IMPROVE- MENTS IN TREATING WOOD AND VEGETABLE FIBRE IN GENERAL TO PRESERVE A communication SAME FROM DECAY, AND IN APPARATUS EMPLOYED THEREIN
Year: 1876

page_text: LETTERS PATENT to Edward Thomas Hughes, of the Firm of Hughes and Son,
Patent Agents, 123, Chancery Lane, London, for the Invention of "IMPROVE-
MENTS IN TREATING WOOD AND VEGETABLE FIBRE IN GENERAL TO PRESERVE
A communication
SAME FROM DECAY, AND IN APPARATUS EMPLOYED THEREIN."
from abroad by John Bennington Blythe, of Bordeaux, France.
Sealed the 21st December 1876, and dated the 27th June 1876.
PROVISIONAL SPECIFICATION left by the said Edward Thomas Hughes at
the Office of the Commissioners of Patents on the 27th June 1876.
EDWARD THOMAS HUGHES, of the Firm of Hughes and Son, Patent Agents,
123, Chancery Lane, London. "IMPROVEMENTS IN TREATING WOOD AND VEGETABLE
FIBRE IN GENERAL TO PRESERVE SAME FROM DECAY, AND IN APPARATUS EMPLOYED
THEREIN." A communication from abroad by John Bennington Blythe, of Bordeaux,
France.
"
This Invention relates to further improvements upon an Invention for which
Letters Patent were granted to me bearing date the 22nd of October 1873,
No. 3437, a communication from the said John Bennington Blythe. Instead of
heating by fire directly applied under the boiler containing the mixture of carbolic
carburetted steam," I
acid, heavy hydrocarbon oil, or creosote and water to make
heat and agitate the mixture in the boiler by high-pressure steam, superheated or
not, blown into it, and I drive the mixed steam so made through pipes into the
oven or cylinder containing the matter to be treated by the action of high-pressure
stean, superheated or not, introduced into the said pipes as often as necessary
between the boiler and the cylinder. The use of these discharges of steam is to
exhaust the vapour from the boiler and force it into the cylinder or oven at a
higher pressure and temperature than exists in the boiler in which it is raised.
These compound discharges are formed by admitting high-pressure steam through
small pipes inside the larger pipes that conduct the vapour from the boiler and
can be introduced at any part of the pipes; but I prefer to let the mixed steam pass
into the ovens through concentric conical discharge pipes in which the high-pressure
steam escapes into the centre of a double cone forming the discharge in much the
same manner as is well known for the injection of water, and arranged to pass gases
instead of liquid.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edward Thomas Hughes in the Great Seal Patent Office on the
26th December 1876.
EDWARD THOMAS HUGHES, of the Firm of Hughes and Son, Patent Agents,
123, Chancery Lane, London. "IMPROVEMENTS IN TREATING WOOD AND VEGETABLE
FIBRE IN GENERAL TO PRESERVE SAME FROM DECAY, AND IN APPARATUS EMPLOYED
THEREIN." A communication from abroad by John Bennington Blythe, of Bordeaux,
France.
This Invention relates to further improvements upon an Invention for which
Letters Patent were granted to me, bearing date the 22nd October 1873, No. 3437,
a communication from the said John Bennington Blythe.
In carrying these improvements into effect I proceed as follows:-Instead of
heating only by fire applied directly under the boiler containing the mixture of
carbolic acid, coal or wood tar, heavy hydrocarbon oil, known as creosote, and water
to make "carburetted steam," I heat and agitate the mixture in the boiler by high-
pressure steam (superheated or not) blown into it, and I drive the mixed steam so
made through pipes into the oven or cylinder containing the wood to be treated by
the action of high-pressure steam (superheated or not) introduced into the said pipes,
and by preference concentrically therewith, as often as necessary between the boiler
and the oven or cylinder. The use of these discharges of steam is to exhaust the
vapour from the boiler and force it into the cylinder or oven at a higher pressure
and temperature than exists in the boiler in which it is raised, and to prevent the
settling down of the hydrocarbon matter in the boiler, and thus avoid the burning
of the plates over the fire. These compound discharges are formed by admitting
high-pressure steam through small pipes inside the larger pipes that conduct the
vapour from the boiler and can be introduced at any part of the pipes; but it is
preferred to pass the mixed steam into the ovens through concentrical conical
discharge pipes in which the high-pressure steam escapes into the centre of a double
cone forming the discharge, in much the same manner as is well known for the
injection of water, but arranged' to pass gases instead of liquids. It is also preferred
to discharge the steam at the bottoin of the matter in the boiler through a pipe or
pipes, in which a number of holes equivalent to the area of the discharge pipe have
been drilled; this arrangement allows "carburetted steam" to be made as fast as
the treatment of the wood in the oven requires it.
By this Invention I am enabled to treat wood in far less time than heretofore,
and also to effect a saving of about 25 per cent. of fuel as well as of a considerable
quantity of hydrocarbon matter heretofore necessary. I treat a charge of railway
sleepers in an hour with a consumption of about one pound of good coal per cube
foot of wood in the charge. The tar, heavy coal oil, or other hydrocarbon matter
used varies, according to the quantity of carbolic or phenic acid it contains. About
one ounce of carbolic acid of commercial strength or 6 to 8 ounces of heavy coal tar
oil is sufficient to treat a cube foot of wood. The consumption of fuel also much
depends upon the economical generation of steam in the boiler as well as on the
state of dryness of the wood.
The chemical action that takes place in this process is brought about by a
circulation of steam charged with a small quantity of carbolic acid acting upon
wood in an oven, and as the carburetted steam condenses in the oven and the wood
gives off its sap, a part of it with oily tarry matter is returned to the boiler and
keeps up the supply of carburetted steam. This circulation is greatly improved
and increased in rapidity according to the number of discharges or exhausts that
are used, for as the pressure is increased on one side of the jet it is diminished on
the other, and it follows that the greater the difference of pressure between the
oven and the boiler the quicker the condensed matter in the oven will return to
the boiler, so that the operation is entirely dependent upon the quantity of high-
pressure steam raised and used in a given time to heat a proportionate quantity of t
wood.

page_text: The apparatus designed and employed in carrying out this Invention will be
clearly understood and ascertained by the following description thereof and the
accompanying Drawings, reference being had to the figures and letters marked
thereon, and in which Drawings-
Fig. 1 is a longitudinal vertical section on line A, B, of Fig. 3; Fig. 2 an elevation
partly in section on line C, D, of Fig. 1; Fig. 3 a plan or top view.
Fig. 4 diagram showing arrangements for introducing mixed steam and vapour
into oven.
Fig. 5 is a transverse section in line A, B, of Fig. 6, and shows the compound
jet as applied to a portable apparatus.
Fig. 6 shows arrangement of portable ovens and tanks for treating and immersing
wood and closing the pores thereof.
Figs. 7 and 8 are transverse and longitudinal sections on lines A, B, respectively
of said Figures, the same representing a portable dipping apparatus.
The apparatus is composed-
Firstly, of two or more cylinders or ovens (two are shown, a, Fig. 2, and a¹, a¹¹,
Figs. 5 and 6) strong enough to support five atmospheres inside pressure.
Secondly. A steam boiler bin which high-pressure steam is generated at a pressure
of about six atmospheres, to which can be added a superheater if necessary.
Thirdly. A boiler d to make the carburetted steam.
Fourthly. A separating vessel i through which the condensed matters pass (when
necessary to separate thein) in returning to the boiler d.
Fifthly. A charging vessel; and
Sixthly. A condenser or closed tank.
The oven a, the steam boiler b, and the carburetted steam boiler d are set in brick-
work when they are not required to be made portable, and the flues from the steam
boiler fire are carried round each of them to the chimney ¹, dampers being arranged
so that the heated gases can be made to pass through the flues of either cylinder on
their passage to the chimney The pipe with cocks f¹, Figs. 3 and 5, forms the
communication between the boiler d and the ovens a, a¹, and a", by the discharge
passages f1, Figs. 1, 4, and 5. The pipes g and cocks g¹ pass the steam from
boiler b by the outlets g" into the centres of the discharges f", as more clearly
shown in Fig. 4. A pipe a, with stop-cock x³, conducts the steam from the boiler b
into the boiler, where it serves to agitate the mixture in the boiler. The pipes /,
with cocks h¹, discharge the ovens into the separator i, Figs. 2 and 3, the said
separator is fitted with cocks which allow of any part of its contents to be discharged
into the boiler & so as to retain either the heavier or the lighter part of the condensed
matter, as may be necessary, or to pass the whole into the boiler by the stop-cock i².
