High-pressure gas atomized water mist dry powder multi-mode combined fire extinguishing device

Abstract

The application discloses a high-pressure gas atomization water mist dry powder multi-mode combined fire extinguishing device, and relates to the technical field of fire extinguishing equipment. The device comprises a power output unit, a power output mechanism, a mixed output device, a dry powder storage device, a gas powder output device and a dry powder pushing device. The end cover of the mixed output device is in a conical cylinder shape, and a plurality of gas guide bevels are uniformly distributed on the inner wall in the circumferential direction. The axis of the gas guide bevel is inclined relative to the axis of the mixed rotating shaft and tends to push the airflow to the side of the outlet of the booster impeller. The inner cavity of the airflow shunt seat constitutes a buffer pressure equalizing cavity. The high-pressure gas is sprayed out in the same rotational direction through the gas guide bevels to form a gas curtain with a rotational speed, and the water mist sheared by the booster impeller is broken again. The three fire extinguishing media are combined in the shell and sprayed out through the same output port. The power output unit is sent to three paths through the power distribution mechanism, and the on-off of the dry powder conveying and the pushing is controlled by two electromagnetic clutches, so that the four fire extinguishing modes are switched.

Description

Technical Field

[0001] This invention relates to the field of fire extinguishing equipment technology, specifically to a high-pressure gas atomization water mist dry powder multi-mode combined fire extinguishing device and control method. Background Technology

[0002] In firefighting operations in high-rise buildings, petrochemical plants, lithium battery storage tanks, and other similar locations, a single extinguishing agent often cannot simultaneously provide cooling, asphyxiation, and chemical inhibition. Current approaches mainly fall into two categories.

[0003] One type involves installing multiple fire extinguishing systems side-by-side on the same device. For example, Chinese patent document CN113577620A discloses a multi-functional integrated fire extinguishing device that combines fine water mist, foam, and dry powder fire extinguishing systems. A water tank, high-pressure pump set, air compressor, and dry powder extinguishing agent storage tank are respectively configured on the frame. The three systems can be used individually or in combination through valve switching. CN105148436A discloses a multi-functional fire extinguishing device that sprays dual extinguishing media, using coaxial inner and outer shaft pipelines and valves, allowing for the selection of one or two extinguishing media to be sprayed simultaneously. CN103751937A discloses a vehicle-mounted high-pressure multi-agent combined spray fire extinguishing device, which uses multiple delivery pipelines to send extinguishing agents from various extinguishing agent storage tanks to the spray cannon, achieving individual or combined spraying through control valves on the pipelines. These devices can cover a variety of fire types, but because each extinguishing agent goes through its own pipeline and nozzle, the whole machine needs to be equipped with multiple power units such as high-pressure pump sets and air compressors. The number of pipelines and actuators is large, the space occupied is large, and the switching process depends on the timing coordination of multiple valves.

[0004] Another type involves atomizing water using gas or mechanical action. For example, CN102302834A discloses an automatic control clutch-type fine water mist fire extinguishing device, which has a swirling water inlet and an axial water inlet inside the spray gun, so that the two water streams collide in the swirling chamber to form a fine water mist; CN107252534A discloses a fire extinguishing agent mixing device, which uses a water turbine as the prime mover, and the water turbine shaft drives the rotating core with spiral grooves and the stirring impeller in sequence to pass foam concentrate or dry powder into the mixing cylinder to mix with water; CN102553113A discloses a multi-functional fire-fighting combined spray unit, which uses a spiral pneumatic conveyor to mix dry powder and compressed air into a dry powder-air two-phase flow before sending it out.

[0005] In the above schemes, the atomization of water-based fire extinguishing agents mostly relies on static mixing or Venturi structures within fixed nozzles. The degree of droplet refinement is limited by a single atomization mechanism, making it difficult to adjust when both droplet fineness and jet axial stiffness need to be considered. On the dry powder side, pneumatic fluidization or in-tank pressurization are commonly used for discharge. After the dry powder becomes damp and clumps in the tank, it is prone to poor discharge or even bridging. Furthermore, dry powder conveying and atomization conveying each require independent power sources, making the power configuration and switching mechanism of the whole machine more complex. Summary of the Invention

[0006] Technical problems to be solved The purpose of this invention is to provide a high-pressure atomized water mist and dry powder multi-mode combined fire extinguishing device and control method, which sequentially completes the mechanical shearing atomization of water flow and secondary atomization of airflow within the same housing, and allows the three fire extinguishing media—water mist, atomized water mist, and dry powder—to converge within the housing and be sprayed out through the same outlet. A further objective of this invention is to use a single power source in conjunction with an electromagnetic clutch to control the on / off of each fire extinguishing media delivery link, thereby enabling the switching of multiple fire extinguishing modes on the same device and providing a disengageable, forced pushing mechanism for caking dry powder in the dry powder tank.

[0007] A high-pressure gas atomization water mist dry powder multi-mode combined fire extinguishing device includes a frame, a power output unit, a power output mechanism, a mixing output device, a dry powder storage device, and a gas-powder output device. The mixing output device includes a housing, a mixing shaft, a booster impeller, an end cover, an output port, an airflow splitter seat, and an air guide inlet. The shell is a hollow cylinder with a water inlet on one side and its front end connected to the airflow splitter. The end cap is a hollow conical cylinder with an outlet at the center of its axial end face. Several inclined air guides are evenly distributed circumferentially on the inner wall of the end cap. The axis of the inclined air guides is inclined relative to the axis of the mixing shaft, and the inclined direction tends to push the airflow towards the outlet side of the booster impeller. An air inlet is opened at the front end of the end cap, which is connected to each inclined air guide through the inner cavity of the airflow splitter. The mixing shaft runs through the axis of the shell and is connected to the output end of the power output mechanism. The booster impeller is fixed on the mixing shaft and located in the cavity of the shell. An annular flow guide gap is left between the outer edge of the blades of the booster impeller and the inner wall of the shell. The discharge end of the air-powder output device is connected to the cavity of the shell through a dry powder inlet 300 opened on the shell. The dry powder in the dry powder storage device is sent into the cavity of the shell in the form of a two-phase flow of air and powder through the air-powder output device and sprayed out from the outlet.

