Solid state longditudinal uv lamps for the disinfection of solids and liquid products

Abstract

The UV lamp comprises a conduit extending along a longitudinal axis of a support (e.g., rectangular aluminium tube 10). At least one of a plurality of LED chips 11 is disposed on each of at least two

Description

Field of the invention The present invention relates to UV lamps, in particular to UV lamps using LED chips for disinfecting solids and liquid products. Background Light emitting diodes (LEDs) have been commercially available for over 40 years and have mainly been used as indicators and in lighting products in the visible light spectrum. Recent technological developments have produced LEDs which emit light in the UV wavelengths, including the germicidal wavelengths of 220 nm to 280 nm, allowing them to kill microorganisms. The individual LEDs at these UV wavelengths are very low power devices (typically 0.01 to 0.1 W) and can require many thousands of devices to make a viable disinfection lamp, and therefore this approach can be impracticable on the grounds of both physical size and cost. UV LED chips are typically less robust than visible light LEDs; they can suffer from drawbacks which should be taken into consideration when designing a UV lamp in order to get good reliability and long life. A UV LED chip may be susceptible to static electricity which can quickly fail the chip by blowing the PN junction; precautions should therefore be taken when handling and testing the chips. UV LED chips can also be very sensitive to overvoltage and therefore the power supply for the chips should preferably take this into consideration. In LED technology, the efficiency of the device reduces as the wavelength gets shorter e.g. the conversion efficiency of power input to UV power output of a 265 nm LED is in the range 16% - 20% compared to 30% for a commonly used mercury arc lamp. It is an aim of the present disclosure to provide an improved UV lamp for applications in the UV disinfection markets. Summary of the invention Aspects of the disclosure are set out in the independent claims and optional features are set out in the dependent claims. Aspects of the disclosure may be provided in conjunction with each other and features of one aspect may be applied to other aspects. Embodiments of the disclosure aim to provide a UV lamp comprising any or all of the following features: a support, the support defining a conduit therein along a longitudinal axis of the support; and a plurality of LED chips configured to emit UV light; wherein the support comprises a plurality of external faces, and wherein each of at least two of the plurality of external faces comprises an LED chip of the plurality of LED chips thereon such that the LED chip is configured to emit UV light outwards with respect to the support; wherein the LED chip is coupled to a heatsink for transferring heat away from the LED chip, the heatsink being at least partially arranged in the conduit such that fluid flowing through the conduit cools the heatsink. This arrangement may provide a UV lamp whose LEDs can provide UV beams radiating outwards to cover a significant portion around the longitudinal axis, while keeping the LED chips at an appropriate operating temperature. An LED chip is a semiconductor device which may be substantially square with a ceramic base. The LED chip may be a Surface Mounted Diode (SMD) chip, for example. The ceramic base may be rigidly fixed into a protective case with a quartz window in front to allow the UV light to radiate out of the LED chip. The LED chip may be configured to emit UV light for killing microorganisms. For example, the LED chip may be configured to emit light in the wavelength range of 220 nm to 280 nm. Using an LED chip for UV disinfection rather than using a mercury arc lamp can be advantageous because an LED chip can be selected such that it only produces specific wavelengths of UV light, without producing any light in the visible or infrared spectrum. This can be contrasted with mercury arc discharge lamps which produce high quantities of both visible light and infrared wavelengths. These arc lamps need to be positioned such that they do not heat the object to be disinfected, which curtails the UV dose somewhat. The net effect is an LED lamp that produces no infrared heating to heat the object to be disinfected, allowing the LED chips to be placed very close to the object, thereby boosting the UV dose. Using an LED chip also addresses a major shortcoming of the arc lamp in that LED chips do not contain mercury, which is a poisonous substance and which can be released if the arc lamp breaks and could contaminate the product being disinfected. A UV LED can be highly susceptible to overheating and may permanently fail if its core temperature reaches 70°C. Therefore, heat sinking for the UV LED can hold the UV LED at a safe working temperature under all working environments. For long life, the core should preferably be no more than 40°C. This is particularly relevant for recent technological advances that have made it possible to increase the power of the device by forming clusters of UV LEDs on a ceramic chip achieving high power in a small size. By maintaining a low core temperature, improvements can be made to reliability, lamp life, and consistency of light output. The UV lamp may be configured such that the beam angles of at least one pair of LED chips on adjacent external faces of the support overlap. In other words, the plurality of LED chips may comprise a first LED chip on a first face of the plurality of external faces and a second LED chip on a second face of the plurality of external faces, the second face being adjacent to the first face. The first LED chip and the second LED chip may have beam angles configured such that their beams overlap. The beam angle of the first LED chip may be the same as the beam angle of the second LED chip. The beam angle of at least one LED chip may be 30°, 60° or 120°. The LED chips may be constructed with a forward looking quartz window. The UV intensity of the device in mW / cm2 is dependent on the beam angle (the smaller the beam angles, the higher