This set of Separation Processes Multiple Choice Questions & Answers (MCQs) focuses on “Crsytallization Equipmemnts”.
1. What is the crystal size range of forced circulation crystallizer?
Explanation: In the forced circulation crystallizer a crystal of size of 30-60mesh are mesh are produced.
2. Why the axial pump flow speed is preferred in forced circulation crystallizer?
a) To reduce primary nucleation rate
b) To reduce the crystal size
c) To increase the crystal size
d) To keep the secondary nucleation rate small
Explanation: An axial flow pump is preferred, the pump speed should be low in order to reduce the energy input so that the secondary nucleation by contact or attrition remains small.
3. What is the crystal size range of draft-tube-baffle crystallizer?
a) 1-2 mesh
Explanation: The crystal size range of draft-tube-baffle crystallizer is 8-30mesh.
4. What is the near ambient temperature range for most inorganic solids?
Explanation: The near ambient temperature range for most inorganic solids is 10-40 degrees.
5. Which type of crystallizers does industry employ?
Explanation: Mostly, evaporative crystallizers or a combination of evaporative and cooling crystallizers is used.
6. What is not an advantage of using mechanical agitation?
a) High purity
b) Uniform crystal size
c) High purity
d) Low rate of primary nucleation
Explanation: A high rate of primary nucleation is required so it cannot be an advantage.
7. What is the result of unagitated batch crystallizers?
a) Undesirably large crystals
b) Impure crystals
c) Entrapment of mother liquor
d) High secondary nucleation rate
Explanation: High secondary nucleation rate is the result of high speed of the agitator.
8. What ensures a reasonable heat transfer rate through a small temperature driving force?
a) High agitation speed
b) High magma velocity
c) High nucleation rate
d) Low nucleation rate
Explanation: A high magma velocity ensures a small temperature driving force.
9. What is the time for a typical cycle, including charging the feed, crystallization, and removal of the magma?
a) 1 hour
Explanation: 2-8hr is the time for a typical cycle, including charging the feed, crystallization, and removal of the magma.
10. What is the specialty of the circulating liquor crystallizer?
a) Supersaturaion is created in separate region
b) Supersaturation is not created
c) Supersaturation is created at every point
d) Crystals are automatically thrown out of crystallizer
Explanation: The speciality of circulating liquor crystallizer equipment is that supersaturation is created in a separate region before the liquor flows into the crystal suspension vessel. The “level” of supersaturation drops down as the liquor from the supersaturated zone mixes up with the slurry.
Sanfoundry Global Education & Learning Series – Separation Processes.
To practice all areas of Separation Processes, here is complete set of 1000+ Multiple Choice Questions and Answers.