Improvements in the Manufacture of Cement and in Apparatus Employed therein.
Year: 1888

page_text: Date of Application, 29th Nov., 1888
Complete Specification Left, 29th Aug., 1889-Accepted, 23rd Nov., 1889
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Cement and in Apparatus
Employed therein.
We JAMES HARGREAVES, Chemist, THOMAS ROBINSON, Ironfounder, and JOHN
HARGREAVES, Chemist, all of Widnes in the County of Lancaster do hereby declare
the nature of this invention to be as follows:-
The object is to improve the manufacture of cement and to provide improved
apparatus therefor.
First. To obtain intimate admixture of the materials forming slurry, that is lime,
clay and water, we agitate these materials when together by means of aeriform fluid
so applied as to give a circular rotating or return motion to the materials. Instead
of air we may use carbonic acid or a mixture of gases with or without air as may be
required.
Second. Apparatus for carrying the first part of our invention into effect consists of
a vessel preferably having a conical bottom provided with aeriform fluid inlets,
preferably placed at a sufficient distance from the bottom of the vessel so as to allow
the heavy particles in the slurry to settle and admit of convenient withdrawal, and to
cause the contents to have rotary motion. Suitable inlet and outlet ways are provided
for the slurry and for the separate removal of the settled heavy particles. The vessel
is preferably covered and capable of withstanding pressure when required to work in
combination with the method of separating water from slurry as described under the
following third and fourth heads.
Third. Apparatus for separating water from slurry or materials to be employed in
the manufacture of cement so as to partly dry the same, consists of a close vessel or
chamber provided with perforated inner vessel or vessels preferably concentric. The
inner perforated vessel is covered with suitable filter cloth through which the water is
caused to pass by means of pressure applied in the other vessel.
Suitable arrangements are provided for taking away the water from the inner
vessel and for withdrawing the slurry from which water has been separated.
Fourth. Apparatus for acting continuously to separate water from slurry or materials
employed therefor consists of a perforated tube or vessel preferably taper covered ou
the inside with filter cloths having an inner protecting screen such as wire gauze. At
the smaller end of the tube or vessel is a discharge opening.
The slurry is forced by pressure into the larger end of the tube or vessel. The
water passes through the filter cloth and the partly dried materials flow continuously
through the discharge opening and are removed from time to time. The outdowing
semi-dry materials are by preference automatically formed into bricks or pieces and
conveyed by means of an endless metallic band through a heated oven.
Fifth. For drying semi dry slurry or other damp constituents of cement to obtain
the same in the form of powder or small pieces we employ apparatus constructed of
brick having shelves made of iron or other suitable material. When the material to
be dried is in fluid condition we preferably make the sides of iron provided with suit-
able non conducting material on the exterior to prevent radiation.
In the centre of the chamber is placed a vertical shaft passing through a hole in
each shaft. Around the hole in each alternate plate is cast or affixed raised pieces or
rings to prevent any fluid slurry or damp materials from falling directly down the
chamber without passing over the shelves. Between the shelves we affix to the said
shaft arms supporting and causing to rotate suitable scrapers, ploughs or rakes, pre-
ferably made of steel fixed rigidly, weighted, or with springs or their equivalents to
enable the scrapers, rakes, ploughs, or their equivalents to detach the dried material
without danger of breaking the said scrapers.
,

page_text: The slurry enters the apparatus at the top and is constantly moved and allowed to
fall from one shelf to another, and in its downward passage meet ascending hot products
of combustion. The dried and heated powdery slurry is conveyed preferably whilst
hot and by mechanical means to a suitable revolver and roasted into cement. The
waste products of combustion from the manufacture of cement are preferably employed
for drying the slurry and excess of oxygen is avoided as far as practicable when it is
desired to eliminate free Sulphur from the slurry...
Sixth. To rapidly weather-that is to carbonate and hydrate cement-we subject
the cement in a finely divided condition to the action of carbonic acid, or carbonie
acid and aqueous vapour.
Seventh. Apparatus for carrying the above treatment (Sixth) into effect consists of
a chamber formed of a series of shelves in which by mechanical means the cement is
constantly stirred and fresh surfaces exposed as it falls from shelf to shelf to the said
carbonic acid or carbonic acid and aqueous vapour. Apparatus of the form described
under the fifth head may be used.
