IMPROVEMENTS IM AERO-STEAM GENERATORS
Year: 1877

page_text: PROVISIONAL SPECIFICATION left by William Robert Lake at the Office
of the Commissioners of Patents on the 24th December 1877. A communi-
cation from abroad by Thomas Lloyd Jones, of Saint Louis, Missouri, United
States of America, Mechanical Engineer.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. " IMPROVEMENTS IM AERO-STEAM GENERATORS."
[A communication from abroad by Thomas Lloyd Jones, of Saint Louis, Missouri,
United States of America, Mechanical Engineer.]
This Invention relates to improvements in aero-steam generators, and is especially
valuable in that class of aero-steam generators in which an ordinary fire is employed
as the heating agent, and in which the air employed in maintaining the combustion
18 together with the gaseous products of combustion passed directly into the water
within the generator, and there retained until the heat of the gaseous and vaporous
currents is communicated to the water.
The prominent features of the said Invention are as follows, that is to say :-
First. For the purpose of thoroughly utilizing their heat causing the gaseous or
vaporous currents to pursue a winding circuitous route throughout the body of the
water in the generator before emerging from the surface thereof, and the means
employed in effecting such circuitous passage.
Second. In combination with the above described method and means for retaining
the heat of the gaseous and vaporous currents, the employment of a furnace lined
with fire-clay or other equivalent heat-resisting material, for the purpose of heating
such currents to a very high degree before delivering them into the generator.
And, Third Causing a vigorous circulation of the water in the generator during
the injection therein of the heated currents, in order to more effectually bring the
latter in contact with the water.
The Invention further relates to various details connected with the furnace
chamber and other parts of the structure.
The said Invention may be considered in three aspects, that is to say :-
First. Where the heat currents are forced into the generator and when an
ordinary fire is employed as a heating agency where the air used for supporting the
Price 4d1

