A compressed air foam extinguisher

Abstract

The application discloses a compressed air foam fire extinguisher, which comprises a water tank, a foam tank, a mixer, a pump group for pumping water in the water tank and foam agent in the foam tank to the mixer for mixing, a spray gun and an air compressor for pressurizing the mixer, and the foam tank comprises a tank body and a movable platform which is located in the tank body and can slide relative to the tank body, and the movable platform and the inner wall of the tank body respectively enclose a hollow area and a liquid storage area. In the application, the movable platform is arranged to slide in the tank body, and an agitator is rotatably connected to one side of the movable platform when the movable platform is located in the liquid storage area. When the pump group pumps the foam agent in the liquid storage area, the air pressure in the liquid storage area is reduced, the movable platform is driven to move away from the hollow area, and the agitator is also driven to rotate. Therefore, the device can feed the material without external driving, and the material can be stirred, so that the problem of stratification of the foam agent in the foam tank under extreme temperature and environmental pressure is avoided.

Description

Technical Field

[0001] This invention relates to the field of fire-fighting equipment technology, and more specifically to a compressed air foam fire extinguisher. Background Technology

[0002] Compressed air foam fire extinguishers utilize a chemical reaction between a mixture of sodium bicarbonate (baking soda) and a foaming agent, and an aluminum sulfate solution. This reaction produces foam containing carbon dioxide gas, which is then sprayed out from a nozzle under pressure to cover the liquid surface, isolating the air and thus extinguishing the fire. It is a type of fire extinguisher suitable for extinguishing oil fires, including those caused by gasoline, kerosene, diesel, benzene, banana oil, turpentine, varnish, and other flammable liquids.

[0003] Patent document CN107088278A discloses a premixed compressed air foam fire extinguisher, comprising a gas cylinder, a liquid tank, a mixer, and a spray gun. The gas cylinder has two outlets, one connected to the gas inlet of the mixer and the other to the inlet of the liquid tank. The liquid tank has an injection port and a corresponding cap at its top, and its outlet is connected to the inlet of the mixer. The foam outlet of the mixer is connected to the spray gun. This premixed compressed air foam fire extinguisher, by incorporating a mixer connected to the gas outlet of the gas cylinder and the outlet of the liquid tank, allows the foam mixture and compressed air to be premixed in the mixer to form foam with good foaming effect and high foam stability before being sprayed through the spray gun, thus improving the fire extinguishing effect.

[0004] However, the aforementioned compressed air foam fire extinguishers still have the following problems: Due to my country's vast territory, large north-south and east-west spans, significant altitude differences, and uneven temperature distribution, winter temperatures vary greatly. In Northeast my country, North China, Xinjiang, and plateau regions, winter temperatures are very low, even below -30℃. Meanwhile, the air pressure in my country's plateau regions is low. For example, the atmospheric pressure on the Qinghai-Tibet Plateau is 600-700 mmHg, with an average altitude of 3000 meters, which is about 150 mmHg lower than standard atmospheric pressure. Under such extreme temperatures and environmental pressures, based on long-term experience, the foam agent in the foam canister of the compressed air foam fire extinguisher is prone to stratification, leading to easy blockage of the pipeline and potential pipeline rupture. Alternatively, it may be difficult to mix with water in the mixer, resulting in insufficient foam quantity and a significant reduction in fire extinguishing effectiveness. Summary of the Invention

[0005] The technical problem to be solved by this invention is how to prevent the foaming agent in the foam can from separating.

[0006] The present invention solves the above-mentioned technical problems through the following technical means: a compressed air foam fire extinguisher, comprising a water tank, a foam tank, a mixer, a pump set for drawing water from the water tank and foaming agent from the foam tank to the mixer for mixing, a spray gun, and an air compressor for pressurizing the mixer. The foam tank includes a tank body and a movable platform located inside the tank body and capable of sliding relative to the tank body. The movable platform and the inner wall of the tank body respectively enclose a hollow area and a liquid storage area. An agitator is rotatably connected to one side of the movable platform located in the liquid storage area. The movable platform can slide inside the tank body according to the air pressure change in the liquid storage area and synchronously drive the agitator to rotate relative to the movable platform.

[0007] By sliding a movable platform inside the tank and rotatably connecting an agitator to one side of the movable platform located within the liquid storage area, the pump unit reduces the air pressure in the liquid storage area when extracting foaming agent, causing the movable platform to move away from the hollow area. Simultaneously, it also drives the agitator to rotate. This allows the device to feed materials without external drive and simultaneously agitate them, avoiding the problem of foaming agent stratification within the foam tank under extreme temperatures and environmental pressures. Furthermore, the movable platform's pushing action helps to push residual foaming agent from the inner wall of the tank to the right, reducing residue.

