THERMAL DIFFUSION IN SPIRAL WIRED COLUMNS WITH TRANSVERSE SAMPLING STREAMS

The equations that may be employed to predict the optimum wire angles of inclination for performance in a concentric-tube thermal-diffusion column with a tight-fitting wire spiral, having a diameter equal to the annular spacing, wrapped on the entire inner tube, and operating with transverse sampling streams, have been derived. Considerable improvement in performance is obtainable if the wire angle is adjusted at the optimum angle, instead of the absence of a wire spiral, so that the convection strength can be properly reduced and controlled, resulting in suppressing the undesirable remixing effect while still preserving the desirable cascading effect. Accordingly, essential savings in fixed charges and operating expense can be achieved, particularly for lower production rate operations or for a smaller degree of separation.     

THE OPTIMUM PLATE-SPACING FOR THE BEST PERFORMANCE IN FLAT-PLATE THERMAL DIFFUSION COLUMNS OF THE FRAZIER SCHEME

The effect of plate spacing on the degree of separation and production rate in flat-plate thermal diffusion columns of the Frazier scheme with fixed operating expense, has been investigated. The equations for estimating optimum plate-spacing for maximum separation and for maximum production rate have been developed. Considerable improvement in performance is obtainable when the thermal diffusion columns with optimum plate-spacing are employed for operation.     

THE PROPER COLUMN NUMBER FOR BEST PERFORMANCE IN THERMAL DIFFUSION COLUMNS OF THE FRAZIER SCHEME WITH TOTAL SUM OF COLUMN HEIGHT FIXED

The effect of column number on the Frazier scheme performances with total sum of column heights fixed has been investigated. The equations that may be employed to predict the optimal number of columns (generally not integers) for the maximum performance are derived. Accordingly, the proper number of columns, which are the integers nearest to and smaller than the optimal column numbers, are obtained for practical applications. Considerable improvement in performance is obtainable if the scheme is constructed with the proper number of thermal diffusion columns, instead of using a single column, with the same total sum of column heights.     

THE OPTIMUM PLATE-SPACING FOR THE BEST PERFORMANCE IN A FLAT-PLATE THERMAL DIFFUSION COLUMN WITH TRANSVERSE SAMPLING STREAMS

The equations for estimating optimum plate-spacing for maximum separation and for maximum production rate in a flat-plate thermal diffusion column with transverse sampling stream and with fixed operating expense, have been derived. Considerable improvement in performance is obtainable if the optimum plate-spacing is selected so that the convective strength can be properly reduced and controlled, resulting in suppressing the undesirable remixing effect while still preserving the desirable cascading effect and thereby leading to improved performance.     

OPTIMAL PLATE ASPECT RATIO FOR THE BEST PERFORMANCE OF THE ENRICHMENT OF HEAVY WATER IN THERMAL-DIFFUSION COLUMNS OF A COUNTERCURRENT-FLOW FRAZIER SCHEME

The effect of plate aspect ratio on the performance of enrichment of heavy water in thermal-diffusion columns of a countercurrent-flow Frazier scheme was investigated. The equation for the optimal plate aspect ratios and the corresponding best performance were derived. Considerable improvement in performance is obtained when thermal-diffusion columns are operated at the optimal plate aspect ratio. Further improvement can be achieved if the scheme is connected and operated in countercurrent flow, instead of concurrent flow.     

OPTIMAL PLATE ASPECT RATIO FOR THE BEST PERFORMANCE OF THE ENRICHMENT OF HEAVY WATER IN THERMAL-DIFFUSION COLUMNS OF A COUNTERCURRENT-FLOW FRAZIER SCHEME

The effect of plate aspect ratio on the performance of enrichment of heavy water in thermal-diffusion columns of a countercurrent-flow Frazier scheme was investigated. The equation for the optimal plate aspect ratios and the corresponding best performance were derived. Considerable improvement in performance is obtained when thermal-diffusion columns are operated at the optimal plate aspect ratio. Further improvement can be achieved if the scheme is connected and operated in countercurrent flow, instead of concurrent flow.     

THERMAL EFFECT ON DIFFUSION OF GASES IN ZEOLITES

A new technique for measuring simultaneously adsorption rate and temperature variation in zeolite hasbeen developed.The transient temperature process during adsorption of gas on zeolite was analyzed by meansof a simple model.It was found that the diffusion of gas in zeolite crystallines could be made almost iso-thermal if the experimental conditions were appropriately designed.Thus the thermal effect on determinationof diffusion coefficient of gas in zeolite could be neglected.     

THERMAL DIFFUSION IN A FLAT-PLATE COLUMN WITH TRANSVERSE SAMPLING STREAMS

The optimum angles of inclination for maximum separation, maximum production rate and minimum column length in a fiat-plate thermal diffusion column with transverse sampling streams, have been determined. Considerable improvement in performance is obtainable if the column is tilted at the optimum angle, instead of being placed vertically, so that the convection strength can be properly reduced and controlled, resulting in suppressing the undesirable remixing effect while still preserving the desirable cascading effect.     

螺旋片导流式分离器分离性能的数值模拟与试验研究

应用计算流体力学（CFD）方法对不同结构参数的螺旋片导流式气液分离器在湍流状态下的流体流动场进行了数值模拟,研究了螺旋个数和螺距对螺旋片导流式气液分离器分离性能的影响,并与试验测定结果对比,由此验证基于数值模拟方法设计螺旋片导流式气液分离器分离效率的可行性与准确性.分析结果表明,数值模拟结果与试验数据基本一致,可以作为螺旋片导流式气液分离器设计的有效工具.     

