IMPROVE- MENTS IN STEAM GENERATORS AND FEED FOR THE SAME, PARTS OF WHICH ARE APPLICABLE TO STEAM GENERATORS GENERALLY
Year: 1877

page_text: LETTERS PATENT to Edward Thomas Hughes, of the Firm of Hughes and Son,
Patent Agents, 123, Chancery Lane, London, for the Invention of "IMPROVE-
MENTS IN STEAM GENERATORS AND FEED FOR THE SAME, PARTS OF WHICH ARE
APPLICABLE TO STEAM GENERATORS GENERALLY." A communication from
abroad by "The Automatic Boiler and Engine Company," of Newhaven, State
of Connecticut, United States of America.
Sealed the 21st June 1878, and dated the 24th December 1877.
COMPLETE SPECIFICATION filed by the said Edward Thomas Hughes at the
Office of the Commissioners of Patents on the 24th December 1877.
EDWARD THOMAS HUGHES, of the Firm of Hughes and Son, Patent Agents,
123, Chancery Lane, London. "IMPROVEMENTS IN STEAM GENERATORS AND FEED
FOR THE SAME, PARTS OF WHICH ARE APPLICABLE TO STEAM GENERATORS
GENERALLY." A communication from abroad by "The Automatic Boiler and Engine
Company," of Newhaven, State of Connecticut, United States of America.
The first part of this Invention relates to improvements in steam generators, with
special reference to generators for small engines, and is illustrated in Fig. 1, which
represents a vertical section of the generator.
Some of the requisites for such a generator are,—
First. That it shall occupy a small space.
Second. That the amount of fuel required shall be small.
And, Third. That the generation of steam shall he rapid.
In the usual construction of boilers, if the amount of fuel be small, it requires
frequent replenishing, and consequently the frequent opening of the fire-box for the
introduction of fresh fuel, and which opening deadens the fire as well as exposes
the radiating surface to the outward atmosphere, resulting in a sudden reduction of
the pressure, which can only be overcome as the replenished fire reheats to generate
new steam.
Again, such construction of boilers necessitate the presence of a large quantity of
water, and a considerable time with a fresh fire must elapse before the water would
be sufficiently heated to generate steam.

page_text: :
The object of this part of the Invention is to overcome these difficulties, and it
consists in a combination of parts in the apparatus, as herein-after described, and
more particularly recited in the claims.
The boiler is of the vertical class. The base A forms the ash-pit, with the usual
opening B; above this is the fire-grate C, which may be of any of the known con-
structions; above this is the fire-box D, and is preferably of cylindrical form,
increasing in diameter from the grate upward; and immediately above the fire-box
are one or more openings E for convenience of examining the fire, should occasion
require; above this open space the shell is contracted for a short distance, and then
continues in a cylinder F of substantially equal diameter throughout, and closed at
its top, and provided with an outlet G for the products of combustion.
Centrally within the cylinder shell F is a cylinder H of less diameter, and so as
to leave a space between the two; this cylinder extends down to near the desired
level of the fire, and is closed at its top by a cover H. The fuel is supplied through
this cylinder, and the cylinder used as a reservoir, into which a considerable amount
of fuel may be placed to automatically supply fresh fuel to the fire as may be
required, and in substantially the same manner as in what are called base burning
stoves.
Around the fire-box is a coil of tubing, and this is continued up through the
space between the inner and the outer cylinders, and near the top, as seen in Fig 1,
preferably the coils are off-set, as shown, so that succeeding coils are not exactly the
one over the other, for the purpose of occupying the whole space, and bringing the
hot gasses as perfectly as possible into contact with the tube; this tube constitutes
the water space of the boiler. Outside the boiler is a steam chamber L of any
desirable form. The upper end a of the water tube opens into the upper end of this
chamber, so that the steam generated within the tube will pass into the said steam
chamber L.
any suitable
In order to discharge the steam into the steam chamber more rapidly than would
be done by the circulation produced by the heat alone, there is combined with this
coil a circulating pump N, here represented as a rotary pump, but
pump may be employed for the purpose From the lower part, or near the bottom
of the steam chamber L, a pipe d leads to the pump, and from the pump a pipe e
leads to the lowest part of the coil in the fire-box. This pump is operated by power
applied in any convenient manner, and drawing as it does from the chamber L, and
discharging into the coil, it follows that a constant and forced circulation' is produced
within the coil, discharging into the chamber L.
Fire having been kindled in the fire-box, and the reservoir H charged with fuel,
the coiled tubing filled with water is very quickly heated; the heat from the fire
and products of combustion passing upward through the space between the reservoir
and the outer cylinder, confines the heat within that small space, and applies it
directly to the successive coils, and the pump in operation forces the rapidly heated
water upward, and discharges it with the steam therein into the chamber L, where
the steam at once separates from the water, the steam to be taken away by a pipe f
or otherwise for power or other purposes. This circulation carries the steam upward
through the coil with very much greater rapidity than it could be discharged by
natural circulation; and the constant circulation of the water and drawing from the
chamber L the water discharged therein exposes the water to the intense heat of the
fire under such forced circulation, and generates steam very much more rapidly than
can be done without such circulation.
Because of automatically supplying the fuel to the reservoir H, there is no
occasion to open the fire-box, and consequently no liability to the sudden deadening
of the fire and cooling the radiating surface, as in the usual construction of steam
boilers; hence a constant heat may be maintained for any desired length of time.
The replenishing of the reservoir should be made before the fuel therein has been
exhausted.
As in this construction of boiler the water tube will contain but a small amentitu

