SOLAR storage energy using black volcanic stone (pouzzolan) as the absorber in the SOLAR collector of the Indirect SOLAR DRYER with oriented flux to dry in continuous is investigated. The collector using crushed pouzzolan as absorber is exposed in the sunshine. Daily and evening experiments were conducted with different loads and oriented air flux in the drying chamber. It is observed that on the day, the irradiance do not affect outlet temperature of collector and in the evening up to 14 hours after the absence of the sun, the temperature difference between the ambient and the collector output is above 7° C. This temperature may be sufficient to reduce or to stabilizise the water intake of the product in the absence of the sun. The model of the discharge equation show that the time constant is a function of the intrinsic characteristics of the thermo physic properties of material and different heat transfers put in place.

One of the ways to use SOLAR energy is to use a SOLAR DRYER. But these kind of DRYERs have low efficiency that optimizes their absorbent plate to increase efficiency and save energy. For this purpose, the air flow inside the compartment of the adsorbent plate of the SOLAR DRYER was simulated using the computational fluid dynamics modeling and the heat transfer process, flow distribution and air velocity inside the compartment were analyzed and finally, the plates were compared in vitro. In this research, three different modes of the page with the same input and three different output modes (circular, conventional and perforated) were investigated. In a porous sheet with porosity, the plate was used with a coefficient of 0. 0314. The results showed that between analytical and empirical data, the explanatory factor (R2) was above 97%. There are circular and conventional heat accumulation in the corners, which, by changing the type of output and converting it to the perforated output state, Heat and heat accumulation are prevented.

This work presents the design and development of SOLAR crop DRYER with drained SAE 20/40 from vehicles oil as heat storage material. The details design, fabrication and experimental analysis procedure of the developed DRYER are explained. The crops used during the experiments were potato slices (2 kg) and ginger (2 Kg) while air velocity maintained at 10 m/s. Potato slices of upper and lower trays have taken the drying time of 5 hours and 6 hour to reach safe storage moisture content of below 15 % and whereas ginger of upper tray and lower tray have taken drying time of 9 and 10 hours to reach moisture content of below 15. The maximum value of instantaneous of the collector (Oil bath) efficiency reported was 57. 48 % and minimum value was 18. 59 %.

This study aims to present a comprehensive mathematical model for study of an indirect–type SOLAR DRYER. For this purpose, using the conservation laws of heat and mass and the physical principles of the performance of such systems, the governing equations related to the SOLAR collector and the fixed–bed DRYER are developed in the unsteady state condition. The governing equations are solved numerically. The effect of some structural and operating parameters of the SOLAR DRYER is studied on its performance. Furthermore, the drying efficiency of the DRYER is determined in various conditions. The obtained results are well adapted with the expectations of the conservation laws and the physical principles of such systems.

Barberry (Berberis vulgaris L.) is an important horticultural plant mostly cultivated in Iran. Since fresh barberry fruit has a high moisture content its shelf life is very short. Therefore, product drying after harvesting is necessary. On the other hand, because the moisture of barberry fruit is capsulated in the skin, its drying is very energy-consuming process. So, the present study proposed an indirect forced flow SOLAR greenhouse DRYER, to evaluate the DRYER, a prototype was constructed, and its performance was experimentally investigated. In this way, the tests were carried out at different drying temperatures (30, 40, and 55oC) and drying air velocities (0.5, 1, and 1.5m/s). The results indicated that raising the temperature from 30 to 55oC decreased drying time by 8%. Similarly, drying time decreased by around 24% when the air velocity increased from 0.5 to 1.5m/s. The obtained specific energy consumption (SEC) values were between 0.11 and 1.1 kWh/kg. The lowest SEC was achieved at the lowest temperature with the highest velocity. Finally, it was found that the higher drying rates, the puffier products.

This study evaluated the use of the SOLAR DRYER at Esfahan Agricultural Research Center for drying prunes. A factorial experiment was carried using a randomized complete block design with four replications. The four methods used to accelerate prune drying were: control group (no treatment), mechanical perforation at one week of drying, blanching, submersion in Australian cold dip method. The drying rate of the prunes was measured at: beginning of drying time (time zero), after 72 h, after 144 h, after 288 h, after 336 h. Weight variation, acidity percentage, humidity percentage and TSS of fruit were measured at each time interval. Measurement of color loss, as well as subjective evaluations of color, taste, appearance and overall acceptability of the dried prunes was carried out at the end of drying process. The dried fruit was then stored for two months and one year and were subjected to color and subjective appearance evaluations. Temperature measurement of the drying chamber indicated that the maximum temperature of the inlet air was 70oC, outlet air was 60oC and in the fruit was 51oC. The control and mechanical perforation pretreatments produced similar drying rates, while the Australian cold dip method pretreatment augmented it. The blanching pretreatment produced an inferior quality of fruit. The average comparison of quantitative color indices (L*, a*, b*) showed that dried fruit produced by the control and mechanical perforation were darkest, blanching produced the most redness and Australian cold dip method pretreatments produced the greatest yellowness. Judges preferred dried prunes subjected to Australian cold dip method for their taste and general acceptability. Also they gave the highest rating to the color of dried prunes subjected to mechanical perforation pretreatment and stored for two months.

In this study, the effect of using heat exchanger on increasing the performance of the collector and SOLAR DRYER was investigated. Moreover, computational fluid dynamics (CFD) method was used to simulate the heat transfer and distribution of thermal counters in the cabinet SOLAR DRYER equipped with heat exchanger with two outlets and porous plate. The results showed that using heat exchanger with half air mass flow rate for the first and second outlets (0. 009 kg/s) increases the efficiency of the DRYER up to 10. 2% related to the DRYER without heat exchanger. Excessive air flow rate inside the heat exchanger decreases the performance of the SOLAR cabinet DRYER. The results of the comparison between the CFD and experimental data shows that CFD method with 6. 9% of relative error has a good correlation with the experimental data. Using heat exchanger has no adverse effect on the color quality of dried tomato samples.

In this work, performance of a newly designed hybrid DRYER was investigated. Drying was done with the support of SOLAR energy to microwave conveyor DRYER. By using collector, which was designed with semisphere shape for having high efficiency from SOLAR energy, hot air was produced and moved through the tunnel with velocity of 3 m s-1 and by using 0. 7, 1 and 1. 4 kW microwave support, drying behavior of 5, 10, and 15 mm zucchini slices were examined. At the end of drying process, drying time, color changes of dried products, energy consumption, collector efficiency, and modelling of drying were determined. Considering the time required for drying the zucchini slices until reaching 10± 1% (wb) moisture content and electrical energy consumption values, the most suitable results were obtained from 1 kW microwave power, air velocity of 0. 245 m min-1, and 5 mm zucchini slice thickness, corresponding to total energy of 1. 143 kWh. The collector efficiency was calculated as 24. 3%, under the environmental conditions of our study.