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Records with Subject: Process Design
Showing records 1605 to 1629 of 2098. [First] Page: 1 62 63 64 65 66 67 68 69 70 Last
Assessment of the Dimensionless Groups-Based Scale-Up of Gas−Solid Fluidized Beds
Faraj M. Zaid, Haider Al-Rubaye, Thaar M. Aljuwaya, Muthanna H. Al-Dahhan
February 21, 2023 (v1)
Keywords: dimensionless groups, fluidized beds, optical probe, phase holdup, pressure transducer, scale-up
The most common scale-up approach for gas−solids fluidized beds is based on matching the governing dimensionless parameters. In the literature, this approach has been validated only by means of measuring global parameters between different sizes of fluidized beds. However, such global measurements are not sufficient to depict all the interplaying hydrodynamic phenomena and hence verify the scale-up relationships. Therefore, to assess this approach, an advanced gas−solids optical probe and pressure transducer measurement techniques have been applied to quantify local hydrodynamic parameters in two different sized fluidized beds. Four different sets of experimental conditions were designed and conducted to examine the assessment of the scaling approach with matched and mismatched dimensionless groups between the two beds. The results indicated that the reported dimensionless groups are not adequate for achieving similarity between the two gas−solids fluidized beds in terms of solids hold... [more]
Precision Calorimeter Model Development: Generative Design Approach
Tatiana A. Andreeva, Nikolay Yu. Bykov, Tatiana A. Kompan, Valentin I. Kulagin, Alexander Ya. Lukin, Viktoriya V. Vlasova
February 21, 2023 (v1)
Keywords: generative design, precision calorimeter, process model
In a wide range of applications, heating or cooling systems provide not only temperature changes, but also small temperature gradients in a sample or industrial facility. Although a conventional proportional-integral-derivative (PID) controller usually solves the problem, it is not optimal because it does not use information about the main sources of change—the current power of the heater or cooler. The quality of control can be significantly improved by including a model of thermal processes in the control algorithm. Although the temperature distribution in the device can be calculated from a full-fledged 3D model based on partial differential equations, this approach has at least two drawbacks: the presence of many difficult-to-determine parameters and excessive complexity for control tasks. The development of a simplified mathematical model, free from these shortcomings, makes it possible to significantly improve the quality of control. The development of such a model using generati... [more]
Design and Dynamic Characteristics Analysis of Novel Support Adjustment Mechanism of Wheeled Downhole Tractor
Jianguo Zhao, Xin Zhao, Xiaohan Wei, Xu Luo, Xuecheng Dong
February 21, 2023 (v1)
Keywords: double push rod-double spring support adjustment mechanism, obstacle surmounting performance, single push rod support adjustment mechanism, wheeled downhole tractor
Conventional design method of the downhole tractor is based on cementing casing, which is only suitable for the smooth wellbore. For the open hole well, the conventional downhole tractor has poor adaptability and even cannot work normally. In order to improve the obstacle surmounting performance of the wheeled downhole tractor (WDR) and expand the application range of the WDR, a double push rod-double spring support adjustment mechanism (DPRDSSAM) is proposed in this paper. Meanwhile, the proposed DPRDSSAM also needs to increase the traction force and the stability of the WDR in the open hole well. Kinematic simulation numerical models of both conventional support adjustment mechanism and the DPRDSSAM are established. The two models comprehensively considere the influence of different obstacle forms and sizes on the obstacle surmounting performance of the tractor. The influence of different obstacle forms on the obstacle surmounting performance of DPRDSSAM and single push rod support a... [more]
Two-Stage Pretreatment of Jerusalem Artichoke Stalks with Wastewater Recycling and Lignin Recovery for the Biorefinery of Lignocellulosic Biomass
Yudian Chen, Nian Peng, Yushan Gao, Qian Li, Zancheng Wang, Bo Yao, Yonghao Li
February 21, 2023 (v1)
Keywords: alkali pretreatment, biorefinery, diluted acid pretreatment, Jerusalem artichoke stalk (JAS), lignin recovery, wastewater recycling
Jerusalem artichoke (Helianthus tuberosus L.) is emerging as one of the energy plants considered for biofuel production. Alkali and alkali-involved pretreatment methods have been widely used for the bioconversion of cellulosic materials due to their high sugar yield and low inhibitor release. However, the recovery and treatment of wastewater (black liquor) have been poorly studied. Here, we present a novel two-stage pretreatment process design for recycling black liquor. Jerusalem artichoke stalk (JAS) was first treated with 2% (w/v) NaOH, after which lignin was recovered by H2SO4 at pH 2.0 from the black liquor. The recycled solutions were subsequently used to treat the NaOH-pretreated JAS for the second time to dissolve hemicellulose. CO-pretreated JAS, hydrolysates, and acid-insoluble lignin were obtained after the above-mentioned two-stage pretreatment. A reducing sugar yield of 809.98 mg/g Co-pretreated JAS was achieved after 48 h at 5% substrate concentration using a cellulase do... [more]
Special Issue on “Modeling, Optimization and Design Method of Metal Manufacturing Processes”
Guoqing Zhang, Zejia Zhao, Wai Sze YIP
February 21, 2023 (v1)
Metal manufacturing processes are essential techniques to convert raw materials into desired metal products, which contributes significantly to the growth of industry and our society [...]
COD Reduction of Aeration Effluent by Utilizing Optimum Quantities of UV/H2O2/O3 in a Small-Scale Reactor
Mehdi Rafiee, Morteza Sabeti, Farshid Torabi, Aria Rahimbakhsh
February 21, 2023 (v1)
Keywords: advanced oxidation processes (AOPs), aeration contaminants, COD reduction, H2O2, ozone, UV
Extensive research has been carried out to figure out safe means of disposing various industrial effluents. Industrial wastewaters from the aeration industry such as heavy metals and oily substances contain a high degree of contamination. The advanced oxidation process is one of the most effective and rapid methods of removing contaminations, which can lead to a high chemical oxygen demand (COD). The aim of the present study is to reduce the COD of an aeration effluent with the initial COD of 13,004 mg/L. About 20 sets of experimental tests were conducted to identify the contribution of H2O2, O3, and UV to the treatment process. The influence of the quantities of additives and the dose of the UV irradiance were, too, among the subjects of the study. These factors were altered throughout the experiments and their mutual effects were measured. To design the experiments, Minitab software 16 was utilized. The experimental conditions were set at the standard values of 25 °C and 1 bar to min... [more]
Effects of Container Design on the Temperature and Moisture Content Distribution in Pork Patties during Microwave Heating: Experiment and Numerical Simulation
Hwabin Jung, Myeong Gi Lee, Won Byong Yoon
February 21, 2023 (v1)
Keywords: container design, evaporation, microwave heating, numerical simulation, pork patty
Effects of the container design on the heat transfer rate and food quality during microwave heating were explored and validated with numerical simulations and experiments. The uniformity of moisture content and temperature was investigated, and to describe microwave heating patterns, a simulation model was created. Pork patties with different moisture and salt contents were heated in three different containers (center and edge-perforated lid as well as without lid) to achieve 80 °C using a domestic microwave oven. Compared to the center or mid-way positions, the temperatures at the edge of the patties rose quickly. By containing the evaporated vapor from the heated pork patties inside the container, the container with a center-perforated lid decreased the heating rate and non-uniformity in temperature and moisture content. A simplified numerical model for the electromagnetics, heat, and momentum transfer coupling simulation was developed to understand the moisture and temperature distr... [more]
Techno-Economic Assessment of Producer Gas from Heavy Oil and Biomass Co-Gasification Aiming Electricity Generation in Rankine Cycle
York Castillo Santiago, Nelson Calderon Henao, Osvaldo José Venturini, Leandro A. Sphaier, Stefany Vera Duarte, Túlio Tito Godinho de Rezende, Guillermo Valencia Ochoa
February 21, 2023 (v1)
Keywords: Biomass, economic assessment, electricity generation, gasification, heavy oil, Rankine cycle
