Gas Atomizing Nozzle for Metal Powder Production
Patent Information
- Authority / Receiving Office
- ID · ID
- Patent Type
- Patents
- Current Assignee / Owner
- LEMBAGA ILMU PENGETAHUAN INDONESIA
- Filing Date
- 2019-12-15
- Publication Date
- 2026-07-14
AI Technical Summary
Existing gas atomization nozzles for producing metal powder lack a simple design that combines high pressure gas with a rotating gas flow, leading to complex manufacturing and inconsistent powder shape, with most designs failing to specify the form of the resulting powder.
A cone-shaped gas atomization nozzle that integrates high pressure gas with a rotating gas flow, featuring a reservoir for molten metal, a separator for cold air, and a gas flow system with tangentially arranged channels, producing a tornado effect to atomize the metal into predominantly round-shaped particles.
The nozzle efficiently produces spherical metal powder with sizes ranging from 0.9 to 200 μm, overcoming the complexity and inconsistency of previous designs by ensuring a uniform rotating gas flow and precise particle shape.
Smart Images
Figure 0_ABST
Abstract
Description
Description GAS ATOMIZATION NOZZLE FOR METAL POWDER PRODUCTION Invention Engineering Field The present invention relates to a device for producing metal powder, in particular a cone-shaped device that uses high-pressure gas and a rotating gas stream to produce metal powder with a spherical shape. Background of the Invention Powdered metal has been widely used to produce high-quality machine parts and components. The manufacturing process involves filling a mold with a suitable metal powder mixture, pressing the mold at room temperature, and then sintering it. The mold is then customized to the desired shape, such as gears and similar parts used in machines. Parts and components produced using powder metallurgy can be manufactured to precise tolerances with minimal finishing operations and from metals that would otherwise be difficult to machine. Metal powders have also been used in brazing and coating other metal alloy surfaces, such as plasma spray, thermal spray, cold spray, and pack coating. The need for metal powders in industrial applications continues to grow and expand, along with the increasing demand for powdered alloys of various metals. The need for metal powders is also accompanied by special requests, such as spherical metal powder shapes with specific sizes. One technique used to produce metal powders is gas atomization. When a stream of molten metal falls vertically, it is broken up by the gas stream into separate particles. In general, gas atomization produces spherical or spherical particles. A more detailed review of patents and literature on atomization can be found in the Handbook of Non-Ferrous Metal Powders: Technologies and Applications (second edition), by Neikov et al. (2019). The key to producing metal powder using gas atomization techniques lies in the gas atomization nozzle. The nozzle must be designed to provide continuous atomization of the molten metal stream. Several patents related to atomization nozzles, including US Patent No. 4,880,162 (1989), disclose and claim a nozzle that can control the width of the spray zone and the angle of convergence that exits the nozzle. This atomization nozzle excels in gas flow regulation with a more complex design. US Patent No. 4,416,600 (1982) discloses and claims a nozzle made of several parts where the nozzle is designed using a spiral channel so that it can produce a gas flow that hits the rotating molten metal to control the resulting particle size. US Patent No.U.S. Patent No. 3,253,783 (1964) discloses and claims a gas atomizing nozzle wherein gas is introduced into a first annular chamber through a hand-held slot and gas from the first annular chamber enters into a second annular chamber through a hand-held slot and then passes out of the nozzle around a molten metal stream to effect the production of metal powder. The molten metal outflow outlet end in the patent (U.S. Patent No. 3,253,783) protrudes further outward than the gas outflow end of the atomizing nozzle. US patent No. 4,619,597 (1989) concerns an apparatus for melt atomization with a concave melt nozzle for gas deflection. The patent claims a gas atomizing nozzle with a special relationship between the outer surface of the melt tube and the hole of the end cover plate, wherein the end cover plate is curved to influence the production of metal powder. US patent No. 4,880,162 (1989) concerns a gas atomizing nozzle for the production of metal powder. This atomizing nozzle features a more advanced design for gas flow regulation. US Patent No. 4,626,278 (1986) concerns a tandem atomization method for very fine metal powders. The tandem atomization described in this patent has a molten metal outlet tip aligned with the gas outlet tip of the atomizing nozzle system. US Patent No. 3,592,391 (1971) concerns a nozzle for atomization. The nozzle is designed with a ring shape that can be used for atomization and is separate from the molten / liquid metal system. In this patent, the tip surface used for the molten metal outlet is flush with the gas outlet tip. Although it shows examples of metals and alloys that can be atomized into metal powders, it does not mention the shape of the resulting metal powder. US Patent No. 1,856,679 (1932) concerns an apparatus for breaking