Iм- IN FURNACES FOR ECONOMISING FUEL AND PREVENTING THE: GENERATING OF SMOKE
Year: 1872

page_text: PROVEMENTS
LETTERS PATENT to Joseph Knott, of Sheffield, in the County of:
York, Steel and File Manufacturer, for the Invention of "Iм-
IN FURNACES FOR ECONOMISING FUEL AND PREVENTING THE:
GENERATING OF SMOKE."-A communication from abroad by Thomas
Say Speakman, of Camden, New Jersey, in the United States of
America, Civil Engineer.
Sealed the 3rd January 1873, and dated the 20th July 1872.
PROVISIONAL SPECIFICATION left by the said Joseph Knott at the
Office of the Commissioners of Patents, with his Petition, on the.
20th July 1872.
I, JOSEPH KNOTT, of Sheffield, in the County of York, Steel and File
Manufacturer, do hereby declare the nature of the said Invention for
" IMPROVEMENTS IN FURNACES FOR ECONOMISING FUEL AND PREVENTING THE
GENERATING OF SMOKE," to be as follows:-
1
The said Invention consists in the arrangement of a downwardly bent
pipe for the exit of the carbonic acid and other saturated
gases generated
in engine fire-places unconnected with the fire-place or the fan case,
3

page_text: which latter creates an artificial draught, and thereby the generation
of smoke incident to the usual combustion is prevented. The supply
air pipe from the fan enters the ash box beneath the fire, which is to
be air-tight, and leads a blast from the fan to just under the fire-grate
of the boiler engine or other furnace, the fan being situated in any
suitable position, and being operated upon by a belt from any convenient
part of the driving machinery. The pipe is provided with a damper
to regulate the quantity of the blast from the fan. The top of the
chimney is provided with a suitable damper which can be regulated
from below by means of a rope, wire, or other suitable appliance. I
prefer a hinged damper, but any well-known kind of damper will answer
the same purpose.
From a suitable distance a tube extends out and
downward from the chimney to a suitable distance.
This improvement may be applied to an engine in which no chimney
is used. In this case the flue extends into a tube, which latter is bent
upward and downward. This tube is surrounded by a barrel in which
the tube may be placed in close coils if desirable, its end extending
through the end of the barrel. This barrel is to be filled with water
which will be heated to a certain degree by the tube, and may be used
as feed water for the boiler, saving fuel as it is already heated.
When found desirable the said Invention can be applied in the
following manner:-Instead of the tube extending outward and down-
ward from the fire-flue as above described, I introduce tubes into the
boiler either in the mode above specified or in a perpendicular spiral
form, with an escape pipe to carry off the residuum of combustion
incident to the same, thus heating the water in the boiler instead of
the water in the outside case. This mode is especially applicable to
locomotives and marine boilers, tho' it may be applied to any other
kind of engine.
In starting the fire a few turns by hand power of the fan will make a
good fire in one half the time it could be done without it.
Where a chimney is used the damper on the chimney is of course
opened until the fire is strong enough to create steam in the boiler
and the engine has been started, from which time the fan is operated
automatically. I prefer to provide the fan shaft with a fast and loose
pulley, so as to enable me by shifting the belt to stop the fan entirely,
should this become necessary or desirable. As soon as steam is created

page_text: and the engine in operation the damper is closed and a back atmospheric
pressure upon the draught is its immediate result. Were there no exit
for the carbonic acid gas this back atmospheric pressure would at once
put out the fire, but this is obviated by the tube which affords an egress
for the carbonic acid, while the blast from the fan keeps up the draught
and creates a more perfect combustion. The back pressure in the
chimney and flue must be of just sufficient force to keep the products
of combustion over the fire until all but the carbonic and other
incombustible gases have been consumed, which when freed easily find
their way out through the tube. The force of the back pressure is
regulated by regulating the draught created by the blast from the fan.
This is easily and promptly effected by means of a damper in the blast
pipe.
The same result is effected by the following means :-)
-In this case
the back pressure upon the draught is produced by the downward bends
of the tube, the carbonic and other incombustible gases escaping
through the same, and as it passes through the tube it heats the water
in the barrel, from which the boiler may be fed in any known automatic
or other manner, thus effecting a great saving in the consumption of.
fuel.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Joseph Knott in the Great Seal Patent Office
on the 18th January 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
KNOTT, of Sheffield, in the County of York, Steel and File Manufacturer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twentieth day of July, in the year of our
Lord One thousand eight hundred and seventy-two, in the thirty-sixth
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Joseph Knott, Her special licence that I, the
said Joseph Knott, my executors, administrators, and assigns, or such
others as I, the said Joseph Knott, my exccutors, administrators, and
assigns, should at any time agree with, and no others, from time to

