Improvements in Bagasse Furnaces and Air Heating Arrangements.
Year: 1892

page_text: Date of Application. 12th Apr., 1892-Accepted, 28th May, 1892
COMPLETE SPECIFICATION.
[Communicated from abroad by THE BABCOCK AND WILCOX COMPANY, of
30, Cortlandt Street, in the City, County, and State of New York, United
States of America.]
Improvements in Bagasse Furnaces and Air Heating Arrangements.
I, HENRY HARRIS LAKE, of the firm of Haseltine Lake & Co., Patent Agents,
45 Southampton Buildings, in the County of Middlesex, 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:-
My invention relates to that type of steam generating furnace in which the fuel
consumed is composed, either wholly or in part of green bagasse.
It is the purpose of my present invention to provide a furnace of this
character having a circular body enclosed by a jacket, wherein the use of bolts
and back-stays or stay-rods, for holding the walls and preventing collapse, shall
be avoided. It is a further purpose of my invention to provide means whereby
a suitable blast may be supplied to the combustion chamber, and to so form
the latter that the bagasse fed thereto shall fall in the centre of a circular
pit, where it will be exposed to a substantially uniform blast upon all sides,
whereby a more perfect combustion is obtained.
It is one object of my invention, also to provide a more convenient and a better
method of heating the blast by the utilization of what was, at one time, merely
waste heat.
The invention consists to these ends in the novel features of construction and new
combinations of parts hereinafter fully described and then more particularly pointed
out and defined in the claims following this description.
To enable others skilled in the art to make, construct and use the invention 'I
will proceed to describe the same in detail, reference being had to the accompanying
drawings, in which
Figure 1 is a horizontal section, taken upon the line C D of Figure 2, showing a
bagasse-burner, an air-heater, a smoke stack and a pair of boilers.
Figure 2 is a vertical section taken upon the line A B, Figure 1.
Figure 3 is a vertical section taken upon the line I K, Figure 1.
Figure 4 is a plan view of the entire furnace.
Figure 5 is a vertical section taken upon the line E F, Figure 1.
Figure 6 is a vertical section upon the line G H, Figure 1.
Figure 7 is a side elevation of the metallic jacket enclosing the fire brick lining
of the upper part of the furnace.
Figure 8 is an elevation of the parts shown in Figure 7 and showing one of the
exit nozzles which hold the refractory lining.
Figure 9 is a plan view of the same.
In the said drawings the reference numeral 1 indicates the combustion chamber
of the bagasse-burner, said chamber being circular and concentric with an upper
dome shaped chamber 2 from which open the draft-passages 3, diametrically
opposite each other and providing lateral passages of communication for the
products of combustion which pass into the boiler chambers 4.
The circular com-
bustion chamber 1 is provided with a suitable blast by means of small blast
openings 5, passing through its wall in radial directions and admitting air from a
tuyere chamber 6, in the wall of the combustion chamber.
The combustion chamber is supplied with bagasse through an opening 7 in the
dome-shaped roof. The green bagasse is brought from the mill by means of a
carrier 8, operated by an engine 9, and as it is delivered by said carrier it falls into
a feeding-chute 10, which is provided with suitable rolls 10*.

