IMPROVEMENTS IN TREATING TIMBER WITH ANTISEPTIC OR PRESERVATIVE FLUIDS
Year: 1879

page_text: LETTERS PATENT to Samuel Bagster Boulton, of No. 64, Cannon Street, in
the City of London, for the Invention of "IMPROVEMENTS IN TREATING
TIMBER WITH ANTISEPTIC OR PRESERVATIVE FLUIDS."
PROVISIONAL SPECIFICATION left by the said Samuel Bagster Boulton
at the Office of the Commissioners of Patents on the 15th May 1879.
SAMUEL BAGSTER BOULTON, of No. 64, Cannon Street, in the City of London.
"IMPROVEMENTS IN TREATING TIMBER WITH ANTISEPTIC OR PRESERVATIVE
FLUIDS."
In treating timber with antiseptic or preservative fluids, such as the heavy oils
of tar, commonly called creosote, or other oily or bituminous liquids, it is of impor-
tance that before such fluid is forced into the timber the latter should be freed as
much as possible from all moisture, such as sap and watery particles contained in
its cells, and in order to effect this it has heretofore been necessary either to stack
the timber for a considerable length of time in the open air, or to adopt various
artificial methods of dessication, which last have been found to be open to many
practical objections.
My present Invention has for its object to obviate the loss of time, and also the
labour, expenses, and other inconveniences attendant upon drying the timber by
the methods above described before subjecting it to the action of the creosote, and
also to enable a greater amount of moisture to be expelled from the timber than
can be extracted by lengthened drying in the open air, so as to ensure its more
perfect saturation with the creosote. Any convenient form of apparatus may be
used for the process I am about to describe, but I generally make use of the well
known pressure tank or cylinder and apparatus, but with the modifications herein-
after described. The timber having been introduced into the cylinder, which is
then hermetically closed, a communication may be open with the air pump, and a
sufficient vacuum may be produced in the usual way in order to facilitate the entry
of the creosote into the cylinder, but this preliminary vacuum is not necessary to
my process. The creosote being introduced into the cylinder, I take advantage of
the fact that the creosote or other heavy oil has a much higher point of ebullition

page_text: and evaporation than the boiling point of water, and I therefore heat the creosote
to a much bigher degree than has heretofore been applied in such pressure cylinder,
and by preference to a temperature higher that that of boiling water, and sometimes
as high as 300° Fahr. or higher. The timber being subjected to this high rate of
temperature the watery. particles contained in it will become evaporated, and I
draw them off by means of an air pump which communicates by a pipe or pipes
with one or more air chambers situated on the top of the cylinder. A condenser or
worm is interposed between the said air chamber and the air pump so that the
steam and any oily particles which may accompany it are condensed, and the latter
may be separated and recovered.
It will thus be seen that by my above described Invention the watery
particles contained in the timber are subjected to a process of distillation by
the heat of the creosote in which it is submerged, assisted by the action of
the air pump and condenser, and the cells of the wood being expanded by the
heat and the escape of vapour become better adapted for the reception of the
antiseptic fluid, which enters the timber and takes the place of the evacuated
moisture. If a very high degree of temperature be applied a large quantity of
creosote will be found to have been absorbed by the wood, so that the process may
in certain cases end here, or it may be supplemented by forcing in further quan-
tities of creosote by the action of the force pump, according to the well known
method. It will be seen that by the above process I am enabled to treat the wood
while still green or saturated with sap or moisture, and in the case of floated
timber to take it direct from the water and to effect the perfect removal of such
moisture and the saturation with creosote in one and the same vessel in a com-
paratively short space of time, and in a more perfect manner than heretofore.
The heating of the creosote may be effected either by steam pipes inside the
creosoting vessel, or by fire heat applied externally thereto, or the creosote may be
heated to the required degree before being introduced into the cylinder.

page_text: "
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Samuel Bagster Boulton in the Great Seal Patent Office on the
14th November 1879.
SAMUEL BAGSTER BOULTON, of No. 64, Cannon Street, in the City of London.
IMPROVEMENTS IN TREATING TIMBER WITH ANTISEPTIC OR PRESERVATIVE
FLUIDS."
In treating timber with antiseptic or preservative fluids, such as the heavy oils
of tar, commonly called creosote, or other oily or bituminous liquids, it is of impor-
tance that before such fluid is forced into the timber the latter should be freed as
much as possible from all moisture, such as sap and watery particles contained in its
cells, and in order to effect this it has heretofore been necessary either to stack the
timber for a considerable length of time in the open air, or to adopt various
artificial methods of dessication, which last have been found to be open to many
practical objections.
My present Invention has for its object to obviate the loss of time, and also the
labour and expense, and other inconveniences attendant upon drying the timber by
the methods above described before subjecting it to the action of the creosote, and
also to enable a greater amount of moisture to be expelled from the timber than
can be extracted by lengthened drying in the open air, so as to ensure its more
perfect saturation with the creosote. Any convenient form of apparatus may be
used for the process I am about to describe, but I generally make use of the well
known pressure tank or cylinder and apparatus, but with the modifications here-
after described. The timber having been introduced into the cylinder, which is then
hermetically closed, a communication is opened with the air pump, and a sufficient
vacuum may be produced in the usual way in order to facilitate the entry of the
creosote into the cylinder, but this preliminary vacuum is not necessary to my
process. The creosote being introduced into the cylinder I take advantage of the
fact that the creosote or other heavy oil has a much higher point of ebullition and
evaporation than the boiling point of water, and I therefore heat the creosote to a
much higher degree than has hitherto been usually applied in such pressure cylin-
der under the ordinary process, and by preference to a temperature higher than
that of boiling water, and sometimes as high as from 250° to 350° Fahr. or higher.
The timber being subjected to this bigh rate of temperature the watery particles
contained in it will become evaporated, and I draw them off by means of an air
pump which communicates by a pipe or pipes with one or more air chambers
situated on the top of the cylinder. A condenser or worm is interposed between
the said air chamber and the air pump so that the steam and any oily particles
which may accompany it are condensed, and the latter may be separated and
recovered. It will thus be seen that by my above described Invention the watery
particles contained in the timber are subjected to a process of distillation by the
heat of the creosote in which it is submerged, assisted by the action of the air p
r pump
and condeuser, and the cells of the wood being expanded by the heat and the
escape of vapour become better adapted for the reception of the antiseptic fluid
which enters the fluid and takes the place of the evacuated moisture. If a very
high degree of temperature be applied a large quantity of creosote will be found to
have been absorbed by the wood, so that the process may in certain cases end here,
or it may be supplemented by forcing in further quantities of creosote by the action
of the force pump according to the well known method. Or this second part of
the process may be carried out and the supplemental quantity of creosote forced
into the wood by substituting for the action of the ordinary force pump the pressure
of steam, gas, or compressed air, as pointed out in the Specification to my Patent
of 16th March 1865, No. 734. It will be seen that by the above process I am
enabled to treat the wood while still green or saturated with sap or moisture, and
in the case of floated timber to take it direct from the water and to effect the

page_text: removal of such moisture and the saturation with creosote in one and the same
vessel in a comparatively short space of time, and in a more perfect manner than
heretofore.
The heating of the creosote may be effected either by steam pipes inside the
creosoting vessel, or by fire heat applied externally thereto, or the creosote may
be heated to the required degree before being introduced into the cylinder.
I claim in respect of the treatment of wood by antiseptic or preservative
fluids,―
First. The method herein described of distilling or expelling the watery particles
from the wood inside closed vessels by means of the highly heated creosote or
other liquid with which the wood is to be impregnated, the resulting steam and
other vapours being exhausted from the vessel and condensed as they are generated.
Second. The method herein described of distilling or expelling the watery
particles from the wood inside closed vessels by means of the highly heated creosote
or other liquid with which the wood is to be impregnated, the resulting steam and
other vapours being exhausted from the vessel and condensed as they are generated,
and the wood being subjected to pressure in the same vessel after completion of
such distillation in order to cause the more perfect penetration of the liquid into
the cells.'
In witness whereof, I, the said Samuel Bagster Boulton, have hereunto set
my hand and seal, this Fourth day of November, in the year of our Lord
One thousand eight hundred and seventy nine.