Abstract:
Gas vaporizer for flashing liquid to vapor received from a source prior to introduction into a compressor or the like, such as in air conditioning or refrigeration systems. In certain embodiments the vaporize includes an adapter member for connection to a liquid source, a connector member having a plurality of flow passages for facilitating the transfer of heat to fluid present therein to vaporize the same, a body portion providing visual access such as via one or more sight glasses to an internal chamber therein for visual confirmation that liquid has been vaporized, and a hose connecting member for connection to a point of destination such as a compressor. In certain embodiments, the connector has an axial bore containing a high thermal conductive material.

Description:
This application claims priority of U.S. Provisional Application Ser. No. 61/300,844 filed Feb. 3, 2010, the disclosure of which is hereby incorporated by reference. 
    
    
     BACKGROUND 
     Mechanical Air Conditioning and Refrigeration is accomplished by continuously circulating, evaporating, and condensing a fixed supply of refrigerant in a closed system. Charging or recharging an Air Conditioning or Refrigeration system with refrigerant is done through the low side suction intake fitting with the use of manifold gauges and service hoses. There are several types of refrigerants used and some can be charged as a vapor and others must be charged as a liquid. 
     For example, R-410A is replacing R-22 refrigerant. R-410A is a mixture of HFC-32 and HFC-125, and is thus considered to be zeotropic. Zeotropic refrigerants such as R-410A must be charged as a liquid from a canister due to the possibility of fractionation of the blend of refrigerants it contains. The range of temperatures at which components in the blended components of R-410A refrigerant boil (temperature glide) is &lt;0.3° F., making it a near-azeotropic refrigerant mixture. 
     Since the two components of zeotropic refrigerants such as R-410A have different boiling points, the components fractionate during boiling. That is, as the temperature increases, the lower boiling point components vaporize first. The vapor thus has a higher concentration of the lower boiling components than the liquid, and a lower concentration of the higher boiling components. When such a fluid blend is stored in a closed container in which there is a vapor space above the liquid, the composition of the vapor is different from the composition of the liquid. If the fluid is then removed from the container to charge an air conditioning system, for example, fractionation can take place, with accompanying changes in composition. Such changes can cause a refrigerant to have a composition outside of specified limits, to have different performance properties or even to become hazardous, such as by becoming flammable. 
     R-410A must be liquid charged into the low side of the system, so the components in the blend do not separate. Charging by weight is the preferred method of admitting the liquid charge. To accomplish this, most R-410A refrigerant cylinders must be inverted, or turned up-side-down, to allow liquid refrigerant to flow freely from the cylinder. A charging manifold valve and services hoses are used to connect the refrigerant cylinder to the system. However, assurance that no liquid is entering the system is essential for proper charging and to avoid damaging the compressor. 
     SUMMARY 
     The shortcomings of the prior art have been overcome by the present disclosure, which relates to a gas vaporizer and method for flashing liquid to vapor received from a source prior to introduction into a compressor or the like, such as in air conditioning or refrigeration systems. In certain embodiments, refrigerant is removed from a source, such as a pressurized cylinder, as a liquid, and is vaporized by the gas vaporizer. The vapor is then introduced into an air conditioning or refrigeration system, such as the compressor or the like. In certain embodiments, the vaporize includes an adapter member for connection to a liquid source, a connector member for facilitating the transfer of heat to fluid present therein to vaporize the same, a body portion providing visual access such as via one or more sight glasses to an internal chamber therein for visual confirmation that liquid has been vaporized, and a hose connecting member for connection to a point of destination such as a compressor. The vaporization of the liquid can be monitored via the sight glass, and can be metered by controlling the flow rate of liquid through the device, such as with the charging manifold valve. Oppositely positioned sight glasses allows for ambient light to enter one side and render the fluid in the chamber visible through the other side. 
     In certain embodiments, the connector member has a plurality of flow passages that facilitate the transfer of heat to the fluid present in the flow passages. In certain embodiments, the connector member includes a high thermal conductive material such as sintered metal to facilitate the transfer of heat to the fluid present in the connector member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front view of a vaporizer in accordance with certain embodiments; 
         FIG. 2  is an exploded, cross-sectional view of a vaporizer in accordance with certain embodiments; 
         FIG. 3  is a cross-sectional view of an inlet adapter in accordance with certain embodiments; 
         FIG. 4  is a front view of a vaporizer body in accordance with certain embodiments; 
         FIG. 4A  is a cross-sectional view of the vaporizer body of  FIG. 4  in accordance with certain embodiments; 
         FIG. 5  is a top view of a connector in accordance with certain embodiments; 
         FIG. 6  is a cross-sectional view of a cap in accordance with certain embodiments; 
         FIG. 7  is a cross-sectional view of a hose nut in accordance with certain embodiments; 
         FIG. 8  is a cross-sectional view of an inlet nipple in accordance with certain embodiments; 
         FIG. 9  is a side view of a hose connector in accordance with certain embodiments; 
         FIG. 10  is an exploded view of a vaporizer in accordance with an alternative embodiment; 
         FIG. 11  is a cross-sectional view of the vaporizer of  FIG. 10  in an assembled condition. 
     
    
    
     DETAILED DESCRIPTION 
     Turning first to  FIGS. 1 and 2 , there is shown a gas vaporizer  10  in accordance with certain embodiments. In the embodiment shown, the vaporizer  10  includes an inlet adapted assembly  12 , a cap  14 , a connector  16 , a main body  18 , and a hose connector  20 . 
     As best seen in  FIG. 3 , the inlet adapter assembly  12  includes a hose nut  21  that mates to one end of inlet nipple  23 . Preferably a neoprene sleeve  22  or the like is interposed between the nipple  23  and the hose nut  21  and serves as a gasket to help effectuate a seal. The opposite end of inlet nipple  23  is threadingly coupled to inlet nut  24  as shown. The hose nut  21 , as seen in  FIG. 7 , includes an internal cavity  81  that is configured to receive in a lower portion thereof the inlet nipple  23 . The upper portion of the cavity  81  is internally threaded with threads  19  to mate to a fluid source such as a refrigerant charging manifold (not shown). Preferably the nut  21  includes one or more (preferably two, spaced 180° apart) axially extending vent slots  90 . The vent slots  90  allow vapor to vent in the direction of the charging manifold upon disconnection of the device from the manifold. 
       FIG. 8  shows inlet nipple  23 , one end of which has external threads  32  for mating with internal threads in inlet nut  24  ( FIG. 3 ). The inlet nipple  23  is stepped, and thus includes a first elongated portion  34  having a first diameter, a second portion  35  defined at shoulder  33  having a second diameter larger than said first diameter, and a third portion  36  defined at shoulder  37  having a third diameter larger than the second diameter. The third portion  36  includes a cavity  38  that is preferably lined with a neoprene sleeve  22  ( FIG. 3 ). Third portion  36  is configured to fit into hose nut  21 , with shoulder  37  seating against a corresponding shoulder  41  in the hose nut  21  ( FIG. 3 ). An axial bore  40  communicates with cavity  38  and axial bore  17  in inlet nut  24  and extends through the inlet nipple  23  as shown. Alternatively, inlet nut  24  can be eliminated and the inlet nipple  23  can be threaded directly into cap  14 . 
     Inlet nut  24  also includes external threads  25  for threading engagement with corresponding internal threads  26  in bore  31  of cap  14 . Preferably the cap  14  ( FIG. 6 ) includes an upper annular portion  28  that has a knurled surface  39  to facilitate grasping and turning of the cap  14  by the fingers of a user. Cap  14  includes external threads  27  that mate with corresponding internal threads  29  of connector  16 . An O-ring ( FIG. 2 ) can be positioned just below the annular portion to help seal the connection between the cap  14  and the connector  16 . 
     Connector  16  is preferably made of a heat conductive material, such as aluminum, in order to aid in the transfer of thermal energy to the liquid refrigerant. Connector  16  is generally cylindrical and has a first end with internal threads  29 , a main body with a plurality of axial bores  43 , and a second end with internal threads  29 ′. The connector  16  also includes a plurality of spaced, annular fins  42  extending radially outwardly from the main body of the connector  16 . In the embodiment shown, there are five such fins  42 , although those skilled in the art will appreciate that more (e.g., eight) or fewer fins can be used. The fins  42  serve to optimize the heat transfer from the ambient to the refrigerant in the internal bores  43  of the connector  16 . As best see in  FIG. 5 , the plurality of spaced axially extending bores  43  are preferably arranged in a circular pattern and extend the length of the connector  16 . The bores  43  are arranged to receive, via inlet adapter assembly  12 , liquid refrigerant. As the liquid refrigerant travels through the bores  43 , heat is transferred from ambient and vaporizes the refrigerant. 
     Connector  16  mates with body  18  via internal threads  29 ′ which correspond to external threads  47  on one end of the body  18 . An O-ring  30 ′ can be used to seal the connection. Preferably body  18  is also made of a heat conductive material, such as aluminum. A centrally located axial bore  50  extends through the body  18 . When the body is assembled to the connector  16 , the bore  50  is in fluid communication with each of the bores  43  in connector  16 , thus any fluid in the bores  43  combines into a single stream in bore  50 . Axial bore  50  communicates with a generally centrally located chamber  52  in body  18 . Chamber  52  has a diameter larger than the diameter of bore  50 . Preferably the chamber  52  is symmetrically positioned in body  18  such that the axial centerline of the bore  50  aligns with the axial centerline of the chamber  52 . 
     The body  18  includes radial apertures  60 ,  61  that provide a vapor window that allows visual access to the chamber  52 . As seen in  FIG. 2 , each aperture  60 ,  61  accommodates a preferably disk-shaped sight glass  65 , sealed in a respective aperture by an O-ring  63  or the like that seats in a respective annular groove  64  formed in the body  18 . Each sight glass  65  is preferably made of glass or other transparent material suitable for the application, and is secured in its aperture by a slip ring  66  and screw  67 , the screw  67  having external threads  68  that mate with corresponding internal threads formed in each aperture  60 ,  61 . Through the thus formed window, the status of vaporization of the liquid in the device  10  can be visually monitored, and can be controlled by increasing or decreasing the residence time of the liquid in the device. 
     Bore  50  expands radially outwardly in tapered end  70  of the body  18  and includes internal threads  71  that mate with external threads  72  on hose connector  20 . The hose connector  20  includes a preferably centrally located axial bore  80  shown in  FIG. 2  and in phantom in  FIG. 9 . When the connector  20  is assembled to the body  18 , the axial bore  80  is in fluid communication with axial bore  50  (and thus chamber  52 ). The connector  20  includes a radially extending hexagonal member  84  to facilitate attachment of the connector to the body  18 , and attachment of a hose (not shown) to the connector, such as by hand or with a wrench. 
     In operation, the hose nut  21  is connected to a refrigerant charging manifold, for example, via internal threads  19  in the nut  21 . The hose connector at the opposite end of the device  10  is coupled to a service hose that is in fluid communication with the low side of an air conditioning or refrigeration unit, for example, via external threads  78  on the hose connector  20 . Liquid refrigerant is then introduced into the device  10 , by opening the valve on the charging manifold. As the liquid refrigerant flows through the device and enters the plurality of axial bores  43  in the connector  16 , the liquid begins to vaporize as a result of heat transfer from the ambient optimized with the annular fins  42 . Since it is desirable, if not imperative, that all of the liquid vaporize before it reaches the air conditioning or refrigeration unit, the status of the vaporization can be monitored visually via the visual window provided in the body  18 . If excessive liquid is present in the chamber  52 , where the liquid and vapor in the flow passages  43  have merged, the flow rate of liquid entering the device  10  can be slowed using the charging manifold valve in order to increase the residence time of the liquid in the device  10 , and particularly in the connector  16  where most of the vaporization occurs. Similarly, if no liquid is present in the chamber  52 , the flow rate of liquid entering the device  10  can be increased, until the optimal flow rate is achieved. 
