IMPROVEMENTS IN SPARK ARRESTERS FOR LOCOMOTIVE AND OTHER HIGH-PRESSURE ENGINES
Year: 1875

page_text: PROVISIONAL SPECIFICATION left by Peter Clarke at the Office of
the Commissioners of Patents, with his Petition, on the 18th
November 1875. A communication from abroad by David Ranny
Proctor, of Gloucester, in the County of Essex, and State of
Massachusetts, in the United States of America, Engineer.
•
I, PETER CLARKE, of Arundel Street, Strand, in the County of
Middlesex, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN SPARK ARRESTERS FOR LOCOMOTIVE AND OTHER HIGH-PRESSURE
ENGINES," (a communication to me from abroad by David Ranuy Proctor,
of Gloucester, in the County of Essex, and State of Massachusetts, in
the United States of America, Engineer,) to be as follows:-
This Invention relates to improvements in spark arresters for
locomotive and other high-pressure engines, and consists in providing a
curved smoke chimney with two screens at or near its upper end in
combination with two return pipes or conductors for the sparks and
cinders; the mouth of the first return pipe is located at the rear of the
chimney and a little below the first screen; this return pipe leads to the
furnace and serves to convey the larger sparks and cinders that are

page_text: capable of being utilized as fuel back again to the furnace to be there
consumed; the second return pipe is also located at the rear of the
chimney and enters the latter between the first and second screens, and
serves for the purpose of conveying the fine particles of sparks and
cinders that are incapable of being again used as fuel, and which have
passed through the first screen to the sand box (in the case of a loco-
motive) or any other suitable receptacle, or to be delivered on the track,
as may be desired. The first screen is made coarse so as to allow fine
sparks and cinders to pass through it, and to arrest and convey only the
large ones to the furnace; whereas the second screen is made so fine as
to arrest nearly all the cinders that have escaped through the first
screen, and to convey them to the sand box or other convenient
receptacle. The first screen being coarse covers the whole area of the
chimney where it is located, and this may be done without diminishing
the draft very materially; but the upper fine screen may, if so desired,
be made to cover only a part of the chimney, at or near the place where
the cinders would be likely to strike, whereas the remainder of the area
of the chimney may be left open and unobstructed so as not to interfere
with the draft.
The gentle curves of the chimney and of the return pipes for the
cinders assist very materially in conducting the sparks and cinders to
the furnace and sand box or other required place without interfering
with the draft, and furthermore the draft in the furnace creates as it
were a partial vacuum in the pipe leading from the chimney to the
furnace, by which the large cinders are drawn as well as propelled to the
furnace from the chimney.
A part of the exhaust steam that escapes through the chimney is
conducted to the furnace, and being there decomposed into its elementary
gases increases the combustion in the furnace.