The fourth phase was completed with the installation of the adsorption tower for Hengli Petrochemical’s world’s largest aromatic compounds processing facility

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　　On March 10, it was learned from the Hengli project site in Dalian, Liaoning, which is under the construction of Si Jian Company, that the installation of the roof covers for two large-scale adsorption towers of Hengli Petrochemical’s 1# Aromatic Units – the world’s largest such facility currently under construction – has been completed by Si Jian Company. The installation work in the plant area has reached the final stage of insulating the process pipelines. It is reported that the team from Sijian Company arrived at the Dalian Hengli project on July 15, 2018. Through the scientific organization by the project management team at Dalian Hengli, as well as the exemplary leadership of Party members and the proactive role of outstanding workers, through hard work and clever strategies, they managed to complete, after 9 months of continuous effort, the installation of the internal components for two key equipment units in the PX unit 1# aromatic compounds section of the Dalian Hengli petrochemical project. According to Liu Jinjun, a skilled worker from Jinmen who is in charge of the installation of this critical equipment, the process flow and the assembly of the internal components for Tower 1 of the PX unit at the Dalian Hengli project are based on patented technology designed by the French company Axens. The two aromatic hydrocarbon absorption towers in Tower 1 of the PX unit at the Dalian Hengli Petrochemical project are currently the largest of their kind in the world. The tower has a diameter of 10 meters and a height of 40 meters; the weight of its shell is over 630 tons. Inside the tower, there are 16 layers of crossbeams, 15 layers of adsorbent packing beds, and 14 layers of distribution pipes. Each layer of distribution pipes consists of 32 flexible hoses that connect the circular chamber around the tower to the grills inside the tower. Each layer of trays is made up of 16 grids, while each layer of crossbeams is composed of 2 main beams and 12 secondary beams; the 14 layers of crossbeams together weigh 20 tons. The crossbeams are placed on the load-bearing supports inside the tower, with the tray sections resting on these crossbeams. The gaps between the tray sections are filled tightly with ceramic fiber ropes, which are then welded in place using gantry clamps. After the distribution pipes are installed, a pressure test is conducted to ensure airtightness. The internal structure is complex, and strict requirements are imposed on the installation process; the coaxiality deviation between both ends of the flexible hoses of each layer of distribution pipes and the flanges of the circular chambers in the tower wall must be less than 10 mm. Due to manufacturing tolerances of the tower and errors in the installation of the grills, many distribution pipes ended up having excessive coaxiality deviations during installation. Nearly 50 installers had to adjust these pipes by cutting them on-site and then reassembling and welding them, in order to meet the stringent inspection requirements set by foreign authorities. After 248 days of hard work, from the lifting of the *root beam to the completion of the installation of all internal components, the task of installing the internal components for the two adsorption towers in the Dalian Hengli Petrochemical project was finally completed safely and to high standards. 　　Since the official installation of the internal components began on September 7, 2018, nearly 6 months have passed. The most challenging part of constructing the absorption tower was the installation of the distribution pipes on each floor – there are over 30 flexible hoses per floor. These hoses connect the tray to the tower wall, and the coaxiality between the two ends of each flexible hose must not exceed 10 mm. The installation length of these hoses must be neither greater than 780 mm nor less than 730 mm. To ensure that the dimensions are correct, the workers carried out the installation in three stages: first, temporary gaskets were installed; after the dimensions were verified to be satisfactory, pressure-test plugs and gaskets were added. If the dimensions still did not meet the requirements, the hoses had to be cut and reassembled until the correct dimensions were achieved before welding could take place. Welding deformation was strictly controlled. Once all 30+ distribution pipes met the required standards, a gas-tightness test was conducted, with the system held under pressure for 2 hours. If the test passed, permanent gaskets were then installed. At present, the installation work of the adsorption tower is coming to an end. All employees involved have carried out each task with great care, completing the installation of nearly 70 tons of adsorbent per layer of the tower with high quality. They overcame various technical challenges and managed to finish covering the top of the adsorption tower, which has helped to accelerate the construction of the Hengli Petrochemical project. Time: 2019/3/13 14:00:59 Source: China Chemical Machinery Network