IMPROVEMENTS IN KILNS FOR BURNING BRICKS, TILES, LIME, POTTERY, AND OTHER ARTICLES OR MATERIALS, AND IN THE PREPARATION OF FUEL TO BE USED IN SUCH KILNS
Year: 1877

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for the Invention of
"IMPROVEMENTS IN KILNS FOR BURNING BRICKS, TILES, LIME, POTTERY,
AND OTHER ARTICLES OR MATERIALS, AND IN THE PREPARATION OF FUEL
TO BE USED IN SUCH KILNS." A communication from abroad by Professor
Henry Wright Adams, M.A., Doctor of Medicine, of Philadelphia, Pennsylvania,
United States of America.
Sealed the 22nd January 1878, and dated the 12th November 1877.
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 12th November 1877.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN KILNS FOR BURNING BRICKS,
TILES, LIME, POTTERY, AND OTHER ARTICLES OR MATERIALS, AND IN THE PREPA-
RATION OF FUEL TO BE USED IN SUCH KILNS." [A communication from abroad by
Professor Henry Wright Adams, M.A., Doctor of Medicine, of Philadelphia, Penn-
sylvania, United States of America.]
This Invention relates to a kiln for burning bricks, tiles, lime, pottery, and other
articles moulded or otherwise formed of clay or other material, and for similar
purposes, and which is to be termed "Adams' Hot-air Blast, Brick, and Lime
Kiln."
The said kiln is provided with grate bars, water pans in the ash-pits, a central
blast pipe, and channels sunk in the top of the floor for circulating the heat from
furnaces under the entire bottom of the charge when set in the kiln for burning.
To prevent the cracking of the walls by reason of the great heat produced in the
kiln during the process of burning a charge, the lower part of the kiln should be
built with mortar in a very thorough manner up as high as 5 feet above the grate-
bars; from this point up to the top of the kiln the bricks may be laid without
mortar and the ends thoroughly plastered with mud or pug.

page_text: There is a cast-iron pipe, closed at one end by a flanged head. The other end is
left open, and is connected to a blower for the purpose of receiving a blast of air
under pressure. The said pipe is cast in sections, and put together by flanges, bolts,
and nuts. It is cast with bevelled or funnel-shaped holes through its two opposite
sides for receiving the ends of the hollow grate bars, which are inade tight in the
same by means of a ring. The grate bars are wrought-iron pipes inserted into the
aforesaid pipe. The sides of the said pipe may have cast on them a boss for making
that part of the pipe thicker in which the ends of the grate bars are fastened.
The said ring is to be cast of brass, as this metal is very serviceable for packing
joints tight in this manner. A slit in it is left open, so that when it is slipped on
the end of the hollow bar and both are inserted into the bevelled hole in the first-
named pipe the ring may be driven home and be made to close the said slit and fit
the end of the hollow grate bar very snugly, and produce a tight packing between
it and the said first-named pipe. This pipe is enclosed in brickwork to protect it from
the great heat of the kiln, and place it beneath the floor of the same, so that it may
not project above it and interfere with the passage of carts through the kiln. This
brick foundation extends entirely across the inside of the kiln, and is situated in
the centre of the same. The said first-named pipe is bricked into this wall across
the whole length of the kiln. The top of the partition wall is flush with the entire
floor of the kiln.
The grate bars extend from the opposite sides of the first-named pipe and enter
pipes located in the opposite side of the walls of the kiln. The centres of these
pipes are parallel with the centre of the first-named pipe.
The grate bars are fastened in these pipes by means of the bevelled rings in
precisely the same manner as they are fastened into the first-named pipe, and
the said pipes extend the whole length of the kiln, and are bricked into its
walls. They are cast in sections, and put together with flanges, bolts, and nuts.
The last-named pipes have on the side through which the bevelled holes are
cast to receive the ends of the hollow grate bars, a boss cast on them to render
them sufficiently strong to receive the packing rings or wedges.
Blast pipes are connected with the said pipes under the grate bars for delivering
a blast of air into the ash-pits, thereby creating a pressure of air under the grate
bars and supplying the fuel more plentifully there with to promote combustion, and
also for the purpose of balancing and resisting the downward pressure of the
incandescent gases above the grate bars caused by the blasts of air injected into the
arches, and preventing their passing down into the ash-pits and creating in them an
inconvenient degree of heat.
Other pipes, also bricked into the walls, have bosses and bevelled holes for
receiving upright or perpendicular pipes and packing rings or wedges. There are
ten of these perpendicular pipes between the other pipes and on each side of the
kiln. The lower ends of the perpendicular pipes enter the other pipes, and are
fastened in them by means of the bevelled wedges. The said perpendicular pipes
are situated between the grate bars, and are bricked into the walls.
Another blast pipe connected with the above-named pipes extends through the
front wall, and through the wall of the kiln into the arches for the purpose of
deliverying a blast of air from the said pipes through and through into the arches in
to intensify the combustion of the fuel in the same, and create the proper degree of
heat and pressure to force it through every part of the charge. A valve is provided
for opening and closing the last-named blast pipe and regulating the quantity and
force of the blast. A hole is made directly over the top of the furnace frame and
entirely through the wall. The blast nozzle enters it a short distance from the out-
side of the wall, so that the end of the pipe is not liable to be melted.
A cast-iron pan is placed in each of the ash-pits to hold water to generate steam
by means of the heat deflected from the furnaces above them to cool the grate
bars, prevent the formation of clinkers upon them, to be partially decomposed by
the glowing coals, and make new combustible gases, and to give out additional
volumes of heat to rise and circulate through all the interstitial spaces of the super-

page_text: incumbent charge of the kiln. These pans extend from the front ends of the ash-
pits to the central partition wall. They slope obliquely towards the bottom, and
rest on the ground. The said pans are cast in sections, which are fastened together
by means of flanges, bolts, and nuts. These pans perform a very important.
function in the said "hot-air blast kiln." The grate bars would be speedily
melted were they not cooled by the aqueous vapor from the boiling water which
they contain.
