Liquid nitrogen fire extinguishing device and method for dangerous cargo container

Abstract

The invention relates to the technical field of liquid nitrogen fire extinguishing, and discloses a dangerous cargo container liquid nitrogen fire extinguishing device and method.The dangerous cargo container liquid nitrogen fire extinguishing device comprises a movable base, a nitrogen storage tank and a gas storage tank are fixedly connected to the top of the movable base, and the dangerous cargo container liquid nitrogen fire extinguishing device further comprises a bearing frame fixedly connected to the top of the movable base; a negative pressure suction cup is inserted into the top of the bearing frame, a nitrogen supply pipe is fixed to and communicates with the top of the nitrogen storage tank, and a forcible entry part for opening a hole in the container is arranged on the negative pressure suction cup. Firstly, the outer wall of the container is cooled through liquid nitrogen to enable the container to be in a brittle state, then through rotation and extrusion of the drill bit, the container can be rapidly tapped, the tapping difficulty and the tapping time are effectively reduced, the fire extinguishing timeliness is improved, harmful substances in the container are effectively prevented from leaking, and the service life of the container is prolonged. And meanwhile, external air is prevented from being supplemented into the container, and the fire extinguishing efficiency and the fire extinguishing safety are effectively improved.

Description

Technical Field

[0001] This invention relates to the field of liquid nitrogen fire extinguishing technology, specifically to a liquid nitrogen fire extinguishing device and method for dangerous goods containers. Background Technology

[0002] Port dangerous goods container yards are key nodes in logistics hubs. These dangerous goods include, but are not limited to, flammable liquids, gases, oxidizers, and toxic substances. They pose potential safety hazards during storage. Once a fire occurs, it can not only cause huge property damage but also seriously threaten the lives of people. Traditional fire extinguishing methods, such as water-based fire extinguishing, foam fire extinguishing, and dry powder fire extinguishing, have obvious limitations when dealing with specific types of dangerous goods. They are often unable to quickly control the fire, especially in large container yards, where a rapidly spreading fire can lead to catastrophic consequences.

[0003] In recent years, liquid nitrogen has received widespread attention as a new type of fire extinguishing medium. Liquid nitrogen has an extremely low temperature, which can quickly absorb heat and reduce the temperature of the combustion zone. At the same time, the nitrogen gas formed after its vaporization can dilute the oxygen concentration and suffocate the flames. More importantly, liquid nitrogen is non-toxic and non-corrosive, and will not cause secondary pollution to the environment, making it suitable for extinguishing fires involving dangerous goods.

[0004] Currently, when extinguishing fires in dangerous goods containers, it is usually necessary to open the container. This causes harmful substances produced by the fire to leak out, which not only pollutes the surrounding environment but also threatens the safety of firefighters. In addition, outside air continuously enters the container, providing a constant supply of oxygen, making it difficult to extinguish the fire quickly and greatly reducing the efficiency of firefighting. Therefore, a liquid nitrogen fire extinguishing device for dangerous goods containers is proposed. Summary of the Invention

[0005] This invention provides a liquid nitrogen fire extinguishing device and method for dangerous goods containers. Liquid nitrogen cools the outer wall of the container, making it brittle. Then, through the rotation and compression of a drill bit, a hole can be quickly opened in the container, effectively preventing the leakage of harmful substances from inside the container and also preventing outside air from entering the container. This solves the problems mentioned in the background art, such as the leakage of harmful substances after opening the container door for fire extinguishing, causing environmental pollution and threatening the safety of firefighters, and the continuous entry of air into the container, making it difficult to extinguish the fire quickly.

[0006] This invention provides the following technical solution:

[0007] A liquid nitrogen fire extinguishing device for dangerous goods containers includes a mobile base, with a nitrogen storage tank and a gas storage tank fixedly connected to the top of the mobile base. It also includes a support frame fixedly connected to the top of the mobile base, with a negative pressure suction cup inserted into the top of the support frame. The top of the nitrogen storage tank is fixedly connected to a nitrogen supply pipe, the other end of which is connected to the inner cavity of the negative pressure suction cup. The negative pressure suction cup has a breaching part for opening holes in the container. A piston box is also included, with a positioning ring fixedly connected to the side wall of the negative pressure suction cup. The piston box is fixedly connected to the top of the positioning ring, and a pressure chamber is fixedly connected to the side wall of the negative pressure suction cup. The piston box has a gas guide part for filling the negative pressure suction cup with carbon dioxide gas stored in the gas storage tank.

