What is solar drying?

Solar drying is a traditional exploitation of solar energy to remove the moisture contained within a product. The simplest approach is open-sun dryers, used mainly for agricultural products, consisting of directly exposing a thin layer of the product to solar irradiation.

How a solar dryer works?

The working principle of these types of solar dryers is a combination of the two former ones. In these dryers, the direct solar irradiance causes the drying of the substances and preheats the air in the solar collector to provide the thermal energy of drying process [1, 41].

How long does a solar dryer take to dry?

The drying duration was 810–870 min with PCM and 900–960 min without PCM. Excellent flow visualization with a maximum drying efficiency of 23.08 percent, a drying duration of 15 h, and a Vmax of 2.7 m/s and T max of 42 °C. Numerical models in solar drying applications offer significant contributions and face notable shortcomings.

Can solar dryers be improved?

These types of dryers are used in single and mixed modes of drying. Several studies have been developed to test different techniques to improve solar dryers, considering the possible use of thermal storage materials, the deep bed drying method, improved solar collector designs and energy hybridization.

What is the drying rate of a solar dryer?

Under an average insolation of 318.74 W/m 2, this novel dryer raised the average air temperature in the drying chamber from 29.36°C to a maximum of 46.7°C during loaded test sessions. Compared with a solar dryer without a backup, the drying rate of the agricultural crop increased from 10.5 to 19.7 g/h.

How long does it take to dry paddy in a hybrid solar dryer?

Aprajeeta Jha et al. optimally set parameters (temperature: 46 °C, milling yield: 71.48 %, drying time: 90 min) for paddy drying in a PV-integrated hybrid solar dryer. Drying time predictions ranged from 75 to 195 min using a quadratic model (R 2 = 0.98).