Heavy oil and biomass co-gasification has been analyzed through a model developed in Aspen Plus™ v 11.0 software. The model was used to assess main gasification parameters, such as cold gas efficiency, yield, low heating value (LHV), and producer gas composition, using air and oxygen as gasification agents. Subsequently, producer gas energy use in the Rankine cycle was performed using a model developed in GateCycle™ v11.1.2.4.850 software. Likewise, the economic indicators of the integrated Rankine cycle-gasification system were calculated. The economic evaluation was developed through Monte Carlo simulation using Crystalball™. The results showed a LHV producer gas decreasing trend as the equivalence ratio (ER) increased, oscillating between 6.37 and 3.63 MJ/Nm3 for ER values greater than 0.30 in the air co-gasification case, while the scenario that used oxygen presented better LHV results, ranging from 9.40 to 11.79 MJ/Nm3. For air co-gasification, the Rankine cycle efficiency range w... [more]
Process Design and Assessment of the Performance of Three Macrophytes in a Biorefinery Polishing Partly Treated Sewage in Novel SHEFROL Bioreactors
Tabassum -Abbasi, Pratiksha Patnaik, S. A. Abbasi
February 21, 2023 (v1)
Keywords: biorefinery, macrophytes, Marsilea quadrifolia, Pistia stratiotes, Salvinia molesta, sewage, treatment
The development of a biorefinery is described based on rapid polishing of partially treated sewage with three different species of macrophytes in the recently developed SHEFROL® bioreactor which functions almost entirely on solar and gravitational energy, requiring no chemicals. It was seen that at a hydraulic retention time (HRT) of just 2 h, suspended solids, COD, BOD, total Kjeldahl nitrogen, soluble phosphorus, zinc, copper, nickel, and manganese are reduced to the extents of 92−95%, 76−78%, 77−81%, 56−61%, 60−66%, 43−46%, 45−48%, 30−35%, and 31−33%, respectively. The treated water meets the water quality standards set for the discharge into surface water bodies. M. quadrifolia was seen to be most effective of the three macrophytes, followed by P. stratiotes and S. molesta, as a sewage cleansing agent, but the difference in the performance of the macrophytes was only marginal, and not highly significant statistically (p ≥ 0.5). The paper also shows that it is possible to extract en... [more]
The Manufacture of Curved Crease Surfaces Starting from Kinematic Analysis of Planar Mechanisms
Alina Duta, Iulian Popescu, Simona-Mariana Cretu, Andrei Corzanu, Valentin Corzanu, Dragos-Laurentiu Popa
February 21, 2023 (v1)
Keywords: curved crease surfaces, FEM deformed shape analysis, marking the folding curve, mechanisms, technological processes
Achieving curved crease surfaces is a current challenge for designers, the field still underexplored. The curve on which the bending is performed can present extremely complicated shapes that must be accurately generated through various technological processes. For this aim, a planar mechanism consisting of an ellipsograph, a conchoidograph and an RRR dyad—whose inner joint generates the targeted connecting rod curve—was proposed in this paper. Parametrizing the lengths of the elements of the RRR dyad, the correlation coefficient of the rotations of the leading elements and the directions of these movements result in different connecting rod curves, which can be used to obtain the folded surfaces; the optimization, according to various criteria, will be explored for the automatic generation of some design solutions. With the help of the Altair program, for some given geometrical data of the mechanism, both the drawing of the curve on plates of different initial shapes and the simulatio... [more]
Design, Manufacture and Assembly of 3D Integrated Optical Transceiver Module Based on an Active Photonic Interposer
Qi Zheng, Haiyun Xue, Fengman Liu, Liqiang Cao, Qidong Wang, Huimin He, Fengwei Dai, Peng Sun
February 21, 2023 (v1)
Keywords: 3D integration, active photonic interposer, optical interconnection, TSV
