利用废玻璃研制泡沫玻璃

利用回收的废玻璃为泡沫玻璃为主要原料,添加少量的发泡剂和一些其它化工原料,采用低温（７６０～８１０℃）发泡工艺,探讨了配合料的配方组成和不同的发泡工艺制度对泡沫玻璃性能的影响。通过比较,得出了合理的泡沫玻璃的配方及发泡工艺制度;试制出的泡沫玻璃具有容重低、抗压强度,烧成周期短,易于控制的特点。     

硼在玻璃和玻璃生产中的应用

1.硼酸盐的存在及应用硼和氧具有很强的亲合力,故而在自然界中,硼总是以被氧化的形式存在的.含量很低的硼酸盐随处可见,但具有工业价值的高品位矿藏却如凤毛鳞角.目前发现的大矿藏仅有两处:一处在美国南加里福尼亚,另一处在土耳其.美国是最大的工业硼酸盐生产国,其次是土耳其.另外,苏联,南美及中国也有少量生产(见表1).在美国B_2O_3总消费量的一半用于玻璃     

真空玻璃

真空玻璃与中空玻璃的性能相似,主要用于建筑物门窗,冷藏柜,保温柜和电冰箱,是优良的保温隔热材料,用在建筑物上还有隔音作用,真空玻璃的保温隔热性能更优于中空玻璃。     

池窑鼓泡对熔制玻璃质量和产量的影响

利用Flutank玻璃熔制过程三维计算机模拟技术,系统研究了鼓泡对熔制玻璃质量、产量的影响.结果表明:鼓泡使窑内熔体温度升高、流速加快,玻璃熔制、均化条件改善,微细气泡澄清条件变差,玻璃单耗降低.对文中选用的浮法窑,鼓泡能提高日产量23%,并维持原有的熔制、均化、冷却条件不变.池窑鼓泡后,日产量增加不会改变可见大气泡(半径小于0.5mm)的排除条件,但影响可见小气泡(半径小于0.25mm)和微细气泡(半径小于0.1mm)的澄清.模拟结果还揭示:鼓泡虽然略微降低出料口截面热均匀性,但不会出现分层现象.鼓泡管间距选择不当会产生有害的"沉降流".     

Shrinkage of an oxygen bubble rising in a molten glass

The mechanisms controlling the evolution of a bubble surrounded by molten glass are important to understand in order to improve melting in glass furnaces, particularly during a change in composition. In order to provide insight into this phenomenon, the behavior of an isolated bubble rising in molten glass is examined both experimentally and numerically.An experimental procedure developed specifically to observe, in situ, a rising bubble is described. Two soda-lime-silica compositions are tested, with low and high iron content, respectively.The numerical model used to describe bubble shrinkage is based on the results recently proposed in Pigeonneau (2009). A specific mass transfer coefficient is used for oxygen where the oxidation–reduction reaction of iron oxides is taken into account.A comparison between the experimental and numerical results shows the importance of the oxidation–reduction reaction of iron in the mass transfer of oxygen. The shrinkage rate of a pure O₂ bubble is enhanced with reduced molten glass iron content.     

Foaming in Glass Melts Produced by Sodium Sulfate Decomposition under Isothermal Conditions

The factors controlling the behavior of foam produced in molten glass by sulfate decomposition are sulfate oversaturation (determined by the initial sulfate concentration, fraction of sulfate dissolved, and melting temperature), bubble nucleation (occurring predominantly on the residual silica grains), and film stability. The connection between the foam generation and variation in melting temperature and silica grain size has been experimentally investigated by observing the melting process in a transparent silica crucible. A generation/release model for the time variation of gas-phase volume retained in molten glass has been developed. The analysis of experimental data using this approach suggests that two forms of sulfate produce foam during melting: (1) sulfate dissolved in melt and (2) sulfate from sulfate-rich melt surrounding sand grains.     

鼓泡技术在节能型玻璃纤维池窑上的应用探讨

介绍了玻璃液鼓泡的过程、作用和应用实施的情况。鼓泡技术的实施有效改善了玻璃液质量,减少微气泡数量,加强了上层玻璃液与深层玻璃液间的热交换,提高了深层玻璃液温度,起到了强制均化作用,达到了提高成品内在质量、节支降耗、增产提效的目的。     

