Chemical Heat Transfer

View factor is important in heat transfer by_____________________? A. Steady state conduction B. Natural convection C. Forced convectionD. Radiation

Forced circulation evaporators are normally used for concentrating liquids having ___________________? A. Scaling characteristics B. High viscosityC. Both A. & B. D. Neither A. nor B.

The equation, Nst = f/2, is the _____________ analogy? A. ColburnB. Reynolds C. Prandtl D. None of these

Which of the following is directly concerned with the heat transfer ? A. Strouhal number B. Sherwood number C. Euler numberD. Grashoff number

The thermal boundary layer at NPr > 1 ? A. Is thicker than hydrodynamic boundary layerB. Is thinner than hydrodynamic boundary layer C. And the hydrodynamic boundary layers are identical D. Disappears

Nucleate boiling is promoted ___________________? A. On polished surfacesB. On rough surfaces C. In the absence of agitation D. None of these

At what value of Prandtl number, conduction is negligible in the turbulent core of a fluid flowing through a heated pipe ? A. 0.5 B. < 0.5C. > 0.6 D. < 0.1

The overall heat transfer co-efficient for a shell and tube heat exchanger for clean surfaces is U0 = 400 W/m2.K. The fouling factor after one year of operation is found to be hd0 = 2000 W/m2.K. The overall heat transfer co-efficient at this time is _____________________? A. 1200 W/m2.K B. 894 W/m2.KC. 333 W/m2.K D….

Cpμ/K is termed as the ______________ number? A. Grashoff B. NusseltC. Prandtl D. Stanton

In a single evaporator system, the steam economy ________________ by creating vacuum in the evaporator? A. Increases B. Decreases C. Remain constant D. May increase or decrease, depends on the vacuum