IMPROVEMENTS IN THE REGENERATION OF HEAT FOR FURNACES AND IN THE ApparatUS OR MEANS TO BE EMPLOYED THEREIN
Year: 1872

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn
Fields, in the County of Middlesex, Gentleman, for the Invention
of "IMPROVEMENTS IN THE REGENERATION OF HEAT FOR FURNACES AND IN
THE ApparatUS OR MEANS TO BE EMPLOYED THEREIN.' -A communication
from abroad by William Sellers, and George H. Sellers, both of
the City and County of Philadelphia, in the State of Pennsylvania,
United States of America.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition,
on the 6th January 1872.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County
of Middlesex, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE REGENERATION OF HEAT FOR FURNACES AND
IN THE APPARATUS OR MEANS TO BE EMPLOYED THEREIN," a communication to me
from abroad by William Sellars, and George H. Sellars, both of the City

page_text: and County of Philadelphia, in the State of Pennsylvania, United States
of America, to be as follows :—
This Invention relates to that class of heat regenerators by means of
which the waste products of combustion from a furnace on their way to
the chimney are employed to heat the gaseous fuel, or the atmospheric
air to be supplied thereto for its combustion, or both the gaseous fuel
and the air on their way to the furnace in which they are to be con-
sumed. Waste products of combustion have heretofore been thus
utilized in the arts under two systems differing from each other.
By one of these systems the heat of the waste products is continuously
given off to a surface of suitable material, through or over which material
it is continuously transmitted to and taken up from the opposite surface.
By the other the heat of the waste products is by alternate inter-
missions given off to and taken up from the same surface.
For convenience I shall desiguate the first system as the double
surface system, and the other as the single surface system.
The first part of the present Invention relates to and is an improve-
ment upon the double surface system, the object being to maintain
continuously the highest temperature heretofore attained only at
intervals in the single surface. According to this part of the said
Invention a chamber is employed in which the waste products of
combustion are received directly from the furnace, in which chamber
these products if unconsumed may be thoroughly consumed, and from
which chamber the products of combustion may be discharged through
series of pipes on each side of this chamber.
Secondary chambers may be combined with the above into which the
pipes on each side of the first chamber discharge the products, and from
which secondary chambers respectively these products pass through
secondary series of pipes, either directly to the chimney or otherwise.
As some of the high temperatures of waste from furnaces cannot be
exhaustively utilized in heating both the air and the gas through the
medium of two or even three sets of chambers, with intermediate series
of pipes as above set forth, it is proposed to multiply the chambers
between the receiving chamber and the chimney (with series of pipes to
correspond) to any number required to extract the desired quantity of
heat from the waste products of combustion, and to impart the heat to

page_text: both the air and the gas, each series of pipes being combined with two
chambers as herein-before set forth.
As in order to obtain the greatest quantity of heat from a given
quantity of waste products of combustion, both the air and the gas on
their way to the furnace in which they are to be consumed should, just
before entering that furnace, be exposed to the highest temperature of
the waste, and as to obtain high temperatures the chamber and series of
pipes must be multiplied, this Invention further consists in arranging
the chambers and the interposed scries of pipes in such order, that as the
products of combustion pass from the receiving chamber through the
pipes and succeeding chambers and series of pipes to the chimney, both
the air and the gas to be consumed in the furnace will move over scrics
of pipes successively in the opposite direction, and as they approach the
furnace pass over successively more highly heated pipes.
The products of combustion moving meanwhile towards the chimney,
and at each series of pipes parting with a portion of their heat, arc
moreover passing successively through series of pipes, the exterior
surfaces of which have been subjected to the earlier action of the
incoming air and gas, and are therefore of successively lower tempe-
rature, so that the difference of temperatures to which the inside and the
outside of each series of pipes are respectively exposed is reduced to the
minimum.
The temperature of the chamber in which the waste products of
combustion are received directly from the furnace being higher than
that of any succeeding chamber, this Invention further consists in
encompassing the receiving chamber with air and gas chambers and flues,
so that any heat that may be transmitted through the walls of the
receiving chamber will be taken up by the air and gas on their way to
the furnace.
This Invention further consists in combining the chambers and series
of pipes, through which the products of combustion pass from the furnace
to the chimney, with the chambers through which the gas and air pass
from their respective entrance flues to the furnace in vertical lines, so
that the passage of both the gas and the air towards the furnace will be
facilitated by actretions of heat taken up from each successive series of
nines in their course.

