Improvements in the Manufacture or Production of Chlorine.
Year: 1895

page_text: Date of Application, 27th Feb., 1895
omplete Specification Left, 27th Nov., 1895-Accepted, 28th Dec., 1895
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture or Production of Chlorine.
I JAMES YATE JOHNSON of 47 Lincoln's Inn Fields in the County of London
Gentleman do hereby declare the nature of this invention (which has been com-
municated to me from abroad by Verein Chemischer Fabriken of Mannheim in
the German Empire) to be as follows:-
The invention hereinafter described is an addition to, and a further development
of the invention described in the Specification of the application for Letters Patent
No. 10604 of May 31st 1894.
The reactions described in the said Specification of the Patent No. 10604" may
be carried out in apparatus the several parts of which are arranged side by side
instead of one above the other.
In this case each of the chambers A should only have as much acid mixture
allotted to it as is capable of combining with HCl gas.
Where three chambers A, A, A, are employed, for example, in bringing about
a reaction between hydrochloric acid and nitric acid, the acid mixture to be
assigned to each chamber should he proportioned as 69: 23 : 8.
Furthermore, each of the chambers A, A, A, wherein the reaction between
hydrochloric acid and nitric acid takes place, should be of a size sufficient not only
to enable the quantity of nitric acid, for the treatment of which each particular
chamber is adapted, to combine therein with hydrochloric acid gas, but to permit
also the acid mixture after use to become saturated with HCI gas in the same
chamber.
All the acid running off from the three chambers A, A. A, is conducted into
one common pipe, through which it passes on to the closed vessel or receiver F,
wherein it is heated to 130° Centigrade and freed from the nitrogen compounds it
contains.
Figure 1 of the accompanying diagrams illustrates the course of the acid through
a horizontal arrangement (or battery) of chambers while Figure 2 indicates the
manner in which it is conveyed through a vertical (or tower-shaped) arrangement.
The removal of the nitrogen compounds from the acid mixture running off after
use may also be effected by the admixture with the acid issuing from the
chambers A, A, A3, of liquid hydrochloric acid, the resulting mixture being then
heated. Where this is intended either the three chambers A, A, A, (in the
horizontal battery), or the one chamber A₁ (in the vertical arrangement) may be
of a smaller size, as, in that case, they are not required to fulfil the secondary
object of saturating the acid mixture, after use with HCl gas.
The nitrous sulphuric acid, obtained by this process, absorbs a small proportion
of chlorine (not exceeding 0'4 per cent.) the consequence being that the whole of
the Cl, which had been in solution in the nitrous sulphuric acid, enters the
chambers C, C, for the purpose of regenerating the nitric acid, and is stored up
therein, as it can neither remain in solution in the regenerated acid mixture
discharged from the chamber E por escape along with the gases issuing from the
chambers C. A quantitive regeneration of nitric acid thus becomes impossible.
My foreign correspondents have found that by heating nitrous sulphuric acid,
which has been used in dissolving chlorine to a temperature of 130° Centigrade
the greater part (riz. as much as 75 per cent.) of the Cl in solution will be caused

page_text: to escape as HCl and NOCI. We therefore interpose between the discharge end
of B, and the admission orifice of E, a vessel or chamber G which may be of cast
iron, through which the nitrous sulphuric acid, discharged from the chambers B, is
thus compelled to pass, and wherein it is heated to about 130° Centigrade. The
gases developing at this juncture are carried off into the gas pipe-connection leading
into B, and as the chlorine still remaining behind in the nitrous sulphuric acid is
apt to interfere with the quantitive regeneration of the nitric acid, it is necessary
to get rid of such chlorine.
We therefore divide the nitric acid generating column C, C₂, at about two fifths
of its height, into two parts (for it is at that point of its height that the greater
quantity of the Cl accumulates). At that point of division we draw off such a
quantity of diluted nitric acid as contains an amount of chlorine corresponding or
equivalent to the amount of chlorine which was contained in the nitrous sulphuric
acid discharged from the chamber G and we add such nitric acid, containing
chlorine, to the regenerated acid mixture discharged from the chamber E.
Dated this 27th day of February 1895.
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.
I JAMES YATE JOHNSON of 47 Lincoln's Inn Fields in the County of London
Gentleman do hereby declare the nature of this invention (which has been
communicated to me from abroad by Verein Chemischer Fabriken of Mannheim
in the German Empire) and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement :-
The invention hereinafter described is an addition to, and a further develo¬ment
of the invention described in the Specification of Letters Patent No. 10604 of
May 31st 1894.
The reactions described in the said Specification of the Patent No. 10604º may
be carried out in apparatus the several parts of which are arranged side by side
instead of one above the other.
In this case each of the chambers A should only have as much acid mixture
allotted to it as is capable of combining with HCl gas.
Where three chambers A, A, A, are employed, for example, in bringing about
a reaction between hydrochloric acid and nitric acid, the acid mixture to be
assigned to each chamber should be proportioned as 69: 23: 8.
Furthermore, each of the chambers A, A, A, wherein the reaction between
hydrochloric acid and nitric acid takes place, should be of a size sufficient not only
to enable the quantity of nitric acid, for the treatment of which each particular
chamber is adapted, to combine therein with hydrochloric acid gas, but to permit
also the acid mixture, after use to become saturated with HCl gas in the same
chamber.
All the acid running off from the three chambers A, A, A, is conducted into
one common pipe, through which it passes on to the cloted vessel or receiver F
wherein it is heated to 130° Centigrade and freed from the nitrogen compounds it
coutains.
Figure 1 of the accompanying diagrams illustrates the course of the acid through
a horizontal arrangement (or battery) of chambers, while Figure 2 indicates the
manner in which it is conveyed through a vertical (or tower-shaped) arrangement.
The removal of the nitrogen compounds from the acid mixture running off after
use may also be effected by the admixture with the acid issuing from the

