Process and Apparatus for obtaining Nitric Acid from low graded Nitro-Oxygen Compounds.
Year: 1897

page_text: Date of Application, 15th Dec., 1897-Accepted, 19th Feb.,
, 1898
COMPLETE SPECIFICATION.
Process and Apparatus for obtaining Nitric Acid from low graded
Nitro-Oxygen Compounds.
I, PETER JENSEN, of 77, Chancery Lane, London, Chartered Patent Agent, do
hereby declare the nature of this invention, (a communication to me from abroad by
Ludwig Rohrmann, Manufacturer, and Hugo Heinrich Niedenfuhr, Chemist and
Engineer, both of Krauschwitz, near Muskau, O/L Germany), and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement:-
In order to make this invention clearly understood I shall premise in a few words
the theory of the conversion of low grades of azotic acids into nitric acid.
Oxydes such as nitrous acid are by the presence of oxygen, oxydized into hyponitric
acid which in contact with water separates into nitric acid and nitrous acid. Then
the process of oxydation and the formation of nitric acid is constantly repeated,
while the percentage of nitro-oxygen compounds in the gases treated is reduced
more and more. In order to meet the weakening of the intensity of the action
while the gases are becoming increasingly diluted, it is necessary to provide by
means of suitable arrangements in the apparatus, an increasingly intimate contact
of the reagents, but also by means of increase in the amount of water necessary for
the separation of the nitric acid, to form a product which becomes more and more
weakened, and that in the best possible manner without involving an extensive
apparatus.
For this purpose the apparatus shewn in the side view Fig. 1 and plan Fig. 2
has been devised.
The regenerating nitro-oxygen compounds pass through a series of reaction columns,
the number of which is adapted to the desired production. In the drawing four
such columns viz. a¹ a a and b are shewn as an example. These are provided
with filling bodies for furthering the reaction, (and by preference with the so-called
Lunge-Rohrmann plates but other suitable constructions may be used) in such
manner that having regard to the phase of concentration of the gases to be regenerated
answering to each column, the number of filling bodies is increased or the plates
placed closer together in the column in question as the concentration is diminished.
Thus the column a¹ has the smallest number of filling bodies and the column 6 the
largest. As in the column b. the most water has to be used in order to obtain the
greatest effect, this column only is fed with pure water and by strong circulation;
the water may be heated.
The products arising in the column 6 besprinkle the other columns so that a
proportionately smaller amount of the reagent necessary for forming nitric acid is
conveyed to them. The products of the columns a¹ a² a³ run to the receptacle c and
are drawn off as pure acid. The vessel d (Nachturill) behind the column 6 serves
to dry in the usual manner the gases passing off.
Having now particularly described and ascertained the nature of the said inven-

page_text: tion, as communicated to me by my foreign correspondents, and in what manner
the same is to be performed, I declare that what I claim is:
1. Process for obtaining nitric acid from low grade nitro-oxygen compounds
characterized by that with the gradual decrease of the gas concentration the quantity
of the water serving to dissolve the nitrous acid is increased, in such manner that
all the water necessary for the process, heated if desired, is brought only to the most
diluted gases and the percentage of water in the product obtained is only applied
for the chemical reaction of the gases in their higher phases of concentration;
substantially as set forth.
2. An apparatus for carrying out the process claimed consisting of a series of
columns on the same level and a final column on a higher level provided with
filling bodies for furthering the reaction in them, in such manner, that every
following column is more closely filled with them in order to meet artificially the
weakened reaction consequent on the decreasing concentration of the gases under
treatment substantially as set forth.
3. The construction of apparatus shewn on the drawing.
Dated this Fifteenth day of December 1091.
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.