top of page


The rotary kiln forms the very heart of pyro-metallurgical processes, objectively determining the actual status of the kiln timeously triggers the relevant proactive corrective or preventive maintenance interventions.

Ultimately this contributes towards maximising the vessel’s overall effectiveness. Dickinson Group in alliance with Fives FCB, a member of the Fives Group offers a revolutionary comprehensive rotary kiln inspection program that has been streamlined to determine the complete status of a rotary kiln within 5 days (for a 3 pier Kiln).

The core parts of the inspection are done while the vessel is in operation, there are however some additional options that require relatively short stoppages (see step 8). This article will give a brief step by step overview of this rotary kiln inspection program.

Pre-Job Briefing and Discussions with the Maintenance Team of The Plant

  • Kiln floating uphill and downhill sequence?

  • Refractory lining chart / history?

  • Last mechanical failures (major issues)?

  • Shell sections replacement history? (Drawing or file?)

  • Load at each pier (general drawing or file?)

  • Last inspection reports and operations performed on the rotary kiln?

  • Shell thickness measurement report?

Kiln Axis Control

  • Measurement of the relative position of the tyres : slope, elevation view and top view of the axial deviation

Rollers Axis And Hydraulic Thrust Position Control

  • Roller bearings support slopes and axis distance

  • Rollers axis slopes (+ distance and parallelism if shaft ends are accessible)

  • Hydraulic thrust position control

Rollers And Tyres Diameters Measurements

  • Measurement of 3 diameters on each rollers and tyres (shape: conicity or concaveness)

  • Step 3 results + Average diameters provide the rollers operating angles and the position of the thrust under tyre.

Tyres and Girth-Gear Run-Out + Shaft Bending

  • Tyres wobbling

  • Girth-Gear wobbling and excentricity (if possible in operation)

  • Shaft bending measurement (variation of loads?)

Kiln Shell Deformation Control

  • Shell profile analysis (roundness and excentricity) + location of existing welds

  • Focus on area of Tyres and Girth Gear + step 5 results provide impact of shell deformation on wobbling & excentricity

  • Specific focus on kiln feed and discharge end areas

Comprehensive Mechanical Inspection

  • Axial position of tyres, rollers, pinion, Girth Gear (kiln in downhill)

  • Contact pattern between rollers and tyres

  • Relative movement of the shell inside the tyre (clearance)

  • Visual inspection (rollers, tyres, blocking systems)

  • Temperatures and global vibrations measurements

  • Visual control of bearings lubrication

  • Rollers skewing control (bearings thrusts position when kiln is in downhill)

  • Hydraulic thrust pressure control (downhill and uphill)

  • Girth-gear inspection in operation (teeth temperature, contact pattern)

  • Inlet and Outel seal visual inspection

  • Possible adjustment range of rollers supports

  • Adjustment range of inlet and outlet seals (if possible)

Debriefing On Site

  • Option 1: Girth-Gear inspection (short stoppage required: 0.5 day)

  • Option 2: Main transmission alignment control (short stoppage required: 0.5 day)

  • Option 3: Assistance for kiln axis and rollers adjustment (to be defined)

  • Option 4: Assistance for Kiln shell thickness measurement (to be defined)

Recent Posts

See All


bottom of page