Abstract:
A method for protecting a user in an enclosed environment includes providing an enclosed environment that holds cargo that has first odor; flowing a gas to the enclosed environment; and adding an odorant having a second odor to the gas, the first odor being distinctive from the second odor such that a presence of the second odorant provides a warning that the gas is present.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    This disclosure relates to fire suppression systems, and more particularly to the use odorants in fire suppression systems. 
         [0002]    It is well known in the art that fire requires fuel, heat, and oxygen to propagate. Some fire suppression methodologies use inert gases to dilute the supply of oxygen in the air to suppress the spread and propagation of fire. 
       SUMMARY OF THE INVENTION 
       [0003]    According to an example embodiment, a method for protecting a user in an environment includes providing an enclosed environment that holds cargo that has first odor; flowing a gas to the enclosed environment; and adding an odorant having a second odor to the inert gas, the first odor being distinctive from the second odor such that a presence of the second odorant provides a warning that the inert gas is present. 
         [0004]    According to another example embodiment a method for protecting a user in an enclosed environment includes; providing an enclosed environment holding cargo that has a first odor; flowing an inert gas to the enclosed environment; and adding an odorant having a second odor to the inert gas, the first odor being distinctive from the second odor such that a presence of the second odorant provides a warning that the inert gas is present and the chosen second odor does cause concern in humans adjacent the enclosed environment. 
         [0005]    According to a still further example embodiment, a method for protecting a user in an enclosed environment includes providing an enclosed environment holding cargo that has a first odor; providing a passenger compartment adjacent the cargo area; providing a fire suppressant system, flowing an inert gas from the suppressant system to the enclosed environment; and adding an odorant having a second odor to the inert gas as the gas flows, the first odor being distinctive from the second odor such that a presence of the second odorant provides a warning that the inert gas is present and the second odor does not cause concern in humans adjacent the enclosed environment. 
         [0006]    These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a prior art depiction of an inert gas discharge pipe and a module containing an odorant. 
           [0008]      FIG. 2  is an embodiment showing a fire suppressant system utilizing the prior art of  FIG. 1 . 
           [0009]      FIG. 3  shows a method of utilizing the embodiments in  FIGS. 1 and 2 . 
           [0010]      FIG. 4  shows an environment for the fire suppressant system of  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0011]    Referring now to  FIG. 1 , prior art conduit  10  through which a gas, which may be an inert gas such as nitrogen, helium argon or the like, flows to suppress a fire (not shown) is shown. The conduit  10  has an elbow  15  in which a module  20  containing an odorant  25  is disposed. The module  20  screws into an elbow bracket  30  to retain it there. A disc seal  35  seals the odorant  25  within the module  20  and ruptures if an inert gas flows through conduit  10 . Typically, the disc seal  35  bursts at five atmospheres of pressure or more, i.e., below the pressure of the flowing inert gas, and therefore other burst pressures are anticipated herein. The odorant  25  is not placed in high pressure canisters  55  (see  FIG. 2 ) because it stays as a liquid if stored in the inert gas canisters and therefore it is difficult to get into the inert gas flow. 
         [0012]    Referring now to  FIG. 2 , a system  45  for use in an enclosed environment  65 , such as a cargo bay, is shown. Gases may accumulate in rooms or pits, and be dangerous to human health. One working in an enclosed environment, which may be enclosed, like a worker entering a cargo bay (shown schematically as  65 —see also  FIG. 4 ) may not be aware of the presence of the inert gas and a worker&#39;s health may be affected. 
         [0013]    The system  45  includes plurality of high pressure canisters  55  that hold an inert gas are connected by conduit  10  and pipes  60  to enclosed environments  65 , such as a storage or cargo bay in an aircraft  63 , where fire may occur and be suppressed. In the aircraft  63  a passenger compartment  67  may be near or adjacent to an enclosed environment  65 . The system  45  ports inert gas to enclosed environments  65  in the event of a fire. 
         [0014]    Each canister  55  is attached to the conduit  10  by a discharge pressure regulator/control valve  70  and to the enclosed environment  65  by a diverter valve  75 . Each enclosed environment  65  has a room pressure transducer  80 , a temperature transmitter  85 , and a fire detector  90  (such as a smoke detector). A control valve  95  is placed in fluid communication with the conduit  10  that prevents inert gas from flowing from the canisters  55  to the enclosed environments  65 . 
         [0015]    Typically, if a fire is detected in an enclosed environment  65 , e.g., from signals from any of the room pressure transducer  80 , the temperature transmitter  85 , and/or the fire detector  90 , a controller  103 , which is conventionally in signal communication with the room pressure transducer  80 , the temperature transmitter  85 , and/or the fire detector  90 , causes the discharge pressure regulator/control valve  70  of one or more of the canisters  55  to port inert gas through conduit  10 , through open control valve  95  to the diverter valves  75 . The diverter valves  75  port the inert gas downstream to the nozzles  100  in the relevant enclosed environment  65  to suppress fire therein. 
         [0016]    The valves such as pressure regulator/control valve  70  and diverter valve  75  and or the canisters  55  may fail or leak. If a failure does occur, or if the system  45  suppresses a fire but the controller  103 , for instance, fails to alert a user that there may be inert gas in the enclosed environments  65 , one who might enter the enclosed environments  65  might be entering an unhealthy place. 
         [0017]    If the regulator/control valve  70  and diverter valve  75  fail, leak or operate properly, enough pressure may be exerted on the odorant module  20  to cause the disc seal  35  to burst and gas passing through the conduit  10  acts as a venturi to pull an odorant  110  into the conduit  10  and odorize the inert gas. In an alternative embodiment, an odorant  110  may be included in the canisters  55  to be released with the gas contained therein. 
         [0018]    By using a particular odorant  110  as discussed hereinbelow, one who enters an enclosed environment  65 , in which the oxygen content in that enclosure may be at unhealthy levels, senses the odorant and vents the enclosed environment  65  and shuts off the system  45  by closing valve  95  before safely entering the enclosed environment  65 . 
         [0019]    In order to optimize the training of the worker, a recognizable odorant  110  may be used consistently within systems  45  that use inert gas for alerting workers of this unhealthy or below appropriate level of oxygen in the air. 
         [0020]    The choice of odorant  110  should be sufficiently different from any odors that might arise from the normal range of cargo  61 , or other goods in an enclosed environment  65 , known to be instantly recognizable, yet at the same time it may not be an odor that might likely cause anxiety or concern if the odorant  110  entered the passenger cabin  67  atmosphere during flight. Generally, odorants  25  used in the prior art are sulfur based chemicals such as thiols or mercaptans, sulfides or similar odorant. These are foul smelling “stench agents.” This practice is so well known that the general public believes that this is in fact the odor of natural gas. Other odorants include limonene, which has a pungent, sickly, orange smell and it is very obvious. When choosing an odorant one may have the following known choices: 
         [0021]    1 Esters 
         [0000]    
       
