Iм- PROVEMENTS IN FURNACES. AND IN THE APPLICATION OF HEATED CURRENTS
Year: 1857

page_text: LETTERS PATENT to Charles William Siemens, of John Street, Adelphi,
in the County of Middlesex, Civil Engineer, for the Invention of "Iм-
PROVEMENTS IN FURNACES. AND IN THE APPLICATION OF HEATED CURRENTS."
Sealed the 11th August 1857, and dated the 11th May 1857.
PROVISIONAL SPECIFICATION left by the said Charles William Siemens
at the Office of the Commissioners of Patents, with his Petition, on
the 11th May 1857.
I, CHARLES WILLIAM SIEMENS, of John Street, Adelphi, in the County of
Middlesex, Civil Engineer, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN FURNACES, AND IN THE APPLICATION OF HEATED CURRENTS,"
to be as follows:-
In puddling iron, and in melting glass, and in many other operations, it is
desirable to avoid the unnecessary contact of the flame of the fire with the iron
or other material under treatment; it is also advantageous in some cases to.
act upon the material by heated currents of air, or gases or vapours; thus a
heated oxidizing current may be applied in puddling iron to remove the
carbon, and a heated reducing current to reduce any oxide of iron which may
have been formed. I effect these objects in the following manner by means.
of regenerators:-The regenerator is a vessel or chamber filled with fire bricks
or fragments of refractory minerals or substances through which the flame or
products of combustion of a fire are conducted. The fire bricks or other
substances become thus heated to a very high temperature at the part of the
A

page_text: vessel nearest to the fire, and the temperature gradually decreases to the othe
end, which may be comparatively cool. If a current of air be now transmitted
in a contrary direction through the regenerator, the air will be gradually heated
as it passes through, and will issue at a very high temperature at the opposite
end. I construct a puddling furnace with a hearth at one end, on which a
fire is made. The flame passes through a chamber, on the bed of which the
iron is laid, and the flame or products of combustion then pass through the
regenerator. When the iron is melted the current of air is reversed, and
intensely heated air is thus driven over the melted iron; the fire is damped
or diminished, and its products of combustion and the heated air are conducted
through another regenerator, which absorbs the heat from them; the iron is
thus puddled in an atmosphere of highly heated air. The puddler may by
altering a valve or valves introduce an oxidizing or reducing current at
pleasure. When the charge is withdrawn another charge is introduced and
the current reversed; air then passes through the second regenerator and
through the fire, and the intensely heated air and products of combustion pass
over the fresh charge, which is soon melted, while the superfluous heat is being
absorbed by the. first regenerator. In this case the iron is exposed for a
portion only of the time to the direct action of the flame. The furnace may,
however, be so arranged that the iron is not at all exposed to the flame, by
conducting the flame from the fire alternately into two or more regenerators,
which alternately serve for heating the current of air which is conducted over
the iron. These furnaces may also be so arranged that one fire may serve for
two puddling furnaces. When required, various gases, or steam, or vapours
inay be passed though the regenerator in lieu of or mixed with air or with
each other. These furnaces and modes of applying heated currents are appli-
cable to puddling furnaces, glass furnaces, furnaces for cupelling and oxidizing
lead and other metals, drying stoves, and a great variety of chemical and other
operations, and with great economy of fuel. When it is required to reverse
or move the valves or dampers at intervals it may be conveniently effected by
self-acting apparatus. Thus, a stream of water is allowed to flow alternately
into two buckets or vessels, which tumble or move over at intervals and give
motion to the valves. The length of the intervals is varied by regulating the
stream of water by a cock or valve, adjusted when required by the aid of a
small water meter.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles William Siemens in the Great Seal Patent Office
on the 11th November 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
WILLIAM SIEMENS, of John Street, Adelphi, in the County of Middlesex, Civil
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eleventh day of May, in the year of our Lord One
thousand eight hundred and fifty-seven, in the twentieth year of Her reign,.
did, for Herself, Her heirs and successors, give and grant unto me, the said
Charles William Siemens, Her special licence that I, the said Charles William
Siemens, my executors, administrators, and assigns, or such others as I, the.
said Charles William Siemens, my executors, administrators, and assigns,.
should at any time agree with, and no others, from time to time and.
at all times thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention.
for "IMPROVEMENTS IN FURNACES, AND IN THE APPLICATION OF HEATED CURRENTS,"
upon the condition (amongst others) that I, the said Charles William Siemens,
my executors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, 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 Charles William Siemens, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement thereof, reference being had to the accompanying Drawings,
and to the figures and letters marked thereon, that is to say :-
In many important manufacturing operations, currents of heated air, or.
gasses of various temperatures and possessing different chemical properties, are
required. Currents of pure air moderately heated are employed to dry or
desiccate vegetable substances, articles of food, textile fabrics, timber, pottery.
wares, and other substances, or they may be advantageously employed to
evaporate brine and other solutions by being passed over their surface..
Currents of highly heated atmospheric air are applicable for roasting ores,.
oxidizing, smelting, and refining metals, and for heating stoves containing
Q

page_text: pottery ware or glass in crucibles, or other substances which are apt to be
deteriorated by particles of smoke or dust, which are unavoidable when the
said stoves or furnaces are heated by the direct application of fire to them.
In the operations of puddling and refining iron, the metal is subjected in a
fluid state to heated currents, which are required to vary in their chemical
properties, an oxygenous current being required when the iron is to part with
its carbon, and a neutral or even a reducing current of intense degree of heat
when the operation of balling is going on. In heating steam boilers and other
vessels, the chemical or mechanical properties of the heated currents applied
are of less importance, but it is important that the entire exposed surface
be acted upon nearly uniformly, in order to produce a high evaporative or
beating effect, without subjecting any one part of the vessel to an excessive or
dangerous degree of heat. This desideratumi could not be realized by the simple
application of a fire without allowing the products of combustion to reach the
chimney in a highly heated condition, entailing great waste of fuel.
My Invention consists in certain mechanical arrangements for producing
heated currents possessing the desired properties according to the intended
application, by means of chambers containing refractory materials called
regenerators, and which were described in the Specification of a Patent
granted to Frederic Siemens, and dated the Second day of December, Oné
thousand eight hundred and fifty-six.
But in order that my Invention may be most fully understood and readily
carried into effect, I will now proceed to describe the best modes I am
acquainted with of performing the same.
same.
Figure 1, Sheet I., of the accompanying Drawings, is a sectional plan of one
of my improved furnaces for furnishing a continuous supply of heated air;
Figure 2 is a longitudinal section; and Figure 3 is a transverse section of the
The same letters refer to similar parts in each Figure. F is the fire-
place, consisting of an inclined hearth, with a channel or ditch a at the lower
part, into which the ashes and clinkers fall, and from which they are removed
from time to time; b, b, b, are mouths or hoppers, through which the coal or
other fuel is introduced. The two ends of the fire place F communicate with
the two regenerators R and R¹, and the other ends of the regenerators com-
municate with the side openings of the four-way valve V. The lower opening
of this valve communicates with the inlet passage I, through which cold air
enters from the atmosphere. The upper opening of the valve communicates
with the chimney or stack S. Figure 4 is a separate sectional view of the
valve V and its case V. The valve V is moveable on an axis, so as to be
capable of being moved into the position shewn by the dotted lines. When

page_text: it is in the position shewn in the section the regenerator R is in communica-
tion with the inlet I, while the regenerator R¹ is in communication with the
chimney; but when the valve V is moved into the position shewn by the
dotted lines the regenerator R is in communication with the chimney, while
R is in communication with the inlet I. Between the two regenerators is.a
chamber or passage O, which serves as the outlet for the heated air. D, D¹,
are two dampers or slides, by opening and closing which either regenerator
may be placed in communication with the outlet O. These dampers are
moved horizontally or vertically by means of rods d, d¹, or otherwise. The
dampers D, D', and their rods d, d', work in cases or passages x, x¹, which
are connected by a small passage to the inlet I. A little cold air is thus
allowed to flow through the passages x, x¹, and the rods d, d', are thus .pre-
vented from becoming overheated. The regenerators are chambers built of
fire brick or other refractory materials, and containing open built walls of fire
brick or other refractory materials so disposed as to admit of the passage of
the air and products of combustion among them. The openings in each wall
are placed opposite to the solid parts of the next wall, so as to form tortuous
passages for the air.
A fire being lighted in the furnace, the air is allowed to pass through
the regenerator R and over the fire, and then through the regenerator R² to
the chimney S. The regenerator R¹ is thus heated by the products of com-
bustion, and becomes very hot at the end nearest to the fire, and gradually
cooler at the other end, until the products of combustion pass into the chimney
nearly or comparatively cold. The valve V is then reversed, and the cold air
enters the cool end of the regenerator R', and becomes gradually heated in its
passage, until it enters the fire place in a highly heated state. It receives
a fresh accession of heat from the fire and then passes out through the
regenerator R, leaving its heat in that regenerator and passing up the chimney
in a comparatively cool state. The valve V being again reversed, the cold air
enters the regenerator R, and arrives in a highly heated state at the hot end of
that regenerator. The damper D being now opened, and the draught being
properly regulated, a portion of the hot air passes away through the outlet O,
while another portion passes through the fire, as before; when the valve V
is again changed, the damper D is closed and D¹ is opened. The air which is
heated by the regenerator R' then divides. into two portions, one of which
passes through the fire and the other through the outlet Q. A continuous
current of highly heated air is thus delivered to the outlet O. This air is con-
ducted to the place where it is required, and it may be diluted
admixture

