METHOD OF RESEARCH OF FRUIT DRYING DURATION IN THE SOLAR DRYER
DOI:
https://doi.org/10.31734/agroengineering2019.23.043Keywords:
solar dryer, optimization criterion, fruit drying, heat accumulatorAbstract
The article describes the method of planning a multifactorial experiment to determine the main indicators of the duration of the drying process in a solar dryer: speed of drying, critical moisture of fruits, coefficient of drying.
Having analyzed the existing equations for calculating of the duration of the convective drying process, the O. Lykov equation (4) for the conditions of a solar dryer was improved. The equation is base on a simplified mechanism of heat and mass exchange, which is described by the differential equation of heat and mass transfer.
The article presents the obtained regression equation, which can be used to calculate dependence of the drying rate, critical humidity of the fruit, drying coefficient within the area of changing of coolant parameters: 10 W/m2 ≤ Q ≤ 460 W/ m2; 20 ºС ≤ Тhc ≤ 50 ºС; 1 m/s ≤ vhc ≤ 2,5 m/s.
The number of experiments, required for our case, was determined as 33. The experimental design matrix was developed and the experimental results were obtained for linear functions: drying rate, critical humidity, drying factor referring to the values of the studied factors: 10 W/m2 ≤ Q ≤ 460 W/ m2; 20 ºС ≤ Тhc ≤ 50 ºС; 1 m/s ≤ vhc ≤ 2,5 m/s.
The work develops a mathematical model of dispersion analysis of the technological process of fruit drying in a solar dryer. The model adequacy is estimated and verifies according to Fisher and Student criteria.
The research substantiates optimum operating modes of the solar dryer in the region: 10 W/m2 ≤ Q ≤ 460 W/ m2; 20 ºС ≤ Тhc ≤ 50 ºС; 1 m/s ≤ vhc ≤ 2,5 m/s. The work describes influence of design parameters (collector area Shc = 1,5 m2 and mass of thermal accumulator mha = 50 kg) on the regularities of change of thermal technical parameters of the environment (ambient temperature Th − 16 − 32 °C, the level of solar activity In − 100 − 824 W/m2) and duration of the fruit drying process according to the following parameters: 10 W/m2 ≤ Q ≤ 460 W/ m2; 20 ºС ≤ Тhc ≤ 50 ºС; 1 m/s ≤ vhc ≤ 2,5 m/s.
References
Adler, Yu. P., Markova, E. V., & Granovskiy, Yu. V. (1976). Planirovanie eksperimenta pri poiske optimalnyh usloviy. Moskva: Nauka, 274.
Bachurskaia, L. D., & Guliaev, V. N. (1976). Pischevyie kontsentraty. Moskva: Pischevaia promyshlennost.
Vedeniapin, G. V. (1973). Obschaia metodika issledovaniia i obrabotki opytnyh dannyh. Moskva: Kolos.
Krasovskii, G. I., & Filaretov, G. F. (1982). Planirovanie eksperimenta. Minsk: Izd-vo BGU im. V. I. Lenina.
Lykov, A. V. (1968). Teoriia sushki. Moskva: Energiia.
Lykov, A. V. (1970). Teplomassoobmen spravochnik. Moskva: Energiia.
Melnikov, S. V., Aleshkin, V. R., & Roschin, P. M. (1980). Planirovanie eksperimenta v issledovaniiah selskohozyaystvennyih protsessov. Leningrad: Kolos.
Rabinovich, S. G. (1978). Pogreshnosti izmerenii. Leningrad: Energiia.
Fedorov, V. V. (1971). Teoriia optimalnogo eksperimenta. Moskva: Nauka.
Finni, D. V. (1970). Vvedenie v teoriyu optimalnogo eksperimenta. Moskva: Nauka.
Azimi, А., Tavakoli, T., & Khademhosseini, H. (2012). Experimental Study on Eggplant Drying by an Indirect Solar Dryer and Open Sun Drying. Iranica Journal of Energy & Environment, 3, 347–353.
Janjai, S., Phusampao, C., Nilnont, W., & Pankaew, P. (2014). Experimental performance and modeling of a greenhouse solar dryer for drying macadamia nuts. International Journal of Scientific & Engineering Research, 5, 1155−1161.
Kaveh, M., Amiri Chayjan, R., & Esna−Ashari, M. (2016). Thermal and physical properties modelling of terebinth fruit (Pistacia atlantica L.) under solar drying. Research in Agricultural Engineering, 61(4), 150–161.
Korobka, S., & Babych, M. (2017). Substatiation of the constructive−technologocal parameters of a solar fruit dryer. Eastern−European Journal of Enterprise Technologies, 1 (8(85)), 13–19.
Khazimov, Z. M., Bora, G. C., Khazimov, K. M., & Khazimov, M. Z. (2014). Modeling of the motion of free convective drying agent in plastic helio dryer. Journal of Engineering Thermophysics, 23(4), 306–315.
Korobka, S., Babych, M., Krygul, R., & Zdobytskyj, A. (2018). Results of research of the technological process of sun fruit drying. Eastern-European Journal of Enterprise Technologies, 1/8(91), 64–73.
Babych, M., Korobka, S., Skrynkovskyy, R., Korobka, S., & Krygul, R. (2016). Substantiation of economic efficiency of using a solar dryer under conditions of personal peasant farms. Eastern−European Journal of Enterprise Technologies, 6 (8(84)), 41–47.
Kituu, G. M., Shitanda, D., Kanali, C. L., Mailutha, J. T., Njoroge, C. K., Wainaina, J. K., & Silayo, V. K. (2010). Thin layer drying model for simulating the drying of Tilapia fish (Oreochromis niloticus) in a solar tunnel dryer. Journal of Food Engineering, 98(3), 325–331.
