Process of Extracting Fat from Wool and other Fibrous Materials.
Year: 1895

page_text: Date of Application, 19th Feb., 1895-Accepted, 23rd Mar., 1895
COMPLETE SPECIFICATION.
Process of Extracting Fat from Wool and other Fibrous
Materials.
I, ERNST FAHRIG, Chemist, of 702 North Monroe Street, in the City of
Baltimore, County of Baltimore, State of Maryland, U.S.A. do hereby declare
the nature of this invention and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement:-
The object of this invention is to provide an improved process of extracting
fat from wool or other fibrous materials by the use of volatile hydro-carbon
solvents, and separating the fat and oils so extracted from said solvents so as to
utilize the same in the arts, while the wool or other fibrous material is rendered
thereby free from oleaginous substances and impurities and better adapted for
spinning and weaving; and the invention consists of the process berein described
of extracting fat from wool or other fibrous materials, which consists, first in
exhausting the air from the fibrous material to be treated, next subjecting the same
to the action of a volatile solvent which is alternately forced through the material
first in one direction and then in the opposite direction, next drawing off the
solvent and the extracted fat and oil, and then subjecting the fibrous material to
heat so
as to evaporate the solvent still retained in the same, and lastly
condensing the resulting vapors.
The invention consists further of the process of extracting fat from wool or
other fibrous materials first by exhausting the air from said material; second, by
subjecting the same to the action of a volatile solvent passed through said
material in one direction; third, drawing off the solvent and extracted fat;
fourth, by subjecting the material to the action of another charge of the solvent
passed through the same in the opposite direction; fifth, drawing off the solvent
and the oil and fat dissoived therein, then subjecting the fibrous material to the
action of heat, so as to evaporate the solvent still remaining in the same, and
finally, condensing the vapors drawn off.
In the accompanying drawings is shown one form of apparatus by which my
improved process is carried out in practice:-
Fig. 1 representing a side-elevation partly in section, of the apparatus, and
Fig. 2 a vertical central section of the extractor drawn on a larger scale, and
Fig. 3 a top-view of the same.
Similar letters of reference indicate corresponding parts.
My process can be used to advantage in removing the fat, oils, &c. from any
oleaginous material, but it is especially designed to remove the oil or fat contained
in wool or other fibrous materials, and at the same time clean the wool and
deliver it ready for manufacturing purposes, without waste or shrinkage and free
from injury to the fibres.
The wool or other material to be treated is first subjected to pressure and baled
while under pressure. The baled material is then placed in a basket 1, made of
non-oxydizable metal, which will not be injurious to the wool. This basket is then
lowered by means of a crane or other suitable device, into the middle compartment 3
of the extractor 4. The compartment 3 is provided with a false perforated
bottom 5, as shown in Fig. 2, and surrounded by a steam-jacket 6. The extractor 4
is constructed so as to withstand high pressure, and is provided with a removable
cover 7. This cover is adapted to fit tightly over the top of the extractor and to

page_text: seal hermetically the compartment 3 of the same. The cover 7 is also provided
with a perforated diaphragm 6, which is suspended therefrom by means of suitable
hanger-bolts. The cover 7 is firmly screwed down by means of hinged screws 10,
and provided with a safety-valve, while the extractor is provided with gauges, a
test tube and other accessories. After the compressed bale of fibrous material is
placed into the compartment 3 of the extractor, the cover 7 is put on and secure l
in place, so as to hermetically seal the compartment 3. The extractor 4 is
connected by a valved pipe 15 with an elevated tank 14 for the naptha or other
volatile solvent and by a valved pipe 12 with an air-pump 13. The jacket of the
extractor is connected by a pipe 23 with a steam-boiler, so as to supply live steam
to the same, while live or exhaust steam is supplied to the interior of the
compartment 3 by a valved pipe 24. The bottom of the extractor is connected by
a pipe 18 with a receptacle 29 for the solvent and the fat extracted from the
material in the extractor, and by a valved pipe 19 with an agitating pump 17.
The bottom of the extractor 4 is further connected by a valved pipe 20 with a
second tank 16 for a second charge of naptha or other volatile solvent. The
tank 14 and the supply-pipe 15 serve to supply the extractor with solvent that
passes through the material in one direction, while the tank 16 and pipe 20 supply
the extractor with another charge of solvent which enters from the bottom and
passes through the material in a direction opposite to that of the solvent from the
tank 14.
In carrying out my improved process of extracting fat from wool, the compressed
material is first placed in the compartment 3 and then the cover put in place, and
hermetically sealed thereon. The valves of all the pipes leading to the extractor
are closed, except the valve 11 of pipe 12. The air-pump 13 is then put in
operation and the air exhausted from the compartment 3 and from the material in
the same.
The valve 11 is closed after the required degree of vacuum is established
in the compartment 3. The solvent from the tank 14 is then let into the compart-
ment through the pipe 15, which preferably enters above the diaphragm 8, so as to
be distributed uniformly by the same over the material below. When the gauges
show that the material is entirely covered by the solvent, the valve in the pipe 15
is closed and the supply of solvent stopped. Owing to the high vacuum in the
extractor the solvent penetrates into all the available spaces of the fibrous material,
so as to act on the entire body of the same. When the solvent has penetrated
the material, the pump 17 is set in operation, and thereby the agitation of the
solvent in the extractor produced, so that it passes through the material and tends
to free it from the fat, oil, and impurities contained therein. The solvent
containing the fat is then drawn off through the pipe 18 into a receptacle R and
pumped back to the tank 14, by the pump P and connecting-pipes so as to be
passed repeatedly through the extractor until it contains from 20 to 25 per cent. of
fat and fatty acids.
In order to completely free the fibrous material from fat, it is subjected to a
second washing, by opening the valve of the pipe 20 and passing a fresh charge
of volatile solvent from the tank through the material, said fresh charge passing
through the material from the bottom in upward direction, that is to say, in an
opposite direction to the direction of the former charge from the tank 14.
Whe:
the material is fully covered by the solvent, the supply of solvent is stopped, and
the valve of the pipe 19 is opened so as to connect with the pump 17, which is then
set again in operation so as to produce the agitation of the solvent in the extractor,
for dissolving the oil in the fibrous material, the material being thus elutriated,
first, by the first charge of solvent in one direction, and then by the second
charge of solvent in the opposite direction. The solvent with the fat extracted
thereby is drawn off through the pipe 18 into the receptacle R and pumped back
to the tank 16 by the pump P, it being used over again until it contains from
20 to 25 per cent. of fat and fatty acids. By the test-tube, the condition of the
material in the extractor is observed from time to time, and the time when the
solvent is to be drawn off regulated thereby.

