Powered air cleaning system and air cleaning method

A powered air cleaning system for use with a device having a variable air flow demand, the system comprising:

• a flow path extending through the system from an inlet to an outlet for supplying air to the device;
• a motor-driven fan located along the flow path to draw particulate debris laden air into the inlet and rotate it about an axis to form a rotating flow that stratifies the debris laden air with the heaviest particles in the outermost orbits of the rotating flow;
• an ejector port for ejecting particulate debris laden air from the stratified rotating flow in the system;
• an air filter located within the rotating flow and across the flow path upstream of the outlet for filtering air from the innermost orbits of the stratified rotating flow;
• a debris strake connected to the air filter for channeling debris away from the filter to the outermost orbits of the rotating flow;
• wherein the motor-driven fan is operable to maintain positive air flow pressure to eject debris laden air from the stratified rotating flow in the system at all rates of air flow demanded by the device.

An air cleaning method comprising:

• drawing particulate debris laden air into an air cleaning system with a motor-driven fan located in the system;
• forming a rotating flow of the debris laden air in the system to stratify the flow with the heaviest particles in the outermost orbits of the rotating flow;
• flowing air from the innermost orbits of the rotating flow through a filter enroute to an outlet of the system, the filter being located within the rotating flow which provides a self cleaning action on the filter;
• channeling debris away from the filter to the outermost orbits of the rotating flow with a debris strake connected to the filter;
• and
• ejecting particulate debris laden air from the stratified rotating flow in the system.

An air cleaning method comprising:

• drawing particulate debris laden air into an air cleaning system with a motor-driven fan located in the system;
• forming a rotating flow of the debris laden air in the system at a positive air flow pressure to stratify the flow with the heaviest particles in the outermost orbits of the rotating flow;
• ejecting particulate debris laden air from the outermost orbits of the stratified, positively pressured rotating flow in the system through an ejector port located radially outward of the outermost orbits of the rotating flow;
• and
• withdrawing air from the innermost orbits of the rotating flow in the system through an air filter and an outlet of the system by applying a vacuum to the outlet, wherein the air filter is swept by the rotating flow to provide a self cleaning action on the filter.