Mixed fuel coal burner for gas turbine engines

Abstract

As shown schematically in FIG. 1 , hot gases, containing oxygen, from generator elements, ( 14 ) and ( 19 ), pass through a bed of coal chunks in an ODD reactor, ( 2 ). The oxygen content of these hot gases is less than stoichiometric, relative to the coal volatile matter content, so that partial oxidation of only the volatile matter occurs within the ODD reactor ( 2 ), during devolatilization therein. Two products are thusly created, a partially oxidized, and hence cleaner burning, volatile matter fuel gas, and a solid devolatilized coke. The hot coke is transferred, by overfeed, into a coke reactor, ( 7 ), where counterflowing primary air, via air meter, ( 12 ), gasifies the coke into carbon monoxide with some carbon dioxide. Finally, the carbon monoxide and the partially oxidized volatile matter, are admixed with overfire air, and burned fully to carbon dioxide in overfire burners, ( 23 ), ( 26 ). The resulting hot burned gases flow into the nozzle inlet, where, after mixing with bypass air, they expand through the expander portion of a gas turbine engine. Coal ashes accumulate at the bottom, ( 9 ), of the coke reactor, ( 7 ), where the overlying coal chunks prevent ash particle carryover into the turbine blades. Low cost coal can thus be cleanly used as an energy source for gas turbine engines.

1 . A mixed fuel coal burner, for the clean and controllable burning of coals containing volatile matter, and without ash being carried over with the burned gases leaving the burner, and comprising: 
 a source of coal chunks containing volatile matter, and at atmospheric pressure;    a source of compressed air at a pressure greater than atmospheric;    an ash receiver at atmospheric pressure;    a receiver of hot burned gases;    and ODD reactor chamber and enclosure, and comprising a lower refuel end, a gas inlet near said refuel end, and an upper gas and coke outlet end;    a coke reaction chamber and enclosure, and comprising a lower ash removal end, a gas inlet near said ash removal end, and an upper gas outlet end;    said gas and coke outlet end of said ODD reactor chamber connecting into said gas outlet end of said coke reaction chamber;    an overfire burner enclosure comprising at least two overfire burner chambers: an ODD overfire burner chamber, connected to said upper gas and coke outlet end of said ODD reactor chamber; and a carbon monoxide overfire burner connected to said upper gas outlet end of said coke reaction chamber; and further comprising igniter means for igniting fuel in air mixtures within said overfire burner chambers; and further comprising a gas outlet into said receiver of hot burned gases;    a refuel mechanism for sealably transferring a refuel quantity of coal chunks, from said source of coal chunks, into said lower refuel end of said ODD reactor chamber, repeatedly, at refuel time intervals so that said ODD reactor chamber is largely filled with a bed of said coal chunks, and so that said coal chunks move through said ODD reactor chamber toward said upper gas outlet end, and pass into the connected upper gas outlet end of said coke reaction chamber, to create a bed of hot coke chunks within said coke reaction chamber;    whereby a flow of coal chunks, and associated coal volatile matter, is created, passing through said ODD reactor chamber;    an ash removal mechanism means for sealably transferring an ash removal quantity of coal ashes, from said lower ash removal end of said coke reaction chamber, into said ash receiver, periodically, at ash removal time intervals;    wherein the depth, of said ODD reaction chamber, is sufficient to contain at least three refuel quantities within said reaction chamber;    wherein the depth of said coke reaction chamber, between said ash removal mechanism and said upper gas outlet, is sufficient to contain more than six layers of coke chunks, within said coke reaction chamber, in addition to a layer of ashes above the ash removal mechanism;    hot gas generator means for creating a flow of hot oxygen-containing gas, through said bed of coal chunks, within said ODD reactor chamber, said gas comprising, a portion of diluent gases, such as nitrogen, or carbon dioxide, or steam, or combinations thereof, and a portion of oxygen, so that the oxygen mol fraction in said hot oxygen containing gas is less than the oxygen mol fraction in air at sea level, and so that the flow of oxygen, into said ODD reactor chamber, is less than stoichiometric relative to the flow of coal volatile matter, into said ODD reactor chamber, and further so that the temperature of said hot, oxygen containing gas at least equals the rapid devolitization temperature of said coal chunks;    wherein said flow of hot oxygen containing gas is connected into the gas inlet end of the said ODD reactor chamber;    whereby oxidative, destructive, distillation of the coal chunks, within said ODD reactor chamber, takes place, and creates two coal derived products, a hot devolatilized coke, which enters the connected upper gas outlet end of said coke reactor, and a partially oxidized volatile matter product, which flows into said connected ODD overfire burner chamber accompanied by the diluent portions of said hot oxygen containing gas;    ODD overfire burner compressed air supply means for supplying a flow of compressed air, from said source of compressed air, into said ODD overfire burner;    whereby a flowing, and ignitable, fuel air mixture is created within said ODD overfire burner and can be ignited by said igniter means and burned to hot burned gases;    coke bed depth sensor means for sensing the depth of the coal chunk bed, above the ash layer, in said coke reaction chamber;    coke bed depth control means, responsive to said coke bed depth sensor means, and operative to adjust said refuel time interval, of said refuel mechanism, so that the coke fuel bed depth, within said coke reaction chamber, exceeds six layers of coal chunks, and remains below the gas outlet end of said coke reaction chamber, by increasing the length of said refuel time interval when the coke bed depth approaches the gas outlet end, and by decreasing the length of said refuel time interval when the coke bed depth approaches six layers of coal chunks;    wherein said coke bed depth sensor and control means can be hand sensor and control means or automatic sensor and control means, or combinations of hand and automatic sensor and control means;    a coke burner air supply means for creating a flow of primary compressed air, from said source of compressed air, into said lower gas inlet end of said coke reaction chamber, and through said bed of hot coke chunks therein, so that: said hot coke reacts with oxygen in the primary air, and is gasified into gaseous carbon monoxide and carbon dioxide and solid ashes, and said coal chunks and ashes move down through said coke reaction chamber, toward said ash removal mechanism, and in a direction opposite to the direction of primary air flow; and said ashes are essentially fully separated from said coke and collect near the lower gas inlet end of said coke reaction chamber; and said carbon monoxide and carbon dioxide gases, together with diluent nitrogen gas from said primary air, flow from said upper gas outlet end of said coke reaction chamber and into said connected carbon monoxide overfire burner;    carbon monoxide overfire burner compressed air supply means for supplying a flow of compressed air from said source of compressed air into said carbon monoxide overfire burner;    whereby a flow of ignitable fuel air mixture is created within said carbon monoxide overfire burner and can be ignited by said igniter means and burned to hot burned gases;    said hot burned gases from said ODD overfire burner and from said carbon monoxide overfire burner flow into said connected receiver of hot burned gases;    ash bed depth sensor means for sensing the depth of the ashes, collected at the lower ash removal end of the coke reaction chamber, above the ash removal mechanism;    ash bed depth control means, responsive to said ash bed depth sensor means, and operative to adjust said ash removal time interval, of said ash removal mechanism, so that;    the ash volume within said coke reaction chamber, and outside said ash removal mechanism, always exceeds the ash removal volume of said ash removal mechanism; and further so that; the ash volume within said coke reaction chamber, and outside said ash removal mechanism, is preferably no greater than three times the ash removal volume of said ash removal mechanism;    wherein said ash bed depth sensor and control means can be hand sensor and control means, or automatic sensor and control means, or combinations of hand and automatic sensor and control means;    whereby a layer of ashes is always present between said ash removal mechanism and said hot burning coke.    
     
