IMPROVEMENTS IN REGENERATIVE GAS FURNACES AND APPARATUS CONNECTED THEREWITH FOR THE MANUFACTURE OF GLASS, ALSO PARTLY APPLI- CABLE TO REGENERATIVE GAS FURNACES GENERALLY
Year: 1870

page_text: LETTERS PATENT to Charles William Siemens, of No. 3, Great George
Street, Westminster, in the County of Middlesex, for the Invention
of "IMPROVEMENTS IN REGENERATIVE GAS FURNACES AND APPARATUS
CONNECTED THEREWITH FOR THE MANUFACTURE OF GLASS, ALSO PARTLY APPLI-
CABLE TO REGENERATIVE GAS FURNACES GENERALLY."-Partly a communi-
cation from abroad by Frederick Siemens, of Dresden, in the
Kingdom of Saxony.
Sealed the 28th October 1870, and dated the 25th May 1870.
PROVISIONAL SPECIFICATION left by the said Charles William Siemens
at the Office of the Commissioners of Patents, with his Petition, on
the 25th May 1870.
I, CHARLES WILLIAM SIEMENS, of No. 3, Great George Street, West-
5 minster, in the County of Middlesex, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN REGENERATIVE GAS FURNACES AND
APPARATUS CONNECTED THEREWITH FOR THE MANUFACTURE OF GLASS, ALSO PARTLY
APPLICABLE TO REGENERATIVE GAS FURNACES GENERALLY," to be as follows:-
One part of this Invention has reference to an improved construction
O of the gas producers of regenerative gas furnaces for the manufacture of
glass.

page_text: In working gas producers of the form and arrangement described in
the Specification to Letters Patent granted to myself and Frederick
Siemens, bearing date 22nd January 1861, No. 167, considerable loss of
effect and inconvenience in working has arisen in consequence of the
condensation of tar and soot in the flues leading from the gas producers
to the furnaces, the cause being that the carbonic oxide gas produced
in the lower portions of the apparatus near the grate mixed within the
flues with the volatile hydrocarbons and other vapours distilled off from
the fuel in the upper part of the producer, which gases not being in a
permanently gaseous condition were thereby condensed to a considerable
extent and deposited in the form of tar and soot.
Now the present improvements have for their object to prevent such
losses of the volatile gases by causing them before passing into the gas
mains to become of a more permanent nature than when first disengaged
from the fuel.
For this purpose we construct the gas producers of three com-
partments or chambers, one of which contains the fuel passing down
upon an inclined plane on to a grate at the bottom, and acts in a
similar manner for the production of the gases as the producers described
in the before-mentioned Patent. Facing the inclined bed of fuel is a fire-
brick wall passing down from the top of the producer to within some
distance above the grate at the bottom, which wall separates the producing
chamber from the two other chambers or compartments at the back with
which it communicates, firstly, by means of the space left at the bottom
of the division wall, and, secondly, by means of a passage connecting
the top of the producing chamber with the top of the back compartments.
At the point where the passage enters these compartments a reversing
valve is placed by means of which the gas passage is alternately made
to communicate with the one or other of the back compartments, while
the other compartment is at the same time put in communication with
the main gas flue. In each of the back compartments zig-zag passages
are formed, the upper ends of which communicate with the gas passage
from the producing chamber, while the lower ends communicate with the
space over the fire-grate thereof. From this arrangement it will be seen
that when decomposition of fuel is going on in the producing chamber the
volatile gases distilled from the fuel at the top of the chamber will pass
through the before-mentioned passage into one of the back compartments,
will pass up and down in the zig-zag passages thercof, thereby becoming

