IMPROVEM wwe TN KILNS FOR RAYING OR BURNING CLAY
Year: 1853

page_text: LETTERS PATENT to John Ferguson, of the Heathfield Brick and
Pottery Works, Glasgow, in the County of Lanark, North
Britain, Brick and Pottery Manufacturer, for the Invention of
"IMPROVEM wwe TN KILNS FOR RAYING OR BURNING CLAY"
Sealed the 29th September 1858, and dated the 25th July 185%.
PROVISIONAL SPECIFICATION left by the said John Ferguson
at the Office of the Commissioners of Patents. with his Petition,
on the 25th July 1858.
I, JOHN FERGUSON, of the Heathfield Brick and Pottery Works,
Glasgow, in the County of Lanark, North Britain, Brick and Pottery
Manufacturer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN KILNS FOR BAKING OR BURNING CLAY" to be as
follows:-
'This Invention relates to the construction and arrangement of the
kiln. The kiln consists of a large chamber in which the articles to be
baked or burnt are deposited. Three or more furnaces are placed at
either end of the chamber and on a level with it, being divided off
from it by partitions reaching almost to the top of the chamber. The
furnaces are arched over in such a manner as to leave a very narrow

page_text: flue space between the arch and the partition, extending the whole
width of the furnaces. The flames and heated gases pass up this flue
in the form of a thin sheet, and enter the kiln chamber through the
narrow opening left between the partition and the top of the chamber,
thence reverberating over the whole chamber, and finally passing off
through the perforated false bottom to flues communicating with the
chimney. These flues are arranged in ramifications, and quite distinct
from each other, in such a manner that all parts of the chamber shall
be subjected to an equal strength of draught, a point upon which the
qual burning of the charge greatly depends. At the narrow part of the
flue between the furnaces and the chamber a thin sheet of air is
admitted through a channel or channels fitted with suitable regulators
or dampers. This current of air may either be admitted direct from
the atmosphere, or it may be caused to pass through channels so
arranged that it shall become more or less heated before its introduction
into the flue. The narrowness of the flue at this part causes the air to
be intimately mixed with the flames and heated gases, and as a conse-
quence a most perfect combustion is obtained, the smoke being entirely
consumed. The effects of this arrangement of kiln are a considerable
saving in the time necessary for the baking.or burning of a charge, as
well as in the quantity of fuel required. Added to this, the articles are.
baked or burned in a much more equal and perfect manner than in
kilns as hitherto constructed.
SPECIFICATION in pursuance of the conditions of the Letters Patent,.
filed by the said John Ferguson in the Great Seal Patent
Office, on the 25th January 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
JOHN FERGUSON, of the Heathfield Brick and Pottery Works, Glasgow,.
in the County of Lanark, North Britain, Brick and Pottery Manu-
facturer, sem greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fifth day of July,. in the year.

page_text: of our Lord One thousand eight hundred and fifty-three, in the seven-
teenth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Ferguson, Her special licence
that I, the said John Ferguson, my executors, administrators, and
assigns, or such others as I, the said John Ferguson, my executors, ad-
ministrators, or 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 Treland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN KILNS
FOR BAKING OR BURNING CLAY," upon the condition (amongst others')
that I, the said John Ferguson, by an instrument in writing under my
hand and seal, 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 John Ferguson, 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 accom-
panying Drawings, and to the letters and figures marked thereon, that
is to say:
My said Invention relates to the arrangement and construction of
kilus for baking or burning clay in making earthen or pottery ware.
The kiln consists of a large chamber in which the articles to be baked
or burned are deposited. This chamber is oblong, and is heated
by furnaces at each end, and divided off from it by partitions
reaching to within a short distance of the top of the chamber. The
furnaces arc arched over, and the arches extend back so far as to leave
a very narrow flue space between themselves and the partition, such
flue space extending the entire width of the chamber. The flames' and
heated gases from the furnaces pass up this flue in the form of a thin
sheet, and enter the kiln chainber through the narrow opening left
between the partition and the top of the chamber, thence reverberating
.

page_text: over the whole chamber, and finally passing off through a perforated
false bottom to flues communicating with the chimney. These flues
are arranged in distinct ramifications, and the perforations are varied
in size in such a manner that all parts of the chamber shall be
subjected to an equal strength of draught, a point on which the equal
burning of the charge greatly depends. At the narrow part of the flue
passage between the furnaces and the chamber a thin sheet or a row
of minute streams of air is admitted through a channel or channels
provided with suitable regulators or dampers. This air current may be
admitted direct from the atniosphere, or it may be caused to pass
through winding channels so arranged as that it shall become more or
less heated prior to its introduction into the flue. The narrowness of
the flue at this part causes the air to be intimately mixed with the
flames and heated gases, so as to produce a very perfect combustion,
the evolved smoke being entirely consumed. With this arrangement
of kiln a considerable saving is effected in the time required to bake or
burn a charge, as well as in the consumption of fuel, and the articles
are baked or burned in a much more equal and perfect manner than
in kilus as hitherto constructed.
And in order that my said Invention may be properly understood
I shall now proceed to describe the several Figures on the ac-
companying Sheet of Drawings. Figure 1, on the said Sheet of
Drawings is a vertical longitudinal section of my improved kiln; Figure
2, is a horizontal section; Figure S, is an external end elevation,
with one of the buttresses and a portion of the chimney broken away
to reduce the Figure within the limits of the Drawing; and Figure 4,
is a transverse vertical section; Figure 5, is a side elevation; Figure
6, a plan; and Figure 7, a transverse vertical section of one of the
bricks forming the flooring of the kiln chamber. The vertical section
Figure 1, is taken at the line 1, 2, 3, 4, in the horizontal section
Figure 2. One half of the latter section to the right hand is taken at
the line 5, 6, in the clevation, the upper half of the remainder is taken
at the line 7, 8, and the lower half at the line 9, 10, in the vertical
section Figure 1. The transverse section Figure 4, is taken at the
line 11, 12, 18, 14, in the horizontal section Figure 2.

