Analysis of control effect of air curtain exhaust hood on high-temperaturesmoke at slag tapping ports of copper Ausmelt furnaces

Due to the influence of process operation and environmental wind, traditional exhaust hoods have poor control effect on the high-temperature smoke from the slag tapping port of a copper Ausmelt furnace. This paper proposes a new type of air curtain exhaust hood and analyses its control effect on the smoke at the slag tapping port. By combining field tests with numerical simulations, the capture efficiencies of SO2and particulate matter by exhaust hoods are compared under different outdoor wind speeds, with and without an air curtain, and different supply and exhaust air volume ratios. The results show that in the absence of air curtain supply, an outdoor wind speed of 4 m/s will result in a decrease in SO2gas capture efficiency from 84.92% to 72.01% and a decrease in smoke and dust capture efficiency from 89.30% to 62.30%, compared with the condition without outdoor wind. Under the same outdoor wind speed (4 m/s) and the same exhaust air volume (30 000 m3/h) conditions, the addition of an air curtain with a supply air volume of 5 910 m3/h to the exhaust hood increases the SO2capture efficiency from 72.01% to 89.35%, and the smoke and dust capture efficiency from 62.30% to 92.67%. The air curtain exhaust hoods can effectively shield against outdoor winds, but the pollutant capture efficiency will decrease significantly at higher outdoor wind speeds. Controlling the supply and exhaust air volume ratio of the air curtain exhaust hood at 0.17 can effectively enhance capture efficiency.