Sandvik Hard Material the world’s largest producer of cemented carbide and is part of the Swedish based Sandvik group, who have a worldwide manufacturing base covering a multitude of industries.
Located in Coventry, Sandvik Hard Materials UK division manufacture a wide range of products including industrial tools and hot rolls for the steel industry.
In 2004 Sandvik carried our a review of their production facilities and the following areas from receipt of raw material to the milling process were
defined for improvement:
- The process was becoming very labour intensive.
- Exposed product, dust and spillage in some areas.
- Occasional quality issues due to weight control malfunctions.
- Occasional cross contamination
- An increase in production was required.
The area of major concern was centered on the transfer of ingredients from the original sealed drums through to the ball mills. A “weigh IBC” moves along on a linear conveyor and is charged with ingredients from three systems; a drum tipping system for intermediate ingredients, four “formulation” systems feeding sequentially to the weigh IBC for the bulk ingredients, and hand tipping of reweighed minor ingredients at the end of the conveyor to the weigh IBC. The weighed IBC is then transported to the ball mills by forklift, where it is emptied into the ball mill by opening a butterfly valve on the IBC outlet and transporting the product sideways using a vibratory conveyor.
The first phase was to provide a front-end study for the complete system, not binding on Sandvik, to produce a design, complete with layout drawings together with firm pricing and project program. As Sandvik was currently using an old-style cone valve weighing system, supplied by an ISL competitor, Sandvik, approached ISL to set up initial trials with their new generation cone valve, to prove the system was capable of fulfilling Sandvik’s requirements. Following successful testing at Sandvik, which showed greater accuracy, a considerable reduction in cycle time, a greater level of containment, and much-reduced cleaning, Sandvik then Sanctioned ISL to carry out an engineering study of their weighing line process. By May of 2005 Sandvik ordered the first phase, for ISL to supply a complete main frame assembly including Discharge Stations complete with frame vibrators (vibrators specified as a result of Sandvik trials), 850-liter stainless steel IBC and a Station Control System which links seamlessly with the existing control system.
The ISL equipment was installed in August 2005 and is operating to expectations: Sandvik’s five review criteria
have been met with the following results:
- Installation of the IBC system meets the labour criteria by reducing the time operators attend the discharge stations as well as less need to clean the process area.
- The ISL cone valve does not tip and leads so there is no spillage during IBC transit, product discharge or storage.
- The weight control malfunctions is addressed in the station control system with the fitting of an ISL rate & position transducer to the IBC discharge stations.
- Cross contamination is negated by the ease of cleaning the discharge station.
- Time taken for each weighment is greatly reduced giving an increase in production.
With the first phase of the ISL IBC system successfully introduced and meeting Sandvik’s expectations attention is turning to the outstanding issues related to the mill feed system, IBC filling and the replacement of the remaining original cone valve IBC’s and discharge stations.