Hydrodynamics of pulsed spouted beds: Effects of pulsation waveform,amplitude, and frequency

The effect of flow pulsations is studied via a discrete element model on hydrodynamics of spouted bed, which is being used in many important industries like drying processes. Decreased horizontal air percolation and preserving upward momentum, increased particle circulation, increased particle traverse distance, and better homogeneity are resulted from flow pulsations in spouted beds. Among the waveforms studied, square and triangular waveforms differ most and least from steady spouting, respectively. The predictions indicate that the pulsed spouted bed has the potential to enhance both gas and particle motion, hence being useful in drying and other operations.     

离心泵与滑片泵流量脉动特性及串联实验研究

对离心泵和滑片泵的流量脉动特性进行研究,探讨两泵串联运行的可行性。然后建立以离心泵为前级泵、滑片泵为后级泵的串联实验平台,通过改变串联中间管路阻力和滑片泵的出口管路阻力对滑片泵的运行特性进行实验研究,实验结果表明:泵与管路所构成的系统流量小于或接近滑片泵的理论流量时,系统才能正常工作,否则会造成整个系统的流量和压力脉动;不可改变串联中间管路阻力,以免滑片泵偏离正常工作状态;可通过改变滑片泵的出口管路阻力调整泵和系统运行参数。     

往复式压缩机管道的振动分析及防振设计

对往复式压缩机管道振动原因分析可知,活塞在汽缸中进行周期性的往复运动,所引起的压力脉动是管道产生振动的主要原因。管道振动的第二个原因是管道系统的固有频率与机器的激振频率相等时,管道发生机械共振。根据API618规定,确定采用何种分析方法,提出在工程设计中应采取的合理防振措施。通过减振实例解决往复式压缩机管道的振动问题。     

均相亚甲基蓝光敏氧化法处理造纸废水研究

本文探讨了利用均相亚甲基蓝光敏氧化法替代高浓度H2O2强化氧化法处理造纸废水的可行性与影响光敏氧化过程的因素。结果显示，在相同的光强下，复合光比紫外光效果好；在反应体系溶解氧高于2．0mg／L，光照4h时，光敏剂对造纸废水COD的去除量与其本身的体积质量比可达到333．5，具有较高的效率。     

提高难选冶金矿金精矿品位的试验研究

依据矿石特性 ,在常规浮选的基础上 ,采用再磨再选和新型组合药剂等工艺措施 ,分别对银河高硫含碳细粒金矿和东北寨低硫含碳砷微细粒金矿等难选冶金矿进行了选矿试验研究 ,所得金精矿品位有了较大幅度提高 ,并对其浮选分离作用机理进行了探讨     

蟠桃果肉饮料加工技术

通过蟠桃果肉饮料的生产，探讨了工化生产的可能性，中试生产证明，蟠桃果肉饮料加工技术切实可行，产品色香味俱佳，具备了工业化生产的条件。     

改性碱法制浆废液降低聚合物泥浆粘度的室内研究

本文介绍了碱法蔗渣制浆废液与丙烯酸、甲基丙烯酸甲酯、丙烯酰胺、一种有机络合剂等直接反应，制备改性碱法制浆废液的方法，研究了该改性制浆废液在膨润土浆和聚合物泥浆中的降粘性能，探讨了降粘机理。结果表明，该改性制浆废液在聚合物泥浆中的降粘能力大大超过ＦＣＬＳ，在膨润土浆中的降粘能力在加量超过约１８０ｍｇ／ｌ后略高于ＦＣＬＳ。     

Distribution of the volatile compounds in the different parts of a white-fleshed peach (Prunus persica L. Batsch)

The quantitative distribution of volatile compounds in the skin, top mesocarp, middle mesocarp, bottom mesocarp, inner mesocarp, and outer mesocarp of a white-fleshed peach (cv. Maura) was investigated. Volatile compounds were extracted by liquid–liquid microextraction (LLME) and analyzed by GC–FID and GC–MS. The results showed that the levels of volatiles in skin were significantly higher than those observed in the other parts of the fruit, whereas top and bottom mesocarp were mainly discriminated by opposite concentrations in unsaturated lactones and C₆-compounds. Distribution of lactones was also found to be different in skin and pulp according to their carbon chain length. Finally, the highest concentrations of benzaldehyde were found to be mainly located close to the stone suggesting that in peach this compound could be derived from enzymatic hydrolysis of amygdalin.     

Investigation of the role of interfacial chemistry on particle interactions, sedimentation and electroosmotic dewatering of model kaolinite dispersions

The influence of pulp chemistry on particle interactions and dewatering behaviour of colloidal kaolinite dispersions has been investigated under coagulation conditions. The dispersion shear yield stress, settling rate and consolidation showed strong dependence upon pH and ionic strength, indicating a maximum at ∼pH 3.2 which was established as the isoelectric point (iep) by particle zeta potential analysis. A “gel point” solid concentration at which the dispersion began to be significantly networked and gravity-driven consolidation of the pulp was completely suppressed, occurred at 13 vol.% (∼28 wt.%). The dewatering rates due to coagulation were significantly lower than those commonly achieved by polymeric flocculation, however the sediment consolidation was ∼25% higher when compared with flocculated pulps. Electroosmosis was found to be effective in consolidating pre-sedimented pulps to spadeable pastes (∼30 vol.%) at pH values away from the iep where zeta potential was higher and ionic strength low (10^− 3 M). This pulp consistency or markedly improved consolidation behavior is not achievable under coagulation and/or flocculation conditions.     

DEVELOPMENT AND APPLICATIONS OF AN ON-LINE THERMAL NEUTRON PROMPT-GAMMA ELEMENT ANALYSIS SYSTEM

This paper introduces the principles, instrumentation, implementation, and industrial applications of an on- line thermal neutron prompt- gamma element analysis system (using a 252Cf neutron source, Am- Be neutron source, or neutron generator). The energy resolution of the system at the H prompt- gamma full- energy photopeak (2.22325 MeV) is 3.6 keV. The concentration measurement error of A12O3, Fe2O3, CaO and SiO2 is ±0.3%,±0.1%.±0.4% and ±0.4%, respectively.The system has been tested on- site at both the Shandong and the Zhengzhou Aluminum Works. Our preliminary on- site measurements confirm that the stability, reliability, measurement range, and accuracy of the system can meet the requirements of the aluminum production process. Facilitation of this measurement at aluminum plants is expected to reduce plant costs by over 3 million dollars annually through reduced energy consumption, more rapid qualification of pulps being mixed during the production process, and in reduced labor costs.