AN IMPROVED METHOD OF EXTRACTING BY VOLATILE SOLVENTS SOLUBLE MATTER FROM SUBSTANCES HannSTAN CONTAINING IT,
Year: 1881

page_text: LETTERS PATENT to Edward Bunting Hart, of Lisnacrec, Strandtown, Belfast,
Ireland, Gentleman, for an Invention of "AN IMPROVED METHOD OF
EXTRACTING BY VOLATILE SOLVENTS SOLUBLE MATTER FROM SUBSTANCES
Hann
PROVISIONAL SPECIFICATION left by the said Edward Bunting Hart at
the Office of the Commissioners of Patents on the 28th April 1881.
EDWARD BUNTING HART, of Lisnacree, Strandtown, Belfast, Ireland, Gentleman.
"AN IMPROVED METHOD OF EXTRACTING BY VOLATILE SOLVENTS SOLUBLE
MATTER FROM SUBSTANCES CONTAINING IT, AN IMPROVED METHOD OF RECOVERING
THE SOLVENT USED, AND APPARATUS TO CARRY OUT THE OPERATIONS."
My Invention has reference, firstly, to an improved method of extracting by
volatile solvents soluble matter from substances containing it, such, for example, as
oil from sceds, fats from animal matters, sulphur from hydrated peroxide of iron,
oil from anthracene, and sugar resins or gums from vegetable matters; and this
part of the Invention essentially consists in boiling and washing the substance on
a filter bed by evaporating the solvent under the filter bed in such manner that
the solvent will ascend as vapor, and be retained in a condensed state in the
substance on the bed so long as the pressure below is not balanced by the pressure
above, and that when the pressures above and below are balanced (which is effected
by the opening of a communication between them) the solvent falls, carrying with
it what it has dissolved.
My Invention has reference, secondly, to an improved method of recovering the
solvent used from the substance operated upon, this method consisting essentially
in the use of steam drawn through the substance by a vacuum or partial vacuum
created by an air pump or otherwise.
My Invention also includes apparatus for carrying out the methods or operations
above referred to.
The manner in which my Invention may advantageously be carried into effect is
as follows:-
I employ as the extractor à vessel divided into upper and lower compartments
by a filtering plate. The top of the vessel is closed by a double or jacketted lid,
Price Sd

page_text: through which either cold water or steam is caused to flow as required. The under
plate of this lid is grooved or roughened in such a way as will cause the condensed
solvent to fall evenly from all, the surface. The lower compartment is jacketted,
and the two compartments communicate with each other by means of a pipe fitted
with a cock or other closing device. Below the filter bed is a spout or gutter to
catch a sample of the liquid falling through the bed, and discharge it into a test
cock; and there is a perforated pipe for admitting steam into the lower com-
partment. From the upper compartment a pipe leads to a worm or other
condenser, and from the lower compartment another pipe leads to the same
condenser. These pipes are each fitted with a cock. The condenser is placed
above a receiver for the solvent, and the bottom of this receiver is in communi-
cation by a pipe with the lower compartment of the extractor, which pipe is
provided with a cock. The condenser is connected with an air pump or exhauster,
the discharge side of which is connected to a second condenser. This condenser is
likewise placed above a receiver, which communicates with the extractor.
The method of working is as follows:-
مل:
The substance to be operated upon is spread on the filter bed of the extractor to
such a depth as may be found suitable, varying from 12 to 24 inches, more or less.
