Magnetic powder core gas atomization device

Abstract

The utility model provides a magnetic powder core gas atomization device which comprises an atomization tank and a smelting crucible communicated with an opening in the top of the atomization tank. A tundish is arranged at the top of the atomization tank, the bottom of the tundish is communicated with a flow guide pipe, the flow guide pipe extends into the atomization tank, and a plurality of high-pressure gas nozzles are distributed in the circumferential direction of the flow guide pipe; the spraying direction of each high-pressure gas nozzle faces downwards, and the high-pressure gas nozzles and the central axis of the flow guide pipe are intersected in the same area; a plurality of stages of electromagnetic coils are further arranged below the flow guide pipe, the electromagnetic coils are wound on the outer surface of the atomization tank and connected with a pulse current source, cooling gas nozzles are further arranged in the atomization tank, the spraying direction of the cooling gas nozzles is downward, and the cooling gas nozzles are located below the spraying direction of the high-pressure gas nozzles. And the cooling gas nozzle is connected with a low-pressure cooling gas inlet pipe. The utility model aims to reduce the particle size distribution range of powder in gas atomization treatment so as to obtain fine and uniform spherical powder.

Description

TECHNICAL FIELD

[0001] The utility model relates to gas atomization device technical field especially relates to a magnetic powder core gas atomization device. BACKGROUND

[0002] At present, gas atomization technology has wide application in the field of powder metallurgy, which produces high-speed and high-pressure vortex airflow by the nozzle of atomization device to instantaneously crush the molten metal or alloy liquid into fine droplets, and relies on the cooling medium to make it quickly cool and solidify into small solid particles. The atomized particles prepared have the advantages of high sphericity, low oxygen content, controllable size and rapid condensation structure. The existing atomization device is prone to produce bubbling and back-splashing phenomenon when preparing metal and alloy powder, which causes great damage to the atomization device, greatly reduces the service life of the atomization device, and the prepared metal and alloy powder has uneven particle size. In addition, the invention patent with the patent number CN113618060A discloses a nickel-based alloy powder and its preparation method, which is produced by using a gas atomization device. The final product is three kinds of graded powder with particle size of 15-53 μm, 53-150 μm and above 150 μm. It can be seen that the particle size distribution range of the obtained powder is wide, which cannot be applied to magnetic powder with higher particle size distribution requirements. SUMMARY

[0003] The main purpose of the utility model is to provide a magnetic powder core gas atomization device, which aims to solve the problem of wide particle size distribution range of the existing magnetic powder core gas atomization device.

[0004] To achieve the above-mentioned purpose, the utility model provides a magnetic powder core gas atomization device, which comprises an atomization tank, a smelting crucible communicated with the top opening of the atomization tank;

[0005] The top of the atomization tank is provided with a tundish, the bottom of the tundish is communicated with a flow guide pipe, the flow guide pipe extends into the atomization tank, a plurality of high-pressure gas nozzles are distributed circumferentially on the flow guide pipe, and each high-pressure gas nozzle is connected with a corresponding high-pressure gas inlet pipe;

[0006] The jet direction of each high-pressure gas nozzle is downward and intersects with the central axis of the flow guide pipe in the same area;

[0007] A plurality of electromagnetic coils are also arranged below the flow guide pipe, the electromagnetic coils are wound on the outer surface of the atomization tank, the electromagnetic coils are connected with a pulse current source, and the electromagnetic coils are used to generate an electromagnetic field perpendicular to the plane where the electromagnetic coils are located below the flow guide pipe;

[0008] A cooling gas nozzle is also arranged in the atomization tank, the jet direction of the cooling gas nozzle is downward and below the jet direction of each high-pressure gas nozzle, and the cooling gas nozzle is connected with a low-pressure cooling gas inlet pipe.

[0009] Optionally, the electromagnetic coil is 20-40 cm away from the vertical distance of the flow guide pipe.

[0010] Optionally, the side wall of the atomizing tank is further provided with an exhaust pipe, and the exhaust pipe is located below the electromagnetic coil.

[0011] Optionally, the bottom of the atomizing tank is provided with a discharge valve.

[0012] Optionally, the inner wall of the atomizing tank is coated with a non-magnetic coating.

[0013] Optionally, the electromagnetic coil is 30 cm away from the vertical distance of the flow guide pipe.

