FIELD OF THE INVENTION

This invention relates to the field of in- flow fluid disinfection, and more specifically to ultraviolet (UV) fluid disinfection, for example using UV-C radiation.

BACKGROUND OF THE INVENTION

Fluid disinfection to obtain a fluid that contains fewer harmful bacteria is widely regarded as an important process. This becomes even more prescient when the fluid in question is, for example, water that is being prepared for human or animal consumption.

UV radiation was first used for the purpose of fluid disinfection on an industrial scale in the 1980's; it has numerous advantages over other methods such as chlorination, especially when the fluid is water that is to be consumed. UV radiation is also widely known for use in the disinfection other fluids such as air.

UV radiation does not affect the PH, composition, taste or odor of the fluid that has been disinfected. The disinfection of the fluid is achieved by deactivating the bacteria, viruses and microbes by altering their DNA through UV radiation exposure. Further advantages of the use of UV to disinfect fluids are simple installation, less maintenance requirements and space efficiency.

The use of UV to treat a fluid eliminates the need to use a chemical process thus removing the risk of a chemical smell or taste in the fluid after disinfection has been completed.

Current UV water disinfection technologies mainly use mercury discharge lamps to provide the UV radiation that disinfects the water. Generally these systems provide UV radiation to fluids flowing past them. The level of disinfection depends on the total effective UV dose received by the fluid. The higher the dose, the higher the level of disinfection, or the lower the amount of remaining pathogens.

Ultraviolet radiation disrupts the DNA of microbes and thereby prevents reproduction. Without reproduction, the microbes become far less of a danger to health. As such, UV radiation is a mutagen, that is to say, UV radiation creates mutations within the structure of DNA.

UV-C radiation, in the short wavelength range of 100-280 nm, acts on thymine, one of the four base nucleotides in DNA. When a photon of UV radiation is absorbed by a thymine molecule that is adjacent to another thymine within a DNA strand, a covalent bond or dimer between the molecules may be created, this is different to the normal structure of DNA wherein the bases always pair up with the same partner on the opposite strand of DNA. This causes a bulge to occur between the two bases, the bulge prevents enzymes from "reading" the DNA and copying it, thus neutering the microbe.

Recently, UV-C LEDs have become available. Their UV-C output power is still low compared to mercury lamps, but LEDs have the advantages of a small size and the ability to generate directional radiation. When UV-C radiation from a UV-C LED is coupled into a UV-C transparent tube filled with a fluid such as water, the directional radiation from the UV-C LED may propagate along the tube via total internal reflection. This allows the fluid to receive a higher effective dose of UV-C radiation, leading to a more effective use of the radiation.

However, considering current LED performance levels, the total effective dose of UV radiation in the fluid is limited. Furthermore, utilizing total internal reflection to deliver a higher effective dose requires the use of a long tube. A long tube such as this may require an unrealistic amount of space, especially when used in a consumer appliance. In this case the tube may be bent in order to save space, however, this requires an additional processing step to bend the tube and results in a less robust product as the bent tube is more vulnerable. SUMMARY OF THE INVENTION

The invention is defined by the claims.

According to examples in accordance with an aspect of the invention, there is provided an interconnection for a modular in-flow fluid purification system, comprising:

a channel having a first end and a second end, wherein the second end of the channel is perpendicular to the first end with an elbow between the first and second ends;

a first port at the first end of the channel;

a UV radiation source positioned at the elbow to allow UV radiation to enter the interconnection at the elbow directed towards the first port; and

a second port at the second end of the channel. This arrangement allows the fluid being purified to pass through the interconnection unhindered, whilst simultaneously introducing the purifying UV radiation to said fluid. By introducing the UV radiation into the fluid within the interconnection, the need for separate fluid purification components is eliminated. Introducing the UV radiation into the fluid at the elbow allows the radiation to pass into the interconnection and through the first port. An optical axis of the output of the UV radiation source is for example parallel with a central axis around which the first port extends, so that the UV radiation is able to pass perpendicularly through the first port (and therefore parallel with a passageway connected to the first port).

In one arrangement, the first port is adapted to receive a pipe. This means that the interconnection may be used in conjunction with a pipe within a fluid purification system.

The UV radiation source for example comprises a UV LED arrangement. The use of a UV LED arrangement allows for a more compact purifying mechanism, when compared to a purifying mechanism that requires a mercury lamp, meaning that the interconnection itself may also be compact. The UV radiation source may for example produce UV-C radiation.

In some designs, the UV radiation source is held by the interconnection. This removes the need for separate components to hold the UV radiation source in the correct position.

According to examples in accordance with an aspect of the invention, there is provided a modular in-flow fluid purification system, comprising:

a plurality of interconnections as defined above, each connected in series with alternating port sequence so as to define adjacent pairs of first ports and adjacent pairs of second ports; and

a pipe connected between each adjacent pair of first ports.

This arrangement allows the fluid to pass through multiple interconnections, which in turn provide multiple doses of UV radiation. In cases where a high level of purification is needed, many interconnections may be used in order to provide a high effective dose ofUV radiation. Conversely, if a high level of disinfection is not necessary, fewer interconnections may be used in order to provide a lower effective dose of UV radiation.

In further or other embodiments, the pipes connected between adjacent pairs of first ports may be straight pipes. Straight pipes are readily commercially available and do not require additional processing to fit into the system. Furthermore, the use of straight pipes results in a more robust system when compared to other arrangements such as bent pipes.

In one arrangement, adjacent pairs of second ports may be directly connected together. This allows adjacent interconnections to occupy a minimal amount of space without requiring an additional pipe connection that does not contribute to the overall purifying process.

In some designs, the interconnections are positioned to form a stack of pipes. This allows for multiple stages of purification to occur in succession meaning that the fluid may be purified to the required level before entering the next element of the system. The stack may form a two-dimensional or three-dimensional array of pipes, so that there is an efficient use of space.

The ability to use the interconnections to form two-dimensional and/or three dimensional arrays of pipes allows for the system to be constructed in a wide variety of forms to meet different required levels of disinfection or different spatial limitations.

The pipes used in the system may be constructed from a UV transparent material, such as glass or quartz. By constructing the pipe from a UV transparent material, it is possible to achieve total internal reflection of the UV radiation within the pipe. In addition the UV radiation source may be adapted to provide directional UV radiation for travelling along the pipe via total internal reflection. This allows for the fluid to receive a longer exposure time to the UV radiation resulting in a higher level of purification to be achieved without the need for additional UV radiation sources. The pipes used in the system may straight in order to provide a more robust purification system.

The interconnection may comprise a seal for sealing the end of the pipe. The system may for example be assembled as a simple push fit or screw fit arrangement.

The system may comprise a water purification system, however, in other embodiments the system may comprise a purification system for another fluid, for example air.

According to examples in accordance with an aspect of the invention, there is provided a purification method for a modular in- flow fluid purification system, which system comprises a plurality of interconnections connected in series, each interconnection comprising:

a channel having a first end and a second end, wherein the second end of the channel is perpendicular to the first end with an elbow between the first and second ends;

a first port at the first end of the channel; a UV radiation source positioned at the elbow to allow UV radiation to enter the interconnection at the elbow directed towards the first port; and

a second port at the second end of the channel,

wherein the method comprises:

providing a fluid flow along a series of the interconnections, arranged with alternating port sequence so as to define adjacent pairs of first ports and adjacent pairs of second ports and with a pipe connected between adjacent pair of first ports; and

providing UV illumination using the UV radiation sources thereby to purify the fluid flow in the pipes.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples of the invention will now be described in detail with reference to the accompanying drawings, in which:

Fig. 1 shows a cross section of an interconnection;

Fig. 2 shows a system comprising a plurality of the interconnections shown in

Fig. 1 ;