page_text: considerably heated, and will then issue at the bottom among the highly
heated layer of fuel on the grate of the producing chamber. By the heat
to which these gases are thus subjected they will become effectually decom-
posed, forming permanent hydrogen and carbonic oxide gases, which mix
with the carbonic oxide gas passing off from the lower part of the layer of
fuel. These mixed gases then ascend through the zig-zag passages of the
other back compartment, giving off the greater portion of their heat to
the walls thereof, and eventually escape into the gas flue to the furnaces.
When by this action the passages of the one back compartment have
become considerably heated, while those of the other compartment have
been cooled by the passage of the cool volatile gases the reversing valve
is moved so as to change the direction of communication, the cool gases
being made to descend through the heated compartment while the
combined heated gases pass away through the cool one. Closed apertures
may be provided in the passages in order that should any deposit of soot
or tar take place therein these may be burnt out by the introduction of
air through such apertures.
In place of establishing the communication between the top of the
producing chamber and two back compartments or regenerators as they
may be termed, there may be only one such back compartment with or
without zig-zag passages, and the volatile gases may be caused to
descend in the producing chamber to the aperture at the bottom of the
division wall, where in passing into the back compartment they come in
contact with the heated fuel on the grate and are acted upon thereby as
before described.
It will be evident that the above described improved construction of
gas producers is also applicable to other regenerative gas furnaces besides
glass furnaces.
Another part of this Invention has reference to an improved con-
struction of the heated gas and air passages or ports of regenerative gas
furnaces for the manufacture of glass for the purpose of producing a
more effectual intermixture of the gas and air on entering into com-
bustion. For this purpose the vertical air ports are raised very nearly
to the roof of the furnace while the side walls of the gas flues are
brought forward towards the heated chamber in a divergent manner
until those of the one gas flue meet those of the adjacent gas flues,
whereby the gas is introduced into the heated chamber below the air
through channels or ports increasing gradually in width towards the
A 2

page_text: furnace where it is met by the air passing in in diverse directions. The
tops of the gas ports are covered in to a certain extent, whereby the gas
on passing up the vertical passages is prevented from passing at once up
through the stratum of air coming in through the raised air ports, the
gas being deflected by the covering and caused to pass some distance
forward through the diverging ports before coming in contact with the
descending stratum of air.
This arrangement is also applicable to other regenerative gas
besides glass furnaces.
furnaces
Another part of the Invention has reference to an improved con-
struction of and mode of working glass pots or tanks of glass furnaces.
Heretofore the materials have been first charged into glass pots or tanks
then melted down, and then worked out completely, after which they
have been recharged and the process repeated, thus entailing con-
siderable loss of time through the intermittent nature of the work.
Now the present improvement has for its object to render the process of
glass making a more uniform and continuous one, and consists in con-
structing the glass pots or tanks with three separate compartments, in
one of which the materials are introduced continuously or at short
intervals, and from which the materials as they melt are caused to flow
into the next compartment where the operation of melting is completed,
and whence the glass flows into the third compartment where it is
worked out continuously. To produce this circulation of the melted
glass through the three compartments advantage is taken of the
gradually increasing specific gravity of the glass as it becomes more and
more heated. Thus, when this Invention is applied to glass pots the first
compartment communicates with the second one through a small
vertical passage into which the melting materials as they descend in the
compartment by virtue of their increasing specific gravity enter through
a hole at the lower end, and in rising up in the passage eventually
flow over into the second compartment. Here as the melted glass
accumulates that portion thereof which has become most highly heated
and is consequently in the most fluid and clarified condition again
descends by virtue of its increasing specific gravity, and finds its way
through an aperture at bottom into the third compartment in which it
rises, and whence it is worked out in the usual manner. This latter
compartment is provided with a cover having a working aperture as in
ordinary glass pots.

