Steam Boiler and other Furnaces.
Year: 1887

page_text: Date of Application, 28th Apr., 1887
Complete Left, 28th Jan., 1888
Complete Accepted, 2nd Mar., 1888
for Steam Boiler and other Furnaces.
I JOHN WILLIAM HOLDEN of 54 Portland Street, Manchester, Engineer, do heroby
declare the nature of my invention to be as follows:-
This invention refers to improvements in Forced draught and smoke consuming
apparatus, and has for its object an improved means of obtaining an artificial draught
of intense velocity in steam boiler and other furnaces whereby I absorb and utilize
much of the valuable heat otherwise wasted on the fire bars in heating the air
travelling through the hollow bars and through an improved air chamber, and forcing
the same at a high temperature and with intense velocity into the furnace. I thus
supply the necessary air for the thorough combustion of the gases arising from the
burning fuel and secure exceptionally complete intermixture of the oxygen of the air
with such gases and I produce instant combustion, thus obtaining the highest
evaporative power out of the coal and utterly preventing smoke.
In performing my invention I take away a portion of the bridge which forms the
wall of the ashpit and substitute a dead plate at this point to carry that part of the
bridge which is above the bars. The rear ends of the hollow bars are carried under
this dead plate and thus I nullify any tendency the suction of the air, entering the
hollow bars, may bave to draw the flame downwards through the spaces between the bars
and leave a sufficient space to form the inlet for air into the hollow bars. The front
ends of the bars are connected to a hollow dead plate from which the air, after
travelling through the bars passes up into an improved air chamber carried from the
hollow dead plate at each side and over the top of the furnace door and from which
chamber it is ejected with intense velocity by jets of steam or compressed air in
combination with a number of ejector tubes secured in front of the air chamber, into
the furnace.
I thus form the front of the furnace as a hollow casing or air chamber in conjunction
or communication with the hollow dead plate, which enables me not only to prevent
the undue radiation of heat at the front of the boiler and especially in marine boilers,
but absorb this heat in increasing the temperature of the blast as aforesaid. I also
ensure the greater durability of the fire bars by keeping them at such a temperature
that it is well-nigh impossible to fuse or the clinkers to adhere to them.
لبحث
1
11007
JOHN G. WILSON;
Agent for the Applicant.

page_text: for Steam Boiler and other Furnaces.
I JOHN WILLIAM HOLDEN of 54 Portland Street, Manchester, Engineer, do hereby
declare the nature of my said invention and in what manner the same is to ho
performed to be particularly described and ascertained in and by the following
statement:-
This invention refers to improvements in Forced Draught and smoke consuming
apparatus, and has for its object an improved means of obtaining an artificial draught
of intense velocity in steam-boiler and other furnaces whereby 1 absorb and utilize
much of the valuable heat otherwise wasted on the fire bars in heating the air
travelling through the hollow bars and through an improved air chamber and forcing
the same at a high temperature and with intense velocity into the furnace. I thus
supply the necessary air for the thorough combustion of the gases arising from the
burning fuel and secure exceptionally complete intermixture of the oxygen of the air
with such gases and I produce instant combustion; thus obtaining the highest
evaporative power out of the coal, and utterly preventing smoke. In carrying out
my invention in most cases I secure what is substantially an assisted draught, the
furnaces working under the ordinary conditions that is with an open ashpit, but my
combination of apparatus is also eminently suited for working with forced draught,
the air for combustion being supplied at a pressure above that of the atmosphere by a
fan or other blowing apparatus, either to a closed ashpit or to a closed stokehold. In
all the modifications of my improved apparatus my object is to increase the velocity
of the draught under the fire bars and below the solid fuel and to supply a current of
heated air above the fuel, thereby securing more rapid and thorough combustion,
eliciting to the fullest extent the evaporative power and speed of the coal, and entirely
preventing smoke.
In order that my invention and the manner of performing the same may be properly
understood I append drawings and descriptions of the same with various modifications
and which I will now proceed to describe.
Fig. 1 is a longitudinal section and Fig. 2 a sectional plan of my improved
combination and arrangement of apparatus applied to a steam boiler furnace for
securing an assisted draught of either a moderate or an intense velocity.
Fig. 3 is an end elevation of the same boiler furnace showing the apparatus as it
appears with the door frame attached on one side and also a section of the apparatus
on the other side through the line y in Fig. 1.
A is a bridge modified in accordance with my invention B is a space between the
rear end of the bars and the bridge A, to allow of the free access of air to the hollow
bars from the ashpit A', CC are the hollow bars with an orifice at their rear end and
communicating at their front extremities with a hollow dead plate D which in turn
communicates with the hollow air chamber E surrounding the fire door and on the
front or inner face of which are mounted ejector tubes F provided with steam jets G.
His a detachable plate for the purpose of cleaning out the hollow dead plate D and
which plate may be applied in any or all of the modifications herein after described.
The action of this part of my invention is as follows:-When the steam jets G are
in use they create a vacuum in the ejector tubes F, and induce a current of air which
is drawn down the ashpit A¹ and enters the hollow bars C at their rear ends and after

