This study aims to analyze the failure characteristics, the distribution of failure locations and the failure mechanism for the blower impeller used for the alkylation waste acid treatment system. The study integrates experimental analysis and computational simulations to identify specific factors contributing to impeller deterioration, providing a comprehensive approach to understanding the complex interactions between impeller components and corrosive environments. Based on a series of physical and chemical testing, microscopic morphology, elemental analysis, chemical structure and phase analysis of the failed impeller and corrosion products are studied. With process gas as the primary phase and sulfuric acid as the secondary phase in the VOF (Volume of Fluid) model, Computational Fluid Dynamics (CFD) simulations are applied to analyze the internal flow fields of the impeller and their effect on failure. The results show that the chemical composition of the blower impeller meets the relevant standards, and the metallographic structure shows no abnormalities. The rear disk and blades of the impeller suffer from significantly more severe corrosion than that the front disk suffers. Specifically, the impeller surface exhibits extensive deposition of dark green corrosion products and significant thinning resulting from corrosion. Scanning Electron Microscopy (SEM) analysis reveals a distinct wavy striation pattern, along with numerous pits of varying sizes aligned with the direction of fluid flow. Additionally, the surface displays a network of extensive cracks, numerous voids, and substantial accumulation of corrosion residues. Energy dispersive spectroscopy (EDS) results show that the corrosion products are mainly Fe, S, Cr and O. Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis further confirm that the chemical corrosion of the impeller substrate is primarily caused by sulfuric acid, resulting in the formation of various sulfate compounds of Fe, Cr, and Ni, including FeSO4∙H2O, NiSO4∙H2O, Cr2(SO4)3, etc., as the predominant corrosion products. The CFD simulations reveal that the uneven distribution of velocity and pressure results in fluid unsteady flow and corrosive medium accumulation, and eventually increases corrosion of the impeller. Sulfuric acid as the corrosive medium is mainly concentrated on the areas of the rear disk, the outer edge of the blade's pressure surface and the blade's suction surface close to the rear disk. And the maximum volumetric concentration is 3.22%. This corresponds with the areas where the impeller exhibits significant corrosion thinning and ultimately suffers perforation failure. Due to variations in fluid velocity and the unstable flow of the corrosive medium, the shear stress on the blade's suction surface and at the center of the rear blade is elevated, reaching a maximum of 79.6 Pa. As a result, significant corrosion is observed with increased depth on the blades near the center of the impeller, and severe corrosion is evident at the central region of the rear disk. These findings are consistent with the actual corrosion conditions observed on the impeller. With the high speed of the chemical industry blower impeller for the process gas, the product acid is formed and the passive film of the impeller substrate is destroyed. The coupling of fluid corrosion and erosion leads to impeller thinning until perforation failure. This study can offer valuable insights into the impeller failure behavior and provides recommendations for extending its service life, including strategies for design and material enhancements to mitigate corrosion and erosion.
Key words
chemical industry blower impeller /
physical and chemical testing /
CFD simulation /
corrosion
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References
[1] AKHMADOVA K K, MAGOMADOVA M K, SYRKIN A M, et al.History, Current State, and Prospects for Development of Isobutane Alkylation with Olefins[J]. Theoretical Foundations of Chemical Engineering, 2019, 53(4): 643-655.
[2] SINGHAL S, AGARWAL S, SINGH M, et al.Ionic Liquids: Green Catalysts for Alkene-Isoalkane Alkylation[J]. Journal of Molecular Liquids, 2019, 285: 299-313.
[3] ZHOU Z M, ZHANG X P, YANG F F, et al.Polymeric Carbon Material from Waste Sulfuric Acid of Alkylation and Its Application in Biodiesel Production[J]. Journal of Cleaner Production, 2019, 215: 13-21.
[4] XIN Y Y, HU Y F, LI M C, et al.Isobutane Alkylation Catalyzed by H2SO4: Effect of H2SO4 Acid Impurities on Alkylate Distribution[J]. Energy & Fuels, 2021, 35(2): 1664-1676.
