Improvements relating to the Preparation and Treatment of Wood for the Preservation of the same; and Apparatus therefor.
Year: 1885

page_text: Improvements relating to the Preparation and Treatment of
Wood for the Preservation of the same; and Apparatus
therefor.
ر
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co, Patent Agents,
Southampton Buildings, in the County of Middlesex do hereby declare the nature
of my invention for "IMPROVEMENTS RELATING TO THE PREPARATION AND TREAT-
MENT OF WOOD FOR THE PRESERVATION OF THE SAME, AND APPARATUS THEREFOR
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
"
This invention is designed for the preparation of wood to receive antiseptics,
and for the application of antiseptics to the wood so prepared.
It is well known that if the sap be removed from timber and its place supplied
by antiseptics a considerable improvement in the durability of timber can be
made.
Among the processes which have been devised for this purpose, one very satis-
factory, upon the whole, was invented in 1869 by Charles Karmrodt, and Nicholas
Thilmany, which is called the Thilmany process. This consisted of three steps;
First, the removal of the sap by a water treatment; second, the saturation of the
wood with a solution of chloride of barium; and third, a subsequent saturation
with sulphate of copper. Their process of driving the water and solutions into
the timber was by gravity and absorption through the ends of the logs. No
machinery except a log cap and pressure pipe was described in their US patent
of March 30th 1869, for performing the work. And it is obvious that impreg-
nation of timber in the manner described in said patent would be a tedious and
difficult process.
In order to perform the work in a large way upon logs of timber, it was desirable
to have machinery adapted for this purpose, and as it was intended to handle large
weights of timber it was desirable to do this work by power.
It has also been found in the interval between Thilmany's invention and the
present time that the use of heat and high pressures will improve and accelerate

page_text: the work. And so it has been common to use for the purpose of impregnating
timber, either by this or other processes, large steaming cylinders to which pressure
can be applied.
Inasmuch as sulphate of copper is used in this process, it is practically essential
that the cylinder to be employed shall be a copper cylinder, and that the pumps
and pipes shall be copper or bronze to a very large degree. But copper is a metal
BO Busceptible to the action of heat that if the steaming of timber is conducted in
the ordinary way in a large cylinder of copper, that is, if the steam is admitted
only at one point, the copper cylinder will expand on one side so much more than
on the other side as to be speedily injured by the working of the joints.
One part of this invention relates to a means of preventing this action; another
part of the invention relates to the arrangement for handling into and out of the
cylinder the heavy loads of timber that are to be treated. Another part relates to
the arrangements adopted for mounting the cylinder so that the sap and materials
used for impregnation can be readily introduced and removed. Another part
relates to the machinery and method of applying pressure to the cylinder. Another
part relates to the general arrangement and combination of the machinery in a
compact form for the purpose of accomplishing the desired result.
In the drawings an apparatus and portions of an apparatus for treating timber
nearly 100 feet or 30 meters long are represented. The cylinder is supposed to be
a copper cylinder.
Fig. 1 is a plan, on about the scale of a twelfth of an inch to a foot of the entire
apparatus, (
scale).
Fig. 2 is a side elevation of the apparatus.
Fig. 3 is a front elevation of the apparatus upon a scale three times as large as
that adopted for Figs. 1 and 2.
Fig. 4 is a transverse section of the cylinder on a still larger scale on the line xx
of Fig. 1, showing certain pipes and connections in elevation.
Fig. 5 is a transverse section showing the impregnating cylinder and the timber
car used therein near the front end of the cylinder, and illustrating the means
employed to lock the car down and steady it in the cylinder during the progress
of impregnation.
Fig. 6 is a vertical section of the back end of the cylinder showing the timber
cars in position, and illustrating the means adopted to lock the cars together and
lock them down at the back end, and also the construction of the cylinder at the
back end for the purpose of allowing the cars to be drawn in by power.
Fig. 7 is a horizontal section at the back end of the impregnating cylinder, with
an unloaded car in place.
Fig. 8 is a side elevation of the impregnating cylinder and the pressure pumps
employed with the gauges and attachments; and this view is taken from a position
at or near the point y on the plan view Fig. 1.
The views Figs. 1 and 2 are on a scale of about 1 of the large apparatus, and
Fig. 3 about a forty eighth of the large apparatus, while the views in Figs. 4, 5, 6, 7
and 8 are on a scale of about a twenty fourth of the large apparatus.
