IMPROVED ARRANGEMENT OF PURNACES WHICH IMPROVEMENTS ARE APPLICABLE IN ALL CASES WHERE GREAT HEAT IS REQUIRED
Year: 1856

page_text: LETTERS PATENT to Frederic Siemens, of 7, John Street, Adelphi, London,
Engineer, for an Invention of "IMPROVED ARRANGEMENT OF PURNACES
WHICH IMPROVEMENTS ARE APPLICABLE IN ALL CASES WHERE GREAT HEAT
IS REQUIRED"
PROVISIONAL SPECIFICATION left by the said Frederic Siemens at the
Office of the Commissioners of Patents, with his Petition, on the
2nd December 1856.
1 FREDERIC SIEMENS, of 7, John Street, Adephi, London, Engineer, do
hereby declare the nature of the said Invention for: "IMPROVED ARRANGEMENT
OP FURNACES, WHICH IMPROVEMENTS ABE APPLICABLE IN ALL CASES WHERE GREAT
HEAT IS REQUIRED," to be as follows:
My improvement consists in so arranging smelting and heating furnaces,
smithfires, etc. that the products of combustion on their passage from their
place of combustion to the stack or chimney shall pass over an extended
surface of brick, metal or other suitable material imparting heat thereto,
which heat serves to heat the atmosphericair or other materials of combustion
in such manner that the coldair or gases are first brought into contact with the
less heated material, nearest the chimney and is brought by degrees into
contact with the more intensely heated portions until it finally passes over that
portion of the said surfaces nearest the place of combustion and which are
consequently heated to the highest degree. The result of this arrangement is
that the air or other materials of combustion are nearly heated to the degree
of temperature of the fire itself, in consequence whereof an almost unlimited
accumulation of heat or intensity may be obtained.
10700

page_text: The particular arrangements I adopt to carry my invention into effect, are
twofold: I either place the materials promiscuously into two air channels
leading from the place of combustion-the opposite ends of these channelsbeing
connected alternately (in periods to be regulated according to circumstances
and pleasure) the one to the chimney and the other to the atmosphere or
a blast pipe, or to gasometers in case other materials of combustion than
atmospheric air are made use of. It will be perceived that in reversing
the current from time to time by means of suitable valves, the materials placed
into the two channels serve alternately to absorb the heat of the fire passing
through it towards the chimney and of heating the air or other gases on their
way to the place of combustion. The channels so employed may be multiplied
and placed in a variety of forms.
The second arrangement consists in arranging the two channels side by
side and connecting the one permanently with the chimney and the other
permanently with the atmosphere, blast pipe or gasometer. The heat
has to pass in this case through the partition dividing the two channels. The
form and construction of these passages may also be varied ad libitum with
a view of obtaining extended, heated and heating surfaces.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Frederic Siemens in the Great Seal Patent Office on the
2nd June 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME I FREDERIC
SIEMENS of 7, John Street, Adelphi, London, Engineer send Greeting
WHEREAS Her most Excellent Majesty Queen Victoria by Her Letters
Patent bearing date the second day of December in the year of our Lord
One thousand eight hundred and fifty six in the twentieth year of Her Reign
did for Herself, Her Heirs and Successors, give and grant unto me the said
Frederic Siemens Her special licence that I the said Frederic Siemens, my
executors administrators and assigns, or such, others as 1 the said Frederic
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: "IMPROVED ARRANGEMENT
OF FURNACES, WHICH IMPROVEMENTS ARE APPLICABLE IN ALL CASES WHERE GREAT
HEAT IS REQUIRED" upon the condition (amongst others) that 1 the said
Frederic Siemens, my executors or administrators by an Instrument in writing

page_text: 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 Frederic Siemens Do hereby declare
the nature of my said Invention and in what manner the same is to be per-
formed to be particularly described and ascertained in and by the following
Statement (that is to say):
My invention consists in certain arrangements of furnaces which have for
their object to recover the heat which is still contained in the flame or products
of combustion on passing away from the fireplace or heated chambers or
flues towards the chimney by causing that heat or a great portion thereof
to be imparted to the current or currents of atmospheric air, gas or other
materials employed to maintain combustion in the same or other fireplaces by
which arrangements heat may be accumulated to an unlimited extent (con-
sistant with the materials employed) and great economy of fuel is effected.
But in order that my invention may be more fully understood and readily
carried into effect I will now describe the best modes I am acquainted with of
performing the same.
Sheet I. represents a heating furnace according to my invention. Fig. 1 is
a sectional plan of the same, Fig. 2. is a sectional elevation through the line
A Bin, Fig. 1; Fig. 3 is a cross section through the line C, D, E, F, in the
Fig. 1; Fig. 4. 5 & 6. represent the valve for changing the direction of
the current on an enlarged scale. The furnace consists of the heating chamber
P with a door a which is separated from two hearths or fireplaces Q & Q¹ by
fire bridges c&c. The fireplaces are supplied with fuel through the openings
d&d which are closed by doors or shutters & e'; f&f are channels
through which the cinders or ashes are removed and which are usually closed
by means of shutters or doors g & g'. .Open passages & lead from the
fire places Q&Q into the chambers R & R' which chambers contain fire-
brick or other refractory material presenting large agregate surfaces for
absorbing beat and which I propose to term "regenerators." Passages i & i¹
lead from the other extremities of the regenerators to the valve V and hence
into the stack or chimney S. The valve consist of a cast iron casing K, which
is open at top and bottom and at two opposite sides. The two remaining closed
sides are perforated in the middle to receive a spindle upon which the valve
plate m is fixed. The moveable valve plate m is made to fit the valve casing
Kso as to intercept the direct passage of air upwards into the chimney when

