Single-stage atomized iron powder production system

Abstract

This application relates to the field of metal powder production technology, and more particularly to a single-stage atomized iron powder production system. Its technical solution includes a tower body, a liquid film generation component, a crushing module, a cooling and dispersing component, a liquid quenching and rapid cooling unit, a circulating cooling system, and a gas extraction system. The liquid film generation component compresses molten metal into an annular thin-walled liquid film, eliminating the gas encapsulation conditions caused by hollow powder at the source. The crushing module adopts a two-stage series layout of a pre-tearing component and a deep crushing component, respectively using low-pressure heated gas and high-pressure gas to perform pre-tearing focusing and secondary deep crushing of the liquid film, achieving a high fine powder yield with low gas consumption. The cooling and dispersing component uses a conical diffusion section to uniformly disperse the powder and fully gas-cool it. The liquid quenching and rapid cooling unit uses concentric annular grooves to perform water quenching and rapid cooling of the powder and achieve gas-water separation, significantly reducing the tower height. This application effectively reduces the hollow powder rate and improves the fine powder yield, making it suitable for the large-scale production of high-quality iron powder.

Description

Technical Field

[0001] This invention relates to the field of metal powder production technology, and in particular to a single-stage atomized iron powder production system. Background Technology

[0002] Metal powders are core raw materials in powder metallurgy, additive manufacturing, and new energy battery materials, and their quality indicators directly affect the performance of downstream products. Especially in the production of battery-grade iron phosphate, extremely stringent requirements are placed on the particle size distribution, spherical morphology, and internal density of the iron source powder. Gas atomization has become the mainstream production process due to its ability to produce metal powders with high sphericity and low oxygen content. Its basic principle is to use a high-speed inert gas jet to impact the molten metal flow, breaking it into fine droplets that cool and solidify during flight.

[0003] However, traditional atomization devices typically use solid metal liquid columns as the breaking-up target. When high-pressure gas impacts the liquid column from the outside, the surface of the liquid column rapidly solidifies and forms a hard shell due to the rapid cooling. The gas dissolved or entrained inside the liquid column does not have time to diffuse outward before the solidified shell seals, ultimately becoming trapped inside the powder particles, forming a hollow structure. This results in a significant decrease in the tap density of the powder, severely impacting the process stability and product yield of subsequent pressing, sintering, or battery material preparation processes. Furthermore, in single-stage atomization processes, the high-pressure gas simultaneously performs the dual functions of droplet breaking and forced cooling. Breaking and cooling occur almost simultaneously, and premature solidification of the droplet surface further blocks the diffusion channels of the internal gas, exacerbating the hollow powder defect. Summary of the Invention

[0004] The purpose of this application is to address the problems existing in the background technology by proposing a single-stage atomized iron powder production system.

[0005] The technical solution of this application is: a single-stage atomized iron powder production system, including a tower body with a liquid supply port at the top;

[0006] A liquid film generating component is installed inside the top of the tower body and connected to the liquid supply port. It is used to squeeze the incoming molten metal flow from a columnar shape into a downward-conveyed annular thin-walled liquid film.

[0007] The crushing module located downstream of the liquid film generation component includes a pre-tear component and a deep crushing component. The pre-tear component is arranged circumferentially around the outlet of the liquid film generation component, and the airflow jet direction of the pre-tear component converges towards the central axis. It is used to perform primary crushing of the annular thin-walled liquid film and to gather the crushed metal droplets towards the center by means of negative pressure effect. The deep crushing component is arranged circumferentially downstream of the pre-tear component, and the airflow jet direction of the deep crushing component is inclined inward. It is used to perform secondary refinement crushing of the gathered metal droplets.

[0008] A cooling and dispersing component is located downstream of the deep crushing component. Its internal channels gradually expand along the flow direction to disperse the secondary refined metal powder radially and reduce its movement speed, thereby extending the air cooling time.

[0009] Optionally, the liquid film generation assembly includes an outer tube and an inner mold coaxially sleeved together, with an annular guide slit defined between the inner wall of the outer tube and the outer wall of the inner mold, and the outlet gap width of the annular guide slit being 1.5mm-2.5mm.

[0010] The lower end of the outer tube is provided with an outward expansion portion, the bottom end of the inner mold terminates at the starting position of the outward expansion portion, and the bottom end face of the inner mold is a tapered guide surface.

[0011] Optionally, the pre-tear assembly includes a plurality of first jet holes, which are evenly distributed on the inclined surface of the outward expansion portion, and the jet directions of each first jet hole converge in the central negative pressure area below the conical guide surface.

[0012] The deep crushing component includes a plurality of second jet holes, which are located 30mm-50mm below the first jet hole, and the jet direction of each second jet hole makes an angle of 15°-25° with the vertical axis.

[0013] Optionally, the pre-tear assembly is connected to a low-pressure gas supply ring and a first gas supply pipe. The working medium of the low-pressure gas supply ring is a preheated inert gas with a pressure of 0.4MPa-0.8MPa.

