Improvements in and relating to Furnaces.
Year: 1899

page_text: Date of Application, 15th Nov., 1899-Accepted, 24th Feb., 1900
[Communicated from abroad by FREDERICK A. DALEY, of 218, La Salle Street,
Chicago, Illinois, United States of America, Mechanical Engineer.]
Improvements in and relating to Furnaces.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent Agents,
45, Southampton Buildings, in the County of Middlesex, 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:-
My invention relates to furnaces, and particularly to that class of furnace
wherein a fuel magazine or retort is employed, draught being afforded to the
burning fuel by means of tuyere blocks arranged along each side of the fuel retort.
One embodiment of my invention may be generally described as consisting of a
fuel magazine or retort located within the heating chamber, along each side
whereof are disposed tuyere blocks, plates being preferably provided between
said tuyere blocks and the walls of the fire box, the space beneath the retort being
practically air-tight, except at the points where the air is admitted and expelled
to supply a draught to the burning fuel, tuyere blocks having passages com-
municating between the said space and the burning fuel within the retort, air
being supplied preferably under pressure to the space beneath the retort and
plates. Under-feeding mechanical stokers are used in connection with the fur-
naces described, and the accompanying drawings, which are illustrative of my
invention, show fuel retorts wherein mechanical stokers are employed to feed
green fuel beneath the burning fuel, the operations of the stoker being adjusted
to the consumption of the fuel. In another embodiment of the invention the air
is conveyed through tuyere boxes, walls of which preferably form portions of the
walls of the retort. Other features of the invention will be explained hereinafter.
In the accompanying drawings:
Figure 1 is a longitudinal sectional view of a furnace constructed in accordance
with my invention;
Figure 2 is a vertical sectional view thereof on line 2-2, Figure 1;
Figure 3 is a longitudinal sectional view of a modified form of furnace con-
structed in accordance with my invention;
Figure 4 is a sectional view thereof on line 44, Figure 3:
Figure 5 is a cross-sectional view showing another modification of my improved
furnace.
Like letters refer to like parts throughout the several figures
In Figures 1 and 2 I have illustrated a furnace to which my invention may be
annlied, comprising a chamber a within which the fuel retort is located, a brick
facing being provided in the front end of said chamber, while a setting dis
provided near the rear of said chamber adapted to support the rear end of the
retort, this setting being carried preferably slightly above the horizontal diameter
of the chamber, over the top of which setting, the products of combustion are.
adapted to pass. The facing and setting serve to make the space beneath the
etort air-tight except where the air is admitted to, and expelled from, the same.
Price 8d.

page_text: The flues e are let into an end plate provided in the rear of the chamber, through
which the products of combustion are passed in their egress to the chimney way.
The water that is to he evaporated to steam, surrounds the chamber a and the
flues e, the water line being constantly above the chamber a to prevent the same
from being burnt out.
Arranged along each side of the retort band within the chamber a are separable
and detachable tuyere blocks f f which are permitted to expand under heat.
Each of the tuyere blocks is provided with a depression in its horizontal face for
receiving slag, and openings communicating with the space beneath the retort,
to which space, air, preferably under pressure, is supplied, imperforate dead
plates being preferably placed between the tuyere blocks and the wall of the
heating chamber a, said space being practically air-tight except at the point
where the air is admitted. A Y pipe connection, as shown most clearly in
Figure 2, is provided, the branches whereof are led through the facing c, while to
the stem a pipe leading to the blowing engine may be attached.
Located at the bottom of the retort is a plunger or ram rod h upon which are
fastened fuel agitating and lifting blocks which are adapted to engage the fuel
as the rod is reciprocated. Fuel is admitted to the retort through the opening
in the hopper i, the fuel being thrust forward within the retort by the head kas
it is reciprocated by means of an engine (as illustrated) or any other suitable
mechanism.
In Figures 3 and 4 I have shown the application of my invention to a furnace
for heating the ordinary tubular boiler. The tuyere blocks ff and dead plates 9 g
are, in this apparatus, similar to those shewn and described in connection with
Figures 1 and 2; the heating chamber, however, is of a different character, vertical
walls, m, being provided, which support the boiler. A bridge wall n is pro-
vided at the rear of the retort, between which and the boiler, the products of com-
bustion are passed to the chimney way. The bridge wall is provided with a
sloping surface o, upon which the clinker may form, and from which it may be
readily removed. The space confined by the retort, tuyere blocks, dead plates,
walls l m n and the floor p is practically air-tight except at the points where
the air is admitted thereto and expelled therefrom upon the burning fuel.
In furnaces provided with tuyere boxes which convey air under pressure to the
tuyere blocks located above. the same, dead plates have sometimes been employed
between the tuyere blocks and the furnace walls. In this form of furnace the
dead plates are liable to be warped by the excessive heat of the furnace since there
is no cool air present to counteract the heat. In a furnace constructed in accord-
ance with my invention the under sides of the dead plates are constantly exposed
to the incoming air, which counteracts the heat from above. I thus avoid the
necessity of so frequent renewal of the dead plates, and by dispensing with the
tuyere boxes as heretofore used, there is secured a saving in complication and
expense.
The air being admitted first to the space beneath the fire box, becomes hoated
before it is driven into the fire box. This results in a better and more complete
combustion than is obtained when the air is introduced to the retort at a lower
temperature. In order to prevent the air from working between the agitating
rod and the wall of the retort through which it passes, I employ an outwardly pro-
jecting cylindrical nose or sleeve, preferably integrally formed with the rear wall
of the retort which also preferably flares upwardly and outwardly, this nose
affording a guide for the rod and being sealed at its outer end to prevent the
passage of air, preferably by the brick work of the furnace.
In Figure 5 I have shown a further modification of my invention, in which
tuyere boxes are provided, the inner walls of said boxes and portions of the out-
wardly flared side walls of the retort being common. The top walls of the tuyere
boxes which support the tuyere blocks in this form, of my invention extend only
partially across the furnace. Each tuyere box is preferably secured upon longi-
tudinal side flanges s of the walls of the retort, by means of bolts which pass

