Another type of device used in the past to feed powders is the Archimedes spiral feeder.
A delivery device based on an Archimedean spiral arrangement, which shifts the powder into the gas transport stream, has also been used. This older method of material transportation was used in the early days of TS but has been superseded by modern and more reliable technology.
Image – Powder-feeding system: Archimedes spiral feeder.
This information is from ASM Handbooks Online, Vol. 5A: Thermal Spray Technology, Coating Structures, Properties, and Materials. To find this information (subscription required), click on the link below and scroll down to Figure 20.
