FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
As amended by the Patents (Amendment) Act, 2005
&
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2005
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
A Pressure Relief Device with safety mechanism
APPLICANTS
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTOR
PAXIL KIRAN SHASHIKANT of Crompton Greaves Ltd, S3 Division; A-3, Ambad M.I.D.C.; Nashik 422010 , 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:

Field of the Invention:
This invention relates to the field of mechanical devices.
Particularly, this invention relates to the field of safety systems for pressurized gaseous containers.
Still particularly, this invention relates to a Pressure Relief Device with safety mechanism.
Background of the Invention:
Various gases are used for different applications. These gases, for industrial purposes are stored in pressurized chambers. The amount of pressurization may render the gaseous state of the nature to be liquefied and hence be stored in its liquefied form. In some cases, the liquefaction is not necessary, and hence, the gases are stored in pressurized gaseous forms, itself.
In cases of switchgears, gases are used for insulation (SF6), cooling, heating, etc.
For purposes of safety of gas filled pressure vessels, enclosures or switchgear, are fitted with Pressure Relief Device (PRD). Typically, PRD opens after preset pressure level and releases the generated high pressure to atmosphere in a short

span of time. In such a case total gas is left in atmosphere, thereby releasing the pressure and un-harming the vessel or container or system.
Not all gases are good for release to the atmosphere. In the state of the current ecosystem, it becomes imperative that greenhouse gases be treated with care. Hence there is need to minimize release of such gases to atmosphere. There is also a need to arrest the release of such gases, as much as possible.
Prior Art:
US20090314356A1 discloses a pressure relief plate of hat shaped for protecting the pressure relief device from external environment.
US5937893A seems to be discloses the use of a shield for attaching to the PRD cover.
US2005133094A1 seems to be discloses an enclosure that confines fluids discharged through the pressure relief device and directs the discharged fluids.
However, none of these devices disclose a mechanism for disallowing release of gases into the atmosphere or recycling of released gases.
Objectives of the Invention:

An object of the invention is to provide a safe pressure relief device.
Another object of the invention is to provide a reliable pressure relief device.
Yet another object of the invention is to provide a mechanism for disallowing release of gases from a pressurized gaseous enclosure, upon increase of pressure beyond acceptable thresholds.
Still another object of the invention is to provide a mechanism for recycling release of gases from a pressurized gaseous enclosure, upon increase of pressure beyond acceptable thresholds.
Summary of the Invention:
According to this invention, there is provided a Pressure Relief Device with safety mechanism for an enclosure enclosing gas, adapted to prevent release of gases to the atmosphere, said device comprises:
a. diaphragm covering an opening of an enclosure, said diaphragm adapted to
rupture at a pre-defined pressure (of gas) within said enclosure;
b. guiding means adapted to guide released gas from said ruptured diaphragm;
c. sealing means adapted to seal said guiding means to said enclosure; and
characterised in that, said device includes:

gas collector means adapted to collect gas which emits out of said enclosure through said ruptured diaphragm.
Typically, said gas collector means is an inflatable gas collector means adapted to be positioned in said device in its deflated condition, and further adapted to inflate upon receiving said gas from said enclosure through said ruptured diaphragm.
Typically, said device includes:
• fastening means adapted to fasten said guiding means to said enclosure; and
• O-rings adapted to secure said fastening means to said enclosure.
Typically, said diaphragm includes centrally meeting seams adapted to collapse and break open said diaphragm upon breach of pre-defined pressure of gas within said enclosure.
Typically, said gas collector means is placed between said diaphragm and said guiding means.
Alternatively, said gas collector means is placed after said guiding means.

Brief Description of the Accompanying Drawings:
Figure 1 illustrates a schematic of the pressure relief device of the prior art; and
Figure 2 illustrates a schematic of the pressure relief device of the prior art, depicting the release of gases.
The invention will now be described in relation to the accompanying drawings, in which:
Figure 3 illustrates a schematic of the pressure relied device; and
Figure 4 illustrates a schematic of the pressure relief device, depicting the release of gases, and its operating mechanism.
Detailed Description of the Accompanying Drawings:
Figure 1 illustrates a schematic of the pressure relief device of the prior art; and Figure 2 illustrates a schematic of the pressure relief device of the prior art, depicting the release of gases.
Typically, an enclosure (or switchgear) (6) is filled with gas at a pre-defined pressure. The switchgear utilizes this gas for purposes of insulation between the various conductors that may be placed inside it. Normally, one such gas that is used is SF6 which is a greenhouse gas. Hence, its release into the atmosphere,

