AN IMPROVED SPARK EXTINGUISHER FOR LOCOMOTIVE, PORTABLE, TRACTION, AND OTHER ENGINES
Year: 1877

page_text: LETTERS PATENT to Conrad Louis Strube, of Buckau, near Magdeburg, North
Germany, for the Invention of "AN IMPROVED SPARK EXTINGUISHER FOR
LOCOMOTIVE, PORTABLE, TRACTION, AND OTHER ENGINES."
Sealed the 28th May 1878 ond dated the 18th December 1877
PROVISIONAL SPECIFICATION left by the said Conrad Louis Strube at the
Office of the Commissioners of Patents on the 18th December 1877.
CONRAD LOUIS STRUBE, of Buckau, near Magdeburg, North Germany. "AN
IMPROVED SPARK EXTINGUISHER FOR LOCOMOTIVE, PORTABLE, TRACTION, AND
OTHER ENGINES."
This improved spark extinguisher or spark extinguishing chimney is specially
applicable to locomotive, portable, and other engines, the exhaust steam of which is
allowed to escape by way of the chimney. This chimney or funnel consists of a
short cylindrical or conical tube, which is surrounded by a jacket in the form of an
inverted cone, and provided with a cap or cover.
Inside the inner tube (the chimney proper) are adapted four spiral ways (the
pitch of which decreases gradually from 90°) in such manner, that the ways divide
the interior space of the chimney next the sides or walls thereof, into four spiral-
shaped divisions. These spirals may have their twist either to the right or to the
left in an upward direction. There is also adapted above the steam exit opening
of the blast pipe, and upon the auxiliary blast pipe a hollow cone, the point of
which projects downwards. The effect of this inverted cone is to deflect the steam
at an angle from the vertical line.
The operation of this apparatus as regards its interior portions is as follows:-
The steam escaping from the blast pipe forms a kind of inverted cone; the heated
gases sucked up from the smoke chamber by this current of steam surround the
same, and move in the direction of the current of steam. The spiral ways however
intersect the space occupied by the heated gases from the furnace, and the heated
gases are consequently compelled to pass through the chimney in spiral lines. By

page_text: means of this spiral movement a centrifugal force will be imparted to the sparks,
whereby they acquire a tendency to fly outwards. As above the inner tube there
is nothing to interfere with this tendency, the sparks fly against the outer jacket
(or against the cover), and are thus thrown down and are prevented from escaping
from the chimney.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Conrad Louis Strube in the Great Seal Patent Office on the 17th June
1878.
"
CONRAD LOUIS STRUBE, of Buckau, near Magdeburg, North Germany. AN
IMPROVED SPARK EXTINGUISHER FOR LOCOMOTIVE, PORTABLE, TRACTION, AND OTHER
ENGINES."
This improved spark extinguisher, or spark extinguishing chimney, is specially
applicable to locomotive, portable, and other engines, the exhaust steam of which is
allowed to escape by way of the chimney. This chimney or funnel consists of a
short tube preferably cylindrical, which is surrounded by a jacket in the form of an
inverted cone, and provided with a cap or cover.
Inside the inner tube (the chimney proper) are adapted spiral ways (the pitch of
which decreases gradually from ninety degrees) in such manner that the ways
divide the interior space of the chimney next the sides or walls thereof into, say,
four spiral-shaped divisions. These spirals may have their twist either to the right,
or to the left in an upward direction. There is also adapted above the steam exit
opening of the blast pipe and upon the auxiliary blast pipe a hollow cone, the point
of which projects downwards. The effect of this inverted cone is to deflect the
steam at an angle from the vertical line.
In the accompanying Drawings Fig. 1 is a vertical section of my improved spark
extinguisher; Fig. 2 is a partial front elevation of the same; Fig. 3 is a plan or top
view of the spark extinguisher.
A, A, is the smoke box rising from which is the chimey B fitted internally with
an inverted conical jacket C, which jacket is partially closed at top by a cover C¹,
a central opening being made therein to provide for the up-draught. This opening
is about the same diameter as the cylindrical tube B which constitutes the chimney,
and between the top of the chimney and the cover C is a free space for the
purpose to be presently explained; D is the blast pipe having its steam exit
opening at D¹
In the centre of this opening is an auxiliary steam pipe E for
conducting a small jet of steam into the centre of the chimney above the blast pipe.
Fitted to the upper part of this steam pipe is an inverted cone F, which serves to
deflect laterally the steam as it issues from the blast pipe.
To the inner periphery of the chimney B is fitted a series of spiral blades G, G,
by preference four in number, of a breadth about equal to the space between the
chimney and the largest diameter of the inverted cone F. These blades extend
upwards to the cover C', and are made fast thereto. They are so arranged as to

page_text: constitute with the cylinder B the spiral ways before mentioned, their pitch
varying from end to end, so that while offering little or no obstruction to the
passage of the ascending gases on entering the spiral ways, they will guide any
particles of incandescent fuel rising therewith into the conical jacket C, the gases
escaping with the steam through the central opening in the cover.
The action of this apparatus may be described as follows:-The steam escaping
from the orifice D¹ of the blast pipe takes a conical form by reason of the inter-
position of the cone F, the heated gases sucked up from the smoke chamber by this
current of steam surround the same, and move in the direction of the current of
steam. The spiral ways however intersect the space occupied by the heated gases
from the furnace, and the heated gases are consequently compelled to pass through
the chimney in spiral lines. By means of this spiral movement a centrifugal force
will be imparted to the sparks, whereby they acquire a tendency to fly outwards.
As above the inner tube there is nothing to interfere with this tendency, the
sparks fly against the outer jacket (or against the cover) and are thus thrown down,
and are prevented from escaping with the steam and gases from the chimney.
Having now set forth the nature of my Invention of "An Improved Spark
Extinguisher for Locomotive, Portable, Traction, and other Engines," I wish it to be
understood that under the above in part recited Letters Patent I claim,-
First. In combination with the chimney tube B fitted with a jacket C, C¹, the
spiral blades G, G, so arranged as to impart a centrifugal action to the ascending
gases of combustion, and thereby to prevent the escape vertically of any particles
of incandescent fuel from the apparatus.
Secondly. In combination with the chimney tube jacket and spiral blades
arranged as above described, the inverted cone F for deflecting laterally the steam
discharged from the orifice D' of the blast pipe.
In witness whereof, I, the said Conrad Louis Strube, have hereunto set my
hand and seal, the Eleventh day of June, in the year of our Lord One
thousand eight hundred and seventy-eight.
CONRAD LOUIS STRUBE. (L.S.)