Fitness for Service Assessment of a Propylene Heat Exchanger Subjected to Fire Damage

Author(s):  
Shanshan Shao ◽  
Luowei Cao ◽  
Guodong Jia ◽  
Zhiyuan Han

Abstract Pressurized equipments maybe deform partially or wholly, and the mechanical properties of the construction material would be degraded due to a fire event. Fitness for service assessment can help to minimize reconstruction costs and allow safe resumption of unit operation as fast as possible. A propylene heat exchanger was exposed to overheating for about 3 hours due to a fire accident five or six meters far away. A fitness for service assessment was conducted according to API 579-1/ASME FFS-1. The material of the propylene heat exchanger is 09MnNiDR. The possible damage was examined by dimensional checks, hardness testing, in-situ field metallography, ultrasonic testing and magnetic particle testing. The heat exposure temperature of the propylene heat exchanger during the fire accident was estimated through the comparison between the results of in-situ field metallography examination and heat exposure simulation experiments. The heat exposure zones were identified based on the results of visual inspection and conjectural heat exposure temperature. The level 2 assessment was adopted to evaluate the heat exposure zones of V and VI. The approximate ultimate tensile strengths for the shell and the eastern head were converted from the hardness testing results. The caculated MAWP of the shell side is higher than the design pressure of the heat exchanger. The finite element method was adopted to evaluate the influence of the bulge in the upper part of the shell. The analytical results showed that the bulge had no significant effect on the operation of the heat exchanger before next inspection.

Author(s):  
Shanshan Shao ◽  
Guodong Jia ◽  
Luowei Cao ◽  
Guide Deng

Abstract Quenched and tempered high strength steel 07MnMoVR provides an excellent combination of strength and toughness potentially providing significant cost savings in petrochemical industry. Exposure to fire will subject steel to thermal conditions that may alter the material’s microstructure and properties. The extent of the fire damage and the potential reusability of the components can be evaluated by fitness-for-service (FFS) assessment after a fire event. According to API 579-1/ASME FFS-1, metallurgical investigation and mechanical testing are the chief means for the assessment of fire damage. This paper presents the details of an experimental investigation on the post-fire metallographic structure and hardness of 07MnMoVR steel. Metallographic analyses and hardness testing were performed on coupons exposed to elevated temperatures varying from 550°C to 850°C for half an hour to 8 hours and then naturally cooled in air or cooled by water. The results show that the microstructure of as-received 07MnMoVR steel consisted of tempered sorbite and bainite. With increasing heat exposure temperature, bainite disappeared gradually. The recovery and recrystallization of ferrite began to occur after heat exposure at 650°C for 5hrs. When the heat exposure temperature exceeded 750°C, the effects of duration time and cooling rate on microstructure were both significant. A linear correlation is indicated by fitting the ultimate tensile strength and hardness. Due to the drastically degradation of impact toughness of 07MnMoVR steel after heat exposure exceeded 650°C, it is suggested that the removal and testing of material samples shall be utilized to evaluate the fire damage of components, besides replication or in-situ field metallography and hardness testing. This study can provide basis data and guidelines for the fitness-for-service assessment of 07MnMoVR steel suffered from a fire event.


Author(s):  
Shanshan Shao ◽  
Guodong Jia ◽  
Luowei Cao ◽  
Chenyang Du

The degeneration of mechanical properties is one of the main concerns in assessment of fire damaged pressure vessels. This study investigates the influence of fire exposure on mechanical properties of Q345R steel which is widely used for pressure vessels in China. Heat treatment with different temperatures and holding times was conducted to simulate various heat exposure conditions in fire event. Hardness testing, metallographic analysis and tensile tests were carried out to investigate the effects of fire exposure temperature and duration. The experimental results indicate that the inflection temperature for mechanical property degeneration of Q345R steel is 700 °C. The decline of hardness, yield and tensile strengths due to spheroidization become more obvious with increasing heat exposure duration. A linear correlation is indicated by fitting the tensile strength and hardness. For the assessment of fire damaged component, the mechanical properties of Q345R steel at room temperature can be determined combining on-situ field metallographic examination and hardness testing with.


Author(s):  
Shanshan Shao ◽  
Luowei Cao ◽  
Zhifeng Li ◽  
Jianjun Liu

When pressure vessels are subjected to fire damage, they maybe deform partially and the mechanical properties of materials would be degraded. Fitness for service assessment can help to minimize reconstruction costs and allow safe resumption of unit operation as fast as possible. The safety of a packed column subjected to fire damage due to spontaneous combustion of FeS during a shutdown period is assessed according to API 579-1/ASME FFS-1. First, the highest temperature during the fire accident was estimated. The possible damage was examined by hardness test, dimensional checks, in-situ field metallography, ultrasonic test and penetration test. The Heat Exposure Zones were defined based on the results of visual inspection and test. The plates containing Widmanstätten or localized distortions were replaced. The column leaned with the vertical deviation of 85mm which could not satisfy the requirement of the national standard GB 50461-2008. The finite element method is adopted to analyze the influence of the vertical deviation with the consideration of wind loading. The analytical results show that the vertical deviation of 85mm has no significant effect on the safe operation of the column before the next inspection.


