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
UNSATURATED POLYESTERIMIDE POLYMER CONCRETE COMPOSITION AND MODIFIED THERMOSYPHONING SYSTEM BY USING THE SAME
APPLICANTS
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTOR
KESHAWATKAR BABURAO of Crompton Greaves Ltd, Conition Monitoring & Diagnostic Centre, Global R&D Centre, Kanjur (E), Mumbai 400042, Maharashtra, India; an Indian National.
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the nature of this invention and the manner in which it is to be performed:

TECHNICAL FIELD OF THE INVENTION:
The present invention relates to unsaturated polyesterimide polymer concrete composition and further to the balls and slabs casted from the said composition of the invention in the thermosyphon system.
The present invention also relates to a thermosyphon system for removal of moisture as well as polar components from the transformer oil.
The present invention also relates to a thermosyphoning method for removal of contaminants from transformer oil by using the said thermosyphon system.
BACKGROUND OF THE INVENTION:
An insulating oil since long time has been used as the basic insulating material in the transformer which also serves as coolant. During service, oil gets oxidized producing undesirable constituents like acid, sludge, water, polar compound etc. The moisture content in the insulating oil of the transformer has a significant impact on its aging, especially aging of the insulating paper. Moisture in the transformer oil also has the detrimental effect on the dielectric strength of oil leading to breakdown in electrical insulation. More than 98% of the moisture in a transformer is in the cellulose insulation and less than 2% in the insulating oil. Reduction of moisture and prevention of moisture migration into transformer insulation has gained utmost importance.
Thermosyphoning system is generally used for dry out of transformer insulation. Water being the major culprit for the insulation system and during any part of installation, servicing or maintenance, some part of moisture is bound to enter into the transformer oil. Generally the online fhermosyphone systems are used to remove the same. In this system the transformer oil moves out of the thermosyphonic media such as molecular sieves, etc and it absorbs out the moisture content of the transformer oil making it dry.

Existing thermosyphon system use alumina beads made of Aluminium Silicate (known as molecular sieve 4 - 6 mm diameter) and are generally used for continuous removal of moisture from transformer oil by disturbing the equilibrium between the moisture in the paper and that of in the oil to the extent that the moisture starts migrating from the (wet) paper to the (dry) oil. This is being a continuous process that slowly dries out the paper and oil in the transformer. The migration of moisture to the oil will slow down as the moisture content of the paper converges to its equilibrium position with dry oil.
Transformers in service for more than 15 years will continuously generate moisture due to ageing of the insulation paper by chemical reaction. Bringing down moisture around an acceptable 1.5% is always advisable.
A traditional method of moisture removal leads rapid drying of the oil by either changing the oil or by rapid dry-out (within days). These methods will readily dry the oil but not the paper insulation system. The rate of drying depends on rate of diffusion of water from the paper into the oil, which is a slow process. Frequent oil processing is required otherwise; the oil will regain its moisture content after a short period of time. Rapid removal of moisture from oil introduces a pronounced (wet) paper (dry) oil condition that will lead to rapid shrinkage of the paper. In this thermo siphoning process which is gradual and on-load and can even be closed down by closing the valve if not required.
Apart from moisture, the other contaminants like polar component, acid, sludge, etc deteriorate quality of oil and affect other insulating materials like paper, pressboard etc. which results in reducing the active service life span of transformer. Usually these impurities are removed under preventive maintenance either by filtration or reclamation of oil.
Thus there is need of the modified thermosyphoning system which will be able to remove moisture and polar components and helps to maintain the dielectric strength of the oil, thus protecting electrical insulation.

OBJECTS OF THE INVENTION:
An object of the invention is to provide unsaturated polyesterimide polymer concrete composition and the balls and slabs casted from the said composition of the invention which are used as adsorbent in the thermosyphon system.
Another object of the invention is to provide a thermosyphon system comprising polyester polyimide cold setting concrete and alumina beads for use within a transformer.
Another object of the invention is to provide a thermosyphon system comprising polyester polyimide cold setting concrete and alumina beads for use within a transformer thereby effectively removing the moisture and other contaminants/impurities such as sludge, polar components, and acid from the transformer oil.
Yet another object of the invention is to provide a thermosyphon system comprising polyester polyimide cold setting concrete and alumina beads for use within a transformer thereby maintaining the dielectric strength of the oil, thus protecting the electrical insulation.
Yet another object of the invention is to provide a thermosyphon system comprising polyester polyimide cold setting concrete and alumina beads for use within a transformer which is efficient and economical.
Yet another object of the invention is to provide a thermosyphon system comprising polyester polyimide cold setting concrete and alumina beads for use within a transformer thereby eliminating waste oil and thus making it eco-friendly.
Yet another object of the invention is to provide a thermosyphon system comprising polyester polyimide cold setting concrete and alumina beads for use within a transformer thereby