page_text: And this Invention further consists in combining serie; of chambers
and series of pipes extending from one chamber to another with air and
gas chambers, so that the pipes extend across the air and gas chambers
respectively, and the products of combustion passing through the pipes
give off their heat to the air, and the gas passing over them.
It will thus be seen that in the herein-before described system or method
of regenerating heat for furnaces, the air and the gas which constitute
the fuel are respectively led through separate chambers and over
successive series of pipes, through which pipes the waste products of
combustion pass on their way to the chimney, and give off their heat to
the air and gas passing through their respective chambers, and over
these pipes on their way to the furnace.
The gas is supplied from a gas producer, and passes from this through
the gas chamber in the regenerative apparatus to the place of com-
bustion, under pressure, whereas the air in the air chamber of the
regenerative apparatus until heated, has no tendency to move towards
the place of combustion, being simply in equilibrio with the external air
and consequently inert. Under these conditions and until the furnace
has become heated, the tendency of the gas after reaching the place of
combustion (at which it should meet the air) would be to descend the
air fluc of the regenerative apparatus, gradually displacing the inert air
in the air chamber, and forming therein a compound liable to explode
upon the gas being ignited at the place of combustion.
Now the second head of this Invention consists of certain improve-
ments in the construction of regenerative apparatus, whereby the above
mentioned as well as others herein-after mentioned objectionable features
are obviated. In order to obviate the liability to explosion on starting
the furnace, provision is made for such a preliminary heating of the air
in the air chamber of the regenerative apparatus as will overcome its
inertia and give it such a commensurate impulse towards the point of
combustion that it may meet the gas at the proper moment, and at the
proper place, thus preventing the descent of the gas, and of course
obviating the danger of explosion above referred to.
Again the respective currents of air and gas have always heretofore
been brought to the place of combustion and introduced into the furnace
upon parallel lines, the particles of air and gas were thus not thoroughly
commingled, and by reason of this fact the combustion at the point of

page_text: their conjunction was only partial and the flame swept through the
furnace towards the chimney accompanied by unconsumed air and
gas, thereby detracting from the degree of heat which would have been
developed by a more perfect combustion of the same fuel.
Now in order to attain a more perfect combustion of the gascous fuel
than heretofore, it is proposed to bring together its constituents, namely,
the air and the gas at the place of combustion from opposite directions
and against each other instead of in parallel lines as heretofore, so that
the concussive action of the meeting currents will thoroughly commingle
the air and gas at that point.
With a view to prevent displacements and distortions arising from
the unequal expansion and contraction due to the intense heat generated
in regenerative apparatus of the kind herein-before described, it is pro-
posed to combine with each of the chambers formed by the vertical
subdivision of the regenerative apparatus a separate arch, each arch
springing from the side walls of the regenerative apparatus, but
extending longitudinally only from one dividing wall to another without
being connected with these dividing walls. These dividing walls as
well as the end and side walls are morcover by preference respectively
carried above the crowns of the arches.
·
By this mode of construction the expansion and contraction of cach
wall and of each arch is independent of and unaffected by that of the
others. Inasmuch however as the dividing walls and the arches arc not
connected but merely touch each other, and as they must still expand
and contract with the changes of temperature in the regenerative
apparatus, the escape of air or gas at their lines of contact is prevented
by filling the space between the walls above the crowns of the arches
with sand.
Should the gas employed be derived from such fuel that it will
deposit tar upon the pipes in the gas chamber, it is obvious that its
accumulation would in time materially contract the spaces through
which the gas must pass on its way to the point of combustion, thereby
impairing the sufficiency of the supply. In order to provide against this
contingency, it is proposed to combine with the gas flue from which the
gas passes through openings for that purpose a door or valve for the
admission of atmospheric air. By first closing a damper provided for
the purpose so as to stop the flow of gas to the gas chamber, and theṇ