Like letters indicate like parts in all the figures.
In describing the apparatus and the relation of the parts to each other, it will
be best to give a description at the same time of the relation of the apparatus to
the process performed by it.
In order that the cylinder may be properly inspected it is mounted over a pit,
shown at A, Figs. 2 and 3, which pit at or about the place of the section line xx
is made considerable wider than it is at other points, as shown in Fig. 3 at B and
in Fig. 4 at B. In this enlarged portion of the pit, which extends for about the
distance shown in Fig. 2, between the points b b, are placed the principal parts of
the piping which form the outside lower connections with the interior of the
steaming cylinder. These are called the lower dome.
The cylinder is properly mounted and set over the pit, and is marked in the
drawings C O¹, Figs. 1 and 2. This cylinder is riveted up in substantially the

page_text: same way that a cylindrical steam boiler is riveted up, and at its front end C there
is a door that can be securely packed and tightly fastened. Through this door the
timber is to be introduced.
The railroad track, marked D, extends up to the front end of the cylinder, and
on this track the cars stand while receiving their load of timber, and over it they
are rolled up to the door of the cylinder.
A continuation of this track extends into the cylinder for substantially its
whole length, as shown at d d, Figs. 4, 5 and 6.
The cars which are employed to carry in the timber are of comparatively short
lengths, about eight feet, or two & a half meters as shown in Fig. 6. They are
made with longitudinal timbers between which the wheels are adapted to revolve,
which timbers are marked E E. Transverse timbers e e bind these longitudinal
timbers together on each side of the wheels, above and below the longitudinal
timbers. Metallic hoops at the ends of each car, substantially conforming in shape
to the interior of the cylinder are made fast to the transverse timbers 6 of the car
and serve to hold the timbers down to the car. These hoops are marked in the
drawing, Figs. 4 and 5, e¹.
car.
Between the longitudinal timbers E, which form the bed of the car, at the part
of the car which is to be the back end, are placed projecting spurs, marked E¹.
These spurs in the car that is run to the back end of the cylinder, lock under a
transverse beam F, which thus serves to hold down the back end of the nearest
These spurs E¹ of the succeeding cars lock under the transverse timbers of
the preceding car, and so lock the cars successively together from one end of the
cylinder to the other. At the front end near the door, the end of the car of the
train close to the door is locked to the rails d by means of the hooks shown in
Figs. 5. The interior longitudinal beams E have small recesses cut in their ends
large enough for the reception of two S-hooks ff, one end of which S-hooks is
adapted to hook into the top of the longitudinal timber E, and the other end to go
under the lateral projection of the rail head upon its outer side. These S-hooks f,
if desired can be applied to the ends of each car, but it is not usually desirable to
do it.
By this system of locking cars to the cylinder the cars themselves are prevented
from flotation when the cylinder is full of the impregnating fluids, and the bands
or hoops e¹ fastened to the car and going over the timber prevent the timber from
being displaced on the car in the cylinder by similar flotation. I also block the
timber away from the cylinder by wedges inserted after the cars are in place.
In order to draw the cars into the cylinder, at the back end is made a man-hole,
shown at F in Figs. 6 and 7. Through this man-hole, when it is required to draw
a train of cars into the cylinder, is passed a rope g, which rope is shown in plan at
Fig. 1 and Fig. 7 and in elevation in Fig. 6, and which leads to the steam winch G,
by means of which the timber-loaded cars are drawn into the cylinder, and when
drawn in the rope g is detached from the back end of the train and the man-hole F
is packed by its cover.
As an essential part of this apparatus there is a steam boiler H for heating the
impregnating solutions and for steaming the wood. This boiler is shown in Fig. 3.
Steam pipes 8 are led from the boiler with branches to the steam pumps I and K,
Fig. 1, for the purpose of supplying the pumps with the steam necessary to work
them, one of these pumps, I, is a liquid pump, and the other, K, an air pump, and
these pumps are connected with the two domes of the cylinder, the air pump to
the upper dome, represented at L, Fig. 2, and the liquid pump I to the lower
dome, M, Fig. 2, and other branches of steam pipes a lead to the tanks O and P for
the purpose of heating the liquids therein contained, one of which is to be chloride
of barium, and the other sulphate of copper. Still other branches of the steam
pipes s lead to the domes L and M. Each branch is controlled by a valve s¹.
