Journal articles: 'The reactor tube'

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Hatamachi, Tsuyoshi, Tatsuya Kodama, Yuki Isobe, Daisuke Nakano, and Nobuyuki Gokon. "Double-Walled Reactor Tube with Molten Salt Thermal Storage for Solar Tubular Reformers." Journal of Solar Energy Engineering 128, no. 2 (April 8, 2005): 134–38. http://dx.doi.org/10.1115/1.2183803.

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This paper proposes a novel-type of “double-walled” reactor tube with molten-salt thermal storage at high temperatures for use in solar tubular reformers. The prototype reactor tube is demonstrated on the heat-discharge and chemical reaction performances during cooling mode of the reactor tube at laboratory scale. The Na2CO3 composite material with MgO ceramics was filled into the outer annulus of the double-walled reactor tube while the Ru-based catalyst particles were filled into the inner tube. The heat discharge form the molten Na2CO3 circumvented the rapid temperature change of the catalyst bed, which resulted in the alleviation of decrease in chemical conversion during cooling mode of the reactor tube. The application of the new reactor tubes to solar tubular reformers is expected to help realize stable operation of the solar reforming process under fluctuating insolation during a cloud passage.

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Gužela, Štefan, František Dzianik, Martin Juriga, and Juraj Kabát. "Shell and Tube Heat Exchanger – the Heat Transfer Area Design Process." Strojnícky casopis – Journal of Mechanical Engineering 67, no. 2 (November 1, 2017): 13–24. http://dx.doi.org/10.1515/scjme-2017-0014.

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AbstractNowadays, the operating nuclear reactors are able to utilise only 1 % of mined out uranium. An effective exploitation of uranium, even 60 %, is possible to achieve in so-called fast reactors. These reactors commercial operation is expected after the year 2035. Several design configurations of these reactors exist. Fast reactors rank among the so-called Generation IV reactors. Helium-cooled reactor, as a gas-cooled fast reactor, is one of them. Exchangers used to a heat transfer from a reactor active zone (i.e. heat exchangers) are an important part of fast reactors. This paper deals with the design calculation of U-tube heat exchanger (precisely 1-2 shell and tube heat exchanger with U-tubes): water – helium.

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Luyben, William L. "Effect of Peak Temperature Limitations on the Design of Processes with Cooled Tubular Reactors." International Journal of Chemical Reactor Engineering 12, no. 1 (January 1, 2014): 191–203. http://dx.doi.org/10.1515/ijcre-2013-0138.

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Abstract Maximum temperature limitations are usually encountered in exothermic catalytic reaction systems due to catalyst deactivation. Therefore, the peak temperature in a cooled tubular reactor can be constrained to some maximum limit. The peak temperature is a function of many design and operating variables such as reactor volume and heat-transfer area (number of tubes, tube diameter and tube length), coolant temperature, inlet reactant concentration, per-pass conversion and reactant feed distribution. These variables affect the design of both the reactor and the separation section of the plant. This paper explores the impact of this peak temperature limitation on the economic design of the entire process. The numerical example used is the production of cumene from benzene and propylene. Results show that costs increase as the peak temperature limitation decreases. Use of two cooled reactors in series with the limiting reactant split between the reactors is more economical than a single reactor.

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Zahradník, Jindřich, and Milan Rylek. "Design and scale-up of Venturi-tube gas distributors for bubble column reactors." Collection of Czechoslovak Chemical Communications 56, no. 3 (1991): 619–35. http://dx.doi.org/10.1135/cccc19910619.

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General principles of ejector distributors performance are surveyed and demonstrated for two particular cases of Venturi tubes commonly employed for gas dispersion in tower reactors with forced liquid circulation. Design recommendations for the two types of Venturi-tube gas distributors are presented and a general method is outlined for ejector distributors scale-up, based on the decisive effect of energy dissipation rate on the distributors performance. As an illustration, the specific case of Venturi-tube gas distributor design for an industrial reactor for catalytic hydrogenation of rape-seed oil is treated in detail. The procedure included design of a small-scale laboratory reactor for kinetic experiments at real process conditions (scale-down step) and subsequent ejector distributor scale up to dimensions corresponding to the industrial reactor (vessel diameter 1.6 m, effective reactor volume ~ 5 m3). Comparison with other modes of gas dispersion proved superiority of Venturi-tube distributors both on the laboratory- and industrial-scale level, regarding the overall rate of reaction process achieved and/or catalyst load requirements.

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Burkholder, Michael, Stanley Gilliland, Adam Luxon, Christina Tang, and B. Gupton. "Improving Productivity of Multiphase Flow Aerobic Oxidation Using a Tube-in-Tube Membrane Contactor." Catalysts 9, no. 1 (January 17, 2019): 95. http://dx.doi.org/10.3390/catal9010095.

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The application of flow reactors in multiphase catalytic reactions represents a promising approach for enhancing the efficiency of this important class of chemical reactions. We developed a simple approach to improve the reactor productivity of multiphase catalytic reactions performed using a flow chemistry unit with a packed bed reactor. Specifically, a tube-in-tube membrane contactor (sparger) integrated in-line with the flow reactor has been successfully applied to the aerobic oxidation of benzyl alcohol to benzaldehyde utilizing a heterogeneous palladium catalyst in the packed bed. We examined the effect of sparger hydrodynamics on reactor productivity quantified by space time yield (STY). Implementation of the sparger, versus segmented flow achieved with the built in gas dosing module (1) increased reactor productivity 4-fold quantified by space time yield while maintaining high selectivity and (2) improved process safety as demonstrated by lower effective operating pressures.

