【Major Equipment in the Chemical Engineering Sector】069 – Efforts to Develop Domestic Composite-Sealed High-Pressure Heat Exchangers
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The past decade has been a period of rapid development for China’s chemical industry, marked by the emergence of many new processes, products, and equipment. There has also been significant progress in China’s chemical processing equipment, which has contributed to the swift advancement of the petrochemical sector. Here, we have compiled some of the achievements and breakthroughs made by Chinese equipment manufacturers in terms of larger-scale production and greater use of domestic equipment. We invite everyone to share their insights and engage in discussions, to cheer for Made in China and to support the development of chemical processing equipment! ***********************************
More people are welcome to participate in the relevant discussions. Click on the blue link to access it: The 【HaiChuan Equipment Guessing Game】 series is being updated continuously in 2022; all equipment enthusiasts are invited to join actively! https://bbs.hcbbs.com/thread-2079686-1-1.html (Source: Huahai Chuanliu – Haichuan Chemical Industry Forum) Summary post on the series 【Major Equipment in the Chemical Equipment Industry】 https://bbs.hcbbs.com/thread-3312079-1-1.html (Source: Huahai Chuanliu – Haichuan Chemical Industry Forum) Summary post discussing the components of cracking furnace equipment for 【Ethylene Cracking】 https://bbs.hcbbs.com/thread-3308724-1-1.html (Source: Huahai Chuanliu – Haichuan Chemical Industry Forum)
Fish General: What types are used for composite seals?
I’m not sure about this; I need to search slowly to see if I can find it
The four feed/reactor gas-phase heat exchangers and one hydrogen/reactor gas-phase heat exchanger, which are the core equipment of the 2.6 million tons per year fluidized bed residue hydrogenation unit at Sinopec Zhenhai Refining & Chemical Co., Ltd. and were designed by Sinopec Luoyang Engineering Co., Ltd. and manufactured by Lansi Heavy Equipment Co., Ltd., are under accelerated development. This device is the first high-pressure heat exchanger with a composite sealing surface to be designed and manufactured in China. Its structural design combines a diaphragm seal on the tube side with an Ω-ring seal on the shell side; it has a diameter of 1500 mm and a length of 13,913.5 mm. The tube sheet of this equipment is designed to withstand full pressure, with a base thickness of 420 mm, and the surfacing layer on the shell side of the tube sheet features a slotted structure ； The expansion joint type between the heat exchange tube and the tube sheet is strength welding + local mechanical expansion + full hydraulic expansion ； Sealing is achieved between the shell-side flanges of the equipment using an Ω seal ring and a C seal ring ； The welding between the two O-ring seals on the equipment flanges must be carried out after the equipment has passed the hydrostatic test, and this should be done without removing the bolts.
At present, the design of such heat exchangers focuses on pressures of 8–12 Mpa and diameters of around 1200 mm; there is still no mature design or manufacturing experience for this in China. In 2016, Sinopec Luoyang Engineering Co., Ltd. joined forces with Zhenhai Refining & Chemical Co., Ltd. to initiate research and development on domestic technology for composite-sealed high-pressure heat exchangers. In 2017, Lansi Heavy Equipment Co., Ltd., thanks to its strong manufacturing capabilities and excellent brand reputation, took on the task of developing such equipment. During the manufacturing process, due to the fact that the high-pressure heat exchanger with a large-diameter Ω ring + diaphragm seal has a structure different from that of a heat exchanger with threaded locking rings, its production process is complex, it requires high precision in processing, and its manufacture is difficult. The technology and production departments implemented strict project management, rigorous process standards, and thorough quality control. Through their advanced manufacturing techniques and diligent work ethic, they overcame various technical challenges, such as the precision manufacturing of saddle-shaped nozzles, the machining of holes in heat exchange tubes, the expansion welding of heat exchange tubes to tube sheets at the grooved areas, and the welding of Omega rings to shell flanges – issues that often led to deformation – thereby accelerating the manufacturing process of the equipment. Composite-sealed high-pressure heat exchangers can reduce the corrosion of the shell-side fluid on the tube sheet and Ω-sealing rings, thereby minimizing internal and external leaks of the fluid in the equipment. The successful development of this project will fill the gap in domestic manufacturing technology for composite-sealed high-pressure heat exchangers, and will open a new chapter in Lansi Heavy Equipment’s efforts to achieve localization of key petrochemical technology equipment.
China’s largest omega ring heat exchanger, manufactured by Lansi Heavy Equipment Co., Ltd., was installed in place 2018-09-02 09:35 Not long ago, China’s largest omega ring heat exchanger, produced by Lansi Heavy Equipment Co., Ltd., was installed at the diesel hydrocracking unit of Hengli Petrochemical’s 20 million tons per year integrated refining and chemical processing project. This heat exchanger features a composite seal structure of omega rings and diaphragms; it has a diameter of 1720 mm and a length of 10,035.5 mm, making it the largest omega-ring type high-pressure heat exchanger designed and manufactured in China to date.
The threaded locking ring type heat exchanger represents the state-of-the-art in heat exchange equipment worldwide; large oil refining companies both domestically and internationally generally use this type of heat exchanger in their hydrocracking and heavy oil hydrodesulfurization units. It features a compact structure, few leakage points, reliable sealing, small footprint, and material savings. However, it has a complex structure, requires extensive processing, is difficult to assemble, and needs specialized tools for disassembly; its maintenance and installation also require the involvement of professional technicians on site.