Dilute carbonic acid such as cool products of combustion mixed with steam or
aqueous vapour may be passed through the chamber for the purpose of carbonating
and hydrating the cement.
Dated the 27th day of November 1888
Per pro J. T. KING,
J. Johnson,
Agent.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Cement and in Apparatus
Employed therein.
We, JAMES HARGREAVES, Chemist, THOMAS ROBINSON, Ironfounder, and JOHN
HARGREAVES, Chemist, all of Widnes in the County of Lancaster, 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 :-
The object is to improve the method of manufacturing cement and to provide
improved apparatus therefor.
First. To obtain intimate admixture of the materials forming slurry, that is lime
clay and water; we agitate these materials when together by means of aeriform fluid
either air so applied as to give a circular rotating or return motion to the materials or
instead of air we may use carbonic acid, or mixture of gases with or without air as
may be required.
When air is the aeriform fluid employed such air may be injected by means of any
well known pumps or injectors.
Second. Apparatus for carrying the first part of our invention into effect consists of
a vessel preferably having a conical bottom, provided with aeriforni fluid inlets placed
at a sufficient distance from the bottom so as to allow the heavy particles in the slurry
to settle and separate from the finer particles, and to admit of convenient withdrawal
of such residue through doors or openings at the bottom of the said vessel. The
aeriform fluid inlets or pipes are arranged in the vessel so that the injection of the
arieform fluid shall cause the contents to partake of say a circular motion and thus
intimately mix the fine particles of lime and clay.
The said apparatus is preferably covered and capable of withstanding considerable
pressure when used in combination with the apparatus described under the following
third and fourth heads.
Fig. 1 is a vertical section of apparatus under the above second part. a is a vessel
made with a conical or hemispherical bottom band fitted with an aeriform fluid inlet
way c leading nearly to the bottom of the vessel, d outlet and valve or door for finer
particles, e outlet and door or valve for coarse particles." The arrows show the direction
of motion of the currents.

page_text: Third. Apparatus for separating water from slurry or materials to be employed
in the manufacture of cement so as to partly dry the same quickly consists
of a close vessel or chamber provided with a perforated inner vessel or vessels, prefer-
ably concentric, the inner perforated vessel is covered with suitable filter cloth through
which the water is caused to pass by means of pressure applied in the outer vessel. A
pipe is provided for taking away the water from the inner vessel and the material
from which the water has been separated is removed usually dug out of the annular
space.
.
Fig. 2 is a vertical section of apparatus under the above third part. fclosed vessel
or chamber provided with an inner perforated chamber g, h filter cloth, i inlet way for
liquid to be filtered, j outlet way for water, j¹ openings through which the filtered
material is extracted.
Fourth. Apparatus for acting continuously to separate water from slurry for cement
manufacture or materials employed in the manufacture of cement consists of a per-
forated tube or vessel, preferably taper, covered on the inside with filter cloth or
its equivalent and with an inner protecting screen such as wire gauze.
In practice we find wire gauze if sufficiently fine and after becoming coated
with semi dry slurry to partially act as a filter cloth.
At the smaller end of the
tube or vessel, should such be taper, is a discharging opening.
The slurry is forced by pressure into the larger end of the tube or vessel, if
made taper.
The water passes through the filter cloth, and the partly dried
materials flow continuously through the discharge opening. The perforated tube
or vessel forming the continuous filter may be worked in vertical, horizontal, or
other convenient position. When vertical the semi dry slurry is preferably dis-
charged from the side at the bottom. The outflowing semi dry materials are by
preference consolidated and formed into bricks or pieces. The exit of the filter is
made of suitable form having a guillotine or other cutter to cut off lengths like
bricks. If desired the bricks or pieces may be further consolidated before or after
drying by subjection to further pressure in a brick or other machine. Final
drying is effected by passing the bricks through an oven, the bricks being laid or
piled on an endless travelling band of metallic plates.
Fig. 3 is a longitudinal section of apparatus under the above fourth part. k per-
forated taper tube clothed with filter cloth and having an inlet for the liquid to
be filtered at m, and an outlet for the filtered material at n. o represents a recipro-
cating blade for cutting the filtered material as it issues at n into lengths. p is a
travelling band for conveying the filtered material to a travelling band, oven of
any usual construction.
