MXPA01008368A - Continuous charge preheating, melting, refining and casting - Google Patents

Abstract

A method and apparatus for casting steel. The apparatus has a variable length secondary belt conveyor (12) for introducing minute charge materials, a skirted self-positioning charging cart (14) engaging the secondary conveyor (12), a charge conveyor (16) for receiving charge material having a means for maintaining a homogeneous scrap bed height that is coupled to the self-positioning cart (14), a dynamic gas seal (18) coupled to both the charge conveyor (16) and a preheater (20), the preheater (20) communicating with the charge conveyor (16) for preheating the charge material on the charge conveyor (16), a connecting car (22) for feeding charge materials into a furnace bath (138) that is removably coupled to the preheater (20) and charge conveyor (16), an electric arc furnace (24) for refining charge therein, an intermediate metallurgical vessel (26) that receives the molten metal discharged from the furnace (24), and a continuous casting device (28) that receives refined-alloyed steel directly from the intermediated metallurgical vessel (26).

Description

MANUFACTURING OF ELECTRIC STEEL CONTINUES WITH PREHEATING OF LOAD, FUSION, REFINING AND EMPTYING CROSS REFERENCE TO RELATED APPLICATIONS This application claims the benefit of the provisional US application no.60 / 121,261 filed on February 23, 1999, and US application no.09 / 344,797 filed on June 25, 1999.

FIELD OF THE INVENTION The present invention relates to the production of steel from raw material and in particular to a method and apparatus for manufacturing continuous electric arc furnace steel and continuous casting having minimum emissions and electric power demand, time that maximizes steel production, including continuous emptying. The invention is ideally suited to provide energy conservation and environmental protection, while maximizing steel production.

BACKGROUND OF THE INVENTION The production of steel and steel products, or products incorporating steel therein, are essential for the maintenance and growth of many economies in various parts of the world. The acquisition and installation of steel refining facilities depends on a variety of important considerations that include environmental impact and cost efficiency. The manufacture of steel using an electric arc furnace (EAF) is a highly advantageous process in the modern steel industry due to the flexibility of the EAF when using mixtures of different fillers, including liquid hot metals and the ability to produce substantially all known grades of steel. One approach to retinal steel is the use of continuous EAF loading, melting and refining systems, which have lateral feed of the EAF, such as those described in US Pat. 4, 543, 1 24 ('124) and U.S. Pat. 5,800, 591 ('591). The systems described in the '1 24 patent and the' 591 patent provide continuity to the preheating of filler materials, the melting of filler materials and the refining of steel. Such continuous preheating, melting and refining systems incorporate furnaces having furnace heights that accommodate side feeding and exhaust gas extraction at low gas flow rates, required to maintain the dust suspension in air. In these systems, a loading trough is located around a material inlet opening on the side of the oven. The loading material is introduced from the tundish to the kiln, and the CO-rich exhaust gas is transferred to the cargo preheater to be used as a fuel for preheating purposes. The systems described in the '124 patent and the' 591 patent are energy conserving. It has been observed that slag builds up below the tundish in such systems and requires removal by beating with a ram. This causes periodic interruptions for the continuity of the refining process. What is needed is an improved method and apparatus for preheating, melting and retinating steel that extends the continuity of the overall steel production system to continuous emptying by eliminating batch operation in the steelmaker's caulking station. wash. In addition, a method and apparatus for preheating, melting and retinating steel is required, which allows lateral feeding in a furnace without requiring an increase in the height of the furnace and which improves the consistency of the load feeding.

Continuous steel preheating, melting and refining systems, which have side power l use a type that interacts with the furnace, such as a connector car, are described in U.S. Pat. 4, 681, 537 and U.S. Patent No. 4,836,732. Such equipment is prone to damage by heat and abrasion and requires periodic maintenance. For example, the trough of the connector carriage is exposed to the splash of molten steel and slag and to high temperature peaks of the exhaust gas. In consecuense, the refining process can be interrupted by the stoppage time required for the repair and maintenance of the connector car. What is needed is a method and apparatus for preheating, melting and retinating steel that facilitates the repair and maintenance of an interchangeable power supply that interacts with the furnace. As previously mentioned, environmental impact and cost efficiency are important considerations before acquiring and installing a steel refining system, as well as during the actual operation. The communities and government request that the industry, in general, decreases its impact on the environment. What is needed is an improved method and apparatus for preheating, melting and retinating steel that provide abatement of emissions without additional energy consumption. In particular, what is needed is a method and apparatus for preheating, melting and retinating steel, having significant reductions in the req uence of electrical energy, consumption of, electrodes, labor, impact on the environment binside and outside of the steel plant and waste bag filter dust.