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Jiang, Yun Bo, and Ke Zheng Zhang. "Study of Discrete and Multi-Tube Pass Number Inorganic Membrane Reactor." Advanced Materials Research 233-235 (May 2011): 3036–39. http://dx.doi.org/10.4028/www.scientific.net/amr.233-235.3036.

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Discrete and Multi-tube Pass Number Inorganic Membrane Reactor offers supplements to single-tube membrane reactor, referencing heat exchanger can provide larger transmission area and plate column can realize multi-stage separation. It realizes the reaction and separation occurs simultaneously many times, and can change the membrane area according to the need, so that reaction and separation process can be matched better. Discrete and multi-tube membrane reactor and fixed bed reactor was experimented in sec-butyl alcohol dehydrogenation system at 150-225, the result shows the new membrane reactor structure is reasonable.

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Yoshino, M., M. Yao, H. Tsuno, and I. Somiya. "Removal and recovery of phosphate and ammonium as struvite from supernatant in anaerobic digestion." Water Science and Technology 48, no. 1 (July 1, 2003): 171–78. http://dx.doi.org/10.2166/wst.2003.0045.

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Removal of phosphorus and nitrogen is required to prevent eutrophication problems in lakes and enclosed coastal seas. And recovery of phosphorus from wastewater has been attracting attention because of lack in phosphorus resources in the near future. In this study, reaction kinetics and design parameters of struvite production are experimentally investigated by using basic reaction type and a draft-tube type reactors. Struvite production rate, which is a very important parameter in reactor design and efficiency estimation, is formulated in an equation consisting of a rate constant (k2), and magnesium, phosphate and ammonium concentrations. The value of k2 is shown to be increased with struvite concentration and mixing intensity in the reactor. The developed equation is applied to the results obtained from the draft-tube type reactor experiments and verified for its applicability. High struvite concentration of 10-25% is maintained in the draft-tube reactor experiments. 92% removal and recovery efficiency with effluent phosphorus concentration of 17 mg/L is achieved under the conditions of 4 minutes reaction time, pH of 8.5 and Mg/P molar ratio of 1.1.

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Mahendra Prabhu, N., K. A. Gopal, S. Murugan, T. K. Haneef, C. K. Mukhopadhyay, S. Venugopal, and T. Jayakumar. "Determining the feasibility of identifying creep rupture of stainless steel cladding tubes on-line using acoustic emission technique." International Journal of Structural Integrity 6, no. 3 (June 8, 2015): 410–18. http://dx.doi.org/10.1108/ijsi-08-2014-0038.

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Purpose – The purpose of this paper is to determine the feasibility of identifying the creep rupture of reactor cladding tubes using acoustic emission technique (AET). Design/methodology/approach – The creep rupture tests were carried out by pressuring stainless steel capsules upto 6 MPa at room temperature and then heating continuously in a furnace upto rupture. The acoustic emission (AE) signals generated during the creep rupture tests were recorded using a 150 kHz resonant sensor and analysed using AE Win software. Findings – When rupture occurs in the pressurized capsule tube representing the cladding tube, AE sensor attached to a waveguide captures the mechanical disturbance from the capsule and these data can be advantageously used to identify the creep rupture event of the cladding tube. Practical implications – The creep rupture data of fuel clad tube is very important in design and for smooth operation of nuclear reactors without fuel pin failure in reactors. Originality/value – AE is an advanced non-destructive evaluation technique. This technique has been successfully applied for on-line monitoring of creep rupture of the reactor cladding tube which otherwise could be detected by thermocouple readings only.

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9

Vakili, Reza, and Reza Eslamloueyan. "Design and Optimization of a Fixed Bed Reactor for Direct Dimethyl Ether Production from Syngas Using Differential Evolution Algorithm." International Journal of Chemical Reactor Engineering 11, no. 1 (June 18, 2013): 147–58. http://dx.doi.org/10.1515/ijcre-2012-0026.

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Abstract Dimethyl ether (DME) is traditionally produced by methanol dehydration in an adiabatic reactor. Recently, a more economical method has been proposed to produce DME in a reactor in which methanol production and dehydration take place simultaneously on a bi-functional catalyst. In the present study, the design and optimization of an industrial scale fixed bed reactor for the direct synthesis of DME from syngas are investigated. A steady state, pseudo-homogeneous model has been applied to simulate the proposed reactor. At first, the preliminary design of the reactor is done based on the reactor design heuristics for industrial reactors. Then, using differential evolution (DE) algorithm as a fast and efficient optimization method, the tentative reactor operating conditions and its internal configuration are optimized. The objective of the optimization is to maximize DME production in each tube of the reactor. The number of tubes, feed inlet and coolant water temperatures are considered as decision variables of the optimization algorithm. At the optimum conditions, the reactor size decreases due to increase of CO conversion and DME productivity in each tube. The results show that the proposed optimum reactor is more economical for large-scale production of DME in comparison to the conventional industrial DME reactor.

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10

Gopaul, S., V. Hopps, Ch Jacobs, M. Khan, R. Patkunam, and I. L. Pioro. "ICONE15-10829 SOME DESIGN FEATURES OF SCW PRESSURE-TUBE NUCLEAR REACTOR." Proceedings of the International Conference on Nuclear Engineering (ICONE) 2007.15 (2007): _ICONE1510. http://dx.doi.org/10.1299/jsmeicone.2007.15._icone1510_429.

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11

Gupta, Gagan, and Anil Kumar Sharma. "Buckling Analysis of Sodium to Sodium Heat Exchanger Tubes." Applied Mechanics and Materials 852 (September 2016): 632–38. http://dx.doi.org/10.4028/www.scientific.net/amm.852.632.

