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:
A propulsion system is disclosed that uses metal fuel particles heated to a range from 3000° K to 6000° K by reaction with oxygen in air inside a cyclone combustor to form metal oxides that are retained and removed from the combustor for re-conversion to metal, while nitrogen in the air is heated to the temperatures that on supersonic exhaust propels 50,000 ton monohull ships to from 50 to 100 knots. The ship can accelerate by electromagnetic force from a MHD generator-accelerator rendered electrically conducting by alkali metal seed injection into the gas. Also disclosed are 10 MW to 1000 MW Closed Cycle MHD power plants fired by natural gas into a top half of a falling pebble bed heat exchanger that transfers 2000° K to 3000° K heat to a noble or diatomic gas in a bottom half of the exchanger that on exit is seeded with an alkali metal rendering the gas conducting.
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:
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.
Abstract:
Disclosed is an interplanetary rocket propulsion to Mars and the Moons of the nearer outer Planets by means of 6000° K temperature, 100 atmosphere pressure, power generation and propulsion systems that utilize a gas cooled nuclear reactor and metal powder combustion, in combination with water wherein dissociation into oxygen to react with certain metals to form on board retained metal oxides, and to heat the hydrogen from dissociated water as well as on-board liquid hydrogen that is seeded with an alkali metal for use in a linear, Faraday magnetohydrodynamic (MHD) generator that is coaxial with a MHD accelerator for propulsion, wherein water and probable metal sources on planetary bodies would provide rocket fueling by metal oxide reprocessing to metal and for manned permanent life support bases, and for search of high value minerals, gold, silver, aluminum, rare minerals, diamonds, for transport with their lesser gravity back to Earth.
Abstract:
Methods by which new or used boilers or furnaces ranging from small industrial to the largest utility units that are designed for coal or oil or natural gas or shredded waste or shredded biomass firing can substantially improve their technical operation and sharply reduce their capital and operating costs by implementing component modifications and process steps that (a) minimize the adverse impacts of coal ash and slag on boiler surfaces and particulate emissions thereby also facilitating the use of oil or gas designed boilers for coal firing, (b) drastically reduce the loss of water used to transport coal in slurry form to power plants, (c) essentially eliminate the combined total nitrogen oxides (NOx), sulfur dioxide (SO2), mercury (Hg), trace metals, and carbon dioxide (CO2) emissions, (d) separate and permanently sequester carbon dioxide released during combustion and (e) improve the coal and solid fuel combustion efficiency.
Abstract:
A process having three steps utilized individually or in combination to reduce nitrogen oxides, NOx, emissions from gas turbines. One or more injectors disperse very fine fuel droplets to achieve rapid and complete combustion in zone one immediately downstream of the fuel injectors. The second step uses one or more injectors inserted into the combustor to disperse water droplets throughout zone two, immediately downstream of zone one, to lower the gas temperature and suppress formation of thermal NOx,. The third step uses one or more injectors to disperse aqueous droplets containing a dissolved NOx reducing agent throughout zone three, immediately downstream of zone two, and whose gas temperature favors the reduction of NOx. Alternatively, the dissolved NOx reducing agent can be mixed with a liquid fuel to convert zone three into slightly fuel rich conditions, enabling nitrogen oxide reduction at higher gas temperatures.
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. The key element in this invention is that the aqueous droplet size distribution is optimized for the specific furnace dimension while the concentration of the reactants, urea or ammonia and lime or very fine limestone, is optimized for optimum reaction rates. Special injectors produce the different size droplets that vaporize throughout said gas zone, thereby distributing said lime or limestone particles and urea or ammonia gas molecules exclusively throughout the combustion gas zone being treated. Also disclosed is a system to produce said aqueous mixture and effectively accomplish this injection. This method can be combined with other NOx and SO2 reduction processes to sharply reduce overall NOx and SO2 emissions from the combustion gas effluent.
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. The spent gas leaving the channel passes through a seed metal condenser and gas cooler, and enters an inflatable balloon which captures the gas for subsequent reuse. The invention discloses critical design features that allow a compact, portable and reliable system.