IMPROVEMENTS IN THE MANUFACTURE OF SULPHURIC ANHYDRIDE AND NORDHAUSEN ACID, AND IN THE CONCENTRATION AND REFINING OF SULPHURIC AND OTHER ACIDS, AND IN APPARATUS THEREFOR."
Year: 1876

page_text: LETTERS PATENT to Roger William Wallace, of the Chemical Works, New
Road, Battersea Park, in the County of Surrey, Manufacturing Chemist, for
the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF SULPHURIC
ANHYDRIDE AND NORDHAUSEN ACID, AND IN THE CONCENTRATION AND
REFINING OF SULPHURIC AND OTHER ACIDS, AND IN APPARATUS THEREFOR."
PROVISIONAL SPECIFICATION left by the said Roger William Wallace at
the Office of the Commissioners of Patents on the 30th May 1876.
ROGER WILLLAM WALLACE, of the Chemica. Works, New Road, Battersea Park,
in the County of Surrey, Manufacturing Chemist. "IMPROVEMENTS IN THE MANU-
FACTURE OF SULPHURIC ANHYDRIDE AND NORDHAUSEN ACID, AND IN THE CON-
CENTRATION AND REFINING OF SULPHURIC AND OTHER ACIDS, AND IN APPARATUS
THEREFOR.
"
This Invention relates to the manufacture of sulphuric anhydride and Nord-
hausen acid, and to the concentration and refining of sulphuric and other acids.
It permits the use of retorts of cheap materials of any desired size in such manu-
facture. It permits the division or separation of the distillates and the delivery
and transport or removal of the anhydride in the vessel in which it is received
from the still, and the process employed in the said manufacture is or may be
continuous.
The bisulphate of soda is introduced into large fire clay retorts, or in retorts
made of glazed plumbago or some similar preparation of earthenware, or of any
other substance which will not decompose the sulphuric anhydride (S O3) into sul-
phurous acid (SO) and oxygen (O). The said retort is heated first to dull redness,
when any free sulphuric acid (H. SO,) and water are driven off. This water is
condensed in a leaden worm, and as soon as the sulphuric anhydride commences to
appear the passage of the gases into the leaden coil is stopped by means of a three-
way cock, and they then pass into a series of receivers or Woulffes bottles con-
structed to retain none of the solid sulphuric anhydride in any of the lutes. The
top of these receivers is detachable, so that the said top can be replaced by blank
plates which are made properly tight, and the acid can thus be delivered or
removed in the same receivers in which it has been collected, thereby saving the
workmen from the noxious fumes which would be given off on the exposure of the
[Price 6d.]

page_text: acid to the air while removing it from one vessel to another. This process may be
made continuous by introducing the requisite quantity of warm sulphuric acid into
the retort before the neutral sulphate of soda. has solidified. In this manner the
bi-sulphate of soda is formed in the retort, and once produced therein need never be
removed. And an absolutely anhydrous solid acid may be obtained without heating
the Nordhausen acid (which is a combination of sulphuric acid and sulphuric an-
hydride) till the latter is driven off and collected as in the usual way of manufac-
turing the crystals from Nordhausen acid made from sulphate of iron in Germany.
Other bi-sulphates may be employed in my process, but sulphate of soda is the
most manageable.
Another manner of obtaining sulphuric anhydride according to my Invention is
by the direct combination of sulphurons acid (SO₁) and oxygen (O). This object
may be effected by distilling sulphuric acid (H, SO,) of a gravity of 1.850 in stills
of glazed plumbago and passing the gas through tubes of the same material heated
to redness. The sulphuric acid (H. SO,) is then decomposed into sulphurous acid
(SO) and oxygen (O); any of the (H. SO,) or water remaining is then absorbed
in scrubbers of chloride of calcium.
Another way of obtaining the sulphurous acid and oxygen is by burning sulphur
in iron or other pans by means of an equivalent of oxygen.
The direct combination of sulphurous acid (SO,) and oxygen is also effected by
passing these gases through tubes heated to dull redness and filled with platinized
pumice asbestos or spongy platinum. I prefer to make these tubes of plumbago
glazed in the interior, as platina is objectionable because of the weight of the
platinized pumice or asbestos or spongy platina; when the latter are used small
holes are quickly formed in the piping unless the same is of great thickness,
which the present price of this metal would render very costly. The sulphuric
anhydride ($ 0₁) is finally condensed in receivers as first above described.