[0008] In a preferred embodiment of the present invention, the demolition part includes a drill rod rotatably connected to a negative pressure suction cup. A drill bit is fixedly connected to the end of the drill rod located in the negative pressure suction cup. The other end of the drill rod passes through the center of the positioning ring and extends into the air pressure chamber. A limiting post is fixedly connected to the side wall of the drill rod. A limiting sleeve is slidably fitted onto the drill rod. The limiting post is inserted into the limiting sleeve and the two are slidably connected. The limiting sleeve is in contact with the side wall of the positioning ring. A drive motor is fixedly connected to the side wall of the negative pressure suction cup. A drive wheel is fixedly connected to the output shaft of the drive motor. The drive wheel and the limiting sleeve are connected by a belt drive.

[0009] As a preferred embodiment of the present invention, the air guide includes a piston plate, which is slidably connected to a piston box. A lifting rod is rotatably connected to the top of the piston plate, and the other end of the lifting rod is rotatably connected to the side wall of the drive wheel. The drill rod is rotatably connected to the air pressure chamber, and an air pressure plate is fixedly connected to the end of the drill rod located in the air pressure chamber. An exhaust pipe is fixed and connected to the side wall of the piston box, and the other end of the exhaust pipe is connected to the inner cavity of the air pressure chamber. A one-way valve is provided in the exhaust pipe.

[0010] As a preferred embodiment of the present invention, two sets of gas storage tanks are symmetrically arranged along the center of the movable seat. The top of each set of gas storage tanks is fixed and connected to a gas supply pipe. The other end of the gas supply pipe is connected to the top of the inner cavity of the piston box, and a one-way valve is provided in the gas supply pipe.

[0011] As a preferred embodiment of the present invention, the bottom of the air pressure chamber is fixed and connected to a mixing pipe, and the connection ports of the mixing pipe and the exhaust pipe are respectively located at both ends of the inner cavity of the air pressure chamber. The other end of the mixing pipe is connected to the inner cavity of the negative pressure suction cup, and a one-way valve is provided inside the mixing pipe.

[0012] As a preferred embodiment of the present invention, the drill rod has multiple sets of receiving grooves circumferentially formed on the outer wall of the side near the drill bit. Each set of receiving grooves is rotatably connected to a fan blade. The drill rod has a limiting groove, and a limiting guide rod is slidably connected in the limiting groove. One end of the limiting guide rod passes through the air pressure chamber and is fixedly connected to its inner wall. A magnetic sleeve is fixedly connected to the end of the limiting guide rod near the drill bit. The magnetic sleeve is magnetically attracted to the side wall of the fan blade.

[0013] As a preferred embodiment of the present invention, a limiting block is fixedly connected to the bottom of each set of storage slots, and a sealing ring is fixedly connected to the outer wall of the limiting guide rod, and the sealing ring slides in contact with the inner wall of the limiting groove.

[0014] As a preferred embodiment of the present invention, the diameter of the rear end of the drill bit is larger than the diameter of the drill rod, that is, the drill bit will penetrate the container side wall which has become brittle due to being cooled by liquid nitrogen through rotation and thrust. After the drill bit has completely passed the container side wall, the drill rod will enter the container and the inner cavity of the negative pressure suction cup will communicate with the inner cavity of the container.

[0015] As a preferred embodiment of the present invention, a negative pressure pump is fixedly connected to the side wall of the negative pressure suction cup, a negative pressure suction groove is formed in the inner wall of the negative pressure suction cup, and the negative pressure end of the negative pressure pump is connected to the inner cavity of the negative pressure suction groove.

[0016] A method for extinguishing a fire in a dangerous goods container using liquid nitrogen, comprising the following steps:

[0017] Step 1: Secure the negative pressure suction cup to the outer wall of the container;

[0018] Step 2: Cool and freeze the outer wall of the container with liquid nitrogen to make it brittle;

[0019] Step 3: Drill holes in the outer wall of the container inside the negative pressure suction cup;

[0020] Step 4: Fill the container with a mixture of liquid nitrogen and carbon dioxide to extinguish the fire.

