Improvements in Draft-air Heating Apparatus for Furnaces.
Year: 1894

page_text: Date of Application, 16th Jan., 1894
Complete Specification Left, 12th Oct.: 1894-Accepted, 16th Jan., 1895
PROVISIONAL SPECIFICATION.
Improvements in Draft-air Heating Apparatus for Furnaces.
I, MICHAEL CALISTUS BROWNE, of No. Parker Street, in the City of
Holyoke and State of Massachusetts, United States of America, Manufacturer,
do hereby declare the nature of this invention to be as follows :-
The object of this invention is to construct, in an improved manner, a boiler, or
any other furnace, so that the products of combustion, after passing away from the
combustion chamber, either directly, or by way of the boiler flues, but before
passing up the chimney or smoke-stack, may be utilized for heating to a material
degree the air to be entered into the furnace chainber for supporting combustion of
the coal, resulting, as manifest, in an economy of fuel.
The invention embodies for employment in conjunction with a furnace, or fire
chamber, a casing, with one end of which the combustion chamber is in com-
munication, the other end being adapted for communication with the smoke-stack,
or chimney, and said casing having openings through its sides at different parts of
its length, also partitions which extend across the width of said casing, alternating
pairs of which are closed at their sides, but open at both ends, thereby constituting
broad, flat, longitudinal smoke flues, while the relatively intermediate alternating
pairs of said partitions are closed at their ends, but open at their sides, or edges, to
the aforesaid side openings, and constituting broad, flat, air-heating passages, and
a conduit communicating with one of the said side-openings and leading to the
combustion chamber.
Air, entering all of the air flues through the one side opening,-by contact
with the flues through which the waste products of combustion are passing, becomes
heated in a material degree so that in being drawn out of the other side opening
and through the pipe connected therewith, in coming into the furnace chamber, is
in a condition to more readily establish combustion than if it were entered cold.
In my air-heating apparatus, as I may construct it, I form the air-flues by long,
rectangular sheets of thin metal bent to produce flattened tube sections, and these
tube sections are placed one above another, with separation between them corre-
sponding to the vertical dimensions of the smoke-flues, and are held in such
separation by longitudinally arranged angle-strips, which are interposed between
the end portions of the contiguous flattened tube sections.
This rectangular formed bank of longitudinal and cross flues, each with wide,
superficial area at top and bottom, is set within a rectangular casing having
preferably a length somewhat longer than the bank of flues, with the ends of which
casing the smoke-pipe and chimney are connected, and through the opposite sides
of which the air openings are formed.
The apparatus, substantially as described, is not necessarily limited to use in
conjunction with a boiler-furnace, as, manifestly, it may be used with other
descriptions of furnaces, or fire boxes, or fire-places. I may also construct the
apparatus so that the smoke flues may be accessible for the entrance thereinto of a
suitable cleaner.
Dated this Second day of January 1894.

