IMPROVEMENTS IN KILNS OR OVENS FOR DRYING AND BURNING BRICKS AND OTHER ARTICLES OF POTTERY OR EARTHENWARE
Year: 1869

page_text: LETTERS PATENT to John Bird, of Kingswinford, in the County of
Stafford, Manager of Works, for the Invention of "IMPROVEMENTS IN
KILNS OR OVENS FOR DRYING AND BURNING BRICKS AND OTHER ARTICLES OF
POTTERY OR EARTHENWARE."
Sealed the 27th July 1869, and dated the 2nd February 1869.
PROVISIONAL SPECIFICATION left by the said John Bird at the Office
of the Commissioners of Patents, with his Petition, on the 2nd
February 1869.
I, JOHN BIRD, of Kingswinford, in the County of Stafford, Manager
of Works, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN KILNS OR OVENS FOR DRYING AND BURNING BRIOKS AND OTHER
ARTICLES OF POTTERY OR EARTHENWARE," to be as follows, that is to say :-
This Invention refers more particularly to the arrangement or con-
struction of kilns or ovens for the above purposes in such manner
that the process of drying the said articles may be rendered more
effectual and economical.
I will describe my Invention as applied to a circular domed kiln
having a series of fire-grates arranged at intervals around it, and to

page_text: each grate an internal jacket or hot air flue, the kiln being also provided
with an outer or adjacent chimney stack or stacks. My Invention may,
however, be applied to all descriptions of kilns or ovens used for the
purposes already referred to.
I form in the outer chimney stack or stacks at a suitable height a
fire-grate or fire-grates furnished with a damper or door for closing up
the flue opening or fire-grate when required, a damper or dampers
being also provided in a short flue or flues upon the top of the kiln.
From the fire-grate in the stack the ordinary air culvert or passage
traverses underneath the floor of the kiln to a central open mouth or
vertical flue into the drying chamber, other traversing or radiating flues
being formed beneath the floor of the kiln and communicating with the
main flue. In the process of drying the bricks or other articles of
pottery or earthenware, which are built up upon the floor in any con-
venient manner, I fire the grate in the outer chimney or stack, at the
same time closing the damper above it to prevent a current of air to
the flue, the said current of air being drawn into the drying chamber
by the opening of the damper or dampers upon the top of the kiln;
thus the hot air created by the fire in the outer chimney or stack passes
into the traversing and radiating flues and also up the central mouth
or flue into, amongst, and through the bulk of the articles being dried,
the surface of the floor of the kiln or oven becoming thoroughly warmed
first, the products of combustion with the waste air and steam escaping
direct from the opening or openings in the top of the kiln. The drying
process having been effected and the articles being ready for burning,
the dampers on the top of the kiln are closed, and the damper in the
outer chimney or stack opened, the grates surrounding the kiln are
then fired, and the burning process conducted as usual.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Second day of February, in the year
of our Lord One thousand eight hundred and sixty-nine, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Bird, Her special license that
I, the said John Bird, my executors, administrators, and assigns, or
such others as I, the said John Bird, 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 KILNS OR OVENS FOR
DRYING AND BURNING BRICKS AND OTHER ARTICLES OF POTTERY OR EARTHEN-
WARE," upon the condition (amongst others) that I, the said John Bird,
by an instrument in writing under my hand and seal, should par-
ticularly 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 John Bird, 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, reference being had to the Drawings hereunto
annexed, and to the letters and figures marked thereon, that is to
say:-
This Invention refers more particularly to the arrangement or con-
struction of kilns or ovens for the above purposes in such manner that
the process of drying and partially burning the said articles may be
rendered more effectual and economical.
I will describe my Invention as applied to a circular domed kiln
having a series of fire-grates arranged at intervals around it, and to each
grate an internal jacket or hot air flue, the kiln being also provided
with an outer or adjacent chimney stack or stacks. My Invention may,
however, be applied to all descriptions of kilns or ovens used for the
purposes already referred to.
I form in the outer chimney stack or stacks at a suitable height
a fire-grate or fire-grates furnished with a damper or door for closing up
the flue opening or fire-grate when required, a damper or dampers