I provide the kiln with bearing bars, the opposite ends of which are bricked into
the sides of the ash-pit walls; several of these bars are placed at convenient distance
from each other in each of the ash-pits. The grate bars rest upon them and prevent
their sagging when highly heated. Perforations are made through each bar in the
under side thereof, for the purpose of injecting forcible streams of heated air from
the hollow bars into the water contained in the aforesaid pans, and aiding to boil
The jets of hot air thus delivered into the ash-pits cause an atmospheric
pressure under the said grate bars and supply the fuel upon them with oxygen to
promote its combustion.
same.
The furnace doors open into the firing chambers of the kiln. These doors are
made of cast iron. They may be lined with clay on the inside to protect them
from the heat; they are of the usual size and shape of doors commonly employed
in brick and lime kilns; they are hung upon cast-iron frames which are bricked
into the walls of the kiln and secured firmly by anchors in the usual way.
The ash-pits extend from the front walls of the kiln to the partition wall. The
top of the floor of the kiln should be laid with tiles, which are larger and stronger
than bricks, and will retain their places better, and will resist the wear and tear of
carts and teams passing over them in a more satisfactory manner. The said floor is
provided with recesses or gutters, whereby the heat from the furnaces when the
kiln is set with bricks may circulate from the fires through them and under the
bottom of the charge to be distributed in a more equable and uniform manner
underneath the lower part of the same, and consequently through the whole body
of the superincumbent bricks to the end that they may be more perfectly and uni-
formly burned. These recesses or gutters occupy the whole floor enclosed within.
the walls of the kiln.
Flues are made in the inside walls of the kiln, which extend from the bottom to
the top of the same, to furnish passages for the heat to enter from the channels
and from the furnaces, and rise up in contact with the outside walls of the kiln
for more effectually heating the said walls, and the bricks, tiles, wares, lime, or
other articles or substances, and burning them to the requisite degree of hardness.
The arches are constructed in the usual manner, and do not require a more
particular description. A partition is built up with green bricks between the
arches every time the kiln is set to prevent the two opposite blasts of air
injected in forcible jets through the respective blast pipes from blowing against
each other, and driving the heat unequally from one side of the kiln to the other.
When the charge is burned this partition is taken down and removed with the other
bricks of the kiln.
Flues built through the brick kiln when the raw bricks are set in it extend
from the crowns of the respective arches through the entire charge, and opening to
the external air. These flues may be perpendicular. They commence directly above
the crowns of the arches. Their cross section is equal to the length and thickness
of an ordinary brick; after setting the kiln about eight courses high above the crowns
of the arches with perpendicular flues as aforesaid, I form channels or flues in a
horizontal direction across the top of the section of the kiln thus set in the form of
a checker board. These horizontal channels or flues are in depth and width equal
to the thickness and width of a common brick.
There are three platting courses of hard-burned bricks laid down as snugly together
as possible, and breaking joints, to constitute as impervious a cover as is practicable
over the entire charge. Through this cover all the flues are left open, so that the
water smoke may escape freely when the kiln is first fired, and until it is exhausted

page_text: and the kiln becomes sufficiently heated, and then the mouths of the said flues may
be gradually closed by bricks or tiles, and the tight and thick cover composed of
the three platting courses of hard-burned bricks aforesaid may convert the kiln into
an oven.
I arrange a series of perpendicular flues between the arches which extend from
the floor to the top of the kiln. These flues are equal in their cross sections to the
length and thickness of an ordinary brick, they are perpendicular and extend from
the floor to the top of the kiln. They commence between the arches and directly
over the recesses made in the floor at points where the aforesaid flues cross each
other.
In the burning of lime it has been customary to mix coal with the lime-
stones broken into small lumps. The combustion of the fuel leaves ashes mixed
with lime, and impairs its value. In my kiln no fuel is mixed with the limestones,
but the charge is burned with incandescent gases. To adapt my kiln to the burning
of lime, all that is necessary is to turn arches with fire-bricks over the grate bars,
filled with with pigeon holes to prevent the falling of the pulverized linie into
the fires.
Another part of my Invention relates to the admixture of ground coal with the
clay, of which bricks, tiles, potteryware, or other molded forms of earthy matter
are composed, and setting them in those parts of the kiln in which the heat is
naturally insufficient to burn them hard without additional fuel.
It has been customary for brickmakers to mix breeze or coal dust with the clay
which composes their bricks. By grinding coal to a fine flour, and then very inti-
mately and uniformly mixing it with the clay when it is tempered, a much larger
per-centage than usual may be employed without bursting or honey-combing the
said bricks. By taking coke which has been heated and expanded, and which is a
much purer fuel than breeze and coal dust, and creates more heat, and which is very
cheap, and grinding it to a fine flour, and mixing it intimately and uniformly at the
rate of 250 lbs. to one thousand ordinary sized bricks, and then setting one
course of them next to the walls of the kiln, and four courses on the top of the kiln,
and then laying down on them three courses of hard-burned bricks, breaking joints,
as a cover in the manner herein-before explained, the top and sides of the kiln will
be raised to such an intense heat by the combustion of the fuel contained in these
bricks as to burn them very hard.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Robert Lake in the Great Seal Patent Office on the 10th
May 1878.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN KILNS FOR BURNING BRICKS,
TILES, LIME, POTTERY, AND OTHER ARTICLES OR MATERIALS, AND IN THE PREPA-
RATION OF FUEL TO BE USED IN SUCH KILNS." A communication from abroad by
Professor Henry Wright Adams, M.A., Doctor of Medicine, of Philadelphia, Penn-
sylvania, United States of America.