the intensity) together with the distance from the object to be disinfected (the farther away from the object to be disinfected, the lower the UV intensity). The at least two external faces may be flat. All of the external faces may be flat. The support may be prism-shaped, i.e. the support may have a constant polygonal crosssection. At least one LED chip may be comprised on every external face of the prismshaped support, i.e. each side of the polygon that defines the prism may comprise at least one LED chip. The width of the LED chip may be the same as the width of at least one side of the prism shaped support. The width of the LED chip may be the same as the width of at least two sides of the prism-shaped support. The width of the LED chip may be the same as the width of all sides of the prism-shaped support. The widths may be measured in the cross-sectional plane, perpendicular to the longitudinal axis. The support may be defined by a triangular prism. The support may be an equilateral triangular prism. Each of the three external faces of the triangular prism may comprise at least one LED chip. The width of the LED chip may be the same as the width of a face (i.e. where the width is measured in the cross-sectional plane, perpendicular to the longitudinal axis). The support may define a triangular conduit. The LED chips may have a beam angle of 30° or 60°. The support may be defined by a quadrilateral prism. The support may be a rectangular or a trapezoidal prism, for example. Each of the four external faces of the quadrilateral prism may comprise at least one LED chip. The width of the LED chip may be the same as the width of a face (i.e. where the width is measured in the cross-sectional plane, perpendicular to the longitudinal axis). The support may define a quadrilateral conduit, such as a rectangular conduit or a trapezoidal conduit. In the case of a rectangular support, which has two short sides and two long sides, the two long sides may have the same width as the width of the LED chip. The two short sides may be shorter than the LED chip. The LED chips may have a beam angle of 120°. In the case of a trapezoidal support, which has a short side parallel to a long side, which are connected by two sloped sides, the width of the sloped slides may be the same as the width of the LED chip (i.e. where the width is measured in the cross-sectional plane, perpendicular to the longitudinal axis). Three of the four sides may comprise an LED chip thereon. For example, the long side and the two sloped sides may each comprise at least one LED chip thereon. The LED chips may have a beam angle of 30°, 60° or 120°. The support may be defined by an octagonal prism. The octagonal prism may be a regular octagonal prism, i.e. in which an octagon defining the prism has eight equal sides with eight equal interior angles. The support may define an octagonal conduit. The width of the LED chip may be the same as the width of a face (i.e. where the width is measured in the cross-sectional plane, perpendicular to the longitudinal axis). Each of the eight external faces of the octagonal prism may comprise at least one LED chip. The LED chips may have a beam angle of 120° or preferably 60°. These geometric designs of the lamp can provide high UV output efficiency and high energy efficiency. The support may comprise at least one clearance hole configured to permit the heatsink to extend from the conduit to the LED chip. The heatsink may comprise a base connected to the LED chip. The heatsink may comprise a plurality of protrusions extending from the base away from the LED chip. The plurality of protrusions may extend from the LED chip in a direction that is transverse to the corresponding external face and to the longitudinal axis. The plurality of protrusions may comprise four protrusions. As such, a given heatsink may be coupled to an LED chip which is on a particular face, and the protrusions of that heatsink may extend transversely (e.g. perpendicularly) to that face and also to the longitudinal axis. In this way, the protrusions may extend towards the centre of the cross section of the support. The UV lamp may further comprise an air mover. The air mover may be disposed at a first longitudinal end of the support. The air mover may be configured to force air through the conduit to cool the heatsink. The UV lamp may further comprise a temperature monitor at a second longitudinal end of the support, being opposite the first longitudinal end. The support may comprise aluminium. The support may be coated with an electrically insulating material. Each external face of the support may comprise two bus bars electrically coupled to the at least two LED chips on the corresponding external face. The plurality of LED chips may comprise at least two LED chips disposed on the same external face. The at least two LED chips may be arranged at different positions along the longitudinal axis. The support may be coupled to an anti-vibration mount. The UV LED chip can be susceptible to vibration and should preferably be isolated from any forms of physical shock or vibration. The internal components of the chip may be connected with very fine gold wire which under vibration or shock may detach or break, causing the UV chip to fail. An anti-vibration mount may prevent the LEDs and LED arrays from being destroyed from external vibration. Embodiments of the disclosure also aim to provide a UV lamp assembly comprising: the UV lamp as described hereinabove; and a reflector member configured to reflect UV light from at least one of the plurality of LED chips. The reflector member may comprise a curved surface. The reflector member may comprise a part-elliptical surface. The reflector member may have a first focal point and a second focal point. The UV lamp may be positioned at the first focal point such that the reflector focuses UV light onto the second focal point. The reflector member may be configured to surround a majority of the support with respect to the longitudinal axis. The support may be defined by a trapezoidal prism. The support may have LED chips on the base and the two sloped slides of the trapezoidal prism. The base