Improvements in or relating to Obtaining more Perfect Combustion in Steam Boiler or other Furnaces and Flues, and in Apparatus therefor.
Year: 1894

page_text: Date of Application, 25th July, 1894
Complete Specification Left, 25th Apr., 1895-Accepted, 24th May, 1895
PROVISIONAL SPECIFICATION.
Improvements in or relating to Obtaining more Perfect Combustion
in Steam Boiler or other Furnaces and Flues, and in Apparatus
therefor.
I, WILLIAM ESPLEN, of 31 James Street, Liverpool in the County of Lancaster,
Consulting Engineer, do hereby declare the nature of this invention to be as
follows:
This invention relates to the economising of fuel in heating furnaces, and it has
for its objects a method of and apparatus for obtaining a greatly increased economy
of fuel by means of a. more complete combustion, in any kind of heating furnace,
but.especially. in steam boiler furnaces. It is well known that coal, or other
combustible material, employed in furnaces,. flues, or the like, does not undergo
complete combustion by reason of the insufficiency of the supply of oxygen which
is necessary for such combustion. The quantity of air usually supplied to heating
furnaces is frequently insufficient to provide the amount of oxygen which is
essential to complete combustion.
Now according to my invention, I obtain a more complete economy of fuel by
keeping the combustion under control and by consuming the smoke. This I
accomplish by introducing into the flues against the current of the effluent gases
and in the hottest part of the furnace compressed air or compressed air and oxygen
in a series of fine jets. All attempts in actual practice of introducing compressed
air in this manner have hitherto resulted in failure, owing to the fact that the pipe
or nozzles are destroyed in a very short time by the abnormal heat of the furnace
at this point.
H
Now my invention is designed to overcome this, and this I accomplish by bringing
the air supply pipe through the boiler with only the end of its nozzle projecting
through the shell. With boilers having corrugated furnace plates, I place the
nozzle in the corrugation with the jets pointing in such direction as to meet the
draught. In an ordinary furnace boiler with cylindrical or curved rouf to
the furnace, I either screw the nozzle or nozzles into the crown, allowing only
their ends to project beyond. the surface of the flue, and arrange the jets in these
ends on one side thereof so'as to point in a direction which will meet the draught;
or, in some cases, I may form a water nozzle projecting into the flue and pass' an
air supply nozzle through the wall of the water nozzle in the right direction.
Instead of having a single nozzle, I prefer to form an arched pipe and have two,
three, or more nozzles entering the furnace chamber at different points in the
circumference, and in order to enable these nozzles to be attached with greater
ease, I form them each in a separate piece, and attach them to the pipe by a screw
coupling.
The supply pipe is regulated by a cock. or other hand regulator, so that the
instant the attendant notices any smoke appearing, he can let in a little more air,
or air and oxygen. In order to secure more perfect combustion, I propose to heat
the air supply before delivery to the furnace. To effect this, 1 provide an air
reservoir or receiver and heat the air in this by passing the supply or exhaust
steam or both through it by suitable pipes or coils, or, if preferred, the exhaust
steam may be employed to heat a water jacket on the exterior of the receiver,
either by passing directly into the jacket or being led through a pipe or pipes on
i

page_text: the interior or exterior of the jacket casing. By means of the above arrangements,
the compressed air is heated to a considerable extent before being forced into the
furnace or flues by the compressor.
By this invention, not only is the smoke burned but the combustion is intensified,
the heat raised in a much shorter period than by the ordinary arrangements, and a
considerable economy in fuel is effected.
The receiver may be provided with a safety valve to let out any surplus air, so.
as to avert the risk of explosion.
Dated this 24th day of July 1894
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.
Improvements in or relating to Obtaining more Perfect Coinbustion
in Steam Boiler or other Furnaces and Flues, and in Apparatus
therefor.
I, WILLIAM ESPLEN of 31 James Street, Liverpool in the County of Lancaster,
Consulting Engineer, 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 :-
--
This invention relates to the economising of fuel in heating furnaces, and it has
for its object to obtain a greatly increased economy of fuel by means of a more
complete combustion, in any kind of heating furnace, but especially in steam boiler
furnaces. It is well known that coal, or other combustible material, employed in
furnaces, flues, or the like, does not undergo complete combustion by reason of the
insufficiency of the supply of oxygen which is, necessary for such combustion. The
quantity of air usually supplied to heating. furnaces is frequently insufficient to
provide the amount of oxygen which is essential to complete combustion.
Now according to my invention, I obtain a more complete economy of fuel by
keeping the combustion under control and by consuming the smoke. This I
accomplish by introducing into the flues against the current of the effluent gases
and in the hottest part of the furuace compressed air or compressed air and oxygen
in a series of fine jets. All attempts in actual practice of introducing compressed
air in this manner have hitherto resulted in partial failure, owing to the fact that
the pipe or nozzles are destroyed in a very short time by the great heat of the
furnace at this point.
My invention is designed to overcome this, and it will be understood from the
following description, reference being had to the accompanying drawings, in
which,
Figure 1 is a longitudinal section through a furnace flue and boiler, showing one
way of carrying out the invention;
Figure 2, a transverse section of a furnace flue, showing another arrangement,
in which two or more nozzles enter the furnace at different points in the
circumference;
Figure 3, a sectional view at right angles to Figure 2, showing how the nozzles
are arranged in a boiler having corrugated furnace plates; and
Figure 4, an enlarged section of a nozzle attached to an ordinary furnace plate.
Referring to these drawings first:-
A is the boiler, B the furnace, C the nozzles, D the furnace bridge. Referring
to Figure 1, I bring the air supply pipe I through the ashpit to the bridge D and
arrange the nozzle at C, but in such a manner that the compressed air shall be
introduced into the furnace at the hottest part, in a series of fine jets, delivered

