Erosion Problems In Pneumatic Transport Installations

In the paper, the analysis of erosion of a fan blade was conducted. Erosion is recorded into two zones on the blade. In the first zone, erosion occurs at the front of the blade and it is caused by particle’s impacts during first contact. This is “impact erosion” zone. Second “friction erosion” zone is formed in the place of the next contact, determined by the angle rotation of the rotor Δϕ and the path of rebound s. The impact takes place at the angle α with participation of friction forces. Dependences of particle’s velocities on stress, which cause plastic strains on surface layer, were presented. Coefficient of velocity restitution in the stream ks=βk was calculated. Restitution coefficient of particle’s velocity in a stream always amounts to β ≥ 1. Its value can be determined by f.e.: shape of particle’s, their diameter, stream velocity. Time τ between successive impacts is the function of rotor angular velocity and restitution coefficient k. Angle of rotation Δφ is only depends on coefficient k. The equation describing dependence of angle rotation Δφ on coefficient ks is as follows: Δφ(1+k) = tg(Δφ). The solution of the equation was presented in a graphical way.