Fig. 3 shows an example embodiment of the system in Fig. 2 arranged into a two-dimensional array of pipes;

Fig. 4 shows an example embodiment of the system in Fig. 2 arranged into a three-dimensional array of pipes;

Fig. 5 shows an embodiment of the system in Fig. 2 adapted to allow the propagation of UV radiation along a pipe via total internal reflection; and

Fig. 6 shows a method of the invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

The invention provides an interconnection for a modular in- flow fluid purification system which includes a channel with a first and second end with an elbow between the first and second end. A UV radiation source is placed at the elbow to allow UV radiation to enter the interconnection.

Figure 1 shows an interconnection 10 which comprises a channel 12 having a first end 14 and a second end 16, wherein the second end 16 of the channel 12 is

perpendicular to the first end 14 with an elbow 17 between the first and second ends. A first port 18 is at the first end and a second port 19 is at the second end. A UV radiation source 20 is positioned at the elbow 17 to allow UV radiation 21 to enter the interconnection at the elbow directed towards the first port 18. In other words, the UV radiation source is positioned so that once the UV radiation has entered the interconnection; it may then leave the interconnection via the first port.

The interconnection is designed to allow fluid to flow along the channel 12 between the first port 18 and the second port 19. The interconnection is adapted to allow UV radiation to enter the interconnection without hindering the flow of the fluid. The interconnection is further adapted to direct the UV radiation towards the first port 18 of the interconnection.

In the example shown in Figure 1, the first port 18 is adapted to receive a pipe

22.

The first port 18 may be threaded in order to receive a pipe with similar threading, but in other arrangements, alternative methods for receiving a pipe may be used, for example a clamping mechanism. Both the first and second ports may be adapted to receive a pipe.

UV radiation 21 passes from the UV radiation source 20 into the interconnection. The UV radiation may then pass through the first port 18 and into the pipe 22. It is directed parallel to the elongate axis of the pipe 22 and hence parallel to a central axis of the first port 18. The UV radiation source for example comprises a UV LED arrangement, having an optical axis which is the general light output direction. This allows directional UV radiation to be introduced to the system meaning that a higher proportion of the UV radiation will travel along the pipe 22 compared to an arrangement that comprises a non-directional UV radiation source (for example a mercury lamp). This directional control for example enables total internal reflection to be used as the mechanism for transferring the light along the pipe 22. The UV radiation emitted by the UV radiation source may be UV-C radiation. Thus, the UV radiation emitted by the UV radiation source may possess a wavelength in the range 100-280 nm.

The UV radiation source 20 may be held by the interconnection, so that an external mechanism for holding the UV radiation source in the correct place is not needed. This means that the interconnection may be used independently within a system without the constraints of an external holding mechanism. Further to this, the UV radiation source is less at risk of emitting the UV radiation in a less optimal direction if there is a predetermined holder within the interconnector. In addition, the holding of the UV radiation source by the interconnection may shield the UV radiation source in some way from the surrounding environment. This shielding may prevent dust from coating the UV LED(s) over time that may reduce the overall effectiveness of the UV LED(s) by blocking the emitted UV radiation.

Figure 2 shows an example of a system 30 comprising a plurality of interconnections 10 as shown in Figure 1 , alternatively, it can be a single u-shaped interconnection wherein the first port and the second port are parallel with each other. In the embodiment shown the interconnections are connected in series with an alternating port sequence. This means that there are adjacent pairs of first ports 18 and second ports 19, wherein a pipe 22 is connected between each adjacent pair of first ports 18.

In the example shown in Figure 2, the adjacent pairs of second ports 19 are directly connected together. By directly connecting the second ports of the interconnections the need for an adjoining length of pipe between the two ports is eliminated. This greatly improves the efficiency of the purifying system as there is a smaller proportion of the fluid flow that is not receiving the purifying UV radiation.

