Patent attributes
A vortex particle separator has an impeller at a housing inlet with impeller blades spiraling around an impeller shaft and longitudinal axis of the separator to impart either clockwise or counterclockwise rotation to air flowing through the impeller when viewed looking downstream along the axis. The upstream end of each impeller blade is inclined in a direction opposite to the direction the air rotates when passing through the impeller, measured from a radial baseline through the axis and the juncture of the blade with the center shaft of the impeller. Thus, in each orthogonal plane along the axial length of the impeller the juncture of the blade with the housing is offset from the baseline in the rotational direction opposite the direction in which air flows through the impeller. An offset angle of 45° to 55° is believed suitable.