长距离浆体管道磨蚀率预测

长距离浆体管道的典型设计寿命通常为15至25年,故管道磨蚀率的确定对管道工程经济效益有较大影响.这里所说的磨蚀是化学腐蚀和物理磨损的综合表征,其中每个因素的影响大小与特定的管道输送工程相关,如细颗粒浆体管道输送工程,化学腐蚀在管道磨蚀中起主导作用,这类管线输送流速一般设计为1.5～2.5 m/s,为高度均质流,其管道底部与顶部磨蚀相差不多,对流速不敏感.但中、粗颗粒如原矿粉及尾矿的管道输送工程,管道的磨蚀方式与细颗粒浆体不同,其主要集中在管道的底部与弯头外弧侧,对流速较为敏感.细颗粒与中、粗颗粒浆体管道沿管线的磨蚀分布规律基本相似.     

浆体长距离输送管道的管理和维护

介绍了瓮福磷矿磷精矿浆长距离输送管道的腐蚀控制、管理和维护经验     

粗颗粒尾矿浆体管道输送速度分布规律研究

基于垂向剪应力呈线性分布假设,给出了零剪应力点的垂直位置计算方法和对应的最大剪应力计算方法,由此,通过借鉴普朗特半经验公式,给出了滑动床上方速度分布计算公式.通过粒径为1.71 mm的粗尾矿颗粒高浓度尾矿管道流动试验,测定了水平管道和倾斜管道中不同条件下若干组浆体速度分布试验数据.计算值和实测值的对比分析表明作者速度预测模型计算值与实测值较为一致,两者最大偏差不超过12.16％.作者速度分布公式的计算结果表明,随着管道倾角的增大而增大,最大速度点偏离管道中心之上的距离越来越大,同时速度分布变得越来越均匀.     

煤浆管道输送浓度的分析研究

煤浆输送浓度与管道输送系统的经济性及安全性有关,为了选择最佳的输送浓度,就浓度对浆体特性的影响进行了分析,从技术指标和经济指标两个方面,对最佳输送浓度的选择确定进行计算讨论,得出最佳输送浓度需要在最佳节能浓度的基础上依据管道运行流速标准校核调整后确定,从而为煤浆管道工程的优化设计提供参考。     

非牛顿型浆体管道阻力降的一种简捷计算方法

本文根据浆体的流变参数，对工程中的非牛顿型均质浆体管道的阻力降，提出了一种简捷的计算方法。     

浆体管道三通后的单孔消能孔板流场研究

为了研究浆体管道三通后的单孔消能孔板流场,使用Fluent对不同流量和孔板安装位置(孔板与三通相连或在三通下游0.5 m的流场进行了数值模拟。首先,工况1孔板后管道北侧出现回流,将对管壁造成冲蚀,工况2孔板后流动未出现明显回流。其次,工况1管道水平段中轴线上的压力沿流向先减小后增大,在三通前取得最小值,在关闭的阀门处取得最大值,但压力波动幅度较小。工况2的压力变化趋势与工况1的类似。最后,安装孔板的管道竖直段中轴线上的压力沿流向先减小后增大。工况2较工况1的消能能力有小幅提升,但压力恢复平稳的位置也往下游移动了约0.5 m。     

关于煤泥成浆性和浆体稳定性研究

本文概括介绍了邢台东庞、南票、乌达、开滦吕家坨等矿烟煤及晋城凤凰山、阳泉二矿无烟洗煤泥在不加任何添加剂，只加机械搅拌情况下，在一定沉降时间内的成浆性与静态沉降稳定性的研究结果；讨论了煤泥粒度、灰分、密度和煤泥浆浓度对煤泥成浆性和浆体沉降稳定性的影响，为煤泥就地制浆并作为动力锅炉的燃料提供了可靠的数据。     

大颗粒流化床中颗粒磨蚀的实验研究

为了进一步丰富和发展大颗粒流态化理论,促进其在水泥煅烧领域的应用,实验通过1个三维流化床试验台研究了大颗粒流化床中颗粒的破损方式为磨蚀,即颗粒在流化过程中表面磨碎后生成细粉,颗粒自身的粒径逐渐变小。实验表明,颗粒粒径、风速以及流化时间对大颗粒流化床中颗粒的磨蚀影响较大,静床高对磨蚀几乎没有影响。最后提出了大颗粒流化床合适的控制参数:粒径范围4—7 mm,表观风速1.3um f—1.6um f,静床高H0/D<2。     

