There are several key things you need to know before you can buy an ozone generator. Before going into details, however, it is important to note that we are talking about corona discharge type ozone generators. These are the most important type of commercial/industrial ozone generators. There are other types of ozone generators, but non corona discharge units are mostly for use in small scale applications, producing typically less than half a pound per day or less than 10 grams per hour of ozone.
This article will review the key selection factors and how it relates to various applications for ozone and the impact on the cost of an ozone generator.
The key factors include: generatorinsight
1. Output: This is how much ozone the machine makes, normally quoted in grams per hour or pounds per day.
2. Concentration: Ozone can be produced at different concentrations ranging from 1-12 weight percent. The concentration of ozone has an effect on most applications and also affects machine output.
3. Gas Feed: you must have a source of feed gas containing oxygen, there are three choices: dry air, oxygen concentrated from air or purchased oxygen (either as liquid oxygen (LOX) or compressed oxygen in cylinders).
4. Generator Cooling: Ozone generator create heat that must be removed, the options for removing this heat are air cooling or water cooling.
Selecting the proper combination of features depends strongly on the application. For example, in water treatment applications higher concentrations of ozone are used while in air treatment applications lower concentrations can be selected.
Ozone Generator Output
This is the most important factor in selecting an ozone generator. The amount of ozone required is based on the application requirements. If the ozone is being used for removal of organic contaminants from water, the amount of ozone is proportional to the amount of organic in the water, the efficiency of the ozone organic reaction and the efficiency of dissolving the ozone into the water.
As a specific example, ozone is often used to reduce chemical oxygen demand (COD) in water. COD is measured in ppm (milligrams per liter – mg/l). It normally takes 2 mg of ozone per mg of COD to remove the COD. So, if we had to treat 10,000 liters per hour of water containing 50 ppm of COD we would need: