Solid recovered fuels (SRF) are commonly used in the cement industry today in lieu of, and in support of, fossil fuels. However, while cement companies assess direct maintenance costs related to the fuel handling system, associated costs linked to material buildup, blockages and degradation of equipment are not always considered. The protection of equipment such as silos, feeders and pipelines can add significant value through system performance and avoid the potential for costly and unnecessary plant shutdowns.
Solid recovered fuels are produced using a typical blend of shredded and coarse mixture of paper, plastics, wood and textiles, along with other waste materials with calorific value. However, during SRF manufacture levels of contamination of miscellaneous materials are entrained and they can be extremely abrasive. Conveying such material in either a mechanical or pneumatic state can be costly and can result in premature failure. The vast range of recycled waste material used to generate energy can significantly impact on a cement plant’s output, as their erosive nature causes equipment wear and perforation. This causes stoppages and ad-hoc maintenance regimes.
Incorporating proven technologies that offer both corrosion and wear resistance along with enhanced material transfer helps protect such equipment and prevents costly shutdowns.
Improving SRF handling
One UK cement producer is installing an alternative fuel system (AFS) at its 1.5 million tpa plant. The project aims to significantly replace its primary fuels usage from coal to SRF. Last year, 32% of fuels usage was derived from waste and the cement manufacturer is now on course to raise this to 37% in 2014. With the new equipment, a 50% long-term target of co-firing will be achieved.
The project involves the erection of an AFS for the unloading, transportation, storage, weighing and injection of SRF into two kilns at the cement plant. Following past successes of supplying equipment to other cement plants, Kingfisher was approached to assist the EPC supplier with the technical design, manufacture and supply of pneumatic conveying injection pipelines feeding the main burner firing system on both kilns.
Graham Bailey, Operations Director for Kingfisher, said: “Having supplied similar systems to both UK and international producers of cement, our knowledge base of the issues and characteristics associated with the handling of SRF, in the various forms of conveyance, from the initial stage of manufacture through to the end-users’ feed system – into the kiln or preheater – is increasing all the time, leading to greater understanding and the improved performance of the systems we offer. As various blends of SRF material are now available and dependent on both the quality and composition of the fuels make-up from the processor, the supply will determine what problems the end-users incur. To give an acceptable level of protection vs budget constraints, we offered our K-BAS ceramic lining pipe work system, which offers a significant level of plant protection by outperforming unlined equipment by a factor of 6 to 1.”
Due to continual shifts with environmental legislation, fuel prices and process needs, ongoing customer support is a key priority for Kingfisher. Even after its systems have been installed and have proven to meet the challenge of the various changes the industry experiences, continuity of performance in terms of service, systems or equipment add significant value to the relationship built over many years.
One such example was for a UK cement plant that had been co-firing solid liquid fuels (SLF) with coal since 2002 but as the previous lining system of cast basalt failed to perform to the expected standard, Kingfisher advised that a different material be trialled – one that had shown dividends at other similar plants handling very erosive material. With successful results achieved, all the existing pipe work connected to both kilns 1 and 2 was replaced and lined with Kingfisher’s 92P K-ALOX wear-resistant lining system. The feedback from the plant mechanical engineer has been very positive and the system longevity has been improved by a factor of six.
Installing the correct plant protection system within any bulk handling system can help add value, increase production uptime and enhance life expectancy.
Written by Kingfisher Industrial Ltd. Posted by Louise Fordham
Read the article online at: https://www.worldcement.com/europe-cis/03092014/protection-from-srf-410/