沉降罐排泥工艺运行探讨

本文简要概述了沉降罐排泥技术的概况和发展现状,然后重点介绍了内置式刮吸泥机排泥、负压排泥技术和静压穿孔排泥三种排泥方式,最后对这三种排泥方式进行了相应的比较。     

沉降罐排泥工艺运行探讨

本文简要概述了沉降罐排泥技术的概况和发展现状,然后重点介绍了内置式刮吸泥机排泥、负压排泥技术和静压穿孔排泥三种排泥方式,最后对这三种排泥方式进行了相应的比较。     

一种新型刮吸泥机的研制与应用

介绍了油田污水站沉降罐排泥情况,并对比了几种大罐排泥情况.为排净大罐污泥,临盘采油厂研制了内置式刮吸泥机,经过在采油二矿四净站实际应用,证明此刹泥机实现了不停产排泥,排泥有效率>95%,具有维护成本低,经济效益显著的优点.     

门式起重机塔架系统稳定性分析

介绍了MYQ型5000t门式起重机塔架系统在最大动载载荷试验、最大静载载荷试验以及单塔悬臂工况最大提升载荷情况下的受力情况,建立了起重机在不同工况下塔架系统有限元模型并分析获得应力云图,结合试验测试数据验证有限元分析的准确性。初步探索了起重机塔架系统的受力情况,并为进一步建立起重机不同工况、不同提升载荷情况下的有限元模型及分析进行了初步研究。     

气固流化床启动阶段挡板内构件受力特性的CFD-DEM模拟

流化床启动阶段内构件会受到较大的破坏性载荷冲击,为了保障流化床内构件的长周期可靠性,需要掌握这个阶段内构件在流化床内的受力特性。首先提出了一种统计内构件表面受力的方法,将微观颗粒-挡板作用信息转换为宏观挡板受力载荷信息。在此基础上采用CFD-DEM方法,统计分析了流化床启动阶段床层中水平挡板内构件的受力载荷特性。研究结果表明：CFD-DEM方法可半定量复现实验中启动阶段内构件表面受到的动态载荷信号,并复现了表观气速和颗粒粒径对挡板峰值载荷强度的影响规律。本研究证明了内构件表面受力载荷强度统计方法的正确性和CFD-DEM统计分析受力载荷的可行性。     

污水处理厂平流沉淀池吸泥机改造

针对北方露天污水处理厂风大,污物多的情况下,平流沉淀池吸泥机出现的问题,通过分析吸泥机的构造,对吸泥机进行优化改造,解决吸泥机管路堵塞,吸泥泵难以起吊以及水下结构不稳定的问题,使得吸泥机运行效果稳定,从而提高环境效益和经济效益。     

载重子午线轮胎帘线受力有限元分析

基于ABAQUS非线性有限元分析软件建立12.00R20载重子午线轮胎有限元模型,并分析轮胎在标准充气压力、不同载荷条件下静态加载时帘线受力变化的基本特征.结果表明,负荷对轮胎接地区域内帘线受力影响显著,带束层和胎体帘布层以接地影响区边缘为帘线受力变化的分界点;胎圈部位胎体帘线受力随载荷增大而减小的幅度很小,有利于减小胎体端部的应变.     

轴向载荷作用下油管接口螺纹的受力分析

由于油管受轴向载荷的作用,其连接螺纹处的受力非常不均匀,导致了油管接口的承载力下降。针对油管中存在的轴向载荷的情况,建立了油管接口螺纹的力学模型,并对油管螺纹的受力情况进行了有限元分析,研究了油管螺纹在轴向载荷作用下,螺纹牙的应力分布规律。研究结果表明:各螺纹牙的受力分布很不均匀,两端螺纹牙受到的应力最大,因此,首先发生强度破坏部位是两端的螺纹牙,在进行油管检测时应着重检测接口两端的螺纹牙。     

抽油杆运动中存在的一个阻尼振动

有杆抽油泵抽汲参数的选择会影响到油气开采的泵效及抽油机和抽油杆柱的使用年限,本文通过分析抽油杆柱的受力模型,知道了抽汲参数对抽油杆柱受力载荷有一定的影响,根据已有资料,导出了抽汲参数与抽油杆柱受力载荷之间的关系。通过Matlab软件绘制了柱塞与泵筒之间的摩擦力和冲次之间关系的曲线图,最后发现柱塞与泵筒之间存在一个与冲次有关的阻尼振动。     

