IMPROVEMENTS APPLICABLE TO STEAM BOILER AND OTHER FURNACES
Year: 1867

page_text: PROVISIONAL SPECIFICATION left by Henry Fisher at the Office of
the Commissioners of Patents, with his Petition, on the 19th September
1867.
I, HENRY FISHER, of Birkenhead, in the County of Chester, do bereby
declare the nature of the said Invention for "IMPROVEMENTS APPLICABLE TO
STEAM BOILER AND OTHER FURNACES," to be as follows:-
This Invention relates to improvements in boiler and other furnaces
constructed according to the Invention of Mr. Joshua Fisher, for which he
obtained Letters Patent, dated 26th December 1865, and numbered 3338, and
is partly applicable to various kinds of furnaces. It has been found from
practical experience the bricks, bars, or rests for the fuel used in the con-
struction of furnaces (particularly those constructed according to the Invention
of Mr. Joshua Fisher herein-before alluded to) are detrimentally effected by
the extreme heat and scoria or earthy matter contained in the fuel.
Now one of the main objects of this Invention is to overcome this defect,
that is to say, to prevent as far as possible the destruction of the materials
forming the furnace; and another object, of this Invention when applied to
furnaces, as described by Mr. Joshua Fisher in the said Patent, consists in
the form of hollow brick fuel rests or tubes for the upper tier thereof, whereby
the midfeather support may be in some cases dispensed with, and also in the
form of the fuel rests when used as water passages, and consist in the use of
a peculiar description of hollow fire-bars or rests for 'the fuel, and in arranging
the same either longitudinally along the furnace or transversely across the

page_text: furnace, which bars or rests for the fuel may be formed of fire-clay or metal,
in which latter case the ends thereof may be connected and open into water
spaces of the boiler, but when fire-clay is used the internal cavities form air
passages extending when arranged longitudinally from the front or mouth end
of the furnace to the rear thereof, or to within a few inches of the rear, from
whence the air is conveyed through suitable pipes, passage, or passages into the
ash-pit or flue, as may be found most desirable.
In applying this Invention to, say, a steam boiler furnace when the bars or
rests for supporting the fuel are arranged longitudinally and made from fire-
clay, along each side of the furnace opening there is placed an oblique angle
iron which extends from the front of the boiler to the rear of the furnace or
thereabouts, and is riveted to the vertical sides thereof. These angular
pieces are used to receive fire-clay tubes or hollow bricks jointed-together end
to end so as to form a complete air passage from the front of the boiler or
furnace into the ash-pit or take-up of the flue, or instead of using angular iron
the sides of the boiler may be so formed as to receive and hold these hollow
tubes, or they may be formed into the brick wall below the boiler, or on a
brick wall built up against the boiler on each side of the ash-pit. Below
the angle irons there are two transverse metal bearing bars, one near the
front and the other near the rear of the furnace, with intermediate ones when
required, which are used to receive, say in a small furnace two longitudinal
flat bars of iron extending from the front of the boiler to the rear of the
furnace or thereabouts, which are formed on their upper surface with a
longitudinal ridge or feather which takes into a groove formed on the under
side of the hollow fire-clay rests for the fuel, which rests are laid on the top
thereof. Between these two flat bearers there is a longitudinal midfeather of
iron wedged shaped or otherwise, with the narrow edge downward and
extending from the front of the boiler to the rear of the furnace or thereabouts,
having two or more shanks or stalks resting on the metal bearing bars, and
longitudinally along the centre on the top thereof there should also be formed
a ridge which takes into the grooves formed on the under side of the bollow
bricks or tubes which are bedded upon it. The several lines of hollow bricks
or tubes form air passages from the front or mouth end of the furnace to the
back thereof, whence the air is conveyed by any suitable channel into the
ash-pit or flue of the boiler. The form of hollow-brick or tube preferred to be
used at the side of the furnace are formed with vertical sides and the top and
bottom at acute angle corresponding with the angle irons on which they
rest. The hollow bricks, tubes, or fuel rests preferred to be used on the mid-
feather and its parallel bearers on the sides thereof, it is preferred should have

