Humidification Flashcards

1
Q

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.

A

humidification

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2
Q

humidification operation may also be classified as

A

dehumidification, air conditioning and water cooling

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3
Q

The operation involves two components and two phases.

A

phase equilibria

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4
Q

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

A

two

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5
Q

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

A

Absolute Humidity

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6
Q

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

A

Absolute humidity

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7
Q

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

A

Relative Humidity

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8
Q

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

A

Relative Humidity

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9
Q

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

A

Vapor pressure

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10
Q

Ratio of absolute humidity and Saturation humidity is equal to the

A

percentage saturation or percentage humidity

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11
Q

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

A

humid volume

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12
Q

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

A

Saturated Volume

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13
Q

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

A

Humid Heat

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14
Q

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

A

Enthalpy of Mixture

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15
Q

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

A

Adiabatic Saturation Temperature

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16
Q

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

A

Wet bulb temperature

17
Q

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

A

adiabatic saturation temperature

18
Q

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

19
Q

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

A

humidity chart

20
Q

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

A

adiabatic humidification

21
Q

the air undergoes a non-adiabatic humidification

A

water cooling

22
Q

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

A

Merkel’s Equation

23
Q

for water cooling, the Hg is

A

height of a transfer unit (HTU)

24
Q

for water cooling, the Ng is

A

number of transfer units (NTU)

25
consists of the enthalpy of air at saturation based on the temperature of water
equilibrium curve
26
equal to the internal energy of the system plus the product of pressure and volume.
enthalpy
27
in humidification, ploting of the operating line is generated using the
enthalpy balance
28
in humidification, the slope of operating line is
L/w
29
obtained by dividing enthalpy transfer equation by the liquid phase heat transfer equation
slope of the tie line
30
if the operating line and equilibrium curve are linear, Ng (Number transfer of unit) can be evaluated by
logarithmic mean driving force
31
if the resistance to heat transfer in the liq phase can be neglected
the slope of tie line becomes infinite
32
for dehumidification and air conditioning
in ref to the humidification: - similar equation - reversed limit - operating line is above the equilibrium curve
33
Mickley's graphical method can be used to determine the
temperature profile
34
plotting of the differential equation obtained from the enthalpy transfer equation and the gas phase heat transfer
mickley's equation
35
limiting flow rates of liquid and gas based on the equilibrium conditions may be obtained from
slope of operating line when it intersects equilibrium curve at the enthalpy temperature diagram