         
               
               
               
             
           
               
                   
               
               
                   
                   
                 Natural  
               
               
                 Compound 
                 Fragrance 
                 occurrence 
               
               
                   
               
             
             
               
                 Methyl formate 
                 Ethereal 
                   
               
               
                 Methyl acetate 
                 Sweet, nail polish 
                   
               
               
                   
                 Solvent 
                   
               
               
                 Methyl butyrate 
                 Fruity, apple, 
                   
               
               
                 Methyl Butanoate 
                 Pineapple 
                   
               
               
                 Ethyl acetate 
                 Sweet, solvent 
                 Wine 
               
               
                 Ethyl butyrate 
                 Fruity, orange 
                   
               
               
                 Ethyl butanoate 
                 Pineapple 
                   
               
               
                 Isoamyl acetate 
                 Fruity, banana 
                   
               
               
                   
                 Pear 
                   
               
               
                 Pentyl butyrate 
                 Fruity, pear 
                   
               
               
                 Pentyl butanoate 
                 Apricot 
                   
               
               
                 Pentyl pentanoate 
                 Fruity, apple 
                   
               
               
                 Octyl acetate 
                 Fruity, orange 
                   
               
               
                 Fructone 
                 Fruity, apple-like 
                   
               
               
                 Hexyl acetate 
                 Apple, floral, fruity 
                   
               
               
                 Ethyl 
                 strawberry 
                   
               
               
                 methylphenylglycidate 
               
               
                   
               
             
          
         
       
     
         [0022]    2 Terpenes 
         [0000]    
       
         
               
               
               
             
           
               
                   
               
               
                 Compound 
                 Fragrance 
                 Natural occurrence 
               
               
                   
               
             
             
               
                 Myrcene 
                 Woody, complex 
                   Verbena , bay 
               
               
                 Geraniol 
                 Rose, flowery 
                   Geranium , lemon 
               
               
                 Nerol 
                 Sweet rose, flowery 
                 Neroli, lemongrass 
               
               
                 Citral, lemonal 
                 Lemon 
                 Lemon myrtle, 
               
               
                 Geranial, neral 
                   
                 lemongrass 
               
               
                 Citronellal 
                 Lemon 
                 Lemongrass 
               
               
                 Citronellol 
                 Lemon 
                 Lemongrass, rose 
               
               
                   
                   
                 
                   Pelargonium 
                 
               
               
