Method and apparatus for compacting coal for a coal coking process
View Patent ↗Relatively high speed methods for increasing the bulk density of coal particles without impacting the coal particles and an apparatus for compacting coal for making metallurgical coke. The method includes depositing coal particles onto a charging plate external to a coking oven. The charging plate has side walls, and at least one movable end wall to provide an elongate bed of dry, uncompacted coal having an upper surface on the charging plate. The uncompacted coal is compacted by passing a vibratory cylindrical compactor along a length of the uncompacted coal for a number of passes sufficient to decrease a thickness of the bed of coal to less than about 80 percent of an original thickness of the uncompacted coal. The vibratory cylindrical compactor has a length to diameter ratio ranging from about 1.4:1 to about 2:1.
1. A relatively high speed method for increasing the bulk density of coal particles without impacting the coal particles to provide an elongate bed of dry, compacted coal for charging to a coking oven, the method comprising the steps of:
depositing coal particles onto a charging plate external to a coking oven, the charging plate having side walls, and at least one movable end wall to provide an elongate bed of dry, uncompacted coal having an upper surface on the charging plate; and
compacting the uncompacted coal by rolling a vibratory cylindrical compactor along a length of the uncompacted coal for a number of passes sufficient to decrease a thickness of the bed of coal to less than about 80 percent of an original thickness of the uncompacted coal, wherein the vibratory cylindrical compactor has a length to diameter ratio ranging from about 1.4:1 to about 2:1 and a compaction energy output ranging from about 2 to about 5 kilograms-force meter per second.
2. The method of claim 1 , further comprising degassing the uncompacted coal during the compacting step to provide a dry, compacted coal bed having a bulk density ranging from about 960 to about 1200 kilograms per cubic meter.
3. The method of claim 2 , wherein degassing the coal bed is comprised of applying a vacuum source to one or more probes inserted in the uncompacted coal bed.
4. The method of claim 3 , wherein the vacuum source provides a vacuum to the uncompacted coal bed ranging from about 185 to about 280 mm of Hg during the degassing step.
5. The method of claim 2 , wherein degassing the coal bed comprises venting air at the side walls of the charging plate during the compacting step.
6. The method of claim 1 , wherein the coal particles are compacted to the bulk density ranging from about 960 to about 1200 kilograms per cubic meter from an initial bulk density ranging from about 640 to about 800 kilograms per cubic meter in less than 5 passes of the vibratory cylindrical compactor.
7. The method of claim 1 , wherein the length of the vibratory cylindrical compactor ranges from about 90 to about 99% of a width of the bed of coal.
8. The method of claim 1 , wherein the vibratory cylindrical compactor is operated at a speed ranging from about 0.5 to about 3.0 kilometers per hour.
9. The method of claim 1 , wherein the vibratory cylindrical compactor is passed along the length of the uncompacted coal from one to four times to compact the coal.
10. A method for compacting coal, the method comprising:
depositing coal particles onto a charging plate external to a coking oven, the charging plate having an elongate surface for supporting a bed of dry, uncompacted coal; and
rolling a vibratory cylindrical compactor along a length of the uncompacted coal, with a compaction energy output ranging from about 2 to about 5 kilograms-force meter per second, for a number of passes sufficient to decrease a thickness of the bed of coal to less than about 80 percent of an original thickness of the uncompacted coal.
11. The method of claim 10 , further comprising degassing the uncompacted coal during the rolling to provide a dry, compacted coal bed having a bulk density ranging from about 960 to about 1200 kilograms per cubic meter.
12. The method of claim 11 wherein degassing the coal bed comprises applying a vacuum source or venting air during the rolling.
13. The method of claim 10 wherein rolling the vibratory cylindrical compactor along a length of the uncompacted coal for a number of passes comprises rolling the vibratory cylindrical compactor along a length of the uncompacted coal for less than 5 passes.
14. The method of claim 10 wherein rolling the vibratory cylindrical compactor comprises rolling the compactor over a bed of uncompacted coal having an original thickness between about 135 centimeters and about 145 centimeters, and wherein the coal particles are compacted to a bulk density greater than 800 kilograms per cubic meter.
15. The method of claim 14 wherein rolling the vibratory cylindrical compactor along a length of the uncompacted coal to decrease the thickness of the bed of coal to less than about 80 percent of the original thickness of the uncompacted coal occurs in six minutes or less.