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Sodium to sodium heat exchanger tubes are small in diameter, long and thin. These tubes are supported at intermediate locations and subjected to compressive and tensile loading during reactor operation. Structural mechanics analyses of a 2-D axi-symmetric model of heat exchanger was performed to estimate the load sharing in these tubes during reactor operation on finite element software ABAQUS. Since the tubes are suppoted at intermediate locations, a 3D model of full tube with intermediate support was made to calculate the critical buckling load and buckling modes. In this paper, structure analysis of heat exchanger and load sharing in tubes, critical load for tube and buckling modes in the tube, and design check of tubes under compression are covered. Tubes which are under compression are checked for buckling and found within the design limit.

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12

Dundulis, Gintautas, Albertas Grybėnas, Vidas Makarevicius, and Remigijus Janulionis. "Application of “Leak Before Break” Assessment for Pressure Tube in Delayed Hydride Cracking." Journal of Disaster Research 5, no. 4 (August 1, 2010): 378–84. http://dx.doi.org/10.20965/jdr.2010.p0378.

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The Ignalina NPP uses an RBMK-1500 reactor, which is graphite-moderated with a water-cooled reactor core. The fuel cell assembly in the center of the moderator column consists of a pressure tube containing the fuel element assembly and through which coolant flows. Pressure tubes are made of Zr-2.5Nb zirconium alloys. Hydrogen absorbed by the zirconium alloy during corrosion is one of the factors determining pressure tube lifetime. If the pressure tube hydrogen concentration exceeds solubility limitations, delayed hydride cracking (DHC) may occur. Hydrides forming under certain conditions may reduce resistance to brittle fracture. Here we evaluate hydride influence on pressure tube fracture and the application of leak before break (LBB) for tubes with DHC. Deterministic analysis employing LBB concept used experimental data. Deterministic LBB analysis confirms that pressure tubes comply with LBB requirements.

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13

Ha, Jong Hyeon, and In-Gu Lee. "Study of a Method to Effectively Remove Char Byproduct Generated from Fast Pyrolysis of Lignocellulosic Biomass in a Bubbling Fluidized Bed Reactor." Processes 8, no. 11 (November 4, 2020): 1407. http://dx.doi.org/10.3390/pr8111407.

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A critical issue in the design of bubbling fluidized bed reactors for biomass fast pyrolysis is to maintain the bed at a constant level to ensure stable operation. In this work, a bubbling fluidized bed reactor was investigated to deal with this issue. The reactor consists of inner and outer tubes and enables in situ control of the fluidized-bed level in the inner-tube reactor with a mechanical method during biomass fast pyrolysis. The significant fraction of biochar produced from the fast pyrolysis in the inner-tube reactor was automatically removed through the annulus between the inner and outer tubes. The effect of pyrolysis temperature (426–528 °C) and feeding rate (0.8–1.8 kg/h) on the yield and characteristics of bio-oil, biochar, and gaseous products were examined at a 15 L/min nitrogen carrier gas flow rate for wood sawdust with a 0.5–1.0 mm particle size range as a feed. The bio-oil reached a maximum yield of 62.4 wt% on a dry basis at 440 °C, and then slowly decreased with increasing temperature. At least 79 wt% of bio-char byproduct was removed through the annulus and was found in the reactor bottom collector. The GC-MS analysis found phenolics to be more than 40% of the bio-oil products.

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CHO, SUNG-KEUN, CHANG-SUNG SEOK, BONG-KOOK BAE, and JAE-MEAN KOO. "EVALUATION OF THE HOOP TENSILE PROPERTIES OF A STEAM GENERATOR TUBE." International Journal of Modern Physics B 20, no. 25n27 (October 30, 2006): 4129–34. http://dx.doi.org/10.1142/s0217979206040970.

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The steam generators in a pressurized water reactor (PWR) are large heat exchangers that use the heat from the primary reactor coolant to make steam on the secondary-side to drive turbine generators. Hoop stress is known to be the main cause of fracture of inner pressurized tubes such as the steam generator tube. However, because the steam generator tube is too small to be manufactured to a standard tensile specimen in the hoop direction, the axial tensile properties of the steam generator tube (or original material properties) instead of hoop tensile properties have been used to estimate the fracture properties of a steam generator tube. In this study, we have conducted not only axial tensile tests but also ring tensile tests. From these test, both the axial and hoop tensile properties of steam generator tubes were obtained, and the reliability of the hoop tensile properties were confirmed by burst test of a real steam generator tube.

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AlMarzouq, Douaa Salman. "Reactions under increased pressure: The reactivity of functionally substituted 3-oxo-2-arylhydrazones toward active methylene reagents in Q-tube." European Journal of Chemistry 12, no. 2 (June 30, 2021): 154–58. http://dx.doi.org/10.5155/eurjchem.12.2.154-158.2065.

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A one-pot two-component reaction of 3-oxo-2-arylhydrazones with active methylene nitriles under high pressure in a Q-tube safe reactor was reported. Comparison between conventional and Q-tube safe reactor-assisted synthesis of organic compounds was done by comparing total reaction time and percentage yield. The results show that the compound 5-cyano-6-oxo-1,4-diphenyl-1,6-dihydro-pyridazine-3-carboxylic acid ethyl ester (3) was synthesized within 2 h in a yield of 97%. In addition, the pyrazolo[3,4-c]pyridines 5b and 5c were obtained in yields of 93 and 95% within 1 h reaction time, respectively. The obtained results suggest that Q-tube safe reactor-assisted syntheses were led to higher product yields within very short reaction times.

