IMPROVEMENTS IN AND CONNECTED WITH APPARATUS FOR PRODUCING AND INJECTING OR FORCING A MIXTURE OF AIR AND WATER SPRAY OR VAPOUR INTO FURNACES
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by Wallace Fairweather at the Office of
the Commissioners of Patents on the 15th March 1881. A communication
from abroad by John Glasier, of Paris, in the Republic of France.
"
WALLACE FAIRWEATHER, of the Firm of W. R. M. Thomson & Co., Consulting
Engineers, and Patent Agents, Glasgow, in the County of Lanark, North Britain.
"IMPROVEMENTS IN
AND CONNECTED WITH APPARATUS FOR PRODUCING AND
INJECTING OR FORCING A MIXTURE OF AIR AND WATER SPRAY OR VAPOUR
INTO FURNACES." A communication from abroad by John Glasier, of Paris, in the
Republic of France..
This Invention relates to certain improvements in and connected with apparatus
for producing and injecting or forcing an admixture of air and water spray or
vapour into furnaces, such as boiler, puddling, or other furnaces requiring an intense
heat, with the object of decomposing the water and producing combustion by the
combination of the resultant gases with the solid incandescent fuel lying on the
furnace grating and with the injected air, thereby economising fuel and consuming
the smoke.
In carrying out the Invention the ashpit of the furnace is made close so as to be
practically air-tight, and a large pipe or tube is fitted through the front immediately
under the fire-grate to lead in the admixture of air and water spray or vapour.
This admixture of air and water spray is produced and injected or forced through
this inlet tube or pipe by means of a fan or blower, into which water is admitted
in the form of spray or jets through small perforated openings or gratings around
the periphery of its casing. The blades or vanes of the fan are preferably curved
back to prevent the water (which by their action they reduce to a fine spray) being
carried round, but cause it to be impelled forward with the air through the exit
pipe or tube leading to the furnace.
The furnace bars are of an improved construction, being made of unusual breadth
and laid close together, but finely perforated for admission of the air and water
spray. These perforations are made conical, being considerably larger on the under
side of the bars than above, so that whilst the air and vapour are freely admitted

page_text: to the furnace the solid fuel on the bars does not tend to fall through or choke the
perforations or openings.
To prevent an excess of the air and vapour, which are injected by the fan or
blower, being carried to the inner end of the furnace and only there entering
through the fire-grate, a horizontal plate of the full breadth of the ash-pit is fitted
and carried from about the centre of the inlet pipe from the fan to about the mid-
length of the ash-pit, and there terminates in an upright end plate, or when there
are two sets of grate bars the central transverse bearing bar may project down
sufficiently to form an end plate.
By this means one half the mixed air and vapour passes immediately above the
horizontal dividing plate to the front end of the furnace, and the other half passes
below the plate to the inner end. The dividing plate is by preference perforated
to equalize the pressure of the mixed air and vapour admitted at both ends of the
furnace.
The conical perforations in the furnace bars may be inclined backwards to direct
the air and vapour towards the bridge of the furnace instead of against the crown
or roof, or part may be inclined and part vertical.
The admixture of air and vapour being forced through the fire-bars at a high
velocity keeps the bars cool, and prevents their deterioration by the action of the
fire, while the fuel on the fire-bars being agitated by the injected currents of air
and water spray is not liable to cake or be formed into clinkers. "Slack" or coal
screenings can thus be used with advantage instead of the more expensive lump
coal, and an intense heat is produced at a minimum cost for fuel. Owing to the
small amount of solid fuel used upon the furnace bars, and the great number of jets
of air and water spray (decomposed into gases) constantly playing through and
above the burning fuel, the escape of unburnt coal or smoke is prevented, thus
making the furnace a smoke consumer.
A valve is provided in the inlet tube from the fan to cut-off or reduce the supply
of air and water vapour admitted to the furnace when stoking the fire, and for
controlling the admission or force of the injected currents, so that when only a
certain or modified heat is required, as in the case of a steam boiler furnace, the
apparatus can be so regulated that a greater or smaller amount of coal is used.