Furnaces – Refuse incinerator – Including air supply means extending vertically within refuse
Patent
1996-08-28
1998-06-23
Lazarus, Ira S.
Furnaces
Refuse incinerator
Including air supply means extending vertically within refuse
110346, 110347, 1101056, F23G 500
Patent
active
057690081
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The invention relates to heat engineering and more particularly, to furnaces for burning organic fuel, and it can be most successfully used for burning powdered fuel.
BACKGROUND OF THE INVENTION
When designing furnaces, a particular stress is laid on providing the complete combustion of the fuel, which is one of the determining factors for a more economical and environmentally oriented performance. The completeness of fuel combustion is known to be increased by a thorough intermixing of fuel and air and using a higher combustion temperature. An increased temperature in the burning zone, however, brings about an enhanced emission of nitrogen oxides due to formation of the so-called "thermal" nitrogen oxides as a result of air nitrogen oxidation. In addition, an increased flame temperature leads to slagging the heat-receiving furnace screens as well as to other negative results.
On the other hand, the reduction of the burning zone temperature by recirculating the combustion products, by a coarser grinding of the fuel, etc., will result in a less economical fuel combustion because of a sharp drop in the combustion reaction rate and consequently, a greater incompleteness of the fuel combustion.
The requirement for a complete fuel combustion also specifies the necessary amount of oxygen (air) supplied to the furnace. In order to burn a particular amount of fuel a strictly definite amount of oxygen is needed. In the case of its deficiency, incomplete burning of fuel occurs, with carbon monoxide formed in the process, with produces a detrimental effect on the environment. However, a considerable increase in the amount of air (oxygen) supplied is not desirable either, because in this case, there is an increased discharge into atmosphere of the excess air (oxygen) heated in the furnace, but not reacting with the fuel, which impairs the cost-effectiveness of the furnace and the entire boiler unit. Therefore, when designing the fuel combustion process, oxygen (air) is generally supplied with some excess.
In the majority of known solid fuel-fired furnaces, the excess-air coefficient is equel to 1.2, since this figure is most favorable in terms of cost-effectiveness. However, it is with such air (oxygen) excess that the maximum discharge of the fuel nitrogen oxides involved in oxidation of the nitrogen contained in the fuel is known to occur (cf. I. Ya. Sigal "Protection of Atmospheric Air from Contamination by Fuel Combustion Products", 1988, Nedra, Leningrad). The fuel nitrogen oxides are produced in the initial secton of the flame, where volatile components are released from the fuel (i.e. its thermal decomposition products).
According to present-day notions, a reduced nitrogen oxide concentration in the combustion products can be achieved by an optimized organization of three major zones in the flame, namely, zone of ignition and active combustion, zone of reduction, and zone of oxidation (reburning).
The ignition and active combustion zone is generally located in the vicinity of the burners. It is the bulk of the fuel that is ignited and burnt out in this zone. The reduction zone may be arranged in any part of the furnace chamber and is characterized by oxygen deficiency. Because of this, as the fuel interacts with the oxidizing agent (i.e. oxygen), partial combustion products (such as carbon monoxide) are formed in this zone, which interact with other oxides, including nitrogen oxides, depriving them of oxygen and reducing to molecular nitrogen. The oxidation zone may be located in any region of the furnace, provided it contains excess oxygen. The incomplete fuel combustion products coming from other zones are further oxidized in this area, for example, transforming the harmful carbon monoxide into a reletively safe carbon dioxide.
Known in the art is a furnace (see G. N. Levit "Pulverization at Heat-Electric Generation Plants", 1991, Energoatomizdat (Moscow), p.132, Fig. 7.2) comprising a vertical combustion chamber having burners for air-fuel mixture supply mounted on its walls. The b
REFERENCES:
patent: 4246853 (1981-01-01), Mehta
patent: 4308806 (1982-01-01), Uemura et al.
patent: 4501204 (1985-02-01), McCartney et al.
patent: 4655148 (1987-04-01), Winship
patent: 4715301 (1987-12-01), Bianca et al.
patent: 4854249 (1989-08-01), Khinkis et al.
patent: 4993332 (1991-02-01), Boross et al.
patent: 5199357 (1993-04-01), Garcia-Mallol
patent: 5495813 (1996-03-01), Chapman et al.
Akhmedov Javad Berovich
Finker Felix Zalmanovich
Glazman Mark Semenovich
Kubishkin Igor Borisovich
Sobczuk Czeslaw
Lam Nhat-Hang H.
Lazarus Ira S.
Maloe Gosudarstvennoe Vnedrencheskoe Predpriyatie "Politekhenerg
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