[0014] The deep crushing component is connected to a high-pressure air supply ring and a second air supply pipe. The working medium of the high-pressure air supply ring is high-pressure inert gas with a pressure of 1.5MPa-3.0MPa. Both the first and second spray holes adopt a Laval nozzle structure.

[0015] Optionally, the cooling dispersion component includes a conical diffusion section connected to the outlet of the deep crushing component, wherein the expansion angle of the conical diffusion section is 30°–45°, and the ratio of its inlet cross-sectional area to its outlet cross-sectional area is 1:3–1:5.

[0016] The conical diffuser section has multiple air film nozzles parallel to the wall surface. These multiple air film nozzles are connected to a gas delivery box, which is connected to an external gas source through a gas delivery pipe.

[0017] Optionally, the cooling dispersion assembly further includes a large-diameter vertical cylinder section connected downstream of the conical diffuser section, wherein the inner diameter of the vertical cylinder section is consistent with the outlet inner diameter of the conical diffuser section, and the axial height of the vertical cylinder section is not less than 5 times its inner diameter.

[0018] Optionally, a liquid quenching unit is further provided downstream of the cooling dispersion component. The liquid quenching unit includes at least one set of cooling modules, and the cooling modules include:

[0019] A concentric annular tank assembly consists of an outer annular water storage tank and an inner annular water storage tank at the same horizontal level. An annular gap is left between the outer annular water storage tank and the inner annular water storage tank to allow airflow to pass through. The two tanks are interconnected by a connecting pipe that spans the annular gap. Multiple drain outlets are provided on the upper surface of the connecting pipe.

[0020] A gap receiving groove is provided directly below the annular gap, the radial width of the gap receiving groove is greater than the radial width of the annular gap, and the minimum width of the annular gap is greater than 100mm;

[0021] The outer ring water storage tank, inner ring water storage tank, and gap receiving tank are all open-top structures, and the top edge of each tank is provided with an overflow guiding structure to allow the overflowing cooling water to form a continuous wall-attached water film along the outer wall of the tank.

[0022] Optionally, the bottom of the outer ring water storage tank is provided with an outer ring powder discharge port, the bottom of the inner ring water storage tank is provided with an inner ring powder discharge port, the bottom of the gap receiving groove is provided with a gap powder discharge port, and the bottom cross-section of the outer ring water storage tank, the inner ring water storage tank and the gap receiving groove are all V-shaped, and the inclination angle of the V-shaped bottom surface is greater than 45°.

[0023] The outer ring water storage tank is also connected to a circulating water supply pipe.

[0024] Optionally, the liquid quenching rapid cooling unit is equipped with a circulating cooling system, the circulating cooling system comprising:

[0025] The liquid collection chamber located at the bottom of the tower body is used to receive the solid-liquid mixture discharged from the outer ring powder discharge port, the inner ring powder discharge port and the gap powder discharge port;

[0026] A solid-liquid separator connected to the outlet of the liquid collection chamber;

[0027] A coolant tank connected to the liquid outlet of the solid-liquid separator, wherein a heat exchanger is provided in the coolant tank;

[0028] A circulation pump and a delivery pipe connected between the coolant tank and the circulating water supply pipe are used to send the cooled liquid back to the outer ring water storage tank.

[0029] Optionally, a gas extraction system is also provided at the bottom of the tower body, the gas extraction system comprising:

[0030] An air extraction port is provided on the bottom side wall of the tower body, and the air extraction port is located above the liquid discharge port of the liquid collection chamber in the height direction;

[0031] A dust collector, a gas-liquid separator, and an air pump are connected in sequence to the air extraction port.

[0032] In summary, this application includes at least one of the following beneficial technical effects:

[0033] This application transforms molten metal from a solid liquid column into a thin-walled annular liquid film using a liquid film generation component, which significantly increases the specific surface area of ​​the metal fluid. Both the inner and outer sides of the liquid film are exposed to the surrounding atmosphere, allowing the encapsulated gas to escape freely from both sides during the liquid film formation stage. This eliminates the gas encapsulation conditions caused by hollow powder from a physical source, fundamentally solving the core defect in traditional atomization processes where the gas cannot escape due to the instantaneous crusting on the surface of the liquid column.

[0034] The crushing module adopts an axially connected series layout of a pre-tearing component and a deep crushing component. The pre-tearing component uses low-pressure heated gas to gently tear the annular liquid film and uses the negative pressure focusing effect to constrain the coarse droplets to the central axis region, so that the surface cooling rate of the droplets is controlled and the internal gas has sufficient time to escape. The deep crushing component uses high-pressure gas to carry out strong impact and refinement in the optimal semi-solid crushing window after the droplets have completed degassing. This realizes the temporal separation and synergistic optimization of crushing and degassing functions, significantly reducing the total gas consumption while greatly improving the fine powder yield and reducing the hollow powder rate to an extremely low level. Attached Figure Description

[0035] Figure 1 Schematic diagram of the atomizing tower structure Figure 1 ;

[0036] Figure 2 Schematic diagram of the atomizing tower structure Figure 2 ;

[0037] Figure 3 This is a schematic diagram of the air extraction system.

