IMPROVEMENTS IN THE MANUFACTURE OF CEMENT, AND IN APPARATUS TO BE USED THEREIN."
Year: 1881

page_text: LETTERS PATENT to John Charles Jeffrey Smith, of Northfleet, in the County
of Kent, Manager, for an Invention of "IMPROVEMENTS IN THE MANUFACTURE
OF CEMENT, AND IN APPARATUS TO BE USED THEREIN."
PROVISIONAL SPECIFICATION left by the said John Charles Jeffrey Smith
at the Office of the Commissioners Patents on the 7th April 1881.
JOHN CHARLES JEFFREY SMITH, of Northfleet, in the County of Kent, Manager.
"IMPROVEMENTS IN THE MANUFACTURE OF CEMENT, AND IN APPARATUS TO BE
USED THEREIN."
"
This Invention relates to the ecomonical and speedy drying and burning of the
slip or slurry from which cement is made, and applies more especially to the manu-
facture of Portland cement by the process and apparatus for which a Patent was
granted to I. C. Johnson, dated 23rd May 1872, No. 1583.
According to that process the kiln is charged with dried slip and coke for the
purpose of producing the burnt clinker, which when reduced to a fine powder forms
the cement in question; the gases of combustion arising from the kiln being utilized
in the drying of the slip or slurry by causing the said gases to pass through an
arched drying chamber on the floor of which the slip is spread. It is found that by
the time the dry slip in the kiln has been thoroughly burned and a clinker of good
quality has been produced, the heat which has been given off through the drying.
chamber during the burning of the charge is insufficient to complete the thorough
drying of the wet slip or slurry on the floor of the drying chamber. It is therefore
customary to add to the charge of dry slip and coke within the kiln an extra
allowance of coke to complete the requisite drying of the wet slip or slurry, by
which system both time and fuel are wasted.
The object of the present Invention is to complete the thorough drying of the
slip or slurry by the time that the dry slip in the kiln has been converted into
thoroughly burned clinker, and this without any unnecessary consumption of fuel,
and in a much shorter period than heretofore.

