Claims:1. An advanced fire prevention system (100), providing nitrogen rich air to deter the ignition of fire in an enclosed area, comprising of:
a. a protected space (22) enclosed on all sides with a plurality of fire-rated panels (23{a, b ,c...n}), wherein the said protected space (22) consists of an air recirculation unit, a plurality of sensors including at least a pair of gas analysing sensors, a plurality of smoke detectors;
b. a plurality of compressors, including a first compressor (1), a second compressor being a redundant compressor;
c. a plurality of filters downstream of the said compressor (1), including a first filter being a pre-filter (2), a second filter being a post filter (3), a third filter being an activated carbon filter (4);
d. a heating unit (7), downstream of the said compressor (1);
e. an air separation unit (11) consisting of a plurality of outlet lines, including a first outlet line to output nitrogen rich air, a second outlet line (11A) to output oxygen rich air;
f. a plurality of valves downstream of the said first output line of the air separation unit (11), including a first control valve (14), a second control valve (15), a third manual valve (16), a fourth control valve (18), a fifth control valve (19), a sixth manual valve (20), a seventh check valve (21);
g. a plurality of sensors, including a first sensor being a pressure sensor (5) upstream of the heating unit (7), a second sensor being a temperature sensor (6) downstream of the said pressure sensor (5), a third sensor also being a temperature sensor (8) placed on the heating unit (7), a fourth sensor also being a temperature sensor (10) downstream of the heating unit (7), a fifth sensor also being a temperature sensor (12) to monitor the temperature of the air leaving the first outlet line of the air separation unit (11), a sixth sensor being a gas analysing sensor (13) upstream of the control valve (14), a seventh sensor also being a gas analysing sensor (17) downstream of the manual valve (16);
h. a line upstream of the heating unit (7), downstream of the pressure unit (5), to provide unaltered fresh air to the protected space (22);
i. a plurality of controllers, including a first modulation controller controlling pressure fluctuations in the said plurality of compressors, a second controller being a logic controller to continuously monitor the parameters of the air in the system (100), and,
j. a manual override switch near the said logic controller.

2. The advanced fire prevention system (100) as claimed in claim 1, wherein the said air recirculation unit does not exchange air with the outside.

3. The advanced fire prevention system (100) as claimed in claim 1, wherein the said fire-rated panels (23 {a, b, c...n}) are preferably insulated metal panels with a tongue and groove system, along with fasteners.

4. The advanced fire prevention system (100) as claimed in claim 1 and claim 3, wherein the inner and outer faces of the said fire-rated panels (23 {a, b, c...n}) are made of metal laminated sheets, the said faces packed with a fire-retardant material in between.

5. The advanced fire prevention system (100) as claimed in claim 1, wherein a sealant is applied between the said fire-rated panels (23 {a, b, c...n}).

6. The advanced fire prevention system (100) as claimed in claim 1 and claim 3, wherein the said fire-rated panels have a standard fire rating of at least 60 minutes.

7. The advanced fire prevention system (100) as claimed in claim 1, wherein the said logic controller consists of hard and soft redundancy.

8. The advanced fire prevention system (100) as claimed in claim 1, wherein the plurality of sensors, plurality of valves, plurality of compressors, and the heating unit (7) are connected to the said logic controller.
9. The advanced fire prevention system (100) as claimed in claim 1 and claim 8, wherein the control valve (19) is controlled by the said logic controller to control the supply of unaltered fresh air to the protected space (22).

10. The advanced fire prevention system (100) as claimed in claim 1, wherein the said control valve (15) is preferably electrically actuated.

11. The advanced fire prevention system (100) as claimed in claim 1, wherein the said air separation unit (11) is preferably a membrane separator.

12. The advanced fire prevention system (100) as claimed in claim 1, wherein the said control valve (14) is preferably a pneumatic valve with i/p converter.

13. The advanced fire prevention system (100) as claimed in claim 1, wherein at least a humidifier is installed in the said protected space (22).

14. The advanced fire prevention system (100) as claimed in claim 1, wherein the said protected space (22) is from a group comprising of, but not limited to, data centers, banks, vaults, cold storages, warehouses, archives, museums and other areas where destruction to property by fire is unacceptable.

