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Key equipment in coking coal pretreatment processes: Main equipment in Nippon Steel’s SCOPE21 process: https://pic2.zhimg.com/v2-fc4bce63f81e370dd7fba0ecb09bb5f1_b.png Fluidized bed dryer； Rapid preheating device for coking coal ； Coal powder granulator ； Main equipment for the DELTA coking coal pretreatment process: https://pic1.zhimg.com/v2-74baa7858d9db1cc5d463e4728af3504_b.png High-temperature fluidized bed dryer (due to the use of high-temperature flue gas, high-temperature fluidized bed drying enables both the drying of coking coal and its rapid preheating; this device can replace Nippon Steel’s fluidized bed dryer and coking coal rapid preheating unit) ； Coal powder granulation molding machine ； The DELTA coking coal pretreatment process essentially consists of high-temperature fluidized bed drying + granulation of ultra-fine coal powder ； The equipment investment for granulating ultra-fine coal powder is only 5-10% of that for high-temperature fluidized bed drying; therefore, the key equipment in the DELTA coking coal pretreatment process is the high-temperature fluidized bed dryer. Although there are no demonstration projects for the DELTA coking coal pretreatment process, there is plenty of successful experience available for reference. Moreover, DELTA possesses two key technologies in this field: high-temperature fluidized bed drying technology for coking coal ； Coal powder granulation technology (water-soluble binder coal rod machine) ； These two key technologies are ahead of Nippon Steel ； Delta Company holds an exclusive patent on high-temperature fluidized bed drying technology. This technology is ； 1. Compilation of the design drawings for high-temperature fluidized bed drying systems from 3 different American companies ； 2. Over 40 years of experience in digestion and absorption of technical improvement data related to 12 sets of high-temperature fluidized bed dryers; the annual cost for technical improvements to these dryers ranges from $1 million to $5 million ； After more than 40 years of technical upgrades, the coking coal high-temperature fluidized bed dryer now features automatic control: it completely eliminates the risk of dust explosions, ensuring safe operation; it also resolves the issue of fires during operation, thus guaranteeing the quality of the dried coking coal ； The coking coal fluidized bed dryer has achieved large-scale production increases, with its current capacity being twice that of the initial design capacity. Current status of the technology for drying coking coal in high-temperature fluidized bed dryers. The figure below shows a schematic diagram of the structure of a high-temperature fluidized bed dryer for coking coal. For high-temperature flue gas with an inlet temperature of over 1000 degrees, the gas distribution plate itself and the parts below it are at 1000 degrees ； At a distance of 100–150 mm above the gas distribution plate, the flue gas temperature drops sharply from 1000 degrees to the exhaust temperature (60–200 degrees). The entire housing of the coking coal high-temperature fluidized bed dryer is made of carbon steel structure, while the high-temperature section only requires a lining of refractory material. The only thing to consider is the gas distribution plate, as it can only be made of metal materials, and the thermal expansion and contraction of metal materials pose a problem at high temperatures. https://pic4.zhimg.com/v2-a88847c91b4dc5525339ca9a274dd7c3_b.png The maximum temperature that fluidized bed dryers available in China and Japan can reach is 450 degrees ； A German company that offers high-temperature fluidized bed dryers capable of reaching 650 degrees Celsius ； 40 years ago, the initial design temperature for the coking coal high-temperature fluidized bed dryers provided by three American companies was 650 degrees. The high-temperature fluidized bed dryer designed by Delta Company uses superalloy materials, and the structural design of the gas distribution plate in the fluidized bed has been modified so that the entire gas distribution plate does not come into direct contact with the high-temperature fluidized bed dryer at all; it can also expand and contract freely in all three dimensions to accommodate the thermal expansion and contraction of the device. Even if a component of the gas distribution plate needs to be replaced, it is completely independent of the equipment’s housing, and the replacement process takes only a few hours. The inlet high-temperature flue gas temperature of the coking coal high-temperature fluidized bed dryer designed by Delta Company depends entirely on the operating temperature of the alloy material selected. Alloys that can operate at excessively high temperatures come at a high cost, while those capable of operating at 1150 degrees have a more moderate price. Therefore, Delta Company’s coking coal high-temperature fluidized bed dryer allows for an inlet flue gas temperature of up to 1050 degrees, which is the highest in the industry. The figure below shows the details above and below the gas distribution plate in the coking coal high-temperature fluidized bed dryer. https://pic1.zhimg.com/v2-a1d5697ce65b636ecf36d812da070c24_b.png Delta Company has also designed high-temperature flue gas furnaces specifically for coking coal high-temperature fluidized bed dryers. The cooling gas required for these furnaces enters tangentially between the shell and the refractory bricks lining it; this not only reduces heat loss but also allows the furnaces to be installed outdoors. They are suitable for positive-pressure drying systems, ensuring the safe operation of coking coal dryers (by reducing the oxygen content in the gases used in the drying process to below 2%, dust explosions can be completely prevented). https://pic3.zhimg.com/v2-c4def3407c9bdcb46eca63afc676fea6_b.png https://pic1.zhimg.com/v2-407021d5c9416e65bf87341d0989aae0_b.png Of course, coking coal high-temperature fluidized bed dryers can also be used for drying lignite and other materials.