Abstract:
A refrigerant recovery/recycling system includes a source container fluidly connected to a recovery/recycling device via a vaporizer. Liquid refrigerant is introduced into the vaporizer via the source container and the vaporizer changes the refrigerant from a liquid into a vapor. In so doing, slow/no flow conditions of both the source container and the recovery/recycling device can be reduced, which increases the rate in which the recovery/recycling device is charged with refrigerant.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Application No. 60/574,577, filed May 27, 2004, which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The disclosure relates generally to refrigerant charging systems and, more specifically, to an improved transfer system for refrigerant recovery/recycling equipment. 
     BACKGROUND ART 
     An example of a conventional refrigerant recovery/recycling system  11  is illustrated in  FIG. 1 . The refrigerant recovery/recycling system  11  includes a source container  12  directly connected to a recovery/recycling device  22  via a line  16 . Typically, a recovery/recycling device  22  is preconditioned and replenished with refrigerant used for charging by drawing refrigerant into the device from vapor phase refrigerant  20  in the source container  12 . This causes the source container  12  to reduce in pressure and thereby chill substantially the source container  12 . 
     This method of replenishing the recovery/recycling device  22  is slow due to low pressure as a result of the chilling effect of depletion of the source refrigerant vapor. If liquid refrigerant  18  is drawn directly into the recovery/recycling device  22 , various components within the recovery/recycling device  22  will become sluggish due to the liquid refrigerant, which again slows the transfer of refrigerant to the recovery/recycling device  22 . Furthermore, if sufficient liquid is drawn into the recovery/recycling device  22 , a compressor powering the recovery/recycling device  22  may fail. There is, therefore, a need for a refrigerant recovery/recycling system that prevents chilling and slowed/stopped flow from the source container to the recovery/recycling device to improve the rate of charging of the recovery/recycling device. 
     SUMMARY OF THE DISCLOSURE 
     Described is a system for charging a refrigerant recovery/recycling system with refrigerant. The system includes a source container fluidly connected to a recovery/recycling device via a vaporizer. Liquid refrigerant is introduced into the vaporizer via the source container and the vaporizer changes the refrigerant from a liquid into a vapor. In so doing, reduced flow of both the source container and the recovery/recycling device can be avoided, which increases the rate in which the recovery/recycling device is charged with refrigerant. 
     In one aspect, the refrigerant recovery/recycling system, comprises a source container for storing refrigerant, a recovery/recycling device, and a vaporizer disposed between and fluidly connected to the source container and the recover/recycling device. In other aspects, the vaporizer may comprise a thermal expansion valve, regulator, a pulsed solenoid, or an orifice. 
     In another aspect, a method for charging a recovery/recycling device with refrigerant is provided and comprises the steps of transferring liquid refrigerant from a source container to a vaporizer separate from said source container, vaporizing the liquid refrigerant using the vaporizer, and transferring the vaporized refrigerant from the vaporizer to the recovery/recycling device. In further aspects of this method, the transferring and vaporizing steps may utilize a vaporizer comprising a thermal expansion valve, a regulator, a pulsed solenoid, or an orifice. 
     Additional advantages will become readily apparent to those skilled in the art from the following detailed description, wherein only an exemplary embodiment of the present invention is shown and described, simply by way of illustration of the best mode contemplated for carrying out the present invention. As will be realized, the disclosure is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of a conventional refrigerant recovery/recycling system; 
         FIG. 2  is a schematic view of a refrigerant recovery/recycling system according to the disclosure; 
         FIG. 3  is a schematic view of a recovery/recycling device and 
         FIG. 4  is schematic new view of a recovery/recycling device according to a further embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An example of a refrigerant recovery/recycling system  21  is illustrated in  FIG. 2 . The refrigerant recovery/recycling system  21  includes a source tank  12  connected to a recovery/recycling device  22  via a vaporizer  24 . The vaporizer  24  is fluidly connected to the source tank  12  with a first line  27  and the vaporizer  24  is fluidly connected to the recovery/recycling device  22  with a second line  28 . Although shown in  FIG. 2  as being positioned away from the recovery/recycling device  22 , the vaporizer  24  can be positioned within the recover/recycling device  22 , as shown in  FIG. 4 . 
     The first line  27  can be connected to the source tank  12  at any location. However, in a current aspect of the refrigerant recovery/recycling system  21 , the first line  27  is connected to the source tank  12  so as to draw liquid refrigerant  18  from the source tank  12 . In this particular instance, the liquid refrigerant  18  is drawn off the bottom of the source tank  12 . 
     Although vaporized refrigerant  20  can be drawn from the source tank  12 , By drawing off liquid refrigerant  18  from the source tank  12 , the aforementioned reduction in pressure in the source tank  12  is reduced. Unlike a conventional system in which the reduction in pressure in the source tank  12  decreases the temperature of the source tank  12 , by maintaining the substantially same pressure within the source tank  12  using the present refrigerant recovery/recycling system  21 , the temperature of the source tank  12  remains substantially the same, thereby preventing the problems of low/no flow rate components, such as a tank valve  14 , within the source tank  12  due to low-temperature refrigerant. 
