Introduction to Baghouse / Fabric Filters: Design Criteria
Ideal air-to-cloth ratios for fabric filters:
- Reverse Gas 1.75:1 “ 2.50:1
- Pulse Jet 3.25:1 “ 4.00:1
- Shaker 2.0:1 “ 2.50:1
P/J System Recommendations
- High and hi-hi hopper level indicators
- Vacuum breaks for top access door
- Inlet injection ports for pre-coat and leak dye
- Lay-down area for bags and cage storage
- Redundant compressed air systems
- Quality compressed air dryers
P/J Can Velocity
- Air volume
- Compartment area (LxW = ft2, measured at bottom of bags
- Bag area (# of bags x area of bag bottom = ft2)
- Open area (collector area “ bag bottom area)
- Can velocity = (air volume ÷ open area)
- Typical P/J can velocity: 200-400 feet per min
R/A System Recommendations
- Quality isolation dampers and actuators (poppet type)
- High and hi-hi hopper level indicators
- Vacuum breaks for top access door
- Inlet injection ports for pre-coat and leak dye
- Lay-down area for bags and cage storage
- Redundant reverse air fans
- Reverse air recirculation system
- Piping for acoustic horns even if not initially installed
Instrumentation Functions
- Differential pressure for entire baghouse and individual compartments
- Inlet and outlet temperature (dew points)
- Emission monitoring for individual compartments (broken bag detectors)
- Reverse gas temperature and pressure
- Compressed air PSI, temp, and flow rate
- Damper positions
- Acoustic horn sounding time and PSI
- High and hi-hi hopper level indicators
- Filter bag permeability tester
Helpful Resources
KnowledgeBase: Baghouse Design Factors
KnowledgeBase: Common Baghouse Misconceptions
KnowledgeBase: Types of Fabric Filters
Our Capabilities: Asset Lifecycle Management
