Project ForgeFluid Mechanics
Mechanical Operations
GATE 2018
Hard
In a roll crusher, rolls of diameter 1m each have minimum clearance 15mm. If the angle of nip is 31°, the maximum particle diameter (mm) that can be crushed is (rounded off to third decimal place)
53.28 mm(± 1 accepted)
Explanation
cos(θ)=(R+c)/(R+r), θ=31°/2=15.5°, R=500mm, c=7.5mm (half-clearance). cos(15.5°)=0.9636. (500+7.5)/(500+r)=0.9636 ⟹ 500+r=526.64 ⟹ r=26.64mm. dmax=2r=53.28mm.
Source: GATE CH 2018 (2018)
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