The air pump K can be used both as an exhaust pump and as an air pressure
pump. The steam connection through the lower dome M with the interior of the
cylinder c c is not for the admission of free steam directly into the cylinder at

page_text: that place, but it admits steam into the perforated pipe, shown at h, Figs. 4, 6 and 7,
which runs through about two-thirds of the length of the cylinder in its longi-
tudinal lower centre. Steam admitted through the upper steam dome L is admitted
through it directly to the cavity of the cylinder.
This perforated steam pipe h, it will be observed in Fig. 7 lies betweon the
tracks d d.
On admitting the steam from the boiler into the cavity of an impregnating
cylinder through the upper and lower domes, and particularly through the lower
dome to the steam pipe h, which lies along nearly the whole length of the central
part of the cylinder, the steam striking against the shell of the boiler will
expand it, and following up the sides will continue to expand it, so that the
cylinder will be comparatively equally expanded on all sides at once. In letting
on steam it should first be admitted through the lower dome.
Of course the mounting of the cylinder over the pit must be such mounting
as well allow the cylinder to move a short distance at each end in consequence
of this expansion, which begins at the centre and is propagated towards each end.
The cylinder having been loaded with timber run in on the cars, and carefully
locked up, the wood is first thoroughly steamed, and by steaming, the soluble
matters and the sap are dissolved in the steam and hot water so introduced.
The pressure of the steam in the boiler may be observed when desired by one of
the gauges m m³, near the steam boiler H, one of which gauges is a pressure gauge
and the other a vacuum gauge. On the same connection with these gauges m m¹
is mounted a thermometer m³ serving to mark the temperature. The bulb of this
thermometer dips into the cavity of the cylinder. I prefer to use the ordinary
mercury thermometer at this place because of the likelihood of a thermometer of
the pressure gauge sort giving disproportionate results on account of the alternating
pressures and exhaustions which occur in the interior of the cylinder.
When the wood has been steamed sufficiently long, which will vary according to
the character and quality of the wood operated on, and which is judged of by the
operator, usually a period of three to six hours, more or less, the water of
condensation and sap are drawn off into the pit through the waste cock n at the
bottom of the lower steam dome, (see Fig. 2). When all the sap and water of
condensation that will run out by gravity have been removed, the waste cock n is
closed and the air pump K set to work to create a vacuum in the steaming
cylinder, and thereby remove from the wood a still further quantity of sap, which
in its turn is allowed to run to waste in the pit.
•
On reference to the Karmodt-Thilmany patent already referred to it will be seen
that the impregnation of wood was directed to proceed in the order of, first, applying
the solution of chloride of barium, and secondly, the solution of sulphate of copper.
I prefer a different order, and am of opinion from experience that it is better to
introduce the sulphate of copper solution first. In order to do this crystals of
sulphate of copper are dissolved in the tank o, and crystals of chloride of barium
in the tank p, making in each a saturated solution. These two tanks stand over
the larger tanks O, P, which are filled with working solutions, the bottoms of which
tanks are above the cylinder c c', so that their contents will readily flow into the
cylinder through the pipes o¹, p, which lead to the lower dome M, and are
governed by two stop valves each o³, o³, p' p³ between the bottom of the tank
and the lower dome. Between each pair of these two sets of stop cocks o², o³, p³ p³
is placed a coupling cock n¹ having on it a coupling to connect a hose n³ to the
return pipe n³ for return of the impregnating liquids to their tanks.
From the sulphate of copper tank O, in addition to the pipe o¹ which leads to the
lower dome, there is another and smaller pipe W, shown in plan Fig. 1, which
leads to the force pump I, by means of which after the cylinder has been filled as
full as it can be by gravity, further quantities of solution may be pumped in to
put pressure upon the interior of the cylinder. This steam pump being practically
automatic and having its speed regulated by the resistance of the work to a

page_text: considerable degree, is to be worked until it is practically stopped by the resistance
of the cylinder pressure employed.
The pump so employed with the sulphate of copper solution must of course be
of gun metal or bronze to prevent injurious action of the solution upon the
working parts of the pump. But I prefer to use the air pump K, worked as an
exhaust to draw in the solution, and the pump I only to put pressure on to a filled
cylinder.
Provision has been made as already described for heating the solution in the
tanks before it enters the cylinder, or at the same or a different time that the
pump is pumping in the solution steam may be admitted to the perforated steam
pipe; but usually the heat of the solution itself will be sufficient to enable the
sulphate of copper to penetrate the wood under pressure.
