Dr. C. L. Jones

1
Lecture 20 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
2
Lecture 20 Materials Handling(Chpt 8
Henderson/Perry)

• Bucket elevators
• Figure 8.8 page 219
• Centrifugal discharge for small grain
• Perfect discharge low cost, slow moving, low
  damage required
• Continuous-bucket type heavy duty use such as
  ores, sand, rocks. Material slides over
  preceding bucket bottom
• Read section in handout.

Dr. C. L. Jones Biosystems and Ag. Engineering
3
Lecture 20 Materials Handling(Chpt 8
Henderson/Perry)

• Bucket elevators
• A bucket elevator has 36 buckets similar to the
  configuration in Fig. 8.10(a) and a lift of 73
  ft. Calculate the HP.

Dr. C. L. Jones Biosystems and Ag. Engineering
4
Lecture 20 Materials Handling(Chpt 8
Henderson/Perry)

• Oscillating conveyors (page 223)

Dr. C. L. Jones Biosystems and Ag. Engineering
5
Lecture 20 Materials Handling(Chpt 8
Henderson/Perry)

• Pneumatic conveyors (page 224)
• Figure 8.14
• Uses fans, vacuums, and conduits
• We will work a problem on Friday for this kind of
  conveyor

Dr. C. L. Jones Biosystems and Ag. Engineering
6
Lecture 20 Materials Handling(Chpt 8
Henderson/Perry)

• Gravity conveyors
• Consist of rollers or wheels set on a level or a
  slight incline.
• Material is moved by hand or by gravity.
• Intermittent service
• Used as a support aide with external power.

Dr. C. L. Jones Biosystems and Ag. Engineering
7
Lecture 20 Materials Handling(Chpt 8
Henderson/Perry)

• Cranes, trucks and carts
• Cranes are not used extensively in ag services
  but are used largely for construction
• Trucks, fork lifts and carts
• Used in warehouses and shipping units
• Generally handle large bulky items
• Can handle variable location items
• Must consider labor efficiency and time/motion
  studies
• Included would be bale spikes and some bale
  loaders

Dr. C. L. Jones Biosystems and Ag. Engineering
8
Lecture 20 Materials Handling(Chpt 8
Henderson/Perry)
Example A bucket elevator has buckets similar to
the configuration in Fig. 8.10(b). The belt
speed is 35 ft/min and there are 52 buckets on
the belt. The lift is 92 ft. Calculate the HP.
Dr. C. L. Jones Biosystems and Ag. Engineering