The paper presents the design and operating characteristics of a model of
reversible axial fan with only one impeller, whose reversibility is achieved
by changing the direction of rotation. The fan is designed for the purpose of
providing alternating air circulation in wood dryers in order to reduce the
consumption of electricity for the fan and increase energy efficiency of the
entire dryer. To satisfy the reversibility of flow, the shape of the blade
profile is symmetrical along the longitudinal and transversal axes of the
profile. The fan is designed with equal specific work of all elementary
stages, using the method of lift forces. The impeller blades have straight
mean line profiles. The shape of the blade profile was adopted after the
numerical simulations were carried out and high efficiency was achieved.
Based on the calculation and conducted numerical simulations, a physical
model of the fan was created and tested on a standard test rig, with air
loading at the suction side of the fan. The operating characteristics are
shown for different blade angles. The obtained maximum efficiency was around
0.65, which represents a rather high value for axial fans with straight
profile blades.