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《分离科学与技术》2012,47(12):2629-2643
Abstract The equations for estimating the optimal plate aspect ratio as well as the corresponding maximum recovery, maximum production rate, and minimum plate surface area for recovery of deuterium from water‐isotopes mixture in flat‐plate thermal diffusion columns of the Frazier scheme, have been derived. Considerable improvement in performance is obtainable if the operation is carried out with the optimal plate aspect ratio. It was found that all the optimal plate aspect ratios, as well as the improvements in performance, do not depend on feed concentration. 相似文献
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Ho-Ming Yeh 《加拿大化工杂志》1997,75(3):605-609
The effects of plate aspect ratio on the degree of separation, production rate and plate surface area in a flat-plate thermal diffusion column of the Frazier scheme, have been investigated. Theoretical considerations show that when the thermal diffusion columns of the Frazier scheme are constructed with the best plate aspect ratio, maximum separation, maximum production rate or minimum plate surface area can be obtained. The optimum plate aspect ratio for maximum separation is obtained with given production rate and plate surface area, while that for maximum production rate is determined with the degree of separation and plate surface area fixed, and that for minimum plate surface area is estimated with known degree of separation and production rate. It is interesting that the optimum plate aspect ratio for maximum separation is exactly the same as that for minimum plate surface area. The maximum separation and maximum production rate are achieved without changing any total expenditure, while the design with minimum plate surface area results in minimizing the total expense. 相似文献
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《分离科学与技术》2012,47(2):227-240
ABSTRACT The effects of plate aspect ratio on the degree of separation, production rate, and plate surface area in a flat-plate thermal diffusion column with transverse sampling streams have been investigated. Theoretical considerations show that when a thermal diffusion column is constructed with the best plate aspect ratio, either maximum separation or maximum production rate or minimum plate surface area can be obtained. The optimum plate aspect ratio for maximum separation is obtained with a given production rate and plate surface area, while that for the maximum production rate is determined with the degree of separation and plate surface area fixed, and that for the minimum plate surface area is estimated with a known degree of separation and the production rate. It is interesting that the optimum plate aspect ratio for maximum separation is exactly the same as that for minimum plate surface area. The maximum separation and maximum production rate are achieved without changing the total expenditure, while the design with minimum plate surface area results in minimizing the total expenditure. 相似文献
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研究从中药厂酒精尾气中回收酒精的吸收 解吸工艺。采用UNIFAC模型和Wilson模型分别预测吸收塔和解吸塔内的平衡关系,并对吸收塔和解吸塔内的工艺参数进行优化。结果表明:当吸收塔理论板数为25,液气比为0.24 L/m3,常温常压下操作时塔顶排气乙醇质量分数为28×10-6,塔釜乙醇回收率接近1;解吸塔为简单精馏塔,采用20块理论板,回流比为3,第10块板进料,塔顶可得91.7%的乙醇,塔釜得到几乎纯净的水,经冷却后作为吸收塔的吸收剂,循环套用。模拟结果对工业过程设计和设备改造具有一定指导意义。 相似文献
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为提高粉煤灰的综合利用率,减少资源浪费,利用传导感应电选试验台进行粉煤灰分选试验研究,通过改变极板板型、极板电压、极板间距、颗粒粒径等参数研究分选效果的影响因素,对分选产物进行对比。研究结果表明:凹型电极板的碳分选效果相对优于凸型电极板;精灰烧失量随电压增加呈先上升后降低的趋势;板间距增大会削弱板间电场强度及影响颗粒运动;粒径越小灰的烧失量越低,且不易分选。对分选产物分析表明,对于粒径48μm的粉煤灰分选效果较为理想,而对于细灰的效果则欠佳。分选中精灰烧失量最大可达21.89%,碳回收率最高达53.02%。 相似文献
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为掌握金属平板结构在近距爆炸载荷下的毁伤特性,以四边固支矩形钢板为对象,开展了柱形TNT装药近距爆炸毁伤试验,根据试验结果划分了钢板的3种毁伤模式:塑性大变形毁伤、临界起裂毁伤和花瓣状破口毁伤,建立了不同毁伤模式下的理论计算和数值模型,并分析了药量、爆距及钢板厚度对其近距爆炸毁伤特性的影响。结果表明,钢板的塑性最大变形随装药质量增加而增加,随爆距增加而减小;钢板的临界起裂毁伤形式为平行于长边的Ⅰ字形裂纹;爆距保持不变时,钢板的最大破口毁伤直径与药量为正相关,2000g药量时的最大破口直径为1000g药量时的1.18倍;相同药量时,随着爆距的增加,钢板最大破口直径呈先增大后减小的趋势,药量为500g和1000g时,最佳毁伤爆距分别为4cm和5cm。 相似文献
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Ho-Ming Yeh 《Chemical Engineering Communications》2000,179(1):179-199