The box safety valves o open a communication between the ovens or cylinders a by
the pipe of, by which pipe the steam is discharged from one oven into the other
when an operation is finished in either of the ovens. A vessel p, Figs. 2 and 3,
or p, p, Fig. 6, receives and condenses the steam and liquid residue when it is let
off from the ovens by the pipes and stop-cocks . I sometimes use two or more
tanks and condense in them alternately; I run off the water and sap from which
the oil or tarry matter has settled and mix the deposit with more oil or tar. I fill
the oven from which I have condensed the steam with the oil and tarry matter,
forcing it back again through the pipe by a pressure obtained from another oven,
which comes into the tank by the pipe v, shown in Fig. 6. A tank y contains the
heavy hydrocarbon oil or other matter to supply the boiler & through the charging
0 vessel, the said vessel being composed of the vessel proper 7, stop-cock r³, which
opens into the tank y, the pipe and stop-cock which connect it with the boiler d,
and the pipe m, with stop-cock, which lets in steam when necessary so as to
force the oil or other matter into the boiler by pressure, or this may be done by a
force pump.
5
I will now describe the treatment of a charge of railway sleepers by this process.
The boiler d is charged with water (about one gallon to each cubic foot of wood
I find to answer very well), and the wood is passed on trucks or trollies into one

page_text: of the two ovens. The steam being "up" in the boiler b (90 lbs. to the square inch,
or thereabouts being preferred) it is let into the boiler & through the pipe x by cock x¹,
the stop-cock g¹ in the pipe g is opened to let steam into the discharge pipe f¹ in the
pipe f, and the stop-cock f¹ is also opened to allow the mixed vapour to pass through
the pipe finto the oven in use; I then open the return pipe h. I now run into the
charging vessel 1, or I pump into the boiler d, the tar, heavy oil, or carbolic acid that is
required to treat the wood, which is generally about four gallons of coal tar oil, or three
to four pounds avoirdupois of carbolic acid of commercial strength, according to its
quality, to each load of fifty cubic feet of wood in the oven, care being taken that
there is not too great a quantity of carbolic acid present so as to avoid excessive
shrinking of the wood. Whatever matter is employed it is heated in the boiler d by
the fire c, which passes under the steam boiler 6, steam being let in by the pipe x,
which, as it becomes charged with hydrocarbon, escapes through the pipe f and
discharge pipes f¹¹, from whence it is forced into the oven a mixed with the high-
pressure steam escaping from the discharge pipes g¹¹ of the pipe g. This action of
the high-pressure steam drawing and forcing in the mixed steam into the oven is
stronger, as the difference of pressure on the steam boiler b is in excess of the
pressure in the oven a. I continue to let in steam, as I have described, until the
pressure in the oven a reaches 60 lbs. to the inch, more or less, according to the
requirements of the wood under treatment, although 60 lbs. I find to be generally
sufficient for the hardest kinds of wood. It is sometimes necessary to maintain
this pressure half an hour or more if the wood is very wet or green, but in wood as
it is generally found, even in winter, it is not often necessary to keep up the pressure
after it has reached 60 lbs. to the inch in the oven, whatever the cube of the wood
may be. During the operation a circulation of steam charged with hydrocarbon
from the boiler & completed by a return of condensed tarry matter from the oven a
to the boiler d is kept up by the high-pressure steam. The vapour in the oven
penetrates the wood across the fibres and drives out the sap in the longitudinal
direction (generally speaking) of the fibre by the ends of the pieces. I sometimes
separate the sap from the oily matter in the separator i, drawing off the lighter and
allowing only the heavier tarry matter to return to the boiler d.