[0008] As a preferred technical solution, a spring is also provided in the hollow area, and the movable platform is elastically connected to the inner wall of the tank through the spring. The pump group can draw foaming agent in the storage area and drive the movable platform to move away from the hollow area, causing the agitator to rotate relative to the moving plug.

[0009] As a preferred technical solution, the active platform includes a movable plug, a rotating ring fixedly disposed at one end of the movable plug located in the liquid storage area, a guide rod fixedly disposed inside the tank body and collinear with the tank body axis and capable of passing through the movable plug, a sliding sleeve provided at the axis of the movable plug capable of sliding and sealing with the guide rod, and the rotating ring being connected to the guide rod through a transmission component.

[0010] As a preferred technical solution, the guide rod is provided with a toothed groove, and a row of teeth is provided in the toothed groove. The outer surface of the teeth is an arc-shaped surface, and the arc matches the arc of the guide rod. At least two sets of sealing inner rings are fixed on the inner wall of the sliding sleeve, one of which can seal against the tooth peaks of the teeth.

[0011] As a preferred technical solution, the inner ring of the rotating ring is provided with annular teeth. The transmission component includes a fixed bracket, a first shaft, a first spur gear, a first bevel gear, a second shaft, a second bevel gear, and a second spur gear. One end of the fixed bracket is fixedly connected to the end of the movable plug located in the liquid storage area. The other end of the fixed bracket is rotatably connected to the first shaft. A first spur gear that meshes with the teeth is fixed at the middle position of the first shaft. Both ends of the first shaft are fixed with first bevel gears. The two sides of the fixed bracket are symmetrically provided with second shafts that are rotatably connected to the plug disc. The ends of the two second shafts are fixed with second bevel gears that mesh with the first bevel gears. A second spur gear that meshes with the annular teeth is fixed on the second shaft.

[0012] As a preferred technical solution, the activity platform is also provided with a sealing outer ring in the circumference and is sealed to the tank body through the sealing outer ring.

[0013] As a preferred technical solution, the distance between adjacent sealing inner rings is 1.5 times the distance between two adjacent teeth.

[0014] As a preferred technical solution, the agitator includes a fixed plate and a stirring blade. The sliding platform is fixed with a plurality of fixed plates arranged in a ring at one end within the liquid storage area. Each fixed plate is fixedly connected with a stirring blade whose edge extends toward the axis of the movable platform.

[0015] As a preferred technical solution, the stirring blade and the transmission component are staggered.

[0016] As a preferred technical solution, one end of the tank is provided with a vent that communicates with the hollow area, and the other end of the tank is provided with a liquid filling port and a liquid outlet that communicate with the liquid storage area.

[0017] The advantages of this invention are:

[0018] (1) In this invention, by sliding a movable platform inside the tank and rotating an agitator connected to the side of the movable platform located in the liquid storage area, the pump unit reduces the air pressure in the liquid storage area and drives the movable platform to move away from the hollow area when it draws out the foaming agent in the liquid storage area. At the same time, it can also drive the agitator to rotate, so that the device can feed the material without external drive and can also achieve stirring of the material, thereby avoiding the problem of foaming agent stratification in the foam tank under extreme temperature and environmental pressure. At the same time, the movable platform can push the foaming agent remaining on the inner wall of the tank to the right, reducing the residue.

[0019] (2) In this invention, by setting the distance between the two sealing inner rings to 1.5 times the distance between two adjacent teeth, any set of sealing inner rings can seal against the tooth peaks. That is, when the movable plug is in any position of the guide rod, the sliding sleeve and the guide rod are in a sealed state, thereby preventing air and foaming agent from seeping from the gap between the teeth. The outer periphery of the movable plug is sealed by the sealing outer ring. The external air balances the air pressure on both sides of the movable plug through the air inlet. That is, the movable plug can move with the change of air pressure in the liquid storage area, which improves the sealing effect of the device. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure provided for an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the internal structure of a foam tank provided in an embodiment of the present invention;

[0022] Figure 3 This is a schematic cross-sectional view of a foam tank provided in an embodiment of the present invention;

[0023] Figure 4 This is an exploded structural diagram of the movable plug and transmission component provided in an embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of the movable plug structure provided in an embodiment of the present invention;

