IMPROVEMENTS IN AND RELATING TO STEAM BOILERS
Year: 1877

page_text: PROVISIONAL SPECIFICATION left by William Robert Lake at the Office
of the Commissioners of Patents on the 12th May 1877. A. communication
from abroad by Messieurs Ch. Bourgois and L. Bouchéz, trading as such, of
Arras, France, Manufacturing Engineers.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, and Co., Patent Agents,
Southampton Buildings, London. " IMPROVEMENTS IN AND RELATING TO STEAM
BOILERS." A communication from abroad by Messieurs Ch. Bourgois and L. Bouchez,
trading as such, of Arras, France, Manufacturing Engineers.
This Invention relates to a steam boiler or generator provided with means for
maintaining the circulation of the water and the products of combustion therein, and
with a furnace supplied with air by injection.
For heating the air which is destined to consume the gases, I make use of the
heat radiated by the walls of the furnace, and create thus a heating with recuper-
ated heat; and in order better to utilize the heat given off by the furnace the
liquid mass is divided into several bodies, and the boiler tubes are formed of sets of
metal tubes of small diameter with a view to diminish the space occupied for a
given power, and to reduce the cost of the apparatus.
The heating is effected in an entirely methodical manner, that is to say, the circu-
lation of the heated gases is produced in a contrary direction to that of the arrival
of the water in the various parts of the boiler of which the water and steam commu-
nications are effected by exterior pipes.
These arrangements also facilitate the flow of the steam and circulation of water
throughout the whole system.
It is to be understood that this Invention relates to the combination of the
above features for the purpose of obtaining a better result than it has been possible
to obtain up to the present time by the employment of the different kinds of boilers
now in use.
In order to utilize the lost heat by means of the radiation of the lateral and upper
walls of the furnace, I provide within the substance of these walls channels formed
either by the bricks of the furnace, or by layers of hollow bricks, these channels
being divided in such a manner that the exterior air may penetrate therein either
at the front or back of the furnace, or on both sides at once. This air circulating
in a perfectly divided state through these narrow channels, which form in reality a
CD 177

page_text: true hot air apparatus, becomes heated and absorbs the heat radiated from the whole
extent of the walls, which heat is lost and wasted in ordinary arrangements, escaping
into the atmosphere and surrounding materials.
The section of the side halves provided to admit the air is calculated, so as
to permit the passage of the necessary quantity to burn all the gaseous part
of the fuel. These side holes are provided with registers to regulate the admission
of air at will.
The currents of air on emerging from the said channels all unite in a chamber
provided in each of the cheeks of the furnace, and are thus, as will be easily under-
stood, heated methodically. This hot air is then injected through a great number of
holes, either behind the bridge and laterally through three tubes combined in horse-
shoe form, so as to produce a stirring or puddling of the gases, and to determine
their intimate mixing, or all around the furnace itself, where the same effects are
produced; I may employ either of these methods, according to the more or less
gaseous nature of the fuel made use of.
According to one arrangement the air penetrates at the front of the furnace
through openings, and at the back through other openings, and circulates under the
whole extent of the upper and lateral walls of the masonry enveloping the boiler,
then the currents of heated air unite in the two chambers provided in the cheeks of
the furnace, going thence to the distributor formed by perforated tubes which send
it into the middle of the gaseous mass produced by the combustible material upon
the bars. I have thus shewn how the first object of this Invention is obtained, that
is to say, the heat radiated by the walls is utilized for heating the air, which heat
would otherwise be lost, and it is thus restored to the apparatus. The expression
'heating with recuperated heat "is therefore justified.
"
The greater the distance from the furnace which is the place of combustion, the
greater is the decrease in the intensity of the hot gases, therefore in order to get
from them all the return possible, and the more so as the distance of the source is
greater, it is necessary to divide the mass which is to be heated in order to present
it in the most favorable condition for the absorption of calorie; for this purpose I
employ multitubular boilers.
In all cases where the available space will permit it, I arrange the tubes of the
said boilers in horse-shoe form, so as to reserve between these tubes a free space
sufficient to allow facility for cleaning to prevent the deposit of soot, and to spread
the said tubes in the elevated zones of the flues where the gases are at a higher
temperature. A very considerable useful heating surface is thus obtained within an
equal space, and the weight and dimensions of the apparatus for an equivalent
power are sensibly lessened. The cost is lessened in the same proportion, and still
more important economy is effected, namely, that the fuel is much better utilized.
The multitubular boiler tubes are united one to another, and to the upper shell by
means of communications exterior to the furnace, and arranged at the back of the
latter and by means of horizontal communications which allow the water an entirely
methodical circulation, that is to say, it takes place in exactly a contrary direction
to the current of smoke circulating in the channels of the furnace. The upper shell
of the boiler and the two inclined lateral shells which accompany it, and which are
equally inclined for facilitating the circulation of the water and steam communicate
by means of vertical pipes with a horizontal shell placed above the furnace,
and forming a reservoir of steam. Upon this shell the safety apparatus are
placed.
In one arrangement the circulation of the smoke is effected inside the different
parts of the boiler, the shell of which is provided with tubes similar to those of the
well-known "Field " boiler, and has interior water spaces for ensuring the circu-
lation of the water in the apparatus. The smoke pipe passes then into a lateral
heating tube, and eventually traverses a lower water receptacle from which the
injector takes its supply, the said injector driving back the water into a bottle-
shaped supply vessel placed near the lateral heater, which has upon it the safety
apparatus, and with which it communicates at its upper and lower part.

