IMPROVEMENTS IN KILNS FOR BURNING BRICKS AND OTHER ARTICLES
Year: 1876

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 AND OTHER ARTICLES." A
communication from abroad by George Snowden Redfield, of Chicago, Illinois,
United States of America.
Sealed the 1st September 1876, and dated the 4th March 1876.
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 4th March 1876.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
"IMPROVEMENTS IN KILNS FOR BURNING BRICKS
Southampton Buildings, London.
AND OTHER ARTICLES." A communication.
This Invention relates to a kiln having a series of separate chambers so con-
structed as to be burned with either an upward or a downward draught combined
with a "gas producer" or apparatus in which carbonic oxide and other gases are
generated by the slow combustion of fuel. I also provide a gas reservoir and
conduits and valves for transmitting the evolved gas to either of the chambers of
the kiln, and for discharging the vapors and products of combustion from one
chamber either directly into the stack, or into one or more of the other chambers,
as may be required. I also provide a test float or gauge, which enables the progress
of the operation to be accurately observed.
The objects of the said Invention are to provide means for burning bricks and
other ceramic products with greater rapidity, economy, and uniformity than has
heretofore been attained, and as far as practicable to reduce the amount of labor and
attention required.
The ordinary brick kilns in use in this and other countries are temporary struc-
tures of more or less crude construction, and while involving considerable time and
expenditure of fuel in burning the bricks fail to yield a uniform product from the
unequal action of the heat upon the mass of bricks, and from the impracticability of
accurately regulating the application of the heat skilled labor and constant attention
are also indispensable. Various improvements have been made, and are the subject
of sundry Letters Patent embodying different constructions of permanent kilns, and
of these kilns known as continuous kilns are most approved by brick manufacturers,
as economy in fuel and greater uniformity of product are afforded by their use,
[Price 6d.]

page_text: although they are as a general rule costly in construction, and do not materially
reduce the amount of skilled labor required in the management of the fires.
My Invention, while embodying all the advantages of the continuous system,
provides such facilities for regulating the application of the heat to the contents of
the kiln as enables the samo to be gradually and regularly burned by ordinary
labourers, and with fuel of the most inferior quality, the duration of the operation
being also very materially reduced.
The kiln is preferably of square or rectangular section, having arched or vaulted
tops, and separated by partition walls, which meet at a central stack or chimney.
Access is had to the several compartments by hinged doors, which should be so
arranged as to be raised by chains and balance weights, and are to be lined with
fire-brick or other suitable non-conductor. The inside of the kiln should also bo
lined with fire-brick.
The burning of the bricks is effected by the combustion of gases generated in a
gas producer placed contiguous to the kiln, and connected therewith as presently
to be described. It is connected by a conduit with a gas reservoir, the object of
which is to store up and provide a regular supply of gas to the compartments placed
on opposite sides of the kiln, and connected by a conduit. From the gas reservoirs
n series of upper gas conduits and lower gas conduits furnished with proper valves
or gates extend to the several compartments of the kiln, the upper conduits opening
into the compartments near the tops thereof, and the lower conduits at or near the
bottoms of the compartments. By means of these conduits the gas may be admitted
either at top or bottom, according as a downward or upward draught is desired, but
the same end may be attained by providing a single conduit for each compartment.
The partition walls separating the several compartments of the kiln are each
provided with a series of upper draught passages near their tops, and a similar series
of lower draught passages contiguous to the floor of the kiln. These passages are
governed by dampers or doors operated by suitable rods from the exterior of the
kiln. Each compartment is likewise provided with an upper stack damper and a
lower stack damper, these dampers governing openings in the central stack for the
escape of the vapours and products of combustion. A suitable number of "peep-
holes" must be provided in each compartment, as well as proper openings for the
admission of air to support combustion, which air may, when convenient to do so,
be previously heated.
In order to indicate with accuracy the settling or shrinkage of the brick I provide
test floats or gauges, which may be of iron covered with fire-clay or other non-
conductor, and which are united to vertical rods passing through openings in the
tops of the compartments. The float rests upon the top of the mass of brick in the
compartments, and as the same settles in the progress of the operation they fall
correspondingly, the rods indicating accurately the exact amount of settling. Marks
may be made upon the rods for this purpose, or the rods may carry indexes adjacent
to stationary pieces marked in inches or otherwise designated to show the extent of
movement of the test floats.
From the facilities which my Invention affords for applying and regulating the
heat, and changing at pleasure its direction through the mass of material to be
burned, the latter is exposed equably to its action, and the loss from vitrification
and excessive burning is reduced to a minimum, uniformity of product is secured,
and the duration of the operation greatly reduced. By the use of my kiln a com-
partment may be burned in thirty hours, as against from one hundred and eight to
one hundred and forty-four hours, which is required in the Scotch kilns generally
used. Labour is also economized, and facilities afforded for conducting the operation
according to fixed rules, instead of depending upon the skill of expert workmen, as
has heretofore been the case.

