IMPROVEMENTS IN FURNACES, AND IN THE COMBUSTION OF FUEL, AND IN APPARATUS CONNECTED THEREWITH
Year: 1858

page_text: LETTERS PATENT to William Gorman, of Glasgow, in the County of
Lanark, North Britain, Engraver, for the Invention of "IMPROVEMENTS IN
FURNACES, AND IN THE COMBUSTION OF FUEL, AND IN APPARATUS CONNECTED
THEREWITH."
Sealed the 20th May 1859, and dated the 23rd November 1858,
PROVISIONAL SPECIFICATION left by the said William Gorman at the
Office of the Commissioners of Patents, with his Petition, on the
23rd November 1858.
I, WILLIAM GORMAN, of Glasgow, in the County of Lanark, North Britain,
Engraver, do hereby declare the nature of the said Invention for "IMPROVE
MENTS IN FURNACES, AND IN THE COMBUSTION OF FUEL, AND IN APPARATUS CONNECTED
THEREWITH," to be as follows, that is to say :-
This Invention relates to an improved process of burning gaseous fuel in
the furnaces usually employed for generating steam in steam boilers or in
draught furnaces employed for other purposes, and consists in preventing air
from getting up through the incandescent or highly heated coke laying on the
grate bars when a fresh charge of coal is laid on, and whilst the gaseous part
of the coal is being evolved. By preventing the access of air to the coke
which had previously been undergoing combustion, no carbonic acid gas is
produced to mingle with and prevent the combustion of those gases which are
being evolved from the superincumbent fresh charge of fuel. The furnace iş
Duice 811

page_text: thus converted into a kind of gas retort, and it is only necessary to supply
sufficient air for the combustion of the gases being evolved from the newly laid
on coals by the highly heated coke. Air may be admitted above the fire to
consume the gases, at the door or at the bridge or sides of the furnace, or in
any suitable place or manner, as desirable, so that the air is supplied to as
many points or parts of the fuel as possible. It is preferable also to direct the
air in jets upon the fuel with considerable force, so as to assist in keeping up
the heat of the furnace, which is generally lower after a new charge of fuel,
taking care not to allow more air than what is just sufficient to prevent the
gases from passing away unconsumed. When the crude coal gases have been
sufficiently consumed, air is supplied to the coke for its combustion in the
usual manner; the air being shut off so as not to act upon the fire from
above, or jets of air may be projected on the fuel from above whilst the coke
is undergoing combustion to increase the combustion, and also to consume any
carbonic oxide gas which is often formed in particular states of fuel and com-
bustion in furnaces. Various means or apparatus may be resorted to for
preventing or regulating the supply of air for the combustion of the coke or
charcoal, so as to permit of the economical burning of the gaseous part of the
fuel,but in general a close-fitting door upon the ash-pit, which may
be opened
and shut or partially closed at pleasure, may.be employed; or the ash-pit-door
may have a regulating valve for the same purpose, which door or valve may be
wrought by the hand or by machinery, as desired. The apparatus known as
the "cataract" may be employed to shut and open the apertures in the furnace
door or ash-pit. According to one practically useful arrangement, both the
furnace and ash-pit doors are fitted with circular disc or "butterfly" valves,
the discs being weighted on opposite sides. The two discs are connected, to
work in concert, one being shut, whilst the other is open. The upper disc is
connected by a catch and detent with a lever, which again is connected
with the cataract "apparatus" or a floating vessel set in a fluid chamber
and fitted with valvular apparatus, so as to cause the vessel to descend
gradually, just as it may be set; such valves, or other valves for a like
purpose,inay also be worked by other operating agencies. It is also intended
that provision shall be made for the partial admission of air through either one
or other ofthe valves during the time of their being virtually closed, as an aid
to effectual combustion.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Gorman in the Great Seal Patent Office. on the
21st May 1859.
:
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
GORMAN, of Glasgow, in the County of Lanark, North, Engraver, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-third day of November in the year of our
Lord One thousand eight hundred and fifty-eight, in the twenty-second
year of Her reigu, did, for Herself, Her heirs and successors, give and
grant unto me, the said William Gorman, Her special licence that I, the said
William Gorman, my executors, administrators, and assigns, or such others
as I the said William Gorman, my executors, administrators, and assigns,
should at any time agree with, and no others, from time to time and at all
times thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVEMENTS IN FURNACES, AND IN THE COMBUSTION OF FUEL. AND IN
APPARATUS CONNECTED THEREWITH," upon the condition (amongst others) that
I, the said William Gorman, my executors or administrators, by an instrument
in writing under my, or their, or one of their hands and seals, should: par-
ticularly describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be filed in the
Great Seal Patent Office within six calendar months next and immédiately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Gorman, do hereby declare the
nature of my said Invention, and in what manner the. same is to be per-
formed, to be particularly described and ascertained in and. by the following
statement in writing, reference being had to the accompanying Drawings,
and to the letters and figures marked thereon, that is to say :-
My said Invention relates to an improved process of burning gaseous fuel
in draught furnaces, such as are usually employed for generating steam in
steam boilers, or in draught furnaces employed for other purposes; and con-
sists in preventing air from getting up through the incandescent or highly-
heated coke lying on the grate bars when a fresh charge of coal is laid on,
and while the gaseous or more volatile part of the coal is being evolved. The
stopping or limiting of the access of air to the coke undergoing combustion
prevents the production of carbonic acid gas, which ordinarily mingles with,

