IMPROVEMENTS IN LIME AND OTHER KILNS
Year: 1878

page_text: LETTERS PATENT to Carl Theodor Burchardt, of Berlin, in the Kingdom of
Prussia and Empire of Germany, Engineer and Patent Agent, for the Inven-
tion of "IMPROVEMENTS IN LIME AND OTHER KILNS." A communication
from Paul Berndt, of Fuerstenberg */ Merchant, and Johann Baldermann,
of Finkenheerd, Glass Maker, in the Kingdom of Prussia and Empire of
Germany.
•
Sealed the 7th February 1879, and dated the 12th August 1878.
PROVISIONAL SPECIFICATION left by the said Carl Theodor Burchardt at
the Office of the Commissioners of Patents on the 12th August 1878.
CARL THEODOR BURCHARDT, of Berlin, in the Kingdom of Prussia and Empire
of Germany, Engineer and Patent Agent. "IMPROVEMENTS IN LIME AND OTHER
KILNS." A communication from Paul Berndt, of Fuerstenberg /。, Merchant,
and Johann Baldermann, of Finkenheerd, Glass Maker, in the Kingdom of Prussia
and Empire of Germany.
The Invention relates to kilns for lime, plaster of Paris, brick, glass, and other
substances, and the object is to run them continuously, not to bring the fuel material
in contact with the substances to be heated, but to generate gas from the former,
which by means of particularly constructed regenerators is heated, and in this
heated state mixed with air, which is heated also, to ignite this mixture, and to
use the flames produced in such way for heating the substances inside the kiln.
The object is also to utilize the fuel material to its greatest advantage, to obtain
the condensable products of the distilled fuel materials, to burn up all carboniferous
parts of the lime, plaster of Paris, or other material, and to avoid the smoking of
such kilns, which is so annoying, and in some instances poisonous to the neighbour-
hood.
The Invention consists,―
1st. In distilling in a separate furnace the fuel material itself by the heat of that
nort of the mot

page_text: 2nd. In carrying the products of this distillation a certain distance through a
condensing channel or chamber where the tar, peat, and other condensable parts
are separated from the gas.
3rd. In introducing this gas after. being heated in a very hot chamber the regene-
rator into the combustion chamber of the kiln through small openings, on issuing
from which it is mixed with hot air issuing from a similar regenerator. In the
kiln the gas burns not only the air, but all the oxygen and carbon and other
foreign matter of the lime, plaster of Paris, or other material, and heats these
substances.
4th. In carrying the hot gaseous products of the combustion into a second set of
regenerators opposite the above-mentioned, to which such gaseous products give a
very high temperature, and from whence they pass through the chimney into the
open air without generating any smoke.
Each set of regenerators consists, as shown above, in one regenerator for the gas
and one for the air, and the gas and air meet only in leaving the apertures of the
openings leading into the hearth of the kiln. By this arrangement a premature
ignition is avoided.
The completely burnt substances are continuously, or at least at very short
intervals, drawn from the bottom of the kiln, while fresh material is fed on its top,
which is provided with an air lock to prevent the gases of combustion from leaving
the kiln through the top thereof instead of passing through the second set of rege-
nerators and the chimney.
After having run the kiln about half an hour in this way the course of the gases
and the air is reversed by turning a reversing valve on the end of the condenser,
aud also one below the air valve, so that they first enter the second set of regene-
rators, pass on across to the first set of regenerators, and to the chimney. Half an
hour afterwards the gases are caused to take their first course, and so on.
regenerators are heated by this means alternately, and raise also in their turn
alternately the temperature of the gas and the air before their entering the com-
bustion chamber of the kiln.
The
It must be here remarked that the details and the arrangement of the parts in
themselves or to each other may be altered as circumstances, materials to be treated,
or other reasons may require.

