Powder satellite-reduction apparatus and method for gas atomization process
The broad applicability of at least certain aspects of the present invention derives from the ability to determine the critical location where secondary satellite formation occurs for any atomization system or design and allows for the rapid assessment of the effectiveness of various satellite reduction strategies, including but not limited to several embodiments detailed herein. Aspects of this invention can be utilized during initial atomization system design in order to evaluate effective chamber geometries and enabling strategies which reduce/eliminate satelliting, or can be retrofit to existing systems and allows for economic evaluation of effectiveness based off of initial capital expenditures versus increased operating requirements/expenses.
1 . A method of operating a high-pressure gas atomization (GA) system to suppress satelliting in the production of particles of metal powders from droplets of an atomized spray of a feedstock in a flow path in a GA spray chamber comprising:
(a) for a given feedstock comprising a metal to be powderized into metal powder particles, proposing a first physical system set-up and a first set of operating parameters of the GA system to be used;
(b) identifying critical location(s) for potential satelliting in the GA spray chamber of the GA system by a computer simulation based on modelling of droplet cooling, particle movement, and process conditions for the first physical system set-up and the first set of operating parameters of step (a);
(c) evaluating the computer simulation and proposing a second physical system set-up and a second set of operating parameters of the GA system;
(d) operating the GA system using the second physical system set-up and the second set of operating parameters for yield of non-, low-, or reduced-satellited metal powder particles of the produced metal powder from the droplets of the atomized spray.
2 . The method of claim 1 further comprising adding an anti-satelliting intervention into the system at or for the critical location(s) that were identified by the modeling.
3 . The method of claim 2 wherein the anti-satelliting intervention comprises:
(a) one or more gas halos relative one or more of the identified critical locations; or
(b) particle filters and Coanda-driven gas sheath flow relative one or more of the identified critical locations; or
(c) external clean process gas recirculation and Coanda-driven gas sheath flow relative one or more of the identified critical locations; or
(d) one or more internal baffles to divert a circulation flow in or to the flow path or to protect a molten or semi-molten region of the atomized spray in the spray chamber.
4 . The method of claim 1 wherein the computer simulation comprises:
(a) droplet cooling and solidification modelling for a given feedstock and GA set-up; and
(b) Lagrangian particle tracking simulations.
5 . The method of claim 1 wherein the identification of critical location(s) comprises identifying an average solidus temperature location in the atomized droplet spray from the computer simulation relative to a given GA chamber set-up.
6 . The method of claim 5 wherein the average solidus temperature is correlated to a GA set-up chamber location.
7 . The method of claim 1 wherein the computer simulation is applied to at least one of:
(a) design of a GA set-up;
(b) design of operating parameters of a GA set-up;
(c) evaluation of a GA set-up operation; and
(d) tuning of operation parameters of a GA set-up.
8 . The method of claim 7 applied to one of:
(a) a GA set-up to be manufactured; and
(b) retrofit of an existing GA set-up.
9 . The method of claim 1 further comprising using the GA system in the production of metal powders, wherein the physical set-up of the GA system comprises (a) a spray chamber size and shape, (b) an atomization die diameter, and (c) an atomization pressure.
10 . The method of claim 9 wherein the metal powders are used for additive manufacturing or additive printing.
11 . The method of claim 1 further comprising proposing one or more subsequent physical system set-ups and/or subsequent sets of operational parameters different from the second physical system set-up and/or the second set of operational parameters.
12 . The method of claim 11 further comprising using the GA system with one of the one or more subsequent physical set-ups and/or subsequent sets of operational parameters.
13 . The method of claim 1 wherein the identification of critical locations relates to one or more of: (a) particle volumetric fraction estimation in the simulations for particles formed in the spray chamber, (b) particle temperature during flow in the spray chamber, and (c) particle diameter during flow in the spray chamber.
14 . The method of claim 1 wherein the computer simulation includes restrictions on computational domain and/or boundary conditions of the modelled spray chamber and operating conditions to reduce computational overhead.
15 . The method of claim 1 wherein the operating of the GA system comprises testing the metal powder for flowability and compaction.
16 . The method of claim 1 wherein the computer simulation comprise displayable visualizations of the GA set-up and processing of the droplets into particles in the set-up.
17 . The method of claim 1 wherein the second physical system set-up and the second set of operating parameters comprises:
(1) addition of an anti-satelliting intervention into the physical set up of the GA system and no anti-satelliting adjustment to the first set of operating parameters of the GA system,
(2) an anti-satelliting adjustment to the first set of operating parameters of the GA system and no addition of an anti-satelliting intervention into the physical set up of the GA system, or
(3) addition of an anti-satelliting intervention into the physical set up of the GA system and an anti-satelliting adjustment to the first set of operating parameters of the GA system.