The new generation of data centers is further evolving towards the direction of high speed and intelligence, which puts forward a great demand for the iteration of optical interconnection technology. Three-dimensional integration based on active photonic interposers can achieve the advantages of high integration, high bandwidth and low power consumption, which has become the main direction for next generation optical module technology. The fabrication and assembly of 3D optical modules based on active interposer-integrated edge couplers and TSV are realized in this paper. Different active interposer processes with integrated edge couplers and RDL-TSV-RDL structures are discussed, manufactured, analyzed and evaluated. The problem of the co-fabrication of the TSV and edge coupler was solved, and perfect electrical and optical characteristics were also achieved. Finally, the fabrication of the substrate and the assembly of the 3D optical module were completed. This paper lays a solid foun... [more]
Activated Carbon Aerogel as an Electrode with High Specific Capacitance for Capacitive Deionization
Wei Wang, Kerui Li, Ge Song, Minghua Zhou, Peng Tan
February 21, 2023 (v1)
Keywords: activation, capacitive deionization, carbon aerogel, desalination, electro-sorption
In this study, carbon aerogels (CAs) were synthesized by the sol-gel method, using environmentally friendly glucose as a precursor, and then they were further activated with potassium hydroxide (KOH) to obtain activated carbon aerogels (ACAs). After the activation, the electrochemical performance of the ACAs was significantly improved, and the specific capacitance increased from 19.70 F·g−1 to 111.89 F·g−1. Moreover, the ACAs showed a stronger hydrophilicity with the contact angle of 118.54° compared with CAs (69.31°). When used as an electrode for capacitive deionization (CDI), the ACAs had not only a better diffuse electric double layer behavior, but also a lower charge transfer resistance and intrinsic resistance. Thus, the ACA electrode had a faster CDI desalination rate and a higher desalination capacity. The unit adsorption capacity is three times larger than that of the CA electrode. In the desalination experiment of 100 mg·L−1 sodium chloride (NaCl) solution using a CDI device... [more]
A New Theobromine-Based EGFRWT and EGFRT790M Inhibitor and Apoptosis Inducer: Design, Semi-Synthesis, Docking, DFT, MD Simulations, and In Vitro Studies
Eslam B. Elkaeed, Reda G. Yousef, Hazem Elkady, Aisha A. Alsfouk, Dalal Z. Husein, Ibrahim M. Ibrahim, Mohamed Alswah, Heba S. A. Elzahabi, Ahmed M. Metwaly, Ibrahim H. Eissa
February 21, 2023 (v1)
Keywords: anti-proliferative, docking, EGFR inhibitors, MD simulation, theobromine
The essential pharmacophoric structural properties were applied to design a new derivative of theobromine as an antiangiogenic EGFR inhibitor. The designed candidate is a (para-nitrophenyl)acetamide derivative of the natural alkaloid, theobromine (T-2-PNPA). The potentialities of T-2-PNPA to inhibit the EGFR protein were studied computationally in an extensive way. Firstly, the molecular docking against EGFRWT and EGFRT790M demonstrated T-2-PNPA’s capabilities of binding with the targeted receptors. Then, the MD experiments (for 100 ns) illustrated through six different studies the changes that occurred in the energy as well as in the structure of EGFR−T-2-PNPA complex. Additionally, an MM-GBSA analysis determined the exact energy of binding and the essential residues. Furthermore, DFT calculations investigated the stability, reactivity, and electrostatic potential of T-2-PNPA. Finally, ADMET and toxicity studies confirmed both the safety as well as the general likeness of T-2-PNPA. Co... [more]
Optimization Design of an Alfalfa Seed Airflow Collection and Drainage System Based on Numerical Simulation
Wenpeng Ma, Shining Zhang, Chengqian Jin, Xiang Yin, Guohai Zhang, Lu Zhu
February 21, 2023 (v1)
Keywords: ADAMS, EDEM, Fluent, pneumatic, seeding device
In order to improve the working performance of an Alfalfa air conveyor, a type of horizontal screw conveyor with a seed stirring function was designed. The working process of the horizontal screw conveyor was co-simulated by EDEM software and ADAMS software. The effects of a seed stirring mechanism on population movement characteristics, population stress, the seed mass flow rate and the variation coefficient of each index were obtained. The results showed that the stirring mechanism can effectively improve the mobility of the population, reduce the local dead zone of the population, and increase the material filling coefficient between the spiral blades. Under the same working conditions, the horizontal screw conveyor with a stirring mechanism has a higher conveying efficiency and better conveying uniformity. In order to optimize the structure parameters of the Venturi injector diffuser and improve seeding efficiency and uniformity, EDEM software and Fluent software were used to co-si... [more]
