Abstract:
A method an apparatus for establishing in a system for dispensing fluid in a gaseous phase a predetermined quantify of the fluid in its liquid phase, and for allowing such fluid in its liquid phase to vaporize into its gaseous phase to replace the gaseous phase fluid that is dispensed to users.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a method and apparatus for filling a dispensing system with fluid in its liquid phase, the system enabling the liquid to subsequently vaporize into its gaseous phase for dispensing to users. 
     2. Description of the Prior Art 
     It is known to fill a dispensing system with a fluid in its liquid phase, with the system being operative to enable conversion of the fluid to its vapor or gaseous phase for dispensing, such as dispensing gaseous carbon dioxide to a carbonated drink dispenser. 
     U.S. Pat. No. 4,936,343, dated Jun. 26, 1990 and issued to John E. Pruitt et al, discloses a “Carbon Dioxide Fill Manifold” comprising a manifold having a fill line which accepts fluid in its liquid phase from a storage vehicle or the like for completely filling one or more liquid storage containers to which it is connected, the liquid storage containers in turn being connected in series with one or more gas storage containers. 
     An atomizer disposed between the liquid and gas storage containers is operative to establish a proper ratio of liquid to gas in the dispensing system. 
     Each time a user dispenses some of the gas, the gas flows through the atomizer and develops a pressure differential between the liquid and gas storage containers. This differential increases as successive gas withdrawals occur. When a certain level of pressure differential is reached, an in-line pressure relief valve in the system opens to automatically permit additional, make-up liquid to flow through the atomizer and replenish the supply of available gas. 
     The added liquid vaporizes and expands into gas which fills the gas storage container or containers, according to the existing pressure differential to their original levels. Liquid/vapor flow continues through the atomizer until the requisite pressure differential is no longer present at the in-line relief valve. At that time the valve closes and shuts off further liquid flow. If overfilling occurs, such that some of the liquid flows into the portion of the gas storage container that is reserved for gas expansion, excess pressure can develop. Consequently, each gas storage container is provided with a rupture disc designed to fail when the container pressure exceeds a predetermined level. If overfilling is prohibitively high, the rupture disc fails and the contents of the container are jettisoned. 
     A similar system that employs a vaporizer or atomizer is disclosed in U.S. Pat. No. 5,113,905, dated May 19, 1992 and issued to Pruitt et al for a “Carbon Dioxide Fill Manifold and Method”. The patent is based upon an application which is a continuation-in-part of the application which resulted in issuance of the above-discussed U.S. Pat. No. 4,936,343. 
     The atomizer of the &#39;905 patent includes an atomizer having a pressure actuated check valve located internally of the atomizer for periodically replenishing the supply of gas in response to the development of a selected pressure differential across the pressure actuated valve. 
     Various other analogous systems are provided in the prior art for dispensing a gaseous phase of a fluid such as carbon dioxide but many, like the two patents just described, are characterized by special relief valves, pressure actuated valves, vaporizers or the like. That is, a regulator such as a check valve or other pressure responsive device is used between the liquid and gaseous portions of such systems to control the change of liquid to gas. This results in a system that is relatively complex, expensive to maintain, and not as responsive to the needs of users as the method and apparatus of the present invention. As will be seen, in the system of the present invention there is no such regulator. All manifold passages are open and interconnected with no pressure differential between them. 
     SUMMARY OF THE INVENTION 
     According to the present invention, a system is provided which is particularly adapted for use as a carbonated beverage dispensing system. The system includes a manifold which can be connected to a supply truck or other source of carbon dioxide fluid in its liquid phase. 
     The manifold includes a controller in the form of a spool valve which is movable to a closed position by the pumping pressure developed when the liquid is pumped into the manifold from the liquid source. The incoming liquid flows around and through the closed spool valve into liquid passages in the manifold that are connected to a set of liquid storage cylinders. However, the flow of liquid is blocked by the spool valve from flowing into a dispenser passage which leads to the dispensing port through which the gaseous form of the fluid is dispensed to a user. The terms “gas”, “gaseous” and “vapor” are sometimes interchangeably used as a matter of convenience. 
     When the liquid storage cylinders are completely filled in the closed position of the spool valve by the incoming liquid flowing past the spool valve, the pump is turned off. The hose from the filling pump is vented when the pump is turned off, so the manifold pressure exceeds the pressure on the inlet or filling port, and the spool is shifted to its open position. The pump can be turned off manually, or automatically in response to an increase in pressure when the system is full of liquid. The liquid within the liquid storage cylinders is now undergoing vaporization, the rapidity of vaporization depending upon the magnitude of the vapor pressure in the system. 