This Invention relates to a kiln for burning bricks, tiles, lime, pottery, and other
articles moulded or otherwise formed of clay or other materials, and for similar
purposes, and which is to be termed "Adams' hot-air blast brick and lime kiln."
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a ground plan of my kiln cut off on a line parallel with the floor of
the same, showing the grate bars water pans in the ash-pit central blast pipe, and
channels sunk in the top of the floor for circulating the heat from the respective
furnaces under the entire bottom of the charge when set in the kiln for burning.
Figure 2 shows a vertical section of my kiln set with bricks taken through one
of the arches, and exposing to view the outside walls, the firing arches with
partition walls between them, the grate bars, the central blast pipe, the ash-pits,
the water pans in them, and the hot-air blast pipes for injecting blasts of heated
air into the arches and into the ash-pits; also the flues arranged in the charge of
bricks from the crown of the arch up through the charge, and opening to the
external air, together with the three platting courses of hard burned bricks laid
down on the top of the kiln for a cover.
Figure 3 represents a vertical section taken transversely through the centre of
the kiln on a line parallel with the central blast pipe B, and shows the flues X
through the charge when set for burning, and one half of the hollow blast pipe B
and the ends of the hollow grate bars inserted into it.
Figure 4 shows a top view of my kiln when set with bricks or filled with lime-
stones for burning, exhibiting the top of the platting courses and the open moutlis
of the respective flues.
Figure 5 is a front view of one side of my kiln from the ground up as high as
the top of the arches, showing the ash-pits, the front ends of the water pans, the
doors of the firing chambers, and the hot-air blast pipes.
Figure 6 is a view of one of the water pans which I employ in the ash-pits of my kiln.
Figure 7 shows one of the metallic rings which I use for tightening the joints of
the pipes.
Similar letters represent corresponding parts throughout the Drawings..
A shows the outside walls of my kiln. In this instance they enclose a space
thirty feet square, with ten ash-pits, furnaces, and arches on each side of the kiln.
These walls should be sunk into the earth far enough to be unaffected by frost.
They should be at least twenty-seven inches in thickness from the bottom up as
high as the top of the arches; from this point up to within four feet of the top they
should be twenty-two inches thick; from this point to the top of the kiln they
should be eighteen inches thick.
To keep the walls from cracking, by reason of the great heat produced in the
kiln during the process of burning a charge, it is recommended that the lower part
of the kiln should be built with mortar in a very thorough manner up as high as
five feet above the grate bars; from this point up to the top of the kiln the bricks
may be laid without mortar, and the ends thoroughly plastered with mud or pug.
This method of construction renders the walls sufficiently tight, and allows the
bricks to accommodate themselves to the action of the heat without cracking or
warping the walls.
1
4.

page_text: B represents a cast-iron pipe three quarters of an inch in thickness, one foot in
internal diameter, and thirty-four and a half feet long. It will then be as long as
the kiln, including the thickness of its walls. One end of this pipe is closed by
means of a flanged head. The other end is left open, and is connected to a blower
for the purpose of receiving a blast of air under pressure. An engine of about.
fifteen horse power is sufficient to operate the required blower. This engine and
blower will run from four to six kilns. The pipe B is cast in sections and put
together by means of flanges, bolts, and nuts. It is cast with bevelled or funnel-
shaped holes through its two opposite sides for the purpose of receiving the ends of
the hollow grate bars C, and which are made tight in the same by means of the
ring Y, shown in Figure 7.
The grate bars are wrought-iron gas pipes, one and a quarter inches in internal
diameter, and one and a half inches in external diameter; they are inserted into the
pipe B three quarters of an inch apart, so as to leave spaces between them for the
air to pass into the fuel, which rests upon them and promote the combustion of
the same; six of these hollow grate bars are employed in each furnace. The
opposite sides of the pipe B may have cast on them a boss for the purpose of making
that part of the pipe thicker, in which the ends of the grate bars are fastened. The
bevelled holes cast in the opposite sides of the pipe B are an inch and five-eighths in
diameter at a point where they enter the pipe B, and two inches in diameter
across the ouside, so as to allow the bevelled ring Y to be driven in tightly around
the ends of the said pipes, and wedge them air-tight into the pipe B. The ring Y
is to be cast of brass, inasmuch as the soft and yielding nature of this metal renders
it serviceable for packing joints tight in this manner; it is in this instance to be
cast two and a half inches long, one and a half inches in internal diameter, two and
a half inches in external diameter at one end, and bevelled off gradually to one inch,
and five-eighths at the other end; a slit lengthwise is left open for one-sixteenth of
an inch in width, so that when it is slipped on to the end of the hollow bar, and both are
inserted into the bevelled hole in B, the ring Y may be driven home, and be made
to close up the said slit, and hug the end of the hollow grate bar very snugly, and
produce a tight packing between it and the pipe B. It will be seen that the pipe
B is enclosed in brickwork. This is for the purpose of protecting it from the
great heat of the kiln and placing it beneath the floor of the same, so that it may
not project above it and interfere with the passage of casts through the kiln.
This brick foundation extends entirely across the inside of the kiln A, and is situated
in the centre of the same. This partition wall is three feet wide and three feet high
from the bottom of the ash-pits. The pipe B is bricked into the wall across the
whole length of the kiln six inches below its top. The top of the partition wall P is
flush with the entire floor of the kiln, which floor is shown by P between the
respective grate bars.
The grate bars C extend from the opposite sides of B, and enter respectively the
pipes D, D, which are located in the opposite sides of the walls of the kilns A. The
centres of the pipes D, D, are parallel with the centre of the pipe.
