论文总字数：23077字

摘 要

本课题的目标是基于实验研究细颗粒的加入对颗粒体系整体的鼓泡特性的影响规律，实验分为两部分：（i）向二维流化床内松散堆积的颗粒中注入单个气泡，利用用高速摄像机捕捉气泡从产生一直到破裂的全过程（做实验时流化床内存放的颗粒有三种，分别是600μm的玻璃珠单颗粒，加入1000μm的玻璃珠混合颗粒以及加入2000μm的玻璃珠混合颗粒）。再通过基于MATLAB的图片处理程序提取气泡的信息，比较细颗粒加入量对单气泡的面积、上升速度以及纵横比的影响规律。（ii）使床内颗粒完全流化，调节流化风速，对比600μm玻璃珠单一尺寸玻璃珠与添加2000μm细玻璃珠的混合颗粒的鼓泡特性，重点关注气泡面积、气泡数量以及纵横比等关键参数。结合上述两部分实验，获得细颗粒的加入对颗粒体系鼓泡特性的影响规律。对于单气泡，在加入细颗粒后在保持相同的静床高度，在通入相同的流化速比时，床内的反应较单颗粒情况来说要更为激烈，表现在混合颗粒气泡的纵横比变化更大以及整个气泡面积更大。不管哪一种工况，气泡上速度的变化都处在一个波动的情况，并且波动规律与静床高度有一定的联系。对于多气泡的情况，床层内物料颗粒的平均直径越小，达到临界临界流化状态越容易，在通以相同流化风速时，平均气泡面积更大、气泡数量越多，并且面积的平均偏差也会变大。相对于大粒径物料，小粒径的所有流化状态都会提前。

关键词：二维流化床、高速摄像机、单气泡、多气泡、混合颗粒

Abstract

The objective of this topic is to study the influence of the addition of fine particles on the bubbling properties of the whole granular system. The experiment is divided into two parts:(i) A single bubble is injected into a loosely packed particle in a two-dimensional fluidized bed, using a high-speed camera to capture the entire process from the bubble to the crack(In the experiment, there are three kinds of particles in the fluidized bed. They are 600 m glass beads, single particles, 1000 m glass beads, mixed particles and 2000 m glass beads mixed particles). Then, the information of the bubbles was extracted by the image processing program based on MATLAB, and the influence of the amount of fine particles on the area, the rising speed and the aspect ratio of the single bubble was compared.(ii) The particle flow, regulate the flow of wind, compared to 600 m glass beads single size glass beads with mixed particles of 2000 m fine glass bead bubble characteristics, focus on the bubble area, bubble number and aspect ratio and other key parameters. In combination with the above two experiments, the influence of fine particles on the bubbling characteristics of granular system was obtained. For a single bubble, in the fine particles in the static bed height in the same pass into the flow of the same speed ratio when compared with single particle bed reaction is more intense, in the mixed particle bubble aspect ratio changes more and more of the bubble area. No matter what kind of condition, the change of velocity on the bubble is in a fluctuating situation, and the law of fluctuation is related to the height of the static bed. For the bubble, the average diameter of particles in the bed decreases, reaches a critical critical fluidization state more easily, with the same fluidization velocity, the average bubble is bigger, the bubble number, and the average deviation of the area will become larger. Compared with the large size material, all the fluidization of small particles will advance.

KEY WORDS：two-dimensional fluidized bed, high-speed camera, single bubble, multi bubbles, mixed particle

目 录

摘 要 2

Abstract 2

第一章 绪论 1

1.1 选题 1

1.2 选题背景及意义 1

1.3 研究方法 3

1.3.1实验方法： 3

1.3.2数据处理： 3

第二章 实验 4

2.1 准备工作 4

2.1.1 筛料 4

2.1.2 测量临界流化速度 4

2.2 实验 6

2.2.1 实验装置简介 6

2.2.2 单颗粒实验 8

2.2.3 混合颗粒实验 10

第三章 数据分析 12

3.1 数据提取 12

3.2 数据处理 14

3.2.1 单气泡 14

3.2.2 多气泡 17

第四章 结论 25

参考文献 26

致 谢 27

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