IMPROVEMENTS IN STEAM BOILERS, IN APPARATUS FOR APPLYING HEAT TO STEAM BOILERS, AND ECONOMISING HEAT OF FURNACES
Year: 1856

page_text: LETTERS PATENT to Charles Benjamin Normand, of Havre, in the
Empire of France, Ship Builder, for the Invention of "IMPROVEMENTS IN
STEAM BOILERS, IN APPARATUS FOR APPLYING HEAT TO STEAM BOILERS, AND
ECONOMISING HEAT OF FURNACES."
Sealed the 5th September 1856, and dated the 29th March 1856.
PROVISIONAL SPECIFICATION left by the said Charles Benjamin Normand
at the Office of the Commissioners of Patents, with his Petition, on the
29th March 1856.
1, CHARLES BENJAMIN NORMAND, of Havre, in the Empire of France, Ship
Builder, do hereby declare the nature of the said Invention for IMPROVEMENTS
IN STEAM BOILERS, IN APPARATUS FOR APPLYING HEAT TO STEAM BOILERS, AND
ECONOMISING HEAT OF FURNACES, to be as follows:-
This Invention relates, firstly, to the construction of marine boilers, the
object being to adapt them to bear a high pressure of steam, and to make
them more compact than heretofore.
In the case of small war steamers, where it is required to set the motive
power apparatus as low as possible (to be out of range of shot), instead of
setting the cylindrical portion of the boiler, containing the tubes, in the rearof

page_text: the fire box, I place it at the side, and cause the flame to communicate with
the tubes through a rectangular fire box. This arrangement will reduce the
boiler to one-half the length of the ordinary boiler, and also render available
the space generally required at the back for cleaning the tubes.
In larger vessels, where more height is to be disposed of, and where a
number of boilers are required, I propose to place the cylindrical portion of the
boiler immediately over the fire box. The flame will then be brought to the
tubes through a vertical rectangular fire box, as in the ordinary marine boiler.
The steam generated around the furnace is made to pass through vertical com-
munications or pipes in the cylindrical part of the boiler, and it there mixes
with that created around the tubes.
The Invention' relates, secondly, to the transmission of the feed water of
marine boilers using salt water of a great part of the heat contained in the
"blow-off." I effect this object by conducting the blow-off water and the
feed water into separate intermediate vessels, which I bring into communication
at their upper parts, so that the steam generated by the gradually reduced
pressure of the blow-off will pass to the feed water, and be carried back to
the boiler.
Thirdly, this Invention relates to certain means for effecting the more
complete combustion of the fuel. This end I obtain by giving to the fire
bars a certain longitudinal motion in alternate directions, by means of suitable
machinery placed in front of the boiler. The advance motion is given simul-
taneously to all the bars, the layer of coals which they carry being brought
forward to the same extent. The return motion is given to each bar, or to a
few separately, so that the coals, by their contact with a greater numberat rest
and the inclined position of the grate, shall remain stationary. When all the
bars have been so brought backwards, a fresh advance motion is given to the
whole, again bringing forward the burning fuel. This arrangement maintains
the fire in a uniform state, and permits of the supply of air being regulated
to the exact proportion required. The coal in its different stages of burn-
ing will be distributed on those parts of the grate most convenient for a
perfect combustion. The firing can be done from a hopper in front of the
furnace without requiring the door to be opened above the grate, and the
longitudinal motion of the bars will keep the intervening spaces free of
clinkers.
The Invention relates, fourthly, to a mode of economizing the heatgiven off
from the furnace. For this purpose I cause the escaping gas to pass
through a drum or cylinder divided by longitudinal partitions into chambers