page_text: chambers A, A, A, of liquid hydrochloric acid, the resulting mixture being then
heated.
Where this is intended either the three chambers A, A, A, (in the horizontal
arrangement) or the one chamber A, (in the vertical arrangement) may be of
smaller size, as, in that case, they are not required to fulfil the secondary object
of saturating the acid inixture, after use with HCl gas.
The nitrous sulphuric acid, obtained by this process, absorbs a small proportion
of chlorine (not exceeding 0-4 per cent.) which is found partly in the form of HCI
and partly as NOCI.
The nitrous acid thus proves to be a solvent for the HCl gas, which is contained
in the gases as an undecomposed remnant.
Furthermore, saturated nitrous sulphuric acid appears to be capable of dissolving
NOCI, without entering into any reaction with it.
When such nitrous sulphuric acid, containing chlorine, is decomposed in the
vessel E, the portion of the chlorine which is dissolved in the form of HCI
undergoes therein a reaction as expressed in the following equation :
2 HNO, + 6 HCI = 2 NOCI + 4 Cl + 4 H₂O.
The gaseous products of this reaction are conducted into the receivers for the
purpose of regenerating the nitric acid.
The portion of the chlorine, which had been dissolved as NOCI passes off into
these receivers unaltered.
In the lower portions of the receivers or vessels C₁ C₂ which contain a strong
warm solution of nitric acid, the mixture which may consist of NOCI and CI,
passes through, unchanged.
In the upper parts of the said receivers C¹ C³ which contain water in excess, il
reaction takes place in accordance with the following equations:
2 NOCI + 2 O + 2 H₂O =2 HNO3 + 2 HCI.
The products of this reaction are dissolved in the excess of water.
The whole of the chlorine which had been dissolved in the nitrous sulphuric
acid, inust therefore collect in the form of HCl in the upper part of the vessels or
receivers C, C2, as it can neither escape with the gases leaving the vessel C², nor
be discharged from the vessel E along with the regenerated acid mixture.
A quantitive regeneration of the nitric acid therefore becomes impossible and
it is necessary to remove the chlorine contained in the nitrous sulphuric acid.
My foreign correspondents have found that by heating nitrous sulphuric acid
which has been used in dissolving chlorine to a temperature of 130° Centigrade,
the greater part (riz. as much as 75 per cent.) of the Cl in solution will be
caused to escape as HCI and NOCI. There is therefore interposed between the
discharge end of B, and the admission orifice of E a vessel or chamber G which
may be of cast iron, through which the nitrous sulphuric acid discharged from
the chambers B is compelled to pass, and wherein it is heated to about 130° Centi-
grade. The gases developing at this juncture are carried off into the gas pipe-
connection leading into B,. And as the chlorine still remaining behind in the
nitrous sulphuric acid is apt to interfere with the quantitive regeneration of the
nitric acid by collecting in the C vessel it is necessary to get rid of such chlorine.
We therefore divide the nitric acid regenerating column C, and C₂ at or about
two fifths of its height, into two parts (for it is at that point of its height that
the greater quantity of the collected chlorine accumulates)."
At that point of division we draw off such a quantity of diluted nitric acid as
contains an amount of chlorine corresponding or equivalent to the amount of

page_text: chlorine which was contained in the nitrous sulphuric acid discharged from the
chamber G and we add such nitric acid containing chlorine to the acid mixture
discharged from the chamber E.
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. Conducting the process the subject of the first claim under the aforesaid
Letters Patent No. 10604" in chambers or vessels arranged side by side, in such
a manner that each succeeding chamber or vessel has allotted to it (for the
purpose of creating a reaction between hydrochloric acid and nitric acid) a
proportionate quantity of the acid mixture which was introduced into the next
preceding chamber or vessel (one third where for example three chambers are
used) so that (where three chambers are used) the first receives 69 per cent., the
second, 23 per cent., and the third, 8
per cent.
2. A modification of the process referred to in the second claim of the Letters
Patent No. 10604 wherein for the purpose of removing (or separating) the nitrous
compounds from the acid mixture leaving the receivers chambers or vessels
hydrochloric acid in the liquid form is added to the said mixture; the new
mixture thus obtained being then heated.
3. A further development of the process covered by the third claim of the
Letters Patent No. 10604% and also referred to in the foregoing first claim of
this present Specification, wherein for the purpose of keeping chlorine ou of the
regenerating column used for regenerating nitric acid or of removing the chlorine
therefrom, the nitrous sulphuric acid as it is discharged from the "B" vessels, is
heated in a vessel G; the gases generated in such heating process being conducted
back to the vessels of the "B" series; and the nitric acid regenerating column
being divided at or about two fifths of its height; at which point as much nitric
acid containing chlorine is drawn off, as corresponds to the quantity of chlorine
remaining behind in the nitrous sulphuric acid previously heated.
Dated this 27th day of November 1895.
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.