Reference no: EM132877297
ENGIN 3501 Underground Production Systems - Federation University
Question 1
A 20 tonne mine locomotive is travelling at 10 km/hr. Determine the retarding force of the brakes required to stop it in 34m on a level track.
Question 2
For the locomotive in question 1, if the locomotive resistance is 14 kg/tonne determine the drawbar pull.
Question 3
A Shuttle car travels at an average velocity of 1.25 m/s from a loading machine to a conveyor belt where it will discharge its payload. If the travel time is 75 seconds, what will be the distance between the loading point and the dump?
Question 4
What is the difference between a drum hoist winding system and a koepe winding system? What factors influence the application of each system?
Question 5
A vertical hoist is to be designed to haul ore at a rate of 1000 tonnes/hour from a depth of 600m at an average skip velocity of 6.1 m/s. Determine the required skip load in tonnes if the maximum acceleration and deceleration are 2 m/s2 and the rest time between winds is 10 seconds.
Design Project: Hoist Design
a) For a hoisting system with a 3 period Trapezoidal speed time diagram determine the hoisting capacity of a shaft if the skip payload is 25 tonnes, hoisting distance is 800m, maximum rope speed is 10 m/s, acceleration and deceleration are 2 m/s2 and the rest time between winds is 10 s.
b) For the following winding conditions determine if a rope with a minimum breaking force of 12 MN gives a satisfactory factor of safety for the winding of ore?
Depth of wind = 850m
Mass of skip and attachments = 10 tonne
Mass of ore wound per wind = 12 tonne
Height of sheaves above skip top when skip unloading at shaft top = 20m
Mass of rope/100m = 750 kg/100m
Note for ore hoisting using a drum winder minimum factor of safety = 7.0
c) If the maximum winding speed for the wind described in part (b) is 12 m/s and acceleration = deceleration = 2 m/s2 (assume linear change of speed during acceleration and deceleration) determine:
• Accelerating period
• Decelerating period
• Distance travelled by skip in accelerating period
• Distance travelled by skip during decelerating period
• Time travelling at maximum speed
• Distance travelled at maximum speed.
• Total cycle time assuming a 10 s rest period between winds
• Number of cycles per hour
• Capacity of the system per hour
Plot a speed-time graph for this situation.
d) The system described in parts (b) and (c) are for an unbalanced hoisting system employing a drum winding system. Determine the total torque required at the drum to drive the system. Rope diameter is 50mm, minimum drum diameter = 80 x rope diameter, diameter of sheaves = 5 m. Skip hoisting system, so k = 1.15. Friction resistance between skip and guides, air resistance, bending resistance etc = k x mass of loaded skip. If required it can be assumed that the Inertia of the system is 130,000 kgm2)
e) Determine the variation of the tractive force at the circumference of the drum and the power at the drive shaft for this system assuming a constant radius of coiling of the rope on the drum (hint do this for each element within the cycle and plot on a torque/power time graph)
f) Determine the rms torque and power for this system.
Attachment:- Underground Production Systems.rar