Experimental Study Of Self-Suction Self-Excited Oscillation Pulsed Jet Aerator

In China, from the 80s of 20 century on, the country has begun the way to the urban sewage treatment. And with the decades of years of development, we have gained some achievements, and the ability of sewage treatment has progressed greatly.Especially in the recent years, with more attention paid by the government and larger the investment than before, its development speed is much faster than before. However, in current main biochemical sewage treatment technology, the aeration devices are the primary energy-consuming equipments, which system costs about 50-70% of the total power consumption. The conventional aeration device has the shortcoming of low oxygen transfer efficiency, high energy-consuming and high running cost. So that, to develop new type of aeration device to improve the aeration capability, reduce the energy consumption, and improve the performance of aeration device has become the urgent affairs in sewage treatment plant establishment and environment protection development, and also becomes an important mission for the Chinese sewage treatment industry.The objective of the research project is to develop a new kind of Self-suction Self-excited Oscillation Pulsed Jet Aerator to overcome the shortcoming of conventional jet aerator to reach the goal of reducing energy consuming. The key of the technology in this new kind of aerator is to design a self-excited oscillation cavity which has special inner structure to replace the mixing tube in conventional jet aerator. The cavity can generate intensive shear field in the cavity without any auxiliary device just depending on its inner special structure when the air-water mixture flow through it and reach the goal of improving aerating performance by the following ways, all of which are the factor of improving the performance:1) Form intensive shear field in the cavity and shear air-water mixture repeatedly in intensive mode, which decreases the size of air bubbles in mixture and increases the interfacial area between sewage water and air;2) Intensive oscillation effect accelerates the renewal of the air-water interface film;3) Ejected mixture in pulsed mode has increased the outflow pressure and velocity and increase the aeration area.Experiments in clear water show that, in the same conditions, the aerating...