     Turning now to  FIGS. 10 and 11 , where like reference numerals designate similar parts in previous figures, the connector  16 ′ includes an internal axial bore  43 ′, which is preferably centrally located within the body of the connector  16 ′. The internal axial bore  43 ′ is configured to receive a high thermal conductive material  89  capable of transferring energy to fluid in the connector. Suitable high thermal conductive materials include sintered copper, sintered brass, sintered bronze, and the like, with sintered copper being particular preferred. The high thermal conductive material can be in the form of a sintered metal filter  90 , which is typically manufactured by selecting metal powder of specific particle size distribution, molding them into the required shape and high temperature sintering in hydrogen to obtain a strong porous structure. Particle sizes ranging from about 50 to about 500 microns, preferably 150-350 microns, most preferably about 250 microns, can be used. Preferably the high thermal conductive material  89  occupies the volume of the bore  43 ′. In certain embodiments, the high thermal conductive material is a sintered metal filter about one inch in length and ⅜ inches in diameter. 
     As is the case with the embodiments of  FIGS. 1-9 , the inlet adapter assembly  12  includes a hose nut  21  that mates to one end of inlet nipple  23 . Preferably a neoprene sleeve  22  or the like is interposed between the nipple  23  and the hose nut  21  and serves as a gasket to help effectuate a seal. The opposite end of inlet nipple  23  is threadingly coupled to cap  14  as shown. The hose nut  21  includes an internal cavity  81  that is configured to receive in a lower portion thereof the inlet nipple  23 . The upper portion of the cavity  81  is internally threaded with threads  19  to mate to a fluid source such as a refrigerant charging manifold (not shown). Preferably the nut  21  includes one or more (preferably two, spaced 180° apart) axially extending vent slots  90 . The vent slots  90  allow vapor to vent in the direction of the charging manifold upon disconnection of the device from the manifold. 
     The inlet nipple  23  is stepped, and thus includes a first elongated portion  34  having a first diameter, a second portion  35  defined at shoulder  33  having a second diameter larger than said first diameter, and a third portion  36  defined at shoulder  37  having a third diameter larger than the second diameter. The third portion  36  includes a cavity  38  that is preferably lined with neoprene sleeve  22 . Third portion  36  is configured to fit into hose nut  21 , with shoulder  37  seating against a corresponding shoulder  41  in the hose nut  21 . An axial bore  40  communicates with cavity  38  and axial bore  17 ′ in cap  14 , and extends through the inlet nipple  23  as shown. Preferably the cap  14  includes an upper annular portion  28  that has a knurled surface to facilitate grasping and turning of the cap  14  by the fingers of a user. Cap  14  includes external threads  27  that mate with corresponding internal threads  29  of connector  16 ′. An O-ring  30  can be positioned just below the annular portion  28  to help seal the connection between the cap  14  and the connector  16 ′. 
     Connector  16 ′ is preferably made of a heat conductive material, such as aluminum, in order to aid in the transfer of thermal energy to the liquid refrigerant. Connector  16 ′ is generally cylindrical and has a first end with internal threads  29 , a main body with axial bore  43 ′, and a second end. The connector  16 ′ also includes a plurality of spaced, annular fins  42  extending radially outwardly from the main body of the connector  16 ′. In the embodiment shown, there are ten such fins  42 , although those skilled in the art will appreciate that more or fewer fins can be used. The fins  42  serve to optimize the heat transfer from the ambient to the refrigerant in the internal bore  43 ′ of the connector  16 ′. 
