Atomizing nozzle

Abstract

The present invention relates to an atomizing nozzle, comprising an upper spray disc and a lower spray disc distributed in an upper and lower manner, wherein the center of the upper spray disc is provided with a flow guide channel extending to the lower end surface of the lower spray disc, and both sides of the lower spray disc are provided with air inlet channels, wherein the upper spray disc and the lower spray disc cooperate to form an air inlet cavity connected to the air inlet channel, and the atomizing nozzle further comprises a rectifying ring connected between the upper spray disc and the lower spray disc, wherein the outer wall of the rectifying ring cooperates with the inner wall of the lower spray disc to form an annular seam-type air outlet connected to the air inlet cavity. The atomizing nozzle provided by the present invention can make the airflow more stable, the atomized powder has a fine particle size, and has less satellite powder; under high temperature and high pressure use environments, the deformation of the air outlet surface is not affected by the deformation of the upper spray disc surface, and has a more stable atomization effect.

Description

Technical Field

[0001] The present invention relates to the technical field of metal powder manufacturing for 3D printing, in particular to an atomizing nozzle. Background Art

[0002] With the rapid development of the metal 3D printing industry, spherical metal powder, as a key raw material for metal 3D printing, and its preparation and production technology are the core of the entire 3D printing industry chain. Currently, the main technologies capable of mass-producing spherical metal powders at home and abroad include plasma rotating electrode method, inert gas atomization method, induction plasma spheroidization method, and induction plasma atomization method. The basic principle of inert gas atomization is to use a high-speed airflow to break up the liquid metal melt into small droplets and solidify them into powder. Due to the advantages of high purity, low oxygen content, controllable powder particle size, low production cost, and high sphericity of the powder produced, it has become the mainstream preparation technology for high-performance and specialty alloy powders. The atomizing nozzle is the core device of gas atomization preparation technology. Through the internal cavity design, the pressure potential energy of the gas is converted into kinetic energy. The liquid metal melt enters the atomization area through a guide tube or free fall, and a high-speed gas jet is ejected from the outlet of the atomizing nozzle to achieve atomization and fragmentation of the liquid metal melt. In order to achieve higher atomization efficiency, high-pressure gas atomization and hot gas atomization technologies that increase the kinetic energy of the gas have been developed in recent years.

[0003] Existing atomizing nozzles primarily utilize an annular seam structure, consisting of an air inlet, an internal air cavity, and an outlet. The central opening serves as a channel for liquid metal melt to flow through via a draft tube or free fall. Due to the high internal pressure of the air cavity and the heat radiation from the molten metal or heat conduction from the draft tube during operation, the structure can easily deform over time, causing changes in the internal air cavity and outlet dimensions, which in turn affects key technical specifications such as the particle size and morphology of the atomized metal powder. This is particularly true for atomizing nozzles with an annular seam outlet for preparing iron-nickel-cobalt-based alloys. Due to alloy superheat exceeding 1600°C, the heat conduction from the draft tube causes the center hole temperature of the atomizing nozzle to reach over 800°C, causing deformation during use. Analysis of gas pressure stress indicates that the internal cavity is subjected to forces perpendicular to the mold surface. Long-term use of the internal cavity structure can cause deformation of the mold surface, which in turn affects the outlet dimensions, leading to abnormal atomization and poor powder quality. Summary of the Invention

[0004] The object of the present invention is to provide an atomizing nozzle to solve the problem that the atomizing nozzle and the internal cavity are easily deformed.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: an atomizing nozzle, comprising an upper spray disc and a lower spray disc distributed up and down, a guide channel penetrating to the lower end surface of the lower spray disc is provided at the center of the upper spray disc, and air intake channels are provided on both sides of the lower spray disc, the upper spray disc and the lower spray disc cooperate to form an air intake cavity connected to the air intake channel, the atomizing nozzle also includes a straightening ring connected between the upper spray disc and the lower spray disc, the outer wall of the straightening ring cooperates with the inner wall of the lower spray disc to form an annular seam type air outlet connected to the air intake cavity.