page_text: opening the said door so as to admit air, and if necessary to introduce
flame, the tar will be ignited and the products of this combustion will
pass off through the furnace, leaving the pipes clean.
Although the herein-before described improvements in the regenerative
apparatus under the second head of this Invention have been more
particularly set forth in connection with the system of regenerating heat
for furnaces herein described under the first head, yet their application
is so obvious and their adaptation so simple and so entirely within the
common skill of a constructor of regenerative apparatus, that the
Inventor does not confine himself to the application of these improve-
ments to the above mentioned system alone of regeneration of heat, but
reserves the right of applying them to other systems.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Henry Johnson in the Great Seal Patent
Office on the 4th July 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixth day of January, in the year
of our Lord One thousand eight hundred and seventy-two, in the
thirty-fifth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said John Henry Johnson,
Her special license that I, the said John Henry Johnson, my
executors, administrators, and assigns, or such others as I, the said
John Henry Johnson, my executors, administrators, or 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 THE REGENERATION OF
HEAT FOR FURNACES AND IN THE APPARATUS OR MEANS TO BE EMPLOYED
THEREIN," a communication to me from abroad by William Sellers
and George H. Sellers, both of the City and County of Philadelphia,

page_text: in the State of Pennsylvania, United States of America, upon the
condition (amongst others) that I, the said John Henry Johnson, my
executors or administrators, by an instrument in writing under my haud
and scal, 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 Scal Patent Office
within six calendar months next and immediately after the date of the
said Letters Patent.
NOW KNOW YE, that I, the said John Henry Johnson, 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, reference being had to the accom-
panying Drawings, and to the letters and figures marked thereon,
that is to say :-
The said Invention relates to that class of heat regenerators by means
of which the waste products of combustion from a furnace, on their way
to the chimney are employed to heat the gaseous fuel or the atmospheric
air to be supplied thereto for its combustion, or both the gaseous fuel and
the air on their way to the furnace in which they are to be consumed.
Waste products of combustion have heretofore been thus utilized in
the arts under two systems differing from each other. By one of these
systems the heat of the waste products is continuously given off to a
surface of suitable material, through which material it is continuously
transmitted to and taken up from the opposite surface by the other. The
heat of the waste products is by alternate intermissions given off to and
taken up from the same surface.
A further distinctive feature of these two systems respectively is that
in the first, one surface always takes up the heat of the waste products,
passing continuously over it, and the other surface gives off this heat to
the incoming air, passing continuously over it, while in the other system
the same surface to and from which the heat of the waste products is
by alternate intermissions given off and taken up is also by alternate
intermissions exposed to the action of the waste products and to the
action of the air (or gas), the waste products passing in one direction
and the air (or gas) in the opposition direction.
In the first system the waste products and the air respectively act
upon all parts of the respective surfaces simultaneously, while in the

