Systems and Methods for Steam Condensation in Aluminum Direct Chill Casting Pit

This application claims the benefit of U.S. Provisional Patent Application No. 63/367,061, filed on Jun. 27, 2022, and entitled SYSTEMS AND METHODS FOR STEAM CONDENSATION IN ALUMINUM DIRECT CHILL CASTING PIT, the content of which is hereby incorporated by reference in its entirety.

This application relates to metal processing generally, and more specifically to steam-generating metal processing such as, but not limited to, direct chill casting.

Steam may be generated during various metal processes. As an example, a casting process such as direct chill (DC) casting may generate steam as the system directs water onto an ingot being cast for purposes of cooling the ingot. Some water may not turn into steam during such processing, and such water in liquid form may be re-cooled by a cooling system and used again during the casting process. Other water may turn into steam during cooling of the ingot. Within the casting pit, such steam may provide a safety hazard by reducing visibility before it is traditionally vented to the environment. Steam also may rise out of the casting pit and re-condense on the equipment around the casting pit and/or above the molten metal, which may reduce the life cycle of the equipment and potentially cause product defects on the head of the ingot. New or make-up water must be introduced into the system on a regular basis to compensate for the water that is lost as steam. Such new or make-up water requirements are costly from both a monetary perspective and a resource perspective.

Embodiments covered by this patent are defined by the claims below, not this summary. This summary is a high-level overview of various embodiments and introduces some of the concepts that are further described in the Detailed Description section below. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used in isolation to determine the scope of the claimed subject matter. The subject matter should be understood by reference to appropriate portions of the entire specification of this patent, any or all drawings, and each claim.

According to various embodiments, a metal processing system for processing a metal substrate includes a steam condensation system for condensing steam generated during metal processing of the metal substrate.

According to certain embodiments, a DC casting system includes a steam condensation system for condensing steam generated during a DC casting process.

According to some embodiments, a DC casting system includes a cooling system that at least partially cools the metal ingot during a DC casting process. In certain embodiments, the cooling system may cool the metal ingot by directing water from a coolant supply onto the metal ingot. The cooling system may include a steam condensation system for condensing steam generated during a DC casting process.

According to various embodiments, a method of DC casting a metal ingot includes cooling the metal ingot emerging from a mold by directing water from a coolant supply onto the metal ingot and condensing steam generated by the cooling of the metal ingot as recycled water. The method includes providing the recycled water to the coolant supply.

According to certain embodiments, a metal processing system for processing a metal substrate includes a steam condensation system for directing a flow of steam generated during metal processing of the metal substrate by spraying water relative to a direction of the flow of the steam.

Various implementations described herein may include additional systems, methods, features, and advantages, which cannot necessarily be expressly disclosed herein but will be apparent to one of ordinary skill in the art upon examination of the following detailed description and accompanying drawings. It is intended that all such systems, methods, features, and advantages be included within the present disclosure and protected by the accompanying claims.

Described herein are systems and methods for condensing steam produced by a metal processing system, such as but not limited to a casting system such as a DC casting system. The systems and methods described herein may condense the steam as recycled water, and in some embodiments, the recycled water may be returned to a cooling system of the metal processing system such that the recycled water can be used for cooling of a metal substrate. The systems and methods described herein may reduce the amount of water that is conventionally lost to the environment, thereby reducing the amount of new or make-up water that needs to be introduced into the system. As such, the systems and methods provided herein may be less costly and less resource intensive compared to traditional metal processing systems that vent any steam generated as a byproduct of metal processing. The systems and methods described herein may also return the recycled water back to a cooling system of the metal casting system, thereby allowing the recycled water to be used as a coolant during a casting process. Various other benefits and advantages may be realized with the systems and methods provided herein, and the aforementioned advantages should not be considered limiting.

illustrates a metal processing systemaccording to various embodiments. The metal processing systemincludes one or more metal processing stations, a cooling system, and a steam condensation system.

The cooling systemprovides a coolant such as liquid water to the metal processing station(represented by arrow). The metal processing stationmay be various metal processing devices, stations, workplaces, etc. as desired that utilize the water from the cooling systemto cool a metal substrate. The metal processing performed by the metal processing stationmay generate steam (represented by arrow), and the steam condensation systemcondenses the steam into recycled water. Optionally, and as represented by arrow, the steam condensation systemmay provide the recycled water back to the cooling systemsuch that the recycled water can be supplied to the metal processing stationas liquid water. The steam condensation systemmay be various systems and devices for condensing the steam from the metal processing station, and non-limiting examples of steam condensation systems are discussed in detail below and illustrated in.

illustrates a non-limiting example in which the metal processing stationis a DC casting system. As illustrated in, the DC casting systemgenerally includes a casting pit with at least one open-ended moldthat defines a casting cavity, and molten metal may be introduced into the casting cavity as represented by arrow. The moldis initially closed at a lower end by a bottom block, and the bottom blockremains in place until a certain amount of molten metal has built up in the casting cavity and begun to cool. The bottom blockis then moved away from the moldsuch that an ingotgradually emerges from the lower end of the mold. The ingotmay be produced with a desired length by movement of the bottom blockand correspondingly continuous supply of molten aluminum to the mold, limited only by the space available below the mold.