[0038] Figure 4 This is a schematic diagram of the water pump circulation system;

[0039] Figure 5 This is a structural diagram of the tower.

[0040] Figure 6 This is a schematic diagram of the internal structure of the tower.

[0041] Figure 7 for Figure 6 A magnified view of a section at point A in the middle;

[0042] Figure 8 for Figure 6A magnified view of a section at point B in the middle;

[0043] Figure 9 This is a schematic diagram of the atomizing nozzle assembly;

[0044] Figure 10 Schematic diagram of a wet quenching device Figure 1 ;

[0045] Figure 11 Schematic diagram of a wet quenching device Figure 2 ;

[0046] Figure 12 for Figure 10 A magnified view of a section at point C.

[0047] Reference numerals: 1. Tower body; 11. Liquid supply port; 12. Liquid collection chamber;

[0048] 2. Liquid film generation assembly; 21. Outer tube; 211. Outer expansion section; 22. Inner mold; 23. Annular guide slit;

[0049] 3. Crushing module; 31. Pre-tear assembly; 311. Low-pressure air supply ring; 312. First air supply pipe; 32. Deep crushing assembly; 321. High-pressure air supply ring; 322. Second air supply pipe;

[0050] 4. Cooling and dispersing components; 41. Conical diffuser section; 411. Vertical cylinder section; 42. Gas delivery box; 43. Film gas nozzle; 44. Gas delivery pipe;

[0051] 5. Liquid quenching and rapid cooling unit; 51. Cooling module; 511. Outer ring water tank; 512. Inner ring water tank; 513. Connecting pipe; 514. Gap receiving groove; 515. Outer ring powder discharge port; 516. Inner ring powder discharge port; 517. Gap powder discharge port; 518. Drain outlet; 519. Circulating water supply pipe;

[0052] 6. Circulating cooling system; 61. Discharge port; 62. Solid-liquid separator; 63. Circulating pump; 64. Liquid delivery pipe; 65. Coolant tank;

[0053] 7. Gas extraction system; 71. Air extraction port; 72. Dust collector; 73. Gas-liquid separator; 74. Air pump. Detailed Implementation

[0054] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0055] Example 1, as Figure 1 and Figure 6 , Figure 7As shown, the single-stage atomized iron powder production system proposed in this application includes a tower body 1 with a liquid supply port 11 at the top, and a liquid film generation component 2 installed inside the top of the tower body 1 and connected to the liquid supply port 11. It is used to squeeze the incoming molten metal flow from a columnar shape into a downward conveying annular thin-walled liquid film. In traditional atomization devices, the molten metal flows out in the form of a solid liquid column. When high-pressure gas impacts the liquid column from the outside, the surface of the liquid column cools and forms a shell instantly. The internal gas does not have time to escape and is trapped in the solidified shell, forming a hollow powder defect.

[0056] The liquid film generation component 2 forces molten iron into an annular thin-walled liquid film, which greatly increases the specific surface area of ​​the metal fluid. Both the inner and outer sides of the liquid film are exposed to the surrounding atmosphere, and the encapsulated gas can escape freely from both sides during the liquid film formation stage. This eliminates the gas encapsulation conditions caused by hollow powder from the physical source. At the same time, the heat capacity and heat conduction distance of the thin-walled liquid film are greatly reduced, providing a more uniform and energy-efficient crushing object for subsequent atomization crushing.

[0057] Furthermore, the liquid film generation component 2 includes an outer tube 21 and an inner mold 22 coaxially sleeved together. An annular guide gap 23 is defined between the inner wall of the outer tube 21 and the outer wall of the inner mold 22. The outlet gap width of the annular guide gap 23 is 1.5mm-2.5mm. The lower end of the outer tube 21 is provided with an outward expansion portion 211. The bottom end of the inner mold 22 terminates at the starting position of the outward expansion portion 211, and the bottom end face of the inner mold 22 is a conical guide surface. The narrow gap of the annular guide gap 23 of 1.5mm-2.5mm forces the molten metal flow into a thin-walled liquid film, ensuring that the liquid film thickness is uniform and controllable.

[0058] The tapered guide surface design at the bottom of the inner mold 22 smoothly guides the high-speed airflow ejected from the pre-tear assembly 31 downward along the outer expansion 211 to the central axis, avoiding the generation of turbulent backflow vortices at the end face, ensuring the stable formation of the central negative pressure zone, and providing structural protection for the precise focusing and guidance of the airflow.

