硅砖隧道窑存在的问题及改进措施

对硅砖隧道窑进行综合技术改造，使其不仅能满足烧成优质硅砖的需要，而且各项经济技术指标也有明显提高。     

热风炉用低蠕变硅砖的研制

为了满足热风炉生产的要求,通过选择硅石原料、确定试样配方和烧成制度研制了一种热风炉用低蠕变硅砖。结果表明,采用混合硅石配料制砖,以65%～75%(w)的硅石A颗粒和25%～30%(w)的硅石B细粉配料,在隧道窑中于1 450℃48 h烧成制备的硅砖,无裂纹,其w(鳞石英)=65%,w(残余石英)=0.66%,高温蠕变率(0.2 MPa,1 500℃,25 h)为-0.03%。     

烧失剂对轻质硅砖的影响

采用废硅砖熟料生产轻质硅砖,通过选用无烟煤粉、复合烧失物XW、焦炭粉等作为烧失剂分别进行添加填充实验,研制出成品轻质硅砖,通过对实验结果的对比分析,优选出一种可以明显减少烧成时制品飞边飞棱现象、提高产品外观质量的烧失物。     

倒焰窑热工特性实验研究

通过对一座燃煤硅砖烧成倒焰窑历时 1 6d的热工过程参数和热平衡测定 ,剖析了倒焰窑的热工工艺、环境及能耗特性 ,并在此基础上探讨了这种设备的改进方向和预期效果。     

硅砖裂纹产生的机制

硅砖生产过程中由于砖体受环境温度的急剧变化,内部产生较强热应力,当强度达到制品的强度极限值时,即产生裂纹甚至开裂。硅砖裂纹主要产生在成型和烧成阶段,但是粉料配料、泥料混炼以及干燥、装车等工序控制不当也会产生裂纹废品。因此,要降低废品率,控制好成型和烧成工序至关重要,但其它工序的操作也不容忽视。     

热风炉高温区用硅砖中鳞石英的结构演变

研究了热风炉蓄热室中部(工作温度1 470℃)使用10a以上硅质格子砖的性状,对使用前后硅砖的相组成、微观结构和物理性能进行了表征和分析,检测了使用前和使用后的硅砖蠕变性能,结果表明:1 450℃使用前后硅砖的蠕变率分别为0.008%、-0.025%;1 550℃使用前后硅砖的蠕变率分别为-0.154%、-0.135%。用后硅砖只有鳞石英相存在,1 450℃用后硅砖蠕变相当于纯鳞石英陶瓷的蠕变特征。用后硅砖中鳞石英呈连续网络状分布,表现为优良的抗蠕变性能。1 550℃用后硅砖蠕变的特征为有部分鳞石英向方石英转变过程。硅砖微观结构从使用前的典型骨料-基质耐火材料结构演变为使用后的均质化鳞石英陶瓷材料结构。建立了硅砖微观结构演变的反应机理模型。     

四元矿化剂对硅砖微观形貌及物理性能的影响

以两种不同粒径的石英砂为原料，石灰乳和纸浆废液为结合剂，经1 430℃高温烧成制备硅砖，研究复合矿化剂及保温时间对硅砖物相组成、显微结构及主要物理性能的影响规律。研究结果表明，经1 430℃保温10 h后，烧成试样由鳞石英、方石英及少量残余石英组成。添加铁鳞粉-CaO-MnO₂-SiC或铁鳞粉-CaO-MnO₂-TiO₂四元矿化剂时，硅砖中典型的骨料-基质耐火材料结构消失，并逐步出现“均质化”效应。当矿化剂为铁鳞粉-CaO-MnO₂-TiO₂时，经1 430℃保温10 h后，烧成试样具有较好的综合性能，其体积密度、显气孔率及常温耐压强度分别约为(1.93±0.01) g·cm^-3、(14.9±0.1)%及(55.05±0.64) MPa。在最佳矿化剂组分及烧成制度基础上，延长保温时间至15或20 h时，材料中残余石英含量降低，但鳞石英含量增大，导致体积膨胀效应增强，使材料的物理性能受损。     

焙烧介质和工艺参数对硅质制品性能和相组成的影响

本文研究了焙烧气体介质和其它工艺因素对硅砖性能及其中氧化硅转化程度的影响。根据试样相组成和性能的对比分析结果，推荐以下参数作为使用干矿化剂的硅砖最佳制造工艺参数：硅石颗粒尺寸不大于２ｍｍ；成型压力不低于５００ＭＰａ，烧成温度１４２０℃。根据岩相研究和Ｘ射线照相研究表明，硅砖在还原介质中焙烧是最好的，它能促进硅砖中石英更完全转化并保证硅质制品具有很高的使用性能。     

Φ4.0 m×60 m回转窑系统提产降耗改造实践

对Φ4.0 m×60 m回转窑系统进行提产降耗技术改造，针对生产中存在的预热器出口温度和压力偏高、冷却机热回收效果差等一系列问题，对烧成系统和辅机设备进行了系统性的改造，克服提产降耗瓶颈，以回转窑为中心，保证前后段烧成设备的性能参数相匹配。改造后窑产量可达4 100 t/d，熟料标准煤耗也有大幅度的降低，改造达到了预期的效果。     

