【摘要】：篩分是各領域中散體料進行粒度分級的主要技術手段;在各類篩分物料中,橢球形或類橢球形顆粒占較大比例,橢球形顆粒長直徑遠大于短直徑的外形特性,導致其篩分特性相對球形顆粒更為復雜。目前,對橢球形顆粒精選篩分,缺乏針對性篩分機理及裝置的研究,采用傳統(tǒng)的篩分方法,并以球形顆粒篩分機理控制參數進行橢球形顆粒篩分,其篩分性能差。為此,本文結合直線振動篩分具有高篩分效率、高生產率,且對橢球形顆粒篩分適應性好的特點,提出橢球形顆粒直線振動篩分方法,以類橢球形顆粒枸杞為篩分對象,開展橢球形顆粒直線振動篩分機理研究。主要研究工作內容與結論如下:(1)橢球形顆粒直線振動篩分理論研究基于直線振動篩分理論,以篩分分離粒度和綜合篩分效率為基礎篩分性能指標,研究橢球形顆粒直線振動篩分過程的顆粒運動學特性、透篩特性及其影響因素;結果表明:篩分分離粒度是一個區(qū)間范圍?d,顆粒沿篩面方向的相對速度越大,分離粒度越小;橢球形顆粒物料在篩面上做周期性相對下滑和相對上滑移動,同時,做周期性相對篩面向上、向下?lián)u擺滾動,因此,若顆粒垂直篩面方向的跳動較大時,不該透篩的較大粒度的橢球形顆粒會豎直或傾斜穿過篩孔,造成誤篩,使得分離粒度上限值增大,分離粒度區(qū)間?d增大,綜合篩分效率降低。研究了厚層橢球形顆粒直線振動分層原理及其影響因素,并設計分層性能指標檢測方法,結果表明:不同粒度顆粒的動能差異是形成顆粒分層的主要原因,細�；虼至ｓw積濃度的變化率是檢測顆粒分層速率的有效可行方法。(2)橢球形顆粒直線振動篩分仿真分析利用離散元軟件EDEM,對單層橢球形顆粒在篩面上的運動特性進行仿真分析,結果表明:顆粒群在篩面x方向的相對速度和絕對速度具有與振動篩面相同的周期性;顆粒群相對速度是時間的類余弦曲線,平均相對速度、平均絕對速度隨著篩分參數(篩面傾角、振幅、頻率、振動方向角)的增大而增大;當篩分參數大于一定值之后,顆粒群出現垂直篩面方向的跳動,且篩分參數值越大,跳動量越大。對單層橢球形顆粒篩分分離粒度、綜合篩分效率進行仿真分析,結果表明:篩分分離粒度為一個范圍(mind~maxd),篩分分離粒度(分離粒度上限maxd、下限mind和中心cd)隨著篩分參數的增大而減小,隨篩孔直徑增大而增大;驗證了?d受顆粒跳動的影響,當顆粒群在垂直篩面方向上有跳動時,?d隨著振幅、頻率和方向角增大而增大,綜合篩分效率降低,篩面傾角在取值范圍內,因顆粒群垂直篩面方向無跳動,?d不變,故不影響綜合篩分效率。對厚層橢球形顆粒直線振動分層特性及顆粒運動動能仿真分析,結果表明:橢球形顆粒振動分層過程中,大顆粒與小顆粒垂直篩面方向的動能差隨著振幅、頻率、振動方向角的增大而增大,篩面傾角對其影響不大;顆粒分層速率隨著振幅、頻率和振動方向角的增大而增大,篩面傾角對顆粒分層速率影響較小,顆粒分層速率隨時間的推移越來越小。(3)橢球形顆粒直線振動篩分性能試驗研究設計直線振動篩分試驗裝置,對橢球形顆粒枸杞進行直線振動篩分性能試驗及結果分析。試驗結果驗證了單層顆粒篩分中振幅、頻率以及篩面傾角對篩分分離粒度以及綜合篩分效率的影響規(guī)律;驗證厚層篩分中振動幅度、振動頻率以及篩面傾角對顆粒分層速率的影響規(guī)律。得到較佳篩分性能參數為振幅為4mm、頻率為20HZ、篩面傾角為8°時,其篩分效率為93.6%,篩分生產率為1.54t/h。
[Abstract]:The sieving is the main technical means for the particle size grading of the dispersion materials in all fields; in the various screening materials, the ellipsoidal or the like-like particles occupy a larger proportion, the long diameter of the ellipsoidal particle is much larger than the outer shape characteristic of the short diameter, and the screening characteristic is more complex with the spherical particles. At present, the selection and screening of the ellipsoidal particles, the lack of the targeted screening mechanism and the research of the device, the traditional screening method is adopted, and the spherical particle screening is carried out by the spherical particle screening mechanism control parameters, and the screening performance is poor. in ord to solve that problem, the linear vibrating screen is combine to have the characteristics of high screening efficiency, high productivity, and good screening adaptability to the ellipsoidal particle, Study on the mechanism of linear vibrating screen for ellipsoidal particle. The main research contents and conclusions are as follows: (1) The theoretical study of the linear vibrating screen of the ellipsoidal particle is based on the principle of the linear vibrating screen, and based on the screening separation size and the comprehensive screening efficiency as the basic screening performance index, The characteristics of the particle kinematics, the characteristics of the screen and the influencing factors of the elliptic particle linear vibrating screen are studied. The results show that the size of the sieve separation is an interval range. d, the greater the relative speed of the particles in the direction of the screen surface, the smaller the separation particle size, If the direction of the vertical screen of the particles is large, the spherical particles of the larger particle size of the screen not to be passed through the sieve are vertical or inclined to cause a false screen, so that the upper limit value of the separation particle size is increased, and the particle size range is separated. and d is increased, and the comprehensive screening efficiency is reduced. The principle of linear vibration of thick-layer ellipsoidal particle and its influencing factors are studied, and the test method of layered performance index is designed. The results show that the difference of the kinetic energy of different particle size particles is the main reason for the formation of the particles. The rate of change in the volume concentration of fine or coarse particles is an effective and feasible method for detecting the rate of particle delamination. (2) The dynamic characteristics of the single-layer ellipsoidal particle on the screen surface were simulated and analyzed by using the discrete element software EDEM, and the results showed that the relative velocity and absolute velocity of the particle group in the x-direction of the screen surface had the same periodicity as the vibrating screen surface. the relative speed of the particle group is the cosine curve of the time, the average relative speed, the average absolute speed is increased with the increase of the sieving parameters (screen inclination, amplitude, frequency, vibration direction angle), and the larger the sieving parameter value, the larger the jump amount. The results show that the separation size of the sieve is a range (mind.to maxd), the size of the separation and separation (the upper limit of the separation particle size maxd, the lower limit mind, and the center cd) decreases with the increase of the screening parameters. Increase with the diameter of the mesh; verified? d is affected by the particle run-out, when the particle swarm has a run-out in the direction of the vertical screen surface? d With the increase of the amplitude, frequency and direction angle, the comprehensive screening efficiency is reduced, and the inclination of the screen surface is in the range of value. and d, so the comprehensive screening efficiency is not affected. The results show that the difference of the kinetic energy of the large particle and the small particle in the plane of the vertical screen increases with the increase of the amplitude, frequency and vibration direction in the process of the vibration of the ellipsoidal particle. The influence of the angle of the screen surface is not large; the particle layer rate is increased with the increase of the amplitude, the frequency and the vibration direction angle, the influence of the inclination of the screen surface on the layer rate of the particles is small, and the layering rate of the particles is smaller and smaller over time. (3) The design of the linear vibrating screen sub-test device for the ellipsoidal particle linear vibrating screen is carried out, and the test of the linear vibrating screen and the result analysis of the ellipsoidal granular medlar are carried out. The influence of the amplitude, frequency and the angle of the screen on the separation size of the screen and the efficiency of the comprehensive screening is verified by the test results, and the influence of the vibration amplitude, the frequency of the vibration and the angle of the screen surface on the rate of the granular layer is verified. The screening efficiency was 93.6% and the screening rate was 1.54t/ h.
【學位授予單位】：江蘇大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TH237.6

