Heated Air to Marine Boiler and other Furnaces.
Year: 1885

page_text: Heated Air to Marine Boiler and other Furnaces.
We ROBERT WYLLIE of Hughenden House Hartlepool in the County of
Durbam Engineer and DONALD BARNES MORISON of 9 South Crescent Hartlepool
in the County of Durham Engineer do hereby declare the nature of said Invention
for "IMPROVEMENTS IN AND CONNECTED WITH MEANS FOR SUPPLYING HEATED
AIR TO MARINE BOILER AND OTHER FURNACES
Our Invention has for its principal object to provide an efficient means for
supplying heated air to marine boiler and other furnaces by utilizing the heat
radiated from the boilers and smoke boxes or other heated portions and the
otherwise waste heat of the spent gases for heating the air supply.
According to our Invention the boilers and smoke boxes or other heated parts
are in whole or in part covered by a casing or casings leaving a space between
itself or themselves and the part or parts which it covers or they cover the inner
plating of this casing or these casings is or are preferably corrugated to give as
large a heated surface as possible for the air The casing is preferably continued
round the base of the funnel and from thence or other convenient part a passage
leads to a fan by which air is drawn into and through the space or spaces enclosed
by the casing or casings. The dampers in the funnel are also made hollow (and
preferably corrugated) and communicate with their axes which are also hollow
and lead into a space or passage in communication with the fan. The fan may
also be provided with a suction box by which air can also be drawn from the
boiler room or engines as required The fan forces the heated air which it has
drawn into the space or spaces enclosed by the casing or casings as aforesaid
through suitable passages into the furnaces the doors of which are each so arranged
that as the door is opened the supply of air to its furnace by the means aforesaid
is cut off. This may be effected by means of a pinion on the axis of the door
gearing with a pinion on the air supply valve spindle or by connecting rods or
levers. The fire doors open inwards so that when the doors are open the air valves
(being then closed) are acted upon by the pressure of air from the fan to keep the
fire doors open the fire doors being balanced by the weight of the air valves.
$
J. HENRY JOHNSON,
Agent for the said Robert Wyllie and
Donald Barnes Morison,

page_text: Heated Air to Marine Boiler and other Furnaces.
We, ROBERT WYLLIE of Huganden House Hartlepool in the County of
Durham Engineer and DONALD BARNES MORISON of 9 South Crescent 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:-
.
Our Invention has for its principal object to provide an efficient means for
supplying heated air to marine boiler and other furnaces by utilizing the heat
radiated from the boilers and smoke boxes or other heated portions and the
otherwise waste heat of the spent gases for heating the air supply.
According to our Invention smoke boxes alone or in combination with other
heated parts are in whole or in part covered by a casing or casings leaving a space'
between itself or themselves and the part or parts which it covers they cover.
The inner plating of this casing or these casings is or are preferably corrugated to
give as large a heated surface as possible for the air The casing is preferably
continued round the base of the funnel, and from thence or other convenient part
a passage leads to a fan by which air is drawn into and through the space or
spaces enclosed by the casing or casings-The damper or dampers in the funnel
is or are also made hollow (and preferably corrugated) and communicate by its or
their axis or axes (which are also hollow) with a space or passage in communication
with the fan The fan may also be provided with a suction box by which air can
also be drawn from the boiler room or engine room as required. The fan forces
the heated air which it has drawn into the space or spaces enclosed as aforesaid,
through suitable passages into the furnaces, the doors of which are each so arranged
that as the door is opened the supply of air to its furnace by the means aforesaid,
is cut off. This cutting off of the air supply may be effected by the fire or ash pit
door, or both or by means of a pinion on the axis of the door gearing with a
pinion on the air supply valve spindle, or by connecting rods or levers. The fire
doors open inwards. so that when the doors are open the air valves (being then
closed) are acted upon by the pressure of air from the fan to keep the fire doors
open, the fire doors being balanced by the weight of the air valves.
And in order that our said Invention may be fully understood we shall now
proceed more particularly to describe the same and for that purpose shall refer to
the several figures in the annexed sheets of drawings the same letters of reference
indicating corresponding parts in all the figures.
Figure 1 of the accompanying drawings shews in elevations at right angles to
each other, an air casing A extending round the front and sides of the smoke
box B and tube doors C, the said casing forming a space between itself and the
parts which it covers and extending to and forming a continuation of a space
between the casing D and the base of the funnel. E is the pipe by which the air
entering at x after being heated in the casings leaves the heating spaces formed by

page_text: them, to be discharged into the furnace or furnaces. Air tubes F may extend
through the smoke box B and base of the funnel the interiors of the said tubes
being in communication with the lower and upper parts of the spaces formed by
the casings so that air passes through them and they assist in heating the air on
its passage to the pipe E.
One or more air tubes F may be employed and they may be disposed as shown
or they may be inclined in the other direction so as to terminate in the sides of the
smoke box instead of the front, or otherwise as may be most convenient.
Figure 2 shews similar views of a like arrangement of casings but with a flat
air channel F through the smoke box in communication with the space formed by
the air casings.
In these figures the air is supposed to be drawn by suction from the space
surrounding the base of the funnel.
.
:
Figure 3 shews an arrangement wherein the suction is from the space formed by
the casings A'at the base of the smoke box, and air is likewise drawn through and
heated in a pipe F opening through the side of the funnel at top; and at bottom
opening into the air space formed by the casing A.
In these arrangements the pipes or passages F F may or may not be used, as
desired. These arrangements of heating the air are drawn for the style of boiler
shewn but the casings may be, of course, adapted to any boiler or number of boilers
the air being either forced or drawn through the passages.
>
The inner plating of the smoke box or other parts covered by the air casings
may be corrugated so as to expose more surface to the hot gases, and to the air to
be heated by the heated surfaces over which it travels, through the spaces formed
by the said casings. In Figure 1 a hollow damper is shewn as combined with the
air, spaces. This hollow damper is hereinafter particularly described in various
arrangements but as it is shown in some of the Figures previous to those parti-
cularly illustrating it it is well to here state that it is a double or box like structure
or chamber with hollow trunnions through which the air enters and leaves the
space enclosed by it, that is to say its interior, the said air being heated therein by.
the otherwise waste heat passing up the funnel.
Figure 4 illustrates an arrangement of two single ended boilers provided with
air heating spaces according to this Invention The air for supplying the furnaces
first enters (at x) the air space formed by the casing over the front of the tube
doors, and then passes into the air space formed by the casings over the front and
sides of the smoke box and base of funnel, and is then drawn into the fan suction
box G. Air also enters the hollow damper H by one of its trunnions and leaves
it by the other of its trunnions, and. this air also enters the suction box G which if
required may in addition have an opening for admitting the heated air from the
top of the boilers.
From the suction box G the heated air is discharged by the fan I into a receiver J
in the smoke box and is then led by pipes or passages K into the furnaces, pre-
ferably through doors arranged as hereinafter particularly described.
The casings covering the furnace fronts may be continuous, extending if necessary
below the ashpit doors, these casings being.c
.common with the receiver in the smoke
box and the whole forming one large receiver instead of employing separate
channels K as illustrated.
Air may be forced directly into the casing covering the furnace mouths the
air passing into the furnaces through doors arranged as hereinafter particularly
described the said air being heated by the radiation from the furnaces the fan
being placed in any suitable position and arranged to draw from any suitable
place.
.
Figure 5 shews an arrangement of two double ended boilers The air channels
are generally similar to those shown in Figure 4 a fan or other blowing apparatus I
is shewn as being used as in that arrangement but it may if desired be situated in
the stoke hold or engine room and be arranged to force air directly into the casing
surrounding the furnace mouths.
E.