     With the spool valve in its open position, fluid communication is provided between all of the manifold passages, i.e. the liquid passages, the gas passages, and the dispensing passage. The evolving gas then can flow through all of these passages and particularly into the gas storage container or containers. 
     There is no pressure differential between any of these passages. The production of gas can therefore occur without the use of any special vaporizer, atomizer or valving arrangement designed to respond to predetermined pressure differentials or the like to produce gas. The generation of gas automatically continues until the liquid has been substantially all vaporized and the resulting gas completely used. When this fill cycle is completed, and the liquid has been substantially all used, with the pump having been turned off and the spool valve moved to its open position by internal manifold pressure or, as will be seen, by bias means acting against the spool valve, the pump can again be manually turned on and the apparatus operated to initiate another fill/use cycle to introduce a fresh supply of liquid for the manifold from the supply vehicle. 
     Reference has been made to a spool valve type of controller but, as will be described, there are other types of valving arrangements which can be used, if desired, to provide the described functions of the spool valve. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a partially schematic view of the system of the present invention; 
     FIG. 2 is a view taken along the line  2 — 2  of FIG. 1; 
     FIG. 3 is a longitudinal cross sectional view of the manifold of the system taken along the line  3 — 3  of FIG. 2, the spool valve being illustrated in its open position, with the use port open and the system in its use mode for dispensing gas to an end user; 
     FIG. 4 is a longitudinal cross sectional view similar to FIG. 3 except that the spool valve is illustrated in its closed position in which the use port is closed and the system is in its fill mode for receiving incoming liquid; 
     FIG. 5 is a detail view in the area designated by the numeral  5  in FIG. 3, showing an embodiment of the invention in which a bias means in the form of a spring in its uncompressed state is disposed between the spool valve and the manifold adjacent the use port; 
     FIG. 6 is a detail view in the area designated by the numeral  6  in FIG. 4, similar to FIG. 5, but showing an embodiment of the invention in which the bias means is in its compressed state to bias the spool valve from its open position of FIG.3 toward its closed position of FIG. 4; and 
     FIG. 7 is a diagrammatic showing of a commercially available three way valve that can be substituted for the spool valve of FIGS. 1-5, the valve being illustrated in a position which places the apparatus in the open state illustrated in FIG. 3 ; and 
     FIG. 8 is a diagrammatic showing similar to the showing of FIG. 7, but illustrating actuation of the piston of the valve to the left, placing the apparatus in the closed state illustrated in FIG.  4 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings, and particularly to FIGS. 1-4, the present apparatus includes a manifold  10  which is connected to a fill conduit  12 . The conduit  12  is connected to a pump  14  that is turned on to initiate a fill cycle by supplying fluid in its liquid phase from a pump supply  16  (not shown) that is typically transportable by a supply truck or the like (not shown). 
     The conduit section between the pump  14  and the manifold  10  includes a vent valve  18  which can be operated to vent the manifold  10  to atmosphere. Once venting is completed the valve  18  is manually rotated counter-clockwise through a ninety (90) degree angle to close off the vent and open a path for liquid from the pump  14  into the fill conduit  12  that extends into the manifold  10 . 
     Various fluids in their liquid phase can be converted in the present apparatus into a vaporous or gaseous phase through atomization, vaporization or the like. Such fluids can be propane, nitrous oxide, and the like, particularly including carbon dioxide which, in the present apparatus, is enabled to evolve from its liquid phase to its vaporous or gaseous phase, usually hereinafter referred to as “gas”. In this gaseous form the carbon dioxide is discharged for use in a carbonated beverage machine (not shown). 
     With the vent valve  18  in its counterclockwise position, the pump  14  can be turned on, and the pumped liquid carbon dioxide passed into the fill conduit  12  through a flexible hose (not shown) which may be adapted for quick connection and disconnection at the fill site. Once the pumped liquid fills the liquid storage or receiver portions of the manifold system, the pump is shut off, the supply line is vented, and the manifold disconnected from the supply truck. In typical circumstances the truck leaves on its delivery route and returns, as needed, with a fresh supply of liquid carbon dioxide. Other liquid supply arrangements can be provided, as desired. 