page_text: other system the waste products and the air (or gas) alternately act
intermittently upon all parts of the same, taking up and giving off
surface.
In the first system however the air alone is heated on its way to the
furnace, while the gas moves toward the furnace in which it is to be
consumed without any elevation of its temperature above that of its pro-
ducing furnace, this temperature being much lower than that of the air
when they meet.
A feature peculiar to the second system is that the air (or gas) as it
enters the furnace to be consumed will pass over a surface which has
been exposed to and which has acquired the highest temperature of the
waste products, and the in-coming air (or gas) will acquire the tem-
perature momentarily; but as the taking-up action of the air (or gas)
continues, the giving-off action of the waste products being suspended,
the temperature of the in-flowing air (or gas) passing to the furnace
must necessarily diminish as its source of supply becomes exhausted, and
the resulting temperature of the air (or gas) as it enters the furnace must
be the mean between the two extremes.
The result which characterizes these two systems respectively is that
the temperature obtained under the first, whilst substantially uniform, is
not so high as might be desired from the same fuel if the gas meet the
air with an equally high temperature, while under the second system the
mean temperature obtained though high is remittant.
For convenience I shall designate the first system as the double surface
system, and the other as the single surface system.
The first part of this Invention relates to and is an improvement upon
the double surface system, the object being to maintain continuously
the highest temperature heretofore attained only at intervals in the
single surface.
In carrying out the first part of this Invention a chamber is employed
for receiving the waste products of combustion directly from the furnace,
in which chamber these products, if unconsumed, may be thoroughly
consumed, and from which chamber the said products of combustion
may be discharged through series of pipes on each side of the said
chamber for purposes herein-after described. And this part of the
Invention further consists in the combination of a chamber in which the

page_text: waste products of combustion are received directly from a furnace, and in
which chamber they may be thoroughly consumed, with a series of pipes
situate on each side of the said chamber, through which pipes the
products may be discharged from the receiving chamber; and with
secondary chambers, into which the pipes on each side of the first
chamber discharge the products, and from which secondary chambers
respectively these products pass through secondary series of pipes cither
directly to the chimney or otherwise, as hercin-after set forth.
I am aware that some of the high temperatures of waste from furnaces
cannot be exhaustively utilized in heating both the air and the gas
through the medium of two or even three sets of chambers with inter-
mediate series of pipes as above set forth, and I therefore multiply the
chambers between the receiving chamber and the chimney (with series
of pipes to correspond) to any number required to extract the desired
quantity of licat from the waste products of combustion, and to impart
the heat to both the air and the gas, cach series of pipes being combined
with two chambers as hercin-before and as herein-after more fully set
forth.
As in order to obtain the greatest quantity of heat from a given
quantity of waste products of combustion both the air and the gas on
their way to the furnace in which they are to be consumed should, just
before entering that furnace, be exposed to the highest temperature
of the waste, and as to obtain high temperatures the chambers and
series of pipes must be multiplied this Invention further consists in
arranging the chambers and the interposed scries of pipes in such order
that as the products of combustion pass from the receiving chamber
through the pipes and succeeding chambers and series of pipes to the
chimney, both the air and the gas to be consumed in the furnace will
move over series of pipes successively in the opposite direction, and as
they approach the furnace pass over successively more highly heated
pipes.
The products of combustion moving meanwhile towards the chimney,
and at each series of pipes parting with a portion of their heat, aro
morcover passing successively through series of pipes, the exterior
surfaces of which have been subjected to the earlier action of the in-
coming air and gas, and are therefore of successively lower temperature,
so that the difference of temperatures to which the inside and the outside

page_text: William Sellers, dated October Third, One thousand eight hundred and
seventy-one, No. 2612. This combination has been found to be most
advantageous in the manufacture of iron, and constitutes the subject of
an Invention for which I have applied for further Letters Patent on
behalf of the said William Sellers on the Fourteenth day of June, One
thousand eight hundred and seventy-two, No. 1799. The gas and air
are consumed in the rotary puddling vessel, and the waste products of
combustion therefrom are discharged into the regenerator.
Figure 2 is a transverse vertical section taken along the line c, d,
(Figure 1); Figure 3 (Sheet 2) is a sectional plan taken along the
line e, f, of Figure 2; Figure 4 is a vertical section taken along the
line g, h, of Fig. 3; and Figure 5 is a vertical section taken along the
line i, k, of Fig. 3.
The regenerator is of rectangular form, with four cross walls extending
from bottom to top in such manner as to form five chambers, as shown
in Figures 1 and 3. The middle chamber is subdivided transversely so
as to form the threc chambers H¹, K', and N¹. The two chambers A¹
and B¹, adjoining the middle chambers, are not subdivided. The two
outer chambers are subdivided so as to form in each two chambers I'
and I and J and M. From the puddling vessel A, in which the air
and gas are to be consumed, a flue T, T, extends down into the
chamber H. Across each of the chambers A¹ and B' respectively a
series of fire-clay pipes d', d², d', e', e¹, e¹, extend from the chamber H'
to the chambers I and J¹ respectively. Below these pipes a second
serics d² and e² of similar pipes in like manner extend across the
chambers A' and B' respectively from the chamber K' to the chamber I'
and J respectively. Below these again a third series of pipes ³ and e³
(which may be of iron) in like manner extend across the chambers A¹
and B' from the chamber K to the chamber L' and M' respectively, and
below these a fourth series of similar pipes d' and ein like manner
extend across the chambers A' and B¹ respectively from the chamber N¹
to the chambers L' and M' respectively.
It is obvious that the number of sets of chambers and series of pipes
may be more or less according to the height of the furnace.
It
may further be observed that as the waste products are reduced in

