用于玻璃电熔窑中钼电极的研究

阐述了钼电极的使用条件及注意事项,从玻璃成分、温度和电流密度等方面分析了钼电极的腐蚀情况,以及在使用过程中气泡排除问题等,并对钼电极在玻璃工业中应用提出一些具体要求.     

马蹄焰池窑内的火焰长度

提出了对马蹄焰池窑内最佳火焰长度的要求。介绍并分析了火焰长度对窑内温度(火焰空间温度、液面温度和窑顶内表面温度)及对窑池内液流影响的数值模拟的结果。     

The Effect of Flame Length on Hydrodynamics of Glass-Melting Tank in a Furnace with Horseshoe-Shaped Flame

It is demonstrated that the hydrodynamics of a melting tank of a contemporary highly efficient glass-melting furnace depends on a set of combined factors. Along with temperature distribution on the melt surface depending on exterior heat exchange, convection flows to a large extent depend on the tank design, the batch loading, and glass melt working conditions, as well as the working flow parameters determined by the specific output of the furnace. The combined analysis of the results of modeling external heat-exchange and the tank hydrodynamics suggest that the most advisable heating regime for the considered furnace design is when the total length of the flame is equal to the furnace length.     

Methods for Controlling Thermal Performance of the Glass-Melting Furnace

The specifics and control algorithms of thermal performance of a glass-melting furnace are described. The methods for setting and monitoring the temperature regulation parameters in the working space are analyzed. The results of calculation of the fuel rate, the maximum roof and glass melt temperatures, and their positions along the furnace depending on its output are given. The advantages of using a mathematical model for the construction of an automated control system for the thermal performance of the glass-melting furnace is demonstrated.__________Translated from Steklo i Keramika, No. 4, pp. 23 – 26, April, 2005.     

Determination of the Heat-Engineering Parameters of a Glass-Melting Tank Furnace in Changing from Oil Fuel to Natural Gas

The distribution of the thermal load between the burners of the glass-melting tank furnace is optimized and the conditions providing for the melting of the batch not further than opposite the second pair of burners are identified. Operating conditions that ensure complete combustion of fuel with an optimum quantity of excess air are determined. Recommendations are issued for the rational implementation of natural gas combustion in this type of furnace.     

Mathematical Model of a Glass-Melting Furnace with Horseshoe-Shaped Flame

A method for the construction and implementation of a mathematical zonal model of heat exchange in a glass-melting furnace with a horseshoe-shaped flame and an output of 300 ton/day is considered. The boundary conditions of modeling are described in detail. The authors give the results of the computation of external heat exchange and hydrodynamics of the melting tank, as well as regression equations of temperature fields for refractory brickwork, the flame space, and the glass melt surface.     

Mathematical Support for the CAD Technological Subsystem of a Glass-Melting Furnace

The advisability of constructing a CAD system for glass-melting furnaces is demonstrated. The main principles of the mathematical support for the CAD technological subsystem are formulated. The principles of constructing a mathematical model of the thermal performance of a furnace are described. The main equations providing for a combined solution of the exterior and the interior problems of heat and mass exchange taking into account the specifics of the physiochemical aspects of the glass-melting process are given.     

The Effect of Furnace Parameters on Fire Severity in Standard Fire Resistance Tests

This paper discusses the predicted results obtained from models developed to determine the effects of furnace depth (2.5 m and 0.5 m), type of furnace lining material type (fireclay brick, insulating firebrick and ceramic fibre insulation) and type of fuel (gas or liquid) on fire severity in fire resistance test furnaces using the CAN/ULC-S101, ASTM E119 and ISO 834 time–temperature relationships. The type of fuel used in the furnace and the type of furnace wall lining material significantly affected the heat absorbed by the test specimen while the furnace depth effect was minimal when the furnace was lined with ceramic fibre insulation. Factors to improve the repeatability and reproducibility of the fire severity in fire resistance test furnaces are provided.     

增加炉管对延迟焦化加热炉工艺参数的影响

对185万t/a延迟焦化装置加热炉进行了改造,在加热炉辐射段顶部新增6根炉管。结果表明,加热炉辐射段外表面积增加230. 81 m~2,辐射换热面积增大至1461. 84 m~2;进炉燃料气流量较改造前减少217 m~3/h;炉膛辐射室顶部、底部温度最高分别降低35℃、73℃。在加工负荷及炉出口温度基本相近的条下,与改造前相比,改造前加热炉反平衡效率为91. 62%,改造后加热炉反平衡热效率为93. 14%,加热炉反平衡效率提高了1. 52%。     

钼电极表面玻璃基防氧化涂层的研究

针对钼在高温下极易氧化的问题,开发了一种在烤窑时防止钼电极被氧化的玻璃基涂层.该涂层是以钡硅酸盐玻璃为主体,以Cr2O3为难熔填料,加入有机粘结剂,用松油醇做溶剂,配制成悬浮液,采用刷涂法涂覆于钼电极表面.研究了Cr2O3的添加量对涂层防氧化性能的影响.通过能谱(EDS)和恒温失重分析,比较了有涂层和无涂层保护时,钼基体表面氧含量的差异.结果表明,该涂层在较宽的温度范围内对钼电极有很好的保护作用.     