[0059] like Figure 1 , Figure 6 , Figure 7 and Figure 9As shown, the atomizing tower in this embodiment also includes a crushing module 3 located downstream of the liquid film generation component 2. The crushing module 3 includes a pre-tearing component 31 and a deep crushing component 32. The pre-tearing component 31 is arranged circumferentially around the outlet of the liquid film generation component 2. The airflow jet direction of the pre-tearing component 31 converges towards the central axis, which is used to perform primary crushing of the annular thin-walled liquid film and use the negative pressure effect to make the crushed metal droplets gather towards the center. When the annular thin-walled liquid film flows out from the annular guide gap 23, it is still a continuous hollow cylindrical surface. Although the thickness is thin, it has not yet broken. The high-speed inert gas ejected from the pre-tearing component 31 impacts the liquid film at a converging angle. The shear force generated by the velocity difference between the gas and liquid phases tears the continuous liquid film into coarse droplets or liquid filaments. At the same time, multiple airflows converge at the central axis to form a central negative pressure zone. The Bernoulli effect generates a strong suction effect, locking the initially torn coarse droplets in a narrow channel near the axis and moving downwards, preventing them from being blown away to the tower wall.

[0060] The deep crushing component 32 is arranged circumferentially downstream of the pre-tearing component 31. The airflow jet direction of the deep crushing component 32 is inclined inward, which is used to perform secondary refinement and crushing of the agglomerated metal droplets. After being processed by the pre-tearing component 31, the molten metal moves downward at high speed along the central axis in the form of a group of coarse droplets. At this time, the droplets are still in a state where the surface is not completely solidified, and the gas trapped inside has basically escaped during the flight. At this position, the deep crushing component 32 ejects a high-pressure, high-speed inert gas, which acts on the coarse droplets with strong shear force and shock wave, further crushing them into fine powder of the target particle size. Since the droplets are now focused near the axis and concentrated, the energy of the second-stage airflow is highly concentrated in the effective crushing area, which greatly improves the energy utilization efficiency.

[0061] Furthermore, the pre-tear assembly 31 includes multiple first jet holes, which are evenly distributed on the inclined surface of the outer expansion portion 211. The jet directions of each first jet hole converge in the central negative pressure area below the conical guide surface. The deep fragmentation assembly 32 includes multiple second jet holes, which are located 30mm-50mm below the first jet holes. The jet direction of each second jet hole makes an angle of 15°-25° with the vertical axis. The first jet holes are evenly distributed circumferentially along the inclined surface of the outer expansion portion 211 to ensure 360° airflow symmetry and avoid generating eccentric torque that causes the droplet group to deviate from the axis.

[0062] The jets converge at a point 5-15mm below the conical guide surface, where the airflow velocity is highest and the pressure is lowest, forming a stable negative pressure zone.

[0063] The second jet hole is located 30mm-50mm below the first jet hole. This distance provides a sufficient time window for the coarse droplets to complete the exhaust process, while ensuring that secondary crushing is carried out during the optimal crushing window of the semi-solid. The 15°-25° co-current micro-impact angle ensures sufficient relative gas-liquid velocity while maintaining the axial order of the flow field.

[0064] Furthermore, the pre-tear assembly 31 is connected to a low-pressure gas supply ring 311 and a first gas supply pipe 312. The working medium of the low-pressure gas supply ring 311 is a preheated inert gas with a pressure of 0.4MPa-0.8MPa. The deep crushing assembly 32 is connected to a high-pressure gas supply ring 321 and a second gas supply pipe 322. The working medium of the high-pressure gas supply ring 321 is a high-pressure inert gas with a pressure of 1.5MPa-3.0MPa. Both the first and second jet nozzles adopt a Laval nozzle structure. The pre-tear assembly 31 uses low-pressure gas of 0.4MPa-0.8MPa, not to pursue the maximum crushing effect, but to reduce the cooling rate of the gas on the droplet surface as much as possible while ensuring that the liquid film is reliably torn. The low-pressure gas has a low flow rate and the heat exchange between the gas and liquid is relatively mild. The droplet surface will not cool down to below the freezing point instantly to form a hard shell, allowing sufficient time for the internal gas to diffuse out. At the same time, the gas is preheated to 400-600℃ to further delay the cooling process of the droplet.

[0065] The deep crushing component 32 uses high-pressure gas of 1.5MPa-3.0MPa to carry out a powerful impact with high kinetic energy density when the droplets have finished degassing and are in the optimal crushing window of semi-solid state, instantly refining them into micron-sized powder.

[0066] The Laval nozzle structure accelerates high-pressure subsonic airflow to supersonic speeds, giving the airflow higher kinetic energy density and shear breaking capacity, resulting in finer powder particle sizes at the same gas mass flow rate.

[0067] like Figure 1 and Figure 6 , Figure 7 As shown, the atomizing tower also includes a cooling and dispersing component 4, which is located downstream of the deep crushing component 32. Its internal channels are gradually expanding along the flow direction to disperse the secondary refined metal powder radially and reduce its movement speed, thereby extending the air cooling time. The cooling and dispersing component 4 includes a conical diffusion section 41 connected to the outlet of the deep crushing component 32. The expansion angle of the conical diffusion section 41 is 30°–45°, and the ratio of its inlet cross-sectional area to its outlet cross-sectional area is 1:3–1:5. After being refined by the deep crushing component 32, the metal powder is carried by the high-speed airflow and moves downward at high speed along the axis in a concentrated bundle. If the tower diameter remains unchanged, the powder bundle will rush straight to the center of the tower bottom, resulting in accumulation and the internal heat cannot be dissipated in time, causing them to sinter and stick together.

