提高无机超滤膜运行效率的措施研究

针对冷轧废水采用无机超滤膜处理工艺运行中存在的问题,从工艺、膜清洗等方面进行分析、探索,总结了提高无机超滤膜处理能力的措施。     

煤矿黏土注浆管路淤堵软化实验与应用

为了解决煤矿黏土注浆管路淤堵问题,开展黏土注浆管路淤堵软化实验和应用研究。在黏土注浆管路淤堵特征剖析的基础上,通过软化剂作用下黏土崩解实验开展相关研究。结果表明:强氧化类的软化剂与黏土试样反应最为激烈,碱性软化剂与黏土试样反应最慢,酸性软化剂与黏土试样反应速度适中。以0.1 mol/L氨基磺酸溶液或0.25 mol/L醋酸溶液作为黏土淤堵软化剂最优。实践证明,采用管路涂抹环氧树脂,重点部位压力监测,淤堵管路浸泡软化剂等手段可以有效防治黏土灌浆管路淤堵问题。     

苏里格南区气井井筒堵塞原因分析与防治对策

针对苏里格南区气井井筒特别是油管内形成大量堵塞物现状,通过现场调研和室内研究,明确气井井筒堵塞原因,并提出相应的防治对策。     

四老沟矿11#层402盘区自燃火灾事故的处理

介绍了大同煤矿集团公司四老沟矿11#层封闭盘区回风巷自燃火灾事故灭火方案的确定及实施,分析了事故原因,提出了防范对策.     

Application of a three-component competitive adsorption model to evaluate and optimize granular activated carbon systems

A recently developed kinetic model for granular activated carbon (GAC) adsorbers (COMPSORB-GAC) that quantitatively describes the adsorption of trace organic contaminant in the presence of competing natural organic matter (NOM) was applied to evaluate the performance of different GAC system configurations: conventional fixed-bed adsorbers, layered upflow carbon adsorbers (LUCA), and moving-bed adsorbers (with few or many bed sections). COMPSORB-GAC separately tracks the adsorption of three components: a trace compound, a strongly competing NOM fraction that reduces trace compound equilibrium capacity, and a pore-blocking NOM fraction that reduces kinetics. Performance was simulated for various design criteria and with model parameters derived for two natural waters with significantly different NOM concentrations. For the range of simulated conditions and with baseline performance defined by a fixed-bed adsorber, LUCA generally reduced carbon usage rates (CURs) by 15-35%. A 2-section and a 16-section moving-bed reactor reduced baseline CURs by 20-30% and 45-55%, respectively. Projected CURs for the water source with a relatively high NOM concentration were 2-3 times higher for all reactor configurations and indicated that NOM preloading would cause performance deterioration in deep GAC beds, which highlights the importance of source water quality. These results show how COMPSORB-GAC can be used in a comprehensive, site-specific optimization of GAC systems to ensure robust system performance and to balance capital and operating costs.     

Pore blockage effect of NOM on atrazine adsorption kinetics of PAC: the roles of PAC pore size distribution and NOM molecular weight

Natural organic matter (NOM) in natural water has been found to have negative effects on the adsorption of various trace organic compounds by activated carbon through two major mechanisms: direct competition for sites and pore blockage. In this study, the pore blockage effect of NOM on atrazine adsorption kinetics was investigated. Two types of powdered activated carbon (PAC) and three natural waters were tested to determine the roles of PAC pore size distribution and NOM molecular weight distribution in the pore blockage mechanism. When PAC was preloaded with natural water, the pore blockage effect of the NOM was found to cause a reduction of up to more than two orders of magnitude in the surface diffusion rate of atrazine compared to simultaneous adsorption of atrazine and NOM with fresh PAC. The surface diffusion coefficient of atrazine for preloaded PAC decreased with a decrease in PAC dose or an increase in NOM surface concentration. Because of the pore blockage effect of NOM, a 30% drop in atrazine removal was observed in a continuous flow PAC/microfiltration (MF) system after 7 days of contact compared to the removal predicted from the batch isotherm test. Large micropores and mesopores were found to play an important role in alleviating the effect of pore blockage. A PAC with a relatively large fraction of large micropore and mesopores was shown to suffer much less from the pore blockage effect compared with a PAC that had a much smaller fraction of large pores. Natural waters with different NOM molecular weight distribution caused different extent of pore blockage. The NOM molecules with molecular weight between 200 and 700 Dalton appeared to be responsible for the pore blockage effect.     