page_text: in either of its extreme positions where it is retained by a tumbling weight p
the lever of which is keyed upon the spindle and stands in the same
angular position with the upper leaf of the valve plate m. It will therefore
oblige the current of air entering from below to proceed in the direction of the
arrows see Fig. 4. through the passage el, the regenerator R1, the fireplace Q
the heated chamber P, the fireplace Q, the regenerator R and the passage i
into the chimney S. By turning the valve m into the position as shewn by
dotted lines (Fig. 4) the direction of the current will be reversed passing
from without through the passage i, the regenerator R, the fireplace Q the
heated chamber P, the fireplace Q', the regenerator R¹ into the chimney S.
The regenerators are in this instance composed of walls of brickwork
built in what is commonly called open flemish bond" so as to
allow of a free passage through them but it is important to observe that the
holes or vacancies in the first wall are opposite to bricks in the second wall
and the vacancies of the second wall are opposite to bricks in the third wall
and so forth, the object being to break and divide the currents at every step
and thereby cause a more perfect absorbtion of heat. The regenerators and
fire places are made easily accessible by holes in the side walls of the solid
brickwork which are closed up with thin brick walls o as will be seen from
the drawing. When the valve stands in the position as shewn on the
drawing the current of fresh air after passing through the regenerator R¹
impinges upon the fuel contained in the fire place Q' and the flame produced
by its combustion traverses the chamber P and the empty fireplace Q and
reaches the extreme wall of the regenerator R which will be heated in
consequence to a considerable degree. The second wall of the regenerator will
be heated to a less degree and the heat not absorbed by the same will pass on
to the third wall which will be still less heated and so forth each succeeding
wall, reducing the temperature of the heated currents of air to a less and less
degree until it reaches the chimney comparatively cool. On reversing the
position of the valve the cold air entering the passage i becomes heated by each
succeeding wall of the regenerator R to a higher and higher degree and
it reaches the fire Q place nearly of the temperature of the flame in proceeding
during the previous operation from the same fireplace into the regenerator R.
The fireplace Q being now supplied with fuel will greatly enhance the
temperature of the heated current by the ensuing combustion and the hot
flame so produced in passing through the chamber l' and fireplace Q heats the
first wall of the regenerator R' to the same increased degree of temperature.
In passing through the regenerator R the heat is successively taken up and
the current reaches the chimney comparatively cool. On reversing again the

page_text: direction of the current the fresh air will be heated in its passage through
the regenerator R' to a higher degree than before and produce still hotter
flame by combustion of the fresh fuel which is now being supplied to the
fireplace Q causing a further rise of temperature in the heated chainber P
and the hotter extremity of the regenerator R. It will be perceived that in
continuing to change the positions of the valve from time to time and supply-
ing the one and the other fireplace with fresh fuel an unlimited accumulation
of heat within the heated chamber P might be effected, which accumulation
would be limited only by the fusion of the materials composing the furnace or
by loss of heat from external radiation. The temperature is however prac-
tically limited by the amount of cold material which is introduced from time
to time into the heated chamber P through the door a and may be regulated
moreover by a damper upon the chimney in the usual manner.
Sheet II. Fig. 1. 2 & 3 represent another arrangement of my improved
furnace in which carburated hydrogen or other inflammable gas may be used
instead of solid fuel.
Fig. 1. is a sectional elevation of the furnace and chimney. Fig. 2 is a
cross section on line A. B of Fig. 1. Fig. 3. is a sectional plan on line C I)
of Fig. 1. R & R' are the two regenerators which in this case are composed
of firebricks so arranged in upright chambers that there are zigzags or
circuitious channels for the air through them. R" is a broad channel between
the two regenerators R & R' for the passage of the inflammable gas which
enters at the bottom through the pipe and regulating cock (a.) P. is the
heated chamber containing in this case a retort (p). V is the valve for
directing the current of air through the furnace and S the stack or chimney
The valve V which is represented separately in section by Fig. 4 Sheet II
consists in this instance of two flaps or plates & v² suspended from hinges
at their upper edge and connected together by a rod to which is jointed at
both ends. The valve is worked to and fro' by a rod which may be connected
to a lever with tumbling weight or be held or secured by other means. It
will be perceived that the chimney S will be put into communication with
the passage i or according to the position of the valve while the remaining
passage
i or will be open to the atmosphere to admit the current of air
to the furnace. The current of atmospheric air passes through the valve V
in the direction of the arrows ascending through the regenerator R' into the
chamber P. where it meets the current of inflammable gas ascending through
R" and combustion having taken place the heated products descend through
the regenerator R into the chimney S. Ou reversing the position of the
valve V the current of air passing upwards through the regenerator R will

