1、Introduction to The Ozone Generation and Its Applications to The Environmental Technology,Saga University Faculty of Science and Engineering Department of Electrical and Electronic Engineering Chobei YAMABE （山部長兵衛(wèi)）,Characteristics of Ozone (O3) : 1)Ozone is one of the strongest oxidants. 2)No undesi

2、rable by-products residues are formed.,Major applications : Removal of order, color and disinfection 1)Treatment of drinking water and waste water. 2)Bleaching processes (paper pulp). 3)Oxidation step involving ozone is also being investigate for dioxins removal from flue gas in incinerator plants.

3、AOT (Advanced Oxidation Technology) such as combined use of O3 / UV is applied for the treatment of dioxins which are exuded from a final place for the industrial wastes.,Studies are required for 1) high ozone concentration : gO3/Nm3 2) high efficiency : gO3/kWh 3) compact size,Different types of re

4、actors 1. Discharge inside the bubbles in water 2. DC positive streamer corona a) discharge conditioning b) series gap effect 3. Superimposed type a) surface discharge and DC b) surface discharge and barrier discharge 4. Double discharge type 5. Rotating electrode type,Factors which influence on ozo

5、ne generation: 1) Raw gas : (oxygen, air with or without humidity) 2) Gas flow rate : (specific power W/Q = electric input power / gas flow rate) 3) Produced ozone concentration : ratio of oxygen atom O vs. oxygen molecule O2 4) Operating pressure : optimum operating condition is determined by the p

6、roduct p and d. Where, p : operating pressure, d : gap distance 5) Cooling temperature for the gas 6) Electrical discharge characteristics of ozonizer tube : capacitance of dielectric material, thermal conductivity, insulating strength 7) Gap discharge : d , pd product, generation in air 8) Electric

7、al input power 9) Applied voltage 10) Operating frequency of electrical power source: Input power increases with the frequency of power source (it means to be compact), and dielectric loss also increases.,従來型発生器基本構(gòu)造 Fundamental structure of conventional ozonizer (ozone generator),放電管基本構(gòu)造 Coaxial tub

8、e type of ozonizer,微小放電電流測定 Measurement of the micro-discharge current,表電荷，電流幅依存性 Dependence of discharge electric charge Q and discharge current pulse width ,Fig.2 : streak-photographs of microdischarges in air (a), with afterglow (b).,陰極距離 z (cm),陰極距離 z (cm),(a) 電子密度分布,(b) 電界分布,in Oxygen and stepp

9、ed voltage is applied,Electron density ne and reduced electric field E / p as a function of distance z from the cathode K,(左図) 放電発光現(xiàn)象比較 （a ： 実験， b ： ）(22) light emission measurement (a) and simulation (b),time,A,K,(K),(A),(K),(A),ne 10(12),中心軸距離（）,誘電體表面電荷蓄積（酸素中）（25) Electric charge density on the di

10、electric material as a function of distance from the center axis for the different time.,ozone generation reactions,(1),(2),(3),(4),(5),(6),(7),ozone destruction reactions,(8),(9),(10),(11),(12),(13),(14),(15),(16),(17),(18),(19),生成効率 ozone generation efficiency,in air, Y (kg / h) = 0.056 W 1.03 whe

11、re, W: kw,Simplified potential energy diagram of O2. The arrow indicates the Franch-Cindon region for excitation from the ground state.,Distribution of electron energy losses as a function of the reduced electric field.,密度（energy density）,電流密度(current density),t,輸送電荷(transfered charge),放電柱斷面積(cross

12、section of micro-discharge ),vdne(t)dt, ne,constant,長， 圧力， 電極系， 誘電體 gap distance, pressure, electrode, dielectrics,生成効率（X10 = O / O2 ）ozone generation efficiency as a function of E/n,酸素原子勵起効率及影響 Influence of atomic oxygen concentration O and excited ozone O3* on ozone generation efficiency,Effective

13、 ozone generation,Establishment of stable, uniform discharge 安定放電形成 Effective dissociation of oxygen molecules O原子効率的解離 + Ozone generation O3生成,(a) 拡散狀放電 (b)放電 diffuse discharge arc discharge,68,electron energy,Generated ozone concentration O3, glow-to-arc transition rate t.r. as a function of series gap distance dm,印加電圧波形立上峻度効果 Effect of the steepness of the rise time of the applied voltage,（f = 50Hz）in O2, 110,収率（ozone generation efficiency）,濃度（ozone con