Supersonic speed circular seam type spraying disc

Abstract

The utility model discloses a supersonic speed circular seam type spraying disc which comprises an integrated spraying disc body, and the spraying disc body is provided with an annular cavity, at least two air inlet channels, a circular seam nozzle, an atomization cavity and a molten metal hole. The atomizing chamber is arranged at the bottom of the spraying disc main body; the molten metal hole vertically penetrates through the spraying disc body, and the bottom end of the molten metal hole communicates with the atomization cavity; the at least two air inlet channels are tangentially connected with the annular cavity, and the bottom end of the annular cavity communicates with the atomization cavity through the circular seam nozzle. The annular seam nozzle is arranged around the molten metal hole and is provided with a Laval structure, formation of supersonic speed and uniform and stable airflow can be achieved, the atomization effect is good, it can be guaranteed that the speed on the molten metal hole is the maximum, meanwhile, the pressure on the molten metal hole is negative pressure, and the atomization effect is good. Therefore, the problems of metal atomization failure and the like caused by reverse spraying of molten metal liquid drops are prevented; the integrated design is beneficial to reducing manufacturing errors, and meanwhile the sealing performance of the structure is improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of gas atomization spray disc, concretely relates to a supersonic ring slit type spray disc. BACKGROUND

[0002] With the rapid development of static pressure forming, 3D printing and other technologies, the manufacturing industry has higher and higher requirements for the yield of metal powder, fineness and sphericity of the powder, in the preparation of metal powder industry, gas atomization technology becomes one of the main methods for producing high performance metal powder. The basic principle of gas atomization technology is that high speed and high pressure gas flow generated by the nozzle crushes the metal melt into small droplets, and then the process of spheroidization, cooling and solidification becomes metal powder. The existing nozzle generates pressure difference by the change of the jet area of the gas flow channel, so that the gas flow is accelerated to sonic speed or even supersonic speed and acts on the metal melt, but there are still problems such as poor gas flow stability and poor controllability of atomization effect. In addition, the existing metal gas atomization nozzle structure is relatively complex, and most of them are made by disassembling process. Since the core size of the gas atomization nozzle is mm level, the disassembling process is easy to produce large assembly error, and it is necessary to increase the design of sealing ring and other structures, which increases the process cost and cannot guarantee the sealing performance. SUMMARY

[0003] The utility model provides a supersonic ring slit type spray disc in view of the deficiency of prior art.

[0004] In order to realize the above purpose, the technical scheme of the utility model is as follows:

[0005] A supersonic ring slit type spray disc, which comprises an integral spray disc body, the spray disc body has a ring-shaped cavity, at least two gas inlet channels, a ring slit nozzle, an atomization chamber and a molten metal hole; the atomization chamber is arranged at the bottom of the spray disc body; the molten metal hole penetrates the spray disc body from top to bottom and is connected to the atomization chamber at the bottom; the at least two gas inlet channels are respectively connected to the ring-shaped cavity tangentially, and the ring-shaped cavity is connected to the atomization chamber through the ring slit nozzle at the bottom; the ring slit nozzle surrounds the molten metal hole and has a Laval structure.

[0006] Optionally, two gas inlet channels are arranged on the opposite sides of the center of the ring-shaped cavity, and the gas inlet directions are arranged at 180 degrees.

[0007] Optionally, the shape of the Laval structure of the ring slit nozzle on the axial section of the molten metal hole is a slit, the slit comprises an inlet section from top to bottom, a throat section extending from the inlet section and narrowing, and an expansion section extending from the throat section and expanding, and the slit is inclined from top to bottom to the direction close to the molten metal hole.

[0008] Optionally, the included angle between the center line of the slit and the axis of the molten metal hole is 15-20° in the axial section of the molten metal hole.

[0009] Optionally, the gas inlet section is a parallel section, the inner side wall of the annular cavity is inclined from top to bottom towards the direction close to the molten metal hole, one of the parallel sections is formed by the inner side wall extending along the inclined direction, and the other is connected with the bottom wall of the annular cavity.

[0010] Optionally, the bottom wall of the annular cavity has an arc surface shape and gradually extends upwards towards the direction close to the molten metal hole, and is connected with the parallel section at the highest point with smooth transition.

