Apparatus to be Used in the said Manufacture.
Year: 1884

page_text: Apparatus to be Used in the said Manufacture.
I WILLIAM GEORGE MARGETTS of Aylesford in the County of Kent Gentleman
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN THE
MANUFACTURE OF PORTLAND CEMENT AND IN APPARATUS TO BE USED IN THE
SAID MANUFACTURE" to be as follows:-
"
My invention relates to the process of manufacturing Portland cement described
in the specification of Letters Patent No 1963 dated 12th July A.D. 1870 granted
to William Goreham and consists of the improvements hereinafter described in the
said process and of the apparatus hereinafter described.
The object of my said improvements is to remedy an objection which I have
found attends the use of the said process the said objection being that the chalk is
liable to pass between the millstones without being thoroughly ground or crushed
and that even when the chalk is thoroughly crushed in passing between the
millstones the particles of crushed chalk sometimes remain in masses among the
clay instead of being thoroughly interspersed therewith. This is a serious
objection as the imperfectly ground chalk and the comminuted masses of chalk
when the mixture of clay and chalk is burned in the kiln are converted into
caustic lime which when the cement is mixed with water and used expands or
blows" and causes disfigurement and injury to work executed with the cement.
According to my said Invention I pass the mixture of clay and chalk or of clay
and chalk and fuel (after being prepared in the wash mill as usual) between rolls
instead of between millstones and after the said mixture has passed between the
rolls I pass it into a rotatory screen or sieve having inclined sides and preferably
of an angular figure in plan. In passing between the rolls the matters of which
the mixture consists are crushed or disintegrated and by the action of the sieve
the particles of the masses of crushed or disintegrated chalk are either separated
from each other and interspersed among the particles of the other matters and
discharged through the meshes of the sieve or the said masses (if the particles
thereof be not separated) are thrown out over the sides of the sieve by centrifugal
action. The matters which pass through the sieve are further treated as usual
in the manufacture of cement which further treatment constitutes no part of my

page_text: Or they
invention The matters thrown out over the sides of the sieve are returned to the
wash mill to be again passed between the rolls and through the sieve.
may be returned to the rolls or to the sieve.
The rolls may be either plain or fluted and may be arranged above the sieve so
that the crushed matters may pass direct from the rolls into the sieve. I prefer to
surround the sieve with a casing communicating by means of a shoot or otherwise
with the wash mill in order that the matters passing over the sides of the sieve
may pass to the wash mill by gravity. The matters may be conveyed from the
wash mill to the rolls by means of an elevator consisting of an endless chain and
buckets or by other convenient means.
In some cases I dispense with the rolls and pass the mixture from the wash mill
direct into the sieve.
By the use of my Invention the particles of the ingredients are thoroughly
interspersed with each other throughout the mixture and less power is required
to drive the machinery in order to treat a given quantity of the mixture than is
required to drive the millstones heretofore used. The original cost of the apparatus
is also less.

page_text: Improvements in the Manufacture or Portland Cement, and in
Apparatus to be Used in the said Manufacture.
I WILLIAM GEORGE MARGETTS of Aylesford in the County of Kent Gentleman
do hereby declare the nature of my said Invention for "IMPROVEMENTS IN THE
MANUFACTURE OF PORTLAND CEMENT AND IN APPARATUS TO BE USED IN THE
SAID MANUFACTURE" and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement:—
My Invention relates to the process of manufacturing Portland cement described
in the specification of Letters Patent N° 1963 dated 12 July A.D. 1870 granted to
William Goreham and consists of the improvements herein after described in the
said process and of the apparatus herein after described.
The object of my said improvements is to remedy an objection which I have
found attends the use of the said process the said objection being that the chalk is
liable to pass between the millstones without being thoroughly ground or crushed
and that even when the chalk is thoroughly crushed in passing between the
millstones the particles of crushed chalk sometimes remain in masses among the
clay instead of being thoroughly interspersed therewith. This is a serious
objection as the imperfectly ground chalk and the comminuted masses of chalk
when the mixture of clay and chalk is burned in the kiln are converted into
caustic lime which when the cement is mixed with water and used expands
or "blows" and causes disfigurement and injury to work executed with the
cement.
According to my said Invention I pass the mixture of clay and chalk or of clay
and chalk and fuel (after being prepared in the wash mill as usual) between rolls
instead of between millstones and after the said mixture has passed between the
rolls I pass it into a rotatory screen or sieve having inclined sides and of an
angular figure in plan or in horizontal section. In passing between the rolls the
matters of which the mixture consists are crushed or disintegrated and by the
action of the sieve the particles of the masses of crushed or disintegrated chalk are
either separated from each other and interspersed among the particles of the other
matters and discharged through the meshes of the sieve or the said masses (if the
particles thereof be not separated) are thrown out over the sides of the sieve by
centrifugal action. I prefer to surround the sieve with a casing communicating by
means of a shoot or otherwise with the wash mill in order that the matters passing
over the sides of the sieve may pass to the wash mill by gravity. The mixture
to be treated may be conveyed from the wash mill to the rolls by means of
an elevator consisting of an endless chain and buckets or by other convenient
means.
The construction and arrangement of the screen or sieve herein before described
and the casing surrounding it are illustrated in the accompanying Drawinga

page_text: Figure 1 being a complete plan Figure 2 a plan partly in section with the cover of
the casing removed and Figure 3 a vertical central section of the sieve and casing.
Figure 4 is a plan of a portion of the sieve and Figures 5, 6, 7, 8 and 9 are details
hereinafter referred to Figures 1, 2 and 3 are drawn to a scale of two inches to the
foot. Figures 4, 5 and 6 are drawn to a larger scale and Figures 7, 8 and 9 are
drawn of the full size. The same letters and figures of reference indicate the same
parts in the several Figures of drawings.
A is the screen or sieve which is carrried by a rotatory shaft B and C is the
casing within which the screen A is mounted. The said casing is arranged in an
aperture in a platform or floor E (see Figure 3) and is supported by brackets c¹, c¹.
The upper part of the said casing is closed by a cover consisting of plates F F F F
which rest at their edges on a flange cand on cross pieces g¹, g¹ secured to a bar G
which is supported at its ends by standards H H and carries the upper bearing of
the shaft B. Apertures f¹, f₁ are formed in the plates F F through which
apertures the matter to be treated passes into the screen A. The interior of the
casing is divided by a circular partition I into two concentric compartments J. K
which respectively communicate with shoots j¹, k¹ by which the matters collecting
in the said compartments pass therefrom as hereinafter described.
The construction of the screen or sieve A. is hereinafter described with reference
to Figures 2, 3, 4, 7, 8 and 9. L is a metal boss secured to the shaft B to which boss
a number of metal rods M M are secured radially and N is a metal hoop to which
the outer ends of the said rods M M are secured. OO are segmental plates bolted
to the innerside of the hoop N between the ends of the said rods. The parts L
M N and O thus connected constitute a skeleton frame of the general figure of the
sieve which frame is covered as hereinafter described with wire gauze or other
suitable reticulated material X of about thirty meshes to the inch run or nine
hundred to the square inch. The wire gauze with which the frame is to be
covered is cut into pieces rather larger than the space enclosed between two of the
rods M M and the segmental plate between them and the said pieces are secured to
the frame by rods m¹, m¹, o¹ each of the pieces being strained between the parts to
which it is secured as shown in Figures 4, 7 and 8 Figure 7 being a transverse
section of one of the rods M with the wire gauze secured thereto by means of one
of the rods m¹ and Figure 8 a transverse section of the hoop N and one of the
segmental plates O showing the wire gauze secured thereto by means of one of the
rods o¹. The gauze is secured near the centre of the sieve by means of a plate P
which is screwed to the boss L over the inner ends of the rods M M. The
periphery of the sieve is supported by rods QQ bolted at their outer ends to the
hoop N and at their inner ends to a boss R secured to the shaft B. The manner
in which the said rods QQ and the rods M M are connected to the said hoop is
clearly shown in Figure 9.
T is a plate secured to the shaft B by screws t¹, t¹ the object of which plate is
hereinafter described. The said plate is shown separately in section in Figure 5
and in plan in Figure 6. The shaft B is supported by and works in a footstep b¹
and carries a band pulley 62. 11 is a shield secured to the boss L which shield
prevents matters passing from the compartment K out of the casing otherwise than
as hereinafter described. m² is a plate secured to the said shield and to one of the
rods M and n¹, n² are plates secured to the hoop N of the sieve the object of which
plates is hereinafter described.
I prefer to form the sieve as hereinbefore described that is of a frame consisting
of radial rods and a hoop on which frame wire gauze is strained whereby a sieve
of angular figure in plan or in horizontal section is produced which figure I have
'found in practice is more advantageous than a conical figure but I do not limit
myself to the number of angles nor to the precise construction of the sieve or
of the parts thereof hereinbefore described as a sieve otherwise constructed and
of hexagonal or other polygonal form in plan or in horizontal section may
advantageously be used.

