Improvements in Boiler and other Furnaces.
Year: 1891

page_text: Date of Application, 5th Feb., 1891
Complete Specification Left, 4th Nov., 1891 - Accepted, 5th Dec., 1891
PROVISIONAL SPECIFICATION.
[Communicated from abroad by WILBUR F. HAWLEY and SOLON N. SAPP,
both of St. Louis, Missouri, United States of America:]
Improvements in Boiler and other 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 to be as follows:
This invention relates to downward-draft furnaces, and more especially to boiler
furnaces and it has for its object to ensure a sufficient downward-draft through
the upper grate, and at the same time a thorough and economical consumption
of the fuel.
The leading feature of the improvement is the combination of a lower, upward-
burning grate with an upper downward burning grate, the bars of said upper
grate being spaced an unusual distance apart, or so constructed as to provide
unusually wide spaces between the bars, whereby ample provision for a downward
draft through the upper fire is provided, as well as for the consumption of such
partially-consumed fuel as may drop from the upper grate, on to the lower grate.
The bars are tubular, and at both ends are connected with the water space in the
boiler to provide for a water-circulation through the said bars. The lower grate
is constructed, and its bars arranged closely together, in the ordinary manner, and
between the grates is a combustion chamber with an escape flue leading therefrom.
The present improvement can be applied either to existing boilers, or it may be
embodied.in new boilers."
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Boiler and other Furnaces.
1, 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
he particularly described and ascertained in and by the following statement:-
This invention relates to downward-draft furnaces and more especially but not
exclusively, to boiler furnaces. Its object is to insure a sufficient downward, draft
through the upper grate, and at the same time a thorough and economical con-
sumption of the fuel.
The leading feature of the invention is the combination of a lower, upward-
burning, grate with an upper downward-burning, grate, the bars of said upper
grate being spaced an unusual distance apart, or so constructed as to provide
unusually wide spaces between the bars, whereby ample provision for a downward
draft through the upper fire is provided as well as for the consumption of said
partially-consumed fuel as may drop from the upper grate, substantially as is
hereinafter set forth.
1
The accompanying drawing shows in perspective what we consider the most
desirable. means for carrying out the invention when applied to an ordinary steam-
boiler, a portion of the furnace-wall being broken away to exhibit the interior.
The upper fire grate.consists of an upper and a lower row of tubes, marked A

page_text: and B respectively. These tubes are sufficiently thick to resist the wear which
occurs through the action of firing, and the lower tubes B, are respectively opposite
the spaces between the upper tubes A. Thus the two rows of tubes, A and B,
constitute an upper fire grate having a series of zig zag spaces, which while being
sufficiently contracted for effectively supporting the fuel during the first stages of
its combustion are yet sufficiently wide to provide for a downward draft, and to
allow the fuel after the earlier part of its combustion is effected, to fall through
the bars of the upper grate, and be caught upon the second fire-grate, C, below.
This last named grate may be constructed of ordinary bars, and arranged in the
ordinary manner, substantially as shown. The tubes A, in practice are arranged
about two and three quarters of an inch apart horizontally, as are also the tubes B,
and the distance between the two sets, A. and B is about one and one half inches.
The tubes A and B are supported in position by having their front ends
inserted in the water-bridge, D and their inner ends similarly fixed in a water
bridge E.
Said front or outer bridge, D, is connected with the boiler, F, by means
of pipes, such as D', and the back or inner bridge E, is connected therewith by
means of pipes such as E'. In the drawing, but a single one of the pipes D' is shown
and but a single one of the pipes E but other similar pipes can be and in practice
are, arranged upon the opposite side of the furnace, and similarly connected. By
means of these connections a circulation of water from the boiler through the
bridges D, E, and the tubes A, B, is maintained. Fire-doors G, are provided
for enabling the fuel to be fed onto the upper grate, and a second set of fire-
doors, H, are also provided for giving access to the fuel on the lower grate C.
The lower grate may be constructed in any suitable manner consistent with the
principle of the improvement. The bridge wall, J is preferably inclined and
extended substantially as shown.
The ash-pit K at the front end thereof, is shown extended and closed over with
a plate or plates L, in which a register 7. of the ordinary kind for regulating the
passage of air may be fitted, or the ash-pits at that point may be left open or
connected with a forced draught.
As the gases, smoke, flame, and the volatile products of combustion given off by
the fuel on the upper fire-grate cannot, by reason of the space between the water-
bridge E, and the boiler, F, being stopped by the fire-brick, e or any equivalent
wall, escape upward, they pass, by the action of the draught, downward through
the spaces between the tubes A, B, and into the combustion chamber, M, between
the grates where they meet and become mixed with the like products escaping
upward from the lower grate, C, and the products of combustion from both the
upper and lower grates are further consumed in the chamber M and thence escape
together under the back water-bridge E into the flue, N, and thence through the
remaining flues of the boiler.
In carrying out this invention I desire not to be limited to any particular construc-
tion at the inner end of the upper grate whereby the downward draft from the upper
fire grate into the chamber, M, is completed. Any suitable form of wall, partition
water-leg, or combined water-bridge and wall, may be used. Nor do desire to
be restricted to any special form of grate-bar, or mode of directing a water circula-
tion through the grate bars and boiler. I prefer however the various forms exhibited
in the drawing, and so far as forming an upper grate so that a downward draft
may be successfully obtained and the fuel enabled to drop, and the upper grate
thereby kept from choking, is concerned, the zig zag system of bars A, B, shown is
much the best, as by means thereof such lumps of the fuel as find their way down-
ward onto the lower bars B have ample room to pass thence sideways and downward
into the chamber M.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, as communicated to me by my
foreign correspondents, I declare that what I claim ís:—
First. In a combined downward and upward draft furnace the combination of

page_text: the lower upward-burning grate, an upper downward-burning grate, an inter-
mediate combustion chamber, and an escape-flue leading from said combustion
chamber, the bars in said upper grate being spaced widely apart, as described, and
at each end thereof connecting with a water-chamber in turn connected with the
boiler, and the bars in said lower grate being spaced closer together than are the
bars of said upper grate, substantially as described.
Second. In a combined downward and upward draft furnace the combination of
the lower upward-burning grate, an upper downward burning grate an inter-
mediate combustion-chamber, and an escape flue lending from said combustion
chamber the bars in said upper grate being spaced widely apart and forming a
series of zigzag spaces, as described, and at each end thereof connecting with a
water chamber in turn connected with the boiler, and the bars in said lower grate
being spaced closer together than are the bars of said upper grate, substantially as
described.
Third. In a combined downward and upward draft furnace the combination of
the lower upward burning grate, an upper downward burning grate, an intermediate
combustion chamber and an escape flue leading from said combustion chamber, the
bars in said upper grate being spaced widely apart, and forming a series of zig zag
spaces, as described, and at each end thereof connecting with a water chamber in
turn connected with the boiler, and the bars in said lower grate being spaced
closer together than are the bars of said upper grate and the ash-pit extending
below the floor of the boiler room and beyond the furnace-front substantially as
described.
Dated this 4th do
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.