Process for Obtaining Pure Nitric Acid Direct in Nitric Acid Reaction Apparatus.
Year: 1891

page_text: Date of Application, 17th Jan., 1:91
Complete Specification Left, 4th Sept., 1891-Accepted, 10th Oct., 1891
PROVISIONAL SPECIFICATION.
[Communicated from abroad by THE CHEMISCHE FABRICK GRIESHEIM, of
Frankfort /Main, Germany.]
Process for Obtaining Pure Nitric Acid Direct in Nitric Acid
Reaction Apparatus.
I, OLIVER IMRAY, of No. 28 Southampton Buildings, Chancery Lane, in the
County of London, Fellow of the Institute of Patent Agents, do hereby declare
the nature of this invention to be as follows:-
Hitherto for production of pure nitric acid it has been necessary first to obtain
crude acid by heating saltpetre with sulphuric acid, and cooling the evolved
vapour, and then to subject the acid to a farther process for its purification.
In consequence of the troublesome character of this process the necessary
transport of the acid was always accompanied by losses and involved a large
expenditure of time and labour. The heat of the vapour from the reaction vessel
subject to the cooling water usually was allowed to go to waste, and afterwards the
crude acids were heated again either directly or with the aid of steam in vessels of
glass or stoneware or apparatus, very sensitive to great changes of temperature,
with or without admission of air.
The following process allows of obtaining nitric acid without loss, from common
salt, commercial saltpetre containing iodine, and crude sulphuric acid directly
behind the reaction vessel, free from hyponitric acid, nitrous acid, and halogen
compounds, in the apparatus of the following description which is in principle a
reflux cooler.
Behind the producing apparatus and connected therewith is a collecting vessel
into which flow the acids condensed in the reflux-cooler, in as heated a condition
as possible, and they are maintained in this condition. The reflux cooler must
work in such a manner that only the lower nitric-oxides, and halogen compounds
as free from nitric-acid as possible, escape. The latter are absorbed in water in a
known manner.
To obtain pure acid, the acid in the collecting-vessel must be kept at a
temperature of about 80° C.
The production of pure acid even at the temperature of 80° C. is considerably
simplified by conducting air or other gases into the acid in the collecting-vessel.
Dated this 17th day of January 1891.
ADEL & IMKAI,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Process for Obtaining Pure Nitric Acid Direct in Nitric Acid
Reaction Apparatus.
I, OLIVER IMRAY, of No. 28 Southampton Buildings, Chancery Lane, in the
County of London, Fellow of the Institute of Patent Agents, 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:-
Hitherto for production of pure nitric acid it has been necessary first to obtain
crude acid by heating saltpetre with sulphuric acid, and cooling the evolved
vapour, and then to subject the acid to a farther process for its purification.

page_text: In consequence of the troublesome character of this process the necessary
transport of the acid was always accompanied by losses and involved a large
expenditure of time and labour. The heat of the vapour from the reaction vessel
subject to the cooling water usually was allowed to go to waste, and afterwards the
crude acids were heated again either directly or with the aid of steam in vessels of
glass or stoneware or apparatus, very sensitive to great changes of temperature,
with or without admission of air.
The following process allows of obtaining nitric acid without loss, from common
salt, commercial saltpetre containing iodine and crude sulphuric acid directly
behind the reaction vessel, free from hyponitric acid, nitrous acid and halogen
compounds, in the apparatus of the following description which is in principle a
reflux cooler.
Behind the producing apparatus and connected therewith is a collecting vessel
into which flow the acids condensed in the reflux-cooler, in as heated a condition as
possible, and are maintained in this condition. The reflux cooler must work in
such a manner that only the lower nitric oxides, and halogen compounds as free
from nitric-acid as possible, escape. The latter are absorbed in water in a known
manner.
To obtain pure acid, the acid in the collecting-vessel must be kept at a
temperature of about 80° C.
The production of pure acid even at the temperature of 80° C. is considerably
simplified by conducting air or other gases into the acid in the collecting-vessel.
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. A method of obtaining nitric acid free from hyponitric acid, nitrous acid, and
halogen-compounds, direct from the generating vessel, consisting in that distillation
is carried on through a collecting vessel in an apparatus working as a reflux cooler
under the condition that the temperature of the acids in the collecting vessel for
obtaining concentrated acids should be kept at least at 80° C., but for acids of less
concentration it may be lower.
2. In the process referred to in the preceding claim promoting the separation
of the lower nitrogen oxides and halogen compounds by introduction of air or other
gases into the acids of the collecting vessel, whereby the temperature of these acids
can be kept lower as indicated in Claim 1.
Dated this 4th day of September 1891:
ABEL & IMRAY,
Agents for the Applicant.