My Invention also comprises a novel process and apparatus for the concentration
and refining of sulphuric acid for the above and other purposes, and the concentra-
tion and refining of other acids by heating air to a temperature of about 700 degrees
in an iron coil, and distributing it by means of pipes made of platina, porcelain, or
other material into a closed vessel made of glass, plumbago, platina, or other
material. The hot air is introduced into the sulphuric acid by means of perforated
pipes or a perforated false bottom, and the required draught through the apparatus
is produced by means of an aspirator or other suitable apparatus properly arranged
in combination with the condenser. Water is at present used as the medium for
condensing the waste fumes and for cooling the sulphuric acid after it leaves the
still; but instead of water I use sulphuric acid for these purposes.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said Roger William Wallace in the Great Seal Patent Office on the 30th
November 1876.
ROGER WILLIAM WALLACE, of the Chemical Works, New Road, Battersea Park,
in the County of Surrey, Manufacturing Chemist. "IMPROVEMENTS IN THE MANU-
FACTURE OF SULPHURIC ANHYDRIDE AND NORDHAUSEN ACID, AND IN THE CON-
CENTRATION AND REFINING OF SULPHURIC AND OTHER ACIDS, AND IN APPARATUS
THEREFOR."
Figure 1 is an elevation partly in section of apparatus comprising a closed vessel,
a condenser, and cooler, herein-after described.
Figure 2 is a plan or top view of the said condenser.
Figure 3 is a coil of tubing.
Figure 4 is a perforated bottom for the said close vessel. Like letters indicate
the same parts throughout the Drawing.
This Invention relates to the manufacture of sulphuric anhydride and Nordhausen

page_text: acid, and to the concentration and purification of sulphuric and other acids. It
permits the use of retorts of cheap materials of any desired size in such manufacture.
It permits the division or separation of the distillates, and the delivery and tran-
sport or removal of the anhydride in the vessel in which it is received from the
still, and the process employed in the said manufacture is or may be continuous.
The bisulphate of soda is introduced into large retorts made of glazed plumbago
or some similar preparation of earthenware, or of any other substance which will
not decompose the sulphuric anhydride (SO), or itself be decomposed into sul-
phurous acid (SO,) and oxygen (O). The said retort is heated first to dull redness,
when any free sulphuric acid (HSO) and water are driven off. This water is
condensed in a leaden worm, and as soon as the sulphuric anhydride commences to
appear the passage of the gases into the leaden coil is stopped by means of a three-
way cock, and they then pass into a series of receivers or Woulffes bottles con-
structed to retain none of the solid sulphuric anhydride in any of the lutes. The
top of these receivers is detachable, so that the said top can be replaced by blank
plates, which are made properly tight, and the acid can thus be delivered or
removed in the same receivers in which it has been collected, thereby saving the
workmen from the noxious fumes which would be given off on the exposure of the
acid to the air while removing it from one vessel to another. This process may be
made continuous by introducing the requisite quantity of warm sulphuric acid into
the retort before the neutral sulphate of soda has solidified. In this manner the
bisulphate of soda is formed in the retort, and once produced therein need never be
removed. And an absolutely anhydrous solid acid may be obtained without heating
the Nordhausen acid (which is a combination of sulphuric acid and sulphuric an-
hydride) till the latter is driven off and collected as in the usual way of manufac-
ting the crystals from Nordhausen acid made from sulphate of iron in Germany.
Other bi-sulphates may be employed in my process but sulphate of soda is tho
most manageable.
Another manner of obtaining sulphuric anhydride according to my Invention is
by the direct combination of sulphurous acid (S O₂) and oxygen (O). This object
may be effected by distilling sulphuric acid (H, SO,) of a gravity of 1.850 in stills
of glazed plumbago and passing the gas through tubes of the same material heated to
redness. The sulphuric acid (H, SO,) is then decomposed into sulphurous acid
(SO) and oxygen (O). Any of the H, SO, or water, remaining is then absorbed
in scrubbers of chloride of calcium, or of pumice stone moistened with sulphuric
acid (H, SO.).
Another way of obtaining the sulphurous acid and oxygen is by burning sulphur
in iron or other pans by means of an equivalent of oxygen, the admittance of
oxygen being regulated by a weighted valve to ensure continuous pressure.