page_text: reach the chamber P in a highly heated condition and meet the inflammable
gas which during its ascent through the heated passage R" has also been
considerably raised in temperature by heat conducted from the regenerators
through the walls of the passage R". The surface exposed to the inflammable
gas during its ascent may be further increased by horizontal partitions in
the
passage R producing zig zag passages for the gas and heating the same
in a similar manner to the air passing through the regenerator R though
to a less degree. The passage R" may be divided longitudinally and a valve
may be applied to pass the current of fresh gas alternately through the one
passage or the other, so as to meet the current of hot air in the heated
chamber Pascending on the one side or other. The second passage R may
be at the same time traversed by the returning current of the products of
combustion.and form a pair of regenerators of its own. The passage Ru
may be made to supply also solid materials of combustion to the chainber P
which materials would in that case also reach the place of combustion in a
heated state. It would be preferable in that case to construct the regenerators
horizontally or even in the inverted position to that shewn making Ru a
hopper. In such cases where the reversing of the currents may be attended
with inconvenience and where the attainment of the highest degree of heat
or economy of fuel is less essential I adopt an arrangement of furnaces as
represented by Fig. 5. 6 & 7. Sheet II. Fig. 6 represents a sectional plan of
this variety of my improved furnace. Fig. 7. represents a sectional elevation of
the same on line A, B, C, D, of the plan and Fig. 5 is a sectional elevation on
line F. Gin Fig. 6 & 7. It consists of two sets of passages R, R, Rand
RR RR. The passages R are open on one side to the atmosphere
and on the other side to the heated chamber P The remaining passages
R' are open at one end to the chamber P. through the passages h, h, h, h,
and at the other extremity to the chimney S. The direction of the currents
which are continuous is indicated by arrows. All the passages R & R
which together act to some extent the part of the pairs of regenerators in the
arrangements before described are contrived in such a manner that the
currents pass in a zigzag or tortuous way through them for the better
absorbtion of heat which is being transmitted continuously from the heated
products of combustion passing through the channels R¹ in one direction to
the currents of air or other gas passing through the channel R in the opposite
direction by conduction through the walls dividing the two sets of channels
or passages. The heated chamber Pis made in this instance to contain the
coke or other fuel, being supplied from above and is retained laterally in
its position on one side by the blocks, c, c, c, e forming an upright grating

page_text: and on the other side by the pots or crucibles 7, p, p, which also act the
part of a grating. It will be readily perceived that nearly a complete entre-
change of temperatures between the products of combustion and the fresh
air or gas supporting combustion in the same or any other fireplace could
be effected in this way provided only the walls or partitious dividing the
passages offered no impediment to the transmission of heat through them
and resisted at the same time the action of the heated currents. The
partitions may be advantageously made of metal plate so arranged as to form
zigzag or tortuous channels. Instead of retaining the fuel between the
upright gratings c, c or between pots it may be disposed upon a solid hearth
as before described in reference to Sheet I. On the other hand I sometimes
employ upright or sloping gratings of firebrick or stone or gratings formed
of pots or crucibles to retain the fuel when regenerators worked by periodic
reversion of currents are used.
My improved furnaces may be varied in form and construction to suit
different applications and purposes. The regenerators in particular may be
constructed of different materials which may be either thrown promisciously
into chambers or passages or may be built up so as to form zigzag or even
straight passages for the heating and heated currents.
The fuel may be
exposed to the action of the heated currents upon solid hearths or upon and
between gratings formed of refractory materials either by itself or in the same
chamber with the crucibles, or of other materials to be heated, melted or con-
verted. One or several fireplaces may be used for heating one chamber, or
one fireplace may be arranged between two chambers to be heated alternately
and forming in point of fact part of regenerators. The chamber of chambers
so heated may be varied in form to contain the substances or objects to be
heated which may be pieces of metals or crucibles containing metals, glass or
other substances. It may be made to contain gas or other retorts, pottery
wares, metallic ores, either separate or mixed with fuel, lime, brick, or other
materials to be baked or heated. The heated chamber may also be so
arranged as to form the flues of boilers, pans or stills for the evaporation of
liquids and one of the advantages of the application of my invention is that
Sinaller heating surfaces than at present required, will suffice to evaporate a
given quantity of liquid owing to the greater intensity of heat that may be
maintained throughout, besides which the smoke of the fire will be consumed
on its passage through the regenerator and a considerable economy of fuel
be effected. The saving of fuel I effect by my improved furnace, becomes
more important however according to the degree of temperature required to
be obtained being greatest of all in melting cast steel and refining metals and

