HBI slow cooling system and method

Abstract

The agglomerate cooling conveyor system includes a skirted pan conveyor. The skirted pan conveyor includes a skirt pan with openings adapted to drain water from the skirted pan conveyor, a carrying strand at an upper portion of the skirt pan, and a return strand at a lower portion of the skirt pan. The agglomerate cooling conveyor system also includes a carriage-side flush hopper positioned between the carrying strand at the upper portion of the skirt pan and the return strand at the lower portion of the skirt pan, and the carriage-side flush hopper is configured to capture fines and water from the system.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] The subject U.S. non-provisional patent application claims priority to U.S. Provisional Patent Application No. 63 / 092,015, filed on October 15, 2020, the contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates generally to the fields of direct reduced iron (DRI) and ironmaking. More particularly, the present disclosure relates to systems and methods for slowly cooling briquettes. Background Art

[0004] Hot Direct Reduced Iron (HDRI) is distributed from the DRI furnace to a briquetting press to form Hot Briquetted Iron (HBI), a dense form of DRI whose quality is improved by cooling the material from an agglomeration temperature of about 650°C-700°C to 400°C in about 2 minutes and not less than about 1.5 minutes. HBI is a dense form of DRI that is easier to handle, transport, and store.

[0005] HBI quality is measured based on the cooling rate downstream of the agglomeration operation. Agglomerates that are slowly cooled to about 400°C are generally high quality agglomerates because they generally exhibit higher strength and lower breakage based on drop tests. A specific drop test commonly employed involves dropping five single agglomerate samples of HBI individually from a height of 5 or 10 meters, then collecting the fragments and measuring the size distribution of the mass fraction. The historical standard was the 10 meter drop test, although the 5 meter drop test has been used more recently for convenience. The key size fraction for quality measurement is the +38 mm size fraction. By employing slow cooling, the +38 mm size fraction can be increased from a range of 55%-65% to a range of 80%-85%. This quality parameter means that more agglomerates remain intact during handling, storage and transportation, which provides the end user (e.g., a furnace operator) with a consistent product stream that is mostly intact agglomerates and / or large fragments. Smaller fines and fragments are generally considered detrimental for a number of reasons, including but not limited to: higher metal losses through increased reoxidation; increased handling difficulty; increased losses due to carryover in the exhaust gas; increased fragment separation leading to bridging / plugging; and increased melting difficulty.

[0006] In recent years, HBI quality assurance has relied on tumble testing, which is often used in conjunction with or instead of drop testing. The tumble test is governed and defined by the International Organization for Standardization (ISO) test procedure (ISO procedure No. 15967-2007), while the drop test is not governed or defined by ISO test procedures. The tumble test involves loading a certain amount of agglomerate into a rotating drum, which tumbles the material for hundreds of revolutions. The agglomerate is then discharged and screened to measure the mass fraction based on the screen size. A typical quality target is that 95% of the material has a measurement greater than 6.35 mm (95% + 6.35 mm). Although the tumble test results may not be meaningful to the end user in terms of defining the quality of the HBI agglomerate, the advantages of the tumble test include that it is easy to replicate, it is a formally recognized standard, and it can be used in combination with the drop test.

[0007] It is noteworthy that the drop test was the original metric used by several HBI plants operated by Kobe Steel to establish the quality of the slow cooling process. The slow cooling process (i.e., cooling the material from an agglomeration temperature of approximately 650°C-700°C to 400°C in approximately 2 minutes and no less than approximately 1.5 minutes) is well-proven, with millions of tons of HBI product delivered since its implementation in the early 1990s.

[0008] The equipment used to implement the slow cooling process has evolved over the ensuing decades. However, each unit can suffer from some combination of the following: high frequency of mechanical maintenance, high mechanical wear and / or breakage of various equipment components, cooling interruptions due to fines accumulation within the equipment, insufficient cooling performance of the equipment for agglomerates, inadequate steam removal from the equipment, and inadequate fines / water separation. The HBI slow cooling process presents an extreme combination of factors that make it difficult to design and implement cost-effective and reliable mechanical equipment.

[0009] Therefore, there remains a need to provide an improved apparatus and method for achieving the desired slow cooling process. Embodiments of the present invention address these and other needs. Summary of the Invention

[0010] Methods deployed for slow cooling of agglomerates to produce HBI products typically use water as the primary cooling medium. Water distribution is regulated and controlled to achieve a slow cooling regime (the material cools from an agglomeration temperature of approximately 650°C to 700°C to 400°C in approximately 2 minutes and no less than 1.5 minutes). Water distribution is typically performed using one of a weir overflow device, which pours water down onto the agglomerates, and a pressurized nozzle, which sprays water onto the agglomerates. However, a problem with using such weir overflow devices and pressurized nozzles is that the components of the skirt conveyor are often damaged to varying degrees by water immersion and constant exposure to water spray. Damage includes damage to the rollers and chains of the skirt conveyor due to failure of water-damaged seals, weakening of the chain links due to corrosion, accumulation of fines, and wear caused by water-borne fines.

[0011] The agglomerates are transported using one of a mesh belt, a skirted pan conveyor, and a vibrating conveyor. Skirted pan conveyors are a particularly advantageous mode of transporting agglomerates. However, skirted pan conveyors used in this application have a high rate of mechanical failure, including support roller failure, carriage track failure, pan wear, and drive chain failure. In some cases, deploying a vibrating unit on a skirted pan conveyor can lead to failures, such as requiring complete replacement or limiting the use of another skirted pan conveyor. Furthermore, the mesh belts used in skirted pan conveyors require regular replacement, such as annually or semi-annually.

[0012] In addition, the collection and removal of fine material is problematic and difficult, causing significant problems with skirted disc conveyors. For example, in existing versions, skirted disc conveyors use fully submerged drag chains, which have proven useful but are prone to high wear and breakage. High wear and breakage lead to repeated repairs and replacements. Newer versions of skirted disc conveyor systems have also encountered problems such as clogging with fine material and inadequate removal of fine material, each of which requires significant maintenance steps to clear the fine material from the system and keep the system clean and operating properly. In addition to the significant maintenance issues, in some cases additional systems such as vacuum systems are installed for the sole purpose of regularly cleaning the pool. These systems require additional capital investment and may require scheduled shutdowns of the system for their use.

[0013] As the volumetric output of HBI at a plant increases, the size of the slow cooling system also increases. Increasing the size of the slow cooling system increases the likelihood of uneven material distribution on the conveyor, which can affect agglomerate cooling and the mechanical performance of the conveyor. For example, increasing the size of the slow cooling system results in an increase in the number of loading points per cooling conveyor. The increase in loading points per conveyor can lead to issues with proper distribution and leveling of agglomerates on the conveyor. Furthermore, the increase in loading points can lead to increased wear on the trays, indicating a need for improved loading.

[0014] Steam removal and extraction are also difficult and may require significant capital investment to improve using current methods. In addition, handling metal and oxide fines entrained in saturated steam is inherently problematic because salting of the fines can accumulate into bridges and block piping systems. Furthermore, cooling HBI emits small amounts of carbon monoxide (CO) gas, which should also be managed. Finally, emission controls should also be managed and improved to meet increasingly stringent regulatory levels for particulate matter and gaseous emissions.

[0015] In view of the foregoing and as described above, there remains a need to provide an improved apparatus and method for achieving a desired slow cooling process. Embodiments of the present invention address these needs and other needs.

[0016] For example, according to embodiments, the HBI slow cooling system and method of the present disclosure include advantageous redesigns to achieve desired process parameters while mitigating negative impacts achieved over an approximately 30-year operational installation span. In particular, the HBI slow cooling system and method herein address demanding service requirements through components specifically adapted to overcome known failure modes.

[0017] More particularly, according to embodiments, the HBI slow cooling systems and methods of the present disclosure are advantageously adapted to shield components from exposure to constant water spray while ensuring that the components are not submerged in water.