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 1st
September 1876.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN KILNS FOR BURNING BRICKS
AND OTHER ARTICLES.' A communication from abroad by George Snowden Redfield,
of Chicago, Illinois, United States of America.
My Invention consists in combining a kiln having a series of separate chambers
so constructed as to be burned with either an upward or a downward draught, with
a "gas producer" or apparatus in which carbonic oxide and other gases are generated
by the slow combustion of fuel, a gas reservoir and conduits and valves for trans-
mitting the evolved gas to either of the chambers of the kiln, and discharging the
vapors and products of combustion from one chamber either directly into the stack
or into one or more of the other chambers, as may be required; also in providing a
test float or gauge, which enables the progress of the operation to be accurately
observed.
The object of my Invention is to provide means for burning bricks and other
ceramic products with greater rapidity, economy, and uniformity than has heretofore
been attained, and as far as practicable to reduce the amount of labor and attention
required.
The ordinary brick kilns in use in this and other countries are temporary struc-
tures of more or less crude construction, and, while involving considerable time and
expenditure of fuel in burning the bricks, fail to yield a uniform product from the
unequal action of the heat upon the mass of bricks, and from the impracticability of
accurately regulating the application of the heat. Skilled labor and constant atten-
tion are also indispensable. Various improvements have been inado, and are the
subject of sundry Letters Patent, embodying different constructions of permanent
kilns, and of these those known as continuous kilns are most approved by brick
manufacturers, as economy in fuel and greater uniformity of product are afforded by
their use, although they are as a general rule costly in construction and do not
materially reduce the amount of skilled labor required in the management of
the fires.
My Invention, while embodying all the advantages of the continuous system
provides such facilities for regulating the application of the heat to the contents of
the kiln as enables the same to be gradually and regularly burned by ordinary
laborers, and with fuel of the most inferior quality, the duration of the operation
being also very materially reduced.
Having explained the nature of my Invention I will proceed with reference to
the accompanying Drawing to describe the manner in which the same is to be
performed.
Figure 1 is a horizontal section at the line x, x, of Figure 2 of a kiln for burning
bricks or other ceramic products embodying my improvements; and Figure 2, a
vertical section of the same at the line y, y, of Figure 1.
The kiln A is preferably of square or rectangular section, and in this instance is
shown as consisting of four chambers 1, 2, 3, 4, having arched or vaulted tops, and
separated by partition walls which meet at a central stack or chimney C. Access is
had to the several compartments by hinged doors a, which should be so arranged as
to be raised by chains and balance weights, and are to be lined with fire-brick or
other suitable non-conductor. The inside of the kiln should also be lined with
fire-brick.
The burning of the brick is effected by the combustion of gases generated in a
gas producer B placed contiguous to the kiln, and connected therewith as presently
to be described. The gas producer, which is in general terins a furnace wherein
fuel undergoes slow combustion, may be constructed upon any approved plan, and
need not be here specifically described, as it, per se, forms no part of my Invention

