Improvements in Obtaining a Continuous Supply of Hydrochloric Acid or Nitric Acid Gas, and in Utilising Acid Sulphates.
Year: 1894

page_text: Date of Application, 26th Nov., 1894
Complete Specification Left, 22nd Aug., 1895-Accepted, 28th Sept., 1895
DIONAL DIECIFICATION.
Improvements in Obtaining a Continuous Supply of Hydrochloric
Acid or Nitric Acid Gas, and in Utilising Acid Sulphates.
I, JAMES WORKMAN WALKER, of Fernlea, Irvine, in the County of Ayr,
North Britain, Technical Chemist, do hereby declare the nature of this invention to
be as follows, that is to say:
My said invention has for its object the obtainment of continuous supplies of
hydrochloric acid and nitric acid gases by improved processes in which acid
Bulphate can be utilised.
In carrying out my invention according to one modification I take a quantity of
common salt and treat it with a quantity of sulphuric acid sufficient to convert the
whole of the sodium into acid sulphate, in a decomposing vessel, fitted with
mechanical stirring apparatus and suitably heated. The salt and acid are fed in
continuously at one end or part of the decomposer and the acid sulphate is
discharged continuously at another end or part, whilst the hydrochloric acid gas
evolved is led off for use by a separate flue or passage. The acid sulphate
obtained as described or in any other suitable known way is after cooling roughly
ground and mixed with salt cake (mono sulphate) and salt in the proportion of
about three parts by weight of acid sulphate and two to three parts of salt cake to
every part of salt. The mixture is fed continuously into a second decomposing
vessel, fitted with mechanical stirring apparatus and suitably heated, with the
result that the hydrochloric acid of the salt is continuously evolved and salt cake
or monosulphate is continuously discharged
Instead of cooling the acid sulphate formed it may whilst still in a fused state
be led continuously into the second decomposer; or both stages of the processes
may be effected in a single elongated vessel at a suitable part of which a weir is
fixed across to divide the vessel into two compartments. The acid sulphate formed
in the first compartment overflows at the weir into the second compartment and at
the position of overflow the salt cake or mono sulphate and second supply of salt
are fed in continuously.
In order to obtain nitric acid gas nitrate of soda is employed instead of common
salt, the processes being otherwise as herein before described
When it is not required to obtain the gases continuously in applying the process
mainly for utilising acid sulphates, the materials may be dealt with in separate
charges.
Dated this Twenty-fourth day of November 1891
EDMUND HUNT,
Applicant's Agent.
COMPLETE SPECIFICATION.
Improvements in Obtaining a Continuous Supply of Hydrochloric
Acid or Nitric Acid Gas, and in Utilizing Acid Sulphates.
I, JAMES WORKMAN WALKER, of Fernlea, Irvine, in the County of Ayr,
North Britain, Technical Chemist, 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, that is to say:-
My said invention has for its object the obtainment of continuous supplies of

page_text: hydrochloric acid and nitric acid gases by improved processes in which acid
sulphates can be utilised.
In carrying out my invention according to one modification I take a quantity of
common salt and treat it with a quantity of sulphuric acid sufficient to convert the
whole of the sodium into acid sulphate, in a decomposing vessel of a usual kind,
which may be fitted with mechanical stirring apparatus, and is suitably heated.
The salt and acid are fed in in a practically continuous manner at one end or part
of the decomposer and the acid sulphate is discharged continuously or intermittently
at another end or part, whilst the hydrochloric acid gas is led off for use by a
separate flue or passage. The acid sulphate, obtained as described, or in any other
suitable known way, is, after cooling, roughly ground and mixed with salt cake
(monosulphate) and salt, in the proportions of about three parts by weight of acid
sulphate and two to three parts of salt cake to every part of salt. The proportions
may vary in different cases, as hereinafter explained. The mixture is fed
continuously into a second decomposing vessel, fitted with mechanical stirring
apparatus and suitably heated, with the result that the hydrochloric acid of the
salt is continuously evolved and salt cake or monosulphate is continuously
discharged.
Instead of cooling the acid sulphate formed, it may, whilst still in a fused state,
be led continuously into the second decomposer; or both stages of the processes
may be effected in a single elongated vessel, at a suitable part of which a weir is
fixed across to divide the vessel into two compartments. The acid sulphate formed
in the first compartment overflows at the weir into the second compartment, and at
the position of overflow the salt cake or monosulphate and second supply of salt
are fed in continuously.
The precise quantity of salt to be used to obtain a good decomposition in the
second stage of the processes will depend on the quantity of sulphuric acid present
in the nitre cake employed, and should be such that its sodium is chemically
equivalent to the sulphuric acid present in the nitre cake in excess of that
forming monosulphate. There should in all cases be sufficient salt cake or
monosulphate present in the second stage to keep the mixture in an unfused
state.
In order to obtain nitric acid gas, nitrate of soda or of potash is employed
instead of common salt, the processes being otherwise as herein before described.
When it is not required to obtain the gases continuously in applying the
processes for utilising acid sulphates or otherwise, the materials may be dealt
with in separate charges.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:
1. For obtaining continuous supplies of hydrochloric acid or nitric acid gas,
heating a mixture fed in a practically continuous manner of common salt or nitrate
of soda or of potash with acid sulphate and with sufficient monosulphate of soda or
of potash to prevent fusion, substantially as herein before described.
2. Utilising acid sulphate by heating it with common salt or nitrate of soda or
of potash, and with sufficient monosulphate of soda or of potash to prevent fusion
substantially as hereinbefore described.
Dated this Twenty-first day of August 1895.
EDMUND HUNT,
Applicant's Agent.