feed pellets making process introduction
The transformation of a soft, often dusty feed into a hard pellet is accomplished by compression, extrusion, and adhesion. The general process involves passing a feed mixture through a conditioning chamber where 4 to 6 percent water (usually as steam) may be added. Moisture provides lubrication for compression and extrusion and in the presence of heat causes some gelatinization of raw starch present on the surface of vegetative ingredients, resulting in adhesion. Within 20 seconds of entering the pellet mill, feed goes from an air-dry (about 10-12 percent moisture) condition at ambient temperature, to 15-16 percent moisture at 80-90°C. During subsequent compression and extrusion through holes in a ring die, friction further increases feed temperature to nearly 92°C. Pellets discharged onto a screen belt of a horizontal tunnel drier or into a vertical screened hopper are air-cooled within 10 minutes to slightly above ambient temperatures and dried to below 13 percent moisture.
Contrary to early belief, finished pellets contain practically all the nutrients found in feedstuffs and additives as compounded. The loss of thermolabile vitamins used in additives, which may be slight or extensive in the case of vitamin C, may be compensated for by extra supplementation of these in the vitamin premix to comply with formula requirements. Diastatic enzymes (alpha and beta amylase)present in whole grains and cereal byproducts are still active after processing by grinding and pelleting, although powdered enzymes added as an ingredient are inactivated.
The general process of feed pellet production project in feed pellet plant. is as follows:
crushing--mixing---pelletizing--cooling-screening--packaging.
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