15. An advanced fire prevention system (101), providing nitrogen rich air to deter the ignition of fire in multiple enclosed areas concurrently, comprising of:
a. a plurality of protected space (50 {a, b, c...n}) enclosed on all sides with a plurality of fire-rated panels (51 {a, b ,c...n}), wherein each of the said protected spaces consist of an air recirculation unit, a plurality of sensors including at least a pair of gas analysing sensors, a plurality of smoke detectors;
b. a plurality of compressors, including a first compressor (24), a second compressor (26), the said first compressor (24) connected in parallel with the said second compressor (26);
c. a plurality of filters (25, 27) downstream of each of the said compressors (24, 26), including a plurality of pre-filters, a plurality of post filters, a plurality of activated carbon filters;
d. a heating unit (30), downstream of the said plurality of filters;
e. a plurality of air separation units (35 {a,b,c...n}) connected in parallel, downstream of the heating unit (30), consisting of a plurality of outlet lines, including a first set of outlet lines to output nitrogen rich air, a second set of outlet lines to output oxygen rich air;
f. a plurality of valves downstream of the said first set of output lines;
g. a plurality of sensors;
h. a line upstream of the heating unit (30), to provide unaltered fresh air to the protected spaces;
i. a plurality of controllers, including a first modulation controller controlling pressure fluctuations in the said plurality of compressors, a second controller being a logic controller to continuously monitor the parameters of the air in the system (101), and,
j. a manual override switch near the said logic controller. , Description:AN ADVANCED FIRE PREVENTION SYSTEM AND METHOD THEREOF
FIELD OF INVENTION
The present invention relates to the field of fire prevention, particularly relates to an advanced fire prevention system that deters the ignition of fire in closed spaces while maintaining the atmosphere of the closed space of a breathable standard for human safety, and the method of operation thereof.
BACKGROUND OF THE INVENTION
Fire prevention is an important aspect to be considered during the construction of every building, not only for the safety of the residents and the people around, but also for the protection of the building, the surrounding buildings as well as the valuables enclosed within the building. The field of fire protection engineering has seen tremendous technological improvements as the need for protecting valuables such as expensive equipments, important documents and material properties of value has increased more than ever. Some of the significant technological improvements in the field of fire protection are effective sprinkler systems and new fire extinguishing techniques including halogenated fire extinguishing agents, hi-ex foams and water mists, and smoke detectors. The significant disadvantage of these systems is that they do not prevent fire; rather they only offer protection by detecting fire at an early stage followed by suppressing the fire before it leads to considerable damage.
This gave rise to the engineering of fire prevention wherein fire prevention systems were developed. Fire prevention systems, also called oxygen reduction systems or hypoxic air systems basically reduce the concentration of oxygen in a closed space such that a fire cannot be ignited in the first place. The oxygen content in hypoxic air systems is less than 18% and is safe for humans to breathe until the oxygen concentration does not go below 13%. Hypoxic air systems have been effective in fire prevention and various technologies have evolved in the field with respect to these systems.
US 6,334,315 relates to a hypoxic fire prevention and fire suppression system for computer cabinets and fire-hazardous industrial containers wherein the said system comprises an air compressor, an air separation device employing a molecular sieve adsorber for separating the air into an oxygen depleted fraction and into an oxygen enriched fraction and a collecting tank operatively associated with the said separation device receiving selectively said enriched-oxygen gas mixture therefrom and an outlet through which the fire retarding oxygen depleted fraction is supplied to the enclosed environment with oxygen content below 12%.
The patent document EP15171399 reveals a system for providing a hypoxic air atmosphere in an enclosed space wherein the system comprises at least a compressor for providing compressed fresh air, pressure switches for continuously monitoring the air inlet pressure, an air separation device having one inlet for the compressed fresh air, one first outlet for the oxygen-depleted air and one second outlet for oxygen-enriched air; a protected zone control valve arranged downstream of the air separation device; and oxygen sensors arranged in the protected zone.
The above cited prior art documents; do not however, give a wholesome fire protection solution. They only prevent the ignition of fire inside the enclosed spaces and do not protect the enclosure from catching fire from the outside. Additionally, the prior art documents do not address the concern of providing a fail-safe fire prevention system. Therefore, there is a need in the art to provide an advanced fire prevention system that addresses all the above mentioned technical problems and can further be applied to multiple rooms concurrently without the effectiveness of the system being affected.
OBJECTIVES OF THE INVENTION
The primary objective of the present invention is to provide an advanced fire prevention system which provides a complete fire prevention solution to enclosed systems.
Another objective of the present invention is to provide an advanced fire prevention system for enclosed spaces such that the atmosphere inside the said enclosure is of breathable standards for human safety.
Yet another objective of the present invention is to provide an advanced fire prevention system which completely protects the enclosed system from fire from within as well as from the outside.
Still another objective of the present invention is to provide an advanced fire prevention system that is fail safe and encompasses additional safety measures to ensure fail proof operation of the system.
Still another objective of the present invention is to provide an advanced fire prevention system which can also be applied to a multi-room set-up.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 represents the process flow diagram of the advanced fire prevention system of the present invention.
Figure 2 represents the process flow diagram of the advanced fire prevention system of the present invention applied to a multi-room set-up.
DETAILED DESCRIPTION OF THE INVENTION
Throughout this specification, the use of the word “comprise” and variations such as “comprises” and “comprising” may imply the inclusion of an element or elements not specifically recited.
The present invention relates to an advanced fire prevention system (100), providing nitrogen rich air to deter the ignition of fire in an enclosed area, comprising of:
a. a protected space (22) enclosed on all sides with a plurality of fire-rated panels (23{a, b ,c...n}), wherein the said protected space (22) consists of an air recirculation unit, a plurality of sensors including at least a pair of gas analysing sensors, a plurality of smoke detectors;
