Solid circulation characteristics in an internally circulating fluidized bed with orifice-type draft tube

Effects of superficial gas velocities to a draft tube, to an annulus section and particle size on the solid circulation rate (G,) have been determined in an internally circulating fluidized bed (0.28 m I.D. × 2m high) with an orifice type draft tube. The solid circulation rate from the draft tube to an annulus section increases with increasing gas velocities to the draft tube(U _d ) and annulus section (U_a) and consequent increase in pressure drop across the orifice (ΔP_or). However, the values ofG _s decrease by 7–21% with increasing particle size from 86 to 288 μm. The pressure drop across the orifice increases with increasingU _d andU _a . However, ΔP_or decreases by 5–23% with increasing particle size. To predictG _s in an internally circulating fluidized bed, a correlation is proposed as a function of ΔP_or This paper is dedicated to Professor Dong Sup Doh on the occasion of his retirement Korea University.     

原油码头管道输送水击问题的研究与分析

原油码头卸船、原油库区装船过程当中很容易出现原油不稳定流动的现象,因此造成水击,水击对原油管道产生很严重的破坏性影响。针对大连长兴岛油船发生水击的现象进行了分析,阐述了产生水击的原因,水击的危害。提出了水击波的流速公式和不同工况时冲击压力的计算公式。最后针对工程的实际情况,从设计、施工、管理三方面提出了预防水击的措施。     

Correlation of the Drop Size in a Modified Scheibel Extraction Column

Experiments were designed to ascertain the main factors for the Sauter mean drop size (d₃₂) of the dispersed phase in a three‐stage modified Scheibel extraction column with no mass transfer. A precise correlation applied to the liquid‐liquid systems with low interfacial surface tension was proposed for calculating d₃₂. The maximum relative error for all data was 16.0 % and the mean relative error ±4.6 %.     

规整填料塔的设计计算模型

针对规整填料塔的特点和近年来的研究进展 ,分析了规整填料内的流体力学和相间传质行为 ,并对规整填料塔内压力降、液泛及气液传质设计计算模型进行比较 ,同时指出了高压填料塔设计计算中应注意的问题。     

丙烯酸脂快干立体锤纹漆的研制

介绍了丙烯酸快干立体锤纹漆的原料组成、配制方法、主要技术性能指标及研制立体锤纹漆的几项技术问题.     

注水工况下的管柱水锤分析

注水过程中管柱内液体具有高压、高速流动的特点,一旦管内液体流动边界发生短时间变化,将会产生管内液体流速及压力的变化,可能造成管柱振动、密封失效甚至断裂。主要针对注水工况下,运用管道振动分析软件AUTOPIPE对管柱注水过程进行水锤模拟分析,重点对管内液体流速、压力、轴向振动速度以及轴向附加应力进行分析,为现场管道施工安全及优化提供参考。     

旋流式蒸汽混合撬的研发与应用

旋流式蒸汽混合撬是直接将蒸汽平稳地掺入需加热介质的设备,在掺入蒸汽的过程中有效避免了水击、需加热介质中杂质较快堵塞管道的问题,不考虑壳程损耗的情况下蒸汽利用率可达100%。本文主要展示了由于工业生产中原油加热脱水时遇到的问题,传统原油脱水加热方法采用物理换热法,即通过金属的热传导作用将温度较高热源介质的热量传递给温度较低的需加热介质,使温度较低的需加热介质达到升温的目的,此种方法设备综合热利用效率普遍低于80%,如果再考虑介质流速、导热材料结垢、介质纯净度等因素,综合热效率不足60%;作者等通过对这些问题的分析设计并制造出旋流式蒸汽混合撬;在设计的过程中首先考虑了水击问题和需加热介质易堵塞通道的问题,颠覆了传统的换热理念,通过对该设备的完善和优化,达到了较理想的效果,同时理论上模拟了不同加热温度的节能指标,以及在现场投入使用后的应用效果评价,认为该设备适用于目前的生产工况,可产生较高的经济效益。     

Droplet Size in Two‐Phase Liquid Dispersed Pipeline Flows

Few experimental data exists on drop size distribution during dispersed liquid‐liquid pipeline flows. In the majority of cases dilute dispersions have been used and the results have mainly been compared with models for drop breakup. A review of this work shows that the Rosin‐Rammler distribution represents satisfactorily the existing experimental data. However, the commonly used Hinze model (Hinze, 1955) often underpredicts the experimentally found maximum drop sizes. Later models, many of which are developments of the Hinze one, are also unable to predict the resulting maximum drop size for a wide range of experimental conditions. A more comprehensive database is needed for the further development and refinement of theoretical models.     

Influence of Anvil Properties on RDX Thin Layer Ignition Behavior

We report on a drop‐impact protocol that arrests sample radial flow to isolate how anvil properties influence ignition in a thin layer of RDX powder. To eliminate sliding friction as a probable heating mechanism, flow arrestment was provided by a waxed weighing paper that shielded the RDX layer from direct contact with the impact surfaces. RDX reaction sensitivity under bare and shielded conditions for the standard O1 hardened steel anvil was compared with that for two deformable anvil types: 1018 steel and C110 copper. Profilometer measurements of anvil deformation and paper impressions quantified anvil plastic work and final radial flow displacement. Post‐test particle analyses correlated particle size distribution to ignition results. Experiments indicated that the impact energy absorbed by the anvils was varied and inhibited ignition accordingly. For the standard anvil, ignition was not inhibited under flow arrestment, suggesting that significant radial sliding or flow is not essential for thin layer ignition.     

固定床渣油加氢反应器结垢原因分析及对策

固定床渣油加氢技术是重油改质的重要手段,是优化重油催化裂化装置原料的主要措施.工业运转表明,反应器结垢是制约固定床渣油加氢装置满负荷生产和长周期运转的最重要因素之一.通过对固定床渣油加氢反应器结垢原因的分析,提出了抑制反应器结垢的措施.认为通过采取强化原料管理和严格日常操作管理等措施,能够抑制反应器结垢,延长装置的运转周期.