BRIEF DESCRIPTION OF THE INVENTION The present invention is an improved method and apparatus for manufacturing continuous electric steel with continuous casting added in cascade. The invention allows lateral feeding in an oven without requiring an increase in the height of the oven. The present invention also makes possible the repair and maintenance of interchangeable load feeding equipment, which interacts with the furnace without interrupting the continuity. When steel is refined and emptied, the present invention provides the abatement of emissions without additional energy consumption. In particular, the present invention provides significant reductions in the electrical power requirement, electrode consumption, labor, impact on the environment both inside and outside the steel plant, and waste bag filter dust. The apparatus invented for continuous preheating, melting, refining and emptying of steel comprises a variable length secondary belt conveyor which is positioned in a loading area to introduce small filler or slag-forming materials, a self-loading cart. edged positioning coupled to the secondary conveyor, a load conveyor that receives the loading material having means to maintain a homogeneous fragment bed height that is coupled to the self-positioning carriage, a dynamic gas seal coupled to both the load conveyor as to a preheater, combining the preheater with the charge conveyor to preheat the charge materials in the charge conveyor, a means of connecting carriage for feeding materials in a kiln bath that is removably coupled to the preheater and cargo conveyor, an electric arc furnace to melt and refine the metal charge therein, at least one electrode sealing ring which is coupled to the furnace electrodes, a directly fed intermediate metallurgical vessel receiving molten metal discharged from the furnace, and a continuous casting device receiving refined alloy steel from the metallurgical vessel intermediate. The connector means comprises a rapidly interchangeable connector carriage having a substantially round loading trough. The furnace comprises a shell which can be either a simple shell structure or split, a furnace roof having vertical openings for receiving the electrodes and a loading opening extending from a top shell portion to a portion of the furnace roof to result in a split entry. The simple shell or split shell is used interchangeably in the invented apparatus. The split entry opening receives the loading tundish, thereby reducing the height of the furnace and minimizing slag accumulation below the tundish during the casting-refining process. An electrode sealing ring is positioned on each electrode opening in the furnace roof to minimize the pick up of air through the electrode openings inside the furnace. The furnace may optionally include a bleeding gusset over a bleeding portion of the furnace and includes a collecting apparatus that is coupled to the dust bag filter bag. The bleeding gusset collects the process powder when the oven is bleeding. The connector carriage is removable and repositionable by means of a top crane. Before removing the connector carriage, the roof of the oven is lifted and pivoted free of the loading tundish and the tundish is removed from the preheater. The connector carriage is then lifted away from the furnace and the preheater by the crane and replaced by a reserve connector carriage. The removable connector carriage and the opening of the slotted inlet furnace facilitate and simplify the repair and maintenance of the connector carriage without interrupting the continuity of the furnace smelting campaign. The intermediate metallurgical vessel and continuous caster extend the continuity of the global steel production system to include secondary refining, deoxidation and continuous alloy of liquid steel and continuous casting. The intermediate metallurgical vessel allows continuous bleeding of liquid steel from the EAF having a temperature and containing the desired carbon, sulfur and phosphorus. The continuous drain receives the refined alloy steel and continuously empties intermediate products that are hot-lamed immediately in the lam-oner that is downstream of the waste. The invented method and apparatus improves every aspect of conventional steel refining systems and extends the absolute continuity of the steel smelting-refining operation not only to the refining of molten steel, but to the production of a semi-finished product of the steel. emptier In addition, the present invention extends the continuity of the steelmaking process to the laminator, so that a hot ingot can be laminated immediately from the caster. For example, the invented method and apparatus do not require a casting crane and a pouring cauldron, which are required by conventional steel refining systems, and provide hot semi-finished product laminating in a long hot rolled product or coil . The invented method and apparatus encompass the introduction of pre-heated loading material, the casting and refining of steel and the production of semi-finished hot rolled product.

OBJECTIVES OF THE I NVE NTION A principal objective of the present invention is to provide an improved apparatus for preheating, melting, retining, pouring and laminating steel that conserves energy and protects the environment. Another object of the invention is to provide a method and apparatus for the electrical production of steel that extends the continuity of the steel production operation to include loading, preheating of charge materials, steel refining, pouring kettle metallurgy, casting and hot rolling semi-product and ensures the absolute continuity of the liquid steel to a continuous draining device. Another object of the invention is to provide a method and apparatus for the electrical production of steel that abate the emmission without consumption of additional energy. Another more particular object of the invention is to provide a method and apparatus for the electrical production of steel which has significant reductions in the requirement of electrical energy, consumption of electrodes, labor and waste of process powders. Another more particular object of the invention is to provide a method and apparatus for the electrical production of steel which maintains the homogeneity of the filler material introduced into the furnace.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects will become more readily apparent upon reference to the following detailed description and the accompanying drawings, in which: FIG. 1 is an isometric view of an apparatus for producing steel according to the present invention, showing the secondary conveyor, the self-positioning loading carriage, the load conveyor, the dynamic gas seal, the preheater, the carriage connector, the EAF, the intermediate metallurgical vessel, and the continuous emptying device; FIG. 2 is a perspective view of the secondary conveyor, the loading carriage and the load conveyor shown in FIG. 1; FIG. 2a is a side view of the de-sprayer and a portion of the load conveyor according to an embodiment of the present invention; The FI G. 3 is a cross-sectional view of the load carrier and the self-positioning loading carriage shown in FIG. 1; FIG. 4 is a side view of the self-positioning load carriage and load carriage shown in FIG. 2; FIG. 5 is a perspective view of the dynamic gas seal shown in FIG. 1, which shows a portion of the preheater in dotted lines; FIG. 6 is a perspective view of the preheater with the hot gas baffle in the central section according to the present invention, showing some of the outlet gas handling devices; FIG. 7 is a sectional view of a portion of the charge preheater according to the present invention, showing the flow of exhaust gas through the preheater; FIG. 8 is a perspective view of the connector carriage according to the present invention; The FI G. 9 is a perspective view of the connecting carriage of the FI G. 9 during the replacement operation; FIG. 1 0 is a perspective view of the electric arc furnace according to the present invention, showing the furnace cover in place; FIG. 1 1 is a side view of the FI G furnace. 1 0 with the cover raised, showing a view of the right angle of the cover in dotted lines; FIG. 1 2 is a perspective view of the electric arc furnace with the bleeding gusset according to an embodiment of the present invention, showing the flow of collected emmissions; FIG. 1 3 is a vertical sectional view of the furnace with the connecting carriage according to the present invention, showing the charging trough of the connecting carriage which protrudes in the furnace in the loading position; FIG. 14 is a sectional view of the roof of the furnace with electrode sealing flotation rings according to the present invention; FIG. 1 5 is a perspective view of the furnace, electrode sealing float rings, intermediate metallurgical vessel and continuous emptying device according to the present invention, showing the bleeding gusset in dotted lines; FIG. 16 is a cross-sectional view of a portion of the furnace, intermediate metallurgical vessel and continuous emptying device of FIG. 1 5, which shows the refining-alloy steel in the intermediate metallurgical vessel; FIG. 17 is a cross-sectional view of an alternative embodiment of the present invention, showing the furnace, protruding the connecting carriage trough in the furnace, the furnace discharge chamber, the furnace discharge mechanism, the exit orifice from the oven to the discharge chamber and the continuous emptying device; FI G. 1 8 is a schematic top view of the IF furnace G. 17, which shows the funnel of FIG. 1 7.

