1. An ultraviolet (UV) curing system (100) having an air cooling unit, the UV curing system (100) comprises: a UV light source (102) placed in an enclosed area (120) inside of a premise to generate UV light; an air cooling unit (104) to cool the UV light source (102), the air cooling unit (104) having: an Air Handling Unit (AHU) (106) placed in an open area (116) to pull fresh air from the atmosphere, wherein the open area (116) corresponds to an area having access to the atmospheric air and includes one of: a terrace, a ground and outside of a building; a duct assembly (108) coupled to the AHU (106) at a first end (118) of the duct assembly (108) to receive the fresh air from the AHU (106) ; one or more hoses (114) coupled to a second end (124) of the duct assembly (108) to supply the fresh air to the UV light source (102) to cool the UV light source (102) .

2. The UV curing system (100) as claimed in claim 1, wherein the enclosed area (120) and the open area (116) are isolated from each other via an isolation member (122).

3. The UV curing system (100) as claimed in claim 1, wherein the duct assembly (108) includes a first duct and a second duct coupled at the isolation member (122) . The UV curing system (100) as claimed in claim 3, further comprises an air filter (110) installed inside the AHU (106) to filter the fresh air. The UV curing system (100) as claimed in claim 1, further comprises a manifold (112) coupled to the duct assembly (108) at a second end (124) of the duct assembly (108) to provide one or more outlets for the fresh air. The UV curing system (100) as claimed in claim 1, wherein the one or more hoses (114) are coupled to each of the outlets of the manifold (112) and the one or more air inlets (202) of the one or more UV cassettes (200) to supply the fresh air for cooling the UV light source (102). The UV curing system (100) as claimed in claim 1, further comprises an exhaust air unit (126) to egress the air circulating in the UV curing system. The UV curing system (100) as claimed in claim 7, wherein exhaust air unit (126) further comprises a flap to control pressure of air ingressing and circulating in the UV curing system (100) based at least on the temperature of the UV light source (102) . The UV curing system (100) as claimed in claim 6, wherein the hose (114) is made of silicon.

10. The UV curing system (100) as claimed in claim 1, wherein the UV curing system (100) is configured to cure photopolymer-based ink, adhesives and coatings.

The present invention generally relates to ultraviolet (UV) curing systems. In particular, the present invention relates to an air cooling unit for a UV curing system.
BACKGROUND OF THE INVENTION
[0002] Ultraviolet (UV) curing systems are used for curing the photopolymer-based inks, adhesives and coatings. The UV curing system includes a UV light cassette having a UV light source to generate a UV light for curing the photopolymers to dry the ink, adhesive or coating. However, operating the UV light source for a long time produces a large amount of heat leading to various problems, such as melting of the walls of the UV cassette and UV light source. Typically, an air cooling unit is coupled to the UV curing system for cooling the UV cassettes for its effective operation. The air cooling unit circulates the air from the ambient space of the UV curing system to the UV cassette to cool the UV cassette.
[0003] However, during prolonged use, the UV curing system diffuses the ink in the air in the ambient space of the UV curing system in the form of an ink mist. Further, the continuous circulation of the ink mist via the air leads to the ingress of the ink in the UV cassettes. The ingress ink deposits on the UV light source to decrease the intensity of the generated UV light falling on the photopolymers leading to inefficient curing of the photopolymer base ink,

adhesive or coating. Therefore, the cycle time of curing the photopolymers is increased due to periodic cleaning of the UV light source. The periodic cleaning also leads to increased downtime and maintenance cost. Further, the life of the UV light source is also decreased because of the permanent deposition of ink.
[0004] In light of the above, there is a need for an air cooling unit for a UV curing system to minimize the deposition of ink on the UV light source and reduce the maintenance of the UV curing system.
SUMMARY OF THE INVENTION
[0005] An embodiment of the present invention disclose, an ultraviolet (UV) curing system having an air cooling unit. The UV curing system include a UV light source placed in an enclosed area inside a premise to generate UV light and an air cooling unit to cool the UV light source. The air cooling unit includes an Air Handling Unit (AHU) placed in an open area to pull fresh air from the atmosphere and a duct assembly coupled to the AHU at a first end of the duct assembly to receive the fresh air from the AHU. The open area corresponds to an area having access to the atmospheric air including a terrace, a ground and outside of a building. One or more hoses coupled to a second end of the duct assembly to supply the fresh air to the UV light source to cool the UV light source.
[0006] In an embodiment of the present invention, the open area corresponds to an area having access to the atmospheric air including a terrace, a ground and outside of a building. Further, the enclosed area and the open