[0006] As a preferred solution, the upper spray disc, the lower spray disc and the rectifying ring are coaxially arranged.

[0007] As a preferred embodiment, the cross-section of the annular seam air outlet along the central axis of the guide channel is formed by a contour line formed by two points P1-P4 and a contour line formed by two points P1'-P4', and the center line forms an angle b1 with the central axis of the guide channel, and the angle b1 is set to 5-45°. The extension line of P1-P4 and the extension line of P1'-P4' are axially symmetrical with respect to the center line.

[0008] As a preferred embodiment, the cross-section of the annular seam air outlet formed along the central axis of the guide channel is formed by the contour line formed by the P1-P2-P3-P4 and P1'-P2'-P3'-P4' nodes, and includes a steady flow section formed by P1-P2 and P1'-P2', a contraction section formed by P2-P3 and P2'-P3', a throat formed by P3 and P3', and an expansion section formed by P3-P4 and P3'-P4'.

[0009] As a preferred solution, line segment P1-P2 is parallel to line segment P1'-P2', and the shortest distance between the two line segments is set to a. The two parallel lines can make the airflow transition stable and reduce turbulence caused by changes in airflow direction.

[0010] As a preferred solution, the projected lengths of the steady flow section, contraction section, and expansion section on the center line of the cross section are L1, L2, and L3, respectively. The length of L1 is set to 2a-5a, the length of L2 is set to 0.5a-5a, the length of L3 is set to 2a-10a, and the width of the throat P3-P3' is set to 0.05a-0.8a.

[0011] As a preferred solution, the length of the line segment formed by P3-P4 is greater than the length of the line segment formed by P3'-P4', and the extra length is the guide segment.

[0012] As a preferred solution, the projected length of the guide segment on the center line of the cross section is L4, and the length of L4 is set to 0.1a-0.4a.

[0013] As a preferred solution, the extended lines of the line segment P3-P4 and the line segment P3'-P4' form an angle b, and the angle b is set to 4-15 degrees.

[0014] As a preferred solution, the line segment P2-P3 is a cubic Bezier curve with a starting point and an end point of P2 and P3 respectively, and the line segment P2'-P3' is a cubic Bezier curve with a starting point and an end point of P2' and P3' respectively. The uniform airflow passing through the steady flow section can be stably compressed and accelerated to the speed of sound, and the profile formed by the curve can be reduced.

[0015] As a preferred embodiment, the atomizing nozzle further includes a diverter ring connected to the upper end surface of the lower spray disc. The diverter ring and the lower spray disc are coaxially arranged, and the diverter ring divides the air inlet cavity into an inner cavity and an outer cavity. The diverter ring sidewall is evenly provided with four diverter holes, and the four diverter holes are equidistant from adjacent air inlet channels. This arrangement allows the airflow entering the outer cavity symmetrically on both sides to be evenly divided into four radially outward-inward streams, reducing circumferential airflow unevenness. The airflow can evenly pass through the diverter holes and converge in the inner cavity, thereby stabilizing the airflow out of the annular gap-type air outlet.

[0016] As a preferred solution, the rectification ring includes a rectification portion and a first annular boss connected circumferentially along the rectification portion. The upper end surface of the lower spray disc is provided with a first annular groove matching the first annular boss. The rectification ring is clamped and fixed to the lower spray disc through the cooperation of the first annular boss and the first annular groove.

[0017] As a preferred solution, the rectifying portion and the first annular boss are connected by a number of equidistantly arranged ribs. The equidistantly arranged ribs enable the airflow to pass through the arc-shaped vents evenly, thereby making the airflow flowing to the annular gap type air outlet more stable and uniform.

