Abstract:
A modular nitrogen generator including a housing including a bracket and defining an interior space, a flow path having an inlet adapted to receive compressed air and an outlet in fluid communication with a storage tank, an inlet manifold, an outlet manifold, and a modular membrane canister supportable on the mounting bracket within the interior space and positioned along the flow path between the inlet manifold and the outlet manifold to receive compressed air from the inlet manifold, extract nitrogen from the compressed air, and deliver the nitrogen to the outlet manifold. The flow path can be adapted to receive an additional modular membrane canister in a parallel flow configuration with the modular membrane canister to increase nitrogen output capacity of the nitrogen generator.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to nitrogen generators utilizing modular membrane canisters to separate nitrogen from compressed air and to a method of operating the same. Specifically, the present invention relates to nitrogen generators that are expandable by adding additional modular membrane canisters.  
       SUMMARY  
       [0002]     In one embodiment, the invention provides a modular nitrogen generator including: a housing including a bracket and defining an interior space, a flow path having an inlet adapted to receive compressed air and an outlet in fluid communication with a storage tank, an inlet manifold, and an outlet manifold. The inlet manifold and the outlet manifold extend through the housing and can be positioned along the flow path between the inlet and the outlet. The modular nitrogen generator further includes a modular membrane canister supportable on the mounting bracket within the interior space and positioned along the flow path between the inlet manifold and the outlet manifold to receive compressed air from the inlet manifold, extract nitrogen from the compressed air, and deliver the nitrogen to the outlet manifold. The flow path can be adapted to receive an additional modular membrane canister in a parallel flow configuration with the modular membrane canister to increase nitrogen output capacity of the nitrogen generator, and the bracket can be adapted to support the additional modular membrane canister in the interior space.  
         [0003]     In another embodiment the invention provides a method of operating a modular nitrogen generator. The method includes the acts of: providing the nitrogen generator with a housing including a bracket and defining an interior space, an inlet manifold, an outlet manifold, an outlet, and a first modular membrane canister connected between the inlet manifold and the outlet manifold, The method further includes supplying compressed air to the first modular membrane canister through the inlet manifold, separating nitrogen from the compressed air as the compressed air flows through the first modular membrane canister, directing the separated nitrogen from the first modular membrane canister to the outlet manifold, directing the nitrogen from the outlet manifold to the outlet, and coupling a second modular membrane canister to the bracket, coupling a first end of the second modular membrane canister to the inlet manifold, and coupling a second end of the second modular membrane canister to the outlet manifold, such that at least some of the compressed air is directed away from the first modular canister and through the second modular membrane canister to expand nitrogen output capacity of the nitrogen generator.  
         [0004]     Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0005]      FIG. 1  is a front perspective view of a nitrogen generator according to an embodiment of the present invention.  
         [0006]      FIG. 2  is a rear perspective view of the nitrogen generator shown in  FIG. 1 .  
         [0007]      FIG. 3  is a front perspective view of the nitrogen generator shown in  FIG. 1  with a front cover removed.  
         [0008]      FIG. 4  is a front view of a portion of the nitrogen generator shown in  FIG. 1 .  
         [0009]      FIG. 5  is a front perspective view of a second configuration of the nitrogen generator shown in  FIG. 1  with the front cover removed.  
         [0010]      FIG. 6  is a front perspective view of a third configuration of the nitrogen generator shown in  FIG. 1  with the front cover removed.  
         [0011]      FIG. 7  is a front perspective view of a fourth configuration of the nitrogen generator shown in  FIG. 1  with the front cover removed. 
     
    
     DETAILED DESCRIPTION  
       [0012]     Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.  
         [0013]      FIGS. 1-7 , illustrate a modular nitrogen generator  10  including a generator body  11  and a storage tank  12 . The generator  10  of the illustrated embodiment includes a housing  14  having first and second removable covers  16 ,  18 . As shown in  FIGS. 1-7 , the nitrogen generator  10  can also include an inlet  20  for receiving compressed air, a body outlet  22  for directing nitrogen from the generator body  11  to the storage tank  12 , and a nitrogen outlet  24  on the storage tank  12  for dispensing nitrogen from the nitrogen generator  10 . In the illustrated embodiment of  FIGS. 1-7 , the inlet  20  and outlet  24  include valves for controlling fluid flow into and out of the nitrogen generator  10  and the storage tank  12 . In other embodiments, valves can be positioned and located throughout the nitrogen generator  10  for controlling fluid flow into, through, and out of the nitrogen generator  10 .  