[0011] Optionally, the expansion angle of the expansion section is 2-5°.

[0012] Optionally, the throat section includes a first transition fillet and a second transition fillet which are smoothly connected, the diameters of the first transition fillet and the second transition fillet are both 0.15-0.25 mm, and the center line of the first transition fillet and the second transition fillet passes through the connection position of the first transition fillet and the second transition fillet.

[0013] Optionally, the diameter of the gas inlet section is 0.8-1.2 mm, the diameter of the narrowest part of the throat section is 0.25-0.40 mm, and the diameter of the end of the expansion section is 0.50-0.70 mm.

[0014] Optionally, the diameter of the bottom of the molten metal hole is larger than the diameter of the top.

[0015] The beneficial effects of the utility model are as follows:

[0016] The supersonic ring slit type spray disc can realize the formation of supersonic, uniform and stable airflow, has good atomization effect, can ensure that the velocity on the molten metal hole is maximum, and the pressure on the molten metal hole is negative pressure, thereby preventing problems such as metal atomization failure caused by reverse spraying of molten metal droplets; the integrated design can be integrally formed by using 3D printing technology, can well ensure that the actual size of the Laval structure nozzle is consistent with the size obtained by simulation optimization, reduces manufacturing error, and improves the sealing performance of the structure. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is a longitudinal sectional view of the supersonic ring slit type spray disc of the embodiment.

[0018] Figure 2 It is a longitudinal sectional view of the supersonic ring slit type spray disc of the embodiment. Figure 1 It is a schematic view of the B-B section.

[0019] Figure 3 It is a schematic view of the B-B section. Figure 1 It is a local enlarged schematic view of the A area (ring slit nozzle).

[0020] Figure 4 is a longitudinal sectional view of a supersonic ring-slit type spray disc with labels;

[0021] Figure 5 is a schematic view of the slit shape of a ring-slit nozzle with labels;

[0022] Figure 6 is a velocity contour of a ring-slit nozzle of an embodiment;

[0023] Figure 7 is a gas flow rate curve on the center line of a molten metal hole of an embodiment;

[0024] Figure 8 is a gas pressure curve on the center line of a molten metal hole of an embodiment;

[0025] Figure 9 is an electron microscope image of metal powder prepared using a supersonic ring-slit type spray disc of an embodiment. DETAILED DESCRIPTION

[0026] The utility model is further explained below in combination with the drawings and specific embodiments. The drawings of the utility model are only schematic to make it easier to understand the utility model, and the specific proportions can be adjusted according to design requirements. The relative position relationship of the elements in the figures described in the specification and the definition of the front / back surface should be understood by those skilled in the art as the relative position relationship in the working state, so the same components can be reversed to present the same components, which should all belong to the scope disclosed in the specification.

[0027] The supersonic ring-slit type spray disc provided by the embodiment has the following advantages: Figures 1 to 3 The spray disc body 100 is integrally formed by 3D printing technology, and the spray disc body 100 has a ring-shaped cavity 1, two gas inlet channels 2, a ring-slit nozzle 3, an atomization chamber 4 and a molten metal hole 5. The atomization chamber 4 is arranged at the bottom of the spray disc body 100. The molten metal hole 5 is located in the middle of the spray disc body 100, penetrates the spray disc body 100 from top to bottom and is connected to the atomization chamber 4 at the bottom end. The two gas inlet channels 2 are respectively tangentially connected to the ring-shaped cavity 1 to realize tangential gas inlet. The ring-shaped cavity 1 is located outside the molten metal hole 5, and the bottom end near one side of the molten metal hole 5 is connected to the atomization chamber 4 through the ring-slit nozzle 3. Therefore, the ring-slit nozzle 3 is arranged around the molten metal hole 5 and has a Laval structure. The gas flow enters the ring-shaped cavity 1 from the two gas inlet channels 2 and generates high-speed, high-pressure gas flow through the Laval structure of the ring-slit nozzle 3 into the atomization chamber 4. The metal melt enters the atomization chamber 4 from the molten metal hole 5 and is pulverized into fine droplets by the high-speed, high-pressure gas flow, and the preparation of metal powder is realized through subsequent processes.

