Abstract:
A trap system for cryogenic environments, which brings a gas to a body of the same material in liquid form, allows the liquefied material in the gas bearing tube to pass through a submerged trap combining the newly condensed liquid with that in the reserve. With this apparatus, for example, pure cold Nitrogen gas can be condensed and recycled in a system requiring cryogenic liquid Nitrogen to start the process. This trap system can also be applied to other gaseous materials stored cooled beyond the condensing temperatures. The trap system brings the newly condensed material into the vessel of already condensed material. The gas that has not condensed into liquid, in the case of Liquid Nitrogen, will release into the atmosphere. It is expected that all the gas of the other material will liquefy and be part of the stored liquid because it is stored below its liquefaction temperature—here using Liquid Nitrogen chambers surrounding the vessel of the liquefied material. Also included are means to maintain a clean reservoir of cryogenic liquids providing means to remove debris on the surface, floating within the liquid and at the bottom of the reservoir. And yet more, keeping the liquid form of material is protected from the gas state material to prevent more rapid evaporation.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    Hydrocarbon Harvesting from Coal, Shale, Peat, and Landfill Seams U.S. application Ser. No. 11/903,346, PCT/US2008/010744; and Hydrocarbon Harvesting from Methane Hydrate Deposits and Shale Seams, U.S. application Ser. No. 12/217,915 include aspects of this invention. Both patents and this application are DuBrucq inventions. The closest prior art application are liquefying Nitrogen in U.S. Pat. No. 7,086,251 of Mark Julian Roberts taking a huge apparatus and U.S. Pat. No. 7,024,835 of Villalobos, which takes a cold pure gas stream and requires compression of the gas before liquefication. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    During cryogenic processing, materials are often liquefied for storage or for preserving the pure materials in gaseous state close to thermal liquefication. What is needed is a means to recycle pure Nitrogen and to separate the just reliquefied portion of that material so it can be included in the reservoir of the liquid state segment of that pure material. It requires a cryogenic tolerant motion to block the contamination of the gas portion from the liquid portion of the material. This invention provides this function and means to clean debris from a filled cryogenic reservoir and to separate out light gases. 
         [0004]    2. Discussion of the Related Art 
         [0005]    Two DuBrucq application Ser. Nos. 11/903,346 and 12/217,915, have exhaust material of pure gaseous Nitrogen, N 2 , molecules at on or around −190° C. temperature. To simply lower the temperature to that of liquid Nitrogen, to −195.8° C., would preserve the pure Nitrogen as a liquid essentially saving having to purchase some of the Liquid Nitrogen needed for the process. What portion of the external purchase requirements will be eliminated by this process is yet to be determined. To this point, only elaborate machinery is used to liquefy Nitrogen, Oxygen and Natural Gases, as, for example, liquefying Nitrogen in U.S. Pat. No. 7,086,251 of Mark Julian Roberts and U.S. Pat. No. 7,024,835, Villalobos, where a cold pure gas stream needs compressed gas before liquefication. 
       SUMMARY OF THE INVENTION 
       [0006]    In accordance with one aspect of the invention, the Nitrogen gas exhaust pipe feeds pure Nitrogen at about −190° C. into a pipe at the surface of the Liquid Nitrogen in the reservoir of Liquid Nitrogen to lower the temperature of the gas to the liquefication temperature of −195.8° C. At a low point in the piping, traps are positioned to catch the newly liquefied Nitrogen. The pipe continues bending upward exhausting remaining gas above the surface of Liquid Nitrogen in the reservoir. 
         [0007]    In another aspect of the present invention, after the pure Nitrogen gas in the pipe liquefies, it flows down a trap or series of traps, straight, solid walled, vertical pipes directed downwards further into the Liquid Nitrogen at the lowest area of the pipe. 
         [0008]    In yet another aspect of the present invention, this trap has solid walls until it passes the bottom of its length and turns 180°. The parallel pipe section in the loop is pierced with holes allowing the newly liquefied Nitrogen to mix with that in the reservoir as it climbs to near the top of the trap pipe where solid pipe comprises the 90° elbow and crosspipe to flow into a “T” in the vertical pipe of the trap. 
         [0009]    In yet another aspect of the present invention, this pipe circuit has a spaced bead chain of balls that fit within the pipe snugly enough to not allow the Liquid Nitrogen to back flow in the pipe, also preventing the chain connecting the beads from being passed over by the next ball in the bead chain. These balls often will bunch where junctions of pierced and solid wall sections of the pipe meet as they circle the trap. 
         [0010]    In yet another aspect of the present invention, the trap entrance has a one-way flow valve to prevent backflow of the Liquid Nitrogen from the reservoir into the entry pipe for the gas phase Nitrogen. 
         [0011]    In yet another aspect of the present invention, the bead balls are lighter in mass than the Liquid Nitrogen and float from the end of the solid “U” connection on the base of the trap to the return pipe running parallel with pierced sides allowing the light weight balls forced downward in the solid entry pipe to float upward as the Liquid Nitrogen enters the reservoir liquid. 
         [0012]    In yet another aspect of the present invention, the chain distance between the ball beads is considerably longer than the distance of solid pipe leading from the end of the pierced pipe section to the trap entrance pipe allowing the difference in distance of pipe to carry the newly liquefied Nitrogen as the ball beads move around the loop of the trap. 
         [0013]    In yet another aspect of the present invention, the exhaust pipe extension floats on the surface of the Liquid Nitrogen enabled by two ball joints allowing it to swivel to stay at the surface of the liquid and again to swivel so the traps are in a vertical configuration. 
         [0014]    In yet another aspect of the present invention, the traps have a valve on the intersection of the exhaust pipe extension and the trap with a ball valve stopping flow from the trap to the exhaust pipe extension where the movement upward causes the ball to lock in the ring inside the top of the trap tube preventing Liquid Nitrogen flow upward. 
         [0015]    As a result of this configuration, the liquid Nitrogen forming in the exhaust pipe extension into the bath of Liquid Nitrogen proceeds into the traps the weight of the liquid pushes the ball beads down the trap pipe and, as they return floating through the pierced pipe where the liquid Nitrogen or other frozen material passes into the reservoir, and then encountering the solid portion near the top of the parallel pipe, the ball moves the contained Liquid Nitrogen through the trap pulling newly liquefied Nitrogen from the exhaust pipe along with it. This limits liquid Nitrogen from the reservoir from entering the trap system to only that contained in the short pipe bends as the loop returns to the run down the trap portion. As the ball beads circulate around this trap system, the newly liquefied Nitrogen is pulled from the exhaust pipe extension into the reservoir of Liquid Nitrogen, recycling the purified gas from the processing system for use in the process. 
         [0016]    In yet another aspect of the present invention, a cold sink is employed to bring the yet lower temperature of the Liquid Nitrogen in the bottom of the reservoir to help cool the exhaust pipe extension liquefying more of the Nitrogen than would happen with just the surface temperature of 195.8° C. 
         [0017]    It is yet another aspect of the invention to care for the Liquid Nitrogen reservoir to first, allow any further light gas removal from the gas reservoir over the surface of the Liquid Nitrogen. 
         [0018]    And yet another aspect of the invention has two methods to remove any accumulated debris from the cryogenic tank—use of a net shovel and use of a drop net, thus keeping the Liquid Nitrogen pure even with the reliquification. 
         [0019]    In yet another aspect of this invention, this same trap system on an exhaust pipe entering a storage tank can be used in the collection of Oxygen and Argon and in capturing the separated or combined Natural Gas components enabling storing them as liquids with sufficient Liquid Nitrogen cooling to their containers to retain the liquid state. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]    Preferred exemplary embodiments of the invention are illustrated in the accompanying drawings in which like reference numerals represent like parts throughout, and in which: 
           [0021]      FIG. 1  provides a vertical cross-sectional view of the exhaust pipe extension coming from the process where waste pure Nitrogen gas emerges at 190° C. or thereabouts. The traps to move the liquefied Nitrogen from the exhaust pipe extensions at the liquid surface. 
           [0022]      FIG. 2  provides an image of the ball beads connected with a chain longer than the distance from the initial solid section of the parallel pipe through its entry into the trap pipe at the “T” section. The balls are spherical and hollow. The cutaway shows the chain connection to the balls in the trap pipe. These seal the passage of the Liquid Nitrogen preventing backflow of Liquid Nitrogen from the reservoir into the trap. 
           [0023]      FIG. 3  provides the complete system with the ball beads installed in the trap system showing how they move pulling limited reservoir Liquid Nitrogen along with newly liquefied Nitrogen from the trap into the reservoir of Liquid Nitrogen, as the Liquid Nitrogen moves as shown in  FIG. 3   a ,  FIG. 3   b ,  FIG. 3   c ,  FIG. 3   d  and  FIG. 3   e.    
           [0024]      FIGS. 4   a  and  4   b  show the ball valve design keeping Liquid Nitrogen from the reservoir from entering the exhaust pipe extension with normal flow in  FIG. 4   a  and backflow prevented in  FIG. 4   b.    
           [0025]      FIG. 4   c  shows the ball and socket joints between the exhaust pipe and exhaust pipe extension allowing the exhaust pipe extension to swivel to stay at Liquid Nitrogen surface with the first joint and for the exhaust pipe extension to swivel to keep the traps vertical. 
           [0026]      FIG. 5  shows the cold sinks coming from the bottom of the Liquid Nitrogen in the reservoir bringing the cold to the exhaust pipe extension allowing more liquefication of the Nitrogen gas in the pipe. It lashes around the pipe to transfer the cold efficiently. 
           [0027]      FIG. 6  shows a shovel net means to remove debris from the cryogenic reservoir. Skimming with the shovel net will remove debris floating on the surface. 
           [0028]      FIG. 7  shows the light gas trap in the lid of the reservoir and a drop net means to remove debris from Liquid Nitrogen surface, floating in and on the floor of the reservoir. 
           [0029]      FIG. 8  shows the trap for liquefied gas as it applies for gases that condense at higher temperatures than Liquid Nitrogen in the fuel harvest process and keeping it liquid. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0030]    Turning now to the drawings and initially to  FIG. 1 , a method of bringing Liquid Nitrogen  2  condensed in the exhaust pipe extension  3  to the trap I flows forward as it condenses and approaches the trap and flows backwards to airflow returning to the trap(s) area  31  if it condenses as the pipe rises to exit the Liquid Nitrogen reservoir. The exhaust pipe extension carries gaseous Nitrogen  20  where a portion of it will liquefy. It enters the reservoir  24  where the −190° C. pure Nitrogen gas  20  leaves the condensing portion of the fuel extraction system  30 , lays on the surface of the Liquid Nitrogen  23  and exits the exhaust pipe extension  3  after a reservoir diameter length out the top of the reservoir. The Nitrogen still in gaseous state  20  flows into the open air. Note the segments of the trap system  1 , with the solid pipe  10  going vertically downward from the “T”  31  in the exhaust extension  3  towards the bottom of the Liquid Nitrogen reservoir  24 , to the “U” of solid piping  11  at the bottom of the trap, to the pierced pipe area  12  parallel to the trap, to the solid elbow  13 , the solid pipe  14  leading into the “T”  15  in the trap pipe  10 . This creates a flow pattern to circulate the ball beads. Note the distance of solid pipe from the beginning of the elbow  13  to the entrance into the trap pipe  15  is significant because it holds the amount of reservoir Liquid Nitrogen  21  that flows with the newly liquefied Nitrogen  22  formed in the exhaust pipe extension  3 . 
