Most Read articles

Published in last 1 year |  In last 2 years |  In last 3 years |  All

All

Please wait a minute...


For Selected: Download Citations EndNote Ris BibTeX Toggle Thumbnails

Select

Numerical simulation of self-baked electrodes in a Titanium slag three-phase arc furnace Quan LIU Xiaoping GUAN Ning YANG Jun XIAO The Chinese Journal of Process Engineering    2025, 25 (4): 323-331.   DOI: 10.12034/j.issn.1009-606X.224185 Abstract （526）   HTML （23）    PDF （3911KB）（123）       Knowledge map    Save During the smelting process, the sintering quality of self-baked electrodes determines whether the arc furnace can operate normally. Taking the Panzhihua Steel Titanium Slag Three-Phase Arc Furnace as a prototype, this paper establishes a multi-physics field model of the coupled electromagnetic field and temperature field, and develops a quick calculation method for electromagnetic field and temperature field to accelerate computation. A comparative analysis of current density, Joule heat, and temperature distributions during the baking process of solid/hollow self-baked electrodes is conducted. The results show that both solid and hollow electrodes exhibit a "low at the center, high at the edge" current density distribution, namely the skin effect, with the skin effect of hollow electrodes weaker than that of solid electrodes, resulting in a more uniform current distribution. Besides, the baking regions of solid and hollow electrodes are located within the contact area of the conductive components, indicating that the self-baked electrodes have enough strength to meet the baking requirements. Meanwhile, the time to reach baking equilibrium for solid and hollow electrodes is about 13.4 hours and 12.8 hours, respectively, with the baking time of hollow electrodes being 4.3% shorter. Related Articles | Metrics

Select

Flow and mixing characteristics of a vortex static mixer Yifan ZHOU Guangyuan JIN Song WU Yuhao JING Zhengshan ZHU Wenkai FENG Chunfang SONG Zhenfeng LI Feihu SONG Jing LI The Chinese Journal of Process Engineering    2025, 25 (5): 471-482.   DOI: 10.12034/j.issn.1009-606X.224298 Abstract （502）   HTML （17）    PDF （7013KB）（89）       Knowledge map    Save Static mixers, which do not require external energy sources, are characterized by their compact design and ease of integration into systems, making them highly valued in the food processing industry. The introduction of vortices can significantly enhance the mixing efficiency of mixers, leading to improved reaction rates and overall effectiveness. Currently, most vortex static mixers achieve high-efficiency mixing by generating vortices through their internal structures, which must withstand the impact of flow and thus carry a risk of damage. Vortex tubes, characterized by their simple structure and strong vortex properties, have yet to be studied for their effectiveness in mixing. Based on this, this work investigates a vortex static mixer, employs numerical simulation methods to study its flow and mixing characteristics, focusing on the effects of inlet velocity and structural parameters such as the chamber aspect ratio (D/H) and the axial diameter ratio (D/Da). The results show that the internal flow is primarily dominated by vortices, accompanied by significant secondary flows, including secondary vortex circulation flow zone, shortcut flow zone, and eccentric vortex zone. Increasing the inlet velocity enhances the internal vortex flow and weakens the secondary flow, significantly reduces the intensity of separation at the outlet. When the inlet velocity reaches 0.223 m/s, complete mixing can be achieved at the chamber outlet. Reducing D/H or increasing D/Da can enhance the internal vortex. The mixing performance improves as the D/H decreases. Specifically, when the D/H is reduced from 6 to 4, the intensity of separation at vortex chamber outlet decreases from 4.03×10-3 to 5.23×10-4. Related Articles | Metrics

Select

Design and performance study on a novel gravity heat pipe based energy storage unit for new energy consumption Shu ZHANG Yuanlin CHENG Hu YU Yi ZHANG Jinlin XIE Xingwei LIAO Ren ZHANG Changhui LIU Yanlong GU The Chinese Journal of Process Engineering    2025, 25 (4): 373-381.   DOI: 10.12034/j.issn.1009-606X.224288 Abstract （462）   HTML （12）    PDF （2378KB）（73）       Knowledge map    Save As the global climate change issue has been escalating in severity, promoting the transformation of the energy structure has emerged as an irresistible trend. This involves reducing reliance on fossil fuels and enhancing the capacity for new energy consumption, particularly in the field of building heating, which contributes significantly to overall energy consumption. In this work, a solid-liquid phase change/vapor-liquid phase change coupling-based thermal storage heating device is designed, which is essentially a combination of a new type of gravity heat pipe and the phase change material paraffin wax, supplemented by the internal and external heat dissipation fins of the heat dissipation cylinder of the heat dissipation cylinder, enabling the completion of heating through natural convection. The wall temperature characteristics, start-up characteristics, heat transfer performance, and uniform temperature performance of the designed new gravity heat pipe with square liquid cavity are investigated experimentally. Subsequently, the heat storage and release characteristics of the heating unit are studied, and it is concluded that the new gravity heat pipe has good start-up characteristics, heat transfer characteristics, and uniform temperature performance, and its minimum heat transfer thermal resistance can be as low as 0.018℃/W, and the maximum equivalent thermal conductivity is 239.15 kW/(m?℃). The minimum starting temperature is 56.9℃, and the minimum homogeneous temperature coefficient is 0.009. The heating unit has a better heating capacity, with a maximum heating coefficient of 3.83. The design and research results of this new energy storage unit have important reference value for the comprehensive utilization of mobile heating units and distributed energy. Related Articles | Metrics

Select

Simulation of shape of liquid bridge and gas-liquid interface energy between two ellipsoidal wet particles Wenzhe WANG Guihuan YAO The Chinese Journal of Process Engineering    2025, 25 (4): 332-340.   DOI: 10.12034/j.issn.1009-606X.224247 Abstract （455）   HTML （18）    PDF （5086KB）（83）       Knowledge map    Save Wet particulate matter widely exists in nature, production and daily life. Surface Evolver was used to investigate the shape of liquid bridge between two ellipsoidal wet particles placed vertically and parallel to each other during the relative rotation and the effects of contact angle, rotation angle, gravity and other parameters were analyzed. Under several different contact angles, the changes in the relative angle between the two particles from 0° to 90° were observed to analyze the changes in the gas-liquid surface area, solid-liquid contact area, and the shape of the contour line obtained by intersecting the plane passing through the center line of the two particles with the surface of the liquid bridge. The differences in the contour line shape of the liquid bridge under the same relative angle with and without gravity were compared. The results showed that the shape of the liquid bridge was a rotationally symmetric body. This body did not satisfy the arc assumption. The variation of the contact angle changed the shape of the liquid bridge. The changes in rotation angle and gravity caused the profile of the liquid bridge to change. Specifically, it changed from an elliptic curve to a hyperbola. The gravity caused the contact line on the upper and lower particles to shift. The rotation of the particles resulted in the reduction of the solid-liquid interface. The gas-liquid interface area of the liquid bridge was sinusoidally related to the relative angle of the particles. The minimum volume required to maintain the liquid bridge under gravity was investigated by gradually reducing the volume of the liquid bridge, and it was shown to be quadratically related to the contact angle and to increase with the increase in liquid density, with the minimum volume required to maintain the liquid bridge when the contact angle was about 90°. Related Articles | Metrics

Select

Multi-physical field coupling simulation study in cement rotary kiln Jing GUAN Yujie TIAN Yinjie LIU Fei LI Jiayuan YE Chengwen XU Chunxi LU Wei WANG Xianfeng HE The Chinese Journal of Process Engineering    2025, 25 (5): 445-458.   DOI: 10.12034/j.issn.1009-606X.224299 Abstract （449）   HTML （22）    PDF （4063KB）（94）       Knowledge map    Save As a key equipment in the cement production process, the combustion of gas-phase pulverized coal particles and the sintering reaction of solid-phase cement are carried out at the same time, which has a decisive impact on the generation of cement clinker products and the quality of products. However, due to the large difference in reaction rate and flow rate between the two processes, most of the existing simulations are limited to the study of a single solid-phase sintering or gas-phase pulverized coal combustion reaction process, and the interaction between the two processes is rarely discussed. In view of this shortcoming, an innovative gas-solid phase coupling simulation method was proposed, which divided the kiln area into three-dimensional gas-phase pulverized coal combustion zone and one-dimensional solid-phase cement sintering zone, which were simulated independently, and the close coupling between the two processes was realized through iterative calculation. The coupled simulation method effectively overcame the simulation challenges caused by the significant difference in flow velocity between the gas phase and the solid phase, and can more comprehensively reveal the interaction mechanism of fluid flow, heat transfer and chemical reaction in the kiln, providing a multi-scale coupled simulation method for the complex system of rotary kiln. The coupled simulation results showed that compared with the traditional single one-dimensional or three-dimensional simulation, this method can significantly improve the simulation accuracy, and the simulation results were highly consistent with the actual clinker output data of the plant. It can effectively guide the optimal design and operation process of rotary kiln, so as to improve the quality of clinker products, and provide an accurate and efficient simulation method for the simulation of cement rotary kiln. Related Articles | Metrics

Select

Study on influence of dust concentrations and moisture contents on formation characteristics of dust cake and filtration performance of coated filter media Lumin CHEN Haijin LI Chen ZHU Wenyuan HU Fuping QIAN Zhimin ZHENG The Chinese Journal of Process Engineering    2025, 25 (4): 416-424.   DOI: 10.12034/j.issn.1009-606X.224303 Abstract （447）   HTML （10）    PDF （3364KB）（64）       Knowledge map    Save In order to meet the latest national ultra-low emission standards, effective management of industrial dust is the key to achieving the goal. This study establishes an experimental test system for filter materials to investigate the influence of dust concentration and dust moisture content on the dust cake formation characteristics and filtration performance of coated filter media by analyzing the pressure drop, filtration efficiency, dust deposition per unit area, the thickness of dust cake and the standard deviation of thickness. The results show that with the extension of the filtration time, the thickness and inhomogeneity of the dust cake gradually increased from the top to the bottom in the vertical direction, however, the unevenness of the dust cake thickness stabilized after a period of time. With the increase of dust concentration, the thickness and inhomogeneity of the dust cake gradually increase. When the dust concentration is low, the overall increase in the thickness of the dust cake from the top to the bottom is slow, and the thickness difference is small. When the dust concentration is high, the thickness of the top of the dust cake increases slowly and the thickness of the bottom increases rapidly. With the increase of dust concentration, the pressure and the dust deposition per unit area increase, the filtration efficiency is around 99.9%, and the porosity gradually decreases overall. With the increase of dust moisture content, the uniformly of dust cake varies significantly, the dust cake uniformity is poor when the dust moisture content is 9% and 13%, and the distribution of dust cake is relatively uniform when the dust moisture content is 10%~12%. The effect of dust moisture content on the filtration performance is mainly reflected in the change of pressure drop, and the increase of dust moisture content helps to reduce the pressure drop of the dust cake, and the effect on the filtration efficiency is not significant. Related Articles | Metrics

Select

Influence and mechanism analysis of sleeve angle on cavitation characteristics of window-type sleeve control valves Kan SHENG Shenzhe ZHANG Zhijiang JIN Jinyuan QIAN The Chinese Journal of Process Engineering    2025, 25 (5): 425-434.   DOI: 10.12034/j.issn.1009-606X.224267 Abstract （445）   HTML （26）    PDF （3732KB）（90）       Knowledge map    Save As common regulators, window-type sleeve control valves are critical components in process industry systems and the core structures of the control system flow. However, the occurrence of cavitation within these valves can lead to issues such as the failure of control capabilities and the wear of the structural surfaces, which can significantly affect the normal flow regulation of the system. In the design process of window-type sleeve control valves, there are two symmetrical installation angles of the sleeve based on engineering practice. This work aims to elucidate the impact of sleeve angles on the cavitation characteristics of window-type sleeve control valves. Numerical simulation methods are employed to investigate the cavitation characteristics and the cavitation mechanisms under different sleeve angles and various operating conditions. The results indicate that changes in the sleeve angle can effectively suppress cavitation within the valve without compromising its flow capacity. Two different sleeve angles are investigated in this research. Under high-pressure drops, the maximum growth rate of the steam phase volume reached 40.29%, while the growth rate of the valve's resistance coefficient is below 5%. This finding means that adjustments to the sleeve angle can be made to minimize cavitation while maintaining the valve's flow capability. Furthermore, the research identifies two distinct mechanisms of cavitation generation within the valve: one resulting from high-speed jets due to abrupt area contractions and the Coanda effect, and the other caused by local pressure drops associated with strong vortex structures at the bottom of the throttling window. Interestingly, a direct correlation is found between the presence of these strong vortex structures and the locations where cavitation occurs. The findings of this study provide valuable insights for setting the sleeve installation angles and optimizing the design of cavitation suppression structures in window-type sleeve control valves, enhancing their performance and reliability in engineering applications. Related Articles | Metrics

Select

Surface structure modulation of CeO2/N-doped carbon composites and the dye removal properties Yaohua HUANG Hao ZHANG Yanqi LIU Binghui WANG Richuan RAO The Chinese Journal of Process Engineering    2025, 25 (4): 389-398.   DOI: 10.12034/j.issn.1009-606X.224210 Abstract （443）   HTML （11）    PDF （4849KB）（71）       Knowledge map    Save In this work, the surface structure of CeO2/nitrogen-doped carbon composites was tuned by controlling the feeding order of cerium nitrate and melamine in their synthesis process. Upon the characterization by TEM, XRD, TG, Zeta potential, and N2 adsorption-desorption isotherms, the synthesized CeO2/N-doped carbon composites were confirmed to be mainly composed of CeO2 and a large amount of N-doped carbon with different structures. Interestingly, it was found that the feeding order had a great influence on the nitrogen content, CeO2 dispersion, surface charge distribution, pore structure as well as specific surface area of CeO2/N-doped carbon composites. Compared to the CeO2/N-doped carbon composites prepared first by adding melamine (MCe), the CeO2/N-doped carbon composites prepared first by adding cerium nitrate (CeM) in their synthesis process had a much higher nitrogen content, which promoted the CeO2 dispersion on N-doped carbon surface and led to the formation of a predominantly positively charged surface in this sample, despite their lower specific surface area and unfavorable pore structure. The removal of Congo red by adsorption was employed to investigate the correlation between the surface structure of adsorbents and their adsorption capacities. It was discovered that the pore structure and specific surface area of CeO2/N-doped carbon composites were not the predominant factors for the adsorption removal of Congo red. Since Congo red presented an anionic state in aqueous solution, the formed Congo red anions could adsorb onto the positively charged surface of the sample via an electrostatic adsorption interaction, achieving high efficient removal of Congo red from the dye waste solution. Therefore, CeM exhibited a higher removal efficiency of Congo red. The adsorption capacities of the CeO2/N-doped carbon composites were further investigated to reveal the effect of different adsorption conditions such as inorganic salt, Congo red concentration, pH value, adsorbent dosage, and adsorption temperature. Related Articles | Metrics

Select

Migration behaviors and deformation characteristics of discrete bubbles in a variable diameter circular tube Feng LI Liang MING Lei XING Minghu JIANG Lixin ZHAO Shuai GUAN The Chinese Journal of Process Engineering    2025, 25 (4): 341-353.   DOI: 10.12034/j.issn.1009-606X.224229 Abstract （431）   HTML （12）    PDF （9843KB）（77）       Knowledge map    Save The morphological evolution and migration dynamics of discrete bubbles in variable diameter pipelines have not been clearly analyzed. The deformation dynamics behavior of discrete bubbles in a variable diameter circular tube is an important theory to guide the transport and separation of gas-liquid two-phase mixture. Therefore, high-speed camera technology, combined with numerical simulation, is used to explore the migration and fragmentation mechanism of discrete bubbles in variable diameter pipes. For the structure of a variable diameter circular pipe, a study on the migration behaviors of discrete bubbles in the variable diameter field is conducted under different Reynolds numbers and bubble sizes. The flow pattern, velocity field and bubble deformation characteristics within the variable diameter circular pipe at various inlet Reynolds numbers are analyzed. The aim is to explore the interaction patterns between the flow field characteristics and discrete bubbles and provide theoretical support for revealing the motion and deformation mechanism of discrete bubbles in variable cross-section field. The results indicate that the surrounding fluid velocity is altered by bubbles. The velocity gradients are increased, and the turbulence kinetic energy in the surrounding flow field is elevated. At the same time, the dramatic change of turbulent kinetic energy in the sudden expansion section leads to the rapid deformation or even fragmentation of discrete bubbles in the variable diameter circular tube field. Additionally, as the inlet Reynolds number increases, the fragmentation position of bubbles in the flow field tends to approach the sudden expansion section. When Re=5.16×103, the shortest bubble fragmentation distance is 16.09 mm. When the Reynolds number is constant, as the bubble radius increases from 2.5 mm to 4.5 mm, the dimensionless maximum deformation of the bubble is increased from 0.26 to 0.67. The numerical simulation results demonstrate good agreement with experimental findings. Related Articles | Metrics

Select

Influence of particle electrostatic effect on flow parameters in gas-solid fluidized beds Hualong YU Jianlong SUN Xia HU Yuhang DING The Chinese Journal of Process Engineering    2025, 25 (5): 459-470.   DOI: 10.12034/j.issn.1009-606X.224305 Abstract （427）   HTML （13）    PDF （4241KB）（71）       Knowledge map    Save The actual value of the transport disengaging height (TDH) in a gas-solid fluidized bed is drastically different from the value that is anticipated. One of the primary reasons for this difference is that the electrostatic impact is ignored. Because it is impossible to quantitatively regulate the charge that is carried by the particles using the experimental procedures that are now in use, it is also difficult to analyze the impact that electrostatic effects have on TDH using experimental methodological approaches. In this work, the CFD-DEM numerical simulation method is used to study the particle entrainment and TDH problems in a three-dimensional fluidized bed. They combine the average height of particles in the free space, the average solid phase concentration, and the longitudinal particle velocity. This is done while taking into consideration the electrostatic effects that occur between particles. The influence and mechanism of the electrostatic force on the entrainment rate and TDH are derived, which provides a theoretical basis for the establishment of a method that is more accurate in forecasting TDH. Specifically, the findings indicate that the electrostatic impact between particles has the potential to impede the entrainment of particles and to decrease the entrainment rate. It is possible for the electrostatic force between particles to increase the average particle height and the longitudinal velocity of particles in free space, which ultimately results in an increase in the TDH when the charge that the particles carry is relatively low. Nevertheless, when the charge that the particles carry is substantial, the electrostatic attraction between the particles is likely to produce particle agglomeration. This, in turn, will reduce the concentration of the solid phase in the free space and hinder the entrainment of the particles, which will result in a decrease in the TDH. Related Articles | Metrics

Select

Experimental study on new type of wire plate electrostatic precipitator under synergistic effect of wet chord grid Houcheng DING Yaqin XUE Quanlong DENG Wenjing ZHANG Zhenyang CHEN The Chinese Journal of Process Engineering    2025, 25 (4): 382-388.   DOI: 10.12034/j.issn.1009-606X.224304 Abstract （418）   HTML （11）    PDF （3889KB）（38）       Knowledge map    Save In order to improve the dust removal efficiency of fine particulate matter in industry, based on the traditional wet string grid filtration dust removal and electrostatic precipitator theory, a new electrostatic precipitator experimental system was built by dividing wet dust removal and electrostatic precipitator into zones, under the synergistic effect of wet string grid. The influence of wavelength and amplitude of corrugated plates on dust removal efficiency under different voltages and wind speeds was explored through a single electrostatic precipitator experiment, and the optimal wavelength and amplitude values of corrugated plates were obtained. The influence of voltage, wind speed, and atomization pressure on the dust removal efficiency was explored through composite wet electrostatic precipitator experiments, and verified the dust removal effect of corrugated plates as dust collection plates in wet electrostatic precipitator systems. The results indicated that the dust removal efficiency in a single electrostatic precipitator was directly proportional to the voltage and inversely proportional to the wind speed. The dust removal efficiency of corrugated plates with different wavelengths and amplitudes was significantly improved compared to flat plates under different voltage and wind speed conditions, the impact of amplitude on the dust removal efficiency of corrugated plates was more significant, the corrugated plate with a wavelength of 150 mm and an amplitude of 60 mm had the best dust removal efficiency. The dust removal effect of the composite wet electrostatic precipitator system was significantly improved compared to a single electrostatic precipitator system, the dust removal efficiency of the combination of corrugated plate and water in the composite wet electrostatic precipitator system was higher than that of the combination of flat plate and water. The dust removal efficiency increased first and then decreased with the increase of wind speed and atomization pressure, which was proportional to the voltage. When the voltage, wind speed, and atomization pressure are 30 kV, 0.6 m/s, and 6 MPa, respectively, the maximum dust removal efficiency of the system reached 96.08%. Related Articles | Metrics

Select

Effects of temperature and atmosphere on the reduction degradation behavior of ferrous burden during reduction process Zhiwei YANG Guang WANG Jingsong WANG Qingguo XUE The Chinese Journal of Process Engineering    2025, 25 (5): 492-499.   DOI: 10.12034/j.issn.1009-606X.224296 Abstract （416）   HTML （15）    PDF （2794KB）（45）       Knowledge map    Save The oxygen blast furnace process is an important low-carbon ironmaking process, and the reduction degradation performance of the ferrous burden significantly impacts the smelting process. In order to guide the selection of ferrous burden under the oxygen blast furnace process, the reduction degradation behaviors of sinter and pellet under the two reduction atmospheres of oxygen blast furnace and traditional blast furnace were studied. The results showed that under traditional blast furnace condition, the sinter degradation index (RDI+3.15) tended to decrease and then increase with increasing reduction temperature. This was due to the fact that as the reduction continued, the internal expansion stress generated by the transformation of Fe2O3 to Fe3O4 gradually increased, leading to an increase in degradation. The degradation index at 700℃ was close to the national standard test value. In the high-temperature range (900℃ to 1100℃), the Fe3O4 at the core of the sinter was rapidly reduced. As FeO and metallic iron gradually formed within the burden particles, and as they moved from the surface to the interior, the volume appeared to shrink and densification increased, thereby weakening the degradation. However, under the oxygen blast furnace condition with high reduction potential, the degradation index of sinter exhibited a decreasing trend from 500℃ to 900℃. Furthermore, the increased concentration of CO and H2 in the reducing gas under oxygen blast furnace condition enhanced the diffusion of the gas into the core of the burden. This led to a gradual shift of the reaction interface from the surface to the core, resulting in more Fe2O3 being reduced to Fe3O4. Consequently, the reduction expansion stress increased, which in turn lowered the degradation index of sinter under the oxygen blast furnace condition compared to that under the traditional blast furnace condition. However, as the reduction index increased and the content of FeO and metallic iron in the sinter rose, the degradation performance of the sinter under oxygen blast furnace conditions at 1100℃ improved, slightly surpassing the degradation index under traditional blast furnace conditions at the same temperature. In addition, the degradation indices for both sinter and pellet under oxygen blast furnace condition were lower than those under the traditional blast furnace condition. A comparison of the two types of burden showed that the degradation index for pellet was higher than that for sinter under both conditions, and RDI+3.15 of the pellet was above 90% for all pellets. Related Articles | Metrics

Select

Preparation and performance of a new type of coal gangue-based paste filling materials with fast hardening characteristics Liang XU Shibing HUANG Zhenghao LI Jiamao LI Yuanbao GAO Chuangang FAN The Chinese Journal of Process Engineering    2025, 25 (5): 483-491.   DOI: 10.12034/j.issn.1009-606X.224295 Abstract （415）   HTML （14）    PDF （1376KB）（56）       Knowledge map    Save In order to improve the efficiency of coal mining, accelerate the backfilling speed of goaf and reduce the pollution and damage of coal-based solid waste to mining environment, coal gangue-based paste filling materials with fast hardening characteristics are prepared using coal gangue, fly ash, sulphoaluminate cement and persulfate cement as raw materials. The influences of aggregate-cement ratio and water-cement ratio on the macroscopic properties of the specimens are studied through a series of characterization tests such as fluidity, unconfined compressive strength (UCS), water absorption, softening coefficient and so on. The microstructure and curing mechanism of the specimens are analyzed by TG/DTA, XRD and SEM. The results show that when the aggregate-cement ratio is 4:1 and the water-cement ratio is 1.5, the initial fluidity of the specimen is 195 mm, and the 8 h UCS is 3.26 MPa, displaying obvious characteristics of early strength and fast hardening, and the UCS at 3, 7, and 28 d are 5.56, 5.66, and 6.61 MPa, respectively. The water absorption rate of the sample at 28 d age is 16.86%, and the softening coefficient is 0.90, indicating its excellent water resistance. The phase composition and micro-morphology analyses show that the early unconfined compressive strength of the filling specimens mainly comes from the accumulation and filling benefits of the gangue aggregate as well as the formation of a large amount of ettringite (AFt) in the cementation part. Moreover, the raw materials such as fly ash induce a pozzolanic reaction and react synergistically with persulfate cement, generating a certain amount of hydration products in the later period of curing, which further improves the densification and mechanical properties of the filling specimens. The results obtained in our current research can provide experimental basis and theoretical guidance for the development and practical application of new coal gangue-based green filling materials. Related Articles | Metrics

Select

Research on the interaction mechanism between the two zone of composite tridimensional rotational flow sieve tray Ping HUO Tianyu LI Hongkai WANG Meng TANG The Chinese Journal of Process Engineering    2025, 25 (5): 435-444.   DOI: 10.12034/j.issn.1009-606X.224259 Abstract （411）   HTML （16）    PDF （4351KB）（75）       Knowledge map    Save Aiming to clarify the interaction mechanism of gas-liquid cross-zone rotating flow in the rotational flow zones and packing zones of composite tridimensional rotational flow sieve tray (CTRST), the CTRST was investigated based on a dual Eulerian two-phase flow simulation method. The flow interaction between the two zones was described by the volume flow ratio of the gas and liquid phases, and the interaction mechanism of liquid phase distribution, pressure and velocity fields under the interaction between the two zones was analyzed, and compared with that of a single rotational flow configuration tray. The results indicated that the mass flow rate ratio of gas-liquid phase in the rotational flow zone always accounted for over 60%, the axial cross-section where the maximum value of the gas-liquid volume flow ratio was located transforms with the change in gas-liquid volume. The cross-section of the maximum gas-liquid phase volume flow ratio rose from Z=25 mm to Z=10 mm as Lw increased, and decreased from Z=25 mm to Z=40 mm as Fs increased. The packing zone had a strong buffering effect on the rotating flow. It significantly slowed down the trend of pressure reduction in the rotational flow zone, and the addition of packing did not affect the balance of pressure drop between the two zones. The structures of the packing zone and the rotational flow zone had a relatively uniform blocking effect on gas-liquid two-phase flow, and the pressure drop distribution was relatively uniform. There was a transition point in the rotational flow zone that changed the direction of the rotating flow, and the position of the transition point moved inward axially towards the inner cylinder. Compared to a single rotational flow configuration tray, the inward shift of the CTRST transition point improved the liquid holding capacity of the rotational flow zone and promoted gas-liquid interaction flow between the two zones. Related Articles | Metrics

Select

Phase equilibria and thermodynamics of the sodium benzenesulfonate-Na2SO4-H2O ternary system Jiahui YI Benren LIAO Peng CHEN Jingyu WEI Han YAO Huiting HUANG Zhihao LU Lehua ZHANG The Chinese Journal of Process Engineering    2025, 25 (4): 408-415.   DOI: 10.12034/j.issn.1009-606X.224274 Abstract （411）   HTML （10）    PDF （2508KB）（51）       Knowledge map    Save Industrial organo-sulfonic acid wastewater contains high concentrations of inorganic salts and various organo-sulfonates, causing significant challenges for their efficient removal, separation, and recovery. These waste streams often arise from complex industrial processes, and their intricate compositions make effective treatment and recycling more difficult. Herein, the phase equilibrium data for the sodium benzenesulfonate (BSNa)-sodium sulfate (Na2SO4)-water (H2O) ternary system were measured at temperatures of 273.15, 283.15, and 313.15 K using both the isothermal dissolution equilibrium method and Schreinemakers' wet residue method. Thermodynamic analysis of the dissolution process was performed using the van't Hoff equation, offering valuable insights into the system's behavior under different temperature conditions. At 313.15 K, the phase diagram indicated one invariant point, two univariant curves, and three distinct crystallization regions, corresponding to Na2SO4, BSNa, and their co-crystal mixture. However, at the lower temperatures of 273.15 and 283.15 K, the system displayed only one invariant point, one univariant curve, and two crystallization regions, specifically for Na2SO4?10H2O and a co-crystal region consisting of Na2SO4?10H2O and BSNa. Notably, no distinct crystallization region or solubility curve for BSNa was observed at these lower temperature ranges. Additionally, freeze crystallization experiments demonstrated no evidence of double salts or eutectic mixtures forming within the ternary system. This suggested that separating the components at lower temperatures, particularly around 283.15 K, was not only more efficient but also more cost-effective for obtaining pure salts. The thermodynamic analysis further revealed that the dissolution of Na2SO4 in this system was an endothermic, non-spontaneous process with an increase in entropy. The changes in enthalpy significantly influence the Gibbs free energy of dissolution, impacting the separation process. This research provided insight into the effective separation and recovery of BSNa and Na2SO4 from industrial wastewater, offering a solid foundation and practical guidance for improving wastewater treatment processes in industrial applications. Related Articles | Metrics

Select

Simulation of flow and mixing characteristics of binary particles in gas-solid fluidized bed (II): mechanical analysis of radial distribution characteristics of flow field Guifang WANG Shuangzhu KONG Jian LI Xiuying YAO Yiping FAN Chunxi LU The Chinese Journal of Process Engineering    2025, 25 (4): 364-372.   DOI: 10.12034/j.issn.1009-606X.224287 Abstract （404）   HTML （9）    PDF （2980KB）（57）       Knowledge map    Save Due to the distinct differences in size, density or shape of the particles' physical properties, the pattern of the two solid phases is complex. The hydrodynamics of binary mixtures of Geldart A particles and Geldart D particles in gas-solid fluidized bed, particularly the radial flow behaviors, are investigated. By comparing relative solid holdup, it is found that Geldart D particles tend to accumulate near the wall. However, few studies have discussed the occurrence for this phenomenon. The Kutta-Joukowski transverse force is introduced to analyze the distribution characteristics of local density and the local fractions of binary particles in the radial direction from the viewpoint of the forces on particles. Considering the fact that non-uniform structures in intermediate scale, the Eulerian-Eulerian multi-fluid model as well as the drag force model based on the energy minimization multi-scale (EMMS) is used. The Kutta-Joukowski transverse force on particles presents a non-uniform distribution in the radial direction. It is related to the gas-solid velocity-difference vector and the particle velocity radial gradient. Based on the radial profile of the Kutta-Joukowski transverse force, the flow regime is divided into three zones, the Kutta-Joukowski uniform influence zone (zone I), the velocity gradient dominant zone (zone II), and the velocity-difference vector dominant zone (zone III). The results show that the Geldart A particles and Geldart D particles exhibit similar tendencies in zone I to move towards the wall, resulting in a uniform distribution. In zone II and III, both Geldart A particles and Geldart D particles are exerted by the Kutta-Joukowski transverse force towards the wall, leading to a core-annulus phenomenon with low concentration at the center and high concentration near the wall. Compared to Geldart A particles, relatively higher Kutta-Joukowski transverse force on Geldart D particles results in a stronger tendency to move towards the wall region in zone II. In zone III, on the other hand, the tendencies for Geldart A particles and Geldart D particles travelling towards the wall are relatively weak. Related Articles | Metrics

Select

Current situation and application prospect of tritiated water purification technology in nuclear energy field Yan XU Menghan WU Baihua JIANG Yuyong WU Tiantian YU The Chinese Journal of Process Engineering    2025, 25 (7): 645-657.   DOI: 10.12034/j.issn.1009-606X.225158 Abstract （398）   HTML （21）    PDF （3093KB）（130）       Knowledge map    Save In the global context of nuclear energy renaissance and green development, the issue of tritium emissions has garnered significant attention. Reducing tritium emissions is a crucial measure for enhancing the environmental and public acceptance of nuclear energy. However, there is currently a lack of comprehensive and objective analysis of tritiated water purification technologies from the perspective of nuclear energy applications, and the overall technical routes and processes remain unclear. Moreover, given the rapid advancements in this field, existing literature reviews are in urgent need of updates. This review begins by outlining the generation scenarios, characteristics, and regulations of tritiated water in the nuclear energy field, highlighting the pressing demand for tritiated water purification technologies in nuclear power plant, spent fuel reprocessing plant, and future nuclear fusion facilities, in particular, inland nuclear facilities have higher requirements for tritium purification, with typical concentration of tritiated water to be purified ranging from 107 to 1012 Bq/L. Subsequently, the work reviews latest research progress in three mainstream tritiated water purification technologies—water distillation (WD), combined electrolysis and catalytic exchange (CECE), and liquid phase catalytic exchange (LPCE). It identifies the exploration and establishment of tritiated water purification mechanism and key physicochemical parameters, the industrial-scale preparation of efficient hydrogen-water isotope exchange catalysts, and the adaptive modification of electrolytic systems as the current research priorities and challenges. Building on this foundation, this work concludes four feasible tritium purification routes from the perspective of application: WD+storage/electrolysis+cryogenic distillation (CD) route, the CECE+storage/CD route, WD+CECE+storage/CD route, and the LPCE+CD route. It provides a comprehensive analysis of their treatment capabilities, applicable conditions, advantages, and disadvantages, aiming to offer references for tritiated water purification technology and engineering construction. Related Articles | Metrics

Select

Effect of addition of hematite and limonite on oxidation kinetics and roasting performance of fluxed magnetite pellets Wei RAN Jian PAN Congcong YANG Deqing ZHU Zengfu WU Qinghua LIU Qian ZHANG The Chinese Journal of Process Engineering    2025, 25 (5): 510-521.   DOI: 10.12034/j.issn.1009-606X.224318 Abstract （387）   HTML （10）    PDF （5911KB）（38）       Knowledge map    Save Firstly, simultaneous thermal analysis (TG-DSC) was employed to uncover the impacts of hematite-limonite and finely ground limestone on the oxidation process of magnetite. It was discovered that the decomposition and escape of calcium carbonate in limestone and the crystallization water in limonite inhibited the oxidation of magnetite. Subsequently, the influence mechanism of adding finely ground hematite-limonite on the oxidation kinetics of fluxed magnetite pellets under different ore blending conditions was emphatically studied. And the internal relationship between the oxidation degree of pellets and their roasting performance under the process conditions simulating the belt roaster was revealed. The results indicated that when the oxidation temperature was within the range of 850~1000℃, the pellets with different ratios of hematite-limonite were controlled by chemical reactions in the early stage of the oxidation reaction. It was also found that the higher the addition of hematite-limonite, the higher the apparent activation energy. Moreover, the apparent activation energy in the early oxidation stage of pellets with limonite added was higher than that of pellets with an equal amount of hematite added at the same basicity. The main reason for this was that the removal of crystallization water from the former pellets took away part of the heat and reduces the oxygen partial pressure during the heating process. Unlike the traditional grate kiln process, for the belt roaster, the oxidation degree of the pellets in the preheating stage was not necessarily the higher the better. When the oxidation degree of the pellets in the preheating stage was too high, it led to less heat being provided by the oxidation of Fe3O4 in the roasting stage, which was detrimental to the improvement of the pellets' strength. Related Articles | Metrics

Select

Leaching behavior of valuable metals from paleo-terrestrial sedimentary rare earth ore leaching residue in sulfuric acid solution Xingyu MAO Xianquan AO Yang CAO Yu GUO The Chinese Journal of Process Engineering    2025, 25 (4): 399-407.   DOI: 10.12034/j.issn.1009-606X.224199 Abstract （385）   HTML （10）    PDF （6313KB）（82）       Knowledge map    Save Paleo-terrestrial sedimentary rare earth ore is a new type of rare earth ore, the process produces a large amount of rare earth residue after acid leaching separation of rare earth elements. Al, Fe, and Ti present in the rare earth residue are important metals, and the separation and extraction of metal elements from the rare earth residue can improve the utilization value of rare earth ores and solve the solid waste disposal problems. Sulfuric acid solution was used to leach the residue from rare earth ore processing to investigate the effect and reaction mechanism of sulfuric acid solution on the leaching behavior of Al, Fe, and Ti. The results showed that the sulfuric acid solution could effectively dissolve silica-aluminate and hematite in the rare earth ores, selectively leach Al and Fe. In contrast, anatase did not easily react with the sulfuric acid solution, and the leaching rate of Ti was low, which stayed in the leaching residue together with Si. The optimal reaction conditions were optimized using one-way and orthogonal experiments, and the leaching rates of Al, Fe and Ti reached 86.44%, 94.00%, and 7.14%, respectively, under the optimal reaction conditions of reaction temperature of 115℃, reaction time of 6 h, acid residue mass ratio of 2.1 g/g and liquid-solid ratio of 4 g/g. It was found that the reaction temperature significantly affected the leaching rates of Al and Fe. Then (NH4)2SO4 was added to the leaching solution, and Al could be converted to NH4Al(SO4)2 crystals and precipitated, and Al2O3 was produced by roasting to realize the separation of Al and Fe. This study realized the selective recovery of Al and Fe elements in rare earth residue, and enriched Si and Ti elements in the leaching residue, which was conducive to the recovery of Ti elements in the next step. Related Articles | Metrics

Select

Hybrid modeling and multi-network optimization for predicting oxygen supply in converter steelmaking Yujie LIU Xinggan ZHANG Qian PENG Dingdong FAN Aijun DENG Yunjin XIA The Chinese Journal of Process Engineering    2025, 25 (5): 500-509.   DOI: 10.12034/j.issn.1009-606X.224252 Abstract （379）   HTML （12）    PDF （4536KB）（43）       Knowledge map    Save The converter steelmaking process is a crucial stage in iron and steel production, where effective control of oxygen supply significantly impacts the stability of the smelting process and the quality of molten steel. Traditional oxygen supply prediction models often focus on either mechanistic or algorithmic aspects but tend to overlook the high noise levels in the converter environment and the randomness in model training, leading to limitations in their practicality and reliability. To address these challenges, this study proposes a hybrid model based on multi-network optimization for predicting oxygen supply in converters. The model first applies the isolation forest algorithm to remove outliers, and then constructs a hybrid prediction model by combining elastic net with a backpropagation (BP) neural network. Five-fold cross-validation improves the model's generalization ability, and grid search ensures a globally optimal solution. The model is validated on data from a 150-ton oxygen converter in an industrial case study, and its performance is compared with three other models. Results show that the proposed model achieve a prediction hit rate of 76.54% within a ±200 Nm3 error range, and 94.61% within a ±300 Nm3 error range, with an R2 of 0.6512, RMSE of 159.7 Nm3, and MAE≤350 Nm3. This study demonstrates that integrating multiple network optimization methods can significantly improve prediction accuracy and model stability, highlighting the importance of MAE as a key metric for model usability. Related Articles | Metrics

Select

Simulation study of operational flexibility of a 25 MW heat-conducting oil furnace Chunhua JIA Yunyu BAI Hailong ZHAO Xiuming LI Di LI Juan WANG The Chinese Journal of Process Engineering    2025, 25 (5): 522-532.   DOI: 10.12034/j.issn.1009-606X.224213 Abstract （378）   HTML （12）    PDF （4119KB）（29）       Knowledge map    Save Heat-conducting oil furnace is a widely used heating equipment in industry. The performance of heat-conducting oil furnaces is affected by different heat loads during the production process. To investigate the operational flexibility of a thermal oil furnace with a designed load of 25 MW and optimize its operating conditions, numerical simulations of the heat-conducting oil furnace are conducted using computational fluid dynamics under five different heat load conditions (30%, 60%, 80%, 100%, and 110%). In order to obtain a more detailed understanding of the flow and combustion characteristics of the heat-conducting oil furnace, the influence of different heat load conditions on the distribution of parameters such as velocity, temperature, and component concentration during the flow and combustion process inside the furnace are studied and analyzed. The current layout of the burner results in a high velocity difference between the high-speed fuel jet and the air, and there are clear boundaries in the area affected by the jet. The suction effect on the surrounding flue gas is significant near the burner. When the heat load exceeds 60%, the reflux area in the furnace is larger, the residence time of flue gas is prolonged, and the overall temperature in the furnace is higher, which is conducive to the heat absorption and temperature rise of the heat transfer oil in the furnace tube. Under full load and overload operation conditions, it is important to pay attention to the impact of higher flue gas flow rate and temperature on furnace tubes and other components and avoid problems such as convection chamber furnace tube vibration, local overheating, and even overheating caused by high workload. The above research results can provide theoretical guidance for the design and the operation of heat-conducting oil furnaces, which has practical significance. Related Articles | Metrics

Select

Advances in direct cooling battery thermal management technology for electric vehicles Xijiao ZHU Huaxia YAN The Chinese Journal of Process Engineering    2025, 25 (6): 533-543.   DOI: 10.12034/j.issn.1009-606X.224250 Abstract （321）   HTML （40）    PDF （802KB）（153）       Knowledge map    Save With the intensification of the global energy crisis and environmental pollution issues, electric vehicles have become the future trend in automotive power due to their high energy efficiency and low emissions. The heat generated by batteries imposes limitations on their performance. Consequently, it is essential to gain a comprehensive understanding of the factors contributing to this heat generation and to devise and implement effective countermeasures. Addressing these issues is critical for optimizing battery performance and ensuring its safety. This review starts with a brief overview of the factors contributing to battery heat generation. It then delves into direct cooling battery thermal management technology, which utilizes the principle of refrigerant evaporation to absorb and dissipate heat effectively. This approach delivers superior cooling efficiency compared to traditional liquid and air cooling systems. Direct cooling systems are distinguished by their more compact design and faster response times, contributing to more effective thermal management and improved performance. By examining recent literature, this work provides a comprehensive review of the research developments concerning direct cooling systems. It includes an in-depth analysis of the structure design, cold plate design, and optimization strategies for various system parameters. It also highlights how the careful selection of refrigerant properties, along with precise adjustments to system parameters and cold plate configurations, can lead to significant enhancements in temperature uniformity under high-rate charge and discharge conditions. These improvements are crucial for extending the battery's operational lifespan and ensuring its safe and reliable performance. Future research efforts on direct cooling battery thermal management systems should prioritize two key areas: the optimization of the direct cooling plate system's design and parameters, and the development of new, highly efficient, and environmentally friendly refrigerants. Focusing on refining the structural design and operational parameters of direct cooling plates will help improve their performance and adaptability. Related Articles | Metrics

Select

Cover and Contents The Chinese Journal of Process Engineering    2025, 25 (4): 0-.   Abstract （312）      PDF （3876KB）（58）       Knowledge map    Save Related Articles | Metrics

Select

Simulation of flow and mixing characteristics of binary particles in gas-solid fluidized bed (I): axial/radial flow field distribution characteristics Guifang WANG Shuangzhu KONG Jian LI Xiuying YAO Yiping FAN Chunxi LU The Chinese Journal of Process Engineering    2025, 25 (4): 354-363.   DOI: 10.12034/j.issn.1009-606X.224286 Abstract （309）   HTML （11）    PDF （4002KB）（93）       Knowledge map    Save In the fields of petrochemical and chemical engineering, some new processes involving the reactions of gas and catalysts with distinct functions and physical properties have been proposed. Since considerable physical properties difference in density, size and shape between two types of particles,the hydrodynamic behaviors of the binary mixture in the gas-solid fluidized bed are undoubtedly complex. This work presents a numerical investigation on the mixing and flow characteristics of binary particles (Geldart A particles and Geldart D particles) and gas in the bottom region of the gas-solid fluidized bed-riser coupling reactor. Considering the non-uniform structures in intermediate scale, the Eulerian-Eulerian multi-fluid model as well as the drag force model based on the energy minimization multi-scale (EMMS) are used. The axial distributions of bed density and pressure in the binary particle fluidized bed are investigated. By analyzing the turning points of these two parameters, the location of interface between the dense phase zone and the dilute phase zone is determined. The cross-sectional average solid holdup of Geldart A particles and Geldart D particles in the axial direction is also discussed. By comparing the parameter, the relative cross-sectional average solid holdup rates of the two types of catalysts, it is found that most Geldart D particles accumulate at the bottom of the bed in the axial direction. Furthermore, when the binary particle system is composed of coarse particles with low density and fine particles with high density, the distribution of the bed density in the bottom region of the bed layer is steady. In the radial direction, by analyzing the radial distributions of the local solid holdups of the two-solid phase, it is seen that both the Geldart A particles and the Geldart D particles tend to travel towards wall area. By introducing the new parameter, the local relative solid holdup, it is revealed that the Geldart D particle has a stronger tendency towards the wall compared to Geldart A particles. Related Articles | Metrics

Select

Influence of alumina on reactivity of biopitch anode for aluminum electrolysis Kunmo ZHANG Wei WANG The Chinese Journal of Process Engineering    2025, 25 (3): 302-310.   DOI: 10.12034/j.issn.1009-606X.224254 Abstract （306）   HTML （11）    PDF （1533KB）（50）       Knowledge map    Save The carbon anode is prepared by baking a mixture of petroleum coke aggregate and pitch at 180℃ for use in the aluminum industry. Due to its good wettability and environmental friendliness towards carbon anode aggregates, the biopitch is considered as a promising carbon anode binder. The biomass conversion technology, substituting traditional coal tar pitch with biopitch, partially or completely in the aluminum production, has recently received domestic and foreign researchers' attention. However, the biopitch typically has a lower coking value which may have a negative impact on its performance. In this work, alumina additives have been added to the biopitch anode to improve its performance. In order to understand the effect of alumina additives on the performance of biopitch anodes, biopitch anode materials were prepared by hot pressing and sintering in the laboratory with alumina as a catalyst. The CO2 reactivity of the anodes was tested with a thermogravimetric analyzer in laboratory. The influence of additives on the performance of the anodes and the CO2 reactivity as well as the wettability of biopitch on petroleum coke were studied by X-ray diffraction analysis, optical microscopy (OM) and high-resolution transmission electron microscopy (HRTEM). The results indicated that the biopitch exhibited better wettability than coal tar pitch with the same surface tension and viscosity. In addition, a transformation occurred from initially less well-ordered to ordered structure for the biopitch anode with alumina additives during baking, thereby increasing the coking value of the biopitch, reducing the CO2 reactivity of biopitch anodes and improving their antioxidant properties. Accompanied by an enhancement in the graphitization degree and an increase of carbon structural orders, the performance of biopitch anodes has been improved significantly with alumina as additives. The biopitch could be used to replace 100% of the coal tar pitch in a carbon anode recipe. This study has provided a theoretical guidance for the application of biopitch anodes and the reduction of energy consumption in aluminum electrolysis. Related Articles | Metrics

Select

Heat transfer characteristics of micro-encapsulated phase change material slurry in metal foam filled microchannels Yongtong LI Jing SUN Weibo WANG Boyu YANG Yunxi YANG The Chinese Journal of Process Engineering    2025, 25 (3): 233-240.   DOI: 10.12034/j.issn.1009-606X.224227 Abstract （299）   HTML （17）    PDF （4566KB）（74）       Knowledge map    Save Micro-encapsulated phase change material slurry (MEPCMs) is a novel kind of functional thermal fluid, which has great potential in the field of electronic thermal management, thermal storage, etc. To improve the thermal management performance of high-power density electronic devices, a dual-enhanced heat transfer method with the combination of MEPCMs and metal foam was employed to improve the cooling performance of mini-channel heat sink in the present study. Numerical methods were utilized to investigate the heat transfer capability, flow resistance, and overall performance evaluation criteria (PEC) by considering the effects of MEPCMs mass fractions (5wt%, 10wt%, and 20wt%), inlet velocities, and metal foam filling ratios. The results indicated that the maximum temperature of metal foam mini-channel decreased and pressure drop increased with increasing the mass fraction of MEPCMs. At an inlet velocity of 0.06 m/s, increasing the mass fraction from 5wt% to 20wt%, the pressure drop increased by 2.09 times. 5wt% MEPCMs presented the best comprehensive heat transfer performance, and the PEC value was improved by 8.15%~12.18% compared with pure water. The filling ratio of the metal foam also significantly affected the heat transfer performance of the microchannel, and the cooling performance was best when the mini-channel was fully filled with metal foam. For the entire range of flow velocities, using 5wt% MEPCMs as the coolant, average Nuave of mini-channel heat sink fully filled with metal foam was 9.06 times of the empty mini-channel heat sink, and the pressure drop came to 56.91 times. With the comprehensive consideration of heat transfer enhancement and flow resistance, the PEC value could reach up to 2.61. The present findings could provide theoretical guidelines for developing more coefficient and compact liquid-cooled electronic devices. Related Articles | Metrics

Select

CFD simulation of bubble columns with tube bundles: impact of turbulence models Nan ZHANG Xiaoping GUAN Kangjun WANG Ning YANG The Chinese Journal of Process Engineering    2025, 25 (3): 261-272.   DOI: 10.12034/j.issn.1009-606X.224206 Abstract （289）   HTML （14）    PDF （6598KB）（63）       Knowledge map    Save The accuracy of CFD simulation results for bubble columns depends on closure models, such as interphase force models and turbulence models. Most of the previous reports were for empty column without internals, and currently, there is a lack of studies related to bubble column with internals. This study examined the effects of six commonly used turbulence models (Standard k-ε, RNG k-ε, Realizable k-ε, Standard k-ω, SST k-ω, and RSM) on the hydrodynamics in the pilot-scale bubble columns without internals and with tube bundles. The results showed that the RSM predicted significantly higher for turbulent kinetic energy, turbulent dissipation rate, and turbulent viscosity in the empty column compared to eddy viscosity models (k-ε and k-ω models). However, this difference was considerably reduced in the bubble column with tube bundles, and the tube bundles significantly suppressed the turbulence intensity in the liquid phase. Meanwhile, by comparing the simulated gas holdup and axial liquid velocity values with experimental data, it was found that the eddy viscosity models accurately predicted the gas holdup in the central region of the empty column, while the RSM accurately predicted the gas holdup in all regions except the central region. However, the radial distribution of gas holdup predicted by six turbulence models in the bubble column with tube bundles was almost identical, with accurately predicting the gas holdup only in the 0.5<r/R<0.7 region. The Realizable k-ε model's predictions of axial liquid velocity in both empty column and the bubble columns with tube bundles were in good agreement with experimental data, significantly outperforming other turbulence models. Therefore, it was recommended to use the Realizable k-ε model for future simulations of hydrodynamics in bubble columns. Related Articles | Metrics

Select

Conver and Contents The Chinese Journal of Process Engineering    2025, 25 (5): 0-.   Abstract （269）      PDF （2982KB）（52）       Knowledge map    Save Related Articles | Metrics

Select

Investigation of enhanced boiling heat transfer characteristics of hierarchical gradient porous copper surface Er SHI Shuangrui YE Youlan WANG Qi PENG Bin ZHAO Changwei JIANG The Chinese Journal of Process Engineering    2025, 25 (3): 273-282.   DOI: 10.12034/j.issn.1009-606X.224233 Abstract （267）   HTML （16）    PDF （4605KB）（49）       Knowledge map    Save To enhance boiling heat transfer for promoting the efficiency of the energy system, the porous surfaces with structural gradients were developed on pure copper substrates by employing the electrochemical deposition method. In this study, honeycomb-like porous structures and hierarchical axial honeycomb gradient porous structures were fabricated using constant current single-step deposition and constant current constant voltage two-step deposition methods, respectively. Saturated pool boiling heat transfer experiments were conducted using HFE-7100 as the working fluid to investigate the influence of the gradient pore size changes on the boiling heat transfer performance of porous surfaces. The results demonstrated that the hierarchical gradient porous surface, which had a total deposition time of 60 seconds and an increased second-step deposition voltage of 3 V, showed the most significant heat transfer enhancement. The wall superheat at the boiling initiation point was 9.5 K, a 43.00% decrease compared to the smooth surface at 16.8 K. Moreover, the critical heat flux and heat transfer coefficient reached 522.02 kW/m2 and 22.76 kW/(m2?K), respectively, exhibiting with enhancements of 193.40% and 261.01% compared to the smooth surface. The hierarchical porous surface had two types of nucleation sites: internal pores and dendritic protrusions. The micropores and the internal micropores of the dendrites exhibited a wide range of pore sizes. This extensive distribution of pore sizes not only increased the density of nucleation sites and effective heat transfer area but also reduced the nucleation energy barrier. The axial pore size gradient accelerated bubble evolution, and the capillary suction force provided by the gradient porous structure and dendrites facilitated the return flow of the working fluid to the nucleation sites both horizontally and vertically, thereby enhancing the boiling heat transfer coefficient and critical heat flux of the hierarchical gradient porous surface. Related Articles | Metrics

Select

Effect of alloying elements on RE2Fe14B (RE=Nd, Pr) based nanocomposite permanent magnets Chuanyou HUO Dianbao ZHANG Xiaoyu BO Erbao QIAN Zhen ZHANG Jinghan NIU Shengnan JIANG Hailing LI The Chinese Journal of Process Engineering    2025, 25 (3): 221-232.   DOI: 10.12034/j.issn.1009-606X.224121 Abstract （257）   HTML （21）    PDF （1330KB）（65）       Knowledge map    Save Nanocomposite magnets have become a promising next-generation permanent magnet material due to their potential high magnetic energy product. The implementation of high magnetic performance depends on precise control of the microstructure, including the grain size and distribution of soft and hard magnetic phases, the content of soft magnetic phases, the orientation of hard magnetic phases, the structure and chemical composition, etc. At present, the microstructure of nanocomposite magnets is mainly controlled by adjusting the alloy composition and preparation process. By adding alloying elements, not only can improve the microstructure of nanocomposite permanent magnets, but also can change the intrinsic magnetic parameters of the main phase in the magnet, which is a common method to improve the magnetic performance of the magnet. In this work, the role of alloying elements in microstructure control of RE2Fe14B (RE=Nd, Pr) based nanocomposite permanent magnet materials is summarized and evaluated. The addition of rare earth elements (La, Ce, Pr, Dy, Tb, etc.) to replace Nd atoms alters the intrinsic magnetic parameters of Nd2Fe14B phase. Elements such as Co, Cr, Ni, and Mn can enter the lattice of α-Fe and RE2Fe14B to replace by the point position of Fe, while changing the intrinsic magnetic parameters of the soft and hard magnetic phases, thereby altering the magnetic properties of the magnet. It has been confirmed that elements such as Nb, Ti, and Zr can enter the main phase Nd2Fe14B, but are more enriched at grain boundaries, playing a role in enhancing domain wall pinning and refining grain size. Elements such as Sn and Ga can improve the high-temperature magnetic performance of magnets and enhance their thermal stability. Adjusting the alloy composition through the addition of alloying elements is an effective way to control the microstructure of nanocomposite magnets, but the content of alloying elements should be controlled within a certain range. Excessive addition will deteriorate the magnetic properties of the magnets. Related Articles | Metrics

Select

Synergistic oxygen-enriched alkaline leaching of vanadium mud and slag for enhanced extraction Chang CHEN Zhenquan ZHANG Baohua WANG Hao DU Jian QI Shaona WANG Haonan LI Minghua WANG Biao LIU The Chinese Journal of Process Engineering    2025, 25 (9): 933-942.   DOI: 10.12034/j.issn.1009-606X.224369 Abstract （254）   HTML （4）    PDF （6729KB）（30）       Knowledge map    Save Vanadium mud is a kind of solid waste produced in the process of vanadium leach solution decontamination, which has a high recovery value. In this study, to address the problem that vanadium mud is difficult to be utilized in large quantities, vanadium is extracted from vanadium mud by alkaline leaching of vanadium mud. The effects of reaction temperature, reaction time and NaOH concentration on vanadium extraction were investigated. The best conditions were found to be: 90℃, 2 hours, 20wt% NaOH, liquid to solid ratio of 2∶1. Under these conditions, the leaching rate of vanadium reached 99.23%, and the V2O5 content in tailings was only 0.48wt%. On the basis of alkaline leaching of vanadium from vanadium mud, the extracting vanadium from vanadium mud and vanadium slag by alkaline leaching was studied based on the existing process of extracting vanadium from vanadium slag by oxygen-enriched alkaline leaching. Under the optimized conditions, the vanadium content in the mixed slag was 0.68wt%, the leaching rate of vanadium from vanadium mud was 92.40%, and the vanadium extraction effect from the vanadium slag was improved by about 6 percentage points. The optimal conditions for the oxygen-enriched alkaline synergistic leaching process were a temperature of 150℃ and an oxygen pressure of 0.5 MPa.The leaching slurry was diluted to NaOH concentration of 25wt%, with adding the initial vanadium slag quality of 10wt% of the vanadium mud, leaching temperature of 90℃, leaching time of 1 h. Finally, the mechanism behind collaborative vanadium extraction was investigated during the extraction process. It was clear that the addition of vanadium mud can change the silicon phase to promote the efficient extraction of vanadium from vanadium slag. The method can realize the efficient synergistic extraction of vanadium from svanadium mud and vanadium slag. Related Articles | Metrics

Select

Optimization strategy of soft magnetic composites properties based on interfacial reaction engineering and carbonyl iron powder doping Kaixuan LI Yang LIU Xingyi WU Rui WANG Huaqin HUANG Zhaoyang WU The Chinese Journal of Process Engineering    2025, 25 (7): 736-747.   DOI: 10.12034/j.issn.1009-606X.224380 Abstract （243）   HTML （6）    PDF （4366KB）（64）       Knowledge map    Save Insulation cladding through interfacial reaction engineering is an important way to optimize the properties of soft magnetic composites (SMCs), but the traditional method faces the problem of lattice mismatch between the insulating layer and soft magnetic powder leading to interfacial cracks. In this study, a carbonyl iron powders (CIPs) doping strategy is innovatively proposed to construct CaSiO3?Ca2Al2O5?CaO composite insulating layer by utilizing their high plasticity and high specific surface area properties in synergy with the thermal decomposition of alkaline compounds. The results show that Ca(OH)2 decomposes into solid-phase CaO and gas-phase H2O during thermal treatment, where CaO tends to nucleate on the surface of FeSiAl soft magnetic powder matrix and grows along the doped CIPs, ultimately forming a composite insulating layer composed of CaSiO3?Ca2Al2O5?CaO. The combination of high plasticity CIPs and the cladding layer effectively fills the internal pores of the SMCs. The high specific surface area of the small particle size CIPs provides more reaction sites for the decomposition of Ca(OH)2 and the growth of the composite insulating layer, which promotes the uniform distribution of the insulating layer on the surfaces of the soft magnetic powders and the CIPs, and realizes the effective doping of the CIPs inside the insulating layer, which weakens the negative impacts of the lattice mismatches between the insulating layer and the soft magnetic powders. The negative effect of the lattice mismatch between the insulating layer and the soft magnetic powder is weakened. By changing the doping amount of CIPs, the magnetic properties of SMCs can be precisely regulated, and when the doping amount of CIPs is 20wt%, the SMCs show the best comprehensive magnetic properties. At 10 mT, 200 kHz, the saturation magnetization intensity reaches 145.1 A?m2/kg, the permeability is 40.5, and the loss is as low as 50.6 kW/m3, which is ideal for high-performance electromagnetic components. Compared with other insulating layer preparation strategies based on interfacial reaction engineering, the method proposed in this study takes advantage of the high plasticity and high specific surface area of CIPs, and the combination with interfacial reaction engineering is expected to be a new idea for solving the lattice mismatch between insulating layers and soft magnetic powders, which provides an ideal solution for performance optimization of SMCs. Related Articles | Metrics

Select

Experimental study on bubble characteristics and boiling heat transfer in parallel microfluidic heat exchanger Junfei YUAN Guyu XING Zicheng FENG Shuoshuo SONG Yu WANG The Chinese Journal of Process Engineering    2025, 25 (8): 834-844.   DOI: 10.12034/j.issn.1009-606X.225032 Abstract （240）   HTML （11）    PDF （39521KB）（117）       Knowledge map    Save To further expand the application range of microchannel boiling heat transfer in the field of high heat flux electronic equipment cooling, an experimental study is conducted on the dynamic characteristics of boiling generation and development, as well as the overall heat transfer characteristics of microchannel heat exchangers with parallel multiple channels. The results indicate that in microchannel heat exchangers with parallel multiple channels, there are significant differences in the initiation positions of boiling bubbles among the parallel microchannels. The deviation in the non-uniformity of the boiling inception position is relatively small under the influence of mass flow rate and decreases initially and then increases with the increase of heat flux density. Both subcooled boiling and saturated boiling heat transfer mechanisms occur simultaneously within the microchannels. Bubbly flow can happen in both boiling mechanisms, while slug flow and annular flow regimes only occur in the saturated boiling region. The heat flux density has a significant impact on the heat transfer mechanism within the channel, the wall temperature along the flow path, and its variation pattern. Within the heat flux density range of 63~80 kW/m2, the sudden expansion effect at the outlet plenum chamber cause the wall temperature at the heat exchanger's outlet reduce first, then increase, and then reduce again. As the heat flux density increases to 104~252 kW/m2, the wall temperature fluctuations in the microchannels are smaller, and temperature uniformity is enhanced. The overall boiling heat transfer characteristics of the heat exchanger show a turning point when the outlet refrigerant dryness at the microchannel exit is 0.02. The overall heat transfer coefficient of the heat exchanger increases with the increase of both mass flow rate and heat flux density, with the mass flow rate having a higher sensitivity to the average heat transfer coefficient. Related Articles | Metrics

Select

The application analysis of mixed matrix membranes in membrane-based carbon capture technology Yu QIN Yuyan HAI Rihua XIONG The Chinese Journal of Process Engineering    2025, 25 (10): 1008-1020.   DOI: 10.12034/j.issn.1009-606X.224358 Abstract （238）   HTML （3）    PDF （2481KB）（57）       Knowledge map    Save In the context of "carbon peak and carbon neutrality", carbon capture, utilization and storage (CCUS) technology is becoming increasingly important. The study of CO2 separation has attracted high-profile as it is the key link in the CCUS process. Among various separation methods, the membrane separation technology stands out with its advantages of low energy and continuous operation. This work reviews the current research status of various CO2 separation membranes for membrane-based carbon capture both domestically and overseas. It emphatically introduces the research progress regarding the CO2 gas permeation and separation performance, as well as the optimized preparation methods, of mixed matrix membrane. The CO2 permeance of most mixed matrix membranes ranges from 0 to 1000 Barrer, and the CO2/N2 separation coefficient is between 20 and 120. In addition, it is proposed that the preparation method of mixed matrix membrane can be optimized by using modified crystalline porous fillers or directly adopting amorphous porous fillers, thereby improving the compatibility between polymer substrates and porous fillers. Meanwhile, from the perspective of the actual needs of subsequent industrial applications, this review analyzes the advantages and disadvantages of various CO2 separation membrane modules, and proposes that the spiral-wound membrane module is the most suitable for the field of membrane-based carbon capture. Mixed matrix membrane exhibit excellent mechanical and thermal stability, outstanding resistance to plasticization, and excellent CO2 permeation and separation performance. Therefore, they have the greatest potential to be fabricated into spiral-wound membrane modules and applied in the field of membrane-based carbon capture in the future. Additionally, it can be concluded that with the current performance of mixed matrix membrane and suitable capture process conditions (e.g., the addition of purge gas), the CO2 capture cost can be controlled within 23 USD/t CO2. From this perspective, the application of mixed matrix membranes in membrane-based carbon capture technology is considered feasible. This work aims to provide guidance for the widespread application of CO2 membrane separation in CCUS technology as soon as possible. Related Articles | Metrics

Select

Numerical study on influence of pulse amplitude on patterns of gas-liquid-liquid three-phase flow in pulsed extraction column with discs and doughnuts Ting YU Xiucheng YU Zonghui LU Zhe XIAO Ming QU Hui HE Guoan YE The Chinese Journal of Process Engineering    2025, 25 (3): 283-292.   DOI: 10.12034/j.issn.1009-606X.224194 Abstract （228）   HTML （13）    PDF （4541KB）（58）       Knowledge map    Save The pulsed extraction columns with discs and doughnuts play a critical role in the field of spent fuel reprocessing. The countercurrent contact between liquid-liquid two-phase fluids in the column is facilitated through periodic pulses, which significantly influences the separation and purification processes of chemical elements. Although a considerable amount of research on pulse extraction columns with discs and doughnuts has been conducted through simulation, few studies have utilized the actual industrial structure of these columns as examples. A gas-liquid-liquid three-phase flow model coupled with PBM (Polulation Balance Model) to evaluate discrete phase droplet diameter distribution, reflecting the actual structure of pulsed extraction column with discs and doughnuts, was established using CFD (Computational Fluid Dynamics) simulation technology. And it verified the accuracy of the modeling through multiple calculation cases, aiming to investigate the influence of pulse amplitude on the evolution of flow field inside a pulsed extraction column. The model's accuracy was demonstrated through comparison with public literature, and the impact of pulse amplitude on the micro-flow behavior inside the pulsed extraction column was calculated, analyzed and verified. Under the working condition with a pulse amplitude of 1.2 cm, the amplitude had a relatively small impact on the motion of water and oil phases, and the water phase accumulated on the baffle. Under the working conditions of pulse amplitudes of 7.2 and 14.4 cm, the amplitude had a significant impact on the direction and velocity of the water and oil phases, with the water phase separating from the baffle and dispersing into smaller droplets. Furthermore, it was found that as the pulse amplitude increased, both the turbulence kinetic energy and turbulence energy dissipation rate also increased, reaching a maximum value in the region where the fluid impacted the solid wall. Finally, from the distribution of droplet diameter fraction, it was evident that as the pulse amplitude increased, the proportion of small diameter aqueous droplets was higher, which enhanced the extraction. This study used the Euler-Euler two-phase flow model coupled with the PBM to accurately simulate the gas-liquid-liquid three-phase evolution phenomenon in pulse extraction columns, providing a reference for the design and process optimization of subsequent pulsed baffle extraction columns, which laid the foundation for introducing the mass transfer model and heat transfer model through CFD method to analyze the chemical process inside the column in further study. Related Articles | Metrics

