Improvements in Furnaces and in Steam Generating Apparatus.
Year: 1893

page_text: Date of Application, 6th May, 1893
Complete Specification Left, 6th Feb., 1894-Accepted, 5th May,
1894
PROVISIONAL SPECIFICATION.
.1
Improvements in Furnaces and in Steam Generating Apparatus.
I, CHARLES ARTHUR ALLISON, of 52 Chancery Lane, London, in the County
of Middlesex, Patent Agent, do hereby declare the nature of this invention, (which
has been communicated to me from abroad by George Ernest Belmor, and
Archibald_Jennings Treat, both of San Francisco, California, United States of
America, Engineers,) to be as follows:-
This invention relates to boilers for generating steam by means of gaseous fuel
produced within or in direct combination with the boiler, and consists of three
elements or functions, to wit: a gas-producing chamber within or enveloped by the
water spaces of the boiler; peculiar combining and combustion chambers in which
the produced gas is mingled with air and consumed, and in the arrangements of
these elements in a steam boiler especially constructed to embody our invention,
and also in other boilers.
The gas-producing chamber is preferably tapering or of hopper form, and is
placed in and surrounded by the water spaces of the boiler. The conduits for
air and gas, also the combining and combustion chambers, being elements of one
structure and contained within the water spaces, main shell, and furnace of the
boiler, so that nearly the whole of the heat generated is imparted by direct
convection and without losses by radiation.
The invention also includes means of impelling the currents of air and gas by
steam jets, fans or otherwise, and when necessary, dampers to control the relative
amount of each supplied to the combining and combustion chambers, with other
essential details to cause and maintain the flow of the gases and air in proper
proportion and volume.
The invention also includes, in connection with the combining or mixing chamber,
heated conduits, surfaces and walls of refractory material, with baffling or
diverting passages leading by and through the same into a combustion chamber,
usually placed at the opposite end of the boiler, or at a proper distance from
the gas-producing chamber, and provided with a separate grate for burning crude
fuel, such as coal, in conjunction with or independent of the gaseous fuel, when
required.
The invention involves controllable inlets for air which may be heated or
impelled, or both, also inlets to the producing chamber for dry steam or air,
impelled and controlled in like manner, the purpose being to embody in one
structure and within the contour and dimensions of a common boiler and its
furnace the various functions hereinbefore named, at the same time enabling
the use of fuel of any kind, even of low-grade, such as cannot be burned in
common furnaces, also an avoidance of smoke, and a saving in the amount of
fuel consumed.
The combining and combustion chambers arranged and operating according to
this invention, are capable of application to steam boilers as commonly erected, and
independent of the gas-producing apparatus herein described. These chambers
are in that case placed behind the common furnace, with modification of the
bridge wall and other parts as required, and the gas supplied from any independent
source.
In the type of steam boilers, when especially adapted for my improvements, the
gas-producing chamber is in the position usually occupied by a fire box. The
combustion chamber and grates being situated at the other end beneath the longi-
tudinal barrel of the boiler, the latter being provided with return flues or tubes in

page_text: the usual manner. Over the gas-producing chamber, or in the end or sides thereof,
is placed an inlet provided with the required valves .or doors to charge the
chamber with crude fuel, which is there converted to gas and conducted to a
combining chamber, heated and mingled with air, as hereinbefore explained.
These improvements are applicable, with proper modification, to land, locomotive,
and marine boilers, also to furnaces for generating heat in other cases, but are
especially applicable to steam boilers, as herein explained.
Dated thie 6th day of May 1803
ALLISON BROS.,.
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Furnaces and in Steam Generating Apparatus.
I, CHARLES ARTHUR ALLISON, of 52 Chancery Lane, London, in the County
of Middlesex, Patent Agent, do hereby declare the nature of this invention,
(which has been communicated to me from abroad by George Ernest Belmor,
and Archibald Jennings Treat, both of San Francisco, California, United States
of America, Engineers,) 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 boilers for generating steam by means of gaseous fuel
produced within, or in direct combination with the boiler.
The invention comprises three main parts or elements:
A gas-producing chamber within and enveloped by the water spaces of the
boiler; a combining chamber wherein the gases from the fuel are mingled with air.
the temperature being at the same time increased by means of a refractory lining
in said chambers; a combustion chamber or chambers in which this heated product
is consumed in contact with the steam-generating surfaces of the boiler, and in the
arrangement of these elements; also in air ducts and air-impelling and regulating
apparatus in combination with steam boilers for stationary, locomotive, or marine
purposes, constructed to embody my invention, also in heating furnaces where the
same methods are applicable.
The objects of the invention are economy of fuel, and to consume, when required,
fuel of low grade, such as lignite, culm, and the like; the avoidance of smoke;
dispensing with a chimney or chimney draft; preserving the heating surfaces of the
boiler from soot or other accumulations, so that no cleaning of these surfaces is
required, and dispensing with the usual work of firing.
In the drawings herewith I illustrate a method of carrying out and applying my
invention in connection with a stationary steam boiler and furnace, especially
arranged for that purpose.
Fig. 1 is a central longitudinal vertical section through a furnace and steam
boiler embodying my improvements.
Fig. 2 is a combined partial end elevation and cross section through the gas
producing compartment or chamber.
Fig. 3 is a horizontal section through the furnace on the line x-x of Fig. 1.
The same letters indicate corresponding parts in all the views.
A main feature of improvement in a boiler and furnace constructed according
to this invention, consists in so arranging the gas-producing chamber and inclosing
it at the top, that this chamber can be contained within the boiler itself and
surrounded by water space, thus preventing a loss of heat by radiation; dispensing
with external iron flues commonly employed to conduct the gases from the producing
chamber to the furnace, which cause a considerable loss of heat by radiation and
convection, and substituting for these an interior downward passage traversing the
water-shell of the boiler, and separated from the gas-producing chamber by means
of a water-containing wall having evaporative surfaces on each side, thus effecting
a further saving of heat; also in a gas-producing chamber with inclined sides as