area are isolated from each other via an isolation member.
[0007] In an embodiment of the present invention, the duct assembly includes a first duct and a second duct coupled at the isolation member.
[0008] Further, the UV curing system also includes an air filter installed inside the AHU to filter the fresh air.
[0009] In an embodiment of the present invention, the UV curing system has a manifold coupled to the duct assembly at a second end of the duct assembly to provide one or more outlets for the fresh air.
[0010] In an embodiment of the present invention, the one or more hoses are coupled to each of the outlets of the manifold and the one or more air inlets of the one or more UV cassettes to supply the fresh air for cooling the UV light source.
[0011] In an embodiment of the present invention, the UV curing system 100 also includes an exhaust air unit 126 to egress the air circulating in the UV curing system. Further, the exhaust air unit has a flap to control pressure of air ingressing and circulating in the UV curing system based at least on the temperature of the UV light source.
[0012] In an embodiment of the present invention, the hose is made of silicon. Further, the UV curing system is configured to cure photopolymer-based ink, adhesives and coatings

[0013] Thus, the invention provides a UV curing system having an air cooling unit to cool the UV cassette. The air cooling unit ingresses fresh air from an AHU installed in an area isolated from the area of installation of the UV cassette for cooling the UV cassette. Thus, the fresh air is free from any ink mist that may be present in the ambient area of the UV cassette. Further, the ingress fresh air is filtered via a filter in the air cooling unit. The cooling of the UV cassette via fresh and filtered air leads to the efficient working of the UV cassette. The deposition of ink on the UV light source is minimized to improve the life of the UV light source. Further, the cycle time for curing the photopolymers is decreased due to requirement of longer gaps between maintenance. Additionally, the air cooling unit provides consistent operating parameters during production like cassette temperature and running intensity. Therefore, the air cooling unit for the UV curing system enables efficient, fast and cost-effective curing of the photopolymers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The present invention is described by way of embodiments illustrated in the accompanying drawing wherein:
[0015] Figure 1 (a) illustrates a schematic representation of an ultraviolet (UV) curing system in accordance with an embodiment of the invention;
[0016] Figure 1 (b) illustrates an isometric view of the UV curing system in accordance with an embodiment of the invention;

[0017] Figure 2(a) illustrates a top view of a UV cassette in accordance with another embodiment of the invention;
[0018] Figure 2(b) illustrates a front view of the UV cassette in accordance with another embodiment of the invention;
[0019] Figure 2(c) illustrates a side view of the UV cassette in accordance with another embodiment of the invention;
[0020] Figure 2(d) illustrates a cross-sectional view of the UV cassette in accordance with another embodiment of the invention;
[0021] Figure 3(a) illustrates an air cooling unit in accordance with an embodiment of the invention;
[0022] Figure 3(b) illustrates an elevation view of an Air Handling Unit (AHU) in accordance with an embodiment of the invention; and
[0023] Figure 3(c) illustrates a plan view of the AHU in accordance with an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The following disclosure is provided in order to enable a person having ordinary skill in the art to practice the invention. Exemplary embodiments are provided only for illustrative purposes and various modifications will be readily apparent to persons skilled in the art. The general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Also, the terminology and phraseology used is

for the purpose of describing exemplary embodiments and should not be considered limiting. Thus, the present invention is to be accorded the widest scope encompassing numerous alternatives, modifications and equivalents consistent with the principles and features disclosed. For the purpose of clarity, details relating to technical material that is known in the technical fields related to the invention have not been described in detail so as not to unnecessarily obscure the present invention.
[0025] The present invention would now be discussed in the context of embodiments as illustrated in the accompanying drawings.
[0026] Figure 1 (a) illustrates a schematic representation of an ultraviolet (UV) curing system in accordance with an embodiment of the invention. Figure 1 (b) illustrates an isometric view of the UV curing system in accordance with an embodiment of the invention. For the sake of brevity, the Figures 1(a) and 1(b) have been discussed together.
[0027] The UV curing system 100 may be configured to cure photopolymer based liquids. The photopolymer-based liquid may without any limitation include, ink, adhesive and coating. In an embodiment of the present invention, the UV curing system 100 may be installed in a printing press for drying photopolymer-based printing ink. In another embodiment of the present invention, the UV curing system 100 may be installed in manufacturing plants, such as a mobile manufacturing plant for drying photopolymer-based adhesive to attach the screen.