This lid is then put on and bolted down, a packing ring being used to make an air
tight joint. The cocks in the pipes leading to the condenser are opened to allow
the air in the extractor to escape. The solvent is then run in from the receivers,
and steam is turned into the jacket of the lower compartment. As soon as all the
air has been expelled from the extractor the cocks in the pipes leading to the
condenser are closed, and also the cock in the pipe which communicates between
the two compartments. Cold water is now caused to flow through the lid to
condense the vapor. The extractor being now completely closed, the vapor generated
from the solvent rises through the substance on the filter bed, and is condensed
partly by the substance-and partly by the lid. The pressure generated in the
lower compartment, generally 1 to 2 lbs., prevents this condensed solvent falling;
it therefore accumulates in the substance on the filter bed, and is kept boiling
there by the vapor below. When it has been sufliciently boiled the cock in the
pipe which communicates between the two compartments is opened; the pressure
being thus equalized the liquid solvent passes down through the filter bed, carrying
with it what it has dissolved.
The above process may be repeated as often as may be desired by alternately
closing and opening the communicating pipe. When the boiling is completed the
communicating pipe is left open, so that the vapor will rise through it, become
condensed on the lid, and fall in a shower on the substance under treatment, and
pass down through it; and this operation is continued until all the soluble matter
has been extracted, as can be ascertained by the test cock.
When this washing process is finished the communicating pipe is closed, and the
cock on the pipe leading from the lower compartment to the condenser opened."
Steam instead of water is then turned on to the lid. and the air pump is started.
The solvent evaporates, is drawn into and condensed by the condensers, the
extracted matter being left in the bottom of the extractor, from which it can be
withdrawn by a cock. When all that will evaporate has left the lower part of the
extractor the cock in the pipe leading from this part to the condenser is closed, and
the cock in the pipe leading from the upper compartment opened, and the air
pump is kept in operation. When the required vacuum is obtained, which will
depend upon the nature of the material operated on, and the desired degree of
heat, steam is admitted to the extractor by the perforated pipe before mentioned,
in such quantity as will not reduce the vacuum. The solvent employed should
have a lower boiling point than water, so that the steam thus admitted will expel
the solvent, and any excess be condensed with it. A test cock serves to shew when
all the solvent has been recovered.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Edward Bunting Hart in the Great Seal Patent Office on the
28th October 1881.
EDWARD, BUNTING HART, of Lisnacrec, Strandtown, Belfast, Ireland, Gentleman.
"AN IMPROVED METHOD OF EXTRACTING BY VOLATILE SOLVENTS SOLUBLE
MATTER FROM SUBSTANCES CONTAINING IT, AN IMPROVED METHOD OF RECOVERING
THE SOLVENT USED, AND APPARATUS TO CARRY OUT THE OPERATIONS."
My Invention has reference, firstly, to an improved method of extracting by
volatile solvents soluble matter from substances containing it, such, for example, as
oil from seeds, fats from animal matters, sulphur from hydrated peroxide of iron or
from other material containing it, oil from anthracene, and sugar, resins, or gums
from vegetable matters; and this part of the Invention essentially consists in
boiling and washing the substance on a filter bed by evaporating, the solvent under
the filter bed in such manner that the solvent will ascend as vapor, and as con-
densed be retained and boiled in the substance on the bed so long as the pressure
below is not balanced by the pressure above, and that when the pressures above
and below are balanced (which is effected by the opening of a communication
between them, or by reducing the pressure below, or increasing the pressure
above, or in any other convenient manner), the solvent falls, carrying with it what
it has dissolved.
My Invention has reference, secondly, to an improved method of recovering the
solvent used from the substance operated on, this method consisting essentially in
drawing steam through the substance by means of a vacuum. or partial vacuum
produced by a pump or exhauster, a steam jet, or in any other convenient manner,
or in allowing steam acting by its own pressure to pass through the substance, this
operation being performed in a vessel having a top or cover heated by steam or
otherwise.
My Invention also includes apparatus for carrying out the methods or operations
above referred to.
In the annexed Drawings I shew an apparatus constructed to carry out or effect
both the said methods or operations, that is to say, the method of extracting
soluble matter by volatile solvents, and the method of recovering the solvent used
from the substance operated upon. Figure 1 is an elevation chiefly in section of
the apparatus; Figure 2 is a section taken at right angles to Figure 1, shewing
the pipe or connection between the two compartments of the extractor, as herein-
after described.