page_text: will suffice in the lower series than is repuired for the larger volume of
their higher temperature.
From the bottom middle chamber (in this instance N¹) a fluc Nº leads
to the chimney, and this flue is provided with a damper N*.
The gas to be consumed in the furnace is admitted through a fluc C
(Figure 4), provided with a valve or damper D', to a chamber, from
which it passes through openings a¹, a¹, a', into the chamber A¹
(Figures 3 and 4). The air to be supplied to the gas at the furnace is
admitted through a valve or damper E. (Figures 2 and 5) to a chamber
or air fluc E, from which it passes through openings c³, c² (Fig. 3) to
the chamber B. From the chamber A' the gas passes to the flue S by
the flue F (Figure 2), and from the chamber B' the air passes to the
flue S by the flue G³, the two uniting in the flue S, which opens into the
puddling vessel A, burst into flame and are utilized therein, the products
of combustion being discharged through the flue T, T, down into the
chamber H.
It will be observed that the chamber H' has on either side of it
the gas and air chambers A' and B', while the gas and air flues F¹
and Gleading to the furnace pass over either side of the top, and the
discharge flue T enters the centre of the top of this chamber, so that
this chamber, which is subjected to the highest temperature of the
waste product of combustion, is entirely surrounded by chambers and
flues, which will take up any heat which may be transmitted through its
sides and return it back again into the furnace.
numerous.
The arrangement shewn in Figures 1 and 2 is the best mode in which
the improvements can be applied, and the advantages combined in it are
The placing of the receiving chamber H¹ in the top of the
middle division of the regenerator, with the air and gas chambers on
either side thereof and the chambers K' and N¹ below it, with the
chambers T and L' on the outer side of the chamber A', and the
chambers J' and M' on the outer side of the air chamber B¹, gives the
best plan for construction, all the lines being vertical, the most con-
venient arrangement for the introduction of the waste products of
combustion from the furnace, and for the introduction of gas and air
to the furnace, the largest area of surface for the transmission of
heat to the gas and air, with the smallest arca for loss of heat for
radiation.