The treatment of railway sleepers usually takes with my process and apparatus
one hour, but it can be regulated by the quantity of steam used for any quantity
of wood so as to treat any quantity in any given time. When the treatment
is finished in one oven the mixed vapour in it is blown off into the other
oven that has been charged with other wood in the same manner as the first by
lifting the box safety valves o, and as soon as the pressure has fallen to an
equilibrium in the two ovens I shut off all the cocks from the first oven and open
those that blow the carburetted steam into the second oven, as before explained,
I then blow off from the
and so commence the treatment in the second oven.
boiler & the matter, if any, that may be in excess, so as to maintain in that boiler a
proper working level, and I charge it with as much carbolic acid, creosote, oil, or
I continue the
other matter as may be required for the wood in the second oven.
treatment as in the case of the first oven, and so on alternately from oven to oven
so long as may be required; I also let off the vapour and residue that remains in
the first oven into the condensing vessel p, then open the oven and take out the
wood. In this state wood can be compressed either by rollers or moulded and
designs given to it for cabinet and other purposes. Wood for all purposes is made
stronger by my process even without rolling, and when it is not required to resist
water or to be rendered incombustible the treatment can be stopped at this stage,
as the wood is sufficiently preserved against rot; or the wood may be saturated
with solutions that will render it impervious to water and damp or incombustible
either while it is in the oven after the treatment or as soon as it is taken out of it.
If I saturate the wood in the oven I open the cock communicating between the
oven a¹ and the closed tank pl, and the cock v, Fig. 6, communicating between all
Fig. 6, and the closed tank pl, the oil and other matter in the two tanks will be
forced into and fill the oven a¹; this pressure may be continued until a sufficient

page_text: quantity of the oil in the tanks is forced into the wood in the oven, or the cock
may be closed and the box safety valves o on the top of the two ovens opened;
the pressure in the oven al will make the pressure on the oil in the oven a¹ as long
as may be necessary, and so on alternately with any number of ovens, as before
described. By this process I put into any wood quantities varying from 20 to 40
per cent. of its dry weight (of course the quantity that can be forced into wood
varies with its specific gravity), but any wood, heart of oak for instance, can be
thoroughly saturated with oils or incombustible solutions by this process of
pressure in the ovens after my treatment. When a sufficient quantity has been
absorbed the oil is let down into the closed tanks by opening the cock and the
air-cock T, the wood is taken out, and can then be compressed, if necessary, by
rolling or otherwise. The oven is recharged and the operation is recommenced by
letting off the steam from the oven a¹¹ into the oven a¹ and continuing with the
oven all the saturation as described for the oven a¹.
This arrangement of apparatus is particularly applicable to the treatment of
paving blocks or railway sleepers, as it may be mounted on wheels or on railway
trucks, the steam boiler band the oil boiler & being also placed on wheels or on a
separate truck, and connected with the ovens by pipes.
In other cases, as for cabinet work, and where it is required to color as well as to
preserve the wood, I use a tank, as shown in Figs. 7 and 8, in which the wood
placed in the openings in the discs q is carried into the dipping liquid, and after
immersion remains to drain over the liquid; or it can be passed repeatedly
through it.
apply the process and apparatus here above described to the treatment of sail-
cloth, cordage, and vegetable fibre in general.
Having now described the nature and particulars of the said Invention, and
shown by the Drawings and description how the same may be carried into effect,
I claim-
First. The use of high-pressure steam (superheated or not) to make carburetted
steam in the boiler d and to pass it into the cylinder or oven a, substantially as
described and shown in the Drawings.
Second. The use of mixed concentric jets or discharges of carburetted and high-
pressure steam, one of which is shown in Fig. 4, as applied to treat wood and
vegetable fibre in general, whereby a jet of high-pressure steam (superlicated or.
not) is made to mix with and give pressure to a current of hydrocarbon vapour or
carburetted steam, substantially as shown and described.
Third. The method of saturating wood and vegetable fibre with liquids after
treatment in the oven or cylinder in which the same has been treated, and of
forcing in the liquids into the said wood or vegetable fibre by the pressure of gases
generated from the treatment of other wood or fibre in another oven or cylinder,
substantially as set forth.
Fourth. The general arrangement and combination of apparatus as applied to
the treatment of wood and vegetable fibre, substantially as herein set forth and
shown in the Drawings.
In witness whereof, I, the said Edward Thomas Hughes, have hereunto set my
hand and seal, this Twenty-third day of December, in the year of our Lord
One thousand eight hundred and seventy-six.
ET. HUGHES. (L.S.)