Ejector-type supersonic dry powder fire extinguishing device

Abstract

The present invention discloses an ejector-type supersonic dry powder fire extinguishing device. A driving gas tank and a low-pressure tank are placed on a trolley. An air injection port is provided on the driving gas tank. The driving gas tank and the low-pressure tank are connected by a metal pipe, and a pressure reducing valve is installed on the metal pipe; a powder storage device is fixed inside the low-pressure tank. One end of a powder conveying metal hose is connected to the bottom of the powder storage device, and the other end extends downward and is divided into two branches and then leads out of the low-pressure tank body and is connected to an ejector nozzle; an ejector nozzle for realizing supersonic powder spraying is arranged outside the low-pressure tank body, and the inlet end of the ejector nozzle is connected to a sealing connector; under the action of air flow, the gas-solid two-phase flow in the ejector nozzle crosses from subsonic speed to supersonic speed to achieve jet flow. The present invention finally expands the high-speed fire extinguishing efficiency of the fire extinguishing device. The setting of ejector-type powder spraying enables full utilization of the dry powder agent, effectively and economically improves the fire extinguishing ability, and achieves a noise reduction effect.

Description

Technical Field

[0001] The present invention relates to a fire-fighting equipment, and more particularly to an ejector-type supersonic dry powder fire extinguishing device. Background Art

[0002] Dry powder fire extinguishers are an important fire-fighting tool, and fire extinguishing devices are equipped in many places. Professional, convenient, and efficient fire extinguishing device design technology is of great significance for quickly controlling the fire, minimizing casualties, and effectively reducing losses. Only by fully understanding the gas-solid two-phase flow behavior inside and outside the dry powder fire extinguishing agent transport channel and systematically mastering the influence laws of geometry, physical properties, and operating parameters can the key technologies for designing the core components of dry powder fire extinguishing devices be provided.

[0003] The common disadvantages of the currently used fire extinguishing devices are complex structure, high manufacturing cost, inconvenient use, and insufficient fire extinguishing performance. In order to better improve the fire extinguishing efficiency and reduce the cost of fire extinguishing agent, it is necessary to develop an ejector-type supersonic dry powder fire extinguishing device. Summary of the Invention

[0004] In order to solve the problems in the background art, the present invention designs an ejector-type supersonic dry powder fire extinguishing device.

[0005] The technical solution of the present invention is as follows:

[0006] I. An ejector-type supersonic dry powder fire extinguishing device

[0007] It includes a trolley, a sealed connector, a driving gas tank, a low-pressure tank, a powder storage device, a powder-transporting metal hose, and an ejector nozzle. The driving gas tank and the low-pressure tank are placed on the trolley. The driving gas tank is provided with an air injection port. The driving gas tank and the low-pressure tank are connected by a metal pipe, and a pressure reducing valve is installed on the metal pipe;

[0008] The powder storage device is fixed inside the low-pressure tank. One end of the powder-transporting metal hose is connected to the bottom of the powder storage device, and the other end extends downward and is divided into two branch paths and then leads out of the low-pressure tank body. Sealed connectors for sealing the tank body are provided at the connections of the two branch paths of the powder-transporting metal hose and the low-pressure tank;

[0009] An ejector nozzle for realizing supersonic powder spraying is arranged outside the low-pressure tank body. The ejector nozzle includes a straight pipe section, a contraction section, and an expansion section connected in sequence from the inlet end to the outlet end. The inlet end of the ejector nozzle is connected to the sealed connector and thus communicates with the inside of the low-pressure tank body. The two powder-transporting metal hoses are respectively connected to the expansion section of the ejector nozzle after leading out of the low-pressure tank body, and the connection positions are close to the contraction section.

[0010] The inner diameter of the straight pipe section of the ejector nozzle remains unchanged; in the direction from the inlet end to the outlet end, the inner diameter of the contraction section decreases from large to small, and the inner diameter of the expansion section decreases from large to small; the radius of the inlet end of the ejector nozzle is 10.2 mm to 12.7 mm, preferably 11.5 mm; the radius of the outlet end is 14.8 mm to 17.3 mm, preferably 16.1 mm; the radius at the connection of the expansion section and the contraction section is 6.85 mm to 9.25 mm, preferably 8.05 mm.

[0011] The axial length of the straight line section is 44.8 mm to 47.2 mm, preferably 46 mm; the axial length of the contraction section is 67.8 mm to 70.2 mm, preferably 69 mm; the axial length of the expansion section is 136.8 mm to 139.2 mm, preferably 138 mm.

