Resumo

TAMARIT-URIAS, Juan Carlos et al. Evaluation of the solar drying process of Guadua aculeata Rupr. ex E. Fourn. culms. Rev. mex. de cienc. forestales [online]. 2023, vol.14, n.78, pp.141-164.  Epub 14-Set-2023. ISSN 2007-1132.  https://doi.org/10.29298/rmcf.v14i78.1384.

The moisture content of freshly harvested bamboo culms is high, near 100 %, and it should be reduced by some drying process. A key step in the processing of culms, which has been under-appreciated by bamboo producers and users, is drying. Outdoor exposure is the most widely used drying method in Mexico; however, it is not very efficient, as it takes weeks to several months, depending on the environmental conditions. The objective of the present study was to evaluate the drying of Guadua aculeata culm sections (6 m long) in a solar tunnel dryer with a rectangular prism shape. The initial average moisture content was 106.72 %, and after a period of 80 days, a final average moisture content of 29.84 % was reached. The drying rate was above 1.0 % per day in the first 20 days, during which their moisture content was reduced by approximately 40 %. In the following 60 days, they lost on average 37.41 % of moisture, at a variable drying rate for each sample culm. The drying curve of the assessed method corresponds to an exponential function. Under the experimental drying conditions, it was determined that 6 m long sections of culms with an average diameter of 12.42 cm can reach an average MC below 18 % in 109 days, thus becoming suitable for use as structural elements.

Palavras-chave : Giant bamboo; moisture content; drying curve; exponential function; solar tunnel dryer; drying rate.