Abstract:
A fuel-conditioning device for removing moisture from fuel includes two replaceable fuel-conditioning cartridges. The cartridges are alternately put in use by selectively positioning a valve actuator. A marking system for the fuel-conditioning cartridges and the valve actuator identifies which cartridge is in use and which can be serviced. A cartridge can be replaced while maintaining a continuous flow of fuel.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to the conditioning of liquefied petroleum fuels, and more specifically to a fuel-conditioning device for removing moisture, or other contaminants from the fuel. 
   2. Description of Related Art 
   Liquid petroleum fuels are often used for appliances such as furnaces, ovens, stoves, water heaters, and direct-fired absorption refrigerant systems. Examples of such manufactured fuels include propane, butane, propylene, butylenes, iso-butane, and various mixtures thereof. 
   As compared to natural gas, manufactured fuels are often a wet, contaminated fuel, due to the industry&#39;s transport, test, and storage methods. Propane, for example, is often transported in bulk rail, truck, and barge containers rather than piped. Water may be introduced into the propane through periodic hydrostatic burst strength testing of the transport/storage containers and/or steam cleaning of the containers following bulk transport of other contaminating materials, such as ammonia. 
   Since propane is hydroscopic and less dense than water, the water tends to collect at the bottom of the containers at the inlet to the container&#39;s off-load standpipe. Consequently, water is often the first material removed when off-loading bulk liquid propane. To minimize this problem, regional and local distributors of propane routinely add methanol to disperse the water more evenly throughout the propane. Unfortunately, the entrained moisture is then forwarded onto the final point of use where the liquid propane vaporizes just prior to combustion. Moisture at this point can contaminate valves, burners and other components associated with the appliance that burns the gas. 
   Once delivered to its general destination of use, propane is routinely stored outdoors in a pressurized tank above ground. Before the propane is conveyed to the heating appliance, a pressure regulator between the tank and the appliance reduces the propane&#39;s pressure to a level appropriate for the appliance. During the winter or when the outdoor temperature is relatively cold, moisture can precipitate at the pressure regulator, due the cold propane becoming even colder as its pressure is reduced. The precipitated moisture can interfere with the function of the pressure regulator and/or interfere with combustion at the appliance. 
   Various driers can be used to remove the moisture from fuel; however, the driers themselves can eventually become saturated with moisture. So, the driers may require periodic servicing to remove the moisture from the system entirely. Unfortunately, periodic servicing of a drier may require that the gas be temporarily shut off, which may interfere with the operation of the appliance. 
   SUMMARY OF THE INVENTION 
   To address the problem of fuel contaminated with water or other contaminants, it is an object of the invention to provide a fuel-conditioning device for removing contaminants without having to interrupt the flow of fuel. 
   Another object is to provide such a device with a housing having a minimal number of parts to reduce the likelihood of a leak. 
   Another object is to provide such a device with a pair of fuel-conditioning elements that can be used alternately to allow one to function while the other is being serviced. 
   Another object is to provide a marking system that clearly identifies which fuel-conditioning element is in use and which can be serviced. 
   Another object is to provide a marking system adapted to employ a variety of distinguishing properties or characteristics including, but not limited to, color, quantity, shape, and alphanumeric identity. 
   Yet, another object is to provide a fuel-conditioning device with a valve actuator whose position identifies which fuel-conditioning element is in use and which can be serviced. 
   A further object is to provide a fuel-conditioning device that removes moisture from propane. 
   A still further object is to provide a fuel-conditioning device that includes fuel-conditioning elements or cartridges that readily screw into a housing for effective sealing and ease of servicing. 
   Another object is to provide a fuel-conditioning device that includes a fuel-conditioning element comprising one or more of a variety of moisture-removing structures including, but not limited to a silica gel, molecular sieve, and activated alumina adsorbent. 
   Another object is to provide a fuel-conditioning device with a valve mechanism that inhibits backflow through the fuel-conditioning device when a fuel-conditioning element is being serviced. 
