Improvement of energy efficiency for glass tube fusing

The fusing of glass tubes for solar thermal collectors is dominated by flame based heating and melting technology. The low energy transfer efficiency of the flame in conjunction with long process times leads to massive gas consumptions. Consequently, there is great opportunity to substitute this process with a more efficient one. By means of CO₂-laser radiation more efficient energy transfer can be obtained. As well, intelligent process management may reduce the energy consumption of the heating process. We present test results for laser fusing of glass tubes for solar collectors with regards to obtained quality and energy consumption. By monitoring the energy consumption all individual process steps have been analyzed and optimized in terms of energy efficiency. The possible energy savings achieved with a CO₂-Laser fusing process are illustrated and a detailed comparison between the competing burner and laser technologies is presented.