     
         2 . A mixed fuel coal burner as described in  claim 1:   wherein none of said coal chunks will pass through a one half inch screen;    wherein said receiver of hot burned gases is the inlet to the expander turbine portion of a gas turbine engine;    wherein said source of compressed air is a portion of the compressor discharge air from the compressor portion of said gas turbine engine.    
     
     
         3 . A mixed fuel coal burner as described in  claim 2:   wherein said hot gas generator means comprises: 
 a source of gas or liquid fuel at a pressure at least equal to the pressure of said source of compressed air;  
 an ODD burner chamber and enclosure comprising two inlets, an outlet end, and an igniter means;  
 an ODD burner fuel meter means for creating a flow of fuel from said source of gas or liquid fuel, into one said inlet of said ODD burner chamber;  
 an ODD burner air supply means for creating a flow of compressed air, from said source of compressed air into the other said inlet of said ODD burner chamber;  
 wherein the ratio of said flow of compressed air to said flow of fuel is within the spark ignitable limits;  
 whereby ignition and burning of said fuel and air occurs within said ODD burner chamber and creates a flow of hot burned gases through said outlet of said ODD burner chamber;  
 an ODD mixer chamber and enclosure comprising two inlets and an outlet, one of said inlets connecting to the outlet of said ODD burner chamber, the outlet of said mixer chamber connecting to said gas inlet of said ODD reaction chamber;  
 an ODD mixer air supply means for creating a flow of compressed air from said source of compressed air into the other said inlet of said ODD mixer chamber;  
 whereby said hot burned gas, from said ODD burner chamber, is mixed with air, in said ODD mixer chamber, to create a hot, oxygen containing gas, which flows into and through said connected ODD reaction chamber, to cause oxidative, destructive, distillation of the coal volatile matter to take place therein;  
 wherein the ratio of the flow of hot burned gases, from said ODD burner, to mixer air flow, into said ODD mixer, is set to create an oxygen mol fraction, within the hot oxygen containing mixer exit gases, less than the mol fraction of oxygen in air at sea level;  
 and further wherein the flow of oxygen, via said hot oxygen containing gas, into said ODD reaction chamber is less than stoichiometric relative to the flow of coal volatile matter into said ODD reaction chamber;  
   wherein said overfire burner chamber, and enclosure, further comprises a supplementary overfire burner chamber, and igniter means;    and further comprising supplementary fuel air mixture generator means for creating a flow of supplementary, ignitable, fuel air mixture into said supplementary overfire burner chamber, and comprising: 
 a generator chamber comprising two separate generator inlets, and a generator outlet connecting into said supplementary overfire burner chamber;  
 a supplementary fuel meter means for creating a flow of fuel, from said source of gas or liquid fuel, into one said generator inlet;  
 a supplementary air supply means for creating a flow of compressed air, from said source of compressed air, into the other said generator inlet;  
 wherein the fuel in air mixture, thusly created within said generator chamber, is ignitable, and flows into said supplementary overfire burner chamber, and is ignited and burned therein to burned gases;  
   and further comprising:    a speed sensor means for sensing gas turbine engine shaft rotational speed;    supplementary fuel air mixture control means for controlling the rate of flow of supplementary fuel air mixture, into said supplementary overfire burner chamber, responsive to said speed sensor means, and operative upon said supplementary fuel air mixture generator means, so that, said flow of supplementary fuel air mixture is increased, when gas turbine engine shaft speed is less than a preset value, and so that said flow of supplementary fuel air mixture is decreased, when gas turbine engine shaft speed is greater than said preset value;    whereby gas turbine engine shaft speed is maintained within a narrow range about said preset value;    a load sensor means for sensing gas turbine engine load;    coal control means for controlling the rate of coal burning in said mixed fuel coal burner, responsive to said load sensor means, and operative upon: said hot oxygen containing gas generator means; said coke burner air supply means; said ODD overfire burner compressed