Abstract: A method of and system for air-fuel injection for stable combustion in fuel combustors. It provides rapid mixing, continuous ignition and stable combustion under very fuel-rich and very fuel-lean conditions, mixtures that may even be beyond flammable limits. The rapid and intimate mixing are achieved by sizing, orienting and operating fuel and air orifices such that the reactant streams directly impinge, and the velocity head in the fluid in greater supply, in multiple orifices, is higher than the velocity head of the other reactant stream, by a factor of two (2) to five (5). The continuous ignition is achieved by preheating air to temperatures sufficiently high such that the resulting air-fuel mixture, after impingement and mixing, is above the fuel autoignition temperature.

Abstract: A method of multi-stage combustion of sulfur and nitrogen-bearing coal which provides high combustion efficiency while preventing formation of sulfur- and nitrogen-bearing air pollutants. In the first stage, a major fraction of the hydrocarbons is burned out of the fuel [stage (1a)] at high temperature and the sulfur bound in the coal is freed therefrom and is then captured by reaction with a solid basic compound such as limestone [stage (1b)] at relatively low temperature. In stage 2 the remaining hydrocarbons in the fuel are burned out, and the residual mixture of coal ash and calcium-sulfur compounds is melted, encapsulating the sulfur in the molten slag, and a major portion of the molten compounds is removed from the gas stream. In stage 3, oxidation of CO and H.sub.2 is almost entirely completed and combustion gases are substantially cooled by heat transfer to the working medium. In stage 4, combustion is finally completed in excess air.

Abstract: A combustion process for nitrogen- or for sulphur- and nitrogen-bearing fuels wherein fuel combustion is divided, by staged oxygen (preferably in the form of air) injection, into at least two combustion zones. The first combustion zone involves providing fuel-rich stoichiometric conditions under which nitrogen chemically bound in the fuel (i.e. fuel-bound nitrogen) is substantially converted to molecular nitrogen. The second (final) combustion zone comprises at least two stages. In the first stage of the final combustion zone, combustion products from the first combustion zone are further combusted under a condition of fuel-rich stoichiometry, preferably at an oxygen/fuel stoichiometric ratio of from about 0.80 to about 1.0 and at a temperature of less than about 2200 K. In the second stage of the final combustion zone, combustion products from the first stage are combusted at an oxygen/fuel stoichiometric ratio of greater than about 1.0 and at a temperature of less than about 1500 K.

Abstract: A combustion process for nitrogen- or for sulphur- and nitrogen-bearing fuels wherein fuel combustion is divided, by staged oxygen (preferably in the form of air) injection, into at least two combustion zones. The first combustion zone involves providing fuel-rich stoichiometric conditions under which nitrogen chemically bound in the fuel (i.e. fuel-bound nitrogen) is substantially converted to molecular nitrogen. The second (final) combustion zone comprises at least two stages. In the first stage of the final combustion zone, combustion products from the first combustion zone are further conbusted under a condition of fuel-rich stoichiometry, preferably at an oxygen/fuel stoichiometric ratio of from about 0.08 to about 1.0 and at a temperature of less than about 2200 K. In the second stage of the final combustion zone, combustion products from the first stage are combusted at an oxygen/fuel stoichiometric ratio of greater than about 1.0 and at a temperature of less than about 1500 K.

Abstract: A process for combusting a sulphur-bearing fuel is disclosed. A mixture of the fuel, a sulphur binding material and a sulphur retaining material is introduced into a first combustion zone. The mixture is combusted in the first zone under conditions of fuel-rich stoichiometry and temperature wherein substantially all of the sulphur is captured in a solid form by the sulphur binding material. The resulting captured sulphur compounds are then physically and/or chemically bound within or with the retaining material. Combustion products are thereby produced which include fuel-rich gases and solid flyash and slag containing mixtures of the captured sulphur and the binding and retaining materials. These combustion products are then further combusted in at least one additional fuel-rich combustion zone at temperatures above the fusion temperature of the solids, to melt the solids and to form complex, refractory mixtures and compounds containing the captured sulphur.

Abstract: The mechanism is used to dampen the recoil or kickback effects of a machine, such as a machine gun, jack hammer, or the like which generates short duration, high-amplitude unidirectional forces. The mechanism includes an ancillary mass interposed between the base and the recoil mass. A relatively stiff spring is engaged at one end to the recoil mass, which is in contact with the ancillary mass at the other end only over part of the recoil cycle. A constant force spring mechanism is interposed between the ancillary mass and the base and is engaged at one end to the base and may be engaged to the ancillary mass at the other end. The mechanism prevents motion of the recoil mass and reduces the maximum recoil force transmitted to the base by transferring the original short-duration, high-amplitude recoil driving force impulse first to the ancillary mass, in the form of momentum of the ancillary mass, and subsequently to the base as a longer duration, lower amplitude recoil force.

Abstract: The mechanism is used to dampen the recoil or kickback effects of a machine, such as a machine gun, jack hammer, or the like which generates short duration, high-amplitude unidirectional forces. The mechanism includes an ancillary mass interposed between the base and the recoil mass. A relatively stiff spring is engaged at one end to the recoil mass, which is in contact with the ancillary mass at the other end, only over part of the recoil cycle. A relatively soft spring is interposed between the ancillary mass and the base and is engaged at one end to the base and may be engaged to the ancillary mass at the other end. The mechanism prevents motion of the recoil mass and reduces the maximum recoil force transmitted to the base by transferring the original short-duration, high-amplitude recoil driving force impulse first to the ancillary mass, in the form of momentum of the ancillary mass, and subsequently to the base as a longer duration, lower amplitude recoil force.

Abstract: A method for substantially reducing emissions of nitrogenous compounds such as NO.sub.x formed during fuel combustion. The fuel is combusted with an oxygen-containing gas in an amount from about 45 to 75% of the total stoichiometric amount of oxygen required for complete combustion of the fuel. The resulting mixture of fuel and combustion products, including NO.sub.x, is maintained at a temperature of at least 1800.degree. K. for a time sufficient to reduce the NO.sub.x content of the mixture to a desired level. Thereafter, combustion may be completed in one or more additional zones at a temperature within the range of about 1600.degree. to 2000.degree. K. Alternatively, the mixture of combustion products and fuel having a reduced NO.sub.x content may be used for other applications without further combustion. For certain embodiments of the invention, various particulates may be added to the combustion zone so as to enhance the rate at which the NO.sub.x is destroyed.