Improvements in and connected with Apparatus for Producing Gaseous Hydrochloric Acid..
Year: 1889

page_text: Date of Application, 3rd. Oct., 1889
Complete Specification Left, 3rd July; 1890-Accepted, 9th Aug., 1890
PROVISIONAL SPECIFICATION.
Improvements in and connected with Apparatus for Producing
Gaseous Hydrochloric Acid..
I, WILLIAM LLOYD WISE, of 46 Lincoln's Inn Fields, in the County of Middle-
sex, Consulting Engineer and Patent Agent, do hereby declare the nature of this
invention (a communication to me from abroad by Messrs. Solvay and Company
of 19, Rue du Prince Albert, Brussels, Belgium, Manufacturers,) to be as follows
In the chemical industry it is sometimes necessary to obtain hydrochloric acid in a
dry and gaseous state from its commercial solution. It has long been known that
distillation pure and simple does not enable the desired result to be obtained and that
it is necessary to employ 'in addition to the distilling operation a dehydrating agent
to remove the water distilled over with the hydrochloric acid gas. Sulphuric acid
has long been employed for this purpose, first in laboratories and subsequently in
industrial establishments. The use of chloride of calcium as the dehydrating agent
has already been patented by my foreign correspondents.
T
The apparatus hitherto employed in the distilling operation hereinbefore referred
to is usually very inconvenient to manipulate ;Jon leaving the apparatus in which the
gaseous hydrochloric acid is evolved, it is necessary to convey the sulphuric acid, or
the chloride of calcium as the case may be, into evaporating apparatus in order to
bring it again to the original degree of concentration, and then to return it to the
evolving apparatus. As only a rather small fall or change from the original degree
or state of concentration is admissible without great inconvenience resuiting from the
hydrochloric residue in the evaporating apparatus, considerable quantities of liquids
must be employed which from their nature and their temperature are not capable of
easy manipulation.
The apparatus hereinafter described is designed to obviate these disadvantages and
is applicable both to the use of chloride offcalcium, tor of sulphuric acid. In the latter
case. the apparatus is made of lead: Aliorizontal rectangular vessel of elongated
form is divided into two compartments-by a partition which at one side stops short of
and at a suitable distance from the end of the vessel so as to establish communication
between the two compartments. This vessel constitutes the. evaporating apparatus
which is heated as desired. The vessel communicates by means of two pipes (one in
each compartment) with another. and smaller vessel which serves for distilling. The
latter.vessel is covered and is not directly heated. The whole apparatus is filled with
sulphuric acid of about 60° Beaumé; or with a concentrated solution of chloride of
calcium, and is brought to a suitable temperature continuous fine-or thread-like
stream of liquid hydrochloric acid is then caused to pass into the distilling vessel; the
gaseous acid is at once evolved and the water combines with the sulphuric acid or
with the chloride of calcium as the case may be.
•
A very simple arrangement of paddle wheel immersed in one of the compartments
of the evaporating vessel imparts to the liquid a slow but continuous circulating
motion. The sulphuric acid, or the chloride 'of calcium, slightly diluted in the
distilling vessel passes out of the latter and enters the evaporating apparatus
through which it slowly flows and in which it becomes concentrated;. it then
returns to the distilling vessel when it has reached its original - degree of
concentration.
In order to prevent the mingling in the latter of the dehydrating agent with liquid
hydrochloric acid heing effected too quickly, and also to prevent the escape of sulphuric
acid or chloride of calcium still holding a small amount of hydrochloric acid in solu-
tion, a number of partitions or baffles are provided in the distilling vessel, and the
liquid hydrochloric acid is caused to enter the same from the side which is nearest to

page_text: the place where the dehydrating agent re-enters this vessel. Instead of a single
evaporating vessel divided into two compartments by an incomplete partition, two
parallel vessels may be employed that are connected at the ends remote from the
distilling vessel by a large communicating passage; these two vessels may also if
desired be replaced by a number of smaller vessels connected with one another.
