Solid fuel system with electrodynamic combustion control

Abstract

A solid fuel combustion system includes a solid fuel burner configured to sustain a combustion reaction of a solid fuel and an oxidant. The solid fuel combustion system includes a first and a second electrode positioned to adjust a shape of a combustion reaction of solid fuel and an oxidant by generating an electric field.

What is claimed is: 
     
         1 . A system, comprising:
 an enclosure defining a combustion volume;   a solid fuel burner disposed within the combustion volume and configured to support a combustion reaction of a solid fuel and an oxidant within the combustion volume, the solid fuel burner including a first electrode being positioned to impart a voltage or charge to the combustion reaction;   a second electrode positioned above the solid fuel burner within the combustion volume; and   a voltage supply electrically coupled to the first and second electrodes and configured to adjust a shape of the combustion reaction by applying an electrical potential between the first and second electrodes.   
     
     
         2 . The system of  claim 1 , wherein the burner includes:
 a grate positioned in the combustion volume and configured to support the solid fuel; and   an oxidant source configured to provide the oxidant to the combustion volume.   
     
     
         3 . The system of  claim 2 , wherein the grate is the first electrode. 
     
     
         4 . The system of  claim 1 , comprising a first support that fixes the second electrode to the enclosure. 
     
     
         5 . The system of  claim 4 , comprising a cooling apparatus configured to cool the first support. 
     
     
         6 . The system of  claim 5 , wherein the cooling apparatus includes a cooling tube positioned proximate to the first support, the cooling apparatus being configured to cool the first support by passing a cooling fluid through the tube. 
     
     
         7 . The system of  claim 6 , wherein the cooling fluid is air. 
     
     
         8 . The system of  claim 7 , wherein the cooling apparatus is configured to pass the cooling fluid into the combustion volume after being heated by the first support. 
     
     
         9 . The system of  claim 6 , wherein the cooling fluid is a liquid. 
     
     
         10 . The system of  claim 6 , wherein the cooling fluid is a gas. 
     
     
         11 . The system of  claim 5 , comprising:
 a third electrode positioned within the combustion volume and coupled to the voltage supply; and   a second support configured to couple the third electrode to the enclosure.   
     
     
         12 . The system of  claim 11 , wherein the second and third electrodes are positioned above and lateral to the solid fuel burner. 
     
     
         13 . The system of  claim 11 , comprising a flue configured to vent flue gasses from the enclosure. 
     
     
         14 . The system of  claim 13 , wherein the second and third electrodes are positioned to inhibit particulates generated by the combustion reaction from exiting through the flue. 
     
     
         15 . The system of  claim 14 , wherein the second and third electrodes inhibit particulates from exiting through the flue by electrically attracting particulates and/or the combustion reaction toward the second and third electrodes. 
     
     
         16 . The system of  claim 11 , wherein the voltage supply is configured to apply a same voltage to the second and third electrodes. 
     
     
         17 . The system of  claim 16 , wherein the cooling apparatus is configured to cool the second support. 
     
     
         18 . The system of  claim 5 , wherein the cooling apparatus is configured to inhibit an electrical current from passing between the first electrode and the enclosure. 
     
     
         19 . The system of  claim 4 , wherein the first support includes a first bracket fixed to the enclosure. 
     
     
         20 . The system of  claim 4 , wherein the first support is a ceramic material. 
     
     
         21 . The system of  claim 1 , wherein the second electrode is a ceramic material. 
     
     
         22 . The system of  claim 21 , wherein the second electrode includes silicon carbide. 
     
     
         23 . The system of  claim 21 , wherein the ceramic material includes aluminosilicate fiberboard. 
     
     
         24 . The system of  claim 1 , wherein the voltage includes an oscillating waveform. 
     
     
         25 . The system of  claim 1 , wherein the electrical potential has a magnitude greater than 10,000 V. 
     
     
         26 . The system of  claim 25 , wherein the electrical potential has a magnitude greater than 45,000 V. 
     