[0018] As a preferred solution, the upper end surface of the rectification portion is provided with a second annular groove, and the lower end surface of the upper spray disc is provided with a second annular boss matching the second annular groove. The upper spray disc is clamped and fixed to the rectification ring through the cooperation of the second annular boss and the second annular groove.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: the atomizing nozzle provided by the present invention, through the special structural setting of the annular seam type air outlet, the setting of the diverter ring and the diverter hole, and the setting of the equidistant ribs in the straightening ring, makes the airflow more stable and has a strong impact, the atomized powder particle size is fine, and there is less satellite powder; through the annular seam type air outlet structure formed by the combination of the lower spray disc and the straightening ring, under high temperature and high pressure use environment, the deformation of the air outlet surface is not affected by the deformation of the upper spray disc surface, and therefore has a more stable atomization effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1A top view of the atomizing nozzle provided by the present invention;

[0021] Figure 2 for Figure 1 Cross-sectional view in the cc direction;

[0022] Figure 3 for Figure 2 A schematic diagram of the enlarged structure of part A;

[0023] Figure 4 Schematic diagram of the structure of the lower spray plate in the present invention;

[0024] Figure 5 Schematic diagram of the three-dimensional structure of the rectifying ring in the present invention;

[0025] Figure 6 Schematic diagram of the cross-sectional structure of the rectifying ring in the present invention;

[0026] Figure 7 Schematic diagram of the structure of the upper spray plate in the present invention;

[0027] Figure 8 Schematic diagram of parameter settings for the annular seam type air outlet in the present invention;

[0028] Figure 9 Schematic diagram of another parameter setting of the annular seam type air outlet in the present invention;

[0029] Figure 10 This is the 200x SEM powder morphology of the metal powder prepared in Example 2 of the present invention;

[0030] Figure 11 This is the 100x SEM powder morphology of the metal powder prepared in Example 2 of the present invention;

[0031] The meaning of each number in the figure is:

[0032] 1. Upper spray disc; 2. Lower spray disc; 3. Rectifier ring; 4. Air inlet channel; 5. Air inlet cavity; 501. Inner cavity; 502. Outer cavity; 6. Annular gap type air outlet; 101. Guide channel; 102. Second annular boss; 201. First through hole; 202. First annular groove; 301. Rectifier; 302. First annular boss; 303. Rib; 304. Second through hole; 305. Second annular groove; 7. Diverter ring; 8. Center line; 9. Central axis of guide channel; 10. Guide section. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0034] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0035] See also Figure 1 、 Figure 2 and Figure 3 This embodiment discloses an atomizing nozzle, including an upper spray disc 1 and a lower spray disc 2 distributed vertically, and a straightening ring 3 connected therebetween. The upper spray disc 1, the lower spray disc 2, and the straightening ring 3 are coaxially arranged.

[0036] Air inlet channels 4 are provided on both sides of the lower spray disc 2. The diameter d2 of the air inlet channels 4 is set to 5-20 mm. The upper spray disc 1 covers and connects to the upper end surface of the lower spray disc 2. The two cooperate to form an air inlet cavity 5 that communicates with the two air inlet channels 4. The rectifying ring 3 and the lower spray disc 2 cooperate to form an annular gap-type air outlet 6 that communicates with the air inlet cavity 5. For details, see Figure 4 The center of the lower spray disc 2 is provided with a first through hole 201. The diameter of the first through hole 201 is set to gradually decrease from the upper end surface of the lower spray disc 2 to the lower end surface of the lower spray disc 2. The upper end surface of the lower spray disc 2 is provided with a first annular groove 202 in the circumferential direction of the outer periphery of the first through hole 201. The groove width is set to 2-12mm. Figure 5 and Figure 6The rectifying ring 3 is disposed within the first through-hole 201 of the lower spray disc 2. The rectifying ring 3 further includes a rectifying portion 301 and a first annular boss 302 circumferentially connected to the rectifying portion 301. The shape of the first annular boss 302 matches the shape of the first annular groove 202. The rectifying ring 3 is secured to the lower spray disc 2 by the engagement of the first annular boss 302 and the first annular groove 202. The connection between the first annular boss 302 and the first annular groove 202 can be threaded or welded. An annular air outlet channel is formed between the rectifying portion 301 and the first annular boss 302. The rectifying portion 301 and the first annular boss 302 are connected by a plurality of equidistantly arranged ribs 303. The ribs 303 evenly divide the annular air outlet channel into a plurality of arcuate air vents. In this embodiment, the equidistantly arranged ribs 303 enable the airflow to pass through the arcuate air vents uniformly, thereby making the airflow to the annular gap-type air outlet 6 more stable and uniform.

