Multi-stage Air Purification System with Hemispherical Discharge

Category-Environmental Engineering

Industry Classification:

NIC (2008)-28195- Manufacture of filtering and purifying machinery or apparatus for liquids
and gases; 28192- Manufacture of air-conditioning machines, including motor vehicles air-conditioners
NAICS (2022)- 333413- Industrial and Commercial Fan and Blower and Air Purification Equipment Manufacturing; 335220- Major Household Appliance Manufacturing; 333415- Air-Conditioning and Warm Air Heating Equipment and Commercial and Industrial Refrigeration Equipment Manufacturing

Applications– Air purifiers and Air conditioners

Market Drivers-

The Air Purifier Market size is estimated at USD 16.83 billion in 2024, and is expected to reach USD 23.60 billion by 2029, growing at a CAGR of 7% during the forecast period.

Indoor air pollutants contain unwanted particulates, gaseous contaminants and microbes, which are emitted by indoor sources, generated as secondary by-products of chemical reactions or infiltrated from outdoors.
Air-conditioning systems with filters remove only particulate pollutants. Moreover, if these filters are not maintained properly then microbial growth can emit microbial Volatile Organic Compounds (VOCs).
Adsorption and photo-catalysis have been used to treat gaseous pollutants. However, pollutant removal efficiency of photocatalytic TiO2 and activated carbon coated filters is reduced due to UV induced byproducts and unstable coating that blows away in the treated air.
There is a need for a self-maintenance adsorption enhanced conductive photocatalytic air purifier with 360 degree discharge that removes various pollutants while not not release harmful byproducts.

The system includes a particle filter cartridge, a photocatalytic oxidation (PCO) filter cartridge coated with composite photocatalysts with porous materials to absorb VOCs using UV light and a granular activated carbon filter to adsorb the residual VOCs.
An ionizer chamber and a UV disinfector are included near the inlet and outlet respectively
The composite photocatalyst comprises a combination of polyelectrolyte solution (CPANI) , an activated carbon (AC) solution (AC/Polystyrene Sodium Sulfonate (PSS)), and a suspension of TiO2 (TiO2P25)
The Hemispherical top dome provides a uniform distribution of purified air in all three dimensions

The particle filter cartridge in combination with the ionizers used in the air system are effective in removing particles below 2.5 μm size with more than 70% removal efficiency.
The air purification system was installed, tested and validated in an office environment. The phocatalyst coating was stable compared to such coatings in conventional purifiers getting blown away on use.
The band gap energy diagram of the photocatalytic filter used in the system (CPAT) in comparison with two other filters (pure TiO2 and composite CSAT filter) show that the filter operates well even when illuminated with a visible light LED.
The purification system effectively removes particulate pollutants, microbes and VOCs. Whereas, conventional HEPA filters are able to remove only particulate matter.

Prof. SM Shiva Nagendra

Department of Civil Engineering

TRL 5

Technology validated in relevant environment

Technology Transfer