Where does the ozone comes from?
According to the energy source, there are 3 ways to make ozone, the corona discharge method, the ultraviolet method and the electrochemical method. For these 3 ways,the principle of ozone generation is similar.
Take corona discharge as an expamle to explain it
As we all know, Corona discharge, the most common form of gas discharging in air, refers to the partial self-sustaining discharge of gas medium in non-uniform electric field. In the vicinity of the tip electrode with a small radius of curvature, the local electric field intensity exceeds the ionization field intensity of the gas, which makes the gas ionize and excite, resulting in corona discharge. When corona occurs, light can be seen around the electrode, accompanied by a hissing sound. Corona discharge can be a relatively stable discharge form, or it can be an early development stage in the process of gap breakdown in uneven electric field.
The formula of electric field intensity of point charge in vacuum E=F/q
A definition applicable to any electric field E=KQ/r2 k=9.0×10^9N.m^2/C^2
When the electrons are distributed on the outer edge of the electrode, especially at the tip, a large number of electrons will concentrate, and each electron will form an electric field strength. According to the principle of electric field superposition, when the electric field strength formed by the electrons on the whole electrode is greater than that of air ionization, part of the air will become a conductor and begin to discharge
So, we think the condition of corona discharge is that E(electric filed) > E(air), According to E = KQ / R2, we know that the square of the corona discharge distance is proportional to the amount of charge, that is, the greater the amount of charge, the farther the discharge distance, that is, the farther the air is broken down
When the air is ionized, that is, when the air becomes a conductor that can conduct electricity, it is full of a large number of freely moving electrons. The free electrons impact and eventually combine with oxygen atoms and oxygen positive and negative ions, and finally generate ozone.