Improvements in the Rectification and Concentration of Acetic Acid, and in Apparatus therefor.
Year: 1888

page_text: Date of Application, 24th Aug., 188S
Complete Specification Left, 25th Apr., 1889-Accepted, 24th Aug.,
1889
LLOYDOIUNAL SPELERATION.
Improvements in the Rectification and Concentration of Acetic Acid,
and in Apparatus therefor.
We, ISIDOR WERBER, Ph. D. of 54 Amity Road, West Ham, and GEORGE HENDRY,
Coppersmith, trading as G. Hendry & Co. of Oaklane Copper works, Oak Lane,
Limehouse in the County of Middlesex, do hereby declare the nature of the said
invention for "IMPROVEMENTS IN THE RECTIFICATION AND CONCENTRATION OF ACETIC
ACID AND IN APPARATUS THEREFOR, to be as follows:-
Column-stills have heretofore been used in the rectification and concentration of
Acetic Acid, but the process as heretofore carried into effect has been intermittent in
as much as a charge, being put into the apparatus, had to be treated and the process
completed, such charge when rectified being withdrawn and a fresh one put in.
Now by the present invention the process is made continuous, that is to say the still
is kept supplied with the crude acid and rectified acid is drawn off until it becomes
necessary to clean the apparatus.
We will first describe the apparatus embodying our improvements and next the
process as carried out therewith.
A pan or container is provided for the reception of the crude acid mixed with the
usual re-agents. If the latter are soluble they may be dissolved in the crude acid and
the operations may then be carried on for a very long time uninterruptedly.
If the re-agent is insoluble a quantity sufficient say for a weeks operations or more
is placed into the pan and the crude acid run in upon it. The pan is best jacketted
and heated by steam as usual though direct firing may be used. Heretofore the pan
containing the crude acid consisted of a single compartment above which the column
of the still rose and the vapours passed upwards through the column, and to condensing
devices so that the empyroumatic impurities of the acid, and water were separated from
the product which returned into the pan so that the acid again took up such impurities
as yet remained in the bulk of the more or less crude liquid.
According to this invention however we divide the
pan into two compartments and
conduct the rectified acid into the second portion of the pan so that it does not again
come in contact with the impure liquid. For this purpose the tube or pipe heretofore
extending from the lowermost plate of the column nearly to the bottom of the single
compartment, is in our apparatus led into the second compartment thereof, reaching
nearly to the bottom of the same. The second compartment is fitted with the usual
head and arm connected with a condensing worm.
We therefore operate as follows: The first compartment is supplied with crude
acid and with suitable re-agents and heated. The vapours rise into and through the
column the empyreumatic impurities of the acid are separated in the usual
manner and the purified and concentrated acid descends into the second compartment.
In the same measure as the pure product is distilled off in the usual manner from the
second compartment, fresh crude acid is supplied to the first and this makes the process
continuous.
As the first portion of acid distilled over may not be of the requisite degree of
purity a draw off-cock is provided in the second compartment to allow the first
running being run off instead of being distilled over as is the case with the pure
product. We may however if preferred provide the pipe leading down from the
lowermost plate of the column with two branches, one leading into the first compart-
ment and the other into the second, a suitable three-way-cock connecting the branches.
Above the three-way-cock a small sample cock or test cock is provided. Now as long
is a sample taken from the sample-cock is not quite pure the column is made to
leliver into the first compartment, as soon as the product appears satisfactory the
hree way cock is turned, and the column delivers into the second compartment.

