Air curtain dust-collecting technology: Investigation of industrial application in tobacco factory of the air curtain dust-collecting system

Abstract The air curtain system can collect the dust particles from hard-to-seal sources, which proves to be a feasible method for satisfying the increasing dust prevention requirements in China. In this study, aiming at addressing the dust escape problem at the tobacco stem loading point in a tobacco factory, a rotational flow air curtain dust-collecting system with a size of 2m x 2m x 2m was used for dust collection. The dust-collecting characteristics using the original dust suction hood and the developed air curtain dust-collecting system were analyzed and compared. Results show that the external dust concentration when the original dust suction hood operated was as high as 83.65 mg/m3, with a dust-collecting efficiency of only 16.35 %, suggesting serious dust escape; after the use of the developed air curtain dust-collecting system, the dust-collecting efficiency reached up to 86.93∼94.76 % under the same operating conditions. By studying the influence of two factors, air curtain jet velocity and exhaust-to-pressure ratio, on the dust collection efficiency of the air curtain system, at an exhaust-to-pressure ratio of 0.8 and an air curtain jet velocity of 13.5 m/s, the corresponding dust-collecting efficiency reached a maximum of 94.76 %. The present test results confirmed a better application effect of the developed air curtain dust-collecting system than the original dust-collecting system at the industrial loading point. Using the developed air curtain dust-collecting system is mainly aimed at the dust source, reduce the dust in the workshop dissemination and dispersion that can lower the transmission path of COVID-19 via aerosol.