Presentation on theme: "Fluidization Engineering Course Code ： 100306E006 Course type ： Elective Credits ： 2 Total hours ： 32 Prerequisites ： unit operation of chemical engineering."— Presentation transcript:
Fluidization Engineering Course Code ： 100306E006 Course type ： Elective Credits ： 2 Total hours ： 32 Prerequisites ： unit operation of chemical engineering Applicable Majors ： chemical engineering and technology, process equipment and control engineering
Course Description The main content of this course consists of knowledge of gas-solid fluidized bed, involving powder properties, fluidization fundamentals, gas-solid dense-phase fluidized bed, fluidization quality, particulate fluidized bed, bubbling fluidized bed, slugging fluidized bed, turbulent fluidized bed, circulating fluidized bed, and commercialization of fluidized bed. Course Objectives To understand powder properties, typical structure of gas-solid dense-phase fluidized bed, the theory of two-phase flow, basic properties of fluidization quality, particulate fluidized bed, bubbling fluidized bed, slugging fluidized bed, turbulent fluidized bed and circulating fluidized bed. To obtain basic knowledge of commercialization of fluidized bed. To train the abilities of searching and analyzing scientific papers, and presenting results.
Language: Chinese + English Course material: Course note, Additional reading material: Marking Scheme: Attendance rate 20% 1 translation 20% final exam 60%
Fluidization Engineering A definition of fluidization “Fluidization is the operation by which particles are transformed into a fluid-like state through suspension in a gas or liquid” BY Kunii and Levenspiel(1991) 流态化：泛指固体颗粒悬浮在气体或液体介质中，其流动状 态转变成象流体一样的流动现象或过程。 Operation: A process or series of acts involved in a particular form of work. 包含在一种特殊工作形式中的一系列动作或过程. No spontaneously moving
Fluidization— 使固体颗粒表现出流体一样的性质 Particles are transformed into a fluid-like state through suspension in a gas or liquid Introduction
Basic conditions of a gas-solid fluidized bed ： Column Distributor Particle bed Gas or liquid Desirable superficial velocity higher than u mf but less than u t
Fluidization in the Nature Desert migration and Sand storm Sediment suspension and transmission 黄河三角洲新生陆地 引 黄 灌 溉 工 程引 黄 灌 溉 工 程 黄河口新生湿地 鸣沙山
Fluidization in the Nature Gas-solid system Sediment suspension and transmission Liquid-solid system Oil-in-water or water-in-oil system Liquid-liquid system Desert migration
When a gas or a liquid passes upward through a packed bed of granular particles, its motion creates friction against the particles, tending to lift them. This lifting force increases as the velocity of the gas or liquid increases, until, at some velocity, the fluid lifts all particles from contacting their neighbors to move freely, that is, they are “fluidized”. Segregated into a multiplicity of small particles, a solid presents more surface to transfer heat and mass or to react with the surrounding gas or liquid as compared to the original lumpy state. Since the 1930’s, fluidization has therefore become a significant technique in the processing of solid materials. ——by Prof. Mooson Kwauk (2008) Early application of fluidization
Ore dressing and Winnowing of grain Song Yingxin 宋应星 (born 1587) also illustrated in his work, Tiengongkaiwu ( 天工开物 ) applications of fluidization, not only in ore dressing but also in winnowing of grain Gold Panning
德国开发了 Winkler 煤气化炉 (1922 年获得专利, 第一台煤气发生炉已有较大的规模 : 炉高 13m, 截面积 12m 2 ） A brown coal gasifier invented in the 1920’s to produce synthesis gas (H 2, CO, CO 2 ) was probably the first to use fluidization on an industrial scale, starting from an initial model of 2 m dia.-13 m h and producing some 2,000 m 3 /h of gas, and improved to 5.5m dia.-23m h processing some 700 t/d of coal
第一代流化催化裂化技术（ FCC ） Fluid Ctalytic Cracking (1942 年在美国建成，处理量为 1700 吨 / 天 ) Through distillation of virgin petroleum only about 20% of its weight could be recovered as gasoline. Although catalytic means to increase gasoline yield was started in the 1920’s, it was as late as 1938 that eight companies joined hands forming Catalytic Research Associates to study catalytic cracking of petroleum by using fluidization, leading to the first of a series of processes.
Two examples of typical industrial application:1955 年南京化学工业公司的黄 铁矿焙烧生产二氧化硫和 1957 年葫芦岛流化焙烧精锌矿 Other industrial applications of fluidization ： Burning, heat transfer, surface coating, drying, granulation Reference ： 流态化工程（中译本），国井大藏、列文斯比尔，科学出版社 The earliest study of fluidization technique in China is the Low temperature carbonization of coal by the Wang Jiading (Wang, 1945).This study has become the earliest report that introduced the fluidized bed in the academic journals of China (Wang, 1948). Advantages of fluidized bed at that time ： The device is stable and evenly distributed ； Small particles can be used ； Ease of continuous operation, etc.