带式烘干机中水产饲料料层厚度对其表面风速场分布的影响
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摘要
水产饲料在生产过程中经过膨化处理之后的含水率过高,需要进行烘干处理。在饲料烘干过程中,饲料层的厚度是一个重要的参数。料层厚度一方面代表烘干机单位时间内的产能(厚度越大,产能越高),影响烘干机的工作能耗;另一方面,料层厚度影响烘干机中的气流分布,从而对料层表面的风速分布的均匀性产生影响。该文研究料层厚度的变化对料层表面风速分布的影响。首先运用计算流体力学(computationalfluiddynamics,CFD)对3种料层厚度下(20、30、40mm)的烘干机的内部气流分布进行模拟仿真。然后基于实际生产,设计并制造烘干机对3种料层厚度下的烘干机内部气流进行试验验证,并在料层表面9个点利用风速传感器测出风速值,将风速模拟值与试验值进行对比分析。研究结果表明,风速模拟值的分布趋势与风速试验值的分布趋势均一致,且料层厚度的变化影响着烘干机内部的气流分布。当料层厚度为20 mm时,料层表面风速场较不均匀,当料层厚度为40mm时,料层表面的风速分布均匀性较好。该文所做研究为带式烘干机在实际生产中饲料层厚度参数的选择提供了理论指导,降低饲料水分的同时,保持良好的水分均匀性。
Moisture content of the aquatic feed after extruder is frequently high in the production process, and drying is necessary to reduce moisture content of the aquatic feed. The thickness of feed layer is an important parameter during the aquatic feed drying. On one hand, the thickness of feed layer represents the capacity of the belt dryer per unit time(the thicker the feed layer, the higher the productivity), which affects the working energy consumption of the belt dryer. On the other hand, the thickness of feed layer also affects airflow distribution inside the belt dryer, thus affecting the distribution uniformity of airflow velocity on the surface of feed layer. The airflow velocity on feed layer surface directly influences the moisture content of aquatic feed after drying, and the uniformity of airflow velocity on feed layer surface directly influences the uniformity of moisture content of aquatic feed. In this paper, effects of aquatic feed layer thickness on airflow distribution in belt dryer and airflow velocity distribution on feed layer surface was studied. Firstly, three different kinds of internal airflow distribution inside the belt dryer were simulated using computational fluid dynamics(CFD), corresponding to three kinds of feed layer thicknesses(20, 30, 40 mm). Secondly, a belt dryer was designed and manufactured as the experimental platform based on the actual production needs in the National Feed Processing Equipment Engineering and Research Center. Thirdly, three series of experiments were conducted using the experimental platform corresponding to three kinds of feed layer thickness(20, 30, 40 mm), and repeated three times in every series of the experiment. Before the experiment, nine airflow velocity sensors were placed at nine points on the surface of the feed layer in order to measure the airflow velocity values of that nine points during the experiment. After the simulations and experiments, not only the simulation results of the airflow velocity distribution on the feed layer surface and experimental results of that were compared, but also the difference of airflow velocity distribution on feed surface between different feed layer thickness were compared. Results showed that the trend of airflow velocity distribution in simulation results and experimental results were consistent, which proved the simulations and experiments in this paper were reliable. Besides, the error between simulations and experimental results were also explained in this paper. According to the simulation and experimental results, aquatic feed layer thickness affected the airflow distribution inside the belt dryer and the airflow velocity distribution on the feed layer surface. When the feed layer thickness was 20 mm, the airflow velocity uniformity of airflow velocity distribution was not good. But when the feed layer thickness was 40 mm, airflow velocity uniformity of airflow velocity distribution was respectively good. The research in this paper provides theoretical guidance for the selection of feed layer thickness parameters in actual production of belt dryers, which can reduce the moisture content of aquatic feed and make the moisture content uniformity of aquatic feed good after drying.
