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Module 2: Characteristics of Gases
The characteristics of gases influence virtually every aspect of air pollution control including ambient monitoring, emission measurement, and engineering. In this Module, you will be introduced to the ideal gas law and to gas flow rates and velocity. This Module also presents the numerous ways of expressing concentrations of constituents in the gas stream. Gas density and gas viscosity at different gas temperatures are also covered.
After completing this Module you will be able to do the following:
- Use the ideal gas law to determine gas volumes and gas flow rates
at different absolute temperatures and absolute pressures.
- Convert gas flow rates between actual and standard conditions and
between a wet and dry basis.
- Calculate the concentration of gaseous pollutants in different units
of measurement and represent that concentration on either a wet or dry
basis and at either a measured or standard oxygen level.
- Calculate the concentration of dioxin-furan compounds in units of
nanograms per cubic meter and Toxic Equivalency Quotient (TEQ) nanograms
per cubic meter.
- Calculate the gas velocity based on the gas flow rate and cross-sectional
area and calculate the average gas velocity in a duct based on the measured
velocity pressure.
- Calculate the treatment time and space velocity of a gas stream in
an air pollution control device.
- Determine the gas density as a function of the absolute gas temperature.
- Determine the change in enthalpy of a gas stream when it changes
temperature.
- Determine the gas viscosity as a function of the absolute temperature
and the oxygen and water vapor concentrations.
- Determine if the gas stream is laminar, transitional, or turbulent based on the calculated Reynolds Number of the gas stream.