Improved Method of and Apparatus for Supplying Air to Marine Boiler Furnaces.
Year: 1893

page_text: Date of Application, 22nd Feb., 1893
Complete Specification Left, 22nd Dec., 1893-Accepted, 27th Jan., 1894
PROVISIONAL SPECIFICATION.
Improved Method of and Apparatus for Supplying Air to Marine
Boiler Furnaces.
I, DONALD BARNS MORISON of the Hartlepool Engine Works, Hartlepool in
the County of Durham, Engineer, do hereby declare the nature of this invention
to be as follows:-
When air is delivered by a fan into open stoke-holds in the manner heretofore
usual for the purpose of assisting the draught in marine boiler furnaces, a large
proportion of the air so supplied is lost by reason of its being drawn up the
ventilating shaft or shafts with the result that power is wasted, and the stokeholds
are not uniformly ventilated. Furthermore with such an arrangement no facilities
are provided for promoting a uniform supply of air to each furnace or for
controlling the supply of air to each furnace."
Now the object of my invention is to obviate the disadvantages above referred to ;.
for this purpose I cause the air supplied by the fan to issue through a nozzle or
nozzles in such a manner that the issuing current or currents of air will be directed
across the stokehold towards the boiler furnace or furnaces and in their passage
will induce the surrounding air to follow in the same direction, so that each furnace
will be supplied with a volume of air sufficient for its maximum requirements and
the stokehold thereby well ventilated, the power expended in driving the fan being
efficiently utilized. An arrangement of apparatus suitable for carrying out my
invention is as follows:-
In the engine room, stokehold or other convenient place is placed a fan which
draws air from the engine room or other desired part as is usual with ordinary arrange-
ments for assisting the draught of marine boiler furnaces. On or near to the
stokehold bulkhead is a receiver into which the air from the fan is discharged and
from this receiver lead pipes or tubes that are arranged to terminate opposite each
furnace. The free ends of these pipes or tubes may be in the form of simple
nozzles, but are by preference each surrounded by one or more auxiliary air supply
cones through which the surrounding air in the stokehold will be induced to flow,
in a manner well understood, by the action of the air flowing through the central
nozzle. Or the air cone may be closed at the back and a pipe connected to it so
as to draw air from any desired part of the ship for ventilating purposes. Each
pipe or tube leading from the air receiver may be provided with a damper so that
the passage of air through it may be regulated or stopped to suit requirement or
each nozzle may be fitted with a flap damper so that the air supply from each or
any nozzle can be stopped to enable the corresponding fire to be cleaned or for
other purposes or can be regulated according to the condition of the fires, as for
instance whether they be clean or dirty. Each pipe, tube or nozzle may be
arranged to rotate or partly rotate so that the air current passing through it can
be directed in any desired direction. By the means described large volumes of air
which are completely under control can be supplied directly to the ashpit of each
furnace, and the stokehold can be uniformly ventilated the air supplied serving
also as a cooling agent for the firemen when at work.
Dated this 22nd day of February 1893.

page_text: Improved Method of and Apparatus for Supplying Air to Marine
Boiler Furnaces.
I, DONALD BARNS MORISON, of Hartlepool Engine Works, Hartlepool, in the
County of Durham, Engineer, do hereby declare the nature of this invention and
in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement:-
When air is delivered by a fan or its equivalent into the stokeholds of steamships
in the manner heretofore usual for the purpose of supplying air to marine boiler
furnaces, a large quantity of the air so supplied does not enter the furnaces by
reason of its escaping through the ventilating shaft or shafts or elsewhere, with the
result that power is wasted, the efficiency of the furnaces is decreased by reason of
the supply to each furnace not being equal, and the ventilation of the stokehold is
not uniform. Furthermore with such an arrangement no facilities are provided for
obtaining a controllable supply of air to each furnace, nor for minimising the supply
to each furnace when firing, or when cleaning fires.
Now the object of my invention is to obviate the disadvantages above referred
to. For this purpose I cause the air supplied by the fan, or its equivalent, to issue
through a nozzle or nozzles in such a manner that the issuing current or currents
of air will be directed across the stokehold towards the boiler furnace or furnaces
and in their passage will induce the surrounding air to follow in the same direction,
so that each furnace will be supplied with a volume of air sufficient for its require-
ments, the stokehold thereby uniformly ventilated and a maximum of the power
expended in driving the fan, or its equivalent, efficiently utilized.
The apparatus
may advantageously be used both with closed and open stokeholds.
An arrangement of apparatus suitable for carrying out my invention is as
follows: In the engine-room, stokehold or other convenient position is placed a
fan, or its equivalent which draws air from any part or parts as may be desired.
On or near the stokehold bulkhead, either above or below the floor, is a receiver
into which the air from the fan is discharged, and from this receiver extend pipes
or tubes terminating in controllable nozzles opposite each furnace. Each pipe or
tube leading from the air receiver may be provided with a valve or damper so that
the passage of air through it may be regulated to suit requirements, and each nozzle
may be fitted with a flap valve at its mouth so that the air supply from each or any
nozzle can be shut off to enable the corresponding furnace to be fired, or the fire to
be cleaned, or for any other purpose.
Each pipe, tube or nozzle may be arranged to rotate or partly rotate so that the
air current passing through it can be directed where desired.
In the accompanying drawings,
Figs. I and 11 show respectively in end elevation and side elevation, apparatus
according to my invention applied to a marine boiler.
Fig. 111 is a similar view to Fig. 11, showing a modified arrangement.
Figs. IV and V are enlarged views in elevation and plan respectively of the
.controllable nozzle.
Referring to Figs. I and II: 1 is a fan provided with a suction pipe 2 drawing
air from above the deck, and also, it may be, with a second suction pipe 2" which
can be led to any desired air space within the ship. In each of these suction pipes
is a valve or damper 3 provided with an operating handle 4, which may be arranged
to work over a quadrant 4* as shown. 5 is the discharge pipe from the fan 1; it
is connected to a receiver 6. From this receiver 6 pipes or tubes 7, 7ª, 7" are led
to controllable nozzles 8, 8, 8b arranged at or near the bulkhead opposite the
furnaces 9, 9, 9 of the boiler 10. Each of the pipes or tubes 7, 7ª, 7" is provided
with a valve or damper 11 as shown more clearly in Figs. IV and V, for regulating
the supply of air to each furnace, and each of the nozzles 8, 8", 8" is provided with

