IMPROVEMENTS IN THE MANUFACTURE OF PORTLAND AND OTHER CEMENTS
Year: 1872

page_text: LETTERS PATENT to Isaac Charles Johnson, of Mayfield, Newcastle
upon-Tyne, in the County of Northumberland, for the Invention
of "IMPROVEMENTS IN THE MANUFACTURE OF PORTLAND AND OTHER
CEMENTS."
Sealed the 19th November 1872, and dated the 23rd May 1872.
PROVISIONAL SPECIFICATION left by the said Isaac Charles Johnson
at the Office of the Commissioners of Patents, with his Petition, on
the 23rd May 1872.
I, ISAAC CHARLES JOHNSON, of Mayfield, Newcastle-upon-Tyne, in
the County of Northumberland, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE MANUFACTURE OF PORTLAND AND OTHER
CEMENTS," to be as follows:-
This Invention relates to the process of drying the moist mixtures
from which cements are made in a more expeditious and more even
manner than heretofore, and without the disadvantages arising from
dislodging the tiles or bricks with which the oven is constructed or from

page_text: the wet mixtures blocking up the flue passages, and interfering with
the draft from the furnace.
My Invention consists in constructing the drying chambers of a
rectangular or other corresponding shape, and with the roof of semi-
circular form springing from the floor or near thereto. One end of the
chamber is open to the heat from the furnace, and the products of com-
bustion pass over the mass to be dryed, and finds an outlet into a
chimney at the opposite end of the chamber through a door in which
the material is preferably inserted. The chamber may be placed in con-
nection with coke ovens, kilns, or other heating appliances, so that the
waste heat can be utilized before passing into the chimney.
The floor of the chamber may be slightly inclined towards the front
to induce the mass to flow down it, and so become more and more
exposed to the top heat which is passing through the chamber in an
opposite direction.
I prefer to arrange the drying chamber about level with the top of
the cement burning kiln, so that the mass when sufficiently dry can be
scraped or pushed over a ledge or bridge into the kiln direct to the burnt
in the ordinary manner.
Several drying chambers may be used in connection with one kiln to
divide the heat if desired.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Isaac Charles Johnson in the Great Seal Patent
Office on the 22nd November 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ISAAC 2
CHARLES JOHNSON, of Mayfield, Newcastle-upon-Tyne, in the County of
Northumberland, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-third day of May, in the year
of our Lord One thousand eight hundred and seventy-two, in the thirty- 3
fifth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Isaac Charles Johnson, Her special licence
that I, the said Isaac Charles Johnson, my executors, administrators,

page_text: and assigns, or such others as I, the said Isaac Charles Johnson, my
executors, administrators, and assigns, should at any time agree with,
and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS
IN THE MANUFACTURE OF PORTLAND AND OTHER CEMENTS," upon the condition
(amongst others) that I, the said Isaac Charles Johnson, my executors
or administrators, by an instrument in writing under my, or their, or
one of their hands and seals, should particularly describe and ascertain
the nature of the said Invention, and in what manner the same was
to be performed, and cause the same to be filed in the Great Seal
Patent Office within six calendar months next and immediately after
the date of the said Letters Patent.
NOW KNOW YE, that I, the said Isaac Charles Johnson, do hereby
declare the nature of my said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, reference being had to the
Drawings hereunto annexed, that is to say :-
This Invention relates to the process of drying the moist mixtures
from which cements are made in a more expeditious and more even
manner than heretofore, and without the disadvantages arising from
dislodging the tiles or bricks with which the flat or oven is constructed
or from the wet mixtures blocking up the flue passages and interfering
with the draught from the furnace.
The Invention consists in constructing the drying chambers of a
rectangular or other corresponding shape, and with the roof of semi-
circular or equivalent form springing from the floor or near thereto.
One end of the chamber is open to the heat from the kiln or furnace,
and the products of combustion pass over instead of under the mass to
be dried, and find an outlet into a chimney at the opposite end of the
chamber through a door in which the material is preferably inserted.
The chamber is sufficiently high for men to work in, and may be placed
in connection with coke ovens, kilns, or other heating appliances, so
that the waste heat in passing over the mass can be utilized before
passing into the chimney.
The floor of the chamber may be slightly inclined towards the front to
induce the mass to flow down it, and so become more and more exposed