[0037] A second through hole 304 is provided in the center of the rectifying portion 301. The inner wall of the second through hole 304 is a cylindrical surface. A second annular groove 305 is provided in the circumference of the upper end surface of the rectifying portion 301. The groove width is set to 1.5-5 mm. Figure 7 A guide channel 101 is located at the center of the upper spray plate 1. This channel is used to guide or allow liquid metal to freely fall through it. Its inner diameter d1 is set to 6-30 mm. The outer diameter of the channel 101 matches the inner diameter of the second through-hole 304. The lower end surface of the upper spray plate 1 is provided with a second annular boss 102 that matches the second annular groove 305. The second annular boss 102 and the second annular groove 305 cooperate to secure the upper spray plate 1 to the rectifying ring 3. The channel 101 of the upper spray plate 1 is inserted into the second through-hole 304 of the rectifying portion 301 and extends to the lower end surface of the lower spray plate 2. The outer wall of the rectifying portion 301 and the inner wall of the first through-hole 201 of the lower spray plate 2 cooperate to form an annular gas outlet 6. This annular gas outlet 6 communicates with the gas inlet cavity 5, and the outlet end of the annular gas outlet 6 is tilted toward the side closer to the channel 101, effectively reducing gas energy loss. Through the annular seam gas outlet 6 structure, the gas is ejected from the annular gas outlet, which can further accelerate the gas, more fully impact the liquid metal melt, and achieve a better crushing effect. At the same time, the annular gas outlet can further increase the gas outlet air flow velocity and uniformity, thereby improving the atomization performance.

[0038] See also Figure 8 and Figure 9The cross-section of the annular seam outlet 6 along the central axis 9 of the guide channel is defined by the contour lines P1-P4 and the contour line P1'-P4'. The extensions of the center lines 8 of the P1-P4 and P1'-P4' contour lines form an angle b1 with the central axis 9 of the guide channel. Angle b1 is set to 5-45°. This angle effectively utilizes the energy of the high-pressure airflow, maximizing its impact on the liquid metal melt and resulting in a finer metal powder particle size. The extensions of the P1-P4 and P1'-P4' contour lines are axially symmetrical with respect to the cross-section center line 8. Furthermore, the cross-section of the annular seam-type air outlet 6 along the central axis 9 of the guide channel is specifically formed by the contour line formed by the nodes P1-P2-P3-P4 and P1'-P2'-P3'-P4'. According to the direction of airflow, the cross-sectional structure formed by the annular seam-type air outlet 6 in the direction of the central axis 9 of the guide channel includes a steady flow section formed by P1-P2 and P1'-P2', a contraction section formed by P2-P3 and P2'-P3', a throat formed by P3 and P3', and an expansion section formed by P3-P4 and P3'-P4'. P1 and P1' are connected to the upstream contour by a rounded transition. Among them, in the steady flow section, the line segment P1-P2 is parallel to the line segment P1'-P2', and the shortest distance between the two line segments is set to a. P2-P3 and P2'-P3' are cubic Bezier curves with starting and ending points P2, P2' and P3, P3' respectively. The projected lengths of the steady flow section, contraction section, and expansion section on the centerline 8 are L1, L2, and L3, respectively. The length of L1 is set to 2a-5a, the length of L2 is set to 0.5a-5a, and the length of L3 is set to 2a-10a. The width c of the throat P3-P3' is set to 0.05a-0.8a. To ensure the direction of gas at the outlet position of the annular seam gas outlet 6, the length of the line segment formed by P3-P4 is greater than the length of the line segment formed by P3'-P4'. The excess length is the guide section 10, and the projected length of the guide section 10 on the centerline 8 is L4. The length of L4 is set to 0.1a-0.4a. The setting of the projected length of the guide section 10 can match the direction of the airflow with the direction of the liquid metal melt passing through the self-guiding channel 101, achieving precise impact of the airflow. Line segment P3-P4 and line segment P3'-P4' are set as two straight line segments, and their extended lines form an angle b, which is set to 4-15 degrees. The setting of this angle and the width of the throat can ensure the formation of high-speed airflow to form a strong impact on the liquid metal melt and obtain finer metal powder.In this embodiment, the airflow undergoes a rounded transition before entering the steady flow section, which can reduce gas flow resistance and energy loss. The steady flow section is set as two parallel lines parallel to the center line 8, which can gradually stabilize the airflow after the rounded transition and reduce turbulence caused by changes in airflow direction; the contraction section adopts a cubic Bezier curve with the starting point at the end of the steady flow section and the end point at the throat, which can stably compress and accelerate the uniform airflow passing through the steady flow section to the speed of sound, and the profile formed by the curve can be reduced; the throat has a smooth transition with the contraction section and the expansion section, which can reduce airflow flow losses; the expansion section profile is a straight line with a certain expansion angle, which reduces processing difficulty, further accelerates the sonic airflow passing through the throat to supersonic speed, and reduces the generation of expansion waves to a certain extent, thereby reducing airflow energy loss.

