Dust is a serious problem – on the moon as well as here on Earth. Well known from the Apollo landing missions, lunar dust is charged by ultraviolet radiation and cosmic rays and because of its small size and low gravity it is easily lofted when the rover or astronauts move on the lunar surface. The dust, which can be harmful to humans, can adhere to surfaces of solar panels, move into bearings, gears, and mechanical seals, as well as adhere to space suits. Inevitably, dust will infiltrate the habitat module, despite the best cleaning efforts.
Researcher Hiroyuki Kawamoto explored the feasibility of an air purification system using electrostatic force, designed to complement existing filtering systems. The system is comprised of an ionic fan, that circulates air and charges floating dust particles, and an electrostatic precipitator, that traps the charged particles. Kawamoto’s simple configuration is outlined in the Journal of Aerospace Engineering, “Feasibility Study on Electrostatic Precipitator Combined with Ionic Fan for Air Purification in Lunar Module.” Learn more about this lightweight, low power system that can reduce the load on existing filtration systems at https://doi.org/10.1061/(ASCE)AS.1943-5525.0001451. The abstract is below.
Abstract
A unique electrostatic precipitator combined with an ionic fan is proposed for air purification in a lunar module, and its feasibility was investigated. Dust contaminating the air in the habitat module is circulated by the ionic wind generated by the ionic fan, which comprises coaxial cylinder electrodes. A positive direct current (DC) voltage exceeding the corona discharge onset voltage is applied to the inner electrode, where the sharpened edge faces the outer cylinder electrode. The migration of charged molecules generated by the corona discharge forms an air stream, and simultaneously, dust particles are charged. Charged particles are introduced into the electrostatic precipitator, which comprises parallel-plate electrodes. A high DC voltage less than the onset voltage of the spark discharge is applied to the electrodes, and the introduced charged dust particles are trapped in the collection electrodes owing to the Coulomb force. It appears that dust is effectively cleaned by a compact system. An ozone filter is installed to decompose the ozone synthesized in the corona discharge field. Because the proposed system affords simplicity, a small configuration without mechanical moving components, lightweight, low power consumption, and silence, it is suitable for use in the lunar habitat module and pressurized rover. The proposed air-purification system would contribute to reduce the load on the mechanical filtration system.
Read the paper in full in the ASCE Library: https://doi.org/10.1061/(ASCE)AS.1943-5525.0001451