page_text: combustion is forced into the furnace chamber, and thence with the products or
combustion into the generator.
Second. When the air for supporting the combustion in the furnace chamber is
drawn into the latter, and thence with the products of combustion into an air-pump
whence the heat currents are forced into the generator.
And, Third. Where the heat currents are drawn into and through the generator.
In carrying the said Invention into practice, the shell of the generator proper or
boiler may have any desirable form and proportions, and to enable it to be used
when desired as an ordinary steam generator it is provided with a furnace chamber
of the usual construction.
I construct also a main furnace chamber whose products of combustion are passed
into the water in the generator. The said furnace chamber is preferably locatod
outside of the shell of the generator, and at the side thereof, and is, preferably,
constructed as follows, that is to say:-There is an enclosed chamber lined with fire-
clay or other suitable heat-retaining material which extends around the side and
over the top of the said chamber, having openings for the admission of fuel after
the fire has been started and for the escape of the heat currents into the generator.
There are also other openings respectively for the insertion of fuel for starting the
fire, for an eye-glass for inspecting the fire, and for the escape of the products of
combustion when steam is not being generated The grate bars of the said furnace
chamber are preferably made hollow, opening at both ends into an annular water
space provided within a casting attached to the shell of the fire-chamber, which
casting forms the base of the same. I provide openings in the shell respectively
for the admission of air, for the removal of ashes, for the inspection of the pit,
and for the removal of the larger clinkers I also provide an enclosed fuel hopper,
preferably attached to the top of the said furnace, the fuel being introduced into
the hopper through an opening which is to be closed when the hopper is full. The
dropping of the fuel from the said hopper into the furnace chamber is regulated by
means of a valve attached to a rock shaft extending through tho shell of the hopper.
For starring the fuel charge I provide an improved poker, which is constructed of
a series of plates, one to each space between the grate bars, arranged vertically in
the ash-pit, and so that they can be moved up and down between the grate bars
The said plates are suitably connected with levers and a rock shaft, so that they
may be conveniently operated.
A tube having a cock by which it may be closed when necessary connects the
fire-chamber with the generator at or above the level of the top of the fire, and
passes through a water space that is connected with the main body of water in the
generator. The said tube connects at its inner end with a tube from which depends
a series of branch tubes by means of which the heat currents are distributed in the
generator. The said branch tubes are provided with valves which serve to prevent
the water or steam from entering the tubes when air blast is not in use. Instead of
allowing the heat currents to pass directly upward through the water, I cause them
to pass through in a circuitous manner by means of a worm or coil arranged in the
water space of the generator in such a position as to intercept the heat currents.
In order to provide for the return of the water urged upward by the heat currents,
the said worm or coil is constructed so as not to extend quite to the sides of the
generator, and it is enclosed in a casing, leaving a space or flue between the said
casing and the shell of the generator. The proportions and form of the said worm
or coil may be varied according to circumstances. Instead of a coil or worm, I
may sometimes use other means for effecting the same object, such for instance as a
vertical series of inclined planes or a vortical series of horizontal partitions open
alternately at opposite ends; I may use one or more worms or coils in the same
generator.
By dividing the generator into different compartments by means of a partition or
partitions, and introducing the heat current or currents into one or a portion only
of the said compartments, leaving the other or others to serve as an independent
flue or flues for the return of the water, the water is kept thoroughly and rapidly
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page_text: in circulation, and thereby brought more effectually in contact with the heat
currents. The water is preferably introduced into the generator as follows, that is
to say-It passes from a feeder through a pipe into the said water space, around tho
grate bars, and thence through a pipe into the generator. The coolest water is
thereby brought directly in contact with heated surfaces By means of a pipe
provided with a cock, and extending outside the shell of the generator, the condi-
tion of the said valves attached to the said branch tubes may be ascertained.
The water may be maintained in the generator to above the top of the worm or
coil. If desired, however, the full length of the worm need not be used, and the
water may be allowed to fall. In such case the water may pass into the space
between the coil and the shell of the generator through openings. To prevent the
heat currents passing through these openings guards are provided, which are in the
form of an annular flange extending around the casing
The aforesaid fuel hopper may be detached from the furnace chamber, and by
means of a crane be swung on one side.
According to one part of my Invention the air for supporting combustion in the
furnace chamber is drawn into the latter, and thence, together with the products of
combustion, into an air pump, from which it is forced into the generator. The air
pump is so arranged as to be surrounded by the water contained in the generator.
The furnace chamber is preferably arranged at the side of the main generator, and
in an extension thereof, and so as to be surrounded by water; it is open above and
beneath to the open air. Tubes lead from the furnace chamber into what I term
a settling chamber, arranged in the water space of the generator, and having a
tapering bottom From the said settling chamber a passage (or passages) leads to
the lower compartment of a valve chamber, also contained in the water space of the
generator.
The valve chamber has an upper and lower compartment, separated by a seat, in
which what I term the hot air valve works, serving to open and close the passage
from the said lower to the said upper compartment. There is a plunger which
works up and down in said upper compartment, its operation being effected pre
ferably by means of an auxiliary engine, whose piston rod connects with the stem
of the said plunger. There are several valves in the said plunger which serve to
open and close communication between the said upper compartment and the main
water space of the generator.
The operation of this mechanism induces an air circulation into the furnace
where it is heated, and thence, together with the products of combustion, into the
said settling chamber, whero the solid particles leaving the furnace chamber have
opportunity to settle. The heat currents are then drawn up through the various
parts of the apparatus, and escape upward through the worm or coil to the upper
part of the generator. The flow of the heat currents from the furnace into the
generator may be made continuous.
In order to prevent overheating I construct the said hot air valve hollow, and
provide it with a hollow stem which opens at its upper end into the water space of
the generator. It can also be open at its lower end into the water space of the
generator, but I preferably extend this part of the stem through the outer wall or
bottom of the generator, and utilize it as an inlet for the feed water. To enable
the heat currents to pass readily with but slight movement of the said hot air valve
the body of the latter is made with re-entering sides. One or more pipes may be
used, and they may lead from any suitable part of the furnace chamber.
According to one part of the said Invention the heat currents may be sucked or
drawn into and through the generator by means of mechanism arranged on the exit
side of the generator.
Sufficient steam will be generated in the generator to move the piston of a con-
densing engine (to be connected with the generator) to one end of the cylinder,
filling the latter with steam, and displacing the air therein; a vacuum is then, by
any suitable means, formed in the cylinder. In filling the cylinder the steam
pressure in the generator will fall nearly to atmospheric pressure, and on the return

page_text: stroke, or soon after the pressure within the generator falls sufficiently below
atmospheric pressure to induce an inflow of air into the generator and through the
furnace chamber and tubes, the air passing through the furnace chamber and into
the generator causes additional steam to be formed in the latter. After the engine
is once.in motion it is not only the agent by which the steam of the generator is
utilized, but it also becomes automatic in forming its own steam. As the pressure
is not above atmospheric the generator can be readily supplied with water by
simply letting it flow in by gravity. By connecting the generator with a con-
densing engine auxiliary mechanism for passing the heat currents into the generator
is not needed; and in establishing and relying upon a pressure within the generator
that is less than atmospheric, for the purpose of inducing the inflow of the heat
currents, a very efficient means is provided for controlling and directing the
latter.