Enhanced photo-catalytic cells

Abstract

A photo-catalytic cell may produce bactericidal molecules in air by passing air across catalyst coated targets. Ultraviolet (UV) energy may be emitted from a source. A first portion of the UV energy from the source may be applied directly onto the targets. A second portion of the UV energy from the source may be reflected onto the targets.

1 . An apparatus for ionizing air, the apparatus comprising:
 a first target including:
 an inner side arranged to receive ultra-violet (“UV”) energy from a UV emitter, 
 an outer side that abuts a region where an airflow is unobstructed, 
 a plurality of passages extending continuously between the inner side and the outer side, and 
 a photo-catalytic coating on the plurality of passages, wherein the photo-catalytic coating comprises titanium dioxide; 
   a first reflector configured to reflect UV energy from the UV emitter towards the photo-catalytic coating of the first target, wherein the first reflector is a specular UV reflector; and   wherein the first target is arranged to:
 receive, through the inner side and at the photo-catalytic coating, UV energy from the UV emitter and UV energy from the first reflector, wherein incident angles of specularly reflected UV ray paths received from the first reflector are greater than incident angles of UV ray paths received directly from the UV emitter, 
 ionize air in response to the received UV energy, and 
 pass the airflow from the inner side and through the plurality of passages to carry the ionized air away from the outer side. 
   
     
     
         2 . The apparatus of  claim 1 , wherein a reflecting surface of the first reflector is electrically conductive. 
     
     
         3 . The apparatus of  claim 1 , wherein the first reflector comprises micro-polished stainless steel. 
     
     
         4 . The apparatus of  claim 1 , wherein the first reflector comprises a material that does not readily oxidize. 
     
     
         5 . The apparatus of  claim 1 , wherein the first reflector comprises a material having a UV reflectivity of about 90% or greater at UV wavelengths of 185 nm and 254 nm. 
     
     
         6 . The apparatus of  claim 1 , wherein the first target comprises a honeycomb matrix. 
     
     
         7 . The apparatus of  claim 1 , further comprising:
 a second target opposite the first target, wherein the second target includes:
 an inner side arranged to receive ultra-violet (“UV”) energy from a UV emitter, 
 an outer side that abuts a region where the airflow is unobstructed, 
 a plurality of passages between the inner side and the outer side, and 
 a photo-catalytic coating on the plurality of passages, wherein the photo-catalytic coating comprises titanium dioxide; 
   wherein the first reflector is further configured to reflect UV energy from the UV emitter towards the photo-catalytic coating of the second target; and   wherein the second target is configured to:
 receive, through the inner side and at the photo-catalytic coating, UV energy from the UV emitter and the first reflector, wherein incident angles of specularly reflected UV ray paths received from the first reflector are greater than incident angles of UV ray paths received directly from the UV emitter, 
 ionize air in response to the received UV energy, 
 pass an airflow from the outer side and through the plurality of passages to carry the ionized air away from the inner side. 
   
     
     
         8 . The apparatus of  claim 7 , wherein the second target comprises a honeycomb matrix. 
     
     
         9 . The apparatus of  claim 1 , wherein:
 each of the plurality of passages includes an ingress opening and an egress opening; and   the size of the ingress opening is the same as the size of the egress opening for a respective passage.   
     
     
         10 . An apparatus including a chamber for ionizing air, the apparatus comprising:
 a first target comprising:
 a first side abutting an interior region of the chamber, 
 a second side abutting a region exterior to the chamber, wherein an airflow in the region exterior to the chamber is unobstructed, 
 a plurality of passages extending continuously between the first side and the second side of the first target, wherein each of the plurality of passages includes an ingress opening and an egress opening, and wherein the size of the ingress opening is the same as the size of the egress opening for a respective passage, and 
 a photo-catalytic coating on the plurality of passages, wherein the photo-catalytic coating comprises titanium dioxide; 
   a first reflector configured to reflect UV energy from a UV emitter towards the photo-catalytic coating of the first target, wherein the first reflector is a specular UV reflector; and   wherein the photo-catalytic coating is arranged to receive UV energy directly from the UV emitter and UV energy reflected from the first reflector.   
     
