排序方式: 共有41条查询结果,搜索用时 15 毫秒
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研究了超临界CO2GAS沉析丙酮溶液中HMX的过程压力、温度、溶液初始浓度和溶液的膨胀速度及影响晶体粒度的因素。结果表明,压力增加,沉析颗粒的平均粒度减小;温度控制沉析晶体的晶型,对颗粒度的影响相对较小,温度增加,沉析平均粒度略有增加;溶液初始浓度对平均粒度的影响相对较大,膨胀速度亦是影响粒度及其分布的一个因素。快速膨胀溶液.并使过饱和度足够大,使过饱和度主要消耗在成核上,可得到颗粒小、分布窄的HMX颗粒。 相似文献
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Griseofulvin (GF) is an antifungal drug whose pharmaceutical activity can be improved by reducing particle size. In this study the rapid expansion of supercritical solution (RESS) was employed to micronize GF.Carbon dioxide with cosolvent acetone was chosen as a supercritical mixed solvent. The solubility of GF in super-critical CO2 with cosolvent acetone was measured using a dynamic apparatus at pressures between 12 and 32 MPa,temperatures at 313, 323 and 333 K and cosolvent concentration at 1.5, 3.0, 4.5 and 6.0% (by mole). The effect of pre-expansion pressure, extraction temperature, spraying distance, nozzle size and concentration of cosolvent on the precipitated particles was investigated. The results show that the mean particle size of griseofulvin precipitated by RESS was less than 1.2μm. An increase in pre-expansion pressure, extraction temperature, spraying distance and concentration of cosolvent resulted in a decrease in particle size under the operating condition studied. With the decrease of nozzle diameter the particle size reduces. The crystallinity and melting point of the original material and the processed particle by RESS were tested by X-ray diffraction (XRD) and differential scanning calorimetry (DSC).No evident modification in the crystal habit was found under the experimental conditions tested. The morphology of particles precipitated was analyzed bY scanning electron microscopy (SEM). 相似文献
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含浸液膜烟气脱硫试验 总被引:5,自引:0,他引:5
研究了以柠檬酸钠,亚硫酸钠、亚硫酸氢钠溶液为膜液,不同的膜液浓度、膜厚、不同孔径的高分子膜、进料气速等因素对SO2通过含浸液膜渗透器时通量的影响,分析各种因素对SO2渗透通量产生影响的原因。采用适宜的膜液及膜液浓度可使SO2的渗透通量得到极大的提高。 相似文献
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液膜法提取发酵液中苯丙氨酸的静电破乳 总被引:3,自引:0,他引:3
采用高压脉冲电场进行电破乳,考察了不同因素对破乳效率的影响,控制电场频率在150HZ,外加电压7KV-8KV、操作温度在40℃,并在破乳初期和海绵状乳化液形成时期适当地搅拌能得到近100%的破乳效率,破乳后的膜相能继续使用多次,并保持较高提高率和乳液稳定性。 相似文献
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一、引言泡沫分离(Foam fractionation)技术的出现巳有二十多年历史,是一新颖的分离技术。它利用待分物质本身具有表面活性(如表面活性剂)或能与表面活性剂通过化学的、物理的力结合在一起的(如金属离子、染料及中间体、有机化合物、蛋白质和酶等)能在鼓泡塔中被吸附于气泡表面的性质,进行表面富集,藉气泡上升带出溶液主体,达到净化主体液、浓缩待分物质的目的。尽管它是一门边缘学科,以表面化学为理论基础,但从工程应用角度看,与常规精馏比,具有流程设备简单、投资费用低、不耗热能、适用于低浓度(一般为ppm级)大容量溶液系统等特点,正逐步被应用于洗涤、 相似文献
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采用超临界CO2流体萃取木香挥发油。探讨了压力、温度、CO2密度对挥发油收率的影响,研究了萃取的最适宜条件。对水蒸汽蒸馏法与超临界萃取法进行了比较。 相似文献
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