page_text: through slots in the flanges whereby the tuyere boxes are capable of longitudinal
expansion.
A very important result gained by means of my invention is the coking of the
green coal near, and below, the tuvere openings before it is pushed up into the
zone where the fuel is consumed. By the process of coking the coal in the retort
before its consumption, great economy is effected.
I preferably employ a deflecting plate which also acts to guide the fuel within
the furnace.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, as communicated to
me by my foreign correspondent, I declare that what I claim is:
-
1. The process of burning fuel, which consists in supplying green fuel to a
retort, maintaining combustion at the upper level of the fuel, forcing air under
pressure, first against the outside of the retort, then into the retort between the
burning and the green fuel, thereby coking the green fuel, and forcing the pro-
duced coke upwardly into the burning mass of fuel, substantially as described.
2. In a furnace, the combination with an elongated fuel retort, tuyere passages
being provided near the upper longitudinal edges of the retort, of means for
forcing air against the outside of the retort and through said passages and thereby
coking the coal, and lifting means for moving the coke upwardly into the burning
portion of the fuel, substantially as described.
3. In a mechanical stoker, the combination with an elongated fuel retort, of a
rod provided with means for pushing the fuel into the retort, and a sleeve united
with one end of the retort adapted to receive the rod and guide it in its travel,
the outer end of the said sleeve being sealed, whereby air is prevented from
passing between the sleeve and rod, substantially as described.
4. In an under-feed mechanical staker, designed to force the fresh fuel from
below up into the burning fuel, the combination with a fuel retort, of tuyere caps
arranged along the sides thereof provided with depressions for the reception of
slag and air openings on their inner sides, and means for feeding the green fuel
to the retort, substantially as described.
5. The combination with a furnace, of an under-feed conduit, means for intro-
ducing fuel thereto, an air passage adjacent to said conduit, removable tuyere caps
located above said passage and provided with openings adapted to introduce air
into said furnace, and means for excluding air from said furnace except that intro-
duced through said passage, substantially as described.
6. In a furnace, the combination with a retort, of fuel supporting means along-
side of the retort, a tuyare box, portions of whose walls are constituted of the said
fuel supporting means and a wall portion of the retort, passages being provided
for establishing communication between the tuyere box and the retort, and means
for conveying air under pressure to the tuyere box, substantially as described.
7. In an under-feed mechanical stoker designed to force the fresh fuel from
below, the combination with an elongated fuel magazine having outwardly flared
sides and rear end and provided with slotted horizontal side flanges, of tuyere
boxes mounted on the said flanges and connected thereto by bolts which slide
in the slots thereof, a feeding mechanism for supplying the magazine with green
fuel, and means for operating said feeding mechanism, substantially as described.
8. In a furnace, the combination with an elongated under-feed fuel retort, of
a plunger or ram for supplying fuel to the same, tuyere boxes arranged along the
sides of the retort, walls of the tuvere boxes also forming parts of the walls of the
retort, said boxes being movably connected to the retort so as to be capable of
longitudinal expansions, and movable tuyere caps secured to the tops of the boxes
and provided with air passages adapted to discharge air at the upper inner edges
of the tuyere boxes above the green fuel, and means for operating the plunger
or ram, substantially as described.
9. In a furnace, the combination with a retort, of a tuyere box along the side
of the retort, a portion of the wall of the retort being also a wall of the tuyere box,

page_text: and means for forcing air into the tuyere box, passages being provided for estab-
lishing communication between the retort and tuyere box, substantially as
described.
10. In a furnace, an imperforate fuel-bearing surface and a retort, dividing the
furnace into a fire-box and an air-chamber, the retort being provided with tuyere
openings or passages for establishing communication between the air-chamber
and the fire-box, and means for conveying air under pressure to the air-chamber,
substantially as described.
11. In a furnace, the combination with a retort of a fuel-supporting means
alongside of the retort, said means and retort separating the furnace into a fire-
box and an air-chamber, the retort being provided with tuyere openings or pas-
sages for establishing communication between the air-chamber and the fire box,
and means for conveying air under pressure to the air-chamber, substantially
as described.
12. In a furnace, the combination with a fuel bearing plate, and a retort
dividing the furnace into a fire-box and an air-chamber, the retort being provided
with tuyere openings or passages for establishing communication between the air-
chamber and the fire-box, and means for conveying air under pressure to the air-
chamber, substantially as described.
13. In a mechanical stoker, the combination with fuel-bearing plates and an
elongated retort, the said retort being located between the plates and serving there-
with to divide the furnace into a fire-box and an air-chamber, the retort being
provided with tuyere openings or passages for establishing communication between
the air-chamber and the fire-box, means for conveying air under pressure to the
air chamber, and means for forcing fuel into the retort, substantially as described.
14. In a mechanical stoker, the combination with imperforate fuel-bearing
plates and an elongated retort, the said retort being located between the plates and
serving therewith to divide the furnace into a fire-box and an air-chamber, the
retort being provided with tuyere openings or passages for establishing com-
munication between the air-chamber and the fire-box, means for conveying air
under pressure to the air-chamber, and means for forcing fuel into the retort,
substantially as described.
15. The combination with a furnace, of an under-feed conduit, means for intro-
ducing fuel thereto, means for introducing a blast of air to openings adjacent
to the conduit, the bottom of said furnace being entirely closed adjacent to the
sides of said conduit, substantially as described.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.