Performance Assessment of a Self-propelled Paddy Grain Thresher under Different Threshing Functional Parameters

2020 ◽  
Vol 36 (2) ◽  
pp. 141-149
Author(s):  
George Ashwehmbom LOOH ◽  
Fondzenyuy Cedric MANGEH (III) ◽  
Xunwei WANG ◽  
Xiushan WANG

HighlightsThis research was aimed at assessing the performance of a self-propelled paddy grain thresher.Increasing cylinder speed increased the threshing percentage and percentage of broken grains of the machine.More broken grains were obtained at a lower concave clearance.The feed rate did not have much significance on the performance parameters that were evaluated. Abstract.This research was conducted to assess the performance of a self-propelled mini combine harvester, model number 4LZ-0.8 under different threshing functional parameters such as cylinder speed, concave clearance, and feed rate. An indoor experiment was conducted using the mini combine with an axial flow threshing cylinder and tangential feeding of material. These functional parameters were set at 5 levels each. The responses were obtained in terms of threshing percentage, percentage of unthreshed grains and percentage of broken grains. Response values were analyzed using the response surface tool (rstool) in MATLAB. Analysis of variance was done to determine the significant effects of the factor variations on the response values. MATLAB was used to present response surface graphs that were used to describe the variations of the responses as the factors changed from one level to the other. Results showed that with an increase in cylinder speed from 697 to 1202 rpm, the percentage of broken grains increased significantly from 0.0384% to 3.4052%, respectively. At cylinder speeds of 697 and 1202 rpm, the percentage of unthreshed grains increased from 0.1515% to 0.2162%, respectively. Furthermore, an increase in feed rate decreased the threshing percentage. The highest threshing percentage was obtained at an average concave clearance of 27 mm. Furthermore, it was realized that increasing the concave clearance from 18 to 35 mm, equally increased the percentage of unthreshed grains from 0.1478% to 0.3177%. The percentage of grain damage decreased from 3.2758% to 0.0268% with an increase in concave clearance from 18 to 35 mm, respectively. From the results obtained, it was tested and suggested that operating the threshing cylinder at a cylinder speed of 1100 rpm, concave clearance of 27 mm and feed rate of 0.9 kg s-1 offered the best machine performance. At these suggested values of the operating parameters, the threshing percentage was 99.9801%, the percentage of broken grains was 0.0134%, and the percentage of unthreshed grains was 0.0199%. Keywords: Assessment, Axial threshing unit, Cylinder speed, Concave clearance, Feed rate, Functional parameters, Threshing percentage.

2021 ◽  
Vol 1750 ◽  
pp. 012012
Author(s):  
Changzhong Wu ◽  
Fan Ge ◽  
Guangchao Shang ◽  
Guitao Wang ◽  
Mingpeng Zhao ◽  
...  
Keyword(s):  

Agriculture ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 88
Author(s):  
Mohamed Anwer Abdeen ◽  
Abouelnadar Elsayed Salem ◽  
Guozhong Zhang

Combine harvesters are widely used worldwide in harvesting many crops, and they have many functions that cover the entire harvesting process, such as cutting, threshing, separating, and cleaning. The threshing drum is the core working device of the combine harvester and plays an influential role in rice threshing efficiency, threshing power requirement, and seed loss. In this study, two structures of rice threshers (conical-shaped and cylindrical-shaped) were tested and evaluated for performance under different thresher rotating speeds of 1100, 1300, and 1500 rpm and different feeding rates of 0.8, 1.1, and 1.4 kg/s. The experiment was designed using the Taguchi method, and the obtained results were evaluated using the same technique. The thresher structure and operating parameters were assessed and optimized with reference to threshing efficiency, required power, and productivity. The obtained results revealed that increasing thresher rotating speed and the feeding rate positively related to threshing efficiency, power, and productivity. The highest efficiency of 98% and the maximum productivity of 0.64 kg/s were obtained using the conical-shaped thresher under a 1500 rpm rotating speed and a feed rate of 1.4 kg/s, whereas the minimum required power of 5.45 kW was obtained using the conical thresher under a rotating speed of 1100 rpm and a feed rate of 0.8 kg/s.


1989 ◽  
Vol 111 (2) ◽  
pp. 246-251 ◽  
Author(s):  
Ping Pan ◽  
B. J. Hamrock

The film thickness and pressure in elastohydrodynamically lubricated conjunctions have been evaluated numerically for a rather complete range of operating parameters (dimensionless load, speed, and materials parameters) normally experienced in practical applications. From the film thickness and pressure throughout the conjunction a number of performance parameters were evaluated. By curve fitting the data, formulas were obtained that allow easy evaluation of the amplitude and location of the pressure spike, the minimum and central film thicknesses, the value of ρeHe, and the center of pressure.


2019 ◽  
Vol 13 (2) ◽  
pp. 4911-4927
Author(s):  
Swagatika Mohanty ◽  
Srinivasa Prakash Regalla ◽  
Yendluri Venkata Daseswara Rao

Product quality and production time are critical constraints in sheet metal forming. These are normally measured in terms of surface roughness and forming time, respectively. Incremental sheet metal forming is considered as most suitable for small batch production specifically because it is a die-less manufacturing process and needs only a simple generic fixture. The surface roughness and forming time depend on several process parameters, among which the wall angle, step depth, feed rate, sheet thickness, and spindle speed have a greater impact on forming time and surface roughness. In the present work, the effect of step depth, feed rate and wall angle on the surface roughness and forming time have been investigated for constant 1.2 mm thick Al-1100 sheet and at a constant spindle speed of 1300 rpm. Since the variable effects of these parameters necessitate multi-objective optimization, the Taguchi L9 orthogonal array has been used to plan the experiments and the significance of parameters and their interactions have been determined using analysis of variance (ANOVA) technique. The optimum response has been brought out using response surfaces. Finally, the findings of response surface method have been validated by conducting additional experiments at the intermediate values of the parameters and these results were found to be in agreement with the predictions of Taguchi method and response surface method.


2018 ◽  
Vol 51 (17) ◽  
pp. 402-407 ◽  
Author(s):  
Yawei Zhang ◽  
Du Chen ◽  
Yanxin Yin ◽  
Xin Wang ◽  
Shumao Wang

2020 ◽  
Vol 10 (15) ◽  
pp. 5386
Author(s):  
Yaoming Li ◽  
Zhan Su ◽  
Zhenwei Liang ◽  
Yu Li

The threshing gap of the thresher device for rice combine harvester has to be adjusted in real time based on different feed rates to ensure the operation efficiency in the harvesting process. However, adjusting the threshing gap by changing the position of concave grid may result in unevenness of threshing gap of the thresher device and further impact on the fluidity of material in the thresher device; in addition, it is also unavailable to adjust the threshing gap by changing the drum diameter when the rice combine harvester is in operation. In view of the above and based on axial flow threshing drum, the design of a variable-diameter threshing drum available for overall and rapid drum diameter adjustment and the research on diameter adjustment device as well as electronic control self-locking device were introduced in this study. Besides, stress analysis was implemented to the diameter adjustment device to ensure the stability of the variable-diameter threshing drum. Field experiment was implemented to identify the difference between the impacts brought to the threshing performance (grain-entrainment loss rate, damage rate, threshing efficiency, and threshing power consumption) by both methods for threshing gap adjustment. The experiment result shows that the drum adjustment method with variable-diameter drum features higher grain-entrainment loss rate, threshing efficiency, and threshing power consumption, yet stable in terms of consumption fluctuation, but a lower damage rate than their counterparts with concave adjustment method.


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