IMPROVEMENTS IN THE MANUFACTURE OF SULPHATES OF SODA AND POTASSA, AND IN THE APPARATUS EMPLOYED THEREIN
Year: 1877

page_text: LETTERS PATENT to James Hargreaves, of Widnes, in the County of Lan-
caster, Chemist, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE
OF SULPHATES OF SODA AND POTASSA, AND IN THE APPARATUS EMPLOYED
THEREIN."
Sealed the 21st August 1877, and dated the 28th February 1877.
PROVISIONAL SPECIFICATION left by the said James Hargreaves at the
Office of the Commissioners of Patents on the 28th February 1877.
JAMES HARGREAVES, of Widnes, in the County of Lancaster, Chemist. "IMPROVE-
MENTS IN THE MANUFACTURE OF SULPHATES OF SODA AND POTASSA, AND IN THE
APPARATUS EMPLOYED THEREIN."
This Invention relates to the manufacture of sulphates of soda and potassa by
the direct action of sulphurous acid, air, and water vapour upon chloride of sodium
or chloride of potassium, that is to say, by bringing sulphurous acid, air, and water
vapour into direct contact with chlorides of sodium or potassium, and consists,-
-
First. As means for preparing the chlorides of sodium and of potassium to be
reacted upon directly by sulphurous acid gas, air, and water vapour, or by sulphuric
acid vapour, in employing steam instead of water for damping such chlorides,
thereby facilitating the drying and caking and economizing fuel.
Second. As means to insure the said chloride being evenly moistened, in first
passing the said chlorides through rollers, and then by means of an Archimedian
screw into a mixing and damping chamber, where it is stored and agitated by a
shaft carrying arms. The steam necessary for moistening the said chloride is allowed
to flow into the said mixing chamber; for economy I employ the exhaust steam from
the engine used to drive the stirring and drying machinery.
Third. As means for most advantageously utilizing heat and space, in causing the
products of combustion to pass under the drying plates to the place where the
chlorides are being placed upon the said drying plates.
Fourth. As means for preventing the chlorides from adhering to the said drying
plates, in placing a hopper full of dry chlorides upon the said drying plates, so that

page_text: as the said plates move under the said hopper a thin layer of dry chloride is left in
direct contact with the said drying plates. The said hopper is arranged to rise and
fall along with the said drying plates, so as to leave the said layer of dry chloride
more or less uniform in thickness. The said drying plates afterwards pass under
the hopper of moist chloride to receive the charge.
Fifth. As means for preventing the moist chloride from adhering to the com-
pressing machinery, in putting a thin layer of dry chloride on the top of the said
charge of moist chloride.
Sixth. As means for supplying the said dry chloride either upon the top of the
moist chloride or directly upon the drying plates, in using a hopper having at its
bottom a serrated roller. The said chloride is distributed by causing the said
serrated roller to revolve. A similar arrangement, but larger, may also be used to
place the charge of damp chloride upon the said drying plates.
Seventh. As means for compressing the said chlorides upon the said drying
plates, in employing two rows of stampers raised by cams and allowed to fall upon
the said chloride. The said stampers are fixed at the end of vertical rods, which
allow the said stampers to follow the course of the layer of chloride without dis-
turbing it.
Eighth. As means for supplying the said chloride to the mixing and damping
machine, in placing an Archimedian screw across the salt store, with its delivery end
over the rollers of the said mixing and damping machine. The said Archimedian
screw is placed in a channel covered over with a series of loose covers, any one of
which may be removed for supplying salt to the screw.
Ninth. As means for economizing fuel, in arranging the said drying plates so as
to rise gradually from the end on which the moist salt is charged to the end from
which the dried salt is discharged.
Tenti. As incan's for economizing fuel and allowing the diffusion of the water
vapour, in causing the products of combustion to pass into the drying oven over the
top of the said drying plates, and in withdrawing the said products of combustion
below the level of the said drying plates. To allow the said products of combustion
to pass from above to below the said drying plates I cause the chain which carries
the said drying plates to pass along rails supported on brackets fixed in the walls of
the drying oven. The said brackets project from the walls of the drying oven
sufficiently to allow the said products of combustion to pass by the edges of the said
drying plates, and I use as my source of heat the waste products of combustion
from the apparatus used in decomposing the said chlorides and from the boilers
used in generating steam for the same.
Eleventh. As means for obtaining stronger and hotter gases when decomposing
chlorides of sodium or potassium by the direct action of sulphurous acid, air and
water vapour, pass the necessary supply of water vapour below the burning
pyrites. To prevent moistening of the burnt pyrites by condensed steam I first
superheat the said steam.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said James Hargreaves in the Great Seal Patent Office on the 28th
August 1877.
JAMES HARGREAVES, of Widnes, in the County of Lancaster, Chemist. " IMPROVE→
MENTS IN THE MANUFACTURE OF SULPHATES OF SODA AND POTASSA, AND IN THE
APPARATUS EMPLOYED THEREIN."
This Invention relates to the manufacture of sulphates of soda and potassa by
the direct action of sulphurous acid, air, and water vapour upon chloride of sodium
or chloride of potassium, that is to say, by bringing sulphurous acid, air, and water
vapour into direct contact with chlorides of sodium or potassium, and consists,―

