US20090288794A1

US20090288794A1 - Method and apparatus for manufacturing metal bars or ingots

Info

Publication number: US20090288794A1
Application number: US12/425,079
Authority: US
Inventors: Michael Lynn
Original assignee: PRIME METALS & ALLOYS Inc
Current assignee: PRIME METALS & ALLOYS Inc
Priority date: 2008-04-17
Filing date: 2009-04-16
Publication date: 2009-11-26

Abstract

Method and apparatus for manufacturing metal bars or ingots. The abstract of the disclosure is submitted herewith as required by 37 C.F.R. §1.72(b). As stated in 37 C.F.R. §1.72(b): A brief abstract of the technical disclosure in the specification must commence on a separate sheet, preferably following the claims, under the heading “Abstract of the Disclosure.” The purpose of the abstract is to enable the Patent and Trademark Office and the public generally to determine quickly from a cursory inspection the nature and gist of the technical disclosure. The abstract shall not be used for interpreting the scope of the claims. Therefore, any statements made relating to the abstract are not intended to limit the claims in any manner and should not be interpreted as limiting the claims in any manner.

Description

BACKGROUND

1. Technical Field
Small diameter bars, and small ingots, sometimes referred to as pig ingots, or concast bars are used throughout many segments of the metals industry. These small bars and ingots (SBI), weigh approximately twenty pounds and are frequently used as raw materials for investment and sand casting foundries, and die casting foundries. They are also used for alloy additions in other melting facilities such as steel mills and vacuum induction furnaces (VIM).
2. Background Information
Background information is for informational purposes only and does not necessarily admit that subsequently mentioned information and publications are prior art.
The traditional manufacturing systems for producing these small ingots and bars are fairly limited and comprise some adverse process characteristics including negative health and environmental impacts, reduced manufacturing flexibility, increased manufacturing costs, and in some cases, poor ingot quality.
The method according to at least one possible embodiment of the present application utilizes a casting system designed to address the problems and limitations of traditional casting technology. The current mainstream technologies for the production of SBI involve one of four basic processes: permanent mold ingots (pigs), consumable sand mold cast ingots, bottom poured ingots or “cast bars,” and bars produced by either a horizontal or vertical continuous caster (concast bars). To fully appreciate the benefits of the process according to at least one possible embodiment of the present application, it is important to first have a basic understanding of the alternative processes for SBI productions.
Permanent Mold Pig Casting
With the permanent mold casting process (PMC), molten metal is top poured into a ladle, a tundish, or both, and then top poured into a “permanent mold” that is moved along by a conveyor. As the name indicates, the molds are reusable, although some do need to be replaced or should be replaced periodically.
The molds have one or more cavities and are often made from cast or ductile iron. The molds are pre-coated with a mold wash, and then preheated prior to receiving the molten metal. The mold wash, which comprises a mixture comprising graphite, zircon, or some similar material, acts as a parting agent for the ingot to mold interface. It also provides some limited protection to the mold during casting.
The pig ingots and molds are typically water sprayed after casting to hasten their cooling, and to prevent, restrict, and/or minimize the molds from becoming too hot during the casting process. After being sprayed with cooling water, the ingots are dumped, or knocked, out of the molds and fall into tubs.
The mold conveyor then moves the mold back to the mold wash station for recoating and then continues to move the mold to the preheater station where excess moisture can be dried off prior the mold being reused.
The initial start up cost of a permanent mold caster is considerably less than the cost of a continuous caster. PMC casters are often used for high volume commodity products such as pig iron. They are also used in some cases for the production of stainless steels, specialty steels, and some nonferrous alloys.
Both permanent and sand cast ingots are prone to developing blow holes in the tops and side walls of the ingots. The permanent mold system is prone to developing blow holes due to an out gassing effect from the mold wash and moisture left from the water spray.
Tumble blast cleaning of the ingots prior to shipment is crucial in order to remove as much of the residual mold wash and other surface contamination as possible.
Other sources of contamination include the mold wash, oxidation formed as the result of the molten metal being exposed to open air during the pouring process, and shot that may become entrapped in blow holes during tumble blast cleaning operations.
Contamination and oxide formation in and around blow holes is a chronic problem. The presence of such contaminates can result in increased production costs and higher rejection rates for the foundry using the pig ingots to produce castings.
During pouring with the PMC system there is also the potential to form metal fins across the tops of adjacent ingots. The formation of these metal fins tends to be more severe when casting grades that have high ductility.
The fins can inhibit the removal of the pigs from mold during the cast. Additional manual rework downstream may become necessary or desired in order to break off the metal fins prior to shipment. This adds additional labor cost and potentially lower yields for the producer.
The permanent mold pig casting process has a number of undesirable attributes. Poor ingot quality, waste, and reduced good product yields when compared to other methods. Additional undesirable environmental and cost concerns may be created from the need or desire to properly dispose of the mold wash materials and contaminated sprayed cooling water. Emissions of fumes from the ladle and molds are fairly common as the molten metal is top poured onto the molds. The ingot sizes during a single cast can vary significantly.
Consumable Sand Mold Cast Ingots
Small ingot production using a traditional consumable sand mold casting process (CSMC) is similar to the permanent mold process in many ways. The ingots have similar shapes, and are top poured into a mold that is moved along by a conveyor either continuously or semi-continuously during the pouring operation. However, in the case of the CSMC process, the mold is consumable. It is used once before it must or should be discarded.
Molten metal is typically top poured into a ladle or tundish. In some CSMC systems, the metal may be top poured directly from the melting furnace into a ladle and then bottom poured into a tundish. The metal is then top poured from the tundish into the sand mold. At each top pouring stage, the molten metal may be exposed to open air and the potential for oxide formation exists. Oxide is a major source of contamination in the ingot and increases the likelihood of scraped castings.
In other CSMC systems, the metal is either poured directly from the melting furnace into the sand molds, or poured into a tundish, and then top poured into the sand molds. Having a precise or general control of the molten stream during the pour is rather difficult and rather time consuming. This often results in producing ingots with a relatively high range of individual ingot heights and weights within a single heat.
Lake sand or some other silica sand is often used as the base raw material and then combined with various binders in order to form the mold. The molds are typically produced from a no-bake sand process and each mold comprises cavities for up to five ingots.
The initial equipment cost for the CSMC process is relatively low. The CSMC process does enable a wide range of flexibility of grades or materials that can be cast. Since metal is simply top poured into the molds, the process is relatively simple, but like the permanent mold process, there are numerous undesirable aspects which can occur.
As mentioned earlier, sand cast ingots often develop blow holes. They also commonly comprise internal voids which form as the result of uncontrolled cooling. The sand molds may comprise loose sand which can become entrapped in the metal during the pouring process. In addition, the molds may break apart before the molten metal has solidified. As a result, additional loose mold sand becomes a source of contamination in the ingot.
As with the PMC process, tumble blast cleaning of the ingots is performed in an effort to remove surface contaminations such as sand, mold wash, or slag. Some producers have experimented with using other consumable mold materials in an effort to reduce the contamination. However, these alternative consumable mold products have had limited success.
The alternative molds have been prone to leaking metal during the casting operation and thus become another potential source for contamination. Sand has remained the prominent mold material in the CSMC process.
Increased manufacturing consumable costs, product size variability, poor ingot quality, concerns about potential hazards from the presence of free silica dust in the workplace, and increased labor requirements are adverse factors for this process. The proper disposal of spent sand molds may also increase costs for the producer.
Emissions of fumes and odors can be rather high for this process. The binders in the molds often emit a strong and unpleasant odor and fumes are created from both the holding tundish, or furnace, and the molds during pouring. The molds commonly continue to emit fumes after the pour has been completed.
Bottom Poured Ingots (Castbars)
Small cast bars produced using the bottom poured ingot process (BPI), are produced by top pouring into a ladle. Once in the ladle, metal refining may or may not be performed. The metal is then bottom poured from the ladle by means of a stopper rod or slide gate on the ladle.
The molten metal is gravity fed through a series of consumable refractory tiles and enters the mold through an opening in the bottom. The molds, which may be “permanent” or consumable, are placed standing vertically on end on top of a cast iron base plate. The refractory system may or may not include a filter. Besides the amount of metal needed or desired to fill the ingot mold, additional metal needs to be produced or should be produced in order to yield a sufficient amount of clean metal to fill the ingot mold. The excess metal from the ladle is poured into a slug and becomes scrap for remelting.
The ingots are removed from the molds and the excess metal that was left inside the refractory system, referred to as “runners,” is removed from the ingots using a torch or lance. The runners, which often comprise a large amount of slag contamination, are normally scraped for remelting. The ingots may require or desire condition grounding to remove metal fins. The tops and bottom of the ingots are cut off to remove impurities.
The cropped pieces become scrap to be remelted. The ingots, or CastBars, are then cut to the desired lengths and weights and may undergo a tumble blast cleaning operation to remove surface contamination.
Producing small bars by this method is very time consuming and labor intensive. Metal may freeze when traveling through the refractory system and the pour must or should be aborted. The metal may also leak out the refractory system or the ingots may become stuck in the molds. Set up and tear down requires or desires excessive labor time.
The BPI process provides the capability of producing a relatively clean bar. The products can be potentially superior in cleanliness when compared to permanent mold or consumable sand mold processes, and similar to the cleanliness of continuous cast bars. The initial set up costs are lower than for the continuous casting process.
High consumable refractory and disposal costs, combined with poor yields and excessive labor costs are negative aspects of the BPI process when it is used to produce small bars. Good product yield loss from the excess metal in the ladle, runner scrap, fins, grinding, and cutting is relatively high compared to other processes.
Continuous Casting (Concast)
The continuous casting process is capable of producing bars that are of high quality for remelting applications in foundries. In this process, molten metal is typically top poured into a ladle and then transferred to a holding tundish. The metal is added to the holding tundish by either top pouring or by bottom pouring. In some cases, the melting furnace also functions as the holding tundish.
From the tundish the metal flows at a controlled rate in to an open-ended, water-cooled mold. The mold assembly comprises a one piece die often made from a composition of graphite or copper-based alloys. The mold system may also utilize a zirconium die port and a break ring. The process is started by plugging the mold with a “dummy bar.” The dies used are a one piece construction and are normally round. However, other geometric shapes are possible.
As the metal enters the mold, it freezes against the mold walls forms a shell. The metal also freezes to the dummy bar and then the bar is withdrawn from the bottom (vertical caster) or end (horizontal caster) of the mold at a rate which maintains the solid to liquid interface constant or substantially constant.
As the concast bar exits from the mold, the center is still liquid metal. Spray water is sometimes employed to help solidify the center. The bar is then typically sheared, saw cut, or torch cut into the desired lengths. For some casters, separate heats are processed back to back. Other producer's process in single heat batches and then the caster is shut down.
There are a large number of variables which can affect the success of the cast and the quality of the bars. The delicate balance between liquid and solid state in the mold must or should be precisely or generally controlled. Too hot, and the liquid metal can “run out” of the die. Too cool and the bar can freeze in the mold.
Casting rates, temperature control, and differences in solidification properties between various grades can limit the grades that can be successfully cast with the continuous casting process. The continuous casting process is most efficient and practical for high volume production where a single grade or size is processed. Emissions of smoke and odors are low relatively with the concast process.
The initial machine and start up costs with this process can be quite expensive. Although the cutting of the bars can be automated to reduce the labor costs, the good product yields are negatively impacted when cutting small size bars for remelting applications.
Another undesirable element is that concast process has limited flexibility. Also, since the set up costs between runs can be expensive and time consuming, the production and consumable costs can be high for a producer who needs or desires to change grades or change sizes. Product diameter changes are somewhat limited and expensive due to mold and die costs, and the need or desire to maintain a precise or general alignment between the molds and drive motors.

SUMMARY

The process according to at least one possible embodiment of the present application addresses the undesirable problems associated with these other processes. In addition, the method of the present application offers flexibility and high quality, improved operating costs, and significantly reduced environmental concerns.
The equipment used in the method of at least one possible embodiment according to the present application is comprised of the following basic components:
1. A holding tundish which includes insulated walls and floor, an emergency inductive heater controlled by an electric power supply and automated control system, controlled heating by use of an induction coil connected to a power supply, an automated control system, an insulated lid with ports for continuous temperature monitoring and ports for backfill flooding with an inert gas such as argon; continuous temperature monitoring equipment, a spout, screw jacks, and either linear position transducers, LPT, or encoders, which are used to precisely or substantially precisely control the tilting of the tundish;
2. A pouring vessel which includes insulated walls, a floor, an insulated lid with ports, continuous or substantially continuous temperature monitoring, and ports for backfill flooding with an inert gas such as argon; continuous temperature monitoring equipment, an emergency run out feature, an automated dual stopper rod system with both a plunge and twist feature and a nozzle clean out feature, stopper rods and a nozzle, and a metal level control system. The stopper rod system is coupled with an automated control system. The stopper rod system is controlled by an electric power supply and an automated control system;
3. A four-part, water-cooled mold system which includes two movable water-cooled mold walls, a movable water-cooled horizontal mold base, a quick-change water-cooled mold size and shape insert, and a motion control system; and
4. A conveyor system and automated product identification equipment, an automated quality vision inspection system, and a packaging unit.
While holding tundishes and pouring vessels are used in numerous applications within metal casting industries, the holding tundish and the pouring vessels used in the present application are designed to permit a high degree of control of both temperature and metal protection, as well as the precision pouring capabilities.
One feature of the equipment for performing the method according to at least one possible embodiment of the present application is the molding and pouring system. The mold has four pieces: two mold halves, a size and shape insert, and a bottom. The mold halves, size and shape insert, and the mold bottom are water-cooled.
The motion control system permits the molds to be indexed before and after pouring. The mold bottom is water-cooled and remains stationary during the cast. The molds are placed directly over the mold bottom during the pour. The mold bottom is pneumatically separated from the molds, thereby creating a bottomless mold. The molds, which house the bars or ingots, index to a position away from the mold bottom. The bars drop onto a removal conveyor and are transported to an inspection station.
The motion control system permits the molds to be indexed before and after pouring. The mold bottom is water-cooled and remains stationary during the cast. The molds are placed directly over the bottom during the pour and then moved to a position away from the mold bottom, thereby creating a bottomless mold. The mold halves pneumatically separate and the ingots drop onto a removal conveyor.
The combination of the holding tundish, pouring vessel, mold system, and conveyor system creates a process whereby the products produced are of exceptional quality and have a high cleanliness and size control. As the result of precise or general temperature control and protection of the metal bath from re-oxidation, this process yields itself to the production of a wide range of alloy types.
The above-discussed embodiments of the present invention will be described further herein below. When the word “invention” or “embodiment of the invention” is used in this specification, the word “invention” or “embodiment of the invention” includes “inventions” or “embodiments of the invention”, that is the plural of “invention” or “embodiment of the invention”. By stating “invention” or “embodiment of the invention”, the Applicant does not in any way admit that the present application does not include more than one patentably and non-obviously distinct invention, and maintains that this application may include more than one patentably and non-obviously distinct invention. The Applicant hereby asserts that the disclosure of this application may include more than one invention, and, in the event that there is more than one invention, that these inventions may be patentable and non-obvious one with respect to the other.

BRIEF DESCRIPTION OF THE DRAWINGS

The present application is explained in greater detail below on the basis of the possible embodiments illustrated in the accompanying figures, in which:

FIG. 1 shows a schematic representation of the equipment used in the method according to at least one possible embodiment of the present application;

FIGS. 2 through 4 show an illustration of a holding tundish for use with the present application;

FIG. 5 shows a schematic illustration of a pouring vessel for use with a method of the present application;

FIGS. 6 and 7 show schematic representations of the molds of a process according to at least one possible embodiment of the present application; and

FIG. 8 shows an automated identification station of at least one possible embodiment according to the present application.