[0021] Compared with the prior art, the present invention provides a liquid nitrogen fire extinguishing device and method for dangerous goods containers, which has the following beneficial effects:

[0022] 1. This liquid nitrogen fire extinguishing device for dangerous goods containers first cools the outer wall of the container with liquid nitrogen, making it brittle. Then, through the rotation and extrusion of the drill bit, it can quickly open a hole in the container, effectively reducing the difficulty and time required for opening the hole, improving the timeliness of fire extinguishing, and thus effectively preventing the leakage of harmful substances inside the container, while also preventing outside air from entering the container, effectively improving the fire extinguishing efficiency and safety.

[0023] 2. This liquid nitrogen fire extinguishing device for dangerous goods containers, when driven by a rotating wheel, coordinates with a lifting rod to move a piston plate up and down within a piston box. First, carbon dioxide gas from the gas tank is drawn into the piston box, and then the gas is continuously injected into the pressure chamber. This firstly creates a continuous forward thrust on the drill rod, ensuring the smooth completion of drilling. Secondly, after the pressure plate passes over the mixing pipe, the carbon dioxide gas pushes the liquid nitrogen into the container, effectively reducing the oxygen content in the combustion zone, providing a stronger asphyxiation extinguishing effect, and further improving the fire extinguishing efficiency.

[0024] 3. This liquid nitrogen fire extinguishing device for dangerous goods containers utilizes the magnetic interaction between the magnetic sleeve and the drill rod. After the drill rod is inserted into the container, the magnetic sleeve and the fan blades will separate from the repulsive area. Under the centrifugal force of the rotating drill rod, the fan blades will be thrown out of the receiving slot. At this time, the fan blades will rotate rapidly with the drill rod, thereby pushing the nitrogen and carbon dioxide gas that have entered the container from the negative pressure suction cup to a larger area, realizing the rapid expansion of the extinguishing gas and thus improving the fire extinguishing efficiency. Attached Figure Description

[0025] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, the elements or parts are not necessarily drawn to actual scale.

[0026] Figure 1 This is a schematic diagram of the overall structure of the present invention. Figure 1 ;

[0027] Figure 2 This is a schematic diagram of the overall structure of the present invention. Figure 2 ;

[0028] Figure 3 This is a partially enlarged structural schematic diagram of the present invention;

[0029] Figure 4 This is a partial cross-sectional structural diagram of the present invention;

[0030] Figure 5 For the present invention Figure 4 Enlarged structural diagram of region A in the middle;

[0031] Figure 6 For the present invention Figure 4 Enlarged structural diagram of region B in the middle;

[0032] Figure 7 This is a partially enlarged structural diagram of the drill bit of the present invention;

[0033] Figure 8 This is a partially enlarged schematic diagram of the limiting sleeve structure of the present invention.

[0034] In the diagram: 1. Movable seat; 2. Nitrogen storage tank; 21. Gas storage tank; 22. Nitrogen supply pipe; 3. Support frame; 31. Negative pressure suction cup; 311. Negative pressure pump; 312. Negative pressure suction groove; 32. Air pressure chamber; 4. Piston box; 41. Positioning ring; 42. Piston plate; 43. Lifting rod; 44. Exhaust pipe; 45. Gas supply pipe; 46. Mixing pipe; 5. Drill rod; 51. Drill bit; 52. Limiting post; 53. Limiting sleeve; 54. Drive motor; 541. Drive wheel; 55. Air pressure plate; 6. Storage slot; 61. Fan blade; 62. Limiting groove; 63. Limiting guide rod; 631. Sealing ring; 64. Magnetic sleeve; 65. Limiting block. Detailed Implementation

[0035] The technical solutions of the embodiments 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. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Example 1:

[0037] Reference Figures 1-8 A liquid nitrogen fire extinguishing device for dangerous goods containers includes a mobile base 1, with a nitrogen storage tank 2 and a gas storage tank 21 fixedly connected to the top of the mobile base 1. The nitrogen storage tank 2 is a non-self-pressurized liquid nitrogen tank to achieve automatic discharge of liquid nitrogen. The gas storage tank 21 is filled with carbon dioxide gas. The device also includes a support frame 3, which is fixedly connected to the top of the mobile base 1 and has a negative pressure suction cup 31 inserted into its top. A nitrogen supply pipe 22 is fixedly connected to the top of the nitrogen storage tank 2 and the other end of the nitrogen supply pipe 22 is connected to the inner cavity of the negative pressure suction cup 31. The negative pressure suction cup 31 is provided with a breaking part for opening the container. A piston box 4 is provided with a positioning ring 41 fixedly connected to the side wall of the negative pressure suction cup 31 and a pressure chamber 32 fixedly connected to the side wall of the negative pressure suction cup 31. The piston box 4 is provided with a gas guide part for filling the negative pressure suction cup 31 with carbon dioxide gas stored in the gas storage tank 21.

