Air sanitizer
A sanitizer has substrates which are coated with an optically-activated nanomaterial TiO2 coating for cleaning air which comes into contact with the surfaces of the coating. UV LED light sources are arranged to emit light to be incident on the surfaces to activate the coatings. There is a large surface for impingement of air on the coatings due to a grille arrangement of the substrates, and the LED-emitted UV light being incident at acute angles on the grille honeycomb structure.
1 . An air sanitizer comprising:
a housing with an air inlet and an air outlet;
substrates coated with a photo-catalytic coating for cleaning air which comes into contact with surfaces of the photo-catalytic coating, and
a light source comprising LEDs arranged to emit light to be incident on said surfaces to activate the photo-catalytic coating,
wherein:
the substrates are arranged as at least one grille,
there is an upstream grille and a downstream grille in a direction of air flow; and
the LEDs are mounted between said upstream and downstream grilles to emit light across an air flow direction to include the upstream and downstream grilles in the LED fields of emission,
the LEDs are arranged to emit light which is directly incident on some of said surfaces of the photo-catalytic coating, and indirectly incident by way of reflection on other surfaces of the photo-catalytic coating,
the surfaces on the substrates are substantially orthogonal to an optical axis of the light source, and are spaced from said optical axis so that diverging light is directly incident on at least some of the surfaces and at least some reflect to be incident on other substrate surfaces; and
the light emission from the LEDs is at an acute angle to orthogonal to an air flow path between the substrates.
2 . The air sanitizer as claimed in claim 1 , wherein the light source is a UV light source and the photo-catalytic coating comprises TiO 2 ; and wherein at least some of the LEDs emit with a wavelength in the range of 320 nm to 440 nm; and wherein the LEDs include LEDs of different wavelengths.
3 . The air sanitizer as claimed in claim 1 , wherein the substrates are in the form of a mesh having an array of air flow conduits extending substantially in an air flow direction; and wherein at least some of the conduits are polygonal in cross-sectional shape.
4 . The air sanitizer as claimed in claim 1 , wherein the substrates are in the form of a mesh having an array of air flow conduits extending substantially in an air flow direction; and wherein at least some of the conduits are polygonal in cross-sectional shape; and wherein at least some of the conduits are hexagonal, providing a honeycomb structure.
5 . The air sanitizer as claimed in claim 1 , wherein the substrates have a thickness in the range of 5 μm to 25 μm; and wherein the substrates are separated by an internal air flow path in the range of 5 cm to 50 cm.
6 . The air sanitizer as claimed in claim 1 , wherein the air sanitizer is adapted for stand-alone operation, comprising at least one fan mounted upstream of said substrates.
7 . The air sanitizer as claimed in claim 1 , wherein the air sanitizer is adapted for stand-alone operation, comprising at least one fan mounted upstream of said substrates; and wherein the air sanitizer comprises a particulate filter upstream of said substrates.
8 . The air sanitizer as claimed in claim 1 , wherein the air sanitizer is adapted for stand-alone operation, comprising at least one fan mounted upstream of said substrates; wherein the air sanitizer comprises a particulate filter upstream of said substrates; and wherein the particulate filter has a cone shape, mounted symmetrically about a longitudinal axis of air flow and narrowing in an air flow downstream direction.
9 . The air sanitizer as claimed in claim 1 , wherein the air sanitizer is adapted for stand-alone operation, comprising at least one fan mounted upstream of said substrates; and wherein the air sanitizer comprises a sanitizer inlet which is annular around an air flow longitudinal axis.
10 . The air sanitizer as claimed in claim 1 , wherein the air sanitizer is adapted for stand-alone operation, comprising at least one fan mounted upstream of said substrates; and wherein the air sanitizer comprises a sanitizer inlet which is annular around an air flow longitudinal axis; and wherein the sanitizer inlet is formed by a gap between a base and a housing main body.
11 . The air sanitizer as claimed in claim 1 , wherein the air sanitizer is adapted for stand-alone operation, comprising at least one fan mounted upstream of said substrates; and wherein the air sanitizer comprises a sanitizer inlet which is annular around an air flow longitudinal axis; and wherein there are a plurality of fans arranged around and/or on a longitudinal air flow axis; and wherein the air outlet is annular around an air flow longitudinal axis.
