Stack Monitoring Calculation : A Comprehensive Guide

In order to better understand the calculation procedure, user must be familiar with the basic terms and glossary provided on this page:

1. Stack Emissions:

   • Definition: The release of pollutants into the atmosphere from an industrial stack or chimney.

2. Particulate Matter (PM):

   • Definition: Tiny particles of solid or liquid matter present in the air, emitted during combustion or industrial processes.

3. Gas Sampling Train:

   • Definition: A system designed to extract and collect representative samples of stack emissions for analysis.

4. Diluent Gas:

   • Definition: A gas used to dilute stack emissions during sampling, often nitrogen or air, to facilitate accurate measurement.

5. Sampling Probe:

   • Definition: A device inserted into a stack to collect samples of the gas emissions for analysis.

6. Isokinetic Sampling:

   • Definition: A sampling method where the velocity of the gas entering the sampling probe is equal to that of the surrounding stack gases.

7. Gas Analyzers:

   • Definition: Instruments used to measure the concentration of specific gases in stack emissions.

8. Continuous Emission Monitoring Systems (CEMS):

   • Definition: Automated systems that continuously measure and record emissions from industrial stacks.

9. Opacity:

   • Definition: The degree to which emissions obscure the passage of light, often measured to assess the density of particulate matter.

10. Calibration Gas:

    • Definition: A known concentration of gases used to calibrate monitoring instruments for accuracy.

11. Reference Method:

    • Definition: An established and standardized procedure for conducting stack emission measurements, as specified by regulatory bodies.

12. Data Logger:

    • Definition: An electronic device that records and stores data from monitoring instruments over a specific period.

13. Quality Assurance/Quality Control (QA/QC):

    • Definition: Procedures and measures implemented to ensure the reliability and accuracy of monitoring data.

14. Zero Gas:

    • Definition: A gas with zero concentration of the target pollutant, used for baseline calibration of monitoring instruments.

15. Relative Accuracy Test Audit (RATA):

    • Definition: A periodic assessment to verify the accuracy of a continuous emissions monitoring system by comparing its readings with a reference method.

16. Particulate Sampling:

    • Definition: The process of collecting and analyzing particulate matter from stack emissions using specialized sampling equipment.

17. Audit Trail:

    • Definition: A record of all activities, calibrations, and adjustments made to monitoring instruments to ensure transparency and traceability.

18. Pollutant Specific Monitoring:

    • Definition: Monitoring procedures tailored to measure specific pollutants emitted from stacks, such as sulfur dioxide (SO2) or nitrogen oxides (NOx).

19. Dioxins and Furans:

    • Definition: Toxic compounds often monitored due to their harmful environmental and health effects, commonly emitted from combustion processes.

20. Compliance Monitoring:

    • Definition: The systematic assessment of stack emissions to ensure adherence to environmental regulations and standards.

21. What is a Stack?

    A stack, essentially a chimney, serves the purpose of expelling hot air, emissions, and particulate matter to significant heights. This dispersal occurs from various types of stacks such as those associated with boilers, flue gas systems, and more. By releasing pollutants at elevated heights, the contaminated air spreads across a vast area, ensuring that concentrations at ground level remain within permissible limits, posing no harm to humans, animals, or vegetation.

    Various types of flue-gas stacks exist, distinguished by the type of fuel injection they handle. Examples include DG set stacks, flue gas stacks, process stacks, furnace stacks, boiler stacks, chimneys, and others. Each plays a specific role in expelling emissions, contributing to environmental protection and maintaining air quality standards.

22. What is Stack Velocity?

    The velocity of emissions from a stack is influenced by various factors, including the design of the stack, the temperature of the emitted gases, and the velocity of the gas within the stack. Understanding stack velocity is important in assessing the dispersion of pollutants in the air. It plays a significant role in determining how pollutants will be transported and diluted in the atmosphere, affecting their concentration levels at ground level.

    Stack velocity is often considered in regulatory frameworks and environmental impact assessments to ensure that emissions disperse effectively and do not pose a threat to air quality or human health. Monitoring and controlling stack velocity are essential components of efforts to manage and mitigate the environmental impact of industrial emissions.

23. Stack velocity refers to the speed at which gases or air pollutants are expelled from an industrial stack or chimney into the atmosphere. It is a crucial parameter in air quality monitoring and environmental assessments. Stack velocity is typically measured in units such as meters per second (m/s) or feet per minute (ft/min).

This stack monitoring glossary provides key terms and their definitions to enhance understanding in the field of air quality assessment and environmental compliance.