2020 ◽  
pp. 103264
Author(s):  
Jochen A.H. Dreyer ◽  
Claus Erik Weinell ◽  
Kim Dam-Johansen ◽  
Søren Kiil

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6903
Author(s):  
Maroua Benkhaled ◽  
Salah-Eddine Ouldboukhitine ◽  
Amer Bakkour ◽  
Sofiane Amziane

Plant-based concrete is a construction material which, in addition to having a very low environmental impact, exhibits excellent hygrothermal comfort properties. It is a material which is, as yet, relatively unknown to engineers in the field. Therefore, an important step is to implement reliable mass-transfer simulation methods. This will make the material easy to model, and facilitate project design to deliver suitable climatic conditions. In recent decades, numerous studies have been carried out to develop models of the coupled transfers of heat, air and moisture in porous building envelopes. Most previous models are based on Luikov’s theory, considering mass accumulation, air and total pressure gradient. This theory considers the porous medium to be homogeneous, and therefore allows for hygrothermal transfer equations on the basis of the fundamental principles of thermodynamics. This study presents a methodology for solving the classical 1D (one-dimensional) HAM (heat, air, and moisture) hygrothermal transfer model with an implementation in MATLAB. The resolution uses a discretization of the problem according to the finite-element method. The detailed solution has been tested on a plant-based concrete. The energy and mass balances are expressed using measurable transfer quantities (temperature, water content, vapor pressure, etc.) and coefficients expressly related to the macroscopic properties of the plant-based concrete (thermal conductivity, specific heat, water vapor permeability, etc.), determined experimentally. To ensure this approach is effective, the methodology is validated on a test case. The results show that the methodology is robust in handling a rationalization of the model whose parameters are not ranked and not studied by their degree of importance.


2019 ◽  
Vol 23 (Suppl. 3) ◽  
pp. 877-885 ◽  
Author(s):  
Zhi He ◽  
Ling Chen ◽  
Tong Lu ◽  
Jing Xie

Obtaining samples of deep in-situ conditions is first step to explore the mysteries of the earth requires. In view of the current problems of insufficient pressure maintaining capacity of the existing equipment, we independently developed the in-situ fidelity coring system and designed the osmotic pressure controller based on the geometry of square cover. The finite element method is used to analyze the pressure maintaining capacity of the pressure controller. It is found that it would produce large deformation and stress concentration when the pressure was applied on, resulting in low pressure maintaining capacity. Then the structural optimization schemes of conical sealing contact surfaces with 25?, 35?, 40?, and 45? apex angles and spherical sealing contact surface are proposed, and the spherical contact surface structure is found to be optimal. Finally, the material is optimized, and a higher strength material such as 45CrNiMoVA alloy is used. Based on the pressure controller with spherical contact surface, the pressure maintaining capacity increased to nearly 70 MPa. The research results obtained in this paper provide the basis for the development of the coring system, the deep exploration of the earth and the establishment of rock mechanics theory.


Pro Food ◽  
2018 ◽  
Vol 4 (1) ◽  
pp. 298-303
Author(s):  
Dhanang Puspita ◽  
Yosephine Diana Tjahyono ◽  
Yunius Samalukang ◽  
Binerd Anthon Im Toy ◽  
Norson Willem Totoda

Miana (Coleus scutellaroides) is an ornamental plant of single leaf a purple color. The purple color found from miana leaves is an indicator of the presence of anthocyanin pigments. Anthocyanin from miana leaves can be utilized as a natural pigment for various staining purposes especially in the food industry, anthocyanin harvesting on miana leaves can be done at any time and does not depend on the season due to its abundant availability in nature.The aims of this study were to isolate, identify, and microencapsulated anthocyanin pigments of miana leaves. The result, pigment extracted from miana leaves had characteristic of purple color and having maximum absorbance at wavelength 529 nm, suspected as anthocyanin derivative (cyanidin-3-routosida).The total microcapsulated anthocyanim was 0.149542 mg / g. Thermostability of encapsulated anthocyanin pigment from miana leaves stable with heat exposure temperature 100C up to 60 minutes. Based on those collected information, encapsulated miana leaves pigment could be used as an additional natural coloring in food industries.Keywords: anthocyanin, miana, microencapsulation, pigment, thermostability. ABSTRAKMiana (Coleus scutellaroides) termasuk ke dalam tanaman hias yang berdaun tunggal dan berwarna ungu. Warna ungu yang terdapat pada daun miana adalah indikator keberadaan pigmen antosianin.Pemanfaatan daun miana sebagai sumber antosianin dapat dimanfaatkan sebagai pigmen alami untuk berbagai keperluan pewarna terutama dalam industri pangan, pemanenan antosianin pada daun miana dapat dilakukan setiap saat dan tidak bergantung pada musim dikarenakan ketersediannya yang selalu melimpah di alam.Tujuan dari penelitian ini adalah untuk mengisolasi, mengidentifikasi, dan mikroenkapsulasi pigmen antosianin dari daun miana.Berdasarkan hasil analisis didapati bahwa ekstrak pigmen daun miana memiliki karakteristik warna nampak ungu dan serapan maksimum absorbansinya berada pada panjang gelombang 529 nm, pigmen diduga sebagai turunan antosianin yaitu sianidin-3-rutinosida.Total antosianim yang sudah dimikroenkapsulasi sebesar 0.149542 mg/g. Dari hasil uji thermostabilitas pigmen terenkapsulasi maltodekstrin, stabilitas pigmen antosianin dari daun miana cenderung stabil dengan adanya pemaparan panas suhu 100C hingga 60 menit.Berdasarkan hasil dan pengujian, pigmen daun miana terenkapsulasi dapat menjadi pertimbangan produk untuk digunakan sebagai bahan tambahan pewarna dalam industri pangan.Kata kunci: antosianin, miana, mikroenkapsulasi, pigmen, termostabilitas.


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