IMPROVEMENTS IN THE GENERATION OF STEAM
Year: 1854

page_text: application for Letters Patent was not given within the time prescribed
by the Act.)
PROVISIONAL SPECIFICATION left by John Henry Johnson at the Office
of the Commissioners of Patents, with his Petition, on the 23rd September
1854. A communication.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, and of Glasgow, North Britain, Gentleman, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN THE GENERATION OF STEAM,"
a communication from Paulin Jean Charles Montety, of Toulon, in the
Empire of France, to be as follows:-
This Invention relates to certain improved constructions and arrangements
of steam boilers or generators for locomotive, marine, or stationary engines,
whereby a great economy both of fuel and water is obtained, as well as the
advantage of having a compact and inexpensive boiler.
The improvements consist, first, in the employment of a peculiar apparatus
for drying and surcharging or superheating the steam before using it; second,
in the peculiar construction and arrangement of evaporating apparatus to
-be used in connection with steanr boilers. In the arrangement for marine
boilers, the flame on leaving the furnaces enters a chamber sittrated over
each set of fire- bars,. which chamber is filled with a coil or coils of steam

page_text: pipes, which I term for distinction "surchargers," communicating at one end
with the top of the boiler, and at the other extremity with a transverse steam
passage situated inside the boiler, which passage is enclosed in brickwork or
fire clay. After traversing the first chamber, the flame and heated air pass
out by lateral openings into two chambers situated on each side of the furnaces,
such chambers being filled with a series of horizontal pipes or tubes, which
afford a passage for the flame and heated air.
On leaving these tubes, the heated air and smoke from each furnace ascend
to two chambers situated immediately over the first-mentioned chambers;
these latter chambers are also filled with a coil or coils of steam pipes, which I
term "steam dryers." Such coil or coils form a continuation of the pipes
which constitute the coils of the first chamber, and serve to dry the steam
which enters them from the top of the boiler before it proceeds to the lower
coils or surchargers, where it is subjected to the direct action of the flame,
whilst in the upper coils or dryers it is merely acted upon by the heated air
and gasses. The steam, having descended from the top of the boiler down the
whole length of the coils, finally enters in a highly surcharged state the trans-
verse passage herein-before referred to, whence it passes to the cylinder, which
may be also enclosed in brickwork or fire clay, to prevent any loss from radia-
tion. Each coil is fitted with two cocks or stop valves, so as to afford facility
for shutting off the steam from any individual coil in case of leakage. This
construction of marine boiler affords facility also for consuming the smoke of
the furnace, by admitting currents of air at the sides under the coils and in the
bridge. The gases, morcover, are brought into direct contact with the coils,
which are heated by the steam and flame to an intense heat, thereby tending
greatly to their ignition.
The evaporator which I propose adapting to steam boilers consists of a great
number of copper tubes of small diameter opening into chambers, the whole
being enclosed in an outside casing, and surrounded with water. The first
of the chambers communicates with the feed pipe, and the last with the
boiler by two other pipes. This evaporator may either be used vertically
or horizontally, the same principle being carried out in each. In locomotivo
engines the same principle of coiled pipes is carried out for drying and sur-
charging the steam, such coils being situated in a large central flue in the
barrel of the boiler. The evaporator in this case is placed vertically near the
bottom of the chimney. The tubes of the evaporator absorb not only the waste
heat passing up the chimney, but also the heat given off by the steam from the
blast pipe.
The evaporator may be replaced by a number of drying tubes situated in

page_text: the chimney; if, however, the draught should be deteriorated by the use of the
evaporator or steam drying pipes, a fan may be placed near the top of the
chimney, and worked by the engine to assist the draught. By a very slight
modification, the system of drying and surcharging tubes may be applied to
ordinary stationary engine boilers. If the boiler is made with a central flue,
the pipes or coils are fitted in such flue immediately behind the bridge; the same
arrangement being observed with regard to those with external flues, the coils
being in that case placed in the flue, but slightly elevated from the bottom
by a suitable series of supporting bars.