[0028] In an embodiment of the present invention, the UV curing system 100 may include one or more UV light sources 102 and an air cooling unit 104. The air cooling unit 104 may include an Air Handling Unit (AHU) 106, a duct assembly 108, an air filter 110, a manifold 112, and one or more hoses 114. The duct assembly 108 may include a first end 118, a second end 124, first duct and a second duct. The detailed coupling and operation of each of the component has been elaborated in subsequent paragraphs.
[0029] In an exemplary embodiment of the present invention, the UV light source 102 may be placed in an enclosed area 120 and the AHU 106 may be placed in an open area 116. In an embodiment of the present invention, the open area 116 and the enclosed area 120 may be isolated from each other via an isolation member 122.
[0030] In an embodiment of the present invention, the UV curing system 100 may also include an exhaust air unit 126. The detailed description of the exhaust air unit 126 has been provided in subsequent paragraphs.
[0031] Figure 2(a) illustrates a top view of a UV cassette having a UV light source 102 in accordance with another embodiment of the invention. Figure 2(b) illustrates a front view of the UV cassette in accordance with another embodiment of the invention. Figure 2(c) illustrates a side view of the UV cassette in accordance with another embodiment of the invention. Figure 2(d) illustrates a cross-sectional view of the UV cassette in accordance with another embodiment of the invention. For the sake of brevity, Figures 2 (a), 2 (b), 2(c) and 2(d) mav be explained toaether.

[0032] In an embodiment of the present invention, each of the one or more UV cassettes 200 may include a UV light source 102 and one or more air inlets 202. In an embodiment of the present invention, an article may be placed under the UV light source 102 of the UV cassette 200. The article may without any limitation include, a sheet printed via a photopolymer-based ink, a mobile screen attached to mobile via photopolymer-based adhesive and a utensil coated via a photopolymer-based paint coating.
[0033] Further, the UV light source 102 may be configured to generate UV light for curing the photopolymer-based liquids applied on the articles. Further, the UV light source 102 may without any limitation include, black lights, short-wave UV lamps, incandescent lamps, gas-discharge lamps, UV Light Emitting Diodes (LEDs), UV lasers and tunable vacuum UV. In an embodiment of the present invention, the UV light source 102 may be coupled to an intensity adjustment device for adjusting the intensity of the UV light source 102.
[0034] Further, the UV cassette 200 may include one or more air inlets 202 to receive air for cooling the UV light source 102. In an embodiment of the present invention, the UV cassette 200 may have an air conduit configured to supply the air from the one or more air inlets 202 to the UV light source 102. Further, the one or more air inlets 202 may be present on the body of the UV cassette 102 at the sides, front, back, top, bottom or a combination thereof.

[0035] Figure 3 (a) illustrates an air cooling unit 104 in accordance with an embodiment of the invention. Figure 3 (b) illustrates an elevation view of an Air Handling Unit (AHU) in accordance with an embodiment of the invention. Figure 3(c) illustrates a plan view of the AHU in accordance with an embodiment of the invention. For the sake of brevity, Figures 3(a), 3(b) and 3(c) may be explained together.
[0036] In an embodiment of the present invention, the air cooling unit 104 may include an Air Handling Unit
(AHU) 106, a duct assembly 108, an air filter 110, a manifold 112 and one or more hoses 114.
[0037] In an embodiment of the present invention, the AHU 106 may be placed in an open area 116. The open area 116 may correspond to an area having access to the atmospheric air, such as a terrace, a ground and outside of a building. Further, the AHU 106 may be configured to pull fresh air from the atmosphere.
[0038] Further, the AHU 106 may include a blower 302, a drive motor 304, a flexible bellow 306, an outlet sleeve 308, a V-belt 310, a pulley 312, a blower base frame 314, a filter mounting frame 316, a thermal break profile 318, an inlet air louver 320, a double skin cabin 322, an AHU base frame 324 and a pre-filter 326.
[0039] In an embodiment of the present invention, the blower 302 may be a Double Inlet Double Width (DIDW). The blower 302 may generate a pre-defined pressure in the pulled air.
[0040] In an exemplary embodiment of the present invention, the blower 302 may intake an air volume within