page_text: The wool or other fibrous material in the extractor will retain a small quantity
of the solvent which will not run off into the tank 29 by the means provided, and
it is therefore necessary to free the material in the extractor of this solvent before
it can be removed from the extractor, and a new charge of wool put into the
same. In order to accomplish this, live steain is let into the jacket 6 of the
compartment. 3 through the pipe 23 and at the same time, steam let into the com-
partment 3 through the valved pipe 24. The steam-pipe 24 is arranged to enter
the compartment 3 above the perforated diaphragm 8 while the steam-pipe 23 is
connected directly with the jacket. After the steam is admitted into the compart-
ment 3, the pump 13 is set in operation, said pump having been previously connected
with the pipe 18 by opening the lower valve of the connecting-pipes 7 and 12.
The heat generated by the steam admitted to the jacket 6 and into the
compartment 3 will vaporize the solvent held in suspension in the material, and
the action of the pump 13 will draw off the vapors thus formed through the pipes 18
and 12, thence through the pump 13 into a washer 28, where the vapors mixed
with water are condensed and then separated therefrom and recovered. The wool
is then removed from the compartment 3, and a new charge placed in the same.
and the operation of extracting the fat from the new charge repeated as before.
When a test shows that the solvent contains from 20 to 25 per cent. of fat and
fatty acids, the separation of the solvent from said fat has to be performed. This
is accomplished in the usual manner by separating the liquid solvent by distillation
from the fatty matter, and then condensing the vapors and collecting the condensed
solvent ready for further use. Before the solvent is separated from the fatty
matter by distillation the raw product which has become dirty and discolored in the
extracting is pressed through the filter so as to remove the foreign matters and
impurities suspended therein. The filtering operation is accelerated by establishing
by the air-pump 13 a low vacuum on the filter 50; but not only the impurities are
removed from the solvent by the filter but also the discoloring matter, so after
distillation of the solvent a pure grease of light color is obtained.
This filtering is accomplished by running the solvent with the fat into the
tank 29, pumping it through the filter 50 and tell-tale 51, and into a tank 52, and
then by the pump P and pipe 31 into the still 32. The still 32 is heated by means
of steam, which is supplied by the pipe 23 to the jacket and to a coil at the interior
of the still. In the still the fat and fatty acids are separated from the solvent and
conducted into the tank 34, while the vapors formed in the still are drawn off into a
catch-all 53, and then into a condenser 36, in which they are condensed.
The condenser 36 consists of a cylindrical vessel having perforated top and bottom
diaphragms, which are connected by vertical pipes, said pipes being surrounded with
water supplied from a suitable tank, the warm water being conducted off by a
suitable waste-pipe. The condensed solvent is passed from the condenser through
a tell-tale 39 into the tank 37, from which it is returned by the action of the
pump P into the tank 14 or 16 so as to be used again for the extraction of fat from
other charges of fibrous materials placed in the extractor.
The separation of the volatile solvent from the fat and fatty acids by distillation
can be accomplished by any other suitable means, as this part of the process is
well-known and can be performed in different ways.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that
what I claim is :-
(1.) The process herein described of extracting fat from wool and other fibrous
material, which consists in the following steps: First, exhausting the air from the
material to be treated; second, subjecting the material in vacuo to the action of a
volatile solvent forced alternately in opposite directions through the material;
third, withdrawing the solvent with the extracted mass from the material in vacuo;
fourth, vaporizing the residual solvent by the action of heat and drawing off the
vapors thus formed from the material in vacuo, substantially as set forth.

page_text: (2.) The process herein described of extracting fat from wool and other fibrous
materials, which consists of the following steps: First, exhausting the air from the
material to be treated; second, subjecting the material to the action of an initial
charge of a volatile solvent passed through the same in one direction; third,
drawing off the solvent with the fat extracted from the material; fourth, subjecting
the material to the action of a second charge of a volatile solvent and passing the
same in opposite direction to the former charge through the material; fifth, drawing
off the second charge of solvent with the extracted fat; sixth, subjecting the
material to the action of heat so as to evaporate the solvent retained in the material,
and lastly, condensing the resultant vapors, substantially as set forth.
Dated this 19th day of February 1895.
CASTLE SMITH,
66
Invention
"
Office, 54, Fleet Street, London, E.C.,
Agent for the Applicant.