[0025] Figure 6 This is a schematic diagram of the transmission component structure provided in an embodiment of the present invention;

[0026] Figure 7 This is a schematic diagram of the tooth structure provided in an embodiment of the present invention;

[0027] Figure 8 This is a schematic diagram of the sealing inner ring structure provided in an embodiment of the present invention;

[0028] Reference numerals: 1. Water tank; 2. Foam tank; 21. Tank body; 211. Air inlet; 212. Liquid inlet; 213. Liquid outlet; 22. Anti-stratification mechanism; 221. Guide rod; 2211. Gear groove; 2212. Tooth; 222. Moving plug; 2221. Plug disc; 2222. Outer sealing ring; 2223. Sliding sleeve; 2224. Inner sealing ring; 223. Transmission component; 2231. Rotating ring ; 2232, Ring gear; 2233, Fixed bracket; 2234, First shaft; 2235, First spur gear; 2236, First bevel gear; 2237, Second shaft; 2238, Second bevel gear; 2239, Second spur gear; 224, Spring; 225, Agitator; 2251, Fixed plate; 2252, Agitator blade; 3, Pump set; 4, Air compressor; 5, Mixer; 6, Spray gun. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, 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.

[0030] See Figure 1 A compressed air foam fire extinguisher includes a water tank 1, a foam canister 2, a pump unit 3, an air compressor 4, a mixer 5, and a spray gun 6. The pump unit 3 is used to draw water from the water tank 1 and foam agent from the foam canister 2 to the mixer 5 for mixing. The air compressor 4 is used to pressurize the mixer 5 and spray the mixture through the spray gun 6. The foam canister 2 includes a tank body 21 and an anti-stratification mechanism 22. The anti-stratification mechanism 22 includes a movable platform located inside the tank body 21 and capable of sliding relative to the tank body 21. The movable platform and the inner wall of the tank body 21 respectively enclose a hollow area and a liquid storage area. The hollow area is a cavity, and the liquid storage area is used to store the foam agent. An agitator is rotatably connected to one side of the movable platform located in the liquid storage area. The movable platform 225 can slide within the tank 21 according to the pressure changes in the storage area, and synchronously drive the agitator 225 to rotate relative to the movable platform. This causes the pump unit 3 to reduce the pressure in the storage area when extracting foaming agent from the storage area, and drives the movable platform to move away from the hollow area. At the same time, it can also drive the agitator 225 to rotate. This allows the device to feed materials without external drive and also to agitate the materials, thereby avoiding the problem of foaming agent stratification in the foam tank 2 under extreme temperature and environmental pressure. At the same time, the movable platform can push the foaming agent remaining on the inner wall of the tank 21 to the right, reducing the residue.

[0031] See Figure 2 The anti-stratification mechanism 2 also includes a guide rod 221, a movable plug 222, a transmission component 223, a spring 224, and an agitator 225. The movable plug 222 is a movable platform. A guide rod 221, which is collinear with the axis of the tank 21 and can pass through the movable plug 222, is fixedly connected inside the tank 21. The transmission component 223 and the agitator 225 are fixed at one end of the movable plug 222 located in the liquid storage area. When the movable plug 222 moves relative to the tank 21, the transmission component 223 drives the agitator 225 to rotate relative to the movable plug 222, thereby agitating the foaming agent in the liquid storage area.

[0032] See Figure 2 , Figure 3One end of the tank 21 has a vent 211 at the top that communicates with the hollow area. The other end of the tank 21 has a liquid inlet 212 and a liquid outlet 213 at the top and bottom that communicate with the liquid storage area, respectively. The movable plug 222 is located in the hollow area and is elastically connected to the inner wall of the tank 21 by a spring 224. The movement of the movable plug 222 is achieved by the negative pressure environment of the inner cavity on the right side. The spring 224 is reset by adding foam through the liquid inlet 212. At the same time as adding foam, the air pressure in the liquid storage area gradually increases, thereby resetting the spring 224. The pump unit 3 can draw foam agent from the liquid storage area and drive the movable plug 222 to move away from the hollow area, causing the agitator 225 to rotate relative to the movable plug.