[0018] According to one aspect of the present invention, a briquette cooling conveyor system includes a skirt tray conveyor. The skirt tray conveyor includes: a) one or more skirt trays, the skirt trays including openings suitable for draining water from the skirt tray conveyor; b) a carrier strand at the upper portion of the skirt tray; and c) a return strand at the lower portion of the skirt tray. The conveyor system also includes a carriage side flush hopper positioned between the carrier strand at the upper portion of the skirt tray and the return strand at the lower portion of the skirt tray. The carriage side flush hopper is configured to capture fine material and water from the system. In addition, the system can be configured to slowly cool the hot briquette from an agglomeration temperature of approximately 650°C-700°C to 400°C in approximately 2 minutes and not less than approximately 1.5 minutes. The system may include a return-side flush hopper positioned below the return strand, wherein the carriage-side flush hopper includes a wash sprayer adapted to wet the sides of the carriage-side flush hopper and a channel flow nozzle configured to generate a channel flow of water to flush solids to a desired output, wherein the flow is between about 50 gal / min and about 150 gal / min. The carriage-side flush hopper may include at least one spiral classifier, and each spiral classifier may include a water overflow flow channel. The carriage-side flush hopper may include a hopper bottom having one of an arc shape, a V shape, and a trapezoidal shape. The conveyor system may include a cooling system, wherein the cooling system includes a plurality of coarse spray nozzles configured to spray water onto the agglomerates in a coarse droplet size having a diameter of about 0.8 mm to about 2 mm. The carriage-side flush hopper and the return-side flush hopper may be configured to discharge the flow to a close-coupled classifier, and the classifier may be configured to discharge the water to a pump sump. The system can be configured to recirculate water to the wash sprayers and water treatment. The conveyor can be inclined on a single plane and the system includes: a hot lump iron loading chute coupled to the conveyor and a load leveling device on the conveyor, the load leveling device configured to evenly spread the iron, the load leveling device including a helical screw. The return strand can be equipped with a cleaning spray nozzle for washing any residual material on the skirt into the return side rinse hopper.

[0019] According to another aspect of the present invention, a method for cooling hot briquette iron includes providing a briquette cooling conveyor system. The system includes a skirted tray conveyor. The skirted tray conveyor includes: a) one or more skirted trays, the skirted trays including openings for draining water from the skirted tray conveyor; and b) a carrier strand at an upper portion of the skirted tray; and c) a return strand at a lower portion of the skirted tray. The system also includes a carriage side flush hopper positioned between the carrier strand at an upper portion of the skirted tray and the return strand at a lower portion of the skirted tray, the carriage side flush hopper capturing fine material and water from the system. The method also includes cooling the hot briquette iron from an agglomeration temperature of about 650°C-700°C to 400°C in about 2 minutes and not less than about 1.5 minutes as the iron travels along the skirted tray conveyor, wherein the discharge temperature is greater than about 85°C and less than about 130°C. The conveyor system may include a return-side flush hopper positioned below the return strand, wherein the carriage-side flush hopper includes a wash sprayer for wetting the sides of the carriage-side flush hopper and a channel flow nozzle for generating a channel water flow to flush solids to a desired output, wherein the flow is between approximately 50 gal / min and approximately 150 gal / min. The carriage-side flush hopper may include at least one spiral classifier, each spiral classifier including a water overflow trough. The carriage-side flush hopper may include a hopper bottom having one of an arc shape, a V shape, and a trapezoidal shape. The system may include a cooling system including a plurality of coarse spray nozzles for spraying water onto the agglomerates in a coarse droplet size having a diameter of approximately 0.8 mm to approximately 2 mm. The carriage-side flush hopper and the return-side flush hopper may discharge flow to a close-coupled classifier, and the classifier may discharge water to a pump sump. The system may recirculate water to the wash sprayer and water treatment. The conveyor may be inclined on a single plane, and the system includes a hot lump iron loading chute coupled to the conveyor and a load leveling device on the conveyor configured to evenly distribute the iron, the load leveling device including a helical screw. The return strand may be equipped with cleaning spray nozzles for washing any residual material on the skirt into the return-side flush hopper. After cooling, the discharged iron may have a retained moisture level of less than approximately 1.5% by weight.

[0020] According to another embodiment and as further described below, the skirt can be the same as described above, and the flush flow can be higher than about 150 gal / min, and there is no classifier in the carriage side flush hopper. The higher flush flow can flush all the slurry to a close-coupled classifier, which separates the solids to a fine material conveyor, and the water overflows to a sump for pumping, as described above. Differences from the previous aspect can include: a) no classifier in the hopper, and b) the higher flow causes all the slurry to flow to a single classifier at the end. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present disclosure is illustrated and described with reference to the various accompanying drawings, in which:

[0022] Figure 1 is a schematic cross-sectional view illustrating an example embodiment of an HBI slow cooling system of the present disclosure;

[0023] Figure 2 It is an icon Figure 1 Schematic diagram of the side of the HBI slow cooling system;

[0024] Figure 3 is a schematic cross-sectional view illustrating another example embodiment of the HBI slow cooling system of the present disclosure;

[0025] Figure 4 is a schematic cross-sectional view illustrating another example embodiment of an HBI slow cooling system or agglomerate cooling conveyor system of the present disclosure, particularly illustrating a cooling spray nozzle;

[0026] Figure 5 is a schematic diagram illustrating a top view of an example embodiment of a HBI slow cooling system of the present disclosure, particularly illustrating the cooling zones and loading points;

[0027] Figure 6 It is an icon Figure 5 a schematic diagram of a side view of;

[0028] Figure 7 is a schematic diagram illustrating a partial side view of an example embodiment of a HBI slow cooling system of the present disclosure, particularly illustrating a channel flow nozzle;

[0029] Figure 8 is a schematic diagram illustrating an example embodiment of a portion of a skirt, particularly illustrating an opening therein;

[0030] Figure 9 is a schematic diagram illustrating an example embodiment of a portion of a skirt, particularly illustrating an elongated slot therein;

[0031] Figure 10 is a schematic flow chart of an example embodiment of the slow cooling method of the present disclosure; and

[0032] Figure 11 is a schematic diagram of an example embodiment of a leveling device of the present disclosure, particularly illustrating an auger screw therein. DETAILED DESCRIPTION

[0033] Likewise, the HBI slow cooling system and method of the present disclosure incorporates advantageous redesigns to achieve desired process parameters while mitigating negative impacts achieved over an approximately 30-year operational span. Specifically, the HBI slow cooling system and method herein address demanding service requirements with components specifically adapted to overcome known failure modes. Advantageously, the HBI slow cooling system and method of the present disclosure are adapted to limit exposure of components to constant water spray while ensuring that the components are not submerged in water.

[0034] As further explained below and in accordance with an embodiment, in the systems and methods of the present disclosure, the carriage side wash hopper (or wash chute) 3 is advantageously sandwiched between the carrier strand 26 and the return strand 28 so that fines and water from the cooling process are captured in the carriage side wash hopper (wash chute) 3 without striking the return strand 28 and avoiding the problems encountered when flushing the slurry into an external ditch where channel velocity is difficult to maintain and solids naturally settle, resulting in significant maintenance issues.

[0035] Advantageously, capturing and conveying the water and fines in a wash hopper (wash chute) rather than in, for example, a box, maintains the wheels and chain from being submerged, thereby avoiding problems encountered in prior designs.

[0036] Advantages of embodiments therefore include improved handling of fines, such as avoiding fines in ditches, reducing water outflow to a single tank and pump, and reducing mechanical complexity by avoiding long drag chains or screw conveyors, while also minimizing the possibility of clogging weirs and nozzles.

[0037] Other advantages of embodiments include sizing the skirt 20 to a desired length, allowing, for example, four loading points or possibly more, and replacing the overflow weir with a coarse spray nozzle 46 (e.g., a scrubber nozzle) to provide a coarse droplet size, as further described below.

[0038] Now refer to Figure 1 and Figure 2 , Figure 1 is a schematic cross-sectional view illustrating an example embodiment of an HBI slow cooling system or agglomerate cooling conveyor system 10 of the present disclosure; and Figure 2 It is an icon Figure 1FIG2 is a schematic diagram of a side view of a system 10. According to an embodiment, the HBI slow cooling system or agglomerate cooling system 10 includes an apron pan conveyor 1, an optional load leveling device 2, a carriage-side wash hopper (the wash hopper may also be referred to herein as a "sluice") 3, a vapor removal hood 5, a vapor scrubber system 8, a return-side residue wash hopper (as described above, the wash hopper may also be referred to herein as a "sluice") 4, a loading chute assembly 7, and a cooling system 6. According to an embodiment, each of these elements is described in further detail below.

[0039] The apron conveyor 1 may include chains, rollers, aprons, a tensioning and balancing take-up system, a carrying rail, a carrying and return conveyor strands, and a drive system. The conveyor 1 is advantageously designed on a single slope, typically 3 degrees from the horizontal and up to 19 degrees, which facilitates flushing or washing of fine material / water and is particularly suitable for HBI and round particles. The speed of the conveyor 1 is typically about 0.05 m / s to 0.3 m / s, for example 0.2 m / s, and can be even faster, and is designed to provide flexible control. It should be understood that other suitable speeds may be employed. Advantageously, the speed may be varied to, for example, match the desired material throughput and cooling. The apron conveyor 1 is typically designed to dewater the material before discharge.

[0040] exist Figure 7 The chain 12, best seen in FIG. 1 , is adapted to withstand heat, corrosion, wear, and any moisture encountered in the HBI slow cool system 10, including temperatures ranging from 100° C. to 700° C., carbonation potential, iron and oxide fines, and water spray.

[0041] Also there Figure 7 The rollers 14, best seen in FIG. 1 , are adapted to maintain sealing and lubrication under the same conditions as the chain 12 described above. The rollers 14 are positioned outside the water impact zone. Advantageously, according to an embodiment, these skirt rollers 14 or wheels are not submerged in water. For example, Figure 6 As shown, rollers 14 are positioned above waterline 16. In a preferred embodiment, rollers 14 can be attached to the chain at every other link to support a skirt attached at each link. Alternatively, the HBI slow cooling system 10 can include rollers 14 in combination with the chain 12, the combination being suitable for reducing wear on the drive sprocket 18.

[0042] The skirt 20, which is engineered for high temperature and water exposure, is similarly adapted to withstand the same conditions described above as the chain 12 and rollers 14. The skirt 20 is also adapted to withstand HBI loading loads that can cause erosive wear, impact deflection, and uneven distribution. The skirt 20 includes a skirt base 22 having an opening 24, such as Figure 8 and Figure 9Best seen in. Figure 8 and Figure 9 is a schematic diagram illustrating an example embodiment of a portion of the skirt 20, particularly illustrating the opening 24 therein. Figure 8 , the opening 24 is shown as a notch in the rear edge. A suitable size may be approximately 1 / 4 inch by 1 inch, although other suitable sizes may be used. Similarly, Figure 9 The openings 24 are shown as elongated slots. Suitable dimensions for these slots may be approximately 1 / 4 inch by 2 inches, although other suitable dimensions may be employed. The skirt 20 may be considered an assembly of horizontal carrying floors and side retaining walls for accommodating deeper beds of material. In accordance with an embodiment, multiple skirts may overlap one another. Figure 8 and Figure 9 The chain 12, skirts or carrier rollers 14 and side walls 74 are further illustrated in FIG.

[0043] Thus, the skirt pan 20 includes openings 24, such as apertures, holes, notches, gaps, slits, etc., adapted to allow for consistent drainage of water from the skirt pan 20. For example, the rear edge may overlap the front edge behind it. Multiple skirt pans 20 may thus overlap one another. The openings 24 may advantageously be cut into the pan 20, such as at the rear edge, so that water can drain into a hopper or sluice below.

[0044] Such a design is advantageous and solves the problem of water collecting in the skirt 20 and supercooling the bottom layer of the material. It has also been advantageously and surprisingly determined that the use of openings 24 is beneficial in achieving the desired product in terms of moisture retention. For example, it is advantageous to maintain moisture retention in the discharged product / material at less than about 2 wt.%, such as between about 1 wt.% and 1.5 wt.%, as it has been found that at higher moisture retention levels, the material may begin to reoxidize. Therefore, according to embodiments, if water is not drained away, for example, via openings 24, the moisture retention level can be significantly increased in the bottom layer of the agglomerate material.

[0045] The tension balancing take-up system is adapted to maintain equal tension in the chain 12, which maintains the alignment of the apron conveyor 1 and balances the load on the drive system.

[0046] The drive system includes head and tail sprockets 18 of the chain-driven conveyor 1. The sprockets 18 are located on a shaft driven by a gear motor or motor-driven reduction system. More specifically, the drive system can include an electric motor drive that drives a head shaft including two reference sprockets 18. As the skirt disc 20 and components thereon are connected, the sprockets 18 can engage the left and right skirt chains 12. It should also be noted that, according to an embodiment, the sprockets 18 are designed and sized to properly fit the carriage-side flush hopper (wash chute) 3 between the carrying strand 26 and the return strand 28, as well as to position the carriage-side flush hopper / wash chute 3 and the return-side flush hopper / wash chute 4, as further described below.

[0047] The carrier rail is adapted to withstand the same conditions as the chain 12 described above.

[0048] exist Figure 2 and Figure 11 The optional load leveler 2, best seen in FIG, is adapted to spread and level any unevenly loaded clumps or loads into a more uniform pile across the width of the skirt 20. In embodiments, the load leveler 2 includes at least one of a fixed rake and a blade adapted to spread and level the clumps across the width of the skirt 20 into a uniform pile. In some embodiments, the load leveler 2 further includes at least one of a rotating and oscillating device adapted to spread the clumps across the skirt 20. For example, Figure 11 is a schematic diagram of an exemplary embodiment of a load leveling device 2 including an auger screw 9. Figure 11 As shown, according to an embodiment, the load leveling device 2 includes a spiral screw 9 for evenly spreading the mass. The spiral screw 9 can be a bidirectional screw, for example, two spirals in opposite directions attached to the shaft 13, as shown in FIG. Figure 11 shown. Figure 11The load-leveling device 2 also includes a shaft 13 mounted on two pivoting frames 15 that move up and down. The yokes of the pivoting frames 15 are mounted vertically and provide pivot points. Rod 17 is a fixed part of the housing 11 and does not move up and down. The slotted opening 23 is part of the fixed housing 11 and allows space for the leveling shaft to move up and down. The circular cover is also fixed and does not move up and down. As best seen near the drive chain system 21, the rod 17 can be broken to provide the slotted opening 23. During operation, the drive chain system 21 drives the shaft 13, and the load-leveling device 2 distributes or spreads the hot mass 40 deposited from the chute 42 of the loading chute assembly 7 onto the skirt 20, creating a more uniform or even distribution across the skirt 20, which promotes more efficient cooling. Because the shaft 13 and the spiral screw 9 rotate slowly and at high torque during typical operation, the spiral or helical blades can stir material from the top of the hot mass 40 to the sides and spread the material for a more even distribution. By way of non-limiting example, the rotation is typically counter-current to the material flow and at a low rotational speed of about 0.5 rpm to about 3 rpm, including about 2 rpm. The rotation is typically forward and downward, advantageously providing a plowing force on the material. It should also be understood that, as with the components of the system 10, the components of the screed 2 can be made of any suitable material, including a suitable metal.

[0049] As described above, according to embodiments, in the systems and methods of the present disclosure, the carriage-side flush hopper (or chute) 3 is advantageously sandwiched or positioned between the carrier strand 26 and the return strand 28, so that fines and water from the cooling process are captured in the carriage-side flush hopper (chute) 3 without hitting the return strand 28, thereby avoiding the problems encountered when flushing the slurry into an external ditch, where channel velocity is difficult to maintain and solids naturally settle, resulting in severe maintenance issues. Advantageously, capturing and conveying water and fines in the flush hopper (chute) rather than in, for example, a tank maintains the wheels and chains from being submerged, thereby avoiding the problems encountered in existing designs.

[0050] exist Figure 1 The carrying strand 26 and the return strand 28 are best seen in Figure 1The diagram illustrates a product load on an apron-type conveyor 1, and the carrier strand 26 and return strand 28 can be considered, for example, a conveyor belt or portions of a conveyor belt. For example, the carrier strand 26 and return strand 28 can refer to the upper and lower portions of such a conveyor system, respectively. Thus, as will be understood, the strands 26, 28 are portions of the continuous apron-type conveyor 1. The return strand 28 can have the same cross-section as the carrier strand 26 and can be considered an inverted or mirrored image of the carrier strand 26. The top or upper carrier side / carrying strand 26 carries the product load, and the return side / return strand 28 is the portion of the conveyor 1 or belt that travels, rotates the tail sprocket, and then returns around in a continuous loop. Typically, only the top or upper carrier strand 26 carries the product load.

[0051] The carry strand 26 and return strand 28 of the conveyor are typically spaced vertically apart by a sufficient distance to avoid flooding of components of the HBI slow cooling system 10 by integrating carriage side wash hoppers or wash chutes 3 (embodied as triangular shaped hoppers as a non-limiting example) between the strands 26, 28 to collect and wash away fines and water as a slurry.

[0052] According to an embodiment, the carry strand 26 and return strand 28 are dispersed or positioned separately, using the aforementioned larger drive sprocket 18 for the skirt 20 and positioning the carriage side wash hopper or wash chute 3 therebetween.

[0053] The carriage side wash hopper (or wash chute) 3 typically includes at least one of a channel flow nozzle 32, a side wash or cleaning sprayer 34, a hopper bottom, a final water effluent discharge point, and a maintenance hatch. Each feature is described in more detail below, depending on the embodiment.

[0054] exist Figure 7 An embodiment of a channel flow nozzle 32 is best seen in FIG. The channel flow nozzle 32 may be part of a tube or other suitable flow device, and the inventors have determined that it is desirable to operate in certain flow regimes, as further described below. The channel flow nozzle 32 or tube nozzle creates an initial channel flow downward from a central portion of the carriage side wash hopper (wash chute) 3. In accordance with the embodiment, it is noted that three streams may generally enter the carriage side wash hopper (wash chute) 3: 1) a reference channel flow from the channel flow nozzle 32, which carries solids to the desired output; 2) a side wash or wash sprayer 34, which is located in the carriage side wash hopper (wash chute) 3; and 3) a side wash or wash sprayer 34, which is located in the carriage side wash hopper (wash chute) 3. Figure 4 best seen in the figure, which keeps the sides of the carriage side wash hopper (wash chute) 3 wet so that any material that may fall in gets the desired wash; and 3) residual cooling water entering the carriage side wash hopper (wash chute) 3 from above.

[0055] According to the embodiment and Figure 1As best seen, the carriage-side wash hopper (or chute) 3 may also include at least one spiral classifier 30. The spiral classifier 30 is included or integrated into the carriage-side wash hopper 3, for example, on the side of the carriage-side wash hopper 3. For ease of reference, see Option 1 herein. Placing the spiral classifier 30 within the hopper 3 offers surprising advantages, and such a design, in the inventor's opinion, has not been previously accomplished. For example, the inventors determined that operating the channel flow of the channel nozzle 32 under a certain flow regime is advantageous, and the spiral classifier 30 can reside in its own recess and be integrated into the side of the carriage-side wash hopper (or chute) 3. The recess provides a channel velocity deceleration point where solids can drop out. According to testing, to ensure adequate sedimentation of solids in the recess of the spiral classifier 30, it is advantageous to adjust the water flow in the channel of the channel nozzle 32 to a minimum and maximum range to achieve a sufficient drop rate for solids in the spiral classifier 30. An example of a suitable range is a water flow between approximately 50 gal / min and approximately 150 gal / min. It has been found that this range for the channel flow nozzle 32 allows the slurry flow to slow down at the classifier groove, thereby allowing more than about 50% of the solids to drop for removal by the spiral classifier. At flow rates exceeding about 150 gpm, the solids drop rate can be reduced, thereby reducing the efficiency of the classifier.

[0056] Thus, according to an embodiment, a spiral classifier 30 residing in its own recess and integrated into the side of the carriage side wash hopper (wash chute) 3 advantageously provides a channel velocity deceleration point where solids can fall. To help regulate the water flow within the above range, a launder ( Figure 1 An overflow point (not shown) or built into the side of the trough removes a volume of water at the spiral classifier 30. Without such a feature, the channel flow could continue to accumulate in the hopper due to, for example, other flows entering the hopper, potentially increasing the range to above the desired maximum water flow of about 150 gal / min.

[0057] According to the embodiment and Figure 1 As best seen in FIG, the bottom end of the spiral classifier 30 is advantageously located below the main channel of the carriage side wash hopper (wash chute) 3, thereby providing a groove effect so that when the channel flow arrives, the channel flow slows down and the solids fall out of suspension. Maintaining the water flow through the channel flow nozzle 32 within the above-mentioned reference range of about 50 gal / min to about 150 gal / min advantageously allows 50% or more of the solids to fall into the groove of the spiral classifier 30, as shown in FIG. Figure 1Advantageously, according to the embodiments and Option 1 herein, the spiral classifier 30 operates in the manner of a screw conveyor, rotating or spiraling the solids up to the top of the classifier 30 where they fall via chutes 36 and the water can remain in the hopper 3.

[0058] The side flush or wash sprayers 34 are adapted to wet the sides of the carriage side flush hoppers (or wash chutes) 3 and the sides of the return side flush hoppers (or wash chutes) 4 to prevent accumulation of fines. Figure 4 As shown in the embodiment of FIG, the sprinklers 34 may include a series of flat spray nozzles positioned at the upper edge of the hoppers 3 and 4 on each side. The sprinklers 34 may form a sheet-like stream of water downward from the sides of the hoppers 3, 4 so that any material (e.g., solids and / or liquids) that may fall into the hoppers 3, 4 may flow downward, thereby avoiding accumulation in the hoppers 3, 4. Such material may be advantageously flushed downward into the main channel by the sheet-like stream of water.

[0059] The hopper bottoms of the carriage side wash hopper (or ore washing chute) 3 and the hopper bottoms of the hopper 4 are usually curved and rounded, but can also be sharp V-shaped or narrow trapezoidal. The hopper bottoms can be equipped with one or more longitudinal channel flow (washing) nozzles to wash solids downward from the carriage side wash hopper (ore washing chute) 3.

[0060] A plurality of the aforementioned spiral classifiers 30 may also be spaced at regular intervals, adapted to partially capture the slurry in a pool, dewater the solids, and discharge the solids from the carriage-side flushing hopper (washing chute) 3. According to an embodiment, the hopper bottom may thus be adapted to flush the solids from the carriage-side flushing hopper (washing chute) 3 downwardly into the classifier pool. At each spiral classifier 30, the aforementioned overflow trough may regulate the accumulated channel flow in the carriage-side flushing hopper (washing chute) 3, as increased channel flow may reduce the efficiency of classifier dewatering.

[0061] Maintenance hatches to the carriage side wash hoppers (wash chutes) 3 and return side wash hoppers (wash chutes) 4 are typically regularly spaced and positioned to allow access during operation to remove any channel blockages, and full access for maintenance during shutdown conditions.

[0062] Final water effluent discharge points may include pipes at the ends of the carriage side wash hoppers (wash chutes) 3 and return side wash hoppers (wash chutes) 4, which lead to, for example, tanks or separation systems.

