Here's a reference from a description of the "Anaconda Smelter Stack" in Montana:
"The smelter had a large network of ***exhaust flues*** from the furnaces that all fed a main flue. The main flue carried the combined smelter exhaust gases a half-mile up the hill to the stack. The flue system and stack combined to provide a natural draft to carry the smelter exhaust gases, and it was claimed to be capable of handling three to four million cubic feet per minute of gas.["
Here's a reference from a description of the "Anaconda Smelter Stack" in Montana:
"The smelter had a large network of ***exhaust flues*** from the furnaces that all fed a main flue. The main flue carried the combined smelter exhaust gases a half-mile up the hill to the stack. The flue system and stack combined to provide a natural draft to carry the smelter exhaust gases, and it was claimed to be capable of handling three to four million cubic feet per minute of gas.["
The translation workplace 