page_text: KILNS."
попу, шпусы
A communication from Paul Berndt, of Fuerstenberg *, Merchant, and
Johann Baldermann, of Finkenheerd, Glass Maker, in the Kingdom of Prussia and
Empire of Germany.
Figure 1 is a vertical longitudinal section of the flues and the furnace of a lime
kiln.
Figure 2 is a plan view and horizontal section on the line L, M, J, K, of
Figure 1.
Figures 3 and 4 are vertical sections of the reversing valves.
Figure 5 is a plan of the furnace room.
Figure 6 is a vertical section of the kiln on the line E, F, of Figure 7.
Figure 7 is a horizontal section of the kiln on the line A, B, and C, D, of
Figure 6.
Figure 8 is a part of a vertical section on the line G, H, of Figure 7.
Figure 9 is a plan view of the air valve.
The Invention relates to kilns for lime, plaster of Paris, brick, glass, and other
substances, and the object is to run them continuously, not to bring the fuel material
in contact with the substances to be heated, but to generate gas from the former,
which by means of particularly constructed regenerators is heated, and in this
heated state mixed with air, which is heated also, to ignite this mixture, and to
use the flames produced in such way for heating the substances inside the kiln.
The object is also to utilize the fuel material to its greatest advantage, to obtain
the condensable products of the distilled fuel materials, to burn up all carboniferous
parts of the lime, plaster of Paris, or other material, and to avoid the smoking of
such kilns, which is so annoying, and in some instances poisonous to the neighbour-
hood.
The Invention consists,―
First. In distilling in a separate furnace the fuel material itself by the heat of
that part of the material which is burning on the grate.
Second. In carrying the products of this distillation a certain distance through a
condensing channel or chamber where the tar, peat, and other condensable parts are
separated from the gas.
Third. In introducing this gas after being heated in a very hot chamber the
regenerator into the combustion chamber of the kiln through small openings, on
issuing from which it is mixed with hot air issuing from a similar regenerator. In
the kiln the gas burns not only the air, but all the oxygen and carbon and other
foreign matter of the lime, plaster of Paris, or other material, and heats these
substances.
Fourth. In carrying the hot gaseous products of the combustion into a second
set of regenerators opposite the above-mentioned, to which such gaseous products
give a very high temperature, and from whence they pass through the chimney into
the open air without generating any smoke.
Each set of regenerators consists, as shewn above, in one generator for the gas
and one for the air, and the gas and air meet only in leaving the apertures of the
openings leading into the hearth of the kiln. By this arrangement a premature
ignition is avoided.
The completely burnt substances are continuously, or at least at very short
intervals, drawn from the bottom of the kiln, while fresh material is fed on its top,
which is provided with an air lock to prevent the gases of combustion from leaving

