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.
Design and Construction
M. Hasannia Samakoush; S. R. Mousavi Seyedi; A. Mahdavian
Abstract
IntrodutionNowadays, supplying the needed food for people is one of the main global issues. Among foods, rice as the second vital crop has an important role in the world. The amount of global rice losses is about 21 percent and in Iran is reported between 16 to 30 percent that the most amount of it belongs ...
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IntrodutionNowadays, supplying the needed food for people is one of the main global issues. Among foods, rice as the second vital crop has an important role in the world. The amount of global rice losses is about 21 percent and in Iran is reported between 16 to 30 percent that the most amount of it belongs to harvest (mowers and crushers) part. The measuring device for rice picker combine losses at lab scale is a tool which could report the losses of separating and cleaning units. One of the advantages of this device is choosing maximum speed by the operator with considering the acceptable amount of seed losses. Therefore, research about detecting and decreasing this type of losses is important. In this research, only the losses of the harvesting step, especially at the end of a combine harvester machine was addressed. Different methods included piezoelectric and acoustic sensors, load cell, and FIS controller were used as the measuring device of rice picker combine seed losses. In this research, on the contrary with other studies, the slope of meshed plate and humidity of product was measured using a piezoelectric sensor at lab scale under different conditions of the rotational speed of meshed plate. Therefore, the general purpose of this research was design, construction, and evaluation of the measuring device for rice picker combine losses based on the piezoelectric sensor at lab scale to measure the seed losses in the straws at the end of the machine at rice picking.Materials and MethodsA meshed plate with the 100 × 60 cm2 dimension was one of the main parts of the measuring device of seed losses. The diameter of its meshes was 7 mm based on the rice seed size. It separates the rice seeds from straws. Separated seeds from this part were fallen on the other plate which is mounted under the meshed plate. The seeds through four separated routes were fallen on the sensors and output pulses from sensors were sent to the operator plus shown at a monitor. The used seeds at tests were selected from Fajr rice cultivar with a high yield and short height. The used piezoelectric sensor had the ability to convert imposed force and pressure to voltage and vice versa. After the seed falling on the sensor and its vibration, the piezoelectric sensor worked as a beam fixed at one end. The used Integrated Circuit (IC) was ATMEGA328, which receives the needed data through the sensor as a processing and action system. An electric motor was used to create the rotational speed of meshed plate. The LCD indicator was used for monitoring the obtained data from the test. The amount of seed losses at the end of rice picker combine machine was studied using the piezoelectric sensor with high sensitivity for detecting seeds to separate the seeds from straws. The tested sample in this research was 1 kg straw plus 52 g seed which was equal to 3 percent loss at the end of the harvest combine machine. The experimental design was a simple randomized complete design with three replications. The used treatments included the rotational speed of meshed plate at 3 levels (50, 75, and 100 rpm), the slope of meshed plate at 3 levels (25, 37, and 45 deg) plus humidity at 3 levels (12, 18, and 24 percent). Then the data analysis was done using the conducted test design. The GenStat software was used for data analysis.Results and DiscussionThe analysis of variance table showed that all treatments have a significant difference in the number of rice lost seeds at 1% probability level. The interaction between the rotational speed of meshed plate and seed humidity had a significant difference at the 1% level. On this base, the best separation of seed from straw recorded at 100 rpm and 12% humidity. The reason was the higher vibration of the meshed plate at high rotational speed and better separation of seeds at low humidity. Increasing the slope of meshed plate and humidity of seeds caused decreasing in the device efficiency. Because the motion speed of the sample on the meshed plate increased with increasing the slope of the meshed plate, a lower period was needed for separating the seeds from straws, and this separation at higher humidity was done hardly. The highest efficiency at this condition was obtained with 12% humidity and 25º slope. Increment of the rotational speed of meshed plate and decrement of meshed plate slope caused the best separation by the device. Its reason was high vibration at the high rotational speed and having enough time for separating the seeds from straws at a low slope of the meshed plate. The best angle for separating was 37º. Increment of the rotational speed of meshed plate, decrement of meshed plate slope, and sample humidity caused increasing the device efficiency. The reasons were high vibration at high rotational speed, having enough time for separating seeds from straws, and decreasing the compression at low humidity amounts. The results showed that the best device efficiency with 95.51% was obtained at 100 rpm rotational speed, humidity of 12%, and 25º slope of the meshed plate.ConclusionIn this research, a measuring device for detecting the amount of seed losses combined by straws at the end of a rice picker combine machine was designed and constructed, and then was assessed. The results of lab tests showed that increment of the rotational speed of meshed plate plus decrement of meshed plate slope and sample humidity causes an increment of device efficiency. With installation and evaluation of this device on the rice picker combine machine, the needed correction at the farm will be done and the amount of losses will be decreased.
Design and Construction
S. Mollapour; D. Kalantari; M. Rajabi Vandechali
Abstract
Introduction Nowadays, the best method for fertilizing trees is spot treatment via hole-digger. Conventional mechanical hole-diggers have several drawbacks such as auger’s non-continuous and limited speeds due to using a mechanical gearbox, and risks of getting stuck inside the hole and motor reaction ...