[5] SUBRAMANIAN C, ROY H, MONDAL A, et al.Failure of Induced Draft-ID Fan Blade in Coal Fired Boiler[J]. Engineering Failure Analysis, 2021, 122: 105282.
[6] FORTINI A, SUMAN A, ZANINI N.An Experimental and Numerical Study of the Solid Particle Erosion Damage in an Industrial Cement Large-Sized Fan[J]. Engineering Failure Analysis, 2023, 146: 107058.
[7] AVŞAR G, EZERTAŞ A A, BAŞKAN PERÇIN Ö. Aerodynamic Design and Performance Optimization of a Centrifugal Fan Impeller[C]//ASME Turbo Expo 2023: Turbomachinery Technical Conference and Exposition, Boston, Massachusetts, USA. 2023
[8] 孙少东, 何时剑, 陈玮, 等. 盐化工风机叶轮早期腐蚀失效的分析与预防[J]. 机械工程材料, 2017, 41(10): 98-102.
SUN S D, HE S J, CHEN W, et al.Analysis and Prevention of Premature Corrosion Failure of Blower Impeller for Salt and Chemical Industry[J]. Materials for Mechanical Engineering, 2017, 41(10): 98-102.
[9] 陈一鸣, 董美, 王博, 等. 含酸性溶解气的气液两相流管道流致腐蚀模拟[J]. 表面技术, 2022, 51(8): 298-306.
CHEN Y M, DONG M, WANG B, et al.Flow-Assisted Corrosion Simulation of Natural Gas Pipeline Flow Containing Sour Dissolved Gas[J]. Surface Technology, 2022, 51(8): 298-306.
[10] 单斌, 陈平, 乔小溪, 等. 基于实验和CFD模拟的煤气化黑水处理系统管道失效分析[J]. 表面技术, 2019, 48(12): 247-256.
SHAN B, CHEN P, QIAO X X, et al.Failure Analysis of Pipeline in Coal Gasification Black Water Treatment System Based on Experiment and CFD Simulation[J]. Surface Technology, 2019, 48(12): 247-256.
[11] ZHANG H Z, ZHAO J L, YANG C G, et al.Corrosion Resistance of Cu-Bearing 316L Stainless Steel Tuned by Various Passivation Potentials[J]. Surface and Interface Analysis, 2021, 53(6): 592-602.
[12] HUNG T S, CHEN T C, CHEN H Y, et al.The Effects of Cr and Ni Equivalents on the Microstructure and Corrosion Resistance of Austenitic Stainless Steels Fabricated by Laser Powder Bed Fusion[J]. Journal of Manufacturing Processes, 2023, 90: 69-79.
[13] 唐园, 曾皓, 黎红英, 等. PANI/EP复合涂层对不锈钢在硫酸溶液中的保护作用[J]. 表面技术, 2020, 49(8): 275-282.
TANG Y, ZENG H, LI H Y, et al.Protection Effect of PANI/EP Composite Coating on Stainless Steel in H2SO4 Solution[J]. Surface Technology, 2020, 49(8): 275-282.
[14] 陈伟, 郑怀礼, 翟俊, 等. 聚合硫酸铁钛混凝剂的制备及红外、紫外-可见光谱分析[J]. 光谱学与光谱分析, 2016, 36(4): 1038.
CHEN W, ZHENG H L, ZHAI J, et al.Study on the Preparation of a New Composite Coagulant: Poly-Ferric- Titanium-Sulfate and Analysis of FTIR Spectrum and UV-Vis Spectrum[J]. Spectroscopy and Spectral Analysis, 2016, 36(4): 1038.
[15] ZHU G C, ZHENG H L, ZHANG Z, et al.Characterization and Coagulation-Flocculation Behavior of Polymeric Aluminum Ferric Sulfate (PAFS)[J]. Chemical Engineering Journal, 2011, 178: 50-59.
[16] 翁诗甫. 傅里叶变换红外光谱分析[M]. 2版. 北京: 化学工业出版社, 2010: 387.