page_text: which are filled with thin heat-absorbing surfaces, and are intended alter-
nately to take up the heat of the escaping gases, and give it off to the supply
air which passes through the drum on its way to the furnace.
A chamber
having been heated by the escaping gases of combustion is converted into
an air-supplying channel, and the escaping gases then pass through an
adjoining chamber. When this is sufficiently heated, the escaping gases are
diverted into a third chamber, and in like manner all the chambers become
in their turn channels for the air supplied to the furnace, which air is
thereby heated at the expense of the escaping gases.
I also effect the like transfer of heat by passing the heated gases and cold
air in opposite directions through channels separated by corrugated or other
like surfaces. By supplying heated air to furnaces, more perfect burning of
the fuel will be ensured..
For the purpose of super-heating the steam in tubular boilers, I cause the
smoke and gases,after they leave the ordinary furnaces and tubes of a cominon
marine tubular boiler, to pass to the chimney through a number of small
vertical tubes, the lower ends of which are inserted in a horizontal plate
rivetted at right angles with the ordinary tube plate. The water which
surrounds them to a certain height protects their attachment to the tube
plate from injurious heat
In vessels making long voyages it is often necessary to put down the fires
in one of the boilers to clean the tubes. During this operation the steam
supply is not only lessened by the withdrawl of one of the boilers, but the
draught of those under fire is much impaired by the rush of cold air ascending
through the opened smoke box doors of the detached boiler. To prevent this
evil propose to fit inside the smoke box dampers moving on horizontal
hinges which may shut off all communication with the chimney while the
tubes are undergoing the operation of cleaning. If partitions are provided in
the fire box corresponding plates may be set in the smoke box, and thus some
furnaces in one boiler may be kept steaming while the tubes over those
adjoining are being cleaned.
The removal of the sediment or scale collecting over the tubes of marine
boilers has hitherto been almost impossible without removing them altogether
from the boiler. The following arrangement is expected to remove the evil.
In boilers where the tubes are disposed in vertical and horizontal rows small
holes are bored in the tube plate, between the existing tube holes at the
crossing of the diagonal centre lines, so as not to injure the strength of the
tube plate, and plugs are tapped iu these holes to close them while steaming.

page_text: When it is desired to clean the outside of of the tubes,the plugs are removed
and a cross-shaped scraper is lowered edgeways, inside the boiler, between
the tubes, and brought opposite one of the tapped holes. A long iron or steel
rod is then screwed in the scraper, passing through the hole in the tube plate,
and by moving this rod lengthways, all the scale collected on the outer part
of the tubes can be removed.
Another mode more effectual for vessels making long voyages consists in
providing inside the boiler a loose tube plate, comprising a certain number of
tubes. The plate, attached to a rod projecting outside the smoke box tube
plate through a stuffing box, may be moved lengthways, so as to scrape the
outside of the tubes as often as the sinoke box doors are opened, and the
sediment is removed or its deposit prevented.
SPECIFICATION in pursuance of the conditious of the Letters Patent, filed
by the said Charles Benjamin Normand in the Great Seal Patent Office
on the 29th September 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
BENJAMIN NORMAND, of Havre, in the Empire of France, Ship Builder, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-ninth day of March, in the year of our Lord
One thousand eight hundred and fifty-six, in the nineteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Charles Benjamin Normand, Her special license that I, the said
Charles Benjamin Normand, my executors, administrators, and assigns, or
such others as I, the said Charles Benjamin Normand, my executors, admi-
nistrators, 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 STEAM BOILERS, IN APPARATUS
APPLYING HEAT TO STEAM BOILERS, AND ECONOMISING HEAT OF FURNACES," upon
the condition (amongst others) that I, the said Charles Benjamin Normand,
by an instrument in writing under my hand and seal, should particularly
describe and ascertain the nature of the said Invention, and in what manner

page_text: 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 Benjamin Normand, do hereby
declare the nature of my 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 Drawings hereunto annexed,
and to the letters and figures marked thereon (that is to say) :-
This Invention relates, firstly, to the construction of marine boilers, the
object being to make them more compact than heretofore when required to
carry a high pressure of steain.
In the case of small war steamers, where it is required to set the motive
power apparatus as low as possible, to be out of reach of shot, instead of setting
the cylindrical portion of the boiler, containing the tubes, in the rear of the
fire box, as is usually the practice, I place it at the side, and cause the flame
to communicate to the tubes through a transverse fire box.
This arrangement, shewn in Fig. 1and 2, Sheet I. of the annexed Drawings,
reduces to about one-half the length of the ordinary marine high pressure
boiler, and dispenses with the space generally required at the back for cleaning
the tubes. Two such boilers would stow very well, side by side, in the hold of
a vessel having much rise of flow. When more heighth is to be disposed of, I
place the cylindrical part of the boiler immediately over the furnace. This
arrangement is shewn in Figs. 3 and 4. The flame and hot gases are brought
to the tubes by a vertical rectangular fire box A, as in the ordinary marine
boiler. The steam generated around the furnace, passes through vertical com-
munications B in the cylindrical part, aud there mixes with that created round
the tubes.
I am well aware that vertical or lateral return tubular boilersare generally
employed in steamers working under moderate pressure, that is, notexceeding
twenty or twenty-five pounds to the square inch. But in this case, furnaces
and tubes being contained in the same outer shell composed chiefly of planes,
which can only be strengthened by long stays or tie-rods passing around the
tubes and furnaces, the strengthening points cannot be disposed at sufficiently
close intervals, such arrangement is therefore impracticable for carrying with
safety a high pressure of steam).
Fig. 5 shews an arrangement of marine boiler intended to supplysurcharged
or super-heated steam. The hot gases, after having travelled through the
ordinary horizontal tubes C, pass to the chimney through a number of vertical
tubes D, the lower ends of which are insertedin a horizontal plate rivetted at

