Improvements in Furnaces.
Year: 1892

page_text: Date of Application, 22nd Nov., 1892
Complete Spécification Left, 25th July, 1893-Accepted, 26th Aug., 1893
PROVISIONAL SPECIFICATION.
Improvements in Furnaces.
We JAMES SCOTT ECKER, Contractor, JAMES LAIDLAW, Merchant, and
JOHN SUTTON LAIDLAW, Mechanical Engineer, all of 16 Front Street. N.,
Portland, in the County of Multnomah, and State of Oregon, United States of
America do hereby declare the nature of this invention to be as follows:-
2
The object of the invention is to provide an improved furnace for steam boilers
and other purposes which is simple and durable in construction and adapted to
utilize the fuel to the fullest advantage.
The invention consists of an air heating chamber arranged in the rear of the
bridge wall and connected by passages with a transverse channel formed in the
bridge wall, the said channel leading to channels in the side walls of the furnace.
The top of the said chamber is flush at its front with the upper edge of the bridge
wall and extends under the rear part of the boiler and is curved concentrically to
the latter to form a radiating channel and combustion chamber.
}
The rear end of the grate connects with the bridge wall, in the rear of which is
formed the air chamber which extends between the bridge wall and the rear end
of the brick-work and also from one side wall of the brick-work to the other. Into
the front end of this air chamber lead a series of longitudinal ports, opening into
the transverse channel formed in the bridge wall, the ends of the said channel
connecting with longitudinally-extending channels formed in the side walls of the
brick-work.
The channels open at their front ends to the air so that the latter can pass
through the channels and ports into the air chanıber. The top of the chamber is
flush at its front end with the top edge of the bridge wall, and extends to the end
wall and the side walls, the underside of this top being formed with an arch, while
an inverted arch forms the upper surface of the said top and is concentric with the
boiler so as to form a segmental space which constitutes a combustion and radiation
chamber for the boiler. The top of the bridge wall slants, upwardly and rearwardly
and is curved to correspond with the curved upper surface or arch of the top of the
air chamber. In the top of said chamber, and passing through the arches are a
series of openings establishing communication between the air chamber and the
combustion chamber. The top of the chamber is built of a large amount of brick,
so as to form a storage chamber for the heat.
The products of combustion from the fire box pass over the inclined curved top
of the bridge wall to and through the combustion chamber around part of the
boiler and mixing with the pure air admitted by the openings from the air chamber
becomes completely consumed. The heat generated heats the top of the air
chamber so that a considerable amount of heat is stored up, and by the peculiar
construction of the inverted arch, the heat thus stored is radiated on the boiler
which is thus heated uniformly and perfectly, while at the same time the fuel is
used to the greatest and fullest advantage.
In constructing the top of the air chamber it is preferably built loosely of
suitable brick, without clay or mortar, so as to allow for expansion and contraction,
without injury to the walls.
By making the top surface of the top concentric to the boiler a perfect radiator
is formed, so as to equalize the heat throughout the entire length of the boiler or
other object to be heated, thus insuring a regular and uniform expansion and
relieving the heated object of the unequal strain of expansion at one point and
contraction at another, thereby securing perfect circulation of water in the boiler
and preventing the formation of scale or sediment therein.

page_text: It will further be seen that by the peculiar construction, a perfect combustion
furnace is formed as the air is taken into the air chamber under the heated top
through the hollow bridge wall provided with the ports as described.
As the air is taken into the bridge wall channel from some point in the side walls
of the brick-work and most convenient for the stoker to regulate the amount by
a suitable damper, the flow of air can be regulated according to the amount of fuel
used in the fire box.
It will be seen that direct connection is made with the outside so as to prevent
the air from circulating through the bricks in the walls and thus becoming heated,
as experience teaches that air so heated becomes detrimental to combustion as the
oxygen has been consumed in the walls before reaching the combustion chamber.