the range of 5000-8000 m3/h, a static pressure of 40-60 mmwg, a velocity pressure of 0-lOmmwg and a total pressure of 10-60mmwg. In another exemplary embodiment of the present invention, the blower 302 may output air at an outlet velocity of 5-10m/s with a fan total efficiency of around 80% and fan static efficiency of around 80% at a fan speed of 1500-1700 rpm. In an embodiment of the present invention, the drive motor 304 may require an operating power of 2.20kW to produce a motor speed of 1300-1500 rpm with a service factor of 2-10%.
[0041] In an embodiment of the present invention, the fan pulley, bush, shaft and motor pulley may have a dimension of 100-120mm, 1500-1700mm, 10-50mm and 100-150mm, respectively. In an embodiment of the present invention, the V-belt 310 may have a length of 1500-1700mm with a capacity of 10-60N and a belt speed of 0.5-1.0m/s. In an embodiment of the present invention, the AHU 106 may have a maximum power absorption of 4-10 kW with a max fan speed of 2000-2600rpm and a temperature range of -30° to +100°. Further, the pre-filter 326 may be a 10 micron pro filter bank. The air filter 110 may be installed inside the AHU 106 to filter the fresh air and remove excess moisture, dust and pollutants.
[0042] In an embodiment of the present invention, the AHU 106 may include a drive control panel (not shown) with an AC drive to control the operation of one or more components of the AHU 106. Further, the AHU 106 may be covered by a protective shed 128 for the protection of the AHU from external environment factors, such as rain, hailstorm and dust.

[0043] In an embodiment of the present invention, the duct assembly 108 may be coupled to the AHU 106 at a first end 118 of the duct assembly 108. The duct assembly 108 may be configured to receive the fresh air from the AHU 106. In an embodiment of the present invention, the duct assembly 108 may include a first duct and a second duct placed in the open area 116 and an enclosed area 120, respectively. The enclosed may correspond to a closed or inside area of a premise, such as a room, a hall and inside of a building. In an embodiment of the present invention, the open area and the enclosed area may be isolated from one another via an isolation member 122, such as a wall.
[0044] In an embodiment of the present invention, the first duct may have a square cross-sectional area. In an embodiment of the present invention, the first duct may be a 22swg sheet fabricated exhaust air ducting with MS flanges bolts, nuts, gaskets and damper finished with enamel paint. Further, the first duct may include thermal insulation and a jacket on the outer surface. Additionally, a duct support structure may be present on either side of the first duct.
[0045] In an embodiment of the present invention, the second duct may be coupled to the first duct at the isolation member 122. The second duct may be configured to receive the filtered fresh air from the first duct. Further, the second duct may have a circular cross-sectional area.
[0046] In an embodiment of the present invention, the manifold 112 may be coupled to a second end 124 of the duct assembly 108. Further, the manifold 112 mav nrovide

one or more outlets for air. In an embodiment of the present invention, the manifold 112 may have 4-10 outlets having 100-130mm diameter each. Further, the manifold 112 may be placed on a machine mezzanine floor and supported by a ducting supporting structure.
[0047] In an embodiment of the present invention, the one or more hoses 114 may be coupled to each of the one or more outlets of the manifold 112 to supply the filtered air to the one or more air inlets 202 of the one or more UV cassettes 200. Further, the one or more hoses 114 may be coupled to the manifold via one or more dampers. In an embodiment of the present invention, the one or more hoses 114 may be made of silicon and have a diameter of 100-130mm.
[0048] In an embodiment of the present invention, the air cooling unit 104 may also include an exhaust air unit 126 to pull the hot air from the UV light source 102 and disperse the hot air in the open area 116. Accordingly, the exhaust air unit 126 may be configured to egress the air circulating in the UV curing system 100. The exhaust air unit 126 may further include exhaust pipes and a flap to control pressure of air ingressing and circulating in the UV curing system 100 based at least on the temperature of the UV light source 102. The flap may be understood as planar structure placed in the exhaust pipe to close or open or partially open the passage of the exhaust pipe. In an exemplary embodiment of the present invention, the orientation of the flap inside the exhaust pipes may be adjusted manually. The orientation of the flap may vary from open to partially

closed to closed, based on the angle of the flap with respect to the exhaust pipe.
[0049] The exhaust air unit 126 may also include a clamp and a flow divider to control the flow of air flowing out of the UV curing system 100. In an exemplary embodiment of the present invention, the flap may be coupled to a damper motor for variation in the orientation of the flap.
[0050] Table 1 illustrates the effects of values of the damper motor on the various parameters of the air control unit 104.