b. a plurality of compressors, including a first compressor (1), a second compressor being a redundant compressor;
c. a plurality of filters downstream of the said compressor (1), including a first filter being a pre-filter (2), a second filter being a post filter (3), a third filter being an activated carbon filter (4);
d. a heating unit (7), downstream of the said compressor (1);
e. an air separation unit (11) consisting of a plurality of outlet lines, including a first outlet line to output nitrogen rich air, a second outlet line (11A) to output oxygen rich air;
f. a plurality of valves downstream of the said first output line of the air separation unit (11), including a first control valve (14), a second control valve (15), a third manual valve (16), a fourth control valve (18), a fifth control valve (19), a sixth manual valve (20), a seventh check valve (21);
g. a plurality of sensors, including a first sensor being a pressure sensor (5) upstream of the heating unit (7), a second sensor being a temperature sensor (6) downstream of the said pressure sensor (5), a third sensor also being a temperature sensor (8) placed on the heating unit (7), a fourth sensor also being a temperature sensor (10) downstream of the heating unit (7), a fifth sensor also being a temperature sensor (12) to monitor the temperature of the air leaving the first outlet line of the air separation unit (11), a sixth sensor being a gas analysing sensor (13) upstream of the control valve (14), a seventh sensor also being a gas analysing sensor (17) downstream of the manual valve (16);
h. a line upstream of the heating unit (7), downstream of the pressure unit (5), to provide unaltered fresh air to the protected space (22);
i. a plurality of controllers, including a first modulation controller controlling pressure fluctuations in the said plurality of compressors, a second controller being a logic controller with hard and soft redundancy to continuously monitor the parameters of the air in the system (100), and,
j. a manual override switch near the said logic controller.
In an embodiment of the present invention, the fire-rated panels which enclose the area to be protected provide air-tightness and pressure-tightness inside the enclosure, and additionally provide good thermal insulation as well. In this embodiment, at least one of the plurality of compressors delivers air at a pressure higher than the ambient pressure. This compressed air is passed through the said pre-filters, post filters and activated carbon filters to remove dust, oil and other contaminants that might be present in the air. An oil water separator works to separate the oil from the water collected in the eco drain valves for safe and environment friendly disposal. The said compressors employed have a modulation control that smoothes out pressure fluctuations in the compressed air. This may help to reduce any hunting effect in the lines and may lead to improved process efficiency. A redundant compressor that acts a backup kicks-in when the said compressors fail. This ensures an uninterrupted flow of compressed air and eliminates any downtime of the process providing a year round active system.
In this embodiment, all of the sensors, valves, compressors and heating units are connected to a logic controller that continuously monitors the parameters of the air in the system. The logic controller used has a hard and soft redundancy built-in so that the process parameters can be monitored and controlled to be within allowable limits at all times. The controller constantly logs data from all sensors and valves and other equipments controlled through it. The data collection paves way for data mining to predict and prevent any future failures in any of the systems.
In the present embodiment, the pressure sensor (5) present at the end of the filters line continuously monitors the pressure of the compressed air. The compressed air from the said compressor is passed through a heating unit (7) to raise the temperature of the air to meet the pre-calculated design conditions of temperature and pressure. The temperature sensors (6, 10) present upstream and downstream of the heating unit (7) respectively, continuously monitor the temperature of the compressed air. The temperature sensor (8) placed on the heating unit coil monitors the correct working of the coil. In case of an abrupt temperature shoot in the compressed air downstream of the heating unit (7), the logic controller will work to cut off the electrical supply to the heating unit (7) until the temperature reaches the preferred set point. Upstream of the heating unit (7) and downstream of the pressure sensor (5), the line that provides unaltered fresh air to the protected space is present. This air will be used for flushing and emergency venting. The opening of this line is controlled by the logic controller through the control valve (19). The manual valve (20) is placed after the said control valve. The check valve (21) with a preset cracking pressure higher than the ambient pressure is placed after the said manual valve (20). The said check valve (21) and manual valve (20) together serve two purposes viz., prevent any backflow to the compressed air line from the protected space (22) and serve to reduce the pressure and flow rate of the air supplied to the protected space (22) to prevent any damages to glass partitions and equipments from rapid pressure build up.
Further, following the heating unit (7), the pressurised and hot air that meets a pre-calculated and pre-designed value, enters the air separation unit (11) which outputs air that is nitrogen rich at one end and oxygen-rich at the sides (11A). This oxygen rich air is safely vented to the atmosphere through a separate line or used for other applications as dictated by specific requirements. Before this nitrogen rich air is supplied to the area to be protected, precautions have to be taken so that the air in the protected space (22) does not contain unsafe levels of nitrogen. This is achieved through the use of the control valve (14) with i/p converter, and the manual valve (16). Upstream of the control valve (14) is the sensor for analyzing the gas concentration (13). The sensor analyses either the oxygen concentration in the nitrogen-air from the membrane or the nitrogen concentration, depending on the requirement. Since the major constituents in air comprise of oxygen and nitrogen, measurement of one of the two, yields the concentration of the other. The sensor (13) present upstream of the control valve (14) continuously sends signals to the logic controller. Based on the sensor data, the logic controller sends current signals to this control valve (14). The control valve (14) converts the current signals into equivalent pressure values and adjusts the valve position to create a back pressure in the line so that the sensors for analysing gas concentrations (13) read pre-determined and calculated values of gas concentration. The control valve (14) is designed to fail to open so that the manual valve (16) present downstream of the control valve will produce air with a nitrogen concentration in the range of 85-90%. The fail-to-open setting makes sure that in the case of an abrupt control valve failure, the valve’s failure will have no