Improvements in Steam Boiler Furnaces with Artificial Draft for 0 Burning Coal-dust.
Year: 1897

page_text: Date of Application, 11th May, 1897-Accepted, 28th Aug., 1897
COMPLETE SPECIFICATION.
Improvements in Steam Boiler Furnaces with Artificial Draft for
0 Burning Coal-dust.
I, HENRY EDWIN PARSON of No. 67 Bremen Street, in the City of Brooklyn,
and State of New York, United States of America, Inventor, 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: —
This invention relates to certain improvements in steam-boiler furnaces which
are arranged for the burning of coal or coke-dust known as
"under
breeze
artificial draft so that the perfect combustion of this fuel which was heretofore
considered as waste and also a very effective and economical source of heat for
steam-boilers and for other heating purposes are obtained.
"
The invention consists of a furnace which is operated by artificial draft created
by a steam blower grate-bars having conical perforations on which the fuel is
placed a platform back of said grate-bars on which the burning fuel is stored
from time to time so as to permit the removal of ashes from the grate bars and
inwardly projecting baffle-walls arranged at the opposite sides of the furnace back
of the fire-bridge so that the products of combustion are completely consumed on
their way to the chimney.
The invention consists further of the special construction of the steam-blower
or other fuel
employed for producing the artificial draft by which the "breeze"
is burned on the grate-bars and which comprises an exterior casing and a nozzle-
frame having radial arms with integral forwardly-projecting nipples interiorly-
threaded bosses arranged in the rear walls of the radial arms in line with said
nipples and adjustable air-tubes screwed into said bosses and adapted to enter
into the conical bases of said nipples for regulating the supply of steam passing
through the same.
In the accompanying drawings:-
Figs. 1 and 2 represent longitudinal sections of an improved steam-boiler
furnace showing the grate and storage platform at the rear of the grate and two
different arrangements of the steam-blower by which artificial draft is supplied
to the grate.
Fig. 3 is a horizontal section on line 3-3 Fig. 2, and
Fig. 4 is a front elevation and Fig. 5 is a vertical transverse longitudinal
section on line 5-5 Fig. 4 of the improved steam blower by which artificial
draft is supplied to the furnace.
Similar letters of reference indicate corresponding parts.
Referring to the drawings-A represents a steam-boiler which is supported
within suitable walls and heated by burning coal or coke-dust breeze or other
small size fuel waste on the grate B which is formed of a number of cast-iron
grate bars provided with conically tapering openings 6 that form channels through
which the artificial blast is forced onto the fuel that is spread evenly over the
grate.

page_text: Each conical opening with its smaller upper end serves in the nature of a nozzle
by which the draft is conducted to the fuel so as to produce the complete
combustion of the same.
The grate-bars are supported on transverse bars B₁ that are set into the side
walls of the furnace the front of the furnace being closed by a suitable metallic
front wall with tightly-closing doors so that no direct access of the outer air is
given to the interior of the furnace. The front wall of the furnace is provided
with doors opening into the combustion chamber above the grate and with doors
for the ash-pit.
Back of the grate B is arranged a platform C to the rear of which is arranged
a fire-bridge D. The platform is provided with a rounded-off front edge and
serves for the purpose of permitting the banking up of the fuel whenever it is
necessary to remove the ashes and cinders from the grate-bars which ashes are
drawn out by means of a rake through the front door of the combustion chamber
after which the burning fuel is returned onto the grate bars and spread over same
evenly.
The produsts of combustion pass over the fire-bridge below the rear part of the
boiler either in a channel E of uniform width as shown in Fig. 1 or preferably
through a gradually deepening channel in which are located a number of
inwardly projecting baffle-walls E¹ which are arranged at a suitable inclination
to the longitudinal axis of the furnace alternately at the opposite sides of the
furnace walls so that the products of combustion are compelled to pass in a
serpentine or zig-zag course around said baffle-walls so
thorough intermingling of the same with the artificial draft forced through the
as to produce the
grate-bars whereby a complete and economical combustion of the fuel is obtained.
The products of combustion pass around the rounded off rear corner E2 (see Fig. 3)
of the channel E in upward direction through the flues of the boiler then out
of the front ends of the same into the space between the front wall and the steam-
boiler and over the same into the chimney as indicated in dotted lines in
Figs. 1 and 2. Sufficient space is left between the upper ends of the baffle-walls
and the boiler to admit of the free circulation of the products of combustion
between the upper end of the baffle-walls and the bottom of the boiler.
The artificial draft which is required for the burning of breeze or small sized
fuel is produced by means of a steam-blower F which is arranged in the rear
wall of the furnace as shown in Fig. 1 in which case a channel F¹ is arranged
below the furnace which communicated with the ash pit.
The steam in this case is conducted from the dome of the steam boiler through
a pipe P that is embedded in the side wall of the furnace and extends longitudinally
through the side and rear walls to the blower so that the steam is superheated by
the heat of the side wall of the furnace while on its way to the steam-blower or
the steam may be conducted from the dome of the furnace through a U-shaped
steam pipe Pi that is arranged in a suitable chamber a located in the side wall
of the furnace as shown in Fig. 3 so that the steam is super-lieated while passing
through the U-shaped pipe on its way to the blower the steam-pipe being then
connected by a valved section-with-the front end of the blower and with a
nozzle-frame F2 that is arranged in the casing F3 of the steam-blower.
casing F3 is preferably made of square cross section and provided with a flaring
mouth and a flange f¹ which abuts against the front wall of the furnace said
flange being arranged back of the frame F2 so as to serve for defining the extent
to which the casing F³ can be extended into the channel F¹ or into the ash pit
below the furnace as shown respectively in Figs. 1 and 2.
The
The nozzle frame F2 is provided with a plurality of radial arms that are
formed with a number of elongated nipples g' that extend at right angles from and
to the ends of the radial arms g and from the centre of the nozzle frame Fº.
The steam is conducted through the pipe 2 forming one of the arms of the
nozzle-frame so as to be conducted through the anterior of the nozzle-frame
and through the nipples into the casing and from the same to the

page_text: asn-pit of the furnace. The nipples are cast integrally with the nozzle frame
and are provided with an interior cylindrical bore and with an outwardly flaring
or conical base g² as shown in Fig. 5. In line with the axis of each nipple is
formed on the rear wall of cach arm and g of the nozzle-frame a cylindrical
By
boss h which has an interior screw-thread and in which is screwed an exteriorly-
threaded air-supply tube ³ that is made tapering at its inner end and extended
into the conical base of the nipple gl The outer end of the air tube g³ is
provided with a suitable nick for permitting its adjustment relatively to the
nipple or the entire closing of the latter against the passage of steam.
adjusting the air-supply tube g³ relatively to the conical base of the nipple gl
a greater or smaller quantity of steam is permitted to pass into the nipples so
that a greater or smaller suction is exerted on the air which passes through the
air supply tubes. The air is drawn in in annular steam jets through the annular
spaces formed between the conical bases of the nipples and the conical tapering
ends of the air-tubes so as to be emitted with the steam and heated up by contact
with the same.
The action of the commingled steam and air ejected from the nipples sets a
larger body of air in motion in the casing of the steam-blower which is drawn
inwardly into the spaces formed between the radial arms g said body of air being
heated up on its way to the grate-bars and supplying the required draft for the
proper combustion of the fuel on the grate. The air and steam which are thus
mingled at high temperature are supplied under pressure through the openings
in the grate-bars to the fuel the steam being disassociated by contact with the
burning fuel so that in connection with the heated air and high temperature a
complete and economical combustion of the fuel dust on the grate-bars is
obtained.
By regulating the relative position of the air-supply tubes to the nipples through
which the steam is ejected a greater or smaller quantity of air can be supplied
simultaneously with the steam to the fuel while by regulating the supply of air
by means of a suitable valve or register arranged in connection with the casing
of the steam-blower any desired pressure of the blast can be obtained. The casing
of the steam-blower is preferably made of a suitable casting and likewise the
nozzle-frame with its nipples and bosses which is formed in one integral casting
by properly coreing the nipples and bosses so that the nozzle-frame forms with the
casing and the adjustable air-tubes a strong durable and comparatively inexpensive
steam-blower by means of which small sized fuel or coal-dust, breeze, etc., can be
effectively and economically burned.
Having thus 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 combination with a steam-boiler having a closed front wall of grate-bars
having conical openings and a steam blower for supplying artificial draft to the
fuel on said grate-bars substantially as set forth.
2. In a steam-boiler furnace a storing platform arranged back of the grate and
In front of the fire-bridge substantially as set forth.
3. The combination with a steam-boiler of grate bars having conical tapering
openings a closed front-wall for the steam-boiler a steam-blower a pipe connecting
he steam-blower with the dome of the steam-boiler and means for super-heating
he steam in its course to the steam-blower substantially as set forth.
4. In a steam-boiler furnace a number of alternately arranged baffle-walls
xtending alternately from the side walls of the furnace in the channel back of
he fire-bridge substantially as set forth.
.
5. A steam-blower for steam-boiler furnaces consisting of an exterior casing a
ozzle-frame arranged in said casing and connected with the steam-supply pipe
he nozzle-frame being provided with radial arms having forwardly projecting
ipples with conical bases cylindrical boss in the rear walls of the radial arms

page_text: and air-tubes adjusted in said bosses and provided with conically tapering inner
ends substantially as set forth.
111L dow of May 1897
TONGUE & BIRKBECK,
Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicant.