Abstract:
A gas manifold system includes a plenum that receives a gas at a positive pressure and a manifold having at least one exit port. One or more valves are disposed between the plenum and the manifold. When opened, the valve(s) permit a stream of the gas at positive pressure to flow from the plenum into the manifold. A baffle is disposed in the manifold between the valve(s) and the exit port(s). The baffle obstructs each stream of gas entering the manifold such that the gas is reduced to substantially zero pressure in the manifold at the exit port(s).

Description:
FIELD OF THE INVENTION 
     The invention relates generally to gas manifolds, and more particularly to a gas manifold system that provides a steady supply of a gas at the system&#39;s outlet. 
     BACKGROUND OF THE INVENTION 
     Motors running on diesel fuel are used in a wide variety of applications. For example, electric power generators used in remote locations (e.g., gas or oil drill sites, mining operations, etc.) are usually operated using diesel fuel. The high cost of diesel fuel has led to the development of dual-fuel supply systems for diesel fuel generators. In general, lower-cost natural gas is supplied directly into a diesel engine&#39;s manifold to reduce diesel fuel consumption. The mixture of gas-to-diesel is established/set for a particular generator motor speed which is typically the steady-state operating speed of the generator&#39;s motor. However, when motor speed must be increased (for higher load requirements) or decreased (for idle down times), the generator&#39;s diesel motor must be returned to “full diesel” operation as the adjustment of the gas-to-diesel ratio requires motor shut down. Such “full diesel” operation can greatly increase the cost of electric power generation. 
     In order to address this problem, gas manifold systems incorporating multiple controllable valves have been proposed for inclusion in the gas supply line of a dual fuel system. Briefly, the valves are controlled to vary the amount of natural gas being supplied. However, the supply of gas at the system&#39;s outlet tends to fluctuate as valve positions are changed. Further, each system must be custom built for each application to account for difference in supply lines, the number of diesel motors being supplied, etc. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a gas manifold system. 
     Another object of the present invention is to provide a gas manifold system that can adjust the amount of gas available at its outlet(s) while keeping a steady gas flow thereat. 
     Still another object of the present invention is to provide a gas manifold system that is readily adapted to a variety of installation configurations. 
     Other objects and advantages of the present invention will become more obvious hereinafter in the specification and drawings. 
     In accordance with the present invention, a gas manifold system includes a plenum adapted to receive a gas at a positive pressure and a manifold having at least one exit port. At least one valve is disposed between the plenum and the manifold such that, when opened, the valve(s) so-opened permit a stream of the gas at positive pressure to flow from the plenum into the manifold. A baffle is disposed in the manifold between the valve(s) and the exit port(s) for obstructing each stream of gas entering the manifold such that the gas is reduced to substantially zero pressure in the manifold at the exit port(s). 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other objects, features and advantages of the present invention will become apparent upon reference to the following description of the preferred embodiments and to the drawings, wherein corresponding reference characters indicate corresponding parts throughout the several views of the drawings and wherein: 
         FIG. 1  is a side, exploded view of a gas manifold system in accordance with an embodiment of the present invention; 
         FIG. 2  is a perspective view of a removable end cap of the system&#39;s inlet plenum in accordance with an embodiment of the present invention; 
         FIG. 3  is a plan view of one side of the system&#39;s valve assembly taken along line  3 - 3  of  FIG. 1  in accordance with an embodiment of the present invention; 
         FIG. 4  is a perspective view of removable end cap of the system&#39;s outlet plenum in accordance with an embodiment of the present invention; 
         FIG. 5  is a side view of the assembled gas manifold system; 
         FIG. 6  is a plan view of the system&#39;s outlet plenum taken along line  6 - 6  of  FIG. 1  to illustrate the system&#39;s baffle in accordance with an embodiment of the present invention; 
         FIG. 7  illustrates an isolated plan view of a baffle in accordance with another embodiment of the present invention; 
         FIG. 8  illustrates an isolated plan view of a baffle in accordance with still another embodiment of the present invention; 
         FIG. 9  is a cross-sectional view of a manually-operated valve provided in the valve system in accordance with an embodiment of the present invention; 
         FIG. 10  is a perspective view of a removable end cap of the system&#39;s outlet plenum provided with two adjustable-flow outlet nozzles in accordance with another embodiment of the present invention; and 
         FIG. 11  is a cross-sectional exploded view of one adjustable-flow outlet nozzle in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings and more particularly to  FIG. 1 , a gas manifold system in accordance with an embodiment of the present invention is shown and is referenced generally by numeral  10 . Gas manifold system  10  is illustrated in an exploded fashion to more clearly show the novel construction thereof. By way of example, gas manifold system  10  will be explained for its use in the supply of natural gas to an electric power generator (not shown) that operates on diesel fuel and natural gas. As is known in the art, the natural gas is supplied to the air intake of a diesel engine manifold  300 . Accordingly, gas manifold system  10  is disposed in a gas supply system that includes a gas supply line  100  through which a gas under pressure (e.g., natural gas) flows and is supplied to system  10 . The gas passes through system  10  and is drawn therefrom through a gas suction line  200  (or multiple gas suction lines). That is, the gas at the outlet(s) of system  10  is at a substantially zero pressure so that the suction in line  200  governs the quantity of gas flowing therethrough. For a diesel/gas electric power generator, this means that the generator&#39;s engine manifold  300  draws an amount of natural gas through line  200  based on the operating needs (i.e., engine speed) of the generator (not shown) coupled to engine manifold  300 . This allows the natural gas to be part of the fuel supply even when the generator&#39;s motor speeds are changed. 
