旋耕刀齿式棉田耕层残膜回收机设计与试验

为减少棉田多年覆膜种植方式下耕层土壤中的残膜存量，修复土壤结构，提出一种旋耕刀齿起膜、膜土抛送分离输送的耕层残膜回收方法，设计了旋耕刀齿起膜装置、输送筛分装置等关键部件；以膜土抛送过程不同落点建立分离模型，分析膜土分离运动过程。计算分析结果表明:当旋耕刀齿起膜装置抛送土块质点速度初始值为2.0 m/s，输送筛网倾角初始值为35°时，土块回落后掉入至田间的位移为1.24 m，即土块通过旋耕起膜抛送至输送筛网后，反向回落至输送带下端，碎土块经筛网过滤掉落至田间；而残膜抛送距离更短且密度较小，输送筛网可直接将残膜传送至回收箱内，从而实现膜土抛送分离。田间试验结果表明:样机作业速度增大，残膜回收率降低，含杂率则升高。当作业速度为5 km/h时，回收率为80.06%，作业效率0.725 hm²/h，含杂率25.47%，此时具有较好的残膜回收效果。全耕层残膜量由作业前的268.29 kg/hm²降低至作业后的16.49 kg/hm²，每个样点的平均残膜片数由作业前的370片减少至作业后的90片。机具在0~200 mm耕层土壤中残膜回收效果明显，可用于新疆棉田耕层残膜回收。

Design and experiment of a rotary tillage knife tooth typeresidual film recovery machine in the plough layer of cotton field

In order to reduce the amount of residual film in the plough layer of cotton field under the mode of film mulching for many years and repair the soil structure, a method for recovering the residual film from the plough layer by raising the film on the rotary blade teeth and throwing, separating and transporting the film soil is proposed. The transmission and screening device and other key components were designed. The separation model was established based on different drop points of the membrane soil in the process of throwing, and the separation process of the membrane soil was analyzed. The calculation results show that when the initial value of the particle velocity of the soil mass thrown by the film lifting device of the rotary blade tooth is 2. 0 m/s and the initial value of the inclination angle of the conveying screen is 35°, the displacement of the soil mass falling into the field after falling back is 1. 24 m, that is the soil mass is sent to the conveying screen through rotary tillage film lifting and falling back to the lower end of the conveyor belt, and the crushed soil mass falls to the field through the screen filtering; Moreover, the throwing distance of the residual film is shorter and the density is smaller. The conveying screen can directly transport the residual film to the recycling box, thus realizing the throwing separation of the film and soil. The field experiment results showed that with the increase of the working speed of the prototype, the recovery rate of residual film decreased, and the impurity rate increased. When the operating speed was 5 km/h, the recovery rate was 80. 06%, the operating efficiency was 0. 725 hm²/h, and the impurity rate was 25. 47%, the residual film recovery effect was better. The amount of residual film in the whole plough layer decreased from 268. 29 kg/hm² before operation to 16. 49 kg/hm² after operation, and the average number of residual film in each sample site decreased from 370 pieces before operation to 90 pieces after operation. In conclusion, the recovery effect of the machine is obvious in the 0 to 200 mm plough layer, which can be used for the recovery of the plough layer residual film in the cotton field in Xinjiang.