共查询到20条相似文献,搜索用时 171 毫秒
1.
2.
三相搅拌气升式内环流反应器中葡萄糖氧化表观反应动力学研究 总被引:7,自引:0,他引:7
在三相搅拌气升式气反应中研究了气体流速、机械搅拌速度和氧浓度等参数对葡萄糖氧化反应过程的影响。根据多相催化反应Langmuir-Hinshelwood模型导出反应器中氧气、葡萄糖、葡萄糖酸的质量平衡微分方程,利用柔性单纯形法优化算出该反应系统的传质系数kLa和参数α,得到氧的动力学级数α约为0.6。 相似文献
3.
用正交试验方法优化Ni-P-SiC化学复合镀工艺 总被引:1,自引:0,他引:1
采用正交试验方法研究了SiC质量浓度、搅拌速度、温度、表面活性剂4因素对Ni-P-SiC化学复合镀镀层沉积速度和镀层显微硬度的影响.试验表明:温度对镀层沉积速度的影响最大,搅拌速度次之;SiC质量浓度对镀层显微硬度的影响最大,搅拌速度次之.当SiC质量浓度为7.5 g/L,搅拌速度为240 r/min,温度为90 ℃,混合添加阳离子表面活性剂和非离子表面活性剂时,镀层沉积速度达28.3 μm/h,镀层显微硬度达756 HV.经400 ℃热处理6 h后镀层显微硬度达1 250 HV.按照优化方案施镀,镀层厚度均匀,微粒在镀层中分布均匀. 相似文献
4.
研究了D201大孔强碱性阴离子树脂吸附浓海水中溴的静态吸附动力学特征,考察了搅拌速度、树脂粒径、温度对吸附速率的影响,并用动边界模型对吸附过程进行描述。研究表明,D201树脂吸附溴的过程为颗粒扩散控制;搅拌速度、树脂粒径对吸附速率的影响不大:吸附速率随温度的升高而增大。计算了不同温度下的表观速率常数和表观活化能。 相似文献
5.
硫酸氢铵分解磷矿动力学研究 总被引:1,自引:0,他引:1
在反应温度40—80℃,硫酸氢铵初始浓度3.65—5.22 mol/L,磷矿粒度0.125—0.18 mm,搅拌速度为400 r/m in的条件下,对硫酸氢铵分解磷矿的反应动力学进行了研究,磷矿分解速率随着搅拌速度、反应温度、硝酸浓度和颗粒细度的增加而增加;氢离子通过液膜的扩散传质是该过程的速率控制步骤。应用固体粒径减小的缩芯模型,将上述各影响因素的实验数据回归得到的动力学模型,方差分析表明模型可靠,为硫酸氢铵分解磷矿工艺条件的优化和反应器的设计提供了理论依据。 相似文献
6.
7.
8.
9.
采用商用聚乳酸(PLA)线材作为熔融沉积成型(FDM)打印材料,以拉伸强度和冲击强度为优化指标,设计正交试验,从分层厚度、打印速度、喷嘴温度、填充角度等元素探究成型工艺参数对FDM打印制件力学性能的影响。利用极差分析法,考察了各工艺参数对制件力学性能的影响情况,通过综合评分法和综合平衡法,获得了最优成型工艺参数组合并验证试验结果正确性。结果表明,分层厚度为0.3 mm,打印速度为90 mm/s,喷嘴温度为220 ℃,填充角度为45 °/45 °时,FDM制件的力学性能最优。 相似文献
10.
11.
Jingqiang Wang Pengfei Xing Xinghong Du Xuetao Luo Yanxin Zhuang Tian Lyu Xue Dong 《SILICON》2017,9(2):265-272
The kinetics of leaching silica sand in hydrochloric acid solution under conventional stirring and ultrasound-assisted conditions was studied. Acid concentration, temperature, stirring speed, ultrasound frequency and particle size had significant effects on the leaching rate while the influence of ultrasound power was negligible. The leaching kinetics followed the shrinking core model with product layer diffusion control as the rate-controlling step for the conventional stirring and ultrasound-assisted leaching process. The apparent activation energies in the presence and absence of ultrasound irradiation was determined to be 43.6 and 67.5 kJ/mol respectively. The presence of ultrasound not only increases the diffusion rate of mass but also promotes chemical reaction. 相似文献
12.
中国主要以矿石为原料生产碳酸锂(Li2CO3),而从锂含量丰富的盐湖卤水中直接生产优质的碳酸锂产品具有广阔的前景。对氯化锂(LiCl)和碳酸钠(Na2CO3)反应结晶生产碳酸锂的过程做了研究,考察了碳酸钠加入量、搅拌速度、温度、氯化锂浓度、添加剂及加料方式对反应结晶过程的影响。得到了较佳的工艺条件:以反加料的方式进行反应,碳酸钠加入量为理论加入量的110%,搅拌速度为400 r/min,反应温度为80 ℃,c(LiCl)=3.2 mol/L。结果表明,搅拌转速对产品产率的影响不明显,碳酸钠加入量、温度和氯化锂浓度对产品的产率有影响,其中温度和氯化锂浓度的影响显著。加料方式和加入聚丙烯酸(PAA)作为添加剂可以得到不同的产品形貌;搅拌速度、反应温度、LiCl浓度以及PAA作为添加剂对Li2CO3纯度均有一定程度的影响。 相似文献
13.
14.
15.
16.
氢氧化钙羰基化合成甲酸钙工艺研究 总被引:1,自引:0,他引:1
对氢氧化钙羰基化合成甲酸钙的工艺进行了初步研究,考察了温度、一氧化碳分压、不同添加剂和搅拌速率对反应速率的影响,实验结果表明,反应速率随着反应温度、一氧化碳分压、氢氧根浓度和搅拌速率的提高而提高,随着甲酸钙浓度的提高而降低,而甲酸钠和氮气的添加对反应速率几乎没有影响. 相似文献
17.
The carbonization of magnesium oxide particles by CO2 was investigated using a stirring mill reactor. The effects of the system temperature, stirring rotation speed, influx rate of CO2 and initial diameter of the magnesium oxide particles on the carbonization process were determined, The results show that the system temperature and the stirring rotation speed are the most significant influencing factors on the carbonization rate. The determi-nation of critical decomposition temperature (CDT) gives the maximum carbonization rate with other conditions fixed. A theoretical model involving mass transfer and reaction kinetics was presented for the carbonization process. The apparent activation energy was calculated to be 32.8kJ·mol-1. The carbonization process is co-controlled by diffusive mass transfer and chemical reaction. The model fits well with the experimental results. 相似文献
18.
19.
20.
Shabnam Hasani Faramarz Doulati Ardejani Mohammad Ebrahim Olya 《Korean Journal of Chemical Engineering》2017,34(8):2265-2274
Adsorption of BR 18 dye onto nano-clay adsorbent was investigated. Nano-clay was characterized by using FTIR, SEM, TEM, XRD and BET analysis. The percent removal increased by increasing nano-clay dose, while pH and stirring speed had no significant effect on the adsorption rate. It was observed that the uptake of dye onto nano-clay initially increased rapidly, and then decreased slowly until the equilibrium was reached. The adsorption capacity rose with an increase in temperature. Moreover, the adsorption kinetics was very fast and followed a pseudo second-order. The intra-particle diffusion was observed to be the rate-controlling step. In addition, equilibrium data fitted well with the Langmuir adsorption model. This paper also presents a numerical simulation incorporating the second-order kinetic expression using COMSOL Multiphysics software. The numerical modelling results and the experimental data were in excellent agreement. 相似文献