共查询到19条相似文献,搜索用时 531 毫秒
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对溶液除湿的除湿器中传热传质进行了热力学分析,根据除湿塔的结构及溶液与空气的流动方式,建立除湿器的热质交换物理和数学模型,模拟计算除湿器入口空气和溶液参数对除湿器出口空气参数的影响,模拟计算中设置入口空气流量0~5kg/s,入口空气温度20~40℃,入口空气含湿量为10~30g/kg,入口溶液温度25~40℃,入口溶液浓度25%~40%,入口溶液流量1~4kg/s,得到各入口参数对出口空气含湿量和温度的影响曲线。结果表明:入口空气含湿量、入口溶液浓度和温度对出口空气含湿量影响显著;入口空气含湿量和流量对出口空气温度影响显著。对模拟结果与实验结果进行了比较,发现两者的变化趋势是相同的,最大误差为13.08%。 相似文献
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为实现金属铝换热器表面的滴状冷凝以提高其传热效率和能源利用率,通过化学气相沉积法在金属铝表面直接生长得到具有高导热系数的垂直定向碳纳米管阵列超疏水结构,其高度和直径分别为7μm和30 nm.采用正交试验法探究反应温度、反应时间、催化剂质量浓度以及溶液注射速率4个因素对疏水角大小的影响程度.结果表明:催化剂质量浓度和溶液注射速率对样品表面疏水性能的影响程度较大,反应温度和反应时间对样品表面疏水性能的影响程度较小,可以通过改变催化剂质量浓度和溶液注射速率进一步对样品接触角大小进行调控,得到理想疏水效果的铝基超疏水结构. 相似文献
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微米级球形HNS的制备及形貌控制 总被引:2,自引:0,他引:2
采用喷雾干燥法制备了微米级六硝基菡(HNS),并对其粒度和形貌控制进行了分析。结果表明,不同入口温度下溶剂的挥发速率有较大差异,过高或过低的入口温度会导致颗粒表面形成凹凸不平或破裂缺陷;随着溶液浓度的增加,HNS的平均粒径呈增大趋势;进料量也是影响HNS粒径和形貌的主要因素,进料量越大,HNS平均粒径越大,而颗粒形状则与不同进料量下料液在高速旋转雾化轮上形成液滴的过程相关。获得了颗粒尺寸分布为1~6μm的表面光滑、球状、高纯度的HNS颗粒,并用SEM、XRD和HPLC等方法对其进行了表征分析。 相似文献
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钛硅分子筛催化丙烯环氧化是生产环氧丙烷的清洁工艺,其多相反应体系的相态研究是优化该反应体系的基础。采用可视相平衡仪对不同氧化剂体系(50%双氧水体系和30%双氧水体系)、不同温度(30~80℃)、不同压力(0.8~3.5MPa)、不同物料配比[甲醇∶双氧水(摩尔比)为5~20,丙烯∶双氧水(摩尔比)为1~4]的进料体系进行了相态观测。结果表明,丙烯进料量和甲醇含量是影响体系相态的关键因素。在相同物料配比和相近的丙烯进料量下,50%双氧水体系比30%双氧水体系液相更易达到均相。此外,对于两种双氧水-丙烯-甲醇体系,甲醇含量一定时,丙烯的进料量越小,体系液相越易呈均相状态。总之,为了使丙烯和双氧水能在液相中充分接触,应使丙烯进料量接近体系温度、压力下丙烯在双氧水-甲醇溶液中的饱和溶解度。 相似文献
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双氧水—丙烯—甲醇体系的相态研究 总被引:1,自引:0,他引:1
钛硅分子筛催化丙烯环氧化是生产环氧丙烷的清洁工艺,其多相反应体系的相态研究是优化该反应体系的基础.采用可视相平衡仪对不同氧化剂体系(50%双氧水体系和30%双氧水体系)、不同温度(30~80℃)、不同压力(0.8~3.5 MPa)、不同物料配比[甲醇∶双氧水(摩尔比)为5~20,丙烯∶双氧水(摩尔比)为1~4]的进料体系进行了相态观测.结果表明,丙烯进料量和甲醇含量是影响体系相态的关键因素.在相同物料配比和相近的丙烯进料量下,50%双氧水体系比30%双氧水体系液相更易达到均相.此外,对于两种双氧水-丙烯-甲醇体系,甲醇含量一定时,丙烯的进料量越小,体系液相越易呈均相状态.总之,为了使丙烯和双氧水能在液相中充分接触,应使丙烯进料量接近体系温度、压力下丙烯在双氧水-甲醇溶液中的饱和溶解度. 相似文献
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In this study, pilot pervaporation experiments of ethanol dehydration from the vapor phase feed have been carried out. The
dehydration time decreased with increasing of the feed temperature and did not vary with the feed flow rate. The temperature
dependence of permeation rate in vapor phase feed was larger than that in liquid phase feed. Contrary to the pilot pervaporation
of liquid phase feed, the higher the feed flow rate, the larger the temperature drop is. The variation of temperature drop
with permeate flux in vapor phase feed is larger than that in liquid phase owing to the heat loss of the membrane module itself. 相似文献
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有毒液体泄漏后的蒸发会导致人员中毒和环境污染,估算有毒液体的蒸发速率对于预测有毒蒸汽在环境中的浓度分布至关重要,尤其是多组分液体,蒸发过程较复杂,蒸发速率的预测大都基于经验模型和半经验模型,且很少考虑热传递对蒸发的影响。文中研究建立了描述二组分液体蒸发质量和液体温度随时间变化的数学模型。设计建造了风洞实验台,并针对不同体积配比下的苯和乙醇混合溶液进行了风洞实验,并将实验测量值同模型计算值进行了比较。结果表明,新建立的模型能够较准确地预测二组分液体蒸发质量和温度随时间的变化,其预测平均偏差分别为25.82%和33.79%,从而为今后研究多组分液体的蒸发过程奠定了基础。 相似文献
