Improvements in the Process of and Apparatus for Thickening Linseed Oil.
Year: 1893

page_text: Date of Application, 7th Mar., 1893-Accepted, 8th Apr., 1893
COMPLETE SPECIFICATION.
Improvements in the Process of and Apparatus for Thickening
Linseed Oil.
I, REGINALD HADDAN, of the firm of Herbert Haddan & Co., of 18, Buckingham
Street, Strand, W.C. London, Patent Agent, do hereby declare the nature of this
invention, a communication to me from abroad by Eugen Schaal, of Feuerbach-
Stuttgart, in the Empire of Germany, Chemist, and in what manner the same is
to be performed to be particularly described and ascertained in and by the
following statement :—
It is a well known fact that when linseed oil is boiled for some time till it
loses about of its weight it becomes thicker, tenacious and viscid and it
dries up still more readily than in the fresh state to a tough, turpentine like
mass, scarcely soluble in oils. It is also a well known fact that linseed oil
heated to about 323°-375° C. takes fire and burns quickly (see Watts Dictionary
of Chemistry, Vol. III lines 23-18 from bottom of page 702) and if the oil
while being heated to the abovenamed temperature comes in contact with
atmospheric air, an explosion takes place. Now I have discovered that by
maintaining a current of steam or of an indifferent gas such as carbonic acid gas
or nitrogen over the surface of the oil during the progress of heating, the tempera-
ture of the oil can be raised to and maintained at 330° to 345° C. and the required
consistency can be rapidly attained without allowing the oil to ignite and all danger
of an explosion is avoided. Furthermore I am enabled to continue the process of
thickening the oil without interruption by admitting fresh oil to the bottom of
the mass while the thickened oil is permitted to flow off from the top. I have
also constructed a novel apparatus which can be used with advantage in carrying
out my new process and the construction of which is pointed out in the following
Specification and illustrated in the accompanying drawing which shows a longi-
tudinal vertical section.
In this drawing the letter A designates a kettle into which the oil is fed through
the pipe d and from the top of which extends a goose neck a which connects with a
pipe extending down into the condenser B. From the top of the condenser
extends a pipe b which leads into the open air or into a chimney. From the side
of the kettle A extends a pipe e which leads into the top part of a vessel Cand
above this pipe is an opening which connects by a tube f¹ with a steam-boiler or
with a reservoir containing an indifferent gas under pressure. T is a pipe for the
introduction of a thermometer. Beneath the kettle A is a fire place F for the
purpose of heating the contents of said kettle.
The kettle A is charged with linseed oil about to a level with the pipe e and the
oil is heated rapidly to about 270°-280° C. while a current of steam or of an
indifferent gas is introduced through the tube f¹ in the direction of the condenser B,
the temperature in the kettle A being permitted to rise to 330°-345° C., and this
temperature is maintained until a test shows that the oil has reached the desired
thickness. Then the fire is removed and while the current of steam or gas is
maintained, the oil is permitted to cool off to about 290° C. when it is ready for
immediate use.
By the current of steam or indifferent gas the atmospheric air is driven out
of the kettle A and the oil is prevented from igniting. If by inadvertence
the temperature in the kettle A should rise above 345° C., cold linseed
oil is introduced through the pipe d and by carrying this cold oil down near to the
bottom of the kettle A while the thickened oil is permitted to flow off at the top
through the pipe e into the vessel C, the temperature in the kettle A can be
regulated and the process of thickening can be carried on for a long time without

page_text: interruption. The oil vapours which are carried into the condenser B by the
current of steam or gas become liquified and are saved.
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. As an improvement in the art of thickening linseed oil the operation of
maintaining a current of an indifferent fluid over the surface of the heated oil,
substantially as described.
2. The within described process of thickening linseed oil which consists in
heating the oil to a temperature of 320°--345° C., maintaining a current of an
indifferent fluid over the surface of the heated oil, introducing fresh oil into the
lower portion of the heated mass and permitting the thickened oil to flow off from
the top, substantially as described.
3. The combination with the kettle A. and its feed pipe d, extending down to the
lower portion of the kettle, of a tube f¹ leading into the kettle, a goose-neck a, a
condenser B connected to the goose-neck, an escape pipe leading from the
condenser, an overflow pipe e leading from the kettle A, and a vessel C connected
with the pipe e, substantially as described.
Dated thin 7th dow of Mach 1902