Electrically controlled combustion system with contact electrostatic charge generation

Abstract

A system for electrically controlling a combustion reaction includes a charging mechanism with a surface of a charging material with a work function that is sufficiently different from a work function of a charge carrier material to be capable of undergoing contact electrostatic charging. The charge carrier material is contacted with the charging material to impart an electrostatic charge to the charge carrier material, which is then fed to the combustion reaction to introduce a charge corresponding to the electrostatic charge. An aspect of the combustion reaction is controlled by application, to the combustion reaction, of electrical energy, characteristics of which are selected to interact in a predictable way with the combustion reaction.

What is claimed is: 
     
         1 . A system for controlling a combustion reaction, comprising:
 a charging mechanism configured to apply an electrostatic charge to particles within a flow of charge carrier material, and to subsequently introduce the flow of charge carrier material to a combustion reaction.   
     
     
         2 . The system of  claim 1 , comprising a burner configured to support the combustion reaction, and wherein the charging mechanism is configured to apply the electrostatic charge to a fuel passing through the burner. 
     
     
         3 . The system of  claim 1 , comprising a burner configured to support the combustion reaction, and wherein the charging mechanism is configured to introduce the flow of charge carrier material to the combustion reaction at a location that is downstream from the burner, with reference to a flow of fuel through the burner. 
     
     
         4 . The system of  claim 1 , wherein the charging mechanism comprises a structure that includes surfaces of a contact electrostatic charging material, and a charge carrier feeder mechanism, configured to direct the flow of charge carrier material into contact with the contact electrostatic charging material. 
     
     
         5 . The system of  claim 4 , wherein the contact electrostatic charging material has a work function of no less than about 4 electron volts. 
     
     
         6 . The system of  claim 4 , wherein the contact electrostatic charging material has a work function of no less than about 4.6 electron volts. 
     
     
         7 . The system of  claim 4 , wherein the charge carrier feeder mechanism is further configured to introduce the flow of charge carrier material to the combustion reaction. 
     
     
         8 . The system of  claim 4 , wherein the charge carrier feeder mechanism includes the surfaces of the contact electrostatic charging material. 
     
     
         9 . The system of  claim 4 , comprising a burner configured to support the combustion reaction, and wherein the charge carrier feeder mechanism is further configured to introduce the flow of charge carrier material to the combustion reaction via an outlet of the burner. 
     
     
         10 . The system of  claim 9 , wherein the charge carrier feeder mechanism is configured to accommodate a flow of a dielectric liquid hydrocarbon as fuel for the combustion reaction. 
     
     
         11 . The system of  claim 9 , wherein the charge carrier feeder mechanism is further configured to introduce the flow of charge carrier material to a flow of fuel that passes through the burner. 
     
     
         12 . The system of  claim 9 , wherein the burner is configured to accommodate a flow of coal as fuel for the combustion reaction. 
     
     
         13 . The system of  claim 12 , wherein the contact electrostatic charging material has a work function of no less than about 3.7 electron volts. 
     
     
         14 . The system of  claim 12 , wherein the contact electrostatic charging material has a work function of no more than about 3.4 electron volts. 
     
     
         15 . The system of  claim 4 , comprising a charge carrier feeder controller configured to control operation of the charge carrier feeder mechanism. 
     
     
         16 . The system of  claim 15 , wherein the charge carrier feeder controller is configured to selectively control a rate at which the flow of charge carrier material is introduced to the combustion reaction. 
     
     
         17 . The system of  claim 15 , wherein the charge carrier feeder controller is configured to selectively control a rate at which the charging mechanism applies the electrostatic charge to the flow of charge carrier material. 
     
     
         18 . The system of  claim 4 , wherein the charge carrier feeder mechanism includes a contact electrostatic generator. 
     
     
         19 . The system of  claim 18 , wherein the charge carrier feeder mechanism includes a controller configured to control operation of the contact electrostatic generator. 
     
     
         20 . The system of  claim 1 , comprising an electrode positioned and configured to apply electrical energy to the combustion reaction. 
     
     
         21 . The system of  claim 20 , comprising an electrodynamic system that includes the electrode, and a voltage source operatively coupled to the electrode and configured to supply a voltage signal to the electrode. 
     