Nanofiltration Treatment of Industrial Wastewater Doped with Organic Dye: A Study of Hydrodynamics and Specific Energy
Rokia Youcef, Nassila Sabba, Amel Benhadji, Hayet Djelal, Nadim Fakhfakh, Mourad Taleb Ahmed
February 21, 2023 (v1)
Keywords: Brilliant Blue FCF, dilution ratio, nanofiltration membrane processes, specific energy consumption, wastewater treatment
This study was conducted to eliminate the ions and molecules present in the industrial wastewater received by the municipal wastewater treatment plant (WWTP) of Reghaia, which is located east of Algiers, Algeria. The process was developed for two different study matrices: (a) the wastewater from WWTP and (b) wastewater mixed with Brilliant Blue FCF (BBF) dye to show the influence of the strength of the ionic solution on the treatment. The most effective operating parameters were determined by assessing the residence time distribution applied to the reactor flow regime. Energy analysis showed the viability of a nanofiltration membrane, improving the permeate flux. The nanofiltration process consumed 1.94 kWh/m3 to reduce the chemical oxygen demand (COD) of 63.58% and 48.35% for raw wastewater and doped BBF wastewater, respectively. The results demonstrated that nanofiltration performance with a volume dilution ratio of 1/2 showed the reduction of the COD of 87.2% after 15 min for undope... [more]
Biochemical Study of Bacillus stearothermophilus Immobilized Lipase for Oily Wastewater Treatment
Abir Ben Bacha, Mona Alonazi, Humidah Alanazi, Mona G. Alharbi, Raida Jallouli, Aida Karray
February 21, 2023 (v1)
Keywords: CaCO3, immobilized lipase, wastewater treatment
Traditional wastewater treatments involve expensive mechanical and physiochemical methods, so researchers have been developing cost-effective, sustainable technologies that use enzymes to produce higher quality effluents and recover more energy and nutrients from wastewater. A thermostable, alkaline, and solvent-tolerant lipase was partially purified from thermophilic Bacillus stearothermophilus. The lipase displayed maximum activity at 50 °C and pH 11.0 and catalyzed both short- and long-chain triacylglycerols at similar rates. B. stearothermophilus lipase also exhibited high stability when incubated at 40 °C for 1 h with anionic and non-ionic surfactants. Studies show that thermostable enzymes can be improved through immobilization and modification of other reaction conditions. Therefore, B. stearothermophilus lipase was immobilized through adsorption on CaCO3, Celite 545, and silica gel with the CaCO3 support producing the best adsorption rate (89.33%). The optimal initial lipase ac... [more]
Effect of Poultry Manure-Derived Compost on the Growth of eucalypts spp. Hybrid Clones
Pedro F. Rizzo, María C. Salinas, Virginia Della Torre, Juan P. Diez, Leonardo F. Sallesses, Nicolás I. Riera, Pablo S. Pathauer, Dimitrios Komilis, Antoni Sánchez
February 20, 2023 (v1)
Keywords: forest valorization, substrates, vegetative propagation
Interspecific hybrids of E. grandis × E. camaldulensis were generated to widen the plantation area. The aim of this study was to assess root capability and development for six different clones of eucalyptus grown in substrates made with three different composts derived from poultry manure. A factorial design was used to assess the effect of different composts on six growth variables. The analysis detected a greater effect from the genotype than the substrate. E. grandis × E. camaldulensis hybrid vegetative propagation was successful in alternative substrates formulated from composted poultry manure. GC8 was the genotype that showed the greatest differences for four the different variables among the substrates, being both the most sensitive and the one with the highest values for all parameters measured. The hybrids’ vegetative propagation was determined in alternative substrates formulated from poultry manure compost. The physicochemical characteristics of substrates composed of pine b... [more]
Special Issue on “Process Design and Sustainable Development”
Peter Glavič
February 17, 2023 (v1)
Thirty years ago, at the United Nations’ (UN) Earth Summit in Rio de Janeiro, Brazil, 178 countries adopted Agenda 21, a global partnership for sustainable development to improve human lives and protect the environment [...]
