Mechanical Operations Questions

• Pick out the wrong statement pertaining to the turbine agitator.
• Rittinger number which designates the new surface prduced per unit of mechanical energy absorbed by the material being crushed, depends on the
• Half the angle of nip, (α), for a roll crusher is given by (where, dr, dp and df are diameters of crushing rolls, feed particles and rolls gap respectively).
• Which one is a filter aid?
• __________ conveyors are also called scrapers.
• Screen capacity is expressed in terms of
• In a size reduction crushing operation, the feed size is 10 to 50 mm, while the product size is 2 to 10 mm. This is a case of __________ crushing.
• With increase in the capacity of screens, the screen effectiveness
• To remove dirt from the flowing fluid, we use a
• Which of the following comes in the category of primary crusher for hard and tough stone?
• A fluid energy mill is used for
• Which of the following is the softest material?
• Filtration rate through a filter cake is proportional to (where, S = filtering surface R = specific cake resistance μ = viscosity of the filtrate)
• Optimum ratio of operating speed to critical speed of a trommel is
• Solid particles of different densities are separated by
• A centrifugal filtration unit operating at a rotational speed of w has inner surface of the liquid (density ρL) located at a radial distance R from the axis of rotation. The thickness of the liquid film is δ and no cake is formed. The initial pressure drop during filtration is
• Dry powdery solid materials are transported by a __________ conveyor.
• In a roll crusher, both the rolls
• What is the critical rotation speed in revolutions per second, for a ball mill of 1.2 m diameter charged with 70 mm dia balls?
• The cake resistance increases steadily with the time of filtration in a plate and frame filter employing constant __________ filtration.