仿柳叶形静态混合元件的流动及混合特性研究

与现有的叶片规则排列的静态混合器相比,仿柳叶结构的不规则叶片排列方式更容易使气流的流动变得紊乱复杂,加剧微团间相互作用,实现短距离混合。本研究采用FLUENT(商用计算流体力学)软件模拟了在叶片与水平方向轴线分别呈不同角度时仿柳叶型混合元件的抗流作用,并在风洞中利用热线风速仪完成了速度场测量。研究表明:静态混合元件不同叶片角度下的流场湍动能分布趋势基本相同;其沿程压降变化趋势也基本一致,当速度标准偏差系数小于20%,叶片与轴线夹角为60°时气流混合距离最短。结合CO与空气在混合装置内的混合情况分析得:仿柳叶型静态混合元件叶片角度的增加能够使流体在速度以及浓度混合均匀时所需距离变短。

Study on Flow and Mixing Characteristics of Willow-like Static Mixing Element

Compared with the conventional static mixer with regular blade arrangement, the irregular blade arrangement of the imitated willow structure is more likely to make the gas flow become more complicated, and the interaction between the micelles is intense and short-range mixing is implemented. In this paper, FLUENT is used to simulate the flow characteristics of the imitated willow type mixing element when the blades are at different angles from the horizontal axis, and the velocity field measurement experiment is completed by hot wire anemometer in wind tunnel. The trend of the turbulent kinetic energy distribution of the static mixing elements at different blade angles is basically the same, and the variation trend of the pressure drop along the same direction is almost the same. When the standard deviation coefficient is less than 20%, the mixing distance of the 60° mixing element is the shortest. Combined with CO and air in the mixing device within the mixed distribution, it can be concluded that the increase of the blade angle of the static mixing element will make it possible to shorten the distance required for the fluid to mix evenly at the speed and concentration. It is of great significance for the development of a static mixer with compact structure and high efficiency.