Fifth. For drying filtered slurry and obtaining it in powder or small pieces for
use in revolving calcining furnace we employ apparatus constructed mainly of brick
with shelves of iron brick or other suitable material.
The shelves when made of metal are covered on the underside with fire clay or brick
to prevent excessive heating.
In the centre of the said chamber is a placed a vertical shaft which passes through
a hole in each shelf. Around the hole in each alternate shelf is cast or affixed raised
pieces or rings to prevent any slurry or damp materials from falling directly down
the chamber without passing over the shelves." On the shaft between the shelves we
affix arms to carry suitable scrapers, ploughs, or rakes preferably made of steel fixed
rigidly, weighted or with springs or their equivalents to enable the scrapers rakes
ploughs or their equivalents to detach the dried materials without danger of breaking
the said scrapers. We cause the said shaft and scrapers or the like to rotate.
The slurry enters the apparatus at the top and is constantly moved and allowed to
fall from one shelf to another and in its downward passage meets ascending hot
products of combustion. The dried and heated powdery slurry is conveyed, preferably
whilst hot and by mechanical means to a suitable revolver and roasted into cement.
The waste products of combustion from the manufacture of cement are preferably
employed for drying the slurry.and excess of oxygen is avoided so far as practicable
when it is desired to eliminate free sulphur from the slurry.

page_text: Fig. 4 is a vertical section of part of apparatus under the fifth part, q are walls of a
tower or furnace provided with iron shelves . r protected below by fire clay or like
material s, t central shaft provided with arms u. v v¹ central and circumferential
openings through the shelves r, w lips or rings to prevent slurry from passing through
the central openings of the shelves r. The arms u have scrapers or rakes attached to
them in any usual way to scrape the slurry alternately from the centre to the circum-
ference, and from the circumference to the centre of the shelves.
Sixth. To rapidly "weather" that is carbonate and hydrate cement we subject the
cement in a finely divided condition to the action of an artificial atmosphere of carbonic
acid or carbonic acid and aqueous vapour.
Seventh. Apparatus for carrying the above treatment (sixth) into effect consists of
a chamber formed of a series of shelves in which by mechanical means the cement is
constantly stirred and fresh surfaces exposed as it falls from shelf to shelf to the said
ascending carbonic acid or carbonic acid and aqueous vapour. Apparatus of the form
described under the fifth head may be used and can be constructed of iron there being
no necessity to provide arrangements to prevent radiation or overheating of the iron.
Dilute carbonic acid such as cool products of combustion free from soot mixed with
steam or aqueous vapour may be passed through the chamber for the purpose of
carbonating and hydrating the cement. A convenient method of separating soot and
supplying aqueous vapour to products of combustion is to pass flue gases through a
wet scrubber before entering the "weathering" apparatus.
Apparatus under the seventh part is of similar construction to that shown in fig. 4,
or of the usual tower and shelf construction for acting on solids by gases.
Having now particularly described and. ascertained the nature of the said
invention, and in what manner the same is to be performed, we declare that what
we claim is :—
First. Intimately mixing lime and clay by means of aeriform fluids in the manner
and for the purpose substantially as described under the first part.
Second. Apparatus for carrying into effect the intimate mixing of lime and clay
substantially as described under the first and second parts.
Third. Filtering apparatus constructed substantially as and for the purpose described
under the third head.
Fourth. The continuous filter constructed substantially as and for the purpose set
forth under the fourth part.
Fifth. With the continuous filter the means and appliances for conveying and drying
bricks or pieces of semi dry slurry in a heated chamber substantially in the manner
and for the purpose set forth under the fourth part.
Sixth. The drying chamber in which slurry is dried by means of products of
combustion brought in contact with the slurry as it is by mechanical means, moved
upon and caused to fall from one shelf to another substantially as set forth under the
fifth head.
Seventh. The drying chamber with shelves rotating shaft and arms for the purpose
set forth under the fifth head.
Eighth. "Weathering" cement by means of an artificial atmosphere of carbonic
acid or carbonic acid and aqueous vapour substantially as set forth under the sixth
head.
Ninth. The apparatus substantially as described under the seventh head for the
purpose set forth.