I employ as the extractor a vessel, such as that shewn, divided into upper
and
lower compartments a, a', by a filter plate b. The top of the vessel is closed by a
double or jacketted lid c, through which either cold water or steam is caused to
flow as required. The under plate of this lid is grooved or roughened, as indicated.
in such a way as will cause the condensed solvent to fall evenly from all the
surface. The lid c is fastened to the top of the vessel a by bolts. a packing ring
being inserted to make an air tight joint. The lower compartment a' is jacketted
and the two compartments a, a¹. communicate with each other by means of a side
pipe d (see Figure 2) fitted with a valve e or other closing device. Below the filter
bed bis a spout or gutter f to catch a sample of the liquid falling through the bed.
and discharge it into a test cock g; h is a perforated pipe for admitting steam into
the compartment a¹. From the compartment, a a pipe i leads to a worm or other
condenser k, and from the compartment a another pipe leads to the same
condenser. These pipes and are each fitted with a cock marked m, and. n
respectively. The condenser, is placed above a receiver o for the solvent, and the

page_text: bottom of this receiver is in communication by a pipe with the lower compart-
ment of the extractor, which pipe is provided with a cock q. The condenser k
is connected by a pipe with a pump or exhauster r, the discharge side of which is
connected to a second condenser .. This condenser is likewise placed above a
receiver o¹, which communicates with the lower compartment of the extractor by
a. pipe p¹ fitted with a cock q¹. This pipe p¹ may either lead directly into the
extractor, or, as shewn in the Drawing, it may terminate in the bottom of the
receiver o, so that the pipe p may form its continuation to the extractor; s is a
pipe for admitting water or steam into the jacket of the lower compartment a¹, or
instead of this jacket a worm may be placed in the compartment a', or other means
of heating this compartment may be adopted; tis a cock to run out the extracted
matter from the compartment a'; u is an escape valve; v, a test cock to ascertain
what is passing through the pipes i and 1; w is a pressure and vacuum gauge;
a, are discharge cocks. to the receivers o, o¹.
X,
The method of working is as follows:-The substance to be operated on is spread
on the filter bed b to such a depth as may be found suitable, varying from 12 to 24
inches, more or less. The lid c is then put on and bolted down, the packing ring
making an air tight joint. The cocks m and n in the pipes i and I are opened to
allow the air in the extractor to escape. The solvent is then run into the compart-
ment from the receivers o, o¹, and steam is turned into the jacket of this
compartment by the pipe s. As soon as all the air has been expelled from the
extractor the cocks m and n are closed, and also the valve e in the pipe d. Cold
water is now caused to flow through the lid e to condense the vapor. The extractor
being now completely closed, the vapor generated from the solvent rises through
the substance on the filter bed b, and is condensed partly by the substance and
partly by the lid c. The pressure generated in the compartment a', generally 1 to
2 lbs., prevents this condensed solvent falling it therefore accumulates in the
substance on the filter bed, and is kept boiling there by the vapor below. When it
has been sufficiently boiled, the valve e in the pipe d'is opened; the pressure being
thus equalized, the liquid solvent passes down through the filter bed b, carrying
with it what it has dissolved. The above process may be repeated as often as may
be desired by alternately closing and opening the pipe d, and this operation will in
many cases be sufficient for the extraction without the washing hereinafter
described. Or the extraction may be effected by putting in a limited supply of the
solvent; this boils up, as before described, and when it is all up the pressure below
is no longer maintained, and the solvent falls, boils up afresh, and so completes
the extraction. The solvent may be caused to fall by any means that will destroy
or neutralize the pressure below. such as stopping the boiling, allowing the
generated vapor to escape to a condenser, cooling the liquid or vapor by water, or
otherwise increasing the pressure in the upper compartment. All that is necessary
is to produce within the extractor equal pressures above and below the filter bed,
and the solvent will fall.
