Importance of Eliminating Residual Amounts of Ozone

Ozone when introduced to a kitchen exhaust stream will oxidize grease and odors to form predominately H2O and CO2. This process is known as ozonolysis. There are four commonly used methods to generate ozone:

  • Corona discharge
  • Ultraviolet (UV) Radiation
  • Electrolysis
  • Radiochemical

Essentially all methods use energy to break the bonds of oxygen molecules (O2) and allow the oxygen atoms to re -form as ozone (O3). Corona discharge generation and UV radiation are the only methods applicable to kitchen exhaust.

Both methods involve drawing air through a modular unit attached onto the side of a Modular kitchen Pune exhaust duct that is under negative pressure. The negative pressure in the duct creates a flow of outside air through a unit containing high voltage plates (corona discharge) or 185nm UV lamps (ultraviolet radiation) generating ozone. The amount of ozone can be controlled via a damper between the unit and the duct. The amount of air an ozone generator can clean is dependent on the contaminant loading and the residence time available. A unit is designed to treat a volumetric amount of air, generally a minimum of 2 seconds residence time is required to allow the ozone to clean the specified volume of air with a moderate contaminant loading before exhausting outside.

One major advantage of ozone generators over in duct/hood UV lights is the location of the unit; grease particles don’t pass through the unit preventing the need to clean the unit. However the UV lights inside units that rely on UV still need to be periodically replaced, this is due to the natural degradation of UV lights over time. Use Best Kitchen Chimney.

There is a major concern relating to residual amounts of ozone that are exhausted to occupied spaces. Ozone exposure in humans has been associated with dizziness, insomnia, coughing, chest pain, reduction in lung function and irreversible obstructive airway diseases. In particular ozone exposure is damaging to the undeveloped lungs of children.

There are three ways to ensure that no residual ozone is present in the final exhaust;

The first option is to install an ozone detector just prior to the building kitchen exhaust point; the ozone level detected here can control the damper position on the outlet of the ozone generator. As the cooking load increases and decreases the amount of ozone consumed varies and therefore the amount required to be generated also changes. Pull-Out Trash Can in Pune

The second option is to install a modest carbon trap to capture any long lived organics and contact them with remaining ozone in the stream, destroying remaining organics; refreshing the carbon surface and containing the residual ozone. This option ensures a higher efficiency of odor removal as additional residence time is effectively created by having both ozone and organics react while adsorbed onto the surface of the carbon.

Thirdly it is recommended to ensure ozone generators are operated under negative pressure, this is to ensure that any leakages will be into the duct and system, eliminating concerns of ozone leaking into populated areas. In any case ozone is not recommended as the sole mechanism to remove both particles and odor, generally the residence time available will only be long enough to completely break down the smaller gaseous phase organics (odor). It is highly recommended that another high efficiency particle removal system is used in conjunction with ozone for complete particle removal.

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