浆态床内颗粒浓度分布的研究

1 前言浆态床内固体颗粒可以是反应物、生成物、固体催化剂或催化剂载体。固体颗粒的大小和浓度分布与其他流体力学因素相互作用,可以改变过程的传质、传热性能,进而影响反应的转化率和选择性。尤其是对强放热催化反应,作为催化剂的固体颗粒,其浓度分布不同,造成了反应器内各处反应速率的差异,从而引起各处不同的温度效应,结果导致反应速率的更大差异。Serpemen 和 Deckwer 对 F—T 合成、CO 甲烷化和丁炔二醇加氢过程中催化剂分布对转化率影响的分析,证明在设计反应器时必须考虑固体颗粒浓度分布。     

洗衣粉悬浮液在惰性粒子流化床中干燥的研究

针对气体分布板开直孔的惰性粒子流化床,开展了洗衣粉悬浮液在床内的干燥性能研究。测定了流化床的床层压降曲线,考察了进料量、进风温度、进风速度及惰性粒子直径对于流化床传热性能的影响,且与气体分布板开斜孔的传热性能进行了初步比较。结果表明,流化床的床层压降主要是由惰性粒子的流化阻力所致;适当增加进料量和进风速度,或减小惰性粒子直径,以及将气体分布板的孔道由直孔改为斜孔,均可提高流化床的传热性能,但过高的进风温度则可能导致传热性能的下降。     

大口径管道直管段制作技术应用

针对大口径管道施工过程中存在施工周期长,施工难度大,工程成本高等问题,提出一种新型优化管段分段技术和管段组对方案。结果表明:该制作技术能保证大口管道安装施工顺利进行;有效地解决现有大口径套管安装过程中的技术难题。该方法具有创新性、实用性、可靠性等优点,在工程建设的许多领域,具有推广应用价值。     

Synthesis of nanostructured large particles of polyaniline

Synthesis of larger particles of conductive polymers is usually favorable due to higher conductivity (as a result of lesser interfacial resistance). On the other hand, advantages of nanostructured materials are well known. Thus, it is desirable to fabricate large particles that have nanostructure, to gain double advantage. A simple method based on chemical polymerization under centrifugal forces is proposed to achieve this goal. It was typically employed for a well‐known conductive polymer, namely, polyaniline to fabricate large particles (e.g., 400 μm) with internal nanostructure of ～100 nm. This also significantly increases the electrical conductivity of the polymer. This is indeed a simple approach, which can be easily performed using a conventional centrifuge system. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 6060–6063, 2006     

Polyethyleneimine‐grafted membranes for simultaneously adsorbing heavy metal ions and rejecting suspended particles in wastewater

Heavy metal ions (HMIs) in wastewater can be removed by polyethyleneimine (PEI) adsorption, however, it is difficult to recycle PEI macromolecules from their mixture with suspended particles in wastewater. A novel HMIs adsorption technique with renewable PEI‐grafted porous membranes was developed. PEI molecules were dispersed with high specific area and structured morphology, which allowed HMIs and suspended particles to be retained separately at different locations of the membrane, with the former adsorbed in matrix and the latter rejected on surface. The membranes with the optimized PEI loading ratio of 30 k wt % behaved excellently with microsphere rejection and Co(II) adsorption reaching 98.5% and 51.0 mg/g, respectively. They successfully decreased Co(II) concentration from 3.0 mg/L to the allowable discharge standard (0.5 mg/L), even with an enhanced flux of 6200 L/m²/h at 0.12 MPa under the cyclic tests. Overall, PEI‐grafted membrane adsorption is highly efficient for removing HMIs and suspended particles simultaneously from wastewater. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4541–4548, 2017     

大颗粒包膜尿素控释肥在冬小麦上的施用效果

在河南驻马店砂姜黑土区及延津潮土区对大颗粒包膜尿素控释肥（CRU）在冬小麦上的施用效果进行了研究.结果表明：相同氮素用量时,大颗粒包膜尿素控释肥比普通尿素（BU）增产,即在100％用量、75％用量及50％用量相比时,驻马店试验增产率为5.7％、10.26％、13.5％,延津试验增产率为3.3％、11.7％、10.4％,增产效果显著.大颗粒包膜尿素控释肥的比表面积较小,可以大量节省包膜材料,减少土壤污染.     

