共查询到19条相似文献,搜索用时 109 毫秒
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为了揭示减压塔汽提工艺的传质过程特性,进而改进汽提操作,采用改进的减压精馏过程模拟方法和传质计算方法,分析了炼油常减压装置的汽提工艺的传质特点。在深化对于汽提工艺的理解基础上论证了采用填料汽提塔(段)的必要性以及设计、分析的基本方法。计算分析结果表明侧线汽提塔内填料分离性能保持恒定,汽提塔的分离效率与减压塔对应分离段接近,所以在设计和操作中应给予汽提塔(段)充分重视。减压塔底汽提段的工艺和水力学特点与侧线汽提塔相同。塔底汽提蒸汽质量流率应小于减压塔进料质量流率1%,否则将导致减压塔整体分离效率降低。 相似文献
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用计算流体力学方法对人字型挡板、盘环型挡板和两段环流3种工业重油催化裂化(Resid Fluid Catalytic Cracking,RFCC)汽提段内的气固两相流动进行了模拟研究,考察了汽提段内的颗粒体积分数分布情况;结合模拟示踪技术得到了催化剂出口处颗粒的停留时间分布(RTD),通过对RTD曲线进行分析,得到了表征汽提段内颗粒混合特性的参数,平均停留时间(tm)、无因次方差(σθ2)、Peclet准数(Pe),以及死区、活塞流区和全混流区的体积分数。模拟结果表明,环流汽提段外环区和内环区间存在密度差,是催化剂环流流动的推动力。人字形挡板汽提段内的tm最小,σθ2最大,Pe值最小,同时死区体积达到了汽提段体积的40%,而活塞流区体积仅占15.8%,说明其中颗粒的返混非常剧烈,汽提效率最低。相对于盘环型挡板汽提段,两段环流汽提段内颗粒的σθ2较大,Pe较小,颗粒的整体返混程度高于盘环型挡板汽提段。但从死区模型的分析看,活塞流流动的增强有利于促进气固间的传质,死区体积增大则是由于环流流动的增强所导致的,这些都有利于提高汽提效率。两段环流汽提段内活塞流区体积为26.8%,死区体积占32.3%,都大于盘环型挡板汽提段,使环流汽提段的汽提效率更高。 相似文献
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依据常减压蒸馏装置减压深拔现状及研究动态,结合8.0 Mt/a常减压蒸馏装置设计实例,分析了为实现减压深拔目标减压系统所采用的工艺技术,包括较高的加热炉出口温度、减压炉防结焦、减压塔塔顶高真空度和全塔低压降、微湿式带汽提操作、减压塔塔底防结焦等工艺,并重点讨论了过气化油流程设置对减压深拔的影响。 相似文献
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催化裂化新型环流汽提器的大型冷模实验 总被引:27,自引:0,他引:27
采用氧气示踪的方法在φ486mm×8000mm的有机玻璃床内对三种不同结构的催化裂化用催化剂汽提器(空筒结构、盘环形挡板结构和两段环流结构)在不同的工况下进行了系统的汽提效率模拟冷态对比实验。最终发现在实验条件下,新型环流汽提器具有更高的汽提效率,和空筒结构相比,最多可减少82%的可汽提焦炭量;和现有工业装置最常用的盘环形汽提结构相比,最多也可以减少48%的可汽提焦炭量。同时该型汽提器还具有结构简单的优点,易于在现有工业装置上改造和推广。 相似文献
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散装填料汽提器流态化试验研究 总被引:1,自引:0,他引:1
用散装塑料阶梯环代替传统汽提段内构件,采用氢气示踪法在Ф90×1 000 mm的有机玻璃装置内研究了汽提气表观线速和催化剂循环量对汽提效率、床层膨胀率和床层平均密度的影响规律,并在同样的操作条件下和空筒汽提段进行了对比。试验中还对比考察了两种汽提段内汽提气的停留时间分布及流动差别。试验结果表明:填料汽提段和空筒汽提段相比不仅具有较高的汽提效率,而且能允许更高的催化剂循环量;提高了床层的有效利用率;填料的加入使汽提气的流动返混程度有所减小。 相似文献
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Arnold M. Gavin Ralph W. Berger 《Journal of the American Oil Chemists' Society》1973,50(11):466A-472A
With continuous deodorizers of the double shell type most of the steam normally used to preheat the feedstock in the deaerating
section can be saved by a modification-the essential feature of which is the addition of a heat recovery section location
between the final deodorizing section and the cooling section, by means of which heat is transferred from the hot deodorized
oil to the feedstock. Consistent with the principles of the original design, no pumping or piping of hot oil outside the deodorizer
is required. Continuous deodorizers of the stripping tray type can be modified for “steam refining” or “stripping” of high
free fatty acid palm oil to reduce the free fatty acid palm oil to reduce the free fatty acids to 0.03% max. This is accomplished
by means of additional trays in the stripping sections of the deodorizer. The capacity, sparge steam temperature, vacuum and
retention time remain the same as with normal deodorization.