In various embodiments, the cooling systemmay be in fluid communication with the moldfor supplying water or other coolant to the mold. The mold wall is typically cooled to provide cooling of the metal within the casting cavity. The ingotemerging from the lower end of the moldin DC casting is externally solid but is still molten in its central core. To maintain the periphery of the ingot and to promote internal cooling and solidification of the ingot, a coolant such as wateris directly applied onto a surfaceof the ingotemerging from the mold. In this procedure, the wateris directed onto the ingot surface. Some of the waterflows downwardly over the ingot surfaceand the remaining water turns into steam. As previously mentioned, the steamgenerated by DC casting is traditionally vented to the environment.

As illustrated in, a steam condensation systemis provided for processing of the steam. In the embodiment illustrated in, the steam condensation systemincludes one or more nozzles or sprayers. The sprayersare configured to spray waterinto the casting pit for interaction with the steam, which in turn causes condensation of the steamas recycled water (represented by arrows). In some embodiments, the sprayersmay spray the waterin various forms. In one non-limiting example, the sprayersoptionally spray the wateras fine droplets, although in other embodiments, the sprayersmay introduce the waterinto the casting pit for interaction with the steamas desired. The sprayersmay be various types of nozzles as desired and may introduce the waterin various spray patterns as desired. As two non-limiting examples, the sprayersmay be nozzles that introduce the waterin a flat spray pattern, a hollow cone spray pattern, a full cone spray pattern, and/or other patterns as desired.

In addition to being various types of nozzles as desired, the number and location of the sprayersshould not be considered limiting as the steam condensation systemmay include any number of sprayersat various locations as desired. In certain embodiments, one or more of a type of nozzle, a location of the nozzle, and a number of nozzles may be controlled to control a rate and/or an amount of condensation of the steam. Additionally or alternatively, other control parameters of the sprayersmay be controlled for controlling the rate and/or amount of condensation of the steam, including but not limited to a pressure of the water, a flow rate of the waterto the sprayers, a temperature of the waterbeing dispensed, combinations thereof, and/or other control parameters as desired. The control parameters also may be controlled and/or changed during the casting process as the conditions of steam generation change. As a non-limiting example, a casting process may start out with low water flow, move to high water flow, and then have a reduced water flow during the casting process.

As mentioned, the waterdispensed by the sprayersin turn causes condensation of the steaminto recycled water(e.g., in liquid form). The watermay be collected using various devices, mechanisms, or techniques as desired, including but not limited to various collecting tanks, drains, suction devices, etc. as desired. The collected recycled wateroptionally may be returned to the cooling systemsuch that the recycled watermay be re-cooled (if needed) and/or otherwise treated as desired. Such watermay then be supplied to the DC casting systemfor cooling of the ingotand/or for use by the sprayers. As mentioned, by condensing the steamgenerated by the metal processing (e.g., DC casting), the system is able to re-use the recycled waterfor subsequent cooling, thereby providing cost and resource savings.

illustrates another example of a steam condensation systemfor a metal processing system according to embodiments. In one non-limiting example, the steam condensation systemmay be used with the DC casting systemin place of or in addition to the steam condensation system. In the embodiment of, the steam condensation systemincludes a conduit, and the steamis condensed into recycled water within the conduit.

In certain embodiments, and as illustrated in, the conduitincludes one or more inlets. In some embodiments, the conduitmay be elongated between opposing ends,, and the one or more inletsmay be provided on a side wallbetween the ends,. As represented by arrows, the steammay enter the conduitvia the one or more inlets. The conduitfurther includes one or more fluid outletsfor discharging the recycled waterafter the steamhas been condensed within the conduit.

The steam condensation systemincludes one or more devices or mechanisms for condensing the steamwithin an internal regionof the conduit.

In some embodiments, and as illustrated in, the steam condensation systemincludes one or more of the sprayersfor spraying the wateronto the steamwithin the internal region. In certain embodiments, the sprayersare within an internal regionof the conduit; however, in other embodiments, the sprayersneed not be within the internal region, and the sprayersmay direct the waterinto the internal region. The number, type, and location of the sprayerswithin and/or relative to the conduitshould not be considered limiting.

In some embodiments, the sprayersand/or nozzles may be controlled such that the wateris directed in various directions relative to steam and/or air flow. In such embodiments, the sprayersmay further be utilized to assist in controlling the direction of steam and/or air flow. As non-limiting examples, the sprayersand/or nozzles may be controlled such that the wateris directed (e.g., in droplet form or otherwise desired) parallel to steam and/or air flow, at a non-zero angle relative to steam and/or air flow, in a cross-flow direction relative to the steam and/or air flow, combinations thereof, and/or as otherwise desired. In certain embodiments, the angle or orientation of the sprayersand/or nozzles may be adjustable such that the angle of waterfrom the sprayersand/or nozzles (and thus the ability to control steam and/or air flow) is adjustable as desired. Such control may be achieved automatically (e.g., using a controller (processor and/or memory) communicatively coupled to the sprayersand/or other actuator as desired) and/or by the operator.

Additionally or alternatively, the steam condensation systemoptionally includes one or more chiller conduitswithin the internal region. A coolant such as chilled water may be directed through the chiller conduitfor reducing a temperature within the internal region, thereby causing condensation of the steam. As another non-limiting example, a chilled gas such as but not limited to chilled air may be used as the coolant. Other devices, materials, and/or mechanisms within the internal regionfor condensing the steammay be utilized as desired.

Similar to the steam condensation system, after the steamhas been condensed to the recycled waterby the steam condensation system, the recycled wateroptionally may be provided to a cooling system before being used as part of cooling during metal processing.

In some embodiments, one or more suction devices, such as air movers, optionally may be included with the conduitfor generating a suction force that draws the steaminto the conduit. As non-limiting examples, the air movermay be a blower or fan that pulls air and the steaminto the conduit. In the embodiment illustrated, the steam condensation systemincludes two air moversprovided at the opposing ends,of the conduit. However, in other embodiments, the steam condensation systemmay include any number of air movers as desired, including omitting air movers, a single air mover, or more than two air movers. The one or more air moversmay be provided at any suitable location.

illustrates another example of a steam condensation systemfor a metal processing system according to embodiments. Similar to the steam condensation system, the steam condensation systemincludes a conduit. Steammay be directed into the conduit(represented by arrow) where the steamis condensed into recycled water. In some embodiments, similar to the steam condensation system, the steam condensation systemmay include the one or more air moversfor generating a suction force that draws the steaminto the conduit.

Compared to the steam condensation systemwith the internal cooling devices or mechanisms for condensing the steam, the steam condensation systemincludes one or more cooling devices or mechanisms on an external surfaceof the conduitfor cooling the temperature of the conduit. The external cooling devices or mechanisms may be various suitable devices or mechanisms as desired.

Referring to, in some embodiments, process gas lines or conduitfor the metal processing system may be provided on the external surfacefor cooling of the conduit. In certain embodiments, because process gases may be provided at lower temperatures, the conduitmay have a reduced temperature, and as such, placing the conduitin contact with the conduitmay provide cooling to the conduit. The process gas linesmay be various process gas lines as desired and may depend on the particular metal processing system. Non-limiting examples of process gas linesmay be one or more of an argon gas line, a nitrogen gas line, a carbon dioxide gas line, a chlorine gas line, combinations thereof, and/or other processing gas linesas desired.

Additionally or alternatively to the process gas lines, the conduitmay include one or more heat exchanger finsalong the conduit. In some embodiments, the heat exchanger finsmay be circular fins on the conduitand optionally may be provided along the length of the conduit. However, in other embodiments, the heat exchanger finsmay have other shapes or profiles as desired, and the heat exchanger finsmay be provided along the conduitas desired. In other embodiments, other devices or mechanisms suitable of externally cooling the conduitmay be used as desired.

The external cooling devices of the steam condensation systemcool the conduit, thereby reducing the temperature within the internal region of the conduit. Such reduction in temperature may cause the steamto condense within the conduit as recycled water. The steamcondensed into recycled water optionally may be held in a storage tankbefore being directed to a cooling system or as otherwise desired (represented by arrow).

While the steam condensation systems,,are illustrated separately, in various embodiments, two or more condensation systems may be employed with a metal processing system. As a non-limiting example and referring to, the DC casting systemmay utilize both the steam condensation systemand the steam condensationand/or may utilize all of the steam condensation systems,,. Various other combinations or sub-combinations of steam condensation systems may be utilized as desired. Moreover, in other embodiments, other steam condensation systems may be utilized in addition to or in place of the steam condensation systems,,.

Referring back to, a method of processing a metal substrate with the metal processing systemhaving the steam condensation systemincludes providing water to the metal processing stationfor a cooling process. In one non-limiting example, providing water to the metal processing stationmay include providing water to the DC casting systemand cooling the metal ingotemerging from the moldby directing the water onto the metal ingot.

The method includes condensing steam generated by the cooling process into recycled water using the steam condensation system. In some embodiments, condensing the steam may include spraying water into the steam. In certain embodiments, condensing the steam may include drawing the steam into a conduit, and condensing the steam using an internal cooling device and/or an external cooling device. Non-limiting examples of internal cooling devices may include sprayers and/or a chiller conduit(s), and non-limiting examples of external cooling devices may include processing gas lines and/or heat exchanger fins.

In certain embodiments, the method optionally includes providing the recycled water from the steam condensation systemto the cooling system. The method optionally includes re-cooling and/or otherwise treating the recycled water with the cooling systemor using another system as desired. The method includes providing the recycled water from the cooling systemto the metal processing stationfor the cooling process.

A collection of exemplary embodiments are provided below, including at least some explicitly enumerated as “Illustrations” providing additional description of a variety of example embodiments in accordance with the concepts described herein. These illustrations are not meant to be mutually exclusive, exhaustive, or restrictive; and the disclosure not limited to these example illustrations but rather encompasses all possible modifications and variations within the scope of the issued claims and their equivalents.

Illustration 1. A DC casting system for casting a metal ingot, the DC casting system comprising a steam condensation system for condensing steam generated during a DC casting process.

Illustration 2. The DC casting system of any preceding or subsequent illustrations or combination of illustrations, wherein the steam condensation system comprises a plurality of sprayers configured to spray water inside a casting pit of the DC casting system.

Illustration 3. The DC casting system of any preceding or subsequent illustrations or combination of illustrations, wherein the plurality of sprayers comprise a plurality of nozzles.

Illustration 4. The DC casting system of any preceding or subsequent illustrations or combination of illustrations, wherein the plurality of sprayers are configured to control a direction of steam flow and/or air flow by spraying the water inside the casting pit.

Illustration 5. The DC casting system of any preceding or subsequent illustrations or combination of illustrations, wherein the plurality of sprayers are adjustable such that the direction of steam flow and/or air flow is adjustable by spraying the water inside the casting pit.

Illustration 6. The DC casting system of any preceding or subsequent illustrations or combination of illustrations, wherein the steam condensation system comprises: a conduit comprising at least one inlet and at least one outlet and configured to receive the steam; a suction device configured to generate a suction force for pulling the steam through the at least one inlet into the conduit; and at least one sprayer within the conduit for spraying water within the conduit.

Illustration 7. The DC casting system of any preceding or subsequent illustrations or combination of illustrations, wherein the conduit comprises a first end, a second end, and a side wall extending from the first end to the second end, wherein the suction device is provided on the first end, and wherein the at least one inlet and the at least one outlet are provided on the side wall of the conduit.

Illustration 8. The DC casting system of any preceding or subsequent illustrations or combination of illustrations, wherein the suction device is a first suction device, and wherein the steam condensation system further comprises a second suction device on the second end of the conduit for pulling the steam into the conduit.

Illustration 9. The DC casting system of any preceding or subsequent illustrations or combination of illustrations, wherein the steam condensation system comprises a conduit for receiving the steam and a cooling device on an external surface of the conduit for cooling the conduit.

Illustration 10. The DC casting system of any preceding or subsequent illustrations or combination of illustrations, wherein the cooling device comprises at least one of a processing gas line for the DC casting process or a plurality of heat exchanger fins.

Illustration 11. A DC casting system for casting a metal ingot, the DC casting system comprising a cooling system configured to at least partially cool the metal ingot during a DC casting process by directing water from a coolant supply onto the metal ingot, the cooling system further comprising a steam condensation system for condensing steam generated during a DC casting process.

Illustration 12. The DC casting system of any preceding or subsequent illustrations or combination of illustrations, wherein the steam condensation system is configured to condense steam generated by the cooling of the metal ingot as recycled water and provide the recycled water to the coolant supply.

Illustration 13. The DC casting system of any preceding or subsequent illustrations or combination of illustrations, wherein the steam condensation system comprises a sprayer configured to spray water for condensing the steam.

Illustration 14. The DC casting system of any preceding or subsequent illustrations or combination of illustrations, wherein the steam condensation system further comprises a conduit and a suction device for pulling steam into the conduit, and wherein the sprayer is within the conduit.