IMPROVED APPARATUS FOR THE CONCENTRATION OF SULPHURIC ACID AND FOR SIMILAR PURPOSES
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by William Robert Lake at the Office of
the Commissioners of Patents on the 7th August 1878. A communication
from abroad by Alarik Liedbeck, of Stockholm, Sweden, Engineer.
"
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. IMPROVED APPARATUS FOR THE CONCENTRATION
OF SULPHURIC ACID AND FOR SIMILAR PURPOSES." [A communication from abroad
by Alarik Liedbeck, of Stockholm, Sweden, Engineer.]
This Invention relates to a novel apparatus for the concentration of sulphuric
acid, which apparatus is also applicable for other purposes.
The said improved apparatus comprises a series of vessels made of glass or
porcelain, and which fit one in the other and are placed in an inclined plane;
and arranged either with as many sand baths as there are vessels, or with a single
sand bath for all the vessels, or for a certain number of the same. They may
even be simply exposed to the naked fire.
The said vessels may be of cylindrical sphero-elliptic or spherical form, their
tubular ends are constructed in such a manner that they may readily enter one
into the other, and thus form a set of successive receptacles.
The joints between the said vessels (which do not need to be hermetically
closed) may be furnished with asbestos.
In order that the vapours may not exercise any pressure in the interior of the
apparatus, it will only be necessary to give to the tubes with which the ends of
the vessels are provided sufficient dimensions and to provide a communication
between the free outlet of a condensing apparatus and the chimney. A slight
suction is thus established in the said connected vessels.
The degree of inclination given to the inclined plane should be such that the
boiling liquid may without running over to the outside traverse the whole series of
vessels.
The construction of the parts which form the supports of the vessels, whether
made of lead or of refractory earth, will naturally vary.
At one end of the apparatus and below the sand baths supporting the vessels
I place the fire-place or grate by means of which the whole apparatus is heated,

page_text: The gases from combustion pass first below the sand baths, thus heating the whole
series of vessels; after this the gases pass into a space limited below by plates
covering a channel containing the vessels, and above by cast-iron plates which
support lead basins. This circulation of the gases has for its object to heat and
evaporate before its entry into the vessels the sulphuric acid coming from lead
chambers, and brought into the said basins which are placed at the upper part of
the apparatus.
Sulphuric acid is concentrated in my said apparatus as follows, that is to say :-
The said apparatus being filled with acid to be concentrated, and the fire having
been lighted in the said fire-place, the acid contained in the vessels and that in the
lead basins is rapidly brought to the temperature which concentration requires.
Then I commence to supply or feed the series of vessels by introducing the acid to
be concentrated into that vessel of the series which is placed at the highest part of
the inclined plane.
The vessel in question is provided for this purpose with a special pipe.
The acid may however be introduced by any suitable means. The acid then
pours out of the first vessel into the second, from the second into the third, and so
on, until it has traversed the whole series of vessels. Then it is conducted by a
pipe ad hoc into a refrigerating receptacle where it is cooled.
During the time that the liquid takes to traverse the said series of vessels, it is
submitted to the action of the heat of the gases from the fire-place, the temperature
of the liquid rises gradually in proportion to its proximity to the fire-place, and its
degree of concentration increases more and more.
In order to effectually carry this operation of concentration into practice, it is
desirable to introduce into the apparatus a quantity of liquid proportionate to that
which goes out of the same, after having reached the degree of concentration
desired, which will be ascertained by the temperature indicated by the thermometer
in the liquid of the last vessel, before the said liquid leaves the apparatus.
The acid which traverses the apparatus is heated only gradually; during its
passage the liquid only reaches little by little the degree of temperature and
concentration required in evolving acid vapours. These vapours traverse the
vessels in a contrary direction to that of the current of the liquid, and after having
traversed the whole series of receptacles they pass into a condensing apparatus.
The said vapours thus traverse successively vessels which are less and less warm, a
part of the acid which they contain is condensed during this passage, and the
vapours when they reach the condensing apparatus contain only an acid of a weak
degree.
It will be understood that this fact constitutes an important advantage as
regards the producing capacity of the apparatus.
The said apparatus giving off, when condensation is going on, only vapours very
weak in acid, the relative quantity of concentrated acid obtained must necessarily
be increased..
An apparatus constructed as above described or somewhat modified may also be
employed for various other similar purposes, comprising the operations for the
condensation, evaporation, and distillation of certain liquids and substances.