Humidification

Question 1

This topic involves the contact of a pure liquid with a gas for the purpose of changing the vapor content of the gas and/or adding or removing heat from the contacting phase for purposes of heating or cooling.

Answer 1

humidification

Question 2

humidification operation may also be classified as

Answer 2

dehumidification, air conditioning and water cooling

Question 3

The operation involves two components and two phases.

Answer 3

phase equilibria

Question 4

Based on the Gibb’s phase rule, the number of degrees of freedom to define equilibrium conditions is

Answer 4

two

Question 5

This refers to the ratio of the mass of vapor per mass of vapor-free gas.

Answer 5

Absolute Humidity

Question 6

through this, the partial pressure exerted by the vapor A in the gas B can be determined

Answer 6

Absolute humidity

Question 7

This refers to the maximum amount of vapor that a gas can contain which is in equilibrium with the liquid at a given temperature.

Answer 7

Relative Humidity

Question 8

The partial pressure of the vapor is in effect equal to the vapor pressure.

Answer 8

Relative Humidity

Question 9

pressure exerted by a vapor that is in equilibrium with its condensed state

Answer 9

Vapor pressure

Question 10

Ratio of absolute humidity and Saturation humidity is equal to the

Answer 10

percentage saturation or percentage humidity

Question 11

This is the volume occupied by one pound of dry gas plus whatever vapor it contains at a given pressure and temperature.

Answer 11

humid volume

Question 12

The specific volume if the gas is saturated with the vapor.

Answer 12

Saturated Volume

Question 13

This is the heat needed to raise the temperature of one pound of dry gas and the vapor it contains by 1°F.

Answer 13

Humid Heat

Question 14

Total enthalpy content of 1 lb of dry gas and its vapor at a given temperature.

Answer 14

Enthalpy of Mixture

Question 15

This refers to the steady state temperature attained by a gas-vapor mixture when saturated with vapor by spraying under adiabatic conditions.

Answer 15

Adiabatic Saturation Temperature

Question 16

This refers to the steady state temperature attained by a small mass of liquid immersed in a large body of gas.

Answer 16

Wet bulb temperature

Question 17

for air-water system the wet bulb temperature becomes identical with the

Answer 17

adiabatic saturation temperature

Question 18

steady temperature attained when a vapor-gas mixture becomes saturated when cooled at constant humidity

Answer 18

Dew Point

Question 19

Many of the humidification properties for air-water system can be obtained from the ________________ at 1 atm pressure.

Answer 19

humidity chart

Question 20

In this operation, the temperature of water is constant and equal to the wet bulb temperature of the gas

Answer 20

adiabatic humidification

Question 21

the air undergoes a non-adiabatic humidification

Answer 21

water cooling

Question 22

in humidification, if the system is limited to air-water, the design may be based on the enthalpy driving force as given by

Answer 22

Merkel’s Equation

Question 23

for water cooling, the Hg is

Answer 23

height of a transfer unit (HTU)

Question 24

for water cooling, the Ng is

Answer 24

number of transfer units (NTU)

Question 25

consists of the enthalpy of air at saturation based on the temperature of water

Answer 25

equilibrium curve

Question 26

equal to the internal energy of the system plus the product of pressure and volume.

Answer 26

enthalpy

Question 27

in humidification, ploting of the operating line is generated using the

Answer 27

enthalpy balance

Question 28

in humidification, the slope of operating line is

Answer 28

L/w

Question 29

obtained by dividing enthalpy transfer equation by the liquid phase heat transfer equation

Answer 29

slope of the tie line

Question 30

if the operating line and equilibrium curve are linear, Ng (Number transfer of unit) can be evaluated by

Answer 30

logarithmic mean driving force

Question 31

if the resistance to heat transfer in the liq phase can be neglected

Answer 31

the slope of tie line becomes infinite

Question 32

for dehumidification and air conditioning

Answer 32

in ref to the humidification:

• similar equation
• reversed limit
• operating line is above the equilibrium curve

Question 33

Mickley’s graphical method can be used to determine the

Answer 33

temperature profile

Question 34

plotting of the differential equation obtained from the enthalpy transfer equation and the gas phase heat transfer

Answer 34

mickley’s equation

Question 35

limiting flow rates of liquid and gas based on the equilibrium conditions may be obtained from

Answer 35

slope of operating line when it intersects equilibrium curve at the enthalpy temperature diagram