System, Apparatus and Method For Combustion of Metals and Other Fuels

Abstract

A system, apparatus and method for the combustion of metals and other fuels are provided. The system can include a fuel combustion apparatus including a combustor having a combustion chamber for burning ground particles from a fuel charge, and a fuel supply apparatus for supplying the ground particles. The fuel supply system can include a fuel charge holder assembly to house and store the fuel charge, a grinder assembly including a grinder configured to pulverize the fuel charge to produce a combustible fuel, and a fuel charge linear feed assembly including a piston in contact with the fuel charge to selectively bias the fuel charge into the grinder to control the consumption rate. Exhaust from the combustion chamber can be used in the incineration of radioactive, chemical and mixed hazardous materials, and in the propulsion of a vehicle in both an air or water environment.

1 . A system for combustion of a fuel, the system comprising:
 a combustion apparatus comprising a combustor having a combustion chamber in which a metal fuel is combusted, the combustor including:
 a closed end portion having a metal fuel inlet extending therethrough to receive the metal fuel, 
 an open end portion having an open end defining a combustion chamber exhaust through which combusted metal fuel exits, 
 an inner tubular member having an inner tubular member main body substantially extending between the closed end portion and the open end portion to form the combustion chamber in which the combustion of the metal fuel occurs, the inner tubular member main body having a plurality of apertures extending therethrough each defining a cooling fluid outlet positioned to allow the cooling fluid to enter the combustion chamber to thereby enhance inner tubular member cooling and oxidation of the metal fuel, 
 an outer tubular member substantially surrounding the inner tubular member to substantially enclose the inner tubular member, and having an outer tubular member main body extending between the closed end portion and the open end portion to form a cooling fluid annulus between the inner tubular member main body and the outer tubular member main body, the outer tubular member also having an aperture extending therethrough to define a cooling fluid inlet to receive the cooling fluid, and 
 an igniter located at least partially within the inner tubular member and positioned to ignite the metal fuel in the combustion chamber adjacent the metal fuel inlet in the closed end portion of the combustor; and 
   a fuel supply apparatus positioned to communicate the metal fuel to the metal fuel inlet of the combustor, the fuel supply apparatus including:
 a metal fuel charge holder assembly including a metal fuel charge holder body axially bounded on either end to substantially enclose the metal fuel charge holder body to thereby contain a metal fuel charge, a carrier gas inlet positioned to receive a carrier gas which carries the particles of metal fuel ground from the metal fuel charge to the metal fuel inlet of the combustor, and a carrier gas outlet positioned to receive the carrier gas and particles of metal fuel carried by the carrier gas, 
 a grinder assembly including a grinder positioned to rotatably grind an end of the metal fuel charge to thereby generate the particles of metal fuel to be conveyed to the combustion chamber through the carrier gas outlet, and 
 a metal fuel feed assembly including a piston located within the metal fuel charge holder assembly, a linear piston rod engaging the piston, a feed motor to selectively feed portions of the metal fuel charge into the grinder, and a drive train connected between the feed motor and the piston rod and positioned to translate rotational movement associated with the feed motor to linear movement of the piston so that when the feed motor is operating, the feed motor actuates the piston rod and piston to bias the metal fuel charge toward the grinder. 
   
     
     
         2 . A system as defined in  claim 1 ,
 wherein the plurality of cooling fluid outlets extend along a substantial portion of the inner tubular member;   wherein the annulus carries the cooling fluid from the cooling fluid inlet along an outer periphery of the substantial portion of the inner tubular member; and   wherein the cooling fluid entering the cooling fluid inlet includes one of the following: air, gaseous oxygen, seawater, or liquid water.   
     
     
         3 . A system as defined in  claim 1 ,
 wherein the grinder assembly includes a rotatable grinder shaft and a grinder motor positioned to rotate the grinder shaft; and   wherein the grinder comprises a mill fixedly secured to the grinder shaft to rotate therewith, the mill having a blade positioned thereon for engaging the metal fuel charge as the mill rotates.   
     
     
         4 . A system for combustion of a fuel, the system comprising:
 a combustion apparatus including a combustor in which ground portions of a fuel charge are combusted, the combustor comprising:
 a first end portion having a fuel inlet extending therethrough to receive the ground portions of the fuel charge, 
 a second end portion having an open end defining a combustion chamber exhaust through which combusted fuel exits, 
 an inner tubular member having an inner tubular member main body substantially extending between the first end portion and the second end portion to form a combustion chamber in which the combustion of the ground portions of the fuel charge occurs, the inner tubular member main body having at least one aperture extending therethrough defining a cooling fluid outlet positioned to allow the cooling fluid to enter the combustion chamber to thereby enhance inner tubular member cooling and oxidation of the ground portions of the fuel charge, and 
 an outer tubular member substantially surrounding the inner tubular member to substantially enclose the inner tubular member, and having an outer tubular member main body extending between the first end portion and the second end portion to form a cooling fluid annulus between the inner tubular member main body and the outer tubular member main body, the outer tubular member also having an aperture extending therethrough to define a cooling fluid inlet to receive the cooling fluid. 
   
