- #1
FAlonso
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I am currently working on designing a conveyor for feeding 1t material to a furnace. Not going into detail of how it works, I would just like to confirm my approach.
Goal: To move 1000 kilograms of mass using steel rope/pulley system. Determining power requirement
It would be a bucket mounted on two wheels running at a very low speed (0.3 m/s) over a mild steel I-beam. From literature around the internet, friciton values are:
mild steel on mild steel (0.74 static, 0.6 dynamic)
rail wheel on steel rail rolling resistance 0.0020
I am calculating power as follows:
Speed desired: 0.3 m/s
Time to achieve the speed: Not important but taking it to be 1s
Mass to be moved: 950 kg + bucket assembly (~50 kg) = 1000 kg
Friction to be overcome while driving: 1000 x 9.8 x 0.002 = 19.6N (2 wheels so 39.2N)
Force to move the mass from rest: F=ma > F=1000 x (0.3-0/1s) = 300N
Total force= 340N
Power required: F x v = 340 x 0.3 = 102 W or 0.13 hp
Am I missing something ? I am a bit skeptical about finding force required to move the mass from rest as it uses the static friction value of 0.72 which makes the required power go up by a large amount.
Regards
Goal: To move 1000 kilograms of mass using steel rope/pulley system. Determining power requirement
It would be a bucket mounted on two wheels running at a very low speed (0.3 m/s) over a mild steel I-beam. From literature around the internet, friciton values are:
mild steel on mild steel (0.74 static, 0.6 dynamic)
rail wheel on steel rail rolling resistance 0.0020
I am calculating power as follows:
Speed desired: 0.3 m/s
Time to achieve the speed: Not important but taking it to be 1s
Mass to be moved: 950 kg + bucket assembly (~50 kg) = 1000 kg
Friction to be overcome while driving: 1000 x 9.8 x 0.002 = 19.6N (2 wheels so 39.2N)
Force to move the mass from rest: F=ma > F=1000 x (0.3-0/1s) = 300N
Total force= 340N
Power required: F x v = 340 x 0.3 = 102 W or 0.13 hp
Am I missing something ? I am a bit skeptical about finding force required to move the mass from rest as it uses the static friction value of 0.72 which makes the required power go up by a large amount.
Regards