IMPROVEMENTS IN APPARATUS FOR PREPARING SLIP OR SLURRY FROM WHICH CEMENT IS MADE
Year: 1877

page_text: LETTERS PATENT to Vitale Domenico de Michele, of No. 5, Westminster
Chambers, in the City of Westminster, County of Middlesex, for the Invention
of "IMPROVEMENTS IN APPARATUS FOR PREPARING SLIP OR SLURRY FROM
WHICH CEMENT IS MADE."
Sealed the 15th March 1878, and dated the 19th September 1877.
PROVISIONAL SPECIFICATION left by the said Vitale Domenico de Michele
at the Office of the Commissioners of Patents on the 19th September 1877.
VITALE DOMENICO DE MICHELE, of No. 5, Westminster Chambers, in the City of
Westminster, County of Middlesex. "IMPROVEMENTS IN APPARATUS FOR PRE-
PARING SLIP OR SLURRY FROM WHICH CEMENT IS MADE."
According to the usual method of preparing slip or slurry from which cement is
made proportionate quantities of the necessary ingredients are placed in a tank or
receiver, termed a wash mill, with a large quantity of water, in which by agitation
and raking the ingredients are reduced to such dimensions as to allow them to pass
through gauze or other sieves, or over a sill into a receptacle, from which as slip or
alurry they are removed into settling vats, in which the ingredients precipitate, and
the supernatent water is drawn off as it becomes clear. This process occupies a
long time consequent upon the slow rate of settling of the ingredients, and the
quantity of water to be got rid of before the slip or slurry is fit for drying. The
process also is not always successful from small pellets or particles of the ingredients
being carried by excessive agitation into the receiver.
According to another process of preparing cement slip or slurry the ingredients
are agitated in a reduced quantity of water and brought to a state of mud in the
wash mill, from which they are lifted by scoops or buckets to ordinary grindstones,
by means of which the mass is reduced to the necessary consistency.
By my Invention I use in the ordinary wash mill a small quantity of water in
proportion to the other ingredients, and as the slip or slurry rises over the edge of

page_text: the mill pan it passes between stone, metallic, or other suitable surfaces, or under
rollers, or rollers and surfaces combined, one of which surfaces forms the rim of the
pan of the wash mill, and the other the runner or traveller, between which and the
rim the particles already partially reduced in the wash mill are further crushed, so
as to permit them to be at once pumped or otherwise removed on to the drying
floor, thus saving the intermediate subsiding process.
In constructing my apparatus I extend some or all of the arms which carry the
rakes in the wash mill, and to these arms I connect a ring of metal, or stone, or
metal and stone combined, or other suitable substance, which may be formed in one
or more pieces, as may be found most convenient, the whole forming a flat ring,
which may be weighted if desired. The under surface of this ring may be smooth
or scored, and the whole is caused to move round on a corresponding rim of the
same or other material, which forms the top of the mill pan, which rim may be
scored or smooth.
For the upper ring in the above arrangement may be substituted a succession of
rollers, travelling on the under ring, and driven by the arms of the wash mill,
reducing the particles passing over the edge of the wash pan; or the rollers and
the travelling plate may be combined, the rollers travelling on the under ring, which
would then be extended inwards sufficiently to carry the rollers placed inside, or
within the travelling ring, which would be driven, and reduce the particles passing
from the wash mill and under the rollers, as before described.
By this plan I am able to use a smaller quantity of water than is used in the
subsiding process, and to reduce the escaping particles of the ingredients at the
wash mill to a proper consistency to be at once removed to the drying floor.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Vitale Domenico de Michele in the Great Seal Patent Office on the
19th March 1878.
VITALE DOMENICO DE MICHELE, of No. 5, Westminster Chambers, in the City of
Westminster, County of Middlesex. "IMPROVEMENTS IN APPARATUS FOR PRE-
PARING SLIP OR SLURRY FROM WHICH CEMENT IS MADE."
According to the usual method of preparing slurry from which cement is made
proportionate quantities of the necessary ingredients are placed in a tank or
receiver, termed a wash mill, in which by agitation and a raking process they are
reduced to such a consistency that they will pass through gauze of certain dimensions
into settling backs or receivers, where the solid matter is precipitated, the super-
natant water flowing away as it becomes clear. This process requires a long time
to complete, as the quantity of water to be removed is large, and the rate of pre-
cipitation slow.
According to another process of preparing cement slurry the ingredients are
agitated in a reduced quantity of water, and brought to a state of thick sludge in
the wash mill, from which the material is lifted to ordinary grindstones, and by
their means reduced to the necessary consistency.
In my Invention I use a small quantity of water with the ingredients, which are
reduced in the manner first described in an ordinary wash inill, and as the slurry
rises over the edge of the pan it finds its way between metallic or other suitable
surfaces, which form the rim of the wash mill, and one of which rotates with the
mill, and is by them reduced to the necessary consistency, and on passing from
them is removed to the drying floors.
My Invention will be clearly understood by the following description, with
reference to the annexed Drawings, in which Figure 1 shows a vertical sectional
elevation, and Figure 2 a plan of my apparatus.
In constructing my apparatus I extend some or all of the arms A, which carry
the rakes B in the wash mill C, and from the ends of them I suspend a circular
plate of metal or other suitable grinding substance D, which may be made in one
piece or built up of segments, united together by bolts or otherwise, as shown in
plan view, Figure 2, and which rotates with, and is driven by, the arms A through
the intermediation of the rods F of the mill. Below this is a similar fixed plate of
metal or other suitable material E, which forms the edge of the mill pan, and the
cement slurry passes between these surfaces, the lower one of which is stationary
and the upper moving, and is thus reduced to the necessary consistency, and falls
into the receiving channel G.
The acting surfaces of the plates or discs, shown on a larger scale in Figure 3, of
whatever material, may be smooth or scored; or instead of the upper revolving
plate a ring of rollers may be used, revolving on their own axes and with the wash
mill arms; or this roller arrangement inay be combined with the circular revolving
plate disc, as seen in Figure 4.
The top plate or the rollers above mentioned, or the combination of the two,
may alone revolve, or the bottom plate may move, the top one being stationary, or
both may have motion given to them.
By the means described above I am enabled to use a smaller quantity of water
than is usually employed; I reduce the particles of the ingredients to the necessary
consistency at the wash mill, and can remove them at once to the drying floor
without any intermediate process.
And having now described the nature of my said Invention, and in what manner
the same is to be performed, I declare that I claim,-
The general arrangement and combination of parts constituting my improvements
in apparatus for preparing slip or slurry from which cement is made, as herein-
before described, and substantially as shown in the annexed Drawings.

page_text: Secondly. The employment in wash mills of the grinding plates D and E for the
purpose of reducing cement slip or slurry in the manner herein-before described,
and substantially as shown in Figures 1, 2, and 3 of the annexed Drawings.
Thirdly. I claim the modification shown in Figure 4 of the annexed Drawings
for the same purpose.
Fourthly. I claim the employment of rollers, either conical or parallel, as shown
in Figure 5, in lieu of the grinding plates D and E, for the purpose of reducing
cement slip or slurry, as herein-before set forth.
In witness whereof, I, the said Vitale Domenico de Michele, have hereunto
set my hand and seal, this Nineteenth day of March, One thousand eight
hundred and seventy-eight.
VITALE DOMENICO DE MICHELE. (L.B.)