Non-condensable gases, or NCGs, are a by-product of the kraft pulping process. NCGs are toxic, foul-smelling and potentially explosive. In the distant past, these gases were largely discharged directly to the atmosphere. This is no longer allowed. The purpose of an NCG system is to collect, condition, and safely deliver these gases to a location within the mill where they are disposed of by incineration. This module will focus primarily on the DNCG type collection system. Dilute systems are also referred to as high volume low concentration (HVLC) systems.
Learning Objectives
At the end of this module, you will be able to:
- State the purpose of an HVLC system
- Describe the makeup of a typical dilute non- condensable gas stream
- Differentiate between the two methods used to safely convey NCGs
- Identify and describe the major equipment and components of an HVLC system
- List the conditions needed for incineration of NCGs
- List the possible NCG incineration locations within a mill
- Identify and describe safety hazards and safety design features of an HVLC system