page_text: shown, so as to reduce the area of the grates, and by reason of this tapering form
of the chamber, cause the bed of fuel to become more compact as it is consumed
and descends toward the grates. This form of the chamber improving the quality
of the gas, by preventing the passage of too much air through the fuel.
Referring first to the steam-generating elements, shown in the drawings, A is
the main shell or body of a boiler of cylindrical form, fitted with horizontal fire
tubes B.
At the front end is situated a gas-producing chamber C, almost wholly inclosed
in a double shell forming part of the water space of the boiler. At the front and
rear ends of the boiler are vertical water-legs E and D, formed by downward
extensions of the main shell, the water-leg D being connected to the water space E,.
at the rear of the gas-producing chamber, by the inclined circulating tubes F, and
a large circulating tube G also connecting the water space E with the lower part
of the main shell A.
To convey steam from the boiler a perforated pipe K is connected to the main.
steam pipe L, the pipe K being made with a telescope joint at M, so the piece N
may be housed to facilitate entrance to the interior of the boiler through the:
manhole O. A steam nozzle P is provided for a safety valve.
Hand holes Q are provided at convenient points, so that all parts of the interior
of the boiler are accessible for inspection and cleaning; also a number of holes R
through the water space forming the front of the producing chamber, to permit
inspection of the fire, and the use of a bar for stirring the fuel. When not in use,
these holes may be closed with plugs S, so as to keep this chamber C hermetically
sealed above the grate J., The door U is for access to the interior of the fire-box,
and is used in kindling the fire, and in cleaning the grate.
The grate bars J may be of any suitable type, but are preferably arranged as
shown, so that they may be given a rocking motion by means of a handle V, in
order to discharge the ashes.and clinkers in to the ash-pit a.
Air for the gas-producing chamber is preferably supplied by a steam jet and
induction pipe b, Fig. 2, the air being forced into the ash-pit through an opening c
at the side.
A charging hopper W is similar in its operation to those commonly applied to
gas-producing furnaces, and is preferably surrounded, where it passes through the
steam space of the boiler, with a layer of non-conducting material ✗, such
as asbestos, in order to prevent chilling the steam when a fresh charge of fuel is
introduced.
Reverting now to what may be called the boiler furnace and the processes of
combustion, including devices for regulating and preheating the supply of air to the
gas-burning furnace, d is a chamber, hereafter referred to as a combining chamber,
having walls of fire brick or like refractory material placed between the gas-producing
chamber C and the flame or combustion chambers f, f.
The stream of gas generated in the combustion chamber C after passing over
the wall I, and down the passage H, enters the combining chamber d through the
passages Y and i, there meeting and mingling with the air which enters through
the passages e and j, and by reason of the refractory lining and high temperature
in this combining chamber d is. thoroughly ignited and converted to intense
flames as the gases escape at m, before being cooled by contact with the boiler
shell. By this means there is attained practically perfect combustion of the gases.
The apertures i and j, for admitting gas and air to the combining chamber d,
are here shown in a form that has operated successfully in practice, but it will be
understood that the mingling of the air and gas is the object in view, and that
such mingling may be accomplished by various arrangements of the ducts for gas
and air. For example, the gas descending through the chamber H, instead of
passing through a perforation or passage Y, in the water leg E, can continue on
and pass beneath the water leg E, and then enter the combining chamber d, the air
passages e, e, being arranged accordingly.
The object in this union of the gas and air is to so bring them into.contact as

