IMPROVEMENTS IN PORTLAND AND ROMAN TWE ASTR ARWEDD STRETTAD KIENO AD FURNACES
Year: 1859

page_text: LETTERS PATENT to Henry Medlock, of Numbers 15 and 20, Great
Marlborough Street, in the City and Liberty of Westminster, Analytical
Chemist, for the Invention of "IMPROVEMENTS IN PORTLAND AND ROMAN
TWE ASTR ARWEDD STRETTAD KIENO AD FURNACES"
PROVISIONAL SPECIFICATION left by the said Henry Medlock at the
Office of the Commissioners of Patents, with his Petition, on the
17th August 1859.
I, HENRY MEDLOCK, of Numbers 15 and 20, Great Marlborough Street, in
the City and Liberty of Westminister, Analytical Chemist, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN PORTLAND AND ROMAN
CEMENT, LIME, AND OTHER SIMILAR KILNS OR FURNACES," to be as follows:-
In order to make the description of the nature of my said Invention clear,
I will first describe one of the common methods of making Portland cement.
Chalk and river mud or clay are ground together with water and afterwards
dried upon a floor which is heated by a flue; this mixture is then broken up
and mixed with coke and put into the kiln or furnace of the form of a double
cone; the coke is ignited and the heat gradually raised, any moisture that
may be in the mixture is first driven off, afterwards from the combustion and
Brice 8d.]

page_text: calcination of the substance in the kiln or furnace, carbonic oxide, sulphur,
and sulphuretted hydrogen are expelled; the evolution of sulphuretted hydrogen
ceases and sulphurous acid is given off. These gases are all of them more or
less deleterious, and the object of my Invention is to prevent their escape into
the air and to do away with a chimney shaft, and to utilize the superfluous
heat produced. In order to prevent the escape of the deleterious, gasses and
vapours I burn the carbonic oxide. The effect of this is to add another equi-
valent of oxygen to the carbon of the carbonic oxide, which is thereby con-
verted into carbonic acid, a harmless gas that may be allowed to escape into the
air. The sulphur which has been sublimed, and the sulphur of the sulphuretted
hydrogen are also, by burning, oxidised and converted into sulphurous acid.
The air from the kiln, together with the carbonic acid and sulphurous acid, is
passed through a grating on which coke or other porous body which is kept
constantly wet by a jet of water, is placed; the water absorbs the sulphurous
acid, which is thus prevented from escaping into the atmosphere. The same
effect Inay be produced by passing them into a chamber with an opening at
the top, in which chamber a fine spray of water is kept constantly playing by
means of a jet. The wetted coke or chamber just described must be at such
a distance from the small coke furnace, herein-after mentioned, as that the
current of air and gasses may be cooled down nearly to the temperature of
the atmosphere. The burning above mentioned is effected in the following
manner: A flue is connected with the upper part of the kiln through which
the products of the combustion and calcination of the fuel and materials are
conducted; a number of iron tubes are placed in the flue at a little distance
from the furnace or kiln running lengthways of it. The products of combus-
tion and calcination pass through the tubes into a small furnace in which a
small quantity of coke or other fuel or gas is kept continually burning; a fan
or blower is placed in the flue between the tubes and the kiln which can be
made to draw the air and products of combustion and calcination from the
kilu and propel them along the flue and through the tubes, and also suck in
air from the atmosphere and propel it with the air and products of combustion
through the tubes. The products of combustion and calcination mixed with
atmospheric air by this means passing into the small furnace and over the
burning coke or other fuel or gas are ignited and burned, and the oxidation
above mentioned takes place. The heat produced by the combustion of the
carbonic oxide is very considerable, and I make use of this to heat the
drying floor for drying the material before burning. For this purpose the flue
is continued beyond the small furnace underneath the drying floor. It is
eventually brought to the wetted coke or chamber containing the jet of water

page_text: In
above mentioned, where the sulphurous acid is absorbed by the water.
order to encrease the draught I sometimes use a blower or fan fixed in the
flue between the drying floor and the wetted coke or chamber above mentioned;
this sucks the air and gases from the furnace or kiln and propels them
towards the wet coke or chamber. The draught produced by the fans or
blowers is sufficient to prevent the necessity of having a tall chimney shaft.
The products of combustion and calcination which escape into the atmosphere
being innocuous, a tall chimney shaft is not required on that account.
In the above description of the nature of my said Invention, I have shewn
its applicability to one of the furnaces or kilns commonly used for making
Portland cement, but it is obvious that it may be applied to any furnace or
kiln giving off similar products of combustion.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry Medlock in the Great Seal Patent Office on the
17th February 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
MEDLOCK, of Numbers 15 and 20, Great Marlborough Street, in the City
and Liberty of Westminster, Analytical Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventeenth day of August, in the year of our Lord
One thousand eight hundred and fifty-nine, in the twenty-third year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Henry Medlock, Her special licence, that I, the said Henry Medlock,
my executors, administrators, and assigns, or such others as I, the said Henry
Medlock, 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 PORTLAND AND
ROMAN CEMENT AND OTHER SIMILAR KILNS OR FURNACES," upon the condition
(amongst others) that I, the said Henry Medlock, my executors or adminis-
trators, 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.