page_text: In applying the Invention to tank furnaces the tank is divided in
its length into three compartments by means of transverse partitions or
bridges provided with air passages in communication with vertical air
shafts for effecting a circulation of cold air through the same. Into the
hindmost of the compartments the crudo materials are introduced and as
they melt they pass through apertures at the bottom of the first bridge
into vertical channels formed in the same in which the melted glass
rises and then flows over the bridge into the second or middle com-
partment where the operation of melting is completed. Lastly, the glass
flows from this compartment through apertures in the bottom of the
second partition into the front or working compartment. The heated
air and gas ports constructed by preference as before described are
arranged along each side of the tank so that the flames play across the
same, thus allowing the requisite temperature to be maintained in cach
compartment by means of a regulated admission of the gas and air
effected by making the ports of different dimensions. For this purpose
also a division wall provided with air passages is carried right across the
furnace at the hindmost partition, thereby entirely separating the
heating chamber to the hindmost compartment from that of the other
compartments, in which a greater heat is maintained. The gas and air
ports are continued backwards through the brickwork of the furnace and
are closed outside by means of slabs, by removing which the glass tank
may be rendered accessible through such ports at any point of its
length.
5 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 25th November 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
WILLIAM SIEMENS, of No. 3, Great George Street, Westminster, in the
O County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fifth day of May, in the year of
our Lord One thousand eight hundred and seventy, in the thirty-third year
of Her reign, did, for Herself, Her heirs and successors, give and grant
5 unto me, the said Charles William Siemens, Her special licence that I, the

page_text: said Charles William Siemens, my executors, administrators, and assigns, or
such others as I, the said Charles William Siemens, my executors, adminis-
trators, 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 REGENERATIVE GAS FURNACES
AND APPARATUS CONNECTED THEREWITH FOR THE MANUFACTURE OF GLASS, ALSO
PARTLY APPLICABLE TO REGENERATIVE GAS FURNACES GENERALLY," the result partly
of a communication made to me from abroad by Frederick Siemens,
of Dresden, in the Kingdom of Saxony, and partly of an Invention and
discovery made by myself, 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
scals, 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 :-
One part of this Invention has reference to an improved construction
of the gas producers of regenerative gas furnaces for the manufacture of
glass and for other purposes.
In working gas producers of the form and arrangement described in the
Specification to Letters Patent granted to myself and Frederick Siemens,
bearing date 22nd January 1861, No. 167, considerable loss of effect and
inconvenience in working has arisen in consequence of the condensation
of tar and soot in the flues leading from the gas producers to the furnaces,
the cause being that the carbonic oxide gas produced in the lower
portions of the apparatus near the grate mixed within the flues with
the volatile hydrocarbons and other vapours distilled off from the fuel
in the upper part of the producer, which gases not being in a permanently
gaseous condition were thereby condensed to a considerable extent and
deposited in the form of tar and soot.

page_text: Now the present improvements have for their object to prevent such
losses of the volatile gases by causing them before passing into the gas
mains to become of a more permanent nature than when first disengaged
from the fuel. For this purpose I construct the gas producers with one
or more separate chambers or compartments behind the combustion
chamber, so arranged that the volatile gases given off at the upper part
of the layer of fuel in the combustion chamber are caused to descend
into the lower portion of the back chamber or chambers where they are
brought into contact with the lower highly heated portion of the fuel
and with highly heated surfaces, thereby being converted into permanent
hydrogen and carbonic oxide gases, while at the same time they are
caused to mix with the highly heated permanent combustible gases
produced in the lower part of the combustion chamber; these combined
gases then rise up through the back chamber or chambers and pass into
the main gas flue.
Variously modified arrangements of such improved construction of gas
producers may be employed.
Figures 1 and 2 on Sheet I. of the Drawings shew the arrangement
which I prefer to employ; Figure 1 shews a vertical section on line 1-1,
Figure 2, and Figure 2 shews two different sections taken respectively
on lines 2-2, and 2-2, Figure 1; similar letters of reference indicate
similar parts in each of the Figures.
The producers are here shown in duplicate arranged back to back, but
they may equally well be arranged in a single row. In this arrangement
the producer consists of the front or combustion chamber A, and the two
back chambers B, B', separated from the combustion chamber by the par-
tition wall C passing down to within a short distance from the fire-grate;
the combustion chamber is of the ordinary construction, the fuel being
introduced through the hopper D, and caused to pass in a thick layer down
the inclined fire-brick plane E on to the grate E¹ at bottom. The top of
the combustion chamber communicates with the upper ends of the
chambers B, B', through a passage F opening into a passage G common to
both the back chambers, with which the passage F is made to communicate
alternately by means of the reversing valve H. In the chambers B, B',
are formed zig-zag flues I, I, I', I', communicating with the passage G at
top, and at bottom with the space J, also common to both the chambers,
and opening into the combustion chamber A below the partition wall C.
The upper passage G also communicates through the opening K with the