X-ray imaging of a high-temperature furnace applied to glass melting

The dynamics of soda-lime-silica glass grain melting is investigated experimentally using a nonintrusive technique. A cylindrical alumina crucible is filled with glass cullet and placed into a furnace illuminated by an X-ray source. This glass granular bed is gradually heated up to 1100°C, leading to its melting and the generation of a size-distributed population of bubbles rising in the molten glass. An image processing algorithm of X-ray images of the cullet bed during melting allows the characterization of bubbles size distribution in the crucible as well as their velocity. The introduction of tin dioxide μ-particles in the glass matrix before melting enhances the texture of the images and makes possible the determination of the bubble-induced molten glass velocity field by an optical flow technique. The bubble size distribution can be fitted by a log-normal law, suggesting that it is closely related to the initial size distribution in the cullet bed. The liquid motion induced by the bubbles in Stokes' regime is strongly affected by the flow confinement and the determination of bubble rising velocity along its trajectory unveils the existence of local tiny temperature fluctuations in the crucible. Overall, the measuring techniques developed in this work seem to be very promising for the improvement of models and optimization of industrial glass furnaces.     

X‐ray tomography of feed‐to‐glass transition of simulated borosilicate waste glasses

High‐level waste feed composition affects the overall melting rate by influencing the chemical, thermophysical, and morphological properties of a cold cap layer that floats on the molten glass where most feed‐to‐glass reactions occur. Data from X‐ray computed tomography imaging of melting pellets comprised of a simulated high‐aluminum feed reveal the morphology of bubbles, known as the primary foam, for various feed compositions at temperatures between 600°C and 1040°C. These feeds were formulated to make glasses with viscosities ranging from 0.5 to 9.5 Pa s at 1150°C, which was accomplished by changing the SiO₂/(B₂O₃+Na₂O+Li₂O) ratio in the final glass. Pellet dimensions and profile area, average and maximum bubble areas, bubble diameter, and void fraction were evaluated. The feed viscosity strongly affects the onset of the primary foaming and the foam collapse temperature. Despite the decreasing amount of gas‐evolving components (Li₂CO₃, H₃BO₃, and Na₂CO₃), as the feed viscosity increases, the measured foam expansion rate does not decrease. This suggests that the primary foaming is not only affected by changes in the primary melt viscosity but also by the compositional reaction kinetic effects. The temperature‐dependent foam morphological data will be used to inform cold cap model development for a high‐level radioactive waste glass melter.     

光学玻璃对含锆耐火材料侵蚀机制研究

通过对光学玻璃电熔窑的实际观测,研究了光学玻璃对含锆耐火材料侵蚀作用。在熔窑的不同关键部位,选取有关耐火材料进行SEM测试,通过熔窑不同部位的耐火材料受高温玻璃液侵蚀的程度,分析了光学玻璃对锆耐火材料侵蚀机理与行为过程。结果表明:熔窑的熔化部耐火材料的受侵蚀程度较小,流液洞与供料道处耐火材料的受侵蚀程度最为严重,上升流道壁砖的竖缝处有严重的耐火材料侵蚀。AZS耐火材料在与高温玻璃液的接触中,形成了成分相互扩散→溶解→再扩散→再溶解的往复循环过程。     

Flutank玻璃熔制过程三维计算机模拟软件系统的应用(1)——浮法熔窑保温对玻璃熔制质量的影响

利用Flutank玻璃熔制过程三维计算机模拟软件研究了浮法熔窑不同部位保温对玻璃熔制、澄清、均化质量的影响.评价指标包括池内玻璃液温度场、速度场、砂粒熔化时间、玻璃液回流量、回流耗热、液流澄清因子分布、澄清气泡消除和逸出情况、出料口玻璃液温度等.结果表明:窑池保温可提高玻璃液温度、缩短熔化时间、增加澄清因子、降低火焰温度,同时,它也增加回流以及微小气泡(半径小0.1mm)随出料流流出池窑的可能性.Flutank模拟软件还可用于窑体保温后火焰温度制度的调整匹配和冷却部液面冷却强度的确定.     

Evaluation of bubble suspension behavior in electrolyte melts

The viscosity of a molten electrolyte mixture commonly used in direct coal fuel cells (DCFCs) was evaluated. The measurements were obtained from near the melting temperature to a high temperature at which a considerably bubbly flow was induced by decomposition. A gravity-driven capillary viscometer was employed to obtain the viscosity data under low Reynolds flow conditions, using a modified Poiseuille flow relationship. The importance of carbon dioxide addition in measuring the intrinsic viscosity was clearly observed. In addition, the effect of the bubble suspension on the viscosity was quantified in terms of the volume fraction and capillary number. The results showed that the increase in viscosity was best explained only by the difference in the volume fraction of spherical bubbles in the electrolyte melt.