A ventilation dust removal system consisting of a dust hood, dust collector, duct fan is called a ventilation dust removal system, as shown in the figure below. However, every system must include this equipment due to the different dust source conditions the dust removal equipment selected. For example, directly the industrial furnace to extract the flue gas, there can be no dust suction hood; when the dust source set up in place at the dust unit, the purified gas is discharged directly into the room, you can duct; when the use of thermal pressure to discharge hot flue gas the use of process equipment residual pressure exhaust, you can set up a fan. However, when the dust concentration of the discharged gas exceeds the emission standard, all of them should be equipped with dust collector.