DETAILED DESCRIPTION The present invention is an improved method and apparatus for manufacturing continuous electric steel with continuous casting added in cascade. The present invention extends the continuity of a steel preheating, casting and refining operation to lengthen the duration of a campaign. In particular, the present invention achieves the objectives of charge preheating, casting, refining, steel metallurgy and casting in a simple closed system and is continuous from one portion of the system to the next portion. Steel metallurgy, for example, deoxidation and alloying, is conducted without a casting cauldron or associated ladle caulking equipment, and hot intermediate product can be immediately laminated from the invented apparatus. Referring now to the figures, and in particular to FIG. 1, an improved apparatus for the manufacture of continuous electric steel, generally shown at 10, comprises a secondary conveyor of variable length 1 2 for introducing dim and slag-forming fillers, a self-positioning loading carriage edged 14, which is coupled to the secondary conveyor 12, a load conveyor generally shown at 16, which has a means for maintaining a homogenous fragment bed height which is coupled to the loading carriage 14 and which receives the loading material, a seal of undynamic gas, shown generally at 18, which is coupled to both the charge conveyor 1 6 and a preheater, generally shown at 20, the preheater 20 preheats the charge materials at the load conveyor 1 6 and includes at least one hot gas deflector 36 (FIG 7) shown in dotted lines, a connector carriage, generally shown at 22, for feeding matte Load cells in a kiln bath that is removably coupled to both the preheater 20 and a load conveyor 1 6, an electric arc furnace (EAF) 24 to melt and retinal the metal charge therein, a metallurgical vessel directly fed intermediate 26 which is alignable with the molten metal discharge from the furnace 24, and a continuous emptying device 28 for continuous emptying. The invented apparatus 10 may additionally include a hot exhaust gas treatment system, generally shown at 30, to comply with local regulation of unwanted emissions. The hot product can be laminated directly from the intermediate product coming out of the continuous emptying device 28. Figure 2 is a perspective view of the secondary conveyor 1 2, self-positioning loading carriage 14 and loading conveyor 1 6 shown in FIG. Fig. 1 . The secondary conveyor 1 2 is positioned at the end of the load conveyor 16 and is coupled to one end of the loading carriage 14. The loading carriage 14 is movable along the length of the load conveyor 16 and the length of the Second deep conveyor 12 is varied according to the position of the charging carriage 1 4. For example, when the loading carriage 14 is positioned closer to the dynamic gas seal 1 8, the length of the secondary conveyor 1 2 is extended from the end of the loading conveyor 1 6 to the position of the loading carriage 14. Smaller loading materials from about 1 mm to about 1 00 mm in size are transported by the secondary conveyor 1 2 and are deposited on the loading conveyor 16 The border 42 of the loading carriage 14 directs the loading materials transported by the secondary conveyor 1 2 and by the raw material handling equipment, shown generally at 44, to the transporter. Load carrier 1 6. The secondary conveyor 1 2 preferably comprises a movable flat belt 50 having a means for varying the length of the secondary band 1 2, while maintaining the tension of the flat belt 50. In one embodiment of the present invention, a surplus portion, generally shown at 46, of the conveyor belt 50 is coupled to a propensity means 48, such as a weight, to maintain the conveyor belt 50 taut, while allowing the secondary conveyor 12 it is extended or retracted depending on the position of the loading carriage 14. The excess portion 46 of the conveyor belt 50 allows the length of the secondary conveyor 1 2 to extend as the loading carriage 14 is moved towards the oven 24. Propensity means 48 gathers the surplus portion 46 of the conveyor belt 50 as the loading carriage 14 is moved away from the furnace 24. Another conventional means for varying the length of the secondary conveyor 1 2 may be used, including but not limited to, a catchment reel. Additionally, the load conveyor 16 may have a de-sprayer, generally shown at 38, which is attached to the load conveyor 1 6 to collect particles, such as dirt, from the loading material on the load conveyor 1 6. The FI G. 2a is a side view of the de-sprayer 38 and a portion of the load conveyor 16 according to an embodiment of the present invention. The defoamer 38 is preferably coupled to an overlapping section of conveyor troughs, shown generally at 40, of the load conveyor 16, in order to collect particles from the loading material as the loading material advances towards the furnace 24. The metals that are collected by de-pulverizer 38 can be recycled. The de-sprayer 38 reduces the amount of slag to be melted by reducing the amount of soil that is introduced into the furnace 24 with the filler material. This reduces the amount of gaseous emissions that can result from slag produced from molten charge material with the accompanying earth. FI G. 3 is a cross-sectional view of the load conveyor and self-positioning loading carriage 14 shown in FIG. 1 . The loading carriage 14 is coupled to a guiding means, such as a pair of rails 52 mounted on the upper part of the loading conveyor 16, which couples a set of rail wheels 54 mounted on the carriage 14, and is therefore movable along the full length of the loading conveyor 1 6. The loading carriage 14 self-positions along the length of the load conveyor 1 6 to be in close proximity to the end of the fragment bed. A load carriage controller (not shown) having a fragment detecting device can be used to locate the end of the fragment bed and position the loading carriage 14 adjacent thereto. Positioning the loading carriage 14 adjacent the end of the fragment bed facilitates a desired construction of the fragment bed and allows the loading material to be introduced homogeneously into the furnace 24. For example, when the loading carriage 14 is positioned adjacent At the end of the fragment bed, the loading truck directs the loading of loading material to the loading conveyor 16, so that the bed of fragments in the loading conveyor 16 is maintained at a consistent height or depth. FIG. 4 is a side view of the self-positioning loading conveyor 16 and loading carriage 14 shown in FIG. 2. The load conveyor 16 comprises a loading rim 34 which is located in a loading section, shown generally at 56, of the load conveyor 1 6 and a conveyor trough 37 (FIG 3) having side walls. of a predetermined height. The load conveyor 16 receives the loading material of variable dimensions and receives, preferably, loading material that it has when it is a length of approximately 1.5 meters. However, the dimensions of the loading material may vary depending on the size of the project. Border 34 of charge conveyor 16 extends from the secondary charge conveyor 12 to a point before the dynamic gas seal 1 8. The charge conveyor 1 6 extends from the loading section 56 through the preheater 20. The conveyor 1 6 may comprise a simple unit having an associated transmission mechanism or a plurality of connected units each having an associated transmission mechanism. When the loading material is loaded on the loading conveyor 16, the raw material handling equipment 44 is preferably positioned on the upper part of the loading carriage 14, so that the rim 42 of the loading carriage 14 can transfer the fragment material to the conveyor bed . Sometimes, the bed of fragments in the loading section 56 may exceed a desired fragment bed height. The height of the rim 34 of the load conveyor 1 6 allows the raw material handling equipment 44, such as a mobile crane with a magnet 36, to easily access the loading material in the loading section of the load conveyor 1 6. In particular, the height of the rim wall of the loading rim 34 is preferably approximately the height of the side walls of the conveyor trough 37. In this way, the rim 34 of the load conveyor 1 6 permits removal. simple loading materials that exceed the desired bed height of fragments and thereby helps to maintain the homogeneity of the fragment bed and the continuity of the overall steel production process. The horizontal conveyor 1 2, the loading carriage 14 and the loading conveyor 1 6 together allow smaller filler materials and additives to be added to the load conveyor 1 6 below or on top of the loading materials greases that are loaded on the load conveyor 16 by the raw material handling equipment 44. This helps maintain the density of the load, which is particularly useful for controlling the overall melting-refining process. FIG. 5 is a schematic view of the dynamic gas seal 1 8 shown in FIG. The dynamic gas seal 1 8 is coupled to a dynamic seal portion, generally shown at 72, of the charge conveyor 16 and has an inlet, generally shown at 58, and an outlet, generally shown in FIG. 60, to allow the cargo materials transported by the cargo conveyor 16 to move along. The dynamic seal 1 8 comprises a cover 62, a downward pushing plate 64, which is positioned at the inlet 58 of the dynamic seal 1 8, a plurality of mechanical curtains, shown generally at 66, which are placed adjacent to each other. at the dynamic seal inlet 58 and the downward push plate 64, and a variable speed fan 68 which is positioned between the curtains 66 and the outlet of the dynamic seal 60. The dynamic gas seal 18 provides a sewer chamber adjacent to an inlet end of loading material, generally shown at 78, of the preheater 20. The dynamic gas seal 1 8 preferably limits the collection of air to the preheater 20 during the continuous preheating of charge materials. The seal cover 62 substantially encloses the dynamic seal portion 72 of the load conveyor 16 to maintain a negative pressure in the same. The conveyor trough 70 in the dynamic sealing portion 72 of the load conveyor 1 6 is Preference is i-round The downward pushing plate 64 directs the material of fragments that are introduced downwardly against the bed of fragments of the loading conveyor 16 as the loading material is advanced towards the oven 24 The push plate downwards 64 can be operated by an interrupter, which is controlled either by a human operator or by a height monitor. For example, a video camera can monitor the height of the fragments as the fragments approach the dynamic seal 1 8 , and whenever a piece of fragment exceeds the height of the seal inlet 58, the downward pushing plate 64 is activated, so that the plate 64 pivots downward, pushing or of the compressible fragment in the loading material, so that the loading material enters the dynamic seal 1 8 The variable speed fan 68 is responsible for differential pressure measurements of the sealing chamber and controls the amount of air entering the sealing chamber. through the dynamic seal 1 8 The combination of the curtains 66 and the variable speed fan 68 can help create a required negative pressure inside the dynamic seal 1 8 The curtains 66 provide obstruction to the air exchange of the outside of the dynamic seal 18 inside the dynamic seal In particular, the curtains 66 and the variable speed fan 68 facilitate the control of the negative pressure required in the dynamic seal 1 8 to minimize the uptake of air in it, shortens the time and energy that are needed to reach the pressure Negative required and shortens the response time of the invented apparatus 10 to changes in the negative pressure in the preheater. A cyclone 76 may be optionally attached to the variable speed fan 68 via a duct 74 to remove dust from the air that may have been entrained in the dynamic seal 1 8 by the variable speed fan 68. Any significant amount. of dust is separated from the air due to the centrifugal force found by the air in the cyclone 76 and is collected at the bottom of the cyclone 76. The bottom of the cyclone 76 discharges the aforementioned dust and the upper part of the cyclone 76 releases air that it has been cleaned by cyclone 76. The cyclone reduces dust emission by the invented apparatus 1 0. FIG. 6 is a perspective view of the preheater 20, with the hot gas baffle 36, shown in dotted lines, according to the present invention. The preheater 20 includes the aforementioned material inlet 78 and a material outlet, generally shown at 80, to allow the cargo materials carried by the cargo conveyor 16 to move along. The preheater 20 comprises a support 82, a cover, generally shown at 84, which is preferably coated with refractory and is attached to the support to form a preheating chamber, a water cooled conveyor trough, semi-round 86, contained within the preheating chamber, and at least one hot gas baffle 36 coupled to the preheater cover 84. The preheater cover 84 substantially encloses a preheater portion 81 of the load conveyor and can be divisible into three or more sections for separation of the load conveyor 1 6. The preheater cover 84 is provided with injectors 83 for introducing combustion air into the preheating chamber. The number and arrangement of the injectors 83 for each section of the preheater cover 84 can be varied depending on the desired combustion air distribution along the preheat chamber. The hot gas baffle 36 is movably attached to the preheater cover 84 and can be raised or lowered in order to direct the hot exhaust gas from the furnace 24 downwards and towards the loading material in the conveyor bed. The baffle 36 is substantially rectangular and slightly curved from the top to the bottom. Although the baffle 36 is described in the context of a rectangular and curved configuration, the baffle 36 is not intended to be limited to such a configuration and may be configured in various forms with various surface contours. A dust removal system 30 is attached adjacent to the inlet 78 to the preheater 20 via a conduit 85. In one embodiment of the invention, the dust removal system 30 comprises a post combustion chamber 88, and a boiler 92 that is connected to a bag filter 94 (FI G. 1). This mode is particularly suitable for energy efficient dust removal. In an alternative mode, as best shown in the FI G. 1, a fire extinguisher 90 replaces the boiler 92 and interconnects the post combustion chamber 88 and the bag filter 94. The dust removal system 30 removes the dust from the exit gas. A draft regulator 87 is positioned in conduit 85 to restrict or constrain the flow of gas therethrough and thereby regulate the flow of gas to the dust removal system 30. The gas flow constriction grad to maintain the desired pressures in the preheater 20 and the dynamic system 1 8. The post-combustion chamber 88 removes or minimizes unwanted emissions. The kettle 92 recycles the thermal energy contained in the outlet gas passing through the same to heat water or generate steam for use in generating additional energy. The extinguisher 90 allows the gas to cool within a desired time frame in order to minimize formation or reformation of unwanted emissions by introducing water or spray mist into the air passing through the exhaust 90. For Further cooling the temperature of the gases entering the bag filter 94 (FIG 1), air can be injected at a lower temperature into the dust disposal system 30 via an air injection duct 89 after the boiler 92 or after of the extinguisher 90.