increasing health of the transformer insulation and thus increasing the life of the aged
transformer.
Yet another object of the invention is to provide a thermosyphoning method for impurities
removal from the transformer oil by using thermosyphon system of the invention which is
efficient, economical and simple to carry out.
DETAILED DESCRIPTION OF THE INVENTION:
In one of the aspect of the invention, there is provided the unsaturated polyesterimide polymer concrete composition comprising
a) first mixture of resin system comprising 15.95 to 19.50 parts by weight of unsaturated polyesterimide resin; 1,44 to 1.76 parts by weight of styrene monomer; 0.216 to 0.264 parts by weight of silane; and 0.386 to 0.472 parts by weight of pigment;
b) second mixture of pretreated filler system comprising 61 to 74 parts by weight of silica having particle size 40 to 800 μ; 9.9 to 11 parts by weight of Aluminium trihydroxide; and 1.44 to 1.76 parts by weight of Rutile; and
c) final mixture comprising the said first mixture and the said second mixture and 0.21 to 0.232 % of hardner selected from methyl ethyl ketone peroxide to form unsaturated polyesterimide polymer concrete composition.
"Thermally pretreated" in this context means that by heat treatment methods the water is removed from the fillers.
In the present invention the filler are subjected to heating at 120 to 125°C for 4 hours followed by cooling down to obtain thermally pretreated fillers.
In another aspect of the invention, there is provided balls and slabs casting with unsaturated polyesterimide polymer concrete by using the unsaturated polyesterimide polymer concrete composition of the invention.

In yet another aspect of the invention there is provided a method of casting balls and slabs by using the unsaturated polyesterimide polymer concrete composition of the invention,
The method of casting balls and slabs by using the unsaturated polyesterimide polymer concrete composition of the invention;
the method comprising pouring the unsaturated polyesterimide polymer concrete composition of the invention under vacuum at 650 mm Hg at 2-3 kg/ minute flow rate into mould followed by fine vibration application to a filled mould for 1-2 minutes for eliminating air bubbles, removing the vacuum and transferring the filled mould for curing at room temperature; and de-mould the casted balls or slabs; and subjecting the casted balls or slabs to post curing at 60 to 80° C for 3-4 hour and cooling down to room temperature.
According to preferred aspect of this invention, there is provided a thermosyphon system for a transformer for removal of contaminant including water, acid, polar component, sludge, etc; the system comprising thermosyphon cylindrical chamber (1) having a plurality of perforated trays (10a) and (10b) comprising a layer of absorbent thereon being disposed in a chamber in a spaced relationship with each other and first connecting pipe (2) being provided at the upper end of said chamber (1) for connecting the top thermal head (5) of the transformer to said chamber; a second connecting pipe (6) being provided at the lower end of said chamber (1) for connecting the bottom thermal head (7) of said transformer to said chamber wherein the layer of adsorbent comprising beads of activated alumina silicate and balls and slabs casted with unsaturated polyesterimide polymer concrete.
In yet another aspect of the invention, the thermosyphon system for use within a transformer has a thermosyphon cylindrical chamber (1) for accommodating the plurality of perforated adsorbent trays having a layer of absorbent provided therein as per the capacity of the transformer, quantity of oil and impurities contents. The trays are big and small and are stacked alternatively in a spaced relationship with each other along with the vertical axis. The trays are secured at either ends thereof to the holding rows, disposed in said chamber. Separators are provided between the trays to provide the space between said trays. A first connecting pipe having a regulator valve

and an air outlet is provided at the upper end of the thermosyphon chamber to connect the chamber with the top thermal head of the transformer. A second connecting pipe having regulator valve and oil drainage valve is provided at the lower end of a thermosyphon chamber to connect the chamber with the bottom thermal head of the transformer.
The absorbent layer provided in the perforated trays comprises of activated aluminium silicate beads having diameter of 4 to 6 mm and balls and slabs casted with unsaturated polyesterimide polymer concrete.
The balls and slabs casted with unsaturated polyesterimide polymer concrete composition is also placed or kept suspended in the thermosyphon chambers to improve efficiency of the thermosyphon system and removes efficiently the contaminants including water, acid, polar -component, sludge, etc.
An adsorbent can be reactivated by discarding Polymer concrete slabs and recovering Aluminium Silicate and reactivated at 250° C for 6 to 8 Hours under vacuum
The size or dimensions and quantity used of the adsorbent bed depend upon capacity of transformer, quantity of oil used and concentration of impurities and moisture in the oil.
The construction material used for cylindrical chamber and perforated trays is stainless steel.
A thermosyphon apparatus according to a preferred embodiment is herein described and illustrated in the accompanying drawings:
Figure 1 depicts the plan view of the apparatus of this invention.
Figure 1 of the accompanying drawing shows the thermosyphon system of the present invention. The apparatus comprises a thermosyphon cylindrical chamber (1). A first connecting pipe (2) at the upper end of chamber (1) connects chamber (1) to the top thermal head (5) of a transformer.

