First, compare the advantages of various types of fans centrifugal fan 1,4-72 The main purpose is to - as factories and large buildings indoor ventilation or air transport and other non-spontaneous, non-explosive, non-volatile, the human body without harm, non-corrosive gases for steel: 2, B4-72 centrifugal fan can be carriage of flammable, volatile gas; 3, F4-72 centrifugal fan is mainly used to transport corrosive gases. ☆ but 4-72, B4-72, F4-72 centrifugal fan gas transported shall contain a viscous material, contained in dust and hard particles should not exceed 1 5 0 mg / m 3, the gas temperature must not exceed 80 ℃. Second, the various types of fans technical parameters 1, B4-72 type centrifugal fan as ventilation ventilation of flammable volatile gases. Gas allowed sticky substances contained in dust and hard particles should not exceed 150mg / m. Gas temperature must not exceed the performance of the choice pieces and foundation size 4-72 80C.B4-72 consistent with the type of fan, according to the sample selection. The fan structure is basically the same as the 4-72, Nn2.8A-6A using B35 type with flange and foot motor, No6 ~ 12C, D motor selection table that corresponds with the Y series YB series, mounting type B3. 2, F4-72 centrifugal fan is mainly used to transport corrosive gas, but the gas delivery shall contain viscous material, contained in the dust and hard particles should not exceed 150mg / m3, gas temperature must not exceed 80 ° C. F4-72 centrifugal fan made of stainless steel, glass, steel or other corrosion-resistant materials, their properties and foundation size 4-72 same centrifugal fan. 3,4-72 type centrifugal fan model specifications 3.6A, motor power is 1.1KW, air volume is 1382-2634M3 / H, pressure is 893-247PA, motor speed 1450 r / min. Conventional materials for steel, stainless steel can be further customized to fiberglass.