The FI G. 7 is a sectional view of the preheater 20 according to the present invention, showing the flow of exhaust gas through the preheater 20, and in particular, through the charge material contained in the conveyor bed. In a first section 96 of the preheater 20, the section located proximally with respect to the furnace 24, the combustion air is injected into the preheater 20 by the injectors 83 (FIG 6) to obtain a partial combustion of CO to CO 2, while a reducing atmosphere is maintained in the first section 96. In a second section 97, the section of the preheater 20 that is adjacent to the first section 96, a pre-determined amount of combustion air introduced by the injectors 83 (FIG. Burns most of the remaining CO to CO2. In the second section, a portion of, or the full hot gas volume, from the furnace 24 is directed in intimate contact with the filler material in the fragment bed by the hot gas baffle 36. This operation increases the efficiency of the gas. the transfer of heat from the salt gas to the loading materials and accelerates the thermal incineration of all the combustible matter that accompanies the cargo materials. As mentioned previously, the hot gas baffle 36 can be pivoted towards and away from the fragment bed in order to control such heat transfer and thermal incineration. In a third section 98, the section of the preheater 20 which is adjacent to the material inlet end 78 of the preheater 20, the combustion air is regulated to maintain approximately 5% excess oxygen concentration. In the third section 98, the atmosphere is completely oxidizing, and the outlet gas temperature remains high to complete the thermal incineration of undesirable emissions in the post-combustion chamber 88. In a preferred embodiment, all sections of the preheater cover 84 they are substantially semi-round with the exception of any section containing a hot gas baffle 36. Alternatively, the sections of the preheater cover 84 may have different contours. Although the preheater 20 is described in the context of three sections, the preheater 20 is not intended to be lid to three sections and additional sections may be provided. Further, although the preheater 20 is described in the context of a hot gas baffle 36, the preheater 20 is not intended to be lid to a hot gas baffle and multiple deflectors may be provided.

The FI G. 8 is a perspective view of a connector carriage 22 according to the present invention. FIG. 9 is a perspective view of the connector carriage 22 of the FI G. 8 during a replacement operation. The interchangeable, fast connector carriage 22 provides an interface between the preheater 20 and the oven 24 for unloading preheated loading materials in the oven 24. The connector carriage 22 is positioned on a raised platform, generally shown in FIG. , between the preheater 20 and the oven 24. The connector carriage 22 comprises a round loading trough 1 04, a lifting port, generally shown at 107, which is attached to the upper part of the connector carriage 22 and a means of displacement for temporarily uncoupling the connector carriage of the preheater 20. Preferably, the charging trough 1 04 is cooled with water in order to withstand the high temperatures of the oven 24. During operation, the tundish 1 04 overlaps with the water-cooled conveyor trough, semi-round 86, of the preheater 20, in order to receive preheater loading material from the preheater 20. The lifting access 1 07 allows that a furnace crane (not shown) is temporarily coupled to the upper part of the connector carriage 22. In one embodiment, the lifting access 1 07 includes a stop cable 1 09 which is attached to the upper part of the connector carriage 22. The raised platform 1 02 has rails 1 06 mounted on the upper part of the platform 102 and track wheels 108 which are mounted on the connector carriage 22. When the connecting carriage 22 is positioned on the platform 1 02, the track wheels 1 08 are coupled to the rails 1 06 and thereby allows the connector carriage 22 to be moved towards or away from the oven 24 and the preheater 20. Although the connector carriage 22 is described in the context of having a rail wheel mechanism, the Connector carriage 22 is not intended to be limited to the rail wheel mechanism and any conventional horizontal scroll mechanism may be used, including but not limited to a wheel and guide device and a rail and support device. During the production of steel, the round loading trough 1 04 of the connector carriage 22 is introduced into the oven 24 through a round material inlet opening 14 (FIGS. 1 0 and 1 5) described in more detail below. ahead. The round loading trough 1 04 and the round material inlet opening 14 allows the oven 24 to be bled without interruption of the steel production process. For example, the connector carriage 22 is not required to be removed from the oven 24 if the oven 24 is required to be tilted on the central axis of the round loading trough 1 04. In a preferred embodiment, the diameter of the loading trough round 104 is of a size sufficient to evacuate the kiln exit gas for a given design capacity, while maintaining the exit gas flow velocity below 10 meters / second. Because the material inlet opening 1 12, the loading trough 1 04 and the combination of the conveyor 86 of the preheater 20 and the first section 96 of the preheater 20 are round, the heat of the exhaust gas from the oven is transferred. effectively to the preheating chamber and the desired system pressures are maintainable and controllable.