干矿化剂硅砖烧成时二氧化硅转化的动力学及物理化学

查明了采用石灰石细粉制造的硅质制品中相形成的规律，Ｘ射线相组成，岩相分析等研究结果表明，利用石灰石细粉配合黄铁矿渣作矿化剂生产硅砖时石英向二氧化硅高温形态的转化过程要比采用传统的石灰铁质混合物作矿化剂时进行得更强烈一些，这与所用矿化剂的矿物组成特点及烧成时发生的物理化过程有关，查明了含有干矿化剂的硅砖于１２００～１４２０℃烧成及于最高温度保温时，二氧化硅向高温形态转化的动力学及其与温度之间的关系，     

汽车用灯头的注射模设计

针对汽车用塑料灯头的结构特点与工作环境,分析了灯头结构的复杂性、材料性能,注身工艺条件、合理地设计了注射成型模具,采用了组合式下模型芯来完成内孔的复杂成型,同时采用组合式侧抽芯来完成外侧面的卡钩与上面的穿线孔的成型,简化了模具的结构。     

Criteria for the affinity of dyes for fibres

An equation was obtained for evaluating the thermodynamic affinity of a disperse dye for a fibre. Quantities Δh _D and K _D , which are functions of the composition of the dye bath, temperature, and state of the fibre material, can characterize the change in the affinity of the dye for the fibre when the dyeing conditions are varied.     

活性石灰回转窑用耐火砖损坏原因及对策

分析了活性石灰回转窑用耐火材料的损坏原因,认为炉衬的附着物质与氧化硅和氧化铁的反应有关,硅酸钙与CaO是结圈的主要成分.改善耐火材料可以提高其使用寿命.     

新型气化型煤粘结剂

介绍一种新型气化煤粘结剂的制备方法和粘结作用机理，该粘结剂属有机粘结剂，粘结能力强，煤种适用范围广。制取的气化型煤机械强度高，灰份低，固定碳含量高。     

Strategy for development of fertilizer solutions for greenhouse tomatoes

A study of fertilization practices in intensively grown tomatoes, leading to a projection of developments in fertilizer usage is presented. Targets of optimal fertilization strategy were defined as follows: maximize fruit yield; maximize fruit quality; minimize environmental pollution with fertilizers; minimize corrosion of the fertilizer distribution system; minimize expenses on fertilizers. Information was gathered by literature searches and by personal interviews and visits to research institutes and growers.Rechecking of some fertilization practices for greenhouse tomatoes grown in detached media is proposed. The review indicates that the following should be rechecked: ammonium/nitrate ratio in fertilizer formulations; use of urea in fertilizer solutions; levels of phosphates applied; levels of sulphate applied; simple iron salts vs. chelated iron application; osmotic potential (OP), expressed as electrical conductivity (EC), of the nutrient solution at various growth stages.EC, pH and estimated prices of fertilizer solutions were calculated and presented in tables.     

Comparison of different flowability tests for powders for inhalation

A series of placebo powders for inhalation was characterized regarding bulk density and powder flowability using different techniques. The powders were of the ordered mixture type and were prepared by mixing a pharmaceutical carrier grade of lactose with different fractions of intermediate sized and fine (i.e., micronized) lactose. A modified Hausner Ratio was obtained by measurement of the poured and the compressed bulk densities. Other tests investigated were the angle of repose, the avalanching behaviour using the AeroFlow, and the yield strength using the Uniaxial tester. Furthermore, the relation between ordered mixture composition and flowability was examined.Of the methods investigated, the modified Hausner Ratio discriminates well between the investigated powders and seems to have the widest measuring range. It was also found that the poured and compressed bulk densities provide information about the packing of the particles in the powders. A good correlation was obtained between the modified Hausner Ratio and the angle of repose. The AeroFlow was suitable for powders with a low percentage of fine particles, but could not discriminate between the more cohesive powders. The Uniaxial tester, on the other hand, seems to be better suited for more cohesive powders.Regarding the powder composition, addition of micronized particles has a strong influence on the flowability of ordered mixtures, while intermediate sized particles have little impact on the powder flow.     

建筑工程玻璃企业生产过程控制措施

房地产业的快速发展也给建筑工程玻璃企业带来了巨大的市场前景。面对如此机遇,企业如何对生产过程进行有效的控制,生产出客户满意的产品,使企业不仅具有良好的市场信誉度,而且也获得了发展空间。     

焊制三通雌雄样板计算机放样软件的开发

应用VC 语言开发了焊制三通雌雄样板放样软件,该软件能快速、准确地完成正三通、斜三通、顺流三通、Y型三通雌雄样板的放样工作。详细介绍了程序的编制过程以及软件的特点。     

Guidance for Mutual Disposition of Chromophores for Singlet Fission

The choice of chromophores and of their mutual geometrical arrangement for optimized singlet fission (SF) rates are considered. The electronic matrix element that enters the Fermi golden rule for the rate of SF is worked out algebraically for a simple model, but the density of states factor is not analyzed here. The model treats only the highest occupied and lowest unoccupied orbitals of the partners. It provides an approximate formula that requires only the knowledge of the expansion coefficients of these orbitals and of overlap integrals between atomic orbitals on the partners to obtain an estimate of the electronic matrix element. An illustrative application to a pair of ethylene molecules suggests that favored geometries will be those in which one of the AOs on the first ethylene overlaps with both AOs on the second ethylene, while the other AO on the first ethylene overlaps with at least one, and preferably both, AOs of the second ethylene as little as possible.