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
Fire fighting system for transformers
APPLICANTS :
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTOR (S):
Singh Aditya, of Crompton Greaves Ltd, Transformer (T3) Division, Plot No 29, 31 and 32, New Industrial Area No 1 AKVN, Manideep, 462046, Madhya Pradesh, 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:

Field of the Invention:
This invention relates to mechanical and chemical engineering.
Particularly, this invention relates to fire fighting equipment.
Still particularly, this invention relates to fire fighting system for transformers.
Background of the Invention:
Transformers are crucial electrical component in companies, industries, factories, power stations and the like. Its efficient working is imperative and hence, its health needs to be monitored for many assemblies are dependant upon transformer working.
The many causes of damage to transformers include insulation failures, design or manufacturing errors, oil contamination, overloading, line surge, loose connections, moisture, fire explosion.
The category of fire or explosion relates to those cases where a heat rise in the oil level of the transformer which may lead to hazardous situations. Transformer explosions and fires are costly and create serious disruptions. A fire fighting system, hence is important for factories and communities using transformers.
Hence, a fire fighting system for a transformer is an important part of any comprehensive Risk Management Program in a factory.

Fires and related fire fighting have been classified into classes. Class B relates to flammable liquids and gases, and Class C relates to electrical equipment. These are the most pertinent classes for a transformer fire.
Water cannot be used to fight or douse such fires, since water is a conductor of electricity. Sodium bicarbonate or Nitrogen is traditionally used for fighting or dousing such fires and for cooling the medium to extinguish the fire.
Prior Art:
GB1374418 discloses a Fire Detection Systems and Apparatus. A fire detection unit including at least three fire detectors for producing output signals when phenomena are detected which occur in the case of fire, or risk of fire, means for producing an alarm signal and means coupling the detectors to the signalling means in such a way that an alarm signal is given in response to output signals from two of said detectors when said output signals occur together but not when one of the output signals occurs alone, said two detectors producing output signals in response to different phenomena, and said alarm signal is also given in response to an output signal from a third of said five detectors.
It uses smoke and temperature detectors and measuring current in resistor is not mentioned.
There is a need for a better and fast responsive fire fighting system in terms of sensing the fire as well as dousing the fire.
Objects of the Invention:
An object of the invention is to provide a fast acting fire fighting system for

transformer.
Another object of the invention is to provide a sensitive fire fighting system for transformer.
Yet another object of the invention is to provide an efficient fire fighting system for transformer.
Still another object of the invention is to provide a fast acting fire fighting system for transformer which senses start of fire quickly.
Yet another object of the invention is to provide a fast acting fire fighting system for transformer which acts towards extinguishing fire quickly.
Summary of the Invention:
According to this invention, there is provided a fire fighting system for transformers, said system comprises:
- plurality of sensing elements, placed in said transformer, adapted to sense change in temperature per unit time;
- relay circuit adapted to be connected to said sensing elements wherein the changing resistance changes the current in the circuit which actuates the current relay; and
- network of valves adapted to inject or release oxygen absorbing material in said transformer upon actuation of relay by sensors.
Preferably, said plurality of sensing elements is a network of sensing elements.

Typically, said oxygen absorbing material is Purple-K.
Alternatively, said oxygen absorbing material is Halon.
Typically, said system includes a processor adapted to adjust the temperature per unit time setting in order to actuate the relay at defined settings.
Preferably, said processor includes position defining means adapted to read position co-ordinates of each of said sensing element in order to provide a relative position of rise in temperature in said transformer.
Preferably, said processor includes position defining means adapted to read position co-ordinates of each of said valves in order to activate a relative valve or a plurality of valves connected to the location sensing rise in temperature.
Brief Description of the Accompanying Drawings:
The invention will now be described in relation to the accompanying drawings, in which:
Figure 1 illustrates a schematic of the system.
Detailed Description of the Accompanying Drawings:
According to this invention, there is provided a fire fighting system (100) for transformers (T).

Figure 1 illustrates a schematic of the system.
In accordance with an embodiment of this invention, there is provided a plurality of sensing elements (S), placed in said transformer, adapted to sense change in temperature per unit time. Temperature of the transformer oil increases sharply at the onset of fire. To detect the fire resistor based sensing elements are used as the resistivity of a material increases or decreases (depending on the material) with the change in temperature.
In accordance with another embodiment of this invention, there is provided a relay circuit (RC) adapted to be connected to said sensing elements. The changing resistance changes the current in the circuit which actuates the current relay.
In accordance with yet another embodiment of this invention, there is provided a network of valves (V) adapted to inject or release oxygen absorbing material in said transformer upon actuation of relay by sensors.
This current relay sends signal to the central box to inject Purple K or Halon through the pressurized lines into the transformer via valves located on the transformer. Halon or Purple K extinguishes fire safeguarding the substation and the transformer.
Purple-K (KNaHC03) is a dry chemical fire suppression agent used in some dry powder fire extinguishers. It is the most effective dry chemical in fighting class B (flammable liquid) fire, and can be used against some energized electrical equipment fires (USA class C fires). Dry Chemical Powder works by directly

inhibiting the chemical chain reaction which forms one of the four sides of the fire
tetrahedron (Heat + Oxygen + Fuel + Chemical Chain Reaction = Fire).
Hal on is a compound in which the hydrogen atoms of a hydrocarbon have been
replaced by bromine and other halogen atoms. It is very stable. Halon 1211 is
bromochlorodifluoromethane.
As extinguishing agents, halons are up to ten times more effective in putting out fires than other chemicals. Most halons are non-toxic and extremely fast and effective. Chemically inert, they are harmless to delicate equipment, including computer circuits, and leave no residue.
There may be provided a processor (P) to adjust the temperature per unit time
i
setting in order to actuate the relay at defined settings.
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. A fire fighting system for transformers, said system comprising:
- plurality of sensing elements, placed in said transformer, adapted to sense change in temperature per unit time;
- relay circuit adapted to be connected to said sensing elements wherein the changing resistance changes the current in the circuit which actuates the current relay; and
- network of valves adapted to inject or release oxygen absorbing material in said transformer upon actuation of relay by sensors.

2. A system as claimed in claim 1 wherein, said plurality of sensing elements is a network of sensing elements.
3. A system as claimed in claim 1 wherein, said oxygen absorbing material is Purple-K.
4. A system as claimed in claim 1 wherein, said oxygen absorbing material is Halon.
5. A system as claimed in claim 1 wherein, said system includes a processor adapted to adjust the temperature per unit time setting in order to actuate the relay at defined settings.
6. A system as claimed in claim 1 wherein, said processor includes position defining means adapted to read position co-ordinates of each of said sensing

element in order to provide a relative position of rise in temperature in said transformer.
7. A system as claimed in claim 1 wherein, said processor includes position defining means adapted to read position co-ordinates of each of said valves in order to activate a relative valve or a plurality of valves connected to the location sensing rise in temperature.