内返料内分级喷浆造粒干燥机的返料分级机理研究Ⅵ．悬浮式螺旋进料口的有效返料系数的理论分析

本文研究内返料内分级喷浆造粒干燥机中悬浮式螺旋进料口的有效返料系数。推导出有效返料系数的计算式，讨论了螺旋进料口的悬浮高度、转筒半径和装载系数对有效返料系数的影响。     

内返料内分级喷浆造粒干燥机的返料分级机理研究 Ⅵ.悬浮式螺旋进…

本文研究内返料内分级喷浆造粒干燥机中悬浮式螺旋进料口的有效返料系数。推导出有效返料系数的计算式，讨论了螺旋进料口和悬浮高度、转筒半径和装载系数对有效返流系数的影响。     

内返料内分级喷浆造粒干燥机的返料分级机理研究Ⅶ．悬浮式螺旋进料口的内分级效率分析

本文建立了内返料内分级喷浆造粒干燥机悬浮式螺旋进料口的内分级效率的计算模型，认为转筒半径、粉料容积分布函数对内分级效率没有影响，推荐返料螺旋进料口相似放大宜采用的４个参量。     

内返料内分级喷浆造粒干燥机的反料分级机理研究：Ⅶ.悬浮式螺旋进…

本文建立了内返料内分级喷浆造料干燥机悬浮式螺旋进料口的内分级效率的计算模型，认为转筒半径，粉料容积分布函数对内分级效率没有影响，推荐返料螺旋进料口相似放大宜采用的４个参量。     

内返料内分级喷浆造粒干燥机的返料分级系统的设计

简述了内返料内分级喷浆造粒干燥机的工作原理,归纳了返料分级过程的数学模型,提出了返料分级系统的设计方法,讨论了返料螺旋通道进料口的改进措施。     

内返料喷浆造粒干燥机分级返料研究

设计磷铵用全内返料喷浆造粒干燥机的关键是返料螺旋的确定,返料的前提是颗粒在回转圆筒内充分有效的分级。本文通过理论分析与简单的几何变换得到了返料螺旋口高度的计算公式,实验验证并得到修正系数。该公式为返料螺旋的确定提供依据     

内分级内返料喷浆造粒干燥机螺旋返料量研究

阐明了内分级内返料喷浆造粒干燥机中返料螺旋的返料机理，并对螺旋返料量的理论计算公式进行了修正。通过实验确定操作参数、结构参数对有效返料系数的影响。该研究对于内分级内返料喷浆造粒干燥机的设计有一定的指导作用     

磷复肥喷浆造粒内返料技术研究与应用

探讨了磷复肥喷浆造粒干燥机内返料数量与质量对造粒的影响，提出返料量计算式，为返料螺旋设计提供理论依据。     

内返料喷浆造粒干燥技术概述

内返料喷浆造粒干燥机集造粒、干燥、分级与破碎为一体 ,并广泛应用于化肥生产中。主要介绍了内返料喷浆造粒技术及其在国内外的发展过程     

内返料内分级喷浆造粒干燥机的返料分级机理研究Ⅴ．料幕分析

本文研究内返料内分级喷浆造粒干燥机的料幕特性。推导料幕密度的计算式和抄板最大撒料角的计算式，并认为料幕密度与物料性质有关。分析径向倾斜抄板对料幕的影响，讨论抄板弯角的合理性。     

有侧吹风环流料封阀水平孔口流动阻力特性

引　言循环流化床锅炉由于具有诸多优点 ,使其在国内外得以迅速发展 .然而在已投运的循环流化床锅炉中也暴露出一些亟待完善解决的问题 .环流料封阀是目前在循环流化床锅炉上应用最多的一种固体颗粒回送控制装置 .实际运行表明 ,这种返料装置结构简单、运行可靠 ,能够很好地满足稳定返料和密封的要求 ,是一种很有发展前途的返料器 .但它缺乏对循环物料的调节和控制能力 ,返料室有时会出现局部流化不良从而导致结焦 .试验研究表明[1～ 3],只要环流料封阀在结构上设计合理 ,它就能像Ｌ阀一样 ,对固体颗粒循环量具有调节和控制作用 ,且可在较宽…     