[0068] The conical diffusion section 41 gradually expands the cross-sectional area of ​​the flow channel, causing the airflow velocity to decrease along the flow path. At the same time, it guides the powder beam to diffuse uniformly in the radial direction, forming an umbrella-shaped dispersion effect. This distributes the powder evenly across the entire tower cross-section, enhancing convective heat dissipation. The expansion ratio of 1:3 to 1:5 and the expansion angle of 30° to 45° ensure that the powder is fully dispersed without causing wall impact and backflow.

[0069] Furthermore, the conical diffuser section 41 has multiple air film nozzles 43 parallel to the wall surface. These multiple air film nozzles 43 are connected to a gas supply box 42. The gas supply box 42 is connected to an external gas source through a gas supply pipe 44. The air film nozzles 43 are arranged parallel to the wall surface of the conical diffuser section 41 and are supplied with gas by the gas supply box 42. A protective air film flowing along the wall surface is formed on the diffuser section wall. This air film exerts a radially inward constraint force on the diffused powder flow to prevent the powder from hitting the tower wall prematurely and causing wall adhesion. On the other hand, the sliding effect of the air film allows the powder to slide off smoothly even if it contacts the wall surface, greatly reducing the risk of wall adhesion and nodule formation.

[0070] The cooling and dispersing assembly 4 also includes a large-diameter vertical cylindrical section 411 connected downstream of the conical diffusion section 41. The inner diameter of the vertical cylindrical section 411 is the same as the outlet inner diameter of the conical diffusion section 41, and the axial height of the vertical cylindrical section 411 is not less than 5 times its inner diameter. The large-diameter vertical cylindrical section 411 provides sufficient air-flying cooling distance for the powder. After being dispersed by the conical diffusion section 41, the powder falls downward at a low speed in the vertical cylindrical section 411, where it undergoes sufficient convection and radiation heat exchange with the inert atmosphere inside the tower. The design of a height not less than 5 times the inner diameter ensures that the powder is cooled to a safe temperature before reaching the bottom and falls into the subsequent collection system in a loose sand-like manner, preventing powder from sticking together and agglomerating.

[0071] The working principle of this embodiment is as follows: Molten iron enters the liquid film generation component 2 at the top of the tower body 1 through the liquid supply port 11. It is squeezed into a thin-walled annular liquid film through the 1.5mm-2.5mm annular guide gap 23 between the outer pipe 21 and the inner mold 22. This liquid film shape greatly increases the specific surface area of ​​the molten iron, and the encapsulated gas can escape freely from both the inside and outside of the liquid film, eliminating the physical conditions for the generation of hollow powder from the source.

[0072] The liquid film continues to descend into the outer expansion section 211 area. The pre-tearing component 31 sprays out heated low-pressure inert gas of 0.4-0.8MPa along the flared mouth slope. Multiple airflows converge in the central negative pressure area below the conical guide surface of the inner mold 22, generating a strong suction focusing effect that draws the annular liquid film into the center of the axis and pre-tears it into coarse droplets. Due to the use of low-pressure heated gas, the surface cooling rate of the coarse droplets is controlled, and the internal gas has sufficient time to escape.

[0073] After flying downwards along the axis for 30-50mm, the coarse droplets enter the working area of ​​the deep crushing component 32. The deep crushing component 32 sprays high-pressure inert gas of 1.5-3.0MPa to deeply crush the semi-solid coarse droplets that have been degassed, refining them into micron-sized powder. The division of labor and precise timing of the two-stage atomization function reduces gas consumption while increasing the fine powder yield and reducing the hollow powder rate. The crushed powder enters the conical diffusion section 41 with the airflow. The expansion of the flow channel cross-sectional area causes the powder beam velocity to decrease and diffuses evenly in the radial direction to form an umbrella-shaped distribution. The protective gas film sprayed by the gas film nozzle 43 along the wall effectively isolates the powder from the wall and prevents it from sticking to the wall. The powder flies and cools to a safe temperature in the large-diameter vertical cylinder section 411, and finally falls into the subsequent collection system in a loose sand-like manner.

[0074] Example 2, as Figures 1 to 4 , Figures 8 to 12 As shown, based on Embodiment 1, in this embodiment, a liquid quenching and rapid cooling unit 5 is further provided downstream of the cooling dispersion component 4. The liquid quenching and rapid cooling unit 5 includes at least one set of cooling modules 51, and the cooling module 51 includes:

[0075] The concentric annular trough group consists of an outer ring water storage tank 511 and an inner ring water storage tank 512 located at the same horizontal height. An annular gap is left between the outer ring water storage tank 511 and the inner ring water storage tank 512 for airflow to pass through. The two are interconnected by a connecting pipe 513 that crosses the annular gap. Multiple drain ports 518 are opened on the upper surface of the connecting pipe 513. The purpose of setting up the liquid quenching and rapid cooling unit 5 is to implement secondary forced rapid cooling of powder on the basis of the initial air cooling completed by the large-diameter vertical cylinder section 411, thereby compressing the overall height of the atomizing tower. By utilizing the huge sensible heat and latent heat of vaporization of the liquid cooling medium, the powder temperature is dropped from several hundred degrees to below 100 degrees within a very short contact distance, allowing the height of the vertical cylinder section 411 to be compressed from the traditional 15-25 meters to 5-8 meters.