[0012] The contraction angle α of the contraction section is between 3.16° and 5.54°, preferably 5.3°; the expansion angle β of the expansion section is between 1.2° and 3.5°, preferably 3.34°; the powder transportation angle θ at the connection of the two powder transportation metal hoses and the low-pressure tank is 45°, preferably 30° to 50°.

[0013] A spherical control dry powder flow valve is installed on the main path of the powder transportation metal hose;

[0014] The spherical control dry powder flow valve is used to control the dry powder flow and prevent the continuous output of dry powder due to gravity;

[0015] A spherical control gas flow valve is installed at the outlet end of the ejector nozzle to control the intermittent operation of the air flow and interrupt the spraying at any time.

[0016] Two pressure gauges are provided on the pressure reducing valve to measure the pressure values in the low-pressure tank and the driving gas tank respectively, so as to facilitate the real-time understanding of the pressure changes.

[0017] The pressure reducing valve is used to control the air flow to reduce the air flow pressure entering the low-pressure tank.

[0018] The pressure value of the low-pressure tank is controlled between 1.4 MPa and 2.5 MPa, and the pressure value of the driving gas tank is controlled between 12.4 MPa and 13.7 MPa.

[0019] The material of the driving gas tank is a high-pressure resistant material.

[0020] Due to the certain weight of the tank body, the driving gas tank and the low-pressure tank are fixed on the trolley through a fixed protection ring, which is convenient to move to the fire extinguishing site.

[0021] A noise reduction device for reducing noise is installed in the expansion section of the ejector nozzle.

[0022] The gas injection port is used to supplement gas.

[0023] According to the specification "GB8109-2005 - Wheeled Fire Extinguishers", the length of the ejector nozzle is 5 meters, and the ejector nozzle should be securely fixed in a storage box or a clamping device to ensure that it can be quickly and easily deployed for use in case of danger.

[0024] II. A working method of an ejector-type supersonic dry powder fire extinguishing device, characterized in that:

[0025] S1: First, open the low-pressure tank, load the dry powder fire extinguishing agent into the powder storage device in the low-pressure tank, and then close the low-pressure tank;

[0026] S2: Inject gas into the driving gas tank through the gas injection port. After the pressure in the driving gas tank rises to a stable value, open the pressure reducing valve. The gas flow in the driving gas tank enters the low-pressure tank through a metal pipe, so that the pressure in the low-pressure tank reaches a stable value;

[0027] S3: Open the spherical control dry powder flow valve and the spherical control gas flow valve. The dry powder fire extinguishing agent in the powder storage device enters the ejector nozzle through the powder delivery metal hose under the pressure of the gas flow in the low-pressure tank. Part of the gas flow enters from the inlet end of the ejector nozzle, and the gas flow velocity at the inlet end is subsonic;

[0028] S4: In the expansion section of the ejector nozzle, the dry powder fire extinguishing agent intersects with the gas flow entering the ejector nozzle to form a gas-solid two-phase flow. The gas-solid two-phase flow is ejected from the outlet end after passing through the expansion section. The gas-solid two-phase flow achieves a jet with the velocity changing from subsonic to supersonic in the expansion section.

[0029] The particle velocity of the dry powder fire extinguishing agent along the axis of the nozzle is calculated by the following method:

[0030] 1) Calculate the initial particle velocity v when the dry powder fire extinguishing agent enters the ejector nozzle. The specific calculation formula is as follows:

[0031]

[0032] where A e is the area of the outlet end of the nozzle; A * is the area of the throat of the nozzle. The throat of the nozzle is the connection between the contraction section and the expansion section; p 0 is the pressure value at the inlet end of the nozzle; p e is the pressure value of the environment; M is the Mach number at the outlet of the nozzle, a is the speed of sound, which is 340 m / s; γ is a constant, and the value is γ = 1.4;

[0033] 2) Input the structural parameters of the ejector nozzle and the calculated initial velocity v into the Fluent 19.0 software to simulate the movement of the gas-solid two-phase flow in the ejector nozzle, so as to obtain the particle velocity of the dry powder fire extinguishing agent ejected from the outlet end of the ejector nozzle.

[0034] The structural parameters of the ejector nozzle include the length, inner diameter, and expansion angle of the ejector nozzle.

[0035] The pressure value p at the inlet end of the nozzle 0 is the pressure value in the low-pressure tank.

