Blower for portable/wearable rpt device

A blower comprising:

• a motor configured to drive a motor shaft, the motor shaft having a first end and a second end extending opposite the first end;
• a first housing including a first inlet;
• a first impeller connected to the first end of the motor shaft, the first impeller configured to be rotated by the motor shaft to deliver a first flow of air from the first inlet toward an outlet,
• the first impeller comprising:
• a plurality of impeller blades, each of the impeller blades is curved along at least a portion of its length such that each of the impeller blades curves away from a direction of rotation of the first impeller;
• and
• a top shroud and a bottom shroud that define a flow passage therebetween through the first impeller,
• the top shroud including a center opening which provides an impeller inlet to allow air to enter the flow passage of the first impeller;
• a second housing including a second inlet;
• and
• a second impeller connected to the second end of the motor shaft, the second impeller configured to be rotated by the motor shaft to deliver a second flow of air from the second inlet toward the outlet,
• the second impeller comprising:
• a plurality of impeller blades, each of the impeller blades is curved along at least a portion of its length such that each of the impeller blades curves away from a direction of rotation of the second impeller;
• and
• a top shroud and a bottom shroud that define a flow passage therebetween through the second impeller,
• the top shroud including a center opening which provides an impeller inlet to allow air to enter the flow passage of the second impeller;
• wherein the plurality of impeller blades for each of the first and second impellers includes primary blades and secondary blades, and wherein each of the primary blades are longer than each of the secondary blades,
• wherein the first flow generated by the first impeller and the second flow generated by the second impeller are configured to flow parallel and opposite to one another along at least a portion of their flow path toward the outlet, and the first and second flows are combined at the outlet, and
• wherein the flow passage of each of the first impeller and the second impeller is configured to produce a mixed flow of air having both an axial and centrifugal component.