The Effect of Foam in Surface Molten Glass and Use of TNBT for the Combustion Process in Furnace to Temperature and Produced Glass Quality (original) (raw)

Effect of furnace atmosphere on E-glass foaming

Journal of Non-Crystalline Solids, 2006

The effect of furnace atmosphere on E-glass foaming has been studied with the specific goal of understanding the impact of increased water content on foaming in oxy-fired furnaces. E-glass foams were generated in a fused-quartz crucible located in a quartz window furnace equipped with video recording. The present study showed that humidity in the furnace atmosphere destabilizes foam, while other gases have little effect on foam stability. These findings do not contradict the generally accepted 'dilution model', suggesting that foaming is more severe in oxy-fired furnaces than in air-fired furnaces because the higher concentration of water in the furnace atmosphere ultimately enhances sulfate decomposition resulting in stronger foaming. The failure to reproduce this effect in laboratory experiments may be attributed to water incorporation into the glass melt occurring during ablation melting in industrial furnaces.

Comparative Analysis of the Own Experimental Techniques of Producing the Foamed Glass-Ceramic

Journal of Engineering Studies and Research, 2017

The paper presents experimental results obtained by a team of researchers from the company Daily Sourcing & Research SRL Bucharest in the field of producing the foamed glass-ceramic from waste bottle glass, coal ash and silicon carbide as foaming agent. The originality of the experiments consists in the use of electricity or microwave energy, unlike all techniques known worldwide consumers of fossil fuel. The product, obtained with low energy consumptions and very low pollutants emissions, has physical and mechanical characteristics of an insulating material, i.e. high porosity, low thermal conductivity and an adequate compressive strength

Foaming of E-Glass II (Report for G Plus Project for PPG)

2000

In a previous study, the effect of the furnace atmosphere on E-glass foaming was investigated with the specific goal to understand the impact of increased water content on foaming in oxy-fired furnaces. The present study extended the previous study and focused on the effect of glass batch chemical composition on E-glass foaming. The present study also included reruns of foam tests performed in a previous study, which resulted in the same trend: the foaming extent increased nearly linearly with the heating rate and no foam was produced when CO 2 + 55% H 2 O atmosphere was introduced at 300°C. It was shown that the lack of foaming in the test with CO 2 + 55% H 2 O atmosphere introduced at 300°C was caused by a loss of sulfate at T <1250°C because of higher water content at the early stages of melting. The tests with new batches in the present study showed that replacing quicklime with limestone tend to decrease foaming, possibly caused by increased sulfate loss during early stages of melting in the batch with limestone. The batches where Na 2 SO 4 was replaced with NaNO 3 , NaNO 3 + CeO 2 , or CeO 2 , produced only very limited foaming regardless of the replacing components. As expected, the foaming extent increased as the sulfate content in the batch increased. The results of the present study suggest that foaming can be reduced by using limestone over quicklime and by decreasing the sulfate addition to a minimum required for refining.

Foaming of E-Glass (Report for G Plus Project for PPG)

2004

The behavior of foams generated in the crucible melts was investigated to study the effect of furnace atmosphere on E-glass foaming, specifically focused on its water content to understand the effect of oxyfiring. A quartz-crucible furnace equipped with video recording was used to observe the behavior and to evaluate stability of foams generated from the PPG E-glass under various atmospheres. The present study preliminarily concluded that the higher foaming in oxy-fired furnace compared to air-fired is caused by the effect of water on early sulfate decomposition, promoting more efficient refining gas generation from sulfate (known as "dilution effect"), not by the effect of humidity on foam lamella stability. A plausible explanation for the difference between soda-lime glass and E-glass in the end result of the dilution effect on glass refining and foaming is presented. A preliminary experiment on the effect of heating rate also suggests that thermal history of glass melting can be a major factor in the rate of E-glass foaming. Approaches to develop the methods to reduce foaming in oxy-fired furnace are recommended.

Foam glass processing using a polishing glass powder residue

Ceramics International, 2013

The foaming behavior of a powder residue/waste of a soda-lime window glass polishing facility was investigated at the temperatures between 700 and 950 1C. The results showed that the foaming of the glass powder started at a characteristic temperature between 670 and 680 1C. The maximum volume expansions of the glass powder and the density of the foams varied between 600% and 750% and 0.206 and 0.378 g cm À 3 , respectively. The expansion of the studied glass powder residue resulted from the decomposition of the organic compounds on the surfaces of the glass powder particles, derived from an oil-based coolant used in the polishing. The collapse stress of the foams ranged between $ 1 and 4 MPa and the thermal conductivity between 0.048 and 0.079 W K À 1 m À 1. Both the collapse stress and thermal conductivity increased with increasing the foam density. The foams showed the characteristics of the compression deformation of the open cell brittle foams, which was attributed to the relatively thick cell edges.