page_text: The furnace of the boiler as in the previously described arrangement is provided
with orifices for the supply of the air necessary for combustion, only this air is not
heated, there being no brick furnace, or else it is heated by the lost heat coming
from the smoke pipe after it leaves the water supply receptacle.
In a modification of this Invention the circulation of the smoke takes place in the
interior of the different parts of the boiler, whose shell is provided with tubes as in
the aforesaid "Field " boiler, and has interior water spaces designed to ensure the
circulation of the water in the apparatus.
A smoke pipe or channel passes then into a lateral heating tube and eventually
traverses a lower water receptacle, from which is supplied an injector which drives
back the water in a bottle-shaped vessel placed near the lateral heater, upon which
are the safety apparatus, and with which it communicates at its upper and lower
part.
The furnace of the boiler, as herein-before described, is provided with orifices
for the supply of the air necessary for combustion, but the air is not heated, there
being no brick furnace, or it is heated by the lost heat coming from the aforesaid
smoke pipe or channel after escaping from the water supply receptacle..
The furnace forming the basement of the boiler comprises the following, that is to
say, an air chest into which the air is injected either by a ventilation or by the
well-known "Koerting" air injector, an ash-pit, a grating, flues conducting the
air above the grating by a series of jets to the fuel, and a feeding apparatus.
The boiler is formed of a central piece of the shape of an ordinary furnace having
at bottom an inclined boiler tube, and at top a series of the well-known "Perkins'
tubes exposed directly to the flames; an obturator forces the flames to play upon
these tubes. The products of combustion pass away by a bent tube to a chimney,
passing on their way, first, upon a serpentine steam superheater, and second, through
a supply vessel and an open cistern. The furnace is surrounded by a cylindrical
diaphragm. Near the said vessel is another vessel, which I call a safety vessel,
communicating at top with the said supply vessel, and with the boiler by the bottom
tube. The said supply vessel communicates also with the boiler by a tube, and the
communications may be controlled or shut off at will by means of cocks provided
for this purpose.
The pipes have their outlet in an ejector of annular form
from whence the water flows after having remained therein a certain time and
become heated.
A bottle-shaped vessel communicates with the boiler above and below the level
of the water by two tubes. It has a float, the stem of which shuts or opens the
upper orifice united by a pipe above the said vessel.
Supposing that, to commence with, the apparatus is entirely empty; to fill it the
water supplied from a reservoir is poured in through a funnel, and rises to a certain
point, whence it flows into the said supply vessel, and afterwards into the ejector
until it has risen to its normal level. Cocks are then closed and the supply is con-
tinued until the supply vessel is full, which is proved when the level disappears in a
tube provided for the purpose. The cistern having been thus filled the boiler is
ready to work under the action of fire. The water in the boiler tube becomes hot
first and rises at the same time that the water thus rises all around the interior
wall or division, the water consequently descends all around the exterior wall or
division of the diaphragm, and the steam that is generated goes to the steam.
chamber; this current determines all the movement in an inverse direction to the
gas. As soon as a certain pressure is given the level will descend a certain distance,
the float will follow the movement, and open the upper orifice of the bottle-shaped
vessel; consequently the steam by means of a bent pipe acts upon the level of the
supply vessel, and if at the moment when the pressure is established the cocks are
opened, the equality of the pressure in the boiler and in the supply vessel determines
the flow of a certain quantity of water from the said vessel, under the pressure due
to the column of water until the level is re-established, the orifice closed, and the
normal level regained. It will be seen therefore that the supply is effected auto-
matically.

page_text: If the stoker, notwithstanding the warning which will be given by a whistle
when the level sinks to a certain point, does not supply the vessel by means of an
injector or pump, a safety vessel provided will act, for the pressure of the steam
acting by a commmunication pipe will cause it to effect the same object without
the knowledge of the stoker through one of the cocks opened at the same time as
the other. These two cocks have their plugs connected by a crank in such a manner
that one cannot be opened without the other. As the capacity is calculated for
at least an hour's working it is impossible that the stoker should not pay attention
eventually.
The injector placed on the safety vessel draws the water from the cistern, and
sends it into the supply vessel, whence it passes into the boiler. It will therefore be
seen that the water takes rigorously an inverse direction to that taken by the products
of combustion.
In case of stoppage the injector may supply the boiler direct through another
pipe.
'The boiler has removable joints, and a special arrangement prevents the door of
the furnace from being opened, without closing at the same time the register at
bottom. The combustion is regulated by the upper register which is worked by
hand.
In adapting the so called "Perkins'" tubes to the purposes of this Invention, I so
arrange them that the descending water is completely separated from the steam,
being generated by taking the water laterally in such manner that all conflict
between the water and the steam is obviated.