     
         27 . The system of  claim 1 , comprising a control circuit coupled to the voltage supply and configured to control the voltage supply. 
     
     
         28 . The system of  claim 1 , wherein the voltage supply is configured to broaden the combustion reaction by drawing the combustion reaction to the first and the second electrodes. 
     
     
         29 . The system of  claim 1 , wherein the solid fuel is a biomass fuel. 
     
     
         30 . A method comprising:
 supporting a solid fuel in a combustion volume defined by an enclosure;   supplying an oxidant to the combustion volume;   sustaining a combustion reaction of the solid fuel and the oxidant within the combustion volume; and   adjusting a height of the combustion reaction by applying an electrical potential between a first electrode and a second electrode, the first electrode being positioned to impart a voltage or charge to the combustion reaction, the second electrode being positioned above the solid fuel and fixed to the enclosure.   
     
     
         31 . The method of  claim 30 , wherein applying the electrical potential generates an electric field between the first and second electrodes, the combustion reaction tending to follow the electric field. 
     
     
         32 . The method of  claim 30 , wherein supporting the solid fuel includes supporting the solid fuel on a grate. 
     
     
         33 . The method of  claim 32 , wherein the grate is the first electrode. 
     
     
         34 . The method of  claim 30 , wherein the electrical potential includes an oscillating waveform. 
     
     
         35 . The method of  claim 34 , wherein the electrical potential includes a peak to peak magnitude greater than 10,000 V. 
     
     
         36 . The method of  claim 35 , wherein the electrical potential includes a peak to peak magnitude greater than 45,000 V. 
     
     
         37 . The method of  claim 34 , wherein applying the electrical potential includes applying the electrical potential between the grate and a third electrode positioned above the solid fuel and opposite the second electrode within the enclosure. 
     
     
         38 . The method of  claim 37 , wherein applying the voltage draws the combustion reaction to the second and third electrodes. 
     
     
         39 . The method of  claim 38 , wherein the second and third electrodes are positioned above the solid fuel and laterally from the solid fuel. 
     
     
         40 . The method of  claim 38  comprising inhibiting particulates generated by the combustion reaction from exiting a flue of the enclosure. 
     
     
         41 . The method of  claim 40 , wherein inhibiting particulates includes electrically attracting the particulates and/or the combustion reaction toward the second and third electrodes. 
     
     
         42 . The method of  claim 30 , wherein the second electrode is coupled to the enclosure by a first support. 
     
     
         43 . The method of  claim 42 , comprising cooling the first support with a cooling apparatus. 
     
     
         44 . The method of  claim 43 , wherein cooling the first support includes passing a cooling fluid through a tube positioned adjacent to the first support. 
     
     
         45 . The method of  claim 44 , wherein the cooling fluid is air. 
     
     
         46 . The method of  claim 45 , comprising passing the cooling fluid from the tube into the combustion volume. 
     
     
         47 . The method of  claim 30 , comprising applying the electrical potential from a voltage supply. 
     
     
         48 . The method of  claim 47 , comprising controlling the voltage supply with a control circuit. 
     
     
         49 . A system comprising:
 an enclosure defining a combustion volume;   a grate configured to support a solid fuel;   an oxidant source configured to supply oxidant to the combustion volume to support a combustion reaction of the solid fuel and the oxidant;   an electrode positioned above the grate;   a support that couples the electrode to the enclosure;   a cooling apparatus configured to cool the support; and   a voltage supply coupled to the grate and the electrode and configured to adjust a shape of the combustion reaction by applying a voltage between the electrode and the grate.   
     
     
         50 . The system of  claim 49 , wherein the cooling apparatus includes a tube disposed adjacent to the support and configured to pass a cooling fluid therethrough to cool the support. 
     
     
         51 . The system of  claim 49 , wherein the enclosure includes a ceramic material. 
     
     
         52 . The system of  claim 49 , wherein the electrode includes a ceramic material. 
     
     
         53 . The system of  claim 49 , including a flue configured to vent flue gas from the enclosure.