TSF导轨软带的粘接

TSF软带是广州机床研究所近几年研制成功的机床导轨抗磨材料。它的特点是摩擦系数低,静动摩擦系数差值小,以及有正斜率的摩擦—速度特性曲线。这就防止了机床的低速爬行。在无油或少油润滑情况下不致咬伤导轨。无论在轻载荷或重载荷下都能快速定位,能有效地消除振动,减少摩擦面的磨损,提高机床加工精度,延长机床使用寿命。这是近几年发展起来的较为理想的机床导轨材料。     

GRAVITY SETTLING OF HANFORD SINGLE-SHELL TANK SLUDGES

ABSTRACT

The U.S. Department of Energy plans to use gravity settling in million-gallon storage tanks while pretreating sludge on the Hanford site. To be considered viable in these large tanks, the supernatant must become clear, and the sludge must be concentrated in an acceptable time. These separations must occur over the wide range of conditions associated with sludge pretreatment. In the work reported here, gravity settling was studied with liter quantities of actual single-shell tank sludge from Hanford Tank 241-C-107. Because of limited sludge availability, an approach was developed using the results of these liter-scale tests to predict full-scale operation. Samples were centrifuged at various g-forces to simulate compaction with higher layers of sludge. A semi-empirical settling model was then developed incorporating both the liter-scale settling data and the centrifuge compression results to describe the sludge behavior in a million-gallon tank. The settling model predicted that the compacted sludge solids would exceed 20 wt % in less than 30 days of settling in a 10-m-tall tank for all pretreatment steps.     

活性污泥法处理污水两个重要参数的理论探讨

负荷、泥龄是活性污泥法处理城市污水设计、运行中的重要参数.给出了有机负荷的动力学表达形式(称之为动力学负荷),并对有机负荷和泥龄的关系,有机负荷和泥龄对水质、污泥沉降性能影响进行了理论探讨.     

THE LOADS OF PAHS IN WASTEWATER AND SEWAGE SLUDGE OF MUNICIPAL TREATMENT PLANT

Abstract

Sewage and sewage sludge from a municipal wastewater treatment plant were analyzed for 16 EPA-PAHs. This plant is a classic mechanical-biological treatment plant, consisting of activated sludge technology with additional chemical treatment for the removal of phosphorus compounds. The process of sewage sludge treatment is carried out in closed as well as open sludge digesters. Primary and mechanically thickened sludge are passed through the fermentation process. Digested sludge is dewatered on filter-press through addition of flocculent. The measurements were obtained to investigate the effect of different treatment stages on PAH content in wastewater and sewage sludge. The following wastewater samples were collected: crude ones and those after sand trap, primary sedimentation, biological treatment and secondary sedimentation. Sewage sludge samples were collected from: primary sludge, digested sludge and dewatered sludge. PAH load in influent, mechanically and biologically treated sewage, as well as in raw digested and dewatered sludge, were calculated. PAHs were extracted from wastewater and sludge samples, with cyclohexane, dichloromethane using an ultrasonic method. Gas chromatograph equipped with mass spectrometry was used for qualitative and quantitative determination of PAHs. Mechanical and biological treatment proved the removal of 83–85% of PAHs from the influent. Despite this its daily PAH load introduced into the environment was high and reached 27–37% of PAH load in influent. In sewage sludge it was 46–70 g/d of PAHs (carcinogenic PAHs content 4–12%). In waste sludge (filter pressed sludge and sand from detrirer) PAH total load reached 42–68 g/d with (10–17% of carcinogenic PAHs).     

