颗粒粒径及粒度组成对狭缝式矩形喷动床流动特性的影响
文献类型：学位论文
| 作者 | 王宝群 |
| 学位类别 | 硕士 |
| 答辩日期 | 2000-06 |
| 授予单位 | 中国科学院研究生院 |
| 导师 | 罗保林 |
| 关键词 | 狭缝式矩形喷动床 颗粒粒径与粒度组成 流动特性 |
| 其他题名 | Effect of Particle Size and COMPOSITION ON Flow Characteristics of Slot-Rectangular Spouted Bed |
| 学位专业 | 化学工艺 |
| 中文摘要 | 同传统的柱锥喷动床相比，矩形喷动床既降低了最小喷动速度和最大喷动压降，提高了最大喷动床高，又具有灵活的几何结构。矩形喷动床还具有气固接触效率好，传热效率高的优点，常用于干燥谷物和糊状物等热敏物质和造粒及片剂表面包覆。近年来，矩形喷动床正受到广泛的关注。混合颗粒的喷动已用于许多工业过程，如煤的燃烧和气化、片剂表面包覆等，但人们对多粒度混合颗粒体系在喷动床中的喷动特性的认识还不足，而且以往的研究大都采用平均粒径将多粒度体系简化成单粒度体系，这显然不能体现粒度组成对喷动床流动特性的影响。本文着重研究不同粒径和粒度组成对狭缝式矩形喷动床中混合颗粒体系的流动特性的影响。本文实验装置为150mm * 50mm * 1100m、底部倒锥角为60°的有机玻璃狭缝式矩形喷动床，狭缝式气体分布板狭缝宽度分别为2mm、4mm和6mm。实验物料体系是筛分出的单一粒径分别为1mm、1.5mm和2mm的玻璃珠和由它们以不同组成所配成的二组分和三组分玻璃珠混合体系。实验在不同的狭缝宽度和床高下，测量不同粒径和粒度组成体系的床层压降，并由喷动床的压降-气速曲线求出最小喷动速度、最大喷动压降等操作参数，进而考察粒径和粒度组成对矩形喷动床流动特性的影响规律，作出粒度组成与上述参数的相图并对之进行关联。实验结果表明：床高、气体入口狭缝宽度、粒径和粒度组成对喷动床的最小喷动速度和最大喷动压降都有影响，但气体入口狭缝宽度的影响程度较另外两种因素小。本文通过因次分析并利用STATSTIC软件对108组实验数据进行拟合，得到本文实验条件下的经验关联式：U_(ms) = 0.25 [H/D_C]~(0.16)[H_s/D_c]~(-0.018)[(ρ_s-ρ_f)/ρ_f]~(0.57)(2gH)~(1/2)Π_(i=1)~n[(d_(pi))/(D_C)]~(0.98X_i) (n = 3) Δ[_(ms) = 0.023[H/(D_C)]~(-0.074)[(H_S)/(D_C)]~(0.028)[(ρ_s-ρ_f)/(ρ_f)]~(0.35)(1-ε)ρ_fgHΠ_(i=1)~n[(dp_i)/(D_C)]~(0.54X_i) (n = 3)公式适用范围：H = 0.06～0.25m, H_s = 2～6mm。 |
| 英文摘要 | The slot-rectangular spouted beds have been the subject of increasingly intensive study in resent years, for its many advantages over conventional spouted bed, such as lower minimum spouting velocity and lower maximum spouted pressure drop, higher maximum spoutable bed height, and rectangular geometry which makes it easier to scale-up than the conventional cylindrical bed. The slot-rectangular spouted bed has been applied for drying of grain and pastelike materials, granulation, tablets coating and combustion and gasification of coal owing to its good gas-solid contact and higher efficiency of heat-transfer. However, there is few research on spouting characteristics in spouted bed of multi-size composition particle mixtures. Especially, mean diameter was usually used for describing particle size of multi-size composition particle mixtures. Apparently, it can not demonstrate the effect of particle size and composition on spouting characteristics. This paper is focused on the effect of particle size and composition on flow characteristics of slot-rectangular spouted bed. The experimental apparatus is a 150 * 50 * 1100mm slot-rectangular spouted bed with 60° base slant angle. The width of gas entry slot varies from 2mm to 6mm. 1mm, 1.5mm and 2mm diameter glass beads and two-composition and three-composition particle mixtures, which consist of these single particles, were used as experimental particle mixture. Spouted pressure drops is slot-rectangular spouted bed of different particle size and composition particle mixtures were measured with different slot widths, static bed heights and gas superficial velocities. The minimum spouting velocity and maximum spouted pressure drop can be obtained from plot of pressure drop vs. gas velocity, in order to investigate the effecting tendency of particle size and composition on spouted characteristics. The experimental results show that the minimum spouting velocity and maximum spouted pressure drops of multi-size composition particle mixtures have relationship with the width of gas entry slot, static bed height and particle size and composition of the particle mixtures. In the present work, the maps for diagramming variation of minimum spouting velocity and maximum spouted pressure drop with particle size and composition for multi-size particle mixtures were obtained, and the empirical relations for minimum spouting velocity U_(ms) and maximum spouted pressure drop P_(ms) were determined to be: [H/D_C]~(0.16)[H_s/D_c]~(-0.018)[(ρ_s-ρ_f)/ρ_f]~(0.57)(2gH)~(1/2)Π_(i=1)~n[(d_(pi))/(D_C)]~(0.98X_i) (n = 3) Δ[_(ms) = 0.023[H/(D_C)]~(-0.074)[(H_S)/(D_C)]~(0.028)[(ρ_s-ρ_f)/(ρ_f)]~(0.35)(1-ε)ρ_fgHΠ_(i=1)~n[(dp_i)/(D_C)]~(0.54X_i) (n = 3) The ranges of operating factors are: H = 0.06 ～0.25m, H_s = 2～6mm. |
| 语种 | 中文 |
| 公开日期 | 2013-09-26 |
| 页码 | 74 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/1941]  |
| 专题 | 过程工程研究所_研究所（批量导入） |
| 推荐引用方式 GB/T 7714 | 王宝群. 颗粒粒径及粒度组成对狭缝式矩形喷动床流动特性的影响[D]. 中国科学院研究生院. 2000. |
入库方式： OAI收割
来源：过程工程研究所
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