CERTAIN IMPROVEMENTS IN STEAM BOILERS
Year: 1853

page_text: LETTERS PATENT to Peter Erard, of Marseilles, in the Empire of
France, and 4, South Street, Finsbury, London, Civil Engineer,
T
Sealed the 30th December 1853, and dated the 6th July 1853.
PROVISIONAL SPECIFICATION left by the said Peter Erard at the
Office of the Commissioners of Patents, with his Petition, on the
6th July 1853.
I, PETER ERARD, of Marscilles, in the Empire of France, and 4,
South Street, Finsbury, London, Civil Engineer, do hereby declare
that the nature of the Invention for "CERTAIN IMPROVEMENTS IN STEAM
BOILERS" to be as follows:-
My improvements consist in construoting two apparatus composed of
iron or brass pipes, varying in number, thickness, and diameter, with
a space left between each of them, and which space varies according to
the dimensions of the furnace to which the apparatus are to be adapted.
Part of these pipes forms a grate to receive the combustibles, and the
other part forms the upper part of the furnace.
Although working independantly of each other, they may be, if
required, connected together by means of the feeding pipes of the

page_text: boiler. All the pipes forming an apparatus are in communication for
the same reservoir.
The steam generated by the heating of the water contained in each
apparatus is introduced into the steam chest of the boiler by means of
pipes connected with it.
The caloric contained in the metal pipes is absorbed by the water
contained in these pipes, instead of being consumed uselessly in the
air, alimenting the combustion of the fuel.
By the construction of my apparatus the bars of the furnace grates,
which, when intensely heated, were liable to melt, is avoided. The
close disposition of my pipes prevents the loss of the powdered coal,
which is burnt in the furnace.
The external parts of the pipes, being in immediate contact with the
fire, give to the heated water a circulation increasing according to the
augmentation of heat in the furnace, and generate a more abundant
quantity of dry steam than can be produced by the boiler itself.
Although these apparatus occupy but a small compass, yet they
produce a saving of thirty-five to forty per cent. on the quantity of
fuel required; generating alone the stetun required for the working of
the engine they allow the boiler to be reduced in bulk.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Peter Erard in the Great Seal Patent Office
on the 6th January 1854.
CAME T
boiler. All the pipes forming an apparatus arc in communication for
the same reservoir.
The steam generated by the heating of the water contained in each
apparatus is introduced into the steam chest of the boiler by means of
pipes connected with it.
The caloric contained in the metal pipes is absorbed by the water
contained in these pipes, instead of being consumed uselessly in the
air, alimenting the combustion.of the fuel.
By the construction of my apparatus the bars of the furnace grates,
which, when intensely heated, were liable to melt, is avoided. The
close disposition of my pipes prevents the loss of the powdered coal,
which is burnt in the furnace.
The external parts of the pipes, being in immediate contact with the
fire,, give to the heated water a circulation increasing according to the
augmentation of heat in the furnace, and generate a more abundant
quantity of dry steam than can be produced by the boiler itself.
Although these apparatus occupy but a small compass, yet they
produce a saving of thirty-five to forty per cent. on the quantity of
fuel required; generating alone the steam required for the working of
the engine they allow the boiler to be reduced in bulk.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed the said Peter Erard in the Great Seal Patent Office.
on the 6th January 1854.
TO ALL TO WHUN THESE PRESENTS SHALL COME, I
PETER ERARD, of Marseilles, in the Empire of France, and 4, South
Street, Finsbury, London, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixth day of July, in the year of
our Lord One thousand eight hundred and fifty-three, in the seven-
teenthi year of Her reign, lid, for Herself, Her heirs and successors
give and grant unto me, the said Peter Erard, Her special licence
that T, the said Peter Erard, my.executors, administrators, and assigns
or such others as I, the said Peter Erard,, my executors, adminis
trators, and assigns, should at any time agree with, and no others

page_text: 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 "CERTAIN IMPROVEMENTS
IN STEAM BOILERS," upon the condition (amongst others) that I, the said
Peter Erard, by an instrument in writing under my hand and 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 Scal Patent Office within six calender
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Peter Erard, do hereby declare
the nature of my said Invention, and in what manner the sume is to
be performed, to be particularly described and ascertained in and by
the following statement thereof, reference being had to the Figures
of the Drawings hereto anexel, and to the figures and letters marked
thereon, that is to say:
My Invention consists in applying to steam boilers of land or marine
engines tubular apparatus for increasing the heating surface of boilers
and economising fuel: These apparatus vary in form, arrangement,
and dimensions, and are susceptible of being taken down for repairs
without stopping the working of the engine. Both apparatus contain
water. One of them is employed in lieu of a fire grate to support the
fuel; the other is set at the top of the grate to receive the flame; and
both serve to heat the water before it proceeds to the main boiler.
The annexed Drawings represent the said apparatus alone, and
uplied to steam engine boilers.