page_text: main gas flue L leading to the furnaces, which opening is so arranged
that when the valve H is in the position for establishing a communi-
cation between the top of the combustion chamber and the one back
chamber it at the same time establishes a communication between
the other back chamber and the gas flue L. From this arrangement
it will be seen that assuming the reversing valve H to be in the
position shewn at Figure 2, the volatile gases distilled off from the
upper part of the layer of fuel in the combustion chamber instead of
escaping directly into the gas flue L as was heretofore the case, are
caused by the draught to pass through the passages F and G into the
compartment B, where they traverse the zig-zag passages I which are
heated partly by the combustion going on in the chamber A and partly
by the previous passage of hot gases as presently described. From
the flues I the gases issue in a considerably heated state into the
space J, where they become further heated to a high degree by being
brought into contact with the lower highly heated portion of the layer
of fuel on the grate and by mixing at the same time with the highly
heated carbonic oxide and other gases generated from the lower part of
the layer of fuel, and thus the converstion of these volatile gases into
permanent hydrogen and carbonic oxide gases is effected. From the
space J these combined gases are now caused by the draught from the
gas flue L to rise into the chamber B¹ where in traversing the zig-zag
flues I¹ they are made to give off a portion of their heat to the walls of
the chamber before issuing through the passage G and opening K. into
the gas flue L. When by this means the chamber B¹ has become con-
siderably heated while the chamber B has become cooled by the passage
of the cooler volatile gases, the position of the valve H is reversed so
as to cause the volatile gases to descend through and take up heat from
the chamber B¹, while the hot gases rise up through and give off heat
to the chamber B, the chambers B, B', being thus made to act to a certain
extent as regenerators. Stoppered apertures are provided at M through
which access can be gained to the passages of the chambers B, B¹, for the
removal of any deposits of soot or tar may take place. The opening K
is also provided with a sliding damper K³ for regulating the draught and
closing the communication between the producer and the main gas flue
when required

page_text: chamber B formed by the division wall C, and the volatile gases instead
of passing off from the top of the combustion chamber, as in the previous
arrangement, are caused to descend in this chamber to the bottom of
the division wall C, where in passing into the chamber B they are
brought into intimate contact with the highly-heated lower portion of
the layer of fuel, and at the same time are mixed with the highly heated
gases produced from such portion of the fuel. The volatile gases aro
thus decomposed and converted into permanent gases as before described ;
and the combined gases then pass up through the chamber B and
through the opening K into the gas flue L; M is as before an aperture
for clearing the chamber B from carbonaceous deposit.
Another part of this Invention has reference to an improved con-
struction of the heated gas and air passages or ports of regenerative gas
furnaces for the manufacture of glass and other purposes (other than
steel melting furnaces) for the purpose of producing a more effectual
intermixture of the gas and air on entering into combustion. For this
purpose the vertical air ports are raised very nearly to the roof of the
furnace, while the side walls of the flues are brought forward towards
the heated chamber in a convergent manner until they meet, whereby
the gas is introduced into the heated chamber below the air through
channels or ports, increasing gradually in width towards the furnace
where it is met by the air passing in in diverse directions. The tops of the
gas ports are covered in to a certain extent, whereby the
gas in passing
up the vertical passages is prevented from passing at once up through
the stratum of air coming in through the raised air ports, the gas being
deflected by the covering and caused to pass some distance forward
through the diverging ports before coming in contact with the descending
stratum of air.
Another part of the Invention has reference to an improved con-
struction of and mode of working glass pots or tanks of glass furnaces.
Heretofore the materials have been first charged into glass pots or
tanks, then melted down, and then worked out completely, after which
they have been recharged, and the process repeated, thus entailing con-
siderable loss of time through the intermittent nature of the work, besides
other disadvantages. Now the present improvement has for its object
to render the process of glass making a continuous and more uniform
one, and consists in constructing the glass pots or tanks with three
separate compartments, in one of which the materials are introduced

page_text: continuously or at short intervals, and from which the materials as they
melt are caused to flow into the next compartment where the operation
of melting is completed, and whence the glass flows into the third
compartment, where it is worked out continuously. To produce this
circulation of the melted glass through the three compartments advan-
tage is taken of the gradually increasing specific gravity of the glass as
the melting down thereof proceeds. By this means a stratification
according to the condition of the mass is effected, allowing of its
being subjected to different temperatures corresponding with the parti-
cular stage of preparation at which the several portions thereof have
arrived.
Figures 4 to 8 on Sheet II. and Figures 9 to 14 on Shect III. of the
Drawings, shew the application of this part of the Invention to glass
pots.
In the arrangement shewn on Sheet II., Figure 4 shews a plan of
the pot Figure 5 shews a sectional plan on line 5-5, Figure 6;
Figure 6 shews a vertical section on line 6-6-6, Figure 5; Figure 7
shews a vertical section on line 7-7, Figure 5; and Figure 8 shows a
vertical section on line 8-8-8, Figure 5. The pot is constructed
with three separate compartments A, B, C, of which A serves to
receive the raw materials, and communicates with the intermediate or
clarifying compartment B by means of the aperture a and the vertical
passage b, while the compartment B communicates with the third or
working-out compartment C through the aperture c at bottom. The
compartments A and B are open to the direct action of the flame, while
the compartment C is closed in at top in order to protect it from such
direct action of the flame, and it is provided with a nozzle d which pro-
jects through the working aperture of the furnace, and through which
the glass is worked out in a similar manner to ordinary glass pots.
The two uncovered compartments A and B serve for the melting down
and clarifying of the melted glass supplied to the working compartment
in the following manner :-The raw materials are introduced in small
quantities into the compartment A which, as shewn in the Drawing, is
maintained as nearly as possible in a filled condition. As the materials
melt they will by virtue of their increasing gravity accumulate in the
bottom of the compartment in such manner that the perfectly melted
particles will be situated quite at the bottom, while the portions that are
in a less perfectly melted condition will be stratified above the same

page_text: according to the degree of heat which they have attained. As the
melting down proceeds the lowest stratum in the compartment will pass
through the aperture a into the channel b, in which it will rise, and
eventually flow over into the compartment B. As this compartment
fills a stratification of the material similar to that in A will take place,
the most perfectly clarified and densest portion of the glass sinking to
the bottom, while that which is less clarified and charged with air
bubbles will remain in the upper part until by the action of the furnace
heat it becomes clarified and in its turn, and is caused by the continued
entrance of fresh material from the passage b to sink to the bottom,
thereby forcing the lower stratum through the aperture c into the com-
partment C. As the lower part of the glass pot is cooler than the upper
part the compartment B serves both to clarify the glass in the upper
part and to cool the same down in the lower portion, in which cooled
condition the glass consequently enters the compartment C ready for
working out. All three compartments are thus always filled with glass in
different stages of preparation, the level of the glass being however different
in each compartment, as shown on the Drawing, corresponding with the
respective differences of the mean specific gravity of the several contents.
It will be understood from the foregoing that in proportion as the glass
is worked out of the compartment C fresh material must be charged
into the compartment A, which operation is effected by the glass blower,
who also from time to time skims the surface of the glass in the com-
partment B in order to remove impurities or imperfectly melted particles.
By this improved construction of glass pots it is rendered possible while
maintaining the furnace heat at one uniform temperature to effect the
four different operations which are requisite for the perfect manufacture
of glass, namely, the melting down of the materials, the clarifying of
the melted mass, the cooling down thereof, and the working out of the
cooled mass.
Figures 9 to 14, on Sheet III., shew a modified form of the above
described improved glass pot; Figure 9 shews a plan of the same;
Figure 10 shews a vertical section on line 10-10, Figure 9; Figure 11
shews a section on line 11-11, Figure 10; Figure 12 shews a sectional
plan on line 12-12, Figure 14; and Figures 13 and 14 shew sections
respectively on lines 13-13-13 and 14-14-14, Fig. 12. The
general arrangement of the pot is the same as in that just described, the
raw material being introduced into the compartment A from which

