自吸式空心环流射流曝气器充氧性能研究（二）

【作者】 尚海涛；

【导师】 王宝泉；

【作者基本信息】 西安建筑科技大学 ， 市政工程， 2001， 硕士

【摘要】 作为污水生化处理核心的曝气工艺是污水厂的能耗大项，其基建投资也十分巨大。因此开发结构简单、能耗低、易管理的曝气设备成为各国共同关心的重要问题。射流曝气，尤其是自吸式射流曝气就可较好地满足这一要求。但国内外现有的普通自吸式射流器的动力效率并不占优，因此影响了它的推广应用。 本课题研制开发出一种自吸式空心环流射流器，其结构特点是在普通自吸式射流器基础上内置一个空心管，其优点是采用内外吸气方式，从而增大了工作介质与引射空气的混合层和剪切层，增大了两者的接触面积，增强了工作介质对引射空气的卷吸和掺混作用。 本文采用正交实验方法对自吸式空心环流射流器的结构参数进行了研究，并考察了各结构参数之间的交互效应。研究结果表明： 1．所考察的三个结构参数对充氧性能影响的显著顺序是：喷嘴收缩角α→喉管长径比L/D→空心管－喷嘴位置关系Lr。 2．结构参数的最佳组合是：α=16°，L/D=10，Lr=100%，其对应的氧总转移系数是 Klas=0.051min^-1，充氧动力效率是 E=2.92KgO₂/Kw·h。 3．L/D与Lr的交互效应最显著，L/D与α的交互效应次之，Lr与α的交互效应不明显。更多还原

【Abstract】 The technique of aeration,as the key part of biochemical treatment in the sewage plant, isthe chief section of energy expenditure and spends a large sum of construction funds. So it hasbecome a problem all the countries in the world to develop a wastewater treatment facilities withsimple structure, low energy expenditure and easy management. Jet aerator especially self-suction jet aerator can meet the need well. However, the available common self-suction jetaerator all over the world has no advantage in power efficiency, which prevents its extension.This project develops a new equipment named coreless-cyclic self-suction jet aerator, whichis made by adding a central pipe in the common self-suction jet aerator. This new device has thecharacteristic of internal-external suction,which enlarges the mixing layer, the shear layer of theactuating medium and the extracted air, and increases the contact area of the two fluids,soreinforces the swirling and mixing functions of the actuating medium to the extracted air.This paper investigates the effect of the new device on oxygen transfer performance byorthogonal experiment designs considering the interaction. The results show that:1. The significance order of the three considered constitution parameters to oxygen transferperformance is: nozzle’s contracting angle（α） has the greatest influence, throat pipe’slength-diameter ratio（L/D） takes second place and central pipe relative location to nozzle（Lr）doesn’t have important influence.2. The optimum combination of the three studied constitution parameters is: α=16°, L/D=10,Lr=100%. The corresponding overall oxygen transfer coefficient（Klas） is 0.051min^-1, thetheoretical power efficiency（E） is 2.92KgO₂/Kw·h.3. The interaction of L/D with Lr is the most apparent, the interaction of L/D with α is a bitless, and that of Lr with α is by far the least.更多还原