     
         11 . The apparatus of  claim 10 , further comprising at least one corner reflector arranged in an interior corner of the chamber, wherein the at least one corner reflector is a specular UV reflector. 
     
     
         12 . The apparatus of  claim 10 , wherein the chamber further includes:
 a second target opposite the first target, wherein the second target includes:
 a first side abutting an interior region of the chamber, 
 a second side abutting a region exterior to the chamber, wherein the airflow in the region exterior to the chamber is unobstructed, 
 a plurality of passages extending continuously between the first side and the second side of the second target, wherein each of the plurality of passages includes an ingress opening and an egress opening, and wherein the size of the ingress opening is the same as the size of the egress opening for a respective passage, and 
 a photo-catalytic coating on the plurality of passages, wherein the photo-catalytic coating comprises titanium dioxide; 
   wherein the first reflector is further configured to reflect UV energy from the UV emitter towards the photo-catalytic coating of the second target; and   wherein the photo-catalytic coating is arranged to receive UV energy directly from the UV emitter and UV energy reflected from the first reflector.   
     
     
         13 . The apparatus of  claim 12 , further comprising a second reflector opposite the first reflector and configured to reflect UV energy from the UV emitter towards the photo-catalytic coating of the first target and the photo-catalytic coating of the second target, and wherein the second reflector is a specular UV reflector. 
     
     
         14 . The apparatus of  claim 13 , further comprising:
 a third reflector located at a corner between the first target and the first reflector;   a fourth reflector located at a corner between the second target and the first reflector;   a fifth reflector located at a corner between the first target and the second reflector; and   a sixth reflector located at a corner between the first target and the second reflector.   
     
     
         15 . The apparatus of  claim 14 , further comprising a seventh reflector on the first target and facing the interior region of the chamber,
 wherein the seventh reflector configured to reflect UV energy that is emitted from the UV emitter in a direction that is almost orthogonal to the first target, and   wherein the seventh reflector is a specular UV reflector.   
     
     
         16 . The apparatus of  claim 10 , wherein a reflecting surface of the first reflector is electrically conductive. 
     
     
         17 . The apparatus of  claim 10 , wherein the first target comprises a honeycomb matrix. 
     
     
         18 . The apparatus of  claim 10 , wherein the first reflector comprises a material having a UV reflectivity of about 90% or greater at UV wavelengths of 185 nm and 254 nm. 
     
     
         19 . An apparatus for ionizing air, the apparatus comprising:
 a first reflector configured to reflect ultra-violet (“UV”) energy from a UV emitter, wherein the first reflector is a specular UV reflector; and   a target including plurality of passages between a region interior to the apparatus and a region exterior to the apparatus, wherein each of the plurality of passages has a photo-catalytic coating, wherein the plurality of passages is arranged to:
 receive direct UV energy directly from the UV emitter, 
 receive specularly reflected UV energy reflected from the first reflector, 
 generate a first number of ions at the photo-catalytic coating in response to receiving the specularly reflected UV energy, and 
 generate a second number of ions at the photo-catalytic coating in response to receiving the direct UV energy, 
   wherein the first number of ions is greater than the second number of ions when passing an airflow of at least 272 feet per minute through the apparatus.   
     
     
         20 . The apparatus of  claim 19 , wherein the plurality of passages is further arranged to:
 receive the direct UV energy at a first incident angle,   receive the specularly reflected UV energy at a second incident angle, and   wherein the second incident angle is greater than the first incident angle.   
     
     
         21 . An apparatus for ionizing air, the apparatus comprising:
 a first reflector configured to reflect ultra-violet (“UV”) energy from a UV emitter, wherein the first reflector is a specular UV reflector; and   a first target having a photo-catalytic coating comprising titanium dioxide and arranged to:
 receive direct UV energy directly from the UV emitter, 
 receive specularly reflected UV energy reflected from the first reflector, 
 generate ions in response to the direct UV energy and the specularly reflected UV energy, and 
 emit the ions into an airflow directed to deliver the ions into an external environment. 
   
     
     
         22 . The apparatus of  claim 21 , wherein the photo-catalytic coating comprises titanium dioxide.