Patent Application
20070290418
An oxygen blast converter system (oxygen blast furnace system) is described in U.S. Pat. No. 6,030,430, the disclosure of which is hereby incorporated by reference in its entirety. The converter system has a blast furnace which employs a continuous oxygen jet blast and can be operated to consume, by conversion, a wide range of raw materials including wastes of many kinds, e.g., a wide range of toxic and hazardous wastes, oil shales and sands and other inferior or difficult-to-process raw materials. These materials are converted into fuel gases, molten metal, molten slag, vapors and dusts. Some conversion products are useable as produced, while others can be converted in other production units in the system.
In U.S. Pat. No. 6,030,430, an injection system for delivering oxygen and other reactants into the converter system includes tuyeres T1 and T2. The tuyere T2 may be used for injection of a minimal amount of endothermic materials or other injectable materials with the oxygen, and the remaining endothermic materials or other injectable materials injected through tuyere T1. Alternatively, the tuyere T2 may be used for injection of all materials; or the tuyere T2 may be used for injection of any portion of materials with the oxygen, and remaining materials being injected through tuyere T1. A process control computer and auxiliary tuyere inputs and outputs can be employed to regulate temperature-controlled activities taking place in the converter zones and the quality of the outputs. These results can be inputted into the process control computer, which can schedule periodic purges through appropriate tuyere sets, e.g., when a build up of materials occurs.
The present invention is directed to a tuyere for use in an oxygen blast furnace/converter system. In one aspect, the tuyere comprises a body and a first conduit extending through a longitudinal center portion of the body. The first conduit has an outboard end external to the furnace and an inboard end extending into the furnace. The first conduit is adapted to receive a medium at the outboard end and discharge the medium at the inboard end through a discharge nozzle inside the furnace. A second conduit is arranged concentrically around the first conduit and is adapted to receive a medium at a first end of the conduit and discharge the medium at a second end of the conduit through a discharge nozzle.
In another aspect, a tuyere comprises a body, a first conduit extending through a longitudinal center portion of the body. The first conduit is adapted to receive a medium at a first end of the conduit and discharge the medium at a second end of the conduit through a discharge nozzle. A plurality of secondary conduits extends through the tuyere body and these are adapted to receive a medium at a first end of the conduits and discharge the medium at a second end of the conduits through a plurality of radially distributed discharge nozzles.
In yet another aspect, a tuyere comprises a body and a first conduit extending through the body. The first conduit is adapted to receive a medium at a first end of the conduit and discharge the medium at a second end of the conduit through at least one discharge nozzle. A second conduit is arranged concentrically around the first conduit and is adapted to receive a medium at a first end of the conduit and discharge the medium at a second end of the conduit through at least one discharge nozzle. A third conduit extends through the tuyere body and is adapted to receive a medium at a first end of the conduit and discharge the medium at a second end of the conduit through at least one discharge nozzle.
In another aspect, a portable oxygen blast furnace system includes an oxygen blast furnace secured to a railcar. The furnace can be partially dissembled, as needed, and transported by rail along with an oxygen separation unit. The portable oxygen blast furnace system is particularly advantageous for use in applications having a temporary need for the system, e.g., gasifying and converting debris at sites afflicted by a hurricane or other natural or manmade disasters.
The present invention will now be described in more detail with reference to preferred embodiments of the invention, given only by way of example, and illustrated in the accompanying drawings in which:
a is a schematic illustration of a tuyere and nozzle assembly using the retrofit design that utilizes a metal plug for embodying the nozzle design and requires no modification to the existing tuyere, simply fitting into the tuyere bore and being held in place by the securing and tensioning arrangement shown in
b is a schematic illustration of a retrofit design that requires only slight modification to an existing tuyere design to integrate the cooling into the existing tuyere cooling system instead of having an independent plug cooling system;
c is an end elevation on the tip of the tuyere of
a-12c illustrate a portable oxygen blast furnace system which can be partially disassembled and transported by a railcar.
The tuyeres of the present invention are useful for injecting materials into oxygen blast converter systems (oxygen blast furnace systems), such as the oxygen blast converter system described in U.S. Pat. No. 6,030,430. The tuyere configurations may vary in shape, distribution pattern, velocities, flow momentum control, cooling, amount of material injected, and other properties. The tuyere configurations described and illustrated herein are only given by way of example, and it should be recognized that the configuration of tuyeres, blast pipes, tensioning arrangements, and other structures can vary widely from the examples described herein without departing from the spirit or scope of the invention.
In one embodiment, an oxygen blast tuyere can have a multi-barrel design with discrete or mixed material flowing through different concentric ringed barrels. The central barrel may have oxygen or a mixed material flow of oxygen, steam, carbon dioxide, or other injectable materials with oxygen compatibility. The outer concentric barrels may be used to inject steam or other injected materials (e.g., pulverized coal, ore, limestone, etc.). The steam or other endothermic materials may be injected in a manner that satisfies the cooling needs of the tuyere and moderation of the adiabatic flame temperature from the oxygen in the central flow to protect the tuyere and the walls of the furnace from the heat from the oxygen flame. Injectable materials may facilitate other conditions inside the furnace, such as tuyere raceway creation and adequate heat or reducing gases. The central barrel may alternatively contain a wide variety of discrete or mixed injectable materials (e.g., pulverized coal, ore, limestone, steam, etc.), and the outer barrel(s) may contain oxygen with or without oxygen-compatible injectable materials, and further outer barrels may contain endothermic materials (steam, carbon dioxide, etc.) to satisfy the above described needs of the tuyere cooling and other described system needs.
In another embodiment, a tuyere has a single central barrel with additional radially distributed nozzles around the central barrel on the tuyere head that inject other injectable materials such as steam, carbon dioxide, etc. These additional nozzles may be on the front of the tuyere nose and/or distributed radially and longitudinally along the taper of the tuyere exposed in the furnace. The central tuyere barrel may have oxygen or mixed material flow of oxygen, steam, carbon dioxide, or other oxygen compatible injectable materials. The radially distributed nozzles may be used to inject steam or other injectable materials in a manner to satisfy the cooling needs of the tuyere and moderate the adiabatic flame temperature from the oxygen in the central flow to protect the tuyere and the walls of the furnace from the heat, as well as to facilitate other conditions inside the furnace such as overall injectant plume geometry for proper operation. The central barrel may alternatively contain a wide variety of discrete or mixed injectable materials (e.g., pulverized coal, ore, limestone, steam, etc.), and the outer radial nozzles may contain oxygen with or without oxygen compatible injectable materials, and further outer nozzles or barrels of endothermic materials (steam, carbon dioxide, etc.).
Any of the various nozzles described herein may be either formed integrally with the tuyere and/or the conduit extending through the tuyere or as discrete structures suitably attached to the tuyere and/or conduit. The nozzles may have various geometries, including those having a uniform cross-section or a non-uniform cross-section. Any of the various nozzles described herein can be, for example, converging, diverging, converging/diverging, or diverging/ converging nozzles. The cross-section, whether uniform or non-uniform, may have various geometries, e.g., generally circular or defined by concentric circles or portions thereof. Alternatively, the cross-section may be defined by straight lines, e.g., rectangular, or may be defined by a combination of curved and straight lines, e.g., crescent moon shaped. The dimensions and geometries of the nozzles can be selected to deliver the respective mediums at appropriate conditions, such as pressure and velocity, to the blast furnace and to achieve desired overall injectant plume geometry.
The flow momentum requirements for the flow from the tuyere to provide a force or thrust continually to move material within the blast furnace to create an adequate tuyere raceway may be controlled through both velocity and mass flow of the materials flowing through the tuyere. Oxygen compatible injectable materials like steam and carbon dioxide may be mixed with the oxygen in the central flow or outer barrel or nozzle flows to provide more mass and thus a greater momentum force or thrust vector when that flow impacts the material in the furnace. Alternatively, a wide variety of injectable materials (e.g., pulverized coal, ore, limestone, steam, etc.) may be injected through either the central barrel or other barrels or nozzles at a velocity to provide additional flow momentum force on the burden materials in the furnace. Another means of increasing the flow momentum or force/thrust is through controlling the velocity of the flow(s). Increased pressure of the oxygen and injectable materials and the use of accelerating nozzles, such as convergent-divergent nozzles, may be used to increase the velocity of the flows, so that the mass that is within the flows exerts more force as it impacts and is decelerated by the material in the furnace tuyere raceway. These principles may be applied to the aforementioned barrel and nozzle arrangement tuyere embodiments.
Steam or hot water injection through the body of the tuyere in any of the aforementioned embodiments may provide both inner tuyere cooling, as well as provide heating for the steam or water, e.g., just prior to being injected into the furnace, thus providing a synergistic effect of heating the steam or water while cooling the tuyere.
The injection of steam or water or other injectable material into the furnace through the tuyere may be performed at different angles and rates depending upon the position of the injection on the tuyere in order to provide an adequate heat insulating and chemically endothermic barrier layer both above and below the tuyere midline as a protection from radiant and convective heat transfer from the oxygen flame. The prevalent upward flow in the furnace may affect the penetration, size, heat distribution, reactions, or other characteristics of the raceway resulting from the injection of oxygen and the insulating layer above or below the tuyere mid-line provided by the steam or other injectants, which may require different distributing patterns, angles, pressure, or flow rates above or below the tuyere mid-line and laterally to provide an appropriately distributed insulating layer.
It may be desirable to create a rotating flow, using the trajectory and rate of injection of steam or water or other injectable materials in order to provide a more even heat distribution within the layer between the oxygen flame and the walls of the furnace and to promote more intimate contact between the injected materials and the deadman carbon in order to drive conversions like C+H2O═CO+H2. It may also be desirable to inject carbon or carbonaceous fuels (e.g., petroleum coke, coal or coke fines) to assist in the conversion of other injected materials like H2O liquid or vapor, if it is found that these injected materials are not being converted to desirable species like O, CO, H2, etc due to insufficient contact between the deadman coke and the injectant flows before the raceway gases ascend. This situation is largely mitigated when utilizing the T1 tuyere set to inject steam or water or other injectable materials like carbon dioxide, as they ascend through the region at the base of the deadman thus mixing with and having greater exposure to the deadman carbon to facilitate desired reactions before ascending through the T2 tuyere region.
Injection at the T1 tuyere to help protect the lining below the tuyere level and provide dissociation of the steam or other injectable materials at a lower level in the furnace may provide a more evenly distributed insulating layer at the furnace wall and allow more heating of CO and H as it approaches and passes the T2 tuyeres for better heat transfer per volume of gas. However, the use of the T1 tuyere requires actual physical modifications to the body of the furnace, which may be undesirable from a production downtime perspective, thus there is an advantage of being able to use a tuyere design at the example T2 tuyere that can support injection of the necessary materials.
The design of the tuyeres at T2 may be designed to fit within an existing blast furnace's tuyere cooler openings, so that tuyeres may be replaced with new oxygen blast type tuyeres without any major replacement of furnace hardware or structural modification. This flexibility allows for utilizing oxygen blast type tuyeres with other blast injectable materials without significant interruption of production to modify the actual furnace body and it also allows for trials and phasing in of the technology by replacing tuyeres incrementally and reversibly.
This embodiment may be used to inject the oxygen blast and the required steam, water, or carbon dioxide for the process in discrete or mixed flows while avoiding the need for an additional set of lower tuyeres, for example the tuyeres T1 used in U.S. Pat. No. 6,030,430 as described above.
In the embodiment of
This embodiment may be used to inject the oxygen blast and the required steam, water, or carbon dioxide for the process in discrete or mixed flows while avoiding the need for an additional set of lower tuyeres, for example the tuyeres T1 used in U.S. Pat. No. 6,030,430 as described above.
In the embodiment of
The usage of the central barrel 303 for the solid injectable materials is preferable in order to minimize wearing of parts in the tuyere and its feeding apparatus due to the abrasiveness of the materials, as well as helping in avoiding blockages in the tuyere and its feeding apparatus. The solid injectable material may be pneumatically conveyed to and through the tuyere using carbon dioxide or cleaned and compressed furnace top gas instead of air in order to avoid introducing nitrogen into the system. Carbon dioxide may be preferable to nitrogen because it may be reduced to carbon monoxide, which is a desired species in the converter system, and the furnace top gas, which will also be nitrogen free, has already been through this process.
Since the momentum force from the oxygen flow from the nozzles 301 will still be important in the creation of the tuyere raceway in the furnace, flow acceleration using convergent-divergent nozzles 304 may be utilized. When a reduction in the total oxygen volume is required for process purposes during operation, the flow rate through some of the nozzles 301 may be interrupted while leaving the rest of the nozzles 301 at full flow rate, so that adequate momentum force is still exerted on the burden in the furnace to create an adequate tuyere raceway. Maintaining full flow rate in a sub-set of oxygen nozzles 30 should allow them to continue to operate at their optimal convergent-divergent nozzle 304 design conditions.
This embodiment may be used to inject the oxygen blast and the required steam, water, carbon dioxide, or other injectable materials for the process while avoiding the need for an additional set of lower tuyeres, for example the tuyeres T1 used in U.S. Pat. No. 6,030,430 as described above. The tuyere can be fabricated by modifying an existing air blast tuyere, e.g., by inserting an assembly into the existing tuyere bore. Alternatively, the tuyere may be cast with these features. This design allows for minimal production interruption and allows for trials, phasing, and reversibility of the installation of the oxygen blast tuyere.
The radial steam nozzles can tap into the nose cooling channel 405 to provide cooling of the tuyere nose and gain additional heating of the steam before injecting it into the furnace. A convergent-divergent nozzle profile 404 may be provided for accelerating the oxygen flow in the radial oxygen nozzles 401 for achieving proper flow momentum force to assist in creating a tuyere raceway. The oxygen and steam nozzles may also be given a tangential directional component to impart a rotational moment to the injectant plume if desired.
