IMPROVEMENTS IN TREATING ALKALINE LIME MUD AND IN APPARATUS " THEREFOR."
Year: 1881

page_text: LETTERS PATENT to James Simpson, of Liverpool, in the County of
Lancaster, Alkali Manufacturer, and Edward William Parnell, of Widnes,
in the same County, Analytical Chemist, for an Invention of "IMPROVEMENTS
PROVISIONAL SPECIFICATION left by the said James Simpson and Edward
William Parnell at the Office of the Commissioners of Patents on the
19th December 1881.
JAMES SIMPSON of Liverpool in the County of Lancaster Alkali Manufacturer,
and EDWARD WILLIAM PARNELL of Widnes in the same County Analytical
Chemist. IMPROVEMENTS IN TREATING ALKALINE LIME MUD AND IN APPARATUS
"
THEREFOR."
In the manufacture of caustic alkali, that is caustic soda and potassa or either
of them from their carbonates a solution of the said carbonates is boiled and
agitated in the presence of caustic lime; the result being the formation or pro-
duction of caustic alkali and an insoluble carbonate of lime, which latter after
being washed and filtered usually with the aid of a partial vacuum is used in place
of limestone in the black ash operations. With the most approved methods and
appliances for washing and filtering hitherto employed a considerable percentage of
alkali still remains in the lime mud, and the latter being in a wet pasty condition
its utilization in the black ash furnaces retards their operation and necessitates
the use of a considerable amount of fuel to evaporate the moisture it contains.
The objects of our Invention are (1) to treat alkaline lime mud so as to free it
as far as practicable from alkali, namely soda and potassa, and from moisture,
and (2) to provide suitable and efficient apparatus to be used in carrying our
improved treatment into effect. Lime mud treated under our Invention is so far
freed from alkali and moisture that the expense of re-working the alkali is avoided,
and a larger amount of work can be done in the black ash furnaces without
additional fuel.
In carrying our Invention into practice steam is caused to pass down through

page_text: alkaline lime mud so as to consolidate the said mud and remove the alkali and
moisture. The lime mud during treatment rests on a filter bed and the steam is
passed therethrough at a pressure suitable to the thickness of the mass under
treatment. The temperature may be raised by superheating.
Apparatus constructed under our Invention for use in treating alkaline lime
mud substantially as above set forth is constructed as follows:-
First. A vessel or chamber capable of standing a considerable pressure has the
bottom or lower portion thereof constructed as a filtering surface, say with per-
forations covered with iron wire gauze or like material unacted on by alkalies.
At the top of the said vessel or chamber there is an inlet way or passage for
steam and at the bottom below the filter surface a passage or way through which
the alkali moisture and steam pass to any suitable receptacle. The top of the
chamber is removable or is provided with a door or way through which the
alkaline lime mud is introduced to the vessel or chamber or the lime mud may be
introduced through the steam passage. One or more scrapers within the said
vessel or chamber receive or receives motion by means of a shaft or shafts passing
through a stuffing box or stuffing boxes to the exterior of the said vessel or
chamber. When the lime mud has been sufficiently treated it is removed from
the vessel or chamber in any convenient manner and a fresh charge is inserted.
Second. Apparatus constructed in the manner first above described has the vessel
or chamber suported_on_pillars_and_is_provided-with-a-loose-bottom-by-opening-
which the block of filtered and dried lime mud can be removed.
In practice we prefer that the said bottom should be raised and lowered by
means of hydraulic power, though screw or other gear may be used. When
hydraulic power is used it is convenient to use a hand pump to put on the final
pressure.
Third. In apparatus provided with a movable bottom as above set forth, the
said bottom is connected to the raising and lowering gear by means of a joint or
joints and a quadrant and rack or tipping gear is provided so that when the
bottom is lowered the block of lime mud shall be discharged and the apparatus
shall be readily put in condition to receive a fresh charge.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said James Simpson and Edward William Parnell in the Great Seal
Patent Office on the 16th June 1882.
JAMES SIMPSON of Liverpool in the County of Lancaster, Alkali Manufacturer
and EDWARD WILLIAM PARNELL of Widnes in the same County Analytical
Chemist. IMPROVEMENTS IN TREATING ALKALINE LIME MUD AND IN APPARATUS
THEREFOR."
"
In the manufacture of caustic alkali, that is caustic soda and potassa or either of
them from their carbonates, a solution of the said carbonate or carbonates is boiled
and agitated in the presence of caustic lime; the result being the formation or
production of caustic alkali and an insoluble carbonate of lime, which latter after
being washed and filtered, usually with the aid of a partial vacuum is used in place
of limestone in the black ash operations. With the most approved methods and
appliances for washing and filtering hitherto employed a considerable per centage
of alkali remains in the lime mud, and the latter being in a wet pasty condition,
its utilization in the black ash furnaces retards the operation and necessitates the
use of a considerable amount of fuel to evaporate the moisture.
The objects of our Invention are (1) to treat alkaline lime mud so as to free it
as far as practicable from alkali, namely soda and potassa, and from moisture, and
(2) to provide suitable and efficient apparatus to be used in carrying our improved
treatment into effect. Lime mud treated under our Invention is so far freed from
alkali and moisture that the expense of reworking the alkali is avoided, and a
larger amount of work can be done in the black ash furnaces without additional
fuel.
In carrying our Invention into practice steam is caused to pass down through
alkaline lime mud so as to consolidate the said mud and remove the alkali and
moisture. The lime mud rests during treatment on a filter bed and the steam is
passed through the said mud and bed at a pressure suitable to the thickness of
the mass under treatment. The temperature of the steam may be raised by
superheating.
Apparatus for use in treating alkaline lime mud substantially as above setforth
is constructed as follows:-
First. A vessel or chamber capable of standing a considerable pressure has the
bottom or lower portion thereof constructed as a filtering surface, say with
perforations covered with iron wire gauze or like material unacted on by alkalies.
At the top of the said vessel or chamber there is an inlet way or passage for steam
and at the bottom below the filter surface a passage or way through which the
alkali moisture and steam pass to any suitable receptacle. The top of the chamber
is removable or is provided with a door or way through which the alkaline lime
mud is introduced to the vessel or chamber, or the line mud may be introduced
through the steam passage. One or more scrapers within the said vessel or chamber
receives or receive motion by means of a shaft or shafts passing through a stuffing
box or stuffing boxes to the exterior of the said vessel or chamber. When the lime
mud has been sufficiently treated it is removed from the vessel or chamber in any
convenient manner and a fresh charge is introduced.
Second. Apparatus constructed in the manner first above described has the
vessel or chamber supported on pillars and is provided with a loose bottom by
opening which the block of filtered and dried lime mud can be removed. In
practice we prefer that the said bottom should be raised and lowered by means of
bydraulic power, though screw or other gear may be used..
When hydraulic
power is used it is convenient to use a hand pump to put on the final pressure,

