Apparatus for ultraviolet disinfection of water

A water treatment and disinfection apparatus is provided, which has separate flow channels to allow entry and exit of separate streams of water through the apparatus, with an ultraviolet light source emitting rays through first and second ultraviolet transparent sleeves having an annular space therebetween to form an inner flow channel and an annular space between the second sleeve and an ultraviolet resistant pressure vessel. The apparatus of the invention is specially suited for disinfection of water in reverse osmosis water purification systems, whereby pre-reverse osmosis (untreated) water and post-reverse osmosis (treated) water are directed inside the apparatus of the invention to be separately and simultaneously disinfected by ultraviolet rays and again separately exit the apparatus.

BACKGROUND OF THE INVENTION 
This invention generally relates to water treatment and disinfection, and 
particularly to a device that utilizes ultraviolet ("UV") rays to 
disinfect water. More specifically, the device of this invention addresses 
the need for UV disinfection related to water treatment processes such as 
those that use reverse osmosis or filtration, where it is important to 
disinfect the water both before and after the water treatment process. 
Water purification and disinfection units are well known in the art. Some 
use mechanical filtration to remove impurities suspended as particles in 
the water, while others use a combination system, such as mechanical 
filtration and ultraviolet rays to purify, sterilize and disinfect the 
water. Other water treatment systems exist, which use well known reverse 
osmosis technology to purify the water. In various water treatment 
processes, such as those using reverse osmosis or other filtration 
systems, it would be desirable and important to disinfect the water both 
before and after the water treatment process. As an example, disinfection 
of the pre-reverse osmosis (untreated) water is important because bacteria 
present in the water can cause biofouling of the reverse osmosis membrane, 
and disinfection of the post-reverse osmosis (treated) water is important 
because of the possibility that bacterial contamination has been 
introduced during the reverse osmosis process or during the storage of the 
treated water. In disinfecting the untreated and treated water, it would 
also be desirable to be able to maintain those bodies of water separate 
and apart from each other during the disinfection process. 
The present invention satisfies these needs by providing a water treatment 
apparatus and process which utilizes separate chambers for flow of 
untreated and treated water which are disinfected by ultraviolet rays that 
can pass through one chamber to the other. The flow capacity of the device 
of the invention is not limited, and can be adapted for manufacture in 
various sizes to meet the particular flow rate needs of the desired water 
treatment process. The size of the device of the invention can be varied 
according to the available technology for producing the desired UV light 
intensity. 
SUMMARY OF THE INVENTION 
In accordance with the invention, a water treatment apparatus is provided, 
wherein an ultraviolet (UV) light source is surrounded by independent and 
separate chambers for flow of separate streams of water, with the UV light 
reaching and disinfecting the water in those chambers. 
In the preferred form, a UV light source is housed inside a first UV 
transparent tube or sleeve, which is in turn housed inside a second UV 
transparent tube or sleeve, with an annular space between the first and 
second sleeves. The first sleeve is closed at one end and sealed at the 
other so as to prevent water or other liquid from coming into direct 
contact with the UV light source which is connected to a power source. The 
second UV transparent sleeve is further housed within a pressure vessel or 
container that is resistant to UV light, with an annular space between the 
second sleeve and the pressure vessel. In this manner, an inner flow 
channel is formed between the first and second UV transparent sleeves, and 
an outer flow channel is formed between the second sleeve and the pressure 
vessel. The upper and lower portions of the two flow channels are sealed 
with each channel having an inlet port and an exit port to allow separate 
streams of water to enter the channels, be treated with UV rays, and then 
exit the channels. 
With this construction, treated water can enter the inner flow channel 
through its inlet port, and untreated water can enter the outer channel 
through its inlet port. After being disinfected by the UV rays passing 
through the bodies of water in the separate channels, the UV treated 
streams of water exit through the exit ports. The flow pattern whereby the 
treated water flows through the inner channel and the untreated water 
flows through the outer channel is preferred, because by having the UV 
rays first pass through the treated/cleaner water in the inner channel, UV 
transmission will not be inhibited by the impurities in the untreated 
water in the outer channel. According to alternative embodiments of the 
invention, other flow patterns with various flow channel configurations 
can also be utilized. 
Other features and advantages of the present invention will become more 
apparent from the following detailed description, taken in conjunction 
with the accompanying drawings which illustrate, by way of example, the 
principles of the invention.