page_text: being also provided in a short flue or flues upon the top of the kiln.
From the fire-grate in the base of the stack the ordinary air culvert
or passage traverses underneath the floor of the kiln to a central open
mouth or vertical flue into the drying chamber, other traversing or
radiating flues being formed beneath the floor of the kiln and com-
municating with the main flue. In the process of drying the bricks
or other articles of pottery or earthenware, which are built up upon
the floor in any convenient manner, I fire the grate in the outer
chimney or stack, at the same time closing the damper above it to
prevent a current of air and the heat from ascending the chimney or
stack, the said current of heated air being drawn into the drying
chamber by the opening of the damper or dampers upon the top of the
kiln; thus the hot air created by the fire in the outer chimney or stack
passes into the traversing and radiating flues and also up the central
mouth or flue into, amongst, and through the bulk of the articles being
dried, the surface of the floor of the kiln or oven becoming thoroughly
warmed first, the products of combustion with the waste air and steam
escaping direct from the opening or openings in the top of the kiln.
The drying process having been effected and the articles being ready
for burning, the dampers on the top of the kiln are closed, the damper
in the outer chimney or stack opened, the grate or fire opening in the
outer chimney or stack being closed up by a suitable door, the grates
surrounding the kiln are then fired, and the burning process conducted as
usual.
I will now proceed to describe my Invention more fully in detail, and
by aid of the accompanying Drawings, which have reference to the
arrangement or construction of a circular domed kiln, and shewn in
sectional view Figure 1, and sectional plan in Figure 2 upon the line
A, A, of Figure 1.
(6) represent a series of fire-grates arranged at intervals around the
kiln, and to each fire-grate (b) is provided an internal jacket or hot
air flue (c); (d) is the ordinary air culvert or passage traversing beneath
the floor of the kiln; (e) is an adjacent or outer chimney stack or flue.
These parts are not new in their application to kilns or ovens and form
no portion of my Invention except in combination with the parts I am
about to describe.
I form in the outer chimney stack or flue (e), as shewn more clearly

page_text: This fire-grate (f) is furnished with a damper (g) for closing up the
flue opening when required, a door also being provided, as shewn at (h),
for shutting up the fire opening when desired. I purpose using any
convenient mechanical arrangement for effecting the opening and.
closing of the damper (9) and door (h), as, for instance, the damper
may be drawn out from or shut over the flue opening (e) by a con-
necting rod and handle (i), Figure 2, whilst the door (2) may be drawn
up and down for opening or closing the mouth of the fire opening by
means of balance weights and chains over pullies (k), the pullies (%)
being mounted upon suitable bracket supports. The fire-grate (f) is
removed when the fire opening is required to be closed up, as herein-
after described. From the fire-grate (f) in the base of the chimney
stack or flue (e) the ordinary air culvert or passage (d), traverses
underneath the floor of the kiln to a central mouth or vertical flue (1)
open to the drying chamber or interior of the kiln, other traversing
and radiating flues (m) being formed beneath the floor of the kiln in
suitable number and position, communicating with the open mouth or
vertical flue (2) at their ends (m²), and having outlets or open mouths
(m) at their other extremities. Upon the top or dome of the kiln I
construct a damper (n), Figure 1, capable of being opened and closed
at will by means of balance weights, chains, and pullies, as shewn, or
by some other convenient method; I also form other dampers or
openings (o), two being shewn in the Drawings, capable of being opened
and closed by some ready means.
The Drawing, Figure 1, illustrates the kiln as set ready for the drying
process to which my improvements more particularly refer, though the
bricks or other articles will be to some extent burned as well as dried
during the drying process, which I will now describe.
The bricks or other articles of pottery or earthenware to be dried are
built up upon the floor of the kiln in any convenient manner. The fire-
grates (6) are sealed or closed up, as also the wicket or entrance (p),
whilst the dampers (n) and (o) upon the top of the kiln are opened;
as shewn in Figure 1, and the damper (9) above the fire closed, so
that upon firing the grate (f) in the outer chimney stack or flue (e),
the current of air and heat is prevented from ascending the flue (e), but
is drawn into the drying chamber by the opening of the damper (n) or
dampers (o) or all of them upon the top of the kiln; thus the heated
air created by the fire in the outer chimney or stack (e) passes into

page_text: and up the central mouth or flue (1) into the traversing and radiating
flues (m), and through the outlets of the flues (m) at (m²) into, amongst,
and through the bulk of the articles being dried, the surface of the floor
of the kiln or oven becoming thoroughly warmed first, and the products
of combustion with the waste air and steam escaping direct from the
opening or openings in the top of the kiln. The drying process having
been effected and the articles ready for burning, the dampers (") and (0)
on the top of the kiln are closed, the damper (g) in the chimney stack
or flue (e) opened, and the fire opening closed by the withdrawal of the
fire-grate (f) and the closing of the door (h); the grates surrounding
the kiln are then fired and the burning process conducted as usual,
with this exception, that the hot air after passing from the hot air
jackets and flues (c) and through the bricks escapes not only by means
of the central mouth or vertical flue (1), but also through the outlets
or mouths (m²) of the traversing and radiating flues (m), thence through
the main air culvert and up the outer chimney or stack.
It will be seen from the foregoing description of the operations that
the current of air or draught is exactly reversed for the two processes of
drying and burning the bricks or other articles.
Having thus described the object and nature of my said Invention,
and the manner in which the same is to be carried into effect, I claim,
without confining myself to these precise details, the improvements in
kilns or ovens for drying and burning bricks and other articles of pottery
or earthenware, such improvements having more especial reference to
the process of drying such articles, substantially in manner as herein
more fully set forth and specified.
In witness whereof, I, the said John Bird, have hereunto set my
hand and seal, this Twenty-ninth day of July, in the year of our
Lord One thousand eight hundred and sixty-nine.