[0063] According to an embodiment, the final water effluent can be captured in the discharge pipe of the wash hopper (wash trough) 3 and directed to a blowdown tank for additional solids settling and separation via a drag chain or spiral classifier. The blowdown tank is suitable for settling the water before it is recirculated to the washdown system via a pump closely coupled to the tank overflow. To balance the entire system, some of the recirculated flow can be diverted to the plant water system as cooling conveyor system blowdown.

[0064] According to other embodiments, the wash hopper (wash chute) 3 is adapted to flush captured water and fines to a single discharge port at a closely coupled classifier tank for dewatering, solids removal, and water recycling back to the wash system and discharge to the plant water system. Here, a channel flow is formed to utilize the overall cumulative flow increase to entrain and transport all captured solids to the classifier for sedimentation and removal. The classifier can be a spiral screw type with an integrated tank and overflow chute that discharges the separated solids to a fines conveyor for transport to a common silo or other container. The overflow water from the classifier chute is then discharged to a deeper portion of the tank, where a pump can circulate the water back to the wash system.

[0065] As described above, according to an embodiment, the carriage side flush hopper 3 is advantageously sandwiched between the carrier strand 26 and the return strand 28, so that fine material and water from the cooling process can be captured in the carriage side flush hopper 3 without hitting the return strand 26, and avoiding the problems encountered when flushing the slurry into an external ditch, where channel velocity is difficult to maintain and solids naturally settle, resulting in serious maintenance problems. In such an embodiment, the recirculating water flow from the settling tank can be balanced with the incoming cooling water from the cooling zone (as captured in the flush hopper 3). This balance can be achieved by diverting some of the recirculating flow as blowdown to the plant process water treatment system for additional treatment. This blowdown portion is approximately equal to the cooling flow supplied to the cooling zone from the plant process water supply. At this point, it is noted that the same balancing principles apply to the aforementioned embodiments. According to an embodiment, the difference includes that the water from the overflow trough at each side classifier can be directed to the end tank for recirculation as described herein.

[0066] A steam removal hood 5 is coupled from the carriage side wash hopper (wash chute) 3 downwardly to the skirt conveyor 1. The steam removal hood 5 typically comprises a bottom rim, piping, cleaning sprayers, and a measurement and balancing system.

[0067] The bottom edge is usually assembled with the skirt sidewalls in a labyrinth arrangement. The labyrinth arrangement of the bottom edge and skirt sidewalls restricts the escape of solids, water and steam from the cooling zone.

[0068] The conduit is adapted to entrain steam and fines into the conduit stream, which is directed to the steam scrubber system 8 .

[0069] The cleaning sprayers are adapted to periodically wet the surfaces of the steam removal hood 5 and the duct surfaces, which can minimize the accumulation of fines thereon.

[0070] The flow measurement and balancing system is adapted to detect unstable flow conditions, such as when large debris or solids buildup enters and becomes lodged in the flow channel, causing a blockage. The flow measurement and balancing system is adapted to provide an indication of such conditions (e.g., a warning, an alarm, etc.) to an operator for maintenance purposes.

[0071] like Figure 1 As best seen, the steam scrubber system 8 is adapted to quench the steam stream, condense the steam into liquid water, and drop fines in the effluent. The steam scrubber system 8 typically includes a slurry effluent, a tank, an induced draft fan, an emissions monitor, and a dedicated settling tank.

[0072] The slurry effluent is suitable for discharge to a tank for further separation of water and solids.

[0073] An induced draft fan is adapted to direct the remaining gaseous effluent therefrom to a dust collection system or a discharge stack.

[0074] Emission monitors are adapted to monitor the gaseous effluent discharged from the steam scrubber system 8 for regulated emission levels. The blowdown slurry is typically pumped to a dedicated settling tank. After settling, the aqueous effluent can be pumped to plant water treatment, where any remaining solids are removed from the water. By removing fines and other particulates from the effluent, the steam scrubber system 8 limits particulate emissions from the HBI slow cool system 10.

[0075] Advantageously, the steam scrubber system 8 is adapted to discharge gas and slurry streams at temperatures well below 100°C and typically in the range of 50°C to 75°C.

[0076] The return-side flush hopper (wash chute) 4 is a secondary capture hopper positioned below the return strand 28. The return-side flush hopper (wash chute) 4 can be described identically to the carriage-side flush hopper (wash chute) 3 described above. However, it should be noted that according to embodiments in which a small classifier 30 is located to the side of the carriage-side flush hopper (wash chute) 3, such a classifier is typically not employed on the return-side flush hopper (wash chute) 3 given the lower amount of solids expected to be captured therein. For example, the return-side flush hopper (wash chute) 4 is typically intended to capture any material (solids / liquids) carried by the conveyor 1 as it is being returned by the conveyor 1.

[0077] The return side flushing hopper (wash chute) 4 typically includes one or more of a hopper channel, a flushing nozzle, and a maintenance hatch.

[0078] The hopper channel is adapted to receive residual fines and water from the conveyor return strand 28 and to isolate them from the upper carrier strand 26. The hopper channel is also adapted to capture and flush residue from the system 10 (and in particular the conveyor return strand 28) in the same or similar manner as the carriage side flush hopper (wash chute) 3. By doing so, flooding of the return strand 28 and sedimentation of fines and water into external pools can be avoided.

[0079] According to an embodiment and Option 1 herein, the hopper channel is adapted to flush the residue to a spiral classifier 30. In an embodiment, the spiral classifier 30 is positioned near the tail end of the skirted disc conveyor 1. In some embodiments, the return-side flush hopper 4 includes only a single spiral classifier 30. According to an embodiment, the return hopper 4 can be washed to the same pump as described above via a single solids dewatering mechanism (e.g., a single classifier or drag chain). Other solids separation techniques may also be employed, including but not limited to the use of a hydrocyclone or an inclined plate separator.

[0080] Maintenance hatches are typically regularly spaced and positioned to allow access during operation to remove any passage obstructions, as well as full access for maintenance during shutdown conditions.

[0081] The loading chute assembly 7 generally comprises a chute 42, a spreader and a loading point. The chute 42 is adapted to minimise the drop height onto the skirt 20 and comprises an angled outlet adapted to promote sliding deposition of the mass onto the skirt 20.

[0082] An optional spreader (screed 2), such as a fixed rake or blade, is adapted to ensure even distribution on the skirt 20 at the outlet of the chute 42. In an embodiment, the loading chute assembly 7 is adapted to minimize the number of loading points based on the layout requirements of a particular HBI plant.

[0083] With respect to cooling system 6, experience and testing have shown that the most uniform cooling of the HBI can be achieved by a well-distributed single layer of agglomerates impinging upon a fine spray field that is carefully controlled to minimize water absorption. However, in practice, such a distribution can be difficult or even impossible to achieve due to the random generation of agglomerate "packs," or the aggregation of agglomerates in counts of two (pairs), four (quad packs), or six (six packs). These aggregations can negatively impact the spray cooling method, resulting in degraded performance. Therefore, a practical design should accommodate multiple layers of agglomerates. Some systems have employed cascades of water overflowing from weir boxes to cool two to four deep beds of HBI. While these weirs can be effective for cooling, they can easily become clogged and ineffective due to the accumulation of fines.

[0084] It has been determined herein that coarse droplet sizes are capable of penetrating the bed to cool multiple layers simultaneously, as opposed to the "top-down" cooling achieved by fine spraying. Accordingly, and supported by research into effective nozzle types, embodiments of the present invention advantageously utilize coarse spray nozzles 46, for example, installed in a header to coat the HBI bed as it traverses the length of the cooling zone 44 of the cooling system 6. Furthermore, these nozzles 46 are suitable for use with "dirty" or relatively high TSS (total suspended solids) water, thereby also mitigating spray nozzle clogging. These nozzles 46 are preferably selected based on testing to provide, for example, a "full cone" spray pattern with large droplets (approximately 0.8 mm to 2 mm diameter, Dp50 basis) to better penetrate the HBI bed. Such nozzles 46 were tested relative to finer spray nozzles to make this selection.

[0085] Therefore, if Figure 1 、 Figure 2 、 Figure 5 and Figure 6 The cooling system 6, best seen in FIG. 1 , generally comprises a manifold, nozzles 46, a temperature measuring device, and an auxiliary drainage nozzle system. According to an embodiment, the skirted conveyor 1 is subdivided into cooling zones 44, and a manifold is positioned above each cooling zone 44. A nozzle 46 may be mounted to each manifold above a cooling zone 44 and oriented to provide optimized cooling to the agglomerates in the corresponding cooling zone 44. The nozzles 46 are adapted to minimize beard formation due to accumulation of fines therein and are adapted to operate using recirculated, typical plant process water containing known levels of impurities.

[0086] The nozzles 46 are typically positioned above the apron conveyor 1 at a height that is easily accessible (eg, without the use of additional equipment) to facilitate quick replacement and cleaning of the nozzles.

[0087] The temperature measuring device may comprise a shield surrounding the temperature measuring device and is generally adapted to assess the temperature of the mass in each cooling zone 44. According to an embodiment, the temperature may be measured upon entry into the first cooling zone and possibly at intermediate locations (e.g. Figure 6 The temperature is measured again at the intermediate temperature measurement zone 72) and then at the discharge zone before leaving the conveyor. The foregoing advantageously allows space for any applied water to dry from the surface before the non-contact zone.

[0088] The auxiliary drain nozzle system is adapted to rapidly quench the agglomerate in the event of an overtemperature event or other abnormal condition. In particular, the auxiliary drain nozzle system is adapted to quench the agglomerate in abnormal operating conditions (e.g., thermal remelting / oxide processing, severe upstream process problems, or other conditions requiring rapid quenching of the conveyed material). The nozzles of the auxiliary drain nozzle system are typically protected (by an inert gas flow) and adapted to remain dry during normal operation of the system 10 until they are needed (e.g., during an abnormal condition). The auxiliary drain nozzle system includes a fast-operating drain valve adapted to open and allow sufficient water flow to fill the auxiliary drain nozzle system.

[0089] In operation, according to the embodiments and with particular reference to Figure 2 The hot mass 40 enters the slot 42 of the loading chute assembly 7 and flows downward therefrom. There, the hot mass 40 typically rests on a bed or other surface on the skirt 20 of the skirt conveyor 1 operating in a continuous, oblong loop. If necessary, the load leveler 2 spreads the material for a more even distribution. The material bed then moves continuously into the cooling zone 44 of the cooling system 6. Also in Figure 6 The cooling zone 44 is depicted in FIG, including a trapezoidal shaped hood. The trapezoidal shaped hood advantageously provides the desired coverage to provide a consistent negative pressure across the cooling zone 44 and a sufficiently low gas velocity to allow larger particles and free water to fall back onto the conveyor 1 rather than being drawn into the steam removal duct. However, it will be appreciated that other suitable designs may be employed. Figure 2 、 Figure 5 and Figure 6 As shown, according to an embodiment, the cooling section is divided into six cooling zones 44. However, depending on the desired system size, etc., more or fewer zones may be employed. Typically, within each cooling zone 44 is a piping header with the aforementioned cooling spray nozzles 46. Advantageously, the flow rate from those nozzles 46 can vary, but typically each nozzle is operated at a set flow rate for a given production rate.

[0090] As described above, embodiments advantageously utilize spray nozzles 46 that can be installed in the header to cover the bed of HBI as it traverses the length of the cooling zone 44 of the cooling system 6. In addition, these nozzles 46 are suitable for use with "dirty water" or relatively high TSS (total suspended solids) water, thereby also mitigating spray nozzle clogging. These nozzles 46 are preferably selected based on testing to provide, for example, a "full cone" spray pattern with large droplets (approximately 0.8 mm to 2 mm diameter, Dp50 basis) to better penetrate the bed of HBI. Such nozzles 46 are tested relative to finer spray nozzles to make this selection. The nozzles 46 may include, for example, Figure 1 The overlapping triangle forms depicted, such as Figure 4The long spray design shown or Figure 5 The header design shown, and other suitable designs, are provided as examples and for reference. Figure 5 Each conduit can have a series of nozzles pointing downwardly toward the conveyor 1. Similarly, it has been determined that selecting the nozzles 46 to provide a coarse droplet size, such as the coarse droplet size referenced above, is advantageous and can provide a cascading waterfall effect on the bed of hot agglomerates 40, which may be a multi-layered layer moving on the conveyor 1. This coarse spray effect, as opposed to a fine spray mist, is achieved by using coarse spray nozzles 46, such as, by way of non-limiting example, full cone spray nozzles providing the coarse droplet size referenced above, to effectively cool the material layer by penetrating deeply into the bed. Such a feature also replaces and solves the existing problem of weir grooves filling with fine material and then becoming clogged, causing little water flow to occur.

[0091] As the bed of agglomerates moves through the cooling zone 44 and cools, it accordingly gives off water vapor or steam which can be removed by the steam removal hood 5 through a piping arrangement 48 into a steam scrubber system 8, as shown. Figure 1 . This "dirty" vapor or steam containing water and some fine material can enter a steam scrubber system 8, where the hot steam is cooled, the water condenses out, and the "dirty" material is removed by the scrubber. The bed of cooled material then travels to the head end of conveyor 1, where the cooled agglomerates can be discharged, for example, to another conveyor for storage, transportation, etc. In this regard, it is noted that embodiments can thus advantageously cool the HBI from an agglomeration temperature of about 650°C-700°C to 400°C in about 2 minutes and no less than about 1.5 minutes, after which the temperature of the material can be further reduced to greater than about 85°C and less than about 130°C upon discharge.

[0092] As further described below, any material that migrates through the skirt 20 via the openings or slots 24 is advantageously allowed to drain for collection in the carriage side wash hopper (wash chute) 3. Thus, below the carry side of the conveyor 1, the carry side wash hopper (wash chute) 3 is located therein, and any unevaporated cooling water can filter downward through the material bed and skirt 20 and advantageously fall into the carry side wash hopper (wash chute) 3 carrying fines and other materials along with the fines. As described above, the carriage side wash hopper (wash chute) 3 is equipped with side wash or cleaning sprayers 34, and channel flow nozzles to capture this water and fines and convey them to the tail end of the conveyor 1, where they can be discharged to, for example, a separator sump or spiral classifier 30 of the carriage side wash hopper (wash chute) 3, where solids can be separated as described above.

[0093] Located below the carriage side wash hopper (wash chute) 3 is the return strand 28 (return side of the conveyor 1). As the conveyor 1 travels back to the tail end, residual fines and other residual solids may have fallen out during the process and are caught in the return side wash hopper (wash chute) 4 where the material is intended to be washed down to the end, such as a sump 48.

[0094] It should also be noted that when the conveyor 1 moves on the return side, a cleaning device 50, such as a sprayer or rotating brush, can be employed to clean the return side (the return strand 28 of the conveyor 1) as it moves around the sprocket 18 at the head end. The advantage of such a sprayer or rotating brush is that it allows any material to be first removed at an early stage and fall into, for example, the carriage side wash hopper (wash chute) 3.

[0095] Further information on operation and special reference Figure 1 and Figure 2 As the conveyor 1 moves through the cooling zone 44, the flow rate of the cooling nozzles 46 can be adjusted to match the cooling rate required for the specific production rate of the material. Again according to the embodiment, the nozzle type of the cooling nozzles 46 is advantageously selected to provide the aforementioned coarse droplet size to avoid overcooling of the top layer of the agglomerate and insufficient cooling of the bottom layer, thereby achieving a balanced cooling effect.

[0096] Now refer to Figure 3 , Figure 3 is a schematic diagram illustrating another exemplary embodiment of the HBI slow cooling system 10 of the present disclosure, which is Figure 1 Further modifications and Figure 1 The HBI slow cooling system is mirrored. Figure 1 The situation is similarly described Figure 3 However, in Figure 3 In the embodiment of the present invention, an overflow trough 52 or weir is present below, for example below each classifier 30. The trough 52 advantageously acts as a cleaning mechanism that allows cleaner water to overflow while "dirty" water remains behind. As described above, it has been determined that it is advantageous to adjust the water flow in the channel of the channel nozzle 32 to a minimum and maximum range to enable an adequate drop rate of solids in the spiral classifier 30. An example of a suitable range is a water flow of between about 50 gal / min to about 150 gal / min. It has been found that this range of channel flow nozzles 32 allows for the drop of solids with over 50% solids retention at the spiral classifier grooves. By using the trough 52, a certain amount of water can be removed from each classifier 30 and help maintain the desired flow rate.

[0097] Figure 3 Further illustrated is a fine solids transport device 54 which may include a conveyor and support structure 51 , the conveyor carrying away solids that fall from the chute 36 . Figure 3Further illustrated is an angle of approximately 35 degrees (approximately the minimum angle to horizontal) for the walls 29 of both the carriage side wash hopper (wash chute) 3 and the return side wash hopper (wash chute) 4. An angle of 35 degrees or greater has been advantageously found to be sufficient.

[0098] Further references Figure 3 , the HBI slow cooling system 10 also includes a steam exhaust port 56 located above the steam removal hood 5 described above. The cooling zone nozzles 46 are shown therein as a spray nozzle manifold having full cone coarse spray nozzles, also as described above. The skirt 20 load side (carrying strand 26) and the skirt 20 return side (return strand 28) are further shown as having a spacing diameter 58 between the skirt 20 load side (carrying strand 26) and the skirt 20 return side (return strand 28) that varies with the depth of the hopper (wash chute) 3. Further shown are discharge pipes 60 for the bracket side wash hopper (wash chute) 3 and the return side wash hopper (wash chute) 4, which flow downward to the pool ( Figure 3 The frame is further shown with the outer wheel width and the frame width 62, 64, respectively.

[0099] It should also be noted that according to an embodiment, the steam removal hood 5 is designed to engage with the side walls of the skirt tray conveyor 20. There may be a flip to reach the side wall, which may overlap the side wall behind it, and at the bottom of the steam removal hood 5 is to (also Figure 3 A labyrinthine cover with side wall seals 66 (shown in FIG) is provided to keep as much vapor and solids inside as possible.

[0100] Now refer to Figure 4 In this embodiment of the HBI slow cooling system or agglomerate cooling system 10, cooling spray nozzles 46 are shown above the load side (carrier strand 26) of the skirt 20. In this embodiment, the classifier 30 may not be incorporated into the carriage side wash hopper (wash chute) 3, nor may the water flow be regulated to within the aforementioned reference range of approximately 50 gal / min to 150 gal / min. Instead, there is sufficient channel flow from the channel nozzles 32 to discharge fines and other materials, such as to a sump. This channel flow is enhanced by the side wash or cleaning sprayers 34.

[0101] Figure 5 is a schematic diagram illustrating a top view of an example embodiment of the HBI slow cooling system 10 of the present disclosure, particularly illustrating the cooling zone 44 and the loading point 68; and Figure 6 It's a picture Figure 5 Schematic diagram of the side view. Figure 2 The situation is similarly described Figure 5 and Figure 6 In addition, Figure 6In FIG, four loading points 68 and chutes 42 for entering the agglomerates are shown at the tail end of the conveyor 1. However, it should be noted that the number of loading points 68 may vary based on the design, particularly for larger plants where more loading points 68 may be required. Figure 5 and Figure 6 Also shown is a temperature measurement zone 70 which facilitates obtaining initial measurements prior to entry into the cooling zone 44 and at the discharge area of ​​the cooling zone, as this has been found to be more accurate than obtaining temperature measurements from within the cooling zone 44. According to other embodiments, for further accuracy, an intermediate temperature measurement zone 72 may exist between any two cooling zones 44, such as in the drying section thereof. Figure 5 and Figure 6 As further shown in FIG, a pumping system such as a blowdown or slurry separator and a pump sump 76 may be located near the conveyor 1 to minimize the distance that such slurry flows from the hoppers (wash chutes) 3, 4. Figure 3 As shown, the discharge pipes 60 of the hoppers (wash chutes) 3, 4 are pipes at the ends of the hoppers (wash chutes) 3, 4, which can flow down to the slurry separation and pump pool 76, and multiple of these pipes can then be connected to a large purification system to receive slurry (e.g., fines and water), where solids are separated from the flow and the overflow water can be sent to the pump pool section.

[0102] Figure 7 is a schematic diagram illustrating a partial side view of an example embodiment of the HBI slow cooling system 10 of the present disclosure, particularly illustrating the aforementioned advantageous channel flow nozzle 32. Thus, according to an embodiment, and which may be referred to herein as Option 2, instead of, for example Figure 1 Using a classifier 30 at the side of the carriage side wash hopper (wash chute) 3 shown, the flow pattern is controlled so that material (e.g., solids such as fines, and liquids) is washed or slurried to the tail end of the conveyor 1 and into, for example, a slurry separation and pumping sump 76, as shown. Figure 6 This design is particularly advantageous for processing large quantities of fine material on an intermittent basis and is particularly useful for larger plants. Therefore, in this embodiment, the carriage side wash hopper (wash chute) 3 is still sandwiched between the return strand 26 and the conveying strand 28, but the spiral classifier 30 can be omitted.

[0103] Figure 8 and Figure 9 is a schematic diagram illustrating an example embodiment of a portion of the skirt 20, particularly illustrating the opening 24 therein. Figure 8 , the opening 24 is shown as a notch in the rear edge. A suitable size may be approximately 1 / 4 inch by 1 inch, although other suitable sizes may be used. Similarly, Figure 9The openings 24 are shown as elongated slots. Suitable dimensions for these slots may be approximately 1 / 4 inch by 2 inches, although other suitable dimensions may be used. Figure 8 and Figure 9 Also shown are the chain 12 , the skirt or carrier rollers 14 , and the side walls 74 .

[0104] Figure 10 is a schematic flow chart of an example embodiment of a slow cooling method of the present disclosure. According to an embodiment, method 84 includes providing a briquette cooling conveyor system at 86, the system including a skirted tray conveyor and a carriage side flush hopper, the skirted tray conveyor including: a) one or more skirted trays, the skirted trays including openings for discharging water from the skirted tray conveyor; b) a carrying strand on an upper portion of the skirted tray; and c) a return strand on a lower portion of the skirted tray; the carriage side flush hopper positioned between the carrying strand on the upper portion of the skirted tray and the return strand on the lower portion of the skirted tray, the carriage side flush hopper capturing fines and water from the system; and cooling the hot briquette iron from an agglomeration temperature of about 650°C-700°C to 400°C in about 2 minutes and not less than about 1.5 minutes as the iron travels along the skirted tray conveyor, wherein the discharge temperature is greater than about 85°C and less than about 130°C.

[0105] Thus, advantages of embodiments of the present invention include using skirt openings 24 of skirt 20 of conveyor 1 to allow adequate drainage into hoppers (wash chutes) 3, 4, as described above, without submerging skirt 20 and components of conveyor 1 in water. In an attempt to achieve the desired slow cooling, existing systems employ skirts that are completely submerged in a water tank for, for example, at least half the length of the conveyor's rotation, which can lead to mechanical failure, wear, and degradation. In some existing systems, solids, such as fines, fall to the bottom of the water tank, which is equipped with a drag chain that pulls the material out, for example, to a removal conveyor. According to embodiments, such water tanks and operations are advantageously replaced by using the aforementioned hoppers (wash chutes) 3, 4.

