Question

Week 1 Project Specifications To bring gravel up to a sorting table in a small dry mining operation, a conveyor system is used. The conveyor belt is 36 inches wide and is roller over equal sized pulleys on each end of the belt. The rollers are 15 feet apart and 18 inches in diameter. The entire conveyor frame and belt will bring up the gravel 5 feet. The estimated maximum conveyor belt tension due to the load will not exceed 1000 lbs. The conveyor belt needs to move the gravel at 60 feet/min. Find the required horsepower n that is sufficient for the system. eeded to move this load and specify a single-phase motor Single Phase 120V Electric Motor Model or Catalog number .Serial number Horsepower (HP) .Speed in RPM Frame Size . Voltage LINE AUx.WENDNG Frequency e1 phase Thru Bolt 5.146 Bolt Circle Thru Bolt 5.812 Bolt Circle C-Face Keyed 56C Frame C-Face Threaded 56J Frame Square Flange SIEMENS Start capacitors briefly increase motor starting torque and allow a motor to be cycled on and off rapidly. A start capacitor stays in the circuit long enough to rapidly bring the motor up to a predetermined speed, which is usually about 75% of the full speed, and is then taken out of the circuit e21 MILL AND CHEMICAL DUTY

Answer 1

To find the power simply use the relation, power = force x velocity. Here force = load = 1000 lbs = 1000 x 0.454 = 454 kg
Velocity = 60 feet/min = 60 x 0.305/60 = 0.305 m/sec

For easy computation, we convert them to SI first and then to HP.

Power output = 454 x 0.305 = 138.47 W = 138.47/745.7 = .0.186 HP which is the required horse power to move the load.

Efficiency of a single phase motor is somewhere around 85%.

So rating of a single phase motor to move this system = 0.186/0.85 = 0.22 HP