                 Linalool 
                 Floral, sweet 
                 Coriander, sweet basil 
               
               
                   
                 Woody, lavender 
                 Lavender 
               
               
                 Merolidol 
                 Woody, fresh bark 
                 Neroli, ginger 
               
               
                   
                   
                 Jasmine 
               
               
                   
               
             
          
         
       
     
         [0023]    3 Cyclic Terpenes 
         [0000]    
       
         
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 Compound 
                 Fragrance 
                 Natural occurrence 
               
               
                   
                   
               
             
             
               
                   
                 Limonene 
                 Orange 
                 Orange, lemon 
               
               
                   
                 Camphor 
                 Camphor 
                 Camphor laurel 
               
               
                   
                 Terpineol 
                 Lilac 
                 Lilac, cajuput 
               
               
                   
                 Alpha-lonone 
                 Violet, woody 
                 Violet 
               
               
                   
                 Thujone 
                 Minty 
                 Cypress, lilac, 
               
               
                   
                   
                   
                 Juniper 
               
               
                   
                   
               
             
          
         
       
     
         [0024]    4 Aromatic 
         [0000]    
       
         
               
               
               
             
           
               
                   
               
               
                   
                   
                 Natural 
               
               
                 Compound 
                 Fragrance 
                 occurrence 
               
               
                   
               
             
             
               
                 Benzaldehyde 
                 Almond 
                   
               
               
                 Eugenol 
                 Clove 
                 Clove 
               
               
                 Cinnamaldehyde 
                 Cinnamon 
                   Cassia , Cinnamon 
               
               
                 Ethyl maltol 
                 Cooked fruit 
                   
               
               
                   
                 Caramelized sugar 
                   
               
               
                 Vanillin 
                 Vanilla 
                 Vanilla 
               
               
                 Anisole 
                 Anise 
                 Anise 
               
               
                 Anethole 
                 Anise 
                 anise, Sweet basil 
               
               
                 Estragole 
                 Terragon 
                 Terragon 
               
               
                 Thymol 
                 Thyme 
                 Thyme 
               
               
                   
               
             
          
         
       
     
         [0025]    5 Amines 
         [0000]    
       
         
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 Compound 
                 Fragrance 
                 Natural occurrence 
               
               
                   
                   
               
             
             
               
                   
                 Trimethylamine 
                 Fishy, Ammonia 
                   
               
               
                   
                 Putrescine 
                 Rotting flesh 
                 Rotting flesh 
               
               
                   
                 Diaminobutane 
                   
                   
               
               
                   
                 Cadaverine 
                 Rotting flesh 
                 Rotting flesh 
               
               
                   
                 Pyridine 
                 Fishy 
                   
               
               
                   
                 Indole 
                 Faecal, flowery 
                 Faeces jasmine 
               
               
                   
                 Skatole 
                 Faecal 
                 Faeces 
               
               
                   
                   
               
             
          
         
       
     
         [0026]    6 Alcohols 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
                   
               
               
                   
                   
                   
                 Natural 
               
               
                   
                 Compound 
                 Fragrance 
                 occurrence 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Furaneol 
                 strawberry 
                   
               
               
                   
                 1-Hexanol 
                 herbaceous, 
                   
               
               
                   
                   
                 woody 
                   
               
               
                   
                 Cis-3-Hexen-l-ol 
                 Fresh cut grass 
                   
               
               
                   
                 Menthol 
                 peppermint 
               
               
                   
                   
               
             
          
         
       
     
         [0027]    7 Aldehydes 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
                   
               
               
                   
                   
                   
                 Natural 
               
               
                   
                 Compound 
                 Fragrance 
                 occurrence 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Acetaldehyde 
                 ungent 
                   
               
               
                   
                 Hexanol 
                 Green, grassy 
                   
               
               
                   
                 Cis-3-Hexen-l-ol 
                 Green tomatoes 
                   
               
               
                   
                 Furfural 
                 Burnt oats 
               
               
                   
                   
               
             
          
         
       
     
         [0028]    8 Ketones 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
                   
               
               
                   
                   
                   
                 Natural 
               
               
                   
                 Compound 
                 Fragrance 
                 occurrence 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Dihydrojasmone 
                 Fruity, woody, 
                   
               
               
                   
                   
                 floral 
                   
               
               
                   
                 Oct-1-en-3-one 
                 Blood, metallic, 
                   
               
               
                   
                   
                 mushroom-like 
                   
               
               
                   
                 2-Acetyl-1-pyrroline 
                 Fresh bread, 
                   
               
               
                   
                   
                 jasmine rice 
                   
               
               
                   
                 6-Acetyl-2,3,4,,5-  
                 Fresh bread, 
                   
               
               