[0076] The concentric annular troughs physically separate the airflow from the powder path. The iron powder falls into the water in the outer annular water storage tank 511 and the inner annular water storage tank 512 and is instantly captured and rapidly cooled. Meanwhile, the high-temperature airflow passes through the annular gap between the two without obstruction. The connecting pipe 513 and the drain outlet 518 on its upper surface are used to maintain the water level balance and water flow exchange between the two tanks.

[0077] It also includes a gap receiving groove 514 located directly below the annular gap. The radial width of the gap receiving groove 514 is greater than the radial width of the annular gap, and the minimum width of the annular gap is greater than 100mm. The outer ring water storage tank 511, the inner ring water storage tank 512 and the gap receiving groove 514 are all open-top structures. The top edge of each tank is provided with an overflow guiding structure to make the overflowing cooling water form a continuous wall-adhering water film along the outer wall of the tank. A small amount of light powder that drifts into the annular gap area is caught by the gap receiving groove 514 located directly below. Its width is greater than that of the annular gap to ensure effective interception of all powder passing through the gap.

[0078] The minimum width of the annular gap is greater than 100mm to ensure that the high-temperature airflow passes through unimpeded and to avoid airflow blockage affecting the pressure balance inside the tower;

[0079] The open top design of each tank, combined with the overflow guiding structure, uses the surface tension of the liquid and the wall adhesion effect to guide the overflow water to form a continuous, uniform, downward flowing thin water film along the outer wall of the tank. This film covers the upper edge and outer wall surface of the water storage tank where powder is most likely to adhere. Any iron powder particles that attempt to adhere are captured, cooled, and washed away by the water film upon contact, fundamentally preventing powder accumulation and nodules at the edges.

[0080] In this embodiment, the bottom of the outer ring water tank 511 is provided with an outer ring powder discharge port 515, the bottom of the inner ring water tank 512 is provided with an inner ring powder discharge port 516, and the bottom of the gap receiving groove 514 is provided with a gap powder discharge port 517. The bottom cross-sections of the outer ring water tank 511, the inner ring water tank 512, and the gap receiving groove 514 are all V-shaped, and the inclination angle of the V-shaped bottom surface is greater than 45°. The outer ring water tank 511 is also connected to a circulating water supply pipe 519. The V-shaped bottom and the inclination angle greater than 45° structure allow the powder to automatically slide along the inclined bottom surface to each powder discharge port located at the lowest point under the action of gravity. At the same time, the water flow converges along the V-shaped bottom surface to the powder discharge port to form a concentrated outflow with strong powder carrying capacity, ensuring that the iron powder falling into the water tank can be discharged in a timely and thorough manner.

[0081] The circulating water supply pipe 519 continuously supplies cooling water to the water storage tank. The water volume is slightly greater than the water volume discharged from the outlet carrying powder. The excess water overflows evenly from the upper edge of the tank to form a continuous water film.

[0082] like Figures 1 to 4As shown, in this embodiment, the liquid quenching and rapid cooling unit 5 is equipped with a circulating cooling system 6. The circulating cooling system 6 includes: a liquid collection chamber 12 located at the bottom of the tower body 1, for receiving the solid-liquid mixture discharged from the outer ring powder discharge port 515, the inner ring powder discharge port 516, and the gap powder discharge port 517; a solid-liquid separator 62 connected to the outlet of the liquid collection chamber 12; a coolant tank 65 connected to the liquid outlet of the solid-liquid separator 62, the coolant tank 65 being equipped with a heat exchanger; a circulating pump 63 and a delivery pipe 64 connected between the coolant tank 65 and the circulating water supply pipe 519, for discharging the cooled liquid... The liquid is returned to the outer ring water storage tank 511. The liquid collection chamber 12 collects the solid-liquid mixture of iron powder and water from each powder discharge port. It is discharged through the discharge port 61 and separated into iron powder products by the solid-liquid separator 62. The separated cooling water flows into the coolant tank 65. The heat exchanger installed in the coolant tank 65 removes the heat carried by the circulating water to restore the water temperature to the set range, ensuring stable cooling capacity. The cooled water is pressurized again by the circulating pump 63 and sent back to the liquid quenching and rapid cooling unit 5 through the liquid delivery pipe 64 and the circulating water supply pipe 519 to complete a complete cooling cycle and realize the recycling of water resources.

