Improvements in Fuel Feeders.
Year: 1898

page_text: Date of Application, 26th Apr., 1898-Accepted, 6th Aug., 1898
[Communicated from abroad by HENRY LAWRENCE DAY, of 234, Franklin Avenue
West, in the City of Minneapolis, County of Hennepin, State of Minnesota,
United States of America, Manufacturer.]
Improvements in Fuel Feeders.
I, WALLACE FAIRWEATHER, C.E., of 62, Saint Vincent Street, in the City of
Glasgow, Chartered Patent Agent, 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 improvements in devices designed for automatically
delivering fuel to furnaces, and the object of the invention is to provide a simple
and economical device which may be used for feeding shavings, fine coal, dust or
other light or fine material to furnaces.
The invention consists generally in means for producing an air-belt or con-
tinuous air-current, with means for supplying the fuel to the current at some
convenient point, and means for separating the fuel from the current and deliver-
ing it to the furnace, so that if any of the fine material is not separated from the
air-current it is carried back again by the current to the point where the fuel is
supplied and then to the point where it is separated from the current. Thus none
of the dust or light material is permitted to escape into the atmosphere or into the
room where the apparatus is located.
In the drawings:
Fig. 1 is a plan view of an apparatus embodying my invention, showing its
location and connection with a furnace, which is here shown partly in section.
Fig. 2 is a side elevation of the same, the furnace being shown partially in
vertical section and the feed hopper being also shown in vertical section.
Fig. 3 is an end elevation showing a modified construction of the feed hopper
and showing also a different form of mechanism for separating the dust or light
material from the air-current.
Fig. 4 is a side elevation similar to Fig. 2, showing the device with the hopper
or separator of the form shown in Fig. 3.
Figs. 5 and 6 are details of the separator shown in Figs. and 4.
In the drawings, 2 represents a suitable furnace of any ordinary or preferred
construction into which the fuel is to be fed. 5 represents a suitable reservoir
within which the fuel is placed and from which it is fed, preferably by gravity.
The reservoir 5 may be arranged to discharge the material through a suitable
gate or slide 5¹ into a small hopper or trough 4 from which it may be fed into
the feed pipe by means of a suitable feed screw 6 arranged upon a shaft 8, said
shaft being provided with a pulley 10 and being driven by a belt 12 from the
shaft 14. The shaft 8 may be arranged vertically as shown in Figs. 1 and 2, or
it may be arranged horizontally, as shown in Figs. 3 and 4. The driving belt 12
for the shaft of the feed screw may be driven from the countershaft 14 which in
turn is driven from the main shaft 35 by means of a suitable belt 31, as shown in

page_text: .
Figs. 1 and 2, or the belt 12 may extend directly from a pulley on the main shaft 35
to the pulley 10 on the shaft 8, as shown in Figs. 3 and 4.
I do not limit myself, however, to any special form of device for feeding the
material into the pipe or conductor as it will be obvious that any suitable con-
struction by which the material may be fed into the pipe without permitting any
material amount of air to enter with it will be suitable for the purpose of this
invention.
The pipe into which the material is fed is designated in the drawings by the
reference figure 9 and it may be of any suitable size and construction. 7 repre-
sents a suitable fan casing within which is located a fan 71 of any suitable con-
struction. The pipe 9 connects with the eye of the fan and the shaft of the fan
is provided with a suitable pulley to which is connected a driving belt 37. This
receives power from the main driving shaft 35 which is provided with a suitable
belt pulley 39. The main driving shaft 35 is driven by any suitable means.
fan casing 7 is connected by a suitable pipe 11 to a suitable separator 13. This
separator may be of any suitable or preferred construction adapted to separate
the dust, shavings or other light material from the air-current.
