ABSTRACT
A common solution for reducing the required aspiration volume comprises bypass ducts that enable internal air recycling while reducing ingress of air from transfer chutes into aspirated cowls. Some of the known solutions have the hollow space of the chute connected with the bypass chamber not only in the upper and lower parts but also along the entire height of the chute by perforating its walls. In order to measure the efficiency of this solution, let us consider aerodynamic processes of air ejection for a case of a uniformly distributed flow of particles in a vertical duct, with particles falling at a constant acceleration (understandably, such a model is applicable for particle flows with a small height of free fall as long as the drag force is still easily overcome by the weight of a falling particle)
dv dt
g
= . (5.1)
In the following text, a tilde above a symbol will be used to distinguish dimensional quantities from their dimensionless counterparts: v is particle velocity (m/s), t is time (s), and g is gravitational acceleration (m/s2).
