IMPROVEMENTS IN THE MANUFACTURE OF OILS AND VARNISHES, AND IN THE APPARATUS TO BE USED IN SUCH MANUFACTURE
Year: 1879

page_text: LETTERS PATENT to Thomas Henry Gray, of Livingstone Road, Clapham
Junction, in the County of Surrey, Varnish Maker, for the Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF OILS AND VARNISHES, AND IN THE
APPARATUS TO BE USED IN SUCH MANUFACTURE."
PROVISIONAL SPECIFICATION left by the said Thomas Henry Gray at the
Office of the Commissioners of Patents on the 23rd June 1879.
THOMAS HENRY GRAY, of Livingstone Road, Clapham Junction, in the County
of Surrey, Varnish Maker. "IMPROVEMENTS IN THE Manufacture OF OILS AND
VARNISHES, AND IN THE APPARATUS TO BE USED IN SUCH Manufacture."
The object of this Invention is so to treat oils, chiefly linseed oil, as to render
the same the better applicable to the various uses in the arts to which the same is
now applied, and by a further process to convert the same into a base for varnish.
To this end I subject the oil to the action of heated air, and obtain therefrom a
deposit oleine. The supernatant oil will then be fit for the market and constitute
an improved quality of raw oil. To complete the manufacture of this oil I submit
it again to the action of heated air, maintaining the operation until the oil has
gained the consistency of treacle. It will then be fit for conversion into a varnish
by the addition of suitable gums thereto; or by mixing with suitable pigments it
may be converted into printing ink.
The oil to be operated upon I charge into tanks of a suitable depth, say of three
feet or thereabouts, and these tanks I fit with radial air pipes which are pierced
with holes, and serve to discharge into the oil near the bottom of the tanks streams
of heated air supplied to such pipes.
The radial air pipes which are inserted in the tanks depend from branches, and
are removable at pleasure from the tanks, and these branches I connect with a
coupling pipe which receives air under pressure and heated in a coil of pipe
contained in a furnace.
The air supplied to this coil of pipe is obtained by preference from what is
known as a Root's blower; and in the pipe leading to the fornace is a three way
cock with a waste pipe, which cock serves to regulate the supply of air and to

page_text: I
discharge any superfluous quantity into the atmosphere. By this means the
temperature of air discharged from the coil of pipe may be regulated, a matter of
material importance to the success of the operation.
The branches which supply air to the radial air pipes of the tanks are each
similarly provided with a three way cock and waste pipe, and thus the pressure of
the air delivered to the tanks may be regulated and the supply may be cut off
when required.
For removing the oleine from the oil I use air under pressure heated from 130° to
150° Fahrenheit; and supposing the tank to contain 5 cwt. of oil I subject the
oil to the action of the heated air for some 5 hours, during which time the air
will drive upwards through the oil and escape from the surface, effecting in its
passage a chemical change in the oil.
After about 5 hours of this action I cut off the supply of air and leave the oil
to settle; the oleine will then deposit at the bottom of the tank, and the oil free
therefrom may be drawn off. The oleine thus obtained may be used in the manu-
facture of soap or otherwise applied.
When the oil is required to undergo the thickening process I submit it a second
time to heated air under pressure, raising the temperature of the air to, say, 350°
Fah., and keeping up the supply to some 8 hours, more or less, until the desired
consistency is obtained.
I would remark that this mode of treating the oil may be carried on with perfect
safety, as the furnace may be conveniently situate far from the oil tanks, and the
overheating of the oil will, with ordinary care, be simply impossible.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Henry Gray in the Great Seal Patent Office on the 23rd
December 1879.
THOMAS HENRY GRAY, of Livingstone Road, Clapham Junction, in the County
of Surrey, Varnish Maker. "IMPROVEMENTS IN THE MANUFACTURE OF OILS AND
VARNISHES, AND IN THE APPARATUS TO BE USED IN SUCH MANUFACTURE."
The object of this Invention is so to treat linseed oil and other drying oils as to
convert the same into a base for varnish, printing inks, and for use in the manu-
facture of elastic compounds.
To this end I subject the oil to the action of heated air, maintaining the operation
until the oil has gained the consistency of treacle. The product thus obtained
will, when cold, be fit for conversion into a varnish by the addition of suitable
gums and solvents thereto; or by mixing with suitable pigments it may be
converted into printing ink.
The oil to be operated upon I charge into tanks of a suitable depth, say of three
feet or thereabouts, and these tanks I may fit with radial air pipes which receive
heated air under pressure from a suitable furnace, the temperature of such air being
regulated and its pressure maintained so as to ensure the delivery of air into the
tanks at a temperature that will not injure the oil, and at a pressure that will
ensure its free passage through the oil from the commencement to the completion
of the heating operation.
In the accompanying Drawing Fig. 1 shews in plan view and Fig. 2 in elevation
(partly sectional) the apparatus which I employ for treating linseed or other drying
oil according to my Invention. A, A, A, is a series of tanks containing the oil to
be operated upon. These tanks are each furnished with an arrangement of
pipes B, B, B, for supplying hot air thereto. These supply pipes terminate in
radial branches which are suspended just clear of the bottom of the tank, and are
pierced with holes to allow of the air supplied thereto being discharged therefrom
in streams into the body of the oil.
The pipes B of the several tanks connect with a pipe B' which is supplied with
heated air directly from the coil C contained in the air heating furnace D.
This coil C is connected with a force pump E, which is by preference a Root's
blower, that form of pump being best suited for maintaining a continuous supply
of air at a sufficiently high pressure for the purpose of my Invention.
F is a cock for regulating the admission of air from the blower to the coil O, and
Gis a safety valve weighted from two to three pounds per square inch.
2
The branch pipes B, B, B, are each supplied with a similar cock F¹ for regulating
the supply of air to the several tanks, and for cutting off the supply as the
operation in the several tanks is completed.
The cocks F and F' may be described as three-way cocks, the construction of
which is shown in the sectional view, Fig. 3, and they serve to discharge the whole
or any portion of the air supplied to them into the atmosphere, as required,
according to the state or progress of the operation. Thus supposing all the tanks
of the series are in use and the maximum supply of air is required for the tanks,
the air being at the time at a suitable temperature, say six hundred degrees
Fahrenheit, then the cock F will be partially open, but should the temperature of
the air in the coil rise much beyond six hundred degrees Fahrenheit, then this cock
must be more fully opened so as to discharge a smaller portion of the air which it
receives from the blower up the waste pipe and an increased amount into the coil.
The effect of thus turning the cock F will be to admit more air to be heated in the
furnace, and thereby to prevent the burning of the oil which should never be raised
above four hundred degrees Fahrenheit.
It will be convenient to carry on the process in such a manner that the oil in the