玻璃熔制技术最新动向

综述了玻璃生产中在提高玻璃熔制质量的同时所采取的节能降耗新技术-全氧燃烧和减压澄清.该技术不仅能节省大量能量,而且还使燃料燃烧产生的氮氧化物得到根除,对环境保护也起到积极的作用.     

A System for Dosed Feeding of Batch and Cullet Into a Glass-Melting Furnace

Possible variants of dosed batch and cullet feeding into a glass-melting furnace are described. The specifics of using discrete and continuous strain-gauge cullet weighing machines produced by Stromizmeteritel' JSC are considered.     

The Role of Convection in Glass-Melting Furnaces

The mechanism of formation and the dynamics of glass melt flows in glass-melting tank furnaces are considered. The results of some studies on this subject are analyzed.     

静电纺间位芳纶纳米纤维的制备工艺参数

通过静电纺丝方法,将氯化锂/N,N–二甲基乙酰胺(Li Cl/DMAc)溶解间位芳纶(PMIA)制备了PMIA纳米纤维,探索了溶液浓度、接收距离、纺丝电压及接收速度等工艺参数对纤维形貌及其直径分布的影响。通过扫描电子显微镜观察了PMIA纳米纤维形貌及应用Image-J软件测量统计了PMIA纤维直径。结果表明,溶液浓度为8%~10%、纺丝电压为16~18 k V、接收距离为15~20 cm,接收速度60~80 r/min的范围内,间位芳纶纳米纤维成型良好,直径分布范围为100~120 nm;PMIA纳米纤维直径随着溶液浓度的减小、静电电压的增加而减小,随着接收速度的增加纤维取向增加。     

先进复合材料球冠壳体结构参数对稳定性影响

先进复合材料层合壳体在航空、航天、国防领域中获得广泛应用。本文结合复合材料球冠光壳的结构特点,基于有限元分析软件ANSYS,采用层合壳单元建立有限元模型,研究了先进复合材料球冠壳体矢径比、厚度、铺层角度对其稳定性的影响。     

Studies of the Hydrogen Evolution Reaction on Raney Nickel—Molybdenum Electrodes

The hydrogen evolution reaction was studied in 1 M KOH at 25 °C on two types of electrodes:(i) pressed powders of Ni or NiMo with Al, heated at 700 °C; (ii) Ni—Al—Mo powders deposited by vacuum plasma spraying. These materials were treated with alkaline solution to leach out aluminum. Very active and stable Raney nickel—molybdenum electrodes were obtained from Al rich alloys. Adding molybdenum significantly improved catalytic activity. Electrochemical impedance spectroscopy was used to determine the apparent and intrinsic activities. Different ac models were tested and the appropriate one was selected. Intrinsic activities of these electrodes are smaller or equal to that of polycrystalline Ni and the origin of high apparent activities is related to the increase in real surface area.     

钼电极水平插入深度的确定

从多年玻璃电熔的设计、研究与实践出发,介绍了钼电极水平插入深度的问题以及复合式钼电极,对玻璃电熔中常用圆棒与矩形条状钼电极在水平插入时防高温蠕变安全使用强度进行了计算与研究,并将其结论长期用于工程设计。     

工艺参数对PS发泡复合材料泡孔形态的影响

在聚苯乙烯(PS)中加入成核剂,用自行研制的动态发泡模拟机研究了不同工艺参数(包括温度、压力、剪切流场等)对含有成核剂的PS发泡复合材料泡孔形态的影响。研究发现,不同的加工工艺参数对泡孔形态有很大影响,当温度、压力、转子转速等参数设定到一定值时,能得到最优的泡孔形态。     

The Effect of Process Parameters on the Pervaporation of Alcohols through Organophilic Membranes

Abstract

Several organophilic membranes were utilized to selectively permeate ethanol, n-butanol, and t-butanol from dilute aqueous mixtures using pervaporation (PV). Poly[1-(trimethylsilyl)-1-propyne] (PTMSP) membranes were utilized to investigate the effect of temperature, pressure, and start-up/transient time on the separation of aqueous ethanol mixtures. Results indicate optimal ethanol selectivity and flux at the lowest permeate-side pressure. Increased temperature significantly enhanced the productivity of PTMSP, but extended operation of the PTMSP membranes at high temperatures resulted in flux degradation. Two other hydrophobic membranes, poly(dimethyl siloxane) (PDMS) and a poly(methoxy siloxane) (PMS) composite, were used to separate n-butanol and t-butanol from dilute aqueous mixtures. The effect of feed concentration on the flux and selectivity was investigated. Both membranes were found to be more permeable to n-butanol than t-butanol. The PDMS membrane was found to be more effective than the PMS membrane in terms of flux and selectivity. The effect of membrane thickness on water permeation and on organic selectivity was also studied using the PDMS membrane.