Fan output and low efficiency are common problems in centrifugal fans. The reasons for the low output and low efficiency of the fan are various aspects, such as problems in the design and manufacture of the fan, as well as problems in the direction of operation and maintenance. The design and manufacturing problems are more complicated and should be improved from the design and manufacture of the fan. Each fan has a certain working range and has high efficiency when operating under design conditions. However, in practice, often because the parameters selected by the fan are too large or too small, as well as pipeline resistance, medium temperature changes, etc., the fan capacity is too large or too small, the fan output is too small, it will not meet the boiler ventilation requirements; If it is too large, the fan will be operated under low load, the throttling loss will increase, and the efficiency will be low. Therefore, the improper selection of the fan parameters or the fact that the fan is not working at the optimal working point is the main factor for the fan output and low efficiency. The unreasonable design of the inlet and outlet of the fan and the unreasonable design of the flue duct are another cause of the low output and low efficiency of the fan. A large-capacity fan does not have a baffle at the right-angle elbow of the fan inlet. Compared with the baffle, the resistance loss will increase by 150-250Pa. If design, install a diversion at the elbow. The plate has a horizontal pipe section with a length of 3 times the diameter of the smoke duct, and the resistance loss can be reduced by 300 Pa compared with the resistance loss without the baffle and the horizontal pipe section. If the direction of rotation of the fan inlet flue gas flow is opposite to the direction of rotation of the impeller, the fan efficiency will be significantly reduced. Change the position of the smoke duct, so that the direction of rotation of the inlet flue duct airflow is consistent with the direction of rotation of the fan, and the fan efficiency is obviously improved. sewshimano , https://www.nb-fzysewing.com