Improvements in Apparatus for Generating and Utilizing Gaseous Fuel in Steam Boiler and other Furnaces.
Year: 1899

page_text: Date of Application, 17th Jan., 1899-Accepted, 18th Mar., 1899
Improvements in Apparatus for Generating and Utilizing Gaseous
Fuel in Steam Boiler and other Furnaces.
I, WILLIAM LUTHER TETER, of 214, North 12th Street, in the City and County
of Philadelphia, and State of Pennsylvania, United States of America, Inventor,
do hereby declare the nature of this invention to be as follows;-
The objects of this invention are to provide a furnace for burning ordinary
fuel with means to ensure a complete combustion of the fuel, and thereby to
obtain a greater and more uniform heat, to increase the intensity of the heat
by the utilization of gaseous fuel in addition to the ordinary fuel employed, and
to effect the consumption of the smoke or unburnt particles of fuel in the pro-
ducts of combustion.
The complete combustion of ordinary fuel renders the generation of heat much*
more economical, and enables inferior and cheaper grades of coal to be used,
and avoids the formation of clinkers," or imperfectly consumed portions of
fuel.
66
In furnaces in which more or less rarified fuel, such e.g. as steam and vaporized
hydrocarbon, have been fed into a retort, so located as to be directly subjected to
the products of combustion arising from the consumption of the fuel on the
grate, and thereby raised to a high degree of heat, whereby the oil and steam
are more or less decomposed into volatile gases, which are supplied to the body
of incandescent fuel on the grate by burners located under it, more or less diffi-
culty has been experienced in constructing a retort capable of withstanding the
great heat to which it is subjected, and possessing a sufficient capacity for con-
traction and expansion without injury or loosening of the joints. A part of the
present invention relates to the construction of a retort, whereby it is enabled
to expand and contract to the required -extent without injury, and to withstand
the intense heat to which it is subjected.
Another part of my invention relates to the employment of a smoke consumer
for consuming the smoke or unburnt portions of the products of combustion,
and to the construction thereof, whereby gaseous fuel may be utilized and the
consumer may be directly subjected to the products of combustion of the fuel on
the grate, without liability to become injured or loosened at the joints by con-
traction and expansion or the intense heat to which it is subjected.
This invention also relates to means for supplying a forced draught of heated
air, or air and superheated steam, to the fuel on the grate to assist the gaseous
fuel supplied by the burners in effecting the complete combustion thereof.
In the accompanying drawings:-
Fig. 1 is a side elevation of a furnace embodying the invention, with the
encasing brick-work in longitudinal section to expose the interior;
Fig. 2 is a plan view enlarged of the retort burners and smoke consumer;
Fig. 3 is a transverse sectional view of the retort on the line of Fig. 2;
Fig. 4 is a perspective view of one of the retort supporting frames;
Fig. 5 is a side elevation similar to Fig. 1 illustrating a modification;

page_text: Fig. 6 is a longitudinal sectional view of one of the retort tubes illustrating
a modification thereof;
Fig. 7 is a plan view of the coil through which a forced draught may be
supplied to the furnace grate; and
Fig. 8 is a perspective view of the furnace illustrated in Fig. 1 with part of
the encasing brick-work broken away to expose the interior.
A is the ordinary furnace grate.
B is the retort located in the rear of the grate. This retort consists of a
tubular structure and is preferably composed of a series of transversely arranged
tubes C, united at their ends by couplings D, and forming a substantially
unitary structure. In my preferred construction the retort tubes C consist of
ordinary wrought iron tubes having a protecting sheathing. This sheathing
is shown in Fig. 3 as a continuous cast iron sheath E, and in Fig. 6 it is shown
as a series of cast iron sleeves or rings El to permit of expansion and contraction,
and to avoid the liability of the retort tubes to crack owing to the inequality of
the expansion of wrought and cast iron. In the latter case the spaces between
the rings or sleeves E may be filled with crucible-clay or other refractory
material as indicated at e¹. In this way the retort tubes will be able to withstand
the intense heat to which they are to be subjected without liability of cracking.
F, F, are supporting frames or boxes of metal or refractory material resting
on fire brick supports, in which the couplings D of the retort tubes are supported.
The boxes F, F, have been shown provided with notches f on their inner faces
adapted to receive. flanged collars e on the ends of the retort tubes. The coup-
lings D within the boxes F are covered with, or embedded in; crucible clay, or
other refractory material, and are thus protected from injury. The boxes F, F,
may move to and from each other when the retort. tubes expand or contract, so
that the retort will not be subjected to strain or be liable to become weakened or
injured at the joints.
G are burners located under the grate A and communicating with the retort B
by a pipe H.
K is a pipe communicating with the retort B, by means of which highly
inflammable fuel such as oil in a more or less rarified condition, is supplied
thereto.
Ris an ejector connected with the pipe K by means of which the oil is
supplied through the pipe K to the retort. The ejector is connected, as by a
supply pipe Q, with the source of oil supply. Steam is supplied to the ejector
by a pipe leading from a supply piper communicating with the steam boiler T
or other source of steam supply. The piper has been shown communicating
with the piper through a steam chamber R.
The oil, in a more or less vaporized condition, mixed with steam, is fed by the
ejector R through the pipe K to the retort B, where, being subjected to intense
heat, it is converted with the steam into volatile gases, which pass through the
pipe H to the burners G, where they escape and pass up into the body of incan-
descent fuel upon the grate A and are consumed, partly therein, and partly in
the space above the grate, thereby greatly increasing the combustion of the fuel
and adding to the intensity of the heat."
I is a smoke consumer, located in the rear of the grate A, and adapted to
consume the unburnt particles which escape from the fuel in the form of smoke.
This smoke consumer is so located that it will be directly subjected to the pro-
ducts of combustion arising from the consumption of fuel on the grate A, whereby
it will be raised to an intense heat, and inflammable fuel, such as steam and oil,
in a more or less rarified condition, supplied to it may be decomposed, to a greater
or less extent, into volatile gases, which are allowed to escape into the products
of combustion and be consumed therewith to burn the unburnt particles of fuel
escaping in the form of smoke. The smoke consumer preferably consists of a
closed portion or receptacle, into which the rarified oil and steam are introduced
and in which they are converted wholly or partly into volatile gases, and a