air supply means; said carbon monoxide overfire burner compressed air supply means; so that: the flow rate of hot oxygen containing gas into said ODD reaction chamber, and the flow rate of primary air into said coke burner and the flow rate of compressed air into said ODD overfire burner, and the flow rate of compressed air into said carbon monoxide overfire burner, are all changed in proportion to gas turbine engine load;    whereby the rate of coal burning is controlled, by said coal control means, so as to be proportional to gas turbine engine load;    comparator means for comparing the rate of coal burning, as controlled by said coal control means to the rate of supplementary fuel air mixture burning, as controlled by said supplementary air fuel mixture control means, to determine the ratio of coal energy release rate divided by the supplementary air fuel mixture energy release rate, and to compare this ratio to a preset value for this ratio, and operative upon said coal control means, to increase said coal burning rate when said determined ratio is less than said preset value, and to decrease said coal burning rate when said determined ratio exceeds said preset value.    
     
     
         4 . A mixed fuel coal burner, as described in  claim 3:   wherein said compressed air supply means are positive displacement air meters.    
     
     
         5 . A mixed fuel coal burner, as described in  claim 1:  wherein said receiver of hot burned gases is a furnace; 
 wherein said hot gas generator means comprises: 
 a source of gas or liquid fuel at a pressure at least equal to the pressure of said source of compressed air;  
 an ODD burner chamber and enclosure, comprising two inlets, an outlet end, and an igniter means;  
 an ODD burner fuel meter means for creating a flow of fuel, from said source of gas or liquid fuel, into one said inlet of said ODD burner chamber;  
 an ODD burner air supply means for creating a flow of compressed air, from said source of compressed air into the other said inlet of said ODD burner chamber;  
 wherein the ratio of said flow of compressed air to said flow of fuel is within the spark ignitable limits;  
 whereby ignition and burning of said fuel and air occurs within said ODD burner chamber and creates a flow of hot burned gases through said outlet of said ODD burner chamber;  
 an ODD mixer chamber and enclosure comprising two inlets and an outlet, one of said inlets connecting to the outlet of said ODD burner chamber, the outlet of said mixer chamber connecting to said gas inlet of said ODD reaction chamber;  
 an ODD mixer air supply means for creating a flow of compressed air from said source of compressed air into the other said inlet of said ODD mixer chamber;  
 whereby said hot burned gas, from said ODD burner chamber, is mixed with air, in said ODD mixer chamber, to create a hot oxygen containing gas, which flows into and through said connected ODD reaction chamber, to cause oxidative, destructive, distillation of the coal volatile matter to take place therein;  
 wherein the ratio of the flow of hot burned gases, from said ODD burner, to mixer air flow, into said ODD mixer, is set to create an oxygen mol fraction, within the hot oxygen containing mixer exit gases, less than the mol fraction of oxygen in air at sea level;  
 and further wherein the flow oxygen, via said hot oxygen containing gas, into said ODD reaction is less than stoichiometric relative to the flow of coal volatile matter into said ODD reaction chamber.  
   
     
     
         6 . A mixed fuel coal burner is described in  claim 5:   wherein said overfire burner chamber, and enclosure, further comprises a supplementary overfire burner chamber, and igniter means;    and further comprising supplementary fuel in air mixture generator means for creating a flow of supplementary, ignitable, fuel air mixture into said supplementary overfire burner chamber, and comprising: 
 a generator chamber comprising two separate generator inlets, and a generator outlet connecting into said supplementary overfire burner chamber;  
 a supplementary fuel meter means for creating a flow of fuel, from said source, of gas or liquid fuel, into one said generator inlet;  
 a supplementary air supply means for creating a flow of compressed air, from said source of compressed air, into the other said generator inlet;  
 wherein the fuel in air mixture, thusly created within said generator chamber, is ignitable, and flows into said supplementary overfire burner chamber, and is ignited and burned therein to burned gases.  
   
     
     
         7 . A coal reactor for transforming coals, containing volatile matter, into two different fuel products, a clean burning gas fuel, derived from the coal volatile matter, and a solid coke fuel, and comprising: 
 a source of coal chunks containing volatile matter;    a coke receiver;    a receiver of volatile matter derived fuel;    an ODD reaction chamber and enclosure, and comprising a lower refuel end, a gas inlet near said refuel end, and an upper gas and coke outlet end;    said gas and coke outlet end, of said ODD reaction chamber, connecting into said receiver of volatile matter derived fuel, and also connecting separately into said coke receiver;    a refuel mechanism means for transferring a refuel quantity of coal chunks, from said source of coal chunks, into the lower refuel end of said ODD reaction chamber, repeatedly, so that said ODD reaction chamber is largely filled with a bed of coal chunks, and so that said coal chunks move through said ODD reaction chamber toward said upper gas and coke outlet end, and pass into the connected coke receiver;    whereby a flow of coal chunks, and associated coal volatile matter, is created passing through said ODD reaction chamber;    hot gas generator means for creating a flow of hot, oxygen containing gas, through said bed of coal chunks, within said ODD reaction chamber, said hot gas comprising, a portion of diluent gases, such as nitrogen, or carbon dioxide, of steam, or combinations thereof, and a portion of oxygen, so that the oxygen mol fraction in said hot oxygen containing gas is less than the oxygen mol fraction in air at sea level, and so that the flow of oxygen, into said ODD reaction chamber, is less than stoichiometric relative to the flow of coal volatile matter, into said ODD reaction chamber, and further so that the temperature of said hot, oxygen containing gas at least equals the rapid devolitization temperature of said coal chunks;    wherein said flow of hot oxygen containing gas is connected into the gas inlet end of said ODD reaction chamber;    whereby oxidative destructive distillation, of the coal chunks within said ODD reaction chamber, takes place, and creates two coal derived products, a devolatilized solid coke product, which passes into said connected coke receiver and a partially oxidized volatile matter product which flows into said connected receiver of volatile matter derived fuel accompanied by the diluent portions of said hot, oxygen containing gas.    
     
     
         8 . A coal reactor as described in  claim 7 , wherein said hot gas generator means comprises: 
 a source of compressed air at a pressure greater than atmospheric; wherein said hot gas generator means comprises: 
 a source of gas or liquid fuel at a pressure at least equal to the pressure of said source of compressed air;  
 an ODD burner chamber and enclosure, comprising two inlets, an outlet end, and an igniter means;  
 an ODD burner fuel meter means for creating a flow of fuel, from said source of gas or liquid fuel, into one said inlet of said ODD burner chamber;  
 an ODD burner air supply means for creating a flow of compressed air, from said source of compressed air into the other said inlet of said ODD burner chamber;  
 wherein the ratio of said flow of compressed air to said flow of fuel is within the spark ignitable limits;  
 whereby ignition and burning of said fuel and air occurs within said ODD burner chamber and creates a flow of hot burned gases through said outlet of said ODD burner chamber;  
 an ODD mixer chamber and enclosure comprising two inlets and an outlet, one of said inlets connecting to the outlet of said ODD burner chamber, the outlet of said mixer chamber connecting to said gas inlet of said ODD reaction chamber;  
 an ODD mixer air supply means for creating a flow of compressed air from said source of compressed air into the other said inlet of said ODD mixer chamber;  
 whereby said hot burned gas, from said ODD burner chamber, is mixed with air, in said ODD mixer chamber, to create a hot, oxygen containing gas, which flows into and through said connected ODD reaction chamber, to cause oxidative, destructive, distillation of the coal volatile matter to take place therein;  
 wherein the ratio of the flow of hot burned gases, from said ODD burner, to mixer air flow, into said ODD mixer, is set to create an oxygen mol fraction, within the hot oxygen containing mixer exit gases, less than the mol fraction of oxygen in air at sea level;  
 and further wherein the flow of oxygen, via said hot oxygen containing gas, into said ODD reaction chamber is less than stoichiometric relative to the flow of coal volatile matter into said ODD reaction chamber.  
   
     
     
         9 . A coal reactor as described in  claim 8:   wherein none of said coal chunks will pass through a one half inch screen;    wherein said source of compressed air is a portion of the compressor discharge air from the compressor portion of a gas turbine engine;    and further comprising:    an ODD overfire burner chamber and enclosure, and comprising: a fuel inlet, a compressed air inlet, a burned gas outlet, and igniter means for igniting fuel in air mixtures within said overfire burner chamber;    wherein said refuel mechanism means for transferring coal into the refuel end of the ODD reaction chamber, thusly transfers a refuel quantity of coal Sealably and repeatedly, at refuel time intervals;    wherein said receiver of volatile matter derived fuels is said ODD overfire burner and chamber, whose fuel inlet is connected to said upper gas and coke outlet end of said ODD reaction chamber;    ODD overfire burner compressed air supply means for supplying a flow of compressed air, from said source of compressed air, into said compressed air inlet of said ODD overfire burner chamber;    wherein said burned gas outlet of said ODD overfire burner chamber, is connected to the inlet of the expander turbine portion of a gas turbine engine;    whereby a flowing and ignitable fuel air mixture is created, within said ODD overfire burner, and can be ignited by said igniter means, and burned to hot burned gases, which flow into the inlet of the expander turbine of said gas turbine engine;    a coke collector at atmospheric pressure;    wherein said coke receiver comprises a coke chamber and enclosure comprising a lower coke removal end, and an upper coke inlet end, said coke inlet connecting to said upper gas and coke outlet end of said ODD reaction chamber; a coke removal mechanism means for sealably transferring a coke removal quantity of coke chunks, from said lower coke removal end of said coke receiver, into said coke collector, periodically, at coke removal time intervals;    coke depth sensor means for sensing the depth of the coal chunks within said coke chamber;    coke depth control means, responsive to said coke depth sensor means, and operative to adjust said coke removal time interval, so that the coke depth remains below said coke inlet end, by decreasing said coke removal time interval when coke depth approaches the upper coke inlet end;    wherein said coke depth sensor and control means can be hand sensor or control means, or automatic sensor and control means, or combinations of hand and automatic sensor and control means.    
     
     
         10 . A process for transforming coal chunks, containing volatile matter, into two separate fuel products, a solid coke fuel, and a partially oxidized volatile matter derived fuel, and comprising the following steps: 
 passing coal chunks through an enclosed ODD reactor;    passing hot, oxygen containing gases concurrently through said ODD reactor;    wherein the molal oxygen concentration, in said hot oxygen containing gases, is less than the molal oxygen concentration in air at sea level;    wherein the temperature of said hot oxygen containing gas exceeds the rapid devolatilization temperature of the coal;    wherein the ratio of oxygen, passing through the ODD reactor, to coal volatile matter, concurrently passing through said ODD reactor, is less than stoichiometric, for full burnup of said volatile matter to carbon dioxide and water vapor;    whereby oxidative destructive distillation of the coal volatile matter takes place inside the ODD reactor, and transforms said coal chunks into a partially oxidized volatile matter derived fuel, and hot solid devolatilized coke fuel chunks;    passing said volatile matter derived fuel out of said ODD reactor, and into a receiver of this fuel product;    passing said hot solid devolatilized coke fuel chunks out of said ODD reactor, and into a receiver of this coke fuel product.    
     
     
         11 . A process for transforming coal chunks, containing volatile matter, into two separate fuel products, as described in  claim 10:   wherein the hot oxygen containing gases are generated by the following process steps:    passing burner air, and a gas or liquid fuel, concurrently, through an ODD burner enclosure, in spark ignitable proportions, to create a fuel in air mixture;    igniting said fuel in air mixture to create a hot burned gas;    passing said hot burned gas, and ODD mixer air, concurrently, through a mixer enclosure, to create a hot oxygen containing gas.    
     
     
         12 . A process for the clean burning of coal chunks, containing volatile matter, and without ash carryover into the resulting burned gases, and comprising the following steps, in addition to the process steps described in  claim 11;   passing said volatile matter derived fuel, from said ODD reactor, through an ODD overfire burner enclosure as a receiver of volatile matter derived fuel;    passing ODD overfire air concurrently through said ODD overfire burner enclosure, to create a fuel in air mixture;    wherein the ratio of said ODD overfire air flow to said volatile matter derived fuel flow, of said fuel in air mixture, within said ODD overfire burner, lies within the spark ignitable limits;    igniting said fuel in air mixture, within said ODD overfire burner enclosure, to create an ODD overfire burned gas;    passing said ODD overfire burned gas, out of said ODD overfire burner enclosure, and into a receiver of hot burned gases;    passing said hot solid devolatilized coke fuel chunks, from said ODD reactor, into the upper end of a coke reactor chamber and enclosure as a receiver of coke fuel product;    passing primary air into the lower end of said coke reactor chamber;    whereby said hot coke fuel chunks react with oxygen, in said primary air, and with the carbon dioxide, formed by said reaction of oxygen with said hot coke fuel, and said hot coke fuel is gasified into carbon monoxide, and carbon dioxide, and residual solid ashes, and said coke fuel chunks, and ashes, move downward through said coke reaction chamber, in a direction opposite to the direction of flow of said primary air, and said residual ashes collect at the lower end of said coke reaction chamber;    maintaining a depth of coke fuel chunks, within said coke reaction chamber, sufficient, that the molal ratio of coke fuel carbon, thusly gasified into carbon dioxide and carbon monoxide, to primary air supplied, preferable exceeds a value of 0.35;    passing said collected ashes, from said lower end of said coke reaction chamber, into a receiver of ashes;    passing said carbon monoxide, and carbon dioxide, together with unreacted portions of said primary air, through a carbon monoxide overfire burner enclosure;    passing carbon monoxide overfire air concurrently through said carbon monoxide overfire burner enclosure to create a fuel in air mixture;    wherein the ratio of said carbon monoxide overfire air flow, to said flow of carbon monoxide and carbon dioxide and unreacted portions of said primary air, within said carbon monoxide overfire burner, lies within the spark ignitable limits;    igniting said fuel in air mixture within said carbon monoxide overfire burner enclosure to create a carbon monoxide overfire burned gas;    passing said carbon monoxide overfire burned gas out of said carbon monoxide overfire burner enclosure and into said receiver of hot burned gases.    
     
     
         13 . A mixed fuel coal burner, for the clean and controllable burning of coals containing volatile matter, and without ash being carried over with the burned gases leaving the burner, and comprising: 
 a source of coal chunks containing volatile matter, and at atmospheric pressure;    a source of compressed air at a pressure greater than atmospheric;    an ash receiver at atmospheric pressure;    a receiver of hot burned gases;    an ODD reactor chamber and enclosure, and comprising a lower refuel end, a gas inlet near said refuel end, and an upper gas and coke outlet end;    a coke reaction chamber and enclosure, and comprising a lower ash removal end, a gas inlet near said ash removal end, and an upper gas outlet end;    said gas and coke outlet end of said ODD reactor chamber connecting into said gas outlet end of said coke reaction chamber;    an overfire burner enclosure comprising at least two overfire burner chambers: an ODD overfire burner chamber, connected to said upper gas and coke outlet end of said ODD reactor chamber; and a carbon monoxide overfire burner chamber connected to said upper gas outlet end of said coke reaction chamber; and further comprising igniter means for igniting fuel in air mixtures within said overfire burner chambers; and further comprising a gas outlet into said receiver of hot burned gases;    a refuel mechanism means for sealably transferring a refuel quantity of coal chunks, from said source of coal chunks, into said lower refuel end of said ODD reactor chamber, repeatedly, at refuel time intervals, so that said ODD reactor chamber is largely filled with a bed of said coal chunks, and so that said coal chunks move through said ODD reactor chamber toward said upper gas outlet end, and pass into the connected upper gas outlet end of said coke reaction chamber, to create a bed of hot coke chunks within said coke reaction chamber;    whereby a flow of coal chunks, and associated coal volatile matter, is created, passing through said ODD reactor chamber;    an ash removal mechanism means for sealably transferring an ash removal quantity of coal ashes, from said lower ash removal end of said coke reaction chamber, into said ash receiver, periodically, at ash removal time intervals;    wherein the depth, of said ODD reactor chamber, is sufficient to contain at least three refuel quantities within said reactor chamber;    wherein the depth of said coke reaction chamber, between said ash removal mechanism and said upper gas outlet, is sufficient to contain more than six layers of coke chunks, within said coke reaction chamber, in addition to a layer of ashes above the ash removal mechanism;    hot gas generator means for creating a flow of hot molecular oxygen-containing gas, through said bed of coal chunks, within said ODD reactor chamber, said hot gas comprising, a portion of diluent gases, such as nitrogen, or carbon dioxide, or steam, or combinations thereof, and a portion of molecular oxygen, so that the molecular oxygen mol fraction in said hot molecular oxygen containing gas is less than the molecular oxygen mol fraction in air at sea level, and so that the flow of molecular oxygen, into said ODD reactor chamber, is less than stoichiometric relative to the flow of coal volatile matter, into said ODD reactor chamber, and further so that the temperature of said hot molecular oxygen containing gas at least equals the rapid devolatilization temperature of said coal chunks;    wherein said flow of hot molecular oxygen containing gas is connected into the gas inlet end of the said ODD reactor chamber;    whereby oxidative, destructive, distillation of the coal chunks, within said ODD reactor chamber, takes place, and creates two coal derived products, a hot devolatilized coke, which enters the connected upper gas outlet end of said coke reaction chamber, and a partially oxidized volatile matter product, which flows into said connected ODD overfire burner chamber accompanied by the diluent portions of said hot molecular oxygen containing gas;    ODD overfire burner compressed air supply means for supplying a flow of compressed air, from said source of compressed air, into said ODD overfire burner;    whereby a flowing, and ignitable, fuel air mixture is created within said ODD overfire burner and can be ignited by said igniter means and burned to hot burned gases;    coke bed depth sensor means for sensing the depth of the coke chunk bed, above the ash layer, in said coke reaction chamber;    coke bed depth control means, responsive to said coke bed depth sensor means, and operative to adjust said refuel time interval, of said refuel mechanism, so that the coke fuel bed depth, within said coke reaction chamber, exceeds six layers of coal chunks, and remains below the gas outlet end of said coke reaction chamber, by increasing the length of said refuel time interval when the coke bed depth approaches the gas outlet end, and by decreasing the length of said refuel time interval when the coke bed depth approaches six layers of coal chunks;    wherein said coke bed depth sensor and control means can be hand sensor and control means or automatic sensor and control means, or combinations of hand and automatic sensor and control means;    a coke reaction chamber air supply means for creating a flow of primary compressed air, from said source of compressed air, into said lower gas inlet end of said coke reaction chamber, and through said bed of hot coke chunks therein, so that: said hot coke reacts with molecular oxygen in the primary air, and is gasified into gaseous carbon monoxide and carbon dioxide and solid ashes, and said coal chunks and ashes move down through said coke reaction chamber, toward said ash removal mechanism, and in a direction opposite to the direction of primary air flow;    and said ashes are essentially fully separated from said coke and collect near the lower gas inlet end of said coke reaction chamber; and said carbon monoxide and carbon dioxide gases, together with diluent nitrogen gas and from said primary air, flow from said upper gas outlet end of said coke reaction chamber and into said connected carbon monoxide overfire burner;    carbon monoxide overfire burner compressed air supply means for supplying a flow of compressed air from said source of compressed air into said carbon monoxide overfire burner;    whereby a flow of ignitable fuel air mixture is created within said carbon monoxide overfire burner and can be ignited by said igniter means and burned to hot burned gases;    said hot burned gases from said ODD overfire burner and from said carbon monoxide overfire burner flow into said connected receiver of hot burned gases;    ash bed depth sensor means for sensing the depth of the ashes, collected at the lower ash removal end of the coke reaction chamber, above the ash removal mechanism, ash bed depth control means, responsive to ash bed depth sensor means, and operative to adjust said ash removal time interval, of said ash removal mechanism, so that: the ash volume within said coke reaction chamber, and outside the ash removal mechanism, always exceeds the ash removal volume of said ash removal mechanism; and further so that:    the ash volume within said coke reaction chamber, and outside said ash removal mechanism, is preferably no greater than three times the ash removal volume of said ash removal mechanism;    wherein said ash bed depth sensor and control means can be hand sensor and control means, or automatic sensor and control means, or combinations of hand and automatic sensor and control means;    whereby a layer of ashes is always present between said ash removal mechanism and said hot burning coke.    
     