page_text: with cold air if too hot for the required purpose. Thus it may be conveyed
into a chamber or drying stove A, or over the surface of brine or other liquid
to be evaporated, as at B in Figure 3; or it may be conducted into a furnace
or chamber for calcining or roasting ores, or for cupelling or for oxidizing lead
or tin, or into an oven for baking bread, or applied to a variety of other
purposes. When the ascensional force of the heated air is not of itself suffi
cient to produce the required current, the chambers into which it is conducted
may be connected to the chimney S, or to separate chimneys, with suitable
dampers or valves by which the draught is to be properly regulated. A damper
is also placed in the chimney S to regulate the draught through the fire. By
adjusting the dampers so as to direct more or less of the current into the
outlet O, the apparatus may be made to furnish a large quantity of moderately
heated air, or a smaller quantity of very highly heated air. E is an aperture for
admitting cold air to dilute the hot air when required. Brine and other
solutions may thus be evaporated with great rapidity without the introduction
of smoke from the fire, which occurs when they are directly heated by the
products of combustion, and also without producing incrustation and burning
the pans, which occurs when they are strongly heated from below. By passing
the current of air over a sufficient surface of brine or similar solution the air
becomes cooled, and nearly the whole of its heat is effectively applied in.
evaporating the solution. When, however, the air is employed for operations
which require it to leave the apparatus at a high temperature, its remaining
heat may be economized by conveying it through other regenerators which are
then employed to assist in warming fresh air; or, if the chemical nature of the
air is not injuriously altered by the abstraction of its oxygen, or by saturating
it with moisture, or otherwise, it may be conducted or driven directly to the
furnace F, or into some part of the regenerators R, R'; or the arrangement
shown in Figures 5, 6, 7, and 8 may be adopted.
Figure 5 is a longitudinal section of a furnace adapted for heating crucibles
or glass pots either by the products of combustion or by a current of highly
heated air. Figure 6 is a horizontal section or plan. The upper half of this
Figure is a section through the line 1, 2, in Figure 5. The lower half of the
Figure is a section through the line 3, 4, in Figure 5, with a portion of
the brickwork removed to show the fire bars. Figure 7 is a transverse section
through the line 5, 6, in Figure 5. Figure 8 is a section through the line 7, 8,
in Figure 5. F, F, are two fire places, which are supplied with fuel at b, b.
The flues from these fires ascend and meet at c in a chamber C, the top
of which is perforated with a number of holes communicating with another

page_text: chamber G. This chamber G has an outlet on each side, furnished with
dampers or slides D, D¹, and communicating with two regenerators R, R'.
The chamber G has also two inlet passages g, communicating with the chamber
A, containing the crucibles or pots a, a, a. o is an opening in the end of the
chamber or furnace A for introducing and removing the pots, and which is
closed by brickwork or masonry when the furnace is in operation. H is a
chamber, which communicates by passages h, h', with the regenerators R, R¹,
and which extends along the centre of the chamber A, with which it com-
municates by apertures i, i; or the top of this chamber may be entirely open
to the chamber A. The further or front end of the chamber H is provided with
a door at L, or may be closed by brickwork when required. The regenerators
R, R', communicate with a chimney S and an inlet for air I by means of
a four-way valve V, like that herein-before described.
The dampers D and D¹ are formed of slabs of fire clay or stone, and are
supported and raised and lowered by means of stirrup-shaped iron bars d, d¹,
entering a groove in the edge of the slab. These bars are protected from the
direct action of the heat by the recesses in which they work. When, however,
the heat is very intense, these bars may be replaced by tubes in which water is
made to circulate; or the dampers may consist of an iron frame filled with
fire bricks, and the frame may be made hollow and traversed by a current
of water to prevent it from becoming injuriously heated. The bars or
tubes d, d¹, are jointed to links e, e, connected to a beam J and to two
levers K, K', forming parallel motions. The beam J turns on a pin or
fulcrum in its centre, and the lever K turns upon a pin at k. The lever K' is
mounted on a shaft or spindle k³, which extends to the farther end of the
apparatus, and carries a lever k³, which is connected by a rod l to a lever m on
the axis of the valve V. The supports or bearings of the shaft and beam and
levers are omitted in the Drawing. By moving the beam J the damper D may
be raised and D' lowered, or vice versa, and the valve V is also moved at the
same time.
To put this furnace in operation, the door L is opened and a quantity
of burning fuel is thrown into the chamber H. The products of combustion
pass into the chamberA,. and thence through the passages g into the chamber
G, and thence descend into and pass through the regenerator R¹ and up the
3 chimney S. When the regenerator R' has become hot the beam J is moved,
so as to reverse the valve V and to raise the damper D¹ and lower D. The
door L is then closed, or it may have been closed as soon as the fire was
lighted. The air now enters at I, and passes through the regenerator R', and