[0039] Preferably, in order to avoid the airflow concentrating on the path of the air inlet channel 4, which causes the airflow to flow unevenly in the air inlet cavity 5, the atomizing nozzle provided in this embodiment also includes a diverter ring 7 fixedly connected to the upper end face of the lower spray disc 2. The diverter ring 7 and the lower spray disc 2, the upper spray disc 1 and the straightening ring 3 are all coaxially arranged. The diverter ring 7 is arranged as an annular baffle, and its side wall has four diverter holes evenly distributed circumferentially. The aperture is set to 0.5-0.75d2, which can be specifically set according to the air flow rate. The distance between each diverter hole and the air inlet channel 4 it is adjacent to is the same, and the axis of the diverter hole and the axis of the air inlet channel 4 are preferably set in the same horizontal plane. The air inlet cavity 5 is divided into an inner cavity 501 and an outer cavity 502 by the diverter ring 7. The diameter of the outer cavity 502 is larger than the diameter of the inner cavity 501. The diameter range of the outer cavity 502 is set to 2-15d1, and the diameter range of the inner cavity 501 is set to 1.5-5d1. By configuring the outer cavity 502 and the inner cavity 501 to match the diameter range of the inner diameter d1 of the flow guide channel 101, the airflow rate is matched to the flow rate of the liquid metal melt passing through the flow guide channel 101. The provision of the diverter ring 7, combined with the diverter holes set equidistant from the air inlet channel 4, symmetrically divides the airflow entering the outer cavity 502 from both sides into four radially outward-inward airflows, reducing circumferential airflow unevenness. The airflow can evenly pass through the diverter holes and converge in the inner cavity 501, thereby stabilizing the airflow out of the annular gap-type air outlet 6.

