Photocatalytic air disinfection
AssigneeUniversal Air Technology
InventorD. Yogi Goswami
Life of this patent
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Abstract
A method for disinfecting an air stream containing microorganisms including the steps of providing an air stream containing microorganisms having a relative humidity greater than about 40%; and contacting the air stream with a photocatalyst having a predetermined band gap energy in the presence of a source of photons having a wavelength corresponding to the band gap energy of the photocatalyst, so that at least a portion of the microorganisms in the air stream are destroyed by photocatalyfic oxidation. Devices embodying the method of the invention are disclosed, such as stand-alone devices and devices incorporated into the HVAC systems of buildings, including the air supply registers. Photocatalyst-coated filter media capable of trapping bioaerosols are also disclosed.
Claims91
A method for disinfecting an air stream containing microorganisms, comprising:
- providing an air stream containing microorganisms having a relative humidity greater than about 40%;
- and
- contacting said air stream with a photocatalyst having a predetermined band gap energy in the presence of a source of photons having a wavelength corresponding to said band gap energy of said photocatalyst, so that at least a portion of said microorganisms in said air stream are destroyed by photocatalytic oxidation.
A device for disinfecting a quantity of air containing microorganisms, comprising:
- a surface coated with a photocatalyst having a predetermined band gap energy;
- means for illuminating said photocatalyst-coated surface with a source of photons having a wavelength corresponding to said band gap energy of said photocatalyst;
- means for contacting said air with said photocatalyst-coated surface;
- and
- means for maintaining the relative humidity of said air above about 40%, so that at least a portion of said microorganisms in said air are destroyed by photocatalytic oxidation upon contact with said photocatalyst when said photocatalyst-coated surface is illuminated with said source of photons.
A device for disinfecting air containing microorganisms comprising:
- a duct through which said air is moved;
- a blower connected to said duct to move said air therethrough;
- a photocatalyst having a predetermined band gap energy disposed in said duct;
- a lamp disposed in sufficient proximity to said photocatalyst to illuminate said photocatalyst with a source of photons having a wavelength corresponding to said band gap energy of said photocatalyst;
- and
- a humidity controller adapted to regulate the relative humidity of said air in said duct above about 40%, so that at least a portion of said microorganisms in said air are destroyed by photocatalytic oxidation upon contact with said photocatalyst when said photocatalyst is illuminated with said source of photons from said lamp.
A device for disinfecting air containing microorganisms comprising:
- a photocatalyst having a predetermined band gap energy disposed in the air supply register of a heating, ventilating and air conditioning system and a lamp positioned in sufficient proximity to said photocatalyst to illuminate said photocatalyst with a source of photons having a wavelength corresponding to said band gap energy of said photocatalyst;
- wherein said heating, ventilating and air conditioning system has a blower to move air through said air supply register and a humidity controller adapted to maintain the relative humidity of said air in said heating, ventilating and air conditioning system above about 40%, so that at least a portion of said microorganisms in said air are destroyed by photocatalytic oxidation upon contact with said photocatalyst when said photocatalyst is illuminated with said source of photons.
A stand-alone device for disinfecting air containing microorganisms comprising:
- a chamber through which said air is moved;
- a blower connected to said chamber to move said air therethrough;
- a photocatalyst having a predetermined band gap energy disposed in said chamber;
- a lamp positioned to illuminate said photocatalyst with a source of photons having a wavelength corresponding to said band gap energy of said photocatalyst;
- and
- a humidity controller adapted to maintain the relative humidity of said air in said chamber above about 40%, so that at least a portion of said microorganisms in said air are destroyed by photocatalytic oxidation upon contact with said photocatalyst when said photocatalyst is illuminated with said source of photons.
Dependencies are inferred from the claim text.