page_text: The operation it will be seen is as follows:-The products of com-
bustion from the chamber H¹ pass through the pipes d', d', d³, into the
chamber I', and through the pipes e', c', e', into the chamber J. From
these chambers respectively the products pass through the pipes d², d³,
and e³, e², into the chamber K. From K¹ they pass through the pipes
into the chamber II, and through the pipes e³, e³, in the chamber
M², and from these chambers they pass through the pipes d', d³, and e', e',
to the chamber N₁, whence they pass into the chimney through the
711
M', and from these chambers they pass through the pipes d³, d', and e*, e*,
to the chamber N₁, whence they pass into the chimney through the
Huc N.
Whilst the products of combustion are thus moving through these
series of pipes successively towards the chimney, the gas is passing
through the chamber A', and the air through the chamber B' towards
the furnace, the air and the gas respectively taking up the heat trans-
mitted by the products of combustion through the pipes and given off
from their outer surfaces, it being obvious that the gas and the air enter
their respective chambers at the bottom (where the pipes being heated
only by the waste products which have passed through all the series
above are reduced to a low temperature) and rise through the spaces
between the higher scries successively, which have had an earlier
contribution of heat from the waste products until they reach the series
of pipes nearest to the chamber H', which are of course more highly
heated than any series below, and the gas and air thus pass to and meet
at the flue S with the highest temperature derivable from the waste
products. On the other hand the waste products passing at their highest
temperature through the series of pipes. nearest the chamber H', and
descending through the successive series of pipes below, reach the lower
pipes which are subjected to the cooling action of the entering air and
gas respectively with a temperature so much reduced that the difference
between the temperatures of the waste products and that of the incoming
air and gas is reduced to the minimum. As the ascending air and gas
acquire and the descending products lose heat at cach stage of the series
it is obvious that the minimum difference of temperature between the
two is obtained at each stage of the series. The accretion of tem-
perature by the air and gas to be supplied to the furnace being
progressive, the flow of air and gas being continuous from the entrance
flues to the point of combustion, and the temperature of the waste
products of combustion being constantly decreasing from the chamber
H' to the chimney, the flow of the waste products also being continuous,

page_text: there are attained by this system a continuous flow of gas and air, a
continuous heating of both, a continuous flow of waste products of
combustion, a constant flame, and the bighest temperature with a
minimum of destructive action upon the regenerative system.
I may here observe that I do not claim under this part of the said
Invention the subjecting the air moving to the furnace in a continuous
current to a progressively increasing temperature, while the waste
products of combustion moving from the furnace to the chimney in a
continuous current are subjected to a constantly decreasing temperature,
nor do I claim the combination in vertical lines of chambers and series of
pipes extending from one chamber to another with an intermediate
chamber across which the pipes extend and through which air or the
waste products of combustion pass, nor do I claim passing the waste
products of combustion through the pipes and passing the air to be
heated over the pipes, so that the heat from the products of combustion
is taken up by the interior surface of the pipes transmitted through the
body to the exterior of the pipes and given off from the exterior surface
to the air passing over the pipes.
In the regenerator herein-before described and illustrated by the
Drawings, the gas is supplied from a gas producer, and passed from this
through the gas chamber in the regenerative apparatus to the place of
combustion under pressure, whilst the air in the air chamber of the
regenerative apparatus until heated has no tendency to move towards
the place of combustion, being simply in equilibrio with the external air
and consequently inert. Under these conditions and until the furnace
has become heated, the tendency of the gas after reaching the place of
combustion (at which it should meet the air) would be to descend the
air flue of the regenerative apparatus, gradually displacing the inert air
in the air chamber, and forming therein a compound liable to explode
upon the gas being ignited at the place of combustion. But in order to
obviate the liability to these and other objectionable incidents, hercin-
after fully set forth, it is proposed according to the second head of this
Invention to make provision for such a preliminary heating of the
air in the air chamber of the regenerative apparatus as will overcome its
nertia, and give it such a commensurate impulse towards the point of
combustion that it may meet the gas at the proper moment and at the
proper place, thus preventing the descent of the gas, and of course
obviating the danger of explosion above referred to.