[0038] Reference Figure 2 , Figure 4 A negative pressure pump 311 is fixedly connected to the side wall of the negative pressure suction cup 31. A negative pressure suction groove 312 is opened in the inner wall of the negative pressure suction cup 31. The negative pressure end of the negative pressure pump 311 is connected to the inner cavity of the negative pressure suction groove 312.

[0039] With the above-described structure, the negative pressure suction cup 31 is attached to the outer wall of the container. Then, the negative pressure pump 311 is turned on to expel the gas in the negative pressure suction groove 312. By using air pressure, the negative pressure suction cup 31 is fixed to the outer wall of the container. Subsequently, liquid nitrogen is supplied to the negative pressure suction cup 31 through the nitrogen storage tank 2. When the liquid nitrogen enters the negative pressure suction cup 31, the side wall of the container is rapidly cooled and turns into a brittle state. At the same time, when the liquid nitrogen rapidly cools the surface of the container, it causes the surface to shrink faster than the interior, thereby generating significant stress. This uneven cooling process causes micro-cracks to form on the surface of the container, thereby further reducing the strength of the metal, so that the container can be opened later.

[0040] Reference Figures 2-4 The demolition section includes a drill rod 5, which is rotatably connected to a negative pressure suction cup 31. A drill bit 51 is fixedly connected to the end of the drill rod 5 located in the negative pressure suction cup 31. The other end of the drill rod 5 passes through the center of the positioning ring 41 and extends into the air pressure chamber 32. A limit post 52 is fixedly connected to the side wall of the drill rod 5. A limit sleeve 53 is slidably sleeved on the drill rod 5. The limit post 52 is inserted into the limit sleeve 53 and the two are slidably connected. The limit sleeve 53 fits against the side wall of the positioning ring 41. A drive motor 54 is fixedly connected to the side wall of the negative pressure suction cup 31. A drive wheel 541 is fixedly connected to the output shaft of the drive motor 54. The drive wheel 541 and the limit sleeve 53 are connected by a belt drive. The air guide section includes a piston plate 42. Piston plate 42 is slidably connected inside piston box 4. Lifting rod 43 is rotatably connected to the top of piston plate 42. The other end of lifting rod 43 is rotatably connected to the side wall of drive wheel 541. Drill rod 5 is rotatably connected to air pressure chamber 32. Air pressure plate 55 is fixedly connected to the end of drill rod 5 located inside air pressure chamber 32. Exhaust pipe 44 is fixed and connected to the side wall of piston box 4. The other end of exhaust pipe 44 is connected to the inner cavity of air pressure chamber 32. One-way valve is installed in exhaust pipe 44. Two sets of air storage tanks 21 are symmetrically arranged along the center of movable seat 1. The top of each set of air storage tanks 21 is fixed and connected to air supply pipe 45. The other end of air supply pipe 45 is connected to the top of the inner cavity of piston box 4. One-way valve is installed in air supply pipe 45.

[0041] It should be noted that the one-way valve in the exhaust pipe 44 can only allow carbon dioxide gas in the piston box 4 to enter the pressure chamber 32; the one-way valve in the air supply pipe 45 can only allow carbon dioxide gas in the air storage tank 21 to enter the piston box 4.