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16

Kwak, Sang Log, Joon Seong Lee, Young Jin Kim, and Youn Won Park. "A Probabilistic Integrity Assessment of Flaw in Zirconium Alloy Pressure Tube Considering Delayed Hydride Cracking." International Journal of Modern Physics B 17, no. 08n09 (April 10, 2003): 1587–93. http://dx.doi.org/10.1142/s0217979203019368.

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In the CANDU nuclear reactor, pressure tubes of cold-worked Zr-2.5Nb material are used in the reactor core to contain the nuclear fuel bundles and heavy water coolant. Pressure tubes are major component of nuclear reactor, but only selected samples are periodically examined due to numerous numbers of tubes. Pressure tube material gradually pick up deuterium, as such are susceptible to a crack initiation and propagation process called delayed hydride cracking (DHC), which is the characteristic of pressure tube integrity evaluation. If cracks are not detected, such a cracking mechanism could lead to unstable rupture of the pressure tube. Up to this time, integrity evaluations are performed using conventional deterministic approaches. So it is expected that the results obtained are too conservative to perform a rational evaluation of lifetime. In this respect, a probabilistic safety assessment method is more appropriate for the assessment of overall pressure tube safety. This paper describes failure criteria for probabilistic analysis and fracture mechanics analyses of the pressure tubes in consideration of DHC. Major input parameters such as initial hydrogen concentration, the depth and aspect ratio of an initial surface crack, DHC velocity and fracture toughness are considered as probabilistic variables. Failure assessment diagram of pressure tube material is proposed and applied in the probabilistic analysis. In all the analyses, failure probabilities are calculated using the Monte Carlo simulation. As a result of analysis, conservatism of deterministic failure criteria is showed.

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Dahl, Jaimee K., Alan W. Weimer, Andreas Z’Graggen, and Aldo Steinfeld. "Two-Dimensional Axi-Symmetric Model of a Solar-Thermal Fluid-Wall Aerosol Flow Reactor." Journal of Solar Energy Engineering 127, no. 1 (February 1, 2005): 76–85. http://dx.doi.org/10.1115/1.1824108.

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A solar-thermal fluid-wall reactor consisting of three concentric vertical tubes is constructed to dissociate methane to hydrogen and carbon black using concentrated solar power. Several aspects of the design are modeled for scaling the system up: the heat transfer and its effect on the integrity of the materials, and the fluid flow of all gas streams within the reactor. It is determined that the inlet gas temperatures, mass flow rates, and permeability of the porous wall affect the gas flow profile through the porous tube wall. By increasing the inlet gas temperature and/or the tube permeability in the hot zone section of the reactor, a more uniform flow profile can be obtained along the length of the tube.

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Zhang, Jisong, Andrew R. Teixeira, Haomiao Zhang, and Klavs F. Jensen. "Determination of fast gas–liquid reaction kinetics in flow." Reaction Chemistry & Engineering 5, no. 1 (2020): 51–57. http://dx.doi.org/10.1039/c9re00390h.

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Li, Zhi He, Wei Ming Yi, Qiao Chun Gao, Yong Jun Li, Xue Yuan Bai, and De Li Zhang. "Research on Pyrolysis Reactors for Bio-Oil Production from Agricultural Residues." Advanced Materials Research 512-515 (May 2012): 459–63. http://dx.doi.org/10.4028/www.scientific.net/amr.512-515.459.

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This paper provides an updated review on fast biomass pyrolysis reactors for bio-oil production in Shandong University of Technology. The technologies that were developed include horizontal entrained bed (HEB), fluidized bed (FB), down flow tuber reactor (DFTR), double concentric cylinder rotary reactor (DCCRR) and new type down flow tube reactor (N-DFTR). The patented DFTR, DCCRR and N-DFTR in China were developed based on the technology of direct heat exchange between hot solid heat carriers and biomass particles during both of the particles flowing in a mixed condition. The process and characteristics of each reactor were discussed in this topic. Contrasting to conventional reactors, the DFTR, DCCRR and N-DFTR are promising technologies due to their characteristics of high solid-liquid conversion rate, energy self-sufficient, easy operation and scaling up.

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Gupta, Suman, and P. Chellapandi. "Assessment of Weld Joint Efficiency for Rolled and Welded Joint for Intermediate Heat Exchanger in Sodium Cooled Fast Reactor." Applied Mechanics and Materials 592-594 (July 2014): 1438–42. http://dx.doi.org/10.4028/www.scientific.net/amm.592-594.1438.

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The tube to tubesheet joint in a heat exchanger is one of the most critical joint and it has to meet stringent requirements as it provides the main barrier between the tube side and shell side fluids of heat exchanger. This paper discusses the various kinds of tube to tubesheet joint in heat exchanger, joint configuration adopted in PFBR IHX, structural analysis of IHX, axial load distribution in tube rows and experimental verification in order to evaluate allowable strength of tube to tubesheet joint. In IHX, tubes in outer rows are under tension and maximum stresses are below the allowable stresses in the tubes. Detailed experimental investigations result shows that the rolled and welded joint is stronger than the basic strength of the tube material. However, the allowable tensile strength of the joint under mechanical loading considered is 0.95 times the allowable value for tubes as per ASME.

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21

Yang, Lu, and Klavs F. Jensen. "Mass Transport and Reactions in the Tube-in-Tube Reactor." Organic Process Research & Development 17, no. 6 (May 30, 2013): 927–33. http://dx.doi.org/10.1021/op400085a.

