Dean Connor Dean Connor é gerente de vendas para a área de piroprocessamento na Metso nos Estados Unidos. Com 36 anos de experiência na indústria de minério de ferro, Dean começou sua carreira como engenheiro de campo, responsável por sistemas Grate-Kiln da Allis-Chalmers. Desde 2001 tem sido responsável pela linha de produtos que inclui também o carro grelha.

1. Iron Ore Straight Grate
Pelletizing Seminar
Machine Maintenance
to improve operating conditions
October 2014

2. © Metso
Tempering
Damper
|
Simplified Grate Kiln System Flow
2
600 oF
315 oC
550 oF
290 oC
1800 oF
980 oC
700 oF
371 oC
230 oF
110 oC
230 oF
110 oC

3. Direct Recup
Header
Downcomer
Air Passage
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METSO MINERALS
Top Strand
Rails
Bottom Strand
Burners
Windbox
Double Dump
Valve
Furnace Hood
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4. Machine Alignment
Machine alignment is critical to health of the major components of the machine.
Pallets, sprockets, guide rails, and machine drive.
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5. Measure bushing axial and radial wear.
Inspect Shaft Seals
5 © Metso BMH 2007

6. Machine Shaft Alignment
1) Machine drive and idler shaft should be level at the pillow blocks within
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1/8”
2) Sprocket Teeth should be aligned perpendicular to the strand centerline
with 1/16” or less. This needs to be done with a laser for accuracy. If
teeth are worn differentially they should be replaced. Sprocket teeth
can be re-aligned using the index provision built into the one of the
sprocket hubs.
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7. Sprocket Indexing
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8. Sprocket Segment- Profile Gauge
Machine alignment guide rail and roller wear can be caused by sprocket
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wear. Use gage to determine. Wear should not be > 3/16”.
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9. Machine Alignment- Flanging
If the sprocket shaft and teeth are within acceptable limits, Pallet wheel
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flanging can be reduced by re-orientation of the pillow blocks by:
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10. Machine Alignment- Flanging
A is dimension measured to location of flanging pallet wheel from
centerline sprocket (Inches)
B is the wheel gap on opposite side of flanging wheel (Inches)
C is centerline sprocket dimension ( use 254 inches)
Amount Pillow movement= X
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X= B*C/(2 *A)
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11. Possible Causes Guide Rails to Sprocket
Misalignment
1) Transverse movement of the sprocket due to end wear of
the shaft bushings
2) Differential or excessive wear of the guide rails
3) Distorted or damaged guide rail supports
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12. Guide Rails to Sprocket Alignment
“A” should be within 1/8” 12
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13. Machine Alignment- Rails and Guide Rails
Gauge
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14. Machine Alignment- Rails and Guide Rails
Gauge
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15. Guide Rails Wear Gauge
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16. 16 © Metso

17. Tipping Wheel Assembly
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18. Tipping Wheel assemble Area
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Discharge
Sprocket
Discharge
Guide Rail
Spillage
Chute
Bearings

19. Mechanical Improvements
Tipping Wheel Shaft Seals
19 © Metso BMH 2007

20. Pallet Roller Turner
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21. Mechanical Improvements
Process Seals - Counterweighted Deadplates
21 © Metso BMH 2007

22. Counterweighted Deadplates
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Direction of Pallet Travel

23. Mechanical Improvements
One Counterweighted Deadplate
23 © Metso BMH 2007

24. Mechanical Improvements
One Set of Counterweighted Deadplates
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25. Pallet End Arrangement
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Pallet
Wheel
(Engages
Rails)
Carrying
Rail
Pallet Roller
(Engages
Sprockets)
Hood Seal
Bar
(Engages
Drop Seal)
Spring Seal
(Engages
Slide Bars)
Windbox
Slide Bars

26. Lintel Wall & Drop Seal Bar
Drop Seal Bars ride against seal plate on pallet car. This prevents
gas from entering/leaving machine.
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27. Pallet Car Camber
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28. Cambered Pallet (New)
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29. Sagged Pallet (Need Maintenance)
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30. Summary
• ALIGNMENT, rails, drive & tipping wheel shafts, lintel walls and windbox
seals
• Monitor sprocket wear, maximum of 5 mm
• Well maintained Pallet Cars
• Well maintained seals
• Maintain daily, weekly, monthly and yearly recommended inspections
30 © Metso
Date Author Title

31. © Metso
Tempering
Damper
|
Simplified Grate Kiln System Flow
31
600 oF
315 oC
550 oF
290 oC
1800 oF
980 oC
700 oF
371 oC
230 oF
110 oC
230 oF
110 oC

32. Available Services
Pallet Repair Program
• Establishes a pallet weld repair procedure
• Supplies gauges and dimensions to monitor wear, determine degree of reconditioning
and to determine when pallets should be turned over.
• Supplies evaluation procedure for end casting repairs and for maximizing wheel/axle
and bearing life.
• Establishes a constant ongoing program of monitoring, repairing and replacing the
most worn pallets.
32 © Metso BMH 2007

33. Available Services
Maintenance Training
• Establishes the pallet repair procedure at the plant level (pallet removal from
machine, repair, assembly and reinsertion into machine).
• Establishes mechanical and electrical preventative maintenance programs for the
entire indurating machine
General Inspections
• Helps to pre-plan maintenance outages for determining and prioritizing needed repairs
• Recognizes and corrects minor problems that can expand into major problems
• Determines that the pallet repair program is being properly maintained and utilized
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