page_text: NOW KNOW YE, that I, the said Henry Medlock, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement, that is to say :-
The object of my said Invention is to prevent noxious and deleterious gases
and vapours, the products of the combustion carried on in Portland cement,
lime, and other similar kilns or furuaces, from escaping into the air, and to
make use of the heat produced by my process, for this purpose for heating the
drying floor or place on which the materials for making the cement are dried
previous to their being introduced into the kiln or furnace. In the manu-
facture of Portland cement as at present practised, the following substances
are generated in, and escape from the furnace or kiln ; namely, carbonic acid,
carbonic oxide, sulphuric, sulphurated hydrogen, and gazeous sulphurous
acid, and where river mud is used in the manufacture, noxious exhalations
from the organic matter contained therein. With the exception of the car-
bonic acid, these are all more or less noxious and deletrious, and I convert
them into harmless substances by the following process :-I conduct all the
products of combustion from the kiln or furnace through a pipe or flue to a
small furnace containing ignited coke. By means of a fan or blower a
certain quantity of air is forced into the pipe or flue before it reaches the coke
furnace, and by the draught so produced the products of the combustion
mixed with air are forced into the coke furnace impinging on the ignited coke
are burned or
By this means the sulphor or sulphurated hydrogen
are converted into sulphurous acid, the carbonic oxide into carbonic acid, and
any exhalations from organic matter are decomposed, and the carbon therein
contained by oxidation forms carbonic acid. The flue or pipe is continued
beyond the coke furnace and passes under the drying floor, and the heat
produced by the combustion of the substances burned in the coke furnace is
thus made use of to heat the drying floor. If the burning or oxidation in the
coke furnace has been complete, the construction of the flue beyond the coke
furnace will contain only common air, nitrogen, a small quantity of watery
vapour, sulphurous acid in a gazeous state, and carbonic acid. All these
substances, except the sulphurous acid, might be allowed to escape into the air
without any injurious effect, but to prevent the escape of the latter in a
gazeous state I continue the flue beyond the drying floor into a chamber
containing a perforated tray on which coke or other porous substance is
placed. The coke or other porous substance is kept moist by a stream of
water playing upon it, and the sulphurous acid is made to pass up through
the coke or other porous substance. The sulphurous acid combines with the
.

page_text: water on the coke or other porous substance, and is thus prevented from
escaping into the air in a gazeous state. There is an opening at the bottom of
the chamber for the water combined with the sulphurous acid to flow away,
and this opening may, if necessary, be trapped to prevent the escape of any
gazeous sulphorous acid by that way. The size of the openings through which
the air is propelled into the flue or pipe by the fan or blower can be increased
or diminished at pleasure so as to regulate the quantity of air forced in; a
sufficient quantity of air must be forced in to burn or oxidise the substances
in the coke furnace as above described. In order to know whether this
combustion or oxidation is complete, a small hole is made in the flue or pipe
beyond the coke furnace, which can be opened or closed at pleasure; a piece
of white bibilous paper, moistened with a solution of acitate of lead, is intro-
duced into the flue through the hole and allowed to remain there a few
minutes, if, upon its being withdrawn, it is not blackened or discolored, no
sulphurreted hydrogen is passing along the fine beyond the coke furnace;
but if it is blackened or discolored it shews the presence of sulphuretted
hydrogen, and that the combustion or oxidation has not been complete
If smoke is observed in the flue beyond the coke furnace it also shews that
the combustion or oxidation has not been complete. If either of the fore-
going tests shew that the combustion or oxidation in the coke furnace is not
complete, more air must be forced into the flue or pipe by the fan or blower,
and the quantity of air increased until perfect combustion or oxidation takes
place. In order to mix the air forced into the flue or pipe more thoroughly
with the products of combustion issuing from the kiln or furnace, one or
more diaphragms of wire gauze or perforated metal plate are fixed in the
fluc or pipe between the fan or blower and the coke furnace. The meshes
or openings of the wire gauze or perforated metallic plate should be from
one-eighth to three-eighths of an inch square.
In the annexed Drawings, Figure A represents a section of the furnace or
kiln, the flue, the fan, or blower, and the coke furnace. In this Figure, 1 is
the interior of the kila or furnace; 2, the grate; 3, moveable fire-bars;
4, 4, are iron supports for the grate; 5 is the ash-pit; 6, 6, 6, 6, 6, 6, 6, are
openings, which can be closed at pleasure, to admit air when required; 7, 7, is
a passage round the kiln or furnace by which the openings 6, 6, 6, 6, 6, 6, 6,
can be got at; 8, 8, is a cover which closes the top of the kiln or furnace;
it is made of iron, hollow at the top, and is kept filled with water to prevent
it being injured by the heat. 9, 9, is the surface of the water; 10, 10, is an
iron tube passing through the middle of the cover, through which the fuel and
materials are introduced into the kilu or furnace. The tube has a rim 11, 11,