up metal, also known as an atomizing device. The device uses a nozzle system that utilizes two separately claimed air intake systems.The first nozzle consists of two tangential airflows entering at a 0° angle. The second nozzle consists of three tangential airflows entering at a 60° angle. However, the patent does not mention the exiting airflow. Furthermore, the resulting powder form is not discussed in the patent. US patent No. 4,631,013 (1986) concerns an apparatus for atomizing an unstable molten stream. This patent is related to US patent No. 4,619,597 (1989) concerning an apparatus for atomizing a melt with a concave melt nozzle for gas deflection. US patent No. 3,501,802 (1970) concerns a method and apparatus for producing metal powder. The nozzle design in this patent uses a tangential air flow at an angle of 180°, which is located close to the edge of the atomizing nozzle. This is to produce a tornado flow with a reduced gas flow design. The molten metal outlet protrudes from the atomizing nozzle surface. This patent indicates the size of the powder produced but does not indicate the shape of the atomized powder. US patent No. 2,440,531 (1946) concerns an apparatus for producing metal powder, where the spray system is separate from the molten metal reservoir. The spray system consists of two nozzles arranged at an angle.US patent No. 5,228,620 (1993) concerns atomizing nozzles and processes. The nozzles consist of multiple gas flow chambers and can produce particles with a dominant size above 500 nm. This patent does not indicate the shape of the resulting metal powder. US patent No. 5,480,470 (1996) concerns atomization with low atomizing gas pressure, reviews the use of low pressure and shows a drawing of the nozzle. In that patent, the molten metal outlet protrudes more than the gas outlet of the atomizing nozzle system. US patent No. 6,142,382 (2000) concerns atomizing methods and nozzles. The nozzles in that patent have a single gas inlet with a molten metal outlet protruding more than the gas outlet of the atomizing nozzle system. US patent No. 2004 / 0031354 A1 (2004) concerns processes and devices for producing metal powders and their alloys, the molten metal exiting the melting channel being sprayed by three spray systems.However, the patent does not indicate the shape of the resulting powder. US patent No. US 9,981,315 B2 (2018) concerns an atomizer for enhancing the production of very fine powder. In this patent, the atomizing nozzle has two gas outlets at certain angles around the metal liquid outlet end and the metal outlet end protrudes more than the gas outlet end of the atomizing nozzle system. CN Patent No. 202951880U (2013) on a two-layer atomization nozzle of fluid flow. The first layer flows vertically downward and the second layer flows from both sides forming an angle of 30-60°. The gas flow produced from the nozzle is stable laminar. AU Patent No. AU2015230636B2 (2015) discloses a metal powder atomization system with a plasma technique. In this invention, metal in the form of a rod is melted with a plasma system and sprayed by gas. Where the gas system is in the form of holes around the falling molten metal. This patent also claims that the resulting powder is spherical in size from 1 to 1000μm. The system in the patent is complicated and the sprayed air does not rotate. In addition, the resulting powder in small sizes (Figure 9 in AU Patent No. AU2015230636B2 (2015)) shows an irregular shape. None of these inventions combines high-pressure gas and a rotating gas stream in a simple nozzle system. Atomizing nozzle designs are also highly complex to manufacture. Existing nozzle systems typically utilize ceramic insulators to prevent cold air from directly contacting the metal melting tip. Furthermore, the molten metal outlet tip is the same or projected more than the gas outlet tip in atomizing nozzle systems. No previous patents describe the powder formation of atomizing nozzles or apparatus. This invention differs from the previous invention, where in this invention the nozzle is designed simply and can be used on high pressure gas and the gas flow that hits the molten metal is rotating. This invention does not use a special system to prevent cold air from directly hitting the tip where the metal is melted. The molten metal outlet tip is protruding inward from the gas outlet tip in the atomizing nozzle system, so that the molten metal outlet tip is in the rotating gas flow system. In addition, the nozzle in this invention produces powder with a predominantly spherical shape. Brief Description of the Invention The present invention aims to create a gas atomizing nozzle that combines high-pressure gas and a rotating gas stream that impacts the molten metal outlet end. This gas atomizing nozzle consists of three main parts, namely: a part that is integrated with the molten metal / liquid system consisting of an inverted cone-shaped container for holding the molten metal and a nozzle hole at the lower end of the container, a separating or blocking part for the cold gas flow, and a system part that delivers the rotating gas to the nozzle hole area. The above-mentioned components are clamped using bolts to provide a complete atomizing unit. Short Description of Image Figure 1 is a schematic drawing of a gas atomizing nozzle according to the present invention. Figure 2 is a top view