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Horák, Josef, and Zina Valášková. "Characteristics for evaluating the reactor regime with endothermic reversible reaction." Collection of Czechoslovak Chemical Communications 52, no. 4 (1987): 929–38. http://dx.doi.org/10.1135/cccc19870929.

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Criteria are proposed in the paper for evaluating the reactor regime (with endothermic reversible reaction, heated by radiation of combustion products) from thermodynamic and kinetic points of view. The limiting reactor regimes in which the controlling process is the process kinetics or the heat transfer are defined. The effect of the catalyst activity on the reactor output and the surface temperature of the reaction tube and the effect of heat input power of the reactor radiation section on the conversion and the surface temperature of the tube are discussed. The results are verified on a simplified mathematical model of steam reforming and employed to discuss the selection of the regime of an industrial reactor.

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Wulandari, Rindi, Sutanto Sutanto, and Asril Pramutadi Andi Mustari. "INTERACTION OF MOLTEN URANIUM WITH ELECTRICAL PENETRATING TUBE OF A BOILING WATER REACTOR DURING SEVERE ACCIDENT." GANENDRA Majalah IPTEK Nuklir 23, no. 2 (September 21, 2020): 55. http://dx.doi.org/10.17146/gnd.2020.23.2.5816.

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INTERACTION OF MOLTEN URANIUM WITH ELECTRICAL PENETRATING TUBE OF A BOILING WATER REACTOR DURING SEVERE ACCIDENT. Fukushima accident was the first severe accident of a BWR type which the core was melted leading to RPV failure at the bottom head. Regarding its complex structures of the bottom head, the scheme of failure is different from that of previous reactor severe accidents that ever happened (i.e. TMI-2 and Chernobyl accidents). There is a lot of penetration tubes through the bottom head leading to a complex interaction between corium and the structures. Eutectic reaction is possible to happen due to high temperature leading to a rapid failure of the RPV. Therefore, it is important to understand the phenomenon of interaction between corium and the structures. In this study, an interaction between molten uranium and structure of electrical tube, one of the penetration tubes, was analyzed by using MPS-LER method. Fluid dynamics of the MPS-LER simulation was validated by experiments of fluid flow by using water and oil.Calculation results of the fluid flow showed a good agreement with that of experiments.The MPS-LER was applied to calculate the penetration rate of molten uranium which flowed through the wall of the electrical tube at the bottom head of a BWR. The penetration rate was high due to eutectic reaction. The rate achieved 555.56 µm/s. Conservatively, it took less than 1 minute of time for the molten uranium to melt the tube wall with a thickness of 1.232 cm.

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Raouf, Fereshteh, Majid Taghizadeh, and Mohammad Yousefi. "Single and Multi-Channel Reactor for Oxidative Coupling of Methane." International Journal of Chemical Reactor Engineering 12, no. 1 (January 1, 2014): 181–89. http://dx.doi.org/10.1515/ijcre-2013-0161.

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Abstract Management of the produced heat has been one of the challenges encountered in the oxidative coupling of methane (OCM) process. In this study, the influence of the thermal conductive tubular reactor on the total productivity and selectivity of OCM was investigated. The reactors were made from three different metal compounds: two stainless steel tubes and one gold-coated copper tube, and their impact on the operating conditions was compared. 5% Li/MgO was prepared as a catalyst for OCM and characterized by XRD, CO2-TPD, FTIR, and BET. In addition, the effect of reactor geometry on the oxidative coupling process was investigated experimentally in the single channel and multi-channel reactors with different hydraulic diameters.

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Wu, Wen-Teng, and Jiumn-Yih Wu. "Airlift reactor with net draught tube." Journal of Fermentation and Bioengineering 70, no. 5 (January 1990): 359–61. http://dx.doi.org/10.1016/0922-338x(90)90152-m.

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Noda, Y., S. Koizumi, and D. Yamaguchi. "Multi-tube area detector developed for reactor small-angle neutron scattering spectrometer SANS-J-II." Journal of Applied Crystallography 49, no. 1 (February 1, 2016): 128–38. http://dx.doi.org/10.1107/s1600576715022797.

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A newly developed multi-tube area detector for a small-angle neutron scattering (SANS) spectrometer (SANS-J-II) at the research reactor JRR-3 in Tokai, Japan, has been implementedviathe use of one-dimensional position-sensitive3He detectors (tubes). Ninety-six active tubes of 8 mm in diameter and 650 and 580 mm in length were filled with 15 atm (1.52 MPa) of3He and aligned vertically parallel in order to cover a sufficiently large area for small-angle scattering measurement. These tubes are enclosed in an air chamber together with neutron encode and GATENET modules (VME boards), which compose a standard data acquisition system for the spallation neutron source of the Japan Proton Accelerator Research Complex. This system facilitates the acquisition of time-of-flight neutron event data. The multi-tube detector is mounted on a truck moving in a vacuum chamber of the SANS spectrometer. After discriminating noise originating from γ-rays, and calibrating the positions and sensitivities of individual tubes, the resolution was determined (i.e.channel widths along parallel and vertical directions along a tube). The counting rate of one tube was determined to be 1.4 × 103counts per second with a counting loss of 1%. This implies that the new detector, composed of 96 tubes, can detect more than 105neutrons per second with a counting loss of 1%. To demonstrate its use, small-angle scattering originating from a diblock copolymer film with a highly oriented lamellar microdomain was observed. The data acquisition in event mode has a great advantage in time-resolved measurements that are synchronized with external stimuli imposed on a sample.

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Yang, Shu, Guang Wei Wang, and Yuan Jian Xu. "New Design of Supercritical Water Oxidation Reactor for Sewage Sludge Treatment." Advanced Materials Research 774-776 (September 2013): 212–15. http://dx.doi.org/10.4028/www.scientific.net/amr.774-776.212.

