Aerodynamic separation of grain from straw and chaff in a dispersed stream
Authors: Misener, G.C. And J.H.A. Lee
Description: The introduction of airflow over the sieve of a combine shoe as a means of dispersing a stream of straw, grain, and chaff to cause separation was presented by MacAulay (6). He found that at low feed rates, the mat of material was broken up, and the straw and chaff were removed from the shoe by the airstream. However, this stream could not disperse the volume of material at higher feed rates consequently, it was blown rear ward as a mat. This suggested the need for a device to present the material in a form that would allow the airstream to completely disperse it. To increase the shoe capacity, Rumble (7) and Lee (4) studied the effect of imparting a high initial velocity to the material before it entered the high velocity airstream. He utilized a system of belt conveyors to introduce the material at a given velocity into the region over the sieve. This presented the material in a form such that the air could easily separate the components. He found that it was possible to double the normal input material rate to the shoe. The objective of the investigation on which this paper is based was to continue studying pure aerodynamic separation by analyzing the mathematical model developed to simulate the action, and to experimentally evaluate the effects of several parameters on the separation pro cess. The parameters under study included the velocity and direction of the air introduced over the sieve and the velocity at which the material was introduced into this airstream. The distribution of the grain in the material stream as it entered the region above the sieve was studied to determine its effect on the optimum angle of the airflow for minimal grain loss during the separation process.
Keywords: aerodynamic separation of grain from straw and chaff in a dispersed stream
Citation: Misener, G.C. and J.H.A. Lee 1973. AERODYNAMIC SEPARATION OF GRAIN FROM STRAW AND CHAFF IN A DISPERSED STREAM. Canadian Agricultural Engineering 15(2):62-65.
Start page number: 62
End page number: 65