Improvements in and relating to the Seasoning or Preserving of Wood.
Year: 1889

page_text: Date of Application, 5th Mar., 1889
Specification Accepted, 13th Apr., 1889
COMPLETE SPECIFICATION,
I
Improvements in and relating to the Seasoning or Preserving
of Wood.
REGINALD HADDAN of the firm of Herbert & Co. Patent Agents of
18 Buckingham Street, Strand W.C. London in the County of Middlesex, Civil
Engineer do hereby declare the nature of this invention a communication to me
from abroad by Samuel Edward Haskin of Avoca, State of New York, United States
of America, Manufacturer and in what manner the saine is to be performed to be
particularly described and ascertained in and by the following statement :-
.
This invention relates to an improved method of seasoning or vulcanizing wood
and it consists in the steps hereinafter described and claimed.
Heretofore, in vulcanizing wood, cold air was forced into the vulcanizing chamber
or so called wood cylinder until the desired air pressure was attained, the air in
the wood cylinder being heated by coils of steam pipe lining such cylinder. There
were several serious objections to such method. If the wood cylinder was of practical
size for instance of about eight feet in diameter and from fifty to sixty feet long, a
mile or more in length of steam pipe was required with which to construct the
heating coils. Such heating coils were not only very expensive, but it was almost
impossible to prevent the leakage of steam from some portion of such an extensive
coil and any leakage of steam in the wood cylinder was a serious objection, in that
the steam discoloured and injured the wood being treated in the cylinder. It will
be readily understood that an expensive boiler plant was required to furnish steam to
supply a coil of such large dimensions and that a high pressure of steam was
required to raise and maintain the temperature say from two hundred and fifty to
four or five hundred degrees Fahrenheit according to the variety and dimensions of
the wood being treated and according to the purpose for which such wood was
intended. These in brief are some of the difficulties encountered in vulcanizing wood
with the method heretofore employed.
My improved method will be more readily understood by referring to the ac-
companying drawings. Fig. 1 is a side elevation, partly in section, the central
portion of the wood cylinder being broken away to reduce the size of the drawing.
Fig. 2 is an elevation in transverse section through the wood cylinder.

page_text: A represents the so called wood cylinder, the same enclosing the vulcanizing
chamber in which the wood is treated. This cylinder may be of any desired size say
about eight feet more or less in diameter and preferably from eiglity to a hundred
feet in length.
The cylinder is made preferably of heavy steel plate rivetted together after the
manner of constructing steam boilers and at least one of the cylinder heads A¹ must
be removable to allow the passage of cars laden with lumber to and from the
cylinder. Inside the cylinder are tracks a for the cars a' to travel on. A series of
cars are employed and the lumber is piled loosely thereon, and the cars are run into
the cylinder, after which the removable head is secured, hermetically closing the
cylinder.
B is the air compressor, C a heater, D a storage tank and E a furnace. The
branch of the induction pipe of the compressor connects with the rear end of
cylinder A, while the other branch F1 opens into the air these two branch pipes being
provided respectively with stop valves fand fl
The eduction pipe of the compressor has a branch pipe G leading direct to tank D,
this pipe passing in at the top of the tank and discharging near the bottom of the
tank substantially as shown, this pipe being provided with valve g. The other
branch G¹ of the eduction pipe leads through heater C, this pipe being provided
with valves gl and g² arranged on either side of the heater. Pipe G preferably joins G
before reaching the tank D.
By manipulating the valves of the eduction pipes, the air from the compressor
may be discharged directly into the tank D or may be made to pass through
heater C on its way to the tank. Heater is provided with induction and eduction
pipes c and c for the passage of steam to and from the heater, exhaust steam being
usually employed for this purpose, thus utilizing the exhaust of the engine that
drives the compressor and other machinery which would otherwise be wasted.
Tank D is provided with safety valve D¹ with glass water gauge d and with drain
pipe and cock d'. The air discharge pipe connects at or near the top of the tank, for
instance as shown. This pipe has a branch H leading direct to cylinder A and
connects preferably near the front end of the latter, this pipe being provided with
valve h.
The other branch H' leads to the furnace E preferably joining branch H, pipe H
being provided on either side of the furnace, with valves, respectively hª and h² and
this pipe being made into a suitable heating coil where it passes through the furnace.
By manipulating these valves, the air from tank D may be passed directly to
cylinder A, or may be passed through the coils in the furnace E on its way to the
cylinder. Pipe I leads from the rear end of the cylinder and connects with pipes G
pipe I having a valve i and having connected in line thereof a fan blower K.
Cylinder A is provided with heat and pressure gauges and with safety valve L of
large capacity. Cylinder A, the heater, tank and pipes are all jacketed so as to
radiate as little heat as possible. Cylinder A having been charged and closed as.
aforesaid, valves f g h and i are closed and valves f¹g g² h¹ and h³ are open and the
compressor is set in motion.
The air, in passing through heater C becomes moderately heated and in passing
through tank D owing to the arrangement of pipes as aforesaid, much of the
moisture of the air is precipitated; and the water that accumulates is drawn off
from the tank from time to time through pipe d¹ to keep the mouth of pipe G
free, the water gauge of course indicating the depth of water in the tank.
The air passing from tank G is superheated in passing through the coils of the
furnace and in such superheated condition is discharged into cylinder. A. The
compressor is kept in operation until the desired air pressure is had in the cylinder A.
The air introduced into the cylinder during the earlier stages of the process, will of
course be chilled and greatly reduced in temperature by contact with the cylinder
and more especially by contact with such large quantity of lumber.
In this
cylinder so to speak the pressure shall always be kept in advance of the temperature
that is to say the pressure should always be such as to prevent the possibility