page_text: Such an arrangement is illustrated by Figure 6 which shews an arrangement of
two single ended boilers. Air is drawn through spaces formed by casings and
passed substantially as herein before described from the suction box G by the
pipe G2 and fan and is forced directly in to space covered by the casing K
surrounding the furnace fronts. Air may be drawn directly from the stoke hold
or engine room and be forced into the receiver formed by the casing K covering
the mouths of the furnaces passing into the furnaces through the doors arranged as
hereinafter described or when more than one fan is used one may draw air from the
suction, box and one or more from the engine room or stoke hold.
Figures 7 to 10 shew arrangements of gunboat boilers the smoke box air passages
being formed by casings substantially as herein before described. but the base of the
funnel is preferably rectangular with transverse air tubes or passages M there
through, leading air from outside or from the enclosed air space A and discharging
into the space enclosed by the casings.
The pipe G from the suction box may be led to fan in any convenient manner.
Figure 9 shews the fan I placed above the boiler and discharging into one
casing K surrounding the furnace mouths and common to both.
Figure 10 shows two separate discharges i and from fan respectively leading into
independent casings K. one for each furnace mouth When the blowing apparatus
or part thereof is placed at the smoke box end of the boilers an air receiver may
be formed in the space between the boilers below the centre line of the boilers, or
a receiver may be formed under the stoke hold plates, with suitable pipes leading to
furnaces, the air passes into the furnaces through the doors arranged as hereinafter
described. It is to be understood that we do not limit ourselves to any particular
mode of or apparatus for inducing or forcing the air current or currents through
the space or spaces provided by the casings arranged according to our Invention.
In the several figures the arrows shew clearly the course the air takes into,
through, and from the spaces formed by the casings surrounding the various heated
parts as herein before explained.
We will now describe several arrangements of the funnel dampers constructed
hollow for the passage there-through and heating therein of air according to our
invention.
Figures 11 and 12 are respectively a vertical section and a plan of a hollow
damper N mounted on hollow trunnions n It may or may not have one or more
vertical pipes n³ extending through it from side to side for the passage there-
through of the products passing up the chimney. The trunnions n are respectively
for the inlet of air to be heated in the damper, and for the escape of the heated air
therefrom to the place where it is to be utilized. The said trunnions may commu-
nicate with the air spaces formed by casings as hereinbefore described but we do
not limit ourselves to this as the air may be led from outside or other place as
desired, and may be taken direct and independently to the place of utilization.
When working, the damper is generally kept at an angle, so that the hot waste
gases impinging on the lower surface of the damper, and escaping through the
vertical pipes (when they are used) heat the air, drawn or forced through the
damper by way of the hollow trunnions. The tube n³ acts as a deflecting plate for
diverting the air and preventing it striking straight across the damper.
Figures 13 and 14 are similar views of a, hollow damper N with corrugated
upper and lower surfaces, either or both surfaces may be corrugated such corrugated
surface being adaptable to any form of hollow damper or system of hollow dampers,
and affording a large heating surface. n³ is a deffecting plate for diverting the air
as explained with regard to the tube n³ in Figure 12.
Figures 15 and 16 are similar views of a rectangular hollow damper in com-
bination with which horizontal air tubes p are shewn extending through the base
of funnel and taking air from and discharging it into the space formed by the
casing round the said base. .
The section figure 16 is taken in different planes shewing respectively the
Hamner and the tubes.

page_text: Figures 17 and 18 are vertical and horizontal sections showing a combination of
a hollow damper. N with an air casing round the base of the funnel and the smoke
box as hereinbefore described with the air supply for the damper taken from
outside the casing...
"
Figures 19 and 20 are vertical and horizontal section's shewing two semi circular
hollow dampers N mounted on hollow trunnions n and connected together by..
levers n so that one pull rod n works both dampers. n³ is a deflecting plate for
the purpose.herein before described.
Figures 21 and 22 shew in vertical section and plan two fixed semicircular
hollow dampers or baffles N2 connected by tubes or other suitable channels n for
the air to pass from one to the other. This arrangement may be used in com-
bination with a hollow damper mounted on trunnions if so desired.
We will now describe arrangements of doors and valves for controlling the
supply of air to the furnaces.