As best shown in FIGS. 8 and 9, the connector carriage 22 can be quickly removed from the raised platform 102, in order to facilitate interchangeable connecting carriages. For example, the connector carriage 22 is removable by a furnace crane that lifts and removes the connector carriage from the platform 102. During the replacement operation, the furnace crane can be temporarily coupled to the lifting port 107 of the connector carriage 22 using any conventional coupling device. Before removing the connector car 22, the roof of the oven 112 (FIGS 10 and 11), described in greater detail below, is lifted and pivoted away from the loading trough of the connector carriage 104 and the loading trough 104 is decoupled from the preheater 20. The connector carriage 22 is then removed vertically away from the oven 24 and the preheater 20 by crane. The interchangeable connector carriage 22 and the split entrance of the oven 24 facilitate and simplify the repair and maintenance of the connector carriage 22. FIG. 10 is a perspective view of the oven 24 according to the present invention, showing the oven cover in place. FIG. 11 is a side view of the furnace of FIG. 10 with the cover raised, showing a view of the right angle of the deck in dotted lines. The furnace comprises a shell 110, the aforementioned furnace roof 112, and the aforementioned round loading opening 114. The upper portion of the shell 110 can be coated with refractory or water cooled. The center of the furnace roof 116 (FIG.14) is lined with refractory and the furnace roof 112 has at least one opening 142 (FIG.14) for receiving an electrode 118 therethrough, described in more detail below. . Additionally, the furnace 24 may additionally include, in a bleeding portion, generally shown at 120, a thermocouple 1 22 and a sensor sensor of steel 1 24, in order to assist in the casting process. refining The thermocouple 122 and the steel analyzer sensor 124 obtain measurements of the steel bath inside the furnace 24. The roof of the furnace 1 1 2 is detachable from the shell 1 10 and can be lifted and pivoted using a furnace crane. The roof portions of the furnace 1 1 2 can be selectively cooled with water using a plurality of cooling tubes 1 14 (FIG 14). The loading opening 1 14 extends from an upper shell portion 126 to a portion of the furnace roof 1 1 2, thereby resulting in a split entry. The loading opening 1 14 is preferably aligned with a tilting axis of the oven 24, so that the central axis of the loading opening 1 14 shares the tilting axis with the oven 24. The combination of the opening round load 1 14 and the round loading trough 1 04 of the connector carriage 22 reduces the overall height of the furnace and minimizes the accumulation of slag under trough 1 04 during the casting-refining process. Furnace 24 may further include a conventional rocking device, generally shown at 1 28, to facilitate tilting of furnace 24. FIG. 1 2 is a perspective view of the electric arc furnace 24 with a bleeding shield 1 30 according to one embodiment of the present invention. The bleeding gusset 1 30 is coupled to the powder disposal system 30 via a gusset duct 1 32. In one embodiment, the bleeding gusset 1 30 is positioned on a furnace platform 134 adjacent to a bleeding portion 1 20 (FI G. 1 5) of the furnace 24. The emissions that are produced during sampling are collected by the bleeding gill 1 30 and directed to the dust disposal system 30 via the gutter pipe 1 32. The selected portions of the pipeline gusset 1 32 can rotate freely around the longitudinal axis of the duct 1 32, in order to accommodate the tilting movement of the furnace 24 during bleeding. For example, the gusset duct 1 32 includes rotational joints, shown generally at 31, which allows the gusset duct 132 to rotate. The gusset duct 132 includes a valve 1 36 for controlling the flow of emissions through the duct 1 32. Although the electric arc furnace 24 and the bleeding shield 1 30 are shown associated with a casting kettle 1 33, the furnace electric arc 24 and bleeding gusset 1 30 are not intended to be limited to association with casting kettle 1 33 and may be associated with an intermediate metallurgical vessel 26 (FIG 1 5). FIG. 1 3 is a vertical sectional view of the oven 24 and the connector carriage 22 shown in FIG. 1, which shows the loading trough 104 of the connector carriage 22 protruding in the oven 24 in a loading position. The loading material is transported from the preheater 20 to the connector carriage 22 and towards an oven bath 1 38. The round configuration of the split entrance of the oven 24 and the cooled trough with water 1 04 of the connector carriage 22, allows a reduction of the opening between the round trough 104 and the inlet opening 1 14, and therefore, slag is not formed on the outside of the trough 1 04. Additionally, the round configuration allows the connector carriage 22 to be coupled with the 24 oven during a whole campaign. In the current state of the art, conventional connector cars must be retracted from the furnace when the furnace is drained. The furnace 24 can be energized either by alternating current or direct current, or it can be an induction furnace, or a plasma arc furnace, and it has a lower profile which until now is possible because the round loading opening 1 14 is in the upper part of the side wall of the shell 1 1 0 and is partially in the roof of the furnace 1 1 2. The round slit entrance, with approximately half the entrance of the roof of the furnace .1 1 2, reduces the required furnace height, with resulting decreased energy costs. FIG. 14 is a sectional view of the furnace roof 12 and the floating electrode seal rings 140 according to the present invention. The center of the furnace roof 1 1 6 is made of refractory and has at least one opening 142 for receiving an electrode 1 1 8 therethrough. When an electrode 1 18 is inserted through a corresponding electrode opening 142 in the center of the roof of the furnace 1 1 6, an orifice, generally shown at 146, is formed between the electrode 1 18 and a wall 148 of the opening of the electrode 142. The hole 142 is necessary because the electrode 1 1 8 swings and exhibits lateral movement when in operation. The electrode sealing ring 140 seals the hole 142 around the electrode 1 18 in order to minimize the uptake of air in the oven 24. In a preferred embodiment, the electrode sealant ring 1 40 is made of refractory and has a diameter Pre-determined interior that provides a limited orifice around and between the electrode 1 18 and the ring 140. The outer diameter of the ring 140 is preferably greater than the diameter of the opening of the electrode 142 to allow the ring to cover a substantial portion of the orifice 142 between the electrode 1 1 8 and the electrode averaging pocket 148. The ring 140 is placed around an electrode 1 1 8 and is positioned in the center of the roof of the oven 1 1 6 and it is free to allow any lateral displacement of the electrode 1 18. By minimizing the uptake of air in the oven 24, the electrode sealing ring 140 helps to control the negative pressure created inside the oven 24 and the pre-heat 20, thereby increasing the efficiency of the global steel production process. FI G. 1 5 is a perspective view of furnace 24, electrode seal floating rings 140, intermediate metallurgical vessel 26 and continuous dump device 28, in accordance with the present invention. the intermediate metallurgical vessel 26 is alignable with the molten metal discharge of the furnace 24 to be fed directly from a furnace discharge point 1 53 (FIG.16) through a feed port 1 55. The continuous dump device 28 it is suitable with the discharge of molten metal from the intermediate metallurgical vessel 26 to be fed directly from the metallurgical vessel 26 through a feed port 1 59. Induction heating (not shown) can be added to the intermediate refining vessel 26 for maintaining the desired temperatures of the molten metal contained in the container 26. The alloy of the molten metal is achieved in the intermediate metallurgical vessel 26, for example, to be introduced in the form of wire, aluminium, manganese, silicon and carbon in the container 26 through an alloy port 1 57. The hot intermediate product can be laminated directly from the pouring device. continuous 28. The intermediate metallurgical vessel 26 and the continuous dump device 28 extend the continuity of the overall steel production process. The intermediate metallurgical vessel 26 is coupled to a rail platform 1 50 in order to simplify and accelerate the replacement of the intermediate metallurgical vessel 26. The platform 1 50 runs along an associated rail 1 52. Additionally, the continuous dump 28 is coupled to a rail platform 1 54 which runs along an associated rail 156. By coupling the intermediate metallurgical vessel 26 and the continuous dump device 28 to rail platforms 1 50, 1 54 traveling to along the lanes 1 52, 1 56, the replacement of either the container 26 or the emptying device 28 requires simply removing the container 26 or the emptying device 28 and an exchange with an intermediate metallurgical replacement vessel (not shown) or a replacement continuous flushing device (not shown) that is remotely located to the invented apparatus 1 0. FIG. 1 6 is a cross-sectional view of a portion of the furnace 24, intermediate metallurgical vessel 26 and a continuous dump device 28 of FIG. 1 5, which shows the flow of molten metal in the intermediate metallurgical vessel 26 to the continuous emptying device 28. The intermediate metallurgical vessel 26 includes means for removing inclusions from the molten metal. A porous plug 160 is positioned at the bottom of the container having a gas injector 162 for introducing inert gas into the molten metal and at least two fixed deviators 164 or dumps, formed within the interior of the container 26. The inert gas injector 162 it generates movement of the molten metal to encourage the inclusions to rise to the surface of the molten metal. The deviators 1 64 control the flow profile of the molten metal contained within the container 26. The intermediate metallurgical vessel 26 further includes a de-coated port 168 positioned on a side wall of the container 26. Although the intermediate metallurgical vessel 26 is shown in a configuration similar to a box, the intermediate metallurgical vessel 26 is not intended to be limited to such a configuration and may have a cylindrical configuration. In the Indian cylindrical configuration, the supports are attached to the exterior surface of the intermediate intermediate metal container in order to prevent the rotational movement of the container. The intermediate metallurgical vessel discharge and continuous discharge device discharge are controlled by a detent bar or slide gate 166. FIG. 17 is a cross-sectional view of an alternative embodiment of the present invention showing a casting furnace 170, a connecting carriage 1 74 having a connecting carriage trough 1 84 protruding in the furnace 1 70, a discharge chamber furnace 173, a furnace discharge mechanism, a bath exit hole, shown generally at 88, from the furnace to the discharge chamber 1 73, and a continuous drain device 1 90. The alternative melting furnace 1 70 has a tilting mechanism, generally shown at 1778, which has a pivot point 1 76 that coincides with the liquid steel discharge point of the melting furnace 1 70. In the alternative embodiment shown in FIG. 1 7, the refining furnace 1 70 is provided with a feed opening, generally shown at 1 72, for loading material into the furnace 1 70. Furnace 1 70 is supported by a frame having a pivotal axis which is generally it is aligned with a pouring nozzle 1 80 of the furnace. The shell of the furnace 1 81 can be lifted by means of hydraulic cylinders 1 82. If it becomes necessary to lift or pivot the furnace 170, the connector carriage trough 183 is withdrawn a sufficient distance away from the furnace 1 70, so that the arcuate surfaces 186 at the inlet or loading side of the furnace 1 70 are free as the furnace 1 70 pivots along an arc in the vicinity having the pivotal axis of the furnace 170. The bath outlet orifice 88, or siphoning hole, of the alternative casting furnace 1 70, separates the cast slag from the liquid steel to be discharged from the melting furnace 1 70. For example, the siphoning hole 1 88 allows the liquid steel, but not the slag, to leave the melting area of the furnace 170 and enter the unloading chamber 173. In this mode, the refining and alloy of the liquid steel is achieved in the discharge chamber 1 73. Additionally, this mode maintains a substantially constant distance between the liquid steel discharge point 176 of the furnace 1 70 and the continuous load device 1 90. This modality is perm. ite more regulation of the steel flow of the furnace 1 70, because the furnace 1 70 is tilted to adjust the steel flow rate of the furnace 1 70 to the continuous casting device 190. In contrast, the steel flow of the furnace 24 shown in FIGS. 1, 10 and 11, is preferably regulated by the throttling of a sliding gate at the point of discharge of the oven 153. FIG. 18 is a top view of the alternative cast honoring 170 of FIG. 17, showing the continuous emptying device or funnel 190, a container holder with three tips 192, and furnace stumps 194. FIG. 18a is a top view of the funnel 190 of FIG. 18. The funnel 190 includes a primary chamber 196 where the liquid steel is received from the furnace 170 through a first port 192. A second port 191 alloys wire to be introduced into the primary chamber 196 so that the liquid steel can be deoxidized and alloyed in it. The funnel 190 also has a pair of secondary chambers 198 that are laterally disposed adjacent the primary chamber 196 and a pair of deviators 195, or dumps, positioned between the secondary chambers 198 and the primary chamber 196. The deviators 195 control the profile of flow of the liquid steel from the primary chamber 196 to the secondary chambers 198. The liquid steel that has been deoxidized and alloyed in the primary chamber 196 flows into the secondary chambers 198, where nozzles are located which feed the liquid steel to a mold of the void . The three-tipped container holder 192 allows a quick and simple exchange of the continuous emptying device 190 during a replacement operation. During the replacement operation, the continuous dump device 190 is rotated away from the oven 170 and a replacement continuous dump device, shown in dotted lines, is simply rotated into alignment with the oven 170.

BRIEF DISC RI PTION D THE ALCAN C E OF THE EFFECT OBJECTS OF THE INVENTION From the foregoing, it is readily apparent that I have invented an improved apparatus for preheating, melting, retining, emptying and laminating steel that conserves energy and protects the environment. The present invention provides a method and apparatus for the electrical production of steel that extends the continuity of the steel production operation to include loading, preheating of loading materials, steel refining, steel metallurgy, pouring and hot laminating. of the intermediate product and ensures the absolute continuity of the liquid steel to a continuous emptying device. The present invention provides a method and apparatus for the electrical production of steel that has significant reductions in electrical power requirement, electrode consumption, labor and process dust debris. The present invention provides a method and apparatus for the electrical production of steel that maintains the homogeneity of filler material introduced into the furnace. It will be understood that the foregoing description and specific embodiments are merely illustrative of the best mode of the invention and the principles thereof, and that various modifications and additions may be made to the apparatus by those skilled in the art, without departing from the spirit and scope of this invention. invention, which, therefore, is understood to be limited only by the scope of the appended claims.

Claims (27)

1. REIVI N DICACIO N ES 1 . An apparatus for preheating, casting, refining and continuous casting of steel, said apparatus comprising: a belt conveyor positioned in a loading area for introducing light and slag-forming materials; a cargo conveyor to receive the loading materials; a dynamic gas seal having an input end of material and an output end of material, said gas seal coupled to said charge conveyor; a preheater coupled to the material outlet end of said dynamic gas seal and communicating with said charge conveyor to preheat the charge materials in the charge conveyor; a connector means removably coupled to said preheater and said load conveyor to feed loading materials in a baking bath; an electric arc furnace to melt and refine the metallic charge in it; means for tilting said furnace; an intermediate metallurgical container fed directly positionable to receive molten metal discharged from said furnace; and a continuous dump device for receiving refined alloy steel from said intermediate metallurgical vessel.
2. 2. An apparatus according to claim 1, comprising means for leveling the loading materials on said conveyor.
3. 3. An apparatus according to claim 1, wherein said web conveyor includes means for varying the length of said web conveyor.
4. 4. An apparatus according to claim 1, wherein said charge conveyor is an elongated vibrating channel.
5. 5. An apparatus according to claim 1, wherein said load conveyor includes means for maintaining a homogenous fragment bed height.
6. An apparatus according to claim 1, wherein said load conveyor comprises: a loading section preceding said dynamic gas seal for loading loading material in a position proximate said loading conveyor and transporting the loading material to and through that dynamic seal; and a preheat section extending from said dynamic gas seal to said furnace to convey preheated charge material from said dynamic seal to said furnace.
7. An apparatus according to claim 6, wherein said loading section comprises: a conveyor trough for receiving loading materials, said conveyor trough having side walls, said side walls having a pre-determined height; and a load edging peripherally positioned to said side walls, said load edging having a rim wall height of approximately the height of the side wall; wherein said loading edging allows the loading materials to be accessed from said conveyor gear by raw material handling equipment from a position close to the loading section of said loading conveyor.
8. 8. An apparatus according to claim 6, further comprising a self-positioning loading carriage that couples said conveyor.
9. 9. An apparatus according to claim 8, wherein said self-positioning load cell comprises: an inclined edging for directing the load materials to said conveyor trough; means for guiding the movement of said load carriage along the length of the load section of the load conveyor; and means for determining the location of the end of a fragment bed in said loading conveyor and positioning said loading carriage adjacent to the end of the fragment bed. 1.
10. An apparatus according to claim 9, wherein said gage means comprises: a pair of rails mounted on the loading section of said loading conveyor; a set of rail wheels mounted on the bottom of said load carriage to couple said pair of rails; and means for moving said load carriage along said pair of rails. eleven .
11. An apparatus according to claim 6, wherein said preheater comprises: a support extending along the length of said preheating section of said conveyor; and a cover removably positioned on said preheating section of said conveyor, said cover forming a preheating chamber with said support; wherein said preheater conducts the exit gas of said furnace through said preheating chamber.
12. 12. An apparatus according to claim 1, wherein said preheater further comprises: at least one deflector pivotably attached to said cover of said preheater to force the hot exhaust gas downwardly into the charge materials in said conveyor.
13. 13. An apparatus according to claim 1, wherein said cover of said preheater includes at least three removable sections.
14. An apparatus according to claim 1, further comprising means for maintaining a progressively changing atmosphere within said preheating chamber to reduce at one discharge end of material of said preheater to oxidize at an input end of material of said preheater.
15. 15. An apparatus according to claim 1, wherein said furnace comprises: a removable furnace roof; a shell having a side wall; means for lifting and pivoting said furnace roof away from said side wall of said shell; a furnace charge opening formed in an upper portion of said shell and a portion of said roof; a bleeding opening formed in a bleeding portion of said furnace; and a home.
16. 16. An apparatus according to claim 1, further comprising an electrode sealing means.
17. 17. An apparatus according to claim 1, wherein said connecting means comprises: a platform; a connector truck positioned on said platform; said connector carriage having a water-cooled charging trough adapted to be received in said oven loading opening; and means for temporarily connecting and sealing said preheater with said furnace.
18. 18. An apparatus according to claim 1, wherein said furnace charge opening and said water-cooled tundish of said connector carriage have a substantially round cross-section.
19. 19. An apparatus according to claim 1, wherein said connecting and sealing means comprises: a pair of rails mounted on said raised platform; and a set of rail wheels mounted on said connector carriage.
20. 20. An apparatus according to claim 1, wherein said furnace roof comprises a center made of refractory, said center having openings for receiving electrodes; and wherein said electrode sealing means comprises at least one electrode sealing ring for coupling with an electrode inserted through said openings, said refractory electrode sealing ring being made. twenty-one .
21. An apparatus according to claim 1, further comprising a dust removal system comprising: a post combustion chamber connected to said preheater; means for reducing the temperature of the exhaust gases of said furnace; a bag filter coupled to both said boiler and said extinguisher to filter the emissions of said furnace; at least one fan for urging the flow of the exhaust gases towards said bag filter; and a rite regulator for selectively directing the flow of the exhaust gases to said extinguisher and said boiler.
22. 22. An apparatus according to claim 21, wherein said reducing means is a boiler coupled to said post combustion chamber to extinguish the exhaust gases of said furnace.
23. 23. An apparatus according to claim 21, wherein said reducing means is an extinguisher coupled to said post combustion chamber.
24. 24. An apparatus according to claim 21, further comprising a bleeding gusset attached to the bleeding portion of said furnace and connected to said dust removal system.
25. 25. An apparatus according to claim 1, wherein said intermediate metallurgical vessel comprises: means for removing inclusions from the molten metal contained within said vessel; and means for maintaining a pre-determined temperature of molten metal contained within said container.
26. 26. An apparatus according to claim 1, further comprising a des-pulverizador a gone to said loading conveyor to remove particles from the loading material.
27. 27. A method for continuous preheating, smelting, refining and emptying of steel, comprising: preheating loading materials; continuously feeding said loading materials into an electric arc furnace; continuously refinishing said filler materials in the furnace to form molten steel; unloading the molten steel directly into a continuous casting device without an intermediate casting cauldron; conduct the pouring kettle metallurgy in the continuous casting device; generating the molten metal directly from the continuous casting device into a continuous casting mold, in which the molten steel begins solidification; removing said partially solidified steel from said mold; cooling said removed steel to form an ingot; equalize the temperature along the ingot; and laminating said ingot to form a desired rolled steel product.