This paper presents theory, modeling, and analysis of a novel electrodynamic concentration approach for submillimeter-sized conductive metal particles focusing in moving gas-powder stream. Such method is of particular interest in blown-powder feeding fabrication industry (e.g., powder-fed additive manufacturing) to generate a tightly focused powder stream. Conceptual design of a concentration generator is proposed with two different configurations: The doublet Halbach permanent magnet quadrupoles (doublet-Halbach-PMQs) and the doublet electromagnet quadrupoles (doublet-EMQs). Analytical models for magnetic forces and concentration angles were built. Numerical calculations were conducted for pure aluminum particles with a radius of 50 150 μm. The particles with a radius of R_{p} = 300 μm can be concentrated with more than 15∘ angle at the frequency of 600 kHz. Therefore, the proposed doublet-EMQs configuration has a great potential to generate a narrowed and finely focused powder stream in the blown-powder feeding fabrication process
