Assessing the carrying capacity of solar dryers applied for agricultural products: a systematic review

Abstract

Most of the review research papers previously published were mostly focused on solar dryer design, development, performance evaluation, modification, technologies of solar dryers, etc. There were no works of literature reviews that specifically concerned how much solar dryers can carry. So, the review gives some clues about the carrying capacity of solar dryers. Measuring or knowing solar capacity has critical importance in the drying industry. It helps to produce quality dried products, design efficient solar dryers, and provide valuable insights for researchers, engineers and policymakers involved in solar drying technologies. The current review systematically examines the relevant scientific literature published between 2000 and 2023. The exclusion and inclusion criteria were used to identify the documents. A total of 1230 studies were selected for analysis, encompassing a wide range of geographical regions, crop types, and solar drying technologies. Based on the review conducted; solar dryers (direct, indirect, mixed, and hybrid) can vary between 1 and 250 kg in capacity applied for agricultural products drying purposes. According to the reviewed articles, the minimum loading capacities designed and recorded in the first, second, third, and fourth quinquennial periods were 1 kg, 1 kg, 4.75 kg.m−2, and 5.4 kg.m−2, respectively. In the same order as the minimum, the maximum loading capacities observed in the stated quinquennial periods were 250 kg/per day, 250 kg, 70 kg, and 45 kg, respectively.