[0008] Furthermore, the air-powder output device includes an air-powder output cylinder, a screw shaft, an air inlet valve, and a first electromagnetic clutch. The air-powder output cylinder is divided into air delivery chambers and material delivery chambers along the axial direction of the screw shaft. The air inlet valve is located on the cylinder wall corresponding to the air delivery chamber, and a dry powder inlet is provided on the cylinder wall corresponding to the material delivery chamber, connecting to the discharge pipe of the dry powder tank. The power input end of the screw shaft is connected to the power output mechanism via the first electromagnetic clutch.

[0009] Furthermore, the dry powder storage device includes a dry powder tank, a pusher cylinder, and a pusher piston, and is equipped with a dry powder pushing device. The dry powder pushing device includes a dry powder pushing worm, a dry powder pushing worm wheel, a second electromagnetic clutch, a pusher connecting rod turntable, and a pusher connecting rod mechanism. The second electromagnetic clutch is connected in series between the dry powder pushing worm wheel and the pusher connecting rod turntable. One end of the pusher connecting rod mechanism is eccentrically hinged to the surface of the pusher connecting rod turntable, and the other end is connected to the pusher piston.

[0010] The present invention also provides a control method using the above-mentioned device, including a water mist mode, an air atomization mode, a dry powder mode, and a combined mode. The four modes are switched by a combination of the on / off switching of a first electromagnetic clutch, a second electromagnetic clutch, and a shut-off valve on the air inlet side.

[0011] In summary, the present invention has the following beneficial effects: First, after the water flows into the casing through the inlet, it is sheared, torn, and accelerated by a high-speed rotating booster impeller, completing the first stage of mechanical atomization. In the gas atomization mode, the high-pressure gas is buffered and pressure-equalized in the airflow distributor, and then ejected obliquely in the same direction of rotation from the circumferentially distributed inclined air guides, forming an axially advancing air curtain with swirl. This air curtain faces the outlet side of the booster impeller, causing a secondary impact and breakup of the liquid flow that has already been initially sheared. The two stages of atomization are completed sequentially in the same chamber. The droplet fineness and the momentum flux of the mist flow can be adjusted by the number and angle of the inclined air guides, without the need to replace the nozzles or increase the inlet water pressure. Under the conditions of an inlet water pressure of 12 MPa and a flow rate of 40 L / min, the droplet Dv0.9 of the atomization mode decreased from 293 μm in the pure water mist mode to 95 μm, while the mist flow flux increased from 74.4 N to 111.2 N. If the pure water mist mode is to achieve the same droplet fineness by simply increasing the inlet water pressure, the inlet water pressure needs to be increased to about 37 MPa, which exceeds the operating range of conventional high-pressure pump sets.

[0012] Second, the three extinguishing media converge in the cavity of the shell and are sprayed out through the same outlet. After leaving the outlet, the multiphase jets are mixed again in the space, which can simultaneously exert cooling, suffocation and chemical inhibition effects. Compared with the structure of independent pipelines and independent nozzles, the number of pipelines and actuators is significantly reduced.

[0013] Third, the power output unit uses one electric motor or one hydraulic motor, which distributes power to the mixing shaft, screw shaft, and dry powder pusher worm gear via a transfer mechanism. Electromagnetic clutches are installed at both the screw shaft and the pusher connecting rod turntable. In pure water mist mode, the first electromagnetic clutch is disengaged, and the screw stops rotating, avoiding unnecessary power consumption and preventing dry powder residue from absorbing moisture and clumping in the feeding chamber. When the dry powder tank is discharging normally, the second electromagnetic clutch is disengaged, and the pusher device is in standby mode, only engaging when the dry powder caking or the discharge flow rate drops below a set threshold.

[0014] Fourth, the second electromagnetic clutch is connected in series between the dry powder pusher worm gear and the pusher connecting rod turntable, rather than in series at the worm input end. The worm and worm gear stage always remain meshed, avoiding frequent engagement impacts. The clutch action only occurs on the lower-speed turntable side, which helps extend the clutch's service life. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a cross-sectional view of the hybrid output device. Figure 3 This is a cross-sectional schematic diagram of the end cap and the airflow splitter. Figure 4 This is a schematic diagram of the venting bevel of the end cap; Figure 5 This is a schematic diagram of the gas-powder output device; Figure 6 This is a schematic end view of the dry powder feeding device along the worm gear axis.