PERFORMANCE OF ABSORPTION AND DISTILLATION COLUMNS IN A LUNAR ENVIRONMENT

The establishment of a permanent lunar base will employ separation processes that may be conducive to column operation. Reclamation of precious bodily fluids and products from chemical manufacture will be a part of routine necessity. The lunar environment, with reduced gravity and pressure, will offer some intriguing possibilities for operation such as vacuum distillation. The area for plate and packed columns will need to be increased in order to compensate for the reduction of gravitational forces responsible for moving the fluids. Plate efficiencies, hence column height, can increase or decrease, depending on the choice of scaling criteria applied to the plate geometry. Packed column height remains almost independent of gravity.     

用热分析技术定量检测复合材料烧蚀性能

对复合材料氧乙炔烧蚀试验及其系列热分析试验的结果进行了计算和分析。运用统计理论和方法,证明了热分析性能值和烧蚀率之间存在显著的相关性。建立了两者的若干一元和二元线性回归方程,并论证了方程的可靠性。     

氯离子在掺不同矿物质掺合料高性能混凝土中的扩散性能

采用改进型电迁移法测试了氯离子在掺不同矿物质掺合料高性能混凝土中的扩散性能．研究表明：在混凝土中分别内掺磨细矿渣、粉煤灰、硅灰、膨胀剂均可提高混凝土的抗渗透性能(Cl^-扩散系数降低),其中以单掺硅灰效果最优;在混凝土中复掺膨胀剂和磨细矿渣或膨胀剂和粉煤灰,对提高混凝土抗渗透性能的效果优于单掺二者之一,也优于单掺效果最好的硅灰混凝土．复掺膨胀剂和细掺料后混凝土内部结构进一步优化、微观结构致密、微缺陷减少,由此,开发了一种低成本配制超高抗渗性混凝土的新途径。     

ENRICHMENT OF HEAVY WATER BY THERMAL DIFFUSION

Equations of the best wire angle of inclination for the maximum separation, maximum output and minimum column height for enrichment of heavy water in a concentric-tube wired thermal diffusion column have been derived. Considerable improvements in performance were obtained by employing the wired column instead of using the open column (without wire). It was also found that the wire inclination for maximum separation is also the wire inclination required to obtain the maximum production rate, or minimum column height, for a specified degree of separation.     

FRP筋混凝土柱及框架抗震性能的研究进展

与普通钢筋相比,FRP筋具有轻质高强、耐腐蚀性能好等优点,但是FRP筋弹性模量较低、为线弹性材料、破坏时脆性大等特性限制了其在混凝土柱,特别是在地震地区结构工程中的应用。介绍了国内外关于FRP筋混凝土柱及框架抗震性能的研究成果,其中包括试验研究和数值模拟研究。国内外研究表明,FRP筋取代钢筋应用于混凝土柱、混凝土框架及其节点是可行的。通过适当配置FRP筋,保证其在弹性范围内工作,则FRP筋混凝土结构能够获得较大的延性和变形能力。最后建议研究FRP筋混凝土柱的破坏模式、抗剪承载力计算、延性评价和设计理论等。系统研究FRP筋混凝土柱基本理论和设计方法具有重要的理论意义和实用价值。     

ON THE LIQUID FLOW REVERSAL IN BUBBLE COLUMNS

The maximum range of the radial position within which liquid flow reversal can be expected to occur in zero net liquid flow bubble columns is predicted. It is shown that existing models, that employ this position as an input parameter for predicting the liquid velocity profile, are intrinsically valid only when the flow reversal dimensiontess radius is confined to ihe narrow range of 0.644-0.707. It is demonstrated that radial positions outside this range are unacceptable on physical grounds. Guidelines for evaluating the appropriate location of the flow reversal point for typical bubble column operating conditions are proposed.     

冷却塔热力性能集成测试软件开发与实现

介绍了一款冷却塔热力性能集成测试软件的开发与实现,其开发平台为C#,本软件的特点是将评价冷却塔热力性能所需的各种温度、流量、压力等参数数据采集与计算方法集成化。详细介绍了软件的层次结构以及各个功能模块的作用及实现方法。同时介绍了将该软件应用于实塔测试的过程,并将测试结果与本软件同时进行的美国CTI协会测试结果进行了对比分析。     

浅论表面润湿与塔填料传质效率的关系

ADISCUSSIOONTHEWETTABILITY-EFFICIENCYRELATIONINPACKEDCOLUMNS1前言70年代以来,填料塔作为重要的传质分离设备在石油炼制、天然气加工、石油化工、精细化工、化肥、医药、及环保等部门得到越来越广泛的应用。现代化工的发展,出现了许多新的特点：生产规模大型化,要求搭设备具有高通量和低能耗;精细化工和材料工业的发展,需要对化工产品深度加工,往往涉及难分离或热敏性物系,要求塔设备具有高效率和低压降;日益严格的环境保护,对处理排放物料的搭设备也提出了苛刻的要求。’。从而推动了塔填料的工业应…     

接触热阻对复合材料身管热性能影响分析

采用金属内衬外部缠绕纤维增强复合材料,可减轻纯金属身管重量,提高身管刚度.为了详细分析复合材料身管分界面接触热阻对身管热性能影响,本文建立考虑复合材料身管分界面接触热阻效应的瞬态传热模型,运用有限差分法编制通用程序对接触热阻效应对复合材料身管热性能影响进行数值定量分析.结果表明,接触热阻对于复合材料身管的传热性能有较大影响,必须采取措施来减小接触热阻,这在复合材料身管的热性能设计中必须重点考虑.