page_text: the melted glass passes into the compartment B, where it is clarified
and whence it descends into the closed compartment C where it is
worked out. The compartment B is however here formed over the com-
partment C, the melted materials being caused to pass from A through
the aperture a and channel 6 into B, from the bottom of which it first
ascends through the aperture c and channel e, and then flows over into
the spacef, communicating at bottom with the compartment C through
the aperture g. From the arrangement of the passages e, f, it will be
seen that though the compartment B is raised entirely above the level
of the glass in C, yet the glass will only flow into the latter compartment
in precisely the same measure as it flows from A into B. In both the
above described arrangements of glass pots the working out compart-
ment C, in place of being formed by a fixed partition in the com-
partment B, may be constructed as a loose compartment in the form
of a deep ring floating in the melted glass in the compartment B so as to
reach nearly to the bottom of the latter, through which ring the melted
glass will rise from the compartment B in the same manner as is the
case with the fixed compartment C.
Figures 15 and 16, on Sheet III., shew the mode of arranging these
improved glass pots in a regenerative gas furnace. Figure 15 shews a
section on lines 15-15 and 15-15°, Figure 16; and Figure 16 shews a
section on lines 16-16 and 16-16, Figure 15. The furnace is con-
structed to contain four glass pots A, A, two of which are arranged on
cach side of the central gas and air flues D, D¹, from the regenerators
F, F. The glass pots are placed so that the nozzles d of the compart-
ments C project through the working apertures H, H, in the end walls
of the furnace, while the raw materials are charged into the com-
partments A, A, through the charging apertures I, I, in the side walls
of the furnace.
I do not claim the construction of these furnaces as forming any part
of the present Invention. I would also here remark in connection with
the before-described improved construction of glass pots that I am aware
that glass pots for melting down and reworking broken glass or glass
lumps in a continuous manner have been constructed with a partition or
with two compartments, into one of which the broken glass or glass
lumps were introduced and melted down and from which the melted
glass was caused to flow into the second compartment from which the
glass was worked out, and I do not therefore claim such a construction
-

page_text: of glass pots, such glass pots are moreover of but limited application,
partly on account of the expensive nature of the materials, and partly
because good glass cannot be manufactured from such materials alone.
Figures 17 to 20, on Sheet II. of the Drawings shew the arrangement
of a regenerative tank glass furnace constructed according to this
Invention, which also shews the before-described improved construction
of gas and air ports; Figure 17 shews a longitudinal section on line
17-17, Figure 18; Figure 18 shews a sectional plan on line 18—18,
Figure 19; and Figures 19 and 20 shew transverse sections respectively,
on lines 19-19 and 20-20, Figure 18. The tank of the furnace is
divided similarly to the before-described glass pots into three separate
compartments A, B, C, of which A serves to receive the raw materials,
while B is the clarifying compartment, and C the working compartment.
The compartment A is fed with raw material through the charging
aperture D at the back end of the furnace; it is separated from the
compartment B by the division wall E, E¹, in which a series of passages
a, a, a, are formed, passing first horizontally from the bottom of the
compartment A, beneath the part E of the partition and then rising
vertically to the top of E¹. Through these passages the melted glass
passes from the bottom of A into the top of B, from the bottom of which
compartment it flows into the compartment C through the passages b,
The division
formed through the bottom of the division wall F.
walls E, E', as also the sides and bottom of the tank are formed with
air passages d, d, d, as shewn, through which cold air is caused to
3 circulate by the draught produced by the chimnies G, G, with which
these passages communicate. The tank is thus maintained in a cooled
condition, so as to enable it the better to withstand any injurious action
of the melted glass. The gas and air ports H, H, H², H², from the
regenerators I, I, I', I', are arranged along each side of the tank, so as
to cause the flames to play across the latter. The air ports H³, H', are
made to rise nearly to the roof of the furnace as shewn, the side walls J
being brought forward in a convergent manner until they meet, while
the gas ports H, H, are covered in somewhat by fire-brick slabs K, K,
so as to deflect the combustible gases rising through the vertical passages
5 and cause them to issue in a horizontal direction into the furnace under-
neath, the heated air issuing in diverse directions over the upper edges
of the walls J. By these means an effectual intermixture of the com-
bustible gas and air is produced, and the air is prevented from coming

