高效沉降槽开发利用的初步评价

本文论述了新型高效赤泥分离沉降槽的槽型结构，与普通沉降槽进行了工业对照试验，得出该工业沉降槽具有强化设备产能，加快固液分离速度，降低△Ａ损、△Ｎ损，减轻过滤机负荷等优点；采用这种新型设备，可大大减轻工人操作的劳动强度，改善赤泥沉降工段的环保状况；从技术经济分析的角度，论证了该技术改造的可行性及效益性，强调了开发利用高效沉降槽是我国烧结法生产氧化铝工业中赤泥分离的一项新技术。     

赤泥沉降槽内液固分离运动计算机数值仿真初探

赤泥沉降槽是一种利用重力实现固体沉淀、固液分离浓缩的设备。本文借助江河泥沙沉降运动和水处理中污泥沉淀的方法比照研究赤泥沉降槽内的赤泥分享浓缩。作者采用计算流体力学中的mixture法试探研究赤泥分离问题。给出了其数学模型和边界条件。并对某一赤泥沉降槽进行了分析。所得到的赤泥沉降过程中赤泥体积浓度分层．这一结果与有关工程设计人员和专家的感知保持一致。     

赤泥分离系统提产途径的研究及开发

在氧化铝生产过程中,矿石或熟料经过溶出后,需要及时将铝酸钠溶液与赤泥进行分离,并对赤泥进行洗涤,以回收赤泥附液中的氧化铝和氧化钠,这一过程一般被称之为赤泥分离洗涤。在氧化铝生产过程中,液固分离设备一般采用真空过滤机和沉降槽。真空过滤机分离彻底,而沉降槽则具有处理量大,运行操作简单、成本低的优点,所以,矿石或熟料溶出后进行液固分离均使用沉降槽。     

强化赤泥沉降分离性能的探讨

本文结合试验和生产实践，对影响赤泥沉降分离性能的因素进行了分析，指出赤泥菜液的浓度、絮凝剂的质量和用量、沉降槽结构等是其重要影响因素。为了强化赤泥的沉降分离性能，不但要改善沉降槽结构，还需要选择高效能的絮凝剂并合理使用。     

赤泥沉降槽固液分离数值仿真技术的研究进展及现状

赤泥沉降槽内固液分离过程的数值仿真研究对沉降槽的高效化生产运行、经济化管理和设计具有重要作用。本文主要阐述了近十几年来国内外学者和专家运用计算流体力学方法并结合商业化计算软件在沉降槽中心桶结构、絮凝剂吸附和耙机设计,以及耦合群体平衡模型（PBM）计算等方面取得的一些重要科研成果,揭示了赤泥沉降槽固液分离计算模型和计算方法的发展历程;针对国内外沉降槽固液分离仿真计算的研究现状,以及固液分离沉降设备亟待解决的问题,展望了沉降槽固液分离数值仿真计算的发展前景,提出未来研究需要更合理、适用性更强的絮凝剂吸附模型,来对沉降槽进行仿真优化计算;最后指出今后沉降槽的发展和研究方向是高分子絮凝剂和沉降槽结构的研究,数值仿真技术仍然是赤泥沉降槽固液分离研究的主要方法和手段,特别是多相流颗粒群体平衡物理场耦合计算。     

拜耳法赤泥沉降分离影响因素探讨

在拜尔法生产氩氧化铝赤泥沉降分离过程中，赤泥分离效率的高低直接影响到产品产量和质量。文章针对矿石成分和品位、磨矿粒度、溶出液苛性比值、赤泥浆液固含、沉降槽温度、絮凝荆选型和用量沉降槽结构八个方面对沉降分离主要影响因素作探讨性分析。     