Moisture content of the aquatic feed after extruder is frequently high in the production process, and drying is necessary to reduce moisture content of the aquatic feed. The thickness of feed layer is an important parameter during the aquatic feed drying. On one hand, the thickness of feed layer represents the capacity of the belt dryer per unit time(the thicker the feed layer, the higher the productivity), which affects the working energy consumption of the belt dryer. On the other hand, the thickness of feed layer also affects airflow distribution inside the belt dryer, thus affecting the distribution uniformity of airflow velocity on the surface of feed layer. The airflow velocity on feed layer surface directly influences the moisture content of aquatic feed after drying, and the uniformity of airflow velocity on feed layer surface directly influences the uniformity of moisture content of aquatic feed. In this paper, effects of aquatic feed layer thickness on airflow distribution in belt dryer and airflow velocity distribution on feed layer surface was studied. Firstly, three different kinds of internal airflow distribution inside the belt dryer were simulated using computational fluid dynamics(CFD), corresponding to three kinds of feed layer thicknesses(20, 30, 40 mm). Secondly, a belt dryer was designed and manufactured as the experimental platform based on the actual production needs in the National Feed Processing Equipment Engineering and Research Center. Thirdly, three series of experiments were conducted using the experimental platform corresponding to three kinds of feed layer thickness(20, 30, 40 mm), and repeated three times in every series of the experiment. Before the experiment, nine airflow velocity sensors were placed at nine points on the surface of the feed layer in order to measure the airflow velocity values of that nine points during the experiment. After the simulations and experiments, not only the simulation results of the airflow velocity distribution on the feed layer surface and experimental results of that were compared, but also the difference of airflow velocity distribution on feed surface between different feed layer thickness were compared. Results showed that the trend of airflow velocity distribution in simulation results and experimental results were consistent, which proved the simulations and experiments in this paper were reliable. Besides, the error between simulations and experimental results were also explained in this paper. According to the simulation and experimental results, aquatic feed layer thickness affected the airflow distribution inside the belt dryer and the airflow velocity distribution on the feed layer surface. When the feed layer thickness was 20 mm, the airflow velocity uniformity of airflow velocity distribution was not good. But when the feed layer thickness was 40 mm, airflow velocity uniformity of airflow velocity distribution was respectively good. The research in this paper provides theoretical guidance for the selection of feed layer thickness parameters in actual production of belt dryers, which can reduce the moisture content of aquatic feed and make the moisture content uniformity of aquatic feed good after drying.
引文
[1]衣晓岩.国内饲料行业发展现状分析[J].山东畜牧兽医,2017,38(8):61-62.
[2]马广鹏.中国饲料行业发展现状及趋势分析[J].饲料工业,2013,34(4):45-47.
[3]2018年饲料行业发展现状分析[J].北方牧业,2018(12):8.
[4]闫奎友.中国饲料工业发展的40年[J].中国饲料,2018(23):9-11.YanKuiyou.ThefortyyearsdevelopmentofChinafeed industry[J]. Chinese Feed, 2018(23):9-11.(in Chinese with English abstract)
[5]ZhuSG.OnMarketinginnovationofaquaticfeed[J].Fishery Information&Strategy, 2012, 27(1):42-46.
[6]Zhang Pengfei, Wu Pengpeng, Zhang Qi, et al. Optimization offeedthicknessondistributionofairflowvelocityinbelt dryerusingcomputationalfluiddynamics[J].Energy Procedia, 2017, 142:1595-1602.
[7]Jaberi-DourakiM,MoghadasSM.Optimalityofa time-dependenttreatmentprofileduringanepidemic[J].Journal of Biological Dynamics, 2013, 7(1):133-147.
[8]Jaberi-DourakiM,MoghadasSM.Optimalcontrolof vaccinationdynamicsduringaninfluenzaepidemic[J].MathematicalBiosciencesandEngineering(Online),2014,11(5):1045-1063.
[9]Jaberi-DourakiM,HeffernanJM,WuJ,etal.Optimal treatmentprofileduringaninfluenzaepidemic[J].DifferentialEquations&DynamicalSystems,2013,21(3):237-252.
[10]ZhangQ,ShiZ,ZhangP,etal.Predictivetemperature modelingandexperimentalinvestigationofultrasonic vibration-assistedpelletingofwheatstraw[J].Applied Energy, 2017, 205:511-528.
[11]李启武.制粒和膨化加工技术在水产饲料生产上的应用分析[J].饲料工业,2001(7):6-8.