     
         14 . A mixed fuel coal burner as described in  claim 13:   wherein none of said coal chunks will pass through a one half inch screen;    wherein said receiver of hot burned gases is the inlet to the expander turbine portion of a gas turbine engine;    wherein said source of compressed air is a portion of the compressor discharge air from the compressor portion of said gas turbine engine.    
     
     
         15 . A mixed fuel coal burner as described in  claim 14:   wherein said hot gas generator means comprises; 
 a source of gas or liquid fuel at a pressure at least equal to the pressure of said source of compressed air;  
 an ODD burner chamber and enclosure comprising two inlets, an outlet end, and an igniter means;  
 an ODD burner fuel meter means for creating a flow of fuel from said source of gas or liquid fuel, into one said inlet of said ODD burner chamber;  
 an ODD burner air supply means for creating a flow of compressed air, from said source of compressed air into the other said inlet of said ODD burner chamber;  
 wherein the ratio of said flow of compressed air to said flow of fuel is within the spark ignitable limits;  
 whereby ignition and burning of said fuel and air occurs within said ODD burner chamber and creates a flow of hot burned gases through said outlet of said ODD burner chamber;  
 an ODD mixer chamber and enclosure comprising two inlets and an outlet, one of said inlets connecting to the outlet of said ODD burner chamber, the outlet of said mixer chamber connecting to said gas inlet of said ODD reactor chamber;  
 an ODD mixer air supply means for creating a flow of compressed air from said source of compressed air into the other said inlet of said ODD mixer chamber;  
 whereby said hot burned gas, from said ODD burner chamber, is mixed with air, in said ODD mixer chamber, to create a hot, molecular oxygen containing gas, which flows into and through said connected ODD reactor chamber, to cause oxidative, destructive, distillation of the coal volatile matter to take place therein;  
 wherein the ratio of the flow of hot burned gases, from said ODD burner, to mixer air flow, into said ODD mixer, is set to create a molecular oxygen mol fraction, within the hot molecular oxygen containing mixer exit gases, less than the mol fraction of molecular oxygen in air at sea level;  
 and further wherein the flow of molecular oxygen, via said hot molecular oxygen containing gas, into said ODD reactor chamber is less than stoichiometric relative to the flow of coal volatile matter into said ODD reactor chamber;  
   wherein said overfire burner chamber, and enclosure, further comprises a supplementary overfire burner chamber, and igniter means;    and further comprising supplementary fuel air mixture generator means for creating a flow of supplementary, ignitable, fuel air mixture into said supplementary overfire burner chamber, and comprising: 
 a generator chamber comprising two separator generator inlets, and a generator outlet connecting into said supplementary overfire burner chamber;  
 a supplementary fuel meter means for creating a flow of fuel, from said source of gas or liquid fuel, into one said generator inlet;  
 a supplementary air supply means for creating a flow of compressed air, from said source of compressed air, into the other said generator inlet;  
 wherein the fuel in air mixture, thusly created within said generator chamber, is ignitable, and flows into said supplementary overfire burner chamber, and is ignited and burned therein to burned gases;  
   and further comprising:    a speed sensor means for sensing gas turbine engine shaft rotational speed;    supplementary air fuel mixture control means for controlling the rate of flow of supplementary fuel air mixture, into said supplementary overfire burner chamber, responsive to said speed sensor means, and operative upon said supplementary fuel air mixture generator means, so that, said flow of supplementary fuel air mixture is increased, when gas turbine engine shaft speed is less than a preset value, and so that said flow of supplementary fuel air mixture is decreased, when gas turbine engine shaft speed is greater than said preset value;    whereby gas turbine engine shaft speed is maintained within a narrow range about said preset value;    a load sensor means for sensing gas turbine engine load;    coal control means for controlling the rate of coal burning in said mixed fuel coal burner, responsive to said load sensor means, and operative upon: said hot molecular oxygen containing gas generator means, said coke reaction chamber air supply means; said ODD overfire burner compressed air supply means; said carbon monoxide overfire burner chamber air supply means; so that; the flow rate of hot molecular oxygen containing gas into said ODD reactor chamber, and the flow rate of primary air into said coke reaction chamber, and the flow rate of compressed air into said ODD overfire burner, and the flow rate of compressed air into said carbon monoxide overfire burner, are all changed in proportion to gas turbine engine load;    whereby the rate of coal burning is controlled, by said coal control means, so as to be proportional to gas turbine engine load;    comparator means for comparing the rate of coal burning, as controlled by said coal control means, to the rate of supplementary air fuel mixture burning, as controlled by said supplementary air fuel mixture control means, to determine the ratio of coal energy release rate divided by the supplementary air fuel mixture energy release rate, and to compare this ratio to a preset value for this ratio, and operative upon said control means, to increase said coal burning rate when said determined ratio is less than said preset value, and to decrease said coal burning rate when said determined ratio exceeds said preset value.    
     