     As is well known in the prior art, the liquid receivers or storage containers are completely filled, but there are vapor or gas receivers which are provided in the system that are empty. The accepted arrangement is to provide one or more ballast or gas storage receivers or containers having space sufficient for the liquid carbon dioxide to vaporize. A typical ratio is to provide approximately one vapor or gas container for every two liquid storage containers. 
     The manifold  10  within which vaporization occurs comprises an elongated body having a liquid supply passage  22  that is characterized by a threaded upstream portion adapted to threadably receive a threaded fitting at the end of the flexible hose or fill conduit  12  that is connected to the pump supply  16 . Downstream of the threaded portion, the passage  22  includes an upstream portion  24 , an intermediate diameter portion  28  having a diameter greater than the upstream portion  24 , and a larger downstream portion  26 . 
     The differences in diameter between the portions  24  and  28  forms a circumferentially extending shoulder or seat  30  which serves as a stop to limit the upstream movement of the controller or spool valve  32  within the liquid supply passage  22 . 
     The downstream extremity of the spool valve  32  includes a circumferentially extending shoulder  34  reciprocally movable within the downstream portion  26  of the supply passage  22 . Its upstream travel is limited by engagement with a leak age seal or O-ring  36  seated within a complemental circumferential groove provided at the juncture of the downstream portion  26  and the intermediate portion  28 . 
     The downstream portion  26  of the liquid supply passage  22  opens into a manifold space or liquid receiver  38  having outwardly directed passages, one of which can be a relief valve passage  40  connected by a conduit  42  to a relief valve  44 , as best seen in FIG.  1 . The opposite passage is a liquid passage  46  connected by a conduit  48  to one or more liquid containers  50  which serve as extensions of the liquid receiver  38 . Such containers  50  each are associated with or mount a valve  52  for manually closing and opening the liquid containers  50 . 
     The manifold  10  is formed in two parts, an upstream portion and a downstream portion which are joined in fluid sealing relation. The upstream portion contains the liquid receiver  38 , and the downstream portion contains an internal gas receiver  54 . The receivers  38  and  54  are coupled together by an interconnecting passage  56  in the manifold  10 . 
     The passage  56  includes a stop or seat which closely accepts in sealed relation a downstream valve extremity  58  of the valve  32 . This seating of the extremity  58  occurs to define the closed status of the manifold illustrated in FIG.  4 . 
     Cessation of flow from the pump causes movement of the valve  32  in an upstream direction, which unseats the valve extremity  58 . This opens the interconnecting passage  56 , and simultaneously causes the valve shoulder  34  to seat upon the O-ring  36  in sealing relation and blocks returning flow of liquid through the liquid supply passage  22 , as illustrated in FIG.  3 . 
     The portion of the manifold  10  containing the internal space or gas receiver  54  also includes outwardly directed passages which extend out of the gas receiver  54 . One of these passages is a pressure gauge passage  60  which threadably receives a conduit  62  that is connected to a pressure gauge  64 . The other of the passages is a gas passage  66  which threadably receives a conduit  68  that is connected to a ballast tank or gas container  70  which forms part of the gas receiver means  54 . If desired, the conduit  68  may include a pressure gauge  72  for determining the pressure in the container  70 . 
     The downstream extremity of the manifold  10  also includes a gas dispensing passage  74  which extends out of the gas receiver means  54  for threadably receiving a conduit  76  whose opposite end is adapted for connection to a dispensing apparatus such as a carbonated beverage dispensing machine (not shown). 
     In operation, the valve  32  is in the closed position illustrated in FIG.  4 . An operator operates the filling pump  14  to pump liquid carbon dioxide from the pump supply  16  and into the fill conduit  12 . There is a clearance or annular space between the adjacent cylindrical surfaces of the intermediate portion  28  of the liquid supply passage  22  and the valve  32 . A similar annular space is defined between the adjacent cylindrical surfaces of the valve shoulder  34  and the downstream portion  26  of the passage  22 . 
     In addition, the valve  32  includes an axial passage  78  which extends longitudinally from the upper surface of the valve  32  to a point just above the shoulder  34  of the valve  32 . At that point a passage  80  extends transversely through the upper portion of the valve  32  to provide fluid communication between the axial passage  78  and the annular space formed between the valve  32  and the larger diameter cylindrical wall of the downstream portion  26  of the valve  32 . 