page_text: becomes heated, and it then passes through the passage h¹into the chamber H
and greatly increases the action of the fire. The highly heated products
of combustion pass into the chamber A and heat the pots a, a, and then pass
through the passages g and chamber G, and through the regenerator R to the
chimney S. In this manner, by reversing the valves and dampers, by moving
the beam J at regular intervals, the fire in the chamber H is kept in vivid
combustion, and nearly all the heat produced is concentrated in the chamber
A containing the pots a, a. By proceeding in this manner the chamber A is
heated by the products of combustion; but by merely reversing the motion of
the valve V with regard to the dampers D, D', the chamber A may be heated
entirely by the hot air. For this purpose the spindle of the valve V carries
another lever, placed opposite to the lever m, and the rod is shifted, so
as to connect it with this second lever. The cold air then enters at I, and
passes through one regenerator R¹, and then through the chamber G and
passages 9 into the chamber or furnace A, and thence through or over the fire
in the chamber H, and through the passage h into the regenerator R, and up
the chimney S. By reversing the valve and dampers by moving the beam J;
the air passes from I through the regenerator R, chamber G, and passages g
into the furnace A, and thence through the chamber H, passage h³, and
regenerator R¹ to the chimney S. The furnace A is thus only heated by the
air which is heated by the regenerators instead of being traversed by the pro-
ducts of combustion. Both these methods of heating may be combined; thus,
in making glass, the pots may be heated by the direct products of combustion
during the operation of founding or melting the materials, and they may then
be heated or kept hot by the hot air during the operations of refining and
blowing or casting.
g
In working the furnace as herein-before described, the fire-places F, F, are
not employed, and may therefore be dispensed with. When they are to be
employed they are filled with coal so as to obtain a thick fire, from which large
quantities of unconsumed gases ascend into the chamber C, and pass through
the holes into the chamber G, where they meet the hot air which is leaving
the chamber A. The gases are thus consumed, and the flame and products of
combustion pass through and heat the regenerators as before. By reversing
the action of the valve V with regard to the dampers D, D', the flame and
products of combustion may be directed into the chamber A by the passages g,
and they will then descend through the chamber H, and pass through the
regenerator to the chimney. The fire in the chamber H is not then required,
and the door L may be closed with brickwork; or the fire in H may be used

page_text: occasionally or continuously in aid of the fires in F, F. Steam may be intro-
duced under the fires in F, F, in order to increase the quantity of gas
produced by them. This steam may be blown in a jet through the centre of
a pipe leading into the ash-pit, which is otherwise close; the jet of steam
will drive in a rapid current of air and increase the action of the fire.
Dampers, which are not shewn in the Drawing, may be applied to the ash-
pits of these furnaces or inserted in their flues to regulate the rate of com-
bustion and the quantity of gas produced; dampers may also be placed in the
chimney S and in the inlet I to regulate the draught and currents of air.
The nature of the flame may thus be varied from a clear oxidizing flame to a
thick carbonaceous reducing flame, as may be required. The chamber A
may be filled with potteryware instead of glass pots or crucibles, and the
pottery ware may thus be baked entirely by hot air, or both by the hot air
and the fire; or the chamber A may contain gas retorts, which may be
heated directly by the fire in the chamber H, and the fires F, F, would then
be dispensed with. The form and dimensions of the chamber A may be
varied. Thus, it may be formed like a puddling or reverberatory furnace and
employed for puddling iron, and by alternating the relative position of the
valve V and the dampers or slides D, D¹, a current of pure hot air or of the
flame and products of combustion may be sent through it.
Sheet II., of the accompanying Drawings shews a reverberatory or
puddling furnace arranged so as to facilitate the regulation of the heated
current according to the requirements of the puddler, varying from the pure
heated current of air to a powerful reducing or deoxidizing flame. Figure 9.
is a horizontal section; Figure 10 is a longitudinal section; Figure 11 is a
transverse section through the centre of the apparatus; Figure 12 is a trans-
verse section through one of the hoppers M¹. A is the chamber which
receives the iron to be puddled or refined; H and H¹ are two chambers or
fireplaces, communicating with the chamber A and also with the regenerators
R and R' by the passages or flues h and h³ respectively; the other ends of
the regenerators communicate by the four-way valve V with the air inlet I
and the chimney S alternately. The fireplaces H and H¹ are fed with coals
from the hoppers M, M¹, through the feeding holes or passages b, b¹, by means
of rectangular plates or pistons'n, n', working in boxes N, N¹, placed under
the hoppers. These pistons n, n', are moved backwards and forwards hori-
zontally by a lever N³, driven in any convenient manner.
As the piston
recedes a small quantity of coal falls from the hopper into the box, and as the
piston advances it pushes this portion of coal forward and causes it to fall

page_text: By this means the coal is
down the passage b or b¹ into the fireplace. Each hopper is provided with a
slide for closing, partially or entirely, the opening at its base, and the supply
of fuel can thus be regulated or stopped at pleasure. The, pistons have pro-
jecting studs, which enter the holes at the base of the hoppers and loosen the
coal and facilitate its descent into the boxes. Figure 13 is a plan, and
Figure 14 is an end view, of one of the pistons n¹.
fed in small quantities and frequently, and being acted upon by the highly
heated air from the regenerator, it bursts into flame and combustion as it falls
into the fireplace. An intense fire may thus be maintained without any large
mass of fuel being required in the fireplace, and thus the fire may be almost
immediately extinguished by stopping the supply of fuel, and again rekindled
when the supply is resumed. The ashes and clinkers are removed from time
to time at a and a¹; fuel may also be introduced, and the fire may be stirred
through the doors or openings I, I'; thus, when a strong heat is required
without oxidizing or reducing action, as in melting the iron when it is first
introduced, the fires in H and H¹ may be fed alternately at each change of
the valve V, and in such manner that when the fresh air is entering through
the regenerator R the fire H may be in operation, and when the air enters
through R¹ the fire H¹ may be in operation. When a powerful oxidizing
current is required this order is reversed, and the fire H is fed while the air
enters through the regenerator R¹³, and vicé versa; the iron will thus bo
exposed to a current of pure highly heated air. If a less oxidizing current is
required both fires may be fed and kept in action simultaneously, and the
nature of the current may be regulated by adjusting the quantity or proportion
of fuel supplied. When a strongly deoxidizing current is required, a quantity
of fuel may be thrown in at the door I or I', and the gas and products of
combustion from it directed through the chamber A.
My Invention is also applicable for heating steam boilers and other vessels
externally. It is desirable for these purposes to obtain a continuous current of
the heated products of combustion, and to effect as nearly as possible perfect
combustion.
Sheet III. shows an arrangement adapted for heating an ordinary stationary
boiler. Figure 15 is a plan, one-half of which is in section; Figure 16 is a
longitudinal section; Figure 17 is a transverse section through the line 1, 2,
in Figure 16; and Figure 18 is a transverse section through the line 3, 4,
in Figure 15. B is the boiler, having a cylindrical flue A, which is
partially lined with fire bricks, forming a chamber or fireplace H, which is
fed with coal through the opening 6 and hopper M; this part may be

page_text: arranged in any convenient manner. Thus the coal may be simply thrown in
through the hopper and the opening closed, or the hopper may be kept full of
coal and a pair of rollers or other contrivance placed at the base of the hopper
to feed the coal into the furnace; or in some cases the coal may be thrown
in until it forms a conical heap in the fireplace, reaching up to the opening b,
and the hopper may then be filled with coal, which will descend gradually as
the heap burns away. R, R¹, are two regenerators, communicating by the
four-way valve V alternately with the chimney S and the cold air inlet I;
the other ends of the regenerators communicate by the passages h, l', with a
similar four-way valve D, placed at the front of the furnace; the upper
opening of this valve communicates with the front of the fireplace H, while
its lower opening communicates with the flue A', which receives the products
of combustion from A. L is the fire door; a is a plate or slide, which is em-
ployed to close the upper opening of the valve D when the ashes or clinkers
are being raked out at the fire door L. A fire being lighted in the fireplace
H, the flames and products of combustion pass through the flues A and A¹
and impart a considerable portion of their heat to the boiler; they then pass
by the valve D and passage h¹ into the regenerator R', and from the other end
of this regenerator by the valve V into the chimney S. The side of the boiler
being inclosed in the regenerator, receives a portion of the heat from the pro-
ducts of combustion, while another large portion is absorbed by the rege-
nerator, and only a small portion of the heat passes up the chimney S with the
products of combustion. The valves V and D being now reversed, the cold
air enters the regenerator R¹, and being heated by it to a high temperature,
it enters the front of the chamber H and passes through the fire, and
through the flues A and A', passage h, regenerator R, and valve V to the
chimney S. When the valves are again reversed, the air passes through and
is heated by the regenerator R and then enters the fire, and after traversing
the flues passes away through the regenerator R¹. The flue A, and the part
of the boiler exposed to the flue A', are thus exposed to a high and com-
paratively uniform temperature, effecting rapid evaporation and generation of
steam. The sides of the boiler contained in the regenerators are exposed
to a high temperature at the end nearest the fire door, and to a tem-
perature gradually decreasing towards the farther end; by this means a great
evaporative effect is obtained, in conjunction with economy of fuel, as com-
paratively little heat escapes up the chimney. The regenerators may be
prolonged beyond the boiler, so as to reduce still more the temperature of the
products of combustion before discharging them into the chimney. The valve D

page_text: is made double or hollow, with openings at the ends communicating with the
spindle, which is also hollow. Cold air is allowed to draw in through the
spindle and valve to cool it, and prevent it from becoming overheated by the
hot air. Its sides may be faced with fire-brick, or bad conducting refractory
materials, still farther to protect it, or it may be traversed by a current of water
if required. The valve V does not require any protection, as one side is con-
stantly exposed to the current of cold air from the inlet I, while the other
side is only exposed to the cooled products of combustion issuing from the
regenerator.
In this Drawing I have shewn a method of working the valves V and D
by water power. Q is a shaft, extending along the furnace and carrying levers
K and K', connected by rods 1, P, to levers m, m³, on the spindles of the valves;
T is an iron box, turning freely on the shaft Q, and having two partitions or
basins q, q', within it; r, r, are weights attached to or cast upon the box T;
8, 8, are two projections, which come in contact with a lever J on the shaft Q.
U is a pipe furnishing a small stream of water, and W is a cistern for
receiving the water from the apparatus. The water runs into one of the
basins q until its weight overcomes the weights r, r, and the box T then tips
over and discharges the water from q into the cistern W, and presents the
basin q' to receive the water from the pipe U. In tipping over from one side.
to the other, the lever J is caught by the projection 8, and the shaft Q is thus
turned a little on its axis, and the valves are shifted. The basin q¹ is then
gradually filled by the water, and after a certain interval it causes the box to
tip back again, and again reverse the valves. The stream of water is adjusted
by a cock, so as to effect the reversal of the valves at the required intervals,
which may be a few minutes, or half an hour, or one or more hours, according
to the capacity of the regenerators and the proportions of the apparatus. By
changing the valves very frequently the regenerators are kept at a more uni-
form temperature than when longer intervals are allowed. If the valves be
left unchanged for too long a period, the regenerator into which the cold air
enters will be gradually cooled so much throughout its length as to have little
or no effect upon the entering air, while the other regenerator will become
gradually heated throughout its length, and the products of combustion will
pass into the chimney in a highly heated state. The whole apparatus will
thus be reduced to the condition of an ordinary furnace without regenerators.
The degree and uniformity of the temperature of the air in the chimney thus
serves as a guide for regulating the frequency of the changes of the valves.
The supply of water may be guaged by a small water meter, or the pipe U

page_text: may be simply provided with two cocks, one of which is adjusted until the
motion of the box T is effected in the required time, and is not afterwards
altered. The other cock is employed to shut off the supply of water when it
is required to stop the apparatus. The boiler may be supplied with water
from the cistern W. In lieu of a steam boiler, a still, or an open boiler or
pan, or other vessel, may be heated in a similar manner. As already men-
tioned, the change of temperature of the air in the chimney serves as a guidé
for reversing the valves, but the change of temperature of the air in the
chimney, or in the ends of the regenerators, may be made to effect the reversal
of the valves by self-acting apparatus. Thus, a close vessel containing air may
be placed in the end of each regenerator next to the chimney, and a pipe
from this vessel is conducted through the wall of the regenerator and bent
down and up again in the form of the letter U. The bend is filled with water,
on which rests a float. These floats are connected by rods to the two ends of
a beam or lever, carrying à balance weight above its centre of motion. As
one regenerator becomes gradually heated, the air in its vessel expands and
forces the liquid up in the open branch of the bent pipe, and thus raises the
float until the beam arrives at and just passes the horizontal position; the
balance weight then tips over and raises the float above the surface of the
liquid, and communicates motion to the valve or dampers by a rod or other-
wise. The air vessel being now exposed to the current of cold air entering
the regenerator, the air within it contracts, and the water descends in the open
branch of the bent pipe; the air in the air vessel in the other regenerator
then begins to expand and gradually raises its float, until the balance weight
is tipped back again to its first position, and the valve is thus restored to its
first position. The gradual expansion of the air is thus made to produce the
sudden reversal of the valves or dampers. In lieu of filling the aforesaid
vessels with air they may contain water, and may act by production and con-
densation of steam, or by the variation of the pressure of the steam. The air
or steam may be made to act upon a well fitted piston or a flexible diaphragm
in lieu of acting upon a mere float, as herein-before described; or two vessels or
bulbs may be connected by a tube, which is mounted on an axis, and so placed
that one bulb is in each regenerator. A quantity of water is placed in this
apparatus; a portion of the water becomes converted into steam in the heated
bulb and forces the water into the other bulb, which causes the apparatus to
tip over on its axis; the valve, which may be on the same axis, or otherwise
connected to it, is thus reversed. The other bulb then acts in a similar
manner, and again reverses the valve, and so on. Apparatus on a similar
principle may be acted upon by the gases ascending the chimney; or the con-*

page_text: traction and expansion of air or steam in a vessel placed in the chimney may
alternately draw up water through a pipe with a valve in it, opening up-
wards, and force the water up another pipe with a valve in it, thus acting
like a pump, and the water thus raised is conveyed into and gives motion
to the buckets, herein-before described.
Figure 19, Sheet IV., is a longitudinal section of the boiler of a locomotive
engine, having my Invention applied to it; Figure 20 is a transverse section
of the same, the right-hand side of which is taken through the tubes of the
boiler, while the left-hand side is taken through the regenerators. Figure 21
is a section through the chimney and smoke box. F is the fire box; B is the
shell or body of the boiler, and A, A, are the tubes. The tubes do not extend
the whole length of the boiler but terminate in two chambers R, R', containing
walls of perforated fire bricks, and forming the regenerators, whose ends com-
municate respectively with the two sides of the four-way valve V. The lower
opening of the valve is open to the air at I, while the upper opening com-
municates with the chimney S. The air enters at I, and passes through one
of the regenerators and one half of the tubes into the fire, and back through
the other half of the tubes and the other regenerator to the chimney. By
reversing the valve V the direction of the current is reversed at intervals; a
portion of air enters through the fire bars as usual, and assists the combustion.
By this means the whole length of the tubes is exposed to highly-heated
currents alternately of flame and hot air, while the products of combustion are
ultimately discharged into the chimney in a comparatively cool state, and the
fuel is thus economized.
Figure 22, Sheet IV., is a longitudinal section, and Figure 23 is a horizon-
tal section, of another reverberatory or puddling furnace constructed according
to my Invention. Figure 24 is a transverse section of the same through the
front part of the fireplace H. Figure 25 is a transverse section through the
back part of the fireplace, and through the regenerators R, R¹. I is the inlet
for the cold air; S is the flue or passage leading to the chimney; V is the
four-way valve, with its axis placed in a vertical position; H is the fireplace;
A is the puddling chamber; and A', a flue which conveys the products of com-
bustion to a four-way valve D, which has two lateral openings communicating
with the two regenerators R, R', while the fourth opening communicates
with openings on each side of the fireplace H by the passages h, h. The
four-way valve D, being exposed to great heat, is formed of a fire-brick
wall or partition, supported by an iron plate on a vertical shaft or spindle d,
turning in a step at the bottom, and in a plate or bearing d. Openings aro
left round this bearing to allow a small quantity of cold air to pass from the

