IMPROVEMENTS IN STEAM GENERATORS
Year: 1870

page_text: PROVISIONAL SPECIFICATION left by Alexander Melville Clark at the
Office of the Commissioners of Patents, with his Petition, on the
28th June 1870.-A communication from abroad by Henry
Petitpierre, of 13, Boulevart St. Martin, Paris, Builder.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County
of Middlesex, Patent Agent, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN STEAM GENERATORS," to be as follows :—
This Invention relates to improvements in steam generators, for which.
Letters Patent were granted to Henri Adrien Bonneville, bearing date:
July 26th, 1866, Number 1941.
The Invention therein described consists of a mode of increasing, the
production of steam in existing boilers of whatever construction by
interposing an apparatus (termed a steam increaser) between the
generator and the cylinder, through which the steam is caused to pass.
The object of the said Invention was to convert the water carried along
with the steam escaping from the generator also into steam by means
of the apparatus referred to. In this manner the power of the generator
is increased, a greater amount of steam being produced with the same

page_text: quantity of fuel. The apparatus consists of a metal pipe disposed|
within the furnace, and.extending longitudinally at the lower part of the
flues, finally returning to the furnace. Through this pipe steam is
conveyed from the boiler charged with a considerable quantity of water,
which in the passage of the steam to the cylinder along the interior of the
furnace is completely evaporated by the heat of the furnace, the steam
being thus dried. A valve in this tube admits the steam thereto by the
pressure in the boiler, the valve closing by its own gravity when the
steam so admitted attains (on becoming superheated) a higher pressure
than that in the boiler, and it then passes to the cylinder. Thus by the
aid of the valve the superheating action is repeated at every admission of
steam to the tube.
The improvements in the above apparatus forming the subject of the
present application for Letters Patent consist 1st., in utilizing the whole
heating surface of the superheating tube, and also in adapting thereto a
small injector, by means of which water may be supplied from the boiler
to the superheating tube in small jets for the purpose of moistening the
steam if necessary. One great advantage derived from the use of this
injector is that water may be supplied direct to the superheating tube
immediately the fires are lighted and before any pressure is obtained in
the boiler; the tube is thus not liable to be injured by the heat, while
the steam produced therein passes into the boiler to assist in raising
pressure therein. A safety valve is also placed on the tube at the end
next the generator.
The 2nd improvement consists in disposing a second valve on the exit
end of the superheating tube opening the reverse way to the first valve,
that is to say, inwards to the boiler, and arranged in such manner as to
require a pressure of steam in the tube exceeding by one and a half
atmospheres that in the boiler, to open the valve, in which case the
steam in the tube passes into the boiler. When the engine is not in
action the steam circulating in the superheating tube returns to the
boiler. In this manner a continuous circulation of steam to and from
the boiler is obtained after traversing the superheater for the purpose of
obtaining increased heat and volume. The tube being also constantly
supplied with steam always retains an equal temperature and will not
be injured by the heat. The apparatus is entirely self-acting, and does
not require any supervision on the part of the stoker.
These improvements are illustrated in the accompanying Drawings,

page_text: which show a part sectional end elevation of a steam boiler with the
improved inexplosive steam increasing apparatus applied.
a, a, boiler barrels; c, steam dome; d, metal tube receiving steam from
dome c; this pipe enters the furnace chamber at one side 1, and along
which it extends so as to be heated by the products of combustion, but
sheltered from direct radiation of the heat, it thence passes behind the
bridge and returns to the furnace at the opposite side 2, where it
connects with the pipe e, supplying steam to the cylinder; f, clack valve
for admitting steam to the apparatus, opening from the boiler into the
tube; g, self-acting valve for regulating the pressure as before explained;
h, injector for regulating the temperature of the pipe d, also as before
explained; i, guage cock for regulating the flow of water from the boiler
to pipe d; j, safety valve; k, k, recesses in brickwork to receive the
steam increasing apparatus. The improvements may be applied to all
kinds of existing boilers.