Abstract:
An air nozzle for introducing secondary air into a furnace and including a housing provided with an inlet at one end thereof for receiving air and an outlet at the other end thereof for discharging the air. A damper is disposed in the housing in the path of the air for splitting the flow of the air into two flow streams which extend to different areas of the furnace and is adapted for pivotal movement in the housing to vary the amount of air flow in each of the streams and the discharge angle of one of the streams.
Abstract:
A method and an arrangement for supplying air to a recovery boiler. In the method, the air is supplied to the recovery boiler at at least one air supply level so that four vortices are formed therein, the vortices spinning, in pairs, in opposite directions to one another so that any two adjacent vortices always spin in opposite directions to one another. The arrangement comprises nozzles that are arranged to blow air so that four vortices are formed in the recovery boiler, any two adjacent vortices always spinning in opposite directions to one another.
Abstract:
This invention is directed to a method and apparatus for improving fluid flow and gas mixing in boilers. More particularly, this invention pertains to a method and apparatus for improved fluid flow and gas mixing in kraft recovery boilers for increased energy efficiency, reduced TRS emissions and increased capacity. The method of introducing air into a boiler furnace comprises: (a) introducing air through at least one opening located on at least a first wall of the interior of the furnace; and (b) introducing air through at least one second opening located on a second wall of the interior of the furnace opposed to the first wall at the same, or different, elevations. The method of introducing air into a boiler furnace may also comprise: (a) introducing air into the furnace in the form of a first set of small and large jets originating from one wall of the interior of the furnace; and (b) introducing air into the furnace in the form of a second set of small and large jets originating from the wall of the interior of the furnace opposite the first wall. The locations of the sources of the first set of small and large jets may be placed so that they oppose the sources of the second set of small and large jets, with small jets opposing large jets, and vice versa. The sizes of the jets may be regulated by varying opening size, number of openings in groups of openings, air pressure upstream of the openings, or combinations thereof.
Abstract:
A clustered concentric tangential firing system (12) particularly suited for use in fossil fuel-fired furnaces (10) and a method of operating such furnaces (10) equipped with a clustered concentric tangential firing system (12). The clustered concentric tangential firing system (12) includes a windbox (20), a first cluster of fuel nozzles (38,40) mounted in the windbox (20) and operative for injecting clustered fuel into the furnace (10) so as to create a first fuel-rich zone therewithin, a second cluster of fuel nozzles (68,70) mounted in the windbox (20) and operative for injecting clustered fuel into the furnace (10) so as to create a second fuel-rich zone therewithin, an offset air nozzle (56) mounted in the windbox (20) and operative for injecting offset air into the furnace (10) such that the offset air is directed away from the clustered fuel injected into the furnace (10) and towards the walls of the furnace (10), a close coupled overfire air nozzle (78) mounted in the windbox ( 20) and operative for injecting close coupled overfire air into the furnace (10), and a separated overfire air nozzle (90) mounted in the window (20) and operative for injecting separated overfire air into the furnace (10).
Abstract:
The known pulverized coal combustion method including the steps of separating pulverized coal mixture gas ejected from a vertical type coal grinder into thick mixture gas and thin mixture gas by a distributor, and injecting these thick and thin mixture gases, respectively, through separate burner injecting ports into a common furnace to make them burn, is improved so as to reduce both an unburnt content in the ash and a nitrogen oxide concentration in exhaust gas while maintaining an excellent ignition characteristic. The improvements reside in that an air-to-fuel ratio of the thick mixture gas is regulated to within the range of 1-2, while an air-to-fuel ratio of the thin mixture gas is regulated to within the range of 3-6, and the range of a degree of pulverization of the pulverized coal is regulated to 100 mesh residue 1.5% or less. The degree of pulverization of the pulverized coal fed to the distributor is regulated either by adjusting the rotational speed of a rotary type classifier in the grinder or by adjusting the angles formed between classifying vanes, rotating about the axis of the rotary type classifier, and the direction of rotation.
Abstract:
PROBLEM TO BE SOLVED: To provide a system and method for reducing NOx and CO excretion in a combustion apparatus employing a plurality of burners. SOLUTION: This furnace combustion system comprises the plurality of burners and an oxidant port that is arranged between at least two burners and is surrounded by these burners. Each burner is separated from other burners, combusts the flow of one fuel or other fuel with the flow of one oxidant or other oxidant to generate flame. The oxidant port sends the jet of at least one of the first oxidant or other oxidant axially to the gap between at least two flames. At least one jet is sent from the oxidant port at a controlled flow rate. COPYRIGHT: (C)2007,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a method for diminishing Hg in an exhausted gas from a combustion of lower grade coals (32, 52) in a combustion system (16). SOLUTION: The method is composed of a step for burning the coals (32, 52) with a low content of Cl in the combustion system, a step for exhausting Cl into the flue gas by burning the coal (34, 54) with the high content of Cl in the combustion system, a step for oxidizing Hg by reacting elemental Hg and Cl exhausted in the flue gas, a step for adsorbing at least a part of mercury oxide formed by burning the coal together with an adsorbent in the flue gas, and a step for recovering both the adsorbent and mercury oxide in combustion waste treatment systems (19, 26). Thus, elemental Hg (Hg 0 ) is exhausted into the flue gas formed by burning the lower grade coal. COPYRIGHT: (C)2005,JPO&NCIPI