Improvements in the Manufacture of Sulphate of Soda and Bleach in one Operation under High Pressure and in the Construction and Use of Apparatus for that Purpose.
Year: 1886

page_text: Date of Application, 27th Nov., 1886
Complete Left, 27th Aug., 1887.
Complete Accepted, 14th Oct., 1887.
Improvements in the Manufacture of Sulphate of Soda and Bleach
in one Operation under High Pressure and in the Construction
and Use of Apparatus for that Purpose.
I WILLIAM BURNS of 32 Elmwood Terrace Leith in the County of Mid-Lothian
Consulting Engineer and Chemist, do hereby declare the nature of this invention to
be as follows:-
I burn sulphur or pyrites in a close blast retort to make sulphurous acid which I
lead into a condenser to be cooled, and then into a close vessel of cold water which
absorbs the sulphurous acid and allows the nitrogen to escape. The sulphurous
acid water, is then run into a close boiler and heated up to the boiling point,
which drives the sulphurous acid out of the water. The sulphurous acid is then
forced along with air and high pressure steam through chloride of sodium
contained in a retort kept at high temperature; which decomposes the salt and
liberates hydrochloric acid. The hydrochloric acid gas is led into a mixing condenser
and mixed with double its quantity of air. From the mixing vessel the mixed gases
are forced through a second decomposing retort or set of retorts filled with peroxide
of manganese or with sesquioxide of iron kept at a red heat. The hydrochloric acid in
passing through the oxide is decomposed into steam and chlorine; the hydrogen of
the hydrochloric acid unites with the oxygen of the metal, and the oxygen of the
injected air reoxidizes the metal, and the chlorine escapes with the steam and nitrogen;
into a condenser where it is cooled; and the steam condensed. The chlorine and
nitrogen is then washed and dried by forcing these gases through sulphuric acid.
The dry chlorine and nitrogen gases are then led into the lime chamber which is
made with a perforated, moveable, false floor, of wood; or slate; and gas tight doors;
the perforated floor is covered with lime from 6 to 9 inches deep, the gases enter the
chamber at one end under the perforated floor; and are forced up through the line,
the lime absorbs the whole of the chlorine, and the nitrogen escapes by a chimney at
the opposite end of the chamber from the entrance.
Bleach can be made by this process much quicker and stronger than by any other
process hitherto tried ; and at less cost.

page_text: The sulphate of soda produced by this method is of a superior quality, containing
less impurities than the salt-cake manufactured in the ordinary manner.
The novelty of this invention consists-In first forcing sulphurous acid, air, and
steam, under high pressure through chloride of sodium in red hot retorts which
produce sulphate of soda and hydrochloric acid gas.
Second. In forcing the hydrochloric acid along with air under high pressure,
through peroxide of manganese or iron, kept at a red heat in suitable retorts, which
decomposes the acid and liberates the chlorine.
Third. In forcing the chlorine diluted with nitrogen through a body of lime
spread on a perforated floor in a gas tight chamber under high pressure.
Fourth. In the manner of conducting the whole process from beginning to end
under high pressure in a novel combination of apparatus.
Dated 26th day of November 1886

page_text: Improvements in the Manufacture of Sulphate of Soda and Bleach
in one Operation under High Pressure and in the Construction
and Use of Apparatus for that Purpose.
I WILLIAM BURNS of 32 Elmwood Terrace Leith in the County of Mid-Lothian,
Consulting Engineer and Chemist, 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:-
I burn sulphur or pyrites in a close blast retort to make sulphurous acid, which I
lead into a condenser and then into a close vessel of cold water which absorbs the
sulphurous acid, and allows the nitrogen to escape. The sulphurous acid water is then
run into a close boiler and heated up to the boiling point; which drives the sulphurous
acid out of the water and forces it along with an additional portion of air through
chloride of sodium contained in a retort kept at high temperature; which decomposes
the salt and liberates the hydrochloric acid. The acid is led into a mixing condenser
and mixed with double its quantity of air. The mixed gases are then forced through
a second decomposing retort, or set of retorts filled with peroxide of iron or manganese
kept at a red heat.
The hydrochloric acid in passing through the oxide is decomposed into steam and
chlorine; the hydrogen of the acid unites with the oxygen of the metal, and the
oxygen of the injected air reoxydizes the metal and chlorine escapes along with the
steam and nitrogen, into a condenser where it is cooled and the steam condensed.
The chlorine and nitrogen is then washed and dried by forcing it through sulphuric
acid. The dry chlorine and nitrogen gases are then led into the lime chamber which
is made with a moveable perforated floor of wood or slate and gas tight doors. The
perforated floor is covered with lime from 6 to 9 inches deep and the gases enter the
chamber under the perforated floor and are forced up through the lime; which absorbs
the whole of the chlorine and the nitrogen escapes by a chimney. Bleach can be made
by this process much quicker and stronger than by any other process hitherto tried
and at less cost. The sulphate of soda produced by this method is of a superior
quality, containing less impurities than the salt cake manufactured in the ordinary
manner.
Referring to the drawings, Fig. 1. is a vertical sectional elevation shewing a
complete connected works for making sulphate of soda and bleach at one operation.
Fig. 2. is a plan of the chlorine chamber. Fig. 4. is a section of the chlorine
chamber through the line A' B shewing the perforated floor and bed of line.
Fig. 3. is part elevation of one side shewing the discharging doors for withdrawing
the finished bleach. P is a pump for filling the vessels with water from the
tanks R' and k.
A on fig. 1. is a vertical iron cylinder lined with fire bricks having a boiler B set on
the top of the retort. The retort is charged with pyrites from the central tube C and
a fire kindled in the necke at m. a blast of air is then blown into the retort through
the pipe F. G. The sulphurous acid passes up the pipe C and enters the condenser D
at the top, and forces its way down into the bottom of the washing vessel H the gas
then enters the condenser I and passes by the pipe J into the bottom of the cooler K,
the gas is forced up through the water, which absorbs, the greater portion of the gas