   These and other objects of the invention are provided by a fuel-conditioning device that includes two fuel-conditioning elements. The elements are alternately put in use by selectively positioning a valve actuator. A marking system for the fuel-conditioning elements and the valve actuator identify which fuel-conditioning element is in use and which can be serviced. 
   The present invention provides a fuel-conditioning device for conditioning a fuel. The device comprises a housing defining an inlet, an outlet, a first passageway, and a second passageway, wherein the first passageway and second passageway are downstream of the inlet and upstream of the outlet, relative to the fuel flowing from the inlet to the outlet. The device also comprises a first cartridge removably attached to the housing; a first fuel-conditioning element attached to the first cartridge and disposed in the first passageway; a second cartridge removably attached to the housing; and a second fuel-conditioning element attached to the second cartridge and disposed in the second passageway. The device further comprises a first valve seat interposed between the inlet and the first passageway; a second valve seat interposed between the inlet and the second passageway; and a valve plug disposed in the inlet of the housing and being selectively movable to a first location and a second location, such that in the first location the valve plug disengages the first valve seat to place the inlet in fluid communication with the first fuel-conditioning element in the first passageway, and in the second location the valve plug disengages the second valve seat to place the inlet in fluid communication with the second fuel-conditioning element in the second passageway. 
   The present invention also provides a fuel-conditioning device for conditioning a fuel. The device comprises a housing defining an inlet, an outlet, a first passageway, and a second passageway, wherein the first passageway and second passageway are downstream of the inlet and upstream of the outlet, relative to the fuel flowing from the inlet to the outlet. The device also comprises a first cartridge removably attached to the housing; a first fuel-conditioning element attached to the first cartridge and disposed in the first passageway; a first marking adjacent the first fuel-conditioning element; a second cartridge removably attached to the housing; a second fuel-conditioning element attached to the second cartridge and disposed in the second passageway; a second marking adjacent the second fuel-conditioning element; a first valve seat interposed between the inlet and the first passageway; a second valve seat interposed between the inlet and the second passageway; and a valve plug disposed in the inlet of the housing and being selectively movable to a first location and a second location. In the first location the valve plug disengages the first valve seat to place the inlet in fluid communication with the first fuel-conditioning element in the first passageway. In the second location the valve plug disengages the second valve seat to place the inlet in fluid communication with the second fuel-conditioning element in the second passageway. The device further comprises a valve operator connected to the housing and the valve plug, wherein the valve operator is movable relative to the housing between a first position and a second position to selective move the valve plug between the first location and the second location, respectively. The device also comprises a first mark disposed on the valve operator and corresponding to the first marking adjacent the first fuel-conditioning element; and a second mark disposed on the valve operator and corresponding to the second marking adjacent the second fuel-conditioning element. The housing covers the second mark when the valve operator is in the first position, thereby indicating the inlet is in fluid communication with the first fuel-conditioning element in the first passageway. The housing uncovers the second mark when the valve operator is in the second position, thereby indicating the inlet is in fluid communication with the second fuel-conditioning element in the second passageway. The device still further comprises a valve mechanism supported by the housing and disposed downstream of the first fuel-conditioning element, downstream of the second fuel-conditioning element, and upstream of the outlet. The valve mechanism is movable to selectively impede backflow of the fuel from the outlet toward the second fuel-conditioning element when the valve plug is in the first location and impede backflow of the fuel from the outlet toward the first fuel-conditioning element when the valve plug is in the second location, thereby facilitating the replacement of the first cartridge when the valve plug is in the first location and facilitating the replacement of the second cartridge when the valve plug is in the second location. 