page_text: and prevents or injures the combustion of those gases which are being evolved
from the superincumbent fresh charge of fuel. The furnace is thus converted
into a kind of gas retort, and it is only necessary to supply sufficient air for
the combustion of the gases being evolved from the newly laid on coals by the
heat of the coke. Air may be admitted above the fire to assist in the com-
bustion of the gases, at the door or at the bridge or sides of the furnace, or in
any suitable place or manner, as may be desirable, provided that the air is
supplied to as many places or parts of the fuel as possible. It is preferable
also to direct the air in jets upon the fuel with force, so as to assist in keeping
up the heat of the furnace, which generally tends to become lower after a new
charge of fuel, taking care not to allow more air than what is just sufficient to
prevent the gases from passing away unconsumed. When the crude coal
gases have been sufficiently consumed, air is supplied to the coke for its com-
bustion in the usual manner through the grate, the air being shut off so as not
to act upon the fire from above, or jets of air may be projected on the fuel
from above whilst the coke is undergoing combustion, to increase the com-
bustion, and also to consume any carbonic oxide gas which is often formed in
particular states of fuel and combustion in furnaces.
Various means or apparatus may be resorted to for preventing or regulating
the supply of air for the combustion of the coke or charcoal, so as to permit of
the economical burning of the gaseous or more volatile part of the fuel, but in
general a close-fitting door upon the ash-pit, which may be opened and shut, or
partially closed at pleasure, may be employed, or the ash-pit door may have a
regulating valve for the same purpose, which door or valve may be wrought
by the hand or by machinery, as desired. Apparatus, such as that known as
the "cataract," may be employed to shut or open the valves in the furnace
door or ash-pit. According to one practically useful arrangement, both the
furnace and ash-pit doors are fitted with circular disc or "butterfly" valves,
the discs being weighted on opposite sides. The two discs are connected to
work in concert, one being shut whilst the other is open. The upper disc is
connected by a catch and detent with a lever, which again is connected with
the "cataract "apparatus, or a floating vessel set in a fluid chamber, and fitted
with valvular apparatus, so as to cause the vessel to descend or ascend
gradually, just as it may be arranged. Such valves or other valves for a like
purpose may also be worked by other operating agencies.
Provision should be made for a partial or limited admission of air below the
grate bars when the main supply of air is being introduced above them, or
vice versâ, as an aid to effectual combustion. The proportion of air to be so
admitted will depend upon the peculiarities of each particular furnace, on the

page_text: quality of the fuel, and also on the quantity of the fuel that may happen to be on
the grate bars at any given time. As a general rule it may be stated that if
the fire does not burn with sufficient brightness or activity whilst airis being
mainly supplied above, a little air should be admitted below the grate bars, but
too much air admitted in this way will at once produce smoke. Again, if,
after the more volatile parts of the fuel are evolved, and the ash-pit valve is
open, the coke happens to be too thick for the quantity of air passing through
the grate bars, carbonic oxide may be formed instead of carbonic acid, in which
case a supplemental admission of air will be required above the fire to burn
this carbonic oxide.
I have delineated upon the accompanying Sheet of explanatory Drawings
two modifications of apparatus suitable for practically applying my said Inven-
tion, and which I shall now proceed to describe, premising that the same
reference letters mark the same or like parts in all the Figures.
Figure 1 is a front elevation of the furnace end of a cylindrical boiler,
with one modification of the apparatus applied thereto; and Figure 2 is a
corresponding longitudinal vertical section.
Figure 3 is a front elevation, showing another modification of the apparatus;
and Figure 4 is a horizontal section, as taken through the fire door and
furnace.
In the first modification the fire door A is fitted with a binged valve or
smaller door B, for at the proper periods preventing the admission of air
through it. The mouth of the ash-pit C is also provided with a valve or
door D, for at the proper periods preventing the admission of air beneath the
fire-bars E. The upper valve B is hinged at its lower edge, whilst the lower
valve D is hinged at its upper edge, and a tongue F fixed on the upper valve
B presses upon the lower valve D, in such a way that the opening of one
valve closes the other. The part of the ash-pit mouth below the valve D is
closed by a plate or door G, which can be removed to get out the ashes. The
valves B and D may both be opened and shut by hand, but it is preferred to
use self-acting mechanism, such as is shown in the Drawing, which dispenses
with any manual adjustment beyond the mere opening and closing of the fire-
door A when introducing a charge of fresh fuel. When the fire-door A is
opened, it acts on a curved lever fast on a short spindle H, in such a way as
to turn this spindle. This spindle H has at its other end a forked lever I, by
which, when turned, it lifts a rod J, acting when doing so on an adjustable
stop on the rod. This rod J passes up to a contrivance of the "cataract
class, consisting of an open bucket K in a vessel L containing water. When
the rod J rises, it by means of a lever M depresses the bucket K into the

