Chemical Engineering - Heat Transfer
Exercise :: Heat Transfer - Section 11
26.
Pick out the wrong statement.
A. 'Solvates' are chemical compounds formed by solute with their solvents. When water is the solvent, then it is called a 'hydrate'. B. In heat exchanger calculations (Δt)weighted is used in place of Δt, when it involves more than one sequence of heating or cooling i.e., desuperheating & condensation or condensation & sub-cooling. C. Heat transfer co-efficient during nucleate boiling is not influenced by the agitation imparted. D. In case of short tube vertical evaporators, area of central downtake is about 50 to 100% of the total tube cross-sectional area.
Answer: Option C
Explanation:
27.
What is the geometric mean of two heat transfer areas A1 and A2 ?
A. A1 . A2 B. A1 + A2 C. A1 . A2 D. 2 A1 . A2
Answer: Option A
Explanation:
28.
Evaporation by thermocompression results in the
A. saving of steam. B. realisation of multiple effect economy in a single effect. C. both (a) and (b). D. none of these.
Answer: Option C
Explanation:
29.
Forced circulation evaporators are normally used for concentrating liquids having
A. scaling characteristics B. high viscosity C. both(a) & (b) D. neither (a) nor (b)
Answer: Option C
Explanation:
30.
Steam economy in case of a triple effect evaporator will be
Answer: Option C
Explanation:
