Corvallis gazette. [volume] (Corvallis, Benton County, Or.) 1900-1909, 1905-11-03
KILN DRYING WOOD.
The Forest Service Studies This
Important Subject.

manufacture. For a long time
the only drying process used or
known was air drying. or the ex-.
posure of wood to the gradual
drying influence of the open air.
Kiln-drying, which is an arti-
fetal method, originated in the
effort to improve or shorten the
process. By subjecting the wood
to a high temperature, or to a
draught of heated air, in con-
fined space OF kiln, time is saved
and certain degree of control
over the drying conditions is Sc
cured.
There are two. points in the
manufacture of lumber at either
of which it may be kiln-dried.
With soft woods, for instance it
is common practice to kiln-dry
the lumber at the sawmill before
it is shipped. This practice,
however, is i'll adapted for hard
woods, in which it would pro-
duce such checking and warping
as would reduce the value of the
product. In practice, therefore,
hard woods are more or less
thoroughly air dried before being
pIacedssin the kiln, where the res
idue of moisture may be reduced
to between 3 and 4 per cent,
which is much lower than is
possible by air drying only. Yet
another practice obtains in the
case of a few woods which give
up their moisture very. slowly.
Of these woods, of which cyprus
is an example, the kiln is resort
ed to at both the sawmill and at
the factory where they are manu-
factured.
Kiln.drying is so important a
process that a need is keenly felt
for fuller information regarding
it, based upon scientific study OF
the behavior of various kinds of
woods at different temperatures
and under different mechanical
drying devices. In the effort tc
developit to the highest efficiency
variety of methods have been
employed, but as yet these
methods have not been carefully
compared with a view to ascertain.
ing which of them is best adapted
to each special requirement ot
species or of manufacture. The
Forest Service has begun a study
of the dry-kilns throughout the
country, first, to acquaint itsel
with the methods now IN vogue
and second, to map out such i'm
provements of the kiln-dryin;
process as may render it in til
highest degree satisfactory ant
profitable.
Mr.. Frederick Dunlap, of th
Office of Forest Products, in tn
Forest Service, who was assigne
to this study, has during the pas
weeks inspected kiln-dryin
methods in the states of Indian
and Wisconsin, and in the cit
of Chicago, He found manufac
turers disposed to aid the stud
by all means in their power.
In Indiana, hard wood re
f gion, the prevailing method {
, kiln-drying, is based upon tn
use of steam pipes, which suppl
, the dry heat required in the kilr
| The pipes run on the floor of th
kiln, and the lumber is place
over them. The radiated hes
from the pipes dries the lumbe.
| In Wisconsin soft woods are moi
> widely manufactured and blowt
: kilns are more generally uset
, In these air is pumped by NEAR
! of a circular fan through steal
( coil and SO heated, and the
passes on to the chamber
which the lumber is piled. Aft
E passing through this chambe
q the air is sometimes returned
be reheated and sometimes alloy
i ed to escape.
: In connection with the turth
\ study of kiin-drying processes
S attention will be given to II
: value of the preparatory steamil
of wood before the kiln-drying
n begun. For this purpose VIC
II, is planned in cooperation WI
+. firms who are interested in e
s. periments to determine the val
lof steam treatment.