Since its introduction in 1998, the infrared rotary drum (IRD) is now in use in more than 50 facilities worldwide for the drying of bulk solids, particularly in the plastics industry. Employing similar principles to the domestic microwave oven, the process uses infrared heat radiation which heats only the solids and fluids and not the surrounding air.

Developer of the process 42Inventions (Hilchenbach / Germany; www.42inventions.com) claims that this has dual benefits. Firstly, it creates propulsive vapour pressure, which helps separate the particles and aids drying. Secondly, as the environment of the heated particles remains relatively cool compared with the temperature of the product, a flow of warm air results, further accelerating the removal of the evaporated moisture.

An IRD unit at Münster / Germany-based Kreyenborg
(Photo: 42 Inventions)

According to 42Inventions, the result is a significant reduction in drying time and energy usage. Energy consumption savings of around 80% are claimed for the process, which the company says can be applied across a range of industrial sectors, whereby almost all drying specifications in plastics engineering can be handled. 42Inventions reports strong demand for applications in PET processing and in the drying of all types of fibres. Drying of powders, chemicals and coatings in the chemical and pharmaceutical industry is a further application.

For the drying of free-flowing products, where it is important that the solids are not irradiated excessively, a drum with a fixed screw that spins and turns the solids, ensuring consistent mixing, has been developed.

Over the past year, the inventor of the technology, Urban Stricker, has entered into licensing agreements with several partners. One of the first was Kreyenborg (Münster / Germany; www.kreyenborg.com), which managing partner Jan-Udo Kreyenborg says is exhibiting IRD at “Powtech” in Nürnberg and at “Fakuma” in Friedrichshafen / Germany. Both events are being held during October.

An IRD-100 unit at UPM in the UK (Photo: 42 Inventions)

As a licensee, UMP Group (Slough / UK; www.upm.co.uk) over the past two years has developed fully automated operation for the process based on new software and controls. The company has also manufactured IRD for the Japanese licence partner Sojitz (Fukuoka / Japan; www.sojitz.com), which is reporting interest from the country´s chemical industry.