A NEW CONSTRUCTION OF FURNACES, CALLED MIXED FURNACES, PARTICIPATING OF THE HEATING BY THE SOLID FUEL
Year: 1855

page_text: LETTERS PATENT to François Théodore Botta, Brewer, of Paris, Empire
of France, for the Invention of "A NEW CONSTRUCTION OF FURNACES,
CALLED MIXED FURNACES, PARTICIPATING OF THE HEATING BY THE SOLID FUEL
Sealed the 23rd November 1855, and dated the 26th May 1855.
PROVISIONAL SPECIFICATION left by the said François Théodore Butta
at the Office of the Commissioners of Patents, with his Petition, on the
26th May 1855.
I, FRANÇOIS THÉODORE BOTTA, Brewer, of Paris, Empire of France, do hereby
declare the nature of the said Invention for "A NEW CONSTRUCTION OF
FURNACES, CALLED MIXED FURNACES, PARTICIPATING OF THE HEATING BY THE SOLID
FUEL AND BY THE COMBUSTION OF THE GASEOUS PRODUCTS," to be as follows:--
My Invention consists of a new arrangement of furnaces for heating boilers,
and other purposes, which I call mixed furnaces, owing to their participating
in the direct heating action obtained immediately from the fire or solid fuel,
and also of the heat generated by the combustion of the oxide of carbon,
obtained by the transformation of the carbonic acid evolved during the com-
bustion of the solid fuel. This mixed furnace consists of a central or main
fire-place, communicating at the top. with two lateral or annexed fire-places,

page_text: which latter are fed by the incandescent coke obtained from the coals with
which the fire in the main or central fire-place is fed. The carbonic acid, the
smoke, and other gaseous products evolved during the combustion of the solid
fuel in the main fire-place, are caused to pass downwards through the incan-
descent coke of the lateral fire-places by means of a double-acting ventilator,
viz., drawing and blowing; and during this passage the smoke is entirely
burned, and at the same time the carbonic acid transformed into oxide of
carbon, the combustion of which latter may be employed at once for overheat-
ing steam, or other purposes. Suitable apertures and partitions are adapted for
guiding the
gaseous products, and those resulting from the combustion of the
oxide of carbon are caused to pass through a regenerator of wire gauze, to
which they deliver their caloric, which latter is returned to the main fire-place
by a current of air acting in a contrary direction, and finally these gases pass
through a water bath or other purifier, in order to obtain the carbonic acid in
a state fit for being transformed into oxide of carbon.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Francois Theodore Botta in the Great Seal Patent Office on
the 26th November 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FRANCOIS
THEODORE BOTTA, Brewer, of Paris, Empire of France, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-sixth day of May, in the year of our Lord
One thousand eight hundred and fifty-five, in the eighteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Francois Theodore Botta, Her special licence that I, the said
Francois Theodore Botta, my executors, administrators, and assigns, or such
others as I, the said Francois Theodore Botta, 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 "A NEW CONSTRUCTION OF FURNACES, CALLED MIXED FURNACES,
PARTICIPATING OF THE HEATING BY THE SOLID FUEL AND BY THE COMBUSTION OF
THE GASEOUS PRODUCTS," upon the condition (amongst others) that I, the said
Francois Thocdore Botta, by an instrument in writing under my hand and

page_text: seal, should particularly describe and ascertain the nature of the said Inven-
tion, 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 Francois Theodore Botta, 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 (that is to say):-
For a long timo past the furnaces of steam boilers have remained without
improvement, and all the systems thought of have not been completely satis-
factory, either as regards economy in fuel, or the consumption of the smoke.
It is to fill up this blank that I have invented my mixed fire-place, or gene-
rator of oxide of carbon, applicable to all boilers in general, whether for use on
land or sea, fixed or moveable, for steam vessels or locomotives, to the heating
of all furnaces for lime, plaster, iron, steel, china, bricks, gas, in short, every-
The same letters indicate the corresponding parts in the different Figures.
First part of the fire-place, intended for burning the coal; second part of the
fire-place, intended for burning the oxide of carbon. I, separating par-
tition between the two parts of the fire-place; K,generator and boiler tubes;
Q, partition in cast iron or in clay; L, principal grate for burning the
coal; M, fine of transformation; M', grating of the flues of transformation;
N', places for taking out the cinders; N, chamber of a ventilator or of a jet
of steam; 0, opening for the air to enter; V, passage for the oxide of carbon;
V', passage for the air coming from 0; W, ventilator, which may be
replaced by a jet of-steam rising and falling; R, flue for burning the oxide.