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Recovery of copper ions from wastewater using a hollow fiber supported emulsion liquid membrane (HFSELM) was studied with LIX984N as carrier, kerosene as diluents, and sulfuric acid solution as strippi... 相似文献
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Experimental measurements for the heat and mass transfer in laminar wavy film absorption with the presence of non-absorbables are presented. Water vapor was absorbed into a falling film of aqueous lithium chloride solution on a vertical tube with the air present in the gas phase acting as the non-absorbable whose concentration was accurately detected by a mass spectrometer gas analyzer. Although the depressing effect of the air on the absorption rate was much more significant in the low air concentration range, the absorption reduction rate with increasing air concentration was found to be lower than that reported previously. The reduction was found to be continuous even up to 30% of air content. Besides the non-absorbables, the effects of other operational parameters such as solution flow rate, inlet solution temperature, inlet solution concentration, absorber wall temperature, absorber water vapor pressure, and effective contact length on the absorption rate were also tested. These effects were shown to follow trends similar to those predicted by a numerical solution for smooth film absorption. The heat and mass transfer coefficients were correlated by using Reynolds number, Prandtl number, Schmidt number, capillary-buoyancy coefficient and air concentration. 相似文献
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《分离科学与技术》2012,47(16):2460-2466
A technology of two-stage continuous foam fractionation for tea saponin recovery was studied for increasing both the enrichment ratio and the recovery percentage. In the first stage, the effect of air flow rate, the initial pH, the feed flow rate, and the feed position were studied at a temperature of 60°C. The results showed that when the conditions of the first stage were at a temperature of 60°C, air flow rate 150 mL/min, pH 5.3, feed flow rate 1.92 mL/min, and feed position at the interface between the liquid phase and the foam phase, the enrichment ratio, and the recovery percentage of tea saponin were 4.02 and 56.4%, respectively, and the effluent solution was added to the second stage as the initial solution. When the conditions of the second stage were at a temperature of 30°C and an air flow rate of 300 mL/min, the recovery percentage of tea saponin reached 47.6%, and the foamate was added to the first stage as feed solution. The total recovery percentage of tea saponin reached 86.3% by the two-stage continuous foam fractionation. 相似文献