   The present invention further provides a fuel-conditioning device for conditioning a fuel. The device comprises a housing defining a first passageway and a second passageway. The housing includes a unitary piece that defines an inlet and an outlet wherein the first passageway and second passageway are downstream of the inlet and upstream of the outlet, relative to the fuel flowing from the inlet to the outlet. The device also comprises a first cartridge screwed into the housing; a first fuel-conditioning element attached to the first cartridge and disposed in the first passageway; a first marking adjacent the first fuel-conditioning element; a second cartridge screwed into the housing; a second fuel-conditioning element attached to the second cartridge and disposed in the second passageway; a second marking adjacent the second fuel-conditioning element; a first valve seat interposed between the inlet and the first passageway; a second valve seat interposed between the inlet and the second passageway; and a valve plug disposed in the inlet of the housing and being selectively movable to a first location and a second location. In the first location the valve plug disengages the first valve seat to place the inlet in fluid communication with the first fuel-conditioning element in the first passageway. In the second location the valve plug disengages the second valve seat to place the inlet in fluid communication with the second fuel-conditioning element in the second passageway. The device additionally comprises a valve operator that includes a valve plug connected to a valve stem. The valve stem is screwed into the housing and is movable relative thereto between a first position and a second position to selective move the valve plug between the first location and the second location, respectively. The device further comprises a first mark disposed on the valve stem and corresponding to the first marking adjacent the first fuel-conditioning element; a second mark disposed on the valve stem and corresponding to the second marking adjacent the second fuel-conditioning element. The housing covers the second mark when the valve operator is in the first position, thereby indicating the inlet is in fluid communication with the first fuel-conditioning element in the first passageway. The housing uncovers the second mark when the valve operator is in the second position, thereby indicating the inlet is in fluid communication with the second fuel-conditioning element in the second passageway. The device still further comprises a valve mechanism supported by the housing and disposed downstream of the first fuel-conditioning element, downstream of the second fuel-conditioning element, and upstream of the outlet. The valve mechanism is movable to selectively impede backflow of the fuel from the outlet toward the second fuel-conditioning element when the valve plug is in the first location and impede backflow of the fuel from the outlet toward the first fuel-conditioning element when the valve plug is in the second location, thereby facilitating the replacement of the first cartridge when the valve plug is in the first location and facilitating the replacement of the second cartridge when the valve plug is in the second location. 
   The present invention further provides a method of conditioning a fuel using a fuel conditioning device. The method comprises the steps of: defining a housing including an inlet, an outlet, a first passageway and a second passageway wherein the first and second passageways are downstream of the inlet and upstream of the outlet relative to the fuel flowing from the inlet to the outlet; removably attaching a first cartridge to the housing; attaching a first fuel conditioning element to the first cartridge wherein the fuel conditioning element is disposed in the first passageway; removably attaching a second cartridge to the housing; attaching a second fuel conditioning element to the second cartridge and disposing said second fuel conditioning element in the second passageway; interposing a first valve seat between the inlet and the first passageway; interposing a second valve seat between the inlet and the second passageway; and disposing a valve plug in the inlet of the housing wherein the valve plug is selectively movable to a first location where the valve plug disengages the first valve seat to place the inlet in fluid communication with the first fuel conditioning element in the first passageway and to a second location such that the valve plug disengages the second valve seat to place the inlet in fluid communication with the second fuel conditioning element in the second passageway. 
   The method provides the further steps of providing a first marking adjacent the first fuel conditioning element; providing a second marking adjacent the second fuel conditioning element; and connecting a valve operator to the housing and the valve plug such that the valve operator is moveable relative to the housing between a first position and a second position to selectively move the valve plug between the first location and the second location respectively. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic diagram of a fuel system incorporating the subject invention. 
       FIG. 2  is a cross-sectional view of a fuel-conditioning device with its valve operator at a first position. 
       FIG. 3  is similar to  FIG. 2 , but with the valve operator at a second position. 
       FIG. 4  is a cross-sectional view of the fuel-conditioning device of  FIG. 2 , but showing a fuel-conditioning cartridge being replaced. 
       FIG. 5  is similar to  FIG. 2 , but of another embodiment. 
       FIG. 6  is similar to  FIG. 2 , but of yet another embodiment. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1  illustrates just one example of a fuel system  10  that includes a fuel-conditioning device  12  for reducing the amount of moisture or other contaminants in the fuel. Although the invention will be described with reference to propane, other fuels are well within the scope of the invention. The term, “propane” generally refers to any hydrocarbon fluid of the methane series CH 3 CH 2 CH 3 , usually derived from crude petroleum. Examples of other fuels include, but are not limited to, butane, propylene, butylenes, iso-butane, and various mixtures thereof. 