[0014] Optionally, the bottom of the atomizing tank is further provided with a cooling liquid loading area for cooling the powder.

[0015] Optionally, each high-pressure gas inlet pipe is connected with a high-pressure nitrogen tank.

[0016] Beneficial effects:

[0017] The electromagnetic coil is slightly away from the outlet of the flow guide pipe, and the pulse frequency control is increased, the vibration and splitting of small particles are induced by the high-frequency electromagnetic field, the skin effect is reduced, and the cooling airflow is introduced to assist the effect of the electromagnetic field. The particles are prevented from overheating caused by high-frequency electromagnetic field, especially suitable for fine control of small particles. At the same time, the multi-pole electromagnetic coil structure is used to avoid the problem that the single-pole magnetic field has too strong adsorption force on the particles, a more uniform distribution force field can be generated, the particles are prevented from accumulating near the nozzle wall, the adhesion and fusion of the particles are reduced, the mutual attraction between the particles is reduced, the generation of satellite balls is further reduced, and finally the fine and uniform spherical powder is obtained. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the structures shown in these drawings without creative labor.

[0019] Figure 1 It is a structural schematic view of an embodiment of the magnetic powder core gas atomization device of the present application.

[0020] Figure 2 It is a model schematic view of the magnetic material in the alternating magnetic field.

[0021] Figure 3 It is Figure 2 It is a schematic view of the magnetic material in the alternating magnetic field under the first direction of electromagnetic force.

[0022] Figure 4 For Figure 2 Schematic diagram of the electromagnetic force of the second direction on the magnetic material in the alternating magnetic field;

[0023] Figure 5 For Figure 2 Schematic diagram of the magnetic field turning process of the electromagnetic force of the first direction and the second direction on the magnetic material in the alternating magnetic field;

[0024] Figure 6 For Figure 1 Pulse current curve in the time change;

[0025] Figure 7 For the SEM diagram of the powder in the prior art without electromagnetic auxiliary;

[0026] Figure 8 For the SEM diagram of the powder prepared by the device in Figure 1 .

[0027] The realization, functional features and advantages of the present application will be further described with reference to the accompanying drawings in conjunction with the embodiments.

[0028] Explanation of the reference signs:

[0029] Reference Name Reference Name 1 Atomizing tank 2 Smelting crucible 11 Tundish 12 Flow guide pipe 13 High-pressure gas nozzle 14 Electromagnetic coil 15 Cooling gas nozzle 16 Exhaust port 17 Discharge valve 131 Discharge valve DETAILED DESCRIPTION

[0030] It should be understood that the specific embodiments described herein are merely intended to explain the present application, and are not intended to limit the present application.

[0031] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0032] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, movement condition, etc. between components in a certain specific posture (as shown in the drawings), and if the specific posture changes, the directional indications will also change accordingly.

[0033] In addition, the description of "first", "second" and the like in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of various embodiments can be combined with each other, but it must be based on the realization of ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor in the protection scope required by the present application.

[0034] As shown in Figure 1 An embodiment of the present application provides a kind of magnetic powder core gas atomization device, the device includes atomization tank 1, with the top opening of atomization tank 1 Communication smelting crucible. Wherein, the top of the atomization tank 1 is provided with tundish 11, the bottom of the tundish 11 is communicated with flow guide pipe 12, the flow guide pipe 12 extends into the atomization tank 1, the smelting crucible is used to melt metal material and pour into tundish 11, and make the metal melt enter the atomization tank 1 by flow guide pipe 12.

[0035] Further, the flow guide pipe 12 is circumferentially distributed with a plurality of high-pressure gas nozzles 13, each high-pressure gas nozzle 13 is connected with a corresponding high-pressure gas inlet pipe 131, and each high-pressure gas inlet pipe 131 is connected with a high-pressure nitrogen tank. In actual application, the number of high-pressure gas nozzles 13 is set to 2 or more. Preferably, the jet direction of each high-pressure gas nozzle 13 is downward and intersects with the central axis of the flow guide pipe 12 at the same region, thereby realizing the force action of high-pressure nitrogen gas on the metal melt to generate metal droplets.

