IMPROVEMENTS IN THE BUILDING OF BOILERS AND BOILER FLUES FOR THE CONSUMPTION OF SMOKE
Year: 1861

page_text: PROVISIONAL SPECIFICATION left by William Hendry at the Office of
the Commissioners of Patents, with their Petition, on the 2nd March,
1861.
.I, WILLIAM HENDRY, Brickbuilder, residing at Number 220; Thistle Street,
Hutchesontown, of Glasgow, in the County of Lanark, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN THE BUILDING OF BOILERS
AND BOILER FLUES FOR THE CONSUMPTION OF SMOKE," to be as follows:-
One improvement for Cornish boilers of two tubes consists in building in
two flues at the back of the boiler, which lead the smoke and flame or heat
from each tube to the side of the boiler farthest from it, or the side nearest
the next tube and through the side flues to the front of the boiler, where a
square vertical hole left in the brickwork is placed leading down to the flame
bed below the boiler, and from thence to the chimney. Opposite this hole is
placed a square pipe of cast iron or other suitable material of the same size
through the brickwork, slanting down to the furnace above the fire-bars, the
furnace being partly in the brickwork in front of the boiler and partly in the
tube. This pipe has a flange cast on the end next the hole with a valve
working on a hinge on the bottom of this flange to close alternately the hole,
and the pipe by a chain fixed on one end to the side of this valve, and on the
other end to a weight working on two pulleys. Where the chain works
through the brickwork it is attached to a small rod passing through a stuffer
on the level of the brickwork, and to the end of this rod is attached the other
: J.

page_text: part of the chain to the valve. The furnaces are fired alternately, so that
when one fire is red or "spent " the other is "green," or newly fired. The smoke
of the "
green" fire passes through the tube and through the flue at the back
to the side flue when it reaches the hole at the front, which is closed by the
fireman by sliding up the weight and letting the valve fall on the hole leaving
the pipe open, which it enters and goes down on the red fire where it is con-
verted into flame before passing the fire-bridge. The flame and heat from
the red fire in the meantime passing through its flues reaches the square hole
at the front of its side flue, which it finds open, and the pipe being shut it
enters the hole which leads to the flame bed, and from thence to the chimney.
By simply opening and closing the pipes and holes by the valve the smoke of
the one fire may be led into the other, or into the chimney, at pleasure, the
suction of the draught keeping the valve air-tight.
For Cornish boilers of single tubes two boilers are placed alongside each
other with the side and back flues, as before described, with this difference,
that there is a wall built in between the two boilers so as to make side flues
with openings to the back flues on the boilers. At the front of the boiler and
end of these flues there is placed a hole (always open) leading down to the
flame bed. In these flues and at the back of the whole there is fixed two
damper frames, in which work two dampers for opening and closing the flues.
The green" smoke of the one furnace passes through its tube and back
flue, and finding the side flue next to the other boiler closed by the damper, so
that it cannot get down to the flame bed, it travels round the other side flue
to the hole at the front, which is closed by the valve when it enters the fur-
nace by the pipe and is converted into flame. The flame and heat from the
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spent" furnace travelling through its tube and back flue and through its two
side flues (the one nearest the other boiler having the damper open, so as to
allow part of the flame and heat to pass down the hole into the flame bed),
reaches the holes and descends into the flame bed and from thence to the
chimney.
For two hemispherical or " egg" ended boilers placed alongside each other
the flues are built precisely the same as in the boilers last described, and if the
main flue or chimney is at the back of the boiler an additional flue, which can
be built in the boiler seat, is required to carry off the flame or heat from the
holes backward to the chimney. If the chimney is in front of the boiler so
such flue is required, as the heat can be led off direct to it.
For a single hemispherical or "egg" ended boiler the flues are built the
same as in the boiler first described. The furnace and flame bed below the
boiler are divided by a brick wall so as to make two distinct furnaces and

page_text: flame beds with either a single or two distinct ash-pits. When the two fur-
naces work with a single ash-pit the division wall is built from the fire-bars
upwards, resting on an iron plate supported on iron columns rising from the
floor of the ash-pit. In all these boilers the furnace bars are preferred to be
sloping down from the back to the front of the furnace so as the more
thoroughly to burn or consume the smoke. The dampers described are
wrought by chains working on pulleys, as previously described.
The pipes leading to the furnace, previously described, may have a small
tube attached from the outside of the brickwork with a cock to let air from
the outside with the smoke as it enters the furnace, and assist in the elements
of combustion.