Interaction Between Gas-Liquid Jets and Fluidized Beds

气液射流与流化床之间的相互作用

• 批准号: 346287-2013
• 负责人: Salcudean, Martha
• 金额: $ 1.68万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=638577
• 关键词: Interaction; Between; Gas; Liquid; Jets

A fluidized bed occurs, under appropriate conditions, when one injects pressurized gas into a bed of small particles through a distributor. In fluidized beds, the particle-gas mixtures behave and can be handled like fluids - they flow, can be pumped, heated, used to mix or separate layers, and can operate continuously. Therefore, they are widely used in the oil, pharmaceutical, food and other industries.In many industrial fluidized bed reactors such as fluid catalytic cracking units, coaters and fluid cokers, the reactant feed is introduced into the system in the form of a gas jet or spray for different purposes. For example, bitumen is sprayed in the fluid coking process, which upgrades bitumen by means of thermal cracking. The liquid bitumen and steam are passed through a nozzle, atomized and injected horizontally into the reactor. The liquid bitumen coats the small solid particles (coke) and chemical reactions occur that produce the desired product. It is important to understand the physical phenomena that occur in the nozzle and in the fluidized bed in the vicinity of the nozzle in order to make sure the coating is uniform and no undesired agglomeration occurs. Agglomeration occurs often when liquid is sprayed into fluidized beds and an agglomerate of particles with liquid trapped inside forms. It can be a desired effect in certain processes, for instance in some pharmaceutical and food processing reactors, or undesirable as in the coking process. For all of these processes, it is important to have a good understanding of the interaction between the jets and the fluidized beds in order to understand the fluid distribution, mixing, coating and agglomerate formation and breakup. The applicant will investigate jet-fluidized bed interaction and will develop novel mathematical models that describe the process and enhance our understanding of the physical phenomena involved. The potential applications of the model to industry are widespread because they allow for process design and operational improvements that enhance the reactor efficiency and increase yield. Improved processes lead to energy savings and less impact on the environment.

在适当的条件下，当人们通过分配器将加压气体注入小颗粒床时，流化床就形成了。在流化床中，颗粒-气体混合物的行为可以像流体一样处理-它们流动，可以泵送，加热，用于混合或分离层，并且可以连续操作。在许多工业流化床反应器如流化催化裂化装置、涂布器和流化焦化器中，反应物进料以气体射流或喷雾的形式被引入系统中，用于不同的目的。例如，在流化焦化工艺中喷洒沥青，该工艺通过热裂化使沥青升级。液体沥青和蒸汽通过喷嘴，雾化并水平注入反应器。液体沥青覆盖在小的固体颗粒（焦炭）上，发生化学反应，产生所需的产品。重要的是要了解喷嘴和喷嘴附近流化床中发生的物理现象，以确保涂层均匀，不会发生不希望的团聚。当液体被喷入流化床时，通常会发生附聚，并且形成内部捕获液体的颗粒附聚物。在某些工艺中，例如在一些药物和食品加工反应器中，它可能是期望的效果，或者在焦化工艺中是不期望的。对于所有这些过程，重要的是要有一个很好的理解射流和流化床之间的相互作用，以了解流体分布，混合，涂层和团聚体的形成和破碎。申请人将研究射流流化床相互作用，并将开发新的数学模型，描述该过程，并提高我们对所涉及的物理现象的理解。该模型在工业上的潜在应用是广泛的，因为它们允许工艺设计和操作改进，提高反应器效率和增加产量。改进的工艺可节省能源，减少对环境的影响。