page_text: direction.
I prefer to arrange the drying chamber about level with the top of
the cement burning kiln, so that the mass when sufficiently dry can be
scraped or pushed over a ledge or bridge into the kiln direct (by men
in the chamber) to be burnt in the ordinary manner.
Several drying chambers may be used in connection with one kiln to
divide the heat if desired.
The Invention will be well understood by reference to the accom-
panying Sheet of Drawings in which Figures 1 and 2 represent a
sectional elevation and sectional plan of a kiln, such as is employed for
burning dry cakey slip or slurry in combination with coke.
The upper part a of the kiln b is built with a flat rim, and is covered
by an arched roof c to put the kiln into communication with the
chimney and smoke vapour outlet d by a long horizontal chamber or
flue e with a flat or slightly inclined floor, upon which the wet slip or
slurry is placed or allowed to flow from the chimney end at f where an
aperture g provided with a door is situated for its reception from trollies,
barrows, boxes, or other articles as found convenient. The roof of the
chamber is of semicircular, segmental, or semi-eliptic form, and the
crown is sufficiently high to enable a man to move along and spread or
level the wet slip upon, and also to remove the dry cakey slip from the
flooring into the kiln 6 or into a receptacle.
The chamber may be of any length, and it may be divided or broken
up so that the smoke and vapour from the kiln would travel in a zig-
zag or circuitous route to utilize the whole of the heat in drying before
it escapes up the chimney.
In some cases the chamber is divided longitudinally by a partition, as
in Figures 3 and 4, when the diameter of the kiln is too large to use
one arch only. The crown of the chamber directly over the kiln is pro-
vided with a damper plate or tile h, Figure 6, which can be removed
wholly or partially to regulate the draft through the chamber, as also to
allow for the escape of the extra gases and fumes which are given off
from the body or mass when it falls at about the half burning, an outlet
being specially required at the moment,
The opening at the base of the chimney through which the wet
semi-liquid slip or slurry is inserted may be of semi-round, semi-oval,

page_text: rectangular, as in Figure 5, or other shape to enable a workman to enter,
and also trollies upon wheels from which the slip can be permitted to
flow, or be scooped from on to the chamber floor.
The trollies can also be used to convey the dried slip to other kilns
if found convenient.
I do not limit myself to drying slip or slurry or other body in a
semi-liquid state in chambers leading from cement kilns only, as such
chambers can be erected in connection with other kilns, furnaces, or
ovens, and other semi-liquid bodies can be dried therein; nor do I limit
myself to making the bed or flooring of the chamber of the same width,
as it may be wider at one end than at the other.
The features of my Invention, and to which I lay claim, are,—
Firstly. The direct or top drying of slip or slurry from which cements
are made, and also other bodies of a semi-liquid character by the waste
heat and vapours given off from kilns, ovens, and other heating apparatus
when such drying is effected in chambers large enough for men to move
in between the heating apparatus and the chimney substantially as
described and shown.
Secondly. I claim the construction of semicircular or equivalent
shaped chambers or flues with flat floors, upon which semi-liquid bodies
used for cements can be dried as described and shown.
Thirdly. I claim dividing or partitioning off spent heat flues or
chambers in which men can move, and the drying of semi-liquid bodies
therein as described.
Fourthly. I claim the combination of a horizontal flue or passage
with a cement burning kiln when such flue is used for drying by passing
the heat over the material to be burnt in such kiln, as also the means
of regulating the draughts substantially as described and shown.
In witness whereof, I, the said Isaac Charles Johnson, have here-
unto set my hand and seal, this Twentieth day of November
One thousand eight hundred and seventy-two.
I C JOHNSON (LS)