IMPROVEMENTS IN THE DISTILLATION OF GLYCERINE, AND IN APPARATUS CONNECTED THEREWITH
Year: 1881

page_text: LETTERS PATENT to William Clark, of 53, Chancery Lane, in the County of
Middlesex, Patent Agent, for an Invention of "IMPROVEMENTS IN THE
DISTILLATION OF GLYCERINE, AND IN APPARATUS CONNECTED THEREWITH.”
A communication from abroad by François Armandy, of Saint Fons par
Venissieux (Rhône), France.
PROVISIONAL SPECIFICATION left by the said William Clark at the Office
of the Commissioners of Patents on the 7th December 1881.
WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex, Patent
Agent. "IMPROVEMENTS IN THE DISTILLATION OF GLYCERINE, AND IN APPARATUS
CONNECTED THEREWITII." [A communication from abroad by François Armandy,
of Saint Fons par Venissieux (Rhône), France.]
The distillation of glycerino with a view to its purification by the separation
from it of the foreign matters it contains in an impure commercial condition
is effected according to most recent methods in stills traversed by a current of
superheated steam. This current facilitates the carrying off of the vapors which
escape into the open air after the separation of the glycerine in the condensers.
These distillatory processes however, in order to be effectual, require a very high
temperature and a considerable volume of steam, the product on the one hand
being greater the higher the steam pressure, while on the other hand the chemical
quality of the glycerine distilled in this manner deteriorates in proportion as the
pressure of the steam is increased.
This Invention relates to an improved process of distillation, and consists
essentially in the employment of a vacuum for the purification of glycerine on a
commercial scale, whereby the expenditure of steam is reduced by one half and the
production of distilled glycerine increased four fold. With this improved process
also I avoid the carbonisation of the glycerine (which is inevitable in distilling it
in the ordinary way owing to the high temperature of the steam employed), and
consequently the formation of tar or other residues and the loss of glycerine carried
off by the escaping vapors which is often considera' le.

page_text: It has been found by experiment that it is preferable to distil the glycerino at
as low a temperature and in as short a space of time as possible. To this end it is
proposed according to this Invention to distil in a closed vessel, and to get rid of
the vapors as they are formed by means of a pump or other exhausting apparatus
capable of maintaining in the still as perfect a vacuum as possible under existing
conditions. I may also distil at a high temperature with only a very small
The specific gravity of the distilled glycerine is raised to an average density
of 1.265, and the operation in the still is rendered more regular and controlled with
greater facility.
quantity of steam.
The Invention thus consists broadly in the application in the process of distilling
glycerine of a more or less perfect vacuum in apparatus which may be of any kind
deemed most suitable for the purpose.
The condensation of the distilled products is effected in condensers of any
suitable kind, but instead of allowing the condensed glycerine to run off direct I
collect it in a series of separate receivers, between which and the condensers is
interposed an apparatus for producing a vacuum, such as a pump, steam jet, aspirator,
or a column of liquid of a height corresponding to the vacuum required. The
distillation is effected in the vacuum by the extraction of the liquid that is condensed
in the refrigerator. When one of the receivers is filled with distilled glycering the
vacuum producing apparatus is connected with the next adjoining receiver and the
glycerine taken out of the first. The vacuum apparatus may be placed eithor in
front or in rear of the receivers, that is to say, between the condensers and the
receivers, or in rear of the latter. A series of cocks or valves would be used to
control the connections of the several receivers.
The following are the advantages realised by the process of this Invention :-
(1.) The distillation is effected at a very low temperature, and there is consequently
little waste by reason of the product being attacked and destroyed, and consequently
a small amount of residuc produced. (2.) The distilling operation is more regular
and furnishes a larger quantity of products of better quality. (3.) The distillation
is effected much more rapidly. (4.) The distilled product is whiter and purer.
(5.) The products are entirely condensed and there is consequently no appreciable
loss of glycerine.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Clark in the Great Seal Patent Office on the 27th May
1882.
WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex, Patent
Agent. "IMPROVEMENTS IN THE DISTILLATION OF GLYCERINE, AND IN APPARATUS
CONNECTED THEREWITH." A communication from abroad by François Armandy,
of Saint Fons par Venissieux (Rhône), France.
The distillation of glycerine in order to purify it by separating it from the
foreign matters it contains in its crude commercial condition is effected according
to most recent methods in stills traversed by a current of superheated steam.
These distillatory processes, however, in order to be effectual, require a very high
temperature and a considerable volume of steam, the product on the one hand being
greater the higher the steam pressure, while on the other hand the chemical quality
of the glycerine so distilled deteriorates in proportion as the pressure of the steam
is increased.
This Invention relates to an improved process of distillation, and consists
essentially in the employment of a vacuum in the purification of glycerine on a
commercial scale, whereby the expenditure of steam is reduced by one half and the
production of distilled glycerine increased four fold, and whereby I avoid altogether
or in great measure the carbonization of the glycerine (inevitable in distilling in
the ordinary way owing to the high temperature of the steam employed), and the
consequent formation of tar or other residues as well as the loss of glycerine carried
off by the escaping vapors which is often considerable.
It has been found by experiment that it is preferable to distil the glycerine at
as low a temperature and in as short a space of time as possible. To this end it is
proposed according to this Invention to distil in a closed vessel, and to extract the
vapors as fast as they are formed by means of a pump or other exhausting
apparatus capable of maintaining in the still as perfect a vacuum as possible under
such conditions. I may also distil at a high temperature by employing only a very
small quantity of steam. The specific gravity of the distilled glycerino is raised to
an average density of 1-265, and the operation in the still is rendered more
regular, and controlled with greater facility. The Invention thus consists broadly
in the application in the process of distilling glycerine of a more or less perfect
vacuum in apparatus which may be of any kind deemed most suitable for the
purpose.
The condensation of the distilled products is effected in condensers of any
suitable kind, but instead of allowing the condensed glycerine to run off direct I
collect it in a series of separate receivers. The apparatus for producing a vacuum
may be a pump, steam jet, aspirator, or a column of liquid of a height corresponding
to the vacuum required whereby the water of condensation in the refrigerator is
extracted and the vacuum maintained.
The following are the advantages realised by the process of this Invention :-
(1.) The distillation is effected at a very low temperature, and there is consequently
little waste by reason of the product being attacked and destroyed, and consequently
a small amount of residue produced. (2.) The distilling operation is more regular
and yields a larger product of better quality. (3.) The distillation is effected much
more rapidly. (4.) The distilled product is whiter and purer. (5.) The product
is entirely condensed and there is consequently no appreciable loss of glycerine.
The accompanying Drawing illustrates an example of the apparatus which may
be employed in carrying out this Invention in practice. A is the still in which the
•

