Improvements in the Manufacture or Production of Nitric Acid, and Apparatus therefor.
Year: 1895

page_text: Date of Application, 19th July, 1895
Complete Specification Left, 18th Apr., 1-96-Accepted. 20th June, 1896
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture or Production of Nitric Acid, and
Apparatus therefor.
I, CHARLES DREYFUS of Clayton near Manchester in the County of Lancaster.
Director and General Manager of The Clayton Aniline Company Limited of
Clayton aforesaid, do hereby declare the nature of this invention to be as
follows:-
:-
The object of my invention is to provide means whereby nitric acid can be
readily obtained from nitrate of soda up to practically the theoretical yield and in
a pure state. According to my invention the process of distillation of the nitrate
of soda is conducted in vacuo and at such a temperature that impurities are not
yielded or given off with the acid vapours distilled off. I also provide means
whereby the vacuum creating apparatus is protected from injury by acid. I have
found that in order to obtain a practically theoretical yield of pure nitric acid from
nitrate of soda it is necessary to employ certain conditions of temperature, such as
will, on the one hand enable the whole or practically the whole of the nitric acid to
be obtained but which will on the other hand not cause impurities to be liberated
or formed and passed off with the acid. To this end I have found that the vessel
in which the nitrate of soda and sulphuric acid are subjected to distillation in vacuo,
should be submitted to a temperature such that it eventually reaches about
from 170° to 190° Centigrade. This heat may be applied for instance by direct
fire heat or by means of superheated steam. To protect the pump or exhausting
device from any acid which might escape condensation, I provide between the pump
or exhausting device and the other parts of the apparatus a tower or towers or
vessel or vessels containing water or an alkali or alkaline earth such as will intercept
any acid. I prefer to use a first tower or vessel into which water is passed, or
sprayed and then a tower or vessel containing an alkali or alkaline earth.
The stills, retorts, condensers, or coolers employed may be of the ordinary, or
any suitable kind.
Dated this 19th day of July 1895.
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.
COMPLETE SPECIFICATION.
Improvements in the Manufacture or Production of Nitric Acid, and
Apparatus therefor.
1, CHARLES DREYFUS, of Clayton, Manchester, in the County of Lancaster,
Managing Director of The Clayton Aniline Company Limited of Clayton,
afor esaid, 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:-
The object of my invention is to provide means whereby nitric acid can be readily
obtained from nitrate of soda, up to practically the theoretical yield, and in a
nura stato

page_text: According to my invention, the process of distillation of the nitrate of soda, is
conducted in vacuo, and at such a temperature, that impurities are not yielded, or
given off, with the acid vapours distilled off; I also provide means whereby the
vacuum creating apparatus is protected from injury by acid. I have found that in
order to obtain a practically theoretical yield of commercially pure nitric acid, from
nitrate of soda, it is necessary to employ certain conditions of temperature, such as
will, on the one hand, enable the whole, or practically the whole, of the nitric acid
to be obtained, but which will, on the other hand, not cause impurities to be
liberated, or formed, and passed off, with the acid. To this end, I have found that
the vessel, in which the nitrate of soda is (with sulphuric acid) subjected to
distillation, in vacuo, should be submitted to a temperature such that it eventually
reaches about, from 170° to 190° Centigrade. This heat may be applied for
instance, by direct fire heat, or by means of superheated steam. To protect the
pump, or exhausting device, from any acid which might escape .condensation, I
provide, between the pump or exhausting device, and the other parts of the
apparatus, a tower or towers, or vessel or vessels, containing water, or an alkali, or
alkaline earth, such as will intercept any acid or I may use first a tower or vessel,
into which water is passed, or sprayed, and then a tower or vessel, containing an
alkali or alkaline earth.
The accompanying drawing represents diagrammatically an arrangement of
apparatus suitable for carrying my invention into effect.
The nitrate of soda and acid are distilled in the still A under the conditions as
to temperature herein before stated applied by a furnace beneath.
The vapours pass from the still into a receiver and therefrom through a cooling
coil in the vessel B, and thence through receivers C, (furnished with taps c) and
through another cooling coil in the vessel D, and thence into the receivers E¹ to E
alternately with and without liquid contained therein the vapours passing into the
liquid by the inlet pipes depending thereinto. The said receivers are provided
with taps e.
The liquid in the vessel E2 is a strong solution of sulphuric acid to
absorb nitrous fumes which may have escaped condensation. The liquid in the
vessel E is water to absorb further gases and the liquid in the vessel E' is an
alkaline solution (say one of caustic soda) to absorb any further gases. The
vapours then pass into and up through the tower F containing coke or the like
down which an alkaline solution (say one of caustic soda) passes to absorb the last
traces of gases. The air pump or other exhauster is attached to the outlet pipe f
from the tower F, and owing to the arrangement is protected from injury
by acid.
The stills, retorts, condensers, or coolers, employed, may be of the ordinary, or
any suitable kind and therefore do not require detailed description.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The manufacture or production of nitric acid by distilling nitrate of soda
in vacuo, under the conditions as to temperature herein before set forth.
2. In apparatus for the manufacture of nitric acid, a tower or towers, or vessel
or vessels, between the pump or exhausting device, and the other parts of the
apparatus, the said tower or towers, or vessel or vessels, containing water, or an
alkali or alkaline earth, or one or more of them containing water, and the other or
others containing an alkali or alkaline earth, as and.for, the purpose hereinbefore
explained.
Dated this 18th day of April 1896
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, Loudon, W.C., Agents.