                   
                 tetrahydropyridine 
                 tortillas, popcorn 
               
               
                   
                   
               
             
          
         
       
     
         [0029]    9 Lactones 
         [0000]    
       
         
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 Compound 
                 Fragrance 
                 Natural occurrence 
               
               
                   
                   
               
             
             
               
                   
                 Gamma- 
                 Intense peach 
                   
               
               
                   
                 Decalactone 
                 flavour 
                   
               
               
                   
                 Gamma- 
                 Coconut odour, 
                 Popular in suntan 
               
               
                   
                 Nonalactone 
                   
                 lotions 
               
               
                   
                 Delta-Octalactone 
                 Creamy note 
                   
               
               
                   
                 Jasmine lactone 
                 Powerful fatty 
                   
               
               
                   
                   
                 fruity peach and 
                   
               
               
                   
                   
                 apricot 
                   
               
               
                   
                 Massoia lactone 
                 Powerful creamy 
                   
               
               
                   
                   
                 coconut 
                   
               
               
                   
                 Wine lactone 
                 sweet coconut odour 
                   
               
               
                   
                 Sotolon 
                 Maple syrup, curry, 
                   
               
               
                   
                   
                 fenugreek 
               
               
                   
                   
               
             
          
         
       
     
         [0030]    10 Thiols 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
                   
               
               
                   
                   
                   
                 Natural 
               
               
                   
                 Compound 
                 Fragrance 
                 occurrence 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Furaneol 
                 strawberry 
                   
               
               
                   
                 1-Hexanol 
                 herbaceous, woody 
                   
               
               
                   
                 Cis-3-Hexen-1-ol  
                 Fresh cut grass 
                   
               
               
                   
                 Menthol 
                 peppermint 
               
               
                   
                   
               
             
          
         
       
     
         [0031]    11 Miscellaneous Compounds 
         [0000]    
       
         
               
               
               
             
           
               
                   
               
               
                 Compound 
                 Fragrance 
                 Natural occurrence 
               
               
                   
               
             
             
               
                 Methylphospine &amp; 
                 Garlic-metallic 
                 Two of the most 
               
               
                 dimethylphosphine 
                   
                 potent odorants known 
               
               
                 Nerolin 
                   
                   
               
               
                 Tetrahydrothiophene 
                   
                   
               
               
                 2,4,6-Trichloroanisole 
                   
                   
               
               
                 Substituted 
                   
                   
               
               
                 pyrazines 
               
               
                   
               
             
          
         
       
     
         [0032]    When choosing the particular odorant  110  to use, one must be aware of the odors in the environment and/or the passenger compartment. For instance if meat is being air freighted, one may choose to avoid any of the odorants (first odors) from the amine group that smell like rotted flesh (not shown) cited hereinabove that conflict with the smell of meat (i.e., first odor). Similarly, if one is transporting flowers (not shown), an odorant (i.e., second odors) from the Terpene groups, that smell like flowers (i.e., first odors) cited hereinabove. If fruit (not shown) is being transported, an odorant (i.e., second odors) from the Ester group that smell like fruit (i.e., first odors) may be avoided. Also, an odorant may be chosen from the list above (i.e., second odor) that has the lowest possibility of matching or resembling the odors (i.e., first odor) that might normally be expected to exist in the passenger compartment and then used on a permanent basis. It should be noted that a first odor may have no distinguishable odor and be deemed ambient odor. The second odor is distinguishable from the ambient or distinguishable first odor. 
         [0033]    In order to take advantage of the distinctive odorants described above, one may determine a type of cargo  61  carried or held in an enclosed environment  65  (step  150 ), choose an odorant that is not likely to alarm, cause anxiety or concern of passengers nearby the enclosed environment  65  as in an aircraft  63  and that is distinctive from a normal odor of the cargo to be carried (step  160 ), educate personnel who may enter the enclosed environment (step  170 ), insert an odorant module  20  including the chosen odorant  110  (step  180 ) and infuse any flowing inert gas with the chosen odorant  110  to an enclosed environment  65  (step  190 ) so that anyone who might enter the enclosed environment is warned of the presence of the inert gas by detecting the chosen odorant  110 . 
         [0034]    Although a combination of features is shown in the illustrated examples, not all of them need to be combined to realize the benefits of various embodiments of this disclosure. In other words, a system designed according to an embodiment of this disclosure will not necessarily include all of the features shown in any one of the Figures or all of the portions schematically shown in the Figures. Moreover, selected features of one example embodiment may be combined with selected features of other example embodiments. 
         [0035]    The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this disclosure. The scope of legal protection given to this disclosure can only be determined by studying the following claims.