Fest‐Flüssig‐Trennung von feindispersen Suspensionen durch Pressfiltration bei pulsierendem Überdruck

The productivity of filtration systems for dewatering of finely dispersed suspensions can be increased by pulsating overpressure. For suspensions of marine organic‐mineral sediments, press filtration processes were investigated under static and pulsating overpressure. The influence of the static pressure component, the pressure amplitude characteristic, the pressure vibration frequency, and the filtration time on the volume of filtrate were determined. Based on Darcy's law, a model of the filtration process under static overpressure was developed. For pulsating overpressure, the mathematical theory of experiment planning and the statistical data analysis method were used.     

压力机的密封

详细介绍了压力机密封的原理,密封的泄漏机理,密封的分类、应用、要求、选择以及安装,并结合压力机的特点叙述了各种密封件在压力机中的应用及其注意事项。     

Press molding of a Si–HDPE hybrid lens substrate and evaluation of its infrared optical properties

A hybrid structure of single-crystal silicon (Si) and high-density polyethylene (HDPE) was developed as a new substrate for infrared lenses by using precision press molding. A thin HDPE film was used to laminate a silicon wafer and their interface was directly bonded by the silane cross-link. The HDPE film is easy to be hot-embossed to form three-dimensional surface microstructures and the silicon wafer provides a high stiffness for the hybrid substrate. The infrared (IR) optical properties of the hybrid substrate were examined by two kinds of measurements, transmittance and image sharpness. Interestingly, the transmittance measurement result shows that the IR transmittance of the hybrid substrate is higher than that of Si itself in some region of wavelength. The imaging test result shows that the hybrid substrate is capable to produce similar image quality as Si itself. These results strongly demonstrate that the developed Si–HDPE hybrid substrate is a promising alternative substrate material for IR lens.     

变压器铁心精确压紧工艺

对变压器的铁心绑扎受力情况进行了分析,并提出了一套精确计算及控制铁心压紧力的工艺方法。     

Extraction,Composition and Functional Properties of Pennycress (Thlaspi arvense L.) Press Cake Protein

This study compared two methods for extracting the protein in pennycress (Thlaspi arvense L.) press cake and determined the composition and functional properties of the protein products. Proteins in pennycress press cake were extracted by using the conventional alkali‐solubilization–acid‐precipitation (AP) method or saline‐based (SE) procedure (0.1 M NaCl at 50 °C). The extraction method has a major influence on the purity and functional properties of press cake protein products. AP had a lower protein yield (23 %) but much higher purity (90 % crude protein) compared with SE (45 % yield, 67 % crude protein). AP protein isolate had high foam capacity (120 ml), high foam stability (96 % foam volume retention) and high emulsion stability (24–35 min), and it was resistant to heat denaturation (3 % loss of solubility at pH 2 and pH 10). On the other hand, SE protein concentrate showed remarkably high solubility (>76 %) between pH 2 and 10 and exceptional emulsifying activity (226–412 m²/g protein), but was more susceptible to heat denaturation at pH 7 and pH 10 (65–78 % loss of solubility). These results strongly demonstrate that higher purity pennycress press cake protein can be produced by either saline extraction or acid precipitation and have functional properties that are desirable for non‐food uses.     

圆柱内壁件下压装配机械手结构实现及弹簧参数优选

根据特定产品生产工艺要求,设计了一种用于圆柱内壁件作业的内撑式抓取与下压装配机械手。该机械手在手指系统与筒状手掌之间采用弹性连接。在高速作业过程中,这类弹性连接形成手指系统的残留振动。在对机械手结构设计思想与结构介绍的基础上,对机械手系统采用Adams运动仿真,分析了弹簧系统参数对手指系统的残留振动的影响,并对影响机械手振动特性的关键参数——连接弹簧的参数进行了优化选择。实际机械手的运行结果表明,该机械手结构与弹性参数的选择可以很好地满足特定对象的作业要求。     

YB32-200型压力机液压系统节能设计

环境恶化和能源危机使得在工程技术领域内,以"节能"、"环保"为特征的绿色液压技术得到推广和应用。材料成型设备YB32-200型压力机应用广泛,从节能角度对原有液压系统进行节能改造,利用蓄能器回收主液压缸无杠腔的高压能量,并应用西门子200PLC代替原有继电器控制,使压力机更加节能、工艺动作更准确、可控性更高。     

基于有限元分析的压机用螺纹的比较

通过有限元软件对压机用锯齿形螺纹和潘克螺纹的齿面应力和齿根应力进行分析比较,阐明了潘克螺纹较锯齿形螺纹具有明显的优势,表现为应力在每一牙上分布的均匀程度高,齿根应力高应力分布范围窄。锯齿形螺纹已经阻碍了现代压机的技术进步,急需一种新型螺纹来代替。期望本文对压机用螺纹技术进步起到积极的推进作用。     

Powder coating of veneered particle board surfaces by hot pressing

The powder coating of veneered particle boards by the sequence electrostatic powder application – powder curing via hot pressing is studied in order to create high gloss surfaces. To obtain an appealing aspect, veneer sheets were glued by heat and pressure on top of particle boards and the resulting surfaces were used as carrier substrates for powder coat finishing. Prior to the powder coating, the veneered particle board surfaces were pre-treated by sanding to obtain good uniformity and the boards were stored in a climate chamber at controlled temperature and humidity conditions to adjust an appropriate electrical surface resistance. Characterization of surface texture was done by 3D microscopy. The surface electrical resistance was measured for the six veneers before and after their application on the particle board surface. A transparent powder top-coat was applied electrostatically onto the veneered particle board surface. Curing of the powder was done using a heated press at 130 °C for 8 min and a smooth, glossy coating was obtained on the veneered surfaces. By applying different amounts of powder the coating thickness could be varied and the optimum amount of powder was determined for each veneer type.     

压力机大型焊接齿轮结构设计与制造

为推广焊接大齿轮设计与制造技术,以我公司6300kN压力机采用的大齿轮为例,详细阐述了焊接大齿轮从设计、校核到焊接、机加工的关键技术与方法.对于焊接大齿轮的有限元校核计算法、焊缝结构、材料焊接性能、焊接工艺、施焊要领作了详细讲解,为此类焊接大齿轮的设计与制造提供了可靠的设计依据和参考模板.