may be positioned to face an opening of the reflector member. The UV lamp assembly may be arranged such that the entire beams of the LED chips on the sloped sides of the support are directed towards the reflector member. The reflector member may be arranged so that such beams are reflected towards the opening of the reflector member. The reflector member may be arranged such that only part of the beam of the LED chip on the base of the support is directed towards the reflector member while the remainder of the beam is directed towards the opening. The reflector member may be provided in fixed relation to the support. The UV lamp assembly may be configured to be movable between a first position in which a first side of a food product is irradiated and a second position in which a second side of the food product is irradiated. The two external faces may comprise a first face and a second face. An external angle between the first face and the second face may be less than 180°. As such, although the faces are external faces, they may at least partly face each other, for example at an angle. The external angle may be approximately 120°. Therefore, with respect to a horizontal, each face may be sloped by 30°, such that using a 60° beam angle provides a vertical beam at the end-most LED chips. The first face and the second face may each comprise at least two LED chips at the same position along the longitudinal axis. The at least two LED chips may comprise at least three LED chips. The reflector member may comprise a first reflector configured to reflect UV light from at least one LED chip on the first face, and a second reflector configured to reflect UV light from at least one LED chip on the second face. The first face may be connected to the second face via the reflector member. The reflector member may be substantially V-shaped. The support may comprise a removable cover to provide access to the conduit. The removable cover may comprise at least one entrance hole configured to receive a flow of air into the conduit and at least one exit manifold configured to permit air to exit the conduit. The reflector member may comprise a parabolic surface. As such, a V-shaped reflector member need not be limited to having straight sides, but may also have curved sides. The present disclosure may also be summarised by the following examples and optional features. The LED lamp may comprise a central metal body whose shape in cross section provides the geometric design of the cross section of the lamp. The UVC light generating device can be individual UVC-LED chip or an array of UVC-LED chips bonded to a printed circuit board. Preferably the metal body material is hollow extruded aluminium tube. Preferably the metal body provides at least one flat outer surface which runs the whole length of the lamp. Preferably the surface of the metal body is coated with an electrically insulating material such as a plastic film. Two metal electrodes (bus bars) per flat surface are rigidly fixed to the coated flat surface using strong glue. The metal electrodes are positioned at each side of the LED chip, flush with the edge of the flat surface of the LED chip and run the whole length of the lamp. Preferably the electrodes and contact material comprise copper. One electrode is the positive and the other electrode is the negative of the power supply for the lamp. The LED chip is a small substantially square device with a ceramic base. The base has the LEDs attached to its top side and the reverse side contains a positive strip contact on one edge and a negative strip contact on the other edge. Running through the centre of the ceramic base and parallel to the power supply strip contacts is a strip contact for a heatsink. This heatsink should be sized correctly to keep the LED chip within its safe temperature limits for reliability and a long life. The ceramic base is rigidly fixed into a protective case with a quartz window in front to allow the UV light to radiate out of the LED chip. Preferably the case is metallic to give robust protection to the LED chip. The selected heatsink is rigidly attached to the heatsink strip contact by soldering or by a thermally conductive adhesive. The LED chip (or an array of LED chips) is positioned straddling the two power supply electrodes with the heatsink positioned through a clearance hole in the aluminium tube protruding into the hollow section in the aluminium tube. The LED chip is rigidly attached to the electrodes, with the positive strip contact connected to the positive power supply electrode and the negative strip contact connected to the negative power supply electrode. Each flat outer surface of the aluminium tube has the LED chips attached in this manner. Preferably, pluralities of LED chips are attached in this manner to the power supply electrodes providing a longitudinal LED lamp. Preferably, for maximum UV disinfection efficiency, in some applications the LED chips are positioned so that their beam angles overlap. Means are provided to cool the heatsinks using forced air cooling with an air mover blowing air through the hollow section in the aluminium tubing past the heatsinks and out to atmosphere. As a safety precaution, a temperature monitor is placed at the exit end of the aluminium tubing so that the exhaust air is continually monitored. Preferably the air mover is in the form of a fan or in the form of clean, dry oil free compressed air or some other suitable device. Brief description of the drawings Embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which: Fig. 1 (A, B, and C) shows various LED chips with their respective beam angles and electrical contacts mounted on bus bars; Fig. 1D shows an LED chip complete with heatsink; Fig. 2 shows a part sectioned view of a rectangular shaped carrier framed LED lamp with attached LED chips and showing the beam angle positions; Fig. 3 shows a part sectioned view of an octagonal shaped carrier framed LED lamp with attached LED chips; Fig. 4 shows a part sectioned side view of an octagonal shaped carrier framed LED lamp with attached LED chips; Fig. 5 shows a part sectioned side view of an octagonal shaped carrier