[12]牛化欣,过世东,谢中国.膨化和制粒加工对饲料氨基酸稳定性的影响[J].中国粮油学报,2013,28(12):86-90.NiuHuaxin,GuoShidong,XieZhongguo.Effectsof extrusion processing and pelleting on stability of feed amino acids[J]. Journal of the Chinese Cereals and Oils Association,2013, 28(12):86-90.(in Chinese with English abstract)
[13]张名伟,梅凤艳,曹志勇,等.饲料配方与制粒工艺对水产饲料质量的影响[J].饲料工业,2016,37(16):53-57.Zhang Mingwei, Mei Fengyan, Cao Zhiyong, et al. Effect of feedformulationandgranulatingprocessonaquaticfeed quality[J]. Feed Industry, 2016, 37(16):53-57.(in Chinese with English abstract)
[14]YueX,ZhaoJ,ShiE,etal.Analysisofairvelocity distribution in a multilayer conveyor dryer by computational fluiddynamics[J].Asia-PacificJournalofChemical Engineering, 2007, 2(2):108-117.
[15]Tomás N, Sun D W. Computational fluid dynamics(CFD)-an effective and efficient design and analysis tool for the food industry:A review[J]. Trends in Food Science&Technology,2006, 17(11):600-620.
[16]BHner M, Barfuss I, Heindl A, et al. Improving the airflow distribution in a multi-belt conveyor dryer for spice plants by modificationsbasedoncomputationalfluiddynamics[J].Biosystems Engineering, 2013, 115(3):339-345.
[17]DefraeyeT.Advancedcomputationalmodellingfordrying processes:A review[J]. Applied Energy, 2014, 131(9):323-344.
[18]Norton T, Sun D W. Computational fluid dynamics(CFD)-an effective and efficient design and analysis tool for the food industry:A review[J]. Trends in Food Science&Technology,2006, 17(11):600-620.
[19]Misha S, Mat S, Ruslan M H, et al. The CFD simulation of traydryerdesignforkenafcoredrying[J].Applied Mechanics and Materials, 2013, 393:717-722.
[20]DarabiH,ZomorodianA,AkbariMH,etal.Designa cabinetdryerwithtwogeometricconfigurationsusing CFD[J]. Journal of Food Science&Technology, 2015, 52(1):359-366.
[21]师建芳,吴中华,刘清,等.不同进风方案下隧道烘干窑热风流场CFD模拟和优化[J].农业工程学报,2014,30(14):315-321.Shi Jianfang, Wu Zhonghua, Liu Qing, et al. CFD simulation andoptimizationofairflowfieldinindustrialtunneldryer withdifferentblowingdesigns[J].Transactionsofthe ChineseSocietyofAgricultural Engineering(transactionsof theCASE),2014,30(14):315-321.(inChinesewith English abstract)
[22]张伟,任广跃,段续,等. CFD在食品干燥过程及其干燥设备设计中的应用[J].干燥技术与设备,2013,11(6):31-35.Zhang Wei, RenGuangyue, Duan Xu, et al. Application of cfdinfooddryingprocessanddryerdesign[J].Drying Technology&Equipment, 2013, 11(6):31-35.(in Chinese with English abstract)
[23]Amanlou Y, Zomorodian A. Applying CFD for designing a new fruit cabinet dryer[J]. Journal of Food Engineering, 2010,101(1):8-15.
[24]李奇.基于CFD烘干平板传热模拟分析[J].中国农机化学报,2013,34(6):129-133.Li Qi. Simulation to heat transfer of flat plate drying based on CFD[J].JournalofChineseAgriculturalMechanization,2013, 34(6):129-133.(in Chinese with English abstract)
[25]MartinB,IsabelB,AlbertH,etal.Improvingtheairflow distribution in a multi-beltconveyor dryer for spice plants by modificationsbasedoncomputationalfluiddynamics[J].Biosystems Engineering, 2013(115):339-345.
[26]ZhangHang,DengShengxiang.Numericalsimulationof moisture-heatcouplinginbeltdryerandstructure optimization[J].AppliedThermalEngineering,2017,127:292-301.
[27]Majumdar R K, Singh R K R. Effect of extrusion conditions on the physicochemical properties and sensory characteristics of fish-based expanded snacks[J]. Journal of Food Processing&Preservation, 2014, 38(3):864-879.