     
     
         5 . A system as defined in  claim 4 ,
 wherein the inner tubular member includes a plurality of cooling fluid outlets extending along a substantial portion of the inner tubular member;   wherein the annulus carries the cooling fluid from the cooling fluid inlet along an outer periphery of the substantial portion of the inner tubular member and to each of the plurality of cooling fluid outlets; and   wherein the combustor further includes an igniter located at least partially within the inner tubular member and positioned to ignite the ground portions of the fuel charge that enter the combustion chamber through the fuel inlet in the first end portion of the combustor.   
     
     
         6 . A system as defined in  claim 5 , further comprising the fuel charge, the fuel charge comprising a metal fuel charge substantially comprising pressed aluminum particles having a particle density of at least approximately 60%. 
     
     
         7 . A system as defined in  claim 5 , wherein the combustor further includes a nozzle region formed within the inner tubular member by inclined walls extending axially inward from the first end adjacent the fuel inlet to thereby increase the velocity of the fuel particles and carrier agent and density of the fuel particles prior to reaching the igniter. 
     
     
         8 . A system as defined in  claim 4 , further comprising:
 a fuel supply apparatus positioned to communicate ground portions of the fuel charge to the fuel inlet of the combustor, the fuel supply apparatus including:
 a fuel charge holder assembly including a fuel charge holder body axially bounded on either end to substantially enclose the charge holder body to thereby contain the fuel charge, a carrier agent inlet positioned to receive a carrier agent which carries the particles of fuel ground from the fuel charge to the fuel inlet of the combustor, and a carrier agent outlet positioned to receive the carrier agent and the particles of fuel ground from the fuel charge and carried by the carrier agent, 
 a grinder assembly including a grinder positioned to rotatably grind an end of the fuel charge to thereby generate the particles of fuel to be conveyed to the combustion chamber, and 
 a fuel feed assembly including a piston located within the charge holder assembly, a linear piston rod engaging the piston, a feed motor to selectively feed portions of the fuel charge into the grinder, and a drive train connected between the feed motor and the piston rod and positioned to translate rotational movement associated with the feed motor to linear movement of the piston so that when the feed motor is operating, the feed motor actuates the piston rod and piston to bias the fuel charge toward the grinder. 
   
     
     
         9 . A system as defined in  claim 8 ,
 wherein the grinder assembly includes a rotatable grinder shaft and a grinder motor positioned to rotate the grinder shaft; and   wherein the grinder comprises a mill fixedly secured to the grinder shaft to rotate therewith, the mill having a blade positioned thereon for engaging the fuel charge as the mill rotates.   
     
     
         10 . A combustion apparatus comprising a combustor in which ground portions of the fuel charge is combusted, the combustor including:
 a first end portion having a fuel inlet extending therethrough to receive the ground portions of the fuel charge;   a second end portion having an open end defining a combustion chamber exhaust through which combusted fuel exits;   an inner tubular member having an inner tubular member main body substantially extending between the first end portion and the second end portion to form a combustion chamber in which the combustion of the ground portions of the fuel charge occurs, the inner tubular member main body having at least one aperture extending therethrough defining a cooling fluid outlet positioned to allow the cooling fluid to enter the combustion chamber to thereby enhance inner tubular member cooling and oxidation of the ground portions of the fuel charge; and   an outer tubular member substantially surrounding the inner tubular member to substantially enclose the inner tubular member, and having an outer tubular member main body extending between the first end portion and the second end portion to form a cooling fluid annulus between the inner tubular member main body and the outer tubular member main body, the outer tubular member also having an aperture extending therethrough to define a cooling fluid inlet to receive the cooling fluid.   
     
     
         11 . An apparatus as defined in  claim 10 ,
 wherein the inner tubular member includes a plurality of cooling fluid outlets extending along a substantial portion of the inner tubular member; and   wherein the annulus carries the cooling fluid from the cooling fluid inlet along an outer periphery of the substantial portion of the inner tubular member and to each of the plurality of cooling fluid outlets.   
     
     
         12 . An apparatus as defined in  claim 11 , wherein the combustor further includes an igniter located at least partially within the inner tubular member and positioned to ignite the ground portions of the fuel charge that enter the combustion chamber through the fuel inlet in the first end portion of the combustor. 
     