WENG S F.Fourier Transform Infrared Spectrum Analysis [M]. 2nd ed. Beijing: Chemical Industry Press, 2010: 387.
[17] CARJA G, HUSANU E, GHERASIM C, et al.Layered Double Hydroxides Reconstructed in NiSO4 Aqueous Solution as Highly Efficient Photocatalysts for Degrading Two Industrial Dyes[J]. Applied Catalysis B: Environmental, 2011, 107(3/4): 253-259.
[18] OLIVARES-XOMETL O, LIKHANOVA N V, NAVA N, et al.Thiadiazoles as Corrosion Inhibitors for Carbon Steel in H2SO4 Solutions[J]. International Journal of Electrochemical Science, 2013, 8(1): 735-752.
[19] JIAN Z, JU P F, WANG C L, et al.Corrosion Behaviour of 316L Stainless Steel in Hot Dilute Sulphuric Acid Solution with Sulphate and NaCl[J]. Protection of Metals and Physical Chemistry of Surfaces, 2019, 55(1): 148-156.
[20] KELLER P, STREHBLOW H H.XPS Investigations of Electrochemically Formed Passive Layers on Fe/Cr-Alloys in 0.5 M H2SO4[J]. Corrosion Science, 2004, 46(8): 1939-1952.
[21] ROKOSZ K, HRYNIEWICZ T.Xps Surface Characterization of Aisi 316L (En 1.1404) Ss Electrochemically Polished in the Mixture of H3PO4, H2SO4 and HNO3 Acids[C]//Proceedings of the 24th International Conference on Metallurgy and Materials. Brno: Czech Republic, 2015.
[22] KISH J R, IVES M B, RODDA J R.Anodic Behaviour of Stainless Steel S43000 in Concentrated Solutions of Sulphuric Acid[J]. Corrosion Science, 2003, 45(7): 1571-1594.
[23] FEI B, CHEN Z L, LIU J X, et al.Ultrathinning Nickel Sulfide with Modulated Electron Density for Efficient Water Splitting[J]. Advanced Energy Materials, 2020, 10(41): 2001963.
[24] MULBAH C, KANG C, MAO N, et al.A Review of VOF Methods for Simulating Bubble Dynamics[J]. Progress in Nuclear Energy, 2022, 154: 104478.
[25] SHEN Z D.The Influence of Cr and Mo on the Formation of the Passivation Film on the Surface of Ferritic Stainless Steel[J]. Materials Today Communications, 2024, 38: 108221.
[26] 李宛静, 周婉秋, 辛士刚, 等. 阴极气体O2对石墨烯/聚苯胺/不锈钢双极板耐蚀性的影响[J]. 表面技术, 2023, 52(5): 163-174.
LI W J, ZHOU W Q, XIN S G, et al.Effect of Cathode Gas Oxygen on Corrosion Resistance of Graphene/Polyaniline/Stainless Steel Bipolar Plates[J]. Surface Technology, 2023, 52(5): 163-174.
[27] 张青, 胡青. 酸性气焚烧和废硫酸裂解一体化工艺应用总结[J]. 炼油技术与工程, 2023, 53(11): 23-28.
ZHANG Q, HU Q.Summary of Integrated Process Application of Acid Gas Incineration and Waste Sulfuric Acid Cracking[J]. Petroleum Refinery Engineering, 2023, 53(11): 23-28.
[28] KHAMME E, SAKDANUPHAB R.Study of Corrosion Properties of Carbon Steel, 304 and 316L Stainless Steels in Sulfuric Acid and Their Degradation Products[J]. Journal of Metals, Materials and Minerals, 2023, 33(4): 1672.
Funding
GuangDong Basic and Applied Basic Research Foundation (2023A1515240006,2024A1515010452); Joint Training Support Project Supported by National Excellent Engineers Innovation Institute of Guangdong-Hong Kong-Macao Greater Bay Area(Foshan) Advanced Manufacturing Industry (2023FCXM002)
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