What is the difference between a coking distillation tower and other distillation towers?

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What is the difference between a coking distillation tower and other distillation towers? 　　(1) The coking fractionation tower has a superheating removal section and a circulating oil heat exchange section for dust washing. The feed to the coking fractionation tower is superheated oil and gas at high temperature, containing coke dust. Therefore, a circulating oil return is provided at the bottom of the tower to cool the superheated oil-gas and wash away coke powder ； 　　(2) The remaining heat in the entire tower is high. The feed to the coking fractionation tower is high-temperature superheated oil and gas at around 420°C. Therefore, while meeting the separation requirements, efforts should be made to minimize the heat absorbed by the top reflux, and increase the heat absorbed by the higher-temperature wax oil circulation fluid as well as by the mid-stage circulation reflux, so as to make full use of the heat at higher energy levels for heat exchange and steam generation ； 　　(3) The system pressure drop requirement is low. To increase the inlet pressure of the compressor, reduce its energy consumption, and enhance its processing capacity, it is necessary to minimize the pressure drop in the fractionation system, the pressure drop across each tray, the pressure drop in the oil and gas pipelines at the top of the fractionation tower as well as in the condensation coolers, and the pressure drop from the oil and gas separator to the compressor inlet ； 　　(4) There is an oil absorption process. In the absorption and stabilization system, diesel fractions are used to absorb the lean gas at the top of the absorption tower in the reabsorption tower, thereby reducing the amount of gasoline carried away with the dry gas. The absorbed, rich-absorption oil is then returned to the distillation tower ； 　　(5) The bottom of the tower is the heat exchange section, where fresh feed material exchanges heat with the high-temperature oil and gas; it also serves to wash away the coke powder carried in the oil and gas ； 　　(6) To prevent coking and blockage at the bottom of the tower, a portion of the oil at the bottom is continuously circulated through a bottom pump and a filter.