The respective grate bars Ċ are fastened in the pipes D, D, by means of the
bevelled rings Y in precisely the same manner as they are fastened into the pipe B.
To this end the pipes D, D, which extend the whole length of the kiln, and are
bricked into its walls to a distance of about four inches from the front sides, are
cast in sections and put together with flanges, bolts, and nuts, like the pipe B.
The pipes D, D, are six inches in internal diameter and three-fourths of an inch
thick, except the side through which the bevelled holes are cast to receive the ends
of the hollow grate bars. A boss should be cast on this side one and a half inches
thick, so as to render them sufficiently strong to receive the packing wedges Y.
It will be seen that, from the location of the grate bars C, they are about one
foot below the top of the floor of the kiln, and about two feet above the bottom of
the ash-pits. This arrangement creates a chamber above the grate bars and between
the side walls P, about one foot deep and fourteen and a quarter inches wide for
the reception and combustion of fuel. The bevelled holes in B, D), and G, for the

page_text: reception of the packing wedges Y are shown by W. E, E, represent blast pipes
connected with D, D, under the grate bars for delivering a blast of air into the
ash-pits O for the purpose of creating a pressure of air under the grate bars, and
supplying the fuel more plentifully therewith to promote better combustion of the
same, and also for the purpose of balancing and resisting the downward pressure of
the incandescent gases above the grate bars caused by the blasts of air injected into
arches, and preventing them from passing down into the ash-pits, and creating in
them an inconvenient degree of heat.
F represents the upright pipes which connect D, D, and the pipes G, G. The
pipes G, G, are also bricked into the walls A directly over and about two and a
half feet above D, D. These pipes are also six inches in internal diameter, three-.
fourths of an inch thick, as long as the kiln, with a boss and bevelled holes for
receiving the upright pipes F and packing wedges Y. There are ten of these per-
pendicular pipes F between D and G, and on each side of the kiln. The lower
ends of the respective pipes F enter the pipes D, D, and are fastened in them by
means of the bevelled wedges Y in the manner herein-before explained. The per-
pendicular pipes F are situated between the grate bars, and are bricked into the
walls A, and are two and a half feet long and three inches in internal diameter.
Corresponding sizes of packing rings are required to fasten them in the pipes D, D,
and G, G.
H represents a blast pipe connected with G in the manner herein-before explained,
extending through the front wall A, and connected by means of an elbow with a
tee, which projects into the hole J through the wall of the kiln A into the arches
S for the purpose of delivering a blast of air from the pipes G through H and J,
and through J into the arches S to intensify the combustion of the fuel in the
same, and create the proper degree of heat and pressure to force it through every
part of the charge. The diameter of the blast pipe H is recommended to be one
and a half inches in internal diameter, so as to deliver a large volume of air with a
moderate pressure.
I represents a valve for opening and closing the blast pipe H, and regulating the
quantity and force of the blast. The hole J is about two inches square, and is
directly over the top of the frame of the furnace door N ; this hole is made entirely
through the wall when it is built. The blast nozzle enters it but a short distance
from the outside of the wall, so that the end of the pipe is not liable to be melted.
K. represents a cast-iron pan placed in each of the ash-pits for the purpose of
holding water to generate steam by means of the heat deflected from the furnaces
above them to cool the grate bars, prevent the formation of clinkers upon them, to
be partially decomposed by the glowing coals and make new combustible gases, and
to give out additional volumes of heat to rise and circulate through all the inter-
stititial spaces of the superincumbent charge of the kiln. These pans extend from
the front ends of the ash-pits to the central partition wall P. Supposing the outside
wall of the kiln to be twenty-seven inches thick, these pans, reaching from the front
side of the wall A to the central partition wall P, will be fifteen feet nine inches
long, measured longitudinally across the top; they slope obliquely towards the
bottom, which is only fifteen feet long; they are thirteen and a half inches wide,
measuring from outside to outside, and nine inches deep; they rest on the ground, and
their bottoms are two feet below the grate bars C. These pans are three-fourths of
an inch thick, and are cast in sections of about five feet long, which are fastened
together by means of flanges, bolts, and nuts. The ashes which fall into them may
from time to time be hoed out with a long-handled hoe. These pans perform a very
important function in my "hot air blast kiln." The grate bars C would be speedily
melted were they not cooled by the aqueous vapor from the boiler water which
they contain.
L represents bearing bars, the opposite ends of which are bricked into the sides
of the ash-pit walls. Several of these bars are placed at convenient distances from
each other in each of the ash-pits. In this instance three are shown a little less

page_text: than four feet apart. The grate bars C rest upon them; they are thus prevented
from sagging when highly heated.
M shows three perforations through each bar in the under side thereof, and not
over one-eighth of an inch in diameter for the purpose of injecting forcible streams
of heated air from the hollow bars C into the water contained in the pans K, and
aiding to boil the same. The jets of hot air thus delivered into the ash-pits cause
an atmospheric pressure under the grate bars C, and supply the fuel upon them
with oxygen to promote its combustion.
N represents the furnace doors, which open into the firing chambers of the kiln.
These doors are made of cast iron; they may be lined with clay on the inside to
protect them from the heat; they are of the usual size and shape of doors commonly
employed in brick kilns and lime kilns; they are hung upon cast-iron frames,
which are bricked into the walls of the kiln, and secured firmly by anchors in the
usual way.
O shows the ash-pits; these extend from the front walls of the kiln to the par-
tition wall P. They are fifteen feet nine inches long, fourteen and a quarter inches
wide, and two feet high, up to the under side of the grate bars C. The side walls
of these ash-pits are carried up the same length and the same distance apart to a
height of twelve inches above the grate bars, and the tops of these walls constitute
the floor of the kiln. This construction leaves recesses twelve inches deep, and
fourteen and a quarter inches wide above the grate bars for the reception and com-
'bustion of fuel. P shows the top of the floor of the kiln. It is recommended that
the top course of this floor should be laid with tiles, which are so much larger and
stronger than bricks, that they will retain their places better, and resist the wear
and tear of the carts and teams passing over them in a more satisfactory manner.
The width of this floor between the inside of the kiln walls and the first set of
grate bars or recess containing them is ten inches. Each longitudinal section of
the floor between the grate bars is thirteen and a half feet long, and twenty-
two inches wide, measuring from the inside of the front walls of the kiln to the
central partition wall in which the pipe B is imbedded. This latter wall is three
fect wide, three feet high, and thirty feet long. The top of this wall is flush and
level with the tops of all the walls between the respective grate bars, so that P in
Figure 1 represents the floor of the kiln. It will be seen that the top of this floor
'contains recesses or gutters. These are four inches wide, and four inches deep, more
.or less, and are made in the bricks or tiles which compose the top of the floor. The
object of these recesses or gutters is, that the heat from the respective furnaces,
when the kiln is set with bricks, may circulate from the respective fires through
them, and under the bottom of the charge, so as to be distributed in a more equable
and uniform manner underneath the lower part of the same, and consequently
through the whole body of the superincumbent bricks to the end, that they may
be more perfectly and uniformly burned. These recesses or gutters are indicated by
'Q, and occupy the whole floor enclosed within the wall of the kiln.
R represents Blues or recesses made in the inside wall of the kiln, and extend
from the bottom to the top of the same. They are about four inches square, and
should be about eighteen inches apart. The object of these flues or perpendicular
'channels is to furnish passages for the heat to enter from the channels Q, and from
the furnaces, and rise up in contact with the outside walls of the kiln for the pur-
pose of more effectually heating the said walls, and the bricks, tiles, wares, lime, or
other substances, and burning them to the requisite degree of hardness. S shows
the arches of my kiln when set with bricks preparatory for being burned. These
arches are constructed in the usual manner of constructing them in all ordinary
brick kilns, and therefore they do not require a more particular description.
V represents a partition built up with raw bricks between the arches S, S, every
time the kiln is set. This partition is about eighteen inches thick, and the bricks
composing it are set three on three in the usual way. The object of this partition
is to prevent the two opposite blasts of air injected in forcible jets through the

page_text: respective blast pipes H, H, from blowing against each other and driving the heat
unequally from one side of the kiln to the other. When the charge is burned this
partition is taken down and removed with the other bricks of the kiln.
T represents a system of flues built through a brick kiln, when the raw bricks
are set in it, and extending from the crowns of the respective arches through the
entire charge, and opening to the external air. These flues may be perpendicular,
as is the case with those indicated by X, but I have shown them in this instance as
represented by the channels marked by T.
The method of constructing them is as follows:-They commence directly above
the crowns of the arches. It will be seen by an inspection of Figure that their
cross section is equal to the length and thickness of an ordinary brick; after setting
the kiln about eight courses high above the crowns of the arches with perpendicular
flues, as aforesaid constructed, at a distance from each other in a longitudinal
direction across the tops of the arches equal from centre to centre of the said flues
to the length of three ordinary bricks, I now run channels or flues in a horizontal
direction across the top of the section of the kiln thus set in the form of a checker
board. These horizontal channels or flues thus constructed at right angles with,
and cutting each other, are in depth and width equal to the thickness and width of
a common brick; then I set the bricks three on three over these horizontal flues to
a height of nine courses, more or less, leaving, as in the first instance, perpendicular
flues midway between those constructed below them. At this height I now
checker-board the top of the sections thus set with another series of horizontal
flues at right angles with each other, and communicating with the perpendicular flues
aforesaid. Then again, above these horizontal flues I carry up the courses of bricks
to the top of the kiln, constructing through them perpendicular flues of the same
size and distance apart as those already described.
The last-named perpendicular flues, it will also be seen, are equidistant from those
in the section below them. The object of these flues is to allow the water smoke a
free passage to escape into the air without condensing and wetting the upper
portions of the kiln, as is commonly the case, and also to allow the great and
increasing heat of the arches to rise more quickly and abundantly to the upper
portions of the charge, and thus prevent the over burning of the bottom of the
kiln, and secure the more uniform and thorough burning of its top and sides.
Besides these advantages, which are very decided and important in themselves,
these flues act as tall chimneys, and by reason of their natural draft create better
combustion of the fuel when the kiln is first fired, and the bricks are wet and cold
and discharge the aqueous vapor or water smoke as soon as liberated from the bricks
contiguous to the furnaces into the air without delay and condensation. The kiln
as thus set will be about forty courses high. It may be more or less.
U, U, U, represent three platting courses of hard burned bricks laid down as
snugly together as possible, and breaking joints to constitute as impervious a cover
as is practicable over the entire charge. Through this cover all the flues aforesaid
are left open, so that the water smoke may escape freely when the kiln is first fired
and until it is exhausted, and the kiln becomes sufficiently heated, and that then
the mouths of the said flues may be gradually closed up by shoving bricks or tiles
over them, and the tight and thick cover composed of the three platting courses of
hard burned bricks aforesaid, may convert the kiln into an oven, and prevent the
escape of the abundant and intense heat which rises up rapidly from the arches
through all the flues, and accumulates under the same and cause it to insinuate
itself through all the interstitial spaces between the raw bricks, and raise them to a
glowing white heat of uniform intensity, so that when gradually cooled and annealed
they shall be uniformly shrunk, homogeneous in substance, non-porous, sonorous, and
hard, like pig metal.
