Kiln shell and girth gear replacement – Mondi Richardsbay

Another successful project under the Robtek belt – The customer needed to replace two sections of their lime kiln shell this entailed a 9.4m long straight section with a diameter of 4.5m.? The 2nd section (4.3m long) required a new riding ring and chair plates to be fitted on the shell before rigging into the final position.??

The 2nd half of the project was to install a brand new girth gear supplied by SEW Eurodrive, which could only commence after the kiln shell sections were complete.

Riding ring, chairs, shell and girth gear were all free issue items from FLS. Teams were sent to start site establishment on 8th Oct 2021.? The shell, riding ring and gear replacement project was expected to take 5 weeks.? Our crews were working round the clock with day and night shifts (15 members per shift).

The existing kiln shell had to be supported using our Robtek custom-built kiln supports before any old shell sections or tyres could be removed.

Due to the weight of the shell section and riding ring a mobile hydraulic 220-ton crane was used for the duration of the project.? The Shell sections were removed weighing 21 tonnes and 49 tonnes respectively (this included the riding ring)

The first new section was successfully rigged and temporarily joined to the old shell.

The shell with the pre-fitted tyre was the last piece to be installed.? All temporary erection steel was installed so the crane could be removed and the shell would be held in place.

Alignment could then begin and once complete the shell sections were joined by means of submerged arc welding.??

The girth gear replacement could now begin.? Due to the size (5.5m dia) and weight of the girth gear (approx. 10 tons), the same crane was used to remove the gear segments.? Our crews prepped the new gear on the ground by installing trailing mounting plates and once the shell was clean and ready it was rigged into place.??

Once the gear was in position alignment brackets were used to align the gear to within 0.5mm radial and axial runout.? Once the alignment was accepted the trailing plates were welded to the shell.

With this being a dual drive kiln both pinions needed to be replaced and aligned.

The final stage of the project was for the guards to be fitted and once this was done the kiln was handed over to the client.