page_text: to effectually incorporate them together, which may be effected by crossing the
currents, or diminishing their velocity by increasing the area of the ducts as they
approach the combining chamber d, hence I do not confine myself to the particular
construction shown, but include any arrangement of the flues and ducts to effectually
attain the purposes in view.
To supply air to the combining chamber d I employ any air-impelling apparatus,
such as air-induction nozzles or a fan b, as shown in Fig. 1, the volume of air
admitted being regulated by a valve S', or in any suitable manner, such
adjustment being required to suit the relative volume or pressure of air applied
by the induction nozzle b, and consequent varying intensity of the fire in the gas-
producing chamber C, the quality and volume of the gas generated and the amount
of heat and steam required.
When the same air-impelling apparatus is employed for the producer chamber C,
and the combining chamber d, the relative pressure or volume, of air supplied to
these chambers can be varied and regulated by valves, and will be in some degree
automatic, such pressures depending one upon the other so long as the fuel and other
conditions remain the same.
In the rear part of the furnace is shown an auxiliary grate g, with a firing door z
in the rear water leg of the boiler, and an ash pit p separated from the combining
chamber by the bridge wall n. This grate is not used during the ordinary
continuous operation of the boiler, but can be employed to ignite the gases, or to
operate the boiler with solid fuel in the ordinary manner without interfering with
the gas-producing and consuming elements described, and in case of derange-
ment or repairs of the latter, so as to insure continuous service under all
circumstances.
At m there is a throat or series of inlets, preferably extending across the entire
width of the furnace, through which the flames issue over the top of the bridge
wall n, into the flame combustion chambers f,f.
...
The inlets for gas and air at i and j, where they enter the combining chamber d,
are preferably tapered and expanded from the chambers H and e to the combining
chamber d, as shown in the plan, Fig. 3, so as to correspondingly diminish the
velocity of flow, thus avoiding impingement against the rear wall n, and the eddies
that result therefrom, so the intermingling and incorporation of the air and gas
will be rapid and complete. The air-inlet passage e to the combining chamber d
is also expanded as shown by dotted lines e-e in Fig. 3, the object being, as in
the case of the gas, to reduce the velocity of the air as it approaches the
combining chamber d.
:
The combining chamber d and passage are covered with refractory tiles t, the
upper layer of which may be made to project more or less beyond the face of
the bridge wall at 7, forming a ledge by which the flame is projected further into the
combustion chambers ff.
After entering the combustion chambers f,f, the flame and hot gases return
under the main shell of the boiler, pass upward around the water tube G, and.
traverse the fire tubes B to the chimney u.
As no smoke or solids of any kind are contained in the escaping gases, the
chimney u requires only to extend beyond a roof, or be so arranged as to convey
the spent gases to the open air. Draught by reason of a high chimney would
attenuate the gases of combustion, and in some degree hinder the objects of this
invention.
The partition, separating the air passage e from the ash pit p and combining
chamber d, is preferably of metal, in order that the downward radiated heat from
the furnace may be taken up by the inflowing air, and thus improve the operation
of the furnace by causing a more perfect combustion of the gases.
Air may be admitted to the chamber d through the side walls, or from the front;
by a conduit passing under the ash pit a, or it may be admitted partly or wholly
from the ash pit a, by a suitable passage leading from the latter to an inlet, as j, in
the wall of the combining chamber d.

page_text: r
Doors and provide access to the ash pits a and p, a door to permits access to.
the passage H, and a door y to the combining chamber d, from the ash pit p.
The combination of devices herein shown, for generating and consuming gas,.
have been described in connection with a steam boiler, or for generating steam, but
it is obvious that the same method may be applied to other like purposes so long-
as the gas-producing and gas-consuming chambers are constructed and operate
substantially in the same manner.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
--
1. In a combined steam boiler, gas-producing and gas-consuming furnace, a
generating chamber formed integrally with the boiler, surrounded by heating
surfaces and water spaces, so the heat of the gas-producing chamber or furnace-
will be directly communicated to the water in the boiler and utilized, in the manner.
substantially and for the purposes as specified and herein set forth.
2. In a combined steam boiler, gas-producing and gas-consuming furnace, a gas-
generating furnace or chamber situated within the boiler and forming an integral
part thereof, surrounded by heating surfaces and water spaces as herein shown,.
and made in tapering form from the top downward, so the fuel as it is conзuined
and descends, is at the same time condensed or compressed, substantially as
described.
3. In a combined steam boiler, gas-producing and gas-consuming furnace as.
herein described, a gas-producing chamber forined integrally with the boiler,
surrounded by heating surfaces and water, a vertical feeding tube also integrally
formed with the boiler, extending upward through the steam space, and provided
with valves or sealing devices to admit fuel and exclude the air, in the manner
substantially as described.
4. In a combined steam boiler, and gas-consuming furnace, combining and
combustion chambers, as herein described, and in combination therewith a common
grate and its accessories, so the boiler if required can be fired in the usual manner,.
and independent of the gas-producing and gas-consuming elements, in the manner
substantially and for the purposes described.
5. In a gas-producing and gas-consuming furnace, as herein described, a gas-
generating chamber, a down-take passage therefrom connecting with a combining
chamber in which the gas is mingled with air; air impelling apparatus connected
with both the gas-producing and combining chambers, so the pressure or quantity
of air supplied to the two chambers can be relatively regulated and thus control
the volume of gas generated and burned in a given time, in the manner substan-
tially and for the purposes specified.
6. In a gas-producing and gas-consuming furnace, as herein described, a gas-
generating furnace or chamber, connecting with a combining and a final combustion
chamber in which the gas is consumed, the intermediate or combining chamber
lined with refractory material, and so arranged as to be maintained at high
temperature, causing the mingled air and gas to be thoroughly ignited and.
expanded before entering the final combustion chamber, in the manner substantially
as herein shown and described.
Dated this 6th day of February 1894
ALLISON BROS.,
Agents for the Applicant.