[0040] The structure of the annular seam type air outlet 6 in the present invention will be further described below through examples:

[0041] Example 1

[0042] The cross-section of the annular seam-type air outlet 6 formed along the central axis 9 of the guide channel is formed by the contour lines formed by P1-P4 and the contour lines formed by P1'-P4'. The extension of the center lines 8 of the P1-P4 contour line and the P1'-P4' contour line forms an angle b1 with the central axis 9 of the guide channel, and the angle b1 is set to 5°. The extension of the P1-P4 contour line and the P1'-P4' contour line are axially symmetrical with respect to the cross-section center line 8. According to the airflow direction, the cross-section structure formed by the annular seam-type air outlet 6 in the direction of the central axis 9 of the guide channel includes a steady flow section formed by P1-P2 and P1'-P2', a contraction section formed by P2-P3 and P2'-P3', a throat formed by P3 and P3', and an expansion section formed by P3-P4 and P3'-P4'. P1 and P1' are connected to the upstream contour by a rounded transition. In the steady flow section, line segment P1-P2 is parallel to line segment P1'-P2', and the shortest distance between the two segments is set to a, which is 1.5 mm. P2-P3 and P2'-P3' are cubic Bezier curves with starting and ending points P2, P2' and P3, P3', respectively. The projected lengths of the steady flow section, contraction section, and expansion section on the center line 8 are L1, L2, and L3, respectively. The length of L1 is set to 2a, the length of L2 is set to 0.5a, and the length of L3 is set to 2a. The width c of the throat P3-P3' is set to 0.05a. The projected length of the guide section 10 on the center line 8 is L4, and the length of L4 is set to 0.1a. Line segments P3-P4 and P3'-P4' are set to two straight line segments, and their extended lines form an angle b, which is set to 4°.

[0043] Example 2

[0044] The cross-section of the annular seam-type air outlet 6 formed along the central axis 9 of the guide channel is formed by the contour lines formed by P1-P4 and the contour lines formed by P1'-P4'. The extension of the center lines 8 of the P1-P4 contour line and the P1'-P4' contour line forms an angle b1 with the central axis 9 of the guide channel, and the angle b1 is set to 15 degrees. The extension of the P1-P4 contour line and the P1'-P4' contour line are axially symmetrical with respect to the cross-section center line 8. According to the flow direction, the cross-section structure formed by the annular seam-type air outlet 6 in the direction of the central axis 9 of the guide channel includes a steady flow section formed by P1-P2 and P1'-P2', a contraction section formed by P2-P3 and P2'-P3', a throat formed by P3 and P3', and an expansion section formed by P3-P4 and P3'-P4'. P1 and P1' are connected to the upstream contour by a rounded transition. In the steady flow section, line segment P1-P2 is parallel to line segment P1'-P2', and the shortest distance between the two segments is set to a, which is 3 mm. P2-P3 and P2'-P3' are cubic Bezier curves with starting and ending points P2, P2' and P3, P3', respectively. The projected lengths of the steady flow section, contraction section, and expansion section on the center line 8 are L1, L2, and L3, respectively. The length of L1 is set to 3.5a, the length of L2 is set to 2a, and the length of L3 is set to 4a. The width c of the throat P3-P3' is set to 0.2a. The projected length of the guide section 10 on the center line 8 is L4, and the length of L4 is set to 0.25a. Line segments P3-P4 and P3'-P4' are set as two straight line segments, and their extended lines form an angle b, which is set to 8°.

[0045] Example 3

[0046] The cross-section of the annular seam-type air outlet 6 formed along the central axis 9 of the guide channel is formed by the contour lines formed by P1-P4 and the contour lines formed by P1'-P4'. The extension of the centerline 8 of the P1-P4 contour line and the P1'-P4' contour line forms an angle b1 with the central axis 9 of the guide channel, and the angle b1 is set to 45 degrees. The extension of the P1-P4 contour line and the P1'-P4' contour line are axially symmetrical with respect to the cross-section centerline 8. According to the flow direction, the cross-section structure formed by the annular seam-type air outlet 6 in the direction of the central axis 9 of the guide channel includes a steady flow section formed by P1-P2 and P1'-P2', a contraction section formed by P2-P3 and P2'-P3', a throat formed by P3 and P3', and an expansion section formed by P3-P4 and P3'-P4'. P1 and P1' are connected to the upstream contour by a rounded transition. In the steady flow section, line segment P1-P2 is parallel to line segment P1'-P2', and the shortest distance between the two segments is set to a, which is 6.5 mm. P2-P3 and P2'-P3' are cubic Bezier curves with starting and ending points P2, P2' and P3, P3', respectively. The projected lengths of the steady flow section, contraction section, and expansion section on the center line 8 are L1, L2, and L3, respectively. The length of L1 is set to 5a, the length of L2 is set to 5a, and the length of L3 is set to 10a. The width c of the throat P3-P3' is set to 0.8a. The projected length of the guide section 10 on the center line 8 is L4, and the length of L4 is set to 0.4a. Line segments P3-P4 and P3'-P4' are set as two straight line segments, and their extended lines form an angle b, which is set to 15°.