page_text: right angles to the ordinary tube plate. The water which surrounds them to
a certain height protects their lower attachments to the tube plate from
injurious heat. In order to maintain a rapid motion of the steam round these
heating tubes, a screen-plate E is provided, which separates them from the rest
of the steam chest. The steam collected at top by the pipe F is admitted at
one side of the rectangular space, and flows transversely to the other, where
the steam pipe is affixed, after having gone across the whole range of heating
tubes.
This Invention relates, thirdly, to the transmission to the feed water of
marine boilers using salt water of a great part of the heat contained in the
"blow-off." The apparatus by which such transfer is effected is shewn in
Fig. 5. The "blow-off" and feed water are brought respectivelyintoseparate
intermediate vessels G and H, which are kept in communicationat theirupper
parts by the pipe I. The temperature of these vessels stands between that of
the boiler and that of the hot well, but nearer to the latter in proportion to
the excess in the volume of feed water to that of the "blow-off."
The steam generated by the reduced pressure of the "blow-off" passes to
the feed water, and raising its temperature, is thus brought back to the boiler.
A supplementary feed pump will have to be placed between the heating vessel
and the boiler, and as in most cases the pressure in the heating vessels will
be below that of the atmosphere, the "blow-off" will have to be drawn by a
ump.
In vessels making long voyages, it is often necessary to put down the fires
in one of the boilers to clean the tubes. During this operation the steam
supply is not only lessened by the withdrawal of one of the boilers, but the
draught of those under fire is much impaired by the rush of cold air ascending
through the smoke box doors of the detached boiler. To prevent this evil, I
propose to fit inside the smoke box, as shewn in Fig. 6, dampers J moving on
horizontal hinges, which may shut off all communication with the chimney
while the tubes are undergoing the operation of cleaning. If partitions are
provided in the fire box to separate the flame and gases of each furnace, corre-
sponding vertical plates may be set in the smoke box, and thus some furnaces
in one boiler may be kept steaming while the tubes over those adjoining are
being cleaned.
The fifth part of this Invention relates to certain mechanical means for
charging the fuel on the grates in a more regular and convenient manner than
is done by the usual hand-firing. Various plans have already been tried or
proposed to perform a mechanical and continuous distribution of the fuel on
the grate bars, in order to obviate the inconvenience of the alternately in-