page_text: into immediate contact with the surface of the melted glass in the tank.
By arranging the gas and air ports along the sides of the tank, I am
enabled to regulate the temperature in the different parts of the furnace
according to the various stages of preparation of the glass in the several
compartments, this regulation being effected by constructing the gas and
air ports of larger dimensions at the compartment A. where greater heat
is required than in the compartment B; and in order the more effectually
to maintain this requisite difference of temperature the compartment A
is by preference entirely separated from the other part of the furnace
by means of the division wall L, carried up to the roof of the furnace,
which wall is provided with air passages e, e, communicating with
chimnies e for keeping it cool. As before stated the raw materials
introduced into the compartment A on being acted upon and melted
down by the surface heat there produced, gradually sink down to the
bottom of the tank, and pass thence up through the passages a, a, over
the top of the partition or bridge E' into the compartment B. By being
thus made to pass in a thin layer in immediate contact with the surface
heat of the furnace the glass becomes perfectly clarified and sinks
gradually to the bottom of the compartment, in thus passing away out
of contact with the surface heat into the lower portion of the tank
cooled by the air passages the glass is cooled down to the requisite
degree, in which state it passes through the passages 6 into the working
compartment C, where it is worked out through the openings M, M,
formed in the semicircular front end of the furnace. The compartment C
is only heated by a portion of the flames in the compartment B, passing
in over the top of the partition wall F and playing out of the working
apertures M, whereby this compartment is maintained at the requisite
cooler temperature for working out the glass. This temperature may be
effectually regulated by regulating the draught of the furnace chimney,
for according as the draught is increased a less amount of the flames
will find their way over the compartment F. If required the partition
wall F might also be carried up to the roof of the furnace so as
to protect the working out compartment C entirely from the direct
action of the flames in a similar manner to the compartment C of
the glass pots before described. As the glass when melted down and
clarified should be exposed as little as possible to the further action of
the furnace heat the compartments B and C are made shallower than A,
in order to maintain only a comparatively thin layer of glass therein,
which layer is cooled by the action of the cold air passages in the sides
b

page_text: and bottom of the tank. It has been stated that in the continuous
circulation of the melted glass through the three compartments of the
tank, as also of the glass pots, advantage is taken of the circumstance
that the specific gravity of the glass increases in proportion to its increase
in temperature. This circumstance is however productive of one in-
convenience, namely, that in those portions of the tank or glass pot
where the glass is caused to ascend in its forward motion, the increasing
density will tend to produce a stagnation of the particles resulting in a
deterioration of the mass. In order to counteract this tendency it is
essential that the passages connecting the compartments A and B of
the tank or glass pot in which the glass has an ascending motion shall
have only such a sectional area as is required for the rate of progress
of the glass from one compartment to another.
The principal advantages resulting from the use of the above-described
improved construction of glass pots and tanks are,-
Firstly. An increased power of production in the furnace, as the full
melting heat may be employed in the same without interruption, instead
of the intermittent action of furnaces of present construction.
Secondly. An economy in working, as less labor will be required for
carrying on the operation than in the ordinary process.
Thirdly. A greater durability of the pots and tanks owing to the
uniform temperature to which they are subjected.
And, fourthly. A much greater regularity of working and more
uniform quality of the product will be attainable thereby.
It will be readily understood that the before-described improved
construction of glass pots and tanks may also be employed for melting
other vitreous substances that admit of being prepared in a similar manner
to glass.
Having thus described the nature of this Invention, and in what
manner the same is to be performed, I wish it to be understood that
I do not claim the application of the before-described peculiar con-
struction of gas and air ports to regenerative steel melting furnaces,
as this application has already been patented by me; but what I claim
is,—
First. Constructing gas producers to regenerative gas furnaces with
one or more separate chambers or compartments behind the combustion

