Ultraviolet Radiation from Combustion of a Dense Magnesium Powder Flow in Air

Combustion of magnesium produces copious ultraviolet and visible light emissions. The ultraviolet emission can be employed potentially in an antibacterial capacity. Ultraviolet radiation from the combustion of a heavily laden flow of magnesium powder with air was measured in a linear test combustor fitted with optical access ports. Silicon photodiode detectors sensitive to ultraviolet emissions were used to determine this broadband flux. A calibration lamp with known values of spectral irradiance was used to validate the ultraviolet flux measurement method, and a mock-up of the optical access port assembly was used to ensure accounting for the proper view factor. The broadband ultraviolet flux measurements were compared for several different air/fuel ratios, ranging from 2 to 7, and different magnesium flow rates. Very fine magnesium oxide particle buildup on the quartz windows limited the length of time during the test runs when measurements could be made.