Solar dehydration characterization

Description

The file contains raw data on the temperature and relative humidity profile in the dryer chamber, according to environmental conditions and the position inside the chamber at different positions along the three-axis and with mango slices and without load. The file also contains the statistical results.

Steps to reproduce

A solar dryer was built for a farmer comunity. The dehydrator consists of two sections, the drying chamber and the photovoltaic module. The drying chamber has a length of 10 m and a width of 2.9 m. The western wall has a height of 2.1 m and the eastern wall 1.6 m. The cover has an arched or vaulted configuration with a length of 3.2 m. The chamber was positioned to achieve maximum exposure time to direct sunlight. The chamber contains 18 stainless steel trays of 1m * 1m, mesh type with 6 mm perforations. The trays are distributed in two sections A and B with 9 trays each. Section A is placed at a height of 1.38 m, while the second or row B is set at a height of 0.8 m and separated by a corridor "C" of 85 cm width. Below the trays, at 0.25m, a geomembrane "G" was installed to reduce energy losses to the ground. During the evaluation window, the effect on temperature and relative humidity within the chamber of the following factors was analyzed: 1. position, with two levels: inside and outside, 2. position with respect to section P(s): high A and low B; 3. position along the main axis P(x) determined by the tray number with 9 values (1-9); 4. Location across the chamber width P(l) with two values C (corridor) or L (side wall); 5. location with respect to height, P(h), at the four levels M, GM, GS and S, corresponding to location above the mesh M or tray, between the tray and geomembrane GM, between the geomembrane and ground GS; and in contact with the ground S; and finally 6. under the three system operation modes, OM1, OM2 and OM3. In all cases, analysis of variance and Tukey's multiple comparison test were performed. Drying Curves For each system operation mode and tray position, fruit weight loss over time was calculated and three standard or thin-layer mathematical drying models were evaluated: 1. Henderson & Pabis Model (MR = a*exp(-kt)), 2. Page Model (MR = exp(-kt^n)) and 3. Lewis or Newton Model (MR = exp(-kt)). The Marquardt method was used for parameter estimation by least squares in nonlinear models. All analyses were performed at a significant level of 0.05 in SAS 9.4 statistical software.

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