复合式浮选搅拌装置喷射器吸气性能的模拟和试验研究

发布时间：2018-03-27 22:06

本文选题：浮选机　切入点：射流　出处：《安徽理工大学》2015年硕士论文

【摘要】：基于将对浮选影响较大的喷射、涡流和搅拌三种流体特征有机结合,通过对机械搅拌式浮选机和喷射式浮选机结构特征的分析,提出了一种新型浮选搅拌装置——复合式浮选搅拌装置。复合式浮选搅拌装置以一定压力的矿浆通过自吸式喷射器吸入空气的同时经喷射器聚合喷射出高速矿浆冲击叶轮,从而驱动叶轮搅拌来达到搅拌矿浆和切割气泡的作用。充气量是评价浮选机性能的重要指标,而复合式浮选搅拌机构的作用原理是复杂的,其既要保证抽吸到大量的空气,又要保证射流具有足够的冲击力从而驱动叶轮搅拌。因此研究复合式浮选搅拌装置的吸气方式及在某种吸气方式下的吸气性能是复合式浮选搅拌装置研发的一个重要方面,对今后的深入研究具有借鉴意义。本文首先利用流场模拟软件对喷射器结构特征进行仿真,寻找吸气性能最优时的喷射器结构参数,然后加工制作出喷射器实物模型并对其进行一系列的试验研究,确定喷射器的可行性,为复合式浮选搅拌装置提供理论基础。结果表明： 1、对于中心进气——周边进料喷射器,吸气管在喷射器所处位置对吸气性能具有重大影响。吸气管从喷射器圆锥部分向圆柱部分移动时,吸气量先迅速增大,在喷射器圆锥圆柱结合处时,吸气量达到最大,吸气管在圆柱段移动时,吸气量逐渐缓慢减小。圆柱段长度l在8-16mm之间时,吸气性能较好。喷射器收缩角a=15。时,对喷射器是有利的。 2、对中心进料——周边进气喷射器,喉嘴距对喷射器吸气性能具有最主要影响。喉嘴距过大过小都会影响喷射器的吸气性能,当喉嘴距为15mm时,喷射器吸气性能最佳。在最佳喉嘴距时,喉管长度对吸气性能影响不大。存在一个最佳喉管直径使吸气性能最佳。 3、对淹没射流来说,收缩角对射流区域轴线速度有一定影响,α=15。的轴线速度最佳,随角度增大,轴线速度有下降趋势。圆柱段长度对轴线速度的影响不显著。 4、对两种喷射器的试验研究表明,试验数据结果跟模拟相比总体偏小,但数据所表现出的趋势和模拟相类似,证明了设计的喷射器的可行性,在具体方面存在更大的优化可能。
[Abstract]:Based on the organic combination of jet, eddy current and agitation characteristics, the structural characteristics of mechanical agitated flotation machine and jet flotation machine are analyzed. A new type of flotation agitator, compound flotation agitator, is proposed. The compound flotation agitator uses a certain pressure slurry to inhale air through a self-priming ejector, and at the same time ejects a high-speed pulp impeller by jet polymerization. Therefore, impeller stirring is driven to achieve the functions of stirring pulp and cutting bubbles. The aeration rate is an important index to evaluate the performance of flotation machine, and the working principle of compound flotation agitating mechanism is complex, which should ensure the suction of a large amount of air. It is also necessary to ensure that the jet has sufficient impact force to drive the impeller agitation.Therefore, it is an important aspect of the research and development of the compound flotation agitator to study the suction mode of the compound flotation agitator and its inspiratory performance under a certain suction mode. It can be used for reference for further study. In this paper, the structural characteristics of the ejector are simulated by using the flow field simulation software, and the structural parameters of the ejector are found when the inspiratory performance is optimal. Then the physical model of the ejector is made and a series of experimental studies are carried out. The feasibility of the ejector is determined and the theoretical basis is provided for the compound flotation agitator. The results show that:. 1. For the central intake-peripheral feed injector, the location of the suction tube in the injector has a significant effect on the suction performance. When the suction pipe moves from the cone part of the ejector to the cylindrical part, the suction capacity increases rapidly. At the conical cylinder joint of the injector, the inspiratory capacity reaches the maximum, and the inspiratory capacity decreases slowly when the tube moves in the cylinder segment. When the cylinder length l is between 8-16mm, the inspiratory performance is better. It's good for the ejector. 2. For the central feed-peripheral air injector, the throat distance has the most important effect on the suction performance of the injector. The suction performance of the ejector is affected by the large or small throat nozzle distance, when the throat nozzle distance is 15mm, The suction performance of the injector is the best. The length of the pipe has little effect on the suction performance at the optimum throat distance. There is an optimum diameter of the throat to make the suction performance the best. 3. For submerged jet, the contraction angle has certain influence on the velocity of axis line in the jet region, and the axis velocity of 伪 _ (15) is the best. With the increase of angle, the velocity of axis line decreases, but the length of cylinder section has no significant effect on the velocity of axis line. 4. The experimental results of the two kinds of ejectors show that the experimental data are smaller than those of the simulation, but the trend of the data is similar to that of the simulation, which proves the feasibility of the designed ejector and the possibility of optimization.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD456

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