[28]GatY,AnanthanarayanL.Effectofextrusionprocess parameters and pregelatinized rice flour on physicochemical propertiesofready-to-eatexpandedsnacks[J].Journalof Food Science and Technology, 2015, 52(5):2634-2645.
[29]Tekasakul P, Dejchanchaiwong R, TirawanichakulY, etal.Three-dimensionnumericalmodelingofheatandmoisture transferinnaturalrubbersheetdryingprocess[J].Drying Technology, 2015, 33(9):1124-1137.
[30]Varma M N, Kannan A. CFD studies on natural convective heatingofcannedfoodinconicalandcylindrical containers[J].JournalofFoodEngineering,2006,77(4):1024-1036.
[31]Le H, Moin P. Direct numerical simulation of turbulent flow over a backward-facing step[J]. Journal of Fluid Mechanics,2011, 330(1):349-374.
[32]ZhangPengfei,MuYanbin,ShiZhenzhen,etal.Computational fluid dynamic analysis of airflow in belt dryer:Effectsofconveyorpositiononairflowdistribution[J].Energy Procedia, 2017, 142:1367-1374.
[2]马广鹏.中国饲料行业发展现状及趋势分析[J].饲料工业,2013,34(4):45-47.
[3]2018年饲料行业发展现状分析[J].北方牧业,2018(12):8.
[4]闫奎友.中国饲料工业发展的40年[J].中国饲料,2018(23):9-11.YanKuiyou.ThefortyyearsdevelopmentofChinafeed industry[J]. Chinese Feed, 2018(23):9-11.(in Chinese with English abstract)
[5]ZhuSG.OnMarketinginnovationofaquaticfeed[J].Fishery Information&Strategy, 2012, 27(1):42-46.
[6]Zhang Pengfei, Wu Pengpeng, Zhang Qi, et al. Optimization offeedthicknessondistributionofairflowvelocityinbelt dryerusingcomputationalfluiddynamics[J].Energy Procedia, 2017, 142:1595-1602.
[7]Jaberi-DourakiM,MoghadasSM.Optimalityofa time-dependenttreatmentprofileduringanepidemic[J].Journal of Biological Dynamics, 2013, 7(1):133-147.
[8]Jaberi-DourakiM,MoghadasSM.Optimalcontrolof vaccinationdynamicsduringaninfluenzaepidemic[J].MathematicalBiosciencesandEngineering(Online),2014,11(5):1045-1063.
[9]Jaberi-DourakiM,HeffernanJM,WuJ,etal.Optimal treatmentprofileduringaninfluenzaepidemic[J].DifferentialEquations&DynamicalSystems,2013,21(3):237-252.
[10]ZhangQ,ShiZ,ZhangP,etal.Predictivetemperature modelingandexperimentalinvestigationofultrasonic vibration-assistedpelletingofwheatstraw[J].Applied Energy, 2017, 205:511-528.
[11]李启武.制粒和膨化加工技术在水产饲料生产上的应用分析[J].饲料工业,2001(7):6-8.
[12]牛化欣,过世东,谢中国.膨化和制粒加工对饲料氨基酸稳定性的影响[J].中国粮油学报,2013,28(12):86-90.NiuHuaxin,GuoShidong,XieZhongguo.Effectsof extrusion processing and pelleting on stability of feed amino acids[J]. Journal of the Chinese Cereals and Oils Association,2013, 28(12):86-90.(in Chinese with English abstract)
[13]张名伟,梅凤艳,曹志勇,等.饲料配方与制粒工艺对水产饲料质量的影响[J].饲料工业,2016,37(16):53-57.Zhang Mingwei, Mei Fengyan, Cao Zhiyong, et al. Effect of feedformulationandgranulatingprocessonaquaticfeed quality[J]. Feed Industry, 2016, 37(16):53-57.(in Chinese with English abstract)
[14]YueX,ZhaoJ,ShiE,etal.Analysisofairvelocity distribution in a multilayer conveyor dryer by computational fluiddynamics[J].Asia-PacificJournalofChemical Engineering, 2007, 2(2):108-117.
[15]Tomás N, Sun D W. Computational fluid dynamics(CFD)-an effective and efficient design and analysis tool for the food industry:A review[J]. Trends in Food Science&Technology,2006, 17(11):600-620.