page_text: the kiln through the top thereof instead of passing through the second set of rege-
nerators and the chimney.
After having run the kiln about half an hour in this way the course of the gases
and the air is reversed by turning a reversing valve on the end of the condenser,
and also one below the air valve, so that they first enter the second set of regene-
rators, pass on across to the first set of regenerators, and to the chimney. Half an
hour afterwards the gases are caused to take their first course, and so on.
regenerators are heated by this means alternately, and raise also in their turn
alternately the temperature of the gas and the air before their entering the com-
bustion chamber of the kiln.
The
In the Drawing is represented as an example a lime kiln constructed according
to the aforesaid principles and arrangements, but it must be here remarked that
the details and the arrangement of the parts in themselves or to each other may
be altered as circumstances, materials to be treated, such as plaster of Paris, brick,
glass, and other substances, or other reasons may require.
A is the furnace where the fuel material is by two funnels placed upon two grates,
arranged as shown, in such quantity that the fuel burning upon them heats the
rest of it and distils it without producing flame. The products of the distillation
enter the condensing chamber B, which is fitted with safety plates or valves to
allow, in case of explosion, an escape of the gas. The bottom of the channel B is
a little sloping towards the centre, so that the tar and the products may be collected
at this point into a separate chamber U.
After having passed the damper W arranged to regulate the quantity of the
passing gas the above-mentioned products are directed by the reversing valve a to
go through the flue G into the regenerator F, and from there through the openings
b, b, into the hearth of the kiln C; at the same time atmospheric air passes through
the valve X into the channel H, and passes, directed by the reversing valve c,
through the flue K, and goes into the regenerator L, and from there through the
openings d, d, also into the hearth of the kiln C.
As the walls of the regenerators have a very high temperature both gas and air
are heated also, and unite readily in flame at the moment they have left the
apertures of the holes b, b, and d, d, which are in directions crossing each other for
the purpose of better mixing the gas and air. The contents of the kiln, the lime-
stones, are now heated to the desired degree, and the burnt lime is drawn off by the
working holes M, M. In the meantime the limestones in the upper part of the
kiln gradually sinking as the lime is drawn out are heated, and the space at the top
representing that from which the lime has been drawn is filled with cold stones.
For the latter purpose a cover S is placed at the top of the kiln, which is made air-
tight by means of sand or water, and a little lower in the throat of the kiln a
counterbalanced cone T, both together forming an air lock, thereby enabling a new
charge to be supplied without leaving the kiln open for a moment.
As the exit of the products of combustion is shut off at the top they have to
take their way into the chimney D, and the open air, by means of the openings b, b,
and d, d, through the regenerators N, O, and flues P, Q, and R.
The regenerators N, O, constructed exactly like those marked F, L, are heated
by the escaping flames, and the regenerators F, L, are cooled down by the com-
paratively cold coal gases and the atmospheric air. The reversing valves a and c
are reversed after about half an hour's work to the position shown in Figures 3
and 4 by dotted lines, so that the gas and air are caused to enter at first the rege-
nerators N, O, and the hot products of combustion; and the flames take their exit
through the regenerators F, L, which are now reheated to a high temperature.
After about half an hour the valves a and c are turned into their, first position,
thereby reversing the draught again, and so on.
Having thus described the nature of the said Invention, and the mode in which
the same is carried into effect, I would remark that I am aware that kilns have t
been before run by gas; 'I do not therefore claim the employment generally of gas

page_text: for such purpose, nor do I claim the use of a regenerator or heating chamber in
general for the gas, but what I claim is,-
First. Constructing lime and other kilns so as to cause the current of the gas and
air, and afterwards of the flames or products of combustion, to reverse their direction
alternately when used on lime, brick, or other kilns run by gas, for the purpose
explained and substantially as shown.
Second. In combination with lime and other kilns run by gas two or more sets
of regenerators, which are worked alternately, substantially as described, and for the
purpose set forth.
Third. The employment of reversing valves a and c or their equivalents in com-
bination with two or more regenerators in gas kilns for lime, plaster of Paris, and
other substances when used for the purpose explained and substantially as shown.
Fourth. A gas kiln for lime, plaster of Paris, brick, and other substances, closed
on top, substantially as shown, in combination with a chimney, a gas generator, two
or more alternately working sets of regenerators, and the necessary flues with
reversing valves, substantially as shown and described, and for the purpose set
forth.
Fifth. The arrangement and disposition of a lime kiln C with alternately working
regenerators F, L, and N, O, in combination with gas generator A, condenser B,
reversing valves a and c, damper W, air valve X, air lock S and T, and chimney D,
substantially as shown and described, and for the purpose set forth.
Sixth. The employment with gas kilns of a damper W and the air valve X, or
their equivalents, the latter being constructed and worked substantially as shown,
and described for the purpose explained.
Seventh. The safety plates or valves Y, Y, or their equivalents on the condenser
of above-described kilns, for the purpose explained.
In witness whereof, I, the said Carl Theodor Burchardt, have hereunto set
my hand and seal, this Second day of February, in the year of our Lord
One thousand eight hundred and seventy-nine.
CARL THEODOR BURCHARDT. (L.S.)