Improvements in Apparatus for Revivifying Spent Limes, and for Calcining Cements and Ores or like Materials.
Year: 1896

page_text: Date of Application 11th Jan., 1896
Complete Specification Left, 12th Oct., 1896-Accepted, 14th Nov., 1896.
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Revivifying Spent Limes, and for
Calcining Cements and Ores or like Materials.
I, GEORGE ROBERTSON HISLOP, of the Gas Works, Paisley, in the County of
Renfrew, Engineer and Gas Works Manager, do hereby declare the nature of this
invention to be as follows:-
This invention relates to apparatus for use in revivifying spent lime of gas works
and for calcining cements, ores, lime from soda ash, spent bleaching powder, alkali
waste, small lime stone, oyster shells, chalk or like materials; and it has for its object
to make provision for more completely exposing the lime or other material to the
action of hot gases by causing any of the said materials in a reduced condition to
traverse rotating furnaces or chambers of extremely small diameter.serving to turn
it over and expose it to close contact with the hot gases which flow through the
chambers in an opposite direction.
The improved apparatus comprises a hopper into which the spent lime or other
material is led and thence fed through crushing rollers into a drying cylinder
arranged to rotate on a horizontal or approximately horizontal axis, this cylinder
being provided with ribs or bars internally to facilitate the stirring up of the materiál
passing through it. The material under treatment is delivered from this drying
cylinder into a distributor rotated or oscillated by suitable means and having a number
of outlet openings which are in turn uncovered to permit the discharge of material
alternately or otherwise to a corresponding number of shoots leading each into a
rotating tubular furnace or chamber in which the lime or other material is calcined.
By preference. the drying cylinders and calcining chambers are arranged in batteries
enclosed in brickwork or masonry a gas producer or furnace with four or other
number of calcining tubes or chambers being generally provided for each drying
cylinder employed, and the rotating chambers being operated in unison by suitable
gearing. The calcining tubes which are preferably of not more than 8 or 9 inches
in diameter internally, but may even be smaller, are slightly inclined and their lower
ends-terminate in the combustion chamber of a gas producer the gas generated in
the latter and mixing with air admitted to the combustion chamber in proximity to
the ends of the calcining tubes being consumed, and resulting in the development of
a very high temperature there. The hot gases pass directly into the calcining tubes
or chambers, which are suitably lined, and force their way through the same in close
contact with the lime or other material which is being stirred up or turned over, as
it proceeds through the tubes, by the rotation of the latter. The material falling
through the ends of the calcining tubes collects in a chamber below having preferably
an inclined floor and an outlet closed by a door, on opening which the material drops
out of the apparatus. The spent gases as they leave the calcining tubes are led by
suitable conduits formed in the brickwork into the drying cylinder whence they pass
into a chimney flue, being utilized in the primary cylinder for drying the material.
Owing to the small-diameter of the calcining tubes, which just suffice for carrying
off the hot gases from the producer or furnace, the lime or material passing through
them in a fine stream is subjected to intimate contact with them and to their high
temperature, and comparatively short travel and little time are required for effecting
the revivifying or calcining operation. The calcining tubes and drying cylinder are
carried on rollers or pulleys and are maintained in their inclined position by roilers

