Transport Processes, Gas Ab Flashcards
The driving force in heat transfer is
temperature gradient
Thermal diffusivity of a material
a. has the unit m2/sec.
b. is defined as k/ρ x Cp.
c. is the ratio of thermal conductivity to thermal capacity.
d. all (a), (b) and (c).
d. all (a), (b) and (c).
Under the same temperature gradient across various metal plates of the same thickness, the heat conducted per unit of surface area will be largest across
copper
If a man touches two metals which were kept together at room temperature, why would one metal feel colder than the other
b. one has a high thermal conductivity
Cork is a good insulator because it has
d. porous body
The insulation ability of an insulator with the presence of moisture would
decrease
Heat transfer in turbulent flow may be described by an empirical equation correlating
c. Nusselt, Prandtl, Reynolds numbers
When heat is transferred from hot body to cold body, in a straight line, without affecting the intervening medium, it is referred as heat transfer by
radiation
An ideal surface that absorbs all incident radiation, regardless of the wavelengths and direction and is also considered to be a perfect emitter is referred to as a
c. black body
In thermal radiation, for a black body
d. α= 1 and ε= 1
In a gas absorption tower, mass transfer occurs primarily
from the gas phase to the liquid phase
Separation of a mixture of two gases by absorption in the liquid solvent depends upon the difference in their
solubility
In gas absorption, one solute is being absorbed while the rest of the components are assumed to be ______ and the liquid is ________.
b. non-soluble, non-volatile
In general, operating pressure should be ___ and temperature ___for an absorber, to minimize stage requirements and/or absorbent flow rate to lower the equipment volume required to accommodate the
gas flow.
a. high, low
What could be the effect of lowering the temperature of stripping?
a. number of stages increases
