A NEW METHOD OF AND APPARATUS FOR PRODUCING A SELF-ACTING CIRCULATION IN TUBULAR STEAM BOILERS EMPLOYED FOR LOCOMOTIVE ENGINES, AND COLLECTING THE PRECIPITATES OF THE WATER OF BOILERS GENERALLY
Year: 1872

page_text: PROVISIONAL SPECIFICATION left by Alexander Friedmann at the
Office of the Commissioners of Patents, with his Petition, on the
25th January 1872.
F
I, ALEXANDER FRIEDMANN, of Vienna, in the Empire of Austria,
Engineer, do hereby declare the nature of the said Invention for
"A NEW METHOD OF AND APPARATUS FOR PRODUCING A SELF-ACTING CIRCULATION
IN TUBULAR STEAM BOILERS EMPLOYED FOR LOCOMOTIVE ENGINES, AND COLLECTING
THE PRECIPITATES OF THE WATER OF BOILERS GENERALLY," to be as follows:-
'
.
It is well known that in the tubular steam boilers employed for
locomotive engines the combustion is vehemently stimulated by the
-blast pipe sucking the air through a relatively small fire grate, so that
the temperature in the fire-box of locomotives is much higher than in
other steam boilers, and that the evaporation of the water. surrounding
the fire-box of the locomotives is much more powerful than that of the.
water remote from the fire-box and near the smoke box..
consequence of this fact must necessarily be, that a determined volume
of the water surrounding the fire-box of the locomotive boilers during
their working must contain much more steam than an equal volume of
water near the smoke box contains; and that therefore the water
The
:

page_text: surrounding the fire-box of the boilers of locomotives is much lighter
than that near the smoke box.
Now the first part of my Invention has reference to this fact, and
consists in fitting outside the boiler employed or to be employed for
locomotives, a tube, the one end of which communicates with the water
remote from the fire-box, and the other end with the water sur-
rounding the fire-box near the fire grate. Thus the water remote
from the fire-box will by its greater weight flow through the said
external tube into the water surrounding the fire-box, and being
there heated more vigorously it will ascend vehemently. Thus a
self-acting and continuous circulation is established. The effect of
this self-acting continuous and powerful circulation of the water will
be, first, that the copper plates of the fire-box exposed to the very high
temperature existing in the fire-box of the locomotive boilers will be
better protected against burning and from getting out of shape, and that
even instead of copper plates it will be possible to employ iron plates, and
secondly, that the whole evaporating power of the boiler will be much
increased.
These two points are very important for locomotives, both because
the temperature in the fire-box of locomotives is so high that a
protection of the plates is very desirable, and also because for locomotive
engines the heating surface and all the dimensions of the boiler are very
limited, and an increase of the evaporating power by other means than
an enlarging of the boiler would be most advantageous. Thus this
self-acting circulation employed for locomotives is so useful that even if
it has already been employed for other engines, the adaptation of it to
locomotives is an important improvement, because in all other cases
there is neither such a high temperature over the fire as to necessitate
copper plates, nor such a limitation of the dimensions of the boiler
as to prevent an augmentation of the evaporating power by enlarging
the boiler or its heating surface.
Instead of a single external circulation tube, two or more tubes or a
tube with branches can be employed in order the better to effect the
circulation of the water.
If the construction of the locomotive or other reasons should render
it not desirable to fit the circulation tube entirely outside the boiler, it
can be made partly inside and partly outside the boiler, only the one

page_text: end of it must communicate with the water near the smoke box, and the
other end with the water surrounding the fire-box near the fire grate.
The second part of my Invention consists in making use of the before
mentioned circulation in so far as it is outside the boiler, to receive or
to take up the deposits or precipitates from the water, by interposing.
in the external circulation tube an apparatus which the whole cir-
culating water will pass through and which is adapted to collect the
said deposits and therefore prevent boiler incrustations.
This part of my Invention although more especially intended for
locomotives in which the quantity of water evaporated in proportion
to the volume of the boiler is enormous, the interior of which is
less accessible than of any other boiler, and the collection of the
deposits outside of the boiler is therefore the most required, is never-
theless applicable to other boilers than those employed for locomotive
engines; because also in those boilers in which the fire is not so
vehemently active as in locomotives the density of the water near the
fire hearth is slightly different from that remote from the fire hearth,
and an exterior circulation tube, the one end communicating with the
water over the fire hearth, and the other end with the water remote
from the fire hearth, will still produce a slight circulation through it,
which could be made available for collecting deposits by interposing
an apparatus in the circulation tube.
The third part of my Invention consists of an apparatus to carry
out the second part of my Invention, that is to say, to take up or
receive the deposits from the water of the boiler. This apparatus which
is interposed in the external circulation tube is composed of a hollow
vessel strong enough to bear the pressure of the boiler, and filled
with pebbles or pieces of stone, slag, coke, or similar materials, the
surface of which is very large in proportion to the whole volume,
and which is capable of bearing the temperature and the pressure
of the water of the boiler without becoming disaggregated or de-
composed. Thus the water of the boiler passing through the external
circulation tube and through this apparatus will deposit its precipitates
on the large surface of the said materials. The apparatus, is provided
with covers to enable it to be filled and emptied, and with two cocks
which when shut intercept the communication between the boiler and
the apparatus, and allow the apparatus to be emptied and filled even
when the boiler is at full pressure.

page_text: The apparatus is also fitted at the bottom with a cock to purge
it when the boiler is at full pressure. The apparatus itself even if
not filled with pebbles will by its great volume have the effect of
collecting a great quantity of precipitates which could be purged by
the said purging cock.