Mixing of Ozone with water is generally termed as Ozone contacting. Although the solubility of Ozone is better than Oxygen in the water, being gas to liquid contact, dissolution of Ozone in water is critical. Thus the design of an efficient Ozonation system needs careful evaluation. The advantages, disadvantages and limitations of Ozone contact methods used in practice are provided in the technical note.
The Ozone can be diffused or bubbled in a tank filled with water. A diffuser or the diffuser network is located at the bottom of the tank from which the Ozone gas is bubbled in the water. The Ozonation tank should not be under pressure otherwise the flow of Ozone can be adversely affected. The height of water column in the tank also important for proper absorption of Ozone. The diameter of tank should be less and height more (A ratio of Diameter & Height, 1:3 should be considered).
The Ozone pipeline from the output of the Ozone Generator is connected to the diffuser or the network in the tank. The Ozone feeding pipe is to be raised at least by three to four feet above tank level to ensure that the water does not return to Ozone Generator from the Contact Tank.
The Ozone can be diffused or bubbled in a tank filled with water. A diffuser or the diffuser network is located at the bottom of the tank from which the Ozone gas is bubbled in the water. The Ozonation tank should not be under pressure otherwise the flow of Ozone can be adversely affected. The height of water column in the tank also important for proper absorption of Ozone. The diameter of tank should be less and height more (A ratio of Diameter & Height, 1:3 should be considered).
The Ozone pipeline from the output of the Ozone Generator is connected to the diffuser or the network in the tank. The Ozone feeding pipe is to be raised at least by three to four feet above tank level to ensure that the water does not return to Ozone Generator from the Contact Tank.
A Ozonation tank is used for consistent Ozone dissolution. The product water enters in from the topside to provide a counter-current flow of Ozone and water. The Ozonated water from this tank is utilized for the process. A separate line is used for the Ozone mixing and consists of booster pump, ventury injector, static mixer, pipeline and a central diffuser. Thus the Ozone mixing is independent of the filling speed, flow rate and the line pressure. The MOC of the system should be SS 316.
| Ozonation Parameters | Diffusion In A Tank | On Line Injection | Recirculation Tank |
| Ozonation System | Ozone Diffused in the Bottom of the reaction tank | Ozone injected through Online Ventury Injection System in filling line | Ozone is injected in a re- circulation line by Ventury Injector and the Ozone Solution is Diffused in the Ozonation Tank |
| Ozonation Method | By Diffusion | Ventury Injection | Ventury Injection & diffusion combination |
| Ozone Contact Duration | Can be Controlled | Not under Control | Fully Controllable |
| Dissolution Efficiency | Low and depends on Water depth in the diffusion Tank | High and depends on the continuity of the production process | Very high & consistent, does not depend on operating parameters |
| Ozone & Water Flow | Counter Current | Counter Current | Counter Current in recirculation Line & Counter Current in Diffusion. |
| Dissolution Continuity Continuous | Dissolution Continuous Even when filling is not in operation | Dissolution Stops When ever filling is not operating | Dissolution Even when filling is not in operation |
| Ozone Utilization | Low (30 - 50% ) | Medium (40 - 60% ) | High ( 65 - 95%) |
| Dependency of Ozonation | Water Depth Ozone Pressure | Water Flow Rate Differ, Pressure across Ventury | Independent of : Water Flow Rate Line Pressure Ozone Pressure Filling yes or no |
| Qty of Ozone Injection | By Ozone Pressure | Not Under Control | By Ozone Pressure |
| Dissolution Consistency | Consistent Ozone Dissolution is Possible | Consistent Ozone Dissolution is not possible | Very Consistent Ozone Dissolution can be achieved |
| Product Quality | Reasonable | Inconsistent | Consistent Quality |
| System Components | Ozone Pipe | Ozone Pipe | SS Ozonation Tank |
| Recirculation Pump | |||
| Ventury & NRV | Ventury & NRV | ||
| Diffusers | Static Mixer | ||
| Flow Control Valve | Radial Diffuser | ||
| Central Diffuser | |||
| Ozone sensing and Controlling System | Possible | Not Possible | Possible & Generally part of the System |
| Ozonation System Cost | Low | Medium | High |