[0083] like Figure 1 and Figure 5 As shown, in this embodiment, a gas extraction system 7 is also provided at the bottom of the tower body 1. The gas extraction system 7 includes: an extraction port 71 opened on the bottom side wall of the tower body 1, which is located above the liquid discharge port 61 of the liquid collection chamber 12 in the height direction; a dust collector 72, a gas-liquid separator 73 and an extraction pump 74 connected in sequence to the extraction port 71. The gas extraction system 7 is used to maintain an inert atmosphere in the tower, discharge high-temperature waste gas and control the pressure in the tower. The extraction port 71 is located above the liquid discharge port 61. The staggered arrangement of the two in height ensures that the gas goes through the gas channel and the water goes through the water channel, avoiding the intake of water when extracting gas.

[0084] The extracted gas first enters the dust collector 72 to capture and recover the trace amounts of ultrafine dust carried in the airflow. Then it enters the gas-liquid separator 73 to condense and separate the water vapor carried in the gas, preventing water vapor from entering the air pump 74 and causing equipment corrosion or performance degradation. Finally, the clean exhaust gas is extracted by the air pump 74. Part of it is recycled after purification treatment, and part of it is discharged to the waste gas treatment system.

[0085] The working principle in this embodiment is as follows: after the iron powder is initially cooled by the large-diameter vertical cylinder section 411, it moves downward with the high-temperature airflow. When it encounters the liquid quenching unit 5, the airflow and the powder path are physically separated. The iron powder falls into the water in the outer ring water tank 511 and the inner ring water tank 512 and is instantly captured and rapidly cooled. The high-temperature airflow passes through the annular gap of more than 100mm between the outer ring water tank 511 and the inner ring water tank 512 without obstruction.

[0086] A small amount of light powder that drifts into the annular gap is caught by the wider gap receiving groove 514 directly below; the overflow guiding structure at the top edge of each water storage tank causes the circulating cooling water to form a continuous wall-adhering water film along the outer wall of the tank, preventing the powder from sticking and accumulating at the edge of the tank. The iron powder falling into the water storage tank slides automatically towards each powder discharge port along the V-shaped bottom surface at an angle greater than 45°, and is discharged into the liquid collection chamber 12 together with the cooling water.

[0087] The solid-liquid mixture collected in the liquid collection chamber 12 is discharged through the discharge port 61. The iron powder product is separated by the solid-liquid separator 62. The cooling water flows into the coolant tank 65, is cooled by the heat exchanger, and is then sent back to the water storage tank by the circulating pump 63 for recycling.

[0088] Meanwhile, the gas extraction system 7 extracts the high-temperature exhaust gas from the tower through the extraction port 71 located above the liquid discharge port 61. After the dust collector 72 captures ultrafine dust and the gas-liquid separator 73 removes water vapor, the gas is discharged by the extraction pump 74, realizing independent operation of gas through the gas channel and water through the water channel. Through the above-mentioned composite process chain of air-cooled pre-condensation, water-quenched rapid cooling, gas-liquid separation and circulating cooling, the tower height is greatly reduced, and iron powder products with low hollow powder ratio and high fine powder yield are obtained.

[0089] The above specific embodiments are merely several optional embodiments of the present invention. Based on the technical solutions of the present invention and the relevant teachings of the above embodiments, those skilled in the art can make various alternative improvements and combinations to the above specific embodiments.

Claims

1. A single-stage atomized iron powder production system, characterized in that, include: The tower body (1) has a liquid supply port (11) at its top. The liquid film generating component (2) is installed at the top inside the tower body (1) and connected to the liquid supply port (11) to squeeze the incoming molten metal flow from a columnar shape into a downward conveying annular thin-walled liquid film. The crushing module (3) is located downstream of the liquid film generation component (2). The crushing module (3) includes a pre-tear component (31) and a deep crushing component (32); wherein: The pre-tear assembly (31) is arranged circumferentially around the outlet of the liquid film generating assembly (2). The airflow jet direction of the pre-tear assembly (31) converges toward the central axis, which is used to perform primary breakage on the annular thin-walled liquid film and to gather the broken metal droplets toward the center by means of negative pressure effect. The deep crushing component (32) is arranged circumferentially downstream of the pre-tearing component (31). The airflow jet direction of the deep crushing component (32) is inclined inward to perform secondary refinement and crushing of the agglomerated metal droplets. The atomizing tower also includes a cooling and dispersing component (4), which is located downstream of the deep crushing component (32). Its internal channels are gradually widened along the flow direction to disperse the secondary refined metal powder radially and reduce its movement speed, thereby extending the air cooling time.

2. The single-stage atomized iron powder production system according to claim 1, characterized in that, The liquid film generation assembly (2) includes an outer tube (21) and an inner mold (22) coaxially sleeved together. An annular flow guide gap (23) is defined between the inner wall of the outer tube (21) and the outer wall of the inner mold (22). The outlet gap width of the annular flow guide gap (23) is 1.5mm-2.5mm. The lower end of the outer tube (21) is provided with an expansion portion (211), the bottom end of the inner mold (22) terminates at the starting position of the expansion portion (211), and the bottom end face of the inner mold (22) is a tapered guide surface.