Oxygen mass transfer coefficient in bubble column slurry reactor with ultrafine suspended particles and neural network prediction

The gas–liquid volumetric mass transfer coefficient was determined by the dynamic oxygen absorption technique using a polarographic dissolved oxygen probe and the gas–liquid interfacial area was measured using dual‐tip conductivity probes in a bubble column slurry reactor at ambient temperature and normal pressure. The solid particles used were ultrafine hollow glass microspheres with a mean diameter of 8.624 µm. The effects of various axial locations (height–diameter ratio = 1–12), superficial gas velocity (u_G = 0.011–0.085 m/s) and solid concentration (ε_S = 0–30 wt.%) on the gas–liquid volumetric mass transfer coefficient k_La_L and liquid‐side mass transfer coefficient k_L were discussed in detail in the range of operating variables investigated. Empirical correlations by dimensional analysis were obtained and feed‐forward back propagation neural network models were employed to predict the gas–liquid volumetric mass transfer coefficient and liquid‐side mass transfer coefficient for an air–water–hollow glass microspheres system in a commercial‐scale bubble column slurry reactor. © 2012 Canadian Society for Chemical Engineering     

Deposition of ultrafine aerosol particles on wire screens by simultaneous diffusion and image force

This paper presents the results of an experimental investigation on the deposition of multiply charged particles on wire screens by the combined mechanisms of diffusion and image force. Experiments were performed with particles having diameters between 25 and 65 nm (transition regime), carrying 0, +1, +2 or +3 elementary charges, and using three different flow rates, two types of wire screen, and two types of test aerosol. The single fiber efficiencies for the mechanisms of image force, η_IM, and diffusion, η_D, are of the same order of magnitude and, furthermore, they are both much smaller than one. Under these conditions, the total capture efficiency can be approximated as the sum of the efficiencies by diffusion and image force deposition. Theoretically, η_IM is proportional to the square root of a dimensionless number, K_IM, which includes all the relevant parameters cited above (i.e., particle size and charge, aerosol flow rate and screen geometry). The available correlations for η_IM, obtained from experiments with particles carrying a large number of elementary charges (K_IM>10^-5), predict that image force should not have any effect in the case of the small particles with very few number of charges that we have tested in our experiments (in our experimentation, K_IM ranged between 10^-7 and 10^-5). Our results, the only ones available to date for this particle size range, show that there is indeed a clear, measurable effect. Although our experimental results are best fitted by the correlation , it is shown that the expression , which is in agreement with the theoretical 1/2 exponent for K_IM, also reproduces reasonably well the measured values.     

Effect of solid particles on gas hold-up in bubble columns

The gas hold-up in bubble columns containing fluidised plastic particles as solid phase was measured as a function of superficial gas velocity and solids concentration. The effects of particle size, density, wettability and concentration on gas hold-up and bubble coalescence were studied. It was found that the addition of non-wettable solids to the air/water mixture promotes bubble coalescence and, therefore, reduces the gas hold-up, while the addition of wettable solids suppresses bubble coalescence and increases the gas hold-up.     

盐泥对钙基固硫剂促进作用的研究

以工业废弃物盐泥为添加剂调质钙基固硫剂,用ZCS-1型智能定硫仪进行脱硫实验。结果表明,盐泥添加剂能够提高钙基固硫剂固硫率,其合理配比为质量比8：1。通过SEM分析发现,调质改善了固硫剂颗粒的孔隙分布,使固硫剂颗粒的表面微观形貌发生改变,从而提高了固硫剂的固硫性能。研究发现,盐泥中的主要成分不仅可以改变钙基固硫剂的微观结构,同时本身也有固硫作用。     

烧结法生料浆流变性的研究

为了降低烧结法氧化铝生产中烧结过程的能耗,从流变学角度测量生料浆在6个不同剪切速率下的剪切应力,通过其流变曲线,研究了生料浆的触变性及水分质量分数、温度、表面活性剂对生料浆流变性的影响。结果表明:含水质量分数为35%的生料浆具有触变性;随着生料浆含水质量分数从34.7%增加到39.7%、温度从40℃升高到80℃,添加适当表面活性剂R—COONa,可降低生料浆的屈服应力和表观粘度,使生料浆的流动性得到一定改善。