DETAILED DESCRIPTION OF ALTERNATIVE EMBODIMENTS 
As shown in exemplary drawings, a water treatment apparatus referred to 
generally by the reference numeral 10 is provided with an ultraviolet (UV) 
lamp 12, e.g., an ozone or non-ozone lamp, that connects to a power source 
(not shown) via a connecting plug 14 and wire 16. A terminal 18 is 
provided with the customary power prongs 18 which go into electrical 
contacts in plug 14. 
The UV lamp 12 is housed inside a first UV transparent cylinder or sleeve 
22, which is sized slightly larger in diameter than the outside diameter 
of the UV lamp 12 and has a closed lower end 24 and an open upper end 26. 
The first UV transparent sleeve 22 is housed within a second UV 
transparent cylinder or sleeve 28, with an annular space therebetween so 
as to create an inner flow channel 30. The first sleeve 22 and the second 
sleeve 28 are preferably made of quartz, but can also be made of other UV 
transparent materials. A pressure vessel 32, preferably made of stainless 
steel, or alternatively of any other UV resistant material suitable to 
withstand pressure, is provided to house and contain the entire assembly 
of the first sleeve 22 and the second sleeve 28, such that there is an 
annular space between the second UV transparent sleeve 28 and the pressure 
vessel 32, which forms a outer flow channel 34. Accordingly, in this 
manner, two independent channels for passage of water are created: an 
outer channel 34, defined by the space between the inside wall of the 
pressure vessel 32 and the outside wall of the second UV transparent 
sleeve 28; and an inner channel 30, defined by the space between the 
inside wall of the second UV transparent sleeve 28 and the outside wall of 
the first UV transparent sleeve 22. 
The upper end of the apparatus is provided with a top plug unit 36 to close 
off the top openings in the outer channel 34, the inner channel 30, and 
the first UV transparent sleeve 22. As shown in FIGS. 1, 2 and 3, the top 
plug unit 36 has a generally cylindrical shape with a larger diameter at 
its upper end 38 to frictionally fit inside the upper end 40 of the 
pressure vessel 32, and a smaller diameter at its lower end 42 which 
extends over the second UV transparent sleeve 28. A pair of O-rings 44 are 
located in a recess over the upper end 38 of the top plug unit 36 to seal 
against the pressure vessel 32, a pair of O-rings 44 are located between 
the lower end 42 of the top plug unit 36 to seal against the exterior of 
the second UV transparent sleeve 28, and a pair of O-rings 44 are also 
located between an interior portion of the top plug unit and the exterior 
of the first UV transparent sleeve 22. In this manner, the upper portions 
of the inner flow channel 30 and the outer flow channel 34 are sealed 
against the top plug unit. In addition, a centrally located hole or recess 
46 in the top plug unit 36 is sized slightly larger in diameter than the 
outside diameter of the first sleeve to allow the first sleeve 22 to 
extend inside the recess 46, as well as to allow the plug 14 to 
frictionally fit inside the top plug unit and connect to the power prongs 
20 of the UV lamp 12 and support the UV lamp 12 inside the first UV 
transparent sleeve 22. In this manner, the UV lamp 12 does not come into 
direct contact with any water entering the unit. Additionally, a top inner 
port 48 is provided in the top plug unit 36 to allow fluid communication 
between the outside of the apparatus and the inner flow channel 30, and a 
top outer port 50 in the top plug unit 36 allows fluid communication 
between the outside and the outer flow channel. Each of these two ports, 
48 and 50, is provided with a connection plug 52 which can be attached to 
a tube (not shown) directing water (or other fluid) supply lines to the 
apparatus of the invention. 
A similar bottom plug unit 54 is provided at the opposite end of the 
apparatus to close and seal the lower ends of the inner flow channel 30 
and the outer flow channel 34. As shown in FIG.3, the bottom plug unit 54 
also utilizes O-rings 44 to seal the plug unit against the interior of the 
pressure vessel 32 and against the exterior of the second UV transparent 
sleeve 28. Similarly, the bottom plug unit 54 is provided with a bottom 
inner port 56 to allow fluid communication between the outside of the 
apparatus and the inner flow channel 30, as well as a bottom outer port 58 
to allow fluid communication between the outside and the outer flow 
channel 34. In this manner, water or other fluid that is to be disinfected 
can be directed to enter the inner flow channel 30 and outer flow channel 
34 independently and separately, undergo UV disinfection, and exit the 
channels separately. The top and bottom plug units, 36 and 54, are 
preferably made of a moldable and machinable plastic, such as high density 
polypropylene, which is rust and corrosion resistant. Stainless steel may 
also be used, but is not as readily workable as plastic to machine the 
recess 46 for the first sleeve. 