Incidence of Electric Field and Sulfuric Acid Concentration in Electrokinetic Remediation of Cobalt, Copper, and Nickel in Fresh Copper Mine Tailings
Rodrigo Ortiz-Soto, Daniela Leal, Claudia Gutierrez, Alvaro Aracena, Marcelo León, Andrea Lazo, Pamela Lazo, Lisbeth Ottosen, Henrik Hansen
February 17, 2023 (v1)
Keywords: electrokinetic remediation, heavy metal removal, mine tailing
In the present study, the assessment of heavy metal contaminant migration from fresh mine tailings was conducted using the electrokinetic remediation technique (EKR). In this sense, a pilot EKR cell was designed to evaluate the recovery potential of copper, nickel, and cobalt species. In particular, the focus was on the impacts of electric field intensity and pH in initial mixture and testing their interaction in copper, nickel, and cobalt migration. Experiments were made using a 22 factorial experimental design with a central point, using DC electric fields from 1.0 to 2.0 V cm−1 and H2SO4 pretreatment solutions from 1.0 to 2.0 mol L−1, along with an ANOVA test with error reduction. The metal removal rates were approximately 7% for cobalt, neglectable for copper, and 6% for nickel. In the best cases, the highest concentrations by migration at the cathodic zone were 11%, 31%, and 30%, respectively. According to ANOVA tests, factor interaction was proven for each metal in the half cell... [more]
Design and Testing of the Peanut Pod Cleaning Device
Chenhui Zhu, Bo Chen, Jiongqi Li, Yuan Liu, Liquan Yang, Wanzhang Wang, Hongmei Zhang
February 17, 2023 (v1)
Keywords: cleaning device, impurities, losses, peanut pod
Due to the design of peanut harvesters and cleaners, peanut pods are often mixed with soil, gravel, peanut straw, and other impurities. To solve this problem, this study focused on designing a peanut pod cleaning device by integrating a negative pressure centrifugal fan, a hydrometric cleaning sieve, and a reversible long-mesh cleaning sieve. The relative motion of the peanut pod on the sieve was discussed, its stress analyzed, the design parameters of the sieve and fan determined, and the operation of the device was monitored by using sensors, which accurately recorded and adjusted the working parameters. Finally, the key parameters were tested, and the results showed that the design requirements were met at a vibration frequency of 5.5 Hz, a hydrometric cleaning sieve inclination of 15°, a reciprocating long mesh cleaning sieve inclination of 5°, and a fan speed of 1500 rev/min; the mean loss is 2.26%, and the mean impurity is 3.18%. The findings can be used to provide technical supp... [more]
Special Issue “Modelling and Optimal Design of Complex Biological Systems”
Jérôme Harmand, Alain Rapaport, Neli Dimitrova, Ivan Simeonov
February 17, 2023 (v1)
At present, complex biological processes are used in many industrial areas [...]