page_text: I, MICHAEL CALISTUS Browne, of No. 3 Parker Street, in the City of
Holyoke, County of Hampden and State of Massachusetts, United States of
America, Manufacturer, 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 this invention is to construct, in an improved manner, a boiler or
any other furnace so that the products of combustion, after passing away from the
combustion chamber, either directly, or by way of the boiler flues, but before
passing up the chimney or smoke-stack may be utilized for heating to a material
degree the air to be entered into the furnace chamber for supporting combustion of
the coal resulting, as manifest, in an economy of fuel. And to this end the
invention consists in arrangements and constructions of parts, all substantially as
will hereinafter fully appear and be set forth in the claims.
Reference is to be had to the accompanying drawings, in which-
Figure 1 is a sectional elevation from front to rear of a boiler furnace with the
present improved appliances combined therewith.
Figure 2 is in part a rear elevation and in part a vertical cross section on
line 2-2, Figure 1.
Similar letters of reference indicate corresponding parts in both views.
In the drawings, A represents a boiler furnace of the type in which the boiler, B,
is set over the fire-box and combustion chamber, it having flues, a, through it from
end to end, as usual, the products of combustion passing from the rear end
forwardly and up the smoke-pipe, b, to the smoke-stack, or chimney, which is
indicated in part at d.
In the improved arrangement it will be seen that the smoke-pipe, b, and
chimney, d, are not, as it were, the one a part of the other, but there are a series
of longitudinally running separated flues, f,, above the boiler, the ends of which
are open to the said smoke-pipe and chimney, b, d. These flues are inclosed
within a casing, g, through which are a series of cross air flues, h, h, the ends of
which are closed, as at h².
At one portion of the casing, at one side, is an air inlet opening, i, for the free
entrance of atmospheric air to the cross flues, while at the other side of the casing,
preferably at a different point along its length, is an air egress opening, j, con-
nected with which is a pipe, m, which leads downwardly to communication with the
furnace chamber.
Air,-entering all of the air flues through the opening, i,--by contact with the flues
through which the waste products of combustion are passing, becomes heated in a
material degree so that in being drawn out of the opening, j, and through the
pipe, m, in coming into the furnace chamber, is in a condition to more readily
establish combustion than if it were entered cold.
In my air-heating apparatus, as I bave constructed it, I have formed the air
flues by long, rectangular sheets of thin metal bent to form flattened tube sections,
(the cross section of which is seen in Figure 1, while the lengths thereof appear in
Figure 2) and these tube sections are placed one above another, with separation
between them corresponding to the vertical dimensions of the smoke-flues, f, and
are held in such separation by longitudinally arranged angle-strips, o, o, which are
interposed between the end portions of the contiguous flattened tube sections. This
rectangular formed bank of longitudinal and cross-flues, each with wide, super-
ficial area at top and bottom,-is set within the rectangular casing having
preferably a length somewhat longer than the bank of flues, with the ends of which

page_text: casing the smoke-pipe and chimney are connected, and through the opposite sides
of which the openings, i and j, are formed.
The apparatus, substantially as described, is not necessarily limited to use in
conjunction with a boiler-furnace, as, manifestly, it may be used with other
descriptions of furnace.
The smoke-pipe, b, has a removable section, t, in front of the bank of flues, h, f,
so that, when opened, the smoke flues become accessible for the entrance thereinto
of a suitable cleaner.
Having now 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. In combination, a furnace and a horizontally extended rectangular casing
thereabove with one end of which the combustion chamber is in communication,
and the smoke-stack with which the other end of said casing communicates, and
said casing having openings through its sides at different parts of its length,
horizontal partitions which extend across the width of said casing, alternating pairs
of which are closed at their sides, but open at both ends thereby constituting broad
flat longitudinal smoke-flues, while the relatively intermediate alternating pairs of
said partitions are closed at their ends but open at their sides to the aforesaid side
openings and constituting broad, flat, intermediate air heating passages and a
conduit communicating with the one of said side openings and leading to the
combustion chamber, substantially as described.
2. The combination with a furnace, of a bank of cross-flues for air and
longitudinal flues for smoke consisting of flattened tube-sections arranged with their
lengths cross-wise of the smoke-flues, and in separation corresponding to the height
of the smoke-flues, the angular or channel strips, o, o, separating the tube sections
at their end portions and forming the side boundaries of the smoke-flues, the casing
into which the bank of flues is set, with the smoke-pipe, b, and smoke-stack, d, con-
nected at its ends, and having the side opening, i, and the side opening, j, and pipe
connected thereat and leading to a forward portion of the furnace-chamber,
substantially as and for the purpose set forth.
3. The combination with the furnace of the bank of flat, end wise opening
longitudinal smoke-flues thereabove, with the intermediate flat air-flues, the smoke-
pipe, b, leading from communication with the combustion chamber to said end wise
opening smoke-flues and having the removable front, t, the sidewise air ingress, i,
and the air conduit, m, substantially as described.
Dated this 1st day of October 1891
MICHAEL CALISTUS BROWNE.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.