AN IMPROVED METHOD OF UTILIZING THE FUMES OR VAPOURS EVOLVED DURING CERTAIN CHEMICAL OPERATIONS."
Year: 1868

page_text: LETTERS PATENT to Rudolph Heilmann, of the City of Manchester,
Manufacturing Chemist, and Peter Hart, of the same Place,
Chemist, for the Invention of "AN IMPROVED METHOD OF UTILIZING
THE FUMES OR VAPOURS EVOLVED DURING CERTAIN CHEMICAL OPERATIONS."
PROVISIONAL SPECIFICATION left by the said Rudolph Heilmann
and Peter Hart at the Office of the Commissioners of Patents,
with their Petition, on the 5th October 1868.
We, RUDOLPH HEILMANN, of the City of Manchester, Manufacturing
Chemist, and PETER HART, of the same Place, Chemist, do hereby
declare the nature of the said Invention for "AN IMPROVED METHOD
OF UTILIZING THE FUMES OR VAPOURS EVOLVED DURING CERTAIN CHEMICAL
OPERATIONS," to be as follows:-
This Invention consists in an improved method. of utilizing the
oxides of nitrogen which are evolved or pass away to waste during
certain chemical operations. For instance in the manufacture of,
sulphuric acid, arsenic acid, and metallic arseniates, the solution of
divers metals in nitric acid, the superoxidation of certain metallic
[Price 8d.1

page_text: solutions, and during the preparation of picric acid, and other chemical
operations in which nitrous vapours are given off.
For the purpose
of absorbing these fumes we employ the oxides of lime or magnesia,
or the carbonates of these oxides either in solution or suspended in
water, or in the solid hydrated form, using any form of apparatus which
may be found suitable for the purpose, or we proceed in the manner
described in the Specification of Letters Patent granted to W. E. Newton,
A.D. 1858, 2nd February, No. 188, for "Improvements in Obtaining
certain Compounds of Nitrogen to be employed in the Composition of
Artificial Manures, and for other useful Purposes." The result of any
of these processes is the production of nitrite or nitrate of lime or
magnesia, which by the application of heat are made to evolve the
previously absorbed oxides of nitrogen, leaving as residue lime or
magnesia which may be used over and over again for the same purpose.
These oxides of nitrogen are or may be used in lieu of the nitrate of
soda, or potash ordinarily used-in-the-manufacture of sulphuric acid or
for other purposes.
By means of this Invention the vapours arising in the. manufacture
of sulphuric acid and other chemical processes where the oxides of
nitrogen are evolved, are recovered and may be used over again,
thereby not only effecting a saving in the material but preventing the
escape into the atmosphere of vapours that are injurious to health and
vegetation.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Rudolph Heilmann and Peter Hart in the Great
Seal Patent Office on the 24th March 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, RUDOLPH
HEILMANN, of the City of Manchester; Manufacturing Chemist; and
PETER HART, of the same Place, Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifth day of October, in the year
of our Lord One thousand eight hundred and sixty-eight, in the thirty-
second year of Her reign; did, for Herself, Her heirs and successors,
give and grant unto us, the said Rudolph Heilmann and Peter

