FACTORS AFFECTING SEASONING OF TIMBER USING SAWDUST OPERATED KILN

Abstract

This study was carried out to investigate the applicability of sawdust operated kiln developed by Senadheera
(2009), by investigating the factors affecting its operation such as burner and cost efficiencies.Most efficient
sawdust feeding rate for the burner was found to be 60 g min-1 having particle diameter greater than 1 mm.
Kiln was tested by seasoning Rubber (Hevea brasiliensis), Mahogany (Swietenia macrophylla),
Lunumidella (Melia dubia) and Albizia (Paraserianthes falcataria). Albizia showed the highest drying rate,
followed by Rubber, Lunumidella and Mahogany. This sawdust operated kiln consumed 144 hours to dry 25
ft3 of 25 mm thick rubber wood from green conditions to 13% of moisture content. The sawdust operated
kiln in the present study showed the lowest cost efficiency compared with two other industrially operating
kilns in the country. The highest cost efficiency was observed in the kiln at Rowood Lanka Pvt Ltd.
However, according to cost – benefit analysis carried out for three kilns, kiln at State Timber Corporation
showed its ability for a long run enterprise. Each kiln contributed approximately 25% of cost on energy out
of total seasoning cost. Cost of seasoning per unit volume of timber and cost of seasoning per unit volume of
timber per unit time for this kiln was 1.7 and 2.5 fold higher than that of kiln at Rowood Lanka Pvt Ltd
respectively. It was found that sawdust operated kiln in the present study will not be sustained as an
enterprise due to higher cost of seasoning.

Key words: kiln seasoning, sawdust, sawdust operated kiln, drying rate, cost efficiency, cost benefit
analysis