Select

Optimization of phosphorus release from anaerobic fermentation of cow manure and phosphorus recovery through vivianite crystallization Zhihao CHEN Weihua LI Tingting YANG Yixin LIU The Chinese Journal of Process Engineering    2025, 25 (3): 293-301.   DOI: 10.12034/j.issn.1009-606X.224223 Abstract （220）   HTML （14）    PDF （2793KB）（20）       Knowledge map    Save With the rapid development of the livestock and poultry farming industry in China, the disposal and resource utilization of livestock and poultry waste have attracted widespread attention. To maximize the recovery of phosphorus from this waste, this study focuses on fresh cow manure, which is rich in phosphorus, and proposes a novel pathway for phosphorus recovery. By examining the effects of different manure concentrations, anaerobic fermentation durations, and initial pH values on phosphorus release during the anaerobic fermentation of fresh cow manure, the study found that optimal conditions for phosphorus release were achieved with a manure concentration of 180 g/L, an anaerobic fermentation period of 14 days, and the initial pH of 7, resulting in a phosphorus release of 156.57 mg/L. To recover phosphorus from the supernatant of anaerobically fermented cow manure, Fe2+ salts were added to induce the vivianite crystallization. L9(34) orthogonal experiments were conducted to investigate the effects of reaction temperature, pH, and Fe/P ratio on the phosphorus recovery rate. The results showed that the factors affecting phosphorus recovery efficiency in order of significance, were the initial pH value, reaction temperature, and Fe/P ratio. The optimal for the process were found to be a reaction temperature of 35℃, a pH of 7, and a Fe/P ratio of 1.9. Under these conditions, the highest phosphorus recovery rate of 84.20% was achieved, and the purity of vivianite was 25%. The recovered products were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. An improved sequential phosphorus extraction method was employed to determine the abundance of vivianite in the recovered products. The research provides a valuable reference for the synthesis of high-value vivianite, based on the effective extraction of phosphorus from fresh cow manure. Related Articles | Metrics

Select

Research progress on the preparation and application of sulfonated carbon Zhengfeng JIANG Ruoxin WANG Fei GAO Zhimao ZHOU Quan SHI Haimeng YU Yingwen LI Huaqun ZHOU Chen HE The Chinese Journal of Process Engineering    2025, 25 (8): 775-791.   DOI: 10.12034/j.issn.1009-606X.225036 Abstract （220）   HTML （12）    PDF （2362KB）（80）       Knowledge map    Save Biomass waste is a plentiful and sustainable resource, and the transformation of this waste into porous carbon materials through uncomplicated and energy-efficient processes has become a significant focus of current research. Acidic carbon materials rich in sulfonic acid (-SO3H), carboxylic acid (-COOH), and hydroxyl (-OH) groups are obtained by in-situ sulfonation or post-grafting sulfonation of biomass or amorphous carbon materials. All of the functional carbon materials incorporating -SO3H groups are referred to as sulfonated carbon. The unique surface structure of sulfonated carbon makes it have great application prospects in the areas of catalysis, energy storage, and environment. This review summarizes the research on the production of raw materials, preparation processes, reaction mechanisms and physicochemical characteristics of sulfonated carbon, describes the current applications of sulfonated carbon in various fields including solid acid catalysts, energy storage materials, adsorbents, soil improvement and carbon-based fertilizers, and points out the problems and challenges facing the application of sulfonated carbon. As the preparation technology for sulfonated carbon continues to improve, further exploration of its stability, selectivity, and wide applicability is necessary. As a highly promising new type of carbon material, sulfonated carbon is expected to have a wide range of applications in various fields. Related Articles | Metrics

Select

Multi-enzyme catalytic preparation of D-alanine Xianbing SONG Yu YANG Manman WANG Ranfeng HE Yuming ZHANG Ziqiang WANG Xiaolian LI Yunshan WANG The Chinese Journal of Process Engineering    2025, 25 (8): 862-871.   DOI: 10.12034/j.issn.1009-606X.224362 Abstract （218）   HTML （7）    PDF （1355KB）（33）       Knowledge map    Save D-Alanine (D-Ala) is an important chiral amino acid with a wide range of applications in the fields of medicine, food, and chemical industry. In this project, a "two-bacteria, four-enzyme" catalytic process for the preparation of D-Ala, a fed-batch fermentation process with pRMA [E.coli BL21(DE3)Alr-Dadx--pRSFDuet-1-MaiA-AspA] and pEAD2 [E.coli BL21(DE3)Alr-Dadx--pETDuet-1-AspR-DaaT] trains was established to achieve co-expression of maleic acid cis?trans isomerase (MaiA)/asparaginase (AspA) and aspartate racemase (AspR)/D-amino acid transcarbamylase (DaaT). Additionally, process parameters for multiple enzyme preparation of D-Ala with maleic anhydride (MA) as the substrate were optimized, including temperature, pH, and concentrations of pyruvate, pyridoxal phosphate, maleic anhydride, and pRMA/pEAD2 cells, leading to the development of an efficient enzymatic conversion process for D-Ala. The results showed that the cell concentration and apparent activity of pRMA reached the maximum value of 72.56 g/L and 554.49±30.96 U, respectively, at 23 h. In contrast, the apparent activity of pEAD2 could reach 513.74±38.25 U at 9 h, and the cell concentration was 30.75 g/L. For the multi-enzyme preparation of D-Ala, the optimized catalytic system was composed of 1.5 mol/L MA, 5.0 mmol/L pyridoxal phosphate and 3.52 g/L pyruvic acid. The dosages of pRMA and pEAD2 cells were 6.60 g/L and 9.80 g/L, added at 3 h intervals. The optimum reaction conditions were pH=8.0, temperature of 50℃, and rotation speed of 200 r/min for 24 h. The substrate conversion rate was up to 99.00%, and the yield of D-Ala reached 93.97%. Under the above optimal conditions, when the reaction volume was scaled up 40-fold, from 100 mL to 4 L, there was no significant difference in substrate conversion and product yield, which laid the foundation for its industrial application. Related Articles | Metrics

Select

Numerical simulation of flow field and power consumption characteristics of double-layer combined impeller in a gas-liquid stirred tank Mengyao ZHANG Yafeng XIAO Zhongtian DONG Shaoping MA Shuang WU Mingzhou YU Qinghua ZHANG Chao YANG The Chinese Journal of Process Engineering    2025, 25 (7): 695-705.   DOI: 10.12034/j.issn.1009-606X.224353 Abstract （207）   HTML （10）    PDF （4980KB）（68）       Knowledge map    Save In the realm of chemical synthesis, the aminolytic synthesis of glycine from chloroacetic acid holds significant industrial importance. To surmount the challenges and optimize this process, with a particular emphasis on enhancing gas dispersion performance, elaborate investigation was carried out. Three innovative impeller combinations, namely the double narrow blade propeller (ZCX-ZCX), the narrow blade propeller-parabolic disc turbine (ZCX-PDT), and the narrow blade propeller-staggered fan-shaped parabolic disc turbine (ZCX-SFPDT), were integrated into the gas-liquid mixing operations within stirred tanks. Employing advanced computational fluid dynamics (CFD) techniques, comprehensive comparative analysis was executed. The complex gas dispersion phenomena within the liquid phase were modeled using the Eulerian-Eulerian approach combined with the dispersed k-ε turbulent model to capture the intricate fluid dynamics. It was found that at the same speed, the ZCX-ZCX configuration manifested the lowest values in velocity distribution, turbulent kinetic energy, gas holdup, and power consumption metrics, but the largest average bubble size. Additionally, its distribution uniformity lagged behind that of ZCX-PDT and ZCX-SFPDT, resulting in suboptimal gas-liquid mixing. In contrast to ZCX-PDT and ZCX-SFPDT, the ZCX-SFPDT stirred tank boasted smaller gas cavities and more uniformity of flow field. Notably, under the same Reynolds number regime, ZCX-SFPDT not only curtailed power number by 6.1% compared to the ZCX-PDT tank, but also augmented mass transfer efficiency by 10.9%. It indicated that the arc-shaped structure decreased the form drag on the blade surface and the length of the resistance arm, which was conducive to reducing the stirring power consumption. Generally, these results unequivocally established that ZCX-SFPDT exhibited superior gas-liquid dispersion and mass transfer capabilities, rendering it the prime candidate for gas-liquid stirred tank applications. Related Articles | Metrics

Select

Numerical simulation of optimization on combustion of high-temperature gas-solid preheating fuel in rotary kiln Yuchen DING Junjie WANG Jun CAI Zhiping ZHU The Chinese Journal of Process Engineering    2025, 25 (7): 748-760.   DOI: 10.12034/j.issn.1009-606X.224343 Abstract （206）   HTML （9）    PDF （4470KB）（55）       Knowledge map    Save Fluidized preheating combustion technology used in rotary kilns can effectively reduce the fuel consumption per unit product and has advantages such as wide fuel adaptability and low NOx emissions. However, compared to pulverized coal, the combustion characteristics of preheated fuel are significantly different. This work employs computational fluid dynamics (CFD) to study the effects of preheating temperature, excess air coefficient within the rotary kiln, and the momentum of the axial flow air passage of the burner on the combustion process of high-temperature preheated fuel within the rotary kiln. Combining the author's previous research on the swirl number of multi-channel burners, an orthogonal design method combined with matrix analysis is used to obtain the importance of the effects of these four factors on combustion characteristics and the optimal parameter combination for comprehensive combustion performance. The results show that as the preheating temperature increases, the flame becomes thicker and shorter; as the excess air coefficient increases, the flame first becomes longer, then shorter; as the momentum of the axial flow air passage of the burner increases, the flame first becomes shorter and thicker, then longer and thinner. The importance of the effects of these four factors on combustion characteristics is in the order of preheating temperature>momentum of the axial flow air passage of the burner>swirl number>excess air coefficient. The optimal parameter combination is a swirl number of 0.2, a preheating temperature of 850℃, an excess air coefficient of 1.1, and a momentum of the axial flow air passage of the burner of 0.5 N/MW. The optimized conditions, compared to the original conditions, result in a 47% increase in flame length, a 37% increase in the average heat flux of the wall in the firing zone, and an 80% increase in the maximum heat flux of the wall in the firing zone. Related Articles | Metrics