of a gas atomizing nozzle according to the present invention. Figure 3 is a cross-section of a separating or barrier portion for cold air of a gas atomizing nozzle according to the present invention. Figure 4 is a scanning electron microscope image of tin metal powder produced using a gas atomizing nozzle according to the present invention. Complete Description of the Invention Figure 1 is a cross-sectional view of a gas atomizing nozzle of the present invention. The nozzle comprises a container for melting or liquefying metal (1) having an upper end (2). The molten metal in the container located at the top of the nozzle (3) which is integrated with the nozzle system can emerge as a downward stream through a nozzle orifice (4). The molten metal container and the nozzle can be made of the same or different metal materials. The lower end of the nozzle (5) has a tapered surface with a maximum angle of 45°. The molten metal emerging from the container (1) of the molten metal at the end of the nozzle orifice (4) is sprayed or jetted by gas from a circular gas orifice portion (7) of the gas flow system. The distance between the nozzle orifice (4) and the gas orifice (7) is not more than 8 millimeters. The gas flow system comprises a gas flow from the gas chamber (6) out through a circular gas orifice (7) around the lower end of the nozzle.The surface (8) has a beveled shape that is inverse to the tapered surface of the lower end of the nozzle. The hole (7) for the gas spray or jet exit has a beveled surface to match the beveled surface of the tapered surface of the lower end of the nozzle (5). The gas space (6) is formed by the separating or blocking part (9) for the cold air from the gas atomizing nozzle with the wall (10) of the gas flow system part. The gas atomizing nozzle assembly is locked or tightened by conventional means such as bolts (11). The gas chamber has a pair of gas inlets (12) arranged tangentially at an angle of 180° and can be at least 1 millimeter apart from the outer boundary wall of the gas chamber (6) as shown in Figure 2. The gas chamber (6) supplies gas to the gas hole (7) which is circular around the lower end of the nozzle. It can be seen in Figure 2 that the gas inlet hole (7) has the role of generating rapid rotation in the gas chamber (6) to create a tornado or rotating effect at the tip of the atomizing nozzle towards the exit through the gas hole (7) and also generates a tornado or rotating effect at the outer end of the atomizing nozzle (13). The gas atomizing nozzle in the present invention can be used for atomizing various substances, such as slag, fertilizer salts, plastic materials, and especially metals and their alloys. Atomizing agents include nitrogen, argon or air. Figure 3 is a cross-sectional view of the separator or barrier section. The separator or barrier section is composed of a flat ring of a certain thickness integrated with a wall (10) that prevents the gas from directly contacting the reservoir (1) and also the nozzle tip (5). The wall (10) has an inverted cone shape that is truncated at the tip. The inside of the cone has a cavity with a certain shape and volume for the nozzle tip (5) to enter. The metal powder resulting from gas atomization using the nozzle in this invention is shown in Figure 4. The resulting powder shape is spherical with a powder size ranging from 0.9 μm to 200 μm.
Claims
Claim 1. A gas atomization nozzle for the production of metal powder, comprising: • a reservoir (1) in the shape of an inverted cone for containing molten metal, which is connected to a nozzle hole (4) at the lower end of the reservoir (1); • a gas chamber (6) that supplies gas to the gas hole (7) which serves to create a tornado effect in the area of the nozzle hole (4); • a gas channel (12) arranged tangentially which serves to supply air to the gas chamber (6); • a barrier (9) connected to a wall (10) located between the lower part of the reservoir (1) and the gas chamber (6), so that the gas does not hit the cone-shaped wall of the reservoir (1) and keeps the gas rotating; and • a bolt (11) for fastening the nozzle.
2. A gas atomization nozzle for the production of metal powder as in claim 1, wherein the melting / melting of the metal is one with the nozzle and is in the shape of an inverted cone with a cone tip angle of not more than 45°.
3. A gas atomization nozzle for the production of metal powder as in claim 1, wherein the inlet gas channel is tangentially disposed at an angle of 180° and can be at least 1 millimeter apart from the outer boundary wall of the gas chamber (6).
4. A gas atomization nozzle for the production of metal powder as in claim 1, wherein the distance between the nozzle hole (4) and the gas hole (7) is not more than 8 millimeters.
5. A gas atomization nozzle for the production of metal powder as in claim 1, wherein the molten metal bed and the nozzle may be made of the same or different metal materials.
6. A gas atomizing nozzle for the production of metal powder as in claim 1, wherein the gas orifices (7) are disposed around the outside of the nozzle orifice (4) which provide gas sprays from various directions onto the metal ejected from the nozzle orifice (4).
7. A gas atomization nozzle for the production of metal powder as in claim 1, wherein the nozzle can produce a full spherical metal powder with a powder size ranging from 0.9 μm to 200 μm.