1. BAGHOUSE 101 TRAINING
Presented by:
March 10, 2005

2. Baghouse 101 Outline Overview Design Fabric Types Shaker Baghouse
Reverse Air Baghouse
Pulse Jet Baghouse
R & D

3. OVERVIEW

4. Why Do We Need A Baghouse
Recover useable product
Keep plant clean and workers safe
Comply with state and federal regulations

5. Typical System Components
Emission Source
Pickup Points
Ductwork
Collection Equipment
Baghouse
Air Mover
Fan

6. Types of Dust Collection
SETTLING: dust settles on surfaces.
CYCLONE: cyclone is utilized to capture larger particles
ELECTROSTATIC PRECIPITATORS: positively charged particles become negatively charged for release.
WET SCRUBBERS: mix water with dust, dust settles in a pond and is drawn back into the system.
BAGHOUSES: dust collection method gathers dust on a piece of filter media and then it is removed from the material by air, or mechanical shaker.

7. Components of a Baghouse
Hopper
Housing
Tubesheet
Plenum

8. 3 Types of Baghouses Shaker Baghouse Reverse Air Baghouse
Pulse Jet Baghouse

9. Shaker Baghouse The first and oldest cleaning style
Utilizes mechanically driven devices to “shake” the filter bag
Particulate collects on the inside surface of the filter bag

10. Reverse Air Baghouse The second and next oldest cleaning style
Utilizes a system of reversing air flow through the filter bag to create a “back washing” effect on the particulate, changing the filter bag surface contour, and releasing the collected particulate.
Particulate collects on the inside surface of the filter bag

11. Pulse Jet Baghouse The third and newest cleaning style
Differs drastically from both the shaker and reverse air baghouse
Utilizes a powerful, short blast of compressed air in a reverse direction
Particulate collects on the outside surface of the filter bag

12. BAGHOUSE DESIGN

13. Baghouse Design Inlet Velocity Can Velocity Inlet Grain Loading
Inlet Temperature
Outlet Emissions
Inlet Grain Loading
Air-to-cloth Ratio
Differential Pressure (P)
Fabric Selection and Efficiency

14. Inlet Grain Load 0.1 to 5.0 grains/ft3 = Light
6.0 to 15.0 grains/ft3 = Medium
16.0 to 30.0 grains/ft3 = Heavy
1.0 Grain = 1/7000 LB

15. Air-to-Cloth Ratio Shaker: 1.5:1 to 3.0:1 Reverse Air: 1.5:1 to 2.5:1
Pulsejet: 4.0:1 to 8.0:1

16. Differential Pressure
Differential pressure (P) not to exceed 6” static pressure water gauge (S.P.W.G).
Magnehelic gauge/manometer used for monitoring differential pressure
Magnehelic gauge

17. Fabric Selection Operating temperature Abrasion resistance
Collection efficiency
Chemical make-up of gas stream
Dust loading
Air-to-cloth ratio
Cleaning method

18. Air Flow Volume (CFM) Temperature Inlet velocity (3000 FPM or less)
Can velocity (300 FPM or less)

19. Outlet Emissions Location dependent Application dependent
Media dependent
Regulatory impact

20. MEDIA TYPES

21. Media Types Natural Fibers Synthetic Fibers – Most Widely Used Cotton
Wool
Paper
Synthetic Fibers – Most Widely Used
Woven
Felts

22. Fabric Selection Chart

23. Fabric Finishes

24. SHAKER BAGHOUSE

25. 3 Basic Styles of Shaking Action
Horizontal Shake
Tube Shake
Cradle Shake

26. Shaker Cleaning

27. REVERSE AIR BAGHOUSE

28. Components of a Reverse Baghouse

29. Reverse Air Cleaning Cycle
Close the outlet or poppet damper
Provide a period of “null” period to provide for settling of particulate
Open reverse air poppet valve to allow reversed air flow to “backwash” through the fabric filters
Close reverse air poppet valve, allowing a “null” period to all for settling of particulate
Open outlet or poppet damper
Compartment is brought back “on-line”