     
         16 . A mixed fuel coal burner, as described in  claim 15:   wherein said compressed air supply means are positive displacement air meters.    
     
     
         17 . A mixed fuel coal burner, as described in  claim 13 , wherein said receiver of hot burned gases is a furnace; 
 wherein said hot gas generator means comprises: 
 a source of gas or liquid fuel at a pressure at least equal to the pressure of said source of compressed air;  
 an ODD burner chamber and enclosure, comprising two inlets, an outlet end, and an igniter means;  
 an ODD burner fuel meter means for creating a flow of fuel, from said source of gas or liquid fuel, into one said inlet of said ODD burner chamber;  
 an ODD burner air supply means for creating a flow of compressed air, from said source of compressed air into the other said inlet of said ODD burner chamber;  
 wherein the ratio of said flow of compressed air to said flow of fuel is within the spark ignitable limits;  
 whereby ignition and burning of said fuel and air occurs within said ODD burner chamber and creates a flow of hot burned gases through said outlet of said ODD burner chamber;  
 an ODD mixer chamber and enclosure comprising two inlets and an outlet, one of said inlets connecting to the outlet of said ODD burner chamber, the outlet of said mixer chamber connecting to said gas inlet of said ODD reactor chamber;  
 an ODD mixer air supply means for creating a flow of compressed air from said source of compressed air into the other said inlet of said ODD mixer chamber;  
 whereby said hot burned gas, from said ODD burner chamber, is mixed with air, in said ODD mixer chamber, to create a hot molecular oxygen containing gas, which flows into and through said connected ODD reactor chamber, to cause oxidative destructive, distillation of the coal volatile matter to take place therein;  
 wherein the ratio of the flow of hot burned gases, from said ODD burner, to mixer air flow, into said ODD mixer, is set to create a molecular oxygen mol fraction, within the hot molecular oxygen containing mixer exit gases, less than the mol fraction of molecular oxygen in air at sea level;  
 and further wherein the flow of molecular oxygen, via said hot molecular oxygen containing gas, into said ODD reactor chamber is less than stoichiometric relative to the flow of coal volatile matter into said ODD reactor chamber.  
   
     
     
         18 . A mixed fuel coal burner as described in  claim 17:   wherein said overfire burner chamber, and enclosure, further comprises a supplementary overfire burner chamber, and igniter means;    and further comprising supplementary fuel in air mixture generator means for creating a flow of supplementary, ignitable, fuel air mixture into said supplementary overfire burner chamber, and comprising: 
 a generator chamber comprising two separate generator inlets, and a generator outlet connecting into said supplementary overfire burner chamber;  
 a supplementary fuel meter means for creating a flow of fuel, from said source of gas or liquid fuel, into one said generator inlet;  
 a supplementary air supply means for creating a flow of compressed air, from said source of compressed air, into the other said generator inlet; wherein the fuel in air mixture, thusly created within said generator chamber, is ignitable, and flows into said supplementary overfire burner chamber, and is ignited and burned therein to burned gases.