A New or Improved Process and Apparatus for the Production of" Chlorine from Gaseous Hydrochloric Acid.
Year: 1894

page_text: Date of Application, 25th Aug., 1834
Complete Specification Left, 13th May, 1895-Accepted, 24th Aug., 1895
PROVISIONAL SPECIFICATION.
A New or Improved Process and Apparatus for the Production of"
Chlorine from Gaseous Hydrochloric Acid.
I, PAUL ROBERT JOHANN KRAUSE, of 174 Moda-Djadessy, Kadi Kieuy, near
Constantinople, Turkey, Engineer, do hereby declare the nature of my said
invention to be as follows:-
My invention has for its object a new or improved process and apparatus for the
production of chlorine from gaseous hydrochloric acid.
The invention consists of gaseous hydrochloric acid being introduced into a
tower similar to a Glover-tower together with sulphuric acid of 1.71 specific
gravity at a temperature of 125° C., and nitric acid.
In this process the sulphuric acid, which has been very much cooled down, is
brought again to its original temperature by vapor introduced along the sides of
the tower and is maintained at this temperature because at a lower one the
hydrochloric acid could not be entirely expelled.
The entering vapor has a two-fold task, increasing by its warmth, and by means
of its absorption of the sulphuric acid, the temperature of the latter, after its
cooling down, and secondly, to accelerate the evaporation of the hydrochloric acid
by moving the mixture of acid descending from the roof of the tower.
The quantity of vapor is to be regulated in accordance with the temperature to
be observed by means of thermometers properly applied.
Further, the quantity of sulphuric acid to be introduced must be so measured
that the specific gravity of the outgoing acid does not sink below 1.45 to 1.5 in
order to prevent the simultaneous evaporation of watery vapors with the gaseous
muriatic acid.
The nitric acid is evaporated, by which process, through the action of the nitric
acid on the hydrochloric acid, according to the known re-action, chlorine and
nitrosyl-chloride are produced; whereas the water produced at the same time by
this reaction is absorbed by the sulphuric acid.
The gaseous muriatic acid may be introduced in a special gasification tower or in
any other known way for instance the fumes of muriatic acid mixed with vapours
escaping out of the sulphate stove of the Leblanc soda manufacture may be used.
The fumes of muriatic acid are conducted to the tower for the production of
chlorine, where they act upon the nitric acid introduced in a watery solution and
evaporated in the above described manner.
In the latter case however the mixture of vapor and muriatic acid must be
carefully watched so as to prevent the possible overheating of the H₂SO..
The construction of the tower like apparatus under consideration here which is
to be utilized for carrying out the method above mentioned, having for its basis
the uniform principle of heating the sulphuric-acid through the latent warinth
resulting from the introduction of vapor is further described as follows:-
In the main this apparatus is built like the Glover-tower a cylindrical column of
bricks resisting the action of acid is surmounted by a leaden cover. The bottom of
the apparatus is of lead and covered with acid proof plates, the ceiling being of the
same material or covered with stone plates.
When it is required to have a uniform temperature in the tower the strength of
this stone lining from the ceiling to the bottom of the tower may be the same.
The tower thus formed is lined as usual with pieces of clay resisting acid.

page_text: For the distribution of acids it is preferable to fix one or several perforated
plates of stone immediately under the top.
All liquid acids are to be introduced in the usual way, from the top, and the
introduction is by means of proper reservoirs, which are provided with water
gauges and scales or other measuring apparatus for the quantity of liquid.
The hot sulphuric acid is heated and concentrated in a proper manner in special
apparatus fixed at such a height that the acid can simply enter into the tower.
As this acid requires to be pumped upwards continually after its leaving the
tower for re-use and concentration, the quantity of the sulphuric acid entering the
tower may be regulated simply by the raising pump, that is to say, by an air
pulsometer, or the quantity may be regulated by a lever.
The main feature and the novelty of the apparatus consists in the application of
a number of tubes converging in the interior of the tower and such a system of
tubes is to be applied at a distance of 0.50 m. to 100 m. from the ceiling of the
tower where the mixture of the acids has most completely taken place and
where, in consequence, the most complete cooling of the sulphuric acid has also
resulted.
A second or third line of vapor tubes may be applied at proper distances at the
lower part of the tower where we must suppose that the temperature of sulphuric
acid has sunk a little in consequence of the radiation of heat outwardly.
The different tubes or systems of tubes are controlled by simple steam
ventilators.
At the circumference of the tower and at different heights, thermometers are
fixed in such a manner that their quicksilver balls are covered by the hot acid of
the interior so that the temperature may be read at any moment and regulated by
the steam taps.
In a case, where, as before mentioned the evaporation of muriatic acid and of
nitric acid for the production of chlorine in separate towers is intended, the hydro-
chloric gas is conducted to the nitric acid tower and may be conducted either from
above to below or from below to above.
Dated this 24th day of August 1894.
GEORGE BARKER,
77 Colmore Row, Birmingham, Agent for Applicant.
COMPLETE SPECIFICATION.
A New or Improved Process and Apparatus for the Production of
Chlorine from Gaseous Hydrochloric Acid.
I, PAUL ROBERT JOHANN KRAUSE of 174 Moda Djadessy, Kadikieuy, in
the Turkish Empire, Civil Engineer, 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 :-
This invention relates to the known method of obtaining chlorine from gaseous
hydrochloric acid by the agency of nitric acid and hot sulphuric acid, and the
object of my invention is to simplify and otherwise improve the process as hitherto
conducted, as well as the apparatus employed therein.
My improvements consist in introducing gaseous hydrochloric acid, hot sulphuric
acid, and nitric acid into a tower constructed similarly to a Glover's tower, and in
blowing dry or superheated steam into the tower simultaneously with the intro-
duction of the above named acids, so as to regulate the temperature of the sulphuric
acid as hereinafter described.
It is well known that heat is generated by the mixture of steam with sulphuric
acid, and I utilise the generation or production of sensible heat by this means for
the purpose of maintaining in the sulphuric acid a temperature of from 125°