The strength of the solution which I employ is usually about five in weight of
sulphate of copper to a hundred in weight of water, a five per cent. solution, and
it will take for ordinary kinds of wood about six to nine hours for the thorough
absorption of the sulphate of copper solution at a hundred pounds' pressure, and a
heat of about a hundred degrees Fahrenheit.
The connection from tank O to the lower dome M is like that from tank P
to the same place. At least two stop valves o³ 03 are inserted in the pipe o, and
a coupling cock n¹ interposed between them. The dome M opens into the interior
of the cylinder. If the valve o' is shut, and the valve o' is open, the interior of the
cylinder communicates with the cock n¹. If a hose n' be coupled to this and to
the pipe and the cock n¹ be opened, the cylinder pressure will drive the solution
very rapidly out. It would not be desirable to open the pipe o at one hundred
pounds (the usual) cylinder pressure, and so by this arrangement and work of the
valves and cock n¹ the cylinder pressure is broken to about twenty pounds, and
then the valve o opened and coupling cock is closed and the solution forced back
to tank O through its bottom, as hereinafter described.
When the wood has taken a sufficient quantity of the sulphate of copper, a
connection is made through the lower dome and waste cock n¹ by means of the
hose n, with a pipe n³, Fig. 4. Only one of the pipes which are represented
by n³ is shown in the drawing, Fig. 4, but both are shown in Fig. 1. This pipe
may lead to the suction side of the pump I, in order that the cylinder may be
pumped out through the pump I and back into the tank; or it may lead directly
to the sulphate of copper tank, or it may lead to a tee, which tee has branches
leading to the sulphate of copper tank, and also to the chloride of barium tank,
each of which branches would be controlled by a stop cock.
It is not usually advisable to pump back all the sulphate of copper solution
through the pump, and it is never advisable to pump the chloride of barium
solution through the pump. So that in order to get the solutions back into the
tank it is preferable to have two pipes n³ for returning the solution, and to apply
to the cylinder C C¹ air pressure through the air and vacuum pump K, keeping
the cylinder closed except at the return pipe, by which the solution will be driven
back through the lower dome, coupling cock n, and through the hose n* and stand
pipe n³ till the pressure is broken, and then through pipe o to the proper tank.
When the sulphate of copper solution has been removed from the cylinder and
restored to the tank, it is to be tested by the hydrometer, and its proper working
strength restored by putting in additional crystals or better saturated solution
from tank o to bring it up.
All connection between the cylinder and the sulphate of copper tank being first
shut off, the chloride of barium solution is now allowed to run into the cylinder
through the lower dome by gravity, and by the air pump K worked as an exhaust
pump. When the chloride of barium solution has filled the cylinder, instead of
pumping a portion of the solution through the pump I, which I have found by
experience to be injurious to the pump, I apply the necessary pressure through the
pump I by pumping water into the impregnating cylinder, and by this means can
get sufficient pressure to force the chloride of barium solution into the pores of the

page_text: wood. This would require, if the water were introduced at the top, the chloride
of barium solution to be a little stronger than would be required for the amount of
copper already forced into the wood; but when water is pumped in at the bottom
it does not seem to interfere with the strength of the solution, or to make it
irregular in its quality.
.
The chloride of barium solution should be of about the strength of three in
weight of crystals to a hundred of water, or a three per cent. solution, and when
the wood has absorbed all the chloride of barium solution that it will take, the
cylinder is emptied of the solution by attaching the hose to the waste cock n¹ of
pipe p' as before, and the other end of the hose to the proper pipe, and driving
the solution back into its tank by air pressure, and the strength of this solution is
then restored to working strength.
Heat may be applied to the chloride of barium solution in the cylinder by the
admission of steam through the steam pipe, as already before described with regard
to the solution of sulphate of copper.
When the chloride of barium solution has been entirely drawn off, the loaded
cars are withdrawn from the cylinder, and the timber removed from them, when
the process may be repeated as above described.
A safety valve t is applied on the upper dome, to prevent excess of pressure, and
a gauge cock at u serves as a means of ascertaining when the exhaustion of the
air pump K has completed its work of filling the cylinder with fluids.
