About a week ago we posted about how ozone is made. That original post gave the fundamentals of how ozone is produced in nature and the basics of how ozone is produced within ozone generators, both UV ozone generators and corona discharge ozone generators. It was pointed out then that most (almost every) industrial ozone generator uses corona discharge to produce ozone. This 2nd installment is dedicated to informing you the reader about ozone generation from corona discharge.
The fundamentals are simple. A spark (corona discharge) is used to split the diatomic oxygen molecule into valant oxygen atoms. These oxygen atoms have a negative charge and will bond quickly with another oxygen molecule to produce ozone! For each split oxygen molecule 2 ozone molecules are produced.
Ozone Generation from Corona Discharge
A power supply is used to produce an electrical discharge across a dielectric, and an air gap. The dielectric is used to diffuse the discharge across a large area as opposed to single point like a normal spark. The oxygen molecules passing through the air gap are exposed to the electrical discharge and are split into ozone (at least that is the hope). A great deal of heat is generated from this process and is removed from the electrodes as shown.
Corona Discharge Tube
This image shows a more complete picture of a very typical ozone generation corona cell. The dielectric is a tube allowing the air gap to flow around the outside of the dielectric, with the electrode around the outside. This allows heat to be dissipated to the outside of the electrode efficiently.
This video shows a great example of ozone production from corona discharge.
There are three main factors when generating ozone from corona discharge:
- Power supply
- Operating voltage
- Operating frequency
- Corona Cell
- Tube – cylindrical style
- Flat plate
When generating ozone from corona discharge there are a few factors that will affect performance that must be evaluated.
- Cooling of the corona cell
- Water cooled
- Air cooled
- Feed gas
- Dry Air
I will try to cover some of these fundamentals and why one may be better than another for your specific application in future installments of “how ozone is made“