Process conditions affecting the physical quality of alfalfa pellets

The physical quality of alfalfa pellets can be optimized by control of the manufacturing process. Process conditions studied were conditioning and pellet temperature, die geometry (length-to-diameter or l/d ratio), hammer mill screen size used in grinding the dehydrated hay chops, and die speed. As conditioning temperature increased, the durability of the pellets also increased. Pellet temperature increased with conditioning temperature. Pellet temperature has a significant effect on pellet durability. The l/d ratio also directly affects pellet durability. The die with a high l/d ratio produced more durable pellets. Differences due to the screen size of the hammer mill used in grinding the chops and the die speeds were not significant. A correlation between energy consumption and pellet durability was developed.