page_text: "
The upper portion of the combustion chamber 1 is surrounded by a jacket 12, of
iron, shown in detail in Figures 7, 8 and 9. This jacket is arranged exterior to
the refractory lining or fire brick, but in the circular fire-chamber 1 the structure
is composed of masonry exclusively, and is provided with a clean-out door 13. This
construction avoids the employment of the large masses of masonry usually
employed in bagasse furnaces, and renders the cracking, which is caused by
expansion and contraction, much less liable to occur. It obviates the necessity,
also of using backstays, bolts and washers, which have been commonly employed in
bagasse furnaces heretofore. I usually form the metal jacket 12 of sheet iron or
other suitable material the seams being riveted together with angle irons.
Diametrically opposite nozzles 14 are provided, to surround the draft-openings 3.
The tuyere openings in the circular wall of the combustion chamber are supplied
with air from the chamber 6 in the circular wall, which is in turn supplied by means
of a pipe 15, (Figure 5) which takes hot air from a heating chamber 16, arranged
in rear of the combustion chamber. This chamber is supplied with air in the
following manner.
The air-heater is composed of a lower annular head, or casting 17, arranged
horizontally and connected by a group of vertical pipes 18, which extend upward
for a suitable distance and are then bent upon themselves and carried downward to
enter the annular head 17 at a point near its axial centre. The interior of the head
or air box 17 is divided by a circular partition into two separate chambers 19
and 20 which can communicate with each other only by way of the vertical
pipes 18.
At a suitable point exterior to the structure, is placed a blower 21, driven by
any suitable type of engine 22, the blower casing having communication with a
pipe 23, which passes to one of the air chambers in the annular head. Opening
from the other chamber is the pipe 15, which enters the tuyere-chamber 6, which
is thus supplied with a constant quantity of air, heated, and under sufficient
pressure to drive it through the blast openings 5 and against the green bagasse
fuel.
The heated gases and products of combustion pass out of the dome 2 of the com-
bustion-chamber through the lateral draft-openings 3, and enter the boiler-
chambers 4, arranged upon both sides of the furnace. The openings 3 enter the
boiler chambers under the boilers, as seen in Figures 2, 5 and 6, said boilers being
usually of the Babcock and Wilcox type. After passing upward between the
boiler tubes, and then downward between the same at, or near, the other end of the
boiler, the waste heat passes out of the boiler-chambers through blast-passages 26
(Figure 3) dampered at 27, and thence enters the air-heater, through which it
passes to the stack 28.
A swinging damper 29 is placed in the air-heater to deflect
the blast and spread it radially, whereby it will flow in between and around the air-
heating pipes and more rapidly and intensely heat the same.
The bagasse burner is preferably arranged between the boilers, and the stack is
usually placed above the air-heater but I may vary both these arrangements to suit
the circumstances of any given case. For example, the bagasse-burner may be
placed in front of the boilers and the stack at any desired point, the connection with
the air-heater being made by a suitable flue.
The bagasse burner I is a circular structure, with a dome-shaped chamber above,
of larger diameter. The central feed-opening in this dome is built up in the form
of a rectangle, extending some little distance above the dome top, and over it is
placed the bagasse feeder, supported by iron beams 30. The feeder may have any
preferred construction as this forms no part of my present invention.
I may, also, make many variations in features of construction, without departing
from my invention. For example in the air-heater, I may use an annular, or other
shape of head at the lower ends of the vertical air-heating pipes and a similar head
at the point where the return-bends are formed in said pipes. When this
construction is employed the lower head, only, will need to be divided by a circular
partition.

page_text: Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed, as communicated to me by my
foreign correspondents, I declare that what I claim is :-
1. A furnace for the consumption of green bagasse as fuel, the same consisting of
a circular combustion-chamber, surmounted by a dome-shaped, secondary chamber
having a jacket, the combustion chamber being composed wholly of masonry,
substantially as described.
2. A bagasse-furnace having a lower combustion-chamber surmounted by a
jacketed chamber of greater diameter, provided with lateral draft-openings
surrounded by nozzles on the jacket, the fire-brick lining being placed inside the
latter, substantially as described.
3. A bagasse-furnace having lateral draft-openings and surrounded above the
point of actual combustion by a jacket having nozzles surrounding the lateral draft-
openings, substantially as described.
4. A bagasse-furnace having a dome-shaped chamber provided with lateral draft-
openings, a smaller, combustion chamber below, a jacket for the upper chamber, and
a tuyere-chamber formed in the circular wall of the lower combustion chamber
and communicating with the latter through radial openings, substantially as
described.
5. A bagasse-furnace having a combustion chamber provided with a tuyere
chamber or chambers in its wall, an air heater consisting of an annular heal divided
into two circular chambers with vertical pipes communicating with one chamber
and extending upward in a passage leading to the stack, bent upon themselves and
returned to enter the other circular chamber which communicates with the tuyere
chamber and means for forcing air into one of said circular chambers, substantially
as described.
6. A bagasse furnace having an air heater consisting of an annular head divided
into two circular chambers, vertical pipes bent upon themselves and having their
ends entering said circular chambers respectively, a pipe connecting one of said
chambers with the tuyere-chamber and an air forcing pipe entering the other
circular chamber, the pipes being arranged in the passage to the stack lying between
the same and the boiler chambers, substantially as described.
7. In a bagasse-burner, a circular combustion-chamber surmounted by a dome-
shaped chamber of greater diameter, said chamber having suitable openings for the
passage of the products of combustion, a jacket enclosing the dome-shaped chamber
and having an angle-iron base and a strengthening band at the top, to sustain the
lateral thrust of the top, substantially as described.
8. In a bagasse burner, an air heater consisting of a passage communicating with
the stack and with the draft passages leading from the boiler chambers, a head
arranged in said passages and having two separate chambers, pipes communicating at
one end with one of said chambers separate pipes communicating with the first pipes
and with the other chambers, a pipe leading from the latter chamber to a tuyerė-
chamber, which supplies the blast openings in the furnace, and an air forcing
apparatus supplying the other chamber to the head, substantially as described.
9. In a bagasse furnace the combination with a waste-flue leading to the stack, of.
a series of pipes, a head having two chambers one of which communicates with one
end of said pipes and the other with their other ends, the pipes being extended in
the flue, a pipe leading from the latter chamber to supply the blast-openings an air-
pipe supplying the other chamber and a damper arranged to be placed across said
flue or to lie substantially parallel therewith, to deflect the products of combustion
and waste heat against the pipes, or allow free escape, substantially as described.
Dated this 12th day of April 1892.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.