page_text: perforated portion connected therewith, into which the volatile gases pass and
from which they escape.
As shown, this smoke consumer consists of a perforated
pipe I supported at its ends by the frames F, F, and connected by a coupling j
with a closed tube or receptacle J similarly supported. The ends of the pipes I, J,
and their coupling may be supported in the frames or boxes F, F, and protected
by fire clay in a manner similar to the ends of the retort tubes C, C, and their
couplings D.
Lis a pipe leading to the smoke consumer and connected with an ejector R³,
to which oil and steam are supplied through supply pipes Q2 and 2, in a manner
similar to that in which the oil and steam are supplied to the ejector R'.
The mixed oil and steam, in a more or less rarified condition, are thus fed by
the ejector R¹ through the pipe L to the smoke consumer, and, being decomposed
in the pipe J, emerge from the burner I in the form of volatile gases, which
are ignited by the Hames from the grate, and burning with an intense heat
act to consume the unburnt particles escaping in the form of smoke.
The oil (usually ordinary hydrocarbon oil) may be supplied to the ejectors in
any convenient manner. To ensure a steady and uniform supply of oil without
the necessity of operating a pump continuously I prefer to employ the following
devices:
M is a tank communicating by a pipe N with a force pump 0, by which a
quantity of oil may be pumped from a reservoir into the tank. Q is a water
pipe by which water under pressure may be supplied to the tank M.
Q3 is a pipe leading from the tank M and having two branches Q1, Q2, leading
to the injectors R1, R2 respectively. Sight gauges g¹, g² may be interposed in
the pipes Q1, Q2, to show the passage of the oil.
R is a steam chamber, to which steam is supplied by the pipe r, and from
which it is supplied to the ejectors R1, R2 by the pipes 1, 2 respectively. S is
a drip pipe from the steam chamber.
Oil is supplied by the pump O to the tank M, to which water under pressure
is admitted by the pipe Q. The oil floats on the top of the water and is forced
by hydrostatic pressure into the pipe Q3, whence it is drawn by the injec-
tors R1, R2, through the pipes Q', Q³, and is forced, in a finely divided condition,
into the pipes K and L. As the oil is drawn by the injectors R1, R2 it becomes
divided and falls in drops, and is therefore in condition to be more readily
atomized or finely divided by the action of the injectors.
In the construction shown in Fig. 5 the smoke consumer I is omitted, and a
forced draught of superheated steam and air is supplied to the furnace under the
grate.
U is a blast pipe opening under the grate A and burners G and communicating
with a funnel inlet u communicating with the external air. W is a steam pipe
leading from the boiler or other source of supply and provided with a nozzle w
in the funnel inlet u, by means of which a forced draught of air and steam
are forced through the inlet u into the pipe U. U is a superheating coil located
within the furnace and interposed between the inlet u and outlet of the blast pipe,
through which the air and steam pass and become superheated before being
supplied to the grate. This forced draught of air and superheated steam
mingling with the volatile gases supplied from the burners G assists in producing
a complete combustion of the fuel on the grate and a more intense heat.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what
I claim is;-
-
1. The apparatus for generating and utilizing gaseous fuel substantially as
described and shown.
2. The tubular retort in combination with the supporting frames F, F,
inde-

page_text: 3. The retort consisting of tubes sheathed in jackets composed of cast iron
rings.
4. The smoke consumer arranged adjacent to the retort.
5. The combined smoke consumer and retort carried by the supporting
frames F, F.
6. In combination with the burners for supplying gaseous fuel to the grate,
the apparatus for supplying a forced draught.
Dated this 6th day of December 1898.
WILLIAM LUTHER TETER,
Haseltine, Lake & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.