Dust CollectorsBaghouses and Cartridge Collectors

Overview

• Dust Collection

• Collectors

• Fabric Filters

• Trends

Grain Loading

Industrial• 0.1 to 100 grains / ft3

– 100 to 100,000 times

• 5 grains / ft3

• 2,000 CFM for 365 days

• 750,857 lbs• 150 lbs in < 2 hours

HVAC• 0.001 grains / ft3

• 2,000 CFM for 365 days• 150 lbs

• Industrial Ventilation– www.ACGIH.org– Design, 28th Edition, $ 140

Media Velocity

Industrial• Filter Rate / Air to Cloth

– 5 FPM– 0.06 mph

– 1 hour to walk a football field

HVAC• 2,000 CFM through…

– 32 ft2 Pleat > 60 FPM– 100 ft2 Box 20 FPM– 200 ft2 HEPA 10 FPM

Purpose of Pollution Control

Comply - Collect - Protect

• COMPLY with Regulations– EPA and OSHA

• COLLECT Product

• PROTECT Resources– Equipment and Occupants

Three C’s of Pollution Control

•Capture

•Convey

•Collect

Pollution Control System

• Pickup Points– Emission Source

• Ductwork• Dust Collector• Removal System• Fan• Exhaust / Return

Pollution Control Components

• Pickup Points– Emission Source

• Ductwork• Dust Collector• Removal System• Fan• Exhaust / Return

Pollution Control Components

• Dust Collector Types– Electrostatic Precipitators (ESP)– Wet Collectors– Dry Centrifugal– Fabric Collectors

Pollution Control Components

• Dust Collector Types– Electrostatic Precipitators (ESP)– Wet Collectors– Dry Centrifugal– Fabric Collectors

Fabric Collectors

• Baghouse– Shaker - Cleans Off

Line– Reverse Air - Cleans Off

Line– Pulse Jet - Cleans On

Line

Fabric Collectors

• Baghouse– Shaker - Cleans Off

Line– Reverse Air - Cleans On

Line– Pulse Jet - Cleans On

Line

Fabric Collectors

• Baghouse– Shaker - Cleans Off Line– Reverse Air - Cleans On

Line– Pulse Jet - Cleans On Line

• Cartridge Collector– Up flow– Cross flow– Down flow / Parallel flow

Fabric Collectors

• Baghouse– Shaker - Cleans Off Line– Reverse Air - Cleans On

Line– Pulse Jet - Cleans On Line

• Cartridge Collector– Up flow– Cross flow– Down flow / Parallel flow

Pulse Jet Components

• Inlet Distribution (1)• Hopper• Housing (2)• Plenum (3)• Tubesheet (4)• Cleaning System

– Header– Blow Pipe– Venturi

Cartridge Collector Components

• Inlet Distribution• Housing• Hopper• Tubesheet• Plenum• Cleaning System

Collector Considerations

• Process Conditions– Temperature– Pressure– Moisture– Chemistry– Grain Load

• Dust Properties– Particle Size– Particle Shape– Explosivity / Flamability– Agglomeration– Abrasive

• Space Constraints– Footprint– Height

• Capital Cost• Operating Costs

– Media– Compressed Air– Energy / P

• AIR FLOW

FiberTensil

e

Abrasion

Resist

AcidResist

Alkali Resist

BurnsTemp

F (Cont)

Temp F (Surge

)

Cotton Good Good Poor Good Yes 180 200

Polypropylene Excellent Excellent Excellent Excellent Yes 170 200

Nylon Excellent Excellent Poor Excellent Yes 200 250

Wool Poor Fair Good Poor No 200 230

HomopolymerAcrylic

Good GoodVery Good

Fair Yes 260 284

CopolymerAcrylic

Average Fair Good Fair Yes 230 248

PolyesterExcelle

ntExcellen

tFair Fair Yes 275 300

AramidVery Good

Excellent Fair Good No 375 425

PTFE Average Fair Excellent Excellent No 450 500

Glass Excellent Fair Good Fair No 500 550

RytonVery Good

Excellent ExcellentVery Good

No 375 425

P84Very Good

ExcellentVery Good

Fair No 500? 550?

Collector Considerations

• Air Velocities– Inlet

– Can / Interstitial

– Media / ACR• Bags

4 to 8 fpm• Pleated

2 to 6 fpm

Example Application

1,880 CFM through 10” line to Model 25S(6)-10

4” Line0.09 ft2

350 CFM

6” Line0.20 ft2

785 CFM

5” Line0.14 ft2

545 CFM

3” Line0.05 ft2

200 CFM

1,880 CFM0.47 ft2

10” Line at 3,450 FPM9” Line at 4,260 FPM

Inlet Duct = 11” Round = 0.66 ft2

Inlet Velocity = 1,880 CFM / 0.66 ft2 = 2,850 FPM

Collector Considerations

• Air Velocities– Inlet

– Can / Interstitial

– Media / ACR

Collector Considerations

• Air Velocities– Inlet

– Can / Interstitial

– Media / ACR

Collector Considerations

Collector Considerations

• Air Velocities– Inlet

– Can / Interstitial

– Media / ACR

12.25 ft242”

42”

Can Velocity = 1,880 CFM / 12.25 ft2 = 155 FPM

Collector Considerations

• Air Velocities– Inlet

– Can / Interstitial

– Media / ACR

42”

42”

Bag Bottom Area = Qty * * Radius2

= 25 * 3.14 * (3”)2

= 4.9 ft2

Interstitial Area = 12.25 - 4.9 ft2

= 7.35 ft2

Interstitial Velocity = 1,880 / 7.35 = 255 FPMInterstitial = 255 / 155 = 1.6 x Can Velocity

Collector Considerations

• Air Velocities– Inlet

– Can / Interstitial

– Media / ACR

Collector Considerations

• Air Velocities– Inlet

– Can / Interstitial

– Media / ACR Bag Area = Qty * * Diameter * Length = 25 * 3.14 * 6” * 120” = 393 ft2

Media Velocity = 1,880/ 393 = 4.8 FPM

Collector Considerations

• Air Velocities– Inlet 2,850 FPM– Can 155 FPM– Interstitial 255 FPM– Media / ACR 4.8 FPM– Exhaust 2,500 FPM

Trends

• New Equipment– High inlets– ePTFE membrane fabric– Pleated filters– Multi-module for off-line cleaning and on-line

maintenance

• Baghouse Modifications– NFPA compliance– ESP / Shaker / Reverse Air conversions to Pulse Jet– Pleat conversions