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Module 4: Liquid Characteristics
This Module discusses some characteristics and properties of liquids that play an important role in air pollution control and emission testing. Some of the situations where this knowledge is used are listed below.
- Cooling hot gas streams in evaporative
cooling towers and condensers
- Using liquids as a tool in air pollution control systems to remove
gaseous and particulate emissions from gas streams
- Condensing vapor to a liquid or solid state by use of condensers
and evaporative cooling towers
- Understanding the behavior of liquid droplets in the atmosphere
- Treatment of liquid waste from control equipment
- Using various types of liquids in air emission sampling trains for determining the amount of specific emissions in the gas stream
A wet scrubber system illustrates the various situations listed above where liquids are commonly used in the field of air pollution control.
This Module emphasizes: (1) the physical properties of liquids such as density, viscosity, and pH, (2) the capacity of water to cool hot gas streams, and (3) the mass transfer between soluble gases and liquids.
After completing this Module you will be able to do the following:
- Describe the properties of the four different types of liquids that
are commonly encountered in air pollution control systems and emission
sampling.
- Determine the density, pH and specific gravity of a liquid.
- Calculate the concentration of solutions on a parts per million,
milligram per liter, molar, and normal basis.
- Explain how temperature affects liquid viscosity and how liquid viscosity
can affect some important processes in air pollution control.
- Calculate the concentration of a gas in equilibrium with the liquid
phase using the vapor pressure.
- Determine the amount of water necessary to cool a gas stream to a
desired temperature by calculating the change in enthalpy.
- Identify the normal operating pH range for air pollution control
systems.
- Explain the factors that affect the absorption of gases into the
liquid phase.
- Using solubility data at a specific temperature, determine the Henry's law constant for a substance that is slightly soluble in a liquid.