环隙式离心萃取器内部两相流动研究进展

环隙式离心萃取器是集成液-液混合与液-液分离于一体的高性能萃取设备,其广泛应用于核工业、化工环保、有色冶金、生物医药等领域。离心萃取器具有优异的水力学特性和传质特性,这主要得益于其环隙中的泰勒涡流以及转鼓内的离心分离流等特殊流动。本文主要依据离心萃取器结构和两相流动特点,综述了环隙内气-液界面变化规律、气泡流动特性、液-液两相流型、液滴流动特性,以及转鼓内的气-液界面等方面的研究进展,还总结了环隙螺旋隔板、转鼓径向叶片等结构的优化对于两相流动、混合或分离效果的影响。在后续研究中,可以从离心萃取过程中的液滴分散和聚并机理、三相流动测试及模拟、结构的模型化设计方法等方面开展更加深入的研究。     

φ230环隙式离心萃取器的流体力学性能研究

研制了一种φ230环隙式离心萃取器。在1500和2090rpm两种转速下,用水-煤油和食盐水-煤油两种体系做了流体力学性能实验。 实验表明设备的机械性能和水力学性能都很好。这种萃取器可以单级或多级串联用于液-液萃取的工业生产。     

环隙式离心萃取器流场研究进展

围绕工业应用,人们在环隙流场稳定性、水力学特性等方面做了大量研究,而对环隙的流场流动机理、泰勒涡流场结构等方面的研究较少,随着线性和非线性理论、计算流体力学和流动可视化技术的飞速发展,对环隙流场流动机理、涡流场的结构进行详细直观描述有了可能,主要从环隙流场可视化、环隙流场数值模拟2个方面对该研究进行了系统的分析总结,并为将来的研究工作提出了几点意见。     

φ50环隙式离心萃取器的水力学性能

<正> 环隙式离心萃取器是我校核能研究所仿美国国立阿贡研究所的ANL-4型离心萃取器研制成的,它已被成功地用于多种化工产品的分离中,其结构简单,更换和组合方便,可实现国产化,是具有推广意义的机种。本文研究此种离心萃取器移植到双水相体系的水力学性能,并确定其应用的可能性。     

环隙式离心萃取器界面半径的测定与关联

采用“快速放液法”测定转筒内的存留量，并用合适的相分布模型计算出相应的界面半径，即实验值。系统研究了转速、流比、重相堰直径、流量、两相密度差和粘度６个参数对环隙式离心萃取器界面半径的影响。用多元回归关联了６个自变量，拟合了界面半径的经验公式。计算值与实验值吻合较好，平均误差３．０３％，可用来确定２０ｍｍ环隙式离心萃取器最佳工作条件。     

圆筒式离心萃取器的探讨

圆简式离心萃取器具有容积效率高、处理能力大、两相停留时间短,并能分离两相密度小至0.01g/cm~2的液系,因此目前在化工、医疗、食品等行业越来越受到重视。本文介绍了该设备的基本原理、水力学特性、操作特性、结构设计等方面问题。     

圆筒式离心萃取器性能研究

以煤油—水—丁酸为体系,通过实验,研究了HL—20型离心萃取器的水力学及传质性能。一、概述圆筒式离心萃取器是60年代后期发展起来的一种离心萃取设备,与其它离心萃取器相比,圆筒式离心萃取器有其自己的特点,即结构简单,适应性强。在离心萃取器的加工中,技术要求最严格的是转鼓。不同规格的转鼓,生产能力可以从每小时几升到100m3/h,且其转鼓是上悬的,浸在液体部分的转动件没有密封的问题,消除了液体的漏液。在圆筒式离心萃取器中由于     

环隙式离心萃取分离技术研究进展

综述了国内外环隙式离心萃取分离技术的研究进展,包括环隙式离心萃取器的结构形式和参数、结构改进、流态及速度分布、水力学特性和传质特性等;介绍了环隙式离心萃取分离技术在核燃料后处理、石油化工及湿法冶金领域的应用;指出环隙式离心萃取分离技术是未来萃取技术的发展方向,环隙间传质因素及转子和堰区域的分离因素等是其今后的研究方向。     