[0036] Further, a plurality of electromagnetic coils 14 are also arranged below the flow guide pipe 12, the electromagnetic coils 14 are arranged on the outer surface of the atomization tank 1, the electromagnetic coils 14 are connected with a pulse current source, and the electromagnetic coils 14 are used to generate an electromagnetic field perpendicular to the plane where the electromagnetic coils 14 are located below the flow guide pipe 12, thereby making the metal droplets after the action of high-pressure nitrogen gas further generate controlled droplet morphology under the action of alternating magnetic field. At the same time, using a multi-pole electromagnetic coil structure can avoid the problem of too strong adsorption force of single-pole magnetic field on particles, can generate a more uniform distribution force field, prevent particles from accumulating near the flow guide pipe, reduce the adhesion and fusion of particles, reduce the mutual attraction between particles, and further reduce the generation of satellite balls.

[0037] Further, a cooling gas nozzle 15 is also arranged in the atomization tank 1, the jet direction of the cooling gas nozzle 15 is downward and below the jet direction of each high-pressure gas nozzle 13, and the cooling gas nozzle 15 is connected with a low-pressure cooling gas inlet pipe.

[0038] Specifically, the frequency and intensity of the electromagnetic coil 14 can be adjusted to adapt to different powder particle size requirements, and the frequency and intensity are determined by first establishing a model through simulation software, simulating the force size of the magnetic particles in the magnetic field, and summarizing the experimental results that when the powder is 100-270 mesh, the frequency is 70 kHz and the current is 30 A; when the powder is 270-400 mesh, the frequency is 50 kHz and the current is 22 A; when the powder is 400-500 mesh, the frequency is 20 kHz and the current is 10 A. The model of the magnetic material in the alternating magnetic field is shown in Figure 2 , and the force of the magnetic material in the alternating magnetic field is shown in Figures 3-4 , Figure 3 , and Figure 4 , the force of the powder under the condition of two opposite magnetic field directions is shown, wherein the unit volume force of different regions of the metal powder is different from the magnetic induction intensity, so that the metal powder rotates under the action of the magnetic field force, and the force direction presented is from inside to outside, and in the alternating magnetic field, the magnetic field direction changes, and the force of the magnetic particles also changes from the external force to the internal force, Figure 5 , the schematic diagram of the magnetic field turning process of the electromagnetic field force of the magnetic material in the first direction and the second direction in the alternating magnetic field is shown. The pulse electromagnetic field used in this embodiment is shown in Figure 6 , which is a pulse current-time curve. A non-continuous high-frequency electromagnetic field is used, the pulse frequency and intensity are adjusted, the electromagnetic force only acts in a specific period of time, the droplet morphology is controlled without affecting the powder forming under the intermittent electromagnetic force, and the particle adhesion is reduced. The atomized powder is guided downward by the low-pressure cooling gas flow to avoid the suspension of the powder near the inner cavity wall. The cooling gas flow can slow down the movement speed of the powder, reduce the force time of the powder in the electromagnetic field, and effectively reduce the adhesion probability.

[0039] Further, the vertical distance between the electromagnetic coil 14 and the flow guide pipe 12 is 20-40 cm. Preferably, the vertical distance between the electromagnetic coil 14 and the flow guide pipe 12 is 30 cm. The electromagnetic coil is installed at a predetermined distance below the nozzle, which can avoid the formation of a strong magnetic field at the flow guide pipe 12. In order to make the electromagnetic force more uniformly distributed, the electromagnetic coil 14 is installed on the periphery of the atomizing tank 1, which ensures that the powder can be constrained by the electromagnetic force for a certain distance after being sprayed, thereby ensuring that the liquid metal is preliminarily atomized before entering the electromagnetic control area, avoiding the interference of the strong electromagnetic field in the initial atomization, and preventing the attraction between the droplets to reduce the formation of satellite balls.

[0040] Further, the side wall of the atomizing tank 1 is also provided with an exhaust pipe opening 16, and the exhaust pipe opening 16 is located below the electromagnetic coil 14. The setting of the exhaust pipe opening 16 can effectively exhaust the gas in the atomizing tank 1.

[0041] Further, the bottom of the atomizing tank 1 is provided with a discharge valve 17 for efficient powder discharge.

[0042] Further, the inner wall of the atomizing tank 1 is coated with a non-magnetic coating.