[0042] With the above-described structure, when the drive motor 54 is turned on, the transmission connection between the drive wheel 541 and the limiting sleeve 53, along with the limiting effect of the positioning ring 41, causes the limiting sleeve 53 to drive the drill rod 5 and drill bit 51 to rotate. Simultaneously, as the drive wheel 541 rotates, the lifting rod 43 causes the piston plate 42 to reciprocate within the piston box 4. During the downward movement of the piston plate 42, the gas within the piston box 4 is compressed, and the one-way valve in the exhaust pipe 44 is opened, allowing the compressed gas to enter the pressure chamber 32 along the exhaust pipe 44, thereby increasing the pressure within the pressure chamber 32. The pressure plate 55 and drill rod 5 are pushed to move towards the side of the container sidewall. As the piston plate 42 moves upward, a negative pressure is generated in the piston box 4, which opens the one-way valve in the air supply pipe 45, allowing the carbon dioxide gas filled in the air tank 21 to be drawn into the piston box 4. This process is repeated, which will continuously increase the air pressure in the air chamber 32. Finally, under the dual action of the rotation of the drill bit 51 and the squeezing of the pressure plate 55, a hole is drilled in the brittle-treated container sidewall. This effectively reduces the difficulty of drilling and the time required for drilling, and enables subsequent fire extinguishing operations to be carried out quickly, improving the timeliness of fire extinguishing. Once drill bit 51 penetrates the cooled and brittle side wall of the container and fully enters the container, the inner cavity of negative pressure suction cup 31 will connect with the container's inner cavity. At this point, liquid nitrogen within negative pressure suction cup 31 will enter the container. Utilizing the vaporization of liquid nitrogen, it will rapidly absorb heat from inside the container and release a large amount of nitrogen gas, thereby diluting the oxygen concentration inside the container and creating a relatively oxygen-deficient environment. This will inhibit the combustion process and extinguish the fire. Furthermore, as mentioned above, this effectively prevents the leakage of hazardous substances from inside the container and also prevents outside air from entering the container, effectively improving fire extinguishing efficiency and safety.

[0043] In addition, during drilling, the negative pressure suction cup 31 needs to be supported (either manually or by other mechanical equipment) to ensure the support force required for drilling, so that drilling can be carried out smoothly.

[0044] In addition, due to the cooling effect of liquid nitrogen, the container sidewalls become brittle, and the drill bit 51 is effectively cooled down. This significantly reduces the possibility of sparks generated by drilling friction. Furthermore, since liquid nitrogen fills the drilling area, it effectively isolates oxygen from contact with flammable materials, further reducing the possibility of sparks. This effectively improves the safety of drilling fire extinguishing.

[0045] See also Figure 4 The setting of the limiting pin 52 and the limiting sleeve 53 can ensure that the limiting sleeve 53 can rotate with the drill rod 5 while also sliding forward along the limiting sleeve 53, thereby generating a dual force of rotation and extrusion at the drill bit 51.

[0046] Reference Figure 3 , Figure 4 The bottom of the air pressure chamber 32 is fixed and connected to a mixing pipe 46. The connection ports of the mixing pipe 46 and the exhaust pipe 44 are located at both ends of the inner cavity of the air pressure chamber 32. The other end of the mixing pipe 46 is connected to the inner cavity of the negative pressure suction cup 31, and a one-way valve is installed inside the mixing pipe 46.

[0047] It should be noted that the one-way valve in the mixing tube 46 can only allow carbon dioxide gas in the pressure chamber 32 to enter the negative pressure suction cup 31.

[0048] With the above-described structure, when the pressure plate 55 passes the connection port of the mixing pipe 46, that is, when the pressure plate 55 is pushed to the other side of the pressure chamber 32, the carbon dioxide gas subsequently injected into the pressure chamber 32 will open the one-way valve in the mixing pipe 46, allowing the carbon dioxide gas to be injected into the negative pressure suction cup 31 along the mixing pipe 46. This firstly increases the spraying speed of liquid nitrogen into the container, and secondly, the carbon dioxide can mix with the nitrogen gas and enter the container together, which can more effectively reduce the oxygen content in the combustion area, provide a stronger suffocation fire extinguishing effect, and thus improve the fire extinguishing efficiency.