[0047] Comparative Example 1

[0048] The difference between Comparative Example 1 and Example 1 is that in Comparative Example 1, the angle b1 is set to 51°.

[0049] Comparative Example 2

[0050] The difference between Comparative Example 2 and Example 1 is that in Comparative Example 2, the angle b is set to 23°.

[0051] Comparative Example 3

[0052] The difference between Comparative Example 3 and Example 1 is that in Comparative Example 3, the width c of the throat portion P3 - P3 ′ is set to 1.0a.

[0053] Comparative Example 4

[0054] The difference between Comparative Example 4 and Example 1 is that in Comparative Example 4, the projection length L4 of the guide segment 10 on the center line 8 is set to 0.06a.

[0055] Table 1 below shows the parameter settings of the annular gap type air outlet of each embodiment and comparative example, and Table 2 shows the laser particle size measurement results of the corresponding metal powders prepared by the atomizing nozzle using the annular gap type air outlet of each embodiment and comparative example.

[0056] Table 1 Parameter setting table of each embodiment and comparative example

[0057] parameter Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 a 1.5 3 6.5 1.5 1.5 1.5 1.5 b1 5° 15° 45° 51° 5° 5° 5° b 4° 8° 15° 4° 23° 4° 4° c 0.05a 0.2a 0.8a 0.05a 0.05a 1.0a 0.05a L1 2a 3.5a 5a 2a 2a 2a 2a L2 0.5a 2a 5a 0.5a 0.5a 0.5a 0.5a L3 2a 4a 10a 2a 2a 2a 2a L4 0.1a 0.25a 0.4a 0.1a 0.1a 0.1a 0.06a

[0058] Table 2 Laser particle size measurement results

[0059] Serial number D10 D50 D90 Example 1 10.507 36.534 110.377 Example 2 9.339 32.816 104.422 Example 3 17.632 43.238 118.678 Comparative Example 1 23.356 57.602 138.413 Comparative Example 2 22.288 56.024 136.340 Comparative Example 3 21.465 53.336 133.12 Comparative Example 4 20.153 52.869 128.860

[0060] Through the measurement results of Example 1, Example 2, Example 3 and 4 comparative examples, it can be seen that the particle size and distribution concentration of the metal powder prepared by using the atomizing nozzle of the present invention and setting the various parameters of the annular gap type air outlet 6 within the parameter setting range of the present invention are better than those of the comparative example, and a powder with a finer particle size and a more concentrated distribution can be obtained. Furthermore, in combination with the setting of the diverter ring 7 and the diverter hole in the present invention and the setting of the equidistant ribs 303 in the straightening ring 3, the air flow is made more stable and uniform, the atomized powder has a fine particle size, and has less satellite powder; and the annular gap type air outlet 6 structure formed by the combination of the lower spray disc 2 and the straightening ring 3, under high temperature and high pressure use environment, the deformation of the air outlet profile is not affected by the deformation of the upper spray disc 1 profile, and thus has a more stable atomization effect. The powder making effect has verified that the normal service life of the atomizing nozzle using the structure of the present invention when preparing iron-based alloy powder is more than 3 times that of the conventional structure nozzle.