         [0014]     The storage tank  12  in the illustrated embodiment of  FIGS. 1-7  is substantially cylindrical and includes a generally round cross-sectional shape. In other embodiments, the storage tank  12  can have any cross-sectional shape, including without limitation oval, polygonal, irregular, triangular, rectangular, and other cross-sectional shapes. As shown in  FIGS. 1-7 , the generator body  11  can be secured to the storage tank  12 . In other embodiments, the generator body  11  can be positioned remotely with respect to the storage tank  12  and one or more conduits can fluidly connect the generator body  11  and the storage tank  12 .  
         [0015]      FIG. 3  illustrates the nitrogen generator  10  with the covers  16 ,  18  removed. A first plate  30  defines a rearward portion of the housing  14 , and is configured to support a number of elements within the nitrogen generator  10 . A second plate  32  is positioned forwardly from the first plate  30 , and is connected to the first plate  30  with supports  34 . As shown in  FIGS. 3 and 5 - 7 , the second plate  32  can be configured to support other nitrogen generator  10  elements.  
         [0016]     As shown in  FIGS. 3-7 , mounting brackets  40  extend through the housing  14  and are secured to the first plate  30 . In the illustrated embodiment, the brackets  40  are spaced apart such that a first bracket  40  is positioned adjacent to an upper end of the first plate  30  and a second bracket  40  is spaced a distance below the first bracket  40 . In other embodiments, the brackets  40  can have other relative orientations, depending upon one or more of the shape and size of the housing  14 , the shape and size of the first plate  30 , and the number and size of membrane canisters supported in the housing  14 . In still other embodiments, the nitrogen generator  10  can include one, three, or more brackets  40  positioned in the housing  14 . In the illustrated embodiment of  FIGS. 3-7 , the mounting brackets  40  are Uni-Strut P3300-PG. In other embodiments, other mounting brackets are utilized with similar effect.  
         [0017]     As shown in  FIGS. 3-7 , the nitrogen generator  10  can include a flow path (represented by arrows  41 ) extending between the inlet  20  and the outlet  24 . The inlet  20  is configured to be connected to a source of compressed air, and includes a valve to control the flow of the compressed air entering the generator  10   
         [0018]     In the illustrated embodiment of  FIGS. 1-7 , the nitrogen generator  10  includes a filtration system  49  positioned along the flow path  41  and having a pair of coalescing filters  50 , a carbon bed  52 , and a carbon filter element  54 . In the illustrated embodiment, the coalescing filters  50  remove water particles, oil particles, and other contaminants from the compressed air. The coalescing filters  50  in the illustrated embodiment are capable of removing about 99.9 percent of all particles greater than or approximately equal to about 0.01 micrometers in diameter. In some embodiments, the coalescing filter  50  can be a Reading Technologies, Inc. IR1500 filter. In other embodiments, other coalescing filters and filter elements can also or alternately be used.  
         [0019]     As shown in  FIGS. 3-7 , clamps  55  can secure the coalescing filters  50  to the second plate  32 . In some embodiments, such as the illustrated embodiment, Reading Technologies, Inc. BK-1 clamps  55  can be used. In other embodiments, other mounting brackets and clamps can also or alternately be used.  
         [0020]     In the illustrated embodiment of  FIGS. 3-7 , during operation of the nitrogen generator  10 , compressed air is forced through the carbon bed  52  to remove water and/or oil particles from the compressed air not removed by the coalescing filters  50 . In some embodiments, the carbon bed  52  is a Reading Technologies, Inc. IR1500-ACV carbon bed. In other embodiments, other filters and filtering elements can also or alternately be used. As shown in  FIGS. 3-7 , the carbon bed  52  can be supported by clamps  56 , which can be connected to the mounting brackets  40 . The clamps  56  of the illustrated embodiment are Uni-Strut P2052-EG clamps. In other embodiments other clamps  56  can also or alternately be used.  
         [0021]     In embodiments, such as the illustrated embodiment, in which the filtration system  49  includes carbon filters  54 , one or more carbon filers  54  are secured to a rear side of the second plate  32  with mounting brackets, such as, for example, Reading Technologies, Inc. N34-95-969-BK brackets. In other embodiments, other clamps and brackets can also or alternately be used.  
         [0022]     In the illustrated embodiment, the carbon filter  54  is a Reading Technologies, Inc. IR1500-AF filter and is operable to remove any carbon dust that may have collected in the compressed air while passing through the carbon bed  52 . In other embodiments, other filters and filtering elements can also or alternately be used.  