The interconnections 10 may be positioned in the system 30 so as to form a stack of pipes 22. The stack of pipes may be expanded or reduced by adding or removing interconnections. By expanding the stack of pipes, a higher effective dose of UV radiation will be introduced into the fluid, leading to a higher level of purification. Where only a low level of fluid purification is required, the stack of pipes may be reduced as a lower effective dose of UV radiation is needed. This modular construction allows the same components to be used in a wide variety of different systems that require fluid purification. The pipes used in the system may be any length as the interconnection's function does not depend on pipe length. Removing the need for a predetermined pipe length from the system further expands its modular capabilities. In some embodiments, the pipes used in the system may be straight pipes. Straight pipes are readily available from commercial retailers and may not require any additional processing to be implemented into the system. The use of straight pipes in the system also results in a more robust product.

The interconnections may be connected together and to the pipes in any rotational orientation. For example, the interconnections at the opposite ends of a pipe may be rotated relative to each other. For example, the interconnections at opposite ends of a pipe may be at 90 degrees or 180 degrees to each other. Similarly, where two interconnections are directly connected together (at their second ports) they may have different relative angular orientations giving flexibility in the overall resulting shape. In this way, a meandering block of pipes may be formed so that an array of parallel pipes is arranged within a cuboid outer volume. This provides an efficient use of space.

Figure 3 shows an example of the system in Figure 2, wherein the stack of pipes has been arranged into a two-dimensional array of pipes 40. In the embodiment shown, the two-dimensional array of pipes may be extended through the use of additional interconnections. A system such as this may be used in a device that requires the purification process to occur in a thin space. A 'thin' space should be understood to mean any space that is limited in size along any one of the three axes that define a three-dimensional space.

Figure 4 shows an example of the system in Figure 2, wherein the stack of pipes has been arranged into a three-dimensional array of pipes 50. In the embodiment shown, the three-dimensional array of pipes may be extended in any direction through the use of additional interconnections. This system is applicable to a wide variety of situations as the array may be altered to fit into any desired three-dimensional space.

Figure 5 shows an embodiment of the system shown in Figure 2, wherein the system 30 is designed to allow the UV radiation 21 to propagate along the pipe via total internal reflection 62. In order to achieve total internal reflection the pipe 22 may be constructed from a UV transparent material such as glass or quartz. In further embodiments the pipe may comprise additional materials such as a reflective material on the outer layer of the UV transparent material.

In the embodiment shown, the UV radiation 21 may propagate along the length of the pipe 22 via total internal reflection 62. This means that the fluid flow 64 being purified is exposed to the UV radiation 21 for a longer time thereby allowing the fluid to receive a higher effective dose of UV radiation. This allows a higher level of fluid purification to be reached without the need for additional UV radiation sources, leading to lower energy consumption.

It has been calculated that a 60mW UV-C LED in a 12cm pipe yields a UV-C dose of approximately 16mJ/cm ² . A valid configuration for the case where a 40mJ/cm ² dose is required would comprise four pipes of length 8cm with eight UV-C LEDs of power 30mW.

Figure 6 shows a method of the invention.

In step 70, fluid is provided to a system comprising a series of interconnections. The interconnections are connected in series with an alternating port sequence so as to define adjacent pairs of first ports and adjacent pairs of second ports. Pipes are connected between each pair of adjacent first ports. In step 72, UV radiation is provided into the fluid at each interconnection by the UV radiation source such that the UV radiation is directed towards the first port of the interconnection.

In step 74, the UV radiation may propagate along the pipes connected between the adjacent pairs of first ports via total internal reflection.

The system may comprise four to twenty interconnections, wherein the first 18 and second 19 ports of the interconnections may be between 10 - 50mm in diameter. The interconnections may for example be constructed from silicone.

All of the embodiments discussed above disclose a L-shaped interconnections but it should be understood that other interconnection shapes can be utilized, for example U shape, twisted elbow interconnection etc. etc.

Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.