Presented at the JOCS-AOCS Joint Meeting, New Orleans, April 1973 相似文献
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裂片型复合超细纤维截面形状与剥离性 总被引:1,自引:0,他引:1
通过对齿轮形、米字形、桔瓣形复合超细纤维截面边界长度的计算,说明了复合超细纤维的截面形状与剥离性的关系,剥离难度随两组分边界线长度的增大而增大。3种纤维比较,桔瓣形剥离难度最大,齿轮形最小。 相似文献
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探索了负压汽提技术在PVC浆料脱吸VCM中的应用,研究了压力、汽提温度、浆料停留时间、浆料流量对VCM脱吸速率的影响。研究结果表明:压力控制在-55^-50 kPa、温度控制在80℃左右时,可保证残留VCM有效脱吸,相对于常压汽提可节约近80%的蒸汽消耗。 相似文献
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用自制的小型固定流化床,以掺入减压渣油、油浆的原油为原料进行化学汽提研究。以相对可汽提碳、汽提气体相对产率、再剂含碳量为评价指标,对比分析化学汽提与水蒸气汽提工艺气体产物组成、汽提效率的差别,考察再剂加入比例、加入温度、反应温度、剂油比对化学汽提效率、汽提温度的影响。结果表明,化学汽提效率随再剂加入比例、加入温度的增加先增大后趋于平缓,随反应温度增加而减小,随剂油比增大而增大;提高再剂加入比例、加入温度时,重质原料汽提温度增幅小于轻质原料。采用化学汽提工艺能改变气体产物分布,使汽提效率提高约20%,再剂含碳量降低7%以上。 相似文献
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In this work,the impact of internal heat integration upon process dynamics and controllability by superposing reactive section onto stripping section,relocating feed locations,and redistributing catalyst within the reactive section is explored based on a hypothetical ideal reactive distillation system containing an exothermic reaction:A + B ←→ C + D.Steady state operation analysis and closed-loop controllability evaluation are carried out by comparing the process designs with and without the consideration of internal heat integration,For superposing reactive section onto stripping section,favorable effect is aroused due to its low sensitivities to the changes in operating condition,For ascending the lower feed stage,somewhat detrimental effect occurs because of the accompanied adverse internal heat integration and strong sensitivity to the changes in operating condition.For descending the upper feed stage,serious detrimental effect happens because of the introduced adverse internal heat integration and strong sensitivity to the changes in operating condition.For redistributing catalyst in the reactive section,fairly small negative influence is aroused by the sensitivity to the changes in operating condition.When reinforcing internal heat integration with a combinatorial use of these three strategies,the decent of the upper feed stage should be avoided in process development.Although the conclusions are derived based on the hypothetical ideal reactive distillation column studied,they are considered to be of general significance to the design and operation of other reactive distillation columns. 相似文献