Chemical Heat Transfer Quiz 7

1 / 50

**Removal of _______ heat is involved in the condensation of a vapor under saturated conditions?**

2 / 50

**The energy radiated from a surface Q at absolute temperature T is related as___________?**

3 / 50

**The critical radius of insulation for a spherical shell is (where, K = thermal conductivity of insulating material h0 = heat transfer coefficient at the outer surface) ?**

4 / 50

**The critical radius ?r? of insulation on a pipe is given by______?**

5 / 50

**Steam condensate is recovered by steam traps and recycled for use as boiler feed water, because of its low_____?**

6 / 50

**Terminal point temperature differences between fluids in case of a heat exchanger is termed as___________?**

7 / 50

**Steam side heat transfer co-efficient in an evaporator is in the range of _______ kcal/hr.m2?C?**

8 / 50

**The advantage of using a 1 ? 2 shell and tube heat exchanger over a 1 ? 1 shell and tube heat exchanger is__________?**

9 / 50

**The critical radius of insulation for cylindrical pipe is (where, hi = heat transfer coefficient at inside of the pipe) ?**

10 / 50

**Rate of heat transfer by vaporisation from pools of water is affected by the ______?**

11 / 50

**Steam is to be condensed in a shell and tube heat exchanger, 5 m long with a shell diameter of 1 m. Cooling water is to be used for removing the heat. Heat transfer co-efficient for the cooling water, whether on shell side or tube side is the same. The best arrangement is______?**

12 / 50

**The equivalent diameter for pressure drop is _________ that for heat transfer?**

13 / 50

**Stefan-Boltzmann law which describes the radiation heat transfer states that, it is proportional to (where, t = temperature in ?C T = absolute temperature in ? K) ?**

14 / 50

**Steam trap is used to__________?**

15 / 50

**Small scale evaporation is done in a__________?**

16 / 50

**Steam is routed through the tube in case of a _______ evaporator?**

17 / 50

**Sensible heat absorbed by 1 lb of water when it is heated from 32 to 212?F may be around _______ BTU?**

18 / 50

**The characteristic dimensionless groups for heat transfer to a fluid flowing through a pipe in laminar flow are________?**

19 / 50

**Reason for operating an evaporator in multiple effects is to secure _____?**

20 / 50

**The actual temperature drop across the heating surface in an evaporator depends on the__________?**

21 / 50

**The capacity of double-effect evaporator is less than half of the capacity of two single effects, each of which is operating over same terminal temperature difference, when the_________ ?**

22 / 50

**Stefan-Boltzmann law applies to ______ body?**

23 / 50

**Steady state one dimensional heat flow by conduction as given by Fourier?s low does not assume that________?**

24 / 50

**The advantage of backward feed multiple effect evaporators over forward feed units is that_____?**

25 / 50

**Stefan?s block body radiation law can also be derived from _______ law?**

26 / 50

**Presence of a non-condensing gas in a condensing vapour_____?**

27 / 50

**Radiant energy received by a body is proportional to (where, d = the distance between the object emitting radiation and that receiving it.) ?**

28 / 50

**Solid angle subtended by the finite surface at the radiating element is__________?**

29 / 50

**Resistance to heat flow by conduction is proportional to (where, t & ? are thickness & density of the material respectively and A = area normal to the direction of heat flow.) ?**

30 / 50

**Steam consumption in kg/hr in case of an evaporator is given by (where, C & E are capacity the economy of the evaporator respectively) ?**

31 / 50

**Radiation energy is emitted by all the substances, which are above______?**

32 / 50

**The driving potential for the crystal growth during crystallisation is the ________ of the solution?**

33 / 50

**Reynold?s analogy states that (where, St = Stanton number f = friction factor) ?**

34 / 50

**Shell side pressure drop in a shell and tube heat exchanger does not depend upon the__________?**

35 / 50

**The film thickness for laminar film condensation on vertical surface ______ from top to bottom?**

36 / 50

**The equation, Nst = f/2, is the ______ analogy?**

37 / 50

**The equation, Nst = (f/2)/[1 + 5 (Npr ? 1) ?(f/2)], corresponds to _______ analogy?**

38 / 50

**Steam traps are provided in steam carrying pipelines to__________?**

39 / 50

**The absorptivity of a grey body at a given temperature ______ with increasing wavelength of radiation?**

40 / 50

**The equivalent diameter for the annulus of a double pipe heat exchanger, whose inner pipe has fins on the outside is _______ compared to the same size pipes without fins?**

41 / 50

**The equation, (NSt ? N2/3 Pr) = f/2, is the _____ analogy ?**

42 / 50

**Steam economy in case of a triple effect evaporator will be __________?**

43 / 50

**Reynold?s analogy states that__________?**

44 / 50

**The actual temperature drop across the heating surface of an evaporator depends on the________?**

45 / 50

**Radiation heat losses from satisfactorily insulated high pressure boiler may be about ______ percent?**

46 / 50

**The film co-efficient is decreased due to the presence of non-condensing gases in the vapors. The film co-efficient of superheated vapor as compared to that of saturated vapor is_____?**

47 / 50

**Radiator of an automobile engine is a _______ type of heat exchanger?**

48 / 50

**The film co-efficient between condensing vapour and metal wall increases with _______?**

49 / 50

**The dimensionless group in mass transfer that is equivalent to Prandtl number in heat transfer is__________?**

50 / 50

**The Dittus-Boelter equation for convective heat transfer [(i.e. h = 0.023 (K/D) (Re)0.8 (Pr)0.4] cannot be used for_________?**

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