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The corrosion of reactor and salt precipitation are two critical obstacles that inhibiting the development of supercritical water oxidation (SCWO) in to a viable industrial process. A new design of double wall reactor has been developed in which SCWO reaction take place inside an inner tube (alumina or titanium, micro porous). The high pressure air layer between inner surface of reactor and surface of tube could prevent non-soluble materials, corrosion ingredients and inorganic salt depositing and attaching to inner surface, thus critical problems have been overcome. The new reactor performance was evaluated by processing sewage sludge from BeiBei waste water treatment plant. There were no salt plugging or corrosion observed in reactor after one month operation.

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Newton, Sean, Steven V. Ley, Eva Casas Arcé, and Damian M. Grainger. "Asymmetric Homogeneous Hydrogenation in Flow using a Tube-in-Tube Reactor." Advanced Synthesis & Catalysis 354, no. 9 (May 29, 2012): 1805–12. http://dx.doi.org/10.1002/adsc.201200073.

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Karasavvas, Evgenios, Athanasios Scaltsoyiannes, Andy Antzaras, Kyriakos Fotiadis, Kyriakos Panopoulos, Angeliki Lemonidou, Spyros Voutetakis, and Simira Papadopoulou. "One-Dimensional Heterogeneous Reaction Model of a Drop-Tube Carbonator Reactor for Thermochemical Energy Storage Applications." Energies 13, no. 22 (November 12, 2020): 5905. http://dx.doi.org/10.3390/en13225905.

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Calcium looping systems constitute a promising candidate for thermochemical energy storage (TCES) applications, as evidenced by the constantly escalating scientific and industrial interest. However, the technologically feasible transition from the research scale towards industrial and highly competitive markets sets as a prerequisite the optimal design and operation of the process, especially corresponding reactors. The present study investigates for the first time the development of a detailed, one-dimensional mathematical model for the steady-state simulation of a novel drop-tube carbonator reactor as a core equipment unit in a concentrated solar power (CSP)-thermochemical energy storage integration plant. A validated kinetic mathematical model for a carbonation reaction (CaO(s) + CO2(g) → CaCO3(s)) focused on thermochemical energy storage conditions was developed and implemented for different material conditions. The fast gas–solid reaction kinetics conformed with the drop-tube reactor concept, as the latter is suitable for very fast reactions. Reaction kinetics were controlled by the reaction temperature. Varying state profiles were computed across the length of the reactor by using a mathematical model in which reactant conversions, the reaction rate, and the temperature and velocity of gas and solid phases provided crucial information on the carbonator’s performance, among other factors. Through process simulations, the model-based investigation approach revealed respective restrictions on a tailor-made reactor of 10 kWth, pointing out the necessity of detailed models as a provision for design and scale-up studies.

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Hayashi, Shinya, Wataru Minami, Tatsuo Oguchi, and Hee-Joon Kim. "Study of Characterization of SF6 Pyrolysis Reaction Using Tube Reactor." KAGAKU KOGAKU RONBUNSHU 35, no. 2 (2009): 252–57. http://dx.doi.org/10.1252/kakoronbunshu.35.252.

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Nguyen, Van Thai, Manh Long Doan, and Chi Thanh Tran. "Evaluation of the Potential for Containment Bypass due to Steam Generator Tube Rupture in VVER-1000/V320 Reactor during Extended SBO sequence using SCDAP/RELAP5 code." Nuclear Science and Technology 9, no. 4 (September 3, 2021): 9–15. http://dx.doi.org/10.53747/jnst.v9i4.133.

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A severe accident-induced of a Steam Generator (SG) tube releases radioactivity from the Reactor Coolant System (RCS) into the SG secondary coolant system from where it may escape to the environment through the pressure relief valves and an environmental release in this manner is called “Containment Bypass”. This study aims to evaluate the potential for “Containment Bypass” in VVER/V320 reactor during extended Station Blackout (SBO) scenarios that challenge the tubes by primarily involving a natural circulation of superheated steam inside the piping loop and then induce creep rupture tube failure. Assessments are made of SCDAP/RELAP5 code capabilities for predicting the plant behavior during an SBO event and estimates are made of the uncertainties associated with the SCDAP/RELAP5 predictions for key fluid and components condition and for the SG tube failure margins.

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Yetisir, M., J. Pencer, M. McDonald, M. Gaudet, J. Licht, and R. Duffey. "The Supersafe© Reactor: A Small Modular Pressure Tube SCWR." AECL Nuclear Review 1, no. 2 (December 1, 2012): 13–18. http://dx.doi.org/10.12943/anr.2012.00014.

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The SUPERSAFE© Reactor (SSR) is proposed as a small modular version of the Canadian supercritical water-cooled reactor (SCWR). The SCWR is Canada’s primary contribution to the Generation-IV (GEN-IV) International Forum’s (GIF) research and development effort toward the study and eventual deployment of advanced nuclear energy systems. All GEN-IV concepts, including the SCWR, have enhanced safety, improved economics, improved sustainability and enhanced security compared to contemporary reactors. The SUPERSAFE© Reactor (SSR) concept incorporates the enhanced features of the SCWR in a smaller core which could be deployed in areas with sparsely distributed population bases where it is impractical to have a full scale SCWR or large centralized energy grid. An overview of the SSR concept is presented in this work.

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MASAI, M., S. TANAKA, Y. TOMOMASA, S. NISHIYAMA, and S. TSURUYA. "REACTANT-CATALYST CONTACT IN RISER-TUBE REACTOR." Chemical Engineering Communications 34, no. 1-6 (March 1985): 153–59. http://dx.doi.org/10.1080/00986448508911195.

