Improvements in Purifying and concentrating Sulphuric Acid, in part applicable to the Manufacture of Nitric Acid.
Year: 1896

page_text: Date of Application, 16th Dec., 1896
Complete Specification Loft 15th Sont 1907 Accepted 20th Oct
4007
PROVISIONAL SPECIFICATION.
Improvements in Purifying and concentrating Sulphuric Acid, in
part applicable to the Manufacture of Nitric Acid.
We, G. KYNOCH & COMPANY LIMITED, and ALLAN THOMAS COCKING, both of
Lion Works, Witton, in the County of Warwick, Manufacturers, do hereby
declare the nature of this invention to be as follows:-
Our invention, relates to purifying sulphuric acid from substances such as
nitrous fumes, and to concentrating the sulphuric acid when purified. Part of
the invention also relates to the manufacture of nitric acid.
So far as our invention relates to sulphuric acid it consists in placing the
sulphuric acid to be purified and concentrated within a cast iron or other suitable
strong still capable of withstanding atmospheric pressure and exhausting by
means of a pump or other suitable device from the still to produce within it a
vacuum or a partial vacuum. During the exhausting process heat is applied to
the acid by a suitable furnace from outside. Under the influence of the reduction
of pressure and the heat, nitrous fumes in the acid are disengaged and carried
away to be suitably condensed or absorbed. When the nitrous or other fumes
are disengaged, the heating and evacuating is continued, and in time the
sulphuric acid loses its water and becomes concentrated.
In carrying our invention into effect according to one method we provide a cust
iron still placed above a suitable furnace, and from the upper part of this still we
lead a long pipe which serves as a condenser. We evacuate this pipe by means of
an air pump, and we play a jet of water on the outside of the pipe to keep it cool.
We condense the nitrous fumes coming off the sulphuric acid in Wolf's bottles
with water, and after the fumes are evolved we continue to evaporate until the
acid is of a suitable density, such as 1.84 specific gravity. The device is intended
to be applied to the weakened acid from the manufacture of nitro glycerine which
acid is run into the still after decomposing any nitro glycerine which it may
contain by well-known methods. The acid still contains nitrous fumes, and at
first the nitrous fumes are got rid of, and then the acid is concentrated as
described. This completes our method of purifying and concentrating the acid.
Our invention, so far as it relates to nitric acid, consists in adding to the
sulphuric acid in the still so concentrated a suitable proportion of nitrate of soda
or nitrate of potash, and distilling from the soda saltpetre or Chili saltpetre,
nitric acid.. By this device we save the removal of the sulphuric acid from one
vessel to another, and we use a nitric acid producing plant not only for the
purpose of producing nitric acid, but also for the purpose of purifying and
concentrating the sulphuric acid required by us.
Dated this 16th day of December 1896
MARKS & CLERK,
18, Southampton Buildings, London, W.C.; and
13, Temple Street, Birmingham, Agents.

page_text: Improvements in Purifying and Concentrating Sulphuric Acid, in
part applicable to the Manufacture of Nitric Acid.
We, G. KYNOCH & Co. LTD., and ALLAN THOMAS COCKING, both of Lion Works,
Witton in the County of Warwick Manufacturers, 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:--
Our invention relates to purifying sulphuric acid from substances such as
nitrous fumes, and to concentrating the sulphuric acid when purified. Part of
the invention also relates to the manufacture of nitric acid.
So far as our invention relates to sulphuric acid it consists in placing the
sulphuric acid to be purified and concentrated within a cast iron or other suitable
strong still capable of withstanding atmospheric pressure and exhausting by
means of a pump or other suitable device from the still to produce within it a
vacuum or a partial vacuum. During the exhausting process heat is applied to
the acid by a suitable furnace from outside. Under the influence of the reduction
of pressure and the heat, nitrous fumes in the acid are disengaged and carried
away to be suitably condensed or absorbed. When the nitrous or other fumes
are disengaged the heating and evacuating is continued, and in time the
sulphuric acid loses its water and becomes concentrated.
Referring to the accompanying sheet of drawings, the figure represents a
diagrammatic view of one form of our apparatus.
In carrying our invention into effect according to one method we provide a cast
iron still A placed above a suitable furnace B, and from the upper part of this
still we lead a long pipe C which serves as a condenser. We play a jet of water
on the outside of the pipe C to keep it cool. We evacuate the still by means of
an air pump. 1) is the pipe leading to the air pump. We condense the nitrous
fumes coming off the sulphuric acid in Wolf's bottles D with water, and after the
fumes are evolved we continue to evaporate until the acid is of a suitable density,
such as 1.84 specific gravity. The device is intended to be applied to the
weakened acid from the manufacture of nitro glycerine, which acid is run into the
still after decomposing by well-known methods any nitro glycerine which it may
contain. The acid still contains nitrous fumes, and at first the nitrous fumes are
got rid of, then the acid is concentrated as described. This completes our method
of purifying and concentrating the acid.
Our invention, so far as it relates to nitric acid, consists in adding to the
sulphuric acid in the still so concentrated a suitable proportion of nitrate of soda
or nitrate of potash, and distilling nitric acid from the soda saltpetre of Chili
saltpetre. By this device we save the removal of the sulphuric acid from one
vessel to another, and we use a nitric acid producing plant not only for the
purpose of producing nitric acid, but also for the purpose of purifying and
concentrating the sulphuric acid required by us.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is:-
1. The method of and process for purifying and concentrating sulphuric acid
es described.

page_text: 2. The method of and process for combining with the purifying and concentrat-
ing of sulphuric acid the manufacture of nitric acid as described.
Dated this 15th day of September 1897.
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13 Temple Street, Birmingham, Agents for the Applicants.