[16]BHner M, Barfuss I, Heindl A, et al. Improving the airflow distribution in a multi-belt conveyor dryer for spice plants by modificationsbasedoncomputationalfluiddynamics[J].Biosystems Engineering, 2013, 115(3):339-345.
[17]DefraeyeT.Advancedcomputationalmodellingfordrying processes:A review[J]. Applied Energy, 2014, 131(9):323-344.
[18]Norton T, Sun D W. Computational fluid dynamics(CFD)-an effective and efficient design and analysis tool for the food industry:A review[J]. Trends in Food Science&Technology,2006, 17(11):600-620.
[19]Misha S, Mat S, Ruslan M H, et al. The CFD simulation of traydryerdesignforkenafcoredrying[J].Applied Mechanics and Materials, 2013, 393:717-722.
[20]DarabiH,ZomorodianA,AkbariMH,etal.Designa cabinetdryerwithtwogeometricconfigurationsusing CFD[J]. Journal of Food Science&Technology, 2015, 52(1):359-366.
[21]师建芳,吴中华,刘清,等.不同进风方案下隧道烘干窑热风流场CFD模拟和优化[J].农业工程学报,2014,30(14):315-321.Shi Jianfang, Wu Zhonghua, Liu Qing, et al. CFD simulation andoptimizationofairflowfieldinindustrialtunneldryer withdifferentblowingdesigns[J].Transactionsofthe ChineseSocietyofAgricultural Engineering(transactionsof theCASE),2014,30(14):315-321.(inChinesewith English abstract)
[22]张伟,任广跃,段续,等. CFD在食品干燥过程及其干燥设备设计中的应用[J].干燥技术与设备,2013,11(6):31-35.Zhang Wei, RenGuangyue, Duan Xu, et al. Application of cfdinfooddryingprocessanddryerdesign[J].Drying Technology&Equipment, 2013, 11(6):31-35.(in Chinese with English abstract)
[23]Amanlou Y, Zomorodian A. Applying CFD for designing a new fruit cabinet dryer[J]. Journal of Food Engineering, 2010,101(1):8-15.
[24]李奇.基于CFD烘干平板传热模拟分析[J].中国农机化学报,2013,34(6):129-133.Li Qi. Simulation to heat transfer of flat plate drying based on CFD[J].JournalofChineseAgriculturalMechanization,2013, 34(6):129-133.(in Chinese with English abstract)
[25]MartinB,IsabelB,AlbertH,etal.Improvingtheairflow distribution in a multi-beltconveyor dryer for spice plants by modificationsbasedoncomputationalfluiddynamics[J].Biosystems Engineering, 2013(115):339-345.
[26]ZhangHang,DengShengxiang.Numericalsimulationof moisture-heatcouplinginbeltdryerandstructure optimization[J].AppliedThermalEngineering,2017,127:292-301.
[27]Majumdar R K, Singh R K R. Effect of extrusion conditions on the physicochemical properties and sensory characteristics of fish-based expanded snacks[J]. Journal of Food Processing&Preservation, 2014, 38(3):864-879.
[28]GatY,AnanthanarayanL.Effectofextrusionprocess parameters and pregelatinized rice flour on physicochemical propertiesofready-to-eatexpandedsnacks[J].Journalof Food Science and Technology, 2015, 52(5):2634-2645.
[29]Tekasakul P, Dejchanchaiwong R, TirawanichakulY, etal.Three-dimensionnumericalmodelingofheatandmoisture transferinnaturalrubbersheetdryingprocess[J].Drying Technology, 2015, 33(9):1124-1137.
[30]Varma M N, Kannan A. CFD studies on natural convective heatingofcannedfoodinconicalandcylindrical containers[J].JournalofFoodEngineering,2006,77(4):1024-1036.
[31]Le H, Moin P. Direct numerical simulation of turbulent flow over a backward-facing step[J]. Journal of Fluid Mechanics,2011, 330(1):349-374.
[32]ZhangPengfei,MuYanbin,ShiZhenzhen,etal.Computational fluid dynamic analysis of airflow in belt dryer:Effectsofconveyorpositiononairflowdistribution[J].Energy Procedia, 2017, 142:1367-1374.