Abstract
A sterilizer apparatus for treating liquids or gasses, utilizing the low wavelength, ozone producing, vacuum UV wavelengths, utilizing a novel reactor chamber built around an ultraviolet lamp operating in the presence of either a vacuum or an oxygen-free medium.
Claims
1. A method to enhance the disinfection process of an intended medium and make disinfection more efficient by using low wavelength vacuum UV (VUV) devices, which comprises: a. an inner germicidal un-doped quartz emitter ultraviolet lamp as source of UV radiation; b. an elongated quartz sleeve, extending around the ultraviolet lamp to protect the lamp to come into contact with the medium under treatment; c. an outer tubular duct (UV reactor) containing an inlet and an outlet port at or close to its opposite ends to allow for easy flow of the medium under treatment constructing the UV reactor chamber; and, d. an internal reactor environment free of oxygen.
2. The medium treatment apparatus described in claim 1 further utilizing the oxygen dissociation ozone production process properties of VUV wavelengths in the intended medium, typically, but not limited to, water, for the purposes of enhanced oxidation based disinfection and/or contaminant destruction set up by the UV photo-catalytic hydroxyl radical (OH) based advanced oxidation process (UV-AOP).
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 represents a typical UV Reactor used for biological sterilization of a liquid using UV radiation.
[0013] FIG. 2 illustrates the typical microorganism's DNA sensitivity curve (200) and the germicidal spectral output of a doped quartz low pressure UV lamp (201). All energy absorbed within the sensitivity curve area (200) has a germicidal effect on the organism. For example it would take five times the amount of energy at approximately 290 nm to have the equivalent germicidal effect on an organism as one unit at 254 nm. All electromagnetic energy within the sensitivity curve (200) is accumulative in the DNA distortion process. In a polychromatic UV lamp (medium pressure UV lamp) where multiple wavelengths are emitted within the DNA sensitivity curve region, all these multiple energy outputs are accumulated at the inactivation levels depending on their wavelengths' into a total effective germicidal dose delivery. Although the peak energy absorption (160%) of the DNA occurs in the very short wavelengths around 200 nm, below 220 nm the wavelengths are trapped by the lamp manufacturers deliberate quartz emitter doping process to prevent the ozone formation (Germicidal UV inhibitor).
[0014] FIG. 3 illustrates the effective DNA absorption region (300) with a UV lamp that has doped quartz material to block all emissions below 220 nm. Any energy band emitted within the area below this curve (301) will have DNA germicidal distortion effects on the organism.
[0015] FIG. 4 illustrates the effective DNA absorption region (400) with a UV lamp that has un-doped quartz material that does not block any emissions below 220 nm. Any energy band emitted within the area below this curve (401) will have DNA germicidal distortion effects on the organism.
[0016] FIG. 5 represents the complete UV Reactor incorporating the novel structure which is the object of this invention. An externally sealed electrical connection (500) is provided as a means to make the electrical connection to the UV lamp (506). A sealed gas nipple (501) is provided as a means to extract the air within the internal parts of the reactor. A system of O-rings (502) is provided in order to maintain an external seal for the reactor and maintain the internal environment from external air ingress. A medium inlet pipe (503) and outlet pipe (505) join the main reactor body (504) and provide a medium flow path means through the reactor in order to effect disinfection on said medium. A quartz sleeve (507) provides an optical path and a mechanical barrier between the medium (gas or fluid) and the internal structure of the reactor. A system of O-rings (508) provides sealing between the quartz sleeve (507) and the reactor (504) to prevent medium ingress into the internal reactor system.
[0017] FIG. 6 represents the medium (601) flow path (602) through the reactor (600).
[0018] FIG. 7 represents the air extraction (702) pathway through the gas nipple, attached to the UV reactor (700) which causes a reactor internal structure vacuum (701). The oxygen depleted (vacuum) area (703) between the UV lamp and quartz sleeve (704) forms the basis of the novel invention.
[0019] FIG. 8 represents an alternative method for providing an oxygen depleted internal reactor environment. At least one gas nipple is used to allow an oxygen free medium to enter the reactors' (800) internal air purged environment, or a second gas nipple is used to allow the medium flow path (801) to enter the reactors' internal environment and then leave at a remote point (802). The methodology of the medium flow path will be to exhaust the ambient oxygen rich air inside the reactor and replace it with an oxygen free medium, nitrogen for example. The absence of oxygen in the internal region of the reactor between the lamp and quartz sleeve forms the basis of this invention.
DETAILED DESCRIPTION OF THE INVENTION
[0020] Certain aspects and features of the present disclosure relate to a UV sterilization apparatus including an oxygen depleted internal environment to enhance the disinfection process by making it highly efficient with the use of low wavelength producing UV lamps.
[0021] Additional aspects relate to the low UV wavelength production of hydroxyl radicals at the surface of the quartz sleeve where the medium, with dissolved oxygen, contacts it. The low wavelength UV electromagnetic energy dissociates the dissolved oxygen (O.sub.2) in the medium, typically but not limited to water, and forms unstable Hydroxyl (OH) radicals. The OH radicals scavenge and oxidize unwanted and complex dissolved contaminants. This feature forms the method of the novel Advanced Oxidation Process (AOP) of this invention. The interaction of OH radicals and the germicidal UV energy form the photo-catalytic basis of UV-AOP.
[0022] In order to utilize all of the electromagnetic energy produced by a non-doped quartz emitter UV lamp, all the air around it must be depleted to form a vacuum.
[0023] FIG. 4 represents the energy absorption curve of DNA; from this it is clear that the lower UV wavelengths have the highest potential germicidal effect (DNA distortion) on the pathogens', however under circumstances, outside the operation of this invention, in an environment where an un-doped quartz emitter UV lamp surrounded by oxygen is used, ozone (O.sub.3) is produced by the sub-200 nm UV wavelengths. Ozone forms a natural UV barrier which envelops the area between the lamp and quartz sleeve and prevents (shields) the low and germicidal UV wavelengths from reaching the medium to be disinfected.
[0024] In this disclosure, either by internal reactor air removal (FIG. 7), or replacement of surrounding air, with an oxygen free medium (FIG. 8); all the UV wavelengths which are emitted from un-doped quartz emitter style UV lamps are able to travel freely to and beyond the quartz sleeve that surrounds it.