page_text: of carbon; R', flue of the mixture with the air; s and s', slits or openings
of the flues; S, partition for the distribution of the flame, formed by a net-
work of tubes placed opposite each other; P, ash pans of the grates; M',
serving as flues for the passage of the oxide of carbon to the ventilator.
Figure 6, explanation of the regenerating chimney, represented in a ver-
tical section. A, chamber, receiving the products of the combustion; B and
B', lateral chimneys of the regenerator; C and C', valves or obturators put
in movement by an intermittent power not designated; D and D', section of
the openings for the passage of the products of the combustion. F and F',
regenerators in metallic canvas, by which pass alternately either the heated
gases or the cold air absorbing the caloric; G, central chimney for conveying
the hot air into the ash pan of the principal fire-place.
Figure 7, section of two jets of steam; the one rises at its circumference,
and the other in the centre. T and T', jets; V and V', tubes, which bring
the steam for the jets; U and U', jet boxes; X and X', tubes, which convey the
steam to be mixed; Z and Z', tubes, which convey the mixed steam to its
destination. The arrows indicate the line of movement of the air, the oxide
of carbon, and the gases of combustion.
EXPLANATION OF THE ACTION OF THE MIXED FIRE-PLACE, OF THE GENERATOR
Of The Oxide OF CARBON, OF THE COMBUSTION OF THE SMOKE, AND OF
THE FORMATION OF THE OXIDE OF CARBON.
Supposing the fire-place to be at work, that the flues of transformation M
are filled with coke in a state of incandescence, and that the line of the load-
ing of the grate L is from 8 to 10 centimetres (3 to 4 inches, English
measure) above the edge of the partition Q; the stoker, before introducing a
fresh quantity, removes with the large poker the coal which is transformed into
coke to the right and left, in order to keep feeding the flues M, and throws a
fresh lot of coal in the middle along the whole length of the grate.
The smoke and the burning gasses produced follow the direction indicated by
the arrows on the Drawing, and rise through the flues M, which are filled with
coke, kept in a state of incandescence by the effect of the ventilator W, which
may be replaced by a jet of steam of a circular form, or by three or more small
jets placed in a triangular or circular form, which will force up the air and the
oxide of carbon by their centre and at their circumference. The forcing
up by the centre of the jets will be stronger than at the circumference.
The smoke in passing through the layer of coke in a state of incandescence

page_text: will be completely consumed, and the carbonic acid produced by the combus-
tion, taking a double equivalent of carbon, is transformed into oxide of carbon.
This transformation of the carbonic acid produces a very considerable cooling,
produced by the generation of the latent heat of the oxide of carbon, which
heat will be afterwards set free by the combustion.
The ventilator W is divided into two compartments; the one forces up and
drives back the oxide of carbon by the passage V into the flue R, whilst the
other compartment forces up and drives back the air by the passage V' into
the mixing flue R'. The oxide of carbon issues by the slits of the flue R,
becomes lighted and burns in consequence of its mixture with the air, and
passes out by the slit s' of the flue R', as indicated by the arrows.
When once the flame has passed through the slits or openings, it is distri-
buted by the partition S under the boiler tubes, and runs along in the upper
flues on the surface of the boiler. The partition S is formed by a network
of tubes in a serpentine form, in which is made to circulate the steam pro-
duced by the generator, leaving by an opening placed more or less low in the
steam chamber, and which will be thus heated to a proper temperature.
The steam being dilated by the effect of the heating, will have acquired a
larger volume, and its expansive force will be increased in proportion to the
number of calorics absorbed; it will be reconveyed by the serpentine tubes to
the dome of the opening for the steam of the generator; it will mix with that
of the generator, will increase its tension, and will dry it. These steams thus
mixed will cause a saving for the working cylinders of a machine; but when
the steam is to serve for heating apparatus, or for other purposes of any kind,
use is made direct of the heated steam coming from the serpentine or network
S, instead of carrying it back into the generator.
There may be also constantly made use of a more or less considerable quan-
tity of expanded steam coming from the working cylinder of the machine, and
that without the use of any mechanical means, by the application of one of the
jets of steam represented in Figure 7. The jet will be produced by the heated
steam of the serpentine S arriving by the tube V or. V' into T or T, which will
force up
in its centre or in its circumference the expanded steam coming by
the tube X or X'; after having produced its effect, the mixture of these two-
steams will take place by the attractive force of the jet produced by the heated
steam. The expanded steam will again imbibe the caloric, which is in super-
abundance in the heated steam. The mixture of these two steams has for
its object to reconstitute and to restore to the expanded steam the number of
calorics which it has lost during its expansive work. This mixture may be

