IMPROVEMENTS IN THE CON- STRUCTION OF MULTITUBULAR STEAM BOILERS
Year: 1870

page_text: PROVISIONAL SPECIFICATION left by Alexander Browne at the Office
of the Commissioners of Patents, with his Petition, on the 26th
April 1870. A communication from abroad by Georg Friedrich
Edelhoven, of Kalk, near Cöln, Germany.
I, ALEXANDER BROWNE, of the Firm of Browne and Company, Patent
Agents, of S5, Gracechurch Street, in the City of London, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN THE CON-
STRUCTION OF MULTITUBULAR STEAM BOILERS," a communication from abroad
by Georg Friedrich Tdelhoven, of Kalk, near Cöln, Germany, to be as
follows:-
This Invention relates to vertical multitubular steam boilers, and
differs in the following respects from this class of boilers as heretofore
constructed.
"
First. In addition to the ordinary safety valve I employ a safety
apparatus of the following construction:-In the top plate of the inner
chamber of the boiler, just above the centre of the fire-place, tapped holes
are made, which are stopped up with screws, the said screws having
holes drilled through them filled with a composition which becomes
dissolved when the pressure of the steam in the boiler is greater than

page_text: the boiler should sustain, and as the composition is dissolved the water
will pass through the holes in the said screws and extinguish the fire.
Secondly. The entire heating surface is direct, as there are no surfaces
external of the boiler to absorb heat, and on account of the equal dis-
tribution of the water in all parts of the boiler the water will be heated
equally in all parts. Besides this the water is equally exposed to absorb
heat, whereas in other boilers the heat has to penetrate a greater body of
water. This improved boiler will therefore produce steam at a much
quicker rate than other boilers.
Thirdly. Especially as regards the fire this improved boiler possesses
great advantages. The gases arising from the fire are heated in ascending
two conical fire-boxes, and expanding in the inner chamber are burned
completely before being emitted from the chimney, especially if care is
taken that the two grates are supplied with fuel alternately, so that the
gases arising from the grate that is being supplied with fuel are met in
the inner chamber by a clear flame from the other grate, and are
properly ignited by its heat, whereas in ordinary boilers the gases in
the fire-tubes remain cold and damp and cannot ignite, but are emitted
from the chimney as smoke.
Fourthly. A great advantage is the easy access to all parts of the
boiler for clearing it. The construction of the inner part of the boiler
being such as to prevent the formation of incrustation, dirt, and mud at
the parts that are exposed to the fire, as the inner chamber and heating
tubes being in a vertical position any solid matter that is left by the
boiling water sinks to the bottom, whence it can be removed by the cock
employed for emptying the boiler. By opening the man-hole it is easy
to clean the inside of the boiler thoroughly and to keep it under proper
control. The owner of the boiler can convince himself of the condition
of the boiler and the heating tubes by looking in at the bottom man-
hole, while the top part of the boiler is lighted by a lamp being
introduced in the top man-hole, whereas with other boilers the owner has
to trust to the integrity of his men, because it is necessary for them to
get into the boiler.
Fifthly, and lastly. These improved boilers can be made any size,
either with only one fire-box for small boilers or with three fire-boxes
for large boilers. They are especially well adapted for marine boilers,
owing to the advantages gained as concerns economy of coal and
consequently economy in room for stowage of the coal.

page_text: The following will serve as an example of the mode of constructing
boilers according to this Invention. Suppose, for example, the boiler to
have a heating surface of 480 superficial square feet. The boiler consists
of a shell, say 11 feet 4 inches in height and 5 feet 6 inches in
diameter, also an inner chamber 5 feet 6 inches high and 5 feet in
diameter, into, which two conical shaped fire-places open from below.
The aforesaid inner chamber contains 68 heating tubes, each 4 inches
in diameter, which extend the entire beigth of this chamber, and open
through the top and bottom plates into the boiler for the water in the
boiler to circulate through. The boiler is provided with two firc-places,
the grates of which consist of wrought-iron bars bent so as to form a
basket shape in order to secure a greater admission of air. These grates
hang on one side on hinges, while the other sides are secured by means
of bolts with handles. By turning these handles the grates turn on
hinges and empty the coals that are on them into the ash-pit below.
The flame enters the inner chamber of the boiler from the fire-places
and heats the same, as also the tubes contained in the inner chamber.
The flame is divided here by striking against the tubes, and after cir-
culating round them escapes through the chimney. For cleaning the
inner chamber a door is provided, through which by means of a scraper
the outside of the tubes, as well as entire inside of the inner chamber,
can be cleared of soot, dirt, or ashes. Besides this by attaching an
india-rubber tube to a guage cock, and introducing the other end into
the fire-doors, any soot and ashes collected during the day may be blown
out through the chimney in the evening.