Improvements in the Manufacture of Cement.
Year: 1898

page_text: Improvements in the Manufacture of Cement.
We, JAMES HASTIE, Writer, of Number Fifteen, Royal Crescent, Edinburgh,
and JOSEPH GILL, Mining Engineer, of Number Four, Jameson Place, Leith
Walk, Leith, both in the County of Edinburgh, do hereby declare the nature
of this invention to be as follows.-
This invention relates to the manufacture of cement by a continuous or prac-
tically automatic process, whereby the raw materials from which the cement is
made are dried, thoroughly intermixed, reduced to any requned degree of fine-
ness and brought to a suitable condition for burning, at a less cost in time and
labour than by the ordinary processes generally in use at the present time, the
resulting cement being of excellent quality and produced at a comparatively
small cost,
According to this invention the materials from which the cement is to be made
are thoroughly died, conveyed from the diving beds and fed in the requisite
proportions to a grinding mill, where they are intermixed and ground to a cer-
tain degree of fineness The ground materials are then conveyed automatically
to a second ginding mill enclosed in a revolving drum, where they are further
ground to an impalpable powder or to the required degree of fineness and in-
timately intermixed.
From this latter mill the powdered material is conveyed through a pipe to a
collecting chamber by means of an exhaust fan, the said mill and collecting
chamber being also connected by a return pipe so that the exhaust fan sets up
a circular current between them and that there is no outlet for the escape of
dust to the atmosphere By means of increasing or decreasing the speed of
the exhaust fan any required degree of fineness of the materials can be obtained,
the materials always remaining in the mill until reduced to such a degree of
fineness as to enable them to be drawn away by the current By this means a
further intimato intermixture of the ground materials takes place and any fine
particles (in the form of dust) which do not readily settle in the collecting cham-
ber are returned to the mull through the aforesaid return pipe
The collecting chamber is constructed in the form of an inverted cone the
angle of which is sufficiently acute to ensure the automatic discharge of its con-
tents The settling of the suspended materials within this chamber and the
convergent movement of the settled materials towards the cential outlet, en-
Bures a further intimate intermixture of the said materials
From this collecting chamber the material is discharged automatically into
a cylindrical mixing machine and from thence it falls into a receptacle from
This press-
which it is elevated and fed into the moulds of a pressing machine
ing machine 18 self feeding and self discharging and compresses the ground
and mixed materials into bricks or blocks of sufficient firmness and compactness
to withstand the subsequent operation of placing them in the kiln.

page_text: From the mould table of the pressing machine the blocks are conveyed on
an endless band to the kiln, and burnt
HASELTINE, LAKE & Co,
45, Southampton Buildings, London, WC,
Agents for the Applicants.
Improvements in the Manufacture of Cement.
We, JAMES HASTIE, Writer, of Number Fifteen, Royal Crescent, Edinburgh,
and JOSEPH GILL, Mining Engineer, of Number Four, Jameson Place, Leith
Walk, both in the County of Edinburgh, 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 the manufacture of Portland or other cement by a
continuous or practically automatic process, whereby the raw materials from
which the cement is made are dried, reduced to any required degree of fineness
and thoroughly intermixed, and brought to a suitable condition for burning,
at a less cost in time and labour than by the ordinary processes generally in
use at the present time, the resulting cement being of excellent quality and
produced at a comparatively small cost.
According to our invention the materials from which the cement is to be made
are, after being dried, mixed and ground to the requisite degree of fineness in
one or more operations, the final grinding being effected in a closed apparatus
from which the materials are exhausted by a current of air and conveyed to a
depositing or collecting chamber containing inclined surfaces, which produce
a still further intimate mixture of the materials The thoroughly mixed and
pulverized materials are then fed to the moulds of a pressing machine and com-
pressed into blocks which are conveyed to a kiln and burned
In order that our invention may be clearly understood and readily carried
into effect we will proceed to describe the same more fully with reference to
the accompanying drawing which represents diagrammatically a suitable form
of apparatus for carrying our invention into practice
a is a grinding mill to which the materials from drying beds are fed in the
requisite proportions, and in which they are mixed and crushed or ground to
a certain degiee of fineness. As soon as the desued degree of fineness is reached
the materials are automatically discharged through a grating into the shoot b
which leads them to the inlet of a second grinding or pulverizing apparatus.
This apparatus preferably consists of a closed revolving drum c having therein a
heavy edge-runner d Elevators e are arranged within the drum, which lift the
material and drop it on the edge runner repeatedly This not only ensures the
requisite degree of fineness in the material, but it also effectively intermixes
the different ingredients We have found that satisfactory results are obtained
by grinding the materials in the first mill until they can be passed through a
3, mesh and further reducing them in the second mill until they will pass
through a mesh of 50 by 50 or 2.500 holes to the square inch The degree of
fineness to which the materials are reduced may however be varied according
to the kind and quality of cement to be manufactured
Obviously it would be possible to effect the grinding operation entirely in
the latter of the two mills The emplovment of two mills, one of which crushes
the materials and the other of which gunds or pulverizes them to the requisite

page_text: degree of fineness, is however, preferable because it avoids unnecessarv wear
in the latter mill, and enables the grinding operation to be more speedily effected.
The outlet, f, from the second mill communicates with the chamber of an air
exhausting device q which may consist of an ordinary revolving fan
By in-
creasing or decreasing the speed of this fan the force of the air current 18 varied
and consequently also the size of the particles which the said current will take
up By this means any required degree of fineness of the materials can be ob-
tained. the materials always remaining in the mill until sufficiently reduced
to enable them to be drawn away by the current of air
From this exhausting device the materials are conveved through a pipe h to
a depositing or collecting chamber i. A pipe k affords direct communication
between this chamber and the interior of the drum e, so that a circular current
is set up by the exhaust device and the finely ground materials are not likely
to escape into the atmosphere Any excess of the floating particles which does
not readily settle in the collecting chamber is returned to the mill through the
aforesaid return pipe k We thus avoid the tendency of the current of air to
blow the floating material through the depositing chamber, which tendency
would exist were no return channel for the current provided
The construction and arrangement of this depositing or collecting cham-
ber i constitute an important feature of our invention It is constructed in the
form of an inverted cone the angle of which is sufficiently acute to ensure the
automatic discharge of its contents The settling of the suspended materials
within this chamber and the movement of the settled particles toward the central
outlet, ensures a further intimate intermixture of the said materials As will
be perceived from the drawing, the materials are delivered into this chamber from
the pipe & through a number of apertures or perforations therein the lowest of which
apertures are above the lowest portion of the said conical surface
In order to pre-
vent the materials from falling duectly down to the outlet and so escaping
the intermixing action we provide a number of conical surfaces / amanged
around the portion of the pipe h within the chamber, which surfaces divert the
materials toward the aforesaid inverted conical surface and also assist in the
intermixing process
Beneath this chamber we may sometimes arrange a cylindrical mixing machine
into which the materials fall through the outlet and in which the said mat-
erials are subjected to a final mixing operation We find however that usually
a further mixing after the deposition is not necessary and we therefore prefer
to arrange for the deposited materials to fall directly into a receptacle m, from
which they are elevated by a chain bucket elevator or other convevor n and fed
into the moulda o of a pressing machine p This machine, which is preferably
self-feeding and self-discharging, compresses the pulverized and mixed materials
into bricks or blocks of sufficient firmness and compactness to withstand the
subsequent operation of placing them in the kiln The compressed bricks or
blocks are then conveved by an endless band g, or otherwise, to a kiln where they
are burned in the usual manner.
By means of our invention we are enabled to prepare, for burning, the raw
materials used in the manufacture of cement, by a continuous process in which
the use of water in effecting the intermixing and preparation of the ingredients
is avoided, the process being practically automatic in so far that no further
attention or manipulation by hand of the materials 18 required after they have
been dried and placed in a crushing or pulverizing machine until they are
brought into a condition ready for burning
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim 18:-
1. The herein described continuous process of preparing the raw materials
used in the manufacture of Portland or other cement. consisting in grinding

page_text: and mixing the dried raw materials, conveying them to a depositing or collect
ing chamber in which further intermixture takes place, then removing them and,
after subjecting them to a still further intermixture if desired, finally com-
pressing the materials into blocks ready for burning
2 The depositing or collecting chamber constructed substantially as and for
the purposes specified
3 The process of preparing, for burning, the raw materials used in the manu-
facture of Portland or other cement substantially as described with reference
to the accompanying diawing and for the purpose specified
Dated the 20th day of Databou 1900
HASELTINE, LAKE & Co,
45, Southampton Buildings, London, WC,
Agents for the Applicants