Figure 23 is a front elevation Figure 24 a vertical section Figure 25 a side view
Figure 26.a section on the line 1, 2 Figure 24, and Figure 27 a section on the
line 3, 4 Figure 24, shewing an arrangement according to our Invention. The
front plate is removed in Figure 23 and in the corresponding succeeding figures.
The fire door is marked Q and the ash pit door is marked R. q and r are
respectively casings which form passages through the air space K formed by the
casing for conveying air to the furnaces, the said casing q r forming the means
of access from the exterior to the furnace and ash pit for stoking or other purpose.
Qis a valve or door so connected to the door Q as to be operated to close the
passage for air to the furnace both above and below the fuel when the furnace
door is open, and R2 is a valve or door for similarly closing. the passage for air to
beneath the fuel when the door R is open. In order to ensure this being done a
pinions is fixed on the spindle of the door Q and another on the valve Q' the
said pinions 8 gearing into each other as is shewn clearly in Figure 25, similarly
pinions 8 on the door R and valve R2 engage together. When therefore the
door Qor the door R is closed both it and its valve Q2 or R² are vertical as shewn
in the drawings, but on either door Q or R being opened inwards to a horizontal
position the valve appertaining thereto (Q2 or R2 is by means of the pinions moved
from the vertical to the horizontal position and its weight in this position may be
made sufficient to hold the doors Q or R open.
In Figure 23 the air valve Q2 is shown extending across the passage K by which
the air travels to the ash pit or the space below the fire bars consequently when
the fire door is opened for firing, the air supply is shut off from the furnace both
above and below the grate bars and so prevents any out-rush of flame from the
fire door.
Figure 26 is a plan of the top of the fire door casing shewing the openings 2 for
admitting air into the casing q for entering the furnace above the firebars. These
openings are preferably in the form of circular holes of small diameter as shewn
and are arranged as shewn in Figure 24 so that the air is directed on to the
surface of the fire. On the top of these openings, a flat gridiron valve may be
fitted it having openings corresponding to those in the top of the fire door casing
so that the said openings 92 may. be regulated or closed entirely if required.
Figure 27 is a plan of the air opening into the ashpit. It is preferably a free
open inlet the air supply being, regulated by a valve in any suitable position in
the air passage. On the ashpit door R being opened the air valve R covers
the opening that is shewn in Figure 27 and so prevents the inflow of air to the
ashpit.
Figures 28 and 29 are a front view and a side view shewing the pinions 8 on the
spindles of the air valves Q and R2 of the fire and ash pit doors connected by by
a rod 82 so that when the firedoor Q is opened both. the air. valves Q³ and R³ close
the openings by which air enters the furnace. In this case it is of course not
necessary that the valve should extend to cover the passage K..

page_text: !
The ashpit door R is balanced by a weight rand opening inwards closes the air
passage below the fire bars.
Should the air be of considerable pressure there may be a further suitable means
of holding the door open in addition to the weight.
. Figures 30 and 31 shew in front view and side elevation an arrangement
wherein the levers on the spindles of the fire and ash pit doors are connected by a
rods as in the last preceding arrangement but with a slot g³ at one end so that on
the fire door being opened, the ash pit door is also opened and the ash pit air valve
closed but so that the ash pit door and its valve can be operated independently.
In the arrangements described there are separate doors for opening the furnace
and ash pit and for closing the air passages, but it will be readily understood that
the doors or valves at Q2 and R2 may be dispensed with and the upturned doors Q
and R may themselves effect the closing of the air passages. Such an arrangement
with regard to the fire door is shewn in Figure 32 wherein the lever on the spindle
on the fire door Q is connected with the lever on the spindle of the valve Rs of the
ash pit door R by the rod 8.
The fire door is balanced by the weight of the ash pit valve and on being opened
the fire door closes the air inlet to the top of the fire bars whilst the valve R' closes
the inlet to the ash pit.
The ash pit door is balanced by a weight 2 and may have any further suitable
means for holding it open in addition to the weight.