[0016] In the diagram: 1—Power output unit; 2—Mixing output device; 3—Dry powder storage device; 4—Air-powder output device; 5—Dry powder pushing device; 6—Power output mechanism; 20—Housing; 21—Mixing shaft; 22—Booster impeller; 23—End cover; 24—Output port; 25—Airflow divider; 26—Air guide oblique port; 31—Dry powder tank; 32—Pushing cylinder; 33—Pushing piston; 40—Air-powder output cylinder; 41—Screw shaft; 42—Air delivery chamber; 43—Feeding chamber; 44—First electromagnetic clutch; 45—Inlet valve; 46—Dry powder inlet; 51—Dry powder pushing worm; 52—Dry powder pushing worm wheel; 53—Second electromagnetic clutch; 54—Pushing connecting rod turntable; 55—Pushing connecting rod mechanism; 100—Water inlet; 200—Air inlet; 300—Dry powder inlet. Detailed Implementation

[0017] Example 1: Overall Structure of the Device The following description, in conjunction with the accompanying drawings, further illustrates this embodiment. In the drawings, the same reference numerals denote the same or corresponding components.

[0018] To better understand the above technical solution, the following will provide a detailed explanation of the above technical solution in conjunction with specific implementation methods.

[0019] like Figure 1 As shown, the fire extinguishing device in this embodiment mainly consists of a power output unit 1, a mixing output device 2, a dry powder storage device 3, an air-powder output device 4, a dry powder feeding device 5, and a power output mechanism 6. All components are mounted on the same frame. The water inlet 100 is connected to high-pressure water on one side of the bottom of the mixing output device 2, the air inlet 200 is opened at the front end of the mixing output device 2, and the dry powder feed inlet 46 is connected to the discharge pipe of the dry powder tank 31.

[0020] In some embodiments of the present invention, the power output unit 1 is an electric motor, which can also be replaced by a hydraulic motor. The power output unit 1 sends power simultaneously or separately to three actuators via the transfer mechanism inside the power output mechanism 6: the mixing shaft 21 of the mixing output device 2; the synchronous pulley of the air-powder output device 4, which is switched on and off via the first electromagnetic clutch 44; and the dry powder pushing worm 51 of the dry powder pushing device 5, which indirectly drives the dry powder pushing worm wheel 52 via the second electromagnetic clutch 53, and finally converts it into the linear reciprocating motion of the pushing piston 33. The three transmissions are each independently equipped with a clutch, so that this embodiment can operate in three basic modes: water mist, air atomization, and dry powder, as well as any combination of them.

[0021] In practical implementation, the power output mechanism 6 employs a gear-driven or sprocket-driven structure to distribute the single-shaft output of the power output unit 1 into three independent transmission branches. The first transmission branch is directly connected to the mixing shaft 21 of the mixing output device 2, providing continuous high-speed rotational power to the booster impeller 22. The second transmission branch is connected to the screw shaft 41 of the air-powder output device 4 via a synchronous belt drive, with a first electromagnetic clutch 44 inserted in the transmission chain to achieve on / off control of this branch. The third transmission branch is connected to the dry powder pushing device 5 via a worm gear pair, with a second electromagnetic clutch 53 inserted in the transmission chain to achieve on-demand feeding action. The power distribution ratio of the three transmission branches can be adjusted according to the load requirements of each actuator. Typically, the mixing shaft 21 receives the maximum power to ensure that the booster impeller 22 can reach the required speed in water mist mode.

[0022] By adopting the above technical solution, three independent drives are achieved through a single power output unit and a transfer mechanism, which significantly simplifies the power configuration of the whole machine, reduces the number of power sources and maintenance costs, and enables flexible switching of multiple working modes through the on and off combinations of the electromagnetic clutch.

[0023] In some preferred embodiments of the present invention, the mixing output device 2 mainly comprises a housing 20, a mixing shaft 21, a booster impeller 22, an end cover 23, an output port 24, an airflow splitter 25, and an air guide oblique port 26. The housing 20 is a hollow cylinder, the front end of which is sealed by the end cover 23, and the front end of the end cover 23 is connected to the airflow splitter 25. The mixing shaft 21 is arranged through the axis of the housing 20, one end of which passes through the shaft hole on the end cover 23 and is connected to the output end of the power output mechanism 6, and the other end extends into the inner cavity of the end cover 23 and faces the output port 24. The booster impeller 22 is fixed on the mixing shaft 21 and located in the cavity of the housing 20. Its hub is connected to the mixing shaft 21 by a key or interference fit. The blades are evenly distributed circumferentially, and an annular guide gap of 1.5 mm to 3 mm is left between the outer edge of the blades and the inner wall of the housing 20. The outlet 24 is located at the center of the axial end face of the end cover 23, serving as the final spray outlet of this fire extinguishing device.

[0024] In practical implementation, the number of blades in the booster impeller 22 is typically 8 to 16, and the blade shape can be straight or backward-curved. When the booster impeller 22 rotates at a speed of 3000 r / min to 6000 r / min, the high-pressure water (inlet pressure of 8 MPa to 20 MPa) from the inlet 100 is sheared, torn, and accelerated between the blades of the booster impeller 22, forming a high-pressure fine water mist. The annular guide gap further shears the water flow as it passes through the outer edge of the impeller, which helps to improve the atomization effect. If the gap is too large, the shearing effect weakens and the atomized particle size increases; if the gap is too small, the flow resistance increases and the flow rate decreases. Therefore, controlling the gap within the range of 1.5 mm to 3 mm can achieve a good balance between atomization fineness and flow rate.

[0025] By adopting the above technical solution, the high-pressure water flow is mechanically sheared and atomized through a high-speed rotating pressurized impeller, which can obtain fine water mist without using traditional nozzles, while avoiding the problem of nozzle clogging and improving the reliability of the fire extinguishing device.