With our arrangement the air in its pure state is introduced into the air chamber
under its arch top and is circulated through the openings to the top inverted surface
for the purpose previously described. As pure oxygen is contained in the air thus
introduced into the combustion chamber, a perfect combustion will take place with
the gases coming from the fire box.
It is understood that the large amount of brick-work in the top of the air
chamber and the porous nature of the brick naturally absorbs the heat and stores it
until ready for use in heating the boiler. The surface of the perforated inverted
top with air passing through openings makes a perfect radiator and with the
combustion of oxygen delivered from the air chamber and the gases from the grate
surface, combustion is complete and the result is a clean boiler and clean flues.
Dated November 22nd 1892.
J. S. ECKER,
J. LAIDLAW,
J. S. LAIDLAW,
Per A. M. & Wm. C.
COMPLETE SPECIFICATION.
Improvements in Furnaces.
We JAMES SCOTT ECKER, Contractor, JAMES LAIDLAW, Merchant, and
JOHN SUTTON LAIDLAW, Mechanical Engineer, all of 16, Front Street N.,
Portland, in the County of Multnomah and State of Oregon, United States of
America, 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 :-
The object of the invention is to provide a new and improved furnace for steam
boilers and other purposes, so constructed to utilize the fuel to the fullest
advantage.
The invention consists of an air heating chamber arranged in the rear of the
bridge wall and connected by passages with a transverse channel formed in the
bridge wall, the said channel leading to channels in the side walls of the furnace.
The top of the said chamber is flush at its front with the upper edge of the bridge
wall and extends under the rear part of the boiler and is curved concentrically to
the latter to form a radiating channel and combustion chamber.
The invention also consists of certain parts and details, and combinations of the
same, as will be hereinafter described and then pointed out in the claims.
Reference is to be had to the accompanying drawings forming a part of this
Specification, in which similar letters of reference indicate corresponding parts in
all the figures.
Figure 1 is a sectional side elevation of the improvement on the line 1-1 of
*Figure 2;
Figure 2 is a sectional plan view of the same on the line 2-2 of Figure 1, with
one of the boilers removed;

page_text: Figure 3 is a transverse section of the improvement on the line 3-3 of Figure 1,
parts being shown in elevation; and
Figure 4 is a transverse section of the same on the line 4-4 of Figure 1.
As illustrated in the drawings, the furnace is built for two steam boilers, but it
may be arranged for a single boiler, or for other devices to be heated. The furnace
proper is provided with the usual brick-work A in which are set the boilers B
extending longitudinally and extending near their front ends into the fire box C
provided with the usual grate D, ash pit and doors, of any approved construction.
The rear end of the grate D connects with the bridge wall E, in the rear of
which is formed an air chamber F, extending between the said bridge wall E, and
the rear end A¹ of the brick-work A, and also extending from one side wall A² of
the brick-work to the other side wall. Into the front end of this air chamber F
lead a series of longitudinally arranged ports G', opening into a transverse
channel G formed in the bridge wall E, the ends of the said channel G connecting
with longitudinally-extending channels H, formed in the side walls A2 of the
brick-work A.
The channels H open at their front ends to the air so that the latter can pass
through the channels H and G, and ports G¹ into the air chamber F. The top I
of the chamber F is flush at its front end with the top edge of the bridge wall E,
and extends to the end wall A' and the side walls A2, the under side of this top I
being formed with an arch I', and an inverted arch I forms the top-surface of the
said top I, and this inverted arch I' is concentric with the boiler B so as to forin a
segmental space J which consists of a combustion and radiation chamber for the
boiler B, as will be seen by reference to Figure 4. The top E of the bridge
wall E slants upwardly and rearwardly, as shown in Figure 1, and is curved to
correspond with the curved top surface or arch I2 of the top I, as will be readily
understood by reference to the said Figure 1.