Chemical absorption in a bubble column loading concentrated slurry

Carbon dioxide was absorbed into aqueous slurries of magnesium hydroxide or calcium hydroxide particles in a bubble column at 308 K and 0.1013 MPa. The volumetric mass transfer coefficient and the effective gas-liquid interfacial area were obtained separately by these absorption experiments. It was found that the liquid-side physical mass transfer coefficient as well as the effective gas-liquid interfacial area decrease with increasing the slurry concentration and that there is an optimal point of fine reactant particle concentration where the chemical absorption rate has its maximum value. The process of gas absorption into slurry in a bubble column was formulated by a film-theory model incorporating a finite dissolution rate of solid particles. The observed absorption rates of carbon dioxide into calcium hydroxide slurries in the bubble column were successfully predicted by the proposed model.     

Experimental study of unloading loose material from container pneumatic transport rotary container

Tipping of loose material from a container is considered, with which there is a uniform tipping stream, lump flight, an increased lump flight, and incomplete material tipping. The maximum lift of the spiral guide, with which there is unhindered passage of containers over the unloading section, is determined. The dependence of the length of the open unloading section on container movement rate, rotation angle at the instant of flight of the last particles within them, and on particle acceleration and angular velocity, are determined.     

旋液流态化流体阻力与传热的试验研究

摘要对某公司换热器的运行情况。采用旋液流态化技术设计了模拟试验方案。首先在φ57mm×3．5mm×2000mmPVC管内进行旋液流态化清洗试验,然后在碳钢管上内置不同螺距的钢丝螺旋线进行流体阻力测试,并进行旋液流态化与空管的对比传热试验。结果表明：旋液流态化技术清洗管道中人工污垢只需时间145s,没有发生粒子沉积和堵塞的现象,安全可靠性好;旋液流态化流体阻力△p随着Re的增大而增大,摩擦系数随着Re的增大而减小,流体总阻力48．7kPa低于供水压力,总传热系数平均提高幅度13．3％,强化传热效果好。     

换热器换热管内插螺旋流态化传热及除防垢的影响因素

通过内插螺旋方法使换热器换热管内流体产生螺旋流,实验研究了管内螺旋流/螺旋流态化的颗粒直径、颗粒浓度、螺旋结构参数及温差对强化传热及除垢、防垢性能的影响. 结果表明,在实验范围内,换热器换热管内螺旋流态化比螺旋流的传热系数提高15%~20%;颗粒直径5 mm比3 mm的传热系数提高5.4%;颗粒浓度15%(j)比5%(j)传热系数提高15.3%;外径螺旋30 mm比20 mm传热系数提高7.7%;螺距20 mm比60 mm传热系数提高11.1%. 随时间连续运行,管内螺旋流态化的传热系数下降幅度远小于螺旋流,表明管内螺旋流态化具有较好的除垢防垢效果. 传热温差变化对螺旋流态化强化传热及除垢、防垢性能影响较小.     

SENSITIVITY ANALYSIS ON THE FLUID DYNAMICS OF A DRAFT TUBE SPOUTED BED WITH BOTTOM PARTICLES FEED

A numerical study was carried out on the parametric sensitivity of the fluid dynamic variables for a draft tube spouted bed (SB) with bottom particles feed. The sensitivities of variables such as the air and particle velocities and voidages in the spout region, as functions of key model parameters, like the spout-annulus air distribution, solids recirculation rates and gas-particle drag coefficient were determined. The model was numerically integrated and sensitivities obtained by the central differences approach. The sensitivities were seen to depend on air inlet flowrates and heights in the bed. For air flowrates close to the minimum spouting velocity the model is very sensitive to all the parameters studied. In most cases, the variables were moderately to highly sensitive to air distribution in the bed. On the other hand, the variables were minimally to moderately sensitive to the drag coefficient and solids recirculation rates. The maps of sensitivity obtained provide useful information for planning of the probe location, hydrodynamic modeling and directing of future work on SB with bottom particles feed.     