[0036] Advantages of the present invention:

[0037] 1) The ejector nozzle of the present invention can generate supersonic airflow, expanding the high-speed fire extinguishing efficiency of the fire extinguishing device. The setting of ejector powder injection enables full utilization of the dry powder agent, effectively and economically improving the fire extinguishing ability;

[0038] 2) The present invention can freely adjust the ejection direction of the ejector nozzle; there are no flying objects during operation, and a noise reduction effect is achieved. Description of the drawings

[0039] Figure 1 is a schematic diagram of the overall appearance of the present invention.

[0040] Figure 2 is a schematic structural diagram of the present invention.

[0041] Figure 3 is a schematic diagram of the ejector supersonic nozzle.

[0042] Figure 4 is a comparison diagram of the particle velocities of the dry powder along the axis of the nozzle in the device of the present invention and the existing fire extinguishing device.

[0043] In the figure: 1 trolley, 2 pressure gauge, 2 gas injection ports, 3 gas injection port, 4 metal pipe, 5 tank body fixed protection ring, 6 pressure reducing valve, 7 driving gas tank, 8 low-pressure tank, 9 powder storage device, 10 spherical control of dry powder flow, 11 sealed connector, 12 powder delivery metal hose, 13 ejector nozzle, 14 noise reduction device, 15 spherical control gas flow valve. Detailed implementation manners

[0044] The present invention will be further described below in conjunction with the drawings and embodiments.

[0045] As Figure 1 and Figure 2 shown, the present invention includes a trolley 1, a sealed connector 11, a driving gas tank 7, a low-pressure tank 8, a powder storage device 9, a powder delivery metal hose 12, and an ejector nozzle 13. Two tanks, the driving gas tank 7 and the low-pressure tank 8, are fixed on the trolley. An air injection port 3 is provided on the driving gas tank for supplying gas. The driving gas tank 7 and the low-pressure tank 8 are connected by a metal pipe 4, and a pressure reducing valve 6 is installed on the metal pipe 4; two pressure gauges 2 are installed on the pressure reducing valve 6 to measure the pressure values in the low-pressure tank and the driving gas tank respectively.

[0046] A powder storage device 9 is installed in the low-pressure tank 8. The powder storage device 9 is connected to a powder delivery metal hose 12. A spherical control dry powder flow valve 10 is provided on the main path of the powder delivery metal hose 12. After leading the powder delivery metal hose 12 out of the tank body, it is connected to the expansion section of an ejector nozzle 13. A sealing connector 11 for sealing the tank body is provided at the connection between the powder delivery metal hose 12 and the ejector nozzle 13; the right lower side of the low-pressure tank is connected to the ejector nozzle. According to the specification "GB8109-2005 - Wheeled fire extinguishers", a metal hose with a length of 5 meters is provided. A controllable injection control valve is equipped at the end of the ejector nozzle for intermittent operation and interruption of injection at any time, and a noise reduction device is installed at the outlet end of the ejector nozzle to achieve the effect of noise reduction.

[0047] Such as Figure 3 In order to Figure 2 The structure diagram of the ejector nozzle after magnifying the circled part. The ejector nozzle 13 includes a straight pipe section AB, a contraction section BC, and an expansion section CD that are sequentially connected from the inlet end to the outlet end; the inner diameter of the straight pipe section of the ejector nozzle 13 remains unchanged; in the direction from the inlet end to the outlet end, the inner diameter of the contraction section decreases from large to small, and the inner diameter of the expansion section decreases from large to small; the radius of the inlet end of the ejector nozzle 13 is 10.2 mm to 12.7 mm; the radius of the outlet end is 14.8 mm to 17.3 mm; the radius at the connection between the expansion section and the contraction section is 6.85 mm to 9.25 mm. The axial length of the straight line section is 44.8 mm to 47.2 mm, preferably 46 mm; the axial length of the contraction section is 67.8 mm to 70.2 mm, preferably 69 mm; the axial length of the expansion section is 136.8 mm to 139.2 mm, preferably 138 mm. The contraction angle α of the contraction section is between 3.16° and 5.54°, preferably 5.3°; the expansion angle β of the expansion section is between 1.2° and 3.5°, preferably 3.34°; the inclination angle θ of the output ends of the two powder delivery metal hoses 12 relative to the horizontal line is 45°, preferably 30° to 50°.

[0048] The driving gas tank is used to provide a gas source and is made of high-pressure resistant material; the pressure reducing valve 6 is used to reduce the pressure; the gas injection port is used to supplement gas; the dry powder fire extinguishing agent is a dry powder fire extinguishing agent with ultra-fine particle size and excellent performance that is controlled in proportion as needed; the spherical control dry powder flow valve 10 is used to control the dry powder flow to prevent continuous output of dry powder due to gravity; the powder delivery metal hose 12 is made of a metal hose to reduce friction; in order to reduce noise, a noise reduction device 14 is installed in the expansion section of the ejector supersonic nozzle; due to the certain weight of the tank body, the tank body is fixed on the trolley 1 through a fixed protection ring 5, which is convenient to move to the fire extinguishing site.

