Improvements in Steam Generators and Furnaces therefor.
Year: 1887

page_text: Improvements in Steam Generators and Furnaces therefor.
I, JAMES WATERS, of the City of Minneapolis, in the County Hennepin, and State
of Minnesota, United States of America, 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 steam generators, and consists in the construction and
arrangements of parts as hereinafter shown and described.
In the drawings
Fig. 1 is a sectional side elevation of the boiler plant complete.
Fig. 2 is a plan view in section on line X X of Fig. 1.
Fig. 3 is a plan view in section on the line Y Y of Fig. 1.
This form of generator, is more particularly applicable to marine uses or upon steam
vessels, but may be used to advantage in many locations on land.
A¹ A², represents two "double shells," or outer casings, capable of holding water in
their lower parts, and steam in their upper parts, and connected at their upper parts
by a "double shell" or flue A³, the latter divided centrally by a diaphragm A', so that
steam cannot pass from one shell to the other.
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In the lower part of the shell A', is a
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concave or inverted cone shaped revolving
grate B, and connected to the lower part of the shell A2, is a smoke exit flue C
Suspended in the shell A', above the grate B', are a series of tubuler boilers D,
united to each other at their upper and lower parts by connections a, and each united
to the shell A', at or near its upper and lower ends by connections b, all the upper
connections a, b, being above the water line, indicated by dotted line d, and all the
lower connections a, b, being below the water line, so that the circulation of the
water is insured and the heat equalized upon all the different parts.
Suspended in the shell A, is a tubular heater" or boiler E, united at or near its
upper and lower endsby connections e, to the shell A³, so that the free communication
of the water between the boiler and outside shell or water case is insured.
By this arrangement the products of combustion pass upward from the grate B',
hrough and around the boilers D, thence over and down through and around the
poiler and heater E, and thence upward, and exits finally through the smoke
tack C.

page_text: Under some circumstances shells A' A², and tubular connection A³, might be made
with single walls, or without the water and steam spaces, and the steain generated
entirely in the tubulat generators, but the construction shown will generally be
employed.
As before stated, the grate B', is a revolving one, and this revolution may be
accomplished in any suitable manner, but for the purpose of illustration I have shown
the outer rim of the grate on the underside, with a circular gear rack g', in which a
pinion journaled on a shaft g³, passing through the shell A, is adapted to engage
to revolve the grate.
The grate is very much larger in diameter that is usual in generators, and is made
"concave, or in an inverted conical shape, so that the fuel will run down toward the
center and cover all parts of the grate, and not remain principally at the outer edges,
as it would if the grate were horizontal or convex.
The boilers D, Geing each the size of an ordinary boiler, the shell A', and grate B',
will be proportionately larger than in ordinary generators, and the fuel to be effective
upon all the boilers must be manipulated differently from the ordinary methods.
The fuel will be fed to the combustion chamber through a hopper F, and falls upon
one side of the revolving grate, B₁, the latter by its constant revolution and concave
form causing the fuel to be distributed in a substantially uniform layer over the whole
surface of the grate so that each of the boilers D, receives its proper share of the heat
and the effect of the combustion.
A door on one side of the hopper F, enables the operator to observe the
operation of the combustion and spread the fuel more evenly upon the grate, if it is
required, just after passing the hopper, and another door F³, on the other side of the
hopper F, enables the operator to releive the fuel from clinkers and ashes just before
it passes the hopper.
The grate being so large it would be very inconvenient to properly supply all parts
of it equally with the fuel, or reach all parts with pokers, but when arranged to be
revolved as shown, the fuel is supplied at all parts of the grate uniformly, and all paris
can be reached through the doors F F³, with pokers, &c.
A fan G¹, adapted to be driven by any motive power, but preferably by a separate
donkey engine, or other similar suitable means, is shown arranged to supply an air
blast, to the combustion chamber through a perforated pipe G², in the ash pit beneath
the grate B, and a pulley; G3, on the shaft of the fan, is shown connected by a belt G,
to the worm gearing G, by which the pinion g², is operated, whereby the speed of the
fan and grate will be made to coincide, so that the power which operates the blast and
the feeding of the fuel to the grate will be utilized to govern ilie generation of the
steam.
The inclination and form of the feed hopper F', will be so proportioned to the grate
and combustion chamber, that the coal will flow from it upon the grate only while the
grate is revolving, and the faster the grate is revolved the faster the fuel will be drawn
from the feed hopper and "vice-versa".
Thus it will be seen that the faster the grate is revolved the faster and greater in
quantity will be the flow of the fuel, and the consequent increase of combustion will
cause an increased generation of the steam, and if the same motive power which
operates the fan or other means for producing the artificial draft, be connected to the
mechanism which revolves the grate, it will be apparent that the generation of the
steam can be made to correspond to the requirements of the motive power which
the steam is utilized to operate, by changing the speed of the motor which operates
the grate and fan.
The fan shaft, and the shaft, to which the grate operating mechanism is attached,
may be supplied with cone pulleys, so that the relative speeds of the fan and grate may
be altered as required.
Any other suitable means than the fan G', may be used to secure the requisite
supply of air to the grate, and any other suitable means than that shown may be
employed to revolve the grate, so long as they are arranged to be connected and work
together.

