The present technology is generally directed to systems and methods for quenching coke. More specifically, some embodiments are directed to systems and methods for improving the coke quenching process by partially cracking an amount of coke in order to improve the efficiency of the quenching process.
Coke is a solid carbon fuel and carbon source used to melt and reduce iron ore in the production of steel. In one process, known as the “Thompson Coking Process,” coke is produced by batch feeding pulverized coal to an oven that is sealed and heated to very high temperatures for 24 to 48 hours under closely-controlled atmospheric conditions. Coking ovens have been used for many years to convert coal into metallurgical coke. During the coking process, finely crushed coal is heated under controlled temperature conditions to devolatilize the coal and form a fused mass of coke having a predetermined porosity and strength. Because the production of coke is a batch process, multiple coke ovens are operated simultaneously.
The melting and fusion process undergone by the coal particles during the heating process is an important part of coking. The degree of melting and degree of assimilation of the coal particles into the molten mass determine the characteristics of the coke produced. In order to produce the strongest coke from a particular coal or coal blend, there is an optimum ratio of reactive to inert entities in the coal. The porosity and strength of the coke are important for the ore refining process and are determined by the coal source and/or method of coking.
Coal particles or a blend of coal particles are charged into hot ovens, and the coal is heated in the ovens in order to remove volatile matter (“VM”) from the resulting coke. The coking process is highly dependent on the oven design, the type of coal, and conversion temperature used. Typically, ovens are adjusted during the coking process so that each charge of coal is coked out in approximately the same amount of time. Once the coal is “coked out” or fully coked, the coke is removed from the oven and quenched with water to cool it below its ignition temperature. Alternatively, the coke is dry quenched with an inert gas. The quenching operation must also be carefully controlled so that the coke does not absorb too much moisture. Once it is quenched, the coke is screened and loaded into rail cars or trucks for shipment.
Because coal is fed into hot ovens, much of the coal feeding process is automated. In slot-type or vertical ovens, the coal is typically charged through slots or openings in the top of the ovens. Such ovens tend to be tall and narrow. Horizontal non-recovery or heat recovery type coking ovens are also used to produce coke. In the non-recovery or heat recovery type coking ovens, conveyors are used to convey the coal particles horizontally into the ovens to provide an elongate bed of coal.
As the source of coal suitable for forming metallurgical coal (“coking coal”) has decreased, attempts have been made to blend weak or lower quality coals (“non-coking coal”) with coking coals to provide a suitable coal charge for the ovens. One way to combine non-coking and coking coals is to use compacted or stamp-charged coal. The coal may be compacted before or after it is in the oven. In some embodiments, a mixture of non-coking and coking coals is compacted to greater than fifty pounds per cubic foot in order to use non-coking coal in the coke making process. As the percentage of non-coking coal in the coal mixture is increased, higher levels of coal compaction are required (e.g., up to about sixty-five to seventy-five pounds per cubic foot). Commercially, coal is typically compacted to about 1.15 to 1.2 specific gravity (sg) or about 70-75 pounds per cubic foot.
Once the coal is fully coked out, the resulting coke typically takes the form of a substantially intact coke loaf that is then quenched with water or another liquid. Because the coke loaf stays intact during quenching, the quenching liquid may encounter difficulty penetrating the intact coke loaf. The difficulty can lead to myriad disadvantages including increased water usage, longer quench times that can cripple the throughput of the coke plant, excessive moisture levels in the coke, large variations in coke moisture, and increased risk of melting plant equipment if the coke is not cooled rapidly enough. This difficulty is compounded in the case of stamp charging, in which coal is compacted before it is baked to form coke. Some conventional systems attempt to improve the efficiency of the quench by dropping the coke loaf a vertical distance of several feet to break up the coke loaf prior to quenching. However, such quenching procedures that include vertical drops of several feet often result in a large amount of coke dust that flies out of the container in which it is otherwise contained, while still not significantly improving the efficiency of the quench. This coke dust (as well as other related drawbacks) may necessitate additional capital expenses for adding removal sheds or special collectors to suppress or reclaim the coke dust.
The present technology describes various embodiments of methods and systems for improved coke quenching. More specifically, some embodiments are directed to methods and systems for improving the coke quenching process by partially cracking coke in order to improve the efficiency of the quenching process. In one embodiment, a coke loaf is partially cracked when placed in vertical communication with a surface over a vertical distance that is less than the height of the coke loaf. In another embodiment, coke is partially cracked when placed in vertical or horizontal communication with one or more uneven surfaces such as a bump plate, an angle ramp plate, an inclined ramp plate, or a combination or hybrid thereof. In another embodiment, a mass of coke is partially cracked when first placed in vertical communication with one or more uneven surfaces such as a bump plate, an angle ramp plate, an inclined ramp plate, or a combination or hybrid thereof, and then placed in horizontal communication with the same or a different uneven surface. In some embodiments, the one or more uneven surfaces may be mounted to a coke oven, train car, hot car, quench car, or combined hot car/quench car. Additionally, in some embodiments, one or more kick plates may be mounted to the tailgate of the train car, hot car, quench car, or combined hot car/quench car to place the rear portions of the coke in further communication with the uneven surface and/or the kick plate when the tailgate is closed. By placing the coke in communication with the uneven surfaces and/or the kick plate, the coke is cracked to yield pieces of coke without generating a significant amount of fly coke. In addition, the cracks in the coke enable liquid used during the quenching process to more efficiently penetrate and lower the temperature of the coke. Accordingly, the present technology improves the quenching process by reducing quench times, reducing liquid usage, minimizing risk to coke plant equipment, and minimizing the amount of fly coke during the quenching process.