镁改性活性炭强化活性污泥处理混合污水研究

基于序批式活性污泥法(SBR)工艺,将镁盐改性活性炭(MgO-PAC)与传统活性炭(PAC)混合而成MPAC材料,用于处理生活与工业混合污水。通过连续30 d的运行实验,探讨了MPAC材料对生活与工业混合污水中COD、NH4^+-N和TP的去除效果以及对污泥的比耗氧速率、沉降性能和微生物多样性的影响。结果表明,投加MPAC材料对污水中COD的去除率提升了12.7百分点,对TP的去除率提升了17.5百分点,对NH4^+-N的去除率超过86.4%。投加MPAC后处理效果更好的重要原因,在于MPAC使得活性污泥的沉降性能和比耗氧速率得到明显改善,也提升了污泥的微生物丰度。MPAC对活性污泥处理生活与工业混合污水具有强化作用。     

高效澄清池在黄浦江原水中的应用试验

高效澄清池作为一种新型的处理工艺 ,将混凝与斜板沉淀、污泥回流、排泥浓缩等多种技术相结合 ,建立了一种新型的混凝沉淀模式。文章介绍了该澄清池处理黄浦江上游原水的中间性试验 ,通过比较分析阐述了其运行特点     

二次沉淀池模型的研究

基于固体通量理论和一维沉淀池各层的物料平衡,提出了澄清-浓缩过程动力学模型。利用VisualBa鄄sic编程工具开发了SCM(SecondaryClarifiersModel)模型,此模型能够模拟沉淀池不同深度的污泥浓度、出水中的悬浮固体浓度和底流污泥浓度。3次试验结果表明,污泥量、出水悬浮固体浓度、底流污泥浓度的模拟平均误差分别为10.6%,68.7%,7.9%。     

低温非丝状菌活性污泥膨胀的控制措施

介绍了低温环境下城镇污水处理厂发生非丝状菌活性污泥膨胀的机理特征,以及对污水处理的影响;提出了通过SVI值、镜检、观感判断非丝状菌污泥膨胀的方法和解决措施。通过采取物化方法改良活性污泥组成结构提高其沉降性能,调整控制生化系统合适的MLSS、DO浓度、稳定进水量、内外回流比等工艺参数,能有效提高污泥的沉降性能,将SVI值由400 m L/g左右降至150 m L/g以下,达到理想的泥水分离效果,出水水质稳定达标。     

Experimental and Theoretical Study of Agitated Contact Drying of Sewage Sludge under Partial Vacuum Conditions

Agitated contact drying experiments were carried out in a cylindrical lab-scale paddle dryer to study the drying kinetics of sewage sludge under partial vacuum conditions. To explore the drying mechanisms, the penetration model for vacuum contact drying of agitated particulate materials, developed by Schlünder and Mollekopf, was applied to simulate the experimental results. The influence of the drying parameters (system pressure, heating temperature, stirrer speed, and dryer load) on the drying kinetics was studied both experimentally and theoretically. The results indicate that pressure and temperature significantly influence the drying rates of sewage sludge, whereas stirring speed and dryer load have no obvious effects on drying rates in the examined range. The experimental and simulated drying rates were in acceptable agreement as long as the temperature difference between dryer and sludge was small. A crust is likely to form on the dryer surface, however, when the temperature difference becomes large; this crust leads to markedly lower drying rates than the calculated ones. Furthermore, a comparison between partial vacuum contact drying and atmospheric contact drying is presented. The results indicate that the mass transfer resistance increases with rising drying potential in the examined experimental range.     

改良型平流式沉淀池流态的实验模拟

沉淀池流体流态对沉降效果有较大影响,通过相似定理制作沉淀池物理模型,以进水挡板位置高度和进水流量为考量因子,进行清水实验与活性污泥实验。结果表明,进水挡板位置高度过低时,停留时间较长,且人流区部分产生堆积现象,影响沉淀池去除效果,进水挡板位置高度过高时,挡板导流作用不明显,流态较差,沉淀池去除率较低。低流量时,人流区产生堆积现象,影响沉降效果,高流量时,产生沿挡板向上的上升流,部分悬浮物被带到清水区,降低沉淀池去除率。在设计进水流量1．39L／min下,清水实验进水挡板位置高度为60mm时流态最佳,污泥实验进水挡板位置高度为40mm时流态最佳。     

炼油厂"三泥"处理研究与设计

通过对炼油厂污水处理场“三泥”性质的调查研究,认为必须经调质、沉降浓缩、絮凝等处理后再离心脱水,才能达到预期的效果。处理后的“三泥”,液相返回调节池,固相送到焚烧炉焚烧,焚烧后气体以CO2的形式排至大气,将污泥降解为无机物,彻底解决了污水处理的二次污染问题。