共查询到20条相似文献,搜索用时 796 毫秒
1.
2.
3.
4.
5.
6.
为研究搅拌槽内液化过程的混合情况,以糙米粉溶液液化过程为研究对象,采用计算流体力学方法对3种搅拌桨的流场分布、混合时间、功率大小、剪切力大小等方面进行了模拟和分析。结果表明:倾斜大直径搅拌桨(ILD)与多叶片组合式搅拌桨(MBC)和最大叶片式搅拌桨(MB)相比有更强的径向混合能力,近桨叶处的径向速度相比多叶片组合桨和最大叶片桨增加4倍左右;倾斜大直径搅拌桨的死区占比最少,对物料的混合效果最好,在相同的操作条件下,倾斜大直径搅拌桨的功率降低了18%,在保持低能耗的同时,倾斜大直径搅拌桨平均剪切速率更大,更有利于非牛顿流体层流条件下的混合。 相似文献
7.
利用计算流体动力学(CFD)方法计算了四叶片倾斜涡轮结晶器内流体混合过程的流动场和浓度场,考察了搅拌桨在不同位置对搅拌混合流场及混合时间的影响,并结合电导率实验对模拟结果进行了验证.结果表明:当搅拌桨离底高度为液体高度的1/3时,结晶器内流场分布比较均匀,混合时间较短,适合工业上底部进料的结晶器. 相似文献
8.
9.
10.
11.
12.
论述了混料式机械化石灰竖窑的发展、主要技术特点及存在的缺陷。通过引进、消化、吸收国外技术,对国内的机械化石灰竖窑进行改造,取得了较好的效果,并对投资建窑提出了合理化的建议。 相似文献
13.
Aleksi Eskelinen Alexey Zakharov Sirkka‐Liisa Jämsä‐Jounela Jonathan Hearle 《American Institute of Chemical Engineers》2015,61(11):3683-3698
A dynamic model of a multiple hearth kaolin calciner has been developed and is presented in this article. This model describes the physical‐chemical phenomena taking place in the six furnace parts: the solid phase, gas phase, walls, cooling air, rabble arms, and the central shaft. The solid phase movement, in particular, is described by a novel mixing model. The mixing model divides the solid bed in a hearth into volumes and the distribution of their contents, after one full central shaft rotation, is identified by the pilot experiments. First, the model is validated by the industrial data, and then the dynamics of the multiple hearth furnace is studied by introducing step changes to the three manipulated variables: the feed rate, and the gas, and air flows supplied. The responses of the gas phase temperature and solid bed component profiles are analysed and the results are discussed. © 2015 American Institute of Chemical Engineers AIChE J, 61: 3683–3698, 2015 相似文献
14.
15.
María Irene Sánchez Cervantes Fernando J. Muzzio 《Chemical engineering science》2006,61(24):8075-8084
Mammalian cells are extremely sensitive to mechanical stress. Ideally, a bioreactor design for mammalian cell culture should assure adequate mixing at low mechanical stress. This paper focuses on the mixing characterization of a novel stirred tank bioreactor configuration, proposed for the culture of mammalian cells, based on the principle of displacing the agitation shaft to an eccentric position and replacing the impellers normally used for mammalian cell culture with a disc impeller with no blades. Experiments in a 1.0 L prototype are conducted to study flow patterns using UV light visualization techniques. Three different impeller shaft positions are tested E=0.0,0.21, and 0.42. For the purposes of this work, eccentricity (E) is defined as the distance between the shaft and the vertical centerline of the tank/tank radius. The mixing performance of two different impeller disc diameters (3.0 and 5.0 cm) are compared. Experimental results show that adequate mixing conditions are achieved at very low Re numbers for some of the eccentric cases considered. Computations are used to illustrate mixing improvement caused by eccentricity, and to validate the existence of globally chaotic conditions for the eccentric cases tested experimentally. 相似文献
16.
中国高灰、高硫、高灰熔融性温度煤的灰熔聚流化床气化 总被引:6,自引:0,他引:6
煤气化将会在未来中国可持续发展中占有相当重要的位置。对目前的煤气化技术和中国的煤种特性进行了描述和分析,介绍了中国科学院山西煤炭化学研究所灰熔聚流化床的研究与开发现状以及一些煤种的实验结果。结果表明:灰熔聚流化床煤气化技术适合中国高灰、高硫、高灰熔融性温度煤的气化。 相似文献
17.
18.
不同助磨剂对水泥粉磨效率的影响 总被引:3,自引:0,他引:3
提高水泥粉磨细度的主要技术措施为改造磨机结构和掺加助磨剂。前者在提高水泥细度的同时将导致磨机产量明显降低,而后者能有效提高磨机的粉磨效率并改善水泥的某些性能,但不同助磨剂对不同的水泥具有一定的适应性。作者选用四种助磨剂(代号分别为T,M,D,C)对掺加不同混合材的立窑和回转窑水泥进行了粉磨试验研究,以寻求各种助磨剂的使用规律和应用效果。实验结果表明:掺加T和M后对各种水泥的助磨效果均优于D;T和M复合而成的C具有良好的助磨效果,且成本低得多,具有重要的实际应用价值;掺加助磨剂可显著提高普通水泥和火山灰水泥的粉磨效率,但对矿渣水泥的助磨效果不明显;混合材种类及掺入量相同时,助磨剂对回转窑水泥的助磨效果优于立窑水泥。 相似文献
19.
Christian Rivera Mourad Heniche Philippe A. Tanguy 《Chemical engineering science》2006,61(9):2895-2907
The performance of a coaxial mixer in the laminar-transitional flow regime was numerically investigated with Newtonian and non-Newtonian fluids. These mixers comprised two shafts: a central fast speed shaft mounted with an open turbine, and a slow speed shaft fitted with a wall scraping anchor arm. To model the complex hydrodynamics inside the vessel, the virtual finite element method (POLY3DTM software) coupled with a Lagrange multiplier approach to cope with the non-linearity coming from the rheological model was employed. Co-rotation and counter-rotation mode were compared, based on several numerical criteria, namely, mixing time, power consumption and pumping rate. It was found that co-rotating mode is more efficient than counter-rotating mode in terms of energy, pumping rate and homogenization time. 相似文献
20.
大掺量市政污泥水泥窑协同处置应用 总被引:1,自引:0,他引:1
为了提高熟料质量,节能降耗,并能利用工业废弃渣生产水泥,获取最佳的经济效益和社会效益,新疆石河子南山水泥厂在机立窑上进行了用萤石-柠檬酸渣作复合矿化剂并采用全黑生料生产的实践探索。结果表明,该复合矿化剂的矿化效果优于萤石-石膏复合矿化剂,其熟料产量提高5%,熟料烧成煤耗下降5%;而且熟料质量提高,w(f-CaO)<3%,R_(28)>55.5 MPa。但生产操作中,应采取提高生料质量和料球质量,合理控制煅烧温度及复合矿化剂的掺量等一系列技术措施,作者对这些配套措施和要求也作了详细介绍。 相似文献