IMPROVEMENTS IN THE MANUFACTURE AND PRODUCTION OF SALICYLIC ACID, AND IN APPARATUS EMPLOYED THEREIN
Year: 1877

page_text: LETTERS PATENT to Max Neustadt, of the Firm of M. Neustadt and Company,
of Mincing Lane, in the City of London, Merchants, for the Invention of
"IMPROVEMENTS IN THE MANUFACTURE AND PRODUCTION OF SALICYLIC ACID,
AND IN APPARATUS EMPLOYED THEREIN." A communication from abroad by
Emanuel Merck, of Darmstadt, in the Empire of Germany, Manufacturing
Chemist.
Scaled the 11th January 1878, and dated the 3rd November 1877
PROVISIONAL SPECIFICATION left by the said Max Neustadt at the Office
of the Commissioners of Patents on the 3rd November 1877.
"
MAX NEUSTADT, of the Firm of M. Neustadt and Company, of Mincing Lane, in
the City of London, Merchants. "IMPROVEMENTS IN THE MANUFACTURE AND
PRODUCTION OF SALICYLIC ACID, AND IN APPARATUS EMPLOYED THEREIN.'
A communication from abroad by Emanuel Merck, of Darmstadt, in the Empire of
Germany, Manufacturing Chemist.
This Invention consists,-
1st. In the preparation of basic salicylic acid soda by the action of carbonic acid
upon dry sodium phenol at a certain or determined temperature, and also under
certain conditions herein-after mentioned.
2nd. In the complete recovery of the carbonic acid set free.
3rd. In the re-utilization of the unconsumed carbonic acid.
And, 4th. In an apparatus to be employed in the manufacture and production of
salicylic acid.
This apparatus consists of a rotary iron cylinder, surrounded by brickwork,
and provided at its front end with a removable cover having an opening leading
into a stuffing box secured thereto. At its back or opposite end it is supported by
a hollow axle or trunnion resting on a support, and on this axle is mounted a
toothed wheel for setting the cylinder in motion through suitable gearing. Iron
Price Bd 1