framed LED lamp with attached LED chips complete with a cooling fan; Fig. 6 shows a part sectioned view of a triangular shaped carrier framed LED lamp with attached LED chips; Fig. 7 shows a part sectioned view of a triangular shaped carrier framed LED lamp positioned inside a semi-elliptical reflector including the beam angles and consequential reflected beam; Fig. 8 shows part sectioned isometric trapezoid shaped carrier framed LED lamp with attached LED chips; Fig. 9 shows a part sectioned view of an isometric trapezoid shaped carrier framed LED lamp positioned inside a semi-elliptical reflector including the beam angles and consequential reflected beam; Fig. 10 shows a part sectioned and improved flat plate LED disinfector including the beam angles and consequential reflected beam; and Fig. 11 shows a part sectioned view of a UVC disinfector which traverses across the object to be disinfected boosting UVC dose. Detailed description of the drawings Referring to Figure 1 (A, B and C) which shows three LED chips each with a different beam angle 7. LED chip A has a beam angle 7 of 120°, LED chip B has a beam angle 7 of 60° and LED chip C has a beam angle 7 of 30°. The LED chip 11 comprises a ceramic base 3 which has the LEDs formed on its top surface. The ceramic base 3 is rigidly fixed inside a metal case 2 which has a quartz window 1 at the front to allow the UV light to radiate out and form the beam angle 7. Means are provided to power the LED chip in the form of a positive contact 8 and a negative contact 9 on the base of the LED chip 11, the positive contact 8 being rigidly fixed to the positive bus bar 6 and the negative contact 9 being rigidly fixed to the negative bus bar 4. It is preferable that when an LED lamp is used in a liquid disinfection application it produces UV radiation over the whole 360° of its disinfection circumference without any gaps. The first embodiment with reference to Figures 1, 1D and 2 shows a geometric design suitable for liquid disinfection and comprises a support, illustrated in this example in the form of a main central rectangular tube 10 (i.e. a rectangular prism) which runs the length of the lamp. Preferably the rectangular tube 10 is made of extruded aluminium. Preferably the rectangular tube 10 is coated with an electrical insulator such as a plastic material. Rigidly attached to the rectangular tube 10 are eight bus bars, four positive bus bars 6 and four negative bus bars 4. Preferably the bus bars 4, 6 are positioned to allow four LED chips 11 to be mounted on the bus bars 4, 6 positioned so that their beam angles 7 intersect with one another to give 360° disinfection circumference. The dimensions of the rectangular tube 10 are chosen such that they allow the LED chips 11 to form a crude rectangular form with the two end LED chips 11 (e.g. the top and the bottom LED chips in Figure 2) overlapping the two side mounted LED chips 11 (e.g. the left- and right-hand side LED chips in Figure 2), enabling the beam angles 7 of the LED chips 11 to overlap. The support defines a conduit therein along a longitudinal axis of the support (i.e. into the page of Figure 2). Means are provided to cool the four LED chips 11, as described in relation to Figure 1, in the form of heatsinks 12 rigidly fixed to the four LED chips 11 via the strip contact 13 fora heatsink 12 and positioned through the rectangular tube 10 via a clearance hole 14. Forced air cooling is achieved by fitting an air mover (not shown for clarity) to feed pressurised air through the centre of the rectangular tube 10, through the heatsinks, and exiting the hot air to atmosphere. The lamp is completed by installing pluralities of LED chips 11 attached in this manner to the power supply bus bars 4, 6 providing a longitudinal LED lamp. Preferably, for maximum UV disinfection efficiency, the LED chips 11 are positioned so that their beam angles 7 overlap, providing 360° circumferential disinfection over the full length of the lamp. This geometric design is particularly suitable for LED chips with 120° beam angles so that the beams intersect with each other and give full 360° disinfection. For an optimised geometric design the second embodiment is the preferred design for the UV disinfection of liquid products. Referring to Figures 1, 1D, 3, 4 and 5, the design comprises a support in the form of a main central octagonal tube 15 (i.e. an octagonal prism) which runs the length of the lamp. Preferably the rectangular tube 15 is made of extruded aluminium. Preferably the octagonal tube 15 is coated with an electrical insulator such as a plastic material. Rigidly attached to the octagonal tube 15 are sixteen bus bars, eight positive bus bars 6 and eight negative bus bars 4. Preferably the bus bars 4, 6 are positioned to allow eight LED chips 11 to be mounted on the bus bars 4, 6 so that their beam angles 7 intersect with one another to give 360° disinfection circumference. The dimensions of the octagonal tube 15 are chosen such that they allow the LED chips 11 to form a crude octagonal form with the eight LED chips 11 mounted and positioned on the eight flat faces of the octagonal tube 15 to enable the beam angles of the LED chips 11 to overlap, giving 360° disinfection. Means are provided to cool the eight LED chips 11 as shown in Figure 3 in the form of heatsinks 12 rigidly fixed to the eight LED chips 11 via the strip contact 13 (see Figure 1D) for a heatsink 12 and positioned through the octagonal tube 15 via a clearance hole 14. Referring to Figure 5, forced air cooling is achieved by fitting a connecter 16 containing a fan 17 to feed pressurised air through the centre of the octagonal tube 15 and through the heatsinks 12 then exiting the hot air to atmosphere. The lamp is completed by installing pluralities of LED chips attached in this manner to the power supply bus bars 4 and 6, providing a longitudinal LED lamp. Referring to Figure 3 and Figure 4, preferably for maximum UV disinfection efficiency the LED chips are positioned so that their beam angles overlap circumferentially and longitudinally to give 360° circumferential disinfection over the full length of the lamp. Preferably the beam angle 