Abstract:
Fuel such as coal is combusted in a staged combustion device in a method comprising feeding into a first combustion stage of said furnace said fuel and gaseous oxidant containing more than 21 vo. % oxygen, and preferably 21.8 to 29 vol. % oxygen, at a stoichiometric ratio below that which, if the stage were operated with air as the only oxidant, would produce the same amount of Nox, and combusting said fuel with said gaseous oxidant in said combustion stage to produce combustion products and unburned fuel.
Abstract:
A method for operating a boiler using oxygen-enriched oxidants includes introducing oxygen-enriched air, or oxygen and air, in which the oxygen concentration ranges from about 21% to about 100 % by volume. Fuel and oxygen-enriched air are introduced into the combustion space within the steam-generating boiler. The fuel and oxygen-enriched air is combusted to generate thermal energy. At least a portion of the flue gases are collected and at least a portion are recirculated through the boiler. In the steam-generating boiler, the oxygen-enriched oxidant is introduced at one or more locations within the radiation zone and the convection zone of the boiler. Additionally, flue gas is collected an recirculated into one or more locations within the radiation zone and/or the convection zone of the boiler. The amount of oxygen enrichment and the total gas flow through the boiler is controlled so as to maintain the heat transfer patterns within the boiler at the originally-design specification for operation by air combustion.
Abstract:
Sinking of a charge in a cross-sectional direction of a melting furnace is made uniform, poor heat-exchange between the charge and a gas due to improper sinking of the charge and local concentration of a gas flow is reduced to minimum, a melting condition of wastes is stabilized irrespective of the composition of the wastes, and a charge of a treating speed of the wastes is restricted, too. A plurality of lower stage tuyeres are disposed vertically in a burning/melting zone, carbonaceous mass-like inflammable matters are mainly burnt by supplying a combustion support gas, a plurality of upper stage tuyeres are disposed vertically in a plurality of stages at the positions above the tuyeres, and a part of the wastes is burnt by supplying the combustion support gas. In this instance, the combustion support gas equivalent to oxygen content of 130 to 600 Nm /t of wastes is supplied, and the combustion support gas is supplied from the upper stage tuyeres so that the proportion of the oxygen content from the upper tuyeres is 0.2 to 0.8 of the sum of those of the lower and upper stages. Further, the supply quantity is controlled so that the oxygen content supplied from the lower stage tuyeres is at least 0.8 times the theoretical oxygen content of the carbonaceous mass-like inflammable matters, and the exhaust gas temperature on the packing layer of the wastes is set to 150 to 700 DEG C.
Abstract:
An X-ray examination apparatus (1) comprises a filter (4) which is arranged between the X-ray source (2) and the X-ray detector (3). The X-ray filter comprises a large number of filter elements (5); the X-ray absorptivity of said filter elements can be adjusted by controlling the quantity of X-ray absorbing liquid (6) in the filter elements. The filter elements are formed by metal capillary tubes, or the wall of the capillary tubes is provided with a metal layer (7). On the metal layer there is provided a dielectric layer (8) and the dielectric layer is covered by a coating layer (9). The dielectric layer is, for example a glass, parylene or polystyrene layer. The coating layer is, for example a Teflon, silane of siloxane layer. The dielectric layer can be dispensed with when a Teflon coating layer is used.