Abstract:
A new combustion chamber design for a quench gasifier. Electrical heating is used in the throat area of the combustion chamber to achieve temperatures up to 3500° F. to melt ash deposits and to increase carbon conversion (reduce soot production). Silicon carbide and/or silicon nitride refractory materials are used in the hot face of the throat to withstand high temperatures and high temperature shocks. The proposed design reduces the capital cost of a gasification plant by eliminating the need for soot recovery and recycle system. This design also reduces the operating cost of the gasification plant by decreasing the frequent refractory damages that have been experienced in the throat area of the existing quench gasifiers.
Abstract:
A combustion method and apparatus in which combustible matter, e.g., waste matter, coal, etc., is gasified to produce a combustible gas containing a sufficiently large amount of combustible component to melt the ash by its own heat. A fluidized-bed furnace (2) has an approximately circular horizontal cross-sectional configuration. A moving bed (9), in which a fluidized medium settles and diffuses, is formed in the central portion of the furnace, and a fluidized bed (10), in which the fluidized medium is actively fluidized, is formed in the peripheral portion in the furnace. The fluidized medium is turned over to the upper part of the moving bed (9) from the upper part of the fluidized bed (10), thus circulating through the two beds. Combustible matter (11) is cast into the upper part of the moving bed (9) and gasified to form a combustible gas while circulating, together with the fluidized medium. The amount of oxygen supplied to the fluidized-bed furnace (2) is set so as to be the same contained in an amount of air not higher than 30% of the theoretical amount of combustion air. The temperature of the fluidized bed (10) is maintained at 450° C. to 650° C. so that the combustible gas produced contains a large amount of combustible component. The combustible gas and fine particles produced in the fluidized-bed furnace (2) are supplied to a melt combustion furnace where they are burned at high temperature, and the resulting ash is melted.
Abstract:
A combustion apparatus in which combustible matter, e.g., waste matter, coal, etc., is gasified to produce a combustible gas containing a sufficiently large amount of combustible component to melt ash by its own heat. A fluidized-bed furnace has an approximately circular horizontal cross-sectional configuration. A moving bed, in which a fluidized medium settles and diffuses, is formed in the central portion of the furnace, and a fluidized bed, in which the fluidized medium is actively fluidized, is formed in a peripheral portion in the furnace. The fluidized medium is turned over to the upper part of the moving bed from the upper part of the fluidized bed, thus circulating through the two beds. Combustible matter is cast into the upper part of the moving bed and gasified to form a combustible gas while circulating, together with the fluidized medium. The amount of oxygen supplied to the fluidized-bed furnace is set so as to be not higher than 30% of the theoretical amount of oxygen necessary to combust the combustible matter. The temperature of the fluidized bed is maintained at 450.degree. C. to 650.degree. C. so that the combustible gas produced contains a large amount of combustible component.
Abstract:
A method for gasifying or combusting solid, carbonaceous material in a circulating fluidized bed reactor. Particles are separated from the product gas at least in two stages so that in the first stage, mainly coarser, so-called circulating particles are separted and returned to the reactor. In the second stage, fine carbonaceous particlates are separated from the gas and are made to agglomerate at a raised temperature. Coarser particles thus recieved are returned to the reactor through a return duct together with circulating particles. Adhesion of agglomerating particles to the walls of the duct is prevented preferably by leading hot particulates to the center of the duct and circulating particles to the walls of the duct.
Abstract:
An apparatus and process for control and maintenance of fluidized beds under non-steady state conditions. An ash removal conduit is provided for removing solid particulates from a fluidized bed separate from an ash discharge conduit in the lower portion of the grate supporting such a bed. The apparatus and process of this invention is particularly suitable for use in ash agglomerating fluidized beds and provides control of the fluidized bed before ash agglomeration is initiated and during upset conditions resulting in stable, sinter-free fluidized bed maintenance.
Abstract:
In a fluidized bed gasification system an ash removal system to reduce the particulate ash to a maximum size or smaller, allow the ash to cool to a temperature lower than the gasifier and remove the ash from the gasifier system. The system consists of a crusher, a container containing level probes and a means for controlling the rotational speed of the crusher based on the level of ash within the container.
Abstract:
An apparatus for withdrawing agglomerated solids, e.g. ash, from a fluidized bed of finely divided solid hydrocarbonaceous material, e.g. coal, is described. Agglomeration is effected by a high temperature reaction between the inorganic constituents of the hydrocarbonaceous material in the fluidized bed environment. A venturi is utilized to serve as a passage for withdrawing the agglomerated solids from the fluidized bed. Spiral or other descending ridges are positioned on the interior surface of the constricted cylindrical opening of the venturi. A tube, through which reaction gases pass, is centrally disposed within the constricted cylindrical opening to permit variable and increased rates of agglomerate discharge with improved separation and classification of the solid materials.
Abstract:
A process and pressurized, gasification reactor apparatus for converting combustible carbon containing materials such as coal char and other carbonaceous solids or carbonaceous solids/heavy oil combinations to an intermediate heating value fuel gas. The gasification reactor includes an insulated fluidized bed reactor chamber, an upper reactor housing for a freely suspended bayonet bundle type heat exchanger for (a) superheating incoming saturated steam and (b) cooling outgoing high temperature product gas, and a lower reactor housing structure which includes a free-floating, conically-shaped perforated plenum chamber. The superheated steam and oxygen are premixed with the plenum chamber before being pressure directed into the fluidized bed reactor chamber for mixture and combustion with the incoming combustible carbon containing materials such as coal char. After reaction of the superheated steam, oxygen and coal char in the fluidized bed reactor at temperatures ranging from 900.degree. F. to 1750.degree. F., the product fuel gases and associated particulate matter are cooled by steam flowing through the bayonet heat exchanger, the steam being superheated by this exchange. After discharge from the heat exchanger, the fuel gas product containing particulate matter is pressure directed into a conventional cyclone separator for (a) separation of the desired product gases and (b) return of the particulate matter for further recycling in the reactor chamber. Undesirable ash clinkers are gravitationally and pressure directed out of the reactor chamber through a central ash withdrawal pipe.
Abstract:
An integral generator/gasifier system in which a vapor generator is provided that includes an upright furnace section and a plurality of nozzles, each having one end registering with the interior of the furnace section. A gasifier extends adjacent to the furnace section and supports a bed of adsorbent material for the sulfur generated as a result of the gasification of fuel introduced to the gasifier. Air is passed through the bed of adsorbent material to fluidize said material so that, upon gasification of the fuel, a substantially sulfur-free product gas is produced. The other ends of the nozzles communicate with the gasifier so that the product gas passes from the gasifier through the nozzles and into the furnace section for combustion.