[0028] The supersonic ring-slit type spray disc provided by the embodiment has the following advantages: Figure 2, two intake passages 2 are located on the opposite sides of the center of the annular cavity 1, and the intake direction is 180°. Compared with the large fluctuation of the suction pressure of the vertical intake disc, the suction pressure of the tangential intake disc changes gently, which is beneficial to reduce the fluctuation of the airflow and improve the stability of the atomized flow field. The intake passages 2 are equally spaced in the circumferential direction of the annular cavity 1, which is more beneficial to the uniformity of the intake. In addition, in other embodiments, a plurality of intake passages can also be provided and preferably equally spaced.

[0029] Reference Figure 3 , the Laval structure of the annular slot nozzle 3 is an annular channel arranged around the molten metal hole 5, and the shape of the annular channel in the axial section of the molten metal hole 5 is two slits on both sides of the molten metal hole 5. The slit includes an intake port section 31 from top to bottom, a throat section 32 extending from the intake port section 31 and narrowing, and an expansion section 33 extending from the throat section 32 and expanding, the slit is inclined from top to bottom to the direction close to the molten metal hole 5, for the sake of description, combined with Figure 4 , the angle between the center line of the slit and the axis of the molten metal hole 5 is α, which is 15°-20°.

[0030] For the sake of description of the structure of the annular slot nozzle 3, the shape of the slit in the axial section of the molten metal hole 5 is described below, and the three-dimensional structure should be an annular channel formed by rotating the slit shape around the axis of the molten metal hole 5 by 360°. Among them, the intake port section 31 is a parallel section, the inner side wall 11 of the annular cavity 1 is inclined from top to bottom to the direction close to the molten metal hole 5, one of the parallel sections is formed by the inner side wall 11 extending in the inclined direction, and the other is connected with the bottom wall 12 of the annular cavity 1. Specifically, the bottom wall 12 of the annular cavity 1 has an arc surface shape, and the arc surface gradually extends upward in the direction close to the molten metal hole 5, and is connected with the parallel section at the highest point, and the connection is smooth transition, so that the airflow enters the annular slot nozzle 3 under the condition of smaller resistance. For the sake of description, combined with Figure 5 , the length L1 of the intake port section 31 is 1.5-2.5mm, and the caliber a (i.e. the distance between the two parallel sections) is 0.8-1.2mm. The throat section 32 includes a smooth connection of a first transition fillet 321 and a second transition fillet 322, the diameters of the first transition fillet 321 and the second transition fillet 322 are both 0.15-0.25mm, and the center line of the first transition fillet 321 and the second transition fillet 322 passes through the connection of the two, including the connection point or the smooth connection section. The length L2 of the throat section 32 is 0.1-0.3mm, and the caliber b at the narrowest part is 0.25-0.40mm. The expansion section 33 is gradually increased in interval, and the expansion angle β (i.e. the angle between the side wall of the expansion section 3 and the center line of the slit) is 2°-5°. The length L3 of the expansion section 33 is 2.5-3mm, and the caliber c at the end is 0.50-0.70mm.

[0031] Combined withFigure 4 The atomizing chamber 4 has a circular cross-section with a diameter d ≥ 80 mm. The molten metal orifice 5 is located at the center of the circle in the atomizing chamber 4. The bottom diameter of the molten metal orifice 5 is larger than the top diameter, forming a downward expanding shape, which ensures that the molten metal liquid gathers and falls better, while not sticking to the orifice wall. The diameter e of the circle containing the center point of the end of the expanding orifice 33 is 20–22 mm.

