Sulphur processing and handling equipment manufacturer IPCO is celebrating 40 years’ continuous production of its market-leading Rotoform sulphur pastillation system.
Such is the quality and reliability of pastille production delivered by Rotoform that it has gone on to become the most widely used premium quality sulphur pastillation system in the world, with more than 750 installed to date.
The development of this innovative rotary dropforming technology in 1980 brought new levels of quality and productivity to the market and changed the face of sulphur solidification.
A premium quality formed product – one with consistent size, moisture and friability specifications – enables safer, easier handling during storage and transportation.
As formed sulphur can be handled many times between solidification and subsequent reprocessing, often being shipped between continents, this predictable quality is a major advantage for the producer, the transportation company and the final customer.
“We had been supplying flaking systems since the early 1950s,” says Johan Sjögren, Managing Director of IPCO’s Equipment division, “and our ranges now encompass storage and handling solutions too, but the introduction of Rotoform was a defining moment in our company’s history. It put us on the map in this respect and the system remains the market leader to this day.”
While the core principle – direct-from-the-melt solidification on a steel belt cooler – remains unchanged, Rotoform technology has undergone significant advances over the years.
The latest models specially designed for sulphur processing are the Rotoform S8, with a capacity of 140 t/d, and the Rotoform HS, a high speed model with a capacity of up to 350 t/d.
“Rotoform has been a cornerstone of our portfolio for forty years,” says Johan Sjögren. “By continuing to focus on how we can make it better, faster and even easier to maintain, we are confident that it will carry on playing a central role in sulphur processing for another 40 years and more.”
The Rotoform consists of a heated cylindrical stator, supplied with molten sulphur via heated pipes and filter, and a perforated rotating shell that turns concentrically around the stator. Drops of the product are deposited by the nozzle bar across the whole operating width of a continuously running stainless steel belt.
A system of baffles and internal nozzles built into the stator provides uniform pres¬sure across the whole belt width, provid¬ing an even flow through all holes of the perforated rotary shell. This ensures that all pastilles are of uniform size, from one edge of the belt to the other.
The rotation speed of the Rotoform is synchronised with the speed of the steel cooling belt to allow gentle deposition of the liquid droplets onto the moving belt. Heat released during cooling and solidifi¬cation is transferred via the steel belt to cooling water sprayed underneath.
This water is collected in tanks and returned to the water recooling system; at no stage does it come into contact with the product.
After the drop has been deposited onto the steel belt, any product residue on the outer shell is returned to the Rotoform via a heated refeed bar which keeps the outer shell clean.
The sulphur droplets are then dis¬charged as solid, hemispherical pas¬tilles at the end of the cooling system. To eliminate the possibility of damage to the pastilles during discharge, a thin film of silicon-based release agent is sprayed onto the steel belt.
This process offers a number of environ¬mental advantages. As the cooling water never comes into direct contact with the sulphur, there is no risk of cross contamina¬tion. Secondly, solidification takes less than ten seconds so there is little time for H2S to escape, resulting in very low emission val-ues. And low levels of sulphur dust levels mean no need for exhaust air treatment. –Tradearabia News Service