     
         22 . The system of  claim 21 , wherein the electrodynamic system comprises a controller configured to control operation of the electrode and voltage source. 
     
     
         23 . The system of  claim 22 , wherein the electrodynamic system is configured to apply the electrical energy with a polarity that corresponds to a polarity of the electrostatic charge. 
     
     
         24 . The system of  claim 22 , wherein the electrodynamic system is configured to apply the electrical energy with a polarity that is opposite a polarity of the electrostatic charge. 
     
     
         25 . The system of  claim 22 , wherein the controller is configured to select a polarity of the electrical energy according to a polarity of the electrostatic charge and an aspect of the combustion reaction that is to be controlled. 
     
     
         26 . The system of  claim 20 , comprising an electrodynamic system that includes the electrode, and a voltage source operatively coupled to the electrode and configured to supply a voltage signal to the electrode. 
     
     
         27 . The system of  claim 1 , comprising a charge carrier collector mechanism configured to recover charge carrier material from the combustion reaction. 
     
     
         28 . The system of  claim 28 , wherein the charge carrier collector mechanism is configured to recover the charge carrier material from a flow of flue gas produced by the combustion reaction. 
     
     
         29 . The system of  claim 28 , wherein the charge carrier collector mechanism is configured to return the recovered charge carrier material to the charging mechanism. 
     
     
         30 . The system of  claim 28 , wherein the charge carrier collector mechanism comprises a recovery electrode positioned and configured to electrical energy to the combustion reaction. 
     
     
         31 . A method for controlling a combustion reaction, comprising:
 applying an electrostatic charge to a flow of charge carrier material;   applying an electrical charge to a combustion reaction by introducing the flow of charge carrier material to the combustion reaction; and   controlling an aspect of the combustion reaction by applying, to the combustion reaction, electrical energy selected to interact with the applied electrical charge.   
     
     
         32 . method of  claim 31 , comprising supporting the combustion reaction. 
     
     
         33 . The method of  claim 31 , wherein:
 supporting a combustion reaction includes providing a flow of fuel via a burner; and   applying an electrostatic charge to a flow of charge carrier material includes applying the electrostatic charge to the flow of fuel.   
     
     
         34 . The method of  claim 31 , wherein:
 the flow of fuel includes coal; and   applying an electrostatic charge to a flow of charge carrier material includes applying the electrostatic charge to particles of coal in the flow of fuel.   
     
     
         35 . The method of  claim 31 , wherein applying an electrostatic charge to a flow of charge carrier material includes directing the flow of charge carrier material into contact with a contact electrostatic charging material. 
     
     
         36 . The method of  claim 35 , wherein directing the flow of charge carrier material into contact with a contact electrostatic charging material includes directing the flow of charge carrier material into a sliding or rubbing contact with the contact electrostatic charging material. 
     
     
         37 . The method of  claim 35 , wherein directing the flow of charge carrier material into contact with a contact electrostatic charging material includes moving a charging structure that includes the contact electrostatic charging material to intersect the flow of charge carrier material. 
     
     
         38 . The method of  claim 35 , wherein applying an electrostatic charge to a flow of charge carrier material includes directing the flow of charge carrier material into contact with a contact electrostatic charging material that has a work function value that is different from a work function value of the charge carrier material at least about 0.1 electron volts. 
     
     
         39 . The method of  claim 35 , wherein applying an electrostatic charge to a flow of charge carrier material includes directing the flow of charge carrier material into contact with a contact electrostatic charging material that has a work function value of material at least about 4.6 electron volts. 
     
     
         40 . The method of  claim 31 , wherein applying electrical energy selected to interact with the applied electrical charge includes selecting a polarity of the applied electrical energy according to a polarity of the electrostatic charge. 
     
     
         41 . The method of  claim 31 , wherein applying an electrostatic charge to a flow of charge carrier material includes applying an electrostatic charge to a flow of charge carrier material that is substantially nonreactive in the combustion reaction. 
     
     
         42 . The method of  claim 41 , comprising recovering charge carrier material from the combustion reaction. 
     
     
         43 . The method of  claim 42 , comprising returning the recovered charge carrier material to the flow of charge carrier material.