page_text: E', Figures 3 and 5) represents the valve which controls the admission
of the air to be heated in the air chamber of the regenerative apparatus
on its way to the point of combustion S (Figure 2), where it should
meet the gas as herein-after more fully described. E (Figure 3 and 5)
represents the air flue from which the air passes through the openings
c', c', (Figure 3) to the air chamber B'. A door E³ (Figures 3 and 5)
located in this instance at the outer end of the flue E admits of the
introduction of fuel and its ignition within the fluc S for the purpose of
heating the flue and the air within it. Of course heat derived from any
other source may be introduced into this fluc for the purpose described
instead of the fuel mentioned.
The products of the combustion thus generated in the fluc E will
pass with the air through the openings C¹, C', into the air chamber B¹,
gradually warming it, thus overcoming the inertia of the air and
inducing a movement through the flues E2 and G³, creating a current
and a consequent resistance to the tendency of the gas coming under
pressure over from the chamber A¹ to pass the point of combustion S
and descend the air flue G¹.
The respective currents of air and gas from heat regenerators have
always heretofore been brought to the place of combustion and in-
troduced into the furnace upon parallel lines, consequently the particles
of air and gas were not thoroughly commingled, and by reason of this
fact the combustion at the point of their conjunction was only partial
and the flame swept through the furnace towards the chimney accom-
panied by unconsumed air and gas, thereby detracting from the degree
of heat which would have been developed by a more perfect combustion
of the same fuel.
A more perfect combustion of the gaseous fuel than heretofore is
however ensured by bringing together, according to the second head
of this Invention, the air and the gas at the place of combustion from
opposite directions and against each other instead of in parallel lines as
heretofore, so that the concussive action of the meeting currents will
thoroughly commingle the air and gas at that point.
At the point of combustion where the flame enters the furnace or
puddling vessel A, an opening S, connects with two flues F' from the gas
chamber, and G¹ from the air chamber, these flues F" and G¹, being so
arranged relatively to each other and to the opening S, that the current

page_text: of air and the current of gas on their way to the furnace meet at the
opening S with an abutting force, whereby the currents are intimately
commingled at this point of combustion and enter the furnace through
this opening S not as heretofore on parallel lines and partially unignited,
but with a more active and more thorough combustion the result of
their concussion and attendant thorough commingling. The products
of combustion leave the furnace or puddling vessel A through the flue T,
which conducts them to the regenerative apparatus, as licrein-fore
fully described. .
The intense heat to which the brickwork in the regenerative
apparatus of furnaces is subjected, (induces such unusual degree of
expansion as to require special provision to counteract this disturbing
clement, but it is proposed under the second head of this Invention to
introduce an improved construction of the chambers composing the
regenerative apparatus which I shall now proceed to describe with
reference to this requirement.
As heretofore constructed the walls enclosing the apparatus being
rectangular, the arch or arches covering the air and gas chambers
sprang from the side walls and covered the dividing intermediate walls,
and for the reception of these intermediate walls recesses were provided
on the under side of the arch or arches so that the vertical sub-divisions
of the chambers were complete, but with the expansion and contraction
incident to the operation of the apparatus the arch and the dividing
walls would change their relative positions to an extent which permitted
the escape between the dividing walls and the arch from one sub-
division to another of the air and the gas, which thus coming
prematurely in contact were liable to ignite in the chambers instead
of passing separately to the proper point of combustion, obviously to
the detriment not only of the process, but of the apparatus.
Morcover this expansion and contraction being unequal at different
points in the length of the arch by reason of the difference of tem-
perature at these different points, the arch itself was liable to crack
so as to permit the escape of the air and gas from the chambers into
the atmosphere.
To prevent these displacements and this distortion, it is proposed to
combine with each of the chambers formed by the vertical subdivision
of the regenerative apparatus herein-before described, a separate arch as

