An Improved Method of Seasoning and Drying Wood.
Year: 1891

page_text: Date of Application, 29th Dec., 1891-Accepted, 2nd July, 1892
COMPLETE SPECIFICATION.
An Improved Method of Seasoning and Drying Wood.
I, CHARLES HOWARD, of 249 E. 21st Street, New York City, N.Y., United
States of America, Chemist, do hereby declare the nature of this invention, and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
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My invention relates especially to an improved method of seasoning or
vulcanizing" and drying wood, and has for its object the provision of a method,
and means for carrying the same into practice, whereby the wood treated will be
thoroughly vulcanized, and dried, while at the same time, it will be subjected to a
much lower temperature than has heretofore been employed, thereby preserving the
fibre of the wood, and preventing injury of the same, while the vulcanizing and
drying is very effectually accomplished.
To attain the desired end, my invention consists in enclosing the wood to be
treated in an air tight cylinder or chamber while cold, exhausting the air from the
chamber, and then subjecting the contents of the chamber to the action of dry heat
by means of hot air circulating in pipes all of which will be hereinafter first fully
described, and then pointed out in the claims.
In the accompanying drawing I have shown one way of carrying out my method,
although it will at once be apparent to those skilled in the art to which my invention
relates, that the apparatus employed, may be greatly varied and modified, without
departing from the spirit of my invention.
In the drawing,
Fig. 1 is a plan view of an apparatus designed for carrying my invention into
practice, and Fig. 2 is a front elevation of said apparatus, looking from the right of
Fig. 1.
Like letters of reference, wherever they occur, indicate corresponding parts in
both the figures.
A, are cylinders made of any approved material and of any desired shape and
size. I have shown two of said cylinders, but one, or any number may be
employed. B is a door, arranged to fit the end of the cylinder air-tight, said door
being held in place by means of a screw C, which passes from the door, through a
threaded hub D, provided with manipulating arms E. F are arms which engage
with a flange G, and a ring H, encircling the screw C, and against which the
hub D bears, when the parts are all in place. Within the cylinders or chambers A,
are tracks I, upon which cars J run, for the reception of the wood or lumber K, to
be treated, as particularly shown in Fig. 2. Lare heating pipes located in the
chambers A.
M is a furnace or stove, having a coil of heating pipe therein, which communicates
with a pipe N, having branches O, which connect with the interior of the cylinders A.
a represents valves in the branches, and 6 are other valves which open into the outer
atmosphere. N¹ is a pipe leading from the furnace M direct to the pipes L in the
cylinders A and a¹ a' are valves therein. P are pipes connected to the back ends
of the cylinders A, also provided with regulating valves c. Pipes P, connect with
a pipe R, which leads to and through a condenser S. T is a pump arranged to
circulate cold water in said condenser. U is an air pump, provided with a pipe V,
which leads to the coil in the furnace M. d is a valve for closing pipe V, and e is
an exhaust valve therefrom. f is a branch pipe, leading around the furnace, and
provided with regulating valves, g and h. W is an exhaust valve opening into the
atmosphere.
When constructed and arranged in accordance with the foregoing description,

page_text: this apparatus is employed for carrying my process or method into effect as follows:
Wood or lumber being placed upon the cars within the cylinders or chambers, the
doors are closed tightly, and the valves between the furnace and the cylinders are
also closed. The air pump is then started, creating a vacuum within the cylinders
after which the valves a¹ between the furnace and the cylinders are opened and
heated air is admitted into the pipes L to circulate therein. As is well known,
water will boil in a vacuum at a much lower temperature than in the open
atmosphere and I utilize this fact by creating the vacuum, and applying the heat,
as above set forth; the result is, that the sap &c., within the wood is acted upon by
the heat at a temperature far below the boiling point in the atmosphere, having the
same result as the high temperature, and by thus using the low temperature in
vulcanizing, the fibre of the wood is in no way injured as is often the case in the
methods heretofore employed for this purpose, and as less heat is required by my
process, the attendant expense is materially reduced.
If it is desired to cause a circulation of the rarefied air through the furnace, the
connections permit this to be obtained and if it is desired, the furnace connections
may be cut out by means of the branch pipe f. The method of vulcanizing and
drying wood will then consist in first enclosing the wood in a cold condition in a
chamber, then drawing the moisture of the external layers of the wood to the
surface by the action of a vacuum, then admitting the heated air to circulate in
pipes in the chamber, and then removing the external water and vulcanizing the
wood and contained sap by a continuous circulation of the remaining dry heated
and rarefied air through the chamber, the absorbed water being removed from the
air by condensation. It will thus be seen that my improved method of vulcanizing
and drying wood admirably answers the uses and purposes for which it is
intended.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is.
1. The herein described method of vulcanizing wood, which consists essentially
in enclosing the wood to be treated in a chamber while cold, creating a vacuum
within said chamber, and then applying heat to said chamber and vacuum.
2. The herein described method of vulcanizing and drying wood which consists
essentially in enclosing the wood to be treated in a chamber, creating a vacuum
within said chamber, applying heat to the wood while in said vacuum, and then
causing a circulation through said chamber and the vacuum producing mechanism.
3. The herein described method of vulcanizing and drying wood which consists
in first enclosing the wood in a cold condition in a chamber, then drawing the
moisture of the external layers of the wood to the surface by the action of a
vacuum, then admitting the heated air to circulate in pipes in the chamber, and
then removing the external water and vulcanizing the wood and contained sap by a
continuous circulation of the remaining dry heated and rarified air through the
chamber, the absorbed water being removed from the air by condensation.
Dated this 29th day of December 1891
CHARLES HOWARD.
Herbert & Co.,
18, Buckingham Street, Strand, London, W.C., Agents for the Applicant.