Analyses Of The Dust-cleaning System Fan's Liberation And Optimization Of Its Cleaning Device

Centrifugal fan is very critical in the industry dust-cleaning system. It is usually used as power in the ventilating,dust-cleaning,delivery system. There is much dust in the gas of the fan. The dust aggregates in the impeller. That caused vibration of the fan. Under this situation, the maintenance department should stop the whole production system to cleaning the dust and do dynamic balance.This paper is divided into two parts. First, a full-scale three-dimensional model of the fan which is used by a steal&iron company is built. Flow field in the fan is numerical calculated by CFX. Compare to the spot observation, the reason which causes fan's dust-sedimentation is determined. The two necessary conditions are:①The dust gets to the dust-sedimentary position;②The flow field of the dust-sedimentary position is good for the dust-sedimentation.The dust-sedimentation at the inlet of the fan is mainly caused by the impact between dust and non-working face. Eddy cause dust-sedimentation at the outlet of the fan.Then, the mathematical model of the fan rotor is made. The reason of the fan's vibration which is caused by dust-sedimentation and quick judge way are analyzed in the view of rotor dynamics.For the fan which is belonged to the rigid rotator, the vibration that is caused by the dust sedimentation is first-order. That is used as the theory to judge if the vibration is caused by dust sedimentation.Usually, the company installs on-line monitoring device, such as balance apparatus. It is possible for the maintenance department judge the dust-sedimentation vibration failure quickly out of the many other failures.Finally, the designed nozzle is installed in the rotating fan. Based on the stimulation result and the practice, the spray-system we are now using is improved. Air is replaced by water to increase blow-medium's kinetic energy. The structure and the position of the nozzle are optimized. The best install way is 20mm from nozzle to the back disk. The included-angle is 20°.Furthermore, long-short blade is introduced to reduce dust-sedimentation at the outlet of the fan.