Photocatalytic degradation rate of oxalic acid on the semiconductive layer of n-TiO2 particles in the batch mode plate reactor Part I: Mass transfer limits

Organic compounds dissolved in water can be decomposed on a layer of n-TiO2 particles irradiated by u.v. light, which generates holes and electrons in the TiO2 material. Dissolved oxygen was used as electron scavenger and holes reacted with water to give OH radicals. The rate of degradation of the dissolved organic compounds by OH radicals is limited by the transfer of either oxygen or of theorganic compounds to the surface of n-TiO2 particles. The consequence of these limits is that, in the batch mode reactor with recirculation of the liquid, the dependence of the concentration of an organic compound on time has either a linear or an exponential form. Experiments with decomposition of oxalic acid in aqueous solutions using a plate reactor (60 cm × 120 cm) confirmed the analysis. Equations for evaluation of the mass transfer coefficient of the dissolved species to the surface of the plate reactor with a moving liquid fil m were developed for the case of the thickness of the Nernst diffusion layer being thinner than the thickness of the liquid. The experimentally obtained decomposition rate of oxalic acid was about 60 to 80% of the theoretical decomposition rate limited by oxygen flux through the film of a moving liquid. The present theory neglects the diffusion of oxygen into the porous layer of n-TiO2.     

Study of the Characteristics of Methanol Synthesis in a Recirculation Slurry Reactor – A Novel Three‐Phase Synthesis Reactor

A process feasibility analysis on the liquid phase methanol synthesis (LPMeOH^TM) process was performed in a recirculation slurry reactor (RSR). In the three‐phase RSR system, a fine catalyst is slurried in the paraffin and this catalyst slurry is continuously recirculated through the nozzle from the slurry sector to the entrained sector by a pump. The syngas is fed concurrently with the downward flow of slurry to form the methanol product. A laboratory scale mini‐pilot plant version of a recirculation slurry reactor system was successfully designed and built to carry out process engineering research, and in addition, an identical cold model was built to measure the mass transfer coefficient in the recirculation slurry reactor. The effects of operating conditions, including temperature, pressure, gas flow rate and catalyst slurry recirculation flow rate on the productivity of methanol were studied. This experimental data helps the scale‐up and commercialization of the methanol synthesis process in recirculation slurry reactors.     

流道结构对膜分离性能的影响

基于CFD技术对不同流道结构的平板式纳滤膜分离器内的流动进行了数值模拟,以考察流道结构对膜分离性能的影响。分析了在平板膜器中加设螺旋形隔板和蛇形隔板后截面流体的次流状况。模拟结果表明在无绕流板流道中加设隔板后存在次流现象,螺旋形流道中流体流动存在二次流漩涡,蛇形流道拐角附近的流体也存在较强的二次流动,对减轻膜污染和浓差极化均有作用。     

内置螺旋挡板流化床颗粒停留时间分布

采用脉冲示踪法在内置螺旋挡板冷态鼓泡流化床上研究了螺旋挡板、加料速率、流化风速、颗粒粒径和床料高度对颗粒在流化床内停留时间分布的影响. 结果表明,颗粒停留时间的无量纲方差从无螺旋挡板时的0.558减小到有螺旋挡板时的0.085,螺旋挡板可有效抑制颗粒返混,增大颗粒运动的平推流趋势;加料速率增大为约2倍时,停留时间减小为约50%,流动更趋向于平推流;床料高度增加,颗粒返混加剧,颗粒平均停留时间及无量纲方差均增大,颗粒运动向全混流靠近;随流化风速增大,颗粒平均停留时间变长;实验范围内,颗粒粒径对颗粒停留时间分布影响不大.