Pet food generally consists of meat, meat by products, cereal, grain, vitamins, and minerals. General grains, such as soybean meal, corn meal, cracked wheat, and barely, are often used to improve the consistency of the products. The meat is mixed with the other ingredients. Dry pet food has a shelf life of about 10 to 12 months. Some manufacturers are adding some kinds of vitamins E and C as natural preservatives. Flow Chart: Mixer → Conveyor → Pre-conditioner → Extruder → air conveyor → Dryer → hoister →flavoring line → Packing Allocation of equipment: Mixer → Screw conveyer→Conditioner→Twin-screw extruder →Big hoister or Air conveyer →Layers Dryer→ Sifter → Flavoring line → Cooling conveyor → Packing machine (for the low capacity line,some of the equipment is unnecessary)