A first connecting pipe (2) has an air outlet (3) and a regulating valve 4. Chamber (1) has a second connecting pipe (6) at the lower end of the chamber (1) and adapted to be connected to the bottom thermal head (7) of the trans-former. Connecting pipe (6) has an oil drainage valve (8) and a regulating valve (9).
A plurality of large perforated trays (10a) and small perforated trays (10b) are stacked in a spaced relationship within chamber 1. Separators (11) are disposed between adjacent trays. An adsorbent is supported on said trays. Trays (10a) and (10b) are horizontal.
In another aspect of the invention, there is provided a thermosyphoning method of removing contaminants from the transformer oil by using the said thermosyphon system of the invention; the method comprising passing transformer oil consisting of moisture and polar component at 55 to 65° C into cylindrical chambers through the second connecting pipe at the lower end of the chamber and passing the oil in upward direction under gravity through a plurality of perforated trays comprising the layer of adsorbent consisting of beads of activated alumina silicate and balls and slabs casted with unsaturated polyesterimide polymer concrete so that oil is coming in close contact with the adsorbent layer for removal of contaminants like moisture, polar component, acid, sludge, etc.
The oil free from contaminants is circulated back to the transformer through the first connecting pipe of the chamber.
The method of removing contaminants from the transformer oil by using the said thermosyphon system of the invention removes the moisture from higher ppm to less than 2 ppm and also removes polar components from the contaminated oil and brings down the acidity of the oil so as to circulate back to the transformer as insulating oil. The method also improves interfacial tension of the transformer oil as well as improves Tan Delta or Dielectric Dissipation factor of the oil. Thus improving overall oil quality index, electrical properties and hence when the oil is circulated back from thermosyphon system to transformer, it improves the health of the transformer insulation. Thus prolongs life of the aged transformer and saves the asset from

damaging. The thermosyphon system and method of removal of contaminants from the transformer oil by using the said thermosyphon system of the invention is efficient and economical. It also eliminates waste oil and thus making it eco-friendly. Thus the method of removal of contaminants from the transformer oil by using thermosyphon system of the invention is efficient, economical and simple to carry out,
The following experimental examples are illustrative of the invention but not limitative of the scope thereof:
Example 1:
a) First mixture
17.731 gm of unsaturated polyesterimide resin was mixed with 1.6 gm of styrene monomer; 0.24 gm of silane; and 0.429 gm of pigment to get the first mixture.
b) Second mixture
67.4 gm of silica having particle size 40 to 800 μ was mixed with 11 gm of Aluminium trihydroxide; and 1.6 gm of Rutile to obtain second mixture.
c) Final mixture
The first mixture was mixed with the second mixture along with 0.21 gm methyl ethyl ketone peroxide as hardner to obtain final mixture.
d) Balls and slabs of unsaturated polyesterimide polymer concrete composition
The final mixture of unsaturated polyesterimide polymer concrete composition was poured under vacuum at 650 mm Hg at 2 kg/ minute flow rate into mould of balls and slabs. The filled moulds are subjected to fine vibration for 1-2 minutes for elimination of air bubbles. The vacuum was removed and filled mould was transferred for curing at room temperature. The slabs and balls were de-moulded and subjected to post curing at 60° C for 3 hour and further cooled down to room temperature.

The balls and slabs casted from unsaturated polyesterimide polymer concrete composition were placed in combination with beads of aluminium silicate in perforated trays in thermosyphon system. The oils viz. Uninhibited Naphthenic Oil of International Origin; Uninhibited Naphthenic Oil of Indian origin and Uninhibited Isoparaffinic Oil of Indian origin were passed though thermosyphon system where the perforated trays were filled with the balls and slabs casted from unsaturated polyesterimide polymer concrete composition in combination with beads of aluminium silicate. The oils obtained after passing through the thermosyphon system was tested for moisture content, acidity, Interfacial tension, Dielectric Dissipation factor at 90° C The test results are tabulated in table 1.
Table 1: Results of Oil Properties Before and after Thermosyphoning

Characteristics Uninhibited Uninhibited Uninhibited
Naphthenic Naphthenic Isoparaffinic
Oil of Oil of Indian Oil
Internationa 1 Origin Origin
Before Thermosyphoning:
- Moisture Content, ppm 16 17 16
- Acidity, mg KOH/g oil 0.0731 0.091 0.0573
- Interfacial Tension, mN/m 25 23 26
- Dielectric Dissipation Factor at 90°C, % 10.89 11.11 6.927
After Thermosyphoning:

- Moisture Content, ppm 2 2 2
- Acidity, mg KOH/g oil 0.0022 0.03 0.021
- Interfacial Tension, mN/m 39 37 40
- Dielectric Dissipation Factor at 90°C, % 3.73 3.70 2.31
From the results obtained, it was found that the moisture content and acidity of the oil was reduced. There was improvement in the Interfacial tension and Dielectric Dissipation factors of the oil.