page_text: inlet passage I round the plate which carries the valve or partition. The
upper surface of this plate is also covered with fire-brick. to protect it from
the heat; the current of cold air which is constantly passing through the
passage I also assists in cooling the iron work. The fireplace H has a single
fire bar or plate H', which is capable of turning upon centres at each end.
By moving this plate on its axis, the ashes and clinkers are broken up and
shaken between the edges of the plate and the sides of the furnace, and they
fall into the ash-pit a. The fuel is introduced through the hopper M and
aperture b until it forms a heap or ridge along the centre of the furnace,
reaching into the mouth of the aperture 6, and preventing the descent of any
more fuel. The hopper is filled up with fuel and closed by a sliding cover.
As the fuel burns away, more descends from the hopper, which is filled up
again at intervals; the motion of the plate or bar H₁ assists in bringing
down the coal from the hopper M. Instead of one bar H, a series of bars
turning on the same or separate axes may be employed. The air enters at the
inlet I, and passes by the valve V through the regenerator R, and is directed.
by the valve D into the passages h, h, which convey it into the fireplace H,
where it impinges upon the two sides of the heap or ridge of coal or other
fuel; the products of combustion pass through the chamber A and flue A¹
to the valve D, which directs them into the regenerator R', and thence by the
valve V to the chimney S. Both valves V and D being now turned on their
axes, the cold air passes through the regenerator R¹, by which it is heated,
and thence through the valve D and passages h, h, to the fire place H. The
products of the combustion pass on through the chamber A and flue A¹ to
the valve D, and thence through the regenerator R to the chimney at S.
By reversing the motion of the valves in relation to each other, the products
of combustion may be directed into the regenerators, and the current of
heated air carried through the chamber A. The character or chemical nature
of the flame may also be varied by working more or less fuel in by the bar
H', and by regulating the admission of air by dampers in the inlet I and
chimney S. In lieu of constructing and feeding the fireplace as herein-before
described, the ordinary fire bars may be employed, and the fire may be fed iu
the ordinary manner at the fire door L.
Figure 26, Sheet IV., is a longitudinal section, and Figure 27 is a trans-
verse section, of another of my improved furnaces, adapted for heating
crucibles for melting steel, or for other purposes. In Figure 26 one end
of the furnace is broken away or omitted, it being similar in every respect
to the other end. The crucibles B, B, are placed in the central part A
of a long chamber, the ends of which communicate by the flues or passages h

page_text: with two regenerators R, R¹, which are placed alternately in communication
with the cold air inlet I or with the flue S, leading to the chimney by
means of the four-way valve V. The parts H, H¹, of the aforesaid chamber
are the fire-places, and are each occupied by a ridge of coal or coke, intro-
duced through the mouths b, 61, of the coal reservoirs or hoppers M, M¹;
o, o, are openings for introducing and removing the crucibles. These open-
ings and the openings of the hoppers or feeders M, M³, are covered by flat
stones or tiles. a, a¹, are apertures which are occasionally opened for raking
out the ashes. The passages h are divided by several vertical walls, which act
as parts of the regenerators, and receive the most intense heat. The rege-
nerators are filled with refractory materials, or open built walls, as before.
The currents are reversed at intervals by moving the valve V. The crucibles
are thus exposed to the flame of one fire urged by the heated air from one
regenerator, which flame and the unconsumed heated air pass over the surface
of the coal in the other fire, and then through the other regenerator into the
chimney. The walls and arch forming the heated chamber are separated
from the surrounding brickwork by narrow spaces or channels y, y, through
which a current of air may be established, to prevent the melting of the
internal brick or stone work.
The regenerators may be constructed of a great variety of forms, and they
may be placed either horizontally, or vertically, or inclined; they are to
be filled with fire brick or other refractory materials at their hot ends.
The cool ends may be filled with less refractory materials, or with plates or
pieces of metal, but I consider it preferable to employ refractory materials
throughout, as in the event of the valves being left unchanged for a
long period the regenerator may become highly heated throughout. Care
should be taken in arranging or placing the materials in the regenerators to
leave sufficient spaces for the passage of the air and products of combustion.
The valves and dampers may be varied in construction, and, as already men-
tioned, the form of the heated chamber may be varied according to the
different purposes for which it may be required. By placing the regenerators
below or at a lower level than the chambers containing the materials which
are to be heated, as in the arrangements shown in Figures 1, 2, 3, 5, 6, 7, 8, 9,
10, 11, 12, 22, 23, 24 and 25, 26 and 27, I am enabled to keep the air or
gases in the heated chamber at the same, or nearly the same, or if required,
even a slightly greater pressure, than that of the atmosphere, so that when the
door of the chamber is opened there may be no influx of cold air to cool the
materials in the chamber. This mode of maintaining a plenum in the furnace
is of importance in puddling iron, and in many other operations in which the