The
In Figs. 1 and 2 I have shown a well known form of centrifugal separator to
the upper portion of which the pipe 11 connects. This separator is adapted to
separate the dust or light material from the air-current which is returned to the
pipe 9 which is also connected to the separator. From the lower end of the
separator a pipe 15 extends to the furnace 2. This pipe is preferably jointed at
its lower end so that it may be withdrawn or inserted through an opening leading
into the furnace, as desired. The fan or blower, the pipe 9, the pipe 11 and the
separator 13 form means for creating a continuous air-current, the air being passed
continuously around the circuit formed by these devices. The material fed into
the pipe 9 is taken up by this air-current and passes along with it into and
through the fan casing and through the pipe 11 to the separator 13. In this
separator the dust, shavings or other light material is separated from the air-
current and passed through the pipe 15 into the furnace while the air and any
dust or remaining light material not taken out by the separator will be returned
through the pipe 9 to the point where the material is fed into this pipe and any
dust that has passed the separator will be added to the body of the material that is
fed into the pipe. For the purpose of supplying air to the pipe 9 to take the
place of the small portion of air that will enter the furnace through the pipe 15
with the material, I provide an inlet pipe 41, the open end of which is preferably
arranged above the furnace 2 so that the air which enters said pipe will be more
or less warmed by the furnace; or, if preferred, said open end may be connected
to a heating chamber 43 provided with heating pipes 45, so that the air will first
pass through said chamber 43 before entering the open end of the pipe 41. In
this manner the air that is supplied to the furnace will be more or less heated,
thereby preventing the delivery of cold air to the furnace. I may also provide
means for supplying air beneath the grate to the furnace, taking such air
from the pipe 9, as shown in the drawings.
For this purpose I have shown a pipe 47 connected with the pipe 9, said pipe 9
being provided with a suitable valve having an operating handle 49. The pipe 47
extends into the furnace, preferably below the grate. By means of the handle 49
the valve within the pipe 9 may be set so as to direct any desired amount of air
into the pipe 47. This pipe may, however, be wholly omitted if preferred. I
may also provide a pressure regulating pipe 51 which is connected to the side of
the separator, preferably near the top thereof, as shown in the drawings, and the
entrance to which is regulated by a suitable valve having a handle 53 by means
of which the amount of air which enters the pipe 51 may be regulated. This pipe
connects with the pipe 15 below the separator. By this means the strength of the
air-current passing through the pipe 15 may be increased or diminished as desired.
The pipe 15 may also be provided with a suitable valve 55 having a counter-
weighted lever or handle 55¹ arranged upon the outside of the pipe.

page_text: In place of using the separator 13 connected to the fan casing by the pipe 11,
as shown in Figs. 1 and 2, I may employ a separator constructed as shown in detail
in Fig. 6.
The fan casing as here shown is provided with a spirally arranged wall 56 which
forms a spiral duct 57 leading from the center portion of the fan casing and having
an unbroken peripheral surface. The duct 57, after extending substantially around
the inner portion of the fan casing, is divided into two parts by the division
wall 58. These two parts I designate as the outer duct 59 and the inner duct 60.
The outer duct 59 leads into an expansion chamber 61 which connects with the
pipe 15 leading to the furnace. A return pipe 62 leads out of the expansion
chamber back into the pipe 9 substantially at the point where it connects with the
eye of the fan casing (see Fig. 5). An adjustable valve 63 is arranged in the
return pipe 62 and is provided with a handle 65 extending outside of the pipe and
adapted to engage a notched segment 67 by means of which it may be held in
any desired position. This valve may be closed or it may be set open, or partially
open, so as to permit a greater or less amount of air from the expansion chamber 61
to be drawn back into the fan casing. The air and the fine material that enters
the fan casing from the pine 9 will be driven through the spiral duct 57 and the
solid particles will, by centrifugal force, be driven against the peripheral wall
of the duct and will travel along this wall and will be taken out by the division
wall or plate 58 and directed through the outer duct 59 into the expansion
chamber 61. The principal portion of the air-current will, however, pass through
the duct 60 and enter the return portion of pipe 9, passing back to the point where
a further supply of material is fed into the pipe. As the air from the fan casing
and the material mingled with it passes into the expansion chamber 61 the air
will be considerably expanded and the fine fuel or material will drop directly into.
the pipe 15 while a considerable portion of the air will pass back through the
pipe 62 into the fan casing. The automatic valve or damper 55, heretofore referred
to, is arranged in this instance in the pipe 15 below the expansion damper 61, as
shown in Fig. 6. The force of the air-current and the weight of the material
passing into the pipe 15 will open the damper 55 permitting the material to pass
below said damper and enter the furnace.
