Cyclone and Dryer Liner Upgrades

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Cyclone and DryerLiner Upgrades

• Dennis Todd
• President, Wear-Concepts, Inc

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• Introduction
• Granulated blast furnace grinding system in
  Midwest U.S.
• Had been online 6 months, OEM material in dryer
  shaft and cyclone showed constant wear and
  needed continual repair during first year of
  operation
• In 2002 system required liner replacements and
  repairs were requested

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• Flash Dryerand Shaft
• Design Polysius
• Year of Manufacture 2001
• Nominal Diameter 1200 mm
• Height 25700 mm
• Feed moisture content max 12
• Residual moisture content 2.5 4
• Throughput Rate 77 t/h
• Collecting System Cyclone

Figure 1. Portion of unit
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Flash Dryer
Figure 2. Upper Duct
Figure 3. Lower Duct
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• High-Efficiency Cyclone
• Polysius
• Unit upstream of cyclone flash dryer
• Dimensions 7740 mm
• Nominal Diameter of Cyclone 3310 mm
• Diameter of Dip Pipe 1740 mm
• Length of Dip Pipe 1895 mm

Figure 4. Polysius High-Efficiency Cyclone
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Problem Overview
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Figure 5. OEM Refractorylining wear
Figure 6. OEM original wearback after 3 months

• At one point, 50 of liner was missing
• Large scale system handled a velocity of 18 22
  m/s up the shaft
• Numerous repairs had been attempted
• Any new solution needed to greatly reduce
  downtime

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The Challenge
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• Wear-Concepts and customer jointly agreed that
  old lining would need to be completely removed
• Dryer shaft stood 7 stories tall and inside main
  body of dryer shaft was only 1.21 meters feet
  wide
• Only three week window in January to repair with
  average outside temperature of only -12 C

Figure 7. Major wear throughout.
Figure 8. Inside dryer shaft.
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The Solution
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• Wear-Concepts has extensive experience with wear
  problems and had upgraded similar slag
  grinding system one year earlier
• Factors to consider outside temps temperature
  differences in dryer shaft (275 C at bottom
  of shaft and 65 C in cyclone) velocity of
  material flow up the shaft and at upper elbow.
• Turn-key solution would require complete
  tear-out of all existing lining material and
  hex expanded material underneath.
• Full install of Wear-Con WC90 alumina weldable
  ceramic tiles throughout vertical portion of
  dryer shaft and major wear areas of cyclone
• Elbow at top of shaft 1 (2.54 cm) thick WC700
  Chrome Carbide

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The Task
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• Scaffolding was constructed to move workers
  through the narrow, 7 story shaft
• Old liner and expanded hex material had to be
  air- hammered and chiseled out

Figure 9. Original liner and expanded metal
removal
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Finally, surface of the walls had to be ground
smooth, then cleaned so that proper adhesion
could be attained
Figure 10. View downdryer shaft
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• Each new brick was spot-welded to the wall and
  a ceramic cap was inserted into the weld hole.
• The cap was then sealed with Premium Grade
  High- Temperature sealant, as were all edges
  and joints.

Figure 11. View oftiled shaft
Figure 12. View of access door in shaft
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Impact zone of elbow received 1 (2.54 cm) thick
custom engineered WC700 Chrome Carbide. Liner
designed into three separate removable wear backs
for ease of installation in high- impact zone
Figure 14. Close up of WC700 Liner
Figure 13. Exterior view of WC700 Liner
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The crew then lined the large cylindrical-shaped
cyclone which measured approximately 3310 mm
across and 7240 mm in height
Figure 15. View of inside cyclone
Figure 16. View of cone sectionof cyclone
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All work was completed safely, within budget and
two days ahead of schedule, despite bitter
weather conditions.
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Follow UpImprovementsAug 03 to present
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August 2003

• Original liner in feed inlet chute to flash
  dryer wore out in summer of 2003
• WC90 Ceramic Liner installed in bottom and
  sides to improve service life

Figures 18. Exterior view offeed inlet chute
Figures 17. WC90 lining andfeed inlet chute
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1-1/4 (3.175 cm) brickinstalled - May 2004

• 1-1/4 (3.175 cm) Brick was installed due to
  fine particle abrasion. Gap filled in.

Figures 19. Gap in upper corner
Figures 20. Gap repaired
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2 (5.08 cm) Brick on WearBack - December 2004

• For added life, 2 (5.08 cm) WC90 Ceramic
  brick was installed to replace portions of 1
  (2.54 cm) WC700 Chrome Carbide

Figures 21-22. 2 Brick on one section of Wear
Back
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Dip Tube RepairedJanuary 2005

• New Dip Tube was lined inside and out with ½
  (1.27 cm) WC90 Ceramic Brick

Figures 23-24. Dip Tube lined
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2 (5.08 cm) Brick on Cyclonewall - June 2005

• New isolated wear required installation of 2
  (5.08 cm) WC90 Ceramic brick on sections of
  cyclone wall

Figures 25-26. 2 (5.08 cm) Brick on Cyclone wall
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• Original manufacturers warranty was 1 year. Only
  provided about 6 months of service life.
• Our lining was warranted for 2 years, but lasted
  3 years
• Production at plant has increased 200
• Six times the service life over OEM designed
  lining.

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Cyclone and DryerLiner Upgrades

• Dennis Todd
• President, Wear-Concepts, Inc

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• This concludes the presentation.
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