Solidification systems manufacturer Sandvik used this year’s Achema fair to highlight the breadth of applications for its Rotoform technology, a melt solidification process that has been used by chemical processors for more than 30 years. Exhibiting under the umbrella message of ‘Go further, explore new possibilities’, Sandvik launched its brand new ThermoCut® system, delivering increased productivity and a better quality end product with high viscosity melts, and also showcased its specialised Rotoform 4G sc system, purpose designed for the pastillation of subcooling melts.
Other themes were the high capacity solidification achievable using steel cooling belts up to 2 m wide, and the ability to deliver systems compliant with GMP (Good Manufacturing Practice) standards.
Sandvik’s new ThermoCut® system is an innovative tool that works in conjunction with the Rotoform system to deliver perfectly formed pastilles when solidifying high viscosity products. One of the challenges associated with this kind of product is the formation of threads, commonly known as ‘angel hair’, that are created when the melt is deposited on the steel belt cooler. The development of the Sandvik ThermoCut® system overcomes this to deliver a significantly better quality end product.
The system works by blasting a narrow jet of high pressure, heated air at the precise place where the drops are formed between the Rotoform and steel belt. This powerful blade of hot air cuts the threads before they have chance to develop further.
As well as delivering a more stable production process with perfectly formed pastilles, the use of ThermoCut® equipment also results in a substantial reduction in the need to clean the machine.
Rotoform 4G sc
Sandvik placed particular emphasis on the benefits of its Rotoform 4G sc system, one model in family of Rotoform solidification systems designed for different applications. The Rotoform 4G sc has been developed to meet the challenge presented by subcooling melts, products that remain liquid even when cooled below their melting point.
The reason they refuse to crystallise and solidify is the lack of the crystal nuclei. Sandvik’s system overcomes this problem by introducing a homogeneous suspension of crystal nuclei into the melt. This is done with the scraped surface heat exchanger, called a precrystalliser, using a cold cylindrical surface and a heated rotor.
The process enables the melt to be crystallised on the steel belt in a very short time and can be used to produce the desired product form, such as pastilles, micropastilles or flakes.
Solidification solutions for every kind of product
The company’s Rotoform system has been its flagship solidification system for more than 30 years and continuous R&D has resulted in an entire family of models. The development of this comprehensive product range has not only led to faster and more efficient pastillation, but has also enabled the processing of chemical products with melt temperatures as high as 300°C, and those with abrasive, sedimenting or corrosive properties.
Systems are available to handle products with viscosities up to 40 000 mPas, and pastilles can be produced in sizes from 0.8 - 36 mm in diameter. Throughput rates can be as high as 15 tph.
The Rotoform itself consists of a heated cylindrical stator, which is supplied with liquid product, and a perforated rotating shell that turns concentrically around the stator, depositing drops of the product across the whole operating width of the steel belt. Steel cooling belts can be up to 2 m wide, enabling high capacity solidification.
Heat released during solidification and cooling is transferred by the steel belt to cooling water sprayed underneath. This water is collected in tanks and returned to the water chilling system; at no stage does it come into contact with the product.
Free flowing, uniform pastilles are produced, which are easy to handle, bag and transport. Because little dust is created in the production process, or subsequently by the pastilles, the entire production is environmentally friendly.
Edited from press release by Claira Lloyd
Read the article online at: https://www.hydrocarbonengineering.com/product-news/24062015/sandvik-at-achema/