page_text: Hart; Her special license that we, the said Rudolph Heilmann and
Peter Hart, our executors, administrators, and "assigns, or such others
as we; the said Rudolph Heilmann and Peter Hart, our executors,
administrators, and assigns, should at any time agree with, and no others;.
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "AN IMPROVED METHOD
OF UTILIZING THE FUMES OR VAPOURS EVOLVED DURING CERTAIN CHEMICAL
OPERATIONS," upon the condition (amongst others) that we, the said
Rudolph Heilmann and Peter Hart, our executors or administrators,
by an instrument in writing under our, or their, or one of our or their
hands and seals, should particularly describe and ascertain the nature
of the said Invention, and in what manner the' same was to be performed,
and cause the same to be filed in the" Great Seal Patent Office within
six calendar months next and immediately after the date of the said
i
Letters Patent.
NOW KNOW YE, that we, the said Rudolph Heilmann and Peter
Hart, do hereby declare the nature of our said 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):-
This Invention consists in an improved method of utilizing the oxides
of nitrogen which are evolved or pass away to waste during certain
chemical operations, for instance in the manufacture of sulphuric acid,-
arsenic acid, and metallic arseniates, the solution of divers metals in
nitric acid, the superoxidation of certain metallic solutions, and during
the preparation of picric acid, and other chemical operations in which
nitrous vapours are given off. For the purpose of absorbing these fumes
we employ the oxides of calcium or magnesium, or the carbonates of.
these oxides either in sclution or suspended in water using any form of
apparatus which may be found suitable for the purpose, or we employ
the said oxides or their carbonates in the solid form, enclosed in
suitable vessels in the manner metallic oxides are commonly used in the;
purification of coal gas, as is well understood, or we proceed in the
manner described in the Specification of Letters Patent granted to.
William Edward Newton, in the year of our Lord One thousand eight
hundred and fifty-eight, Second February, No. 188, for "Improvements.
in Obtaining certain Compounds of Nitrogen to be employed in the

page_text: Composition of Artificial Manurés and for other useful Purposes."
The result of any of these processes we find to be the production of
nitrite or nitrate of lime or magnesia but chiefly nitrite, from which
we expel the nitrous gases for use in the manufacture of sulphuric acid
or for other purposes by any of the following methods :-
First. We evaporate these solutions or salts to dryness and heat them
to a low red heat either in the pyrites furnace, sulphur furnace, or in
a separate retort heated by coal or other fuel, and we conduct the
expelled gasses into a sulphuric acid chamber, the residue remaining
being lime or magnesia fit for use in absorbing nitrous fumes from any
source.
Secondly. We run the solution of these salts into a suitable closed
vessel preferably of flagstone, and bring this to a boiling heat by means
of a steam jet, and when boiling we run in a slow stream of sulphuric
or hydrochloric acid, until the whole of the nitrous fumes are evolved;
these fumes are conducted into the sulphuric acid chamber. For this
purpose also we claim the use of the free hydrochloric or other acid
existing in the chloride of manganese which is run to waste during the
manufacture of chloride of lime and other processes when chlorine is
produced; which chloride of manganese we employ in the manner we
have first-described in lieu of the hydrochloric or sulphuric acid there
mentioned.
Thirdly. We decompose the nitrates or nitrites of lime or magnesia
so obtained by heating the same to a low red heat in the manner stated
above, having previously mixed them with their chemical equivalents
of sulphate or chloride of iron, manganese, or zinc. The residue consists
of sulphate or chloride of calcium, or magnesium, and the oxides of
iron, manganese, or zinc, as the case may be, while the nitrous vapours
We have thus shewn
are conducted into the sulphuric acid chamber.
that these oxides of nitrogen are or may be used in lieu of the nitrate
of soda or potash ordinarily used in the manufacture of sulphuric acid
or for other purposes; by means of this Invention the vapours arising
in the manufacture of sulphuric acid and other chemical processes where
the oxides of nitrogen are evolved, are recovered and may be used over
again, thereby not only effecting a saving in the material but preventing
the escape into the atmosphere of vapours that are injurious to health
and vegetation.
We wish it to be understood that we do not claim the absorption of

page_text: nitrous fumes by means of lime or magnesia or their carbonates, being
aware that the same is described in the Specification of the Patent
granted to William Edward Newton, in the year of our Lord One
thousand eight hundred and fifty-eight, Number 188, above referred to;
but we do claim their expulsion by the several means we have pointed
out, and also we claim the use of the lime or magnesia left after
decomposition by our first method for again absorbing nitrous
fumes.
In witness whereof, we, the said Rudolph Heilmann and Peter
Hart, have hereto set our hands and seals, this Twenty-third
day of March, One thousand eight hundred and sixty-nine.
R. HEILMANN. (L.S.)
PETER HART. (L.S.)