흡입관 주위에 형성된 공기차단막이 흡입성능에 미치는 영향

Abstract

A study is conducted to improve the suction performance on suction devices which are used to remove polluted air generated by welding or machining process in a spacious working place of industry. Air-curtain is applied around the inlet of suction duct to interrupt the inflow of fresh air from the downstream region where is located opposite to the polluted air source. Two different air-curtain devices, such as a 45o backward and a fully backward, are adopted. Suction region is experimentally investigated by measuring the suction velocities using a hot-wire anemometer. Contours of the suction velocity are compared with the computed results. The suction condition is selected to 110,000 Reynolds number which is widely used on typical suction devices, and a width of blowing passage for creating the air-curtain is chosen to 9.38% of the suction duct diameter. The experimental results show that the suction performance obtained with the 45o backward air-curtain was better than that obtained with the fully backward air-curtain. On the suction duct using the 45o backward air-curtain, the suction region estimated on basis of the 0.4m/sec is improved by 66% at the same input power.