page_text: This Invention is applicable both to furnaces which have a chimney.
and to furnaces which have no chimney.
In the case of furnaces which have a chimney a damper is placed at
the top of the chimney, or in some other part of it, above the downwardly
bent pipe, tube, or flue, before described. I prefer a hinged damper, but
any known kind of damper will answer the purpose. This damper may
be regulated from below by means of a rope, wire, or other suitable
appliance. This damper is opened when the furnace is lighted, but as
soon as the engine is well started this damper is closed and a back,
atmospheric pressure upon the draught is the result. Were there no exit
for the carbonic acid gas and other saturated gases the fire would then
go out but for the downward bent tube.. I insert however into the
chimney, at a suitable distance below the damper, one end of a tube;
pipe, or flue, which tube, pipe, or flue leads out of the chimney and is
then bent downwards and carried downwards to a suitable distance.
This tube, pipe, or flue permits the said gases to escape, and produces a
downward draught upon the surface of the fire, which being met by a
sufficient amount of upward draught from a supply fan produces in the
body of the fire a more complete and perfect combustion, and in com-
bination with a damper where a chimney is used, and thus the generation
of smoke is lessened, the combustion of smoke increased, and the fuel
economized. The air blast should be so regulated, having regard to the
length of the downward bent tube, pipe, or flue, as to keep the products
of combustion over the fire until all of them that are combustible are
consumed.
.
In the case of a furnace where there is no chimney the said tube, pipe,
or flue is an extension of the flue of the furnace, and is bent upwards
and downwards as often as may be necessary. This tube, pipe, or flue
may be carried through a barrel, tank, or cistern of water in which the
tube may be, and if necessary in close coils, its extremity being carried
out of the bottom or side of the barrel, tank, or cistern. The water will
be heated and may be used as feed water for the boiler. This tube, pipe,
or flue at once permits the escape of the gases, as aforesaid, and also
exerts a backward pressure or retardation on the draught and economizes
fucl.
In the two modes of annlving this Invention last dosomiliod th

page_text: necessary to open the nre doors the damper in The blast pipe must b
closed.
DESCRIPTION OF THE DRAWINGS.
Similar letters of reference refer to like parts in all the Figures. 1
Fig. 1 is a longitudinal section of a boiler and furnace with a
chimney; Fig. 2 is a longitudinal section of a boiler and furnace
without chimney.
A is the boiler resting on the bed B; C is the flue, in the fore part of
which the fire may be placed; the fire may be placed under the boiler,
but this is not usual. D is the flue connected with the chimney E;
Fis the damper in the chimney. In Fig. 1 it is placed at the top of
the chimney, but it may be at any point above the tube G. The tube G
(a pipe or flue will do as well) is open at the bottom; H is the fan or
blower; H 1, the blast pipe, and L the damper in the blast pipe; M is the
hopper, from which the fire is fed; I is the strap by which the fan is
driven; J, in Fig. 2, is the tank or cistern in which is inserted the
tube K, bent upward and downward. The tube K heats the water in
the tank J. In Fig. 2 the tube K passes out at the side of the tank,
but it may be carried through the bottom of the tank.
At
Having thus described the nature of the said Invention, and in what
manner the same is to be performed, I declare that I do not limit myself
to the precise details herein-before described and illustrated in the
accompanying Drawings, as the same may to some extent be varied
without departing from the essential features of my Invention.
the same time I am aware that processes for burning fuel under
pressure by means of a forced supply of air have been in use before
various provisions being in such cases made for the escape of the
carbonic acid and other saturated gases. I do not therefore claim
broadly the providing a mode of escape for such gases, while retarding
the draught, as my Invention relates to the specific devices which I
employ to this end.

page_text: 1. The arrangement of the pipe G bent downwardly in the chimney
of a furnace, substantially as and for the purposes set forth.
2. The combination of the tube K (Fig. 2) with the flue C, and
cistern or tank J, substantially as and for the purposes set forth.
3. The combination of the fan H (Fig. 1), bent pipe or tube G, and
damper F, when arranged to separate, substantially as and for the
purposes set forth.
In witness whereof, I, the said Joseph Knott, have hereunto set
my hand and seal, this Eighteenth day of January, in the year
of our Lord One thousand eight hundred and seventy-three.
JOSEPH KNOTT. (L.S.)