Search
.Management Sciences
Category: Mechanical Operations
Pick out the wrong statement ?
A. For the compressible cake, voidage & the specific resistance of the cake can be assumed to be
constant
B. Cake resistance is independent of the pressure drop
C. Crushing of explosive materials are done by employing dry-grinding
D. Gyratory crusher is a coarse crusher
_____________ Centrifuge is normally used in sugar mills?
A. Tubular bowl
B. Disc-bowl
C. Suspended batch basket
D. Perforated horizontal basket continuous
Hot, lumpy & abrasive materials are best transported by using a/an ___________ conveyor ?
A. Apron
B. Belt
C. Screw
D. Flight
For coarse reduction of hard solids, use ____________________?
A. Impact
B. Attrition
C. Compression
D. Cutting
A tube mill compared to a ball mill__________________?
A. Has a higher length/diameter ratio
B. Produces a coarser product
C. Has a higher diameter/length ratio
D. Uses much larger balls
The optimum moisture content in solids to be crushed/ground ranges from _______________ percent?
A. 3 to 4
B. 8 to 10
C. 10 to 15
D. 15 to 20
Production rate _____________ with increased fineness, with a given energy input to the size reduction machine?
A. Decreases
B. Increases
C. Remains unchanged
D. May increase or decrease; depends on the machine
Actual operating speed of a ball mill may vary from 65 to 80% of the critical speed. Which of the following duties would require the ball mill to be operated at maximum percentage of critical speed ?
A. Wet grinding in low viscous suspension
B. Wet grinding in high viscous suspension
C. Dry grinding of large particles (upto 1.25 cms)
D. Dry grinding of large particles in un-baffed mills
As the product becomes finer, the energy required for grinding___________________?
A. Decreases
B. Increases
C. Is same as for coarser grinding
D. Is 1.5 times that for coarser grinding
Recent Comments