Transcript Slide 1
Lecture 19 – Materials Handling (Chpt 8 Henderson/Perry) • Types of conveyors: – Belt Conveyors – Chain Conveyors – Screw Conveyors – Bucket Elevators – Oscillating Conveyors – Gravity Conveyors – Cranes – Lift and Carrying Trucks and Carts Dr. C. L. Jones Biosystems and Ag. Engineering Lecture 19 – Materials Handling (Chpt 8 Henderson/Perry) • Belt conveyors: Page 200 – High mechanical efficiency – Low damage to product being handled – Long distances an option – Limited by angle of elevation – Long service life – High initial investment cost Dr. C. L. Jones Biosystems and Ag. Engineering Lecture 19 – Materials Handling (Chpt 8 Henderson/Perry) • Belt conveyors: – Consist of endless belt operating between 2 pulleys Dr. C. L. Jones Biosystems and Ag. Engineering Lecture 19 – Materials Handling (Chpt 8 Henderson/Perry) • Belt conveyors: – Consist of endless belt operating between 2 pulleys Dr. C. L. Jones Biosystems and Ag. Engineering Lecture 19 – Materials Handling (Chpt 8 Henderson/Perry) • Belt conveyors: Design (preliminary and basic) – Width determined by amount of material conveyed, quantity, and type of service. – Cross section: Fig. 8.3 – Surcharge = portion of load above the horizontal line – Surcharge angle large for lumped material. 20 degrees for most materials – Example pg 204 and 205 Dr. C. L. Jones Biosystems and Ag. Engineering Lecture 19 – Materials Handling (Chpt 8 Henderson/Perry) • Chain conveyors: Page 206 – Not as expensive – Noisy – Slow – Inefficient – Design versatility – Suited for many different kinds of jobs – 3 kinds: trolley, scraper, and apron Dr. C. L. Jones Biosystems and Ag. Engineering Lecture 19 – Materials Handling (Chpt 8 Henderson/Perry) • Chain conveyors: – – – – Trolley: Fig. 8.4 Can make sharp turns up to 180 degrees Steep inclines Good for immersing into baths (fryers, paint coating, cooking) Dr. C. L. Jones Biosystems and Ag. Engineering Lecture 19 – Materials Handling (Chpt 8 Henderson/Perry) • Chain conveyors: – – – – – – – – – Scraper Flight cross-sections Fig. 8.6 page 209 Good for granular, nonabrasive materials Simple Cheap Steep inclines Raw products Portable Chain driven Dr. C. L. Jones Biosystems and Ag. Engineering Lecture 19 – Materials Handling (Chpt 8 Henderson/Perry) • Chain conveyors: – Apron – Flights are replaced by flat slats, plates or boards – Used for sacked materials and large units Dr. C. L. Jones Biosystems and Ag. Engineering Lecture 19 – Materials Handling (Chpt 8 Henderson/Perry) • • • • • Chain conveyor design: Page 210 Theoretical Power Equation 8.4 Incline versus capacity Page 211 Friction Coefficients Page 211 Table 8.2 Example page 212 Dr. C. L. Jones Biosystems and Ag. Engineering Lecture 19 – Materials Handling (Chpt 8 Henderson/Perry) • Screw Conveyors: Page 213 – Fine powders, heavy viscous materials, chemically active hot substances, granular materials – Simple – No cracks, crevices, sharp recesses – Can be dust tight – Good for food products: powdered milk, p-butter – Used as feeder for batch and continuous mixing – Inexpensive but high power requirements – Length of sections is limited Dr. C. L. Jones Biosystems and Ag. Engineering Lecture 19 – Materials Handling (Chpt 8 Henderson/Perry) • Screw Conveyors: – Standard pitch = diameter – Inclines up to 20 degrees Dr. C. L. Jones Biosystems and Ag. Engineering Lecture 19 – Materials Handling (Chpt 8 Henderson/Perry) • Screw Conveyors: Page 213 – Capacity calculation: pg. 214 eqtn. 8.5 – Table 8.3 and 8.4 capacity data and material classification – Equation 8.6 for HP Dr. C. L. Jones Biosystems and Ag. Engineering Lecture 19 – Materials Handling (Chpt 8 Henderson/Perry) • Next Lecture will cover: – – – – – – Bucket elevators Oscillating conveyors Pneumatic conveyors Gravity conveyors Cranes, trucks and carts Work conveyor problems Dr. C. L. Jones Biosystems and Ag. Engineering