page_text: materials operated upon require to be stirred or to be withdrawn, or other
materials have to be introduced; at the same time by adjusting the dampers
the air may be made to enter at the door if required. By this mode of
obtaining a plenum in the heated chamber I am enabled to dispense with the
large cones or chimneys now required for glass furnaces. Furnaces constructed
according to my Invention may be used for the manufacture of sulphate of
soda by decomposing common salt by sulphuric acid. The hydrochloric acid
gas passes with the products of combustion through the regenerators, and
issuing from them in a cooled state is more easily condensed than when it
leaves the furnace with the products of combustion at a very high temperature,
as in the ordinary method of manufacturing sulphate of soda in reverberatory
furnaces. By placing the regenerators below the furnace and by adjusting
the dampers, the air may be made to enter very slowly at the door or working
hole, by which means the workman will not be inconvenienced by the escape
of the acid gas, while the furnace will not be cooled to any great extent
by the small influx of air at the door. It will thus be seen that the
Invention may be readily adapted to furnaces for a great variety of
purposes.
Having now described the nature of the Invention, and in what manner
the same is to be performed, I wish it to be understood that I do not claim
generally the use of regenerators or chambers filled with refractory materials,
nor do I claim all the details of the furnaces herein-before described for tho
purpose of illustrating my Invention, nor do I confine myself to the particular
arrangements herein-before described in reference to the Drawings; but
what I claim is,-
First, obtaining currents of heated atmospheric air by means of two re-
generators and one fire or set of fires, by dividing the current of fresh air
after it has passed the one regenerator and before it has reached the fire-
place by means of valves or dampers, as herein-before described in reference
to Figures 1, 2, and 3.
Second, obtaining continuous currents of highly heated air or of flame and
the products of combustion by means of two regenerators and two four-way
dampers or pairs of slides or other valves, to be worked simultaneously, by
means of which the currents of heated air and of the products of combustion
are transmitted alternately and in opposite directions through the regenerators,
but pass continuously through the heated chamber and fireplace, as herein-
before described in reference to Figures 5, 6, 7, 8, 15, 16, 17, 18, 22, 23, 24,
and 25.
'

page_text: furnace currents, varying in their chemical properties from heated air to a
thick carbonaceous or reducing flame, by means of regenerators, in combination
with one, or two, or more self-acting or mechanical feeding apparatus under
the control of the operator, as herein-before described in reference to Figures
9, 10, 11, 12, 22, 23, 24, 25.
Fourth, constructing and applying fireplaces and regenerators and the
heated currents therefrom in such manner, that a ridge of fuel is fed in
from the top of the fireplace and has its surface exposed to and acted upon
by a current or currents of heated air proceeding from a regenerator, as
herein-before described in reference to Figures 22, 23, 24, 25, 26, and 27;
also, the application to such fireplaces of the moveable bar or plate H¹, shewn
in Figures .22, 24, and 25, by moving which the fire may be moved. and fed
and the ashes discharged mechanically without the necessity of opening the
fireplace.
Fifth, constructing and applying fireplaces and regenerators and the
heated currents therefrom in such manner, that the fuel is fed in at the
top of a solid inclined plane and has its surface exposed to and acted
upon by a current or currents of heated air proceeding from a regenerator, as
herein-before described in reference to Figures 1 and 2, and 9, 10, 11, 12, and
15, 16, 17, and 18.
Sixth, producing intensely heated flame by mixing a current or currents of
heated air proceeding from a regenerator with the heated gases produced by
the partial combustion or distillation of coal, effected by the admission (either
alone or mixed with steam) of a quantity of air insufficient to produce
perfect combustion, as herein-before described in reference to Figures 5, 6, 7,
and 8; also, the mode of varying the chemical nature of such flame by
means of campers or valves regulating the supply of air and gases, as herein-
before described.
Seventh, constructing puddling, melting, and other furnaces, which require
to be opened frequently for inspection or for the admission of the workmen's s
tools, or for other purposes, in such manner that the currents of heated air
ascend. by a passage or passages from the regenerators to the heated chamber
containing the materials or articles to be heated, whereby I am enabled to
obtain in the chamber a plenum, or a pressure equal to, or where required
slightly greater, than that of the atmosphere, and thus to prevent the entrance 3
of cold air at the door or openings, as herein-before described.
Eighth, the construction and application of regenerators within or in
contact with steam boilers or pans, or similar vessels, as herein-before
described

page_text: Ninth, reversing or working the valves and dampers employed in working
regenerator furnaces mechanically at suitable intervals, by means of a stream
of water capable of regulation, acting upon buckets or floats, as herein-before
described in reference to Figures 15, 17, and 18; also, regulating the motion
of the water in a self-acting manner by the changes of temperature in
the regenerators or in the chimney.
In witness whereof, I, the said Charles William Siemens, have hereunto
set my hand and seal, this Eleventh day of November, in the year of
our Lord One thousand eight hundred and fifty-seven.
Witness,
CHARLES COWPER,
20, Southampton Buildings,
Chancery Lane, London.
C. W. SIEMENS. (L.S.)