[0061] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely preferred examples of the present invention and are not intended to limit the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. An atomizing nozzle, characterized in that: The atomizing nozzle comprises an upper spray disc (1) and a lower spray disc (2) which are arranged in an upper and lower manner, wherein the center of the upper spray disc (1) is provided with a flow guide channel (101) which passes through to the lower end surface of the lower spray disc (2), and both sides of the lower spray disc (2) are provided with air inlet channels (4), and the upper spray disc (1) and the lower spray disc (2) cooperate to form an air inlet cavity (5) which is connected to the air inlet channel (4); the atomizing nozzle also comprises a rectifying ring (3) connected between the upper spray disc (1) and the lower spray disc (2), and the outer wall of the rectifying ring (3) cooperates with the inner wall of the lower spray disc (2) to form an annular seam-type air outlet (6) which is connected to the air inlet cavity (5); The atomizing nozzle further comprises a diverter ring (7) connected to the upper end surface of the lower spray disc (2), the diverter ring (7) and the lower spray disc (2) are coaxially arranged, the diverter ring (7) divides the air inlet cavity (5) into an inner cavity (501) and an outer cavity (502), the diverter ring (7) is evenly provided with four diverter holes in the circumferential direction, and the four diverter holes are at the same distance from the adjacent air inlet channel (4); The rectification ring (3) comprises a rectification portion (301) and a first annular boss (302) connected circumferentially to the rectification portion (301); the upper end surface of the lower spray disc (2) is provided with a first annular groove (202) matching the first annular boss (302); The rectifying portion (301) and the first annular boss (302) are connected via a plurality of ribs (303) arranged at equal intervals.

2. The atomizing nozzle according to claim 1, characterized in that The upper spray disc (1), the lower spray disc (2) and the rectifying ring (3) are coaxially arranged.

3. The atomizing nozzle according to claim 1, characterized in that The cross section of the annular seam-type air outlet (6) along the central axis (9) of the guide channel is formed by a contour line formed by two points P1-P4 and a contour line formed by two points P1'-P4', wherein the center line (8) forms an angle b1 with the central axis (9) of the guide channel, and the angle b1 is set to 5-45 degrees, and the extension line of P1-P4 and the extension line of P1'-P4' are axially symmetrical with respect to the center line (8).

4. The atomizing nozzle according to claim 1, characterized in that The cross section of the annular seam-type air outlet (6) formed along the central axis (9) of the guide channel is formed by a contour line formed by nodes P1-P2-P3-P4 and P1'-P2'-P3'-P4', and includes a steady flow section formed by P1-P2 and P1'-P2', a contraction section formed by P2-P3 and P2'-P3', a throat formed by P3 and P3', and an expansion section formed by P3-P4 and P3'-P4'.

5. The atomizing nozzle according to claim 4, characterized in that The line segment P1-P2 is parallel to the line segment P1'-P2', and the shortest distance between the two line segments is set to a.

6. The atomizing nozzle according to claim 5, characterized in that The projected lengths of the steady flow section, the contraction section, and the expansion section on the cross-sectional centerline (8) are L1, L2, and L3, respectively. The length of L1 is set to 2a-5a, the length of L2 is set to 0.5a-5a, the length of L3 is set to 2a-10a, and the width of the throat P3-P3' is set to 0.05a-0.8a.

7. The atomizing nozzle according to claim 5, characterized in that The length of the line segment formed by P3-P4 is greater than the length of the line segment formed by P3'-P4', and the extra length is the guide segment (10).

8. The atomizing nozzle according to claim 7, characterized in that The projected length of the guide section on the cross-section centerline (8) is L4, and the length of L4 is set to 0.1a-0.4a.

9. The atomizing nozzle according to claim 4, characterized in that The extended lines of the line segment P3-P4 and the line segment P3'-P4' form an angle b, and the angle b is set to 4-15 degrees.

10. The atomizing nozzle according to claim 1, characterized in that The upper end surface of the rectifying portion (301) is provided with a second annular groove (305), and the lower end surface of the upper spray disc (1) is provided with a second annular boss (102) matching the second annular groove (305).

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