✗ represents a series of perpendicular flues between the arches, which extend from
the floor to to the top of the kiln. These flues are equal in their cross sections to
the length and thickness of an ordinary brick, like the flues already described, only
in this instance they are perpendicular, and extend from the floor to the top of the

page_text: kiln. They commence between the respective arches and directly over the recesses
made in the floor at points where the said flues Q cross each other. The object of
these perpendicular flues is the same as that described in relation to the flues herein-
before mentioned.
This system of constructing perpendicular flues from the bottom to the top of the
kiln permanently in the inside walls of the kiln, and every time the kiln is set
through the raw bricks for the purposes herein-before described, is a very important
and valuable part of my Invention.
Y represents a bevelled ring, cast of brass or other suitable metal, to be employed
as a packing wedge to tighten the joints of the respective pipes, herein-before
described, and shown as parts of my kiln. When employed to fasten the hollow
grate bars C into the pipes B and D, D, which pipes, in this instance, are recom-
mended to have an external diameter of about one and a half inches, this packing
ring has the same internal diameter, that is to say, one and a half inches, so that it
may be slipped on to the end of one of these bars. It is two and a half inches long,
one and five-eighths inches in external diameter at one end, and bevelled gradually
to two and a half inches in external diameter at the other end. Longitudinally
through this ring a slit is made, one-sixteenth of an inch wide, so that when the
end of the grate bar C with the ring Y slipped on to it is inserted into the bevelled
hole made in the pipes B and D, D, and the ring Y is driven home and wedged
tightly into the chamber W, it may close up this slit, and clasp the end of the pipe
tightly and secure it firmly, and make the joint air-tight. This furnishes a simple,
cheap, and ready method, without any expensive lathe work of connecting the
various pipes of my kiln. Other sizes are required for larger joints.
Having thus fully described the construction and arrangement of my hot-air blast
brick and lime kiln, which may be built of any other dimensions, either larger or
smaller, I will now explain the mode of its operation. In the first place, the kiln
is to be filled with raw bricks, set three on three in the usual manner, with flues
through the same, as herein-before shown, and covered with the platting courses
'as described. Fires are now kindled in the furnaces S, S, the engine is started, and
the blower operated by it, and connected with the pipe B, drives a forcible volume
of air into the said pipe, which passes through the respective grate bars C into the
horizontal pipes D, D, up through the perpendicular pipes F into the horizontal
pipes G, G, and into the branch pipes H. The stop-cocks I are now partially opened,
and a blast of air escapes from the ends of these pipes into and through the passages
J and into the firing chambers S, S. The blast pipes E, E, fed with air from D, D,
are now slightly opened, and a slight blast of air is injected into the ash-pits O.
Small streams of air shoot down through the orifices M of the respective grate
bars, and strike the surface of the water which nearly fills all the pans K. In a
short time the fuel on the grate bars C becomes ignited, and under the operation of
the blast enters into a very brisk combustion. As the grate bars become heated the
air passing through them under pressure is highly elevated in temperature, and the
forcible jets escaping in large volumes from the respective blast pipes H into the
firing chambers S, S, and over the burning fuel of the same, produce the most intense
combustion.
The raw bricks composing the arches and the base of the kiln first feel the heat
of the fires and begin to breathe off the aqueous vapor which they contained in the
form of water, and these vapours charged with gas, and constituting what is
commonly called water smoke, rise into the flues R, T, X, and escape from their tops
into the open air; this water smoke is expelled from the kiln by two forces acting in
conjunction. In consequence of the tight platting courses U, U, U, the flues R, T, X,
have a powerful natural draught and are like tall chimneys, and thus throw the water
smoke as soon as it is formed in quickly ascending volumes into the open air.
The forcible air blasts H, H, and E, E, and M create a pressure of air and heated
gases in the arches and flues Q in the floor of the kiln, which communicate with the
flues R, T, X, and force columns of water smoke from their mouths with great
rapidity and power into the air. The heat freely passes through all the channels Q

page_text: in the floor of the kiln from the respective furnaces, and into the perpendicular
flues X and through all the superincumbent portions of the kiln. These flues Qin
the floor of the kiln have a most excellent effect in circulating and distributing the
heat generated by the fires under the entire bottom of the charge. The fires burn
briskly without smoke, and the heat rises so rapidly and uniformly that the water
smoke will be expelled in from fifteen to twenty hours after lighting the fires.
As this begins to disappear the mouths of the flues on the top of the kiln are
gradually closed up by shoving bricks or tiles over them.
When the charge becomes red hot all the mouths of these flues are closed up as'
tightly as possible, and the kiln is converted into an oven. The crevices through
the three platting courses of hard burued bricks which are laid down on the top of
the kiln as tightly as possible, and breaking joints, now constitute the only vent
through which the products of combustion can escape. These crevices are so small
and yet so numerous and uniformly distributed through the entire top of the kiln
that the heated gases rising from the fires are held under pressure under cover of
the kiln, and sift through them in uniformly divided jets and reduced velocity.
The pressure of the heated gases in the kiln causes them to fill all the interstitial
spaces between the bricks, and supply them with an equal amount of caloric.
The powerful heat created in the arches has such abundant and ready ways of
escape through the flues Q, R, T, X, as well as through the interstitial spaces
between the bricks that it rises up into the upper portions of the charge and spreads
to the sides of the kiln so quickly and intensely that the upper and outermost
courses of bricks are burned almost as quickly and as hard as those in the arches
and base of the kiln. This is a very great improvement over the kilns in
common use.
Those kilns have no flues through them from the bottom to the top like mine,
but the bricks in them are piled closely together three on three, so that the water
smoke which rises from the base of the kiln when the fires are first started, in
struggling up through the honeycomb of the cold and wet bricks, is condensed to a
considerable extent in the top courses of the kiln, and the moisture thus deposited.
in contact with the raw bricks frequently creates a mortar on the surfaces of tho
same, and seals them together so tightly as to close up the draught and deaden the
fires. In such cases it takes a long time to dry out the top and sides of the kiln, to
open passages through it for the water smoke and gases to escape, and to produce a
clearing heat through the charge; this causes the arches and the lower part of the
kiln to get ahead of the top and sides. The consequence is that the arches and
the bricks in their neighborhood are overburned and damaged by the re-abundant
heat long before the top and sides are burned into even soft bricks. The firing of
the arches has to be continued long after they are sufficiently burned in order to
partially bake the upper and lateral courses of the bricks. The damaging con-
sequences are very serious in a commercial point of view. The color and hardness
of the superincumbent courses from the tops of the arches to the top of the kiln
gradually diminish in value, so that a great want of uniformity in the bricks
generally exists, and only those bricks which compose the heart of the kiln approxi-
mate to anything like perfect bricks.
In soft burned bricks the molecules of the clay are not softened and semi-fused
by the heat so as to mash into each other and close up the pores between them, and
cause the bricks to shrink and become a solid homogeneous non-porous body capable
of shutting out moisture and resisting the action of the elements, and maintaining
permanently their shape. Moreover the heat in such bricks is not sufficient to
oxydize the iron in the clay to the sesquioxyd, and produce a beautiful red color;
consequently such bricks possess a colour varying from pale red to a dirty yellow line.
They are porous and absorbent of water, which when frozen expands and bursts
the bricks to powder.
The value of these bricks in the market is only about one-half that of those
which are burned hard; yet it costs just as much to dig the clay, temper it, mould
it into bricks, dry them, set them in the kiln, burn them and handle. them as

page_text: it does to make hard bricks. A brick is nothing but a chunk of mud until it is
properly burned; the same is the case with tiles, drain pipes, potteryware, and all
other forms of moulded clay. From these considerations it is obvious that a kiln
which is capable of burning all the bricks in it uniformly hard and of a beautiful
and brilliant red colour is a very great and valuable improvement in its commercial
aspects. To perfect such a kiln and to remedy the defects in those now and heretofore
used from immemorial time has been the object of my studies and labors for
many consecutive years.
The devices, herein-before enumerated, comprehending my method of creating,
distributing, and confining my intense and glowing heat under pressure in every
part of the charges of my kiln, and providing for its ready transmission to the top
and sides of the same, by which means the water smoke is discharged without con-
densation as soon as it becomes volatile, and the heat created in the arches is
readily taken away and transported to the upper and lateral sections of the
same, present a combination of elements so practicable and scientific as to commend
themselves to the intelligent appreciation of those skilled in the art of brick-
burning.
My kiln is also capable of burning lime in a much better manner than has hereto-
fore been done. In the burning of lime it has been customary to mix coal with the
limestone broken into small lumps. The combustion of the fuel leaves ashes mixed
with the lime and degenerates its value. In my kiln no fuel is mixed with the
limestone, but the charge is burned with incandescent gases. The consequence is
that the lime is whiter, purer, and more valuable. To adapt my kiln to the burning.
of lime, all that it is necessary to do is to turn arches with fire bricks over the grate
bars filled with pigeon holes so as to prevent the pulverized lime from falling into
the fire. By charging the kiln with larger stones on the floor, and gradually
diminishing their size in the upper portions of the charge, and spreading small
stones over the top and then laying down on the same three platting courses of
burned brick, breaking joints, and leaving flues through them precisely as in the
cover of the kiln; when employed for burnng bricks an entire kiln of lime can be
burned successfully. No flues need be built through the body of the charge, as is
done in a brick kiln, inasmuch as the whole charge of limestone will necessarily
leave sufficient spaces for the heat to rise through it. When such a lime kiln
becomes hot the open flues through the brick cover can be gradually closed up by
shoving bricks or tiles over them and the heat held in the kiln in the same manner
as heretofore described. As it requires great heat to burn such a kiln of lime or
bricks it will be seen how well adapted the construction of my kiln is for creating
and distributing it. With my hot-air blast there is scarcely any limit to the
intensity of heat which I can create.
Another part of my Invention which may or may not be used, as circumstances
may require, relates to the admixture of ground coal with the clay of which bricks,
tiles, potteryware, or other moulded forms of earthy matter are composed, and
setting them in those parts of the kiln in which the heat is naturally insufficient to
burn them hard without additional fuel.
It has been customary for brickmakers' to mix breeze or coal dust with the clay
which composes their bricks, but only a small quantity can be thus mixed without
bursting or swelling them during the process of burning, and rendering them porous
and easily broken, inasmuch as the breeze or coal dust is so coarse and contains such
large particles as to swell in the bricks and produce so much local heat in the
different parts of each brick as to burst many of them and leave ashes in the places
occupied by the lumps of coal. I have found by many and accurate experiments
that by grinding coal to a fine flour and then very intimately and uniformly mixing
it with the clay when it is tempered that a much larger per-centage than usual may
be employed without bursting or honeycombing the said bricks. By taking coke.
which has been heated and expanded all that fire is capable of doing, and which is
a much purer fuel than breeze or coal dust, and creates more heat, and which is
very cheap, and grinding it to a fine flour and mixing it intimately and uniformly

page_text: at the rate of two hundred and fifty pounds to one thousand ordinary sized bricks,
and then setting one course of them next to the walls of the kiln, and four courses
on the top of the kiln, and then laying down on them three courses of hard burned
bricks, breaking joints as a cover, in the manner herein-before explained, the top
and sides of the kiln will be raised to such an intense heat by the combustion of
the fuel contained in these, bricks as to burn them very hard.