page_text: made at the utmost in the proportion of 9/10th of waste steam to 1/10th of
heated steam.
The economy which will result from this mixture will be to indefinitely
retain the latent heat of the steam, excepting 1/10th, which after each renewal
of steam in the cylinder will be lost by escaping, or will be condensed.
Figure 6 represents a vertical section of the regenerating chimney, inten-
tionally separated from the generator, in order that it may be more readily
examined. A is a prolongation of the upper flue of the generator or chamber,
which receives the gases for burning, and which, according to the indication
of the arrows, pass alternately either by D' or by D into B¹ or B-through
the regenerators in metallic canvas F and F¹..
The valves or obturators C and C are united. together by an iron triangle
or rod, in such a manner that when one is open the other must be shut. The
working of this rod is caused by a small excentric wheel or pulley, which in
turning-produces an inte
an intermittent movement backward and-forward. This
small wheel is itself acted on by a spring similar to that in a spit or meat jack,
or in any other manner. These different petty movements could not be repre-
sented on Figure 6, being placed on the outside of the chimney, which is not
in the Drawing.
The effect which is produced while the gases for burning ascend from A by
D' into B' through the regenerator F' is, that the cold air descends by the
regenerator F, imbibing the caloric left by the hot gases on the metallic
canvas passing by G, to be conveyed into the ash-pan of the principal fire-place
or into the flue R', destined for burning the oxide of carbon. In fine, there
will continually exist a current of heated gas alternating its ascensional move-
ment either to the left or right, and a current of cold air descending and
also alternating its course, but in an opposite sense to that of the heated gas.
The saving which results from the regenerating chimney is very considerable,
for the heated gases of the combustion which mix with the atmosphere have a
temperature of from 300 to 400 degrees, that temperature will not be more
than from 40 to 50 degrees.
The mixed fire-place or generator of the oxide of carbon may be modified
in its ensemble, or in the different parts of which it is composed, according to
Fits destination or application. If the intention is to heat two generators of
equal force, or for one to be stronger than the other, the weaker will be heated
entirely with coal, and with the oxide of carbon arising from the transforma-
tion the stronger one will be heated. It will be the same for the boilers of
steam vessels; others with several tubular or other fire-places, or with hori-

page_text: 10,000 calorics, which will produce from 18 to 20 kilogrammes of steam for
every kilogramme of coal burnt.
The remainder of the principle of the transformation of the carbonic acid into
oxide of carbon rests on the principle of effecting that transformation outside
the principal fire-place, in order to avoid a very considerable cooling, and on
the principle of generating the oxide of carbon downwards, that is to say,
in the same direction as the supply of fuel arrives; otherwise there would
escape a too considerable quantity of carbonic acid not transformed into oxide
of carbon. In all other known gazogenes the fault is committed of effecting
the transformation in the principal fire-place, and of generating the oxide
of carbon from below upwards, that is to say, in a contrary direction to the
way the fuel is put in; for this reason no practical result is obtained sufficiently
satisfactory to completely justify the theory.
To sum up, the privilego which I claim niore specially bears on the
following reserves :-
1st, on the special form of the mixed fire-place and of the flues, mixing
the oxide of carbon and the acids placed one in the other.
2nd, on the generating of the oxide of carbon outside the principal firo
place, in order to be able to utilise the direct heat of the combustible, and to
effectively and completely burn the smoke.
3rd, of generating the oxide of carbon from above downwards, and even
horizontally, but always in the direction in which the fuel is put in.
4th, in the application of the jets of steam for the draft of the mixed
fire-place, for the mixture of the steams and for their particular form, which
produces a double effect in the centre and at the circumference, resulting from
two concentric tubes.
5th, on the application of the regenerating chimney to all chimneys in
general, and wherever they may render service.
6th, on the application of the whole or part of the mixed fire-place to all
objects and organs set forth and mentioned in the description of the Patent.
7th, in the system of heating the steam in a serpentine, placed below or in
any other part of the boiler, by the oxide of carbon.
8th, on the mixture of an expanded steam with another steam which is not
so, and that without the use of any mechanical means.
9th, on the mixture of the heated steam with that contained in the
generator itself.
10th, in the application of the power of attraction to mix streams of different
density and temperature.

page_text: 11th, that I have the power of establishing my fire-places, apparatus, and
their different organs and pieces, of all dimensions and of any metal or other
substance or material; as also to vary the form according to circumstances
and applications, and generally for all the effects produced by the agency or
the assemblage of the different pieces and organs set forth and pointed out
in the description of the above Specification.
In witness whereof, I, the said Francois Theodore Botta, have hereunto
set my hand and seal, this Twenty-fourth day of November, in the
year of our Lord One thousand eight hundred and fifty-five.
Witness,
V. HENRY, Fabricant,
Rue St. Denis, 114.
PAULIN RICHARD, Nég*,
Rue St. Denis, 110.
F. THEOD. BOTTA,
Rue N. Dame de Nazareth, 44.