page_text: First. As means for preparing the chlorides of sodium and of potassium to be
reacted upon directly by sulphurous acid gas, air, and water vapour, or by sulphuric
acid vapour, in employing steam instead of water for damping such chlorides,
thereby facilitating the drying and caking and economizing fuel.
Second. As means to insure the said chloride being evenly moistened, in first
passing the said chlorides through rollers, and then by means of an Archimedean
screw into a mixing and damping chamber, where it is stirred and agitated by a
shaft carrying arms. The steam necessary for moistening the said chloride is allowed*
to flow into the said mixing chamber; for economy I employ the exhaust steam from.
the engine used to drive the stirring and drying machinery.
:
Third. As means for most advantageously utilizing heat and space, in causing the
products of combustion to pass under the drying plates to the place where the'
chlorides are being placed upon the said drying plates.
Fourth. As means for preventing the chlorides from adhering to the said drying
plates, in placing a hopper full of dry chlorides upon the said drying plates, so that.
as the said plates move under the said hopper a thin layer of dry chloride is left in
direct contact with the said drying plates. The said hopper is arranged to rise and
fall along with the said drying plates, so as to leave the said layer of dry chloride
more or less uniform in thickness. The said drying plates afterwards pass under
the hopper of moist chloride to receive the charge.
Fifth. As means for preventing the moist chlorides from adhering to the com-
pressing machinery, in putting a thin layer of dry chloride on the top of the said
charge of moist chloride.
Sixth. As means for supplying the said dry chloride either upon the top of the
moist chloride or directly upon the drying plates, in using a hopper having at its
bottom a serrated roller. The said chloride is distributed by causing the said
serrated roller to revolve. A similar arrangement, but larger, may also be used to
place the charge of damp chloride upon the said drying plates.
Seventh. As means for compressing the said chlorides upon the said drying
plates, in employing two rows of stampers raised by cams and allowed to fall upon
the said chloride. The said stampers are fixed at the end of vertical rods, which
allow the said stampers to follow the course of the layer of chloride without dis-
turbing it.
Eighth. As means for supplying the said chloride to the mixing and damping
machine, in placing an Archimedean screw across the salt store, with its delivery end
over the rollers of the said mixing and damping machine. The said Archimedean
screw is placed in a channel covered over with a series of loose covers, any one of
which may be removed for supplying salt to the screw.
Ninth. As means for economizing fuel, in arranging the said drying plates so as
to rise gradually from the end on which the moist salt is charged to the end from
which the dried salt is discharged.
Tenth. As means for economizing fuel and allowing of the diffusion of the water
vapour, in causing the products of combustion to pass into the drying oven over the
top of the said drying plates, and in withdrawing the said products of combustion
below the level of the said drying plates. To allow the said products of combustion
to pass from above to below the said drying plates I cause the chain which carries
the said drying plates to pass along rails supported on brackets fixed in the walls of
the drying oven. The said brackets project from the walls of the drying oven
sufficiently to allow the said products of combustion to pass by the edges of the said
drying plates, and I use as my source of heat the waste products of combustion
from the apparatus used in decomposing the said chlorides, and from the boilers used
in generating steam for the same.
Eleventh. As means for obtaining stronger and hotter gases when decomposing
chlorides of sodium or potassium by the direct action of sulphurous acid, air, and
water vapour, I pass the necessary supply of water vapour below the burning
pyrites. To prevent moistening of the burnt pyrites by condensed steam I first
superheat the said steam.