         [0031]    Viewing  FIG. 2 , the ball beads  4  are shown with the chain  40  separating them such that the chain is longer than the distance in  FIG. 1  between the entrance to the elbow  13  to the entrance into the trap  15 . This allows the ball beads  4  to block the entrance to the pipe  13  so no further Liquid Nitrogen enters the trap system. The chain  40  and its attachment to the ball surface shown magnified off ball  45  prevents the chain  40  from being pulled past the ball in the trap  1 , keeping the chain  40  between the two balls it is attached to. Likewise, Liquid Nitrogen does not pass between the ball  4  and the pipe wall. 
         [0032]      FIG. 3  shows the ball beads  4  and chain sections  40  installed in the trap system  1 . Note, in  FIG. 3   a , as one ball bead  45  enters the solid pipe elbow  13  that it blocks the flow of Liquid Nitrogen into the system as ball bead  41  enters the trap system,  FIG. 3   b , the ball flows down the vertical solid trap pipe  10  stretching out the chain as it descends. As the chain  40  stretches to its full length, as ball  41  continues to descend it pulls ball  45  into the elbow  13  and along the short pipe  14  and ball  44  locks the entrance to the solid elbow  13  from reservoir sourced liquid Nitrogen  21 ,  FIG. 3   c . As ball  41  descends further,  FIG. 3   d , ball  45  is pulled into the trap and it descends extending the chain  40  between balls  45  and  44  until ball  43  is pulled into the elbow and seals the pipe at elbow  13  preventing further reservoir Liquid Nitrogen  21  from entering the trap  1 ,  FIG. 3   e . As the balls stretch apart in the trap  1 , the newly liquefied Nitrogen  22  enters the trap below the “T”  15  emptying the newly Liquefied Nitrogen  22  from the exhaust pipe lower area  31  to flow with the reservoir sourced Liquid Nitrogen  21  caught between elbow  13  and “T”  15 . 
         [0033]    What features do these materials need for this cryogenic control system? First, the density of the balls including the chain lengths must be less than the density of Liquid Nitrogen which is 80% of that of water. And the pipe coefficient of expansion must be like that of the balls. One pair of materials that can qualify is using stainless steel pipe for both the solid and pierced portions and having hollow Beryllium—Aluminum alloy ball and chains. These are both dimensionally stable and rugged enough at cryogenic temperatures to not fail in use. 
         [0034]      FIG. 4   a  shows the trap  1  connection valve  46  between the exhaust pipe extension  3  and the trap  1  during normal flow of the newly liquefied Nitrogen.  FIG. 4   b  shows how regurgitation of the reservoir contained Nitrogen  21  into the extension  3  is prevented. This valve  46  consists of the ball bead  4  without a chain which sits on the net catch  84  allowing the newly liquefied Nitrogen  22  flowing into the vale  46  passing through on the “c” shaped piping. In  FIG. 4   b , the ball  4  is forced upward by reservoir sourced Liquid Nitrogen  21  preventing its flow back into the exhaust pipe extension  3  by sealing the entrance to extension  3  at the seating ring  83 . Newly liquefied Nitrogen  22  in the exhaust extension  3  pushes the ball bead  4  down to rest on the net catch  84  as it enters the trap flowing around the ball in the “c” pipe of the valve  46  in  FIG. 4   a.    
         [0035]      FIG. 4   c  illustrates the two ball and socket joints  47  needed at each the entrance of the exhaust pipe extension into the Liquid Nitrogen reservoir  24  and at the end of the pass over the surface of the Liquid Nitrogen  23  near where the remaining gaseous Nitrogen  20  exhausts into the atmosphere. The double ball socket joints have balls with passage  48  attached to the pipe section attached  49  fit into a 90° elbow. One ball  48  is in the exhaust pipe extension  3  entrance and exit pipes and the other is in the part of the pipe  31  passing low over the surface of the Liquid Nitrogen in the reservoir where the traps  1  are located. The first ball joint allows the lower pipe section  31  to ride on the surface of the Liquid Nitrogen  23  in the reservoir. The second ball joint allows the traps to extend vertically into the reservoir Liquid Nitrogen  21 , and not at any other angle. 