[0106] Other advantages of the embodiment include the ability to maintain the chain 12 and rollers 14 from being submerged; and proper and improved handling of water and fine material. The foregoing can be advantageously achieved, for example, by positioning the carriage side wash hopper (wash chute) 3 between the transport strand 26 and the return strand 28 of the skirt disc conveyor 1.

[0107] A further advantage of the embodiment includes selecting the cooling nozzles 46 to provide a coarse droplet size. The coarse spray effect achieved by using the coarse spray nozzles 46, as opposed to the fine spray spray, effectively cools the agglomerate layer by penetrating deep into the bed. These features also replace and solve the existing problem of grooves filling with fine material and then becoming clogged with the material.

[0108] According to the embodiments and as described above, additional advantages include: using Figure 1 The classifier 30 integrated into the side of the hopper (wash chute) 3; the use of side flush or cleaning sprayers 34 in the hoppers (wash chutes) 3, 4; and favorable channel flow all help provide improved processing of the system 10.

[0109] Further advantages and features of various embodiments of the present invention include: the carriage side wash hoppers (wash chutes) 3 include weirs arranged in series and include spiral classifiers 30, wherein each classifier 30 may include a water overflow trough to regulate the cumulative hopper channel flow with known operating parameters; the hoppers 3 discharge to a close coupled classifier, which discharges water to a sump pump, and the pumping system recirculates the water to the wash sprayers, a portion of which is used for blowdown of the plant process water treatment; the carriage side wash hoppers 3 and return side wash hoppers 4 are configured to discharge flow to a close coupled classifier 78, and the classifier 78 is configured to discharge water to a pump sump 80; the system is configured to recirculate water to the wash sprayers and water treatment (shown at 82); the blowdown flow is balanced with the cooling spray flow in the cooling zone; the conveyor 1 is inclined on a single plane to allow the wash chute to flow back to the grading system; the length and position of the HBI loading chute are matched to this inclination; the cooling section is equipped with one or more non-spray areas to facilitate non-contact temperature monitoring by wide field of view sensing equipment; the control system is configured to monitor the incoming HBI mass flow and temperature and adjust the conveyor speed and cooling flow to achieve the desired cooling target at the discharge point; wherein the cooling target is greater than about 85°C and less than 130°C at discharge to retain sufficient energy in the HBI to reduce the retained moisture level to less than about 1.5% by weight. According to a further advantageous and non-limiting embodiment, a skirted pan conveyor includes: a) a plurality of skirts including openings adapted to drain water from the skirts; b) a pair of conveyor chains connecting the skirts on both sides together into a continuous strand to form a carrier side or strand that carries product out of the conveyor, and a return side or strand after the product is discharged from the conveyor and the chain leaves the drive sprocket; c) rollers that support the skirt as it moves to convey the product; d) a support track on which the rollers run; e) a pair of drive sprockets on a head shaft that provide traction for the chain to move the product; and f) a pair of tail sprockets on a tail shaft for guiding the skirts back to capture the product discharged into the conveyor.

[0110] Although the present disclosure is illustrated and described with reference to preferred embodiments and specific examples thereof, it will be apparent to those skilled in the art that other embodiments and examples may perform similar functions and / or achieve similar results. All such equivalent embodiments and examples are within the spirit and scope of the present invention and are therefore contemplated. In addition, all features and elements described herein may be used in any combination with one another.

Claims

1. A briquette cooling conveyor system comprising: A skirt tray conveyor comprising: a) a plurality of skirt trays, the skirt trays including openings adapted to drain water from the skirt tray conveyor; b) a carrying strand at an upper portion of the skirt trays; and c) a return strand at a lower portion of the skirt trays; a carriage side flush hopper positioned between a carry strand on an upper portion of the skirt pan and a return strand on a lower portion of the skirt pan, the carriage side flush hopper being configured to capture fines and water from the system; and a return-side flush hopper positioned below the return strand, and wherein the carriage-side flush hopper comprises: a wash sprayer adapted to wet the sides of the carriage side wash hopper; and a channel flow nozzle configured to generate a channel water flow to wash solids to a desired output, wherein the channel water flow is between 50 gal / min and 150 gal / min.

2. The briquette cooling conveyor system according to claim 1, wherein: The system is configured to slowly cool the hot agglomerate from an agglomeration temperature of 650-700°C to 400°C in 1.5 to 2 minutes.

3. The briquette cooling conveyor system according to claim 1, wherein: The carriage side flush hopper includes at least one spiral classifier, and each spiral classifier includes a water overflow trough.

4. The briquette cooling conveyor system of claim 1, wherein: The bracket side flush hopper includes a hopper bottom that is one of an arc shape, a V shape, and a trapezoidal shape.

5. The agglomerate cooling conveyor system of claim 1 , comprising a cooling system, wherein the cooling system comprises a plurality of coarse spray nozzles configured to spray water onto the agglomerates in a coarse droplet size of 0.8 mm to 2 mm in diameter.

6. The briquette cooling conveyor system of claim 1, wherein: The carriage-side flush hopper and the return-side flush hopper are configured to discharge flow to a close-coupled classifier, and the classifier is configured to discharge water to a pump sump.

7. The briquette cooling conveyor system of claim 1, wherein: The system is configured to recirculate water to the wash sprayers and water treatment.

8. The briquette cooling conveyor system of claim 1, wherein: The conveyor is inclined in a single plane, and the system includes a hot lump iron loading chute coupled to the conveyor, and a load leveler on the conveyor configured to evenly spread the iron, the load leveler including a helical screw.

9. The briquette cooling conveyor system of claim 1, wherein: The return strand is fitted with cleaning spray nozzles for washing any residual material on the skirt disc into the return side flush hopper.

10. A method of cooling hot agglomerated iron, comprising: A briquette cooling conveyor system is provided, the system comprising: A skirted tray conveyor comprising: a) a plurality of skirt trays, the skirt trays including openings for draining water from the skirted tray conveyor; b) a carrying strand at an upper portion of the skirt trays; and c) a return strand at a lower portion of the skirt trays; a carriage side flush hopper positioned between the carry strand on the upper portion of the skirt pan and the return strand on the lower portion of the skirt pan, the carriage side flush hopper capturing fines and water from the system; and a return-side flush hopper positioned below the return strand, and wherein the carriage-side flush hopper comprises: a wash sprayer for wetting the sides of the carriage side wash hopper; and a channel flow nozzle for generating a channel water flow to flush solids to a desired output, wherein the channel water flow is between 50 gal / min and 150 gal / min; and The hot agglomerated iron is cooled from an agglomeration temperature of 650-700°C to 400°C in 1.5 to 2 minutes as it travels along the skirt tray conveyor, with a discharge temperature greater than 85°C and less than 130°C.

11. The method according to claim 10, wherein: The carriage side flush hopper includes at least one spiral classifier, and each spiral classifier includes a water overflow trough.

12. The method according to claim 10, wherein: The bracket side flush hopper includes a hopper bottom that is one of an arc shape, a V shape, and a trapezoidal shape.

13. The method according to claim 10, wherein: The agglomerate cooling conveyor system includes a cooling system comprising a plurality of coarse spray nozzles for spraying water onto the agglomerates in a coarse water droplet size of 0.8 mm to 2 mm in diameter.

14. The method according to claim 10, wherein: The carriage side flush hopper and the return side flush hopper discharge flow to a close coupled classifier, and the classifier discharges water to a pump sump.

15. The method according to claim 10, wherein The agglomerate cooling conveyor system recirculates water to the wash sprayers and water treatment.

16. The method according to claim 10, wherein The conveyor is inclined in a single plane, and the system includes a hot lump iron loading chute coupled to the conveyor, and a load leveler on the conveyor configured to evenly spread the iron, the load leveler including a helical screw.

17. The method according to claim 10, wherein The return strand is fitted with cleaning spray nozzles for washing any residual material on the skirt disc into the return side flush hopper.

18. The method according to claim 10, wherein After cooling, the discharged iron has a retained moisture level of less than 1.5% by weight.

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