3. The single-stage atomized iron powder production system according to claim 2, characterized in that, The pre-tear assembly (31) includes a plurality of first jet holes, which are evenly distributed on the inclined surface of the outer expansion portion (211), and the jet directions of each first jet hole converge in the central negative pressure area below the conical guide surface. The deep crushing component (32) includes a plurality of second jet holes, which are located 30mm-50mm below the first jet hole, and the jet direction of each second jet hole makes an angle of 15°-25° with the vertical axis.

4. The single-stage atomized iron powder production system according to claim 3, characterized in that, The pre-tear assembly (31) is connected to a low-pressure gas supply ring (311) and a first gas supply pipe (312). The working medium of the low-pressure gas supply ring (311) is an inert gas that has been preheated and has a pressure of 0.4MPa-0.8MPa. The deep crushing component (32) is connected to a high-pressure air supply ring (321) and a second air supply pipe (322). The working medium of the high-pressure air supply ring (321) is high-pressure inert gas with a pressure of 1.5MPa-3.0MPa. Both the first and second blow holes adopt the Laval nozzle structure.

5. The single-stage atomized iron powder production system according to claim 4, characterized in that, The cooling dispersion component (4) includes a conical diffusion section (41) connected to the outlet of the deep crushing component (32). The expansion angle of the conical diffusion section (41) is 30°–45°, and the ratio of its inlet cross-sectional area to its outlet cross-sectional area is 1:3–1:

5. The conical diffuser section (41) has multiple air film nozzles (43) parallel to the wall surface. The multiple air film nozzles (43) are connected to a gas delivery box (42). The gas delivery box (42) is connected to an external gas source through a gas delivery pipe (44).

6. The single-stage atomized iron powder production system according to claim 5, characterized in that, The cooling dispersion assembly (4) further includes a large-diameter vertical cylindrical section (411) connected downstream of the conical diffuser section (41), the inner diameter of the vertical cylindrical section (411) being consistent with the outlet inner diameter of the conical diffuser section (41), and the axial height of the vertical cylindrical section (411) being not less than 5 times its inner diameter.

7. The single-stage atomized iron powder production system according to claim 6, characterized in that, Downstream of the cooling dispersion component (4) is a liquid quenching unit (5), which includes at least one set of cooling modules (51), the cooling modules (51) including: The concentric annular tank group consists of an outer ring water storage tank (511) and an inner ring water storage tank (512) located at the same horizontal height. An annular gap is left between the outer ring water storage tank (511) and the inner ring water storage tank (512) to allow airflow to pass through. The two are interconnected by a connecting pipe (513) that spans the annular gap. Multiple drain outlets (518) are provided on the upper surface of the connecting pipe (513). A gap receiving groove (514) is provided directly below the annular gap. The radial width of the gap receiving groove (514) is greater than the radial width of the annular gap, and the width of the annular gap is greater than 100 mm. The outer ring water storage tank (511), the inner ring water storage tank (512), and the gap receiving tank (514) are all open-top structures. The top edge of each tank is provided with an overflow guiding structure to allow the overflowing cooling water to form a continuous wall-attached water film along the outer wall of the tank.

8. The single-stage atomized iron powder production system according to claim 7, characterized in that, The bottom of the outer ring water storage tank (511) is provided with an outer ring powder discharge port (515), the bottom of the inner ring water storage tank (512) is provided with an inner ring powder discharge port (516), and the bottom of the gap receiving groove (514) is provided with a gap powder discharge port (517). The bottom cross-section of the outer ring water storage tank (511), the inner ring water storage tank (512) and the gap receiving groove (514) are all V-shaped, and the inclination angle of the V-shaped bottom surface is greater than 45°. The outer ring water storage tank (511) is also connected to a circulating water supply pipe (519).

9. The single-stage atomized iron powder production system according to claim 8, characterized in that, The liquid quenching and rapid cooling unit (5) is equipped with a circulating cooling system (6), which includes: The liquid collection chamber (12) located at the bottom of the tower body (1) is used to receive the solid-liquid mixture discharged from the outer ring powder discharge port (515), the inner ring powder discharge port (516) and the gap powder discharge port (517); A solid-liquid separator (62) is connected to the outlet of the liquid collection chamber (12). A coolant tank (65) is connected to the liquid outlet of the solid-liquid separator (62), and a heat exchanger is provided inside the coolant tank (65). A circulation pump (63) and a delivery pipe (64) connected between the coolant tank (65) and the circulating water supply pipe (519) are used to send the cooled liquid back to the outer ring water storage tank (511).

10. The single-stage atomized iron powder production system according to claim 9, characterized in that, The bottom of the tower body (1) is also provided with a gas extraction system (7), which includes: An air extraction port (71) is provided on the bottom side wall of the tower body (1), and the air extraction port (71) is located above the liquid discharge port (61) of the liquid collection chamber (12) in the height direction; A dust collector (72), a gas-liquid separator (73), and a vacuum pump (74) are connected in sequence to the air extraction port (71).

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