7 of the LED chip 11 is 60°. For this geometric design it is preferable to use LED chips with 120° beam angle and / or 60° beam angle so that the beams intersect with each other and therefore give full 360° disinfection. The UV intensity is maximised when the 60° beam angle 7 is used. Figure 5 shows the LED cooling arrangement comprising a coupling 16 pressed into the octagonal tube 15 and which is retained by the compressed "O" ring 18 in the "O" ring groove 19, thereby forming an air-tight seal. Rigidly fixed to the coupling 16 is a fan 17 which, when energised, blows air into the hollow centre of the octagonal tube 15, through the heatsinks 12 and out to atmosphere at the other end of the octagonal tube 15. Some UV disinfection applications require a single forward projected beam whereby all of the LED illumination is gathered and projected forward. In the third embodiment and referring to Figure 6, a support in the form of a triangular geometric shaped central body 20 (i.e. a triangular prism) is shown. Preferably, the triangular body 20 is made from extruded aluminium. The LED chips 11 are mounted, as explained in the second embodiment, with the LED chips 11 straddling the bus bars 4, 6 with their heatsinks 12 protruding through the walls of the triangular body 20 into the hollow space 21 via the clearance hole 14. Forced air cooling is accomplished by blowing air from an air mover (not shown for clarity) into the hollow space 21 and through the heatsinks 12 and out through the other end to atmosphere. Preferably the air mover is a fan, clean oil free compressed air or some other suitable air mover device. The lamp is completed by installing pluralities of LED chips 11 attached in this manner to the power supply bus bars 4 and 6, providing a longitudinal LED lamp 25. In the triangular lamp configuration 25, if this lamp is positioned inside a reflector 22 then all of its UV illumination is captured and then projected in a substantially forward directed beam ready to UV disinfect a solid object. With reference to Figure 7, there is shown a triangular geometric shaped lamp 25 producing a substantially forward projected (i.e. down the page) beam 46. The configuration comprises a reflector 22 which is capable of reflecting UVC light to a high efficiency. As such, a UV lamp assembly comprising the lamp 25 and the reflector 22 is provided. Preferably the efficiency of the reflector 22 is a minimum of 92% for reflecting germicidal light (220 nm to 280 nm). Preferably the reflector 22 is made from a high purity extruded aluminium. Preferably the reflector 22 extends to both extremities of the lamp. Preferably the aluminium reflector22 has an interior surface 47 which has a mirror polished finish. Preferably the aluminium reflector 22 has an interior surface 47 which has been coated with a high reflectance material for UVC light. Preferably the reflector 22 internal profile is of a semi elliptical shape with a first focal point 24 and a second focal point 23. The triangular lamp configuration 25 is placed at the first focal point 24 and the semi elliptical reflector substantially focuses the UV light onto the second focal point 23 maximising the UV light intensity and hence the UVC dose. This triangular lamp configuration 25 gives the best UVC light intensity with LED chips 11 with 60° and 30° beam angles. At 120° beam angle there is a loss in UVC intensity as the extremity of the reflected upper beam cannot pass the triangular lamp configuration 25 and therefore is lost, see dotted lines 26. The fourth embodiment referring to Figures 8 and 9 shows a support in the form of an isometric trapezoid geometric design (i.e. a trapezoidal prism) which allows the use of LED chips 11 with 120°, 60° and 30° beam angles without any loss in UVC energy or UVC dose. The design comprises a support in the form of a central isometric trapezoid shaped hollow support tube with the LED chips 11 attached as explained in the second embodiment. Preferably the isometric trapezoid body 48 is made from extruded aluminium. The LED chips 11 are mounted as explained in the second embodiment with the LED chips 11 straddling the bus bars 4, 6 with their heatsinks 12 protruding through the walls of the isometric trapezoid body 48 into the hollow space 28 via the clearance hole 14. Forced air cooling is accomplished by blowing air from an air mover (not shown for clarity) into the hollow space 28 and through the heatsinks 12 and out through the other end to atmosphere. Preferably the air mover is a fan or clean, dry and oil free compressed air or some other suitable air mover device. The lamp is completed by installing pluralities of LED chips 11 attached in this manner to the power supply bus bars 4 and 6 providing a longitudinal LED lamp. In the isometric trapezoid lamp configuration not all of the beam angles 7 of the LED chips 11 intersect with each other, however if this lamp is positioned inside a reflector 22 then all of its UV illumination is captured and then projected in a substantially forward directed beam 49 ready to UV disinfect a solid object 31. With reference to Figure 8, there is shown an isometric trapezoid geometric shaped lamp 29 producing a substantially forward projected beam. The configuration comprises a reflector 22 which is capable of reflecting UVC light to a high efficiency. Preferably the reflector 22 has a reflection efficiency of at least 92% for UVC light. Preferably the reflector 22 is made from high purity extruded aluminium. Preferably the reflector 22 extends to both extremities of the lamp 29. Preferably the aluminium reflector22 has an interior surface 30 which has a mirror polished finish. Preferably the aluminium reflector 22 has an internal surface 30 which has been coated with a high reflectance material for UVC light. Preferably the reflector 22 internal profile is of a semi elliptical shape with a first focal point 24 and a second focal point 23. The lamp configuration 29 is placed at the centre of the first focal point 24 and the semi elliptical reflector substantially focuses the UV light onto the second focal point 23 maximising the UV light intensity and hence the UVC