We Claim:
1. An unsaturated polyesterimide polymer concrete composition comprising
a) first mixture of resin system comprising 15.95 to 19.50 parts by weight of unsaturated polyesterimide resin; 1.44 to 1.76 parts by weight of styrene monomer; 0.216 to 0.264 parts by weight of silane; and 0.386 to 0.472 parts by weight of pigment;
b) second mixture of pretreated filler system comprising 61 to 74 parts by weight of silica having particle size 40 to 800 μ 9.9 to 11 parts by weight of Aluminium trihydroxide; and 1.44 to 1.76 parts by weight of Rutile; and
c) final mixture comprising the said first mixture and the said second mixture and 0.21 to 0.232% of hardner selected from methyl ethyl ketone peroxide to form unsaturated polyesterimide polymer concrete composition.

2. The composition as claimed in claim 1, wherein the filler are subjected to heating at 120 to 1250C for 4 hours followed by cooling down to obtain thermally pretreated fillers.
3. The balls and slabs casted by using unsaturated polyesterimide polymer concrete composition of claim 1.
4. A method to cast balls and slabs by using the unsaturated polyesterimide polymer concrete composition of claim 1;
the method comprising pouring the unsaturated polyesterimide polymer concrete composition of the invention under vacuum at 650 mm Hg at 2-3 kg/ minute flow rate into mould followed by fine vibration application to a filled mould for 1-2 minutes for eliminating air bubbles, removing the vacuum and transferring the filled mould for curing at room temperature; and de-mould the casted balls or slabs; and subjecting the casted balls or slabs to post curing at 60-80° C for 3-4 hour and cooling down to room temperature.

5. A thermosyphon system for a transformer for removal of contaminant including water,
acid, polar component, sludge, etc;
the system comprising thermosyphon cylindrical chamber (1) having a plurality of perforated trays (10a) and (10b) comprising a layer of adsorbent thereon being disposed in a chamber in a spaced relationship with each other and first connecting pipe (2) being provided at the upper end of said chamber (1) for connecting the top thermal head (5) of the transformer to said chamber; a second connecting pipe (6) being provided at the lower end of said chamber (1) for connecting the bottom thermal head (7) of said transformer to said chamber wherein the layer of adsorbent comprising beads of activated alumina silicate and balls and slabs casted with unsaturated polyesterimide polymer concrete composition as claimed in any of claims 1 to 4.
6. The thermosyphon system as claimed in claim 5 further comprises the balls and slabs casted with unsaturated polyesterimide polymer concrete composition suspended in the thermosyphon chambers to improve efficiency of the thermosyphon system and removes efficiently contaminants including water, acid, polar component, sludge, etc.
7. The thermosyphon system as claimed in claim 5 wherein a plurality of large perforated trays (10a) and small perforated trays (10b) are stacked in a spaced relationship within chamber 1; separators (11) being disposed between adjacent trays; an adsorbent being supported on said trays and trays (10a) and (10b) being horizontal.
8. A thermosyphoning method of removing contaminants from the transformer oil by using the said thermosyphon system of claim 5;
the method comprising passing transformer oil consisting of moisture and polar component at 55 to 65° C into cylindrical chambers through the second connecting pipe at the lower end of the chamber and passing the oil in upward direction under gravity through a plurality of perforated trays comprising the layer of adsorbent consisting of beads of activated alumina silicate and balls and slabs casted with unsaturated

polyesterimide polymer concrete so that oil is coming in close contact with the adsorbent layer for removal of contaminants like moisture, polar component, acid, sludge, etc.
9. The thermosyphoning method as claimed in claim 8 further comprises circulation of the oil free from contaminants back to the transformer through the first connecting pipe of the chamber.
10. The thermosyphon system and method of thermosyphonic by using the system as claimed in any of the preceding claims wherein the use of adsorbent comprising beads of activated alumina silicate and balls and slabs casted with unsaturated polyesterimide polymer concrete composition as claimed in any of claims 1 to 4 improving interfacial tension of the transformer oil; Tan Delta or Dielectric Dissipation factor of the oil; overall oil quality index, electrical properties and health of the transformer insulation.