IMPROVEMENTS IN THE CONSTRUCTION OF STEAM BOILERS AND APPARATUS CONNECTED THEREWITH
Year: 1859

page_text: PROVISIONAL SPECIFICATION left by James Fernihough at the Office
of the Commissioners of Patents, with his Petition, on the 15th October.
1859.
I, JAMES FERNIHOUGH, of Dukinfield, in the County of Chester, Engineer,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN THE
CONSTRUCTION OF STEAM BOILERS AND APPARATUS CONNECTED THEREWITH," to be as
follows:-
My Invention consists, firstly, of the internal flue, flues, or tubes of steam
boilers being constructed in the manner hereafter described for the purpose of
manifoldly increasing the ordinary circular strength thereof, thereby more
completely insuring the same against the danger of collapses, and affording a
more ample space required for a due circulation of water.
Secondly, of making such other new arrangements in the construction of.
the boiler shell, internal flue, flues, or tubes, the apparatus for the admission
of atmospheric air into such internal flue, flues, or tubes, and the feed water.
apparatus, so as to avoid the dangerous evils that usually result from the
unequal, expansive, and contractive force which commonly takes place in
boilers as usually constructed.
The nature of my Invention will be understood by reference to the accom-
=

page_text: panying outline Drawing, which is a longitudinal section of my improved
boiler. a represents the internal flue, the peculiar form of which will readily be
seen to give an enormous circular strength sufficient to render the liability of
collapses almost impossible, affording a more ample space for the circulation of
water, and at the same time being particularly adapted (at plates h) to yield
to the longitudinal, expansive, and contractive force which so often produces
such mischievous results; the peculiar method of constructing the said flue
being also applicable to the construction of the boiler shell where greater
circular strength is required, or any additional security needed to avoid the
b is a brass or iron
evil results caused by unequal expansion and contraction.
stuffing box attached to the front end of the boiler, through which the flue or
tube passes, and which enables the same to expand and contract according to
the increase or decrease of temperature in the flues and boiler, especially
during the time steam is being raised, when the heated products of combustion
causes very considerable longitudinal expansion to take place in the flue or
flues long before any sensible heat can be imparted to the bottom of the boiler
shell, which, however well made, so frequently fractures, and in all cases
sustains injury either more or less in consequence of not being able to resist
the enormous strains so frequently caused by unequal expansion. c, c, are the
screw pins passing through the gland boiler end and into the ring of the stuffing
box, by which the joints of the same are made secure; d is the feed water
pipe (which is usually either connected to the bottom of the boiler shell or
otherwise arranged so as to conduct the feed water as near the bottom of the
boiler as practicable). The object of my arrangement, however, is to cause
the feed water pipe d, which I attach in any convenient place, to deliver the
feed water in jets through the perforated holes e immediately under the water
line, so as to enable the feed water (which is cooler and of a greater specific
gravity than that in the boiler) to produce a downward current on entering the
hot water, thereby securing a more perfect circulation, and fully preventing the
violent contractions which the feed water usually produces in the plates at the
bottom of flued and other boilers. By this arrangement the safety of the
flues immediately above the fire is likewise insured against becoming over-
heated, in case of any disarrangement of the feed pump or feed apparatus,
which not unfrequently occurs; in which case the water in the boiler cannot
be forced out lower than the level of the feed pipe d, which is considerably
above the level of the top of the internal flue.
Though I prefer the foregoing flue arrangement, I may, if necessary, con-
struct the boiler shell in the form shewn by the dotted lines g, for the purpose

page_text: of securing larger ends to the same, thereby allowing them to yield to
longitudinal expansive force of the flue, flues, or tubes which are rivetted or
attached to both ends in the ordinary way.
I nevertheless in carrying out the principle of my Invention combine and
apply the whole or any part thereof as the nature or circumstances of any
particular case may require.