摘要
针对茶叶风选装备存在结构简单、风选效果差及风选试验对象单一等问题,为提高茶叶风选效果及茶叶品质,设计了一款绿茶风选装备并开展不同工序下茶叶的风选性能试验。首先,根据风选装备的工作原理,设计了绿茶风选装备,并确定了风选室、风机、传动装置以及物料传递装置的相关设计参数;然后,基于流体力学仿真方法研究风选室内部流场的流线、速度及压力情况,基于离散元仿真方法模拟不同时刻茶叶颗粒群的风选状态,探究不同风速对茶叶风选效果的影响,得出风机风速为6~6.5 m/s时流线稳定,且风选效果较好;最后,对风选装备进行了性能测试、风选效果等试验,探究了不同运行频率对风选效果、不同风选顺序对成品茶品质的影响。试验结果表明,绿茶风选装备4种风机变频器频率下风速变异系数均小于8%,风机变频器最佳运行频率为35 Hz;单位有效宽度生产率大于7 kg/(cm·h),千瓦小时产量大于420 kg/(kW·h),绿茶风选装备性能测试的各项指标符合国家规程要求;茶鲜叶及杀青叶由B级提升为A-和A级,茶叶复选率均高于90%,风选效果显著,茶叶品质得到提升;各试验组中,主出茶口整体优于其余出茶口,杀青分级中主出茶口茶叶品质最佳,茶叶感官评审得分最高。
In response to the problems of simple structure,poor air separation effect,and single air separation test object in tea air separation equipment,in order to improve the air separation effect and tea quality,a green tea air separation equipment was designed and tea air separation performance tests were conducted under different processes.Firstly,the basic structure and working principle of the tea air separation equipment were elaborated,and its key components were theoretically analyzed.The relevant design parameters of the air separation room,fan,transmission device,and material transfer device were determined.Then,based on fluid mechanics,the simulation of fluid in the air separation room was carried out,and the movement of particles in the air separation process was simulated by discrete element simulation.It was concluded that the streamline was stable when the fan speed was 6~6.5 m/s,and the air separation effect was good.Finally,validation tests were conducted on the air separation performance of famous and high-quality green tea air separation equipment.Prototype performance tests and air separation effect tests were conducted to explore the impact of different operating frequencies and air separation sequences of fans on tea quality.The experimental results showed that the wind speed variation coefficients of the wind separation equipment were all less than 8%,and the optimal operating frequency of the fan frequency converter was 35 Hz.The productivity per unit effective width was greater than 7 kg/(cm·h),and the output per kilowatt hour was greater than 420 kg/(kW·h).The fresh and killed leaves of tea was upgraded from B grade to A-grade and A grade,and the selection rate of tea was higher than 90%,indicating a significant improvement in the air selection effect.In each experimental group,the main tea outlet was overall superior to the other tea outlets,and the tea quality of the main tea outlet was the best in the green killing grading,with the highest sensory evaluation score for tea.
作者
张开兴
马国良
胡芳源
高华峰
周长安
赵秀艳
ZHANG Kaixing;MA Guoliang;HU Fangyuan;GAO Huafeng;ZHOU Chang’an;ZHAO Xiuyan(College of Mechanical and Electronic Engineering,Shandong Agricultural University,Taian 271018,China;Rizhao Shenghua Tea Machinery Co.,Ltd.,Rizhao 276800,China;College of Information Science and Engineering,Shandong Agricultural University,Taian 271018,China)
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2023年第S02期366-374,387,共10页
Transactions of the Chinese Society for Agricultural Machinery
基金
山东省科技成果转移转化补助项目(鲁渝科技协作)(2021LYXZ019)
山东省科技型中小企业创新能力提升工程项目(2022TSGC1323、2023TSGC0557)
关键词
绿茶
风选装备
仿真
风选性能试验
green tea
air separation equipment
simulation
air separation performance test