page_text: in other cases involving the necessity of intense heat. Instead of producing
the currents of air and of the products of combustion by means of a chimney
or chimneys, artificial means such as fans or blowing cylinders may be resorted
to, particularly for the purpose of smelting iron or other metals, the ores of
which may be made to fill the heated chamber completely and inay or may
not be mixed with the fuel supporting combustion. Care must be taken in
that case to close the sides of the furnace in a proper and efficient manner.
My invention may also be rendered applicable to stoves and fireplaces of
every description. The arrangements of the valves employed for changing
the direction of the currents may also be varied to suit particular purposes
and one or more chimneys may be employed in connection with them.
Having now described the nature of my invention and in what manner the
same is to be performed I wish it to be understood that I do not confine
myself to the details or particular combinations of parts described in reference
to the drawings for the same are susceptible of great variation.
I do not claim generally the alternate passing currents of air of different
temperatures in opposite directions through the same apparatus so as to effect
au interchange of heat as I am aware that arrangements of that nature have
been adopted for heating and cooling air and steam for working engines; nor
do I claim generally the heating of atmospheric air or other materials to
support combustion by the heat produced during combustion; or the valves or
other details herein before described when separately considered: but what
I claim is
1stly Constructing furnaces in such manner that the heat of the products of
combustion is abstracted by passing the same through chambers containing
refractory materials so arranged as to present extensive heat absorbing surfaces
and is communicated to currents of air or other gases by passing the latter
currents alternately over the same heated surfaces.
2ndly Constructing furnaces in such manner that the products of combustion
and currents of fresh air or other gases destined to support combustion, are
directed atintervalls in opposite or nearly opposite directions through chambers
containing refractory materials so arranged as to present extensive surfaces
with a view of effecting an exchange of temperatures between the two alternate
currents.
3rdly Arranging two chambers containing materials presenting extensive
surfaces in connection with one furnace containing one ore more fireplaces in
such manner that while the materials contained in one chamber, are being
heated by the current or currents containing the products of combustion the
heated materials in the second chamber impart heat to the current or currents

page_text: of air or other gases intended to maintain combustion and visa versa, the
heating and heated currents being passed alternately through each of-the
chambers in opposite directions.
4th Arranging a valve or valves in connection with furnaces in such a
manner that by changing the position of the same from time to time
the current or currents of air and heated gases in the furnace and chamber or
chambers containing heated materials, are reversed in their direction but are
made to enter and issue without interruption through the same apertures so
that they may be impelled by one chimney or blowing apparatus.
5thly Arranging two or more pairs or sets of chambers containing refrac-
tory materials and which I have termed "Regenerators" in relation to one
furnace and one or more fireplaces in such manner that while one pair of
Regenerators serves to transfer the heat of one heated current to a current of
fresh air supporting combustion, a second pair of Regenerators may be employed
to impart heat to the carburetted hydrogen, carbonic oxide or other gaseous
material intended to enter into combination with the heated air produced by
the first mentioned pair of Regenerators.
6thly Constructing furnaces with two or more Regenerators so arranged as
to be traversed alternately in opposite directions by the products of combustion
and the air employed to support the combustion and at the same time to
communicate heat by conduction to the gas or fuel which passes from the cool
end to the hot end of the Regenerators through a separate passage or passages
and thence into the fireplace or combustion chamber of the furnace as herein-
before described in reference to Figs. 1. 2 & 3. Sheet II.
7thly Constructing furnaces with a series of zigzag or tortuous passages
for the entrance of continuous currents of air or gases for maintaining com-
bustion which currents are heated by the products of combustion passing in
the opposite direction through another series of passages alternating with the
above said passages and divided from them by thin walls or partitions through
which the heat is transmitted in the manner herein before described in
reference to Figures 5. 6 & 7. Sheet II.
In witness whereof I the said Frederic Siemens have hereunto set my
hand and seal this second day of June one thousand eight hundred
and fifty seven.
FREDERIC SIEMENS. (L.S.)