[0032] In a preferred embodiment, the angle α between the centerline of the annular nozzle 3 and the molten metal orifice 5 is 17°, the expansion angle β is 3°, the diameter a of the inlet section 31 is 1 mm, the diameter b at the narrowest point of the throat section 32 is 0.32 mm, the diameter c at the end of the expansion section is 0.6 mm, the length L1 of the inlet section 31 is 2 mm, the length L2 of the throat section 32 is 0.2 mm, the length L3 of the expansion section 33 is 2.7 mm, the diameter e of the circle containing the center point of the end of the expansion section 33 is 21 mm, and the diameters of the first transition fillet 321 and the second transition fillet 322 are 0.2 mm. Under these conditions, the velocity contour plot of the annular nozzle 3 is as follows: Figure 6 As shown, the gas flow velocity along the center line of the molten metal hole 5 is as follows: Figure 7 As shown, the gas pressure is as follows Figure 8 As shown, the x-axis represents the centerline of the molten metal orifice 5, with the zero point of the x-coordinate located inside the molten metal orifice 5. The test starting point (i.e., the starting point of the test curve) is the airflow outlet from the molten metal orifice to the atomization chamber. This structural parameter enables the formation of supersonic, uniform, and stable airflow, resulting in good atomization. It also ensures maximum airflow velocity at the molten metal orifice 5, while maintaining a negative pressure at the molten metal orifice 5 to prevent metal atomization failure caused by molten metal droplet backflow. (Reference) Figure 9 It can prepare small-sized metal powders on the scale of tens of micrometers, and the metal powders have good dispersion uniformity and particle size uniformity.

[0033] The supersonic circumferential spray disc provided in this embodiment can be manufactured in one piece using 3D printing technology, and the interior is polished using abrasive flow technology. Therefore, it can ensure that the actual size of the Laval structure nozzle is consistent with the size obtained from simulation optimization, reduce manufacturing errors, and improve the sealing performance of the structure.

[0034] The above embodiments are only used to further illustrate a supersonic circumferential spray disc of the present invention, but the present invention is not limited to the embodiments. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A supersonic loop-strut type impeller characterized by: The nozzle body has an annular cavity, at least two air inlet channels, an annular slot nozzle, an atomizing chamber and a molten metal hole; the atomizing chamber is arranged at the bottom of the nozzle body; the molten metal hole penetrates the nozzle body from top to bottom and is connected to the atomizing chamber at the bottom end; the at least two air inlet channels are respectively connected to the annular cavity tangentially, and the annular cavity is connected to the atomizing chamber through the annular slot nozzle at the bottom end; the annular slot nozzle surrounds the molten metal hole and has a Laval structure; the shape of the Laval structure of the annular slot nozzle on the axial section of the molten metal hole is a slit, which includes an air inlet section, a throat section extending from the air inlet section and narrowing, and an expansion section extending from the throat section and expanding, and the slit is inclined from top to bottom towards the molten metal hole.

2. The super-sonic ring-slit type spray disc according to claim 1, characterized in that: The two air inlet channels are located on the opposite sides of the center of the annular cavity, and the air inlet directions are arranged at 180°.

3. The super-sonic ring-slit type jet disc according to claim 1, characterized in that: The included angle between the center line of the slit and the axis of the molten metal hole on the axial section of the molten metal hole is 15°-20°.

4. The super-sonic ring-slit type jet disc according to claim 1, characterized in that: The air inlet section is a parallel section, the inner side wall of the annular cavity is inclined from top to bottom towards the molten metal hole, one of the parallel sections is formed by extending the inner side wall in the inclined direction, and the other is connected to the bottom wall of the annular cavity.

5. The super-sonic ring-slit type jet disc according to claim 4, characterized in that: The bottom wall of the annular cavity has an arc shape and gradually extends upwards towards the molten metal hole, and is connected to the parallel section at the highest point with smooth transition.

6. The super-sonic ring-slit type jet disc according to claim 1, characterized in that: The expansion angle of the expansion section is 2°-5°.

7. The super-sonic ring-slit type jet disc according to claim 1, characterized in that: The throat section includes a first transition fillet and a second transition fillet connected smoothly, the diameters of the first transition fillet and the second transition fillet are both 0.15-0.25 mm, and the center line of the first transition fillet and the second transition fillet passes through the connection position of the two.

8. The super-sonic ring-slit type jet disc according to claim 1, characterized in that: The diameter of the air inlet section is 0.8-1.2 mm, the diameter of the narrowest part of the throat section is 0.25-0.40 mm, and the diameter of the end of the expansion section is 0.50-0.70 mm.

9. The super-sonic ring-slit type jet disc according to claim 1, characterized in that: The bottom diameter of the molten metal hole is larger than the top diameter.

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