page_text: running round it and projecting downwards into the water on the top of the
cover to prevent any escape of gas. It has also a lid 1, which closes it
when required. The edge of the lid dips into a channel 13, 13, running
round the outside of the tube, the channel is kept filled with water to prevent
the escape of gas through the tube when the lid is on. The repetition of the
Figure 14, indicate openings round the top of the kiln or furnace, which
lead into a circular flue 15. The products of combustion pass through these
last-mentioned openings into the circular flue 5, and thence along the flue 16.
17 is the fan or blower, the vanes of which are made to revolve in the direc-
tion of the arrow by the wheel band 18, passing round the drum 19, on the
axis of the vanes. The wheel band is driven by a steam engine or any other
sufficient power. 20 is the opening through which air is forced into the flue
by the blower; 21 is a sliding door for regulating the supply of air; 22 is the
continuation of the Hue; 23, 24, and .25, are diaphragms of wire gauze or
perforated metal for mixing the air with. the products of combustion as
above described; 26 is the coke furnace; 27 is the ignited coke; 28 is
the fire-bars; 29 is the ash-pit; 30 is the continuation of the flue to the
drying floor. The drying floor is not shewn in the Drawings. 31 is the
opening in the flue which is used for ascertaining whether the combustion
or oxidation is complete as above described.
Figure B is a plan corresponding to Figure A; 1 is the lid of the tube
through which the fuel and materials are introduced into the kiln or furnace ;
2, 2, is the surface of the water in the cover of the kilu or furnace; 3, 3, the
sides of the cover to hold the water. The openings of the kiln or furnace
leading into the circular flue 5, are indicated by the Figure 4. 6 is the opening
from the circular flue 5, into the flue 7; 8 is the fan or blower; 9 is the drum
on the axis of the vanes; 10 is the opening through which air is forced into
the flue; 11 is the slide for regulating the quantity of air forced into
the flue; 12 is the continuation of the flue; 13, 14, and 15, are the diaphragms
of wire gauze or perforated metal plate; 16 is the coke furnace; 17 is the
opening used when feeding the coke furnace, which is at other times kept
closed; 18 is the continuation of the flue towards the drying floor; 19 is
the opening in the flue used for the purpose of ascertaining whether the
combustion or oxidation is complete as above described.
Figure C is a section of the chamber used for combining the gazeous sul-
phurous acid with water as above described. 1 is the flue through which
the gazeous sulphurous acid enters the chamber; 2 is the chamber; 3 is the
perforated tray; 4 the coke or other porous substance upon it; 5 is the pipe
through which a stream of water is kept playing on the coke; 6 is the opening

page_text: for the escape of air and carbonic acid; 7 is the opening through which the
sulphurous acid combined with water runs away; 8 is the trap to prevent
the escape of gazeous sulphurous acid through the opening 7.
Figure D is a plan corresponding to Figure C; in this Figure, 1 is the
flue; 2 is the chamber with the perforated tray on which the coke or other
porous substance is placed; 3 is the pipe through which a stream of water is
kept playing on the coke; 4 is the opening through which the sulphurous
acid combined with the water runs away; 5 is the trap to this opening.
The annexed Drawings shew the mode of constructing a kiln or furnace for
the manufacture of Portland cement according to my said Invention, to which
furnace my Invention is particularly applicable, but it is obvious how it may
be applied to kilns or furnaces for burning lime, or to any other similar kiln
or furnace, I claim only as my Invention the burning or oxidation of the
noxious and deletirious gasses or or vapours produced in the kiln or furnace
so as to render all but the sulphurous acid in a gazeous state innoxious in the
manner above described, the making use of the heat produced by the said
burning or oxidation to heat the drying floor, and the combination of the
gazeous sulphurous acid with water so as to prevent its escape into the air.
In witness whereof, I, the said Henry Medlock, have hereunto set my
hand and seal, this Seventeenth day of February, in the year of our
Lord One thousand eight hundred and sixty.
HY. MEDLOCK. (L.S.)