dose. This isometric trapezoid geometric lamp configuration 25 gives the best UVC light intensity with LED chips 11 with a 30° beam angle, but all beam angles can be used in this configuration. The object to be disinfected 31 is shown in position inside the focused beam. Some applications require larger areas to be disinfected and the most common solution has been to use a flat plate with LED chips fixed to the plate to generate a broad beam UVC disinfection area. This approach is very energy inefficient in as much as a lot of UVC energy is lost due to beam spread around the edges of the UVC disinfection area; the larger the beam angle of the individual LED chips, the higher the energy loss, resulting in a deterioration in efficiency. The disclosure aims to address this problem by using a configuration shown in the fifth embodiment. With reference to Figure 10, there is shown a metal base frame 32 and 33 which provide a rigid carrier (i.e. a support) for the LED chips 11. The LED chips 11 are assembled and mounted onto the carrier base frames 32 and 33 in the same manner as described in the second embodiment with the LED chip 11 straddling the negative and positive bus bars 4 and 6 and with the heatsink 12 protruding through the metal base frames via the clearance holes 14 provided. The carrier base frames 32 and 33 comprise at least two external faces 34 and 36, respectively, which are flat. LED chips are mounted to the external faces 34 and 36 such that they are configured to emit UV light outwards with respect to the support. As shown in Figure 10, the two external faces 34 and 36 (i.e. a first face and a second face) have an external angle therebetween which is less than 180°. In the example show, the angle is approximately 120°. Each of the external faces 34 and 36 comprises at least three LED chips in the example shown. The geometric design is suitable for LED chips with 120° beam angle, 60° beam angle and 30° beam angles. The metal base frames 32 and 33 are rigidly fixed together at the base of the curved reflector 42. As such, the first face 34 is connected to the second face 36 via the curved reflector. Figure 10 shows LED chips 11 with 60° beam angles 7. As such, to get the edge of beam angle 7 on the two outside LED chips to be vertical, the metal base frames 32 and 33 are inclined at an angle of 30° from the horizontal. Preferably the flat undersides 34, 35, 36 and 37 are coated with an electrically insulating coating such as plastic. The curved undersides 38 and 39 are left uncoated so that the UVC light can reflect off these surfaces unhindered. The curved reflector 42 may be considered as a reflector member comprising a first reflector 38 and a second reflector 39, where the first reflector 38 is configured to reflect UV light from an LED chip on the first face 34, and the second reflector 39 is configured to reflect UV light from an LED chip on the second face 36. Preferably the shape of the curved surfaces 38 and 39 is parabolic so that any UVC light from the LED chips 11 is projected substantially down onto the disinfection surface 40. Preferably the parabolic surfaces 38 and 39 are polished to a mirror finish. Preferably the parabolic surfaces 38 and 39 are coated with a material that reflects UVC light to a very high efficiency. Preferably the UVC efficiency of surfaces 38 and 39 are a minimum of 92% for UVC light. The UVC disinfector is completed by installing pluralities of LED chips 11 attached to the power supply bus bars 4 and 6 providing a longitudinal UVC LED surface disinfector. This geometric design may be suitable for LED chips with 60° beam angle 7, 30° beam angle 7 and 120° beam angle 7. Means are provided to cool the heatsinks 12 by adding a removable air tight cover 41 which provides an airspace 50 above the heatsinks 12. Rigidly fixed through the cover 41 are air movers 43 which blow air through the entrance holes 45 into the air space 50 and through the heatsinks 12 and exits to atmosphere via the exit manifolds 44. One way of significantly boosting dose is described in the sixth embodiment using the geometric design described in the fourth embodiment. Figure 11 shows a UVC disinfector of the isometric trapezoid geometric profile placed inside a semi elliptical reflector. Means are provided to allow the UVC disinfector 51 to scan across the object to be disinfected 31 in the form of a traversing mechanism (not shown for clarity) which moves the UVC disinfector 51 from its start position A to its stop position B and back again. The traversing mechanism is designed to keep the focal point of the UVC disinfector close to the surface of the object to be disinfected 31 therefore boosting the UVC intensity (mW / cm2) and hence the dose (mWsec / cm2). The dose can be varied by the rate at which the UVC disinfector 51 traverses the surface of the object to be disinfected 31 and the number of traverse cycles completed across the surface. This method significantly boosts the dose delivered to the object to be disinfected 31 as significantly all of the UVC energy is concentrated over a relatively small area hence very high UVC intensity. Persons skilled in the art can produce traversing mechanisms to accomplish the required movement. In all of the embodiments described above, the sub-assemblies may use at least one antivibration mount (not shown for clarity). Such an anti-vibration mount may prevent the LEDs and LED arrays from being destroyed from external vibration. This may be particularly relevant to UV lamps used for liquid disinfection, where the LED array replaces typical 5 mercury arc lamps and can fit directly into the body of a disinfector in which the whole sub assembly is mounted on at least one anti-vibration mount. It will be appreciated from the above description that many features of the different examples are interchangeable and combinable. The disclosure extends to further 10 examples comprising features from different examples combined together in ways not specifically mentioned. Indeed, there are many features presented in the above examples and it will be apparent to the skilled person that these may be advantageously combined with one another.

