A Side Channel Blower is a simple machine to impart momentum to air/gas. Fig (a) shows the basic design concept for a Side Channel Blower, which comprises an impeller with blades located on its periphery that impels the gas through a channel surrounding a toroidal core that extends the length of the perimeter. The gas spirals around the core, interacting with the impeller blades several times before leaving the blower. In this way the Side Channel Blower uses a single impeller to impart multiple stages of pumping to the gas.