page_text: To this end I place within the drying chamber one or more baffle plates or
screens, preferably of sheet iron, of suitable thickness, and I so arrange them as to
compel the heated gases issuing from the charged kiln to traverse the drying
chamber in close contact with the surface of the slip or slurry. I place these baffle
plates or screens at an angle of about 40° to the floor of the drying chamber and
at a suitable distance from the mouth of the kiln, leaving a space of about one foot
between the lower edges of the said screen and the floor of the chamber. Each
screen may be conveniently constructed in three portions, that in the centre being
readily removable to allow of the free passage of the workmen when required, and
those at the sides being permanently fixed. These screens may be conveniently
supported in position by means of iron stays or rods placed at a suitable incline,
and fixed into the roof and floor of the drying chamber, or in any other convenient
manner.
By means of this arrangement a much stronger draught may be employed,
thereby hastening the conversion of the dry slip into clinker, and the slip or slurry
in the chamber will be perfectly dried by the time that the charge of dry slip in
the kiln has been properly burned.
The two operations will thus be completed simultaneously with a great saving of
fuel and time. The gain in rapidity of production over the old process amounts to
from 50 to 70 per cent., while the accelerated drying and burning of the slip
produces both slip and clinker of the best quality.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Charles Jeffrey Smith in the Great Seal Patent Office on
the 7th October 1881.
JOHN CHARLES JEFFREY SMITH, of Northfleet, in the County of Kent, Manager.
"IMPROVEMENTS IN THE MANUFACTURE OF CEMENT, AND IN APPARATUS TO BE
USED THEREIN."
This Invention relates to the economical and speedy drying and burning of the
slip or "slurry" from which cement is made, and applies more especially to the
manufacture of Portland cement by the process and apparatus for which a Patent
was granted to Isaac Charles Johnson, dated Twenty third May, One thousand
eight hundred and seventy two, No. 1583.
According to that process the kiln is charged with dried slip and coke for the
purpose of producing the burnt clinker, which when reduced to a fine powder forms
the cement in question; the gases of combustion arising from the kiln being utilized
in the drying of the slip or slurry by causing the said gases to pass through an
arched drying chamber on the floor of which the slip is spread.
It is found that by the time the dry slip in the kiln has been thoroughly burned
and a clinker of good quality has been produced, the wet slip or slurry on the
floor of the drying chamber has not been thoroughly dried.
It is therefore customary to add to the charge of dry slip and coke within the
kiln an extra allowance of coke to complete the requisite drying of the wet slip or
slurry, by which system both time and fuel are wasted.
The object of the present Invention is to effect the thorough drying of the slip or
slurry by the time that the dry slip in the kiln has been converted into thoroughly
burnt clinker, and this without any additional or unnecessary consumption of fuel,
and within a much shorter period than heretofore.
To this end I place within the drying chamber one or more deflectors or screens,
preferably of sheet iron, of suitable thickness, and I so arrange them as to compel
the heated gases issuing from the charged kiln to traverse the drying chamber in
close contact with the surface of the slip or slurry.
The construction and disposition of these deflectors or screens will be understood
on reference to the Drawings, in which Fig. 1 is a diagram-view, representing in
longitudinal vertical section a kiln and drying chamber for the manufacture of
cement with my improvements applied thereto.
In this Figure, A. is the kiln, and B the arched dying chamber, on the floor of
which is spread the wet slip or slurry intended to be dried.
D, D, D, represent the deflectors or screens, placed preferably at an angle of about
forty degrees to the floor of the chamber, the better to deflect the gases of
combustion arising from the kiln onto the surface of the slip or slurry C.
Fig. 2 is a cross section on an enlarged scale taken on the line 1, 2 of Fig. 1,
and shows the apertures b, b, in the end wall of the drying chamber B, by which
the gases finally escape to the flue E.
As the gases are hottest at that end of the chamber which is nearest to the
mouth of the kiln, they are capable of drying a greater depth of slip at that end
than they can at the remote end of the chamber, and for this reason the floor of the
chamber is made to slope gradually towards the kiln, as shown in Fig. 1.
Fig. 3 is a cross section of the arched drying chamber B, taken on the line 3, 4,
of Fig. 1, and shows on an enlarged scale one of the deflectors in position. In this
Fig., D is the deflector or screen, preferably constructed of sheet iron, and supported
at an angle of about forty degrees to the floor of the chamber B by the iron rods
or stays d, d, the ends of which are respectively embedded in the brickwork or

page_text: The
masonry of the roof and floor of the arched drying chamber B (as shewn in the
Drawing), or secured in position in any other convenient manner. The deflector D
rests upon pins or studs d', projecting from the inclined rods or stays d, d.
lower edge of the deflector D when it is in position should reach to within twelve
inches or thereabouts of the level of the slip or slurry on the floor of the drying
chamber.
I preferably construct the deflector D in three portions, the two side portions
being permanently secured in position by rivetting or otherwise to the inclined
rods or stays d, d, and the central portion being readily detachable from the
supports d, d, so as to allow of the workmen entering the chamber and moving
freely therein to remove the slip or slurry therefrom when dried. The central
portion D may be temporarily fixed in position on the supports by means of studs
or pins projecting therefrom, as already described, or in any other convenient
manner.
By means of this arrangement a much stronger draught may be employed,
thereby hastening the conversion of the dry slip in clinker, and ensuring the
perfect drying of the slip or slurry in the chamber by the time that the charge of
dry slip in the kiln has been properly burned.
The two operations will thus be completed simultaneously with a great saving
of fuel and time. The gain in rapidity of production over the old process amounts
to from fifty to seventy per cent., while the accelerated drying and burning of the
slip produces both slip and clinker of the best quality.
Having now set forth the nature of my Invention of "Improvements in the
Manufacture of Cement and Apparatus to be Used therein," and having explained
the manner of carrying the saine into effect, I wish it to be understood that under
the above in part recited Letters Patent I claim,-
The application to the drying chambers used in the manufacture of cement of
deflectors for causing the gases of combustion from the kiln to travel over the
surface of the slip or slurry, in the manner and for the purpose above set forth,
such deflectors being wholly or in part removable to facilitate access to the drying
chamber.
In witness whereof, I, the said John Charles Jeffrey Smith, have hereunto set
my hand and seal, the Sixth day of October, in the year of our Lord One
thousand eight hundred and eighty one.
J. C. JEFFREY SMITH. (L.S.)