By use of the auxiliary tanks o and p each containing a saturated solution, the
strength of the working solutions can be more rapidly and certainly brought up,
and danger of injury to the pump I or to the valves from grit avoided.
By employing the air pump to draw in the solutions and by the use of water to
obtain pressure in the cylinder instead of pumping the solutions to obtain pressure,
iron pumps and pipes may be used instead of copper or bronze. And if water
pressure only is used, the pump I will have a force pipe w₁ branches to the
tanks O, P, o, p, and to the lower dome M and a water supply pipe w³ as shown in
Fig. 4, and will have no induction connection with the tanks. But it is believed
preferable to have a copper pump and draft and force the last part of the copper
solution by the pump L
After breaking the pressure as described by having valve o' or p³ open, and
valve o³ or p³ shut, according to the solution, by aid of the hose connection and
coupling cock n¹ and pipe n³, valves o* or ps are opened, and the solution returned to
the proper tank by the way it came, when the pipe o or p will be closed by shutting
a valve in it.
Of course the pump I, if used to pump the copper solution must be wasked out
by pumping water afterwards.
•
It will be seen that the combination of the dome M with the tank O by its
proper pipes, valves, cocks and hose is just the same as its combination with the
tank P by its proper pipes, valves, cocks and hose, and that each of these tanks O
and P alternates with the other in combination with the cylinder, and that both
may be shut off from the combination with the cylinder and the cylinder will then
only have communication through the done and waste cock n with the pit B.
It is obvious that instead of the two valves o³, o³ or p³, p³, with the cocks n¹
between them, one of the valves o³ or p³ and the cock n' might be dispensed with,
and the connection of the hose n³ made with cock n, but this would involve a
common pipe for the two solutions and be apt to injure the valves. I therefore
prefer the way described, although the principle of breaking pressure by a small
cock placed between two valves would be practiced in the case supposed.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed as communicated to
me by foreign Correspondent I declare that what I claim is
1. In combination with a wood steaming cylinder C, C¹ the two independent
steam entrances L, communicating directly with the cavity of the cylinder, and M,

page_text: in combination with the perforated floor pipe h, communicating through the
perforated floor pipe with the cavity of the cylinder at various points along the
median line of the bottom of the cylinder, one of said entrances L being at the top
of said cylinder, and the other of the steam entrances M, being at the bottom of
the cylinder, for the simultaneous admission of steam to the cavity of the cylinder,
diametrically but not necessarily longitudinally, opposite each other, above and
below the axis of the cylinder, to prevent the unequal heating and warping of the
cylinder, substantially as described.
2. In combination with the upper dome L of the cylinder C, C³, and with said
cylinder and the storage tanks O'P, the pressure and exhaust pump K, substantially
as described.
3. In combination with the cylinder C, C¹, and the tank O, the pipe o¹, and the
valves o, o³, and intermediate coupling cock n¹, substantially as and for the
purposes described.
4. The combination of the cylinder C, C¹, the perforated pipe h, the steam pipe 8,
boiler H, force pipe i, pump I, and controlling valves i¹ and 8, whereby liquid or
steam can be supplied at will to the interior of the cylinder through the perforated
floor pipe, either simultaneously or alternately, substantially as and for the purposes
described.
5. In combination with the cylinder C, C₁, the locking bunter F, substantially as
and for the purpose described.
6. The combination of the impregnating cylinder C, C³, provided with the
locking bunter F, and with a railway track upon its floor, with a series of timber
carriages, each member of which series is provided with wheels which fit and ride
upon rails within the cylinder, and with tongues E¹, at one end, and transverse
beams e at the opposite end, whereby the forward member of the series is locked
down by the engagement of tongues E¹ with the transverse bar e of the preceding
member, substantially as and for the purposes described.
7. The combination of the cylinder C, C¹, provided with rails upon its floor, and
with the locking bunter F, with the sectional timber train, by means of the
tongue El and trausverse beam e, and of the sill beams E of the rear of the last
section of the train, with the rails, by 8-hooks f, substantially as and for the
purposes described.
8. The combination of the tank P at a greater elevation than the top of the
cylinder C, C¹, with the pipe p¹ and a dome M, whereby the cylinder may be filled
with an impregnating fluid by the aid of gravity, and with an independent water
supply and pump I, whereby pressure may be put upon the contents of the cylinder
without passing the impregnating fluid through the pump, all substantially as and
for the purpose described.
Dated thin 2nd 1...N