         [0023]     As shown in  FIGS. 3-7 , the nitrogen generator  10  can also include a separation system  59  having at least one modular membrane canister  60 , such as, for example, an Air Liquide/Medal 4241 canister. In the illustrated embodiment of  FIGS. 3-7 , the modular membrane canisters  60  can include a substantially cylindrical housing that surrounds a bundle of long, thin tubes having porous walls. During operation of the nitrogen generator  10 , compressed air is forced into the tubes as it enters a first end  62  of a membrane canister  60 . As the compressed air passes through the tubes, smaller oxygen molecules tend to pass radially outwardly through the porous walls, while larger nitrogen molecules tend to flow through the length of the tubes without passing through the porous walls.  
         [0024]     Apertures  66  are located along the length of each of the modular membrane canisters  60  for venting oxygen molecules exiting the thin tubes to atmosphere. The tubes supported in the modular membrane canisters  60  terminate at a second end  64  of the membrane canisters  60 . As the compressed air travels through the modular membrane canisters  60  toward the second ends  64  of the modular membrane canisters  60 , most of the oxygen is removed from the compressed air while most of the nitrogen molecules are retained so that the fluid exiting the second ends  64  of modular membrane canisters  60  includes a relatively high concentration of nitrogen molecules and a relatively low concentration of oxygen molecules.  
         [0025]     In the illustrated embodiment of  FIGS. 3-7 , clamps  68 , such as, for example, Uni-Strut P2042-EG clamps, secure the membrane canisters  60  to one or more of the mounting brackets  40 . In other embodiments, other clamps  68  can also or alternately be used.  
         [0026]     As shown in  FIGS. 3-7 , the nitrogen generator outlet  22  can includes a metering valve  70 , a check valve  72 , and a pressure sensor  74 . In embodiments, such as the illustrated embodiment, having a metering valve  70 , the metering valve  70  is adjustable to control the flow of nitrogen leaving the generator  10 . The metering valve  70  can be a ball valve, gate valve, or other similar valve capable of controlling or regulating fluid flow.  
         [0027]     The check valve  72  can be positioned between the metering valve  70  and the pressure sensor  74 . In the illustrated embodiment of  FIGS. 3-7 , the check valve  72  is a one-way valve that permits the flow of nitrogen outwardly from the generator body  11  to the storage tank  12 , but does not permit the flow of nitrogen from the storage tank  12  back into the generator body  11 . As shown in  FIGS. 3-7 , the pressure sensor  74  can be positioned between the check valve  72  and the storage tank  12  to measure the pressure of the nitrogen stored in the storage tank  12 .  
         [0028]     In some embodiments, such as the illustrated embodiment of  FIGS. 3-7 , the nitrogen generator  10  can include a shut-off valve  42  for regulating the pressure in the storage tank  12  measured by the pressure sensor  74 . In the illustrated embodiment, the shut-off valve  42  is positioned between the filtration system  49  and the separation system  59 .  
         [0029]     During operation, the shut-off valve  42  is closed when the pressure in the storage tank  12  reaches a pre-determined limit, preventing compressed air from flow along the flow path  41  from the filtration system  49  into the separation system  59 . When the pressure in the storage tank  12  drops below a predetermined limit, the shut-off valve  42  can be opened, causing compressed air to flow along the flow path  41  from the filtration system  49  into the separation system  59 .  
         [0030]     Compressed air enters the nitrogen generator  10  through the inlet  20  and flows along the flow path  41 , through a conduit  80 , through a fitting  82  and into the coalescing filters  50 . In some embodiments, a pressure gauge  84  is positioned along the flow path  41  for recording the air pressure in the flow path  41 . In some such embodiments, the pressure gauge  84  can include a display visible to an operator of the generator  10  through the cover  18 . In the illustrated embodiment of  FIGS. 3-7 , the pressure gauge  84  is connected to the fitting  82  to measure the pressure of air entering the filtration system  49 . In other embodiments, pressure gauges and other sensors can be located in other locations along the flow path  41  for monitoring air flow through the flow path  41 .  
         [0031]     The compressed air then flows along the flow path  41  through the coalescing filters  50 , a second conduit  86 , the carbon bed  52 , and a third conduit  88  before entering the carbon filter  54 . After passing through the filtration system  49 , the clean compressed air flows from the carbon filter  54 , along the flow path  41 , through a fourth conduit  90 , and toward a fitting  92 .  
         [0032]     In the illustrated embodiment of  FIGS. 3-7 , an air purity gauge  94  and a pressure gauge  96  are positioned along the flow path  41  and are connected to the fitting  92  to measure the purity or quality of air leaving the filtration system  49  and the pressure of the cleaned compressed air, respectively. As shown in  FIGS. 3-7 , the air purity gauge  94  and the pressure gauge  96  can be connected to the second plate  32  and can include displays that are visible to an operator from outside the housing  14 .  
         [0033]     From the fitting  92 , the compressed air flows along the flow path  41  through the automatic shut-off valve  42 , through a fifth conduit  100 , and into an inlet manifold  101 . From the inlet manifold  101 , the compressed air flows through an elbow fitting  102  and into the first end  62  of a modular membrane canister  60 , where oxygen is separated and removed from the compressed air, leaving relatively pure nitrogen.  
         [0034]     From the second end  64  of the modular membrane canister  60 , the nitrogen flows along the flow path  41  through an elbow fitting  106  and outwardly along an outlet manifold  107 , including a sixth conduit  104 . From the outlet manifold  107 , the nitrogen flows through the metering valve  70  and past the pressure sensor  74  before exiting the flow path  41  through a seventh conduit  110  toward the storage tank  12  where the relatively pure nitrogen is stored.  
         [0035]     In some embodiments, such as the illustrated embodiment of  FIGS. 1-7 , the flow path  41  of the nitrogen generator  10  can be reconfigured to adjust the nitrogen output capacity of the nitrogen generator  10 . For example, as shown in  FIG. 5 , tee-shaped fittings  108 ,  109  can be connected to the inlet and outlet manifolds  101 ,  107 , respectively. A second modular membrane canister  60  can then be added to the nitrogen generator  10  and can be connected to the flow path  41  to increase the nitrogen output of the nitrogen generator  10 .  
         [0036]     In the illustrated embodiment of  FIG. 5 , the first and second modular membranes  60  are connected between the inlet and outlet manifolds  101 ,  107  to provide a parallel flow configuration such that a first portion of the compressed air is directed through the first modular membrane canister  60  and a second portion of the compressed air is directed through the second modular membrane canister  60 , thereby significantly increasing the nitrogen output capacity of the nitrogen generator  10 .  
         [0037]     As shown in  FIG. 5 , clamps  68 , such as, for example, Uni-Strut P2042-EG, secure the modular membrane canisters  60  to one or more of the mounting brackets  40 . In other embodiments, other clamps  68  can also or alternately be used.  
         [0038]     In the illustrated embodiment of  FIG. 5 , longitudinal axes of the modular membrane canisters  60  are substantially parallel. In other embodiments, the modular membrane canisters  60  can have other relative orientations and configurations while still being connected along the flow path  41  in a parallel flow configuration such that a first portion of the compressed air is directed through the first modular membrane canister  60  and a second portion of the compressed air is directed through the second modular membrane canister  60 .  
         [0039]     For example, in some embodiments, the longitudinal axes of the first and second modular membrane canisters  60  can be substantially normal or at an acute angle with respect to one another. In other embodiments, the first and second modular membrane canisters  60  can have other relative orientations and configurations wile still being connected along the flow path  60  in a parallel flow configuration.  
         [0040]     As shown in  FIG. 6  and in  FIG. 7 , in some embodiments, third and fourth modular membrane canisters  60  can also or alternately be connected to the flow path  41  such that the first, second, third, and fourth modular membrane canisters  60  are all connected in a parallel flow configuration to further increase the nitrogen output capacity of the nitrogen generator  10 . In these embodiments, additional tee shaped fittings  108 ,  109  can be connected to the inlet and outlet manifolds  101 ,  107  to connect the third and fourth modular membrane canisters  60  to the flow path  41 .  
         [0041]     As shown in  FIGS. 6 and 7 , clamps  68 , such as, for example, Uni-Strut P2042-EG, secure the modular membrane canisters  60  to one or more of the mounting brackets  40 . In other embodiments, other clamps  68  can also or alternately be used. In the illustrated embodiment of  FIGS. 3-7 , the mounting brackets  40  are sized to support as many as four modular membrane canisters  60 . In the illustrated embodiment, the length of the brackets  40  is greater than four times the width of each of the modular membrane canisters  60 . In this manner, an operator can purchase and operate a nitrogen generator  10  having a first nitrogen output and then add additional modular membrane canisters  60  to the nitrogen generator  10  to significantly increase the nitrogen output capacity of the nitrogen generator  10  without being required to purchase costly new equipment and/or make significant modifications to the nitrogen generator  10 .  
         [0042]     Various alternatives and embodiments are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter regarded as the invention.