4-72, B4-72, F4-72 centrifugal fan First, use 4-72 centrifugal fan can be used as general room ventilation factories and large buildings ventilation, air and other transportation is not spontaneous combustion, the human body harmless, non-corrosive gases for steel. B4-72 type fan can be used as volatile flammable gas with ventilation. Allowed sticky substances gases contained in the dust hard particles should not exceed 150mg / cubic meter. Gas temperature must not exceed 80 C. Performance selection of parts and ground size 4-72 is consistent with the B4-72 type fan, according to the sample selection. The fan structure is basically the same as the 4-72, №2.8 ~ 6A using B35 type with flange and foot motor, №6 ~ 12C, D motor selection in the table corresponds to the Y series YB series, mounting type B3. F4-72-type fan with fiberglass (FRP) material used to transport corrosive gas, its performance and size are the same foundation 4-72. Second, the form from the motor side of the face, the impeller rotates clockwise, called D-blower to "right" means; counterclockwise rotation of the impeller, called L-blower to "left". Export position of the fan to the cabinet said outlet angle. 4-72 fans are made when one kind №2.8 ~ 6 factory type, the use of units in accordance with the requirements to install into the desired position, without specify when ordering. №2.8 outlet position adjustment range from 0 to 225 degrees, 45 degrees apart, №3.2 ~ 6 outlet position adjustment range from 0 to 225 degrees, 225 degrees interval. №8 ~ l2 outlet position adjustment range from 0 to 225 degrees, the interval is 45 degrees. №16,20 outlet position made three fixed: 0,90, l80 degrees, can not be adjusted. Need to specify when ordering. Fan drive way there are A, B, C, D four. 4-72 Blower №2.8 ~ 6 with A-type transmission, №8 ~ l2 using C, D type transmission, №l6 ~ 20 using the B-type transmission. Third, the structural characteristics of 4-72 Blower No2.8 ~ 6 mainly allocated by the impeller, housing, air inlet and other units which consists of direct-coupled motor. No8 ~ 20 In addition to having the above section, there are transmission parts and so on. 1) impeller by 10 after dipping airfoil blades, curved front plate after plate composed pull peace. With steel or cast aluminum alloy, and by the dynamic and static balance correction, air good performance, high efficiency and smooth operation. 2) housing made of two different types. №2.8 ~ 12 chassis made whole, can not open, №16 ~ 20 chassis made of three open, except along the equatorial plane is divided into two halves, the upper half is further divided into two halves along the vertical centerline. Rejection bolted. 3) inlet formed integrally mounted on the fan side, parallel to the axial cross-section a curved shape. The gas can smoothly enter the impeller, and minor damage. 4) transmission parts from the spindle, bearing housing, bearings, pulleys or coupling components.