located inside the sensing block (9) and the inner wall of the outer ring of the sensing block (9).

7. A liquid level alarm device for fire-fighting tanks according to claim 6, characterized in that, The rebound component includes a spring (14) and a guide post, wherein the guide post is perpendicular to the clamping conductive contact (12) and fixed on the inner wall of the outer ring of the sensing block (9), the spring (14) is sleeved on the outside of the guide post, and the two ends of the spring (14) abut against the surface of the clamping conductive contact (12) and the inner wall of the sensing block (9), respectively.

8. A liquid level alarm device for fire-fighting tanks according to claim 6, characterized in that, The sensing block (9) has a resistance wire coil (15) inside one of the rebound components. The resistance wire coil (15) has a winding shaft (16) inside. A resistance wire (17) is wound on the winding shaft (16). One end of the resistance wire (17) passes through the resistance wire coil (15) and is connected to the current-carrying wire (10). The other end of the resistance wire (17) is connected to the top conductive contact (12) via the winding shaft (16).

9. A liquid level alarm device for fire-fighting tanks according to claim 8, characterized in that, The surface of the display control panel (3) is provided with a power indicator light (301) electrically connected to the power supply (2) and a sensor light (302) respectively connected to multiple power-conducting wires (10).

10. A liquid level alarm device for fire-fighting tanks according to claim 9, characterized in that, The controller within the display control panel (3) is also electrically connected to multiple sensor-activated changing lights (302).

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