[0049] The specific working process of the implementation of the present invention:

[0050] First, open the low-pressure tank 8 and load dry powder into the powder storage device 9. Close the low-pressure tank 8 and fill it with gas. After the pressure in the gas driving tank rises to a stable value, open the pressure reducing valve to make the pressure in the low-pressure tank reach a stable value. At this time, open the spherical control dry powder flow valve 10 and the spherical control gas flow valve 15. The dry powder in the powder storage device enters the input end of the ejector nozzle through the powder conveying metal hose 12 under the action of the air flow pressure. Part of the air flow enters the injection metal hose. In the expansion section of the ejector nozzle 13, the dry powder fire extinguishing agent intersects with the air flow entering the ejector nozzle 13 to form a gas-solid two-phase flow. The gas-solid two-phase flow is ejected from the outlet end after passing through the expansion section. The velocity of the gas-solid two-phase flow crosses from subsonic to supersonic in the expansion section to achieve jetting.

[0051] As Figure 4 shown, according to the Fluent 19.0 software simulation, the comparison diagram of the particle velocity of the dry powder along the axis direction of the nozzle in the device of the present invention (ejector powder feeding) and the existing fire extinguishing device (axial powder feeding) can be obtained. It can be seen that the particle velocity of the ejector powder feeding is greater than that of the axial powder feeding, and the ejector powder feeding of the present invention can spray a farther distance while maintaining a high speed compared with the axial powder feeding, so the effect is better.

[0052] The highest particle velocity of the present invention can reach 415 m / s.

[0053] The calculation method of the particle velocity of the dry powder fire extinguishing agent along the axis direction of the nozzle in the device of the present invention is as follows:

[0054] 1) Calculate the initial particle velocity v when the dry powder fire extinguishing agent enters the ejector nozzle 13. The specific calculation formula is as follows:

[0055]

[0056] Among them, A e is the area of the outlet end of the nozzle; A * is the area of the throat of the nozzle. The throat of the nozzle is the connection between the contraction section and the expansion section; p 0 is the pressure value at the inlet end of the nozzle, which is the pressure value in the low-pressure tank; p e is the pressure value of the environment; M is the Mach number at the outlet of the nozzle, a is the speed of sound, which is 340 m / s; γ = 1.4;

[0057] 2) Input the structural parameters of the ejector nozzle and the calculated initial velocity v into the Fluent 19.0 software to simulate the movement of the gas-solid two-phase flow in the ejector nozzle 13, so as to obtain the particle velocity of the dry powder fire extinguishing agent ejected from the outlet end of the ejector nozzle 13.

Claims

1. An ejector-type supersonic dry powder fire extinguishing device, characterized in that: It includes a trolley (1), a sealed connector (11), a driving gas tank (7), a low-pressure tank (8), a powder storage device (9), a powder delivery metal hose (12) and an ejector nozzle (13). The driving gas tank (7) and the low-pressure tank (8) are placed on the trolley (1). An air injection port (3) is provided on the driving gas tank (7). The driving gas tank (7) and the low-pressure tank (8) are connected by a metal pipe (4), and a pressure reducing valve (6) is installed on the metal pipe (4); A powder storage device (9) is fixed inside the low-pressure tank (8). One end of the powder delivery metal hose (12) is connected to the bottom of the powder storage device (9), and the other end extends downward and is divided into two branch paths and then leads out of the low-pressure tank (8) body. Sealed connectors (11) for sealing the tank body are provided at the connections of the two branch paths of the powder delivery metal hose (12) with the low-pressure tank (8); An ejector nozzle (13) for realizing supersonic powder spraying is provided outside the low-pressure tank (8) body. The ejector nozzle (13) includes a straight pipe section, a contraction section and an expansion section connected in sequence from the inlet end to the outlet end. The inlet end of the ejector nozzle (13) is connected to the sealed connector (11) and thus communicates with the inside of the low-pressure tank (8) body. The two powder delivery metal hoses (12) are led out of the low-pressure tank (8) body and are respectively connected to the expansion section of the ejector nozzle (13), and the connection is close to the contraction section; The working method of the ejector-type supersonic dry powder fire extinguishing device includes the following steps: S1: First, open the low-pressure tank (8), load the dry powder fire extinguishing agent into the powder storage device (9) in the low-pressure tank (8), and then close the low-pressure tank (8); S2: Fill the driving gas tank (7) with gas through the air injection port (3). After the pressure in the driving gas tank (7) rises to a stable value, open the pressure reducing valve (6). The air flow in the driving gas tank (7) enters the low-pressure tank (8) through the metal pipe (4) to make the pressure in the low-pressure tank (8) reach a stable value; S3: Open the spherical control dry powder flow valve (10) and the spherical control gas flow valve (15). The dry powder fire extinguishing agent in the powder storage device enters the ejector nozzle (13) through the powder delivery metal hose under the pressure of the air flow in the low-pressure tank (8). Part of the air flow enters from the inlet end of the ejector nozzle (13), and the air flow speed at the inlet end is subsonic; S4: In the expansion section of the ejector nozzle (13), the dry powder fire extinguishing agent intersects with the air flow entering the ejector nozzle (13) to form a gas-solid two-phase flow. The gas-solid two-phase flow is ejected from the outlet end after passing through the expansion section. The speed of the gas-solid two-phase flow crosses from subsonic to supersonic in the expansion section to achieve jet flow.

