Effects of particle size on the magnetic cleaning system for manned lunar explorations

Abstract

A magnetic cleaning system comprising a permanent magnetic roll with a non-magnetic sleeve and a particle collection component is a unique dust mitigation technology in lunar explorations. Enhanced cleaning performance can be achieved by optimal balancing of the forces applied to the particles. The effects of particle size on the capture and release performances were investigated through experiments using size-sorted particles of a lunar regolith simulant and a simple analysis of the force balance varying with the particle size. Experimental and calculated results clarified that the capture of the particles was predominantly facilitated by the magnetic force, while their release was primarily due to the centrifugal force. Although the release of captured particles smaller than 25 μm is one of the challenges in this system due to the adhesion force, this force also contributed to the capture of the small particles with lower magnetic permeability. This magnetic cleaning system, demonstrating its utility in removing particles not only from spacesuits but also from other equipment, achieved the capture and release rates exceeding 70 % and 90 %, respectively, when the simulant particles were dispersed on a flat surface. Moreover, the capture rate of simulant particles with higher magnetic permeability improved, reaching approximately 85 %.