page_text: shewn in Figure 1, each arch springing from the side walls of the
regenerative apparatus, but extending longitudinally only from one
dividing wall to another, but not connected with these dividing walls;
and these dividing walls as well as the end and side walls being by
preference respectively carried above the crowns of the arches for a
purpose presently described.
By this mode of construction the expansion and contraction of cach
wall and of each arch is independent of and unaffected by that of the
others. Inasmuch however as the dividing walls and the arches arc
not connected, but merely touch each other, and as they must still
expand and contract with the changes of temperature in the regene-
rative apparatus, the escape of air or gas at their lines of contact is
prevented by filling the space between the walls with sand, as shewn in
Figure 1.
An accumulation of tar in the gas regenerative chamber may
sometimes result from the use of certain fuels, and no adequate
provision has been made for removing the same, but it is hereby
proposed to provide in the regenerative apparatus simple and convenient
means by which any such tarry accumulation may be consumed.
Should the gas employed be derived from such fuel that it will
deposit tar upon the pipes in the gas chamber, it is obvious that its
accumulation would in time materially contract the spaces through
which the gas must pass on its way to the point of combustion, thereby
impairing the sufficiency of the supply. The provision against this
contingency consists in combining with the gas flue C³ (Figures 3
and 4), from which the gas passes through the openings a¹, a¹, a door or
valve 2, Figure 3. By closing the valve or damper D¹ so as to stop the
flow of gas to the gas chamber, and then opening the door z so as to
admit air and if necessary to introduce flame, the tar will be ignited
and the products of this combustion will pass off through the furnace,
leaving the pipes clean.
Although these several last-mentioned features of the said Invention
have been devised in connection with, and are specially adapted to the
particular class of regenerative apparatus herein-before referred to, yet
their application is so obvious and their adaptation so simple and so
entirely within the common skill of a constructor of regenerative
apparatus, that I do not confine myself to the application of these
B

page_text: improvements to the above-mentioned system of regenerative apparatus,
but claim them whether used therein or in the Siemens' system.
Having now described and particularly ascertained the nature of my
said Invention, and the manner in which the same is or may be used or
carried into effect, I would observe in conclusion that what I consider
to be novel and original, and therefore claim as the Invention secured
to me by the herein-before in part recited Letters Patent is,—
First. The improvement in the art of regenerating heat for furnaces
herein-before set forth, which consists in subjecting both the air and
the gas moving to the furnace in continuous currents substantially as
described to a progressively increasing temperature, while the waste
products of combustion moving from the furnace to the chimney in a
continuous current are subjected to a constantly decreasing temperature
for the incoming currents both of air and gas.
Secondly. The combination of a central chamber in which the wasto
products of combustion are received from the furnace scries, of pipes,
through which the waste products are passed and over which the
incoming air and gas move towards the furnace and side chambers
into which the waste products are discharged from the pipes on their
way to the chimney, substantially as described.
Thirdly. The combination of a central chamber in which the waste
products of combustion are received from a furnace series of pipes
through which the waste products are discharged from the central
receiving chamber, side chambers into which these products are dis-
charged by the pipes, and secondary series of pipes through which the
waste products pass to the chimney, or to a second central chamber
connected with the chimney, while the incoming air and gas move
towards the furnace over the pipes, substantially as described.
Fourthly. The combination of a chamber in which the waste products of
combustion arc received directly from the the furnace with encompassing
air and gas chambers and air and gas flues, substantially as and for
the purpose set forth.
Fifthly. The combination in vertical lines of the chambers series of
pipes through which the products of combustion pass from the furnace
to the chimney with the chambers through which the gas and air pass

page_text: for the purposes described.
Sixthly. The combination of series of chambers and series of pipes,
extending from one chamber to another with air and gas chambers,
so that the pipes extend across the air and gas chambers respectively,
substantially as and for the purposes described.
Seventhly. The combination with the air chamber of means for a
preliminary heating of the air in this chamber, for the purpose
described.
Eighthly. In a heat regencrative apparatus, the combination with
the opening into the furnace of a gas flue and an air flue, by which
flues the air and gas are brought to said opening from opposite
directions, so that at said opening they abut against each other,
substantially as described.
Ninthly. A chamber formed by four vertical walls and an arch,
the arch resting upon and being connected with two of the walls, and
interposed between but not connected with the other two walls, as and
for the purposes described.
Tenthly. The combination with a chamber formed by four vertical
walls and an arch, the arch resting upon and being connected with two
of the walls, and interposed between but not connected with the other
two walls of a sand packing or its equivalent, for the purposes described.
Eleventhly. The combination with the valve D' and the gas chamber
A' of the door Z or its equivalent, for the purposes described.
In witness whercof, I, the said John Henry Johnson, have to this
my Specification set my hand and seal, the Third day of July
One thousand eight hundred and seventy-two.