page_text: sufficient and excessive supply of air through the varying thickness of coals, also
to distribute the fuel in its different stages of burning on those parts of the
grate where it can produce the best effect. This result is, to a certain degree,
attained in the moveable, endless, and in the circular turning grate, but practical
inconveniences have prevented these devices from coming into general use.
My proposed self-feeding grate is represented in Figs. 1 and 2, Sheet II. of the
annexed Drawings. The grate bars A B C, A' B'C', A" B" C", &c., are
made in the usual way, or better cast two together, so as to be stiffer and better
supported. The grate bars extend out beyond the front of the boilers, and
form a bottom for the hopper D, which contains the fuel. Two transverse
shafts E and F, turning in opposite directions under the advanced portion of
the grate, act by means of cams on projections G, cast at the under side of the
grate bars, and give them a short reciprocating longitudinal motion. The
forward motion is given simultaneously to all the grate bars by the single came,
keyed on the shaft E, and ranging through its whole length. The fuel is
naturally brought onward to the same extent by the advance of all the parts
on which it rests. Under the hopper, where some resistance may arise, notches
on the upper side of the bars ensure the advance of the fuel. The return
motion is given separately to a small number of bars at a time, which bars are
not contiguous, thus the bars A A' A", B B B", CCC, will be moved
back by their respective cams aa' a", b b¹ b, c c¹c", which are arranged in
progressive groups around the shaft F. Each series of grate bars so brought
back slides under the layer of fuel kept still by its contact with a greater
number at rest, and the prevalence of this adhesion from the inclination of the
grate.
In this manner the whole line of grate bars is brought to its first
position ready to receive and transmit a fresh impulse to the burning fuel.
The fuel is distributed in its different stages of burning on those parts of the
grate most suited for its complete combustion. The unconsumed gases arising
from the fresh lighted coal near the door flowing over the whole length of the
furnace will mix with the heated and partly unburned air rising from the
foremost parts of the grate,'and they mutually complete and perfect their com-
bustion. The layer of fuel, although varying in thickness through the length
of the grate, is kept in a uniform state, to which the supply of air can be made
to correspond in a more convenient manner than in the ever varying hand-
fired furnace. The longitudinal motion of the bars will tend to keep the inter-
vening spaces clear of cinders or clinkers, and that which might not have fallen
through the bars drops at the end of the furnace, and may be removed on
raising the door K. To prevent an excess of air from passing between the
bars at the inner or forward end of the grate where the layer of fuel is much

page_text: reduced in thickness, a door L is disposed at about the middle of the length of
the furnace, by which the excess of air is checked and the required regulation
obtained. The furnace door H slides vertically, and its height is regulated by
means of a pair of pinions J on the shaft I gearing into lateral racks. The
position ofthis door determines the thickness of the layerofcoals to be delivered
on to the fire-bars. If anything prevents or disturbs the convenient working
of the grate, the firing can be carried on in the ordinary way, the hopper D
being removed and the door opened when required by the gearing above
described.
In the production of steam, and in almost all operations where fuel is
employed,a considerable loss isencountered from the high temperatureretained
by the smoke and gases in the chimney or stack. The sole use of the heat
thus carried away is to create a natural draft, which is, however, too often
insufficient, and might be supplied artificially by a small part of the power
which the heat in the smoke represents. This temperature retained by the
smoke cannot be much reduced in the case of boilers, especially those working
under considerable pressure, on account of thehigh temperature of the steaming
surfaces; a reduction is still less possible in those metallurgical operations
where the masses under treatment stand at a temperature little below the
highest point in the furnace, and consequently a very small fraction of the hent
evolved is rendered useful.
My proposed improvement consists in directing the escaping gases and
supply air of the furnace alternately, and in opposite directions, in the same
channels filled with extensive heat-absorbing surfaces. These surfaces take
up and store the heat contained in the smoke, and when the currents are
altered they give it back to the supply air of the furnace.
Figs. 1 and 3 in Sheet II. represent the application of the above apparatus
to a marine tubular boiler of the return kind. The gases of combustion, after
having exerted their usual duty on the sides of the furnace and tubes, ascend to
the chimney through one-half of a cylinder N, which is divided by a central
plate in two equal parts. This cylinder is entirely filled with thin metal plates T,
leaving but small spaces between them, and presenting an extensive heating
surface. The temperature of these plates decreases from the under part
upwards, from the temperature of the gases to that of the surrounding air, or
thereabouts. The gases rising through one-half of the said cylinder come in
contact with cooler and cooler surfaces, to which they abandon their heat.
The supply air flows in an opposite direction in the other half of the cylinder,
and meeting,as it passes downwards, with surfaces hotter and hotter, arrives at
the grate with a temperature little below that at which the gases of combustion