DESCRIPTION OF EMBODIMENT OR EMBODIMENTS

With the method according to at least one possible embodiment of the present application, molten metal is refined and then transferred to a ladle. The metal is protected from the atmosphere by use of an insulating ladle cover, such as a rice hulls or vermiculite. Argon stirring is employed to improve and/or promote the homogeneity of chemistry and temperature, and to further improve and/or promote cleanliness. Argon shrouding is also used to protect, restrict, and/or minimize the molten metal from coming in contact with air. This greatly reduces, restricts, and/or minimizes the opportunity for re-oxidation to occur.
The molten metal is bottom poured (see FIG. 1), using the inert argon shroud, into a sealed holding tundish. The holding tundish of the present application comprises a lid and a base. The lid has openings which permit argon backfill flooding of the sealed holding tundish, and a port for continuous temperature measurement. The sealed design minimizes heat and argon losses during the casting process. The base incorporates an induction coil or a coreless induction heater connected to a power supply, screw jacks or electric cylinders that permit a very precise or general pouring rate of metal into the pouring vessel, and a positioning system to maintain the synchronized or substantially synchronized movement of the screw jacks or electric cylinders.
In one possible embodiment of the present application, an ABP ITM-300 coreless inductor and an ABP ITM-300/400Kw power supply may be utilized.
If necessary and/or desired, the metal may be skimmed prior to sealing the holding vessel. Continuous or substantially continuous monitoring of the metal temperature is performed by use of a pyrometer or probe which is inserted in the molten bath and connected to a digital display. Additional monitoring may be performed using an optical pyrometer device, a similar non-contact measuring device, or an immersion temperature measuring device.
The holding tundish, illustrated in FIGS. 2 through 4, is designed to maintain precise or substantially precise temperature control during the pouring operation and to minimize the chance of any possible re-oxidation. The holding tundish is controlled by a programmable logic controller (PLC1) or a computer.
Within an inert environment, metal is transferred from the holding tundish to a pouring vessel (FIG. 5). The pouring vessel of at least one possible embodiment of the present application comprises an insulated lid that helps to minimize temperature losses and also comprises ports for argon backfill flooding. The pouring vessel has ports which permit metal level control with a detection device, for example a radar detection device, and temperature measurement. The pouring vessel also has stopper rods. The insulated lid is designed to minimize argon losses during the casting process. The pouring rate into the pouring vessel is controlled by the use of load cells, a laser level detection device, a radar detection device, a level detection device, measuring rods, and/or a tilting device. The tilting device may be a screw jack, electric cylinder, or trunnion assembly depending upon the application. An encoder, a linear position transducer (LPT), or a similar device connected to the tilting device provides position feedback.
Strict temperature and quality controls are maintained throughout the casting process. There are two stopper rod nozzle assemblies in the bottom of the pouring vessel. A second programmable logic computer (PLC2) will send a signal from the machine control panel to each of the rods, alternating them between open and closed positions.
The two stopper rod nozzle assemblies are designed to operate independently of each other. The two independent stopper rod nozzle assemblies enable the casting of metal to continue on one line in the event that a problem is incurred with one of the two stopper rods or mold lines. Both stopper rod nozzles are controlled by PLC2. The stopper rod system utilizes a plunge and twist type stopper rod system with a clean out plunger. Automated stopper rod systems are used in the casting of various iron grades such as gray iron or ductile iron. However, the method according to at least one possible embodiment of the present application, which includes temperature control, precise or substantially precise, yet adjustable casting rates, and the protective inert environment, make it possible to utilize an automated stopper rod system for pouring many other materials such as steels, superalloys, nickel base, cobalt base, copper based grades, and for casting raw material master alloys.
From an inert environment within the pouring vessel, metal is bottom poured into a multi-part copper based mold system (shown in FIGS. 6 and 7). The molding system assembly comprises moveable water-cooled sidewalls, water-cooled size and shape inserts, and a water-cooled bottom base plate. The standard compositions of the mold are Chrome-Zinc Alloy grade #108, C18150, or Alloy grade #101, but may vary depending upon the products to be cast. The molten metal is metered into the top of the mold assembly at the casting station.
The molds continue to be water-cooled while returning to the casting position. Simultaneously or substantially simultaneously, a second set of ingots is produced in the casting station using a second mold assembly. Then the semi-continuous process starts another cycle. A programmable logic computer is used to control the movement and timing of the mold system. Upon entering the mold, the metal begins to freeze against the sides and bottom of the mold.
The mold bottom is water-cooled and remains stationary during the cast. The molds are placed directly over or generally over the mold bottom during the pour. After solidification begins, the mold bottom is pneumatically separated from the molds thereby creating a bottomless mold. The molds, which house the bars or ingots, index to a position away from the mold bottom. The bars drop onto a removal conveyor and are transported to an inspection station.
The sides of the mold and the newly formed ingot are pneumatically indexed with slide rails to a position away from the water-cooled base plate. Near the end of the water-cooled base plate is the discharge point. The sides of the water-cooled mold pneumatically separate, allowing the bar to drop onto a collection conveyor.
The sides of the mold and the newly formed ingot index to a position away from the water-cooled base plate. The water-cooled base plate is the discharge point. The sides of the water-cooled mold pneumatically separate, allowing the bar to drop onto a collection conveyor.
An automated vision system may be utilized to inspect the surface of each bar and to verify that the bars are free or substantially free from the presence of slag or refractory. The small bars are then collected and transported to an automated identification station (see FIG. 8) where the bars are automatically identified by heat number and grade. Afterwards, the bars are packaged into the desired shipping containers, as can be seen in FIG. 4. The bars are then weighed, labeled, and staged for shipment.
The small bars are collected and transported to an automated identification station where the bars are stamped with their heat number and grade. Afterwards, the bars are inspected and packaged into the desired shipping containers, as can be seen in FIG. 4.
The process according to at least one possible embodiment of the present application is designed to produce bars that are approximately three to four inches in diameter and weigh approximately fifteen to twenty-five pounds each. However, the production of other sizes and shapes is possible by simply changing the size and shape mold inserts and varying the casting parameters.
The method of at least one possible embodiment of the present application does not utilize sand, mold wash, or cooling water sprays. Emissions of fumes or undesirable odors are extremely low, nonexistent, restricted, and/or minimized with the method according to the present application. In addition, as a result of the level of process control utilized with the method of at least one possible embodiment of the present application, product sizes variations are very low, restricted, and/or minimized. The mold size and shape inserts are designed for rapid changeover to enable or promote product type changes or product size changes to be accomplished in a minimal time frame.
Surface defects on bars made according to the method of the present application are minimized. Shearing, saw cutting, or torch cutting is not necessary or not desired because the method of the present application produces a near net shape product. Set up times are minimal and the process is suitable for small production runs. Initial set up costs are relatively inexpensive when compared to a fully automated continuous caster system.
The pouring system enables a very wide range of grade compositions to be cast by simply modifying the operating parameters. The process according to at least one possible embodiment of the present application may be used for small ingot or bar applications, and may be easily adaptable to produce a product for other applications and industries, such as the production of castings or alloying raw materials.
