Round Filters in Dust Collection Baghouses and Cartridge Collectors

Todd Hensley, CAFS

Trenton, SC

Overview

ï Pollution Control

ï Collectors

ï Filters

ï Baghouse Conversions

Purpose of Pollution Control Comply - Collect - Protect

ï COMPLY with Regulations

ñ EPA and OSHA

ï COLLECT Product

ï PROTECT Resources

ñ Equipment and Occupants

Pollution Control Components

ï Pickup Points

ñ Emission Source

ï Ductwork

ï Dust Collector

ï Removal System

ï Air Mover / Fan

ï Exhaust / Stack

Pollution Control Components

ï Pickup Points

ñ Emission Source

ï Ductwork

ï Dust Collector

ï Removal System

ï Air Mover / Fan

ï Exhaust / Stack

Pollution Control Components

ï Dust Collectors

ñ 0.1 to 100 gr/cfm

ï Air Filters

ñ 0.001 gr/cfm

ï Source

ñ Industrial Ventilation ï www.ACGIH.org

ï 25th Edition, 2004

ï $100

ï Dust Collector Types

ñ Electrostatic Precipitators (ESP)

ñ Wet Collectors

ñ Dry Centrifugal

ñ Fabric Collectors

Fabric Collectors

ï Baghouse

ñ Shaker - Cleans Off Line

ñ Reverse Air - Cleans On Line

ñ Pulse Jet - Cleans On Line

Fabric Collectors

ï Baghouse

ñ Shaker - Cleans Off Line

ñ Reverse Air - Cleans On Line

ñ Pulse Jet - Cleans On Line

ï Cartridge Collector

ñ Up flow

ñ Cross flow / Up flow

ñ Down flow / Parallel flow

Pulse Jet Components

ï Inlet Distribution

ï Hopper

ï Housing

ï Tubesheet

ï Plenum

ï Cleaning System

ñ Blow Pipe / Others

ñ Venturi

Cartridge Collector Components

ï Inlet Distribution

ï Hopper

ï Housing

ï Tubesheet

ï Plenum

ï Cleaning System

Collector Considerations

ï Air Properties

ñ Air Flow

ñ Temperature

ñ Moisture

ñ Explosivity

ñ Chemistry

ï Dust Properties

ñ Particle Size / Shape

ñ Grain Load

ï Space Constraints

ñ Footprint

ñ Height

ï Capital Cost

ï Operating Costs

ñ Media

ñ Compressed Air

ñ Energy / DP

ï AIR TO CLOTH

Collector Considerations

ï Air Velocity

ñ Inlet Velocity

ñ Can Velocity

ñ Interstitial Velocity

ñ Media Velocity

ï Air to Cloth / A:C

ï Bags 4 to 8 fpm

ï Pleated 2 to 6 fpm

Inlet Duct = 12î Round = 0.8 SF Inlet Velocity = 3000 CFM / 0.8 SF = 3750 FPM

Collector Considerations

ï Air Velocity

ñ Inlet Velocity

ñ Can Velocity

ñ Interstitial Velocity

ñ Media Velocity

Collector Considerations

ï Air Velocity

ñ Inlet Velocity

ñ Can Velocity

ñ Interstitial Velocity

ñ Media Velocity

11.1 Sq Feet 40î

40î

Can Velocity = 3000 CFM / 11.1 SF = 270 FPM

Collector Considerations

ï Air Velocity

ñ Inlet Velocity

ñ Can Velocity

ñ Interstitial Velocity

ñ Media Velocity

40î

40î

Bag Bottom Area = Qty * p * Radius2

= 25 * 3.14 * (3î)2 = 4.9 Sq Feet Interstitial Area = 11.1 - 4.9 Sq Feet = 6.2 Sq Feet

