新型内循环生物流化床反应器氧传质特性研究

实验对新型内循环生物流化床几种结构的氧传质系数进行比较 ,从而选出最优结构。在此基础上考察了空气流量、固含率、曝气装置对该反应器氧传递特性的影响。实验结果表明挡板尺寸大 ,距反应器底部近 ,气量大氧传质效果好。同时 ,固含率影响氧传递效果。     

四喷嘴射流曝气器性能的三维数值模拟与实验研究

应用FLUENT对四喷嘴射流曝气器在不同工况下的引射空气性能进行三维数值模拟,分析了射流器内的场分布特性与气液两相流动结构;同时建立射流器性能实验台,对四喷嘴射流曝气器的性能进行实验研究。研究表明,四喷嘴射流器性能较高,能量损失较少,两相流动结构稳定;相对于单喷嘴射流器,四喷嘴射流器的流量比和效率随压力比的变化显著;四喷嘴射流曝气器在工况4下工作性能最好,其流量比q为3.20,效率η为36%,而相似工况下单喷嘴结构流量比q仅为1左右,效率η不超过20%;数值模拟结果与实验结果吻合较好。     

射流曝气的气液两相流的数值模拟

射流曝气在活性污泥处理方法中起着重要的作用.采用数值模拟的方法研究自吸式单级单喷射流器中的气液两相流动状况,通过对不同长径比和喷嘴面积比的射流曝气器模型的气液两相流的计算,定量分析长径比和喷嘴面积比对射流曝气器流场和空气与工作介质流量比的影响,为进一步设计开发新型高效的射流曝气器提供参考.     

低压供气式射流器工业化性能研究

简要介绍了低压供气式射流器的工作原理和作用,对其在氧化沟污水处理工艺中的氧利用率和动力效率等因素做了测试和分析,比较了不同水深对充氧性能的影响。结果表明,低压供气式射流曝气器氧利用率达23.17%,动力效率达2.43 kg O2/(kW.h),优于其他形式的曝气设备,可以有效降低能耗。     

分体式射流曝气器的试验研究

设计研制了一种新型的射流曝气器(也称分体式射流曝气器),提出了分体式设计的概念,它主要应用于小型和高浓度工业废水的实际处理工程中.在较宽的试验范围内着重研究了3个参数(长径比R₁、喉嘴比R₂和吸嘴比R₃)对吸气量的影响.结果表明:在较宽的喉嘴比范围内,吸气量存在波动,最佳喉嘴比出现的位置与混合管的长度有关;吸嘴比对吸气性能影响不大;长径比对吸气性能影响较大,最佳长径比可以在过渡区中寻找;试验结果同时也证实应用CFD数值仿真进行射流器的设计是可行的,本射流器的吸气量(900～1 100 L/min)和搅动范围均较大.     

Destratification and oxygenation efficiency of a water-lifting aerator system in a deep reservoir: Implications for optimal operation

Thermal stratification is a common phenomenon in lakes and reservoirs and has a significant influence on water quality dynamics.Heihe Reservoir is a canyon-shaped reservoir in Shaanxi Province with strong thermal stratification.Therefore,eight water-lifting aerators(WLAs) were installed in this reservoir,which could overcome thermal stratification and increase oxygenation with gas flows between 20 and 50 m3/hr,and oxygenate the hypolimnion with gas flows less than 20 m3/hr.To examine the destratification efficiency of the WLA system,we used a threedimensional hydrodynamic module based on MIKE 3 to simulate the thermal structure of Heihe Reservoir and compared the simulations with measured data.Results showed that operation of the WLA system promoted water mixing and effectively oxygenated the hypolimnion.Through the established energy utilization assessment method,the energy utilization efficiency of the WLA system was between 5.36% and 7.30%,indicating the capability of the technique for destratification in such a large reservoir.When the surface water temperature dropped to the theoretical mixed water temperature calculated by the energy utilization assessment method,reducing gas flow could save energy.This would prevent anaerobic conditions from occurring in the bottom water and maintain good water quality in Heihe Reservoir.     

国内外的潜水搅拌机和倒伞曝气机能效比较

本文对国内外污水处理设备中的潜水搅拌器（机）和倒伞曝气机在能耗和效率方面进行了对比，应用实践证明，国产污水处理设备的能效比远远优于引进及仿制的国外同类产品。     

氧化沟的水力计算

阐述了氧化沟进水流量、循环流量和断面平均流速的关系 ,分析了沟内平均流速所起的作用及调节方法 ;分析了提升水头与水头损失的关系 ,给出了它们的计算方法 ;对弯道导流板的作用进行了剖析 ,提出了导流板偏置可以减少导流板的数量 ,降低弯道摩阻 ,并可以避免弯道隔墙背流处的固体沉淀。     

FIELD TESTING OF AN ICE-PRESERVING WINTER LAKE AERATION SYSTEM1

ABSTRACT: Artificial aeration is used to prevent winter fish kills due to oxygen depletion in ice-covered lakes. Conventional aeration by air bubble plumes and other techniques usually mixes the water column and produces hazardous open water in the ice cover. A non-mixing winter lake aeration system which creates a fish refuge was designed and field tested to oxygenate the water and maintain water temperature stratification in a lake such that no open water is created. The system uses a cascade aerator and has a design discharge and dissolved oxygen input rate of 85 1/s and 70 kg/d, respectively. Aerated water is discharged near mid-depth with minimum disturbance of the ambient water through a specially designed diffuser. The system was tested in a shallow 3 m deep lake of 17 ha surface area during two winters and was found to perform as expected. Significant photosynthetic production of dissolved oxygen under the ice-cover was also observed during snow-free periods.     

微孔盘曝气系统中悬浮填料挂膜特征研究

在微孔盘曝气系统中,针对悬浮填料挂膜过程,展开中试试验研究。试验结果表明,在HRT仅1h的连续流曝气系统中,悬浮填料挂膜快。曝气强度不同,悬浮填料挂膜特性和生物膜量以及对COD的去除效果相差很大。试验发现微孔盘曝气系统中悬浮填料的最适宜曝气强度范围为8～10m3/(m2·h),在此范围内,系统的溶解氧为3.9～5.2mg/L,生物膜量为3.3～3.5g/L,对COD的去除率在70%～80%。在上述基础上还对不同型号的悬浮填料进行了优选。