It is difficult to exhaust the polluted air and dust effectively, only by the ventilator or fan. Then, a compound swirl type exhaust device has been newly developed by the authors. The compound swirling jet consists of a circular free jett and the annular swirling jet mounted on the same axis by a double coaxial pipe. This system can constitute the gas range in the kitchen, smoking room and dusty factory. This system can achieve more effective ventilation than conventional system. In this study, the proposed system is visualized and analyzed by using PIV.