Foam glass processing using a polishing glass powder residue.pdf

The foaming behavior of a powder residue/waste of a soda-lime window glass polishing facility was investigated at the temperatures between 700 and 950 1C. The results showed that the foaming of the glass powder started at a characteristic temperature between 670 and 680 1C. The maximum volume expansions of the glass powder and the density of the foams varied between 600% and 750% and 0.206 and 0.378 g cm À 3 , respectively. The expansion of the studied glass powder residue resulted from the decomposition of the organic compounds on the surfaces of the glass powder particles, derived from an oil-based coolant used in the polishing. The collapse stress of the foams ranged between $ 1 and 4 MPa and the thermal conductivity between 0.048 and 0.079 W K À 1 m À 1 . Both the collapse stress and thermal conductivity increased with increasing the foam density. The foams showed the characteristics of the compression deformation of the open cell brittle foams, which was attributed to the relatively thick cell edges.

New Manufacturing Method of Glass Foam by Cold Expansion of Glass Waste

Journal La Multiapp, 2021

An innovation cold manufacturing method of glass foams is presented in the paper. Traditional foaming agents used in conventional expansion processes of glass waste at high temperature were substituted with aluminium powder in aqueous solution of calcium hydroxide, which releases hydrogen forming gas bubbles in the viscous sludge and then, by solidification, a porous structure typical for the glass foam. The manufactured foam is adequate for using as a thermal insulation material for inner wall of buildings, having the apparent density of 0.31 g·cm-3, the thermal conductivity of 0.070 W/m·K and the compressive strength of 1.32 MPa. The process originality is the use of recycled aluminum waste, melted by an own microwave heating technique and sprayed with nitrogen jets. The process effectiveness is remarkable in economical and energy terms.

Effective microwave heating method for manufacturing glass foam from glass waste

Revista Romana de Inginerie Civila/Romanian Journal of Civil Engineering, 2021

Rezumat. In lucrare este prezentată o tehnică originală de fabricare a spumei de sticlă prin sinterizarea la temperatură înaltă a deșeului de sticlă datorită încălzirii cu microunde. Încălzirea materiei prime este realizată predominant direct și parțial indirect utilizând un tub ceramic din SiC cu o grosime optimă a peretelui de 2,5 mm. Această metodă contribuie la reducerea semnificativă a consumului specific de energie, a vitezei de incălzire și a duratei procesului comparativ cu tehnicile convenționale de încălzire. Caracteristicile spumei de sticlă sunt similare cu acelea ale spumelor fabricate conventional și pot fi utilizate ca înlocuitori ai materialelor de construcție existente. Cuvinte cheie: spumă de sticlă, microundă, încălzire predominant directă, agent de spumare, eficiență energetică Abstract. An original technique for manufacturing glass foam by high temperature sintering of glass waste due to the microwave heating is presented in the paper. The heating of the raw material is performed predominantly direct and partially indirect by using a SiC ceramic tube with an optimal wall thickness of 2.5 mm. This method

Prospects and physical limits of processes and technologies in glass melting

Journal of Asian Ceramic Societies, 2019

The paper is devoted to the physics of continuously operating fuel-fired glass furnaces with supplementary electrical boosting. Furnaces are treated in their basic function as heat exchangers and chemical reactors. First, as an expression of the 1 st law of thermodynamics, a general heat balance is elaborated in detail. The function as heat exchanger is characterized by three dimensionless key indicators: the temperature efficiency (comprising adiabatic flame, glass exit, and environmental temperature), the heat capacity flow match of hot and cold stream, and the number of heat transfer units. A 2 nd law treatment reveals the bottle neck of furnace optimization between two conflicting objectives. i.e., high production rates and high energy efficiency. Based on this treatment, an evaluation procedure for furnace performance is presented. It rests on a retrospective analysis of furnace operation data and allows one to quantitatively compare furnaces of different sizes and production capacities as well as the effect of different batches used in the same furnace. A number of industrial case studies demonstrate the usefulness and reliability of the approach. Finally, an expression for the ultimate physical limit of energy utilization efficiency of a fuel fired furnace in general is derived.