page_text: bearing against flanges on the outside of the tubes. Rotatory motion is conveniently
imparted to the several tubes of each battery by means of a worm shaft and a worm,
or other gearing engaging worm or other wheels fitted or formed around the tubes,
the worm shaft being driven by belting from a counter shaft from which the shafts
operating the drying cylinder and the crushing rolls are also driven so as to ensure
comparatively uniform feeding forward of the material under treatment.
Dated this 10th day of January 1896.
WALLACE FAIRWEATHER,
Chartered Patent Agent,
62 St. Vincent Street, Glasgow, Agent for the Applicant.
Improvements in Apparatus for Revivifying Spent Limes, and for
Calcining Cements and Ores or like Materials.
I, GEORGE ROBERTSON HISLOP, of the Gas Works, Paisley, in the County of
Renfrew, Engineer and Gas Works Manager, 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 :-
This invention relates to apparatus for use in revivifying spent lime of gas works
and for calcining cements, ores, lime from soda ash, spent bleaching powder, alkali
waste, small lime stone, oyster shells, chalk or like materials; and it has for its object
to make provision for more completely exposing the lime or other material to the
action of hot gases by causing any of the said materia! in a reduced condition to
traverse rotating furnaces or chambers of extremely small diameter serving to turn it
over and expose it to close contact with the hot gases which flow through the
chambers in an opposite direction.
The invention is illustrated by the accompanying drawings, Fig. 1 being a front
elevation, Fig. 2 a side elevation and Fig. 3 a plan of the improved apparatus which
comprises a hopper A into which the spent linie or other material is led and thence
fed through crushing rollers B and thence by a conduit B' into a drying cylinder C.
This drying cylinder is arranged to rotate on a horizontal or approximately horizontal
axis, and is provided with ribs or bars internally to facilitate the stirring up of the
material passing through it. The material under treatment is delivered from this
drying cylinder Cinto a distributor D rotated by bevel gear as shown or oscillated
by suitable means and having a number of outlet openings which are in turn
uncovered to permit the discharge of material alternately or otherwise to a corre-
sponding number of shoots E leading each into a rotating tubular furnace or
chamber F in which the lime or other material is calcined. By preference the
drying cylinders and calcining chambers are arranged in batteries enclosed in
brick work or masonry a gas producer or furnace G with four or other number of
calcining tubes or chambers F being generally provided for each drying cylinder C
employed, and the rotating chamber F being operated in unison by suitable gearing
such as shown on the drawings in which worms H gear with worm wheels I
surrounding the tubes F. The calcining tubes F which are preferably of not more
than 8 or 9 inches in diameter internally, but may even be smaller, are slightly
inclined and their lower ends terminate in the combustion chamber of the gas
producer G, the gas generated in the latter mixing with air admitted to the combustion
chamber by means of a damper J situated in proximity to the ends of the calcining
tubes F and being consumed, results in the development of a very high temperature
there. The hot gases pass directly into the calcining tubes or chambers F which
are suitably lined, and force their way through the same in close contact with the
lime or other material which is being stirred up or turned over, as it proceeds

page_text: through the tubes, by the rotation of the latter. The material falling through the-
ends of the calcining tubes F collects in a chamber K below having preferably an
inclined floor and an outlet closed by a door K', on opening which the material drops.
out of the apparatus. The spent gases as they leave the calcining tubes are led by
suitable conduits L, M, formed in the brickwork N into the drying cylinder C whence-
they pass into a chimney flue O, being utilized in the primary cylinder for drying
the material and for discharging a portion of the H2S in the case of gas lime by
means of the CO, in said gases.
Owing to the small diameter of the calcining tubes, which just suffice for carrying
off the hot gases from the producer or furnace G, the lime or material passing-
through them in a fine stream is subjected to more intimate contact with them than
is possible with tubes of greater diameter in which latter case the gases pass along
the crown of the tubes without sufficient contact with the material, and because of
the high temperature of the former tubes comparatively short travel and little time
are required for effecting the revivifying or calcining operation. The calcining
tubes and drying cylinder Care carried on rollers or pulleys F, C, respectively,
the former tubes being maintained in their inclined position by rollers F2 bearing
against flanges on the outside of the tubes F. The shaft which carries the worm or
other gear for rotating the calcining tubes F is driven by belting A from a counter
shaft from which the shafts R, S, operating the drying cylinder and the crushing
rolls respectively by similar gearing are also driven by means of belting T, U, so as
ensure comparatively uniform feeding forward of the material under treatment.
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-
1. In apparatus for revivifying spent limes and for calcining cements and ores or
like materials, the employment of rotating calcining tubes or furnaces of small
diameter arranged in sets or batteries as described and adapted to effect intimate-
contact of the gases with the material to be calcined substantially as described.
2. In apparatus for revivifying spent limes and for calcining cements and ores or
like materials the arrangement in sets or batteries of rotating calcining tubes or
furnaces, of small diameter, and of means for charging them substantially as and
for the purpose set forth.
3. In apparatus for revivifying spent limes and for calcining cements and ores or
like material the arrangement or combination of devices for feeding the calcining
tubes or furnaces with the material to be calcined, and consisting of a hopper
provided with crushing rollers, a drying cylinder, and a rotating distributor, adapted
to discharge the material to be calcined alternately or otherwise into the calcining.
tubes or furnaces substantially as described.
1
WALLACE FAIRWEATHER,
Of the Firm of Cruikshank & Fairweather, Chartered Patent Agents,.
62 St. Vincent Street, Glasgow, Agent for the Applicant.