Optimization And Design The Main Parameters Of Scalping Screen

With the degree of mechanization unceasing enhancement of our country’s grain harvest,cause grain impurity rate rose significantly. Due to the lack of form a complete set of effectiv-e cleaning equipment in harvest of grain,The impurities in the filling has a large number of st-raw and husks.Led to in the process of storing heat, insect, mildew, pollution,grain loss cause-d directly even reached 6%.A great influence on the downstream processing of food, serious-y affected the grain processing product quality, increase the cost of the processing enterprise-s.This topic is mainly aimed at the new development of the combine harvester integrated cle-aning equipment, the main parameters of scalping screen optimization and design.The screening separator was made use of the edem software to discrete element analys-is. Set some operating conditions of the screening separator, take the filling coefficient of w-heat were 0.3, 0.45;Sieve cylinder speed along anticlockwise respectively 10r/min, 12 r/min,15 r/min, 18 r/min, 20r/min that have in the following situation::(1) with the improvement of cylindrical screen rotation speed, wheat grain and the average forces between the cylindrical screen show progressively larger trend.(2)Due to the sieve drum speed increases gradually, m-ake the wheat grain in the screen distance shortened, time reduced the screen.(3) under the s-ame filling coefficient, we can know that with the improvement of cylindrical screenrotation speed,the number of particles in contact with the sieve tube along with the increase of the ro-tational speed increasing.When the speed of the sieve drum, small number of particles in con-tact with the sieve tube also shows the tendency of decrease.Ansys Workbench software for l-oading the force analysis of cylindrical screen,comprehensive comparison in different speed of stress and strain.it is concluded that the filling coefficient of wheat and sieve cylinder spee-d values.Secondly use the Ansys Workbench software to analysis the cylindrical screen’s modal.Studying the characteristics of natural frequency of the cylindrical screen and the characterist-ics of vibration mode.Because of the speed reducer between the working frequency and natu-ral frequency of the cylindrical screen no overlap or close to occur, thus between won’t produ-ce resonance phenomenon.Using EDEM software of the simulation analysis data, in the finit-e element software Ansys Workbench to load the actual stress distribution of cylindrical scre-en.Transient dynamics analysis of cylindrical screen, check the analysis of the structure of c-ylindrical screen stress nephogram and displacement nephogram. Due to the stress cloud ima-ges show that the maximum stress and allowable stress of the cylindrical screen close, so for the structure strength of cylindrical screen insufficient place structure improvement.Make sla-t thickening of cylindrical screen, as well as adding two screen surface support plate, structu-re optimization, the cylindrical screen after setting of cylindrical screen size.Analysis struct-ure improvement again after the changes of natural frequency and vibration model of cylind-rical screen.Due to the working frequency and the structure of the reducer improved cylindr-ical screen no overlap or close to the natural frequency of the phenomenon, so resonance w-ill not occur.Then simulating the actual stress of sieve tube at work to load, the transient dyn-amics analysis, view the analysis of the stress contours and strain contours.The local maxim-um stress of the stress nephogram of cylindrical screen display obvious low and allowable s-tress, thus increase the strength of the screening separato’s structure[2].Integrated the above knowable, through to the cylinder scalping screen discrete element analysis, finally it is concluded that the filling coefficient of the wheat and the rotational spee-d of cylindrical screen the best value.Limited analysis was carried out on the cylinder scalpin-g screen, to get the frequency characteristics and formation characteristics of the cylindricals-creen, as well as the deficiency of the structural strength of cylindrical screen.In the form of structure optimization to improve the structure of cylindrical screen, effectively improve the deficiency of the strength of cylindrical screen.