page_text: the boiler. T, T, circulating tubes. A, A, front box or receiver, set
beyond reach of the fire, and supplied at the back part of the boiler;
C, cover of the front part of the apparatus; E, the interior of the tubes,
seen when the cover C, is removed; 7, 1, conical plugs used to stop the
tubes when required.
Drawing 11. Figures 1, and 2, marine boiler with double internal
furnace, having the upper and lower apparatus, Figures 1, and 2, of
Drawing 1, applied.
Figure 1, is a front view, part of the cover of the receiver being taken
off to shew the inside.
Figure 2, a longitudinal section of the same. A, upper evaporating
apparatus; B, double tubular grate, set between the two hearths in
front of the boiler; B, Figure 1, single tubular grate; C, feeding tube.
Each apparatus may have a separate supply of water. D, steam con-
duct pipes; E, atmospheric valve.
Figure 3, is a front view of a cylindrical boiler with internal furnace,
having the upper apparatus applied.
1
Figure 4, a longitudinal section, Figure 5, back view of the boiler,
part of the back plate being taken off to shew the inside. m, m³, m",
flame circulating pipes. A, upper evaporating apparatus of
Figure 3, Drawing I., extending the whole length of the boiler. O, P,
smoke boxes; I, steam chest; G, grate. The arrows shew the direc-
tion of the flame or gases.
Drawing III Figure 1, front view of the boiler with interval furnace,
and provided with the upper circulating tubular apparatus, Figure 3,
Drawing 1.
Figure 2, longitudinal section of same.
Figure 3, view of back boiler and of the conical stoppers 1, 1.
Figure 4, is an end view, and Figure 5, a section of a cylindrical
boiler with internal furnace, provided with flame pipes and with the
tubular apparatus A, of Figure 3, Drawing I. The tubes are more
numerous than in the proceeding boilers, and are set circularly. They
inay be closed air-tight by the conical stoppers 1, 1. G, G, ordinary fire
grate; F, F, feeding pipes; V, V, V, steam conduct pipes; m, m³, ml,
smoke boxes. When required to withdraw the boxes or receivers it

page_text: will be merely necessary to revove the external plates. Staves may be
applied round the boilers to retain the heat. The grate or lower appa-
ratus, Figure 1, Drawing I., may be either single or double, and is
made of iron or copper tubes. Their number, thickness of metal,
external diameter, and space left between them, varying according to
the size of the furnace, the kind of fuel, and draught obtained. The
tubes are set in one or two horizontal rows, half of which meet in one
common box or reservoir set externally in front of the boiler, between
the bottom of the furnace door and top of the hearth door. A pipe of
large diameter, having one extremity set in this reservoir and the other
passing into the boiler between the two hearths at the bottom, serves to
supply the smaller tubes of the grate, which terminate in the said reser-
voir, with water. This water first proceeds to the bottom of the furnace,
where their upper extremities meet in a box serving as reservoir
common to all, and passes thence into the other tubes, which conduct
it into the front reservoir made for tlic return tubes. An ascending
tube is also adapted at one extremity of the latter reservoir, and the
other extremity to the boiler, at the height of the water's level, where
it discharges the water, overheated during its double passage thro'
the tubes of the grate, in a state of water and steam, as seen at Figures
1, & 2, Drawing II. The water in the grate which holds the lighted
fuel absorbs the caloric directly it penetrates through the metal com-
posing them, and becoming lighter than the water contained in the
boiler circulates through the apparatus by means of the ascending tube,
and is replaced by water coming from the bottoni of the boilers through
the large tube, by which means a circulation is necessarily kept up,
the rapidity of which is proportionate to the vivacity of the fire.
The second or upper apparatus, Figure 2, Drawing 1, consists, like
the grate, of a variable number of tubes, set in three horizontal or
circular rows, and either superposed or placed in the form of a quincunx,
and may vary in their diameter, dimensions, material, and form, accord-
ing to circumstances and the pressure required. Wrought iron taps
or plates are applied to the alimentary and evaporating pipes, and serve
to shut off communication between them. The apparatus are fixed
only at the front part of the boiler, the bottom part remaining free, so

page_text: that it may slide out and be withdrawn. The heated water follows the
same direction as. before. The water with which the apparatus" is
supplied acquires a temperature of 112° to 114° by being submitted
twice to the direct action of the fire in the tubes before returning to
the boiler, while the water in the boiler is at a temperature of 40°.
The heated water which passes through the large ascending tube,
entering the boiler with the stean, serves to overheat the whole mass
of water in the boiler.
The combined apparatus will produce nearly all the steam necessary
for working an engine, and permits of the boilers receiving smaller
dimensions. The steam chest may be larger, and space may be gained
by the suppression of the flame tubes in the interior of boilers.
The economy to be effected by the adoption of this new system is
estimated at about 35 or 40 per cent.
And having how described the nature of my said Invention, and
the manner in which the same is to be put in execution, I wish it to be
understood that I do not claim as of my Invention the mechanical
organ's herein described, taken separately; but what I do claim is, the
construction of apparatus for heating boilers of marine or land engines
as herein-before described and referred to in reference to the Figures of
the Drawings.
In witness whereof, I, the said Peter Erard, have hereto set my
hand and seal, this Second day of January, in the year of
our Lord One thousand eight hundred and fifty-four.