2. The ejector-type supersonic dry powder fire extinguishing device according to claim 1, characterized in that: The inner diameter of the straight pipe section of the ejector nozzle (13) remains unchanged; in the direction from the inlet end to the outlet end, the inner diameter of the contraction section decreases from large to small, and the inner diameter of the expansion section decreases from large to small; The radius of the inlet end of the ejector nozzle (13) is 10.2 mm to 12.7 mm, and is 11.5 mm; the radius of the outlet end is 14.8 mm to 17.3 mm, and is 16.1 mm; the radius at the connection of the expansion section and the contraction section is 6.85 mm to 9.25 mm, and is 8.05 mm.

3. An ejector type supersonic dry powder fire extinguishing device according to claim 1, characterized in that: The axial length of the straight pipe section is 44.8 mm to 47.2 mm, and is 46 mm; the axial length of the contraction section is 67.8 mm to 70.2 mm, and is 69 mm; the axial length of the expansion section is 136.8 mm to 139.2 mm, and is 138 mm.

4. An ejector type supersonic dry powder fire extinguishing device according to claim 1, characterized in that: The contraction angle α of the contraction section is between 3.16° and 5.54°, and is 5.3°; the expansion angle β of the expansion section is between 1.2° and 3.5°, and is 3.34°; the powder conveying angle θ at the connection of the two powder conveying metal hoses (12) and the low-pressure tank (8) is 45°, and is 30° to 50°.

5. An ejector type supersonic dry powder fire extinguishing device according to claim 1, characterized in that: A spherical control dry powder flow valve (10) is installed on the main path of the powder conveying metal hose (12); A spherical control gas flow valve (15) is installed at the outlet end of the ejector nozzle (13).

6. An ejector type supersonic dry powder fire extinguishing device according to claim 1, characterized in that: Two pressure gauges (2) are provided on the pressure reducing valve (6) for respectively measuring the pressure values in the low-pressure tank (8) and the driving gas tank (7).

7. An ejector type supersonic dry powder fire extinguishing device according to claim 1, characterized in that: The pressure reducing valve (6) is used to control the air flow to reduce the air flow pressure entering the low-pressure tank (8).

8. An ejector type supersonic dry powder fire extinguishing device according to claim 1, characterized in that: The pressure value of the low-pressure tank (8) is controlled between 1.4 MPa and 2.5 MPa, and the pressure value of the driving gas tank (7) is controlled between 12.4 MPa and 13.7 MPa.

9. The working method of the ejector type supersonic dry powder fire extinguishing device according to claim 1, characterized in that: The particle velocity of the dry powder fire extinguishing agent sprayed along the axis direction of the nozzle is calculated by the following method: 1) Calculate the initial particle velocity v when the dry powder fire extinguishing agent enters the ejector nozzle (13), and the specific calculation formula is as follows: Among them, A e is the area of the outlet end of the nozzle; A * is the area of the throat of the nozzle; p 0 is the pressure value at the inlet end of the nozzle; p e is the pressure value of the environment; M is the Mach number at the outlet of the nozzle, a is the speed of sound, which is 340 m / s; γ is a constant, and the value is γ = 1.4; 2) Input the structural parameters of the ejector nozzle and the calculated initial velocity v into the Fluent software to simulate the movement of the gas-solid two-phase flow in the ejector nozzle (13), so as to obtain the particle velocity of the dry powder fire extinguishing agent ejected from the outlet end of the ejector nozzle (13).

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