Convective heat transfer co-efficient in case of fluid flowing in tubes is not affected by the tube length/diameter ratio, if the flow is in the __________ zone.
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The actual temperature drop across the heating surface in an evaporator depends on the
Which of the following is not used as a medium for high temperature heating ?
In case of evaporators, liquid entrainment results primarily due to
Air is to be heated by condensing steam. Two heat exchangers are available (i) a shell and tube heat exchanger and (ii) a finned tube heat exchanger. Tube side heat transfer area are equal in both the cases. The recommended arrangement is
Baffles in the shell side of a shell and tube heat exchanger
The number of kg vaporised per kg of steam fed to the evaporator is defined as
Economy of a multiple effect evaporator is not influenced much by the
Increasing the liquor level in the evaporator results in the
The equivalent diameter for pressure drop is __________ that for heat transfer.
Controlling heat transfer film co-efficient is the one, which offers __________ resistance to heat transfer.
The heat flux (from outside to inside) across an insulating wall with thermal conductivity, K= 0.04 W/m.oK and thickness 0.16m is 10 W/m2. The temperature of the inside wall is - 5oC. The outside wall temperature is
Thermal conductivity of a conducting solid material depends upon its
The average heat transfer co-efficient for laminar film condensation on vertical surface is inversely proportional to (where, ΔT = Temperature drop across condensate film )
Bulk of the convective heat transfer resistance from a hot tube surface to the fluid flowing in it, is
Which of the following is concerned with both heat and mass transfer ?
A backward feed multiple effect evaporator is better than forward feed for concentrating cold feed, because it provides
A 10 cm dia steam pipe, carrying steam at 180oC, is covered with an insulation (conductivity = 0.6 W/m.oC). It losses heat to the surroundings at 30oC. Assume a heat transfer co-efficient of 0.8 W/m2.oC for heat transfer from surface to the surroundings. Neglect wall resistance of the pipe and film resistance of steam. If the insulation thickness is 2 cms, the rate of heat loss from this insulated pipe will be