Claims

1. A UV lamp comprising:a support, the support defining a conduit therein along a longitudinal axis of the support; anda plurality of LED chips configured to emit UV light;wherein the support comprises a plurality of external faces, and wherein each of at least two of the plurality of external faces comprises an LED chip of the plurality of LED chips thereon such that the LED chip is configured to emit UV light outwards with respect to the support;wherein the LED chip is coupled to a heatsink for transferring heat away from the LED chip, the heatsink being at least partially arranged in the conduit such that fluid flowing through the conduit cools the heatsink.

2. The UV lamp of claim 1, configured such that the beam angles of at least one pair of LED chips on adjacent external faces of the support overlap.

3. The UV lamp of claim 1 or claim 2, wherein the at least two external faces are flat.4, The UV lamp of any preceding claim, wherein the support is prism-shaped.

5. The UV lamp of claim 4, wherein at least one LED chip is comprised on every external face of the prism-shaped support.

6. The UV lamp of claim 4 or claim 5, wherein the support is defined by a triangular prism.

7. The UV lamp of claim 4 or claim 5, wherein the support is defined by a quadrilateralprism.

8. The UV lamp of claim 4 or claim 5, wherein the support is defined by an octagonal prism.

9. The UV lamp of any preceding claim, wherein the support comprises at least oneclearance hole configured to permit the heatsink to extend from the conduit to the LED chip.

10. The UV lamp of any preceding claim, wherein the heatsink comprises:a base connected to the LED chip; anda plurality of protrusions extending from the base away from the LED chip; wherein the plurality of protrusions extend from the LED chip in a direction that is transverse to the corresponding external face and to the longitudinal axis.

11. The UV lamp of any preceding claim, further comprising an air mover at a first longitudinal end of the support, the air mover being configured to force air through the conduit to cool the heatsink.

12. The UV lamp of claim 11, further comprising a temperature monitor at a second longitudinal end of the support, being opposite the first longitudinal end.

13. The UV lamp of any preceding claim, wherein each external face of the support comprises two bus bars electrically coupled to the at least two LED chips on the corresponding external face.

14. The UV lamp of any preceding claim, wherein the plurality of LED chips comprises at least two LED chips disposed on the same external face, wherein the at least two LED chips are arranged at different positions along the longitudinal axis.

15. The UV lamp of any preceding claim, wherein the support is coupled to an antivibration mount.

16. A UV lamp assembly comprising:the UV lamp of any preceding claim; anda reflector member configured to reflect UV light from at least one of the plurality of LED chips.

17. The UV lamp assembly of claim 16, wherein the reflector member has a first focal point and a second focal point, and wherein the UV lamp is positioned at the first focalpoint such that the reflector focuses UV light onto the second focal point.

18. The UV lamp assembly of claim 16 or claim 17, wherein the reflector member is configured to surround a majority of the support with respect to the longitudinal axis.

19. The UV lamp assembly of any of claims 16 to 18, the support being defined by a trapezoidal prism and having LED chips on the base and the two sloped slides thereof, wherein the base is positioned to face an opening of the reflector member.