An Integrated Method of Bayesian Optimization and D-Optimal Design for Chemical Experiment Optimization
Xinye Huang, Shuyuan Zhang, Haoran Li, Tong Qiu
February 17, 2023 (v1)
Keywords: Bayesian optimization, chemical experiment optimization, D-optimal design, experiment space exploration
The smart chemical laboratory has recently emerged as a promising trend for future chemical research, where experiment optimization is of vital importance. The traditional Bayesian optimization (BO) algorithm focuses on exploring the dependent variable space while overlooking the independent variable space. Consequently, the BO algorithm suffers from becoming stuck at local optima, which severely deteriorates the optimization performance, especially with bad-quality initial points. Herein, we propose a novel stochastic framework of Bayesian optimization with D-optimal design (BODO) by integrating BO with D-optimal design. BODO can balance the exploitation in the dependent variable space and the exploration in the independent variable space. We highlight the excellent performance of BODO even with poor initial points on the benchmark alpine2 function. Meanwhile, BODO demonstrates a better average objective function value than BO on the benchmark Summit SnAr chemical process, showing its... [more]
Analysis of the Flow Field at the Tip of an Axial Flow Compressor during Rotating Stall Process Based on the POD Method
Yueheng Wang, Moru Song, Jiali Xin, Bo Yang
February 17, 2023 (v1)
Keywords: axial flow compressor, proper orthogonal decomposition method, rotating stall, stall cell, stall mode
Rotating stalls are one of the most dangerous phenomena to be avoided in the designing and operating of axial flow compressors. An understanding of the evolution of the flow characteristics around the rotor tip region is important to study the process of stall development. In this paper, some critical characteristics of the stall-related structures, which could not be observed by the traditional analysis methods, are understood by using the proper orthogonal decomposition (POD) method. The detailed unsteady flow fields in a typical transonic axial flow compressor during the stall process are obtained by the validated numerical simulation. Thereafter, the proper orthogonal decomposition method, as a method for model reduction and decomposition, is adopted to extract the flow characteristics from the numerical results of the stall process. It is found that the flow characteristics during the stall process can be well decomposed by the POD method. The pre-stall POD results show that the i... [more]
Design and Development of a High-Speed Precision Internal Grinding Machine and the Associated Grinding Processes
Zhou Chang, Qian Jia, Lai Hu
February 17, 2023 (v1)
Keywords: high-speed grinding, hydrostatic bearings, internal grinding machine, machining dynamics, precision machine design
In order to meet the P2-grade bearing grinding requirements, we designed a high-speed internal grinding machine to be used for grinding bearing raceways and inner circles. The machine has a T-type layout and a four-axis numerical control linkage. It is supported by hydrostatic pressure and driven directly by a torque motor. In addition, it is equipped with a high-speed hydrostatic grinding wheel spindle. Our design includes a hydrostatic workpiece shaft and hydrostatic turntable, and the process has a good engineering application value. Finally, the designed precision grinding machine was used to grind a P2-grade bearing raceway.
A Simultaneous Design and Optimization Framework for the Reaction and Distillation Sections of Methanol to Olefins Process
Ning Li, Liwen Zhao, Dan Li, Huifeng Sun, Di Zhang, Guilian Liu
February 17, 2023 (v1)
Keywords: Distillation, methanol to olefins, model, Optimization, Reaction
The reaction and separation sections are the keys to the methanol-to-olefins (MTO) chemical processes, and they should be optimized to reduce the cost of production. This work develops a framework for the simultaneous design and optimization of the reaction and distillation sections. An optimization model with shortcut and rigorous methods combined is established for distillation columns to improve accuracy and efficiency. With the auxiliary devices and the selection of utilities considered, the reaction and distillation sections are integrated to maximize profits. The genetic algorithm targets the optimal parameters, including the catalyst’s coke content and reaction temperature, each column’s operating pressure, and the allocation of utilities and auxiliary devices. For the studied MTO process, the optimal reaction temperature and catalyst’s coke content were identified to be 496 °C and 7.8%, respectively. The maximum profit is 15.3% greater than that identified with only the separat... [more]
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