Im- PROVEMENTS IN KILNS OR FURNACES
Year: 1875

page_text: LETTERS PATENT to Frederick Arthur Cowell, of Gunnislake, Calstock,
in the County of Cornwall, Engineer, for the Invention of "Im-
PROVEMENTS IN KILNS OR FURNACES."
Sealed the 18th February 1876, and dated the 20th December 1875.
PROVISIONAL SPECIFICATION left by the said Frederick Arthur
Cowell at the Office of the Commissioners of Patents, with his
Petition, on the 20th December 1875.
I, FREDERICK ARTHUR COWELL, of Gunnislake, Calstock, in the
County of Cornwall, Engineer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN KILNS OR FURNACES," to be as follows,
that is to say :-
'
My Invention has for its object to provide greater working faculties
at diminished cost in kilns or furnaces constructed partially or entirely.
upon the continuous action principle.
In carrying out my Invention I employ a series of chambers or com-
partments constructed by preference in the form of an archway or
tunnel. These chambers or compartments are formed by divisional

page_text: walls built transversely, and which extend through the crown of the
archway or tunnel. In the lower part of these walls I form suitable
apertures with dampers for the purpose of conveying the heated air and
other products of combustion into the adjoining chamber when the same
are not required to pass directly to the chimney.
I construct at one end of each chamber a perforated wall, parallel to
and at a suitable distance from the end or divisional wall. This per-
forated wall extends to about one half the height of the chamber, the
top of the channel or aperture thereby caused being left open. At each
end of these channels, and within the width of the walls near to the
bottom, I dispose suitable grate bars for the fuel, having a dip or angle
of about forty-five degrees towards the centre of the bottom of the
channels.
Over each set of grate bars is provided a passage for the admission
and regulation of cold air from the outside in addition to the one used
for introducing fuel.
At the opposite end of each chamber I form another channel below
the line of floor communicating with a flue leading to the chimney.
This sunk channel is provided with a damper, which may be operated as
the varying conditions of working require.
I cover the sunk channel with suitable blocks so placed as to leave
interstices between them, and so arranged that the smallest openings
are left nearest the entrance to the flue and gradually enlarged towards
the point at the greatest distance from it. This arrangement has the
effect of equalizing and rendering more uniform the passage of heat
through the chamber.
In certain cases I provide a hollow bottom (consisting of a series of
flues) to each chamber or kiln covered by a perforated floor and com-
municating with the sunk channel just described.
The usual method of working is to pass the heat from the fires over
the dwarf perforated wall through the mass of bricks and other goods
placed in the chamber, and thence by means of the perforated divisional
wall into the adjoining chamber, where a similar process is repeated.
When, however, it is desired to stop the process of burning at any one
chamber the dampers in the divisional walls are closed, the damper in
the sunk flue leading to the main flue is opened, and the products of
combustion are thence drawn off to the chimney.

page_text: -
"
I form a main flue, which runs parallel with the line of chambers or.
kilns at the outside, terminating with a suitable chimney or "stack."
The chambers are each provided with one or more " wickets
openings for introducing the goods to be operated upon.
"
or
The outer walls of the kilns are provided with and supported by:
longitudinal and transverse bars or girders.
:
I provide suitable openings for the purpose of "testing" and:
'cooling" in the top of each chamber. I also provide transverse flues,›
some of which communicate with these holes or openings and lead into:
a main longitudinal flue formed at the top of one of the side walls of
the kilns. Over these flues I form a drying floor to be heated by them..
I arrange dampers in these flues, so that in burning or cooling any one:
or more of the chambers the waste heat can be made to circulate under
the whole of the drying floor.
According to my Invention, and as one of its essential features, while.
baving only one chimney for the whole series of kilns, it is practicable-
to use any one or any number separately from the rest.
In the present description I have given my Invention in the form of a
straight line, but while maintaining the essential features I sometimes
build my kilns or furnaces according to the annular form or principle.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Frederick Arthur Cowell in the Great Seal Patent
Office on the 20th June 1876.
4
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERICK
ARTHUR COWELL, of Gunnislake, Calstock, in the County of Cornwall,
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twentieth day of December, in the year
of our Lord One thousand eight hundred and seventy-five, in the thirty. :
ninth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Frederick Arthur Cowell, Her special.
licence that I, the said Frederick Arthur Cowell, my executors, admini->
strators, and assigns, or such others as I, the said Frederick Arthur.