page_text: chamber so arranged that the volatile gases given off at the upper portion
of the layer of fuel in the combustion chamber are caused to descend
into the lower portion of the separate chamber or chambers, where they
are brought into contact with the lower highly heated portion of the
fuel and with highly heated surfaces, and are at the same time mixed
with the heated permanent gases passing off from the lower portion
of the fuel, substantially as and for the purposes herein-before set
forth.
Second. Constructing gas producers having two separate chambers or
compartments behind the combustion chamber so arranged that the
volatile gases given off at the upper portion of the layer of fuel are
caused to enter at the top of one or other of the back chambers, where
in descending they are brought into contact with extended heating
surfaces, and are then caused to mix with the permanent and highly
heated gases entering such chamber at the bottom, after which the
combined gases are caused to ascend through and give off heat to the
second back chamber, substantially as and for the purposes herein-before
set forth and described with reference to Figures 1 and 2 of the accompany-
ing Drawings.
Third. Constructing the gas and air ports of regenerative gas furnaces
(other than steel melting furnaces) in such manner that the vertical
air ports rise nearly to the roof of the furnace while the tops of the
gas flues are partly covered in at a lower level, the side walls of the
flues being extended forward in a convergent manner until they meet,
whereby the air is caused to issue into the furnace in diverse directions
above the combustible gas, substantially as herein-before described with
reference to Figures 17 to 20 of the accompanying Drawings.
Fourth. Constructing pots or tanks for the continuous melting of
glass and other vitreous substances with three compartments arranged
to communicate with each other in such a manner that the raw material a
is introduced and melted down in the one compartment, from the lower
part of which the melted material is caused to flow into the top of the
next compartment, whence it passes into the bottom of the third com-
partment, from which it is worked out, substantially as and for the
purposes herein-before set forth.
Fifth. Constructing such aforesaid glass pots or tanks in such manner
that the compartment into which the raw material is introduced is open
to the direct action of the flame, while the working out compartment is

page_text: closed against such direct action of the flame, and is consequently
maintained at a lower heat, substantially as described with reference
to Figures 4 to 14 of the accompanying Drawings.
Sixth. Constructing regenerative tank furnaces for the continuous
melting of glass and other vitreous substances with transverse partitions
dividing the tank into three compartments through which the melted
materials are made to flow successively while the gas and air ports are
arranged along each side of the tank so as to cause the flame to play
transversely across the same, allowing of the proper adjustment of heat
in each compartment, substantially as herein-before described with
reference to Figures 17 to 20 of the accompanying Drawings.
Seventh. Providing regenerative tank glass furnaces constructed as
aforesaid with a partition wall for separating the compartment of the
tank into which the raw material is introduced from the other com-
partments in order to allow of different temperatures being maintained in
the separate parts of the furnace, substantially as herein before described
with reference to Figures 17 to 20 of the accompanying Drawings.
In witness whereof, I, the said Charles William Siemens, have
hereunto set my hand and seal, this Twenty-second day of
November, in the year of our Lord One thousand eight hundred
and seventy.
Witness,
CHAS. D. ABEL
C. WILLIAM SIEMENS. (L.S.)
20, Southampton Buildings.