     The axially extending bore  43 ′ is arranged to receive, via inlet adapter assembly  12 , liquid refrigerant. As the liquid refrigerant travels through the high thermal conductive material contained in the bore  43 ′, heat is transferred from ambient and vaporizes the refrigerant. Those skilled in the art will appreciate that although a single bore  43 ′ is shown, a plurality of spaced bores  43 ′, each containing a high thermal conductive material, can be used. If a plurality of axial bores are used, the connector  16 ′ can be manufactured in two separate parts, as described with respect to the embodiments of  FIGS. 1-9  where body  18  is a separate part from connector  16 , in view of the manufacturing steps necessary to have a plurality of the axial bores conjoin in the region where they communicate with the bore  50 . Alternatively still, where a plurality of bores is used, some can be devoid of high thermal conductive material (as in the embodiments of  FIGS. 1-9 ). 
     Connector  16 ′ includes a preferably centrally located axial bore  50 ′ in fluid communication with the bore or bores  43 ′. The axial bore  50 ′ is positioned downstream, in the direction of fluid flow, of the bore  43 ′, and communicates with a generally centrally located chamber  52 ′. Chamber  52 ′ has a diameter larger than the diameter of bore  50 ′. Preferably the chamber  52 ′ is symmetrically positioned in the connector  16 ′ such that the axial centerline of the bore  50 ′ aligns with the axial centerline of the chamber  52 ′. 
     Radial apertures  60 ,  61  in connector  16 ′ provide a vapor window that allows visual access to the chamber  52 ′. Each aperture  60 ,  61  accommodates a preferably disk-shaped sight glass  65 , sealed in a respective aperture by an O-ring  63  or the like that seats in a respective annular groove  64  formed in the connector  16 ′. Each sight glass  65  is preferably made of glass or other transparent material suitable for the application, and is secured in its aperture by a slip ring  66  and screw  67 , the screw  67  having external threads  68  that mate with corresponding internal threads formed in each aperture  60 ,  61 . Through the thus formed window, the status of vaporization of the liquid in the device  10 ′ can be visually monitored, and can be controlled by increasing or decreasing the residence time of the liquid in the device. 
     Bore  50 ′ expands radially outwardly in tapered end  70  of the connector  16 ′ (and downstream, in the direction of fluid flow, of the chamber  52 ′) and includes internal threads  71  that mate with external threads  72  on hose connector  20 . The hose connector  20  includes a preferably centrally located axial bore  80 . When the hose connector  20  is assembled to the connector  16 ′, the axial bore  80  is in fluid communication with axial bore  50 ′. The hose connector  20  includes a radially extending hexagonal member  84  to facilitate attachment of the hose connector to the connector  16 ′, and attachment of a hose (not shown) to the connector, such as by hand or with a wrench. 
     In operation, the hose nut  21  is connected to a refrigerant charging manifold, for example, via internal threads  19  in the nut  21 . The hose connector at the opposite end of the device  10  is coupled to a service hose that is in fluid communication with the low side of an air conditioning or refrigeration unit, for example, via external threads  78  on the hose connector  20 . Liquid refrigerant is then introduced into the device  10 ′, by opening the valve on the charging manifold. As the liquid refrigerant flows through the device and enters the axial bore  43 ′ containing a high thermal conductive material  89  in the connector  16 ′, the liquid begins to vaporize as a result of heat transfer from the ambient optimized with the annular fins  42 . Since it is desirable, if not imperative, that all of the liquid vaporize before it reaches the air conditioning or refrigeration unit, the status of the vaporization can be monitored visually via the visual window provided in the connector  16 ′. If excessive liquid is present in the chamber  52 ′, where the liquid and vapor in the bore  43 ′ have merged, the flow rate of liquid entering the device  10 ′ can be slowed using the charging manifold valve in order to increase the residence time of the liquid in the device  10 ′, and particularly in the connector  16 ′ where most of the vaporization occurs. Similarly, if no liquid is present in the chamber  52 ′, the flow rate of liquid entering the device  10 ′ can be increased, until the optimal flow rate is achieved.