The direct combination of sulphurous acid (S O₂) and oxygen is also effected by
passing these gases. through glazed plumbago tubes heated to dull redness, and
fitted with platinized pumice asbestos or spongy platinum. I make these tubes of
plumbago glazed in the interior as platina is objectionable because of the weight of
the platinized pumice or asbestos or spongy platina, as when the platina is used
small holes are quickly formed in the piping unless the same is of great thickness,
which the present price of this metal would render very costly. The sulphuric
anhydride (SO) is finally condensed in receivers as above described.
My Invention also comprises a novel process and apparatus for the concentration
and refining of sulphuric acid for the above and other purposes, and the concentra-
tion and refining of other acids.
The said apparatus is illustrated in Figures 1, 2, 3, and 4.
According to this process I heat air to a temperature of about 700 degrees in an
iron coil a, and distribute it by means of pipes b, made of platina, porcelain, or other
material, into a closed vessel c, made of glass, glazed plumbago, platina, or other
material. The hot air is introduced into the sulphuric acid in this chamber by
means of the said perforated pipes or a perforated false bottom d, and the required
draught through the apparatus is produced by an air pump or aspirator, or other

page_text: suitable means. Water has hitherto been used as the medium for condensing the
waste fumes and for cooling the sulphuric acid after it leaves the still, but instead
of water I use sulphuric acids for these purposes.
The condenser c, Figures 1 and 2, is constructed with an outer casing e¹ and an
inner box or casing e² of lead or other suitable material. Pipes f extend vertically
through the said inner casing, and the latter is connected with the neck of the still
or closed vessel c. The sulphuric acid used as the condensing medium flows through
the said pipes, and the air and gas from the closed vessel surround the same. g is a
cock for drawing off the condensed liquid froin the casing c²; h is a cooler or vessel
for cooling the liquid acid from the vessel e; h¹ is a coil of pipe, and * is a cock in
the same.
The bottom of the retort or closed vessel c may be heated by the flame which
hents the aforesaid iron coil, and the latter may serve as a support for the said
retort. Therefore the acid will be concentrated externally by the flame and inter-
nally by the hot air. The weak acid fumes are condensed and pumped to the top
of the chamber used for the manufacture of sulphuric acid, and by means of an
injector the condensed weak acid is distributed in the said chamber in the form of
spray. I thus effect a saving of steam in the sulphuric acid chambers, and econo-
mize the fuel used for concentration by the use of the weak acid instead of water
or steam.
Having thus fully described my said Invention and the manner of performing
the same, I wish it understood that I claim-
First. The manufacture of sulphuric anhydride (SO) or Nordhausen acid by a
process in which bi-sulphate of soda is heated in retorts formed of a material which
will not decompose or be decomposed by sulphuric anhydride, and in which the
livision of the distillates is effected by means of cocks, or valves, or their equiva-
lents, as above set forth.
Second. The receivers provided with detachable covers, which are replaced by
blank plates when required, as above set forth and for the purpose specified.
Third. The aforesaid process of manufacturing sulphuric anhydride or Nordhausen
acid rendered continuous by the introduction during the said process of warm sul-
phuric acid, as above specified, into the retort before the neutral sulphate has
solidified.
Fourth. The process of obtaining sulphuric anhydride by first decomposing sul-
phuric acid gas into sulphurous acid (SO) and oxygen (O), and after dehydration
the combination of these two gases (SO) and (O) in glazed plumbago vessels and
pipes, as above set forth.
Fifth. The process above described for the concentration and refining of sulphuric
acid (H, SO) and other acids by means of heated air, applied as above set forth.
Sixth. The employment of sulphuric acid instead of water for condensing the
fumes and for cooling the liquid acid from the still, as above set forth.
Seventh. In the said process for the concentration and refining of sulphuric
and other acids the distribution of the weak acids in the form of spray in the
sulphuric acid chainber, as above set forth and for the purpose specified.
Eighth. The apparatus for carrying the above process into operation, comprising
the coil, the pipes, the close:l vessel with its false bottom, the condenser, and cooler,
constructed and combined as above set forth for the purpose specified.
In witness whereof, I, the said Roger William Wallace, have hereunto set my
hand and seal, this Thirtieth day of November, in the year of our Lord One
thousand eight hundred and seventy-six.
ROGER WILLIAM WALLACE. (1.s.)