     
         13 . An apparatus as defined in  claim 12 , wherein the igniter is adapted to be fueled by a combustible gas. 
     
     
         14 . An apparatus as defined in  claim 12 , wherein the combustor further includes a nozzle region formed within the inner tubular member by inclined walls extending axially inward from the first end adjacent the fuel inlet to thereby increase the velocity of the fuel particles and carrier agent and density of the fuel particles prior to reaching the igniter. 
     
     
         15 . An apparatus as defined in  claim 12 , wherein the fuel charge comprises a metal fuel charge substantially comprising pressed aluminum particles having a particle density of at least approximately 60%. 
     
     
         16 . An apparatus as defined in  claim 12 , wherein the fuel charge comprises a metal fuel charge substantially comprised of magnesium. 
     
     
         17 . An apparatus as defined in  claim 12 , wherein the fuel charge substantially comprises at least one of the following types of metals: alkali metals, alkaline earth metals, transitional metals, actinides, lanthanides, and poor metals. 
     
     
         18 . An apparatus as defined in  claim 12 , wherein the fuel charge substantially comprises coal. 
     
     
         19 . A system for combustion of a fuel, the system comprising a metal fuel combustion apparatus comprising:
 a central chamber;   a side wall surrounding the central chamber, the distance between at least a portion of said side wall and said central chamber increasing from the periphery with respect to radial distance;   a working fluid inlet means to receive a combustible working fluid;   a working fluid outlet means positioned adjacent to said working fluid inlet means to discharge combusted working fluid;   a cooling fluid inlet means to receive cooling fluid through an annulus between said side wall and said central chamber;   a cooling fluid outlet means to discharge said cooling fluid from said annulus between said side wall and said central chamber and mix it with said combustible working fluid to produce a combustible fuel mixture; and   a fuel ignition means to ignite said combustible fuel mixture to produce said heated working fluid.   
     
     
         20 . A method for combusting a fuel, the method comprising the steps of:
 introducing a metal fuel charge into a metal fuel charge holder of a metal combustion device, the metal fuel charge biased in direct contact with a mechanical grinding device;   initiating the mechanical grinding device to pulverize the metal fuel charge within the metal fuel charge holder to create a metal combustible fuel;   providing a carrier gas to carry the metal combustible fuel from the mechanical grinder device to a combustion chamber of a combustor of the metal combustion device, the combustor comprising an inner tubular member including an inner tubular member main body surrounding a substantial portion of the combustion chamber and having a plurality of cooling fluid outlets positioned to allow a cooling fluid to enter the combustion chamber, and an outer tubular member including an outer tubular member main body surrounding the inner tubular member to substantially enclose the inner tubular member to form a cooling fluid annulus between the inner tubular member main body and the outer tubular member main body and including an aperture to receive the cooling fluid positioned to deliver the cooling fluid to the annulus; and   providing an oxygenated cooling fluid through the aperture of the outer tubular member main body and through each of the plurality of cooling fluid outlets to cool the inner tubular member main body and provide an oxygen source for combustion within the combustion chamber.   
     
     
         21 . A method as defined in  claim 20 , further comprising the steps of:
 pulverizing the metal fuel charge within the metal fuel charge holder; and   forming the metal combustible fuel, the metal combustible fuel comprising ground metal combustible fuel particles; and   wherein the step of providing a carrier gas comprises providing a non-oxidizing medium to thereby minimize formation of an oxide layer around ground metal combustible fuel particles prior to combustion in the combustion chamber of the combustor, the non-oxidizing medium comprising a neutral carrier gas.   
     
     
         22 . A method as defined in  claim 20 , further comprising the steps of:
 introducing the oxygenated cooling fluid into the combustion chamber;   introducing the metal combustible fuel carried by the carrier gas into the combustion chamber adjacent an igniter positioned to deliver a nonmetal combustible fuel;   mixing the oxygenated cooling fluid with the metal combustible fuel to create a combustible fuel mixture including the metal combustible fuel; and   activating the igniter to initiate a metal combustion reaction by the combustible fuel mixture to thereby generate a combusted working fluid.   
     
     
         23 . A method as defined in  claim 22 ,
 wherein the step of activating the igniter includes the steps of:
 introducing the nonmetal combustible fuel in the combustion chamber, and 
 igniting the nonmetal combustible fuel in the combustion chamber; and 
   wherein the method further comprises the step of sustaining the metal combustion reaction by continued pulverization of the metal fuel charge and by continued positioning of the metal fuel charge in direct contact with the mechanical grinding device until the metal fuel charge has been substantially consumed.