基于 FOA 优化的 CSSVM 管道堵塞状态识别研究

针对城市排水管道正常与堵塞故障状态在数据获取上的不平衡性造成的运行状态识别准确率下降的问题,提出了一种基于果蝇优化算法的代价敏感支持向量机的管道堵塞状态识别方法。根据排水管道内各运行状态下采集到的不平衡数据集,首先对不平衡数据集进行小波包分解,其次,提取各个分解系数的能量熵、近似熵指标构建特征向量集合;采用果蝇优化算法(FOA)对不同类样本惩罚因子C_m和核函数参数g进行优化选取,即对代价敏感支持向量机(CS-SVM)模型优化,将特征集合输入优化后的CS-SVM模型中,对排水管道的正常和堵塞状态识别,通过增大对少数类样本错分的惩罚代价,结果表明,提升了少数类的识别准确率。     

混凝土灌注桩桩头渗水的处理及预防措施

混凝土灌注桩桩头渗水对桩体混凝土受力和基底防水产生影响,对混凝土结构中的钢筋造成腐蚀。结合工程实例,对桩头渗水产生的原因进行分析,主要有操作经验不足、责任心不强,灌注器具不合格,混凝土质量指标不符合要求,灌注接近结束时拔管速度过快、灌注终了超灌高度测量不准,基土含水量高、水压大等;出现桩头渗水可采用人工剔除或注浆封堵处理;介绍了预防措施,包括加强作业人员培训,强化灌注器具检查,严控混凝土质量,重点监管终灌时的状态,做好基坑内降水工作等。     

Study on the blockage in pores due to asphaltene precipitation during different CO2 flooding schemes with NMR technique

CO₂ flooding is an effective way in the tertiary oil recovery. While asphaltene often precipitates from the crude oil during the CO₂ flooding, and the mechanisms of blockage resulting from asphaltene precipitation is still unclear in different CO₂ flooding schemes. In this work, pure-CO₂ flooding, water-alternating-CO₂ flooding (WAG), and CO₂-foam flooding were applied to conduct the core-flooding experiments. Then, as for each flooding scheme, we quantitatively investigated the blockage degree in different pores due to asphaltene precipitation with nuclear magnetic resonance (NMR) technique. Tests results show that CO₂-foam flooding has a relatively higher blockage degree both in the smaller pores and the larger pores than WAG and pure-CO₂ flooding. Although pure-CO₂ flooding has the least asphaltene precipitation and blockage degree among three flooding schemes, its oil recovery degree is far less than the other two flooding schemes. Compared with pure-CO₂ flooding and CO₂-foam flooding, WAG flooding has the highest oil recovery and an acceptable asphaltene precipitation.     

中间包水模型数据的流出百分比分析方法

针对已有停留时间分布曲线或F曲线分析方法在归一化过程中,将单流中间包流出百分比或多流中间包中各流流出百分比之和限定为100%,将示踪剂流出总量信息掩盖,导致结果不精确的问题,本工作提出了流出百分比的分析方法,通过计算可以将物理实验结果转化为各流实时的流出百分比曲线。以流出百分比曲线为基础,计算得到时间加权平均方差和剩余示踪剂百分比,并以此对单流、四流中间包水模型实验结果进行分析。结果表明,采用流出百分比方法能对实验结果进行校对,进一步验证实验的可重复性。同时可对比双挡墙和U型挡墙控制装置设置下,四流中间包监测时间终点流出百分比差异及两倍理论停留时间时刻的死区比例大小。并可直观对比多流中间包不同挡墙下各流的一致性,及在单流堵塞后示踪剂在其他各流的分配及一致性。