page_text: water, until the latter flows in over its edges, and fills it to a greater or less
extent. The parts are weighted in such manner that when the closing of the
fire-door A releases the spindle H, the rod J tends to descend, and the bucket
K to rise, this movement being regulated as regards the time it occupies by
the outflow of the water from the bucket back into the cistern or vessel L,
through a small adjustable valve provided for the purpose in the bottom of the
bucket. The position of the air valves B, D, just before opening the fire-door
is the reverse of that in which they are shown in the Figures, the valve B
being closed, and the valve D open. On the fire-door being opened, it acts on
a tongue U fixed on the ash-pit valve D, and closes the latter, which is caught
and beld shut by a latch N, whilst the fire-door valve remains open by its own
weight. A weight P is fitted to the ash-pit valve D, to give it a tendency to
open, and when the cataract bucket K rises sufficiently, the corresponding
descent of the rod J releases the latch N, to which its lower end is connected,
as shown, and the ash-pit valve D opens, and by the tongue F closes the fire-
door valve B. It will be understood from what has already been said, that
the cataract movement is so regulated or timed, as to allow the gaseous or
more volatile parts of the fuel to be evolved before the ash-pit valve Dopens.
For the purpose of admitting a little air beneath the fire-bars at the time that
the fire-door valve B is open, a small sliding valve Q is provided in the ash-
pit valve D. In order that the air admitted at the fire-door may be directed
towards or upon as many points of the fuel as possible, the fire-door A is
formed with a box on its inuer side, which box is furnished with a series of
horizontal bars or division plates R, to divide the passage through the door
into a number of channels or jet openings. The bottom of each bar R is bent
upwards at its outer edge, to prevent the direct radiation outwards of heat
from the fire, and each bar is formed with vertical ridges, to subdivide the
spaces between every two bars. These vertical ridges may be disposed
according to various designs. In Figure 4 one arrangement is shown in
which the ridges are so disposed as to give divergent directions to the air jets;
the ridges are also made of greater thickness at their inner ends with the view
of contracting, and thereby concentrating each jet. The several bars or
division plates may be made with different arrangements of the ridges; thus,
for example, the ridges of the alternate bars may be inclined towards one side
of the furnace, and those of the intermediate bars towards the other side.
In carrying out my improved system, I would further recommend the con-
structing of the fire-bridge S with a forward overhanging upper edge, as
shown in Figure 2; in some cases, indeed, this overhanging edge may be
carried forward to a considerable extent, as indicated by dotted lines at T. In

page_text: all cases the fire-door bars R should be constructed to direct the air jets not
higher than the overhanging edge of the bridge.
In the modified apparatus represented in Figure 3, the fire-door and ash-pit
valves B, D, are made to slide in grooves, and to open or shut by means of
levers V, W, the ash-pit valve D having a co unterweight P applied to it to
give it a tendency to close. The lever V is mounted on the fire-door A, but
does not interfere with the opening thereof, whilst it is put in connection with
the rod J on closing the fire-door, by simply depressing its free end so as to
enter beneath an adjustable stop X on the rod. Similarly the valve D and
lever W are carried by a door covering the ash-pit mouth, the lever W being
made with a fork or notch to embrace the rod J when the door is closed. In
this arrangement the spindle H acts on a separate rod J¹, by means of which
it depresses the bucket of the cataract apparatus at L. In this arrangement
also the closing of the fire-door valve B,and the opening of the ash-pitvalveD,
are not instantaneous, but gradual, and, if desired, the modification of appa-
ratus represented in Figures 1 and 2 may be made to act in the same gradual
way by causing the rod J to act on the ash-pit valve Dby a lever or link,instead
of on a latch N, which does not release the valve until the cataract movement
terminates.
Although in the accompanying Drawing only one class of furnace is
represented, the apparatus may obviously be modified to suit any kind of
furnace, including stationary, marine, and locomotive boiler furnaces, and it
may be remarked that as with my improved system a much reduced quantity
of air is required, the apparatus for carrying it out may be applied to existing
furnaces with full effect.
I would further recommend as an aid to complete and economical com-
bustion that the fire-bars be made as thiu and as wide apart as practically
possible, and in connection with this, I may mention that I have obtained very
good results with fire-bars only three-eighths of an inch in thickness at their
upper edges and set three-eighths of an inch apart, and thinner bars would
give still better results.
Having now particularly described my said Invention, and the manner in
which the same is or may be used or carried into effect, I have to state that I
do not restrict myself to the precise details herein-before described or
delineated, and that I do not claim to have invented every separate detail
herein-before described and delineated; but that what I belive to be novel
and original, and claim as the Invention secured to me by the herein-before
in part recited Letters Patent, is,―
The herein-beforedescribed system or mode of conducting or regulating the

page_text: action of draught furnaces, and the application and use in the practice thereof
of contrivances such as are herein.before described.
In witness whereof, I, the said William Gorman, have hereunto set my
hand and seal, this Twentieth day of May, in the year of our Lord
One thousand eight hundred and fifty-nine.
Witness,
EDMUND HUNT,
28, S. Enoch Square,
Glasgow.
Wч. GORMAN. (L.S.)