[0033] See Figure 4 The movable plug 222 includes a plug disc 2221, a sealing outer ring 2222, a sliding sleeve 2223, and a sealing inner ring 2224. The sealing outer ring 2222 is circumferentially fixedly connected to the plug disc 2221 and seals against the inner wall of the tank body 21 through the sealing outer ring 2222. A sliding sleeve 2223, which can slide and seal with the guide rod 221, is fixedly connected to the axis of the movable plug 222. (See reference...) Figure 3 The guide rod 221 has a toothed groove 2211, and a row of teeth 2212 is provided in the groove 2211. The outer surface of the teeth 2212 is arc-shaped, and the arc matches the arc of the guide rod 221, so that the movable plug 222 fits better with the guide rod 221, improving the sealing performance and allowing the movable plug 222 to slide left and right on the guide rod 221 when the air pressure changes. (See reference...) Figure 7 , Figure 8 The inner wall of the sliding sleeve 2223 is fixed with at least two sets of sealing inner rings 2224. Any set of sealing inner rings 2224 can seal against the tooth peak of the tooth 2212. When one sealing inner ring 2224 is in the tooth valley of two adjacent teeth 2212, the other sealing inner ring 2224 is just in the tooth peak of one of the teeth 2212. That is, the sliding sleeve 2223 and the guide rod 221 are in a sealed state when the movable plug 222 is in any position of the guide rod 221, thereby preventing air and foaming agent from seeping from the gap of the teeth 2212. In this embodiment, the distance between adjacent sealing inner rings 2224 is 1.5 times the distance between two adjacent teeth 2212.

[0034] See Figure 5 , Figure 6The transmission component 223 includes a rotating ring 2231, an annular gear 2232, a fixed bracket 2233, a first shaft 2234, a first spur gear 2235, a first bevel gear 2236, a second shaft 2237, a second bevel gear 2238, and a second spur gear 2239. The rotating ring 2231 is fixedly mounted on one end of the movable plug 222 located in the liquid storage area. The rotating ring 2231 is connected to the guide rod 221 via the transmission component 223. The inner ring of the rotating ring 2231 has an annular gear 2232. One end of the fixed bracket 2233 is fixedly connected to the end of the movable plug 222 located in the liquid storage area. The other end of 2233 is rotatably connected to a first shaft 2234. A first spur gear 2235 that meshes with teeth 2212 is fixed at the middle position of the first shaft 2234. A first bevel gear 2236 is fixed at both ends of the first shaft 2234. A second shaft 2237 that is rotatably connected to the stopper disc 2221 is symmetrically arranged on both sides of the fixed bracket 2233. A second bevel gear 2238 that meshes with the first bevel gear 2236 is fixed at the end of each of the two second shafts 2237. A second spur gear 2239 that meshes with the ring gear 2232 is fixed on the second shaft 2237.

[0035] See Figure 3 The agitator 225 includes a fixed plate 2251 and an agitator blade 2252. The movable plug 222 is located in the liquid storage area and has multiple fixed plates 2251 arranged in a ring. Each fixed plate 2251 has an agitator blade 2252 that extends from one edge toward the axis of the movable plug 222. The agitator blade 2252 and the transmission component 223 are staggered.

[0036] It should be noted that an air inlet 211 is provided on the upper side of one end of the tank body 21. External air balances the air pressure on both sides of the movable plug 222 through the air inlet 211. Specifically, when a negative pressure occurs in the liquid storage area on the right side of the movable plug 222, the movable plug 222 slides to the right. The air pressure in the hollow area on the left side of the movable plug 222 decreases due to the sliding of the movable plug 222, resulting in a negative pressure. This allows external air to enter the inner cavity on the left side of the movable plug 222 through the air inlet 211, thereby achieving the balance of air pressure on both sides of the movable plug 222. A filter screen is installed at the air inlet 211 to filter dust in the air. A liquid inlet 212 is provided on the upper side of the other end of the tank body 21 for adding foaming agent. The liquid inlet 212 is equipped with a valve for sealing when not adding foaming agent. A liquid outlet 213 is provided on the lower side, which is connected to the pump group 3 through a pipeline for discharging foaming agent for fire extinguishing.

[0037] How to use:

[0038] During use, the foaming agent to be mixed is stored in the reservoir area on the right side of the movable plug 222. When the pump unit 3 extracts the foaming agent from the reservoir area during the fire extinguishing process, the air pressure in the reservoir area decreases, causing the movable plug 222 to move to the right under negative pressure. Specifically, since the distance between the two sealing inner rings 2224 is 1.5 times the distance between two adjacent teeth 2212, when the movable plug 222 slides horizontally on the guide rod 221, when one of the sealing inner rings 2224 is in the valley of the teeth of two adjacent teeth 2212... At this time, the other sealing inner ring 2224 is exactly at the peak of one of the teeth 2212, that is, the sliding sleeve 2223 and the guide rod 221 are in a sealed state when the movable plug 222 is in any position of the guide rod 221, thereby preventing air and foaming agent from seeping out from the gap of the teeth 2212. The outer periphery of the movable plug 222 is sealed by the sealing outer ring 2222, and the external air balances the air pressure on both sides of the movable plug 222 through the air inlet 211, that is, the movable plug 222 can move with the change of air pressure in the liquid storage area;

