Battery separators

The ideal battery separator would be infinitesimally thin, offer no resistance to ionic transport in electrolytes, provide infinite resistance to electronic conductivity for isolation of electrodes, be highly tortuous to prevent dendritic growths, and be inert to chemical reactions. Unfortunately, in the real world the ideal case does not exist. Real world separators are electronically insulating membranes whose ionic resistivity is brought to the desired range by manipulating the membranes thickness and porosity. It is clear that no single separator satisfies all the needs of battery designers, and compromises have to be made. It is ultimately the application that decides which separator is most suitable. We hope that this paper will be a useful tool and will help the battery manufacturers in selecting the most appropriate separators for their batteries and respective applications. The information provided is purely technical and does not include other very important parameters, such as cost of production, availability, and long-term stability. There has been a continued demand for thinner battery separators to increase battery power and capacity. This has been especially true for lithiumion batteries used in portable electronics. However, it is very important to ensure the continued safety of batteries, and this is where the role of the separator is greatest. Thus, it is essential to optimize all the components of battery to improve the performance while maintaining the safety of these cells. Separator manufacturers should work along with the battery manufacturers to create the next generation of batteries with increased reliability and performance, but always keeping safety in mind. This paper has attempted to present a comprehensive review of literature on separators used in various batteries. It is evident that a wide variety of separators are available and that they are critical components in batteries. In many cases, the separator is one of the major factors limiting the life and/or performance of batteries. Consequently, development of new improved separators would be very beneficial for the advanced high capacity batteries.     

Electrostatically enhanced cyclone separators

The separative performance of a cyclone can be enhanced if electrical forces are employed to supplement the inertial forces. By precharging the particles and applying a radial electric field within the cyclone, collection efficiency is improved. In the present paper, a model is developed for such an electrostatically augmented cyclone. The model assumes that turbulence promotes complete radial mixing within each of three regions: the entrance region, the downflow region and the core (or upflow) region. Based on this model, an analytic expression for the collection efficiency of cyclone separators is developed.     

Design and control for recycle plants with heat-integrated separators

This work analyzes the tradeoff between steady-state economics and dynamic controllability for heat-integrated recycle plants. The process consists of one reactor, two distillation columns, and two recycle streams first studied by Tyreus and Luyben (Ind. Eng. Chem. Res. 32 (1993) 1154) and further explored by Cheng and Yu (A.I.Ch.E. J. 49 (2003) 682) and, in this work, the two distillation columns are heat integrated. The design problem differs from typical column sequencing and heat-integration design, because we can design the reactor composition. Optimal trajectories for heat-integrated recycle plants with direct and indirect sequences are analyzed as the reactor composition of C (z_C) varies. Provided with correct direction for heat integration, at any given z_C, the flowsheet is established for both sequences. It turns out the heat-integrated recycle plant with direct sequence is economically optimal throughout the entire range of z_C. For dynamic controllability, the reachable production range is identified as the recycle ratios (recycle flow rate/production rate) vary. Results show that the steady-state controllability deteriorates gradually as the degree of heat integration increases and, to the extreme, at the 50% energy saving line, we have lost one control degree of freedom. However, if the recycle plant is optimally designed (z_C≈0.6), acceptable turndown ratio is observed and little tradeoff between steady-state economics and dynamic operability may result. Finally, rigorous nonlinear simulations are used to test control performance of different process configurations (with and without heat integration). The results reveal that improved control can be achieved for well-designed heat-integrated recycle plants (compared to the plants without energy integration). More importantly, better performance is achieved with up to 40% energy saving and close to 20% saving in total annual cost.     

高压分离器的制造

介绍高压分离器的结构特点、主要部件的制造工艺、检测和整体组装.     

耐磨材料在选粉机上的应用

选粉机机件的磨损和防磨损是一个矛盾体，掌握常用耐磨材料各自的特点，再根据不同部位的磨损性质和工作条件，有针对性地选择适宜的耐磨材料和防磨方法，才能有效提高选粉机的综合抗磨损能力，从而提高设备的整体寿命和可靠性。     

Investigation and development of gravity separators with a standardized experimental setup

This contribution presents a standardized experimental setup for the development of gravity separators. Two different optical measurement techniques for the characterization of the inlet and outlet dispersion with a droplet spectrum of 20-2000 μm are used. The settling behaviour in a standardized batch settling test (ERICAA cell) serves as a basis for predicting the drop diameter resolved separation efficiency of a horizontal continuous separator. The latter (DN150, length 0.65 m) was operated and monitored with a phase fraction of up to 15% and a load of up to 17.0 m³ m⁻² h⁻¹. A paraffin oil with a viscosity of 10 mPa s was the dispersed and water the continuous phase. Sauter mean diameters of dispersions measured inline show a good agreement with those calculated from batch settling tests. Additionally, the modelled separation efficiencies are compared to the experimental results produced with the continuous separator.     

Metal separators coated with carbon/resin composite layers for PEFCs

A new type of metal separator coated with corrosion-resistant and electronically conductive carbon/resin composite layers has been developed. A flat, stainless steel plate was coated with a thin composite layer, and then ribs were formed of a similar composite over the thin layer as gas flow channels. The composite consisted of graphite, epoxy resin and a phenol hardener. By optimizing the combination and composition of materials, target values for the bulk electric conductivity and the chemical stability in hot water were cleared. The separator pieces exhibited a good corrosion resistance during soaking tests in 0.1 M H₂SO₄ at 90 °C over 2000 h or even at 120 °C over 1200 h. The area-specific resistance of the separator coated with the thin protecting layer and the rib layer was less than 13.8 mΩ cm².     

设计演化算法实现精馏分离序列优化综合

采用演化算法求解具有组合爆炸特征的精馏分离序列优化综合问题。由于精馏分离序列与二叉树之问具有同构性．在数据结构上精馏分离序列可以抽象为二又树,直接采用二叉树结构编码方案可以同时表达个体的基因型和表现形。借鉴生物界父本可以经过有性繁殖或无性繁殖得到子代的现象。对遗传算子进行设计。应冒图论方法建立有效的二叉树结构演化重组机制,从而形成基于双亲或单亲父本的交叉算子。实例表明：双亲遗传操作其空间搜索率较低,而单亲遗传操作其最优解命中率较高。因此。演化算法能够成功解算大规模精馏分离序列优化综合问题。     

选粉机的故障诊断和分析

采用振动测试的方法，对振动信号的时域和频域进行分析，达到对选粉机的状态监测与故障诊断的目的，测试分析结果与实际情况相吻合。该方法对其他同样类型旋转机械的振动测试具有一定的参考价值。     

旋液分离器的计算机设计

在综合分析切割粒径、压降、效率和分股比数学模型的基础上,建立了旋液分离器的设计模型。采用FORTRAN语言,开发了可用于串并联组合旋液分离系统设计的计算机程序。实例表明该设计程序与其它软件相比具有较高的准确性和更宽的适用范围。     

Optimization of cyclically operated reactors and separators

An efficient version of a numerical gradient optimization procedure for the computation of solutions to periodic optimal control problems is presented. This procedure consists of a first order gradient method in combination with the Newton-Picard shooting method. The first order gradient method is able to compute the optimal control of a periodic process under one or more nonlocal constraints, such as a minimum purity constraint. The Newton-Picard method computes very efficiently periodic solutions to the state and adjoint equations. The presented numerical procedure is used to optimize a rapid pressure swing reactor and a rapid pressure swing adsorber. It is shown that the optimal cycle scheme consists of four steps: a no-inflow pre-pressurization step, a pressurization step, a no-inflow post-pressurization step, and a depressurization step.