Cupola is a vertical cylindrical smelting furnace, which is divided into front furnace and rear furnace. It is called cupola because the furnace top opening is upward; It is an important equipment for melting cast iron in casting production. The casting is obtained by melting the cast iron into molten iron, pouring it into the sand mold, cooling it, and then unpacking it; The high-temperature dust-containing gas from the cupola first enters the turbulence cooler, which is the first time that the high-temperature dust-containing gas is cooled, and the temperature can drop to 150~160 ℃. At the same time, some coarse particles settle down under the effect of gas expansion, flow rate reduction and cyclone; Then the dusty gas enters the multi-pipe water cooler, the flue gas will be further cooled, and the temperature will drop below 100 ℃, and the dusty gas will enter the bag filter for complete dust removal; The purified gas is pumped to the exhaust funnel by the fan for exhaust