Topics in Processing

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

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

3. 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

4. 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

5. 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

6. Materials Handling • Belt conveyors • Idlers • 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

7. 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

8. 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

9. Materials Handling • Chain conveyors • Trolley • 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

10. Materials Handling • Screw conveyors • 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

11. 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

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