[0026] In some preferred embodiments of the present invention, the end cap 23 is a hollow conical cylinder structure, with its large end facing the booster impeller 22 and its small end having an outlet 24. A plurality of oblique air guide ports 26 are provided on the inner wall of the end cap 23. The oblique air guide ports 26 are evenly distributed circumferentially along the axis of the end cap 23, and their axis is inclined relative to the axis of the mixing shaft 21, with the inclination direction set to tend to push the airflow towards the booster impeller 22. The air inlet 200 is located at the front end of the end cap 23 and communicates with the inner cavity of the airflow splitter seat 25, which forms a buffer pressure equalization chamber. The high-pressure gas entering the air inlet 200 is first buffered and pressure equalized within the airflow splitter seat 25, and then ejected obliquely from each of the oblique air guide ports 26 in the same swirling direction.

[0027] In practical implementation, because the air guide inlets 26 are inclined and evenly distributed circumferentially, the ejected airflow forms an axially advancing air curtain with a certain degree of vortex within the casing 20, which directly faces the outlet side of the booster impeller 22. This allows for thorough mixing with the liquid flow that has already undergone preliminary shearing at the impeller outlet, ultimately converging at the output port 24 for ejection. The number and inclination angle of the air guide inlets 26 can be adjusted according to the required atomization fineness and range. The angle between the axis of the air guide inlets 26 and the axis of the mixing shaft 21 is 20°–55°, and the number of air guide inlets 26 is 6–12. A larger angle and a greater number of inlets enhance the secondary atomization effect on the droplets, resulting in finer droplets; conversely, a smaller angle results in higher axial stiffness of the jet and a longer range. The specific values ​​of these parameters can be determined experimentally based on the injection pressure and flow rate conditions. For example, when the finest droplets are needed to extinguish lithium battery fires, a configuration with a 45° angle and 10 oblique air inlets 26 can be selected; when a longer range is needed to extinguish fires outside high-rise buildings, a configuration with a 25° angle and 6 oblique air inlets 26 can be selected.

[0028] By employing the above technical solution, the combination of a conical end cap and an inclined air guide allows high-pressure gas to form a swirling axial air curtain within the casing. This air curtain then impacts and breaks up the water mist at the outlet of the booster impeller, achieving synergistic two-stage atomization. Compared to traditional fixed nozzle atomization methods, this solution allows for flexible adjustment of droplet fineness and jet stiffness by changing the number and angle of the inclined air guides, adapting to the firefighting needs of different fire scenarios without requiring replacement of the nozzle assembly.

[0029] In some preferred embodiments of the present invention, the dry powder storage device 3 comprises a dry powder tank 31, a pusher cylinder 32, and a pusher piston 33. The dry powder tank 31 is arranged on one side above the frame, and its bottom discharge pipe is connected to the pusher cylinder 32. The pusher cylinder 32 is located below the dry powder tank 31, and the pusher piston 33 is installed inside the pusher cylinder 32, performing a reciprocating linear pushing motion inside the cylinder; the discharge end of the pusher cylinder 32 is connected to the dry powder inlet 46 opened on the cylinder wall of the feeding chamber 43, so that the dry powder pushed out by the pusher piston 33 directly enters the feeding chamber 43.

[0030] The air-powder output device 4 mainly consists of an air-powder output cylinder 40, a screw shaft 41, an air delivery chamber 42, a feeding chamber 43, a first electromagnetic clutch 44, an air inlet valve 45, and a dry powder inlet 46. The air-powder output cylinder 40 is a hollow cylindrical shell, with the screw shaft 41 running through it along its axis. The air delivery chamber 42 and the feeding chamber 43 are arranged in sections along the axis of the screw shaft 41. The first electromagnetic clutch 44 is installed at the power input end of the screw shaft 41, and its input end is connected to the synchronous pulley led out by the power output mechanism 6. The synchronous pulley is driven by the synchronous belt to the output end of the power output mechanism 6. The air inlet valve 45 is installed on the side wall of the air-powder output cylinder 40 and is located at the corresponding position of the air delivery chamber 42. The dry powder inlet 46 is opened on the cylinder wall corresponding to the feeding chamber 43 and is connected to the discharge pipe of the dry powder tank 31.

[0031] In the specific implementation process, the spiral blades on the screw shaft 41 forcibly push the falling dry powder in the feeding chamber 43 section. In the air supply chamber 42 section, the spiral blades mainly play a disturbing and dispersing role, so that the dry powder is fully mixed with the high-pressure gas entering the air supply chamber 42 through the air inlet valve 45, forming a two-phase flow of gas and powder, which is then sent to the mixing output device 2 and sprayed out from the output port 24. The first electromagnetic clutch 44 is used to cut off the power input of the screw shaft 41 when the fire extinguishing device switches to the pure water mist mode, so that the screw stops rotating, which avoids unnecessary power consumption and prevents the dry powder from remaining in the feeding chamber 43 after shutdown, absorbing moisture and clumping. The air inlet valve 45 is a solenoid valve or a pneumatic valve, and its opening and closing are automatically controlled by the control system according to the current working mode. After the high-pressure gas enters the air delivery chamber 42 through the air inlet valve 45, it is fully mixed with the dry powder under the stirring action of the spiral blades of the screw shaft 41. The gas-powder ratio can be adjusted according to the type of dry powder and the fire extinguishing needs. The dry powder delivery rate is 1.5 kg / min to 3 kg / min, and the gas-powder mass ratio is usually controlled in the range of 3:1 to 8:1.

