IMPROVEMENTS IN APPARATUS FOR DRYING, CALCINING, ROASTING, OR INCINERATING SODA ASH, SULPHATE OF SODA, AND CARBONATE OF POTASH, AND ORES OF SULPHUR, COPPER, ZINC, AND LEAD, AND APPLICABLE ALSO IN THE TREATMENT OF OTHER SALTS. ORES. AND SUBSTANCES.
Year: 1875

page_text: IN
ETTERS PATENT to Robert Milburn, of Hatcham Iron Works,
Pomeroy Street, New Cross Road, in the County of Surrey, and
Henry Jackson, of 16, Park Square, Leeds, in the County of York,
AND
THE METHOD OF
for the Invention of "IMPROVEMENTS IN
APPARATUS FOR DRYING, CALCINING, ROASTING, OR INCINERATING SODA ASH,
SULPHATE OF SODA, AND CARBONATE OF POTASH, AND ORES OF SULPHUR,
COPPER, ZINC, AND LEAD, AND APPLICABLE ALSO IN THE TREATMENT OF OTHER
SALTS. ORES. AND SUBSTANCES.
"
PROVISIONAL SPECIFICATION left by the said Robert Milburn and
Henry Jackson at the Office of the Commissioners of Patents, with
their Petition, on the 12th February 1875.
We, ROBERT MILBURN, of Hatcham Iron Works, Pomeroy Street,
New Cross Road, in the County of Surrey, and HENRY JACKSON, of
16, Park Square, Leeds, in the County of York, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN THE METHOD OF and In
APPARATUS FOR DRYING, CALCINING, ROASTING, OR INCINERATING SODA ASH,

page_text: SULPHATE OF SODA, AND CARBONATE OF POTASH, AND ORES OF SULPhur, Copper,
ZINC, AND LEAD, AND APPLICABLE also in the TreATMENT OF OTHER SALTS, ORES,
AND SUBSTANCES," to be as follows :-
Our Invention has for its principal object to effect the calcination of
soda ash in the manufacture of carbonate of soda and other salts of soda,
but is or may also be applicable in the calcination of other salts, and in
the calcination or roasting of ores of sulphur, copper, zinc, lead, iron,
or other metals or substances, or for drying earths and some. other
materials.
To effect the said calcination, or roasting, or drying, we feed the
substances to be treated, say, for example, soda salts, on to a bed, over
which two endless chains carrying a succession of scrapers and revolving
stirrers are caused to travel, so as to stir up the ash and to propel it
towards the delivery end of the bed. The stirrers are formed with
trunnions, which work in bearings formed in the chain links. Each
stirrer is also provided with a pinion which gears with a fixed spur rack,
or with a row of teeth or studs, so that as the said stirrers traverse along
the bed they are caused to revolve and thus to stir up the ash. The
scrapers are fixed in the chain links, and are prismoidal in form, or
nearly so, having two scraping edges.
We prefer to make both the stirrers and scrapers nearly prismoidal
in form, but we do not confine ourselves to this shape. The chains,
with stirrers and scrapers attached thereto or mounted thereon, are by
preference made of cast iron. The said stirrers and scrapers have a
to-and-fro motion, as well as a progressive motion, towards the delivery
end of the bed.
Upon the shaft on which the driving chain pullies are fixed at one
end of the bed we loosely mount a worm wheel, which is caused to
revolve by a worm at a speed suitable to impart the required progressive
movement to the chains. Near the periphery of the worm wheel we
mount a crank shaft on which is fixed a spur wheel, which gears with
another spur wheel mounted loosely on the first named shaft. The last
named spur wheel is caused to revolve by suitable means and imparts
motion to the said crank shaft. The crank on the said crank shaft is
connected by a connecting rod to an arm or rocking lever fixed on the
first named shaft. The said crank as it revolves gives the intermittent
motion to the chains, and as it revolves with the worm wheel around