[0049] Reference Figure 4 , Figure 6 and Figure 7 Multiple sets of storage slots 6 are annularly formed on the outer wall of the drill rod 5 near the drill bit 51. Each set of storage slots 6 contains a fan blade 61 rotatably connected to it. A limiting groove 62 is formed inside the drill rod 5, within which a limiting guide rod 63 is slidably connected. One end of the limiting guide rod 63 penetrates into the air pressure chamber 32 and is fixedly connected to its inner wall. A magnetic sleeve 64 is fixedly connected to the end of the limiting guide rod 63 near the drill bit 51. The magnetic sleeve 64 is magnetically attracted to the side wall of the fan blade 61. Each set of storage slots... The bottom of each of the 6 is fixedly connected to a limiting block 65, and a sealing ring 631 is fixedly connected to the outer wall of the limiting guide rod 63. The sealing ring 631 slides in contact with the inner wall of the limiting slide groove 62. The rear end diameter of the drill bit 51 is larger than the diameter of the drill rod 5. That is, the drill bit 51 will penetrate the container side wall that has become brittle due to cooling by liquid nitrogen through rotation and thrust. When the drill bit 51 has completely passed the container side wall, the drill rod 5 will enter the container. At this time, the inner cavity of the negative pressure suction cup 31 will communicate with the inner cavity of the container.

[0050] With the above structure, as the drill rod 5 extends into the container, the limiting groove 62 inside the drill rod 5 will gradually move along the limiting guide rod 63. At this time, the magnetic sleeve 64 will gradually leave the area where it is magnetically attracted to the fan blade 61. When the front end of the drill rod 5 is fully inserted into the container, the magnetic sleeve 64 and the fan blade 61 will completely separate from the magnetic attraction area. At this time, under the centrifugal force generated by the rotation of the drill rod 5, the fan blade 61 will be thrown out of the receiving groove 6. At this time, the multiple sets of fan blades 61 will rotate rapidly with the drill rod 5, thereby pushing the nitrogen and carbon dioxide gas that enter the container from the negative pressure suction cup 31 to a larger area, realizing the rapid expansion of the extinguishing gas, and thus improving the extinguishing efficiency.

[0051] Example 2:

[0052] Reference Figures 1-8 Similar to Example 1, but based on Example 1, a method for extinguishing fires in dangerous goods containers using liquid nitrogen is proposed, with the following steps:

[0053] Step 1: Fix the negative pressure suction cup 31 to the outer wall of the container;

[0054] Step 2: Cool and freeze the outer wall of the container with liquid nitrogen to make it brittle;

[0055] Step 3: Drill holes in the outer wall of the container inside the negative pressure suction cup 31;

[0056] Step 4: Fill the container with a mixture of liquid nitrogen and carbon dioxide to extinguish the fire.

[0057] Reference Figures 1-8In this invention, during use, the movable seat 1 is quickly pushed to the container in the port yard where the fire has occurred, and the negative pressure suction cup 31 is taken out from the support frame 3. Then, the negative pressure suction cup 31 is attached to the outer wall of the container, and the negative pressure pump 311 is turned on to discharge the gas in the negative pressure suction groove 312. In this way, the negative pressure suction cup 31 is fixed to the outer wall of the container by air pressure. Then, liquid nitrogen is delivered into the negative pressure suction cup 31 through the nitrogen storage tank 2. When the liquid nitrogen enters the negative pressure suction cup 31, the side wall of the container will be rapidly cooled and transformed into a brittle state. At the same time, when the liquid nitrogen rapidly cools the surface of the container, it will cause the surface to shrink faster than the inside, thereby generating significant stress. At this time, this uneven cooling process will cause micro-cracks to form on the surface of the container, thereby further reducing the strength of the metal, so that the container can be opened later. Next, the drive motor 54 is turned on. Through the transmission connection between the drive wheel 541 and the limiting sleeve 53, and with the limiting effect of the positioning ring 41, the limiting sleeve 53 drives the drill rod 5 and the drill bit 51 to rotate. At the same time, during the rotation of the drive wheel 541, the piston plate 42 is driven to move up and down in the piston box 4 through the setting of the lifting rod 43. During the downward movement of the piston plate 42, the gas in the piston box 4 is compressed, and the one-way valve in the exhaust pipe 44 is opened, so that the compressed gas enters the air pressure chamber 32 along the exhaust pipe 44, thereby increasing the air pressure in the air pressure chamber 32 and pushing the air pressure plate 55 and the drill rod 5 to move towards the side of the container side wall. Thus, under the dual action of the rotation of the drill bit 51 and the compression of the air pressure plate 55, a hole is drilled in the container side wall after the brittle treatment.