Interstitial Velocity = 3000 / 6.2 = 480 FPM Interstitial = 1.8x Can Velocity

Collector Considerations

ï Air Velocity

ñ Inlet Velocity

ñ Can Velocity

ñ Interstitial Velocity

ñ Media Velocity

40î

40î

Bag Area = Qty * p * Diameter * Length

= 25 * 3.14 * 6î * 120î = 393 Sq Feet

Media Velocity = 3000 / 393 = 7.6 FPM

Collector Considerations

ï Air Velocity

ñ Inlet Velocity 3750 FPM

ñ Can Velocity 270 FPM

ñ Interstitial Velocity 480 FPM

ñ Media Velocity 7.6 FPM

Collector Considerations

ï Baghouses

ñ Can Change ï Media Type

ï Media Area

ï Filter Type

ï Length

ñ Cannot Change ï Tubesheet Hole

ï Cartridge Collectors

ñ Can Change ï Media Type

ï Media Area

ï Materials

ñ Cannot Change ï Envelope Size

ï Cap Design

Filter Considerations Bag Fabric

ï Felted Fiber

ñ Polypropylene PP

ñ Polyester PET

ñ Aramid Nomex

ñ Polyphenylene Sulfide PPS

ñ Polyimide P84

ñ Fiberglass

ï Basis Weight oz / sq yd

ï Finish

ñ Singed / Glazed

ñ Metallized

ñ Epitropic

ñ HydroOleophobic

ñ Membrane

ï Support

ñ Fiber

ñ Scrim

Filter Considerations Fiber Properties

Filter Considerations Pleated Bag

ï Fabric

ñ Spunbond Polyester ï Epitropic / Metallized

ï HydroOleophobic

ï Membrane

ñ Pleatable Felts ï Membrane

ñ Area ï Pleat Count / Height

ï Limited Length

ï Felt Thickness

ï Construction

ñ Installation ï Top Load

ï Bottom Load

ï Tubesheet Seal

ñ Materials ï Potting Compounds

ï Core

ñ Retainer ï Bands

Filter Considerations Cartridge

ï Fabric

ñ Spunbond Polyester ï Epitropic / Metallized

ï HydroOleophobic

ï Membrane

ñ Pleatable Felts ï Membrane

ñ Area ï Pleat Count / Height

ï Limited Length

ï Felt Thickness

ï Construction

ñ Installation ï Open / Open

ï Open / Closed

ï Flanged Cap

ñ Materials ï Potting Compounds

ï Core

ñ Retainer ï Bands

ï Cage

Baghouse Conversion

ï Original with 3000 CFM

ñ 25 PET Felt Bags

ñ 6î OD x 120î OAL

ñ Fabric 393 SF

ñ Inlet 3750 CFM

ñ Interstitial 480 FPM

ñ Media 7.6 FPM

ñ Problems ï High Pressure Drop

ï Bag Wear

Baghouse Conversion

ï Original

ñ 25 Bags

ñ 6î OD x 120î OAL

ñ 393 Sq Feet

ï Pleated Bags

ñ 6î OD x 72î OAL ï 45 Pleats at 1î

ñ 1,078 Sq Feet ï 175% more fabric

Baghouse Conversion

ï Original

ñ 25 Bags

ñ 6î OD x 120î OAL

ñ 393 Sq Feet

ï Pleated Bags

ñ 6î OD x 72î OAL ï 45 Pleats at 1î

ñ 1,078 Sq Feet ï 175% more fabric

ï Replace all of the bags

ñ Lower Air to Cloth ï From 7.6 to 2.8 FPM

ñ Gain Efficiency ï Better Media

ï Lower A:C

ñ Lower Pressure Drop ï Better Pulse Cleaning

ñ Drop Out Zone Adds 4í

Baghouse Conversion

ï Replace 10 and Plug 15

ñ Lower Air to Cloth ï From 7.6 to 7.0 FPM

ñ Gain Efficiency ï Better Media

ï Lower A:C

ñ Cut Interstitial Velocity ï From 480 to 330 FPM

ñ Drop Out Zone adds 4í

Questions