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Erection and retrofit services for rotary drums, girth gear drives and kilns

Kumera Machinery Ltd, as a fully owned subsidiary of Kumera Corporation, takes challenges beyond normal manufacturing operations for services covering retrofitting existing kiln installations, renewing drive systems by replacing gearboxes and girth gear drives with modern technological solutions. All these measures are carried out on a turn-key basis.

This means:

  • On-site installation services for heavy equipment as a turnkey solution, including the necessary assembly and construction work, project management, inspections, and logistics.
  • Erection of rotary drums and kilns and retrofitting shells, riding rings, and rollers.
  • Retrofit of girth gear drives, the old girth gear and power transmission units replaced with Kumera’s modern drive solutions.
  • In-house assembly and installation adapt to a wide range of different equipment and deliver these pre-assembled to the site.

Adaptive assembly cell

The assembly of equipment at the manufacturing plant is reasonable, because transportation of large subassemblies is more practical than of a loose set of parts. Moreover, assembly in a factory environment is faster and a higher level of quality can be achieved than by the assembly at the delivery site. For this purpose we have agile assembly operations, which can adapt to a wide range of different equipment. This operation is situated in a cleanroom environment. This arrangement keeps dust and other contaminants away from sensitive subassemblies.

On-site services for industrial plants

Regardless of the subassemblies' degree of readiness, the final assembly of equipment takes place usually at the delivery site. Installation of heavy equipment is not a “plug-and-play” process; it requires to be properly integrated with the surrounding plant. We are competent to undertake this service as a turnkey solution, including the necessary installation and construction work, project management, inspections, and logistics.

Erection of rotary drums and kilns

Large cylindrical and conical shell sections are among our main rotary drum products; consequently, we are also proficient in erecting them at the site. Even transportation of huge shell sections (up to 75 000 mm in length and 250 t in weight) is a logistical challenge, without forgetting the lifting and supporting them on piers and the installation of the riding rings and girth gears. The longest drums are delivered in multiple sections to make this all possible. The sections' joints are welded at the site maintaining a high standard of quality and keeping the shell free of deformations. After the alignment of the drum, a girth gear drive is installed.

Retrofit of girth gear drives

Continuously running rotary process equipment, such as ore mills, furnaces and kilns, may have a lifespan of decades. However, harsh environmental conditions, variable load, dust and temperature differences in combination with poor gear alignment and poor lubrication may lead to wearing out of the girth gear and its mechanical power transmission.

We master the retrofitting of both flange and spring mounted girth gear drives. Flange mounted girth gears are typically used in cold and fast rotating drums and ore mills, while spring mounted gears are found in kilns and furnaces, where thermal expansion does not allow use of bolt hardware.  Especially in case of welded spring elements utmost care is taken to align the new girth gear without runout. A particular welding procedure contributes to the minimization of heat deformations when mounting spring elements to the drum's shell. With a correctly aligned gear pair and carefully picked components, the new girth gear drive may as well endure for decades.


  • Holding an ASME U Stamp which allows pressure vessel deliveries to, mainly, the Americas.
  • Capable of PED (Pressure Equipment Directive (97/23/EC)) pressure equipment deliveries in the European Community in accordance with the module G (EC unit verification).
  • Capable of working under the rules and surveillance of maritime classification societies.
  • Certified to comply with the requirements of ISO 9001 Quality Management Systems, ISO 3834-2 Quality Requirements for fusion welding of metallic materials, and ISO 14001 Environmental Management Systems.

Retrofit services

Kumera Corporation, Kumerankatu 2 FI-11100 Riihimäki, Finland Tel. +358 20 7554 200[email protected] Legal Notice / Privacy / Code of Conduct