page_text: making the circuit of the hollow bars, hollow dead plate D and air chamber E is
ejected over the fire at a velocity which is regulated by the pressure and quantity of
steam used.
In Fig. 4 I represent a side sectional view of a modification of my improved
apparatus which is similar to that shewn in Figs. 1, 2 and 3 with the exception that
there are no steam jets used, and which arrangement is more especially adapted for
furnaces which do not generate steam or where steam is not available or in cases
where a draught of intense velocity is not required.
Corresponding parts are represented by similar letters of reference to those used in
Figs. 1. 2 and 3.
In this arrangement the waste heat taken up from the bars and air chamber is the
motive power as the air in passing through the hollow bars becomes heated and
rarefied and the unbalanced pressure of the heavier atmosphere outside forces it
forward thus creating a constant circulation of air down the ashpit, through the
hollow bars, hollow dead plate and air chamber and which is expelled above the fire
through the tubes.
In this arrangement, ospecially when the furnaces are very wide 1 sometimes prefer
to divide the hollow dead plate and air chamber into two or more compartments (as
hereinafter described with reference to Figs. 5 and 6) so that a more even circulation
of air through the hollow bars is secured.
In Figs. 5 and 6 I represent a side sectional and front sectional view of a
modification of my invention which is used more especially in Marine Boilers and
where the chimney or funnel has only a feeble action. It is a similar arrangement to
that shewn in Figs. 1 and 2 but has an additional feature in-as-much as I divide the
hollow dead plate a by preference into three compartments b. c. d and take an
auxilliary or excess tube e from the centre compartment c. and carry it by preference
up through the smoke box f into the funnel 9 using a steam jet h or other means to
exhaust the air through the hollow bars which have their outlet into the centre
compartment c of the hollow dead plate a and force it by preference up into the
funnel g. In this case the air which is exhausted through the bars which have their
outlet in the other compartments 6 and d of the divided hollow dead plate a is
exhausted up through the air chamber and ejected over the fire in the manner
hereinbefore described. By this arrangement the quantity and velocity of air above
and below the fire may be regulated to the greatest advantage and the funnel draught
be considerably accellerated and improved.
Fig. 7 is a side section and Fig. 8 a front sectional view of an arrangement of my
invention used more especially in Marine boilers where the air for combustion is
supplied under pressure say through a pipe j to a closed ashpit j¹ with a fan or other
blowing apparatus-in this case and in order to regulate the pressure of air above and
below the fire to the greatest advantage, I use an air chamber k the front plate of
which is perforated with a sufficient number of small holes being regulated in size.
and number so that there may not be an undue pressure over the top of the fire. I
also divide the hollow dead plate m by preference into three compartments n. o. p
and from one or all of these compartments, I take branches into an excess air tube
communicating with a common excess tuber and which is carried by preference up
through the sinoke box into the funnel. These excess tubes or openings q and r afford
a most convenient outlet for the air (which is being forced into the closed ashpit j) to
escape into the funnel for instance whenever the furnace door is opened at a rate
similar to that at which it is being forced into the ashpit and in this way the pressure
in the furnace is effectually reduced at such times thus rendering it unnecessary to
have any mechanical arrangement for stopping the fan or blowing apparatus when the
fire door has to be opened.
These branch tubes are operated by preference by one common regulating valve or
slide which is so arranged that it may be opened and closed by the fire door for
instance by means of a pinion s on the axis t of the door gearing with a toothed rack
on the regulating slido u (which takes the form of a grating sliding in front of a
corresponding fixed grating so as to open and close with a small traverse) or by any

page_text: other convenient arrangement. By these means I secure that when the fire door is
opened, the regulating slide is also openod, permitting the air to escape into the
excess tubes and relieving the pressure in the furnace until the door is closed again
when the regulating slide is also closed and the furnace is once more working under
pressure. The excess tube taken from the centre compartment of the hollow dead
plate being so arranged that there shall at all times be a sufficient circulation of air
through the hollow bars which have their outlet in the centro compartment of the
hollow dead plate. The air which passes through the hollow bars having their outlet
in the other compartments of the hollow dead plate is forced up through the air
chamber and expelled through the perforated holes over the top of the fires. At any
time when it is desirable to work under natural draught the fan or blowing apparatus
may be stopped and the ashpit doors opened.
This last modification is equally applicable (with the exception of the self-acting
regulating valve or valves) and with or without excess tubes in cases of Marine
boilers where the air for combustion is supplied under pressure by a fan to a closed
stokehold.
In all the foregoing arrangements and modifications of my invention I am enabled
not only to prevent the undue radiation of heat at the front of the boiler and especially
in marine boilers but I absorb this heat in increasing the temperature of the blast
as aforesaid also ousure the greater durability of the fire-bars by keeping them at
such a temperature that it is well nigh impossible to fuse or the clinkers to adhere
to them.
Having thus particularly described and ascertained the nature of my said invention
and the manner of performing the same I have to state that I do not restrict myself to
the precise details herein before described, but that which I believe to be novel and
claim is
1st. The combination of apparatus or arrangements of hollow bars, hollow dead plate,
air chamber and ejector tubes in conjunction with the steam jets substantially as
herein before described and illustrated in Figs. 1. 2 and 3 of the drawing annexen.
2nd. The combination of apparatus or arrangements of hollow bars, hollow dead
plate, air chamber and ejector tubes and with or without divisions or compartments in
the hollow dead plate, substantially as hereinbefore described and illustrated on the
accompanying drawings.
3rd. The combination of apparatus or arrangement of hollow bars, hollow dead
plate, air chamber and ejector tubes in conjunction with steam jets, hollow dead plate
having divided compartments from the centre one of which is taken an auxilliary or
excess tube in conjunction with a steam jet, the parts being arranged and operating
substantially as and for the purposes herein before described.
4th. The combination of apparatus or arrangements for supplying air to the
furnaces of Marine and other boilers wherein the air is supplied under pressure by a
fan or blowing apparatus and first passes into a closed ashpit in conjunction with
hollow bars communicating with a hollow dead plate and air chamber the front plate
of the air chamber being perforated and the hollow dead plate being divided into
compartments having within them suitably proportioned branches or openings fitted
with regulating dampers or valves through which the air under pressure may readily
escape into the funnel or chimney thereby reducing the pressure in the furnace, the
parts being arranged and operating substantially as and for the purposes hereinbefore
described.
Doted this 97th do ut Ton1000