玻璃钢离心萃取器及其应用

介绍玻璃钢离心萃取器的结构设计和性能实验，包括材料的选定，对样机进行连续运转７００ｈ的力学性能实验，以及流体力学性能和传质性能实验。结果表明玻璃钢离心萃取器具有良好的性能，可应用于工业生产有萃取、净化流程中。     

直联式离心萃取分离机的研制与应用

介绍了一种新型离心萃取分离机--CTL直联式离心萃取分离机的结构、工作原理及其典型应用情况,并与国内外同类设备进行对比,重点介绍了该设备的技术创新以及优点,指出该设备在湿法冶金、环保、制药工业等众多领域可广泛应用,尤其适合于一些难以处理的特殊物料体系.     

Effect of Cylinder Rotation on Flow Characteristics of the Annular Region in Annular Centrifugal Extractor

The flow patterns in the annular region of a 50 mm annular centrifugal extractor (ACE) were studied using phase particle image velocimetry (PIV), by which the distributions of radial velocity, axial velocity, vorticity, turbulent kinetic energy (TKE), and micromixing time of a fluid under different rotating Reynolds numbers were investigated. In the center of the annular region, both the radial and axial velocities of the fluid are close to zero, regardless of the rotating Reynolds number changes. The TKE of the fluid along the radial direction is small at center and large on the edge. The results show that the mixing process mainly occurs at the region near the outer cylinder’s sidewall, and the mixing time in this region is less than that in the internal annular region. Besides, the whole mixing efficiency is proportional to the rotational speed when the speed is below a certain level, and then gradually reaches a plateau when the speed is further increased.     

Computational Fluid Dynamics (CFD) Study of the Flow in an Annular Centrifugal Contactor

Abstract

This study presents an initial scoping analysis of the application of computational fluid dynamics (CFD) to modeling the flow in an annular centrifugal contactor. The unsteady, turbulent nature of this multi‐phase flow presents significant challenges to quantitative CFD modeling. Existing methods for confronting these obstacles are considered and initial results of the steady‐state flow of a single liquid phase in the annular mixing zone are presented. The flow of particulates and the effects of changes in geometric and operational parameters were also evaluated. Even with simplifying assumptions qualitatively accurate results could be obtained using widely available CFD models.     

Thirty Stage Annular Centrifugal Contactor Thermal Profile Measurements

A thirty stage 5 cm annular centrifugal contactor cascade was assembled and tested to obtain thermal profiles during both ambient and heated input conditions of operation. Thermocouples were installed on every stage as well as feed inputs, and real-time data was taken during experiments lasting from two to eight hours at total flow rates of 0.5 to 1.4 liters per minute. Ambient temperature profile results show that only a small amount of heat is generated by the mechanical energy of the contactors. Steady state temperature profiles mimic the ambient temperature of the lab but are higher toward the middle of the cascade. Heated inlet solutions gave temperature profiles with smaller temperature gradients, more driven by the temperature of the inlet solutions than ambient lab temperature. Temperature effects of solution mixing, even at rotor speeds of 4000 rpm, were not measurable.     

离心萃取器在咖啡因工业生产中的应用

在咖啡因工业生产中,一般是采用静态混合器为萃取设备、氯仿为萃取剂来回收母液中的咖啡因,主要缺点是萃取率只在90％左右以及氯仿损失大。离心萃取器是一种高效的液一液萃取设备,具有许多显著优点,为此,采用了4台Ф230离心萃取器代替静态混合器组成串联逆流萃取流程,对该生产环节进行了技术改造,结果表明,萃取率提高到了99％,氯仿用量降低到了25％。     

新型离心萃取机的开发及其应用前景

介绍了离心萃取机的结构和工作原理,国内外发展历程,对比了国内外机型的技术参数。着重分析了自行开发的新型离心萃取机的技术创新点和优点,探讨了新型离心萃取机在核能、环保、湿法冶金、生物制药、精细化工等行业的市场应用前景。     

