Free Fluid Flow Operations MCQs with Answers
909 Fluid Flow Operations MCQs from Chemical Engineering, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
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909 questions · page 39 of 46
- A. Jaw crusher
- B. Hammer crusher
- C. Ball mill
- D. Tube mill
Explanation: A hammer crusher is commonly used to reduce ROM coal for domestic ovens because its impact action readily breaks relatively brittle coal…
Correct answer: Hammer crusher- A. Clarification
- B. Sedimentation
- C. Classification
- D. Flocculation
Explanation: Elutriation separates fine particles according to their settling velocities in an upward-flowing fluid, so it is a classification…
Correct answer: Classification- A. Colloidal
- B. Fine
- C. Coarse
- D. Dissolved
Explanation: Ultra-centrifuges generate very high centrifugal forces and are used to separate colloidal or extremely fine solid particles.
Correct answer: Colloidal- A. Sizing
- B. Sorting
- C. Classification
- D. Flocculation
Explanation: Sizing is the separation of a solid mixture into fractions according to particle size.
Correct answer: Sizing- A. Dicers
- B. Tube mills
- C. Slitters
- D. Knife cutters
Explanation: Dicers, knife cutters and slitters remove material by cutting action. A tube mill reduces solids mainly by impact and attrition, so it is…
Correct answer: Tube mills- A. 1.5
- B. 1
- C. None of these
- D. √2
Explanation: In the Taylor sieve series, successive sieve openings differ by a linear-size ratio of √2.
Correct answer: None of these- A. None of these
- B. Small loads & long runs
- C. Heavy loads & long runs
- D. Heavy loads & short runs
Explanation: Apron conveyors use overlapping plates or pans and are strong enough for heavy, abrasive loads, but they are normally selected for…
Correct answer: Heavy loads & short runs- A. [(DP/18). (ρs - ρ/μ)] ω2r
- B. [(DP2/18). (ρs - ρ/μ)] ω2r
- C. [(DP/18). (ρs - ρ/μ)] ω2r2
- D. [(DP2/18). (ρs - ρ/μ)] ω2r
Explanation: For a small particle in a cyclone, Stokes-law motion gives velocity proportional to particle diameter squared, density difference…
Correct answer: [(DP2/18). (ρs - ρ/μ)] ω2r- A. Packed wet
- B. Hollow wet
- C. Venturi
- D. Co-current
Explanation: A Venturi scrubber gives very high gas-liquid relative velocity, producing fine droplets that efficiently capture sulphuric acid mist.
Correct answer: Venturi770. Which of the following can be most effectively used for clarification of lube oil and printing ink ?
- A. Sparkler filter
- B. Pre-coat filter
- C. Disc-bowl centrifuge
- D. Sharpies super-centrifuge
Explanation: A Sharples super-centrifuge is a high-speed clarifying centrifuge used to remove fine suspended solids from liquids such as lubricating…
Correct answer: Sharpies super-centrifuge- A. Diatomaceous earth
- B. Calcium silicate
- C. Sodium carbonate
- D. Silica gel
Explanation: Diatomaceous earth, also called kieselguhr, is the most widely used filter aid because its porous structure forms a permeable cake that…
Correct answer: Diatomaceous earth- A. Viscosity
- B. Density
- C. Surface tension
- D. Thermal conductivity
Explanation: In turbulent agitation, the power correlation contains density through the power number, with approximately P proportional to rho N^3D^5.
Correct answer: Density- A. 4
- B. 1
- C. 1/4
- D. 1/2
Explanation: In a plate-and-frame press, washing is slower because the wash liquid passes through the deposited cake under less favorable flow…
Correct answer: 1/4- A. gm-1
- B. gm/cm-1
- C. cm/gm-1
- D. cm-1
Explanation: Filter-medium resistance appears in the filtration equation as a resistance per unit length, so its dimensions are inverse length…
Correct answer: cm-1- A. Over medium
- B. Over cake
- C. Overall
- D. None of these
Explanation: For a compressible cake, the specific cake resistance changes as the cake is compressed, so it depends on the pressure drop across the…
Correct answer: Over cake- A. Removal of fines from liquid
- B. Liquids having high vapour pressure
- C. None of these
- D. Liquids of very high viscosity
Explanation: Vacuum filtration is unsuitable for very high-viscosity liquids, high-vapour-pressure liquids, and slurries requiring removal of extremely…
Correct answer: None of these- A. None of these
- B. Wettability
- C. Particle shape
- D. Gravity separation
Explanation: The float-and-sink test separates coal according to density differences, so it predicts whether gravity-based cleaning can remove the…
Correct answer: Gravity separation- A. Increases capacity
- B. Requires more energy
- C. Gives less wear on chamber walls
- D. Complicates handling of the product
Explanation: Water helps distribute solids and remove heat in wet grinding, commonly allowing a higher throughput than dry grinding.
Correct answer: Increases capacity- A. Over-sizes are present in undersize fraction
- B. Screen is plugged with solid particles
- C. Under-sizes are retained in oversize fraction
- D. Screen capacity is abruptly increased
Explanation: Blinding occurs when openings in a screen become blocked by particles, preventing material from passing through them and reducing…
Correct answer: Screen is plugged with solid particles- A. Pressure filter
- B. Vacuum filter
- C. Centrifugal filter
- D. Gravity filter
Explanation: A vacuum lowers the liquid’s boiling point, so a volatile liquid can evaporate or flash during vacuum filtration.
Correct answer: Vacuum filter