page_text: •
said bottom is connected to the raising and lowering gear by means of a joint or
joints and a quadrant and rack or tipping gear is provided so that when the
bottom is lowered the block of lime mud shall be discharged and the apparatus
shall be readily put in condition to receive a fresh charge.
· DESCRIPTION OF THE DRAWINGS.
Figs. 1 and 2 are side elevations at right angles to each other, and Fig. 3
• a vertical section of apparatus used under our Invention in treating alkaline lime
mud.
a is a cast iron vessel or chamber; steel or other cast or wrought metal may be
used, carried by pillars 6 secured to the sole plate c. d movable bottom carrying
the perforated plate e covered with wire gauze or like material so as to form a
filtering surface, f steam inlet way or passage, g discharge passage or way, h door
or valve through which the chamber a is charged with alkaline lime mud, i
weighted lever for closing the door or valve h. j'scrapers secured to the spindle k,
1 stuffing box and gland, m gearing for giving motion to the spindle and scrapers.
The spindle k has a keyway or slot cut therein to allow of its receiving end motion
as well as rotary motion, n hydraulic rams for raising and maintaining the
movable bottom d in position, the water is obtained from a reservoir or any
-suitable-source-of-supply, o-hydraulic hand pump, p stop or regulating valve.
q rack, r quadrant attached to the movable bottom d. 8 bearings by which
the movable bottom d is connected to the rams and on which it is free to be
turned.
་
The apparatus above described for the treatment of alkaline lime mud is used as
follows:-
The parts being in the position shewn alkaline lime mud is run into the vessel
or chamber a through the door or valve / or through the pipe f until the said
chamber or vessel is nearly full. The door or valve is then closed and steam is
Edmitted into the vessel or chamber a through the inlet way or passage f. The
steam passes down through the lime mud and carries the moisture and caustic
alkali in solution through the filter bed into the discharge passage or way g
whence it flows into any suitable receptacle. According as the pressure of the
steam varies so the time of treatment will be longer or shorter. During treatment the
scrapers are caused to act on the lime mud to close up or prevent the formation
of cracks or passages through which the steam might flow away without doing its
work. When the lime mud has been sufficiently treated, the water beneath the
rams is allowed to flow away and the bottom of the vessel or chamber descends
bringing with it the block of consolidated and dried lime mud. As the bottom'd
descends the quadrant comes into gear with the rack q, and the said bottom is
tilted on its bearings so as to cause the block of lime mud to slide into a wagon or
other receptacle. Water is now allowed to flow beneath the rams say from: a
reservoir or main and the movable bottom d is again raised into position. The
stop or regulating valves p are then turned so as to shut off the water from the
reservoir or main and open communication between the rams and the hand pump o.
The hand pump is operated so as to put sufficient water pressure beneath the
rams to make a steam tight joint between the bottom & and the vessel or chamber a.
More lime mud is then run into the vessel or chamber and the treatment proceeds
as above setforth.
It will be obvious that when the water pressure is sufficient whether obtained
from a reservoir, main or engine that the hand pump may be dispensed with. It will
further be obvious that the turning or tilting motion necessary to cause the lime
mud block to slide off the movable bottom may be obtained by means of many
mechanical devices other than a rack and quadrant. Screw or lever gear may be
used instead of hydraulic gear and one or any desired number of hydraulic rams
may be used.

page_text: Having now described and particularized the said Invention in such manner
that others will be enabled to carry our improvements into effect we claim :-
First. Passing steam downwards through alkaline lime mud for the purposes set-
forth.
Second. Apparatus for treating alkaline lime mud substantially as herein set-
forth.
Third. The combination in apparatus for treating alkaline lime mud of a
chamber or vessel filtering surface inlet and outlet passages or ways and scrapers
substantially as setforth.
Fourth. Apparatus for treating alkaline lime mud constructed with a movable
bottom and raising and lowering appliances substantially as setforth.
Fifth. In apparatus for treating alkaline lime mud ineans for discharging the
treated mud substantially as setforth.
In witness whereof I the said James Simpson for myself and for the said
Edward William Parnell have hereunto set my hand and seal this
Fourteenth day of June in the year of our Lord, One thousand eight
hundred and eighty two.
JAMES SIMPSON. (L.S.)