Acoustic initiation of powder flow in capillaries
Acoustic initiation of powder flow in capillaries
Second generation solid freeforming devices will have the capability to render both shape and the spatial arrangement of composition directly from a computer file. In order to build three-dimensional functional gradients in selective laser sintering it is necessary to have a computer-controlled mixing and dispensing system. We report such a system based on the horizontal acoustic vibration of vertical capillary tubes that provides both switching and flow rate control. An orchestra of such tubes can be constructed to deposit a multi-component system onto a building platform. Our concern is the initiation of flow. It requires an “attack” waveform to break the domes that provide flow arrest and release the potential energy of powder above the dome. The intensity of attack also influences the mass that flows out before a new dome forms, i.e., the response time of the valve. Neither the extension to vibration caused by ringing nor the wave amplitude account for the over-run of the valve. Much better correlation is obtained with acceleration and with calculated kinetic energy of horizontally vibrating particles.
powder flow control, solid freeforming, acoustic vibration
413-421
Yang, Shoufeng
e0018adf-8123-4a54-b8dd-306c10ca48f1
Evans, Julian R.G.
4eee463a-4dd3-4ef2-b9bc-784246b68ad2
January 2005
Yang, Shoufeng
e0018adf-8123-4a54-b8dd-306c10ca48f1
Evans, Julian R.G.
4eee463a-4dd3-4ef2-b9bc-784246b68ad2
Yang, Shoufeng and Evans, Julian R.G.
(2005)
Acoustic initiation of powder flow in capillaries.
Chemical Engineering Science, 60 (2), .
(doi:10.1016/j.ces.2004.07.124).
Abstract
Second generation solid freeforming devices will have the capability to render both shape and the spatial arrangement of composition directly from a computer file. In order to build three-dimensional functional gradients in selective laser sintering it is necessary to have a computer-controlled mixing and dispensing system. We report such a system based on the horizontal acoustic vibration of vertical capillary tubes that provides both switching and flow rate control. An orchestra of such tubes can be constructed to deposit a multi-component system onto a building platform. Our concern is the initiation of flow. It requires an “attack” waveform to break the domes that provide flow arrest and release the potential energy of powder above the dome. The intensity of attack also influences the mass that flows out before a new dome forms, i.e., the response time of the valve. Neither the extension to vibration caused by ringing nor the wave amplitude account for the over-run of the valve. Much better correlation is obtained with acceleration and with calculated kinetic energy of horizontally vibrating particles.
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Published date: January 2005
Keywords:
powder flow control, solid freeforming, acoustic vibration
Organisations:
Engineering Mats & Surface Engineerg Gp
Identifiers
Local EPrints ID: 165075
URI: http://eprints.soton.ac.uk/id/eprint/165075
ISSN: 0009-2509
PURE UUID: 9f6662db-a826-4c7d-bfc4-78dc5727bfb8
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Date deposited: 07 Oct 2010 13:33
Last modified: 14 Mar 2024 02:09
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Author:
Julian R.G. Evans
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