Modélisation de nanofiltration/osmose inverse en tenant compte du facteur de séparations minimale et maximale

Based on theorical analysis of existing models and on experimental observations, a model that allows us to connect the permeate flux tothe intrinsic separation factor takingaccount of the termsof the minimal and maximalseparation factors, was established. The experiments covering a large range of permeate flux (from several 10^?9 μL/m 2.s) to several 10.³ mL/(m 2.s)) permit us todetermine the values of maximal seaparation and minimal separation, as well as the solute transport parameterr for the solutions of sodiumchloride and sodium sulfate.     

3D cold pressure welded components – From the bonding mechanisms to the production of high strength joints

In this work, a comprehensive analysis of the bonding mechanism involved in the formation of highly stable cold pressure welded aluminum‐steel components is presented. After identification of relevant process steps to realize bonding the process is modified. Focusing on surface preparation methods, systematic manipulations are employed to identify the relevant parameters promoting the bond formation. The analysis is carried out by tensile stress testing of micro and macro samples as well as high resolution imaging of the joint zone. The results are enables in a deeper understanding of the bonding mechanism.     

微波消解技术在元素分析中的应用

简要讨论了微波作用的基本原理及微波如何大大加快对样品消解速度。介绍了微波消解系统的组成及设备。比较了开口容器和密闭容器消解的特点。提出了建立微波消解方法的原则及根据。评述了微波消解技术在微量元素测定。金属元素的形态分析和自动微波测试系统等方面的应用情况及发展前景     

Nanocomposite‐Beschichtungen auf CBN‐Werkzeugen

Nanocomposite coatings on CBN‐tools CBN (cubic boron nitride) cutting materials are often used to improve the properties of cutting tools. This allows new applications and processes, which are not possible with common cutting materials (e.g. hard metals). Today CBN cutting materials are mostly coated to estimate the wear by an optical evaluation. Coatings on CBN cutting materials for enhancement of the tribological properties are normally not used. For improvement of the properties of used CBN tools during the cutting process a coating technology was developed. This technology combines the advantages of CBN cutting materials with the excellent properties (e.g. hardness, temperature stability) of nanostructured materials. Investigations with different coating systems and pre‐treatment processes were done to test the CBN cutting tools. These investigations have been shown, that nanocomposite coatings can be used to enhance the tool life of CBN cutting tools. Important for an increase in the tool life is a very good coating adhesion, which can be reached by special adhesion layers and an optimized coating structure.     

Modification and experimental research on vortex tube

Vortex tube (VT) is a simple energy separating device which is compact and simple to produce and to operate. Although intensive research has been carried out in many countries over the years, the efficiency is still low. In order to improve the energy separate efficiency of vortex tubes, three innovative technologies were applied to vortex tubes. A new nozzle with equal gradient of Mach number and a new intake flow passage of nozzles with equal flow velocity were designed and developed to reduce the flow loss. A new kind of diffuser invented by us was installed for reducing friction loss of air flow energy at the end of the hot end tube of vortex tube, which can greatly improve the performance of vortex tube. The experiment results indicated that these modifications could remarkably improve the performance of vortex tube. The developed vortex tube was not only superior to the conventional vortex tube but also superior to that made by two companies in world under big cold gas mass flow ratio.     

Force estimation of mechanical removing processes of mushy structure in an aqueous solution

In a system of producing liquid ice with mechanical removing processes of mushy structure in an aqueous solution, a solid layer as thermal resistance does not stack up on a cooling surface. It prevents refrigerator's COP dropping and also prevents ice production rate dropping. However, some extra energy is needed for mechanical removing processes of the mushy structure from cooling surfaces. In this paper, the required force for removing the mushy structure is expressed as a function of experimental conditions based on bending-beam theory. The mushy structure is regarded as an elastic body. The estimated values of modulus of elasticity and values of adhesion force are reasonable compared with the observed results. Parameters that affect on mode difference, maximum force and steady force are shown.     

Numerical and experimental investigations of the effects of the breakup of oil droplets on the performance of oil–gas cyclone separators in oil-injected compressor systems

A numerical simulation was conducted of the dynamic trajectories and the separation performance of oil droplets, with a focus on the breakup of oil droplets in an oil–gas cyclone separator. The separation efficiency was also studied experimentally, and the oil droplets' diameter distributions before and after the separator were measured with a Malvern particle size analyser to verify the simulation model. Both the experimental and simulation results showed that the breakup of oil droplets occurred in the separation process, clearly influencing the separation efficiency. In addition, the results indicated that inlet velocity played an important role in separation efficiency, as it not only significantly affected the tangential velocity inside the separator, but also determined the possibility and degree of the breakup of oil droplets.     

莲籽壳仁分离清选机的研究

根据莲籽壳、仁间的物理属性，设计了能一次完成莲籽壳、仁分离和清选的机械；并对分离过程中莲籽混合物的相关运动特性及运动轨迹进行了分析，确定了相关的主要参数。     

Vapor–liquid separation in a vertical impact T-junction for vapor compression systems with flash gas bypass

This paper presents results from experimental study of vapor and liquid refrigerant separation in vertical impact T-junctions using R134a and R410A for application in but not limited to vapor compression systems. Inlet flow rate and quality are varied in the range of 10–35 g s⁻¹ and 10–25%. Flow patterns in the T-junction separator are identified and characterized. It is found that liquid separation efficiency strongly depends on the flow pattern right above the impact region (junction). The efficiency deteriorates dramatically when mist turns into churn flow regime, with increasing inlet flow rate and/or quality. An empirical correlation to predict churn flow transition is proposed as a function of Fr and X_tt. That correlation is a bases for good design of T-junction separators.