Design and Construction
P. Ghiasi; M. Salatin; R. Soon; S. M. Mir Esmaeili; K. Pirvandi; Gh. Najafi
Abstract
IntroductionThe world today is facing the issue of population growth, which will result in food shortages. One way to supply food to this growing population is to facilitate the production of agricultural products to meet the growing demand. Medicinal plants are an important product of the agricultural ...
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IntroductionThe world today is facing the issue of population growth, which will result in food shortages. One way to supply food to this growing population is to facilitate the production of agricultural products to meet the growing demand. Medicinal plants are an important product of the agricultural sector. In Iran, manual harvesting reduces the productivity of these crops, and the use of manual harvesting poses challenges related to available manpower. The costs and time required for manual harvesting are additional obstacles. Given the importance of developing medicinal plants, designing and constructing a mechanized machine for harvesting them could improve the harvesting process.Material and MethodsIn designing the machine for harvesting medicinal plants in cultivation rows, different scenarios were examined regarding the position of the machine relative to the tractor. The advantages and disadvantages of each scenario were listed separately, and finally, the continuous placement of tractors, harvesters, and trailers was defined. One of the goals of designing this machine is to perform harvesting operations for two row spacing’s - 80 and 160 cm. To achieve this goal, mechanisms were added to the machine that allow for changing the position of the harvesting head, as well as the cutting height. Moreover, due to the sensitivity of the harvested product to soil contact, the plants should be transferred immediately after cutting. Therefore, a transfer mechanism was designed and built to move the cut products to the trailer. Independent variables, including forward speed at two levels, type of reel in two types, and cutting blade in two types, were considered. Dependent variables also included harvesting efficiency, percentage of damaged plants, and harvesting capacity.Results and DiscussionThe results of variance analysis for different treatments show that the forward speed, type of reel, and cutting blade type have an effect on harvest efficiency. The difference in harvest efficiency is significant at a 1% probability level. A star cutting blade provides higher efficiency than a 40-teeth cutting blade. The rubber reel prevents plants from falling to the ground by creating a closed space in front of the blade. However, the inner parts of the rods reel are empty, and the plant can fall to the ground. Additionally, the plant may get wrapped around the rods, causing a decrease in harvesting efficiency. Another essential parameter when identifying and evaluating a harvesting machine is crop damage. Some plants get crushed and torn due to the impact on metal components. This situation reduces the quality of the harvested product, leading to a decline in the final product's price. The star-cutting blade causes more leaf rupture. In contrast, the teeth in the 40-teeth blade are continuous, making it unlikely for the leaf to get caught between the two teeth. However, with the star blade, the distance between the two blades is large, allowing the plant to get stuck in between and re-cut.ConclusionBased on tests conducted for eight different positions of the harvester, it was observed that the G test outperformed the other tests with 85.88% harvesting efficiency, a capacity of 344.8 kg h-1, and only 1.34% peppermint leaf damage. Therefore, for harvesting similar peppermint products, we recommend using a combination of a star blade, rubber carousel, and a forward speed of 1.2 meters per second. However, new tests should be conducted on other products like lavender and those with strong stems.
Modeling
P. Ghiasi; M. Safari
Abstract
Introduction Sunflower planting is mostly carried out for two particular purposes; oil production and as nut. Harvesting is one of the biggest problems in both types of sunflower. The difficulty of harvesting and less scientific research have led us to study the mechanized harvesting of this kind of ...