page_text: glycerine is placed furnished with a rose e at the lower part by which the super-
heated steam introduced by pipe T is distributed uniformly through the glycerine.
The resulting mixture of steam and glycerine passes out through the neck f and
traverses a series of condensers R in which the glycerine alone condenses, the
steam passing on to the refrigerating worm R' where it is condensed. The water
of condensation is extracted by the pump P and may be pumped into any suitable
receiver or run away. In consequence of the vacuum thus produced in the
condensers R the whole of the glycerine is condensed therein while the steam
remains in the state of vapor, even at the temperature (about 175° F.) which reigns
in the last of the series of condensers. The distillation is consequently very active,
and I am enabled to obtain four times the quantity of glycerine at a higher density
(1-260) than by the processes now employed, the best of which yield an inferior
product of a density barely reaching 1160. The glycerine is entirely condensed,
because the quantity of steam employed in the distillation being less, the glycerine
is not carried off and the temperature of the last condenser is much lower. Tho
distilled and condensed glycerine may be withdrawn from the condensers every
two hours, or as often as may be required, without interrupting or delaying the
operation, for which purpose each condenser is connected with a separate horizontal
cylinder V beneath, with which it can be put in communication when necessary
as hereafter described. The cylinder V is connected with the condenser by a pipe
attached to the lowest part of the latter and furnished with a cock B and also by
another pipe attached to the condenser at about the middle of its height and
furnished with a cock D. C is an air inlet cock. To draw off the distilled and
condensed glycerine from the condenser the air inlet cock C is shut and cock D
opened, and the draw off cock g being shut a vacuum is formed in the cylinder V.
The cock B is then opened and the glycerine runs into the cylinder V, and when all
has been thus withdrawn the cocks B, D, are shut, and the air inlet cock C being
then opened, the glycerine can be drawn off at cock g.
Having described the nature of the said Invention and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
hereinbefore in part recited Letters Patent is,-
1st. In the process of distilling commercial glycerine for the purpose of purifying
it, the effecting the said operation in vacuo, substantially as herein described.
2nd. The herein described method of distilling glycerine in vacuo in or by means
of the apparatus, substantially as herein shown and described.
3rd. The combination with a still of the apparatus, substantially as hercin
described and shown in the Drawings, for the distillation of glycerine in vacuo.
In witness whereof, I, the said William Clark, have hereunto set my hand
and seal, this Twenty fourth day of May, A.D. 1882.
W¼ CLARK. (L.S.)