page_text: tubes placed in the brickwork and heated by the hot air of the furnace keep up the
temperature of the cylinder. Sliding doors in the brickwork facilitate the emptying of
the cylinder. A coiled pipe is placed in the heating chamber for heating the carbonic
acid which passes into the cylinder through the hollow axle or trunnion. A pipe,
enclosing a thermometer, is placed in an outflow pipe passing through the stuffing
box at the front end of the cylinder, and carries off into a receiver or condenser the
carbolic acid as distilled off with any carbonic acid which may remain unconsumed.
For the preparation of the basic salicylic acid the dry sodium phenol is placed in
the cylinder, in which iron balls have been previously placed. One of the sliding
doors having been closed the outflow pipe carrying the thermometer and its pipe is
then introduced into the stuffing box of the cylinder, which is then set in motion.
The condenser or receiver is closed air-tight and the carbonic acid introduced into
the coiled pipe which lies above the heating tubes.
The carbonic acid on its way through the coiled pipe becomes heated to between
170° and 180° cent., and enters the cylinder containing the sodium phenol through
the hollow axle.
By the rotary motion of the cylinder and the movements of the balls the
incoming carbonic acid meets constantly a fresh surface of the sodium phenol, and
the carbolic acid as produced is liberated, and regular distillation thereof goes on.
The carbolic acid distilled off goes through the outflow pipe into the condensation
chamber, where it is taken up, and the carbonic acid, going over with it, is led
through an overflow pipe to the gas holder, to be used for the working of another
mass of the sodium phenol.
The temperature in the interior of the cylinder is kept up during its rotation by
its rotating in the heating chamber, and by the entering carbonic acid being heated
to the same degree.
The whole working can be easily regulated by the operator, and a large quantity
of salicylic acid obtained by this apparatus.
The temperature can be allowed to fluctuate between 170° and 185° cent., and
the temperature of the mass within the cylinder is watched by means of the
thermometer.
The quantity of salicylic acid and the yield of basic salicylic acid soda is extremely
large, and the purification of the acid is effected with but little ceremony.
The loss of carbonic acid, as well as the consumption of fuel, are very small, and
for attending to the apparatus only one man is required.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Max Neustadt in the Great Seal Patent Office on the 3rd May.
1878.
MAX NEUSTADT, of the Firm of M. Neustadt and Company, of Mincing Lane, in
the City of London, Merchants. " IMPROVEMENTS IN THE MANUFACTURE AND
PRODUCTION OF SALICYLIC ACID, AND IN APPARATUS EMPLOYED THEREIN."
A communication from abroad by Emanuel Merck, of Darmstadt, in the Empire of
Germany, Manufacturing Chemist.
This Invention has for object improvements in the manufacture and production
of salicylic acid, and in apparatus employed therein, and consists,—
1st. In the preparation of basic sodium salicylate by the action of carbonic
acid upon dry sodium carbolate at a certain or determined temperature, and also
under certain conditions herein-after mentioned.
2nd. In the complete recovery of the carbolic acid set free.
3rd. In the re-utilization of the unconsumed carbonic acid.
And, 4th. In apparatus to be employed in the manufacture and production of
salicylic acid, such apparatus being shewn in the accompanying Drawings, in which
Figure 1 is a longitudinal sectional elevation taken on the line C, D, of Figure 3;
Figure 2 is a vertical section taken on the line A, B, of Figure 3; Figure 3 is a plan,
partly in section; and Figure 4 is a section taken on the line E; F, of Figure 1.
For the preparation of basic sodium carbolate the dry sodium carbolate is placed
in the cylinder G, which is provided with a number of iron balls T by removing the
cover H. The cover is then replaced, and the toothed wheel L is put in gear with
the driving wheel K. After one of the iron sliding doors X has been closed, the
outflow pipe P, with the thermometer Q pushed through the support U, and the
receiver R being fastened, carbonic acid will be introduced to the pipe N by the
opening V.
On its way through the coiled pipe N, which lies above the heating tube O, the
carbonic acid becomes heated to between 170-180° cent., and it then enters by the
hollow axle k into the cylinder G, wherein is the sodium carbolate.
By the rotary motion of the cylinder and the movement of the balls the incoming
carbonic acid is constantly meeting with a fresh surface of the sodium carbolate,
the contained carbolic acid is partly liberated, and the regular distillation thereof
goes on.
The carbolic acid distilled off goes through the outflow pipe P into the conden-
sation chamber R, where it is taken up. The carbonic acid going over with it is led
through the pipe S to the gas holder, to be used for the working of another mass of
sodium carbolate.
The temperature in the interior of the cylinder is kept up during the rotation of
the cylinder by its rotating in the heating chamber, and by the entering carbonic
acid being heated to the same degree.
The whole working can be easily regulated by the operator, and the obtaining of
a large output of salicylic acid secured, which cannot be obtained by any other
construction of apparatus.
The temperature can be allowed to fluctuate between 170 and 185° cent., and
the temperature of the mass within the cylinder is watched by means of the
thermometer.
The formation of the basic sodium carbolate will be relatively small, whilst with
the correct introduction of the carbonic acid the free carbolic acid will be distilled
off in a powerful stream and in large quantities down to the last portion of the
mass.
It follows similarly that the resulting basic sodium salicylate is free from any
contamination of carbolic acid, and that the treatment of sodium carbolate and the
purification of the salicylic acid to the highest degree can be profitably conducted.
The operation upon each charge occupies from 4 to 5 hours, and each apparatus

page_text: can, by removing the cover H, be re-charged with fresh sodium carbolate as soon as
it has been emptied.
The output of the salicylic acid and the yield of basic sodium salicylate is extremely
large, and the purification of the acid is effected with but little ceremony, because
through the changing of the sodium carbolate all resinous matters are completely
avoided.
The loss of the carbonic acid, as well as the consumption of fuel, are very small;
and for attending to the apparatus only one man is required.
The basic sodium salicylate thus produced by means of this apparatus is then
dissolved in water; and by adding sulphuric acid to it, it becomes a neutral salt, and
can be easily purified by passing it througli animal charcoal.
By precipitating it with sulphuric acid, and then recrystallizing it in spirits of
wine, a salicylic acid is produced which is distinguished by its purity, absence of
smell, and beautiful appearance.
In witness whereof, I, the said Max Neustadt, have hereunto set my hand
and seal, this Twenty-ninth day of April, in the year One thousand eight
hundred and coventy
Witness,
E. MERCK.
MAX NEUSTADT. (L.S.)