Mechanical Operations Quiz 6

Sphericity is the ratio of the surface area of a spherical particle having the same volume as the particle to the surface area of the particle. Which of the following has the maximum value of sphericity ?

Sphericity of a cubical particle, when its equivalent diameter is taken as the height of the cube, is _________ ?

Screen efficiency is________?

Size reduction of ______ is accomplished in steam heated rollers and roll crushers?

Size reduction of ice and gypsum can be accomplished suitably by a ________ crusher?

The capacity of a belt conveyor depends upon two factors. If one is the cross-section of the load, the other is the ______ of the belt?

The controlling resistance in a rotary drum vacuum filter is the _________ resistance?

Sulphuric acid mist is arrested by using a _____ scrubber?

The crushed material received for separation is called feed or__________?

Shell and leaf filter as compared to plate and frame filter _______?

Size reduction of moulding powders, waxes, resins & gums are done in a ________ mill?

Tabular bowl centrifuges as compared to disk bowl centrifuges_____?

Solid particles of different densities are separated by _______?

Sedimentation on commercial scale occurs in______?

Tabling process used for separating two materials of different densities by passing the dilute pulp over a table/deck, which is inclined from the horizontal surface at an angle of about_________?

Separation of a suspension or slurry into a supernatant clear liquid (free from particles) and a thick sludge containing a high concentration of solid is called___________?

Separation of solid suspended in liquid into a supernatant clear liquid and a denser slurry employs a process termed as the_____?

The capacity of a pneumatic conveying system depends upon the ________?

Stamp mills are generally used for crushing___________?

The basic filtration equation is given as dt/dV = (?/A ?P). [(? .CV/A) + Rm], where, V is volume of the filtrate; A is the filtration area, a is specific cake resistance, ? is viscosity of the filtrate, and C is the concentration of the solids in the feed slurry. In a 20 minutes constant rate filtration, 5 m3 of filtrate was obtained. If this is followed by a constant pressure filtration, how much more time in minutes, it will take for another 5 m3 of filtrate to be produced? Neglect filter medium resistance, Rm; assume incompressible cake ?

The capacity of a classifier in ?tons of solid/hr? is given by (where, A = cross-sectional area in m2, V = rising velocity of fluid in m/sec, S = percentage of solids in the suspension by volume, ? = density of solids in kg/m3)__________?

The cake resistance increases steadily with the time of filtration in a plate and frame filter employing constant _______ filtration?

Sphericity for a non-spherical particle is given by (where, V and S are volume and surface area respectively of one particle. and, D = equivalent diameter of particle)?

The critical speed of a trommel (N) is related to its dia D. as _______?

Temperature of the product during ultrafine grinding_______?

Tank filter (e.g., Nutsche filter) is_____?

Separation of materials of the same density based on their sizes by using then-different rates of flow is called___________?

Specific surface area is the surface area of a unit ________ of materials?

Soft & non-abrasive materials can be made into fines by__________?

Screw conveyors are_________?

The capacity of a gyratory crusher is _______ that of a jaw crusher with the same gape, handling the same feed & for the same product size range.?

Separation of materials into products based on the difference of their sizes is called_____?

Sorting classifiers employing differential settling methods for separation of particles make use of the differences in their__________?

Separation of isotopes is generally done using a/an ________ centrifuge?

Size reduction mechanism used in Jaw crushers is___________?

Size reduction of asbestos and mica is done by______?

The energy required per unit mass to grind limestone particles of very large size to 100 ?m is 12.7 kWh/ton. An estimate (using Bond?s law) of the energy to grind the particles from a very large size to 50 ?m is_________?

The constants (Kb, Kr and Kk) used in the laws of crushing (i.e., Bond?s law, Rittinger?s law and Kick?s law) depend upon the__________?

Size measurement of ultrafine particles can be best expressed in terms of_____?

Size reduction does not occur due to compression in case of_________?

Solid particles separation based on the difference in their flow velocities through fluids is termed as the___________?

Separation of solid particles based on their densities is called__________?

Size reduction of the _______ can be suitably done by ball mills, crushing rolls and rod mills?

Sphericity of raschig ring (whose length and diameter are equal) is_____?

Supporting legs of a plate and frame filter is normally made of_________?

Screen capacity is proportional to (where, S = screen aperture)______?

The energy consumed by a ball mill depends on___________?

The equivalent diameter of channel of a constant non-circular cross-section of 3 cm by 6 cm will be ________ cms?

Shape factor for a cylinder whose length equals its diameter is__________?

Sizing of very fine particles of the order of 5 to 10 microns is done by elutriation, which is a ______ operation?