When the boiling is completed the pipe d is left open, so that the vapor will
rise through it, become condensed on the lid c, and fall in a shower on the substance
under treatment and pass down through it, and this operation is continued until
all the soluble matter has been extracted, as can be ascertained by the test cock g.
When this washing process is finished the pipe d is closed, and the cock n, on
the pipe, leading from the compartment a¹ to the condenser, opened. Steam
instead of water is then turned on to the lid c and the pump ris started. The
solvent evaporates; is drawn into and condensed by the condensers k, k¹, the
extracted matter being left in the bottom of the extractor, from which it can be
withdrawn by the cock t. When all that will evaporate has left the lower part of
the extractor the cock n is closed and the cock m in the pipe leading from the
compartment a, opened, and the pump is kept in operation. When the required
vacuum is obtained, which will depend upon the nature of the material operated on
and the desired degree of heat, steam is admitted to the extractor by the perforated
pipe h in such quantity as will not reduce the vacuum. The steam is drawn by,

page_text: the vacuum through the substance on the bed b and expels the solvent remaining
therein, and this solvent is likewise condensed by the condensers k, k¹; any excess
of steam is condensed with it. The test cock v serves to show when all the solvent
has been recovered, as then only water will be obtained at this cock. The solvent
employed should have a lower boiling point than water.
Instead of evaporating the whole of the solvent and condensing it, as above
described, the solvent which remains in the lower compartment a¹ after the
extracting operation may be run off into a suitable receiver, and then only the
solvent remaining in the substance on the bed b will be evaporated, this being
effected by means of the steam admitted by the pipe h, and by heating the lid c, as
already described. Instead of the pipe i leading to the condenser, and pump being
above the bed band the steam inlet h. below the bed, the position of these parts
may be reversed, or they may by otherwise arranged so long as the steam is drawn
by a pump or otherwise, or passes by its own pressure through the substance which
has been treated by volatile solvents in the extractor. When it is desired to allow
the steam to act by its own pressure the pump or exhauster r, and the second
condenser k¹, and receiver o¹, may be dispensed with.
Although I much prefer to carry out my two operations of extracting the soluble
matter and recovering the solvents in one combined apparatus, such as that
hereinbefore described, the two operations may if desired be applied separately.
In this case my extractor will not require the steam pipe h or an inlet for steam
to the jacketted lid c and my method of recovering the solvent may be applied to
other forms of extractor in which steam can be drawn or allowed to pass, as
hereinbefore explained, through the substance which has been treated by a volatile
solvent.
Having now described the nature of my said Invention, and in what manner
the same is to be performed, I declare that I claim,-
First. The method or process hereinbefore described of extracting by volatile
solvents soluble matter from substances containing it, the said method or process
consisting in boiling and washing the substance under treatment on a filter bed by
evaporating a solvent and allowing it to ascend as vapor through the filter bed so
that it will as condensed be retained and boiled in the substance on the bed so long
as the pressure below is not balanced by the pressure above, and that when the
pressures above and below are balanced the solvent will fall, carrying with it
what it has dissolved, all substantially as set forth.
Second. The method or process hereinbefore described of recovering volatile
solvents which have been used in extracting soluble matter from substances
containing it, the said method or process consisting in drawing steam by means of
a vacuum or partial vacuum through the said substances, or in allowing steam
acting by its own pressure to pass through the said substances, this operation being
performed in a vessel having a top or cover heated by steam or otherwise, all
substantially as set forth.
Third. Constructing apparatus, substantially as hereinbefore described, for
carrying out in the manner set forth the operations of extracting by volatile
solvents soluble matters from substances containing it, and of recovering the
solvent used.
In witness whereof, I, the said Edward Bunting Hart, have hereunto set
my hand and seal. this Twenty fourth day of October, One thousand
EDWARD B. HART. (L.S.)