用离心萃取器连续逆流提取氢化可的松的研究

采用环隙式离心萃取器进行了提取氢化可的松的研究。用醋酸丁酯从发酵液中萃取氢化可的松 ,其传质过程受扩散因素控制 ,且分配系数随平衡水相浓度的增大而增大。开发了用环隙式离心萃取器连续逆流提取氢化可的松的工艺流程 ,当转速为 340 0～ 380 0r/min ,总流量为 40～ 75mL/min ,V(O ,有机相 )∶V(A ,水相 )为 (0 35～ 0 42 )∶1 0 0时 ,氢化可的松的萃取率为91 0 8%～ 93 16 % ,而厂家现行生产工艺采用的V(O)∶V(A)是 0 7∶1 0 ,氢化可的松的萃取率为90 %。因而 ,新工艺提高了氢化可的松的萃取率 ,降低了萃取剂耗量     

Extraction of Caffeine with Annular Centrifugal Contactors

Abstract

An extraction process for caffeine has been developed with annular centrifugal contactors. The caffeine distribution ratio in the mother solution effluent‐chloroform system was measured to be about 18.6. Both the pilot tests and the plant tests have been completed with Φ20 mm and Φ230 mm annular centrifugal contactors, respectively. The extraction rate higher than 99% was achieved in the pilot tests, when the rotor speed was 3000‐4500 r/min, the total flow was 20‐80 mL/min, and the flow ratio (A/O) was 2/1. When the rotor speed was 1800 r/min, the mother solution flow was 2000 L/h, and the chloroform flow was 1000 L/h; the extraction rate was also more than 99% in the plant tests.     

Demonstration of an Improved Total Partitioning Process for High Level Liquid Waste Using Annular Centrifugal Contactors

High level liquid waste (HLLW) produced from the reprocessing of the spent nuclear fuel still contains moderate amounts of uranium, transuranium (TRU) actinides, ⁹⁰Sr, ¹³⁷Cs, etc., and thus constitutes a permanent hazard to the environment. The partitioning and transmutation (P&T) strategy has increasingly attracted interest for the safe treatment and disposal of HLLW, in which the partitioning of HLLW is one of the critical technical issues. An improved total partitioning process, including a TRPO (tri-alkylphosphine oxide) process for the removal of actinides, a CESE (crown ether strontium extraction) process for the removal of Sr, and a calixcrown ether extraction process for the removal of Cs, has been developed to treat Chinese HLLW at the Institute of Nuclear and New Energy Technology (INET), Tsinghua University, China. A demonstration test of the improved total partitioning process was carried out using 74-stage 10-mm-dia annular centrifugal contactors and simulated HLLW. The test results showed that the decontamination factors were >1.2 × 10⁶, 4600, and 7500 for Nd, Sr, and Cs, respectively. In the test, Nd was used to simulate Am. During the test, 74-stage 10-mm-dia annular centrifugal contactors worked stable continuously with no stage failing or interruption of the operation.     

Synergistic Extraction of Lanthanides in a Liquid-Liquid Countercurrent Centrifugal Extractor

We have developed a liquid-liquid countercurrent centrifugal extractor that induces Taylor vortices in the annular fluid region. To demonstrate extraction of multiple species (Nd/Sm/Eu/Gd/Dy) with N,N,N′,N′-tetraoctyl diglycolamide (TODGA), additional chemical agents, such as a surfactant (sodium bis(2-ethylhexyl) sulfosuccinate (AOT)), a synergist (nonanoic acid) and a masking agent (N,N,N′,N′-tetraethyl-3,6-dioxaoctane-1,8-diamide (DOODA(C2))) were employed. When only TODGA was utilized, extraction performance was not effective due to the insufficient dispersion even under a high rotating speed. By combining TODGA and other chemical agents, the separation performance was improved considerably in the countercurrent flow of aqueous and organic phases due to the synergistic effect and improved dispersion.