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Introduction Sunflower planting is mostly carried out for two particular purposes; oil production and as nut. Harvesting is one of the biggest problems in both types of sunflower. The difficulty of harvesting and less scientific research have led us to study the mechanized harvesting of this kind of crops. In this research, head losses and grain losses for the inner section of combine were investigated during mechanized harvesting of oily sunflower and a regression model was used based on the experimental tests for head losses and grain losses in the inner section of the combine.Materials and Methods After preparing an especial head for harvesting sunflower, the head was set up on the combine for measuring the harvest losses. The cutting, threshing and clearing process for sunflower seeds were done during the tests. The design of the head is the same as the sunflower bushes are firstly bent by the bar and then sequentially the cutting, and transferring processes are done. The tests were implemented in an oily sunflower farm by a combine harvester (1055 john deer) in 3 replications. The farm performance was 2170 kg ha-1 and was located in Kermanshah province in Iran. A pre-test was done to define the best combine forward speed and finally 2.5 km h-1 was adjusted for combine forward speed. The bar height (BH) in two levels (20 and 70 cm) and head height (HH) in two levels (60 and 120 cm) were independent parameters to evaluate the head. The dependent parameters were the combine losses and head losses. For the analysis of variance of the variable parameters, a 2×2 factorial plot with 3 replications was used. A regression model was defined based on experimental tests.Results and DiscussionHaving done the experimental tests, data were analyzed and the effect of independent parameters on the head and combine grain losses were investigated. The effect of the bar height on the head grain losses was significant at 1% level and the effect of the head height and interaction between bar height and head height on the head grain losses was also significant at 5% level. Results showed that with increasing in bar height, the head grain losses increased. With a change in the bar height, the location of the cutting point is changed and this led to a change in the head grain losses. The effect of the bar height on the combine grain losses was significant at 5% level but the effect of the head height and interaction between bar height and head height was not significant on the combine grain losses. Increasing in the bar height led to increase in material other grain (MOG) which enters to the combine, and also resulted in increasing in combine grain losses. The coefficient of determination of head grain losses in the regression model was 0.97. The model was able to explain the relationship between the bar and head height with head grain losses due to the relationship between independent and dependent parameters. The amount of R-squared for the combine grain losses in the regression model was 0.53. Because of the effect of other parameters in the inner section of the combine, the output of the model predicted that increasing in the bar height and head height, resulted in increasing in head grain losses, and also increasing in the bar height and decreasing in head height let to increasing in combine grain losses. The output of model showed that regulating the bar height and cutting height could reduce the harvest losses by less than 3%. This R-squared is obviously less than R-squared of head grain losses model. The output of the regression model predicted that the increase in the bar height and head height was associated with increase in the head grain losses, and increasing in the bar height and decreasing in head height, resulted in increasing in combine grain losses. The output of the regression model showed that the harvest losses can be reduced less than 5% by regulating the bar height and cutting height.ConclusionOne of the most important parameters for mechanized harvesting is the head mechanism which cuts the crops and transfers them to the threshing unit. The cutting height in the sunflower head was defined by the bar height and head height. According to the linear relationship between the head and combine losses with the bar height and head height, and the interaction between them, the regression model was able to predict the result successfully. This model of grain losses in the head and combine model can be used in the intelligent combine to minimize the harvest losses. The optimization of the bar height and head height for minimizing the harvest losses can be the subject of next researches.
P. Ghiasi; A. Masoumi; A. Hemmat; Gh. Najafi
Abstract
Harvesting is one of the most important field operations in sunflower production. Seed damage and low separation efficiency are the top concerns of harvesting sunflower. In this study, a threshing cylinder with rubber teeth and a concave for harvesting sunflower were designed and evaluated. The variable ...
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Harvesting is one of the most important field operations in sunflower production. Seed damage and low separation efficiency are the top concerns of harvesting sunflower. In this study, a threshing cylinder with rubber teeth and a concave for harvesting sunflower were designed and evaluated. The variable parameters were threshing cylinder speed (TCS), threshing space (TS) and moisture content (MC) of sunflower head. Azargol variety was used to evaluate the threshing unit. The tests were performed at three cylinder speed levels (280, 380 and 480 rpm), two threshing spaces (8 and 10 cm) and two moisture content of sunflower head based on the crop condition (20% and 45% wet basis). An ANN model was developed to predict the amount of materials in each part of the concave. Results showed that the sunflower seeds had no damage during the threshing process and the presented model could predict the amount of materials in each part of the concave with a regression coefficient R2=0.95. Based on the ANN model, with a decrease in MC and TS, and an increase in TCS, the separation efficiency was increased. Furthermore, optimal parameters for the threshing unit which were suggested by Design Expert software to maximize the separation efficiency were 18% w.b, 450 rpm and 10.5 cm for MC, TSC, and TS, respectively and in this condition separation efficiency was determined to be 94.92%.