The usage of the central barrel 403 for the solid injectable materials in pulverized form may be preferable in order to minimize wearing of parts in the tuyere and its feeding apparatus due to the abrasiveness of the materials, as well as helping to avoid blockage of the formation of obstructions in the tuyere and its feeding apparatus. The solid injectable material may be pneumatically conveyed to and through the tuyere using carbon dioxide or cleaned and compressed furnace top gas rather than air in order to avoid introducing nitrogen into the system. Carbon dioxide is generally preferable to nitrogen because it may be reduced to carbon monoxide, which is a desired species in the converter system, and the furnace top gas, which will also be nitrogen-free, has already been through this process.
Since the momentum force from the oxygen flow from the nozzles 401 will still be important in the creation of the tuyere raceway in the furnace, flow acceleration using convergent-divergent nozzles 404 may be utilized. When a reduction in the total oxygen volume is required for process purposes during operation, the flow rate through some of the nozzles 301 may be interrupted while leaving the rest of the nozzles 301 at full flow rate, so that adequate momentum force is still exerted on the burden in the furnace to create an adequate tuyere raceway. Maintaining full flow rate in a sub-set of oxygen nozzles 401 should allow them to continue to operate at their optimal convergent-divergent nozzle 404 design conditions.
This embodiment may be used to inject the oxygen blast and the required steam, water, carbon dioxide, or other injectable materials for the process while avoiding the need for an additional set of lower tuyeres, for example the tuyeres T1 used in U.S. Pat. No. 6,030,430 as described above.
In this embodiment, an oxygen blast tuyere can be fabricated by modifying an existing air blast tuyere, e.g., by creating injection nozzles 402 in the nose of the tuyere down into the nose cooling channel 405 and using steam in the nose cooling channel 405. A radial convergent-divergent oxygen nozzles 401 and central barrel 403 can be inserted into the existing tuyere shaft. Alternatively, tuyeres of this design may be cast with these features. This design allows for minimal production interruption and allows for trials, phasing, and reversibility of the installation of the oxygen blast tuyere.
As shown, for example, in
In some instances an existing tuyere can be retrofitted without requiring modification of existing structure such as blowpipe shell geometry, attachment, and mating mechanisms. Such retrofitting can be accomplished, for example, by inserting a metal plug 180 that fits inside the tuyere bore, as shown in
The plug 180 is held in place by a tensioning force at the back of the shaft that connects to it and forces it up against the inner walls of the existing tuyere 100. Existing blow pipe shells and their blast furnace attachment and tuyere mating mechanisms can be used without modification. The back of the blow pipe can be cut off and the internal opening inside the blow pipe can be modified as shown in
Retrofitting can be accomplished by inserting an assembly into the existing tuyere 100 that is configured with any of the previously described conduit arrangements (e.g., one having an oxygen inlet 101 pipe and a concentric outer conduit, as shown), and removing the outboard fittings and internal refractories of an existing blast pipe. The existing blast pipe cone fabrication 100 and nose casting 100a can remain in place along with the tuyere and its cooling channels 104. The tensioning arrangement 150 and tuyere/blast pipe tensioning brackets can be used to secure the conduit assembly, as shown in
In another aspect, a portable oxygen blast furnace system includes an oxygen blast furnace secured to a railcar. The furnace can be partially dissembled, as needed, and transported by rail along with an oxygen converter unit, e.g., placed on a separate railcar. The portable blast furnace system is particularly advantageous for use in applications having a temporary need for blast furnaces, e.g., gasifying and converting waste material at sites afflicted by a hurricane or other natural or manmade disasters.
With reference to
When the portable blast furnace arrives at its destination, the removed upper section(s) 2 and 3 can be reinstalled onto the base portion 1, as shown in
When the portable blast furnace is no longer needed at a particular destination, it can be dissembled by removing the refractories and the upper section. The removed upper section and oxygen separation unit and other ancillary equipment can be placed on separate railcars, and the temporary foundation removed. The unit can then be transported by rail to a new location and reinstalled in same manner as previously described.
While particular embodiments of the present invention have been described and illustrated, it should be understood that the invention is not limited thereto since modifications may be made by persons skilled in the art. The present application contemplates any and all modifications that fall within the spirit and scope of the underlying invention disclosed and claimed herein.
This application claims benefit under 35 U.S.C. §119(e) to Application No. 60/746,085, filed May 1, 2006, the disclosure of which is incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60746085 | May 2006 | US |