page_text: of the sap of the wood boiling or vaporizing under whatever degree of heat
is being employed, otherwise the boiling of the sap would injure the fibre of the
wood, and the sap being vaporized would escape from the wood thus defeating the
With a
object in view, to wit, to retain and vulcanize all of the sap in the wood.
compressor of the ample capacity desired during the first stage of the process the
pressure is likely to be kept considerably in advance of the temperature and under
such conditions, valve f' may be partially closed and valve f partially opened to give
a circulation of air through cylinder A and cause at least a portion of this air to
again pass through the heating coils of the furnace. When the compressed air has
reached such high temperature that no additional heat will be imparted in the heater
during such circulation of the air, valve g is opened, and valves g¹ and g² are
closed, thus cutting out the heater. This would not likely occur as long as cold.
air is being forced in by the compressor. When the air pressure in cylinder A has
reached the maximum desired, valve is closed and valve g had better be closed
also and valve i opened instead, and the blower K, used to give the necessary circulation
to keep the compressed air at the required temperature by passing it through the
heating coils of the furnace for the reason that the fan blower is likely to work better
than the compresser with the air at a high temperature. Meantime as there are
preferably several storage tanks D only one of which is shown and usually only one
at a time being used for precipitating the moisture of the compressed air the
compressor may be used to advantage in forcing air into such auxiliary storage
tanks, the pressure in which latter should reach something more than the maximum
pressure wanted in cylinder A, so that if it is desired to increase the pressure in
cylinder A at any time, for instance, during the latter stage of the process, it may
be done by admitting air from these reserved tanks rather than resorting direct to
the compressor.
When such auxiliary storage tanks are provided and kept charged
with compressed air, the air from these tanks may be used to advantage, and first
filling cylinder A and much time may be saved by such practice over filling the
cylinder entirely from the compressor. Such auxiliary tanks are all connected in
the pipe system substantially like the tank shown so that either of them may be
used in connection with heater and furnace E. I will remark that it will be
better practice to provide a series of small furnaces E with the heating coils
passing through the series rather than rely on one large furnace for the reason
that one or more such furnaces may be used at a time as may be required and the
temperature, passing through the heating coils can be better regulated than with
one large furnace. After the wood has been treated from four hours to twenty
four hours and subjected meantime to a temperature of from two hundred and
twenty five to four or five hundred degrees Fahrenheit according to the variety
and dimensions of the wood, and the uses for which the wood is intended,
cylinder A and contents is cooled down in the following manner. With
valves f g g h h² and i closed and with valves f g and open, the compressor is
set in motion to force cold air into cylinder A, such air of course passing by the
heater and furnace, but passing through tank D for the purpose aforesaid. The
safety valve L is set to maintain the maximum pressure had during the vulcanizing
process and the surplus air had by operating the compressor is blown off through
valve L. As the temperature in cylinder A becomes reduced, safety valve L may,
from time to time be changed to reduce the pressure care being had not to reduce
the pressure below the boiling point so to speak. The operator having memorized
the table giving the degrees of heat necessary to reach the boiling point under
different pressures and with the pyrometer and pressure gauge of cylinder A
before him will have no difficulty in cooling down the wood cylinder keeping
always such a pressure therein as to preclude the possibility of the sap boiling in
the wood and when a temperature somewhat below two hundred and twelve degrees
Fahrenheit is reached, the air pressure may be dispensed with and the wood cylinder
opened and its contents discharged. The method herein described marks a radical
advance in the art of vulcanizing wood. In the matter of initial cost, the apparatus
for carrying out this improved method is much less expensive than the necessary

page_text: apparatus for carrying out the old method. For instance by dispensing with the
heating coils in the wood cylinder from two to three thousand dollars is saved and
the wood cylinder is made to contain several thousand feet more of lumber. The
heating furnace and coils connected therewith are much less expensive to construct
and operate than the necessary boiler plant used with the old method. Considerablo
saving is effected by using the exhaust steam of the engine that drives the compressor
in heater Cas aforesaid. Also, precipitating the moisture of the air in tank D is
found to be of great advantage in this, that the quality of the vulcanized product is
much improved by such practice. In the absence of the heating coils in cylinder A
the latter is cooled down in perhaps a third of the time formerly required.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is.
1. The method herein described of vulcanizing wood and consisting essentially in
introducing heated air into the vulcanizing chamber and under such pressure as will
prevent the evaporation of the sap of the wood being treated substantially as
set forth.
2. The method herein described of vulcanizing wood and consisting essentially of
introducing heated air into the vulcanizing chamber under such pressure as will
prevent the evaporation of the sap of the wood being treated more or less of the
moisture of such compressed air having been precipitated before the air is discharged
into the wood cylinder substantially as set forth.
3. The methoil herein described of vulcanizing wood and consisting essentially in
compressing air and heating the same, second, precipitating the moisture of the air,
third, superheating the air and introducing such dry superheated air into the
vulcanizing chamber under such pressure as will prevent the evaporation of the sap
of the wood being treated substantially as set forth.
Dated this 5th dose of Manah 1020