CAJ | 학술논문

在一套?300 mm×3000 mm的有机玻璃冷模流化床实验装置上，考察了石英砂二元混合颗粒的初始流化特性。所有二元混合颗粒均由颗粒密度相同但粒径不同的A、B、C、D四类颗粒组分两两按照一定质量分数混合而成。采用FXC-II/32型压力巡检仪测得了不同轴向位置床层的压降曲线，得到了不同二元混合颗粒的起始流化过程特性曲线和起始流化速度。实验结果表明，两种颗粒组分平均粒径大小和差异及其组分质量分率对二元混合颗粒的起始流化特性具有显著影响。A类颗粒加入可显著改善B、C和D类颗粒的流化质量；C类颗粒加入量过大会使混合颗粒在流化过程中出现严重的沟流现象；当浮升组分(小颗粒)质量分数为0.4时，组分粒径差异较大的二元混合颗粒在流化过程中最容易发生完全分级现象；对于粒径差别较大的二元颗粒组分，床层最小流化速度随小颗粒组分的增多而下降，而对于具有较强颗粒间作用力组分的二元颗粒组分，床层最小流化速度则随小颗粒组分的增多而增大。根据实验数据对等密度BD二元混合颗粒的起始流化速度预测公式进行了修正，发现实验值与计算值吻合较好。
재일투?300 mm×3000 mm적유궤파리랭모류화상실험장치상，고찰료석영사이원혼합과립적초시류화특성。소유이원혼합과립균유과립밀도상동단립경불동적A、B、C、D사류과립조분량량안조일정질량분수혼합이성。채용FXC-II/32형압력순검의측득료불동축향위치상층적압강곡선，득도료불동이원혼합과립적기시류화과정특성곡선화기시류화속도。실험결과표명，량충과립조분평균립경대소화차이급기조분질량분솔대이원혼합과립적기시류화특성구유현저영향。A류과립가입가현저개선B、C화D류과립적류화질량；C류과립가입량과대회사혼합과립재류화과정중출현엄중적구류현상；당부승조분(소과립)질량분수위0.4시，조분립경차이교대적이원혼합과립재류화과정중최용역발생완전분급현상；대우립경차별교대적이원과립조분，상층최소류화속도수소과립조분적증다이하강，이대우구유교강과립간작용력조분적이원과립조분，상층최소류화속도칙수소과립조분적증다이증대。근거실험수거대등밀도BD이원혼합과립적기시류화속도예측공식진행료수정，발현실험치여계산치문합교호。
The initial fluidization processes of binary mixture particles of quartz sands are studied in an experimental fluidization cold model made of perspex with the dimensions of?300 mm×3000 mm. Four quartz sand particle groups with equal particle density and different mean diameters, corresponding to Groups A, B, C, D according to the Geldart classification method, respectively, were used. Different two groups of particles with different mass fractions mixing together forms the different binary particle systems in this study. The initial fluidization curves (Δp-ug) and minimum fluidization velocities umf were measured by a FXC-Ⅱ/32 pressure measurement system. Experimental results show that, for each binary particle mixture, the particle sizes, size difference and mass fractions of the two particle components have important impacts on its initial fluidization properties. It was observed that Group A component can improve the fluidization quality of other components, i.e. the Group B, C, D component. With too much Group C component, binary particle mixtures show serious channeling in the initial fluidization process. There exists a critical mass fraction for the flotsam component (i.e. particle component with smaller mean diameter) xf=0.4, under which the complete segregation of the two particle components is readily to happen during initial fluidization processes. For binary mixtures with large particle size differences, the minimum fluidize velocity umf decreases with increasing smaller particle fraction. However, for binary mixtures with one component having strong inter-particle forces, umf increases with The initial fluidization processes of binary mixture particles of quartz sands are studied in an experimental fluidization cold model made of perspex with the dimensions of?300 mm×3000 mm. Four quartz sand particle groups with equal particle density and different mean diameters, corresponding to Groups A, B, C, D according to the Geldart classification method, respectively, were used. Different two groups of particles with different mass fractions mixing together forms the different binary particle systems in this study. The initial fluidization curves (Δp-ug) and minimum fluidization velocities umf were measured by a FXC-Ⅱ/32 pressure measurement system. Experimental results show that, for each binary particle mixture, the particle sizes, size difference and mass fractions of the two particle components have important impacts on its initial fluidization properties. It was observed that Group A component can improve the fluidization quality of other components, i.e. the Group B, C, D component. With too much Group C component, binary particle mixtures show serious channeling in the initial fluidization process. There exists a critical mass fraction for the flotsam component (i.e. particle component with smaller mean diameter) xf=0.4, under which the complete segregation of the two particle components is readily to happen during initial fluidization processes. For binary mixtures with large particle size differences, the minimum fluidize velocity umf decreases with increasing smaller particle fraction. However, for binary mixtures with one component having strong inter-particle forces, umf increases with increasing smaller particle fraction. Finally, in this study a modification was made for the existing umf correlation of the BD binary mixture, which has better agreements among the measured and predicted results.