MENTS IN FURNACES FOR THE CONSUMPTION OF SMOKE
Year: 1876

page_text: PROVISIONAL SPECIFICATION left by Thomas Stone at the Office of the
Commissioners of Patents on the 29th December 1876.
THOMAS STONE, of Preston, in the County of Lancaster, Engineer.
MENTS IN FURNACES FOR THE CONSUMPTION OF SMOKE."
"IMPROVE-
The ordinary bridge of any furnace that I fit up with my apparatus I remove,
and in its place fix hot-air chamber the whole breadth of the fire-place. This hot-
air chamber is so constructed as to receive its air just below the bottom edge of the
fire-bars from the ash-pit or space under the bars and is of L shape. At the back
of this chamber or near top I fit in a valve to regulate the quantity admitted by
means of a screw, which I set at such a distance as the nature and size of the
furnace may require. In the front of the aforesaid hot-air chamber and on top 1
case such chamber with fire-brick. This chamber I may construct of iron, brick,
or any other equivalent. This chamber forms the back of my bridge coming with
the top of a decline towards the fire to allow of a thicker fire-brick casing where
the intense heat mostly is accumulated. At the top of this chamber at back of
bridge is an air space fitted with the valve before named. At a distance from the
bridge up the flue, which distance will be regulated by size and length of furnace,
I build or fix a second bridge or diaphragm of any suitable material built as high
or a little higher than the first bridge. Between these two bridges, I call the first
or combustion chamber there will be an opening at the bottom of this bridge for
the free escape of the heavy gasses or non-inflamible matter, and where it is
necessary I fix a third of fourth bridge or similar construction to last, I also fix at
suitable intervals in the outside flues of boiler diaphrams of iron, or its equivalent,
made to fit the flue and to work on pivots top and bottom. These may then be set
at any angle and will act as dampers or to bring the flame or hot gas nearer the
boiler while passing at every diaphragm, thereby getting all that possibly can be
got out of the fuel.
When fresh coal is put on any fire more gas is suddenly liberated then there is
air in the furnace to consume, and both flame and gas pass to the back edge of front
bridge where it meets with the hot air, when immediate combustion takes place in
what I call the combustion or first chamber. The light or inflamable gases rise
and pass over the second (and third and fourth bridge when such are required).
The heavy gas-es falling pass through the openings provided at the bottom of such

page_text: bridges on to the chimney and not through the side flues (if any). By this means
all the heat-producing power is alone passed through the side flues past the dia-
phragms, which may be closed or opened by the attendant at will by rods connected
to such diaphrams and coming to the front of the boiler. This series of diaphragms
are therefore so arranged as to prevent the hot air from rushing to the chimney 5
without having done its work; it is thereby passed in thin streams in close contact
with the boiler, utilising all the heat, which must of necessity save fuel.