page_text: The rolls hereinbefore described (which are not shown in the accompanying
Drawings) may be mounted in any suitable situation and the matter passing
between them may be conveyed from them to the sieve herein before described by
any suitable means I have found cylindrical rolls of about one foot diameter
arranged horizontally about one sixteenth of an inch apart and driven one at
double the speed of the other answer well I however do not limit myself to the
size of the rolls or their form as they may be fluted instead of cylindrical.
The method of using the apparatus hereinbefore described and its action are as
follows:-
The rolls hereinbefore described are caused to rotate by means of gearing
connected with any suitable motor and continuous rotatory motion is communi-
cated to the sieve A by any suitable means the speed of one of the said rolls being
about double that of the other and the speed of the sieve being about one hundred
and fifty revolutions per minute. While the apparatus is in motion the mixture of
chalk and clay or of chalk and clay and fuel is passed by means of an elevator
consisting of an endless chain and buckets or by other suitable means from the
wash mill to the said rolls by passing between which any coarse particles in
the said mixture are crushed or disintegrated. After passing hetween the rolls the
said mixture passes or is conveyed by means of a shoot or pipe or otherwise
through the apertures f¹, f¹ in the cover of the casing C onto the plate T whence
the said mixture passes onto the wire gauze of the rotating sieve. By the action
of the sieve the particles of any masses of crushed or comminuted chalk which pass
from the rolls are thoroughly disseminated and interspersed with the particles of
the other matters before passing through the meshes of the wire gauze the angular
figure of the sieve being greatly conducive to this action. Those portions of the
matters which pass through the meshes of the wire gauze collect in the compart-
ment K and are swept by the blade or plate m² round the said compartment until
they are brought over the mouth of the shoot when they pass down the said
shoot out of the casing. The coarser particles which are too large to pass
through the meshes of the sieve are by centrifugal action thrown out over its
periphery and pass into the compartment J where they are swept round by the
blades or plates n', n¹ until they pass out of the casing by the shoot j¹. The
object of the plate T is to protect the wire gauze from injury by the falling thereon
of masses of the mixture passing from the rolls into the sieve through the
apertures f, f¹. The matters which pass through the shoot k' are further treated
as usual in the manufacture of cement which further treatment constitutes no part
of my invention. The matters which pass through the shoot j' are returned to the
wash mill to be again passed between the rolls and into the sieve or they may be.
returned direct to the rolls or to the sieve.
In treating a mixture of chalk and clay alone the rolls may be dispensed with
the mixture being passed from the wash mill direct into the sieve.
By the use of my invention the particles of the several ingredients of the
mixture are thoroughly interspersed with each other throughout the mixture and
less power is required in order to treat a given quantity of the mixture than is
required to drive the millstones heretofore ordinarily used. The first cost of my
apparatus is also less than that of the millstones and gearing used in carrying out
the process described in the specification of the aforesaid Patent.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
First. Passing the mixture of chalk and clay or of chalk and clay and fuel
from the wash mill between rolls and afterwards through a rotatory screen or sieve
arranged and acting as hereinbefore described previously to drying and burning
the said mixture.
Secondly. Passing the mixture of chalk and clay direct from the wash mill
into and through a screen or sieve arranged and acting as hereinbefore described.

page_text: i
Thirdly. A screen or sieve for use in the preparation of materials for the
manufacture of cement constructed and mounted substantially as herein before
described with reference to the accompanying drawings that is to say a frame
covered with wire gauze or other suitable reticulated material and mounted on a
I vertical shaft capable of rotatory motion the frame being so formed and the
reticulated material so strained thereon as to constitute a screen or sieve of
concave form and of angular or polygonal figure in plan or in horizontal section.
Dated this thinto final dow of Anomat 1005
W. T. WHITEMAN,
Agent for the Applicant.