Abstract: A method for the combined reduction of sulfur dioxide, SO2, and nitrogen oxides, NOx, in the gas stream of a furnace from the combustion of fossil fuels is disclosed. In a narrow gas temperature zone in a furnace, NOx is converted to nitrogen by reaction with a reducing agent such as urea or ammonia with negligible residual ammonia and other reaction pollutants. In about this same temperature zone, SO2 will react with calcium oxide particles, derived from the calcination of lime, Ca(OH)2, or limestone, CaCO3, to form CaSO4 particles. A wide size distribution of aqueous droplets, containing dispersed lime or very fine limestone particles and dissolved urea or ammonia, is injected at the outer edge of the furnace gas zone at which the SO2 and NOx reduction reaction are effective.

Abstract: Nitrogen oxides, NOx, resulting from the excess air combustion of solid fuels in a combustor or burner in a furnace are reduced. By introducing sufficient additional fuel to the combustion gases in the furnace downstream of the primary combustion zone, a fuel rich gas zone is created in a temperature range that favors the conversion of NOx to nitrogen, N2. Further downstream sufficient additional air is added to complete the combustion of any unburned fuel. Alternatively, the fuel rich gas zone can be confined to a central region of the furnace. In that case, final combustion takes place when the fuel rich gas mixes with the untreated gas further downstream in the furnace. The preferred embodiment of this invention is to introduce the additional fuel in said downstream combustion zone as solid particles dispersed in aqueous droplets of varying size that vaporize throughout the furnace gas zone being treated. The dispersed solid fuel particles burn as they evolve from the droplets.

Abstract: A method for the combined reduction of sulfur dioxide, SO2, and nitrogen oxides, NOx, in the gas stream of a furnace from the combustion of fossil fuels is disclosed. In a narrow gas temperature zone in a furnace, NOx is converted to nitrogen by reaction with a reducing agent such as urea or ammonia with negligible residual ammonia and other reaction pollutants. In about this same temperature zone, SO2 will react with calcium oxide particles, derived from the calcination of lime, Ca(OH)2, or limestone, CaCO3, to form CaSO4 particles. A wide size distribution of aqueous droplets, containing dispersed lime or very fine limestone particles and dissolved urea or ammonia, is injected at the outer edge of the furnace gas zone at which the SO2 and NOx reduction reaction are effective.

Abstract: Method for reducing nitrogen oxides (NO.sub.x) in the gas stream from the combustion of fossil fuels is disclosed. In a narrow gas temperature zone, NO.sub.x is converted to nitrogen by reaction with urea or ammonia with negligible remaining ammonia and other reaction pollutants. Specially designed injectors are used to introduce air atomized water droplets containing dissolved urea or ammonia into the gaseous combustion products in a manner that widely disperses the droplets exclusively in the optimum reaction temperature zone. The injector operates in a manner that forms droplet of a size that results in their vaporization exclusively in this optimum NO.sub.x -urea/ammonia reaction temperature zone. Also disclosed is a design of a system to effectively accomplish this injection.

Abstract: A compact portable apparatus and method for heating gases for periods ranging from about one tenths of a second to several minutes to temperatures as high as 2700.degree. Celsius in 4 hrs. Graphite or metal oxide spherical pebbles which are placed in an externally thermally insulated cylindrical bed. The pebbles enclose and are heated by electrical resistive elements from which they are physically isolated. High heat storage density is achieved by designing the bed for high pressure loss operation and gas flow is in the downward direction. The bed is pressurized prior to initiating the gas flow with a quick acting valve or burst disc placed at the heater outlet. Typical applications are as a heat source for magnetohydrodynamic channels or wind tunnels. For magnetohydrodynamic applications a pulsed liquid seed metal injection method producing micrometer diameter liquid particles is disclosed.

Abstract: Apparatus and method for non-equilibrium MHD generation including a cyclone combustor, in which particulate metal is oxidized to form non-gaseous by-products. A low molecular weight working gas, such as hydrogen or helium, is energized by mixture thereof in said cyclone generator. Substantially non-gaseous oxidation by-products are removed by cyclonic action from the working fluid. The thus energized working fluid, with its swirling movement neutralized by the introduction of a further portion of working fluid, is then delivered through a nozzle to the MHD generator.

Abstract: Coal combustion and the capture of pollutants are optimized by a method which applies two mechanisms for sulphur capture, one in which pulverized coal particles suspended in the gas stream in the injection zone of the combustor are affected by reaction with a suspended sorbent, and another in which the particles are reentrained in the gas stream by a "sand storm" effect near the wall of the combustor. Use of the two mechanisms results, in commercial scale cyclone combustors, in 70 to 90% sulphur capture at economical Ca/S ratios. The method also minimizes emission of ash by removal from the pulverized coal fuel particles too small to be retained in the combustor and too large to be completely burned in the combustor, minimizes reevolution of sulphur compounds from slag by rapid and continuous removal of slag from the combustor, minimizes emission of NO.sub.x pollutants by maintaining a favorable overall fuel-rich stoichiometry.

Abstract: An air-cooled cyclone coal combustor comprises a horizontally disposed shell, provided with a non-sacrificial refractory liner. The liner is surrounded by an array of air-cooling tubes, the tubes serving both to cool the liner and to physically support and reinforce it. Air cooling in the manner disclosed facilities precise control of the thickness and flow of slag on internal walls of the combustor, so as to avoid reevolution from the slag of the sulfur pollutants. Pulverized coal fuel and a pulverized sulfur sorbent (limestone or the like), as well as primary and secondary combustion air, are introduced into the chamber at an end wall. The cooling air, heated regeneratively in the cooling tubes, provides the secondary air, and is introduced in the chamber in helical flow, at a radius outwardly from the radius at which the solids and primary combustion air are introduced into the chamber. A thermally insulated nozzle provides an outlet for combustion gases.

Abstract: Ceramic electrode is brazed to compliant support, a plurality of curved metal strips mounted on edge, opposite edges being brazed to cooling block. Compliance permits expansion and distortion of electrode when heated without development of stress damaging to brazed joints or to electrode.