page_text: 'the under side formed flat with a centre groove, into which takes the longitudinal
ridge or projection of the iron midfeather with parallel vertical sides, and on
the top at an obtuse angle; or the under part of the upper tubes and the upper
part of the lower tubes may be segmental, also the upper and centre fuel rest,
whether formed of brick or other material may be continued down below the
air passages to the fuel, but the peculiar form of these and the two lateral
hollow tubes may be varied at pleasure. It will be observed there are now
five hollow fuel rests described, the two side ones resting on the angle iron,
and the centre one on its midfeather are parallel and in line with each other,
whilst the two intermediate passages resting on the flat bearers run parallel
with the others, but are below and generally project beneath the upper ones,
thus leaving passages for the air for supporting combustion to pass through
between the under side of the upper hollow fuel rests and over the top of the
lower ones, the space between them being preferred to be about two inches.
manner.
A convenient size and form of hollow brick or tube for the central fuel rests
would be about seven inches across its base, three high on its vertical sides,
and (including its oblique angular top) about five inches in height, and the
intermediate fuel rests placed below the central one may be of a similar shape.
The convenient thickness of the material of which the hollow brick fuel rest or
tube is made will be about one inch and a quarter, but of course the dimensions
and forms may be varied as circumstances may direct. The longitudinal bearers
and midfeather on which the hollow tubes or rests for the fuel are supported may
be of any convenient form and fixed longitudinally in position in any convenient
Of course it will be readily understood that other material than
fire-clay may be used for the hollow fuel rests or tubes when the air is conveyed
through them, but when it is desirable to cause a circulation of water through
the longitudinal or transverse tubes or fuel rests it is preferred that the ends
thereof should be connected and open into the water spaces of the boiler, and
in which latter case it is also preferred that the bars should be slightly
deflected or curved to insure the circulation of the water through them, and
that in section they should be circular or of the form described for brick tubes,
or of any convenient form, and also it is sometimes desirable that the upper
and lower tubes or fuel rests be connected by tubes or pipes running trans-
versely, and also that one or more of the upper fuel rests or tubes be connected
with the water space above by a vertical tube to insure a more perfect
circulation of the water. Instead of arranging the hollow fuel rests or tubes
longitudinally they may be arranged transversely across the fuel chamber, and
in which case when used as air channels the ends thereof on one side of the
fuel chamber connect with a common passage formed parallel to the side of

page_text: the ash-pit extending from the front to the rear of the same, and closed in
the rear, but open in the front, through which the air enters and passes through
the tubes to the opposite side and down into the ash-pit or flue, as may be
found most convenient. The tubes or hollow rest for the fuel, described in the
above furnace as the centre and upper one, is formed sometimes when of metal
with projections at intervals of, say, every one or more feet, and when
similarly formed of fire-clay the tube will be composed of a series of fire-clay
tiles of, say, 12 inches long, each end of which for, say, 1 inches is made wider
and deeper than the remaining 9 inches, so that they may bed or rest on the
hollow fuel rests below, and being thus supported the iron midfeather may be
dispensed with. By this construction of the upper hollow fuel rests it will be seen
that instead of a continuous air passage to the fuel between the upper and lower
hollow bars there will be a series of air passages of, say, 6 inches long by 2 deep.
And it will readily be understood that the two lateral hollow fire-clay fuel
rests may be similarly constructed of tiles, so that the ends thereof on their
under and inner sides may bed on the upper surface of the hollow fuel rests
below. The longitudinal bearers on which the bollow fuel, rests or tubes are
bedded instead of being extended from the outside front of the furnace opposite
the fuel chamber to the rear of the furnace or thereabouts as herein-before
intended to be described may extend only the length of the fuel bed, any
suitable arrangement being made in the front of the furnace for admission
of air to the same hollow fuel rest, either through or under the door, or below
or on either side of the door mouth. It will be understood that the current
of air through the hollow fuel rests may be either from the mouth end of the
furnace or front of the boiler to the rear of the furnace, or inversely.