There are so many types of ozone generator. The non-corona discharge is in most use for small scale applications. This article reviews key things to consider its relation to other ozone applications and cost impacts of the generator. Four key things to consider here are:
- Output from generator
- Ozone concentration
- Gas feed from generator
- Generator cooling
A proper selection will depend on the application.
Output From Generator
This is what the ozone generates in grammes per hour or pounds per day based on the application requirements.
It is an essential factor to consider when choosing a generator.
For removal of organic contaminants from water the amount of ozone will be relative to the efficiency and amount of organic in the water.
Ozone is frequently used for reduction of chemical oxygen demand (COD) in water.
COD is measured in milligrammes per litre – mg/l (ppm).
To get rid of COD, It can take 2mg of ozone for a mg of COD. Below is an example:
10,000 litres of water holding 50 mg of COD needs to be treated in an hour. It would require
The litre/hr * mg/l COD * Ozone/mg COD = X mg /hour.
Hence: 10,000*50*2 = 1,000,000mg/hr or 1,000 g/hr or 1 kg/hr
This means that 1 kg/h of ozone or 52.8 pounds of ozone daily needs to be dissolved.
Not all ozone in the water dissolves. Hence there is a need for calculating the transfer efficiency.
Minimum ozone of 90% can be dissolved if using a venturi injector.
Hence, for the above example it would require 1,000,000mg/h ÷ 0.90 = 1111111.11 mg/h or 58.7 pounds of ozone daily.
If the concentration of ozone rises, a given system will generate less ozone.
The dissolving ozone rate rises with rising ozone concentration.
This will establish the required size of the machine.
There is a need for pilot and laboratory studies to establish the needed amount of ozone.
Then an engineer can evaluate to choose the proper balance between generator size, concentration and ozone dose.
This evaluation comes at a cost.
Concentrations produced by ozone can range from 1-12 weight percent.
For gas and water treatment, it is 1-3 and 5-10 weight percent respectively.
This concentration affects applications as well as machine output.
Ozone with high concentrations cost more as well as does more in some applications.
The essential part of ozone concentration is by comparing it with various generators.
Here is an instance:
Output (grams/hour) Concentration (%) cost
Seller 1 60 6 5,500dollars
Seller 2 60 4 3,800dollars
In related concentrations the result can change:
Seller 2 60 6 6,000dollars
This allows the comparism of generators that appears the same.