page_text: left the boiler. If these streams were maintained without alteration, one-half
of the apparatus would soon be entirely heated and the otherremainquitecool,
but the cylinder containing the heat-storing surfaces is so disposed and actuated
by gearing thatitis turned one-h..lfrevolution at given intervals. Thestreams
of hot and cold gases are thus inverted; that part which had been heated, now
submitted to a contrary action, gradually gives off its heat, while that part
which had been cooled is receiving a fresh store of caloric. These alternate
changes must take place at sufficiently short intervals, so that the extreme
The
temperatures of the upper and lower parts are not much altered.
advantages of this disposition will not only consist in the amount of escaping
heat brought back to the boiler increasing the temperature of the furnace, but
also in a more perfect combustion being caused by this higher temperature.
To maintain the complete separation of the air and sinoke passages, the
rotating cylinder, containing the heat transferring surfaces, is provided at top
and bottom with turned flanges, and rests over a dressed crown piece, com-
prising the two flues P of the smoke and Q of the supply air; this last
opens in the furnace by the aperture R below the grate bar. The lower
flange of the rotating cylinder is provided with bevilled gearing, which is
actuated by suitable machinery to produce the necessary intermittent motion.
One half of the top of the rotating cylinder is opened for the admission of
the supply air, the other half, comprising the smoke passage, is covered by the
chamber S, over which stands the chimney. To permit of the variable expau-
sions of the parts, and remove from the whole system the weight of the
chimney, the communication is maintained by means of an hydraulic joint.
It may be found desirable, when using this apparatus, to quicken the draft
by means of a fan or blower. The heat-transferring surfaces have been repre-
sented in the shape of thin metallic plates. They might be made of wire
gauze or of other substance infusible aud unoxidizable at the temperature
of the gases of combustion which circulate through them.
Instead of the above arrangement the heat-storing surfaces might be dis-
posed in separate fixed channels, as shewn in Fig. 7, Sheet I., the course of
the currents of gas and air being diverted into different channels by means
of the dampers K, K, and L, L, moving simultaneously. In order to dis-
pense with all mechanism and motions, the streams might be conducted one
within the other, and separated by thin metal plates, corrugated so as to
present under a small volume an extensive heat-transferring surface.
Fig. 8, Sheet I., represents a section of such channels, the central one M
being that for the smoke and heated gases, and the lateral space N that of the
supply air or vice versa.

page_text: The above description and annexed Drawings refer to an application of the
heat transferring apparatus to a marine boiler, but I propose to apply it, not
only to land or locomotive boilers, but also to furnaces used in metallurgical
operations, the object being to utilize the great amount of heat generally
emitted in the chimneys or stacks, the heat transferring surfaces would in the
latter case have to be made of thin tiles of earthenware or porcelain on
account of the high temperature they would have to sustain. I also propose
to use such apparatus for the external application of heat in those motive
power engines working by the expansion of air or other gas. I am aware
that analogous means have been employed for the internal working of such
engines, and only claim the described improvement for turning into use the
heat carried away in the chimneys of these engines.
Having now set forth the nature and object of my Invention of "Improve-
ments in Steam Boilers, and in Apparatus for applying Heat to Steam Boilers,
and Economizing Heat of Furnaces," and explained the manner ofcarrying the
same into effect, I wish it to be understood that under the above in part
recited Letters Patent I claim,-
First, the arrangements shewn and described of returu tube boilers adapted
to working under a high pressure of steam, such return taking place laterally
or vertically. The furnace and heating tubes being contained respectively in
separate outer shells.
Second, I claim super-heating steam by carrying the smoke and
gases of
combustion to the chimney in ordinary tubular boilers through a number of
small vertical tubes situate in the steam chest, as described.
Third, I claim the arrangement above described for transferring to the feed
water the heat contained in the "blow-off."
. Fourth, I claim the disposition of dampers in the smoke box of marine
tubular boilers, for the purpose of isolating the several boilers, or the furnaces
in one boiler, and thus permitting of the cleaning of the tubes of one boiler
or furnace without destroying the draught of the other furnaces or boilers, as
explained.
Fifth, I claim feeding the fuel to and distributing it over the grate bars by
the simultaneous advance and tardy back traverse of the grate bars, effected
in the manner and for the purpose above explained.
Lastly, I claim transferring to the supply air of boiler or other furnaces the
heat contained in the escaping gases of combustion, by bringing streams of the
supply air and of the gases alternately through the same channels provided
with extensive heat absorbing surfaces in the manner above described. And
I also claim effecting the said transfer of heat by passing the hot gases and

page_text: cold air in contrary directions in channels separated by corrugated or other
like heat absorbing surfaces.
In witness whereof, I, the said Charles Benjamin Normand, have here-
unto set my hand and seal, the Twenty-third day of September, in the
year of our Lord One thousand eight hundred and fifty-six.
BI DENISE,
Of Havre-de-Grace.
C. B. NORMAND (L.s.)