need our technical
expertise? |
|
what our composites products specialists
can do for you...
DRYLOG
Computer Model for Log Drying During Storage
FPInnovations is presently developing DRYLOG, a model to simulate
the drying of logs during storage for the purpose of improving the
way green wood inventories are managed in OSB mills.
 A
common practice in the composite wood panel industry is to stockpile
great quantities of logs in the mill yard so that a constant supply
of wood is available throughout the year. In most cases, the management
of these inventories is limited to using these logs in chronological
order, without considering their source, harvest period or moisture
content.
Ideally, the wood entering the mill should have a uniform moisture
content (MC) – not too low, not too high. The methods currently
used to manage green wood inventories do not enable the mill to
be supplied with wood having a uniform MC. On the other hand, we
know that moisture content varies widely depending on the species,
the source of the wood and the season in which it was harvested.
In addition, during storage, the wood dries more or less quickly
depending on the species, its initial moisture content, local climatic
conditions and the storage method.
Poorly controlled rotations cause wide variations in the logs’
moisture content. In the case of OSB mills, this has repercussions
on almost all production operations. To address this problem, Forintek
is presently developing a model to simulate the drying of logs during
storage. The information provided by this software will help to
make informed decisions for managing green wood inventories.
 In
2001-2002, a program prototype called DRYLOG was developed. This
program makes it possible to track the moisture content of a wood
pile, one species at a time. This simulation tool takes several
factors into account, such as the species’ intrinsic characteristics,
the pile parameters (geographic orientation of the logs, log length,
diameter classes and proportion belonging to each class), and the
air characteristics (temperature, relative humidity, wind speed
and direction). The simulation results provided by the program concern
the change in the wood pile average MC pile in relation to time,
the MC change for each diameter class and the radial and longitudinal
MC profiles inside the log for each diameter class.
Once validated, the program will be an essential tool for wood
product manufacturers, especially OSB mills. A 5%-increase in fine
particles resulting from the milling of logs that are too dry represents
annual losses of some $1 million, for an average-sized mill with
a production capacity of 400 million square feet per year. Furthermore,
savings in energy associated with lowering the wood’s moisture
content by 10% are equivalent to the heating power of 1,000,000
m3 of natural gas per year, for an average mill.
For more information contact Gilles
Brunette at (418) 659-2647
26/07/10
|