30. Reverse Air Cleaning

31. Points of Inspection Hanging structure Tensioning hardware
Failure due to weight and elevated temperatures
Chemical reaction will also deteriorate hanging hardware
Filter caps may contain corrosion
Clamps and fasteners usually cannot be used safely more than once

32. Points of Inspection Condition of thimbles
Corrosion
Particulate build-up
Broken welds
Cell plate for broken welds, corroded leakage
Exterior door seals
Biggest cause of compartment corrosion and collection efficiency

33. Points of Inspection Hopper evacuation equipment
Hopper screws, rotary airlock valves, dump valves
Magnehelic gauges. All lines should be cleared and cleaned before gauges are inspected
Particulate removed from the hopper

34. Filter Bag Installation
Cell plates should be carefully cleaned
Thimbles should be brushed to remove particulate build-up
Cell plates without thimbles should be carefully swept and holes brushed clean of particulate build-up

35. Filter Bag Installation (cont)
Filter bags should be located in boxes, nearest the locations that they are to be installed. Beginning should be furthest from the compartment entry and furthest from any provided walkways
Install hanging hardware prior to installing filters
Attach filter bags at the top first, leaving the bottom of the filters to remain loose.

36. Filter Bag Installation (cont)
Install bottom of filter bags
Seams of each filter bag should face the walkway that serves that row of filters
Check that seams are not twisted
Tension filter bag

37. Installing Bag On Thimble
STEP 1
STEP 2
STEP 3
INSTALL ONE SIDE OF BEADED
CUFF OF BAG OVER THIMBLE BEAD
INSTALL OTHER SIDE OF BEADED
CUFF OF BAG OVER THIMBLE BEAD
INSTALL CLAMP ABOVE BEADED
CUFF OF BAG JUST UNDER THIMBLE BEAD
IMPROPER
IMPROPER
IMPROPER

38. Proper Tensioning Typical Filter Bag Tension 5” diameter 35 lbs.
11.5” diameter 50 lbs. (Polyester)
11.5” diameter 75 lbs. (Fiberglass)

39. Tension Guidelines Excessive Tension:
Results in high stress around ring covers and cuffs.
Prevents the proper flexing needed to release the dust cake.
Insufficient Tension:
Results in bag to bag abrasion.
Results in bag to structure abrasion.
Inhibits flow of dust out of bag.
Accelerates fatigue failures.

40. Operating Instructions for M-C Tensioning Tool
Instruction SHEET

41. Daily Preventive Maintenance
Walk through the baghouse area to check for normal or abnormal visual and audible conditions
Check Differential Pressure
Check the proper operation of the cleaning cycle
Monitor the evacuation system
Observe the stack for clean air particulate (opacity)

42. Weekly Preventive Maintenance
Check poppet valves for proper operation
Inspect fans/blowers for corrosion and vibration

43. Monthly Preventive Maintenance
Clean the monitoring equipment lines
Check the filter cleaning sequence to see that all poppit valves are seating properly
Check all moving parts on the evacuation system
Inspect inlet and outlet ducts for corrosion, leaks, and particulate build-up

44. Quarterly Preventative Maintenance
Calibrate all monitors, particularly the outlet (opacity) monitors

45. Yearly Preventative Maintenance
Inspect filter bags for leaks and holes
Inspect compartments for particulate build-up
Inspect hoppers for abrasion and corrosion
Inspect door and port gasketing
Inspect baghouse structural for corrosion

46. Start-Up Procedure Process air should be brought up gradually
Pre-coating fabric filters can reduce initial particulate impact and help to prevent blinding during initial process air introduction
Monitoring systems should be observed and noted