【參考文獻】

相關期刊論文 前10條

1 崔守娟;張西良;徐云峰;粟強;孫祥;張宇;;基于LS-SVM的螺旋定量加料預測及試驗研究[J];排灌機械工程學報;2016年12期

2 孫啟波;劉寧;楊玲;楊維仁;張桂國;楊在賓;;粉碎機篩孔直徑對玉米和小麥粉碎粒度、生產效率和飼料性狀的影響[J];糧食與飼料工業(yè);2016年07期

3 鄭健;王燕;蔡煥杰;張恩繼;孫雨欣;;秸稈顆粒形態(tài)對溝灌入滲特征影響的試驗研究[J];排灌機械工程學報;2016年01期

4 朱賀嘉;趙章風;姜曉亮;;平面圓篩機的篩分過程研究和模型構建[J];機電工程;2015年08期

5 馮忠緒;李學武;劉治文;;混合料攪拌設備篩孔尺寸優(yōu)化配置[J];中國公路學報;2014年10期

6 周良富;薛新宇;賈衛(wèi)東;丁素明;孫竹;;CFD技術在果樹風送噴霧中的應用與前景分析[J];排灌機械工程學報;2014年09期

7 趙章風;張立彬;汪曉華;張憲;甘建仁;;茶葉圓篩條件分析與過程數值模擬[J];茶葉科學;2014年01期

8 周偉;庾朝富;王濤;王偉;白建杰;;煤泥分級浮選中分級工藝的研究[J];選煤技術;2013年06期

9 Jianzhang Xiao;Xin Tong;;Characteristics and efficiency of a new vibrating screen with a swing trace[J];Particuology;2013年05期

10 肖建章;童昕;;基于DEM的進料速率對顆粒篩分影響的研究[J];煤炭工程;2012年10期

相關博士學位論文 前1條

1 侯勇俊;筒式網鉆井篩工作理論研究[D];西南石油學院;2002年

相關碩士學位論文 前7條

1 陳成;秸稈螺旋篩分理論分析與篩分性能研究[D];江蘇大學;2016年

2 李海龍;基于ADAMS的直線往復振動篩篩分性能研究[D];昆明理工大學;2014年

3 姚宣;循環(huán)流化床回路流動及顆粒分層特性研究[D];清華大學;2010年

4 張紅霞;大型直線振動篩動力學分析與研究[D];青島科技大學;2009年

5 付允強;振蕩篩篩分機理的分析與研究[D];長安大學;2008年

6 許京偉;懸臂篩網振動篩篩分理論及產品優(yōu)化設計[D];山東大學;2006年

7 王煥友;顆粒體的彈性與分層的研究[D];中南大學;2004年

，

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