[0032] By adopting the above technical solution, the air-powder output cylinder is divided into two functional sections: an air delivery chamber and a material delivery chamber. The screw shaft is used to simultaneously realize the forced pushing of dry powder and air-powder mixing. The structure is simple and compact. Furthermore, the on-demand start and stop of the dry powder circuit is realized through the on-off control of the first electromagnetic clutch, which avoids the problem of residual moisture absorption of dry powder in non-dry powder mode and improves the reliability and service life of the device.

[0033] In some preferred embodiments of the present invention, the dry powder pushing device 5 comprises a dry powder pushing worm 51, a dry powder pushing worm wheel 52, a second electromagnetic clutch 53, a pushing connecting rod turntable 54, and a pushing connecting rod mechanism 55. The dry powder pushing worm 51 is driven by a power output mechanism 6 and meshes with the dry powder pushing worm wheel 52; the second electromagnetic clutch 53 is connected in series between the dry powder pushing worm wheel 52 and the pushing connecting rod turntable 54; one end of the pushing connecting rod mechanism 55 is eccentrically hinged to the surface of the pushing connecting rod turntable 54, and the other end is connected to the pushing piston 33, so as to convert the rotation of the pushing connecting rod turntable 54 into the reciprocating linear motion of the pushing piston 33 in the pushing cylinder 32.

[0034] In practical implementation, the second electromagnetic clutch 53 is connected in series between the pusher worm gear 52 and the pusher connecting rod turntable 54, rather than in series at the worm input end. Its function is to ensure that the worm-worm gear stage remains engaged and does not experience frequent engagement impacts. The clutch action only occurs on the low-speed turntable side, which helps to improve the clutch's service life. The pusher connecting rod mechanism 55 can be a crank-slider mechanism or a four-bar linkage. The distance from the eccentric hinge point on the pusher connecting rod turntable 54 to the center of the turntable determines the stroke of the pusher piston 33. Typically, the stroke is 0.3 to 0.5 times the inner diameter of the pusher cylinder 32 to ensure that the pusher piston 33 can complete an effective reciprocating pushing action within the pusher cylinder 32. The engagement of the dry powder feeding device 5 is controlled by the second electromagnetic clutch 53. When the dry powder inside the dry powder tank 31 becomes caking due to moisture or prolonged storage, and the discharge flow rate drops below a set threshold (this set threshold is taken as 60% to 80% of the rated discharge flow rate of the dry powder tank 31), the second electromagnetic clutch 53 engages. Power is transmitted from the dry powder feeding worm gear 52 to the feeding connecting rod turntable 54 via the clutch, and then the feeding connecting rod mechanism 55 drives the feeding piston 33 to reciprocate linearly within the feeding cylinder 32, periodically squeezing and feeding the dry powder inside the dry powder tank 31. Combined with the forced conveying of the screw shaft 41's spiral blades within the feeding chamber 43, the continuous and stable descent of the dry powder can be restored. When the discharge returns to normal, the second electromagnetic clutch 53 disengages, the feeding connecting rod turntable 54 stops rotating, and the dry powder feeding device 5 enters a standby state, relying solely on the weight of the dry powder and the air pressure inside the tank to achieve discharge, thereby reducing wear and power consumption of the feeding mechanism.

[0035] By adopting the above technical solution, a disengageable dry powder feeding device is installed. During normal dry powder feeding, it remains in standby mode to reduce wear and power consumption. Forced feeding is only activated when dry powder caking causes feeding difficulties. This ensures both the continuity and reliability of the dry powder supply and avoids ineffective operation of the feeding mechanism. Placing the electromagnetic clutch on the low-speed turntable side rather than the worm gear input end effectively reduces clutch engagement impact and extends service life.

[0036] In some embodiments of the present invention, the following working modes can be achieved by controlling the on / off combination of the first electromagnetic clutch 44, the second electromagnetic clutch 53, and the shut-off valve on one side of the air inlet 200.

[0037] (1) Water Mist Mode. Only the mixing shaft 21 is driven, the first electromagnetic clutch 44 is disengaged, the second electromagnetic clutch 53 is disengaged, and the shut-off valve on the side of the air inlet 200 is closed. High-pressure water enters the inner cavity of the housing 20 through the water inlet 100, is sheared and atomized by the booster impeller 22, and is sprayed out through the output port 24 to form a high-pressure fine water mist, which is suitable for extinguishing Class A solid material fires. In this mode, the speed of the booster impeller 22 is 3000 r / min to 6000 r / min, the water inlet pressure is 8 MPa to 20 MPa, and the median diameter D50 of the sprayed fine water mist droplets is usually between 100 μm and 300 μm.

[0038] (2) Gas atomization mode. The mixing shaft 21 is driven, and high-pressure airflow is simultaneously introduced into the airflow splitter 25 through the air inlet 200. After the high-pressure water is initially atomized by the booster impeller 22, it is then subjected to a secondary impact by the high-speed airflow obliquely ejected from the guide port 26. The droplets are further broken up and refined and accelerated by the airflow before being ejected from the outlet 24. The pressure of the high-pressure gas is 0.6MPa to 1.2MPa. In the gas atomization mode, the median droplet diameter D50 can be further reduced to 30μm to 80μm, and the axial velocity of the jet is also significantly improved. This mode produces finer droplets and has higher flow rate and axial stiffness, and can maintain the ability to penetrate the fire plume while refining the droplets. It is suitable for occasions with high requirements for droplet fineness and penetration.