     In its illustrated embodiment, gas manifold system  10  is modular for easy adaptation to a particular type of gas supply line  100  and/or one (or more) gas suction line  200  where each suction line  200  would be coupled to a separate engine manifold  300  of an associated electric generator. System  10  includes two open-ended tubes (e.g., cylinders)  20  and  30 , end caps  22  and  24  (associated with cylinder  20 ), end caps  32  and  34  (associated with cylinder  30 ), one or more valves  40  disposed between end caps  24  and  32 , and a baffle  50  disposed in cylinder  30 . The various elements of the present invention are constructed of materials designed to withstand the rigors of their operating environment as would be understood by one of ordinary skill in the art. 
     Cylinders  20  and  30  are of rigid-wall construction with cylinder  20  being part of a gas plenum that holds gas under pressure supplied via line  100 . Coupled/sealed to either open end of cylinder  20  are end caps  22  and  24 . Cylinder  30  is part of a gas manifold that makes gas at a substantially zero pressure available to line(s)  200 . Coupled/sealed to either open end of cylinder  30  are end caps  32  and  34 . 
     In one embodiment of the present invention, end cap  22  is configured to work with one of the well known coupling interfaces (e.g., DIN  65 , DIN  80 , etc.) used on gas supply lines. To accommodate a DIN coupling, end cap  22  has a raised annular flange  22 A on its exterior face circumscribing a port  22 B passing through end cap  22 . Dispersed around annular flange  22 A are a number of threaded rods (i.e., bolt shafts)  22 C. The size of annular flange  22 A and number/size/placement of threaded rods  22 C are selected predicated on the type of hose coupling  102  terminating supply line  100 . Accordingly, gas manifold system  10  can be adapted to work with any type of hose coupling  102  simply by changing end cap  22 . 
     End cap  24  is coupled/sealed to cylinder  20  at its open end that opposes the end accepting end cap  22 . End cap  24  along with end cap  32  also form a support structure for one or more valves  40  disposed between and coupled/sealed to end caps  24  and  32 , while also allowing valves  40  to be in fluid communication with cylinders  20  and  30 . Accordingly, end caps  24  and  32  have one or more ports extending therethrough. For example, the illustrated embodiment has four ports  24 A (as illustrated in  FIG. 3 ) distributed about an annular region of end cap  24  to support four of valves  40 . A similar number and locations of ports are provided in end cap  32 . The mounting/sealing of valves  40  to end caps  24  and  32  can be achieved in a variety of ways without departing from the scope of the present invention. For example, bolt holes  24 B can be provided around each of ports  24 A to facilitate the attachment of valves  40  to end cap  24 . Similar bolt holes could be provided in end cap  32 . 
     End cap  34  is coupled/sealed to cylinder  30  at its open end that opposes the end accepting end cap  32 . End cap  34  has one or more nozzle(s)  34 A ( FIG. 4 ) coupled to or integrated with end cap  34 . The size/shape of nozzle  34 A is designed to work with suction line  200 . If system  10  is to be used with multiple suction lines  200 , end cap  34  is provided with a corresponding number of nozzles  34 A. 