Figure 33 shews an arrangement wherein the fire and ash-pit doors, Q and R,
are each balanced by a weight ² and on opening inwards, respectively close the air
inlet to the top and bottom of the fire bars. The doors may have any further
suitable means for holding them open in addition to the weights.
Figures 34, 35 and 36 illustrate in front view, side view and plan, an arrange-
ment wherein the fire door Q turns upon vertical hinges. The fire-door Q, is
connected by the arm t, link to and lever t³ to a valve Q2 for closing the air inlet.
The air pressure on back of valve tends to keep the fire-door open, and the
valve Q closed. The ash-pit door R, opens inwards and is balanced by a weight r³
or held open by other suitable means and when open, itself closes the air inlet to
the ash-pit.
Figure 37 is a front view and Figure 38, a side view of an arrangement wherein
the fire-door opens inwards and is provided with a valve for shutting off the air
supply to the furnace, as hereinbefore described, whilst the ash pit door is vertically
hinged and is provided with independently operated valve R2 for shutting off air
supply to ash-pit.
Figures 39 and 40 are front and side views of an arrangement wherein the fire-
door Qopens inwards and is provided with a balanced valve Q as hereinbefore
described; whilst the ash-pit door R, turns on a vertical hinge, the valve R² which
closes the passage for air to the ash-pit, being operated by hand, and balanced by a
weight r².
Any of the hereinbefore described and illustrated horizontally hinged doors may
open outwards and be balanced by the air closing valve if required, as will be
obvious from the preceding explanations without special description or illustration.
When working with natural draught, the ash-pit doors remain open.
Having now particularly described and ascertained the nature of our said
Invention and in what manner the same is to be performed we declare that what
we claim is.
First. For supplying heated air to the furnaces of marine boilers, or to other
furnaces, a casing or casings surrounding or partially surrounding the smoke box or
smoke box and tube doors of one or more boilers and provided with an air inlet or
with air inlets and passages for conveying the air (heated in the space enclosed by
the said casing or casings) into the furnace or furnaces substantially as hereinbefore
described and explained with reference to the accompanying drawings.

page_text: Second. The combination of the subject matter of the preceding claiming clause
with a casing or jacket surrounding the base of the funnel and forming a means
in conjunction with the casing or casings referred to in the said preceding claiming
clause for heating the air for supplying the furnaces substantially as hereinbefore
described with reference to the accompanying drawings.
Third. The several arrangements and combinations of parts constituting the
several means for supplying heated air to marine boiler and other furnaces sub-
stantially as herein before described and illustrated by figures 1. 2 3. 4. 5. 6. 7. 8. 9
and 10 of the accompanying drawings.
Fourth. For heating air for supplying to the furnaces of marine boilers or to
other furnaces a hollow funnel or chimney damper or hollow funnel or chimney
dampers provided with means for causing air to pass thereto and for conveying the
air (so heated in its passage) to the furnace or furnaces; also the several arrange-
ments for this purpose hereinbefore described and illustrated by figures 11 to 22 of
the accompany drawings.
Fifth. In furnaces for marine boilers or in other furnaces horizontally hinged fire
or ashpit doors, or both, which are so balanced by a valve or valves that on the
fire or ash pit doors being opened the said valve or valves automatically shut off
the air supply to the furnace either above or below, or above and below, the grate
bars, substantially as herein before described and illustrated in the accompanying
drawings.
Sixth. In furnaces for marine boilers and in other furnaces fire or ash pit doors
horizontally or otherwise hinged which on being opened inwards themselves close
the opening through which air is supplied to the furnace above or below the
fire bars or both such doors being balanced by weights or held open by any
suitable mechanism substantially as hereinbefore described and illustrated in the
accompanying drawings.
Seventh. The several combinations of parts constituting the several arrangements
of fire doors and ash pit doors and air supply controlling devices substantially as
berein before described and illustrated in figures- 23 to 40 of the accompanying
drawings.
Dated thia 21at dow of Moush 1000