     The liquid carbon dioxide being pumped into the liquid supply passage  22  at this time can thus flow around and through the valve  32 , into the liquid receiver 38 , into the relief valve conduit  42  and into the liquid passage conduit  48 . However, there is no flow of liquid into the gas receiver  54  because the downstream extremity  58  of the valve  32  is seated against the  0 -ring mounted within the adjacent end of the interconnecting passage  56 . 
     Liquid flow into the liquid receiver  38  continues until liquid fills all of the liquid containers  50  forming part of the manifold liquid receiver  38 . 
     When liquid completely fills the liquid receiver  38 , the operator shuts off the pump  14 . The operator next opens the valve  18  to vent the fill manifold  10 . 
     At this time the internal pressure within the liquid receiver  38  moves the valve  32  to its open position, as seen in FIG.  3 . In some applications the internal pressure may not be sufficient to rapidly move the valve  32  to its open position, which is important to prevent reverse flow of liquid from the liquid supply passage  22 . For that reason, the compression spring  82  illustrated in the embodiment of FIG. 5 can be provided to insure movement of the valve  32  into its closed position. 
     Referring now to FIG. 5, the compression spring  82  is shown in its uncompressed state corresponding to the open state of the apparatus shown in the corresponding FIG.  3 . Likewise, in FIG. 6, the compression spring  82  is illustrated in its compressed state corresponding to the closed state of the apparatus illustrated in FIG.  4 . In this state the spring  82  exerts a bias against the valve  32  which desirably tends to move the valve  32  to the position of FIG. 3 in the absence of pump pressure. 
     The liquid in the manifold portion of the receiver  38  now can flow into the gauge passage  60  and into the gas passage  66 . Its vapor pressure causes a portion of the liquid to vaporize, and evolving gas can then fill the gauge passage  60 , the gas passage  66 , and the gas dispensing passage  74 , enabling its dispensation to a user operating the usual valve arrangement common in dispensing systems (not shown). 
     At this time all spaces comprising any part of the liquid receiver  38  and the gas receiver  54  are at the same pressure. This enables replacement gas to evolve freely, automatically, and continuously through vaporization of the of the liquid in the system, contemporaneously with consumption of gas dispensed to the end user. There is no need for the existence of differential pressures to trigger regulating devices to vaporize the liquid carbon dioxide. 
     When the liquid in the system is completely consumed, the operator can simply turn on the pump  14  again until the liquid receiver  38 , including the liquid containers  50 , is filled, and the previously described cycle of venting through the valve  18 , and filling and dispensing. 
     Other valves may be used to change the apparatus from its closed state to its open state, and vice versa. One example is a valve identified as a PD10-40 marketed by Hydra Force, Inc., 500 Barclay Boulevard, Lincolnshire, Ill.  60069-4306 . It is merely exemplary of one form of externally piloted three way valve that can be used. Any form of three way valve that can be externally piloted can be used, such as ball or needle valves, for example, but not by way of limitation. Where possible, numerals with the subscript “a” have been used to designate components of the valve comparable to components of the valve  32  which are generally similar. 
     FIG. 7 is a longitudinal cross sectional view of such a valve  32   a having a suitably vented manifold  62   a with passageways corresponding to the passageways of the embodiment of FIGS. 3 and 4. However, the valve  32   a is moved, not by pump pressure as in the first embodiment, but by a compressed air system  84  shown schematically as positioned to act against an end of the valve  32   a to move it inwardly from the open state of FIG. 3 to the closed state of FIG. 4 in which liquid under pump pressure flows into the fill conduit  12   a , through an annular passage on the exterior of the valve  32   a , and into the relief valve conduit  42   a and the liquid conduit  48 , but not into any of the gas passages. When air pressure is not applied, the valve  32   a is biased to move to the right to the open state of FIG. 3, in which further liquid cannot enter through the fill conduit  12   a , but evolved gas can flow into all passages, including relief valve passage  42   a , liquid passage  46   a , pressure gauge passage  60   a , gas passage  66   a , and gas dispensing passage  74 . 
     As will be apparent, the operative characteristics correspond with the embodiment of FIGS. 3 and 4, which is characterized by the aforementioned existence of the same pressure in all parts of the liquid and gas receiver portions of the apparatus, enabling replacement gas to evolve freely, automatically, and continuously through vaporization of the of the liquid in the system, contemporaneously with consumption of gas dispensed to the end user. There is no need for the existence of differential pressures to trigger regulating devices to vaporize the liquid carbon dioxide. 
     While several forms of the invention have been illustrated and described, it will be apparent that various modifications can be made without departing from the spirit and scope of the invention.