[0039] As the moving plug 222 moves to the right under negative pressure, the first shaft 2234 is driven to rotate by the meshing of the first spur gear 2235 and the teeth 2212 on the guide rod 221. The first shaft 2234 is driven to rotate by the meshing of the second bevel gear 2238. The second shaft 2237 is driven to rotate by the meshing of the second spur gear 2239 and the ring gear 2232 on the second shaft 2237. This, in turn, drives the rotating ring 2231 to rotate, thereby driving the stirring blade 2252 on the outer side of the rotating ring 2231 to rotate.

[0040] In summary, as the moving plug 222 moves from left to right, the continuous rotation of the stirring blade 2252 can mix the foaming agent in the storage area to prevent the foaming agent components from separating. At the same time, the movement of the moving plug 222 can push the foaming agent remaining on the inner wall of the tank 21 to the right, reducing the residue.

[0041] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. 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. Such 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 compressed air foam fire extinguisher, comprising a water tank, a foam tank, a mixer, a pump unit for drawing water from the water tank and foaming agent from the foam tank to the mixer for mixing, a spray gun, and an air compressor for pressurizing the mixer, characterized in that, The foam tank includes a tank body and a movable platform located inside the tank body and capable of sliding relative to the tank body. The movable platform and the inner wall of the tank body respectively enclose a hollow area and a liquid storage area. An agitator is rotatably connected to one side of the movable platform located in the liquid storage area. The movable platform can slide within the tank body according to changes in air pressure within the liquid storage area, synchronously driving the agitator to rotate relative to the movable platform. A spring is also provided within the hollow area, and the movable platform is elastically connected to the inner wall of the tank body via the spring. The pump unit can draw foaming agent from the liquid storage area and drive the movable platform to move away from the hollow area, causing the agitator to rotate relative to the movable plug. The movable platform includes a movable plug, and a rotating ring is fixedly provided at one end of the movable plug located in the liquid storage area. A guide rod is fixed inside the tank body, collinear with the tank body axis and capable of passing through the movable plug. A sliding sleeve is provided at the axis of the movable plug, capable of sliding and sealing with the guide rod. The rotating ring is connected to the guide rod via a transmission component. The guide rod has a toothed groove with a row of teeth inside. The outer surface of the teeth... The sliding sleeve has an arc-shaped surface, and the arc matches the arc of the guide rod. At least two sets of sealing inner rings are fixed on the inner wall of the sliding sleeve, one of which can seal against the tooth peaks of the gear. The inner ring of the rotating ring is provided with annular teeth. The transmission component includes a fixed bracket, a first shaft, a first spur gear, a first bevel gear, a second shaft, a second bevel gear, and a second spur gear. One end of the fixed bracket is fixedly connected to the end of the movable plug located in the liquid storage area. The other end of the fixed bracket is rotatably connected to the first shaft. A first spur gear that meshes with the teeth is fixed at the middle position of the first shaft. Both ends of the first shaft are fixed with first bevel gears. The two sides of the fixed bracket are symmetrically provided with second shafts that are rotatably connected to the plug disc. The ends of the two second shafts are fixed with second bevel gears that mesh with the first bevel gears. A second spur gear that meshes with the annular teeth is fixed on the second shaft. One end of the tank is provided with a vent that communicates with the hollow area. The other end of the tank is provided with a liquid filling port and a liquid outlet that communicate with the liquid storage area.

2. A compressed air foam fire extinguisher according to claim 1, characterized in that, The activity platform is also provided with a circumferential sealing outer ring, which seals the tank body.

3. A compressed air foam fire extinguisher according to claim 1, characterized in that, The spacing between adjacent sealing inner rings is 1.5 times the spacing between two adjacent teeth.

4. A compressed air foam fire extinguisher according to claim 1, characterized in that, The agitator includes a fixed plate and a stirring blade. The movable platform is fixed with a plurality of fixed plates arranged in a ring at one end within the liquid storage area. Each fixed plate is fixedly connected with a stirring blade whose edge extends toward the axis of the movable platform.

5. A compressed air foam fire extinguisher according to claim 4, characterized in that, The stirring blades and the transmission components are misaligned.

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