Air coolers housed in a “large heating room” – clever solutions to prevent freezing and condensation in DMTO units

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Recently, it was learned from the DMTO unit at the Olefins Center that the 42 air coolers in the unit’s quench and stripping area were placed in a \"heated environment.\" This not only eliminated the risk of freezing in the tubes in that area but also enabled further recovery and utilization of waste heat. It is understood that the air coolers in the quench stripping area are the key anti-freezing areas in the reverse regeneration unit of the DMTO plant. Due to the presence of catalysts and waxy substances in the medium of the air cooler tubes, blockages or freezing risks can easily occur in the tube bundle area at the bottom of the air cooler in low-temperature environments. Once the tubes are frozen and blocked or cracked, the effectiveness of the quench stripping unit in reducing the temperature of the reaction gas stream is significantly reduced, and in severe cases it may cause process fluctuations in the plant. To address this potential problem, the DMTO plant came up with a clever solution: it covered the air coolers with a \"large enclosure\" and installed \"air conditioning\" equipment. The so-called “large house” refers to the installation of insulated color steel plates around the air cooler, which allows the air cooler to be like it is inside a “house,” thereby reducing the heat exchange between the tubes at the bottom and the low-temperature outdoor air ； The \"air conditioner\" functions by using a \"reverse\" setup to direct the heat emitted by the high-temperature tube banks at the top of the air cooler to the low-temperature tube bank area at the bottom of the air cooler. A responsible official from the DMTO facility said that the \"house + air conditioner\" anti-freezing system effectively eliminated the areas where the air coolers were prone to freezing, ensuring the safe and stable operation of the facility throughout the winter. This had a positive impact on the facility’s efforts to meet its annual olefin production targets.