Iron Ore Straight Grate Pelletizing Seminar

Machine Maintenance

to improve operating conditions

October 2014

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Tempering

Damper

|

Simplified Grate Kiln System Flow

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600 oF

315 oC

550 oF

290 oC

1800 oF

980 oC

700 oF

371 oC

230 oF

110 oC

230 oF

110 oC

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METSO MINERALS

Rails

Top Strand

Bottom Strand

Burners

Direct Recup Header

Windbox

Double Dump Valve

Air Passage

Downcomer

Furnace Hood

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Machine AlignmentMachine alignment is critical to health of the major components of the machine.

Pallets, sprockets, guide rails, and machine drive.

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Measure bushing axial and radial wear.Inspect Shaft Seals

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Machine Shaft Alignment

1) Machine drive and idler shaft should be level at the pillow blocks within

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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Sprocket Indexing

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Sprocket Segment- Profile Gauge

Machine alignment guide rail and roller wear can be caused by sprocket

wear. Use gage to determine. Wear should not be > 3/16”.

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Machine Alignment- Flanging

If the sprocket shaft and teeth are within acceptable limits, Pallet wheel

flanging can be reduced by re-orientation of the pillow blocks by:

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Machine Alignment- Flanging

X= B*C/(2 *A)

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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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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Guide Rails to Sprocket Alignment

“A” should be within 1/8”12

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Machine Alignment- Rails and Guide Rails Gauge

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Machine Alignment- Rails and Guide Rails Gauge

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Guide Rails Wear Gauge

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Tipping Wheel Assembly

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Discharge Sprocket

Discharge Guide Rail

Tipping Wheel assemble Area

Spillage Chute

Bearings

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Mechanical ImprovementsTipping Wheel Shaft Seals

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Pallet Roller Turner

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Mechanical ImprovementsProcess Seals - Counterweighted Deadplates

© Metso© Metso Date Author Title

Counterweighted Deadplates

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Direction of Pallet Travel

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Mechanical ImprovementsOne Counterweighted Deadplate

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Mechanical ImprovementsOne Set of Counterweighted Deadplates

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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)

WindboxSlide Bars

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Lintel Wall & Drop Seal BarDrop Seal Bars ride against seal plate on pallet car. This prevents

gas from entering/leaving machine.

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Pallet Car Camber

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Cambered Pallet (New)

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Sagged Pallet (Need Maintenance)

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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

Date Author Title30

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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

© Metso© Metso BMH 200732

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.

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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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