Gas Atomization Nozzle with Swirling Flow Stabilization
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Solution Overview
Problem
Existing gas atomization nozzles produce metal powder with large variations in particle size and low yield of fine powder, as the supersonic gas flow leads to unstable injection and particle agglomeration, resulting in inefficient production of metal powders with particle sizes of 45 µm or less.
Innovation Solution
A gas atomization nozzle with a Laval nozzle portion inclined at a predetermined angle and a swirling motion imparting mechanism, featuring spiral-shaped holes around a central through-hole, stabilizes the supersonic gas flow and imparts a centrifugal swirling motion to the gas, reducing particle size variation and preventing powder agglomeration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a Laval nozzle is used to accelerate gas to supersonic speed, then the gas flow velocity is improved, but the flow direction becomes unstable due to turbulence causing large particle size variation
Solution Approach 1:
The patent introduces a swirling flow component by curving the gas flow path through a spiral-shaped flow path or by providing a swirl generator. This curvature transforms the linear supersonic flow into a rotating flow pattern, which stabilizes the flow direction through centrifugal forces while maintaining the high velocity achieved by the Laval nozzle.
Solution Approach 2:
The patent introduces a swirling flow as an intermediary mechanism between the supersonic gas flow and the molten metal. This swirling flow acts as a mediator that organizes the turbulent supersonic flow into a more stable pattern, reducing direct turbulence impact on particle formation while maintaining atomization effectiveness.
2Manufacturing precision
If supersonic gas flow is used for atomization, then fine powder production is improved, but particle agglomeration and nozzle blockage occur due to unstable flow
Solution Approach 1:
The swirling flow created by curving the gas flow path generates centrifugal forces that push particles outward and away from the nozzle centerline. This prevents particles from aggregating in the nozzle vicinity and reduces the likelihood of nozzle blockage, while the rotational motion also promotes more uniform particle size distribution.
Solution Approach 2:
The patent applies the swirling flow modification to the gas flow before it contacts the molten metal. This preliminary action of imparting rotation to the supersonic flow prepares a more stable atomization environment, preventing particle agglomeration and nozzle blockage before they can occur during the atomization process.
3Ease of manufacture
If the nozzle structure is simplified, then ease of manufacture is improved, but the ability to produce fine powder with consistent particle size is reduced
Solution Approach 1:
The patent achieves the swirling flow effect through relatively simple structural modifications such as a spiral-shaped flow path or a swirl generator element that can be integrated into the existing Laval nozzle design. These modifications are manufacturable using conventional techniques while delivering the particle size control benefits of swirling flow.
Solution Approach 2:
The patent combines the Laval nozzle structure with a swirling flow generator in an integrated design. By merging the supersonic flow generation function with the flow stabilization function into a single unified nozzle structure, the patent achieves fine powder production with consistent particle size without requiring separate complex systems.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The nozzle effectively produces fine metal powder with reduced particle size variation, improving production efficiency and preventing nozzle blockage, while ensuring consistent particle distribution and enhanced sinterability in metal injection molding.
Implementation Method 1
a nozzle portion configured of a Laval nozzle which is disposed around the center line and provided to be inclined at a predetermined angle toward the center line
Implementation Method 2
gas that is a supersonic flow is injected toward the molten metal
Implementation Method 3
swirling motion imparting means for imparting a swirling flow around the center line to gas which is injected from the nozzle portion
Implementation Method 4
the produced metal powder is dispersed by a centrifugal force due to the swirling flow
Data Source
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AI summary
The purpose of the present invention is to generate fine powder with less variation in particle size. Provided is a gas atomization nozzle comprising: a through-hole (3A) formed along a center line (C); a nozzle portion (3D) configured as a Laval nozzle, which is disposed along a periphery of the center line (C) and inclined at a predetermined angle (α) with respect to the center line (C); and a swirling motion imparting means for imparting a swirling flow around the center line (C) to gas emitted from the nozzle portion (3D).