FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
As amended by the Patents (Amendment) Act, 2005
AND
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2005
COMPLETE SPECIFICATION (See section 10 and rule 13)
TITLE OF THE INVENTION Infra-Red (IR) heater systems
APPLICANTS
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTOR
Chaudhari Sushil Ekanath and Bhattacharya Subhendu both of Crompton Greaves Ltd, Advanced materials and process technology Centre , Condition Monitoring & Diagnostic Research Centre, CG Global R&D Centre, Kanjur (E), Mumbai 400042, Maharashtra, India; both Indian Nationals.
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the nature of this invention and the manner in which it is to be performed.

Field of the Invention:
This invention relates to the field of heater systems for heating and curing a substance.
Particularly, this invention relates to Infra-Red (IR) heater systems.
Background of the Invention:
Currently, in the manufacture of transformers, the core packet with resin is cured by placing into oven. It is a time consuming process. There is a need to reduce this cycle time to cure the resin system.
IR short wave radiation, unlike thermal radiation, has deeper penetration power. Thermal radiations generally have very large wavelengths and hence they generally are ineffective in providing localized heat transport.
IR heaters are used in industrial manufacturing processes including curing of coatings. An infrared heater is a body with a higher temperature which transfers energy to a body with a lower temperature through electromagnetic radiation.
The geometry of a transformer is such that variable heat flux is required at various zones. Hence, an oven for curing is not a good solution and apparatus.
Prior Art:
DEI0126150 discloses a Process for preparation of uni-directional fiber reinforced laminated profiled parts by thermal curing of heat curable impregnated synthetic resin fiber strands using infrared radiation. Use of infrared (IR) radiation for

thermal curing of heat curable impregnated synthetic resin fiber strands is disclosed.
JP 53142447 discloses curing of epoxy resin coating continuously and rapidly, by irradiating with actinic radiation together with a heat radiation such as IR light.
GB801400 discloses a Method of coating surfaces such as hulls of boats and ships with cold-curing resin-containing sheets. The patent discloses use of infrared lamps, infra-red heat, steam or hot air as a means of heat for curing resin.
GB1165222 discloses a Process for coating a Cellulose Substrate with a Film-Forming Resin Composition. The patent discloses heating under infra-red heat, to a temperature of up to 350 F to cure a film of thermoplastic-thermosetting resin composition.
US7045174 discloses a Method and Device for Insulating Electro-technical Components. The patent discloses method for hardening electro-insulating materials by the utilization and/or co-utilization of near-infrared radiation (MR) having a wavelength of 500 nm to 1400 nm
However, IR radiation having directional control for directing the radiation in a particular direction for curing a particular area is not known in the art. Further, IR system having a specific dimension in combination with reflectors with specific structural dimension is also not disclosed in the art.
Objects of the Invention:
An object of the invention is to provide localized curing.

Another object of the invention is to provide an apparatus which provides a faster curing process.
Yet another object of the invention is to provide variable heat flux at various zones.
Still another object of the invention is to achieve cycle time reduction in relation to the process of curing.
An additional object of the invention is to achieve quick heating.
Yet an additional object of the invention is to provide a system which cures a resin on a substrate, said system and process being a relatively lower cost system and process.
Summary of the Invention:
For the purposes of this specification, a 'sample' may refer to a transformer housing with resin which is to be cured or any such housing upon which resin is applied and needs curing.
According to this invention, there is provided an Infra-Red (IR) heater system for curing samples, said system comprises:
a. cylindrical IR tube housing placed across a sample;
b. at least an IR emitter disposed along the inner wall of said cylindrical IR
tube housing, said IR emitter adapted to emit IR radiation;
c. plurality of reflectors located at pre-determined positions on opposing
interior walls of said cylindrical IR tube housing, said reflectors adapted to

reflect said emitted IR radiation targeted towards pre-defined zones of said sample; and d. Plurality of monochromators located at pre-defined zones for reflecting a selectable band of wavelengths of said IR radiation, targeted to pre-defined zones of said sample.
Typically, said tube housing is compact tube housing.
Typically, said tube housing includes concentrators adapted to counteract the effect of an indirect IR radiation source used to cure samples which are not directly in front of the IR system.
Typically, said tube housing includes multiple IR emitters at pre-defined distances with respect to each other.
Typically, said tube housing is an aluminum housing coated with aluminum foil on the surface along with a layer of black coating on the top of the surface.
Brief Description of the Accompanying Drawings:
The invention will now be described in relation to the accompanying drawings, in which:
Figure 1 illustrates a single source IR system; and
Figure 2 illustrates a multiple source IR system.