page_text: The building is an oblong structure, very strongly built of fire bricks,
and arched over throughout its entire length, as shewn in Figure 4;
and the side walls are strengthened by solid buttresses A. The kiln
chamber B, is separated from the furnaces at each end by partitions C
which reach within a short distance of the summit of the arch. The
furnaces D, are in this instance two at each end of the structure; E,
are the grate bars; F, the ash pits; and G, the openings for feeding
the fires. The furnaces are arched over as at H, and a broad flat ver-
tical flue passage I, is formed at the back of the furnaces between
the arches and the partition C. The flames and heated gases pass up
this flue in a broad sheet, and enter the kiln chamber at J. Air is
admitted to the flue through long passages between and on each side of
the furnaces. The mouths of these passages are at K, and are provided
with dampers to regulate the inlet of air. The air passes along the
lowest passage K, to the back of the furnace; it returns to the front
by the passage L, goes back again by the third passage M. and again
returns by the passage N. It passes up the vertical passage O, and
then down the passage P, immediately behind the flue partition Q, as
represented at the right hand side of Figure 1. These passages being
carried along the sides of the furnace, the radiated heat of the latter
will necessarily be imparted to the passing current of air, which will
a. .o meet with a great accession of heat in passing down the passage P.
immediately behind the partition Q, which is in an exceedingly highly
heated state when the kiln is in operation. The air enters the flue I,
at the bottom of the passage P, immediately above the furnace arch H.
The entrance to the flue is effected through a number of slits R, which
serve to divide the current into a number of small streams, so that it
may mix more intimately with the gases passing up the fine. The
slits are formed by building up the partition at this part so as to leave
a number of interstices between the bricks. If deemed desirable, the
length of air passage may be somewhat shortened by only carrying the
passage O, to the top of the arch H, and taking it straight across as
at S, on the left hand side of Figure 1, and right hand side of Figure 4,
to the air holes R. Or a still more direct communication may be made
with the atmosphere by making an opening at T, into the passage S.

page_text: The atmospheric air passing through the openings R, into the flue I,
becomes intimately mixed with the ascending gases, and greatly assists
their combustion. The flaines and heated gases then pass over the par-
tition C, at I, and spread over the whole chamber B, containing the
articles to be burned, and finally pass off through the perforated. flooring
U. A chimney stalk V, is place at each side of the structure. Each
chimney has two horizontal cross flues W, reaching to the centre of
the chamber B, and provided with dampers at X. Each cross flue W,
communicates with five longitudinal flues Y, passing under the per-
forated floor U. The floor is composed of bricks of the form repre-
sented in Figures 5, 6, and 7. This brick is a parallelopiped in
general shape, but portions are cut away from the sides, as at Z. in
such a manner that the body of the brick tapers downwards, as shewn
in the cross section, Figure 7. When these bricks are placed side by
side, a narrow slit is left between, each such slit being wider at the
bottom than at the top. These bricks are placed across the longitudinal
flues Y, but they are not all of the same size, for as the draught is
much stronger near the root of the chimney than at the ends of the
chamber a means of compensation is required in order to equalize the
draught, and this is effected by making the apertures or interstices in
the flooring smaller the nearer they are to the central cross flues W,
and for this purpose bricks of a gradually varying size are used, as is
represented in Figures 1, and 2. In these Figures one half of the
floor is supposed to be removed in order to shew the arrangement of
Hues beneath. The portion of the 'flooring immediately over the
central cross flues W, is not perforated. The perforated floors of these
kilns may be constructed in various ways. But the mode which I
prefer is by the use of such bricks or tiles as are represented in
Figures 5, 6, and 7, on my Sheet of Drawings. Such bricks I also
prefer to make all of the same external dimensions, the graduations in
the apertures through or between them being arranged by varying the
inclination and depth of the recessed or cut away portions Z. This
plan affords many conveniences in arranging and building such bricks.
Having now described and particularly ascertained the nature of my
said Invention, and the manner in which the same is or may be used

page_text: or carried into effect, I may observe, in conclusion, that I do not
confine or restrict myself to the precise details or arrangements which I
have had occasion to describe or refer to, as many variations may be
made therefrom without deviating from the principles or main features
of my Invention; but what I consider to be novel and original, and
therefore claim as the Invention secured to me by the herein-before in
part recited Letters Patent, is,-
First, the general arrangement and construction of kilns or cham-
bers for baking or burning clay, as herein-before described.
Second, the application and use in kilns of open or permeable
flooring with graduated apertures.
Third, the application and use in open kiln floors of bricks or tiles
with graduated taper or inclined sides.
Fourth, the system or mode of effecting superior combustion, and
preventing the formation of smoke, by the application and direction of
air, as herein-before described.
In witness whereof, I, the said John Ferguson, have hereunto
set uy hand and seal, Twenty-third day of January, in the year
of our Lord One thousand eight hundred and fifty-four.
TATT
JOHN FERGUSON. (L.S.)