可调湍流涡旋絮凝技术的试验研究

发布时间：2018-07-26 07:00

【摘要】：传统水处理设备对原水流量和突发性水质变化的适应性较差,造成了出水品质不稳定的普遍现象。针对这一问题,本文根据涡旋絮凝理论设计出了可调湍流涡旋絮凝池。试验研究发现,通过放置弧形叶片以及调整叶片的旋转角度可以获得较好的絮凝效果,从而提高出水品质。本文首先介绍了胶体的结构以及脱稳方式,然后详细阐述了絮凝动力学机理和湍流涡旋絮凝理论。以传统往复式隔板絮凝池为平台,在此基础上设计了可调湍流涡旋絮凝池,通过控制原水浊度、原水流量、絮凝剂流量和叶片旋转角度来研究絮凝过程,得出不同控制变量下的最优工况。与传统絮凝池的试验研究不同,本文不仅对十二廊道可调湍流涡旋絮凝池的絮凝效果进行试验研究,还创新地把可调湍流涡旋絮凝池分段组合,通过研究絮凝池前两个廊道的絮凝效果,加深对絮凝机理的认识。絮凝池前段反应过程是絮凝反应的初期,在整个絮凝过程中是很重要的一部分。两廊道絮凝试验中,相同原水流量、不同原水浊度、不同叶片工况下,第一、二廊道叶片角度是45?时,絮凝效果最好。十二廊道絮凝试验中,不同原水流量、不同原水浊度、不同絮凝剂流量、不同叶片工况下,廊道中放置叶片比没有放置叶片的絮凝效果好;同时叶片角度为45°比0°絮凝效果好。由试验结果可得,在往复式隔板絮凝池中安装适宜角度弧形叶片组对絮凝过程会起到很好的促进作用。由絮凝的动力致因可知,水和水中颗粒的密度(惯性)不一样,当水流速度变化(水流时平均速度大小或水流运动方向)时,会造成水中的颗粒与水流产生相对运动,这为不同尺度的颗粒碰撞提供了动力条件。水流流经弧形叶片会产生涡旋,涡旋的产生改变了水流方向从而改变水流速度,最终造成颗粒与水流产生相对运动,为絮凝创造了水动力条件。所以通过控制叶片角度产生适宜尺度的涡旋,可以创造有利于絮凝的水动力条件,从而增加胶体颗粒碰撞的有效次数,最终形成致密的絮体沉淀,达到降低出水浊度的效果。
[Abstract]:The adaptability of traditional water treatment equipment to raw water flow and sudden change of water quality is poor, which results in the instability of effluent quality. According to the theory of vortex flocculation, an adjustable turbulent vortex flocculation cell is designed. The experimental results show that better flocculation effect can be obtained by placing the arc blade and adjusting the rotating angle of the blade so as to improve the quality of the effluent. In this paper, the structure and destability of colloid are introduced, then the flocculation kinetics and the theory of turbulent vortex flocculation are described in detail. Based on the traditional reciprocating baffle flocculation tank, an adjustable turbulent vortex flocculation tank was designed. The flocculation process was studied by controlling the turbidity of raw water, the flow rate of flocculant and the rotating angle of blade. The optimal conditions under different control variables are obtained. Different from the experimental study of the traditional flocculation tank, this paper not only studies the flocculation effect of the adjustable turbulent vortex flocculation pool in 12 corridors, but also innovatively combines the adjustable turbulent vortex flocculation pool. By studying the flocculation effect of the two corridors in front of the flocculation tank, the flocculation mechanism was further understood. The reaction process in front of flocculation tank is the initial stage of flocculation reaction, and it is an important part in the whole flocculation process. In the flocculation test of two corridors, under the same raw water flow rate, different turbidity of raw water and different blade conditions, the first and second corridor blade angles are 45? The flocculation effect is the best. In the flocculation experiment of 12 corridors, different raw water flow, different turbidity of raw water, different flowrate of flocculant, different working conditions of blade, the flocculation effect of placing blade in corridor is better than that without blade, and the flocculation effect of blade angle is 45 掳to 0 掳. From the experimental results, it can be concluded that the installation of an appropriate angle arc blade group in the reciprocating baffle flocculation tank can promote the flocculation process well. According to the dynamic cause of flocculation, the density (inertia) of water particles is different from that of water particles. When the velocity of water changes (the average velocity of water flow or the direction of flow movement), it will cause the particles in water to move relative to the water flow. This provides dynamic conditions for particle collisions of different scales. The vortex produced by the flow through the arc blade changes the direction of the flow and changes the velocity of the flow, resulting in the relative movement of particles and the flow, which creates the hydrodynamic conditions for flocculation. Therefore, by controlling blade angle to produce a vortex of appropriate scale, hydrodynamic conditions conducive to flocculation can be created, thus increasing the effective number of collisions of colloidal particles, finally forming a dense flocculation sedimentation, and achieving the effect of reducing the turbidity of effluent.
【学位授予单位】：杭州电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ085.4

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