Value of Damper Motor (in V) 7.1 5.4 5.8 5.6 6.3
Flap Position (in %) 70 50 58 56 63
Exhaust air temperature (in °C) 87 87 88 87 87
Reflector temperature 1 (in °C) 53 53 56 53 54
Reflector temperature 2 (in °C) 53 53 55 54 55
Water temperature supply (in °C) 43 43 44 44 43
Water temperature return (in °C) 53 53 55 54 55
Temperature of UV light source (in °C) 61 61 64 62 66
TABLE 1
[0051] Thus, the value of the damper motor may be controlled to adjust the opening percentage of the flaps. In an embodiment of the present invention, the value of the damper motor may be selected from 7.1V to 5.4V to adjust the opening of the damper from 70% to 50%. Further, the exhaust air temperature, reflector

temperature 1, reflector temperature 2, water temperature supply, water temperature return, temperature of UV light source may be maintained at 87-88°C, 53-56°C, 53-55°C, 43-44°C, 53-55°C and 61-64°C, respectively.
[0052] In an embodiment of the present invention, the air cooling unit 104 may require filter cleaning every quarter, a body cleaning of blower cabinet every month, a body cleaning of air duct every quarter and a body cleaning of UV cassette covers every week. Further, the air filter may be replaced based on the condition and requirements of the user.
[0053] Accordingly, the present invention provides the following effects or advantages.
[0054] The invention provides a UV curing system 100 having an air cooling unit 104 to cool the UV light source 102. The air cooling unit 104 pulls fresh air from an AHU 106 installed in an open area isolated to cool the UV light source installed in an enclosed area isolated from the open area. Thus, the fresh air is free of any ink mist that may be present in the enclosed area where the UV light source 102 is installed. Further, the fresh air is filtered via an air filter 110 in the air cooling unit 104. The cooling of the UV light source 102 via fresh and filtered air leads to the efficient working of the UV light source 102. The deposition of ink on the UV light source 102 is minimized to improve the life of the UV light source 102. Further, the cycle time for curing the photopolymers is decreased due to large periods of maintenance. Additionally, the air cooling unit 104 provides consistent operating parameters during

production like cassette temperature and running intensity. Therefore, the air cooling unit 104 for the UV curing system 100 enables efficient, fast and cost-effective curing of the photopolymers.
[0055] While the exemplary embodiments of the present invention are described and illustrated herein, it will be appreciated that they are merely illustrative. It will be understood by those skilled in the art that various modifications in form and detail may be made therein without departing from or offending the scope of the invention as defined by the appended claims.

We claim:

1. An ultraviolet (UV) curing system (100) having an
air cooling unit, the UV curing system (100)
comprises:
a UV light source (102) placed in an enclosed area (120) inside of a premise to generate UV light;
an air cooling unit (104) to cool the UV light source (102), the air cooling unit (104) having:
an Air Handling Unit (AHU) (106) placed in an open area (116) to pull fresh air from the atmosphere, wherein the open area (116) corresponds to an area having access to the atmospheric air and includes one of: a terrace, a ground and outside of a building;
a duct assembly (108) coupled to the AHU
(106) at a first end (118) of the duct assembly
(108) to receive the fresh air from the AHU
(106) ;
one or more hoses (114) coupled to a second end (124) of the duct assembly (108) to supply the fresh air to the UV light source (102) to cool the UV light source (102) .
2. The UV curing system (100) as claimed in claim 1,
wherein the enclosed area (120) and the open area
(116) are isolated from each other via an isolation member (122).
3. The UV curing system (100) as claimed in claim 1,
wherein the duct assembly (108) includes a first

duct and a second duct coupled at the isolation member (122) .
The UV curing system (100) as claimed in claim 3, further comprises an air filter (110) installed inside the AHU (106) to filter the fresh air.
The UV curing system (100) as claimed in claim 1, further comprises a manifold (112) coupled to the duct assembly (108) at a second end (124) of the duct assembly (108) to provide one or more outlets for the fresh air.
The UV curing system (100) as claimed in claim 1, wherein the one or more hoses (114) are coupled to each of the outlets of the manifold (112) and the one or more air inlets (202) of the one or more UV cassettes (200) to supply the fresh air for cooling the UV light source (102).
The UV curing system (100) as claimed in claim 1, further comprises an exhaust air unit (126) to egress the air circulating in the UV curing system.
The UV curing system (100) as claimed in claim 7, wherein exhaust air unit (126) further comprises a flap to control pressure of air ingressing and circulating in the UV curing system (100) based at least on the temperature of the UV light source (102) .
The UV curing system (100) as claimed in claim 6, wherein the hose (114) is made of silicon.

10. The UV curing system (100) as claimed in claim 1, wherein the UV curing system (100) is configured to cure photopolymer-based ink, adhesives and coatings.