[0039] (3) Dry powder mode. The first electromagnetic clutch 44 is engaged, and the second electromagnetic clutch 53 is selectively disengaged or engaged depending on the caking of the dry powder. The dry powder falls from the dry powder tank 31 through the pusher cylinder 32 and the dry powder inlet 46 into the feeding chamber 43, and is forcibly pushed to the dry powder inlet 300 by the spiral blades of the screw shaft 41; at the same time, the high-pressure gas entering through the air inlet valve 45 mixes with the dry powder in the air delivery chamber 42 by the rotation of the spiral blades of the screw shaft 41, and the gas-powder two-phase mixture is sprayed out through the outlet 24. This mode is suitable for fighting Class B and Class C fires and fires involving electrical equipment.

[0040] (4) Combined Mode. Depending on the fire situation, two or three of the above three channels can be activated simultaneously. For example: water mist and dry powder can be sprayed simultaneously to cool deep-seated fires of solid fuel and quickly suppress surface flames; airflow and dry powder can be sprayed simultaneously to improve the diffusion range and adhesion efficiency of dry powder on the surface of objects; water mist, airflow and dry powder can be activated simultaneously to deal with complex disasters. After the three channels converge, they share an output port 24. The multiphase jets sprayed out are mixed again in the space, which can simultaneously play a triple role of cooling, suffocation and chemical inhibition.

[0041] In practical implementation, the switching between the above modes is achieved by the coordinated action of the electrically controlled valve assembly and two electromagnetic clutches. The selection of valves and clutches, their action sequence, and interlocking logic can be configured by those skilled in the art based on the actual fire situation, flow rate, and pressure conditions. The control system can use an electrical control unit with a PLC or microprocessor as its core, which can achieve automatic switching between modes through a preset program. Alternatively, a manual operation panel can be provided for operators to manually select the working mode according to the site conditions.

[0042] The above technical solution enables flexible switching between four fire extinguishing modes through the combination of two electromagnetic clutches and a shut-off valve. The switching process for each mode is simple and reliable, requiring no complex valve timing coordination. In combined mode, the three extinguishing media share the same outlet and are mixed again in the space, simultaneously exerting a triple extinguishing effect of cooling, asphyxiation, and chemical inhibition, significantly improving extinguishing efficiency and applicability. In practical applications, the control system can automatically determine the current fire type based on feedback signals from fire temperature and smoke sensors, and automatically select the optimal extinguishing mode or mode combination accordingly, thereby achieving intelligent fire extinguishing response.

[0043] Example 2: Comparison of atomization performance This embodiment provides comparative data on the atomization performance of the above-mentioned device under different operating conditions to illustrate the influence trend of various structural parameters and operating parameters on the atomization effect. The calculation conditions for the data are: water inlet flow rate 40L / min, impeller diameter 100mm, rotation speed 4500r / min, annular guide gap 2.0mm, 8 oblique air guide ports with a diameter of 3mm, the angle between the axis and the mixing shaft axis 35°, compressed air source, ambient temperature 20℃; droplet size is the value at 1.0m from the output port, and the effective range is the horizontal distance at which the velocity of the mist flow axis decreases to 2m / s.

[0044] The relationship upon which the calculation is based is as follows. The characteristic diameter of the droplets is determined by the semi-empirical correlation of air-assisted atomization: Dv0.9 = K·(1 + mL / mA)·σ / (ρg·Ueff) 2 The calculation is as follows: K is the device coefficient, taken as 1.48 according to the structure of this device; mL / mA is the mass flow ratio of water to gas; σ is the surface tension of water, taken as 0.0728 N / m; ρg is the air density, taken as 1.2 kg / m³. 3Ueff represents the effective relative velocity between gas and liquid. The outlet mist velocity is calculated as v0 = Cv·(2p / ρL)^0.5, with the flow coefficient Cv taken as 0.72 and ρL as the density of water. In pure water mist mode, Ueff is taken as 0.40v0; in gas atomization mode, Ueff is taken as 0.40(vg-v0)·(sinθ / sin35°)^0.6, where vg is the airflow velocity at the outlet of the guide vane, taken as 310 m / s based on critical flow, and θ is the inclination angle of the guide vane. The effective range is calculated using the droplet swarm resistance model x = ln(v0 / ve) / [λ·3Cd·ρg / (4ρL·d)], with the droplet swarm resistance reduction factor λ taken as 0.35, the resistance coefficient Cd taken as 0.44, the droplet diameter d taken as Dv0.9 under this condition, and ve taken as 2 m / s. The values ​​listed in the table below are all calculated using the above model.

[0045] Table 1. Comparison of atomization performance between the two modes at an inlet water pressure of 12 MPa

[0046] As shown in Table 1, under the same inlet water pressure and flow rate, the atomization mode achieves significantly finer droplets and increased mist flow flux in exchange for a reduced effective range. Droplet finerness increases the specific surface area per unit mass of water and the heat absorption rate, which are the main factors determining the extinguishing efficiency of Class A deep-seated fires and Class B liquid fires. The approximately 49% increase in mist flow flux ensures that the finer mist still possesses the axial stiffness and wind resistance to penetrate the fire plume and reach the flame root. Both modes have their applicable scenarios, which is precisely the engineering significance of this device's multi-mode switching capability.

[0047] Table 2. Effect of air source pressure on air atomization mode (inlet water pressure 12MPa)

[0048] As shown in Table 2, as the gas source pressure increases, the droplets become finer and the effective range decreases accordingly. In actual use, the gas source pressure should be selected according to the fire conditions: a higher gas source pressure should be used for close-range situations or situations requiring rapid cooling, while a lower gas source pressure should be used for long-range situations or situations requiring a larger coverage area, or the pure water mist mode should be switched directly.