   Referring further to  FIG. 2 , device  12  includes two replaceable cartridges, a first cartridge  14  and a second cartridge  16 . Cartridges  14  and  16  respectively hold first and second fuel-conditioning elements  18  and  20  that extract moisture or contaminants from the propane. To provide uninterrupted flow, a valve system of device  12  selectively directs propane to flow through one of the cartridges, so the other can be replaced when necessary. 
   In the example of  FIG. 1 , a storage tank  22  holds the propane as a pressurized liquid or gas. A fuel line  24  leading from tank  22  conveys the propane to a conventional pressure regulator  26 , which reduces the propane&#39;s pressure before another line  28  delivers the propane to a metering valve  30 . Metering valve  30  reduces the pressure further to a level appropriate for a burner nozzle  32  of a propane-burning appliance  34 . Examples of a propane-burning appliance include, but are not limited to, furnaces, ovens, stoves, water heaters, and direct-fired absorption refrigerant systems. 
   Fuel-conditioning device  12  is preferably installed in fuel line  28 , between pressure regulator  26  and metering valve  30 . Alternatively, device  12  could be installed anywhere between tank  22  and nozzle  32 . 
   In  FIG. 2 , fuel-conditioning device  12  is shown comprising a housing  36  that defines a propane inlet  38 , a propane outlet  40 , a first passageway  42 , and a second passageway  44 . The first and second passageways  42  and  44  are situated to convey propane from inlet  38  to outlet  40 . The portion of housing  36  that defines inlet  38  and outlet  40  is preferable of a single, unitary piece to minimize the likelihood of a leak. 
   To remove moisture or other contaminants from the propane, first fuel-conditioning element  18  is disposed in first passageway  42 , and second fuel-conditioning element  20  is in second passageway  44 . Elements  18  and  20  are schematically illustrated to represent any structure or substance that can help filter, absorb or remove contaminants (especially water) from the propane. Examples of elements  18  and  20  include, but are not limited to, a silica gel having an affinity for water, a molecular sieve whose micro porosity helps separate water molecules from fuel, an activated alumina adsorbent (i.e., any aluminum oxide having an affinity for water). 
   To facilitate the replacement of fuel-conditioning elements  18  and  20 , the elements are each preferably supported by their own cartridge that screws into housing  36 . In this case, first cartridge  14  supports element  18 , and second cartridge  16  supports element  20 . 
   To enable the replacement of a cartridge and its element without interrupting the flow of propane to burner  32  (FIG.  1 ), device  12  includes a valve operator  46  connected to move a valve plug  48  between a first location ( FIG. 2 ) and a second location (FIG.  3 ). In the second location (FIG.  3 ), valve plug  48  is against a first valve seat  50  to direct propane across second fuel-conditioning element  20 . And in the first location (FIG.  2 ), plug  48  is against a second valve seat  52  to direct propane across first element  18 . 
   Valve operator  46  includes a handle  54  connected to a threaded valve stem  56 , which in turn screws into housing  36  and connects to valve plug  48 . Turning handle  54  thus moves valve operator  46  between a first position ( FIG. 2 ) and a second position (FIG.  3 ), which moves plug  48  between valve seats  52  and  50 , respectively. When valve plug  48  is halfway between its first and second locations, both valve seats  50  and  52  are at least partially open to ensure flow from inlet  38  to outlet  40 . In other words, valve plug  48  operates in a make-before-break manner to avoid interrupting flow upon switching from one cartridge to another. 
   When valve operator  46  is at its first position and valve plug  48  is at its first location against second valve seat  52 , second cartridge  16  can be replaced by another second cartridge  16 ′, as shown in FIG.  4 . Similarly, when valve operator  46  is at its second position and valve plug  48  is at its second location against first valve seat  50 , as shown in  FIG. 3 , first cartridge  18  can be replaced by another similar second cartridge. 
