Use of concentrated radiation for solar powered glass melting experiments

Abstract

To investigate the feasibility of using concentrated solar radiation to provide process heat for glass production, a high flux solar simulator was used to melt glass forming batches. Initial experiments involved melting various glass forming batches which demonstrated that rapid and full conversion of the crystalline raw materials into an x-ray amorphous vitreous state was possible. A pure silica batch produced an x-ray amorphous product but it was not possible to refine the melt in these exploratory tests. A powdered, ternary soda-lime-silica (SLS) glass forming batch melted vigorously, with rapid gas removal, resulting in a completely transparent glass. Industrial SLS pellets were subsequently used in semi-continuous melting experiments, whereby the batch was intermittently fed into the melting zone while the beam was kept on. Additional secondary heating and insulation around outlet of the melting zone was required to achieve a semi-continuous flow of molten glass to an output crucible.

Solar Heat for Materials Processing: A Review on Recent Achievements and a Prospect on Future Trends

“…The raw material of lunar origin is lunar regolith, from which plagioclase concentrate, high silica content slag, and calcium oxide are obtained. More recently (2014), the study of the feasibility of using concentrated solar radiation to provide process heat for glass production/melting was revisited by Ahrnad et al [23], in this case using a high-flux solar simulator. The research included static, as well as semi-continuous melting experiments.…”

“…Further experiments to investigate the feasibility of generating a semi-continuous flow of molten glass using the concentrated radiation were conducted, and a series of semi-continuous glass melting experiments were completed to iteratively optimise pellet feed rate, radiant power intensity and crucible geometry. After the small-scale demonstration, the authors have concluded that, due to the non-linearity of productivity and efficiency on scale-up, significant further experimental work on a larger scale is required before the commercial feasibility of solar powered glass melting can be evaluated to any reasonable degree of certainty [23].…”

High flux solar simulators for concentrated solar thermal research: A review

“…Very similar analysis for justifying the use of HFSS can be done to other type of material processing. Ahmad et al [101] carried out glass melting experiments using the PSI 50 kWth solar simulator. They controlled the temperature at the outer surface of a crucible, which contained the melting material.…”

“…At this point, they reached temperatures of 1450 ºC, therefore, higher values should be achieved inside the crucible. In their paper, Ahmad et al [101] presented a comparison between the solar irradiance spectrum and the spectral absorptance of melting glass to highlight the agreement between maximum intensities of both spectrums. It is relevant in the case of glass because it is transparent to the solar radiation in a wide range of wavelength.…”

Eco-efficient melting of glass frits by concentrated solar energy

“…However, no research has been previously conducted aiming to use CSE for producing glasses or glassy materials such as glass frits or glass enamels. Recently, the feasibility of using high flux solar simulator to provide a sustainable source of process heat for glass production was investigated (Ahmad et al, 2014). Initial experiments involved melting a ternary common sodalime-silica (SLS) glass batch, which demonstrated that rapid and full conversion of the crystalline raw materials into an X-ray amorphous vitreous state was possible.…”