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Mohammed, Ibrahim. "ICONE19-43489 PRESSURIZED WATER REACTOR VESSEL INTERNALS GUIDE TUBE GUIDE CARD WEAR AGING MANAGEMENT." Proceedings of the International Conference on Nuclear Engineering (ICONE) 2011.19 (2011): _ICONE1943. http://dx.doi.org/10.1299/jsmeicone.2011.19._icone1943_196.

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35

Huang, Yuanlong, Matthew M. Coggon, Ran Zhao, Hanna Lignell, Michael U. Bauer, Richard C. Flagan, and John H. Seinfeld. "The Caltech Photooxidation Flow Tube reactor: design, fluid dynamics and characterization." Atmospheric Measurement Techniques 10, no. 3 (March 9, 2017): 839–67. http://dx.doi.org/10.5194/amt-10-839-2017.

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Abstract. Flow tube reactors are widely employed to study gas-phase atmospheric chemistry and secondary organic aerosol (SOA) formation. The development of a new laminar-flow tube reactor, the Caltech Photooxidation Flow Tube (CPOT), intended for the study of gas-phase atmospheric chemistry and SOA formation, is reported here. The present work addresses the reactor design based on fluid dynamical characterization and the fundamental behavior of vapor molecules and particles in the reactor. The design of the inlet to the reactor, based on computational fluid dynamics (CFD) simulations, comprises a static mixer and a conical diffuser to facilitate development of a characteristic laminar flow profile. To assess the extent to which the actual performance adheres to the theoretical CFD model, residence time distribution (RTD) experiments are reported with vapor molecules (O3) and submicrometer ammonium sulfate particles. As confirmed by the CFD prediction, the presence of a slight deviation from strictly isothermal conditions leads to secondary flows in the reactor that produce deviations from the ideal parabolic laminar flow. The characterization experiments, in conjunction with theory, provide a basis for interpretation of atmospheric chemistry and SOA studies to follow. A 1-D photochemical model within an axially dispersed plug flow reactor (AD-PFR) framework is formulated to evaluate the oxidation level in the reactor. The simulation indicates that the OH concentration is uniform along the reactor, and an OH exposure (OHexp) ranging from ∼ 109 to ∼ 1012 molecules cm−3 s can be achieved from photolysis of H2O2. A method to calculate OHexp with a consideration for the axial dispersion in the present photochemical system is developed.

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MOCHIZUKI, Hiroyasu, and Mohammed A. QUAIYUM. "Contact Conductance between Cladding/Pressure Tube and Pressure Tube/Calandria Tube of Advanced Thermal Reactor (ATR)." Journal of Nuclear Science and Technology 31, no. 7 (July 1994): 726–34. http://dx.doi.org/10.1080/18811248.1994.9735215.

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Lee, Joon Seong, Sang Log Kwak, and Chang Ryul Pyo. "Failure Probability Estimation of Pressure Tube Using Failure Assessment Diagram." Solid State Phenomena 120 (February 2007): 37–42. http://dx.doi.org/10.4028/www.scientific.net/ssp.120.37.

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Pressure tubes are major component of nuclear reactor, but only selected samples are periodically examined due to numerous numbers of tubes. Pressure tube material gradually pick up deuterium, as such are susceptible to a crack initiation and propagation process called delayed hydride cracking (DHC), which is the characteristic of pressure tube integrity evaluation. If cracks are not detected, such a cracking mechanism could lead to unstable rupture of the pressure tube. Up to this time, integrity evaluations are performed using conventional deterministic approaches. So it is expected that the results obtained are too conservative to perform a rational evaluation of lifetime. In this respect, a probabilistic safety assessment method is more appropriate for the assessment of overall pressure tube safety. This paper describes failure probability estimation of the pressure tubes using probabilistic fracture mechanics. Failure assessment diagram (FAD) of pressure tube material is proposed and applied in the probabilistic analysis. In all the analyses, failure probabilities are calculated using the Monte Carlo simulation. As a result of analysis, failure probabilities for various conditions are calculated, and examined application of FAD and LBB concept.

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38

Roohi, Parham, Reza Alizadeh, Esmaeil Fatehifar, and Mehdi Salami Hosseini. "Application of Finite Element Method for Modeling of Multi-tube Fixed Bed Catalytic Reactors." Chemical Product and Process Modeling 9, no. 1 (June 1, 2014): 1–8. http://dx.doi.org/10.1515/cppm-2013-0030.

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Abstract In this article, the finite element method (FEM) was applied for modeling of multi-tube fixed bed catalytic reactor (FBCR). For this purpose, a more sophisticated 2D pseudo-heterogeneous model was used to calculate steady-state temperature and partial pressure profiles through the reactor. This model has a vast capability in the prediction of temperature and partial pressure distribution, separately, in the fluid and catalyst phases. The finite element results were compared with de wasch and Froment’s numerical work which developed for a well-established reaction in the multi-tube FBCR (o-xylene partial oxidation). The R-squared analysis indicated that the FEM results agree favorably with finite difference results which reported in the literature. Numerical solution coincidence of FEM and FDM increases with reduction of inlet gas temperature. The results show that the finite element as a powerful numerical method can be used to describe the multi-tube fixed bed catalytic reactor.

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Mallia, Carl J., Paul M. Burton, Alexander M. R. Smith, Gary C. Walter, and Ian R. Baxendale. "Catalytic Chan–Lam coupling using a ‘tube-in-tube’ reactor to deliver molecular oxygen as an oxidant." Beilstein Journal of Organic Chemistry 12 (July 26, 2016): 1598–607. http://dx.doi.org/10.3762/bjoc.12.156.