although not harmful or toxic, is not desirable, in terms of current regulations concerning release of greenhouse gases.
A Pressure Relief Device, is typically, is a safety mechanism for the enclosure. In instances, wherein the gas pressure increases beyond permissible thresholds, then a safety system needs to be employed in order to release the developed pressure. The PRD takes care of the increase in pressure. Typically, a diaphragm (2) is used such that said diaphragm is made of a material or of a construction such that it breaks beyond a defined threshold. The defined threshold is the bearing capacity of the enclosure. Thus, the diaphragm breaks open, and the gases inside the chamber may be released. At normal pressure (i.e. below rupture pressure of the Pressure Relief Device), the diaphragm acts as a barrier. Typically, O-ring type sealing (4) is used to seal the gas.
There is also provided a guiding means (guiding plate) (7) which guides the released gas into guided directions for release. The arrows (as shown in Figure 2 of the accompanying drawings) show the guided direction for released gases. This guided direction is important so that the gas does not come into direct contact with a person near the enclosure. The guiding means is fitted to the enclosure by means of fasteners (8).
In accordance with the prior art, the Pressure Relief Device is the diaphragm and the guiding means (guiding plate).

Here, all the gases are released to the atmosphere.
According to this invention, there is provided a Pressure Relief Device with safety mechanism for an enclosure enclosing gas, adapted to prevent release of gases to the atmosphere.
Figure 3 illustrates a schematic of the pressure relied device; and Figure 4 illustrates a schematic of the pressure relief device, depicting the release of gases, and its operating mechanism.
In accordance with an embodiment of this invention, there is provided a diaphragm (2) covering an opening of an enclosure (6), said diaphragm adapted to rupture at a pre-defined pressure (of gas) within said enclosure. The diaphragm is held in place, as long as the gas within said enclosure is within a pre-defined range of pressure. However, the design, construction, and material of the diaphragm is such that, as the pressure breaches the defined threshold, the diaphragm is adapted to rupture, thereby allowing the gas to escape through the ruptured diaphragm, and thus, decreasing the pressure in the enclosure.

In accordance with another embodiment of this invention, there is provided a guiding means (7) adapted to guide released gas from said ruptured diaphragm, The guided gas is depicted by arrows in Figure 4 of the accompanying drawings.
In accordance with yet another embodiment of this invention, there is provided a sealing means (8, 4) adapted to seal said guiding means to said enclosure. The sealing means, typically, is a set of fasteners (8) and O-rings (4).
In accordance with still another embodiment of this invention, there is provided a gas collector means (1) adapted to collect gas which emits out of said enclosure through said ruptured diaphragm. Typically, said gas collector means is an inflatable gas collector means adapted to inflate in order to receive decompressed gas out of said enclosure.
As the pressurized gas ruptures the diaphragm, the gas decompresses upon exit, and fills the gas collector means. The gas collector means is typically an inflatable air bag. This gas collector means, thus expands from its initial deflated condition. The gas collector means also expands in accordance with the space provided in between the fasteners and as guided by the guiding means. This is shown in Figure 4 of the accompanying drawings.

We claim,
1. A Pressure Relief Device with safety mechanism for an enclosure enclosing gas, adapted to prevent release of gases to the atmosphere, said device comprising:
a. diaphragm covering an opening of an enclosure, diaphragm adapted to
rupture at a pre-defined pressure (of gas) within, said enclosure;
b. guiding means adapted to guide released gas from said ruptured
diaphragm;
c. sealing means adapted to seal said guiding means to said enclosure; and
characterised in that, said device includes:
gas collector means adapted to collect gas which emits out of said enclosure through said ruptured diaphragm.
2. A device as claimed in claim 1 wherien, said gas collector means is an inflatable gas collector means adapted to be positioned in said device in its deflated condition, and further adapted to inflate upon receiving said gas from said enclosure through said ruptured diaphragm.
3. A device as claimed in claim 1 wherein, said device includes:
• fastening means adapted to fasten said guiding means to said enclosure; and

• O-rings adapted to secure said fastening means to said enclosure.
4. A device as claimed in claim 1 wherein, said diaphragm includes centrally meeting seams adapted to collapse and break open said diaphragm upon breach of pre-defined pressure of gas within said enclosure.
5. A device as claimed in claim 1 wherein, said gas collector means is placed between said diaphragm and said guiding means.
6. A device as claimed in claim 1 wherein, said gas collector means is placed after said guiding means.