IMPROVE- MENTS IN AND CONNECTED WITH STEAM BOILER FURNACES
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
I, JOHN WHITTLE of 156 Bolton Street Bury, in the County of Lancaster
Mechanical Engineer do hereby declare the nature of my invention for IMPROVE-
MENTS IN AND CONNECTED WITH STEAM BOILER FURNACES to be as follows:-
A method of introducing a Steam Blast immediately over the front of the fire,
a short pipe for that purpose being introduced through the door frame above the
door. I also increase the height of the bridge at back end of the fire bars so as to
retard the hot gases and products of combustion in their passage to the chimney.
The Invention I claim is in introducing the blast at the beginning of the fire
thereby allowing perfect combustion to take place all along the surface of the fire-
bars any other steam jets in use being introduced at such a distance from the
beginning of the fire as to merely have the effect of carrying over the products of
combustion to the chimney.
The steam blast being placed over the centre of the fire causes the flame to rise
along the sides of the flue meeting in the crown and thus greater efficiency of
evaporating power is obtained from the same amount of fuel. '
The perfect combustion attained in the furnace by my arrangement allows the
heated gases to be retained for a longer time in and around the flues and
economizers thereby causing a greater evaporation of water with the same amount
of fuel.
I also have discovered a method of introducing the blast in such a way as to
obviate all tendency to damage the flue by corrosion, viz: by slightly bending down
the nozzle of the pipe at the point of delivery so as to throw the whole blast upon
the burning fuel instead of impinging upon any part of the flue which has
heretofore been a serious drawback to the introduction of this method of obtaining
a draught.
Finally by means of my Invention I claim to have discovered a method of
producing a more perfect combustion-of using the products of that combustion in
a more efficient manner-viz: of evaporating a larger quantity of water from
a given quantity of coal than has heretofore been possible of preventing the
formation of smoke by the peculiar point at which my steam blast is introduced
and by the peculiar arrangement of my fire-bridge, I render unnecessary the large
amount of cold air which heretofore has been the practice to pass over the
incandescent fuel.

page_text: I, JOHN WHITTLE of Bolton Street, Bury, in the County of Lancaster Mechanical
Engineer do hereby declare the nature of my invention for IMPROVEMENTS IN AND
CONNECTED WITH STEAM BOILER FURNACES and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement:-
My Invention consists in the peculiarity of the position in which my steam jet
is introduced, the peculiar form and length of the pipe and the form of firebridge
which is introduced at the back end of firebars so as to retain the products of
combustion for a longer time in contact with the crown plates of the flues.
The accompanying drawings show my invention-Fig. 1 is the front view of
a boiler with the pipes attached-Fig. 2 is the longitudinal section of the Boiler
furnace showing the position and form of pipes where the steam jet is introduced
and the form of bridge which acts as a baffle plate to obstruct the heated gases in
their progress through the flues-Fig. 3 is front view of firebridge.
A is the point at which the steam enters the pipes above the water line of the
boiler. B, B are two taps so that either furnace may be shut off as required for
stokeing purposes &c. C, C, are the points at which the jet is introduced into the
furnace, D shows the form of pipe and length of the same which is the principal
feature and most important part of my Invention E shows the altered fire bridge
consisting of an arch of fire bricks as shown.
By the introduction of the steam jet at the very commencement of the fire
I produce such a powerful heat that the gases are liberated in a state of
incandescence thereby preventing the formation of smoke this has not been done
hitherto by any of the steam jets in use owing to their being placed in such
a position that smoke is formed before being subjected to their action, the
impossibility of burning smoke after being once formed being well known. Hence
the value and importance of my invention which is different in action and principle
from that of any steam jet in use. My experience led me to see that all the
present appliances are introduced in wrong positions in the furnace and by a long
series of experiments I gradually found the exact point and form of nozzle whereby
the fire is urged to such a degree as to prevent the formation of smoke and at the
same time the peculiar form of pipe is such as to prevent the blast impinging upon
the furnace crown or sides whereby many of the present steam jets have come to
be disused.
The peculiar form of firebridge is also part of my Invention its use being to
retard the intensely heated products of combustion thereby enabling their heat to
be imparted to the water surrounding the flue to a greater extent. It also acts in
this way the strong blast and intake being once broken or baffled, the further
progress of the same through the internal and external flues of the boiler is reduced
in speed thus allowing the water in the boiler more time to absorb the heat from
the heated gases during their passage to the chimney.
The action of my steam jet when working is as follows. A partial vacuum is
formed immediately over the fire. A powerful blast of air rushes up through the

page_text: fire bars to destroy this vacuum-This inrush of air is of such force as to bring
the fuel up to such a heat that the gases are liberated in a state of incandescence
instead of being mixed with black smoke as they usually are in steam boiler
furnaces This partial vacuum forming immediately over the fire has the effect of
setting up a circular motion in the heated gases whereby they lap round the crown
plates of the flue in a way which is not secured by any other invention in use for
this purpose
This peculiar action evidently gives great facilities for imparting
heat to the water.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
1. The point of introduction of the steam jet.
2. The length of the pipe introducing the same into the furnace crown.
3. The peculiar form of the nozzle giving the steam blast a certain direction.
4. The peculiar form and arrangement of iny firebridge.