Detailed Description of the Accompanying Drawings:
According to this invention, there is provided a single source IR system with reflector emitter arrangements for propagation and emission of heat. Figure 1 illustrates a single source IR system.
According to this invention, there is also provided a multiple source IR system. Figure 2 illustrates a multiple source IR system.
The heat is used to generate localized thermal gradients which can be further used for curing of epoxy resin used as an adhesive between two substrates.
Also, since IR radiations have the characteristics of light they can actually dilate a surface and enter inside. Such localized heating for core packets can substantially cut down the power consumption for curing. Also, the penetration of IR radiation would improve cross linking density. The rate of heat transport is much better than thermal heating techniques.
In accordance with an embodiment of this invention, there is provided a cylindrical IR tube housing (12) placed across a sample. This is the IR heater body.
In accordance with another embodiment of this invention, there is provided at least an IR emitter (14) disposed along the inner wall of said cylindrical IR tube housing, said IR emitter adapted to emit IR radiation. This is the IR source. Figure 1 shows a single IR emitter placed vertically. Figure 2 shows a first IR emitter (14a) placed vertically and a second IR emitter (14b) placed horizontally.

In accordance with yet another embodiment of this invention, there is provided a plurality of reflectors (16) located at pre-determined positions on opposing interior walls of said cylindrical IR tube housing, said reflectors adapted to reflect said emitted IR radiation targeted towards pre-defined zones of said sample. The distance between two reflectors is governed by the sample geometry or the locations where localized curing is required.
The distances (exemplary) are shown in the Figures 1 and 2 of the accompanying drawings.
In accordance with still another embodiment of this invention, there is provided a plurality of monochromators (18) located at pre-defined zones for reflecting a selectable band of wavelengths of said IR radiation, targeted to pre-defined zones of said sample.
According to the system of Figure 1, the distance between second reflector and third on the inner lateral operative right wall is 0.5m. The length of the tube housing is 5m. The distance between two monochromators is 0.42m.
According to the system of Figure 2, the distance between first reflector and second reflector on the inner lateral operative left wall is 0.5m; the distance between the second reflector and the third reflector on the inner lateral operative left wall is 0.42m; the distance between the third reflector and the fourth reflector is 0.3m. The length of the tube housing is 5m. The distance between first reflector and second reflector on the inner lateral operative right wall is 0.6m; the distance between second reflector and third reflector on the inner lateral operative right wall

is 0.42m. The distance between horizontal emitter and vertical emitter is 2.5m.
According to an exemplary embodiment, a sample of pressboard (22 gm) would rise to a temperature of 120 degrees in 47 seconds using the IR heating technique.
According to another exemplary non-limiting embodiment, a solvent less epoxy resin was applied to a polyester fleece and placed between substrates. The temperature of the sample was raised using IR heating technique and the sample was cured for 15 minutes. The post curing bond strength was found to be very good and equivalent to the case of thermally heated core packets in an oven.
The solid angle heat flux coverage for a cylindrical IR tube heater is increased by a series of reflector and emitter arrangement geometry so that a single heat source can be used. The short wave IR travels at the speed of light i.e. at a speed of 300000 m/s. Hence, subsequently it can cover the distance between two reflectors of a few centimetres in nanoseconds. At the reflector surface, the IR radiation gets reflected without loss of heat flux since the enclosure housing is very compact. Interestingly, concentrators can also be used to counteract the effect of an indirect IR radiation source used to cure samples which are not directly in front of the IR lamp. Hence, a single source IR lamp can be used for covering a larger overall distance. In case of a multi-source system, the IR lamps are placed at specific distances inside an aluminum housing coated with aluminum foil on the surface along with a layer of black coating on the top of the surface. This reduces the process lead time by about 30%.
It is to be understood that a similar or same design would be replicated as the size of the job changes or load changes. Also, the number of monochromators would scale accordingly.

While this detailed description has disclosed certain specific embodiments of the present invention for illustrative purposes, various modifications will be apparent to those skilled in the art which do not constitute departures from the spirit and scope of the invention as defined in the following claims, and it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

We claim,
1. An Infra-Red (IR) heater system for curing samples, said system comprising:
a. cylindrical IR tube housing placed across a sample;
b. at least an IR emitter disposed along the inner wall of said cylindrical IR
tube housing, said IR emitter adapted to emit IR radiation;
c. plurality of reflectors located at pre-determined positions on opposing
interior walls of said cylindrical IR tube housing, said reflectors adapted to
reflect said emitted IR radiation targeted towards pre-defined zones of said
sample; and
d. Plurality of monochromators located at pre-defined zones for reflecting a
selectable band of wavelengths of said IR radiation, /targeted to pre-defined
zones of said sample.
2. A system as claimed in claim 1 wherein, said tube housing is a compact tube housing.
3. A system as claimed in claim 1 wherein, said tube housing includes concentrators adapted to counteract the effect of an indirect IR radiation source used to cure samples which are not directly in front of the IR system.
4. A system as claimed in claim 1 wherein, said tube housing includes multiple IR emitters at pre-defined distances with respect to each other.
5. A system as claimed in claim 1 wherein, said tube housing is an aluminum housing coated with aluminum foil on the surface along with a layer of black coating on the top of the surface.