A. Condensation rate
B. Surface configuration
C. Liquid flow rate from the surface
D. All A., B. and C.
Related Mcqs:
- For condensation of pure vapors, if the heat transfer co-efficients in filmwise and drop-wise condensation are respectively hf and hd, then__________________?
A. hf = hd
B. hf > hd
C. hf < hd
D. hf could be greater or smaller than hd - A composite flat wall of a furnace is made of two materials ‘A’ and ‘B’. The thermal conductivity of ‘A’ is twice of that of material ‘B’, while the thickness of layer of ‘A’ is half that of B. If the temperature at the two sides of the wall are 400 and 1200°K, then the temperature drop (in °K) across the layer of material ‘A’ is________________?
A. 125
B. 133
C. 150
D. 160 - Thickness of thermal boundary layer is more compared to that of hydrodynamic boundary layer, when the value of Prandtl number is_________________?
A. 1
B. < 1
C. > 1
D. > 5 - The heat transfer co-efficient in film type condensation is _______________ that for dropwise condensation?
A. Greater than
B. Lower than
C. Is same as
D. Half - The local surface conductance for laminar film condensation on vertical surface is (where, t = film thickness) _________________?
A. ∝ t
B. ∝ 1/t
C. ∝ √t
D. Independent of ‘t’ - The film thickness for laminar film condensation on vertical surface _____________ from top to bottom?
A. Cumulatively increases
B. Cumulatively decreases
C. Remain constant
D. And the surface conductance increase - Corrosiveness of steam condensate is due to the presence of________________?
A. CO2
B. Dissolved O2
C. Both A. & B.
D. Neither A. nor B. - A process stream of dilute aqueous solution flowing at the rate of10 Kg.s-1 is to be heated. Steam condensate at 95°C is available for heating purpose, also at a rate of 10 Kg.s-1. A 1 – 1 shell and tube heat exchanger is available. The best arrangement is_______________?
A. Counter flow with process stream on shell side
B. Counter flow with process stream on tube side
C. Parallel flow with process stream on shell side
D. Parallel flow with process stream on tube side - Steam condensate is recovered by steam traps and recycled for use as boiler feed water, because of its low___________________?
A. Hardness
B. Dissolved solids content
C. Suspended solids content
D. All A., B. and C. - A wall has two layers of materials A and B; each made of a different material. Both the layers have the same thickness. The thermal conductivity of material A is twice that of B. Under the equilibrium, the temperature difference across the wall is 36°C. The temperature difference across the layer A is ______________ °C?
A. 6
B. 12
C. 18
D. 24