page_text: a flap valve 12, for shutting off the air supply when firing, or when a fire is being-
cleaned, or at any other desired time. Each of the valves or dampers 11 is provided
with a handle 13 arranged to work over a quadrant 14. Instead of the damper II
being fitted inside the pipe 7, it may be fitted within the nozzle 8 as shown by
dotted lines at 11 in Fig. IV. In connection with each flap valve 12 there may
be provided a catch 1 by which the said valve can be held closed when it is.
desired to entirely shut off the air supply from the corresponding nozzle 8.
flange &* of each nozzle may be provided with oval holes or slots 8" so that when it
is connected to the lower end of the pipe 7 above by bolts and nuts, the nozzle 8-
can be turned about a vertical axis so that its delivery end can be arranged to point.
in any desired direction.
The
In
In the modified arrangement shown in Fig. III, the fan 1 is shown arranged in.
the engine room, and the suction pipe 2 in addition to being provided with a valve
or damper 3 and handle 4 for controlling the air supply from above the deck, is.
provided with a suitable device, such as a sliding door 15 by opening which a
controllable supply of air can be drawn from the engine room. By this means the
temperature of the air supplied to the stokehold can be varied and regulated so-
that the stokers are not inconvenienced by the air being too hot or too cold.
hot weather the whole of the air supply may be taken from the outer air, and in
cold weather from the engine room, or by a suitable regulation of the valve or
damper 3 and the sliding door 15 the temperature of the air discharge into the
stokehold may be suitably regulated to suit requirement. The suction pipe 2 is.
preferably not rigidly connected to the fan but allowed to project loosely into a.
casing 16 carried by the fan and which is made of large internal diameter for the
purpose. A loose ring 17 is placed on the top of this casing 16 through which
the suction pipe 2 also projects. By this means it will be seen that any vibration
to which the suction pipe 2 may be subjected will not be transmitted to the fan.
Although one boiler only is shewn in the drawings there may be any number and.
they may be of any type.
Having now particularly described and ascertained the nature of the said inven--
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The herein described method of supplying air to marine boiler furnaces by
causing the air, supplied by a fan or its equivalent, to issue through a controllable.
nozzle or nozzles in such a manner that the air supplied by the nozzle or nozzles
can be regulated and shut off and by being directed across the stokehold towards.
the boiler furnace or furnaces it will in its passage induce the surrounding air in
the stokehold to follow in the same direction as set forth for the purposes.
specified.
2. Apparatus for supplying air to marine boiler furnaces, comprising a fan or its
equivalent, a receiver in connection therewith, one or more pipes leading from said
receiver and each terminating in a nozzle arranged directly opposite a boiler
furnace, and means for controlling the flow of air through each pipe and its nozzle,.
the arrangement being such that a current of air can be directed across the stoke-
hold from each nozzle to the corresponding furnace substantially as herein described
for the purpose set forth.
3. Apparatus for supplying air to marine boiler furnaces constructed arranged.
and operating substantially as hereinbefore described with reference to and shown.
in Figs. I, II, IV, and V, or modified according to Fig III.
Dated this 22nd day of December 1893.