page_text: the axis of the first named shaft it also imparts the progressive motion
to the said chains, stirrers, and scrapers. The ash is thus thoroughly
stirred and turned over and carried forward by the continued action of
the scrapers and stirrers. The ash in its progress over the bed is
submitted to the action of heated gases, or of heated gases and flames,
generated in a furnace or in furnaces, and caused to pass over the said
bed and through a chamber formed by enclosing the said bed.
In the form of apparatus which we consider to be most suitable the
said bed is carried upon metal bearers in order that the endless chains
with the stirrers and scrapers may on their return pass under the bed
from one set of chain pullies to the other set. Suitable openings are
formed in the said chamber for feeding in the salts and for withdrawing
the finished ash. Doors are also provided for the purpose of examining
the progress of the substance over the bed.
The said form of apparatus may also be employed in the manufacture
of salt, and also for recovering alkalies from waste liquors, and is also
applicable for other purposes than those herein-before enumerated.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Robert Milburn and Henry Jackson in the Great
Seal Patent Office on the 9th August 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, ROBERT
Milburn, of Hatcham Iron Works, Pomeroy Street, New Cross Road,
in the County of Surrey, and HENRY JACKSON, of 16, Park Square,
Leeds, in the County of York, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twelfth day of February, in the year
of our Lord One thousand eight hundred and seventy-five, in the thirty-
ninth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said Robert Milburn and Henry Jackson,
our executors, administrators, and assigns, Her special license that we,
the said Robert Milburn and Henry Jackson, our executors, admi-
nistrators, and assigns, or such others as we, the said Robert Milburn
and Henry Jackson, our executors, administrators, and assigns, should

page_text: at any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVEMENTS IN THE METHOD OF AND IN APPARATUS FOR DRYING, CALCINING,
ROASTING, OR INCINERATING SODA ASH, SULPHATE OF SODA, AND CARBONATE OF
POTASH, AND ORES OF SULPHUR, COPPER, ZINC, AND LEAD, AND APPLICABLE ALSO IN
THE TREATMENT OF OTHER SALTS, ORES, AND SUBSTANCES," upon the condition,
amongst others, that we, the said Robert Milburn and Henry Jackson,
our executors or administrators, by an instrument in writing under our
or their hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be
performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date
of the said Letters Patent.
NOW KNOW YE, that we, the said Robert Milburn and Henry
Jackson, do hereby declare the nature of the said Invention, and in
what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement and accompanying
Drawings, that is to say :-
Our Invention has for its principal object to effect the calcination of
soda ash in the manufacture of carbonate of soda and other salts of soda,
but is or may also be applicable in the calcination of other salts, and in
the calcination or roasting of ores of sulphur, copper, zinc, lead, iron,
or other metals or substances, or for drying earths and some other a
materials.
To effect the said calcination, or roasting, or drying, we feed the
substances to be treated, say, for example, soda salts, on to a bed over
which two endless chains carrying a succession of scrapers and revolving
stirrers are caused to travel, so as to stir up the ash and to propel it
towards the delivery end of the bed. The stirrers are formed with
trunnions, which work in- bearings formed in the chain links. Each
stirrer is also provided with a pinion, which gears with a fixed spur rack
or with a row of teeth or studs, so that as the said stirrers travel along
the bed they are caused to revolve, and thus to stir up the ash. The 3
scrapers are fixed in the chain links, and are prismoidal in form, or
nearly so, having two scraping edges..