[0049] Table 3. Effect of inlet water pressure on pure water mist mode

[0050] As shown in Table 3, while increasing the inlet water pressure in pure water mist mode can refine the droplets, the refinement is limited by the upper limit of the pump pressure and pipeline losses. According to the model above, to achieve a droplet fineness (Dv0.9≈95μm) comparable to the air atomization mode (air source 0.8MPa) in pure water mist mode solely by increasing the inlet water pressure, the inlet water pressure would need to be increased to approximately 37MPa, exceeding the 20MPa operating range of conventional high-pressure pumps. Even if it were to operate at 20MPa, the flow rate would drop below 20L / min due to pump characteristics, resulting in a mist flux of less than 50N, significantly lower than the air atomization scheme. Therefore, this device, by introducing secondary atomization of airflow within the housing cavity, can obtain ultrafine droplets within the pressure range of conventional pumps while maintaining a large mist flux.

[0051] Table 4. Effect of the inclination angle of the air guide on the air atomization mode (inlet water pressure 12MPa, air source 0.8MPa).

[0052] As shown in Table 4, under the premise that the gas source pressure and water inlet pressure remain unchanged, increasing the inclination angle of the air guide inlet can enhance the secondary abrasion effect of the airflow on the droplets, thus further refining the droplets. When the inclination angle is less than 20°, the tangential component of the airflow is insufficient, and the secondary abrasion effect is not obvious; when the inclination angle is greater than 55°, the axial component of the airflow is too small, and the mist flow is prone to divergence after leaving the outlet, resulting in a decrease in axial stiffness. Therefore, in this invention, the angle between the axis of the air guide inlet and the axis of the mixing shaft is set to 20° to 55°.

[0053] In some embodiments of the present invention, the power output unit 1 can be replaced with an independent motor set, which provides power to the synchronous pulleys of the mixing shaft 21, the screw shaft 41, and the dry powder pushing worm gear 51, respectively, and the start-stop and speed are coordinated by a unified electronic control unit; this variant is consistent with the present embodiment in terms of the correspondence of reference numerals, connection relationship and working mode.

[0054] In some embodiments of the present invention, the pushing piston 33 in the dry powder pushing device 5 can be replaced by a cylinder or hydraulic cylinder that drives it directly. The mechanical transmission chain of dry powder pushing worm 51 - dry powder pushing worm wheel 52 - pushing connecting rod turntable 54 - pushing connecting rod mechanism 55 is replaced by cylinder direct drive.

[0055] In some embodiments of the present invention, the air guide oblique port 26 may also be opened on the mating surface of the airflow splitter seat 25 and the end cover 23. As long as its air outlet direction maintains the same rotation direction and tends to point to the outlet side of the booster impeller 22, it also falls within the protection scope of the present invention.

[0056] In summary, the high-pressure gas atomization water mist dry powder multi-mode combined fire extinguishing device and control method provided by the present invention achieves two-stage atomization by setting a booster impeller and an inclined air guide inlet in the same housing, realizes multi-mode switching by using a single power source in conjunction with an electromagnetic clutch, and solves the problem of poor material feeding caused by dry powder caking by using a disengageable dry powder feeding device. It effectively solves the technical problems of complex pipelines, redundant power configuration, and unreliable dry powder feeding in existing multi-mode fire extinguishing devices.

[0057] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

Claims

1. A high-pressure gas atomization water mist dry powder multi-mode combined fire extinguishing device, comprising a frame, a power output unit (1), a power output mechanism (6), a mixing output device (2), a dry powder storage device (3), a gas-powder output device (4), and a dry powder feeding device (5), characterized in that: The mixing output device (2) includes a housing (20), a mixing shaft (21), a booster impeller (22), an end cover (23), an output port (24), an airflow splitter seat (25), and an air guide inlet (26). The housing (20) is a hollow cylinder with an inlet (100) for water flow on one side, and its front end is connected to the airflow splitter seat (25). The end cover (23) is a hollow conical cylinder with the output port (24) at the center of its axial end face. Several air guide inlets (26) are evenly distributed circumferentially on the inner wall of the end cover (23). The axis of the air guide inlets (26) is inclined relative to the axis of the mixing shaft (21), and the inclination direction of the air guide inlets (26) tends to push the airflow toward the outlet side of the booster impeller (22). An air inlet (200) is opened at the front end of the end cover (23). A shut-off valve is provided on the road to control its opening and closing. The air inlet (200) is connected to each of the air guide inlets (26) through the inner cavity of the airflow splitter seat (25). The mixing shaft (21) is arranged through the axis of the housing (20) and connected to the output end of the power output mechanism (6). The booster impeller (22) is fixed on the mixing shaft (21) and located in the cavity of the housing (20). An annular flow guide gap is left between the outer edge of the blade of the booster impeller (22) and the inner wall of the housing (20). The discharge end of the gas-powder output device (4) is connected to the cavity of the housing (20) through the dry powder inlet (300) opened on the housing (20). The dry powder in the dry powder storage device (3) is sent into the cavity of the housing (20) in the form of gas-powder two-phase flow through the gas-powder output device (4) and sprayed out from the output port (24).

2. The high-pressure gas atomization water mist dry powder multi-mode combined fire extinguishing device according to claim 1, characterized in that: The inner cavity of the airflow splitter (25) forms a buffer pressure equalization cavity. The outlet vortex of each of the air guide oblique ports (26) is consistent, so that the high pressure gas entering the air inlet (200) is pressurized in the buffer pressure equalization cavity and then sprayed into the cavity of the housing (20) obliquely by each of the air guide oblique ports (26) in the same vortex direction.