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Introduction Nowadays, the best method for fertilizing trees is spot treatment via hole-digger. Conventional mechanical hole-diggers have several drawbacks such as auger’s non-continuous and limited speeds due to using a mechanical gearbox, and risks of getting stuck inside the hole and motor reaction force to the operator. On the other hand, a three-point hitch hole-digger has problems such as the lack of maneuverability in confined spaces and high prices. Meanwhile, preparation of these hole-diggers by most farmers and gardeners has no economic justification. Thus, in this research it has been aimed to handle the mentioned problems and to optimize the working quality of hole-diggers via designing and manufacturing a new hydraulic hole-digger. Materials and Methods To start design the machine, displacement volume and power requirement of the hydro-motor and consequently displacement volume requirement of a hydro-pump were calculated using the appropriate formulas (70.83 cm3, 2.3 kW & 7.5 cm3, respectively). According to available hydro-motors and hydro-pumps in the market and using obtained values of displacement volume, an orbital hydro-motor, BMR-80 model with the maximum torque of 220 N.m and an external gear pump REXPORT-2APF8 with displacement volume of 8 cm3 and flow rate of 12 L.min-1 were chosen. In the following, hydro-pump’s parameters were used to select the internal combustion engine. The engine power requirement was 2.875 kW (3.85 hp); thus according to the available engines in the market, a single cylinder gasoline engine, WX168F-1 model that made in Kato company of China with 6.5 hp power and maximum speed of 3600 rpm was chosen. To transmit the power from the engine to the hydro-pump, a coupling DK-42 model was used. Also, two pressure gauges, LB-250 model with maximum pressure of 250 bars were used in the entrance and the exit of the hydro-motor. An hydraulic oil tank with total volume of 24 liters was made from a sheet metal with thickness of 3 mm. The helical auger used in this research, was made in china by LIONS Company with cone tip, total diameter of 200 mm and pitch of 180 mm. The fabricated digger has a working depth and diameter of 30 cm & 20 cm, respectively; rotational speed between 100-160 rpm and maximum power equal to 6.5 hp. In order to evaluate the stress distribution in the auger set, the static analysis based on maximum dynamic torque exerting on auger’s axle and maximum dynamic force exerting on auger’s blades, was used in SOLIDWORKS 2013 software. The maximum force 214.07 kgf (2100 N) proportional to the maximum exerting torque (210 N.m) from soil to the edge of the auger’s blade were considered in the modelling. Farm experiments were carried out in two citrus gardens with silty-clay and sandy-loam texture based on factorial test in Completely Randomized Design with three replications. Soil moisture content as high and low humidity levels (24.85% and 16.12% in sandy-loam and 25.95% and 16.48% in silty-clay) as the first factor and soil depth as the second factor varied in three levels of low, medium, and high (10, 20 and 30 cm), respectively. The measured parameters consisted of specific fuel consumption, machine efficiency, auger torque, auger power and used energy. To determine the auger’s torque, the oil pressure measurement method with two manometers was used in the entrance and the exit of the hydro-motor. After measuring the time and power needed to dig pits, for determining the used energy, the area under the power-time graph was calculated in Excel software. Also, to determine the fuel consumption during the experiments, the filled fuel tank method was used. Data analysis including analysis of variance (Anova), mean comparisons and interaction between the parameters were performed using the SPSS 22 software. Results and Discussion The numerical stress analysis results of the auger showed that the maximum von - Mises stress is occurred in the position of the blade-auger axis connections, with a magnitude of 86 MPa. The obtained experimental results in this study indicated that influence of soil depth and moisture content on the measured parameters were significant. in both soil textures and the influence of soil moisture on machine efficiency was non-significant in the silty-clay texture. With increasing soil depth, measured parameters excluding machine efficiency were increased in both soil textures. In high depth and also in low moisture, regarding to the increasing soil bulk density and shear strength, more torque was needed for the rotating auger in the soil that this has led to an increasing in specific fuel consumption of the device. Regarding the results obtained in this study, minimum specific fuel consumption value of the device (0.0014 liter pit-1) was obtained at the low working depth (10 cm) and the high soil moisture (25.95%) in the silty-clay soil. The hole-digger working capacity at 30 cm working depth and soil moisture content as high and low humidity levels in silty- clay obtained equal to90 and 88 pits per hour and in sandy-loam obtained equal to 101 and 95 pits per hour, respectively. Also, the maximum device’s power (2.548 kW) occurred in deep soil (30 cm) and low soil moisture in silty-clay texture. Conclusion Stress analysis and field qualitative observations results indicated that the fabricated device has sufficient resistance and strength against maximum torque from tested soils. Field evaluation of the fabricated machine showed that pit digging operations in soil is not appropriate in low moisture content because of the high fuel consumption and environmental pollution issues.
