An ozone generator is an indispensable part of an ozone installation, it converts oxygen into ozone. An ozone generator is also called an ozonator, ozonisator or ozoniser, these are all different names for exactly the same machine. Ozone is produced from oxygen but the supply gas does not have to be pure oxygen. Air can also be used as a supply gas because it consists of 21% oxygen.
Every type of supply gas has its pro’s and cons. The conversion of oxygen into ozone happens in ozone generators using UVC light or high voltage. The latter is used the most because the energy consumption is way lower. Below you’ll find more information about ozone generators and a couple options with their pro’s and cons.
O3-3000B ozone generator
Generating ozone with UV
A short wavelength (185nm) is necessary to effectively generate ozone using UV. Special lamps are necessary for this because the well-known UV lamps to remove algae have a much longer wavelength of 254nm. At this wavelength, ozone gets broken down into oxygen.
In theory, 130 grams of ozone can be generated with 1 kWh using UV light. In practice, these UV based generators need around 100 to 150 watt to generate 1 gram of ozone.
This method does hold one advantage, dry supply air isn’t necessary.
Advantages:
- Simple construction
- No dry air needed as a supply gas
Disadvantages:
- High energy consumption
- Low ozone concentration
- A lot of maintenance (replacing UV lamps)
Generating ozone with high voltage
These days, almost all ozone generators use high voltage to generate ozone. Colloquially, this method is known as “corona discharge” but this is actually the wrong term for it. Corona discharge is based on an electric field between 2 electrodes without an isolator in between them. Almost all commercially used generators do use an isolator, which is why the correct term isn’t “corona discharge” but “dielectric barrier discharge”.
Ozone generators based on high voltage are more economical, about 20 watt per gram of ozone on dry air. On oxygen even around 20 watt per gram of ozone. This type of ozone generator does need a dry supply gas because moisture will damage the ozone cell.
The ozone generators we sell are all based on high voltage.
Advantages:
- Energy efficient
- High ozone concentrations are possible (up to 14% weight)
- Relatively cheap to buy and inexpensive to maintain
Disadvantages:
- Dry sypply gas is required
- Oxygen as a supply gas is recommended for optimal operation
Air as a supply gas
Air as a supply gas is mostly used in smaller ozone generators up to +/- 10 grams of ozone per hour. This type of generator is mostly used for ponds, pools and spas because they are relatively cheap. This type is barely used in the industry however, because the maximum ozone concentration is too low, around 3%wt. (on dry air)
For proper functioning, the supply air has to be dried. That’s because any air present will cause th formation of nitric acid, tarnish on the ozone cell and a low ozone concentration (ozone yield). This means that there shouldn’t only be dry air in the generator when it’s in operation, but when it’s turned off too. There won’t be any formation of nitric acid when the generator isn’t in operation, but the tarnish will form and damage your ozone cell!
Please note that almost all manufacturers of this type of ozone generator measure their ozone yield with dry air as a supply gas. With dry air, they mean air with a dew point of -40°C down to -70°C. Those kind of dew points are barely achievable with your typical air dryer. On our webside, you can find exactly under which conditions the ozone yields were measured. Unfortunately, there are barely any manufacturers that state the measuring conditions. So please ask for more information before buying an ozone generator to be sure you’re buying what you need.
Advantages:
- Low investment costs
- Simple to use
Disadvantages:
- Relatively high maintenance
- Low ozone concentration
- Moist air will cause the ozone yield to be drastically lower
- Ozone gas contains pollution like nitric acid
- Energy consumption is relatively high
Oxygen as a supply gas
Ozone generators that use oxygen as a supply gas mostly have an ozone yield of more than 10 grams. On smaller generators, producing the oxygen is too expensive to effectively use. That is why oxygen fed ozone generators are mostly found in the industry, big pools, zoos and the aquaculture. The ozone yield of oxygen fed generators is about 2kg/hr. These kinds of amounts are almost exclusively used in drinking water production and wastewater treatment.
Oxygen produced by an oxygen concentrator or oxygen from a bottle already has quite a low dew point, which is why it’s not necessary to dry it even further in most cases. The maximum ozone concentration that can be reached with oxygen is high, up to 15%. This makes these ozone generators highly suitable for disincentive purposes.
Advantages:
- Very high ozone concentration (to more than 15%)
- Low energy consumption
- Low maintenance
- Clean ozone gas
Disadvantages:
- High investment
- Oxygen concentrator uses quite a lot of energy, especially on smaller systems
What ozone generator suits me best?
What ozone generator you need for your application depends on the situation.
Air treatment
A UV device or a simple high voltage unit would be the best choice to treat small areas (cars, homes). For air treatment in office buildings, a high voltage based unit would be a great choice. An oxygen fed high voltage ozone generator would be best if you want to treat storage areas, warehouses and cold stores.
Ponds and pools
The most important factors for generators on ponds and pools will probably be the price and energy consumption. For this application, a dry air fed ozone generator would be best. A simple air dryer consisting of a tube filled with silica gel crystals will suffice for proper functioning.
Public pools, zoos and amusement parks
To this group, energy consumption and maintenance costs will be of importance. In most cases an air fed ozone generator with automatically regenerating air dryer is the best choice. However, when it concerns bodies of water bigger than +/- 200m³ it’s more sensible to choose an oxygen based system.
Industry
Oxygen fed high voltage systems are almost always used in the industry, simpy because they can reach high ozone concentrations and don’t need a lot of maintenance.
For more information about an ozone generator, please contact us, we’re glad to help.