Abstract:
A porous, low-conductivity material formed of metal or ceramic fibers provides the burner face of a gaseous fuel combustor for gas turbines capable of minimizing nitrogen oxides (NOX) emissions in the combustion product gases. A preferred burner face, when fired at atmospheric pressure, yields radiant surface combustion with interspersed areas of blue flame combustion. A rigid but porous mat of sintered metal fibers with interspersed bands of perforations is illustrative of a preferred burner face that can be fired at pressures exceeding 3 atmospheres at the rate of at least about 500,000 BTU/hr/sf/atm. By controlling the excess air admixed with the fuel in the range of about 40% to 150% to maintain an adiabatic flame temperature in the range of about 2600° F. to 3300° F., the NOX emissions are suppressed to 5 ppm and even below 2 ppm. At all times, carbon monoxide and unburned hydrocarbons emissions do not exceed 10 ppm, combined.
Abstract:
The present invention discloses metallic fiber boards having catalytic functionality and processes for producing the same. The boards are formed from a mesh of metallic fibers, each fiber having a first layer of an oxide and a second layer of a porous oxide. A catalyst, either disposed on the surface of the second layer, or dispersed within the second layer, provides catalytic functionality to the fiber board. The first layer is produced by thermal oxidation of the metallic fibers, while the second layer and catalyst are produced by thermal decomposition of precursor materials applied to the fiber board while in solution, typically as a spray of atomized droplets. The resulting boards are used to catalyze the combustion of hydrocarbons, especially methane, and particularly in household boilers.
Abstract:
A gas burner has a perforated, hollow body around and defining a combustion chamber. Gaseous fuel is fed to one side of the body, combustion occurs on the other side and the perforations provide a spatial connection between the fuel feed side and the combustion side. The new burner reduces exhaust gas emissions and offers a wide range of performance in the amount of heat energy provided, in the permissible range of gas pressure and in the range of fuels and fuel/air mixtures that can be used with it.
Abstract:
The disposal of troublesome substances, especially global-warming halogenated compounds is difficult enough, but is particularly difficult when associated with particulate-forming matter, such as silane and arsine commonly encountered in waste gas streams of the semiconductor industry. The combustive destruction of the troublesome substances in such a waste gas stream is simply and successfully achieved by injecting the stream admixed with fuel gas into a combustion zone surrounded by the radiant surface of a foraminous gas burner that is separately fed fuel gas and excess air sufficient to burn all the combustibles entering the combustion zone. A simple apparatus integrates the combustion zone with a quenching zone for the combustion product stream.
Abstract:
An inshot-gas burner for gas burning furnaces and other gas burning appliances has a flame retention head at the outlet formed from porous ceramic foam with a central opening through which a flame may project. A velocity reducing insert is located within the mixing chamber of the burner for reducing the velocity of the mixture received by the head in the area spaced about the central openings so that the head is radiant in operation. The porosity of the foam is in the order of 20 to 60 pores per inch. When radiant, the head permits the burner to operate at higher primary aerations, and provides faster burning velocity and thus lower residence time, and additionally provides a lower maximum temperature and a stable quiet flame. This permits the burner to emit low amounts of nitric oxide and nitrogen dioxide without increasing the amount of carbon monoxide emissions. The head may be formed from other materials and the velocity reduction may be provided by other structures, one of which is a composite head having restrictive discreet porting.
Abstract:
An apparatus for controllably mixing air with a combustible gas to form a combustible mixture. The apparatus includes a housing having an internal gas mixing chamber in communication with an elongated narrow gas inlet throat which is formed by a pair of converging, smoothly curved walls. A gas injector manifold is disposed proximate the gas inlet throat and is arranged so that air flows around and about the injector as it is drawn into the inlet throat either by a fan or through aspiration. Due to the novel aerodynamic shape of the walls which form the gas inlet throat, the combustible gas is thoroughly and efficiently mixed with the air to produce a combustible mixture that burns efficiently with a minimum of harmful emissions being produced.
Abstract:
The combustion apparatus is composed of: a porous burner component being made of a permeable metallic material and having a centrally located first region (11a, 11aa, 11ba, 11ca) where the fuel-air mixture is ejected and the red heat condition is formed on the surface of downstream side and having a second region (10b, 11ab, 11bb, 11cb) being located outside of the first region to recover heat from high temperature product gas coming from a combustion chamber, wherein the heat recovered in the second region is conducted to the first region; the combustion chamber (8) being located covering both the first region and the second region and enclosing these regions; a fuel-air mixture supply passage (7) to feed the fuel-air mixture into the central first region; and an exhaust passage (6) to lead the flue gas discharged from the second region to the exhaust opening (9), which exhaust passage is located adjacent to and outside of the fuel-air mixture supply passage and is separated by a separation wall (4) therefrom. A combustion apparatus is further provided with a porous burner component having a third region (10c, 11ac, 11bc, 11cc) through which the fuel-air mixture permeates, which third region is located at outside of the second region, and is provided with a peripheral fuel-air mixture supply passage (5) to lead the fuel-air mixture permeated through the third region into the central fuel-air mixture supply passage.
Abstract:
The combustion apparatus having a heat-recirculating function comprises: a porous burner component (4) being made of permeable metallic material and having a first region (4a) through which a fuel-air mixture flows and is ejected therefrom into the combustion chamber at a velocity higher than the burning velocity of the fuel-air mixture to form a flame base on the periphery of the fuel-air mixture ejection area and having a second region (4b) being located adjacent to and outside of the first region to recover heat from high temperature product gas generated from the combustion of the fuel-air mixtures by red-heating the surface of the second region on the combustion chamber side while the product gas is penetrating through the burner component (4), wherein the heat recovered in the second region is conducted to the first region; the combustion chamber (5) being located to cover both the first region (4a) and the second region (4b) and enclosing these regions, and a cylindrical wall (6) separating a fuel-air mixture supply passage (9) from a product gas exhaust passage (10 ) by placing the fuel-air mixture supply passage at the inside thereof. Such a combustion apparatus having a heat-recirculating function comprises: a porous burner component (4) having more than one first region (4a) and more than one second region (4b); a combustion chamber (5); and more than one cylindrical wall (6).
Abstract:
A cooking assembly for a cooker or a cooking top and comprises a cooking plate (1) and at least one heat generator (200) enabling a receptacle to be heated without coming directly into contact therewith. The cooking plate (1) includes an opening (4) associated with each heat generator (200) and enabling said generator to act directly, together with retractable closure means such as a moving plug (203) associated with each opening (4) to close said opening when the heat generator (200) is not in use, the moving plug (203) then being flush with the top surface (2) of the cooking plate (1), motorized means being provided for retracting said moving plug in order to unmask the heat generator so that it can be put into use. The invention is applicable to cooking assemblies for gas cookers and/or electric cookers having a cooking plate made of molded glass, of vitroceramic, or of agglomerated inorganic fibers.
Abstract:
A nested fiber gas burner is formed with a burner body having an inlet on one end and a burner port on the other end. A mat of fibers is formed from discrete fibers of material randomly deposited into a mold having the general configuration of the burner port. After the fibers are deposited in the mold to a depth of about 0.5 inch, they are heated to a temperature of about 1200.degree. C. for about two hours, which causes the fibers to bond together. Thus bonded, the fiber mat is secured in place in the burner port.