[0043] Further, the bottom of the atomizing tank 1 is also provided with a cooling liquid loading area for cooling the powder, which is to further realize the cooling of the atomized particles.

[0044] Further, when the device is actually applied, the total length of the molten liquid atomization time is about 3 min, 20s pulse electromagnetic field is emitted every 10s, and the SEM diagram of the finally obtained powder is as shown in Figure 8 , while the SEM diagram of the powder without electromagnetic assistance in the prior art is as shown in Figure 7 . Figures 7-8 It can be seen from

[0045] Further, before and after applying electromagnetic assistance, the powder is coated according to the effective magnetic permeability μe=60 coating process, and is pressed into 106 standard ring electrical performance comparison (φ0.8mm*26Ts), the structure is shown in Table 1 as follows.

[0046] Table 1 Electrical performance comparison of 106 standard ring before and after applying electromagnetic assistance

[0047]

[0048] As can be seen from Table 1 above, the electrical performance of the magnetic powder core prepared by the device is better than that without magnetic field assistance in actual application, and further, the gas atomization of the device can reduce satellite balls, control powder particle size, and improve the stacking effect of the magnetic powder core, so that the magnetic powder core can adapt to the application scene with higher requirements.

[0049] It should be noted that in this text, the term "includes", "comprises" or any other variant thereof is intended to cover non-exclusive inclusions, so that the process, method, article or system including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or includes elements inherent to such process, method, article or system. Without more limitations, the element defined by the statement "includes a" does not exclude the existence of other identical elements in the process, method, article or system including the element. The above embodiment serial numbers of the present application are only for description, not representing the advantages and disadvantages of the embodiments.

[0050] The above is only the preferred embodiment of the present application, and does not limit the patent range of the present application. Any equivalent structure or equivalent process transformation using the content of the present application specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection range of the present application.

Claims

1. A magnetic powder core gas atomization apparatus characterized by comprising: The device comprises an atomizing tank (1), a smelting crucible (2) communicated with the top opening of the atomizing tank (1); The atomizing tank (1) is provided with a tundish (11) at the top, the bottom of the tundish (11) is communicated with a flow guide pipe (12) extending into the atomizing tank (1), and the flow guide pipe (12) is circumferentially provided with a plurality of high-pressure gas nozzles (13), each high-pressure gas nozzle (13) is connected with a corresponding high-pressure gas inlet pipe (131); The jet direction of each high-pressure gas nozzle (13) is downward and intersects with the central axis of the flow guide pipe (12) at the same region; A plurality of electromagnetic coils (14) are further arranged below the flow guide pipe (12), the electromagnetic coils (14) are arranged on the outer surface of the atomizing tank (1), the electromagnetic coils (14) are connected with a pulse current source, and the electromagnetic coils (14) are used for generating an electromagnetic field perpendicular to the plane where the electromagnetic coils (14) are located below the flow guide pipe (12); The atomizing tank (1) is further provided with a cooling gas nozzle (15), the jet direction of the cooling gas nozzle (15) is downward and below the jet direction of each high-pressure gas nozzle (13), and the cooling gas nozzle (15) is connected with a low-pressure cooling gas inlet pipe.

2. The magnetic powder core gas atomization apparatus according to claim 1, wherein The vertical distance between the electromagnetic coils (14) and the flow guide pipe (12) is 20-40 cm.

3. The magnetic powder core gas atomization apparatus according to claim 1, wherein The side wall of the atomizing tank (1) is further provided with an exhaust pipe opening (16) below the electromagnetic coils (14).

4. The magnetic powder core gas atomization apparatus according to claim 1, wherein The bottom of the atomizing tank (1) is provided with a discharge valve (17).

5. The magnetic powder core gas atomization device according to any one of claims 1 to 4, characterized by, The inner wall of the atomizing tank (1) is coated with a non-magnetic coating.

6. The magnetic powder core gas atomization apparatus according to claim 2, wherein The vertical distance between the electromagnetic coils (14) and the flow guide pipe (12) is 30 cm.

7. The magnetic powder core gas atomization apparatus according to claim 5, wherein The bottom of the atomizing tank (1) is further provided with a cooling liquid loading area for cooling the powder.

8. The magnetic powder core gas atomization device according to claim 6 or 7, characterized by Each high-pressure gas inlet pipe (131) is connected with a high-pressure nitrogen tank.

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