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The tubular generator E, is mentioned as being a generator," or "heater," and
by reason of the functions which it performs it is both of these at the same time.
, represents the exhaust pipe from the engine or engines driven by this generator,
as a whole, and which is conducted into the combined generator and heater E, above
the water line. It may be conducted into the shell A, above the water line, if
preferred, instead of into the heater E, direct. 2, is a pipe leading through a pump H,
from the generator E, just below the top of its water line, to the shell A¹ near its
bottom, whereby the main generators AD, are supplied with feed water from the
generator E, the latter thus serving as a feed water heater to the main generator and
also as a generator to supply steam through a pipe h³, to a secondary engine, or in-
connection with the steam pipe 4, from the main generator, to supply the steam to a
system of compound engines."
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The pressure of steam in the parts A' D, of the generator, will be greater than in the
parts A E, when used to operate "compound" engines, hence the necessity for the
diaphragm A, to keep them separated.
I have shown four of the generators D, in the shell A', but it is evident that a greater
or lesser number may be used, as desired, the only changes necessary to increase or
decrease the number, being to increase or decrease the diameter of shells A' A², and
grate B, and also to increase or decrease the capacity of the combined heater and
generator E, to conform therewith.
Retarding plates i, may be inserted into the spaces between the generators D, and
the shell A, to retard the products of combustion and cause a proper portion to pass
through the flues in the generators.
These retarding plates may be constructed in any suitable manner,
but will generally
be formed of firebrick, supported upon iron brackets, and left somewhat open so that
a small quantity of smoke and other products of combustion may pass through them,
but close enough together to retard the greater mass and cause it to pass around and
through the generators.
I claim many advantages by this construction of the boilers.
The arrangement of the shells A' A³, enables me to utilize the space between the
walls for holding a supply of water and steam in addition to that in the main
generators D, and the combined generator and heater E, and also enabling me to
superheat the steam in that part of the shells above the tubular generators.
The arrangement of the tubular generators D, is an important feature of my
invention, as a very extensive heating surface is thereby obtained, and a very large
amount of steam generated in a generator occupying comparatively small space.
An extensive plant" of boilers is thereby obtained with one combustion chamber
common to all, and that requires but very little more space for its fire-hole than a
single boiler, or nest of boilers.
The latter advantage is a very important one, especially on steam vessels, and in
other places where space is valuable or where it is absolutely necessary to confine the
generators within certain prescribed limits.
By this construction the "fireing "is all done on one side of the generator, as in an
ordinary boiler plant of the same capacity constructed in the ordinary manner, eacli
boiler would require its own separate fuel door, and space in front for the fireman.
By this construction on the other hand it will be readily seen that I only require a
small space on one side of the generator for the fireman to work in, and this space
would be only a very little, if any, larger than a single generator.
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-
1st. A combustion chamber, and a series of steam generators suspended within the
same, in combination with a single constantly rotating grate at the lower part of said
chamber beneath all of said generators, and a single feed opening for supplying fuel
to said grate, substantially as set forth.
2nd. A hollow water holding shell, and a series of steam generators suspended

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within the same, in combination with a constantly rotating grate mounted within said
shell and beneath all of said steam generators, substantially as set forth,
3rd. A shell A', with a combustion chamber provided with a constantly rotating
grate in its lower part and having a series of connected tubular generators suspended
therein above said grate, said combustion chamber adapted to be supplied with fuel
through a single opening in said shell, means for supplying an artificial air draft io
said combustion chamber, and means for connecting the motive power which rotates
said grate with the mechanism which operates said artificial air draft, substantially as
set forth, whereby the movement of the grate and the supply of air to said combustion
chamber correspond to regulate the generation of steam in said generators.
4th. A shell A, with a combustion chamber provided with a constantly revolving
grate in its lower part, and having a series of connected tubular generators suspended
therein above said grate, said combustion chamber adapted to be supplied with fuel
through one opening only in said shell, means for supplying an artificial air draft to
said combustion chamber, and means for connecting the motive power which operates
said artificial air draft producing mechanism with the mechanism which revolves the
grafe, whereby the feeding of the fuel and the supply of air to said combustion chamber
correspond to regulate the generation of the steam in said generators, substantially as
set forth.
5th. The hollow shells A' A, capable of holding water and sicam between their
walls, and with their interiors connected at their upper ends by tubular chamber A³,
having diaphragm A, for separating the steam chambers of said shells, grate B', in
the lower part of said shell A', tubular generators D, suspended in said shell A', above
said grate, and connected to each other and to said shell A', tubular heater and
generator E, suspended in said shell A³, and connected thereto, and exit fine C
leading from said shell A, substantially as set forth.
6th. A hollow water holding steam generating shell, and a series of steam generators
suspended within the same, said generators communicating with said shell, and said
shell being extended up beyond the tops of said generators, whereby a superheating
chamber is formed, in combination with a grate B' located within said shell and
beneath said generators, substantially as set forth.
7th. A combustion chamber, and a series of steam generators suspended within the
same, in combination with a single constantly rotating concave grate at the lower part
of said chamber beneath all of said generators, and a single feed opening for supplying
fuel to said grate, substantially as set forth.
Dated this 20th day of Danausher 1886