page_text: of about forty-five degrees towards the centre of the bottom of the
channel, as in a Siemens' furnace.
At the opposite end of each chamber I form another channel below
the line of floor, communicating with a flue leading to the chimney.
This sunk channel is provided with a damper, which may be operated as
the varying conditions of working require.
I cover the sunk channel with suitable blocks so placed as to leave
interstices between them, and so arranged that the smallest openings are
left nearest to the entrance to the flue and gradually enlarged towards
the point at the greatest distance from it. This arrangement has the
effect of equalizing and rendering more uniform the passage of heat,
through the chamber.
In certain cases I provide a hollow bottom (consisting of a series of
flues) to each chamber or kiln covered by a perforated floor and com-
municating with the sunk channel just described.
I form a main flue, which runs parallel with the line of chambers or
kilns at the outside, terminating with a suitable chimney or stack.
"
The chambers are each provided with one or more "wickets' or
openings for introducing the goods to be operated upon.
The outer walls of the kilns are provided with and supported by longi-
tudinal and transverse bars or girders, or in some cases by granite or. -
other stone buttresses.
>
I provide suitable openings for the purpose of. "testing" and
cooling" in the top of each chamber. I also provide transverse flues,
some of which communicate with these holes or openings and lead into
a main longitudinal flue formed at the top of one of the side walls of
the kilns. Over these flues I form a drying floor to be heated by them.
I arrange dampers in these flues, so that in burning or cooling any one
or more of the chambers the waste heat can be made to circulate under
the whole of the drying floor.
According to my Invention, and as one of its essential features, while
having only one chimney for the whole series of kilns, it is practicable
to use any one or any number separately from the rest.
In the present description I have given my Invention in the form of
a straight line, but while maintaining the essential features I sometimes
build my kilns or furnaces according to the annular form or principle.
:

page_text: Cowell's Improvements in Kilns or Furnaces.
Having thus described the nature of my said Invention I will now,
proceed to more particularly describe the manner of performing the
same by reference to the accompanying Drawing, in which-
Figure 1 is a longitudinal section, and Figure 2 a horizontal section
of a series of six kilns arranged in a line and constructed according to
my improvements.
Figure 3 is a transverse section of a series of kilns constructed
according to my improvements, but arranged in the form of an oval.
Figures 1 and 2 are drawn to a scale of about one-quarter of an inch
to the foot, and Figure 3 to a scale of about one-eighth of an inch to 1
the foot.
Similar letters and figures of reference are used in all the Figures to
represent similar parts..
Numbers 1, 2, 3, 4, 5, and 6 represent the chambers or compartments
constructed in the form of a tunnel or archway divided by the divisional 1
walls a, a, a, extending through the crownf of the kilns; b, b, are the
apertures in the lower part of the walls a, a, such openings being pro-
vided with dampers for shutting off the communication between the
chambers when the heated air and products of combustion are required
to pass direct to the chimney; c, c, c, are the perforated dwarf walls a
parallel to the divisional walls; d, d, are the grate bars in the channels
e, e, between the divisional walls a, a, and the perforated walls c, c; g is
the mouth of the fire-hole or furnace for introducing fuel; h, h, h, shew
the sunk channels below the line of floor, which floor is sometimes per-
forated. Each of these sunk channels or passages h communicates with 2
the main flue & leading to the chimney or stack K, and is provided with
a damper ij, j,j, shew the perforated coverings of the channels h, such
coverings being formed of blocks placed with interstices between them,
the object being to secure an equal circulation of heat in the process of
burning, both in the case of its being operated singly as well as when
used as a terminal outlet to the stack; 1 shews one of the wickets or
openings for introducing the goods to be operated upon; m shews one of
the dampers through which the waste gases pass and are controlled;
n, n, coloured blue, are the wrought-iron bars or girders in the outer
walls of the kilns for supporting them and resisting expansion; o, o, is a
the annular longitudinal flue formed at the top of one of the side walls
of the kilns. Into this longitudinal flue transverse flues communicate;

page_text: Having thus described the nature of my said Invention and the best
means with which I am acquainted for carrying the same into effect, I
wish it to be understood that I do not confine myself to the precise
details herein laid down and shewn in the accompanying Drawing, as
the same may be varied without departing from the peculiar character
of my Invention; but what I do claim and wish to be protected by the
herein in part recited Letters Patent is,-
Firstly. The general arrangement and construction of continuous
action kilns whereby such kilns may be worked either continuously or
in single or any series of chambers, and at variable speeds, in the manner :
herein-before described and shewn in the accompanying Drawing.
i
Secondly. The construction of kilns with perforated divisional walls
fitted with dampers and perforated dwarf walls in combination with
sunk flues or channels, in the manner and for the purpose herein-before
described and represented in the accompanying Drawing.
: Thirdly. The method described of regulating the passages through
which the products of combustion pass, so as to ensure an equal dis-
tribution thereof.
Fourthly. The construction of kilns whereby the heat may
be caused
to take a reverse action so as to ensure a regular and uniform burning of
bricks or other articles under treatment, as herein-before described and
represented in Figure 4 of the accompanying Drawing.
Fifthly. The method or arrangement described, whereby the air to
support combustion is brought to the fuel of one chamber or kiln
through the mass of heated or burnt bricks (or other articles), contained a
in the preceding chamber, substantially as herein-before described.
In witness whereof, I, the said Frederick Arthur Cowell, have
hereto set my hand and seal, this Fifteenth day of June,
in the year of our Lord One thousand eight hundred and seventy-
six..
FREDERICK ARTHUR COWELL. (L.S.)