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A flow system to perform Chan–Lam coupling reactions of various amines and arylboronic acids has been realised employing molecular oxygen as an oxidant for the re-oxidation of the copper catalyst enabling a catalytic process. A tube-in-tube gas reactor has been used to simplify the delivery of the oxygen accelerating the optimisation phase and allowing easy access to elevated pressures. A small exemplification library of heteroaromatic products has been prepared and the process has been shown to be robust over extended reaction times.

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Kitajima, Yuko, Takehisa Hino, Katsuhiko Sato, Shigeki Maruyama, and Noboru Jimbo. "ICONE19-43935 Development of a Helical-Coil Double Wall Tube Steam Generator for 4S Reactor." Proceedings of the International Conference on Nuclear Engineering (ICONE) 2011.19 (2011): _ICONE1943. http://dx.doi.org/10.1299/jsmeicone.2011.19._icone1943_347.

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Bouwman, Jordy, Andras Bodi, Jos Oomens, and Patrick Hemberger. "On the formation of cyclopentadiene in the C3H5˙ + C2H2 reaction." Physical Chemistry Chemical Physics 17, no. 32 (2015): 20508–14. http://dx.doi.org/10.1039/c5cp02243f.

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Schleier, D., P. Constantinidis, N. Faßheber, I. Fischer, G. Friedrichs, P. Hemberger, E. Reusch, B. Sztáray, and K. Voronova. "Kinetics of the a-C3H5 + O2 reaction, investigated by photoionization using synchrotron radiation." Physical Chemistry Chemical Physics 20, no. 16 (2018): 10721–31. http://dx.doi.org/10.1039/c7cp07893e.

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43

Gao, Na-Na, Jie-Xin Wang, Lei Shao, and Jian-Feng Chen. "Removal of Carbon Dioxide by Absorption in Microporous Tube-in-Tube Microchannel Reactor." Industrial & Engineering Chemistry Research 50, no. 10 (May 18, 2011): 6369–74. http://dx.doi.org/10.1021/ie1024886.

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44

Liang, Yan, Guangwen Chu, Jiexin Wang, Yan Huang, Jianfeng Chen, Baochang Sun, and Lei Shao. "Controllable preparation of nano-CaCO3 in a microporous tube-in-tube microchannel reactor." Chemical Engineering and Processing: Process Intensification 79 (May 2014): 34–39. http://dx.doi.org/10.1016/j.cep.2014.03.006.

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45

Tomaszewski, Bartłomiej, Richard C. Lloyd, Antony J. Warr, Katja Buehler, and Andreas Schmid. "Regioselective Biocatalytic Aromatic Hydroxylation in a Gas-Liquid Multiphase Tube-in-Tube Reactor." ChemCatChem 6, no. 9 (August 8, 2014): 2567–76. http://dx.doi.org/10.1002/cctc.201402354.

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Cuoc, Eduardo, Eugene Shwageraus, Alisha Kasam, and Ian Scott. "CORE DESIGN OF BREED & BURN MOLTEN SALT FAST REACTOR." EPJ Web of Conferences 247 (2021): 01004. http://dx.doi.org/10.1051/epjconf/202124701004.

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Previous designs of once-through solid-fuelled breed-and-burn (B&B) reactor and the conventional molten salt reactor (MSR) concepts suffer from material limitation of neutron irradiation damage and chemical corrosion. A novel breed-and-burn molten salt reactor (BBMSR) concept uses separate molten salt fuel and coolant in a linear assembly core configuration. Similar to Moltex Energy Stable Salt Reactor (SSR) design, the configuration with fuel salt contained in fuel tubes and coolant salt in pool type reactor vessel has been previously studied. The study confirmed that breed-and-burn operation is feasible in principle, however with a low neutronic margin. The objective of this paper was to seek improvements of the neutronic margin with a metallic natural uranium blanket design. A parametric study was performed for the natural uranium blanket design. BBMSR neutronic performance simulation was modelled using Serpent, a Monte Carlo reactor physics code, with a single 3D hexagonal channel containing a single fuel tube in an infinite lattice with reflective radial and vacuum axial boundary conditions. The addition of a metallic natural uranium blanket inside the fuel tube, which increases the natural uranium metal to fuel salt ratio (ϒ) of the BBMSR, was shown to significantly increase the neutronic performance of the BBMSR.

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Martinek, Janna, and Alan W. Weimer. "Design considerations for a multiple tube solar reactor." Solar Energy 90 (April 2013): 68–83. http://dx.doi.org/10.1016/j.solener.2013.01.004.

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Lodha, Himanshu, Roshan Jachuck, and Saravanan Suppiah Singaram. "Intensified Biodiesel Production Using a Rotating Tube Reactor." Energy & Fuels 26, no. 11 (October 15, 2012): 7037–40. http://dx.doi.org/10.1021/ef301235t.

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Shatilla, Youssef. "A pressure-tube Advanced Burner Test Reactor concept." Nuclear Engineering and Design 238, no. 1 (January 2008): 102–8. http://dx.doi.org/10.1016/j.nucengdes.2007.07.003.

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Shimizu, Masataka, Kentaro Nobori, and So Takeoka. "Methanol decomposition by an inner fin tube reactor." KAGAKU KOGAKU RONBUNSHU 14, no. 1 (1988): 114–17. http://dx.doi.org/10.1252/kakoronbunshu.14.114.

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Journal articles on the topic 'The reactor tube'

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