12 . The air sanitizer as claimed in claim 1 , wherein the air sanitizer is adapted for stand-alone operation, comprising at least one fan mounted upstream of said substrates; and wherein the air sanitizer comprises a sanitizer inlet which is annular around an air flow longitudinal axis; and wherein the air sanitizer comprises a sub-assembly of components which are interconnected and removable from the housing, said sub-assembly of components comprising a fan, a filter, said LEDs, and said substrates; and the sub-assembly of components is interconnected by a plurality of arms which extend parallel to a housing longitudinal axis.
13 . The air sanitizer as claimed in claim 1 , said substrates comprise a plurality of spaced-apart substrates, wherein the air sanitizer is adapted for stand-alone operation, comprising at least one fan mounted upstream of said substrates; and wherein the air sanitizer comprises a sanitizer inlet which is annular around an air flow longitudinal axis; and wherein a sub-assembly of components comprises at least one bracket which maintains an axial separation between said plurality of spaced-apart substrates and also a gap between said plurality of said spaced-apart substrates and a housing internal surface.
14 . The air sanitizer as claimed in claim 1 , wherein the air sanitizer is adapted for stand-alone operation, comprising at least one fan mounted upstream of said substrates; and wherein the air sanitizer comprises a sanitizer inlet which is annular around an air flow longitudinal axis; and wherein the LEDs are mounted to emit UV light incident on the substrates and also on a housing internal surface for reflection from said housing internal surface to the substrates.
15 . An air sanitizer comprising:
a housing with an air inlet and an air outlet;
substrates coated with a photo-catalytic coating for cleaning air which comes into contact with surfaces of the photo-catalytic coating, and
a light source comprising LEDs arranged to emit light to be incident on said surfaces to activate the photo-catalytic coating,
wherein the air sanitizer has a substantially rectangular box shape, with a depth dimension which is less than a width dimension, and the width dimension is less than a length dimension, and the LEDs are mounted to emit across the width dimension and the substrates are mounted for air flow through the depth dimension; and wherein the air sanitizer comprises mounting fixtures for mounting to a cooler with a fan,
wherein:
the substrates are arranged as at least one grille,
there is an upstream grille and a downstream grille in a direction of air flow; and
the LEDs are mounted between said upstream and downstream grilles to emit light across an air flow direction to include the upstream and downstream grilles in the LED fields of emission,
the LEDs are arranged to emit light which is directly incident on some of said surfaces of the photo-catalytic coating, and indirectly incident by way of reflection on other surfaces of the photo-catalytic coating,
the surfaces on the substrates are substantially orthogonal to an optical axis of the light source, and are spaced from said optical axis so that diverging light is directly incident on at least some of the surfaces and at least some reflect to be incident on other substrate surfaces; and
the light emission from the LEDs is at an acute angle to orthogonal to an air flow path between the substrates.
16 . A cabinet or display case comprising a housing for supporting shelves for placement of products, a cooler with a fan for circulating air and delivering cooled air around said products, and an air sanitizer mounted in an air path to or from the cooler, wherein said air sanitizer comprises:
a housing with an air inlet and an air outlet;
substrates coated with a photo-catalytic coating for cleaning air which comes into contact with surfaces of the photo-catalytic coating, and
a light source comprising LEDs arranged to emit light to be incident on said surfaces to activate the photo-catalytic coating,
wherein the air sanitizer has a substantially rectangular box shape, with a depth dimension which is less than a width dimension, and the width dimension is less than a length dimension, and the LEDs are mounted to emit across the width dimension and the substrates are mounted for air flow through the depth dimension; and wherein the air sanitizer comprises mounting fixtures for mounting to the cooler with the fan,
wherein:
the substrates are arranged as at least one grille,
there is an upstream grille and a downstream grille in a direction of air flow; and
the LEDs are mounted between said upstream and downstream grilles to emit light across an air flow direction to include the upstream and downstream grilles in the LED fields of emission,
the LEDs are arranged to emit light which is directly incident on some of said surfaces of the photo-catalytic coating, and indirectly incident by way of reflection on other surfaces of the photo-catalytic coating,
the surfaces on the substrates are substantially orthogonal to an optical axis of the light source, and are spaced from said optical axis so that diverging light is directly incident on at least some of the surfaces and at least some reflect to be incident on other substrate surfaces; and
the light emission from the LEDs is at an acute angle to orthogonal to an air flow path between the substrates.
17 . The cabinet or display case as claimed in claim 16 , wherein the air sanitizer is mounted at an inlet of the cooler, and wherein the cooler and the air sanitizer are in a chamber underneath a product volume, being separated by a floor.