Q. How does grains roasting machine work?

Answer

A grain roasting machine contains an elongated hollow roasting drum which is mounted for rotation about its central axis. There a burner for producing roasting flame within the drum. Grains placed in the drum are skirted through the periphery of the flame and then dropped in a second linear path. Most of the grains fall across the drum and through the roasting flame and then returns to the first path.