In another possible embodiment of the present application, the casting equipment for performing the method according to at least one possible embodiment of the present application comprises a five-part, water-cooled mold system which includes two pneumatically movable vertical water-cooled mold walls, a fixed water-cooled horizontal mold base, two changeable mold size inserts, along with a motion control system. In another possible embodiment of the present application, the mold system could comprise additional changeable mold size inserts.
One feature or aspect of an embodiment is believed at the time of the filing of this patent application to possibly reside broadly in a method for the manufacture of metal bars using a bar mold system comprising: a ladle; a ladle cover; an argon shroud; a holding tundish; a temperature control device; a probe; a monitor device; a pouring vessel comprising two independently operated stopper rod assemblies on the bottom of said pouring vessel; a controller to operate said stopper rod assemblies; a pouring control arrangement; a mold arrangement comprising moveable water-cooled side walls, size inserts, and a water-cooled bottom base plate; a collection conveyor; and an identification station; said method comprising the steps of: refining molten metal for a first run of metal bars; transferring molten metal into a ladle; maintaining homogeneity of molten metal by means of argon stirring; protecting molten metal from re-oxidation by use of an argon shroud and a ladle cover; bottom-pouring molten metal while surrounded by an argon shroud into a holding tundish; maintaining temperature control of the molten metal with a temperature control device and minimizing the chance of re-oxidation in the tundish; monitoring the molten metal temperature with a probe that is connected to a monitor device; transferring the molten metal surrounded by an argon shroud into a pouring vessel; controlling the pouring rate of molten metal with a pouring control arrangement; transferring molten metal into a mold system; freezing molten metal against the sides and bottom of the mold upon entering the mold; separating moveable water-cooled side walls and allowing the newly formed metal bar to drop onto a collection conveyor; transporting metal bars to an identification station; stamping metal bars with the heat number and grade for first run; inspecting metal bars from first run; packaging metal bars from first run into desired shipping containers; and refining molten metal for a second run of metal bars.
The components disclosed in the various publications, disclosed or incorporated by reference herein, may possibly be used in possible embodiments of the present invention, as well as equivalents thereof.
The purpose of the statements about the technical field is generally to enable the Patent and Trademark Office and the public to determine quickly, from a cursory inspection, the nature of this patent application. The description of the technical field is believed, at the time of the filing of this patent application, to adequately describe the technical field of this patent application. However, the description of the technical field may not be completely applicable to the claims as originally filed in this patent application, as amended during prosecution of this patent application, and as ultimately allowed in any patent issuing from this patent application. Therefore, any statements made relating to the technical field are not intended to limit the claims in any manner and should not be interpreted as limiting the claims in any manner.
The appended drawings in their entirety, including all dimensions, proportions and/or shapes in at least one embodiment of the invention, are accurate and are hereby included by reference into this specification.
The background information is believed, at the time of the filing of this patent application, to adequately provide background information for this patent application. However, the background information may not be completely applicable to the claims as originally filed in this patent application, as amended during prosecution of this patent application, and as ultimately allowed in any patent issuing from this patent application. Therefore, any statements made relating to the background information are not intended to limit the claims in any manner and should not be interpreted as limiting the claims in any manner.
All, or substantially all, of the components and methods of the various embodiments may be used with at least one embodiment or all of the embodiments, if more than one embodiment is described herein.
The purpose of the statements about the object or objects is generally to enable the Patent and Trademark Office and the public to determine quickly, from a cursory inspection, the nature of this patent application. The description of the object or objects is believed, at the time of the filing of this patent application, to adequately describe the object or objects of this patent application. However, the description of the object or objects may not be completely applicable to the claims as originally filed in this patent application, as amended during prosecution of this patent application, and as ultimately allowed in any patent issuing from this patent application. Therefore, any statements made relating to the object or objects are not intended to limit the claims in any manner and should not be interpreted as limiting the claims in any manner.
All of the patents, patent applications and publications recited herein, and in the Declaration attached hereto, are hereby incorporated by reference as if set forth in their entirety herein.
The summary is believed, at the time of the filing of this patent application, to adequately summarize this patent application. However, portions or all of the information contained in the summary may not be completely applicable to the claims as originally filed in this patent application, as amended during prosecution of this patent application, and as ultimately allowed in any patent issuing from this patent application. Therefore, any statements made relating to the summary are not intended to limit the claims in any manner and should not be interpreted as limiting the claims in any manner.
It will be understood that the examples of patents, published patent applications, and other documents which are included in this application and which are referred to in paragraphs which state “Some examples of . . . which may possibly be used in at least one possible embodiment of the present application . . . ” may possibly not be used or useable in any one or more embodiments of the application.
The sentence immediately above relates to patents, published patent applications and other documents either incorporated by reference or not incorporated by reference.
All of the references and documents, cited in any of the documents cited herein, are hereby incorporated by reference as if set forth in their entirety herein. All of the documents cited herein, referred to in the immediately preceding sentence, include all of the patents, patent applications and publications cited anywhere in the present application.
The description of the embodiment or embodiments is believed, at the time of the filing of this patent application, to adequately describe the embodiment or embodiments of this patent application. However, portions of the description of the embodiment or embodiments may not be completely applicable to the claims as originally filed in this patent application, as amended during prosecution of this patent application, and as ultimately allowed in any patent issuing from this patent application. Therefore, any statements made relating to the embodiment or embodiments are not intended to limit the claims in any manner and should not be interpreted as limiting the claims in any manner.
The details in the patents, patent applications and publications may be considered to be incorporable, at applicant's option, into the claims during prosecution as further limitations in the claims to patentably distinguish any amended claims from any applied prior art.
The purpose of the title of this patent application is generally to enable the Patent and Trademark Office and the public to determine quickly, from a cursory inspection, the nature of this patent application. The title is believed, at the time of the filing of this patent application, to adequately reflect the general nature of this patent application. However, the title may not be completely applicable to the technical field, the object or objects, the summary, the description of the embodiment or embodiments, and the claims as originally filed in this patent application, as amended during prosecution of this patent application, and as ultimately allowed in any patent issuing from this patent application. Therefore, the title is not intended to limit the claims in any manner and should not be interpreted as limiting the claims in any manner.
The abstract of the disclosure is submitted herewith as required by 37 C.F.R. §1.72(b). As stated in 37 C.F.R. §1.72(b):

- A brief abstract of the technical disclosure in the specification must commence on a separate sheet, preferably following the claims, under the heading “Abstract of the Disclosure.” The purpose of the abstract is to enable the Patent and Trademark Office and the public generally to determine quickly from a cursory inspection the nature and gist of the technical disclosure. The abstract shall not be used for interpreting the scope of the claims.
  Therefore, any statements made relating to the abstract are not intended to limit the claims in any manner and should not be interpreted as limiting the claims in any manner.

The embodiments of the invention described herein above in the context of the preferred embodiments are not to be taken as limiting the embodiments of the invention to all of the provided details thereof, since modifications and variations thereof may be made without departing from the spirit and scope of the embodiments of the invention.

Claims

1. A method of manufacturing small diameter bars or ingots using a bar mold system; said method comprising the steps of:

refining molten metal for a first run of small diameter bars or ingots;

transferring said refined molten metal into a ladle;

protecting said refined molten metal from the atmosphere with an insulating ladle cover;

argon-stirring said refined molten metal in said ladle to promote homogeneity, temperature, and cleanliness of said refined molten metal;

protecting said refined molten metal from re-oxidation with an argon shroud and said insulating ladle cover;

bottom-pouring said refined molten metal into a holding tundish while protecting said refined molten metal with said argon shroud;

maintaining temperature control of said refined molten metal with a temperature control device and minimizing re-oxidation in said holding tundish;

monitoring the temperature of said refined molten metal with a probe, which probe is connected to a monitor device;

transferring said refined molten metal into a pouring vessel while protecting said refined molten metal with said argon shroud;

controlling the pouring rate of said refined molten metal with a pouring control arrangement;

minimizing temperature losses with an insulated pouring vessel lid and minimizing argon losses with said insulated pouring vessel lid;

sending a signal from a control device to a plurality of stopper rod nozzle assemblies and alternating said plurality of stopper rod nozzle assemblies between open and closed positions;

metering said refined molten metal from said pouring vessel, through said plurality of stopper rod nozzle assemblies, and into a multi-part bar mold system;

freezing said refined molten metal against the water-cooled side walls of said multi-part bar mold system and the water-cooled bottom of said multi-part bar mold system, upon said refined molten metal entering a cavity of said multi-part bar mold system, and producing a small diameter bar or ingot;

moving said water-cooled side walls, and thereby said small diameter bar or ingot, away from said water-cooled bottom of said multi-part bar mold system and allowing said small diameter bar or ingot to drop onto a collection conveyor;

controlling said moving with said control device;

transporting said small diameter bar or ingot to an identification station;

identifying the heat number and grade of said small diameter bar or ingot at said identification station;

packaging said small diameter bar or ingot into a predetermined shipping container;

weighing said predetermined shipping container;

labeling said predetermined shipping container; and

staging said predetermined shipping container for shipment.

2. A small diameter bar or ingot manufacturing arrangement for performing the method of manufacturing small diameter bars or ingots using a bar mold system according to claim 1; said small diameter bar or ingot manufacturing arrangement comprising:

a refining arrangement being configured to refine molten metal for a first run of small diameter bars or ingots;

a transferring arrangement being configured to transfer refined molten metal into a ladle;

an insulating ladle cover being configured to protect refined molten metal from the atmosphere;

an argon-stirring arrangement being configured to argon-stir refined molten metal in said ladle to promote homogeneity, temperature, and cleanliness of the refined molten metal;

said insulating ladle cover and an argon shroud being configured to protect refined molten metal from re-oxidation;

a bottom-pouring arrangement being configured to bottom-pour refined molten metal into a holding tundish while refined molten metal is being protected with said argon shroud;

a temperature control device being configured to maintain temperature control of refined molten metal and to minimize re-oxidation in said holding tundish;

a probe being configured to monitor the temperature of refined molten metal, which probe is connected to a monitor device;

a transferring arrangement being configured to transfer refined molten metal into a pouring vessel while refined molten metal is being protected with said argon shroud;

a pouring control arrangement being configured to control the pouring rate of refined molten metal;

an insulated pouring vessel lid being configured to minimize temperature losses and minimize argon losses;

a control device being configured to send a signal to a plurality of stopper rod nozzle assemblies and alternate said plurality of stopper rod nozzle assemblies between open and closed positions;

a metering arrangement being configured to meter refined molten metal from said pouring vessel, through said plurality of stopper rod nozzle assemblies, and into a multi-part bar mold system;

water-cooled side walls and a water-cooled bottom of said multi-part bar mold system being configured to freeze refined molten metal, upon refined molten metal entering a cavity of said multi-part bar mold system, and produce a small diameter bar or ingot;

a moving arrangement being configured to move said water-cooled side walls, and thereby a small diameter bar or ingot, away from said water-cooled bottom of said multi-part bar mold system and allow the small diameter bar or ingot to drop onto a collection conveyor;

said control device being further configured to control said moving arrangement;

said collection conveyor being configured to transport a small diameter bar or ingot to an identification station;

said identification station being configured to identify the heat number and grade of a small diameter bar or ingot;

a packaging arrangement being configured to package a small diameter bar or ingot into a predetermined shipping container;

a weighing arrangement being configured to weigh a predetermined shipping container;

a labeling arrangement being configured to label a predetermined shipping container; and

a staging arrangement being configured to stage a predetermined shipping container for shipment.

3. The method of manufacturing small diameter bars or ingots using a bar mold system according to claim 1, wherein:

said water-cooled bottom of said multi-part bar mold system is configured to remain stationary during said steps of metering, freezing, moving, and controlling said moving; and

said method further comprises:

moving said water-cooled side walls over said stationary water-cooled bottom prior to said step of metering said refined molten metal from said pouring vessel; and

moving said water-cooled side walls away from said water-cooled bottom of said multi-part bar mold system after said step of freezing said refined molten metal, thereby creating a bottomless mold.

4. The method of manufacturing small diameter bars or ingots using a bar mold system according to claim 3, wherein said method further comprises:

skimming said refined molten metal in said holding tundish;

sealing said holding tundish to minimize heat losses and argon losses; and

inserting a pyrometer or probe into said refined molten metal and monitoring the temperature of said refined molten metal.

5. The method of manufacturing small diameter bars or ingots using a bar mold system according to claim 4, wherein said holding tundish and said pouring vessel are configured to permit:

control of the temperature of said refined molten metal;

protection of the homogeneity and cleanliness of said refined molten metal; and

substantially accurate transferring and bottom-pouring of said refined molten metal.

6. The method of manufacturing small diameter bars or ingots using a bar mold system according to claim 4, wherein said holding tundish comprises:

insulated walls;

an insulated floor;

an induction coil;

a power supply;

an automated control system;

an insulated lid, which insulated lid comprises ports for temperature monitoring and ports for argon backfill flooding;

a spout;

at least one of: screw jacks and electric cylinders; and

at least one of: a plurality of linear positions transducers and a plurality of encoders.

7. The method of manufacturing small diameter bars or ingots using a bar mold system according to claim 6, wherein:

said pouring vessel comprises:

insulated walls;

a floor;

said insulated pouring vessel lid, which insulated pouring vessel lid comprises ports for temperature monitoring and ports for argon backfill flooding;

a temperature monitoring arrangement;

an emergency run out arrangement;

an automated dual stopper rod system with both a plunge and twist arrangement and a nozzle clean out arrangement;

stopper rods;

a nozzle;

a metal level control system; and

an automated control system;

said multi-part bar mold system further comprises:

at least one quick-change water-cooled mold size and shape insert; and

a motion control system configured to move said water-cooled side walls before and after said step of metering said refined molten metal from said pouring vessel;

said insulating ladle cover comprises at least one of: a rice hulls or vermiculite;

said multi-part bar mold system is comprised of one of: Chrome-Zinc Alloy grade #108, C18150, or Alloy grade #101;

said pouring control arrangement comprises at least one of: load cells, a level detection device, measuring rods, a tilting device, a screw jack, and a trunnion; and

said pouring control arrangement further comprises at least one of: an encoder, a linear position transducer, or a similar device, in order to monitor the position of said pouring vessel; and

said method is used for the manufacture of small diameter bars or ingots comprising at least one of: steels, superalloys, nickel base, cobalt base, copper-based grades, and raw material master alloys.

8. A method of manufacturing small diameter bars or ingots; said method comprising the steps of:

refining molten metal for a first run of small diameter bars or ingots;

transferring said refined molten metal;

protecting said refined molten metal from the atmosphere;

argon-stirring said refined molten metal to promote homogeneity, temperature, and cleanliness of said refined molten metal;

protecting said refined molten metal from re-oxidation;

bottom-pouring said refined molten metal while protecting said refined molten metal from re-oxidation;

maintaining temperature control of said refined molten metal and minimizing re-oxidation;

monitoring the temperature of said refined molten metal;

transferring said refined molten metal while protecting said refined molten metal;

controlling the pouring rate of said refined molten metal;

minimizing temperature losses and minimizing argon losses;

metering said refined molten metal;

freezing said refined molten metal and producing a small diameter bar or ingot;

moving said small diameter bar or ingot and allowing said small diameter bar or ingot to drop; and

transporting said small diameter bar or ingot.

9. Means for performing the method of manufacturing small diameter bars or ingots according to claim 8; said means comprising:

means for refining molten metal for a first run of small diameter bars or ingots;

means for transferring refined molten metal;

means for protecting refined molten metal from the atmosphere;

means for argon-stirring refined molten metal to promote homogeneity, temperature, and cleanliness of the refined molten metal;

means for protecting refined molten metal from re-oxidation;

means for bottom-pouring refined molten metal while protecting the refined molten metal from re-oxidation;

means for maintaining temperature control of refined molten metal and minimizing re-oxidation;

means for monitoring the temperature of refined molten metal;

means for transferring refined molten metal while protecting the refined molten metal;

means for controlling the pouring rate of refined molten metal;

means for minimizing temperature losses and minimizing argon losses;

means for metering refined molten metal;

means for freezing refined molten metal and producing a small diameter bar or ingot;

means for moving a small diameter bar or ingot and allowing the small diameter bar or ingot to drop; and

means for transporting a small diameter bar or ingot.

10. A small diameter bar or ingot manufacturing arrangement for performing the method of manufacturing small diameter bars or ingots according to claim 8; said small diameter bar or ingot manufacturing arrangement comprising:

a refining arrangement configured to refine molten metal for a first run of small diameter bars or ingots;

a first transferring arrangement being configured to transfer refined molten metal;

a first protecting arrangement being configured to protect refined molten metal from the atmosphere;

an argon-stirring arrangement being configured to argon-stir refined molten metal to promote homogeneity, temperature, and cleanliness of the refined molten metal;

a second protecting arrangement being configured to protect refined molten metal from re-oxidation;

a bottom-pouring arrangement being configured to bottom-pour refined molten metal while the refined molten metal is being protected from re-oxidation;

a maintaining arrangement being configured to maintain temperature control of refined molten metal and minimize re-oxidation;

a monitoring arrangement being configured to monitor the temperature of refined molten metal;

a second transferring arrangement being configured to transfer refined molten metal while the refined molten metal is being protected;

a controlling arrangement being configured to control the pouring rate of refined molten metal;

a minimizing arrangement being configured to minimize temperature losses and minimize argon losses;

a metering arrangement being configured to meter refined molten metal;

a freezing arrangement being configured to freeze refined molten metal and produce a small diameter bar or ingot;

a moving arrangement being configured to move a small diameter bar or ingot and allow the small diameter bar or ingot to drop; and

a transporting arrangement being configured to transport a small diameter bar or ingot.

