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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Journal of Particle Science & Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Mathematical modelling,Shrinkage,Drying rate,Vibro-Fluidized Bed Dryer,Hawthorn Drying
- چکیده:
- چکیده انگلیسی: The drying kinetics of hawthorn in a pilot-scale experimental fluidized bed dryer with and without vibration was investigated. The effect of operating parameters, such as vibration intensity, drying air flow rate, and temperature, on the drying rate and shrinkage of hawthorn was studied. The hawthorn fruit was dried at various drying air temperatures ranging from 40-70oC and drying air volume flow rates ranging from 22-30 m3/h with the vibration intensity ranging from 6.8 to 8.2 Hz. The entire drying process occurred in the falling rate period and no constant rate period was observed in the drying of hawthorn. Four mathematical drying models investigating the drying behavior of hawthorn were evaluated and then the experimental moisture data were fitted in these models. The quality of the models fitting was assessed using the coefficient of determination, chi-square and root mean square error. The logarithmic and Page models for drying rate and the Ratti and Vazquez models for shrinkage were found to be the most suitable for describing the drying and shrinkage curves of hawthorn. The results showed that the vibration intensity, drying air temperature and flow rate has no significant effect on the shrinkage of hawthorn. All mentioned parameters had a significant effect on the drying rate of hawthorn, but the effect of drying air temperature was considerably more compared to the other parameters. It was observed that shrinkage varies linearly with respect to moisture content, and the reduction in radial dimension of hawthorn samples was around 40% at the end of the drying process.
- انتشار مقاله: 27-10-1395
- نویسندگان: Elham Farzan,Mahmood Reza Rahimi,Vahid Madadi
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Oil and Gas Science and Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: treatment,oil and gas,Produced water,Spray dryer
- چکیده:
- چکیده انگلیسی: The current work investigates the performance of a single-stage, bench-scale system using a spray dryer to treat produced water. The produced water is generated in three large reservoirs of Ahvaz, Maroon, and Mansouri fields, which have different compositions but the same high total dissolved solids (TDS) and total organic carbon (TOC). The results of this study indicate that the newly developed bench scale rig is able to reduce the amount of TDS in the water produced in Ahvaz, Maroon, and Mansouri reservoirs to 98.78, 98.65, and 98.90, and TOC decreases the three types of the produced water to zero. Investigating the effect of independent parameters on the performance of this system using response surface methodology shows that the most effective parameters affecting the efficiency of the produced water treatment system are the entering carrier gas temperature (TGIT), the flow rate of the produced water (QL), the carrier gas flow rate entering the spray dryer (QG), and the atomizer pore size (d). Additionally, the optimal conditions are obtained as follows: TGIT = 113.7 °C, QL = 20.8 cc/min, QG = 59.9 m3/hr., and d = 0.03 mm.
- انتشار مقاله: 06-05-1398
- نویسندگان: Mohammad Razaghiyan,Mahmood Reza Rahimi,Hajir Karimi
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Chemistry and Chemical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Response surface methodology,Thermal efficiency,Matricaria recutita flower,Vibrofluidized bed dryer,Moisture removal
- چکیده:
- چکیده انگلیسی: Drying of Matricaria recutita flower was investigated experimentally in a VibroFluidized Bed Dryer (VFBD). The aim of the present work was to optimize the best operating conditions for the drying of Matricaria recutita flower in the VFBD based on experimental design techniques. Response Surface Methodology (RSM) and Central Composite Design (CCD) based on 4-variable with 5-level have been employed to achieve the desirable possible combinations of frequency of vibration (7-15 Hz), inlet air temperature (36-68 °C), air flow rate (16-24 m3/h), and drying time (30-70 min) for the highest responses in terms of moisture removal (MR) and thermal efficiency (). A full quadratic model was used to describe the effects of individual and interactive parameters on the responses. The analysis of the obtained results showed that the inlet air temperature has the largest effect on responses. The optimal process parameters were as follows: frequency of vibration of 10.88 Hz, inlet air temperature of 64.08 °C, air flow rate of 20.63 m3/h and drying time of 69.11 min in which the predicted value for the MR (%) and (%) was 86.76 and 53.05, respectively. The proposed optimal conditions were examined in the laboratory and MR (%) and (%) achieved as 87.12±0.25% and 52.78±0.34%, respectively. The experimental values agreed with those predicted by RSM models, thus indicating the suitability of the model employed and the success of RSM in optimizing the drying conditions.
- انتشار مقاله: 28-04-1395
- نویسندگان: Sahar Zamani,Mahmood Reza Rahimi,Hossein Sadeghi
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Rotating Packed Bed,Height of Transfer Unit,Mass transfer,Absorption,Carbon Dioxide
- چکیده:
- چکیده انگلیسی: Carbon dioxide capture is a key issue in climate change mitigation. For decades the removal of carbon dioxide has been an essential step in many industrial processing operations such as the synthesis of ammonia, natural gas purification, and oil refining. In this study, a rotating packed bed has been designed for absorption of carbon dioxide from an air stream. The rotating packed bed is a compact device which can be used to replace the conventional absorption technology because of its high efficiency, compact size, and reduced weight. Experiments have been done for carbon dioxide absorption and the effect of parameters such as rotational speed, gas and liquid flow rates, and concentration of the MEA solution on the height of transfer unit investigated for different packing types. The results show that the height of transfer unit values for carbon dioxide absorption were 2.4~ 4 cm depending on the rotational speed, absorption solution concentration, and gas and liquid flow rates.
- انتشار مقاله: 31-06-1393
- نویسندگان: Mahmood Reza Rahimi,Soleiman Mosleh
- مشاهده