page_text: We prefer to make both the stirrers and scrapers nearly prismoidal
in form, but we do not confine ourselves to this shape. The chains
with stirrers and scrapers attached thereto or mounted thereon are by.
preference made of cast iron. The said stirrers and scrapers have a to-
and-fro motion, as well as a progressive motion, towards the delivery end
of the bed. The ash in its progress over the bed is submitted to the
action of heated gases, or of heated gases and flames, generated in a
furnace or in furnaces, and caused to pass over the said bed and through
a chamber formed by enclosing the said bed.
In the form of apparatus which we consider to be most suitable the
said bed is carried upon metal bearers in order that the endless chains
with the stirrers and scrapers may on their return pass under the
bed from one set of chain pullies to the other set. Suitable openings
are formed in the said chamber for feeding in the salts and for with-
drawing the finished ash. Doors are also provided for the purpose of
examining the progress of the substance over the bed.
The said form of apparatus may also be employed in the manufacture
of salt, and also for recovering alkalies from waste liquors, and is also
applicable for other purposes than those herein enumerated.
And in order that our said Invention may be fully understood we
have appended hereunto a Sheet of Drawings made to a scale of about
three quarters of an inch to a foot, and marked with letters of reference,
corresponding marks indicating the same parts in the various Figures.
Referring in this place to the said Drawings, Fig. 1 represents a
vertical longitudinal section of a calcining furnace constructed and
arranged in accordance with our Invention; Fig. 2 is a plan of a part
of the said furnace; and Fig. 3 is a vertical cross section on the line A
in Fig. 1.
In the said Figures, or in one or more of them, D¹ is a floor or bed
formed of fire-brick, or of fire-clay slabs, or of other suitable material, and
sustained within a calcining chamber by means of iron bearers E', which
are built into the side walls of the said chamber. The said chamber is
formed at one end with a furnace, which is provided with an ordinary
grate of fire-bars H₁. The flames and heated gases generated in the said
furnace flow through the opening I¹ and over the bed D¹ in the direction
indicated by the arrows into a side opening, or into side openings K¹,
.

page_text: which convey the said gases to a chimney. Chain wheels D and E are
fixed on shafts G and H, which are fitted to revolve in bearings which
are fixed in outer recesses or wall boxes formed or fixed in the side
walls of the chamber. On the said chain wheels are mounted two pitch
chains A, A. In the example the said chains are formed of cast iron t
links joined together and connected by means of wrought-iron pins or
bolts, but we do not confine ourselves to this method of construction.
The said chains sustain and actuate scrapers B and revolving stirrers C,
which are preferably made of cast iron. Each alternate link of each
chain is formed with a mortice or slot, into which one end of a scraper 1
is inserted, the said end being suitably formed to fit into the said mortice.
Each scraper
is or may be made of the prismoidal form indicated in
Fig. 1; the side which slides upon the floor D¹ being made concave in
order that the scraping edges may act with more effect. The inter-
mediate links are formed with bearings, in which the trunnions of the 1
said revolving stirrers are fitted to revolve. Upon each of the said
trunnions is fixed a pinion which gears with a rack G¹ which is fixed to
the side of the chamber, so that when the chains are set in motion the

page_text: motion by means of a strap acting on the pulley S, and imparts motion
to the wheels V and W; and as the latter wheel is in gear with the.
wheel Y the crank arm A¹ is caused to revolve and to impart a to-and-
fro rocking movement to the shaft G, whereby the chains are moved
to and fro, the scrapers being thus caused to move the ash to and fro
on the floor D¹. As the said chains move to and fro the stirrers are
caused to revolve, and thereby to stir up and turn over the ash. The
said driving shaft also imparts motion to the shaft O, whereby the
wheel I is caused to revolve in the direction indicated by the arrow, and
the crank arm A¹ is thus caused to revolve around the shaft G, the effect
being to impart a progressive movement to the chains in addition to the
reciprocating movements, so that each scraper and stirrer when recipro-
cating moves to a greater extent in the direction towards the delivery
end of the bed than in the reverse direction, whereby the ash is gradually
moved along the bed until it is discharged from the delivery end thereof.
The chain of scrapers and stirrers returns below the bed D' to the chain
wheels D. The ash is fed on to the floor through a hopper which is
provided with a pair of grooved feeding rollers, to which a revolving
motion is imparted, and is removed through the opening M'. The said
feeding arrangement may be varied as preferred or found to be most

page_text: And, lastly. The means for imparting the said combined motions,
substantially as herein-before set forth and indicated.
In witness whereof, we, the said Robert Milburn and Henry
Jackson, have hereunto set our hands and seals, this Twenty-
ninth day of July, in the year of our Lord One thousand eight 5
hundred and seventy-five.
Witness,
JNO. WHITE, Jun.
ROBT. MILBURN.
(L.S.)
HENRY JACKSON. (L.S.)