effect on the back pressure in the lines and hence no effect on the concentration of nitrogen in the air coming out of the membrane. This ensures that unsafe nitrogen levels never reach the protected space (22). The manual valve (16) is adjusted and set permanently in such a way that the back pressure created by this valve produces nitrogen rich air with a concentration of 85-90% N2. Studies have shown that no serious illness or damages to the human body occur at this level of nitrogen in air for short exposure times. The sensor (17) continuously analyses the percentage concentration of air present downstream of the said manual valve. The said sensor (17) sends signals to the logic controller and an alarm is raised whenever unsafe nitrogen concentrations are reached. In the case of an unsafe nitrogen concentration detected by the said sensor (17), a separate line that arises downstream of the gas concentration analyser (13) and the control valve (14) will vent the air with unsafe levels of N2 concentration. The opening of this venting line is controlled through the use of an electrically actuated control valve (15) that is operated by the logic controller. If the control valve (15) in the venting line were to open, a control valve (18) present downstream of the manual valve (16) and the sensor for analysing gas concentration (17) will close, preventing any supply to the protected space (22). As an additional safety measure, a manual override switch is present near the logic controller. Activating the said switch leads to three actions, viz., the control valve (18) that supplies the nitrogen rich air to the protected space (22) will be closed; the control valve (15) will open and any air coming out of the air separation unit (11) will be vented to the atmosphere; the control valve (19) will open and fresh air will be pumped to the protected space (22) until N2 concentrations reach safer levels. The system (100) thus ensures that the air in the protected space (22) never reaches a concentration that endangers human life. To maintain the temperature in the enclosed protected space (22), an air recirculation unit that does not exchange air with the outside is installed. The said air recirculation unit recirculates the air and maintains the temperature at optimum levels depending on the requirement.
In the present embodiment, the sensors fitted in the protected space (22) analyse the concentration of gases such as CO2, O2 and N2 and others. The said sensors send data to the logic controller which dictates the actions of the other components of the system. The smoke detectors installed detect smouldering and pyrolysis.
In another embodiment of the present invention, one or more humidifiers may be installed in the protected space (22) to maintain comfortable humidity levels.
In a specific preferred embodiment, for the best method of working of the present invention, the fire rated panels have a standard fire rating of at least 60 minutes or more depending on the assessment of risk. These fire-rated panels are modular in nature and are insulated metal panels that have a tongue and groove system with fasteners for easy and fast assembly. To improve tightness, sealants are applied between the panels. These panels are generally made of metal laminated sheets for the interior and exterior faces. The inner insulation material that offers fire retardation is made of mineral wool or similar fire retardant material with a fire rating of at least 60 minutes or more. These panels form the ceiling and walls of the area to be protected. The pressure-tight and air-tight fire rated panels minimize the fresh ambient air leakage into and out of the protected space. Any glass panes and doors used have a standard fire rating of at least 60 minutes or more.
In the said specific embodiment, the air separation unit (11) is a membrane separator and the control valve (14) present downstream of the said air separation unit (11) is a pneumatic valve with an i/p converter.
The system as a whole offers fire protection and fire prevention from the inside of the protected space (22), through the nitrogen rich air, and also from the outside of the protected space (22), through the fire rated panels (23 {a,b,c...n}).
In another embodiment of the present invention, the set-up is extendable to multiple rooms through the use of one or more compressors and one or more air separation units. The advanced fire prevention system (101), providing nitrogen rich air to deter the ignition of fire in multiple enclosed areas concurrently, comprises of:
a. a plurality of protected spaces (50 {a, b, c...n}) enclosed on all sides with a plurality of fire-rated panels (51 {a, b ,c...n}), wherein each of the said protected spaces consist of an air recirculation unit, a plurality of sensors including at least a pair of gas analysing sensors, a plurality of smoke detectors;
b. a plurality of compressors, including a first compressor (24), a second compressor (26), the said first compressor (24) connected in parallel with the said second compressor (26);
c. a plurality of filters (25, 27) downstream of each of the said compressors (24, 26), including a plurality of pre-filters, a plurality of post filters, a plurality of activated carbon filters;
d. a heating unit (30), downstream of the said plurality of filters;
e. a plurality of air separation units (35 {a,b,c...n}) connected in parallel, downstream of the heating unit (30), consisting of a plurality of outlet lines, including a first set of outlet lines to output nitrogen rich air, a second set of outlet lines to output oxygen rich air;
f. a plurality of valves;
g. a plurality of sensors;
h. a line upstream of the heating unit (30), to provide unaltered fresh air to the protected spaces;
i. a plurality of controllers, including a first modulation controller controlling pressure fluctuations in the said plurality of compressors, a second controller being a logic controller with hard and soft redundancy to continuously monitor the parameters of the air in the system (101), and,
j. a manual override switch near the said logic controller.
Similar to the advanced fire prevention system (100), in this embodiment, a line for supplying fresh compressed air to the protected spaces arises upstream of the heating unit (30) and the opening of this line is controlled by the logic controller through a control valve (49). The compressed air from the said compressors (24, 26) is passed through the heating unit (30) to raise the temperature of the compressed air to the pre-calculated design values. Pressure and temperature sensors (29, 31, 32) monitor the parameters of the compressed air before it enters the batch of air separation units (35 {a,b,c...n}). The entry to each batch of said air separation units is controlled by the logic controller through a control valve (34). Depending on the requirements of the enclosed spaces (50 {a,b,c...n}), the logic controller decides the batches of air separation units to be opened. Each batch typically contains 4 to 6 air separation units. The air coming out of the air separation units is sent to the sensor (39) for analysing the concentration of N2 in air through the opening of the control valve (38). A manual valve (40) present downstream of this sampling line creates back pressure such that the sensor reads a concentration of 85-90% N2.