         [0036]      FIG. 5  shows this trap system in the beginning  51  and end  59  of the Fuel Extraction system  5 , where the exhaust pipe  30  feeds into the exhaust pipe extension  3  and allows the gaseous Nitrogen  20  to flow through the extension  3  across the surface of the Liquid Nitrogen  23  where the traps  1  extend down in the reservoir  24  where its Liquid Nitrogen  21  is at and below −195.8° C. This can liquefy the gaseous Nitrogen  20  in the lower part of the extension  31  to form liquid Nitrogen  22 . To enhance this process, it is believed that the Liquid Nitrogen  21  at the bottom of the reservoir  24  is colder than that at the surface because of the weight of the Liquid Nitrogen on top of it. Therefore cold sinks  25 , copper plates, extend deep into the reservoir and are lashed  26  to the lower extension pipe  31  super cooling it to liquefy  22  more of the Nitrogen gas  20  as it passes through the exhaust system. Also illustrated here is the exit  51  of Liquid Nitrogen  21  from the reservoir to the Fuel Extraction System  5  and the entrance  59  of the exhausted Nitrogen gas  20 . This Nitrogen gas  20  passes through the Exhaust Pipe Extension  3 , through the double swivel ball joint  59 , along the low section of the extension  31  where the cold sink lash  26  encircle the pipe lowering the temperature further, and the traps  1  are attached at “T” section and where the valves  46  keep the Reservoir Liquid Nitrogen  22  out of the exhaust system. On the exit end of the exhaust extension is the second ball joint which feeds remaining Nitrogen gas  20  into the atmosphere or inside the lid for one more pass through a light gas catch  60  shown in  FIGS. 6 and 7 . 
         [0037]      FIGS. 6 and 7  show means of maintaining a clean Liquid Nitrogen reservoir. 
         [0038]      FIG. 6  shows use of a net shovel  90  to remove debris  9  from the bottom or surface of the Liquid Nitrogen  2  in the reservoir  24 . The net shovel  90  has a beveled edge  91  allowing it to get under loose debris  9  and move to have the debris come onto the net. The net section has two straight edges and two edges that are the same arc as the inner surface of the cylindrical reservoir. This way, if the debris is at the edge, the arc sides can capture it for removal. Parts of the shovel  90  include lines  92  that can raise and lower the net  90  from each corner and a pole  93  with line locks to control the planar angle of the shovel. This allows one to extend it over the surface to have the outer end just above the debris  9  to be removed and lower it to the right position to capture the debris. The mirror  94  helps one guide the net into position allowing viewing of the debris  9  and net edge  91  as the shovel  90  shoves under the debris allowing removal on the net surface. The bottom of the reservoir  99  is where these debris items are resting.  FIG. 6   a  shows the initial approach of the net shovel  90 ;  FIG. 6   b  shows its pushing under the debris; and  FIG. 6   c  shows the debris removed from the floor of the reservoir  99  and, along with the lowest part of the reservoir, the other part of  FIG. 6   c  is shown with the shovel  90  and the debris  9  out of the reservoir  24  of Liquid Nitrogen  2 . 
         [0039]    Also defined here are the Nitrogen gas  20  over the surface of the Liquid Nitrogen  2 , the lid to the reservoir  27  and the light gas catch  60  with some captured Hydrogen, Helium and Neon, the light gases  6 . 
         [0040]      FIG. 7  tackles the problem of floating debris  9  where some can be settled on the bottom  99  and some floats mid-way in the Nitrogen and other debris floats on the Liquid Nitrogen  2 . If this is a problem, the reservoir  24  can be fitted with tracks  97  mounted nearly to the bottom  99 , but with enough room for escape space  98  for the heavy balls  96  which are attached around the drop net  95 . The heavy ball tracks  97  are “c” shaped keeping the heavy balls in the track until they can escape at the bottom of the reservoir. The drop net captures the surface, floating and bottom debris as it drops and then is pulled closed by the lines  92  attached at each ball position that are gathered in the tube handle  93  and pulled out as far as possible before lifting the drop net from the bottom of the reservoir. 