page_text: DESCRIPTION OF THE DRAWINGS.
Fig. 1 is a sectional elevation, and Fig. 2 a sectional plan illustrative of my
Invention; Fig. 3 is a sectional elevation, also illustrative of my Invention.
Second head, Figs. 1 and 2. 1 are rollers between which chloride is fed into the
mixing and damping chamber 2, where it is stirred and agitated, whilst at the same
time steam is admitted to damp such chloride.
Third head, Fig. 3. Here the products of combustion pass in the direction of the
arrows beneath the drying plates 3 to the place 4 where the chlorides are being fed
on the said drying plates. In this arrangement the drying plates are suspended from
or attached to the carrying chains 6 by pivots, so as to be free to hang down during
their return through the oven. When the plates are fixed the products of com-
bustion escape, as shown at 19 on Fig. 1.
Fourth head, Figs. 1 and 2. 7 is a hopper to supply dry chloride to the plates 3
before the damp chloride is fed at 4 to such plates. The hopper 7 is suspended
from the centre 8 and balanced by the weight 9, so as to be free to rise and fall
with the said plates, and thus leave a layer of chloride more or less uniform in
thickness.
Fifth head. 10 shows a hopper for supplying a layer of dry chloride above the
moist chloride, so as to prevent such damp chloride from sticking to the compressing
machinery.
Sixth head. The hoppers 7 and 10 are supplied with serrated rollers 11, which by
their revolution regulate the supply of dry chloride above and below the damp
chloride.
Seventh head. 12 are stampers raised by cams 13 and allowed to fall upon the
chloride, so as to compress it.
Eighth head. 14 is an Archimedean screw leading from the salt store and
delivering the chloride into the hopper above the rollers 1; 15 are loose covers
above the screw, to allow of salt being fed thereto from any desired part of the
store. When it is not convenient to deliver direct from the screw to the hopper,
say when the floor of the store is below the level of the hopper, an endless band or
like appliance may be used to convey the salt from one to the other.
Ninth head. This head is illustrated by the position of the plates 3, which rise
gradually from the charging end 4 to the delivery end 16 of the drying oven 17.
Tenth head. The products of combustion pass into the drying oven 17 by the
opening 18 above the plates 3, and are withdrawn from the said drying oven
through the opening 19 below the level of the said plates. When loose hanging
plates are used the products of combustion are taken away, as shown by the arrows
in Fig. 3; 20 are brackets fixed in the walls of the oven to support the carrying
chains 6.
Having now described and illustrated the said Invention in such manner that
others will be enabled to carry my improvements into effect, I claim,―
Under the first head. Damping chlorides, substantially as and for the purposes set
forth.
Under the second head. The improvements in ensuring the even damping or
moistening chlorides, in the manner and for the purposes set forth.
Under the third head. The improvements substantially as set forth.
Under the fourth head. The improvements substantially as set forth
Under the fifth head. The improvements substantially as set forth.
Under the sixth head. The improved means of supplying chlorides to the drying
plates, substantially as set forth.
Under the seventh head. The improved means for compressing chlorides, sub-
stantially as and for the purposes set forth.
Under the eighth head. The improved means for supplying the chlorides from the
salt store to the compressing rollers.
Under the ninth head. The improvement substantially as set forth.

page_text: Under the tenth head. The improvements substantially as set forth.
Under the eleventh head. The improvement substantially as set forth.
In witness whereof, I, the said James Hargreaves, have hereunto set my
hand and seal, the Twenty-fourth day of August, in the year of our Lord
One thousand eight hundred and seventy-seven.
Witness,
JAMES JOHNSON,
Patent Office,
Clayton Square,
Liverpool.
JAMES HARGREAVES. (LS.)