Spotlight: Energy efficiency and heat treatment

Materials World magazine
29 Oct 2012

With large amounts of energy required for heating ovens and fuelling furnaces, heat treatment and thermal processes have a relatively large carbon footprint. But several manufacturers are addressing the problem by reducing the environmental impact of their equipment.  

One example can be seen at UK manufacturers of wire and strip, Webster & Horsfall. Switching from steam to thermal fluid heating has significantly reduced the company’s energy bills and carbon footprint. A TPC600B thermal fluid heating system from Babcock Wanson is being used to heat tanks for metal treatment. The system uses 20–50% less energy than traditional steam heating systems and features control systems, safety devices and an integrated burner.  

Further improvement in efficiency is demonstrated in BTU International Inc’s PYRAMAX dual-lane reflow ovens. These provide electronics manufacturers with a doubled throughput in a single reflow by allowing two boards to be run at once. The ovens use dualspeed to create two independent thermal profiles and can run boards with significantly different settings. The ovens use the HE flux management system that collects residue by processing oven atmosphere from multiple extraction points through a series of heat changers. One lane can also be adjusted while the other continues production. These features allow users to process batches with greater speed and in fewer loads, reducing the amount of oven use overall.  

Other systems are reducing environmental impact by limiting the waste of materials. The Rotoform 4G system for granulating chemical melts is similar to previous Rotoform models, but with a redesigned refeed bar. The refeed bar is heated and automatically positions itself to ensure that any surplus material left on the depositor is forced back through a channel to be remixed with the product. The belt is cooled indirectly by water sprayed on the underside of the belt, which reduces the risk of cross-contamination between product and cooling water, further limiting the amount of waste produced.  

Heat treatment systems may also be helping to create sustainable energy resources by improving the production of solar cells. The Safire firing furnace and DriTech dryer from Despatch have been designed to help solar cell manufacturers achieve maximum product yield, quality and consistency. The Safire features dual chambers with no lane-to-lane influences. This feature ensures firing repeatability and capability for cell efficiency optimisation in a high capacity platform. The innovation demonstrates how these systems are not only reducing their own carbon footprints, but are also helping to create green energy.