Patent Number: 
Section: claims

1. A non-invasive UV light disinfectant apparatus for a fluid medium, comprising a housing having a pair of upstanding end walls, a pair of upstanding sidewalls between the end walls, a bottom wall and an apertured toy wall closed by a cover, a UV chamber formed within the housing between the pair of upstanding sidewalls, one or more capillary tube assemblies that extend through the UV chamber between and supported on the upstanding sidewalls and through which the fluid medium flows through the UV chamber for exposure to UV light, wherein each of the one or more capillary tube assemblies includes multiple UV light-transmissive Hillary tubes extending between the upstanding sidewalls across the UV chamber with open ends of adjacent capillary tubes connected in fluid medium flow relation by a respective U-bend connector tubing that resides outside of the UV chamber and that redirects the fluid medium to flow back through the next adjacent capillary tube in the opposite direction from the direction in which the fluid medium flowed in the preceding adjacent capillary tube, whereby each of said one or more capillary tube assemblies provides multiple passes of the same fluid medium through the UV chamber, and a UV light source disposed on one of the upstanding end walls so as to reside in the UV chamber to expose the fluid medium in the UV light-transmissive capillary tubes to UV light. 2. The apparatus of claim 1 having light reflecting surfaces that define the UV chamber. 3. The apparatus of claim 1 wherein the multiple capillary tubes each comprises transparent glass. 4. The apparatus of claim 1 including a fan disposed on the apertured ton wall outside of the UV chamber to draw air through apertures in one of the end walls, through the UV chamber, and through an air exhaust aperture in the top wall to control temperature in the UV chamber. 5. The apparatus of claim 4 including an air deflector adjacent an end of the UV chamber. 6. The combination of a biofilm reactor that receives the fluid medium from the UV disinfectant apparatus of claim 1. 7. The combination of claim 6 wherein the biofilm reactor is a planar flow cell. 8. The apparatus of claim 1 wherein the open ends of the adjacent capillary tubes are received and supported in respective tubing reducer fittings received in respective holes in the upstanding sidewalls.