In cases where the presence of air in the gaseous hydrochloric acid obtained, is
necessary, such air is caused to bubble up in the distilling vessel and has the effect
of further hastening the distilling operation which however takes place very easily in
the absence of air. This injection of air may even serve as a motive power for drawing
along and circulating the current of dehydrating liquid on the principle of the injector.
The paddle wheel hereinbefore mentioned, may thus be dispensed with. It may also
be replaced by a helix or screw conveyor provided at a suitable part of the circulating
passage or channel.
It will be clearly understood that the advantage of the apparatus hereinbefore
described consists in the fact that there is no hot liquid and acid to be pumped; that
the whole operation takes place in a horizontal apparatus, with only a nominal
consumption of motive power; and that the dehydrating agent may be in excess to
any desired amount without increasing the labor of manipulation.
In practice when using the ordinary commercial hydrochloric acid, which is always
charged with sulphuric acid, it is advantageous to employ sulphuric acid as the
dehydrating agent.
When using pure hydrochloric acid in solution the use of chloride of calcium has
the advantage that it can be heated in apparatus made of wrought or cast iron. The
distilling vessel alone is then made of lead protected by sandstone; or it may with
advantage be made entirely of sandstone.
"
COMPLETE SPECIFICATION.
Improvements in and connected with Apparatus for. Producing
Gaseous Hydrochloric Acid.
A communication to me from abroad by Messrs. SOLVAY & Co., of 19, Rue du Prince
Albert, Brussels, Belgium, Manufacturers.
.
I, WILLIAM LLOYD WISE, of 46, Lincoln's Inn Fields, in the County of
Middlesex, Consulting Engineer and Patent Agent, 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 :-
+
[
In the chemical industry it is sometimes necessary to obtain bydro-chloric acid in a
dry and gaseous state from its commercial solution. It has long been known that
distillation pure and simple does not enable the desired result to be obtained, and that
it is necessary to employ in addition to the distilling operation a dehydrating agent
to remove the water distilled over with the hydrochloric acid gas. Sulphuric acid
has long been employed for this purpose first in laboratories, and subsequently in
industrial establishments. The use of chloride, of calcium as the dehydrating agent
has already been patented by my foreign correspondents...
The apparatus hitherto employed in the distilling operation hereinbefore referred to
is usually very inconvenient to manipulate. On leaving the apparatus in which the
gaseous hydrochloric acid is evolved, it is necessary to convey the sulphuric acid, or
the chloride of calcium, as the case may be, into evaporating apparatus, in order to
bring it again to the original degree of concentration, and then to return it to the
evloving apparatus. As only a rather small fall or change from the original degree
or state of concentration is admissible without great inconvenience resulting from the
hydrochloric residue in the evaporating apparatus, considerable quantities of liquid
must be employed which from their nature and their temperature are not capable of
easy manipulation.

page_text: The apparatus hereinafter described is designed to obviate these disadvantages and
s applicable both to the use of chloride of calcium, or of sulphuric acid. In the latter
case the apparatus is made of lead.
In the accompanying drawings Fig. 1 is a vertical section and Fig. 2 a plan of
apparatus according to this invention.
A is a horizontal rectangular vessel of elongated form divided into two compart-
ments B B by a partition which at one end stops short of and at a suitable distance
from the end of the vessel so as to establish communication between the two compart-
ments. This vessel constitutes the evaporating apparatus which is heated as desired;
it may be by a furnace at D having a flue D' beneath the vessel A. The vessel
communicates by means of two pipes E and F (one to each compartment) with another
and smaller vessel G which serves for distilling. The latter vessel is covered, and is
not directly heated. The whole apparatus is filled with sulphuric acid of about
60° Beaume, or with a concentrated solution of chloride of calcium, and is brought to
suitable temperature. A continuous fine or thread-like stream of liquid hydro-chloric
acid, is then caused to pass into the distilling vessel through the inlet pipe H; the
gaseous acid is at once evolved and passes off by the outlet pipe I and the water
combines with the sulphuric acid, or with the chloride of calcium as the case may be.>
A very simple arrangement of paddle wheel J immersed in one of the compartments
of the evaporating vessel imparts to the liquid a slow but continuous circulating
motion. The sulphuric acid, or the chloride of calcium, slightly diluted in the distilling
vessel, passes out of the latter and enters the evaporating apparatus through which it
slowly flows and in which it becomes concentrated; it then returns to the distilling
vessel when it has reached its original degree of concentration.