Specific details of several embodiments of the technology are described below with reference to
A person of ordinary skill will appreciate that open bump plate 200, closed bump plate 300, or hybrid bump plate 400 may be fastened to surface 230, surface 330, or surface 430 in a variety of ways that may or may not require the use of mounting holes 210, 310, or 410, including welded or chemically bonded connections.
Angle ramp 515 may rest on one or more support structures situated between angle ramp 515 and base 505. For example, in one embodiment, angle ramp 515 may rest on wedge support 535, which is situated between the angle ramp and the base. Additionally or alternatively, angle ramp 515 may rest on stud support 540, which is situated between the angle ramp and the base. By including wedge support 535 and/or stud support 540, angle ramp plate 500 thereby becomes capable of cracking a larger and heavier amount of coke. A person of ordinary skill will appreciate that angle ramp plate 500 may be fastened to surface 530 in a variety of ways that may or may not require the use of mounting holes 510, including welded or chemically bonded connections. A person of ordinary skill will further appreciate that wedge support 535, stud support 540, or additional structures (not shown) may be used either alone or in various combinations to enclose the area underneath angle ramp 515 to prevent coke, water, steam or other undesirable materials from becoming trapped underneath the angle ramp. A person of ordinary skill will further appreciate that angle ramp 515, wedge support 535, stud support 540, or additional structures (not shown) used to enclose the area underneath the angle ramp may contain one or more breather holes (not shown) to allow coke, water, steam, or other undesirable materials to exit the area underneath the angle ramp.
A person of ordinary skill will appreciate that a variety of plate designs may be used in accordance with embodiments of the invention, including designs that differ in shape and construction from the plates described herein, designs that incorporate and/or omit specific aspects of various designs described herein, and designs that combine various aspects from different designs described herein to form alternative or hybrid designs. For example,
One or more plates may be coupled together to form a plate array that covers a larger area than an individual plate and is effective at cracking coke that is placed in vertical or horizontal communication therewith. For example,
To place the remaining coke in communication with the plate array, the tailgate 1050 of the train car may be equipped with a kick plate mounted thereto. In one embodiment, depicted in
In some embodiments, train car 125 may also include one or more stoppers 1065 or 1070 that prevent the coke from blocking one or more drain gates (not shown) on the train car as the coke is pushed farther inside of the train car. The stoppers may be placed on all sides of the train car, no sides of the train car, or one or more particular sides of the train car. For example, Figure 10C illustrates an embodiment having stoppers on three sides of the train car while omitting the stopper on the fourth side of the train car. By not allowing the coke to block the drain gates, liquid used during quenching drains from the train car more rapidly, thereby improving the efficiency of the quenching process. A person of ordinary skill will appreciate that the stopper may take a variety of different shapes, such as a trapezoid (e.g., stopper 1065) or a square (e.g., stopper 1070).
In addition to cracking coke by placing the coke in horizontal or vertical communication with an uneven surface, other embodiments crack coke prior to quenching by dropping the coke loaf over a distance that is less than the height of the coke loaf. For example,
1. A method of producing quenched coke, comprising:
disposing an amount of coal into a coke oven located at a first location;
heating the amount of coal to produce coke;
cracking the coke at a second location, wherein the cracking comprises placing the coke in communication with an uneven surface having a base and one or more raised portions extending from the base; and
quenching the coke to form quenched coke.
2. The method of example 1, wherein the one or more raised portions comprises one or more bumps attached to the base, each bump having a rounded portion.
3. The method of example 1, wherein the one or more raised portions comprises one or more angle ramps attached to the base, each angle ramp being attached to the base at an angle that is between 90 and 180 degrees with respect to a front portion and a side portion of the base.
4. The method of example 1, wherein the one or more raised portions comprises one or more inclined ramps attached to a base, each inclined ramp being attached to the base at an angle that is between 90 and 180 degrees with respect to a front portion of the base.
5. The method of example 1, wherein the uneven surface is mounted to a coke oven.
6. The method of example 1, wherein the uneven surface is mounted to a train car.
7. The method of example 1, wherein the uneven surface is mounted to a hot car.
8. The method of example 1, wherein the uneven surface is mounted to a quench car.
9. The method of example 1, wherein the uneven surface is mounted to a combined hot car/quench car.
10. The method of example 1, wherein the amount of coal is stamp charged.
11. The method of example 1, wherein the amount of coal is not stamped charged.
12. The method of example 1, wherein the first location and the second location are substantially parallel.
13. The method of any of example 6, 7, 8, or 9, further comprising cracking the coke by partially or fully closing a tailgate that is attached to the car, wherein the tailgate includes a kick plate mounted thereto, wherein the kick plate comprises an angle wedge, and wherein the partially or fully closing the tailgate places the kick plate in communication with the coke to further crack the coke.
14. The method of any of example 6, 7, 8, or 9, further comprising cracking the coke by partially or fully closing a tailgate that is attached to the car, wherein the tailgate includes a kick plate mounted thereto, wherein the kick plate comprises one or more tines that are substantially perpendicular to the tailgate, and wherein the partially or fully closing the tailgate places the kick plate in communication with the coke to further crack the coke.
15. A system for producing quenched coke, comprising:
a coke oven for receiving an amount of coal and heating the amount of coal to produce coke;
one or more uneven surfaces for cracking the coke when the coke is put into communication with the one or more uneven surfaces, the one or more uneven surfaces having a base and one or more raised portions extending from the base;
a quenching tower for receiving the coke and quenching the coke; and
one or more train cars for transporting the coke from the coke oven to the quenching tower.
16. The system of example 15, wherein the one or more raised portions comprises one or more bumps attached to a base, each bump having a rounded portion.
17. The system of example 15, wherein the one or more raised portions comprises one or more angle ramps attached to a base, each angle ramp being attached to the base at an angle that is between 90 and 180 degrees with respect to a front portion and a side portion of the base.
18. The system of example 15, wherein the one or more raised portions comprises one or more inclined ramps attached to a base, each inclined ramp being attached to the base at an angle that is between 90 and 180 degrees with respect to a front portion of the base.
19. The system of example 15, wherein the uneven surface is mounted to a coke oven.
20. The system of example 15, wherein the uneven surface is mounted to a hot car.
21. The system of examples 15, wherein the uneven surface is mounted to a train car.
22. The system of example 15, wherein the uneven surface is mounted to a quench car.
23. The system of example 15, wherein the uneven surface is mounted to a combined hot car/quench car.
24. The system of example 15, wherein the amount of coal is stamp charged.
25. The system of example 15, wherein the amount of coal is not stamped charged.
26. The system of example 15, wherein the coke oven and the uneven surfaces are substantially parallel.
27. The system of any of examples 20, 21, 22, or 23, further comprising cracking the coke by partially or fully closing a tailgate that is attached to the car, wherein the tailgate includes a kick plate mounted thereto, wherein the kick plate comprises an angle wedge, and wherein the partially or fully closing the tailgate places the kick plate in communication with the coke to further crack the coke.
28. The system of any of examples 20, 21, 22, or 23, further comprising cracking the coke by partially or fully closing a tailgate that is attached to the car, wherein the tailgate includes a kick plate mounted thereto, wherein the kick plate comprises one or more tines that are substantially perpendicular to the tailgate, and wherein the partially or fully closing the tailgate places the kick plate in communication with the coke to further crack the coke.
29. A method of producing quenched coke, comprising:
disposing an amount of coal onto a coke oven;
heating the amount of coal to produce a coke loaf having a height;
transferring the coke loaf from a first location having a first elevation to a second location having a second elevation, wherein the difference in height between the first elevation and the second elevation is less than the height of the coke cake, and further wherein the transferring includes cracking the coke loaf by placing the coke loaf in vertical communication with the second location; and
quenching the coke to form quenched coke.
30. The method of example 29, wherein the first location is a coke oven and the second location is a train car.
31. The method of example 29, wherein the first location is a coke oven and the second location is a hot car.
32. The method of example 29, wherein the first location is a coke oven and the second location is a quench car.
33. The method of example 29, wherein the first location is a coke oven and the second location is a combined hot car/quench car.
34. The method of example 29, wherein the first location is a first train car and the second location is a second train car.
35. The method of example 29, wherein the first location is a hot car and the second location is a quench car.
36. The method of example 29, wherein the amount of coal is stamp charged.
37. The method of example 29, wherein the amount of coal is not stamped charged.
38. A method of producing quenched coke, comprising:
disposing an amount of coal into a coke oven;
heating the amount of coal to produce coke;
transporting the coke from the coke oven to a train car, wherein the transporting includes cracking the coke by placing the coke in communication with an uneven surface mounted in the train car as the coke travels from the coke oven to the train car, wherein the uneven surface has a base and one or more raised portions extending from the base;
transporting the cracked coke to a quench tower; and
quenching the coke to form quenched coke.
From the foregoing it will be appreciated that, although specific embodiments of the technology have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the technology. Further, certain aspects of the new technology described in the context of particular embodiments may be combined or eliminated in other embodiments. Moreover, while advantages associated with certain embodiments of the technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the technology. Accordingly, the disclosure and associated technology can encompass other embodiments not expressly shown or described herein. Thus, the disclosure is not limited except as by the appended claims.
This patent document is a divisional application of and claims benefit of priority to U.S. patent application Ser. No. 13/730,796, filed on Dec. 28, 2012, the disclosure of which is incorporated by reference herein in its entirety.
Number | Date | Country | |
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Parent | 13730796 | Dec 2012 | US |
Child | 17140564 | US |