陶瓷膜是过滤高温含尘烟气最有效的材料之一,其过滤性能和再生性能与尘粒在陶瓷膜孔道内的沉积和脱附机制相关.本文建立了不同孔隙率的陶瓷膜物理模型,然后结合连续性方程、动量方程和能量方程,设定边界条件以及沉积条件,模拟了陶瓷膜过滤和脉冲反吹时,高温烟气的流动以及尘粒的沉积与脱附过程.结果表明,过滤速度较低和陶瓷膜孔隙率较高时,尘粒易于沉积在陶瓷膜孔道内;脉冲反吹时,增加反吹压力,延长反吹时间,尘粒易于从陶瓷膜孔道脱附.采用厚度为20 mm,长度为1.5 m,孔隙率为40%的陶瓷膜管过滤温度为1000℃,流速为1 m·min~(-1),压力为0.1 MPa的含尘烟气时,反吹气压力应不低于0.3 MPa,反吹时间不短于0.02 s,尘粒脱附时间在13 s,脉冲反吹时间间隔应高于452 s.
国家针对细颗粒物的排放制定出愈发严苛的排放标准,这也掀起了相关领域对细颗粒物高效捕集研究的热潮。综述了国内外有关纤维过滤细颗粒物的研究,包括单纤维捕集理论、颗粒物滤料捕集的模拟研究、静电增强纤维对亚微米颗粒的捕集效果、细颗粒物在滤料中的沉积与穿透特性以及纳米纤维对细颗粒物的捕集研究等,旨在为探索细颗粒物的滤料捕集机理做出贡献。
CdSe epilayers were grown on GaAs(0 0 1) substrates by molecular beam epitaxy (MBE) in a wide range of VI/II beam-equivalent-pressure (BEP) ratio from 1.1 to 8.5. X-ray diffraction (XRD) theta-2 theta scan reveals all the CdSe samples possess cubic zinc blende structure with (0 0 1) orientation. The film grown at a low VI/II ratio of 1.1 has rough ...
CdSe thin films have been grown on GaAs (0 0 1) substrates by molecular beam epitaxy (MBE). The effects of substrate temperature and annealing treatment on the structural properties of CdSe layers were investigated. The growth rate slightly decreases due to the accelerated desorption of Cd from CdSe surface with an increase in the temperature. The ...
A series of transition films from amorphous to microcrystalline silicon was successfully prepared by very high frequency plasma enhanced chemical vapor deposition(VHF-PECVD).Effects of gas pressure on the microstructure, photoelectric and transport properties of the films were investigated.The results indicate that increase of gas pressure improve ...
We report the latest results of the3C-SiC layer growth on Si(100) substrates by employing a novel home-made horizontal hot wall low pressure chemical vapour deposition(HWLPCVD) system with a rotating susceptor that was designed to support up to three50 mm-diameter wafers.3C-SiC film properties of the intra-wafer and the wafer-to-wafer, including cr...
n-ZnO/p-GaN heterojunction light-emitting diodes with and without a sandwiched AlN layer were fabricated. The electroluminescence (EL) spectrum acquired from the n-ZnO/p-GaN displays broad emission at 650 nm originating from ZnO and weak emission at 440 nm from GaN, whereas the n-ZnO/AlN/p-GaN exhibits strong violet emission at 405 nm from ZnO with...