When the air-current is shut off and the device not in use, it is designed to have
the lower end of the pipe 15 withdrawn from the furnace.
The construction may obviously be varied in many particulars without depart-
ing from my invention the essential feature of which consists in providing a con-
tinuous air-current into which the dust or fine material is fed and from which it.
is separated and conducted into a suitable furnace, the air being returned again to
the point where the fuel is fed into the current and thus being used continuously
and no portion of it being permitted to escape into the atmosphere of the room
or place in which the device is located. The device may be used in any place
where it is desired to feed fine fuel or material to furnaces and it is thus especially
applicable for use in large buildings of any kind or in connection with the
furnaces of steam plants, or it may be employed for feeding the furnaces of steam
vessels. The material that can be fed by means of this apparatus is of a character
that is often totally wasted such as shavings, saw-dust, fine coal dust or any other
fine material suitable for fuel.
.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is;-
1. Means for feeding fuel to furnaces, comprising in combination, means for
producing a continuous air-current or air-belt, means for directing the fuel into
said air-current, and means for separating the fuel from said air-current and
directing it into a suitable furnace."
2. Means for feeding fuel to furnaces, comprising in combination, mechanisia
for producing an air-belt or continuous air-current, means for feeding the fuel into

page_text: said current, means for separating the fuel from said current and directing it into
a suitable furnace, and means for supplying air to said air-belt to take the place
of the air which passes into the furnace with the fuel.
3. Means for feeding fuel to furnaces, comprising in combination, a fan or
blower, a separator, pipes connecting said fan and separator, whereby a continuous
air-current or air-belt may be produced, means for delivering fine fuel into one of
said pipes, to be separated from said air-current by said separator, and means
for conducting such fuel from said separator to said furnace.
.4. Means for feeding fuel to furnaces, comprising, in combination, a suitable
fan or blower, air-conductors connected to the inlet and outlet of the casing of
said fan or blower and communicating with each other, means for directing fuel
into said air-conductors, means located in said fan casing for separating the
fuel from the air-current, and means for directing said fuel into a suitable furnace,
for the purpose set forth.
5. Means for feeding fuel to furnaces, comprising, in combination, a suitable
fan or blower, a fan casing provided with a spiral duct leading from its central
portion and having an unbroken peripheral surface, a suitable wall dividing said
duct into an inner and an outer part, a pipe or conductor connected to the inner
part of said duct and communicating with a pipe or conductor leading to the
inlet of the fan casing, means for feeding fuel into said conductors and means for
directing the fuel from the outer part of said duct into a suitable furnace.
6. The combination, with the fan, of the separator, the pipes connecting said fan
and said separator, whereby a continuous air-current may be produced, a pipe
extending from said separator to the furnace, and means for feeding the fuel into
one of the pipes connecting the fan and separator, for the purpose specified.
7. The combination, with the fan and separator, of the pipes connecting said
fan and separator, means for supplying air to one of said pipes, a pipe connect-
ing the separator with the furnace, and means for feeding the fuel into one of
the pipes between the fan and separator.
8. The combination, with the fan and separator, of pipes connecting said fan
and separator, whereby a continuous air-current may be formed, means for feed-
ing the fuel from the separator to the furnace, means for supplying heated air to
the pipe between the separator and the fan, to compensate for that which passes
though the pipe into the furnace, and means for feeding the fuel into one of the
pipes between the fan and the separator.
Dated this 25th day of April 1898.