page_text: from fine holes, slits or the like in an angular direction, and contrary to the current
of the effluent gases. The nozzle C is built up in the brickwork of the bridge
with only its perforated portions uncovered by brickwork, thereby preventing the
burning of the nozzle by the abnormal heat of the furnace at this point. The
supply pipe is regulated by a cock or other regulator, so that the instant
the attendant notices auy smoke appearing he can let in a little more air or air and
oxygen.
Referring to Figures 2, 3 and 4, in. an. ordinary furnace boiler.with cylindrical
or curved top to the furnace. I may, instead of locating the nozzle.jor; nozzles. C in
the furnace bridge, screw them into the crown, allowing only their ends to project
beyond the surface into the flue.and, arrange the perforations in the nozzles on one
side, so as to point in a direction which will meet, the draught. The air supply
pipe L is carried through the boiler, so that the heat thereof will further. heat the
air before being injected into the furnace.
Instead of having a single nozzle C, I may form in some cases an arched pipe I,
Figures 2 and 3 and have two, three or more pipes K leading to nozzles entering
the furnace chamber at different points in the circumference, and in order to
enable these nozzles to be attached with greater, case, I form them each in a
separate piece and attach them to the pipe by.a, screw coupling.J (Figure 4).
With boilers having corrugated furnace plates, I.,place the nozzle C in a
corrugation, with the jets pointing in such direction as to meet the draught, as
shown in Figure 3.
In order to secure even more perfect combustion I propose to further heat the
air supply before delivery to the furnace. To effect this, I provide an air reservoir
or receiver E. The air is heated in this by passing the compressed air through
suitable pipes or coils.
In Figure 1, F is the device for compressing the air, G the steam pipes for
heating the air, H the steam exhaust pipes, I the air pipes, i a safety valve to let
out any surplus air so as to avert the risk of explosion. If preferred exhaust
steam may be employed for heating a jacket around the receiver E.
Referring now to Figures 5, 6 and 7.
In these, Figure 5 is a transverse section through the boiler showing a variation
of my device:
Figure 6 a longitudinal section near the centre line :
Figure 7 a sectional view through said centre line.
In these K' K' K' are three branch pipes from the pipe I supplying the hot
air. The pipe I can if desirable pass through a hollow firebar instead of through
the ashpit as shown. Pipes K' are united to a nozzle N which is screwed through
holes in the pipe M so that the extreme end of the nozzle projects slightly beyond
or is level with the surface of the pipe M. This pipe M which is supplied with
water and forms a water jacket for the nozzles N is buried in the brickwork except
at the points where these nozzles project, where a radiating opening is formed so
as to allow the jets of hot air to escape backwards into the furnace as shown at O.
The working of this variation is similar to those already expressed. The advantage
however of the arrangement is that the nozzles are completely protected by a
water jacket. 1 do not however limit myself to this particular form of water
jacket as an almost infinite variety of water jackets can be made for such pipes.
By means of the above arrangements the compressed air is heated to a considerable
extent before being forced into the furnace or flues by the compressor.
The mode of action is as follows:-
--
The furnace being alight, compressed air is passed through the jets C, the result
is a powerful induced draught of air above the bars and a very vivid combustion is
caused in the furnace. The air coming out at the bridge or at the crown of
furnace in a direction contrary to the hot effluent gases causes a vivid combustion,
the smoke is burnt and heat raised in a much shorter period than by the ordinary
arrangements, moreover a considerable economy in fuel is effected. The attendant

page_text: jean regulate the admission of air by a cock, this just after firing he can admit a
larger quantity of air to overcome the smoke than at other times.
.:
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
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1. In a furnace, the combination of an air pump, accumulator or other source of
compressed air, with a pipe or pipes leading to the bridge, and one or more nozzles
placed near the top of the bridge and pointing in an inclined direction and contrary
to the current of effluent gases, said pozzle or nozzles being protected from burning
in the great heat at this point, substantially as described.
2. In steam boiler or other furnaces or flues, arranging the forced air supply
pipe which conveys the air from the compressor to the injection nozzles within the
boiler or a connection thereof and submerged in the hot water,whereby the heat
of the water will further warm the air before being injected into the furnace and
the nozzle will be kept from burning substantially as described.
3. In a steam boiler or other furnace, the combination with an air pump,
accumulator, or other source of compressed air, of forced air injector tubes passing
through the boiler and submerged in the hot water therein, arched pipes I provided
with radial branches K, leading to nozzles in the crown of the furnace and adapted
to discharge air at or from the crown of the furnace at various points in its
circumference to create a forced draught substantially as described.
ה
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WM. P. THOMPSON & Co.,
Of Liverpool, Manchester, Birmingham, and London, Patent Agents.
10
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