G4-73 and Y4-73 boiler pass, induced draft fan is suitable for power plant 2 ~ 670T / h steam boiler pass, induced draft fan systems. In no other special requirements, G4-73 can be used for mine ventilation and general ventilation. Fan transmission medium is air, the maximum temperature not exceeding 80 ℃; media induced draft fan for conveying flue gas temperature must not exceed 250 ℃ fan and induced draft fan made single inhalation, each with a total of 12 No8-28. machine number. Before the induced draft fan, dust removal device must be installed to minimize the fan into the dust content in the flue gas. According to the general plant use, not less than 85% removal efficiency. Fan drive way D-type, all with flexible coupling drive. Fan mainly by the impeller, housing, air inlet, the damper and transmission parts. Impeller, from 12 backward wing beveled blade welding arc cone in the middle of the front plate and the rear plate flat shape, the same number of aircraft through the same draft fan impeller. Chassis: The chassis is welded steel with ordinary snail shape. Single suction fan casing made of three different forms: No8-12 cabinet made the overall structure, can not be disassembled. No14-16 made two open chassis. No18-28 cabinet made three open. On the induced draft fan, snail-shaped plate made thicker to prevent wear appropriate. Inlet: Convergence, streamlined inlet into the overall structure, bolted to the fan inlet side. Valve: means for adjusting the flow rate of the fan, axially mounted in front of the air inlet. Adjustment range from 0 ° (fully open) to 90 ° (fully closed).