11. The method of manufacturing small diameter bars or ingots using a bar mold system according to claim 8, wherein:

said step of metering further comprises metering said refined molten metal from a pouring vessel, through a plurality of stopper rod nozzle assemblies, and into a multi-part bar mold system;

said multi-part bar mold system comprises water-cooled side walls and a water-cooled bottom;

said method further comprises controlling said moving with a control device;

said step of moving said small diameter bar or ingot and allowing said small diameter bar or ingot to drop further comprises moving said water-cooled sidewalls, and thereby said small diameter bar or ingot, away from said water-cooled bottom of said multi-part bar mold system and allowing said small diameter bar or ingot to drop onto a collection conveyor;

said method further comprises:

12. The method of manufacturing small diameter bars or ingots using a bar mold system according to claim 11, wherein:

said method of bottom-pouring further comprises bottom-pouring said refined molten metal into a holding tundish while protecting said refined molten metal with a shroud comprising an inert gas;

said method further comprises:

skimming said refined molten metal in said holding tundish;

sealing said holding tundish to minimize heat losses and argon losses; and

13. The method of manufacturing small diameter bars or ingots using a bar mold system according to claim 12, wherein:

said step of transferring said refined molten metal while protecting said refined molten metal further comprises transferring said refined molten metal into a pouring vessel while protecting said refined molten metal with said shroud comprising an inert gas;

said holding tundish and said pouring vessel are configured to permit:

control of the temperature of said refined molten metal;

protection of the homogeneity and cleanliness of said refined molten metal; and

14. The method of manufacturing small diameter bars or ingots using a bar mold system according to claim 13, wherein said holding tundish comprises:

insulated walls;

an insulated floor;

an induction coil;

a power supply;

an automated control system;

a spout;

at least one of: screw jacks and electric cylinders; and

15. The method of manufacturing small diameter bars or ingots using a bar mold system according to claim 14, wherein:

said pouring vessel comprises:

insulated walls;

a floor;

an insulated pouring vessel lid, which insulated pouring vessel lid comprises ports for temperature monitoring and ports for argon backfill flooding;

a temperature monitoring arrangement;

an emergency run out arrangement;

stopper rods;

a nozzle;

a metal level control system; and

an automated control system;

said multi-part bar mold system further comprises:

at least one quick-change water-cooled mold size and shape insert; and

said step of transferring said refined molten metal further comprises transferring said refined molten metal into a ladle;

said step of protecting said refined molten metal from the atmosphere further comprises protecting said refined molten metal from the atmosphere with an insulating ladle cover

said step of controlling the pouring rate further comprises controlling the pouring rate of said refined molten metal with a pouring control arrangement;

said pouring control arrangement comprises at least one of: load cells, a level detection device, measuring rods, a tilting device, a screw jack, and a trunnion;

said pouring control arrangement further comprises at least one of: an encoder, a linear position transducer, or a similar device, in order to monitor the position of said pouring vessel;

said method is used for the manufacture of small diameter bars or ingots comprising at least one of: steels, superalloys, nickel base, cobalt base, copper-based grades, and raw material master alloys; and

said shroud comprising an inert gas comprises an argon shroud.

16. A method for the manufacture of metal bars using a bar mold system comprising: a ladle; a ladle cover; an argon shroud; a holding tundish; a temperature control device; a probe; a monitor device; a pouring vessel comprising two independently operated stopper rod assemblies on the bottom of said pouring vessel; a controller to operate said stopper rod assemblies; a pouring control arrangement; a mold arrangement comprising moveable water-cooled side walls, size and shape inserts, and a water-cooled bottom base plate; a collection conveyor; and an identification station; said method comprising the steps of:

refining molten metal for a first run of metal bars;

transferring said molten metal into said ladle;

maintaining homogeneity of said molten metal by means of argon stirring;

protecting said molten metal from re-oxidation by use of said argon shroud and said ladle cover;

bottom-pouring said molten metal while said molten metal is surrounded by said argon shroud into said holding tundish;

maintaining temperature control of said molten metal with said temperature control device and minimizing the chance of re-oxidation in said holding tundish;

monitoring the molten metal temperature with said probe that is connected to said monitor device;

transferring said molten metal surrounded by said argon shroud into said pouring vessel;

controlling the pouring rate of said molten metal with said pouring control arrangement;

transferring said molten metal into said mold arrangement;

freezing said molten metal against said moveable water-cooled side walls and said water-cooled bottom base plate of said mold arrangement upon said molten metal entering said mold arrangement;

separating said moveable water-cooled side walls from said water-cooled bottom base plate and allowing the newly formed metal bar to drop onto said collection conveyor;

transporting said newly formed metal bar to said identification station.

17. The method for the manufacture of metal bars using a bar mold system according to claim 16, wherein:

said water-cooled bottom base plate of said mold arrangement is configured to remain stationary during said steps of transferring said molten metal into said mold arrangement, freezing, and separating; and

said method further comprises:

moving said moveable water-cooled side walls over said stationary water-cooled bottom base plate prior to said step of transferring said molten metal into said mold arrangement; and

moving said moveable water-cooled side walls away from said water-cooled bottom base plate of said mold arrangement after said step of freezing, thereby creating a bottomless mold.

18. The method for the manufacture of metal bars using a bar mold system according to claim 17, wherein said method further comprises:

skimming said molten metal in said holding tundish;

sealing said holding tundish to minimize heat losses and argon losses; and

inserting said probe into said molten metal and monitoring the temperature of refined molten metal.

19. The method for the manufacture of metal bars using a bar mold system according to claim 18, wherein said holding tundish and said pouring vessel are configured to permit:

control of the temperature of said molten metal;

protection of the homogeneity and cleanliness of said molten metal; and

20. The method for the manufacture of metal bars using a bar mold system according to claim 19, wherein:

said holding tundish comprises:

insulated walls;

an insulated floor;

an induction coil;

a power supply;

an automated control system;

a spout;

at least one of: screw jacks and electric cylinders; and

and at least one of: a plurality of linear positions transducers and a plurality of encoders;

said pouring vessel comprises:

insulated walls;

a floor;

a temperature monitoring arrangement;

an emergency run out arrangement;

stopper rods;

a nozzle;

a metal level control system; and

an automated control system;

said mold arrangement further comprises:

at least one quick-change water-cooled mold size and shape insert; and

a motion control system configured to move said moveable water-cooled side walls before and after said step of transferring said molten metal into said mold arrangement;

said mold arrangement is comprised of one of: Chrome-Zinc Alloy grade #108, C18150, or Alloy grade #101;