In the top I and passing through the arches I¹, and 12 are arranged a series of
openings or ports I³ establishing communication between the chamber F and the
chamber J. It will be seen that this top I for the chamber F is built of a large
amount of brick, so as to form a storage chamber for the heat arising, as hereinafter
more fully described. Suitable doors K are arranged in the rear wall A' of the
brick-work A to give ready access to the air chamber F in order to clean the same
whenever necessary. Similar doors L are also arranged in the said end wall A¹
and lead to the top surface of the top I to clean the combustion chamber whenever
required.
The operation is as follows:
The fuel burning on the grate D in the fire box C, generates heat, which passes
over the inclined curved top E', of the bridge wall E to and through the chamber J
around part of the boiler B, and this heat consisting of smoke and gases, comes in
contact and mixes with the pure air passing upward through the openings I³ from
the air chamber F. This additional supply of air for the smoke and gases causes
combustion of the same, so that all the smoke is consumed before it passes to the
rear end of the boiler B and through the flues of the same to the chimney.
Furthermore the heat generated by this second combustion heats the top I of the
air chamber F so that a considerable amount of heat is stored in this top I, and by
the peculiar construction of the inverted arch 12, the heat thus stored is radiated on
the boiler through the chamber J whereby the said boiler is heated uniformly
and perfectly, at the same time using the fuel to the greatest and fullest advantage.
In constructing the top 1 it is preferably built loosely of suitable brick, without
clay or mortar, so as to allow for expansion and contraction, without injury to the
walls. As before mentioned, a large body of brick-work thus forms the top I and
has considerable storage capacity for heat utilized, as before described.
By making the top surface of the top I concentric to the boiler B, a perfect
radiator is formed, so as to equalize the heat throughout the entire length of the
boiler or other object to be heated, thus insuring a regular and uniform expansion

page_text: and relieving the heated object of the unequal strain of expansion at one point and
contraction at another, thereby securing perfect circulation of water in the boiler
and preventing the formation of scale or sediment therein.
It will further be seen that by the peculiar construction, a perfect combustion
furnace is formed as the air is taken into the air chamber under the heated top I
through the hollow bridge wall provided with the ports as described.
As the air is taken into the bridge wall channel from some point in the side
walls A of the brick work A, and most convenient for the stoker to regulate the
amount by a suitable damper (not shown), the flow of air can be regulated according
to the amount of fuel used in the fire box C..
It will be seen that direct connection is made with the outside so as to prevent
the air from circulating through the bricks in the walls and thus becoming heated,
as experience teaches that air so heated becomes detrimental to combustion as the
oxygen has been consumed in the walls before reaching the combustion chamber.
With our arrangement the air in its pure state is introduced into the air chamber
under its arch top and is circulated through the openings I to the top inverted
surface for the purpose previously described. As pure oxygen is contained in the
air thus introduced into the combustion chamber J, a perfect combustion will take
place with the gases coming from the fire box C.
It is understood that the large amount of brick-work in the top of the air
chamber F and the porous nature of the brick naturally absorbs the heat and
stores it until ready for use in heating the boiler. The surface of the perforated
inverted top with air passing through openings makes a perfect radiator and with
the combustion of oxygen delivered from the air chamber and the gases from
the grate surface, combustion is complete and the result is a clean boiler and clean
flues.
Having now, particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is,
A furnace comprising the brick-work A, the fire chamber C in the front end
thereof, the ash pit therebelow, the curved bridge wall E having its top E' inclined
upwardly and rearwardly from the grate and having a transverse channel G com-
municating with the outer air through passages H leading through the side walls to
the furnace front, a chamber F between the bridge wall and rear end of the
brick-work A, and formed of brick-work with an arched top I and an inverted
arched radiating surface I2, registering at one end with rear edge of the curved
inclined top E', openings G¹ connecting the chamber F and passage G, and series
of vertical openings 13 leading through the top I, substantially as set forth.
Dated this 25th day of July 1893.
J. S. ECKER,
JAS. LAIDLAW,
J. S. LAIDLAW,
By A. M. & Wm. Clark.