Conveyors
Conveyors exercises
C-1. Design for constrained space
Design drive system for the conveyor situated in a narrow passage. L = 120 cm (see the sketch).
Fig.1. Explanation for the
task.
Available information:
- One drum to be driven
- No overloads, duty cycle - 100%
- Dusty environment, abundant heat removal capability, wet floor
- Grid 400 V
- Distance between the driven drum of the conveyor and the FC (cable length) - 30 m
- Rated torque 10 kNm
- Speeds: min - 200 rpm, max - 250 rpm
- Cooling water available
Design for: (A) Design system for lowest cost. (B) Design system for highest efficiency
C-2.Design for applications with different duties
Design drive system for the three conveyors with different duties (a) duty 100%, (b) 70%, (c) 50%. Duty cycle period - 1 min.
Available information:
- One drum to be driven
- Rated torque 50 kNm
- Speeds: min - 75 rpm, max -150 rpm
- No overloads
- Air-conditioned clean power house, abundant heat removal capability
- Grid 400 V
- Distance of conveyor from FC (cable length) - 40 m
- Cooling water not available
Use helical gearbox with ratio 1:5.
Summarize the data in a table like the one below. Explain the results.
Case | Duty | Motor type | FC type | Cost motor | Cost FC | Cost total |
---|---|---|---|---|---|---|
1 | 100% | |||||
2 | 70% | |||||
3 | 50% |
C-3.Design for applications with different overloads
You are chief engineer at a plant. Design drive system for the five conveyors. Design for the following overload variants:
- (a) No overloads (0%),
- (b) 100% 2 sec each 1 min,
- (c) 100% 1 min each 10 min,
- (d) 100% 2 min each 20 min.
- (e) 50% 1 min each 10 min.
Available information:
- One drum to be driven
- Rated torque 10 kNm
- Speeds: min - 400 rpm, max - 630 rpm
- Duty 100%
- Air-conditioned clear power house, abundant heat removal capability
- Grid 400 V
- Distance pump from FC (cable length) - 40 m
- Cooling water not available
Explain the results.
Case | Overload | Motor type | FC type | Cost motor | Cost FC | Cost total |
---|---|---|---|---|---|---|
1 | No | |||||
2 | 100% 2 sec each 1 min | |||||
3 | 100% 1 min each 10 min | |||||
4 | 100% 5 min each 20 min | |||||
5 | 50% 1 min each 10 min |
C-4. Design for lowest system cost
Design drive system for the four conveyors with different speeds (the same power).
Given parameters:
- No overloads
- Duty - 100% (uninterruptible operation)
- Location/environment - clean room
- Grid - 690 V
- Cooling water not available
- Speeds and torques according to the table:
Case | speed, rpm | torque, kNm |
---|---|---|
1 | 100...500 | 10 |
2 | 300...500 | 10 |
3 | 20...100 | 50 |
4 | 70...100 | 50 |
Design for: lowest investment cost (CAPEX). Assume energy efficiency is not important. Present total system efficiency at 100% load, 50% load
C-5. Design for long and short cables
Design drive system for the conveyor with two drums to be driven. Load sharing 50/50%. You are free to choose where the drive and the transformer (if any) will be located. Also free to choose voltage level.
Note: only one possible variant is shown on the sketch in Fig.1.
Fig.1. Explanation of the
task.
Available information:
- Rated torque 60 kNm (for the total conveyor)
- Operational speeds 40 - 200 rpm
- 20% overloads
- Duty cycle - 100%
- Choose between two power houses with 6000 V and 690 V voltage sources
- Power houses: constrained space (try to minimize footprint)
Design the system for lowest cost.