FB rEVOLUTION scraper chains are the latest generation of scraper chains. They combine the best of two worlds, the wear resistance of drop forged link chains and the innovative and field-proven features of modern FB-conveyor chains with welded pins and bushes, as well as hardened side link plates made of FB1000.
During a meeting with the maintenance manager of a well-known German producer of chip and MDF boards, FB were challenged to provide a forged scraper chain that could run faster, over a longer distance and had an increased working life with reduced down time. When selecting the type of chain to use in a scraper conveyor the benefits of drop forged link chains have to be balanced against the advantages of conveyor chains to meet as many of the customer expectations as possible, but there is always some compromise, in this case our customer did not want to make any concessions.
In reviewing his request the FB team realised that there was an opportunity for an optimized solution of scraper chains for the MDF sector and also for many other sectors with similar ever increasing requirements to reduce operating costs and increase operational up time. They therefore decided to design a scraper chain based on conveyor chain to DIN8167/ISO1977 but using a new link plate material, FB1000 and welded pins and bushes. As a result of using these materials and the optimized construction, the breaking force and fatigue strength are increased by between 30% and 50% compared to DIN–ISO conveyor chains. This new type of scraper chain offers up to 90% larger bearing-area compared to drop forged link chains or round steel chains. The bearing-pressure can thus often be halved which has a very positive effect on the wear and the life of conveyor chains and sprockets.
The next challenge was to fit this new chain to the existing conveyor system with no reconstruction works and no impact on capacity or speed. Based on flexible and modern manufacturing capabilities and tools, FB can build almost any pitch chain. The conveyor symmetry thus remains unchanged. This means that the level of chain-guides, pitch circle diameter of sprockets and diameter of the pulleys require little or no adjustment. Forged chain is mostly driven by split-sprockets with removable-tooth segments. Wear-resistant tooth-segments for the FB rEVOLUTION chains can fitted to the existing hub body saving time, money and trouble.
This style of chain also has a number of other advantages compared to drop forged link chains or round steel chains, including much more space for welding scrapers or attachments. This increased area allows for a stronger weld and the possibility of a greater variety of shapes and designs of scrapers avoiding common issues with welded scrapers on drop forged chain with their case-hardened or high hardness links. If something should get stuck in the conveyor system, FB-rEVOLUTION conveyor chains can also be reversed, unlike drop forged chains which cannot.
The addition of stainless steel and hardened AISI420V pins and bushes allows the chain to be used with moist or acidic conveyed material that is found in scrapers used for wet ash, biomass or coal infeed systems, wood chip or bark as well as for alternative fuels in cement factories and in recycling plants.