[0058] Once the drill bit 51 penetrates the cooled and brittle side wall of the container and enters the container completely, the inner cavity of the negative pressure suction cup 31 will connect with the inner cavity of the container. At this time, the liquid nitrogen in the negative pressure suction cup 31 will enter the container. Utilizing the vaporization effect of the liquid nitrogen, it will quickly absorb the heat inside the container and release a large amount of nitrogen gas inside the container, thereby diluting the oxygen concentration inside the container and creating a relatively oxygen-deficient environment, thus inhibiting the combustion process and extinguishing the fire. Furthermore, as the piston plate 42 moves upward, a negative pressure is generated within the piston box 4, thereby opening the one-way valve in the air supply pipe 45. This allows the carbon dioxide gas filled in the air tank 21 to be drawn into the piston box 4 and ultimately fills the pressure chamber 32, pushing the drill rod 5 forward. When the pressure plate 55 passes the connection port of the mixing pipe 46, that is, when the pressure plate 55 is pushed to the other side of the pressure chamber 32, the carbon dioxide gas subsequently filled into the pressure chamber 32 will open the one-way valve in the mixing pipe 46, allowing the carbon dioxide gas to fill the negative pressure suction cup 31 along the mixing pipe 46. This firstly increases the spraying speed of liquid nitrogen into the container, and secondly, the carbon dioxide can mix with nitrogen and enter the container together, which can more effectively reduce the oxygen content in the combustion area, providing a stronger suffocation fire extinguishing effect, thereby improving the fire extinguishing efficiency.

[0059] Furthermore, as the drill rod 5 extends into the container, the limiting groove 62 inside the drill rod 5 gradually moves along the limiting guide rod 63. At this time, the magnetic sleeve 64 gradually moves away from the area where it is magnetically attracted to the fan blade 61. When the front end of the drill rod 5 is fully inserted into the container, the magnetic sleeve 64 and the fan blade 61 will completely separate from the magnetic attraction area. At this time, under the centrifugal force generated by the rotation of the drill rod 5, the fan blade 61 will be thrown out of the receiving groove 6. At this time, the multiple sets of fan blades 61 will rotate rapidly with the drill rod 5, thereby pushing the nitrogen and carbon dioxide gas that entered the container from the negative pressure suction cup 31 to a larger area, realizing the rapid expansion of the extinguishing gas and thus improving the extinguishing efficiency.

[0060] Components not described in detail in this article are existing technologies.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A liquid nitrogen fire extinguishing device for dangerous goods containers, comprising a movable base (1), characterized in that, The top of the movable base (1) is fixedly connected to a nitrogen storage tank (2) and a gas storage tank (21), and also includes: A support frame (3) is fixedly connected to the top of the movable seat (1), and a negative pressure suction cup (31) is inserted into the top of the support frame (3). The nitrogen storage tank (2) is fixed at the top and connected to a nitrogen supply pipe (22). The other end of the nitrogen supply pipe (22) is connected to the inner cavity of the negative pressure suction cup (31). The negative pressure suction cup (31) is provided with a breaking part for opening the container. The piston box (4) has a positioning ring (41) fixedly connected to the side wall of the negative pressure suction cup (31), the piston box (4) is fixedly connected to the top of the positioning ring (41), and a pressure chamber (32) is fixedly connected to the side wall of the negative pressure suction cup (31). The piston box (4) is provided with a gas guide section for filling the negative pressure suction cup (31) with carbon dioxide gas stored in the gas storage tank (21).

2. The liquid nitrogen fire extinguishing device for dangerous goods containers according to claim 1, characterized in that, The demolition section includes a drill rod (5), which is rotatably connected to a negative pressure suction cup (31). A drill bit (51) is fixedly connected to the end of the drill rod (5) located in the negative pressure suction cup (31). The other end of the drill rod (5) passes through the center of the positioning ring (41) and extends into the air pressure chamber (32). A limiting post (52) is fixedly connected to the side wall of the drill rod (5). A limiting sleeve (53) is slidably sleeved on the drill rod (5). The limiting post (52) is inserted into the limiting sleeve (53) and the two are slidably connected. The limiting sleeve (53) is in contact with the side wall of the positioning ring (41). A drive motor (54) is fixedly connected to the side wall of the negative pressure suction cup (31). A drive wheel (541) is fixedly connected to the output shaft of the drive motor (54). The drive wheel (541) and the limiting sleeve (53) are connected by belt drive.

