Engine air intake preseparation using electrostatically active materials

A spin tube assembly, comprising:

• a tube body having the air inlet at first end and a second open end with a flow passage therebetween for communicating the air flow stream;
• a vortex generator comprising at least one vane providing the baffle imparting a vortex to the air flow stream within the tube body;
• a vortex finder extending coaxially relative to the tube body proximate the second open end, the vortex finder defining an opening to provide a clean air outlet, and wherein a region radially between the vortex finder and the tube body defines a contaminant outlet;
• and
• wherein the tube body and the vortex generator comprise different plastic materials with different triboelectric charge properties.

A preseparator for removing particles from an air flow within an engine air intake system, the preseparator comprising:

• i. an air inlet duct;
• ii. a dust collection chamber with internal walls and dust ejection opening, downstream of the air inlet duct;
• iii. at least one spin tube supported within the dust collection chamber, the at least one spin tube including an outer wall and internal helical vanes, and being located downstream of the air inlet duct to receive air flow from the air inlet duct;
• iv. a spin tube vortex finder downstream of the at least one spin tube to receive air flow from the at least one spin tube;
• and
• v. an air outlet duct downstream of the spin tube vortex finder to receive air flow from the spin tube vortex finder;
• wherein the air inlet duct is of a material having either positive or negative electrostatic charge, such that positive or negative charge is induced in particles in the air flow passing through the inlet duct;
• wherein the spin tube outer wall is of a material having the same electrostatic charge as the air inlet duct, and
• wherein at least one of the internal helical vanes, spin tube vortex finder and internal walls of the dust collection chamber is formed of a material having an opposite electrostatic charge as the air inlet duct, such that particles are attracted to the spin tube outer wall, and repelled from the at least one of the internal helical vanes and spin tube vortex finder, when passing through the preseparator.