Corus Process Engineering has been working closely with Castle Cement to refurbish several items of cement manufacturing plant.
Over the last few years, due to its technical expertise and comprehensively-equipped manufacturing facilities in the UK, Corus Process Engineering (CPE) has been able to successfully undertake a variety of repair and refurbishment projects for companies operating in the UK cement industry.
CPE, part of Corus' maintenance and engineering services division Corus Northern Engineering Services (CNES), initially specialised in the refurbishment and manufacture of steelmaking machinery and equipment for the nuclear industry but, over recent years, has transferred this expertise into helping companies in the mineral processing sector.
For cement manufacturers, CPE and CNES offer a range of services including strip-down, inspection, repair, refurbishment and re-manufacture. Projects to date have included the refurbishment of mill roller assemblies, kiln fan assemblies, screens, kiln support rollers, classifier shafts, impactor shaft assemblies, clinker breaker rotors and bucket-wheel shaft assemblies. The company possesses some of the largest, most comprehensively equipped workshops and manufacturing facilities in the UK, which enables it to handle units up to 130 tonnes in weight.
One of the UK's largest cement manufacturers, Castle Cement Limited has been working closely with CPE over the last six years. Currently, the company meets around one-quarter of the UK's total demand for cement. The company has three production sites based in Padeswood in North Wales, Ribblesdale at Clitheroe in Lancashire, and Ketton in Rutland, employing around 1000 people in the UK. The three production plants are supported by marine terminals in Avonmouth and Humberside and by a network of other depots. The company is part of HeidelbergCement, a worldwide building materials group.
Initially CPE began working with Castle Cement on refurbishment of roller assemblies for raw mills, of which there are three types: an Atox and a Krupp Polysius twin-roller assembly at Ketton; and a Pfeiffer Mill at Ribblesdale. CPE has carried out maintenance and refurbishment work on the roller assemblies for these three types of mill. The mills grind raw material into a fine powder, which is then blown by air for further processing.
David Needham, CPE Business Development Engineer, has been working closely with Castle Cement over the last few years. He says: "We have carried out various projects for Castle, mainly involving the stripping down, inspection and refurbishment of kiln roller assemblies. What sets CPE apart from other companies, and why companies such as Castle want to work with us, is that we have the necessary technical expertise and machining facilities to enable us to handle this type of heavy refurbishment work.
"It is very demanding work and there are not many companies of our size and experience left in the UK. If Castle needs support, we are on hand quickly to provide it. We can handle up to 130 tonne assemblies at our facilities, whereas many suppliers can only handle up to 10 or 20 tonnes. We can carry out strip, inspection, repair or replace parts, plus welding and machining. Often we need to undertake the job without any detailed drawings of the assembly, as the OEMs do not release detailed drawings of their equipment. Fortunately we have the necessary skills and expertise in-house to determine the work required."
Roller refurbishment and repair
A typical project involves CPE representatives agreeing with the customer a method of repair or refurbishment. Some parts may need replacing, others can be repaired. The hub on a raw mill roller assembly, for example, often gets damaged or worn. On the Atox hub for Ketton, CPE has machined the flat sides and fixed new wear plates, then re-assembled the segments onto the refurbished hub. On the Pfeiffer fabricated hubs at Ribblesdale, CPE has machined the outside diameter of the hubs, weld-cladded them, then re-machined the diameters to bring them back to drawing sizes before re-assembly.
Detailed work programmes are normally compiled for each roller assembly, covering key operations such as inspection of bearings, changing of seals, replacement of segmented tyres and re-assembling with new components where required.
Machining facilities at CPE are also key. The company's vertical borer at Workington can handle up to 75 tonnes and has a 16-foot diameter table. The workshop also has a 130-tonne overhead crane.
Needham states: "Reliability and building a close working relationship with the customer are key. We liaise closely with the engineers and management teams throughout the projects and have an excellent working relationship with engineers from both the Ribblesdale and Ketton Works."
David Holgate, the Engineering Manager at Castle Cement's Ribblesdale plant, comments: "We are reliably confident working with CNES. The company's steel industry background, its machining capacities and its particular understanding of the cement industries' needs lead them to be an excellent service provider for equipment used in the harsh and demanding environment of cement manufacture."