     Upon entering the vaporizer  24  from the first line  27 , the liquid refrigerant is substantially completely vaporized. Any type of device capable of vaporizing a liquid refrigerant is acceptable for use with the refrigerant recovery/recycling system  21 . For example, the vaporizer may be a thermal expansion valve, regulator, pulsed solenoid, orifice, or a combination thereof. Although shown being separate from the recovery/recycling device  22 , the vaporizer  24  may be incorporated within the recovery/recycling device  22 . 
     When the liquid refrigerant is vaporized using the vaporizer  24 , a reduction in pressure of the refrigerant occurs. However, because the vaporization occurs away from the source tank  12 , the problems associated with the components in the source tank  12  being chilled by low-temperature refrigerant can be reduced. The vaporized refrigerant is then transferred to the recovery/recycling device  22  via the second line  28 . 
     An example of a refrigerant recovery/recycling device  22  is illustrated in  FIG. 3 . A refrigerant recovery/recycling device for recovering/recycling refrigerant from a refrigeration system and a charging the refrigeration system with refrigerant is known in the art, and any refrigerant recovery/recycling device so capable is acceptable for use with the refrigerant recovery/recycling system  21 . For example, a refrigerant recovery/recycling device is illustrated and described in U.S. Pat. No. 6,427,457 to Pfefferle et al., incorporated herein by reference. 
     To withdraw refrigerant from the tank  12 , a compressor  37  creates a pressure differential between the recycling/recharging device  22  to draw liquid from the tank  12 , through the lines  27 ,  28  and the vaporizer  24  and into the recycling/recharging device  22 . Upon entering the recycling/recharging device  22 , the refrigerant is stored in a refrigerant recovery tank  50 . 
     The recycling/recharging device  22  is also adapted to be connected to the air-conditioning system of an automotive vehicle (not shown) using a connector  30 . The connector  30  is coupled through a suitable filter and a vacuum solenoid valve  31  to an oil separator  32  for removing oil from the refrigerant, and the output of the oil separator  32  is in turn connected to a vacuum switch  33  and, through an oil separator solenoid valve  34 , to a master filter/dryer  35 . The output of the master filter/dryer  35  is connected through a manifold  36  to the suction port of a compressor/pump  37 , and the discharge of the compressor pump  37  is coupled to the input of an oil separator/reservoir  38 . 
     The recycling/recharging device  22  may also be provided with a low pressure cutoff switch  41  connected to the input of the oil separator solenoid  34  and a high pressure cutoff switch  42  connected to the output of the oil separator reservoir  38 . The output of the oil separator/reservoir  38  is also connected to a vent line  44  via a vent solenoid valve  43 . A process port of the compressor/pump  37  is connected through a solenoid valve  45  to a return port of the oil separator/reservoir  38 . 
     The output of the condenser  40  is connected through a moisture indicator  46  and a liquid solenoid valve  47  to the input of the refrigerant recovery tank  50  through suitable anti-blowback valves. The input of the tank  50  is also connected through a purge solenoid valve  51  and an air filter  52  in a purge line, and is also connected to a purge transducer  53 . The refrigerant recovery tank  50  has a liquid outlet coupled through a filter and suitable anti-blowback valves, and then through a charge solenoid valve  55  and a check valve  56  to the automotive connection point  30 . The output of the oil separator  32  is connected through a filter bypass solenoid valve  58  to a vacuum conduit, the other end of which is normally connected to the manifold  36 . 
     A vacuum pump  26  has a suction port and an exhaust port, and in order to install the vacuum pump  26  in the recycling/recharging device  22 , a cap or plug  29  is removed from the suction port of the vacuum pump  26 , the lower end of the vacuum conduit is disconnected from the manifold  36  and reconnected to the suction port of the vacuum pump  26 , and the plug  29  is then installed on the port of the manifold  36  from which the vacuum line was just disconnected, resulting in the arrangement illustrated in  FIG. 2 . The discharge port of the vacuum pump  26  is vented to atmosphere. 
     Through use of the present refrigerant recycling/recharging system and methodology, refrigerant transferred from the source container into the refrigerant recovery tank of the recycling/recharging device is performed at a greater rate due to reducing the chilling of the source tank. Also refrigerant can be withdrawn from the source tank in either the vapor or liquid phase. Furthermore, as the pressure of the refrigerant is kept higher using the system and method described above, the compressor used to draw the refrigerant from the source tank does not have to work as hard, thereby increasing the life of the compressor. 
     The disclosed concepts may be practiced by employing conventional methodology and equipment. Accordingly, the details of such equipment and methodology are not set forth herein in detail. In the previous descriptions, numerous specific details are set forth, such as specific formulas, processes, techniques, etc., in order to provide a thorough understanding of the present invention. However, it should be recognized that the present invention may be practiced without resorting to the details specifically set forth. 
     Only an exemplary aspect of the present disclosure and but a few examples of its versatility are shown and described. It is to be understood that the present invention is capable of use in various other combinations and environments and is capable of changes or modifications within the scope of the inventive concept as expressed herein.