     Referring additionally now to  FIG. 5  where the above-described elements of system  10  are joined together, gas under pressure supplied via line  100  is passed through end cap  22  and into cylinder  20 . One or more of valves  40  is opened predicated on the amount of gas needed in suction line  200 . For any of valves  40  that are opened, a volumetric stream of gas is introduced into cylinder  30  through end cap  32  where each such stream is referenced by numeral  104 . By way of illustrated example, two of valves  40  are opened such that two corresponding streams  104  of gas are introduced into cylinder  30 . In general, streams  104  are obstructed by baffle  50  in cylinder  30  such that the admitted gas cannot flow directly to any nozzle  34 A in end cap  34 . The combination of the volume of cylinder  30  and the obstructed flow provided by baffle  50  assures that the pressure of the gas at outlet nozzle(s)  34 A is reduced to a substantially zero pressure. In this way, the amount of gas supplied to any suction line  200  is completely governed by the demand/needs of its manifold  300 . 
     Referring additionally now to  FIG. 6 , baffle  50  can be a plate having one or more holes therethrough with the hole(s) being positioned based on location(s) of valve(s)  40 . For the illustrated embodiment, baffle  50  is a solid plate with a hole  50 A through its central region. More specifically, hole  50 A is located such that it will not overlap any cross-sectional portion of a stream  104  of gas passed through an opened one of valves  40  when stream  104  impinges on baffle  50 . Accordingly, the cross-sectional shapes of each possible stream  104  is indicated by dashed-line circles in  FIG. 6 . Thus, the size, shape, and location of the solid regions of baffle  50  are strategically selected to fully obstruct each such gas stream cross-section if the corresponding valve  40  is opened. Baffle  50  can be mounted in cylinder  30  by providing an annular channel  30 A on an inside wall thereof. For greater flexibility in designing and positioning baffle  50 , additional annular channels  30 A can be provided in cylinder  30 . 
     Although the above-described baffle  50  has a solid annular region circumscribing a single central hole, the present invention is not so limited. For example,  FIG. 7  illustrates another baffle  52  in which a solid annular region circumscribes a plurality holes  52 A in the baffle&#39;s central region. Still another baffle  54  is illustrated in  FIG. 8  where the outer annular region incorporates slots  54 B with a single hole  54 A circumscribed by the baffle&#39;s annular region. Note that slots  54 B do not overlap any portion of stream cross-sections  104 A. 
     Valves  40  can include manual and powered valves. Powered valves would generally have control lines (not shown) coupled thereto with some remotely-located controller governing the opening and closing the valves. For manual valves, hand-operated controls must be accessible. To improve adaptability of system  10  to a wide variety of installation configurations, the present invention can include the use of one or more of the manual valves illustrated in  FIG. 9  where a valve body  42  defines a central flow region  42 A. Threaded holes  42 B and  42 C provided on sides of valve body  42  are transverse to its flow region  42 A. Holes  42 B and  42 C are aligned with one another such that a screw  44  can threadably engage one or both of holes  42 B and  42 C to partially span or fully cut off flow region  42 A. Screw  44  can be started in either hole  42 B or  42 C. In this way, valve  42  can be controlled from either side thereof simply by changing the entry point for screw  44 . To assure that valve  42  only permits flow through flow region  42 A regardless of the position of screw  44 , a threaded plug  46  is screwed partially into the hole  42 B or  42 C that opposes the start hole for screw  44 . In the illustrated embodiment, plug  46  is screwed into hole  42 C thereby sealing it even if screw  44  is positioned for partial or full flow through flow region  42 A. 
     As mentioned above, end cap  34  can include a plurality of nozzles  34 A. Further, each such nozzle can incorporate a valve thereby providing additional adjustability in the flow of gas moving through a particular outlet nozzle. Accordingly,  FIG. 10  illustrates an end cap  34  with two nozzles  34 A provided thereon or integrated therewith. Referring additionally to  FIG. 11 , each nozzle  34 A can incorporate an adjustable valve created by providing a hole  36  in each nozzle  34 A and providing a screw  38  threaded into/through hole  36  such that the screw  38  can regulate the amount of gas passing through nozzle  34 A. 
     The advantages of the present invention are numerous. The gas manifold system provides readily-varied quantities of gas at substantially zero pressure so that one or more suction lines can draw the amount of gas needed. These features are particularly advantageous when the gas manifold system is used to support the gas needs of an electric power generator using both diesel fuel and natural gas. The present invention supports a variety of speeds of the generator&#39;s motor thereby insuring a lower-cost and more efficient generator operation during all operating modes thereof. The gas manifold system is readily adapted to different supply/suction line installations simply by changing one or both of the system&#39;s outboard end caps. 
     Although the invention has been described relative to a specific embodiment thereof, there are numerous variations and modifications that will be readily apparent to those skilled in the art in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described.