Abstract
The density of a Na2SO4 smoke particle formed by means of spray-drying of the aqueous solution was determined by measuring the particle size and mass concentration of the spray-dried smoke and further the change due to aging in the sedimentation velocity of the particle. It was found that the particle density is smaller by several times than the bulk density of crystalline solid of Na2SO4.
The effect of water vapor upon the stability of the smoke was also examined, with the result that the higher the humidity, the lower the stability.