page_text: The two compartments may be either two divisions of the pan separated by a parti-
tion or they may be entirely independent of one another.
Dated this 24th day of August 1888.
BERNHARD DUKES,
226, High Holborn, London, W.C., Agent for the Applicants.
COMPLETE SPECIFICATION.
Improvements in the Rectification and Concentration of Acetic Acid,
and in Apparatus therefor.
Wo ISIDOR WERBER, Doctor of Philosophy of 54 Amity Road, West Ham in
the County of Essex, and GEORGE HENDRY Copper-smith trading as George
Hendry & Co. of Oak Lane Church Row, Limehouse, in the County of Middlesex,
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
Column-stills have heretofore been used in the rectification and concentration of
Acetic Acid, but the process as heretofore carried into effect has been intermittent in
as much as a charge, being put into the apparatus had to be treated and the process
completed, such charge when rectified being withdrawn and a fresh one put in.
Now by the present invention the process is made continuous, that is to say the
still is kept supplied with the crude acid without allowing the apparatus to cool and
rectified acid is drawn off until it becomes necessary to clean the apparatus.
We will first describe the apparatus embodying our improvement and next the
process as carried out therewith.
A pan or container is provided for the reception of the crude acid mixed with the
nsual re-agents. It is preferable that the latter be soluble and dissolved in the crude
acid; the operations may then be carried on uninterruptedly.
If the re-agent is insoluble a quantity sufficient, say for a weeks operations or more
may be placed into the pan and the crude acid run in upon it. The pan is best
jacketted and heated by steam as usual though direct firing may be used. Hereto-
fore the pan containing the crude acid consisted of a single compartment above which
the column of the still rose and vapours passed upwards through the column; and to
condensing devices so that the empyreumatic impurities of the acid and water were
separated from the product which returned into the pan and there the acid again took
up such impurities as remained in the bulk of the more or less crude liquid.
According to this invention however we divide the pan into two compartments and
conduct the rectified acid into the second portion of the pan so that it does not again
come in contact with the impure liquid. For this purpose the tube or pipe heretofore
extending from the lowermost plate of the column nearly to the bottom of the single
compartment is in our apparatus led into the second compartment thereof; reaching
nearly to the bottom of the same. The second compartment is fitted with the usual
head and condensing worm.
We therefore operate as follows: The first compartment is supplied with crude acid
and with suitable re-agents and heated. The vapours rise into and through the column
the empyreumatic impurities of the acid are separated in the usual manner and the
purified and concentrated acid descends into the second compartment. When the pure
product is distilled off fresh crude acid is supplied to the first compartment and con-
nection is made between the column and the first compartment without stopping
distillation from the second compartment and thus the process is carried
continuously.
on
As the first portion of acid distilled over may not be of the requisite degree of
purity, a draw-off cock may be provided in the second compartment to allow the first
running, being run off instead of being distilled over as is the case with the pure
product. But we prefer to provide the pipe leading down from the lowermost plate
of the column with two branches one leading into the first compartiment and the other

page_text: into the second a suitable two-way cock is provided. Now as long as a sample taken
from the sample-cock is not quite pure the column is made to deliver into the first
compartment, as soon as the product appears satisfactory the two-way cock is turned
and the column delivers into the second compartment.
The two compartments may be either two divisions of the pan separated by a
partition, or they may be entirely independent of one another.
The improved portions of the said apparatus are shown in sectional olevation in the
annexed drawings.
A, B, are the two compartments into which the still is divided and C the partition
separating the same. D is the lower part of the column. The column being of the
usual construction its upper parts are not represented. E is the feed-pipe for the
compartment A the pipe F receives the acid which descends in the still.
This pipe is
at G fitted with a sample cock and at H with a two-way cock. I is a pipe leading
into compartment A, J is a pipe leading to the compartment B. By means of the
cock H the pipe F can be made to feed either into pipe I or into pipe J.
K is a pipe
tube or casing enclosing the pipe J. It is closed at the bottom and open at
the top.
Before turning the two way cock H so as to connect the column with compartment B,
the pipe or tube K is filled or nearly filled with pure acetic acid so as to prevent the
vapours from compartment A and the column "blowing through." A and B' aro
level indicators, A and B are hand holes with suitable covers to allow waste materials
to be removed. L is the ordinary still-head.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :
1.) The continuous rectification and concentration of Acetic acid by means of a
divided still and a column as set forth.
2.) A still for rectifying and concentrating acetic acid consisting of the compart-
ments A and B and working in conjunction with a column and accessory parts of the
usual construction, as described and shown in the drawings.
3.) In a still for rectifying and concentrating acetic acid having two compartments,
the means for passing the product coming from the column into one or the other
compartment, consisting of a pipe or tube F, the cock H, the pipe I and the pipe J
surrounded by tube K all combined and operating as set forth and shown.
Dated this 25th day of April 1889.
BERNHARD DUKES,
226, High Holborn, London, W.C., Agent for the Applicants.