20. The UV lamp assembly of any of claims 16 to 19, wherein the reflector member is provided in fixed relation to the support, and wherein the UV lamp assembly is configured to be movable between a first position in which a first side of a food product is irradiated and a second position in which a second side of the food product is irradiated.

21. The UV lamp assembly of claim 16, wherein the two external faces comprise a first face and a second face, and wherein an external angle between the first face and the second face is less than 180°.

22. The UV lamp assembly of claim 21, wherein the first face and the second face each comprise at least two LED chips at the same position along the longitudinal axis.

23. The UV lamp assembly of claim 21 or claim 22, wherein the reflector member comprises a first reflector configured to reflect UV light from at least one LED chip on the first face, and a second reflector configured to reflect UV light from at least one LED chip on the second face.

24. The UV lamp assembly of any of claims 21 to 23, wherein the first face is connected to the second face via the reflector member.

25. The UV lamp assembly of any of claims 21 to 24, wherein the support comprises a removable cover to provide access to the conduit.AMENDMENTS TO THE CLAIMS HAVE BEEN FILED AS FOLLOWS18 03 2623CLAIMS:

1. A UV lamp comprising:a support, the support defining a conduit therein along a longitudinal axis of5 the support; anda plurality of LED chips configured to emit UV light;wherein the support comprises a plurality of external faces, and wherein each of at least two of the plurality of external faces comprises an LED chip of the plurality of LED chips thereon such that the LED chip is configured to emit UV light outwards with respect 10 to the support;wherein the LED chip is coupled to a heatsink for transferring heat away from the LED chip, the heatsink being at least partially arranged in the conduit such that fluid flowing through the conduit cools the heatsink;wherein the support comprises at least one clearance hole configured to permit the heatsink to extend from the conduit to the LED chip;wherein the heatsink comprises:a base connected to the LED chip; anda plurality of protrusions extending from the base away from the LED chip; and20 wherein the plurality of protrusions extend from the LED chip in a direction that istransverse to the corresponding external face and to the longitudinal axis.

2. The UV lamp of claim 1, configured such that the beam angles of at least one pair of LED chips on adjacent external faces of the support overlap.

253. The UV lamp of claim 1 or claim 2, wherein the at least two external faces are flat.4, The UV lamp of any preceding claim, wherein the support is prism-shaped.30 5. The UV lamp of claim 4, wherein at least one LED chip is comprised on everyexternal face of the prism-shaped support.

6. The UV lamp of claim 4 or claim 5, wherein the support is defined by a triangular prism.

7. The UV lamp of claim 4 or claim 5, wherein the support is defined by a quadrilateral prism.5 8. The UV lamp of claim 4 or claim 5, wherein the support is defined by an octagonalprism.

9. The UV lamp of any preceding claim, further comprising an air mover at a first longitudinal end of the support, the air mover being configured to force air through the 10 conduit to cool the heatsink.

10. The UV lamp of claim 9, further comprising a temperature monitor at a second longitudinal end of the support, being opposite the first longitudinal end.CM 11. The UV lamp of any preceding claim, wherein each external face of the supportCO comprises two bus bars electrically coupled to the at least two LED chips on thecorresponding external face.co12. The UV lamp of any preceding claim, wherein the plurality of LED chips comprises 20 at least two LED chips disposed on the same external face, wherein the at least two LED chips are arranged at different positions along the longitudinal axis.

13. The UV lamp of any preceding claim, wherein the support is coupled to an antivibration mount.2514. A UV lamp assembly comprising: the UV lamp of any preceding claim; and a reflector member configured to reflect UV light from at least one of the plurality of LED chips.3015. The UV lamp assembly of claim 14, wherein the reflector member has a first focal point and a second focal point, and wherein the UV lamp is positioned at the first focal point such that the reflector focuses UV light onto the second focal point.

16. The UV lamp assembly of claim 14 or claim 15, wherein the reflector member is configured to surround a majority of the support with respect to the longitudinal axis.

17. The UV lamp assembly of any of claims 14 to 16, the support being defined by a 5 trapezoidal prism and having LED chips on the base and the two sloped slides thereof, wherein the base is positioned to face an opening of the reflector member.

18. The UV lamp assembly of claim 14, wherein the at least two external faces comprise a first face and a second face, and wherein an external angle between the first 10 face and the second face is less than 180°.

19. The UV lamp assembly of claim 18, wherein the first face and the second face each comprise at least two LED chips at the same position along the longitudinal axis.

20. The UV lamp assembly of claim 18 or claim 19, wherein the reflector member comprises a first reflector configured to reflect UV light from at least one LED chip on the first face, and a second reflector configured to reflect UV light from at least one LED chip on the second face.20 21. The UV lamp assembly of any of claims 18 to 20, wherein the first face is connectedto the second face via the reflector member.

22. The UV lamp assembly of any of claims 18 to 21, wherein the support comprises a removable cover to provide access to the conduit.18 03 26A

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