Topics in Processing Materials Handling Dr. C. L. Jones Biosystems and Ag. Engineering

Materials Handling Assignment: Read Chapter 8 handout Dr. C. L. Jones Biosystems and Ag. Engineering

Materials Handling All manufacturing facilities, elevators, feed/food processing centers, retail stores, warehouses, …have handling devices Classification Belt conveyors Chain conveyors Screw conveyors Bucket conveyors Oscillating conveyors Pneumatic conveyors Gravity conveyors Cranes Lift and carrying trucks and carts Dr. C. L. Jones Biosystems and Ag. Engineering

Materials Handling Belt conveyors Endless belt between two or more pulleys High mechanical efficiency Antifriction bearings Little material damage High capacity Long service life Low cost Dr. C. L. Jones Biosystems and Ag. Engineering

Materials Handling Belt conveyors Belt – carries the load Drive At the discharge end Usually a belt drive Tension or take-up Takes up the stretch in the belt due to contraction/expansion Dr. C. L. Jones Biosystems and Ag. Engineering

Materials Handling Belt conveyors Idlers Loading device See Fig. 8.1 Loading device Hand fed Mechanically fed Continuous or intermittent flow Discharge device Over the end of the belt Diagonal scraper Tilting Tripper….Fig. 8.2 Dr. C. L. Jones Biosystems and Ag. Engineering

Materials Handling Belt conveyors (Fig. 8.3 and Table 8.1) Surcharge angle and belt selection (ex. pg 204) HP to drive empty conveyor (eqtn. 8.1, 8.2, 8.3)(ex. pg 205) Dr. C. L. Jones Biosystems and Ag. Engineering

Materials Handling Chain conveyors Cheaper than belt conveyors Noisy Slow Not efficient Versatile Good for intermittent operation Dr. C. L. Jones Biosystems and Ag. Engineering

Materials Handling Chain conveyors Trolley Scraper Apron Overhead track Can make sharp turns, steep inclines Scraper Used for granular products Can make steep inclines Power requirements and wear are high Fig. 8.6 Apron Like scraper with flat slats, steel plates or boards. Used for conveying sacked materials and large unit sizes Dr. C. L. Jones Biosystems and Ag. Engineering

Materials Handling Screw conveyors Horizontal Inclined Used to handle fine materials…powders, granular materials, sticky viscous materials Simple Inexpensive High power requirements Limited in length Inclines up to 20 degrees Horizontal Inclined Less efficient mechanically and volumetrically aka augers Dr. C. L. Jones Biosystems and Ag. Engineering

Materials Handling Bucket Conveyors Classified as either belt or chain or both Range from simple to large, expensive Fig. 8.8 Centrifugal discharge: small grain Perfect-discharge: slow speed, cheap, handles delicate material well Continuous bucket: heavy duty use, ores, sand…discharges by sliding over bottom of preceding bucket Two variations of buckets: Fig. 8.10 Equation 8.11 for HP Dr. C. L. Jones Biosystems and Ag. Engineering

Materials Handling Wednesday Meet in Ag Hall 3:30 to 4:20 More conveyors Dr. C. L. Jones Biosystems and Ag. Engineering