Mohsen Pouya; Babak BEHESHTI; Ali mohamad Borghei; Gholam Hassan Asadi
Abstract
This study evaluated the performance of a thermal dryer with a closed air circulation system equipped with a metal-organic framework (MOF) system. Dryer sections included: product drying chamber, the MOF containing chamber nano-absorbents, measurement and control systems. Dryer yield on mint was compared ...
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This study evaluated the performance of a thermal dryer with a closed air circulation system equipped with a metal-organic framework (MOF) system. Dryer sections included: product drying chamber, the MOF containing chamber nano-absorbents, measurement and control systems. Dryer yield on mint was compared at three temperature levels (40, 50, and 60 °C). Finally, the energy consumption and drying mint leaves was evaluated. The results showed that the closed air circulation system reduces the dry time by 27% to 50%, the penetration coefficient of mint leaves increased with increasing temperature. Its values in cases of not using and using nano-absorbent plates were determined respectively (4.05690×10-11) and (2.8215×10-10) m2/s. The activation energy in two methods of not using and using the nano-absorbents was 45.72 and 51.96 kJ/mol, respectively, which is consistent with the researchers' results. Also, the coefficient of performance, the rate of moisture evaporation, and the rate of specific moisture evaporation showed the effectiveness of using nano-absorbent in the dryer system and reducing energy consumption. The total color index (ΔE) did not change much with increasing temperature from 40 to 50 °C, but from 50 to 60 °C, the increased total color index. There wasn't a clear difference in total color index between the two methods of using and not using nano-adsorbent.
A. H. Ahmadbeyki; Mohammad Ghahderijani; A. M Borghaee; H. Bakhoda
Abstract
The increase in the area under greenhouse cultivation in Tehran Province is important for the increase in production and for its substantial social importance due to the preservation of agricultural land, especially small farms. In addition, the increase in the number of greenhouses producing summer ...
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The increase in the area under greenhouse cultivation in Tehran Province is important for the increase in production and for its substantial social importance due to the preservation of agricultural land, especially small farms. In addition, the increase in the number of greenhouses producing summer crops in this province attracts idle capital to the agriculture sector thereby creating jobs. The present research used stratified cluster sampling for selecting the counties of interest having the largest areas under greenhouse cultivation of summer crops in Tehran Province in order to select the producers in each greenhouse size range (taking into consideration the number of producers in it) via random sampling in which a table of random numbers was employed. Fifty-five greenhouses were selected in the province, 22 greenhouses producing only cucumbers, 15 greenhouses producing cucumbers and tomatoes, and 18 greenhouses producing cucumbers and bell peppers. The results of the cost-benefit analysis (CBA) showed that production of greenhouse summer crops was economically justified for greenhouses larger than 3000 m2 in surface area. However, the trend in the profitability of activities was a rising one for greenhouse surface areas of up to 4500 m2 beyond which a falling trend was observed. Finally, it was suggested that the Jihad Agricultural Organization of Tehran Province refuse to issue an establishment license for the production of greenhouse summer crops in areas lower than 1500 square meters and provide the necessary incentives for the production of greenhouse summer crops in Tehran, in areas between 5000 to 7500 square meters.
Javad Nemati; Babak BEHESHTI; Ali Mohammad Borghei
Abstract
One of the important processes in agriculture is separating of agricultural products. The use of cyclones is one of the methods that with lower costs, shorter separation time and simpler operation, has a high efficiency compared to other separation methods (Such as separation by hand and so on). The ...
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One of the important processes in agriculture is separating of agricultural products. The use of cyclones is one of the methods that with lower costs, shorter separation time and simpler operation, has a high efficiency compared to other separation methods (Such as separation by hand and so on). The aim of this research is to designing, simulation and construction a cyclone separation device and evaluation it in order to separate the stigma from the saffron petals. In this research, cyclone simulation was performed using ANSYS FLUIN software and computational fluid dynamics (CFD) analysis method and the separation efficiency was obtained. The device was designed using SOLID WORKS software and its prototype was made and evaluated at three levels of 1.5, 2.5 and 3.5 m/s of air speed and at five levels of moisture content (10, 20, 40 and 60)%wb. For this purpose, a factorial experiment with completely randomized design with three replications was used. The evaluation results of the device showed that the highest separation of the device at 20% moisture content and 3.5 m/s air speed was 80% efficiency and the lowest was 11% efficiency for 80% moisture content and 1.5 m/s air speed which was very close to the best result of simulating the device in ANSYS FLUINT software which it was 89% efficiency at 3.5 m/s air speed.