Downstream of the said manual valve is present a temperature sensor/transmitter (41) that detects the temperature of the flow, a gas concentration analyser (42) and a pneumatic valve with i/p converter (44). The opening and closing of this valve is controlled by the logic controller with inputs from the gas concentration analyser. The pneumatic control valve with i/p converter (44) is designed to fail-to-open so that the manual valve (40) present downstream of the control valve will produce air with a nitrogen concentration in the range of 85-90%. The supply of nitrogen rich air and fresh air for flushing purposes for each of the protected areas is controlled through solenoid valves (46, 49). The fail-to-open setting makes sure that in the case of an abrupt control valve failure, the valve’s failure will have no effect on the back pressure in the lines and hence no effect on the concentration of nitrogen in the air coming out of the air separation unit. This ensures that unsafe nitrogen levels never reach any of the protected areas. The multi-room system has the same set of precautionary and emergency venting lines to ensure that the N2 concentrations never reach unsafe levels in any of the protected spaces. This includes the emergency manual override switch located nearby the logic controller.

It will be apparent to a person skilled in the art that the above description is for illustrative purposes only and should not be considered as limiting. Various modifications, additions, alterations, and improvements without deviating from the spirit and the scope of the invention which may be made by a person skilled in the art, shall still fall within the scope and purview of the present invention.