In order to prevent the mingling of the dehydrating agent with liquid hydro-chloric.
acid in the distilling vessel G being effected too quickly, and also to prevent the escape
of sulphuric acid, or chloride of calcium still holding a small amount of hydro-chloric
acid in solution, a number of partitions or baffles K are provided in the distilling
vessel, and the liquid hydro-chloric acid is caused to enter the same from the side
which is nearest to the place where the dehydrating agent re-enters this vessel. Instead
of a single evaporating vessel divided into two compartments by an incomplete partition
as in the example shewn, two parallel vessels may be employed that are connected at
the ends remote from the distilling vessel by a large communicating passage; these
two vessels may also if desired be replaced by a number of smaller vessels connected
with one another.
In cases where the presence of air in the gaseous hydrochloric acid obtained, is
necessary, such air is caused to bubble up in the distilling vessel and has the effect of
further hastening the distilling operation which however takes place very easily in the
absence of air. This injection of air may even serve as a motive power for drawing
along and circulating the current of dehydrating liquid on the principle of the injector.
The paddle wheel hereinbefore mentioned may thus be dispensed with. It may also
be replaced by a helix or screw conveyor provided at a suitable part of the circulating
passage or channel. The gaseous hydrochloric acid produced as described can after-
wards be condensed in pure or distilled water to obtain a pure solution of hydro-chloric
acid.
It will be clearly understood that the advantage of the apparatus herein before
described consists in the fact that there is no hot liquid and acid to be pumped; that
the whole operation takes place in a horizontal apparatus, with only a nominal
consumption of motive power; and that the dehydrating agent may be in excess to
any desired amount without increasing the labour of manipulation.
In practice when using the ordinary commercial hydrochloric acid, which is always
charged with sulphuric acid, it is advantageous to employ sulphuric acid as the
dehydrating agent.
When using pure hydro-chloric acid in solution the use of chloride of calcium has
the advantage that it can be heated in apparatus made of wrought or cast iron. The
distilling vessel alone is then made of lead protected by sandstone; or it
advantage be made entirely of sandstone.
may
with

page_text: Having now fully described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. For disengaging hydrochloric acid in a dry and gaseous state from its commercial
solution, an apparatus comprising two main parts or vessels, one for concentrating the
dehydrating agent employed, and the other for distilling or decomposing the commercial
solution of hydrochloric acid used, these two main parts or vessels being placed
horizontally with reference to each other and the arrangement being such that the
dehydrating agent can be caused to circulate in a slow and continuous manner through
the two parts or vessels by suitable means such as for example, a paddle wheel, or a
screw propeller, or by injection of air as set forth.
2. The improved apparatus for producing gaseous hydrochloric acid froin its
commercial solution substantially as described and shewn.
3. The herein described method of producing pure liquid hydrochloric acid from its
commercial solution and continuously re-concentrating the dehydrating agent, by
causing the said solution of hydrochloric acid to flow into a vessel that is in direct
communication with a horizontal evaporating vessel, causing the dehydrating agent to
circulate through both vessels in a slow and continuous manner, and condensing in
pure water the dry and gaseous hydrochloric acid evolved, as set forth.
Dated this 3rd day of July 1890.
W. LLOYD WISE,
Per F. J. Brougham.