         [0041]    Defined here in  FIG. 7  are, in  FIG. 7   a , the detailed light gas catch  60  with the light gases  6  on the feed pipe  61  and the capture means for the light gases  6 , the mylar type balloon and string tie  62 . This balloon is filled when one pushes the catch  60  down allowing the light gases  6  to pass into the balloon  62  which is then tied and replace with another balloon  62  for the next catch  60  full of light gases  6 . 
         [0042]    The sequence of capture of debris is shown in  FIGS. 7   b - 7   e  where in  FIG. 7   b  the net is fit over the surface and heavy balls  96  attached to the drop net  95  are placed in the tracks  97  and the drop net  95  lowers through the Liquid Nitrogen  2 . In  FIG. 7   c  the drop net  95  nears the bottom and the balls  96  are free from the track  97  escaping in the gap  98  between the end of the track  97  and the floor of the reservoir  99 . In  FIG. 7   d , the lines  92  are pulled tightly so the heavy balls  96  gather at the base of the handle  93  capturing the debris items  9  in the drop net  95 . In  FIG. 7   e , the drop net  95  and debris  9  are out of the Liquid Nitrogen  2  in the reservoir  24  and the material in the debris  9  disposed of. Since the temperature in the reservoir Nitrogen is −195.8° C. and lower, the debris items could well melt as they warm up suggesting that the net be over a containment or the solid debris be quickly placed in jars and sealed or, if it is know what the material is, like, for instance, water, it can be allowed to melt and then evaporate. 
         [0043]    The pathway of the heavy balls  96  is illustrated in the far left track  97  where it lowers and escapes  98  from the track at the bottom  99  and then is pulled by the line  92  to the center where the handle tube  93  guides the line so the operator can pull the net circumference to the middle and then, holding the lines  92  locked close to the outer end, lifts the handle and drop net  95  with the heavy balls  96  and debris  9  out of the Liquid Nitrogen reservoir. 
         [0044]      FIG. 8  shows the traps  1  serving to bring condensed material into their holding tanks where the exit  8  from the Fuel Extraction System  5 . The containers for the material  80 ,  81  are surrounded and based on Liquid Nitrogen  2  and Nitrogen gas  20  and the gaseous state of the material  70  comprise the gases over the liquid material  7 . The containers drawn to be transparent contain the liquid state material  72 . New liquid material  71  is pouring into the presently empty vessel  81  through the traps  1  in the forward vessel. The vessel behind  80  was just filled and should be exchanged for an empty vessel and sealed for portage to the refinery. The switching mechanism  82  is triggered to change vessels to be filled by the height of the liquid in the container. The liquid  7  in container  80  has met that height requirement and is now ready for replacement. Note that these traps  1  are coming off submerged pipe extensions  3  to prevent long drops of the liquid material since it may cause some of the material to evaporate as it falls. Minimal drop means minimal evaporation of liquid form material  7 . To prevent further evaporation in the tank, a film  85  is placed over the surface. The film material can be edge sealed “bubble plastic” with the bubbles on one sheet fitting between the bubbles of the other sheet. Having this film  85  in two parts, it can move upward on either side of the traps  1 . 
         [0045]    Once the reservoir  80  of the liquid material  72  is full, an empty reservoir  81  next to it begins to fill. A “T” valve  82  which will stop the flow into the full reservoir  80  allowing the remaining Liquid  7  to begin filling the next reservoir  81 . The filled reservoirs  80  are stored at cryogenic temperatures below that of the liquid  7 . Materials collected this way include the Natural Gas components of Butane, Propane, Ethane, and Methane, and common gases as Oxygen and Argon. 
         [0046]    Many changes and modifications could be made to the invention without departing from the spirit thereof. The scope of some of these changes can be appreciated by comparing the various embodiments as described above. The scope of the remaining changes will become apparent from the appended claims.