When the separation is performed in a parallel-plate thermal diffusion column with the operating expense fixed, either increasing the plate spacing and operating at the corresponding optimum inclined angle, or increasing inclined angle and operating at the corresponding plate spacing, will increase the maximum separation and maximum production rate. Il was found that the cosine of optimum inclined angles increase with the plate spacing in the exponents of -9/2 and —4, respectively, for maximum separation and maximum production rate, while the optimum plate spacings increase with the cosine of inclined angle in the exponents of -2/9 and — 1/4, respectively. The plate spacing is generally so small that changing it, as well as changing the inclined angle, may not cause additional fixed change. However, increasing the plate spacing will lead to increasing the difference of plate temperatures in order to keep the operating expense, as well as the energy consumption due to heat conduction between the hot and cold plates, unchanged. Therefore, additional cost is needed to maintain a high value of temperature difference. There do not exist simultaneously the optimum inclined angle and the optimum plate spacing for the best performances. 相似文献
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为提高煤化工高浓度含酚废水萃取脱酚的处理效果,减轻废水排放环境污染,采用Aspen Plus流程模拟软件对煤化工废水萃取脱酚流程进行了优化设计。模拟采用真实煤化工废水的组成设置物流数据,废水进料流量为100 t/h,温度为40℃,压力为0.1 MPa,并利用UNIQUAC和NRTL活度系数模型,分别对萃取脱酚塔、溶剂回收塔、溶剂汽提塔进行了参数调整。模拟结果表明,当萃取脱酚塔萃取级数n=6,萃取相比R=1∶4时;溶剂回收塔的理论塔板数N=10,进料位置为第5块塔板时;溶剂汽提塔的理论塔板数N=5,进料位置为第1块塔板时,废水总酚浓度从18 600 mg/L降至400mg/L以下,单元酚浓度从14 000 mg/L降低至50 mg/L以下,萃取剂回收利用率达到99%以上。 相似文献
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Ho‐Ming Yeh 《加拿大化工杂志》2000,78(3):596-600
The solutions of the optimum plate aspect ratio as well as the corresponding maximum separation, maximum production rate and minimum plate surface area in thermal diffusion columns of the Frazier scheme for enrichment of heavy water have been obtained, analogous to those obtained in the previous work for separation of a binary system. It was found that all the optimum plate aspect ratios do not depend on feed concentration, while the corresponding best performances do. It is found that considerable improvement in performance is obtained when the operation is carried out with the optimal plate aspect ratio. 相似文献
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This study investigates heavy water enrichment using the Frazier scheme of flat‐plate thermal diffusion columns with the column number adjusted and the column heights varied at a constant ratio with the total sum of column heights fixed. The equations for predicting the best number of columns and the best column‐height ratio for maximum separation are derived. Considerable improvement in performance is obtainable if the column‐height ratio and/or column number in a modified Frazier scheme are properly assigned, instead of using the conventional Frazier scheme of uniform column height with the same total sum of column heights. © 2013 Canadian Society for Chemical Engineering 相似文献
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T. Lozano J. Laria P.G. Lafleur S. Sánchez‐Valdés F. Rodríguez‐González A.B. Morales‐Cepeda 《Polymer Engineering and Science》2012,52(8):1672-1677
The β‐phase in polypropylene (PP) induced by shear rate in a single‐screw extruder was studied. PP samples were extruded with and without a breaker plate at the exit of the extruder at five different screw rotational speeds: 20, 40, 60, 80, and 100 rpm. Differential scanning calorimeter was used to observe the melting behavior of the samples. The β‐phase was quantified by wide angle X‐ray diffraction. Extruded samples with a breaker plate showed higher values of β‐phase of PP than those extruded without a breaker plate. With a breaker plate, the maximum percentage of β‐phase was observed at 60 rpm (19.9%), whereas the maximum β‐phase content without breaker plate was observed at 40 rpm (13.6%). The higher level of β‐phase with the breaker plate was attributed to the shear rate induction and to the orientation by shear of the polymer chains through the orifices of the breaker plate. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers 相似文献
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The effect of plate-spacing on the degree of recovery and production rate for the recovery of deuterium from water-isotopes mixture in flat-plate thermal-diffusion columns of the Frazier scheme with fixed operation expense has been investigated. The equations for estimating optimum plate-spacing for maximum recovery and maximum production rate have been developed. Considerable improvement in performance is obtainable when thermal-diffusion columns with optimum plate-spacing are employed for operation. 相似文献
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介绍了大型草甘膦溶剂回收装置的技术改进,改进型组合塔板和DCS的成功运用,使装置具有回收效率高、节能显著及操作简便等优点。 相似文献