page_text: to 130° C. during its passage through the tower, by controlling the admission of
steam.
The nitric acid, coming into contact with the hot sulphuric acid, is volatilised
and at once acts upon the gaseous hydrochloric acid, so that chlorine, nitrosyl
chloride, (NOCI,) and water are produced, the water being absorbed by the
sulphuric acid.
If the quantity of the gaseous hydrochloric acid passing through the tower in
unit time he approximately known the equivalent quantity of nitric said to be
introduced during the same time can be ascertained by means of the formula :—
introduced during the same time can be ascertained by means of the formula :-
6 HCl + 2 HNO, 4 Cl + 2 NOCI + 4 H₂O,
and can be regulated by suitable measuring apparatus.
The quantity of sulphuric acid to be used can also be easily determined by noting
its strength at the point of outflow from the tower. At this point the acid should
have a specific gravity which should never be allowed to fall below from 1.45
to 1.50.
The improved apparatus which I employ is represented in vertical section by the
accompanying drawing which will be hereinafter referred to.
In this drawing a is the tower constructed in a similar manner to an ordinary
Glover tower. b is a concentrating apparatus for the sulphuric acid which is used
over and over again. This concentrating apparatus may be of the ordinary or any
suitable construction. As illustrated it consists of a tank heated by hot gases from
a furnace passing through flues constructed below the tank.
The sulphuric acid enters the top of the tower a at 1, and flows out of the bottom
of the tower at 2, into the vessel 3, whence it flows into the tank c, from which it is
pumped by the pump d back into the concentrating apparatus b, for re-use.
Nitric acid is stored in the tank e whence it flows into any suitable measuring
apparatus such as that indicated at f.
From the measuring apparatus f the nitric acid
tower at 4.
flows into the top of the
The gaseous hydrochloric acid enters the tower at 5. Below the point of entry
of the above named acids, there is erected in the tower a stone or similar
diaphragm 12, having a number of perforations as indicated, for the better diffusion
of the acids.
The produced chlorine and nitrosyl chloride gases escape from the bottom of the
tower through the pipe 8.
The dry or superheated steam is admitted to the tower through the tuyeres 6 6,
of which there may be one ring at from 18 in. to 3 ft. from the top of the tower, and
one or more rings below, according to the dimensions of the tower. The admission
of the steam is controllable by the cocks 7 7.
--
The conduct of the process is very simple, and is as follows -The interior of
the tower is first impregnated with the hot sulphuric acid which is kept flowing
continuously through it. Gaseous hydrochloric acid, derived from decomposing
pots, or any other suitable source, is then introduced continuously and simul-
taneously with an equivalent quantity of nitric acid as indicated by the above
formula.
In the meantime, steam is admitted for the purpose of maintaining or raising the
temperature of the sulphuric acid whenever it may have been cooled by the action
of the nitric acid, by convection, or by radiation. Thermometers 9, 10, are
provided in the walls of the tower for the purpose of indicating the temperature
inside, which must be maintained at about 125° C. The outflowing sulphuric acid
also must shew this temperature, otherwise traces of nitric acid may go into solution
and thus be lost. On the other hand, the temperature of the sulphuric acid in the
tower should never be allowed to exceed 130° C. as, if this temperature were
exceeded the nitric acid might, in part, be split up into its components and form
nitrogen, or such lower oxides as would be difficult to recover as nitric acid and
which would be lost.

page_text: The strength of the sulphuric acid leaving the tower may conveniently be
ascertained by means of a hydrometer.
The chlorine and nitrosyl chloride issuing from the apparatus as the product of
the process, may be collected and utilised in and by the known devices and in the
known manner.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, 1 declare that what I
claim is :-
1. The improved process for the manufacture or production of chlorine which
consists in the continuous and simultaneous introduction into a Glover's tower or
similar structure of gaseous bydrochloric acid, hot sulphuric acid, and nitric acid,
together with a sufficient supply of dry or superheated steam to maintain the
temperature of the sulphuric acid, substantially as hereinbefore set forth.
2. Apparatus for use in the production of chlorine from hydrochloric acid gas,
and consisting essentially of a Glover's tower or similar structure, apparatus for
concentrating sulphuric acid, a nitric acid tank, devices for measuring the admission
of the sulphuric and nitric acids, tuyeres for admitting dry or superheated steam-to
the tower with a pump to return the acid therefrom to the concentrating apparatus,
and suitable inlets and outlets for the acids and gases, substantially as hereinbefore
described with reference to the accompanying drawings.
Dated this 11th dor of MoA D1005
W. E. HEYS & SON,
Agents for the Applicant.