Once the assembly of the first and second UV transparent sleeves and the 
top and bottom plug units is completed, the assembly is positioned inside 
the pressure vessel 32. The lower end of the pressure vessel 32 is 
slightly curved inward so as to prevent the assembly from sliding out of 
the pressure vessel. A retaining ring 60 is also provided between the top 
plug unit 36 and the interior of the pressure vessel to secure the 
assembly inside the pressure vessel so that it cannot become dislodged 
under water pressure. 
In the preferred embodiment of the invention, for example, in conjunction 
with a reverse osmosis water treatment system, where it is important and 
desirable to disinfect the water both before and after the water treatment 
process, the pre-reverse osmosis (untreated) water is directed through the 
top outer port 50 to enter the outer flow channel 34, and the post-reverse 
osmosis (treated) water can be directed through the top inner port 48 to 
enter the inner flow channel 30. Inside the separate water chambers, the 
pre-reverse osmosis and the post-reverse osmosis bodies of water remain 
separate, and are treated through exposure to the UV rays of the UV lamp 
12 which travel through the transparent first and second sleeves, 22 and 
28. After exposure to the UV rays and the resulting disinfection, the 
stream of water flowing through the outer channel 34 exits through the 
bottom outer port 58, and the stream of water flowing through the inner 
channel 30 exits through the bottom inner port 56. (It should be noted 
that, the flow direction through each of the inner and outer channels is 
reversible). This flow pattern is recommended because if the untreated 
water were to pass through the inner channel 30, it would inhibit the 
transmission of UV light into the outer channel 34 due to impurities in 
the untreated water. 
According to alternative embodiments of the invention, shown be way of 
example, in FIGS. 4 and 5, various water flow patterns may be utilized. 
For example, as opposed to two independent flows shown and discussed 
above, as shown in FIG. 4 (which only shows a schematic of the bottom end 
of the apparatus of the invention), the apparatus can be modified to 
achieve a single flow of water that passes by the UV light source two 
times, once inside the outer channel 34 and another time inside the inner 
channel 30. In this alternative embodiment, the two connection plugs 52 in 
the bottom plug unit 54 are eliminated, and the water the water is 
directed from the outer channel into the inner channel through a port 62 
located in the bottom plug unit 54. 
According to another alternative embodiment, shown by way of example in 
FIG. 5, a triple pass system can be used, whereby an additional flow 
channel can be added. This would require modification of the top plug unit 
36 and the bottom plug unit 54 so as to have three connection plugs on 
each of the top and bottom plug units; e.g., resulting in bottom inner 
port 56, bottom intermediate port 57 and bottom outer port 58, with a 
similar arrangement for the three top ports. This embodiment would also 
require the addition of a third UV transparent cylinder or sleeve 29 
positioned and spaced between the first sleeve 22 and the second sleeve 28 
so as to result in three flow channels; i.e., the inner flow channel 30, 
an intermediate flow channel 31, and the outer flow channel 34, each with 
independent water flows. A variation of this alternative embodiment (not 
shown) can also be used so that two of the flow channels are 
inter-connected to create two independent flows, one with a single pass 
and one with a double pass. Yet another variation of this alternative (not 
shown) can be used to accomplish a triple pass of a single flow of water. 
This variation would require connecting ports in the bottom plug unit 54 
similar to that shown in FIG. 4. The concept of various flow patterns with 
various number of passes by the UV lamp can be expanded as necessary to as 
many flow channels and passes as needed. 
The water treatment apparatus of the invention thus provides a versatile 
yet relatively simple device and process for simultaneous disinfection of 
separate streams of water or other fluid by ultraviolet rays. 
A variety of further modifications and improvements in and to the water 
treatment apparatus of the invention will be apparent to persons skilled 
in the art. Accordingly, no limitation on the invention is intended by way 
of the foregoing description and accompanying drawings, except as set 
forth in the appended claims.