3. A liquid nitrogen fire extinguishing device for dangerous goods containers according to claim 2, characterized in that, The air guide section includes a piston plate (42), which is slidably connected to the piston box (4). A lifting rod (43) is rotatably connected to the top of the piston plate (42). The other end of the lifting rod (43) is rotatably connected to the side wall of the drive wheel (541). The drill rod (5) is rotatably connected to the air pressure chamber (32). The end of the drill rod (5) located in the air pressure chamber (32) is fixedly connected to an air pressure plate (55). An exhaust pipe (44) is fixed and connected to the side wall of the piston box (4). The other end of the exhaust pipe (44) is connected to the inner cavity of the air pressure chamber (32). A one-way valve is provided in the exhaust pipe (44).

4. A liquid nitrogen fire extinguishing device for dangerous goods containers according to claim 3, characterized in that, Two sets of gas storage tanks (21) are symmetrically arranged along the center of the movable seat (1). The top of each set of gas storage tanks (21) is fixed and connected to the gas supply pipe (45). The other end of the gas supply pipe (45) is connected to the top of the inner cavity of the piston box (4), and a one-way valve is provided in the gas supply pipe (45).

5. A liquid nitrogen fire extinguishing device for dangerous goods containers according to claim 3, characterized in that, The bottom of the air pressure chamber (32) is fixed and connected to a mixing pipe (46), and the connection ports of the mixing pipe (46) and the exhaust pipe (44) are located at the two ends of the inner cavity of the air pressure chamber (32), the other end of the mixing pipe (46) is connected to the inner cavity of the negative pressure suction cup (31), and a one-way valve is provided in the mixing pipe (46).

6. A liquid nitrogen fire extinguishing device for dangerous goods containers according to claim 2, characterized in that, The drill rod (5) has multiple sets of storage slots (6) arranged in a ring on the outer wall of the side near the drill bit (51). Each set of storage slots (6) is rotatably connected to a fan blade (61). The drill rod (5) has a limiting slide groove (62). A limiting guide rod (63) is slidably connected in the limiting slide groove (62). One end of the limiting guide rod (63) passes through the air pressure chamber (32) and is fixedly connected to its inner wall. A magnetic sleeve (64) is fixedly connected to the end of the limiting guide rod (63) near the drill bit (51). The magnetic sleeve (64) is magnetically attracted to the side wall of the fan blade (61).

7. A liquid nitrogen fire extinguishing device for dangerous goods containers according to claim 6, characterized in that, Each set of storage slots (6) has a fixed limit block (65) at the bottom, and a sealing ring (631) is fixedly connected to the outer wall of the limiting guide rod (63). The sealing ring (631) slides in contact with the inner wall of the limiting groove (62).

8. A liquid nitrogen fire extinguishing device for dangerous goods containers according to claim 2, characterized in that, The diameter of the rear end of the drill bit (51) is larger than the diameter of the drill rod (5), that is: The drill bit (51) will penetrate the container side wall that has become brittle due to being cooled by liquid nitrogen through rotation and thrust. After the drill bit (51) has completely passed the container side wall, the drill rod (5) will enter the container, and the inner cavity of the negative pressure suction cup (31) will be connected to the inner cavity of the container.

9. A liquid nitrogen fire extinguishing device for dangerous goods containers according to claim 1, characterized in that, A negative pressure pump (311) is fixedly connected to the side wall of the negative pressure suction cup (31), and a negative pressure suction groove (312) is opened in the inner wall of the negative pressure suction cup (31). The negative pressure end of the negative pressure pump (311) is connected to the inner cavity of the negative pressure suction groove (312).

10. A method for extinguishing a fire in a dangerous goods container using liquid nitrogen, comprising a liquid nitrogen fire extinguishing device for a dangerous goods container as described in any one of claims 1-9, characterized in that, The steps are as follows: Step 1: Fix the negative pressure suction cup (31) to the outer wall of the container; Step 2: Cool and freeze the outer wall of the container with liquid nitrogen to make it brittle; Step 3: Drill holes in the outer wall of the container inside the negative pressure suction cup (31); Step 4: Fill the container with a mixture of liquid nitrogen and carbon dioxide to extinguish the fire.

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