47. PULSE JET BAGHOUSE

48. Components of a Pulse Jet Baghouse

49. Pulse Jet Cleaning Cycle
Uses compressed air from air compressors
Cleaning pressures of 80 – 110 PSI
Components
Sequential timer
Solenoid valve
Diaphragm valve
Air header
Blowpipes

50. Cleaning Mechanism
Air compressors are used to develop higher pressure air
Air is distributed from the compressor storage tank to the baghouse “header” assembly via pipe plumbing
Pulse valve is attached to each of the pulse tubes and connected to the compressed air source
On command, pulse valves momentarily open and close, allowing a short blast of compressed air to enter the pulse tubes and be distributed to each filter served in that row by that pulse tube

51. Pulse Jet Cleaning

52. Clean on Demand vs. Continuous Cleaning
Cleaning system is activated when differential pressure reaches high limit set point and deactivated when differential pressure reaches low limit set point. Always keeping a consistent dustcake
Continuous Cleaning
Cleans on a specific on-time and off-time

53. Points of Inspection
Inspect cages for corrosion, damage, broken wires and areas that might abrade or cut filter surfaces
Pulse tubes and nozzle openings for blockage and corrosion
Venturis should be observed for uneven abrasion wear
Flexible tube connectors inspected for cracks, holes and leaks

54. Points of Inspection
Diaphragm valves and solenoid valves for proper operation
Timer board inspected and tested for firing sequence and pulse duration
Hopper door and plenum doors should be inspected for seal damage, wear and leaks

55. Points of Inspection
Evacuation equipment inspected to be sure hopper is continually emptied as needed
Tubesheet should be cleaned and inspected for corrosion and physical stress leaks
Inspect manometer and clean lines
Hoppers should be emptied completely and swept clean

56. Installation Procedure for Snapband Bag
Step 1: Bend the snapband into a kidney shape. Place the grooved gasket into the tubesheet hole.
Step 2: Move the snapband into place. A sharp popping noise should be noticed as the band is properly seated around the circumference of the tubesheet hole.
Step 3: Check to make sure you cannot twist the snapband and that band is securely seated with the metal tubesheet fitted into the center of the band groove.

57. Installation Procedure for Bag and Cage Assembly

58. Installation of Top Removal Blowtubes

59. Daily Preventive Maintenance
Walk through the baghouse area to check for normal or abnormal visual and audible condition
Check Differential Pressure
Check the proper operation of the cleaning cycle for both time between cycles and duration of cleaning cycle
Check compressed air and water traps on clean, pulse air system- #1 reason for cleaning problem

60. Daily Preventive Maintenance
Monitor the evacuation system
Observe the stack for clean air particulate (opacity)

61. Weekly Preventive Maintenance
Spot check for fabric filter leaks and holes

62. Monthly Preventive Maintenance
Clean the monitoring equipment lines
Check temperature indicating equipment
Check the compressed air lines and operation of “dryer” if available

63. Quarterly Preventative Maintenance
Perform a leak detection test
Calibrate all monitors, particularly the outlet (opacity) monitors

64. Yearly Preventative Maintenance
Inspect hopper and interior of compartments for corrosion and leaks
Inspect all control valves and plumbing
Inspect entire cleaning air system for moisture and corrosion contamination

65. What Not To Do When Installing Bags
Do not open carton or remove bags until they are ready to install.
Do not sit on, stand on, or walk on bags. Damage will occur that is not visible to the naked eye.
Do not drag bags over catwalks, guard rails, thimbles, or any rough surface.
Do not have hand tools or sharp instruments in pockets or pouches near bags.
Do not pull on any loose threads.
Do not stack cartons higher than five
Do not install bags you have reason to believe will fail prematurely.

66. RESEARCH & DEVELOPMENT

67. Typical Fabric Tests Tensile Test Pounds/1” of width to pull apart.
Air Permeability Test
First Bubble Point
Inches w.g. with Isopropyl alcohol  2.5 mean for paper
Mullen Burst Test
Approximately 90 (wet) psi for strong paper.
MIT Flex Test