US Patent 7682412 Multi-cyclone dust collection apparatus

A multi-cyclone dust collection apparatus is disclosed that comprises a first cyclone having an air inlet, in which the air introduced into the first cyclone through the air inlet is caused to swirl and ascend in the first cyclone so that dust is separated from the air; and a plurality of second cyclones arranged around the lower part of the first cyclone, in which the air discharged from the first cyclone into the second cyclones is further caused to swirl and ascend so that dust is separated from the air. Each of the second cyclones is provided with an air outlet through which the purified air is discharged. The air inflow port is provided at the bottom of the first cyclone and the outflow ports are provided at the lower ends of the second cyclones.