Construction and evaluation of a timber-drying solar kiln

Abstract

The solar-assisted drying of timber at industrial scale has a dome -shaped roof and requires the installation of the dome to be East-West direction. The roof structure consists of 3 layers: The outer layer is transparent sheet while the middle layer is a solar absorbent material. The bottom layer is steel sheet to keep the absorbing heat panels. The roof can absorb sunlight with an absorption efficiency of over 90%, the air temperature around the absorber layer can reach 70 o C depending on the weather condition. Drying volume: 120 m 3 , drying capacity: 40 m 3 of sawn timber per time. Air circulation system: 05 fans with reverse rotation function. The fan system is located in the middle of the roof and blows the air down or up. The dehumidify system consists of 04 fans placed on both side of the drying oven. Control device is LG -38 Helios semi-automatic oven controller that records data from 02 temperature probes (dry and wet) of the environment; 04 sensor s were used for measuring wood moisture and timer reversing the fan. The solar kiln plan is suitable for the Central and Southern regions