page_text: oil in one tank is completed a fresh tank may be brought under treatment, and so
on, until the whole supply of oil has been operated upon
So soon as one tank of oil is finished its cock F is shut off and the heated air
cut off therefrom, instead of passing to the other tanks, where it would act
injuriously by unduly raising the temperature of the oil therein, will be discharged
up the waste pipe fi
Supposing the tanks to contain some fifty gallons of oil I deliver heated air
thereto, so as to raise the temperature to, say, two hundred and fifty degrees
Fahrenheit, and this temperature of the oil I maintain for, say, five hours. I then
allow the temperature to increase until the oil indicates some four hundred degrees
Fahrenheit, taking care that it does not rise to a higher temperature. This I
maintain for some five or six hours more, driving off from the oil copious acrid
vapours.
As an indication of the completion of the operation I may state that these
vapours will gradually cease to be evolved, and the oil will then suddenly thicken
to the consistency of stiff treacle. When this last stage is reached I stop the
supply of heated air and run off the oil into a cooling tank by the cock a On
cooling the oil will be found to be completely free from fatty matter, and it will
present somewhat the appearance of a bright jelly.
The acrid vapours given off, consisting chiefly of oleine, may, if desired, be
collected by condensation and applied to various useful purposes. Fig. 4 shews a
modification of the pipe which delivers the hot air into the tank. In this example
the pipe terminates in a T-piece which lies longitudinally of the tank, and is not
pierced with holes, but is open at its ends to allow the hot air to discharge into the
oil in two streams. This modified form of pipe I use when the length of the tank
is about double its breadth.
Having now set forth the nature of my Invention of "Improvements in the
Manufacture of Oils and Varnishes, and in the Apparatus to be Used in such
Manufacture," and having explained the manner of carrying the same into effect, I
wish it to be understood that under the above in part recited Letters Patent I
claim,―
First. Submitting linseed and other drying oils to currents of heated air, as
above explained, and thereby converting such oils into a gelatinous substance
suitable for use in the manufacture of varnishes, printing inks, and elastic com-
pounds.
Secondly. The arrangement of apparatus above described for maintaining oils at
a given temperature, as and for the purpose above set forth.
In witness whereof, I, the said Thomas Henry Gray, have hereunto set my
hand and seal, the Twenty second day of December, in the year of our Lord
One thousand eight hundred and seventy nine.
THOMAS HENRY GRAY (LR)
THOMAS HENRY GRAY (1.8)