Air Pollution Control – Design Considerations:. General Objectives:. Background for equipment design To be conversant with equipment manufacturers Understand expectations for normal operation . Specific objectives & expectations:.
A single collection system will process a total gas flow rate, Qf (m3/s), and particulate loading, mP(g/s). It will be characterized by a collection efficiency,(mass fraction-weighted for all particle sizes), and pressure drop,Pf.
If a single system does not give adequate collection efficiency, we may use systems in series:
When pressure drop considerations are important, the inlet flow stream can be split into parallel streams. Since Pf ~(Qf)2, this can lead to substantial cost savings.
Increased efficiency can be realized when the collection efficiency increases with lower gas flow rates through the units (true for most collection devices except cyclones)
A combination of series and parallel arrangements might be used to give optimum collection efficiency and pressure drop. This method often involves components of the same type of collection device (or elements of the same type of device). The parallel lines can be turned off (or isolated) in a regular timed sequence for periodic cleaning (baghouse filtration units) or routine maintenance.
Relies on the terminal velocity of a particle to settle out of a gas stream …
A conventional design based on flow cross section expansion and dust collection hoppers.