   When a cartridge is removed, as shown in  FIG. 4 , an opening  58  is temporarily left in housing  36 . A backflow of propane from outlet  40  through opening  50  can be inhibited by providing housing  36  with a valve mechanism  60 . The term, “valve mechanism” refers to any device for selectively obstructing flow. Valve mechanism  60  is schematically illustrated to represent any such valve mechanism. Examples of a valve mechanism include, but are not limited to, a check valve, globe valve, gate valve, ball valve, solenoid valve, spool valve, and various combinations thereof. Valve mechanism  60  is schematically shown as a valve plate  62  that is free to pivot about an axis  64 . 
   In the situation shown in  FIG. 4 , propane flowing through first cartridge  14  and outlet  40  urges plate  62  to pivot downward to obstruct propane from flowing back from outlet  40  to opening  58 . In  FIG. 3 , propane flowing through second cartridge  16  and outlet  40  urges plate  62  to pivot upward to allow the servicing of first cartridge  14 . 
   To determine which cartridge  14  or  16  may be replaced without interruption of propane flow, fuel-conditioning device  12  is provided with a marking system. In some embodiments, for example, a first marking  66  is placed adjacent first fuel-conditioning element  18 , a second marking  68  is placed adjacent second fuel-conditioning element  20 , and a first mark  70  and a second mark  72  are placed on valve operator  46 . First and second markings  66  and  68  can be distinguished from each other by various characteristics. Examples of such characteristics include, but are not limited to, quantity, color, shape, alphanumeric identity, etc. Also, the first marking adjacent the first fuel-conditioning element preferably corresponds to the first mark on the valve operator. And the second marking adjacent the second fuel-conditioning element preferably corresponds to the second mark on the valve operator. 
   The marks on the valve operator are positioned such that the position of the valve operator relative to the valve housing determines the extent to which the marks are displayed, or uncovered. With device  12  in the configuration shown in  FIG. 2 , for example, second mark  72  is hidden underneath housing  36  (i.e., covered by a gland plate  74  of housing  36 ), while first mark  70  is visible. A single mark  70  being visible corresponds in quantity to first marking  66  adjacent first fuel-conditioning element  18 , which indicates first cartridge  14  can be serviced. When device  12  is as shown in  FIG. 3 , two marks  70  and  72  are visible, which corresponds in quantity to second marking  68  adjacent second fuel-conditioning element  20 , thereby indicating second cartridge  16  can be serviced. In some embodiments, first marking  66  and first mark  70  are both red, so they correspond to each other. Meanwhile, second mark  72  is green, while second marking  68  includes a red mark and a green mark to correspond to both red and green marks  70  and  72  being visible when valve operator  46  is in the position of FIG.  3 . 
   In a similar embodiment, shown in  FIG. 5 , a fuel-conditioning device  12 ′ includes a first marking  66 ′ disposed on a first cartridge  14 ′ and a second marking  68 ′ on a second cartridge  16 ′. Markings  66 ′ and  68 ′ correspond to a first mark  70 ′ and a second mark  72 ′ on a valve operator  46 ′. Markings  66 ′ and  68 ′ are distinguishable from each other by their unique alphanumeric identities. The same is true for marks  70 ′ and  72 ′. 
   In another similar embodiment, a fuel-conditioning device  12 ″ includes a first marking  66 ″ disposed on a first cartridge  14 ″ and a second marking  68 ″ on a second cartridge  16 ″. Markings  66 ″ and  68 ″ correspond in shape to a first mark  70 ″ and a second mark  72 ″ on valve operator  46 ″. Markings  66 ″ and  68 ″ are distinguishable from each other by their unique shape. Likewise, the same is true for marks  70 ″ and  72 ″. 
   Although the invention is described with reference to a preferred embodiment, it should be appreciated by those skilled in the art that other variations are well within the scope of the invention. Therefore, the scope of the invention is to be determined by reference to the claims, which follow.