By preparing and setting a kiln of bricks, tiles, pipes, pottery ware, or other
moulded forms of clay in this manner, and constructing my flues as herein-before
explained, through bricks or tiles, but not through potteryware or charges of lime,
as the passages through these are sufficiently large without such flues, such kilns
may be very uniformily and successfully burned without my hot-air blast; but I do
not recommend this method to the exclusion of my hot-air blast kiln, as herein-
before described. This kiln can be relied upon every time is a certain and
sure success. It will not disappoint the expectations of any man who builds
it and operates it in the manner shown, and described by these Drawings and
Specification.
Having thus fully described the said Invention as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it distinctly
understood that although I have described and shown only one method of carrying
my improvements into practice, a great variety of shapes and sizes of kilns may be
constructed according to the principles upon which the said Invention is based, but
I claim,
First. The central pipe B, the hollow grate bars C, the pipes D, D, the upright
pipes F, the pipes G, G, and the blast pipes H, in combination with the furnaces of
a kiln, as and for the purposes shewn and described.
Second. The pipe B, hollow grate bars C, pipes D, D, and blast pipe or nozzle E,
in combination with the ash-pits o, as and for the purposes set forth.
Third. The holes J through the walls of a kiln over the fire-doors, in combination
with the blast pipes H, as and for the purposes set forth.
Fourth. The blast nozzles E, in combination with the ash-pits O of a kiln, as
shewn and described, and for the purposes set forth."
Fifth. The pans K for holding water to be evaporated, in combination with the
ash-pits O in a kiln for burning bricks, tiles, pipes, potteryware, lime, and other
substances, as shewn and described, and for the purposes set forth.
Sixth. The jet holes M in the hollow grate bars C, in combination with the
evaporating pans K, substantially as and for the purposes described.
Seventh. The packing ring Y, in combination with the pipes B, D, D, F, G, G,
and H, as and for the purposes described.
Eighth. The packing ring Y, in combination with the hollow grate bars C, as and'
for the purposes set forth.
Ninth. The packing ring Y, in combination with the chamber W, as shewn and
described, and for the purposes set forth.
Tenth. The arrangement of furnaces in a kiln for burning bricks, lime, tiles, pipes,
pottery, bones, ores, or other similar substances with jets of air discharging into
them, substantially in the manner and for the purposes described.
-
Eleventh. The heat-conducting channels Qin the floor of a kiln, as and for the
purposes described.
Twelfth. The flues R in the inside walls of a kiln, as shewn, and described, and
for the purposes set forth.
Thirteenth. The flues T constructed through the charge to be burned in a kiln,
substantially in the manner and for the purposes set forth.
Fourteenth. The flues. X constructed through the charge to be burned in a kiln,
substantially in the manner and for the purposes set forth.
Fifteenth. The cover U, U, U, in combination with the flues T of the kiln, as and
for the purposes set forth.
Sixteenth. The cover U, U, U, in combination with the flues X of the kiln, as and
for the purposes set forth.

page_text: Seventeenth. In a kiln for burning bricks, lime, tiles, pipes, bones, ores, pottery-
wares, and other wares, the cover for preventing the escape of the heat from the
said kiln, in combination with blast pipes for discharging forcible jets of air or steam
into the furnaces of the same, for the purpose of creating, distributing, and com-
pressing the heat in and through the charge being burned in the said kiln, in the
manner and for the purposes set forth:
Eighteenth. In a kiln for burning bricks, lime, tiles, pipes, bones, ores, pottery-
ware, or other wares or substances, the cover for holding the heat in the kiln in
combination with flues constructed through the charge to be burned, or in combi-
nation with openings through the said cover to discharge the water smoke into the
air when the kiln is first fired, to be gradually closed up after the said water smoke
is exhausted, in order to convert the kiln into an oven, in the manner and for the
purposes set forth.
Nineteenth. The process of grinding to flour coal, and intimately and uniformly
mixing the same in the clay or other matters to be moulded into forms to be burned,
in the proportion of two hundred and fifty pounds, more or less, to one thousand
ordinary-sized bricks, and corresponding proportions of ground coal in larger or
smaller sizes of moulded clay or other matters to be burned, and setting these mixed
and moulded bricks, tiles, pipes, or wares in those parts of the kiln where the heat
from the furnaces is insufficient to burn them properly, as at the sides and top of
the charge, for the purpose of increasing the heat in those localities, and burning
the whole product of the kiln more uniformly hard, in the manner and for the
purposes described.
Twentieth. The construction of pigeon-holed arches composed of fire-bricks over
the grate bars C of a kiln for burning lime, bones, ores, and other similar substances
which require calcination, to keep such calcined materials from falling into the fires,
in combination with blast pipes for discharging forcible blasts of air under the said
arches and thereby intensifying the combustion of the fuel and the heat of its
gaseous products and forcing them through the charge, in the manner and for the
purposes set forth.
Twenty-first. The cover U, U, U, or equivalent device, with vent holes for dis-
charging the water smoke, laid down upon a charge of limestone, bones, ores, or
other similar substances requiring calcination, which vent holes may be closed after
the charge becomes sufficiently heated to convert the kiln into an oven and retain
the rising heat in the same, save fuel, and burn the top and sides of the charge more
perfectly, in the manner and for the purposes described.
Twenty-second. The partition wall V, between the firing chambers S, S, to
prevent the two opposite blasts from blowing against each other, as shown and
described.
Twenty-third. The constructing, equipping, charging, and burning a kiln of 4
bricks, lime, tiles, bones, ores, pottery, or other wares or similar substances, in the
manner and for the purposes herein-before set forth.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Tenth day of May, in the year of our Lord One thousand
eight hundred and seventy-eight.