The 405-ton new alkali scrubber tower for Fushun Petrochemical’s 800,000 tons/year ethylene plant was hoisted into place as part of the project to remove bottlenecks and improve energy efficiency

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On August 11, at the site of the capacity expansion and energy efficiency improvement project for Fushun Petrochemical’s 800,000 tons per year ethylene plant, a 1,000-ton crawler crane extended its massive arms to lift the new alkali scrubber tower, which was 53.75 meters tall and weighed 405 tons. Like a giant ballerina, the tower was slowly raised from a horizontal position until it settled precisely into the holes in the foundation bolts; the lift was successful on the first attempt. This success acted as a catalyst to accelerate the progress of the project and initiated the comprehensive maintenance work on the plant. From manufacturing to installation, the alkali scrubber tower was entirely handled by CNPC No.7 Construction Company. The alkali scrubber tower plays a crucial role in removing acid from the pyrolysis gas in the ethylene plant; its processing capacity directly affects the stable operation of subsequent process units such as compression and separation. The renovation and upgrading of the alkali scrubbing tower is an important part of the ethylene capacity expansion project. The new alkali scrubbing tower is not only larger in size but also features a completely redesigned internal structure, all aimed at improving absorption efficiency, reducing pressure drop, and enhancing operational flexibility, so as to ensure that the alkali scrubbing unit can continue to operate efficiently even when the flow rate of the pyrolysis gas increases by 20%. Due to the large size of the alkali scrubber tower, a method of \"segmental prefabrication, on-site assembly, and overall lifting\" was adopted. The tower was first prefabricated in two sections, upper and lower, at the factory. After it arrived at the site on June 10, the factory focused on the scheduled milestones, made careful plans, and coordinated all relevant teams and contractors to work together efficiently. The installation sequence was optimized to improve efficiency; welding and assembly were carried out on the base. Extra hours were worked to weld elements such as platform ladders, pipelines attached to the tower, and anti-corrosion insulation layers, ensuring that the caustic scrubber tower was equipped with these components of high quality, ultimately forming a complete hoisting unit. “This equipment is too large in size; it is located right next to the operating ethylene plant. Lifting it requires overcoming the challenge of limited space while also ensuring precise alignment, which is no easy task. ”The factory uses the \"single-mainframe lifting and delivery method\" for lifting operations, that is, two crawler cranes with capacities of 1,000 tons and 320 tons work together to precisely plan the crane positions and the movement routes of the equipment in order to lift the caustic washing tower into place. To overcome spatial limitations, the factory conducted site surveys in advance and carried out detailed simulations of the entire process, focusing on crane placement and the movement paths of equipment. The site was leveled and compacted in advance; the tower’s balance tests were carried out, the lifting lugs were reinforced, temporary supports were welded, and obstacles such as street lights were removed. To ensure a foolproof lifting process, the factory implemented safety measures one by one, organized review meetings involving professionals from areas such as equipment, processes, and safety, and improved more than a dozen safety safeguards. Based on the actual on-site simulations, detailed instructions were provided prior to lifting, specifying key parameters such as the coordination commands between the main crane and the auxiliary crane, as well as the lifting angle of the tower. Multiple emergency response plans were developed to address potential issues that might arise. At 9:58 on August 11, the lifting and positioning operation officially began. The 1,000-ton main crane gradually applied force, while the 320-ton tail crane assisted in adjusting the angle of the tower, gradually turning this \"steel giant\" from a horizontal position to a vertical one. After testing the lift to confirm balanced forces, the main crane continued to raise it; the tower rotated in mid-air and finally settled precisely into the foundation bolt holes. The entire lifting process took 1 hour, and all parameters met the design requirements.