3. The high-pressure gas atomization water mist dry powder multi-mode combined fire extinguishing device according to claim 2, characterized in that: The air guide oblique port (26) is evenly distributed around the axis of the end cap (23), and the angle between the axis of the air guide oblique port (26) and the axis of the mixing shaft (21) is 20° to 55°.

4. The high-pressure gas atomization water mist dry powder multi-mode combined fire extinguishing device according to claim 1, characterized in that: The large end of the conical cylinder of the end cover (23) faces the booster impeller (22), and the small end opens the output port (24). The output port (24) is located on the axis of the mixing shaft (21). The blades of the booster impeller (22) are evenly distributed circumferentially and their blade outlet side faces the inner cavity of the end cover (23).

5. The high-pressure gas atomization water mist dry powder multi-mode combined fire extinguishing device according to claim 1, characterized in that: The air-powder output device (4) includes an air-powder output cylinder (40), a screw shaft (41), an air inlet valve (45), and a first electromagnetic clutch (44). The air-powder output cylinder (40) is a hollow cylindrical shell. The screw shaft (41) is installed through the air-powder output cylinder (40) along its axis. The air delivery chamber (42) and the feeding chamber (43) are arranged in sections along the axial direction of the screw shaft (41) in the air-powder output cylinder (40). The air inlet valve (45) is installed on the cylinder wall corresponding to the air delivery chamber (42). A dry powder inlet (46) connected to the discharge pipe of the dry powder storage device (3) is opened on the cylinder wall corresponding to the feeding chamber (43). The power input end of the screw shaft (41) is connected to the power output mechanism (6) via the first electromagnetic clutch (44).

6. The high-pressure gas atomization water mist dry powder multi-mode combined fire extinguishing device according to claim 5, characterized in that: The input end of the first electromagnetic clutch (44) is provided with a synchronous pulley, which is connected to the power output end of the power output mechanism (6) via a synchronous belt; when the first electromagnetic clutch (44) is in the disengaged state, it cuts off the power transmission between the screw shaft (41) and the power output mechanism (6).

7. The high-pressure gas atomization water mist dry powder multi-mode combined fire extinguishing device according to claim 5, characterized in that: The dry powder storage device (3) includes a dry powder tank (31), a pusher cylinder (32) and a pusher piston (33). The pusher cylinder (32) is located below the dry powder tank (31) and is connected to the dry powder tank (31) via a discharge pipe. The pusher piston (33) is installed inside the pusher cylinder (32). The dry powder pushing device (5) includes a dry powder pushing worm (51), a dry powder pushing worm wheel (52), a second electromagnetic clutch (53), a pusher connecting rod turntable (54) and a pusher connecting rod mechanism (55). The dry powder pushing worm (51) meshes with the dry powder pushing worm wheel (52). One end of the pusher connecting rod mechanism (55) is eccentrically hinged to the surface of the pusher connecting rod turntable (54), and the other end is connected to the pusher piston (33).

8. The high-pressure gas atomization water mist dry powder multi-mode combined fire extinguishing device according to claim 7, characterized in that: The second electromagnetic clutch (53) is connected in series between the dry powder pushing worm wheel (52) and the pushing connecting rod turntable (54). The driving end of the second electromagnetic clutch (53) is connected to the dry powder pushing worm wheel (52), and the driven end is connected to the pushing connecting rod turntable (54). The dry powder pushing worm (51) is constantly meshed with the dry powder pushing worm wheel (52).

9. The high-pressure gas atomization water mist dry powder multi-mode combined fire extinguishing device according to claim 7, characterized in that: The power output mechanism (6) is a split mechanism with three output ends. The power output unit (1) is a motor or a hydraulic motor. The power output mechanism (6) sends the power of the power output unit (1) to the mixing shaft (21), the screw shaft (41) and the dry powder pushing worm (51) respectively.

10. A high-pressure gas atomization water mist dry powder multi-mode combined fire extinguishing control method, using the high-pressure gas atomization water mist dry powder multi-mode combined fire extinguishing device according to any one of claims 1 to 9, characterized in that, Includes the following modes: Water mist mode: The first electromagnetic clutch (44) and the second electromagnetic clutch (53) are both disengaged, the shut-off valve on the side of the air inlet (200) is closed, the mixing shaft (21) is driven to drive the booster impeller (22) to rotate, and the high-pressure water enters the housing (20) from the water inlet (100) and is sheared and atomized by the booster impeller (22) to form a water mist flow that is sprayed out from the output port (24); Gas atomization mode: Keep the mixing shaft (21) rotating, and at the same time, high-pressure gas is introduced into the airflow splitter (25) through the air inlet (200). The high-pressure gas is sprayed out obliquely in the same direction through each of the air guide oblique ports (26), and the water mist at the outlet of the booster impeller (22) is broken up twice and then sprayed out through the outlet (24). Dry powder mode: The first electromagnetic clutch (44) is engaged, and the screw shaft (41) pushes the dry powder falling from the dry powder storage device (3) into the cavity of the housing (20). At the same time, high-pressure gas is introduced into the air delivery chamber (42) through the air inlet valve (45) to form a gas-powder two-phase flow. The gas-powder two-phase flow is ejected through the output port (24). When the dry powder feed flow rate is lower than the set threshold, the second electromagnetic clutch (53) engages, and the pusher piston (33) periodically squeezes the dry powder in the dry powder tank (31). Combined mode: Two or three of the above three channels of water mist, gas atomization and dry powder are activated at the same time, and the media of each channel are combined in the housing (20) and sprayed out through the output port (24).

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