page_text: the remainder by the pipe J' along with the water into the bottom of the absorbing
vessel M, which is a cylindrical vessel enclosed within another N, N, the gas forces its
way up through a cup and ball agitator which causes complete absorption of the
sulphurous acid. The nitrogen escapes by the valve V, and enters the annular
space N, N. The nitrogen being relieved from pressure in N, rapidly expands and
keeps the vessel M cool; the gas then passes by the pipes n. n. through the condensers
and escapes into the air.
The water charged with sulphurous acid overflows by the pipe O and enters the
jacket E at the bottom P, and passes up and overflows at Q into the boiler B. The
water in passing through the jacket E absorbs heat from the hot gas in the condenser D,
and the temperature is further raised in the boiler by the burning pyrites. The hot
water overflows from the boiler at the point R where the sulphurous acid is liberated
and passes by the pipe T into the annular space U formed by the concentric iron
cylinders W. In the centre of the cylinders I fix a taper pipe X perforated with a
number of small holes. The pipe passes through the bottom of the cylinder W and is
joined to the pipe Y by Y'. The interior cylinder W is perforated with a number of
small holes through which the gas passes from the annular space U. These combined
cylinders, I set in a furnace F and completely surround them with the flue ii. The
annular space W, W, I fill with salt and turn a blast of air into the pipe S, the
sulphurous acid and steam from the boiler B along with air passes into the annular
space U, then through the salt by the perforations in the cylinder, the salt is rapidly
decomposed, the hydrochloric acid passes into the perforated tube X, and then
into the condenser Z by the pipes Y. X. The salt cake is withdrawn from the
cylinder by the door l. For every measure of hydrochloric acid that passes into
the condenser Z two measures of air must be blown in by the pipe p; the mixed air
and hydrochloric acid then passes by the pipes a, a, into the decomposing retort b
which is made of iron having iL perforated tube fitted into the bottom as shewn at r
the retort is filled with oxide of iron or manganese so as to completely surround and
cover the perforated pipe the acid gas in passing through the oxide is decomposed into
chlorine and steam. The mixed gases then pass from the decomposing retort into the
condenser and then through the sulphuric acid vessel e, from which the gases pass
into the chlorine chamber and force their way up through the lime on the perforated
floor g the lime absorbs the whole of the chlorine and the nitrogen escapes by the
ventilator j. h. h. are hatches for charging the lime on to the floor, which is spread
evenly by long rakes worked through the doors t. The finished bleach is drawn by
rakes from the floors through the doors into barrels without requiring the men to
go into the chamber,
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,
1st. I claim forcing sulphurous acid air and steam under high pressure through salt
in a red hot retort which produces sulphate of soda and hydrochloric acid.
Second. I claim forcing hydrochloric acid gas and air under high pressure through
peroxide of iron or manganese kept at a red heat in suitable retorts, which liberates
the chlorine from the acid.
Third. claim forcing chlorine diluted with nitrogen through a body of lime
spread on a perforated floor in a gas tight chamber, under high pressure.
Fourth. I claim the manner of conducting the whole process from beginning to end
under high pressure in retorts and vessels constructed and operated substantially as
herein described.
Dated this 96th day of August 1887