拜耳法赤泥沉降槽高效化改造

本文结合沉降槽生产实践，叙述了由传统沉降槽改造为高效沉降槽的改造方法和具体步骤。对传统沉降槽的高效化改造可强化赤泥分离洗涤指标，提高设备产能。     

拜耳法赤泥沉降工序工艺指标对生产的影响

对影响赤泥沉降工序的混合效率、沉降槽底流固含、洗水量、滤饼含水率、赤泥压滤液及细种子苛化液加入点等工艺指标分别进行计算，分析识别影响沉降工序处理能力因素。研究发现，分离及洗涤沉降槽底液液固比降低、混合效率提高、滤饼含水率降低、洗水量增加，都能够使赤泥的碱附损量降低。因此，可通过改进沉降槽、静态混合器、压滤机等来进一步优化生产指标；同时，赤泥压滤液及细种子苛化液的最佳加入点应为矿浆碱浓度高于且最接近洗水浓度的那一级沉降槽。     

氧化铝生产过程中赤泥快速分离的调控方法探析

本文阐述了在烧结法生产氧化铝过程中,影响溶出液采用沉降槽进行赤泥快速分离的主要因素,结合生产实践,指出了赤泥快速分离的有效措施。     

拜耳法赤泥沉降槽高效化改造

结合沉降槽的生产实践，介绍了由传统沉降槽改造为高效沉降槽的改造方法和具体步骤。在仍利用原有土建基础的前提下，按照高效沉降槽技术改进传统沉降槽结构，选用高效絮凝剂，增加絮凝剂加入点。传统沉降槽经过高效化改造后，可强化赤泥分离洗涤指标，提高设备产能。     

初级氧化槽预先部分脱砷工业化试验研究

在初级氧化的2#槽上利用旋流器进行预先脱砷工业化试验,在保证正常生产的情况下,将试验槽内的砷离子浓度降到了7 g/L左右(参照槽的砷离子浓度在11 g/L左右),减少了溶液中砷对细菌的影响,提高了氧化能力,试验期间试验槽的平均日处理量比对比槽提高了13%左右。     

矿浆电解槽内固液搅拌对隔膜变形的影响

矿浆电解作为一种短流程湿法冶金工艺,隔膜袋在搅拌桨搅动及矿石的磨损下会产生变形,甚至出现破裂,严重制约了生产效率.针对该问题,基于单向流固耦合原理,采用计算流体力学与固体有限元相结合的方法对矿浆电解搅拌槽内隔膜变形规律进行了全三维解析.研究发现隔膜袋两侧压差是导致变形的根本原因,最大变形量出现在垂直高度y=1.2 m位置处,且搅拌转速越大,隔膜变形所需的最佳液位差越小.当阴极区压力不足时,隔膜袋向内挤压变形;压力增加后,则向两侧鼓包.隔膜最大变形量随流体域固体体积含量（SL）的增加先减小后增加,在SL=15%时,隔膜变形达到最小值226.7 mm;越靠近槽下部,SL对绝对压力的影响越大.添加框架约束后,隔膜最大变形量减小到0.664 mm.通过可视化的解析,可以为矿浆电解工业控制提供参照.     

Improvement of Submerged Biofilter Process by Bioelectrochemical Method

A bioelectrochemical method was applied to a submerged biofilter process to improve its nitrogen removal performance. Packed beds of activated carbon submerged into the aerobic tank of the submerged biofilter process were used as the electrodes and support for attached microbial growth. The experiments were conducted under different temperatures, dissolved oxygen (DO) concentrations and electric currents. The results showed that nitrification and denitrification rates were enhanced by supplying oxygen and hydrogen, respectively, from the substratum through electrolysis of water. The nitrification and denitrification rates were increased with increasing electric current. The effects of electric current on nitrification and denitrification rates were clearly shown under lower bulk liquid DO concentration. There was an optimum DO concentration to give the largest nitrogen removal rate in the bioelectrochemical compartment. The optimum DO concentration was in the range of 1.5–2.0 g∕m3.     