page_text: It is connected by conduits b with a gas reservoir D, the object of which is to store
up and provide a regular supply of gas to the compartments. The Drawing shows
two gas reservoirs D, D¹, placed on opposite sides of the kiln, and connected by a
conduit b¹. From the gas reservoirs D, D¹, a series of upper gas conduits d and
lower gas conduits d¹ furnished with proper valves or gates extend to the several
compartments of the kiln, the upper conduits opening into the compartments near
the tops thereof, and the lower conduits at or near the bottoms of the compartments.
By means of these conduits the gas may be admitted either at top or bottom,
according as a downward or upward draught is desired, but the same end may be
attained by providing a single conduit for each compartment, having openings at
top and bottom, governed by valves, or a central gas conduit may be substituted for
the stack shown in the Drawings, in which case separate chimneys would be required
for the several compartments.
The partition walls separating the several compartments of the kiln are each
provided with a series of upper draft passages a¹ near their tops, and a similar series
of lower draught passages a² contiguous to the floor of the kiln. These passages
are governed by dampers or doors operated by suitable rods from the exterior of the
kiln. Each compartment is likewise provided with an upper stack damper c, and a
lower stack damper c¹, these dampers governing openings in the central stack for
the escape of the vapors and products of combustion. A suitable number of " peep
holes" are to be provided in each compartment, as well as proper openings for the
admission of air to support combustion, which air may when convenient to do so be
previously heated.
In the progress of the operation of burning bricks the mass of bricks gradually
shrinks and settles in the kiln, and the period and extent of such settling enable
the burner to determine when to slacken or extinguish his fires. There has hitherto
been no means of observing with any degree of accuracy the settling of the brick,
and the skill and judgment of the operator must be relied on entirely in determining
the proper time to discontinue the application of heat. In order to indicate with
accuracy the settling or shrinkage of the brick I provide test floats or guages E,
which may be of iron covered with fire-clay or other non-conductor, and which are
united to vertical rods E¹ passing through openings in the tops of the compartments.
The floats rests upon the top of the mass of brick in the compartments, and as the
same settles in the progress of the operation they fall correspondingly, the rods E¹
indicating accurately the exact amount of settling. Marks may be made
upon the
rods for this purpose, or the rods may carry indices adjacent to stationary pieces e
marked in inches or otherwise designated to show the extent of movement of test
floats.
The operation of the kiln is as follows:-The bricks being properly set or stacked
in the different compartments gas is admitted from the upper conduits d to com-
partment 1, the doors of the lower draught passages d² in the partition wall
between compartments 1 and 2 and the upper stack damper C of compartment 2
having been first opened. A moderate supply of gas is first admitted and ignited
to expel the "water smoke" or evolve the vapor from the bricks; this moderate
combustion is continued in practice for a period of about ten hours. A stronger
heat is then to be applied (for a period of about twenty hours in practice), the down
draught being continued, and the products of combustion continuing to pass into
compartment 2, after which the gas is shut off from the upper conduits and admitted
through the lower, the doors of the upper draught passages in the partition between
compartments 1 and 2 are opened and the lower ones closed, and the upper stack
damper of compartment 2 is closed and the lower opened. The operation is con-
tinued with the upward draught for a period of about ten hours, the length of time
being dependent upon the nature of the materials to be burned, and being regulated
by observation of the test floats, after which the gas is shut off from compartment 1,
which is gradually allowed to cool, while the operation may be continued in the
remaining compartments consecutively in a similar manner.
It will be observed that the waste heat from one compartment dries and heats up

page_text: the bricks in the adjacent compartment, so that while the bricks in one compart-
ment are being cooled those in the next are being burned; those in the succeeding
one dried, and those in the last being set, the operation of the different compartments
of the kiln thus being consecutive and continuous.
From the facilities which my Invention affords for applying and regulating the
heat, and changing at pleasure its direction through the mass of material to bo
burned, the latter is exposed equably to its action, and the loss from vitrification
and excessive burning is reduced to a minimum, uniformity of product is secured,
and the duration of the operation greatly reduced. By the use of my kiln a com-
partment may be burned in thirty hours as against from one hundred and eight to
one hundred and forty-four hours, which is required in the Scotch kilns generally
used. Labor is also economized, and facilities afforded for conducting the operation
according to fixed rules, instead of depending upon the skill of expert workmen, as
has heretofore been the case.
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 understood
that I am aware that gas burning kilns have been heretofore known, and do not
therefore broadly claim such kilns, neither do I claim by itself a kiln divided into
separate chambers or compartments, but I claim,-
First. The combination of a gas producer, a kiln having a series of separate
compartments adapted for continuous operation, and conduits and valves to provide
a supply of gas to the compartments with either an upward or a downward draught,
as above set forth.
Second. The combination of a gas producer, gas conduits, and valves for upward
or downward draught, and kiln compartments having upper and lower draught
passages, and upper and lower stack dampers, as above set forth.
Third. The combination of a gas producer, a gas reservoir, gas conduits, and
valves, and a compartment kiln, as above set forth.
Fourth. The combination with a brick kiln of a test float or gauge, as above set
forth.
In witness whereof, I, the said William Robert Lake, have hereunto set my hand
and seal, this First day of September, in the year of our Lord One thousand
WM. ROBT. LAKE (L.S.)