Chemical Oxygen Demand and the Mechanism of Excess Sludge Reduction in an Oxic-Settling-Anaerobic Activated Sludge Process

A modified activated sludge process, called the oxic-settling-anaerobic (OSA) process, achieved effective reduction in excess sludge production. Its key feature is the insertion of a sludge holding tank in the sludge return circuit to provide an anaerobic sludge zone. Our previous studies suggested that such excess sludge reduction might be associated with an increased sludge decay rate and the effective consumption of organic substrates generated during the retention of the thickened sludge in the sludge holding tank under a low oxidation-reduction potential (ORP) at ?250?mV. To confirm this suggestion, we analyzed the chemical oxygen demand (COD) balance in the sludge holding tank through batch experiments to simulate the sludge concentration, ORP level, and retention time in the sludge holding tank. The COD generated from the sludge reduction in the tank was utilized by organic gas (mainly CH4) production, denitrification, sulfate reduction, and phosphorus release, among which the gas production accounted for 50% of the COD utilization. We confirmed that the mechanism of the excess sludge reduction in the OSA process is through enhancement of the sludge decay rate in the anaerobic sludge zone, which increases the soluble COD level, which in turn is mainly transformed into methane gas and carbon dioxide during denitrification.     

Air Injection in Water with Different Nozzles

Air injection systems have a wide range of environmental engineering applications. In this study, we conducted experiments on air injection in a relatively large water tank to investigate the effect of nozzle type, including single/multiple orifice nozzles and a porous airstone, on the characteristics of the bubbles and the induced flow structure. Measurements of bubble characteristics and flow field surrounding the bubble core were obtained using a double-tip optical probe and particle image velocimetry, respectively. The results revealed that bubble velocity did not change significantly with different nozzles, but bubble size decreased significantly while interfacial area, liquid entrainment rate, and kinetic energy of the mean and turbulent flow increased significantly by using the porous airstone instead of nozzles with large orifices. The results for a nozzle with multiple orifices of small diameter are comparable to those for the airstone, which suggests the suitability of its use for systems susceptible to clogging of the pores. Correlations using adequate length and velocity scales are also proposed to describe both bubble and liquid flow characteristics. Finally, applications of the results for different artificial aeration/mixing systems are presented.     

210t RH精炼炉脱氢工艺研究与应用

文章分析了钢水增氢原因以及影响RH精炼脱氢效果的因素,指出在目前状况下真空处理时间超过20 min对脱氢效果不明显,真空下部槽减薄后对RH脱氢效果较明显,RH精炼的平均脱氢效率为76%。     

舞钢VOD炉热井液位PID控制系统的开发及应用

针对舞钢公司VOD炉热井系统对恒液位的需要,介绍了一种水箱恒液位PID控制系统的开发与设计。该系统通过西门子S7-400系列PLC指令实现对液位的PID闭环控制,液位传感器将液位值作为反馈信号传给PLC,对变频器进行调节控制,实现电机转速调节,从而达到恒液位控制目的。运行结果表明改造取得了节能降耗的效果。     

WHJ型泵在洗酸罐设施中的试验与研究

介绍使用WHJ型泵抽取硫酸罐车中的余酸或洗罐液的情况，可彻底吸净余酸或洗罐液，减少中和过程中碱的使用量，对工厂环保具有积极意义。     

定炉定罐制度在张钢的应用

为了消除铁水罐底铁对生铁质量的影响 ,张钢制定了定炉定罐制度 ,每只高炉铁水由固定罐装运 ,从而保证了生铁质量 ,提高了工作效率 ,有效地指导高炉顺产 ,品种铁炼出率提高 5 .2 % ,取得了显著效益。     

Effect of Tank Size and Geometry on the Flow Induced by Circular Bubble Plumes and Water Jets

Ambient flow field and circulation patterns induced by circular bubble plumes and water jets in tanks of different sizes were studied in rectangular and square water tanks. A nonstationary nature of the flow was observed in all experiments and its dominant oscillation frequency was found to directly relate to the tank size. The flow circulation patterns were similar for bubble plumes and water jets, but changed significantly with tank size and geometry. Strong three-dimensional effects were observed in a rectangular tank, resulting in flow entraining in the longer plane and flow detraining in the shorter plane, especially for the bubble plume tests. A relationship was developed to relate the tank size to the patterns of circulation cells. Nearly isotropic turbulent flow conditions were obtained in all experiments, but the effect of tank size and geometry on the magnitude of the turbulent stresses was more pronounced in the bubble plume tests.