page_text: predetermined level; this may be done with a common force pump if the requisite
care and attention be given to it, but to avoid the necessity of such constant care
and attention there is combined with the apparatus an automatic feed which acts to
maintain a certain predetermined level, and so that if the water in the boiler should
rise above that predetermined level, the surplus would be at once removed from the
boiler; if, on the other hand, the water should fall below said level, then the defi-
ciency will be immediately supplied; this is accomplished by the arrangement of a
tube h opening into the chamber L at the actual water line, so that if the water
rise above that line it will be drawn out through the said tube h, and if below, then
more water will be introduced through the said tubes, or at any other point. Any
practical automatic feed may be employed for the purpose.
The peculiar automatic feed illustrated will be described hereafter as the second
part of this Invention.
While the circulating pump is desirable, and very greatly facilitates the practical
operation of the boiler, it may be dispensed with, and a natural circulation depended
upon to convey the steam from the coil.
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It will be understood from the foregoing that it is not the intention in this appli-
cation to claim broadly an automatic fire-feed, but that in using such an automatic
feed there is combined a water space, and so as to concentrate the heat upon such
water space between the automatic feed and the outer shell
The second part of this Invention relates to an improvement in apparatus for
feeding steam boilers, specially adapted for use with boilers containing a small
quantity of water and designed for rapid generation, but applicable also to boilers
generally, the object of this part of the Invention being to maintain in the boiler a
constant predetermined water level; and the Invention consists in the combination
and arrangement of pumping device as herein-after described and more particularly
recited, and is illustrated in Fig. 2, showing a sectional plan view, and Figs. 3 and 4,
detached views.
A is a common force or plunger pump, to the plunger B of which power is applied
by an eccentric C or otherwise; as here represented, the said eccentric is arranged
upon a driving shaft D, to which power is applied to maintain the constant revo-
lution; E is the inlet valve and F the outlet valve for the said pump, water being
supplied to the inlet valve from the reservoir.
G is a second pump cylinder, in which the plunger H is worked by an eccentric I
on the shaft D or otherwise, it only being essential that the plungers of the respec-
tive pumps shall work relatively to each other, as more particularly herein-after
described. L is a pipe leading from the water level of the boiler to the inlet
valve M, so that as the plunger H rises it will draw from the boiler through the
valve M, and on its descent will discharge whatever it may draw from the boiler
through the valve N into a chamber P, the said chamber here represented as a coil
of pipe, the other end of the pipe returning to the pump above the discharge, and
as at a.
Transversely through the plunger is an opening or port b, which at certain times
in the movement of the plunger opens to the inlet passage a, and also to the cor-
responding outlet passage d; from this outlet passage a pipe R leads to the boiler
in the usual manner for the water supply pipe, that is, preferably at the lowest
point.
From the pump A and through the outlet valve F a pipe S leads and opens into
the chamber P, and in this pipe S, or between the valve F of the pump A and the
chamber P, a pressure regulated valve T is arranged, here represented as a spring
valve, and shown in section in Fig. 2 The pressure of this valve is somewhat
greater than the boiler pressure, the object of which will be horeafter explained.
The operation of this apparatus is as follows:-Supposing the plunger H to be
down, as indicated in broken lines, Fig. 2, as it rises to the highest point, as indi-
cated in Fig. 4, it draws from the water level of the boiler through the valve M into
the pump; and supposing that the water in the boiler be slightly below that level,

page_text: then the plunger-H will draw steam_only; descending, it will force that steam
through the valve M into the chamber P.
When the plunger H has risen so as to close the passage b through it, as in Fig. 2,
having previously discharged the contents below it into the chamber P, the plunger B
of the other pump begins to descend, and the pump having been filled with water
from the reservoir, that water will be forced through the valve F, thence into the
chamber P, compressing and taking the place of the steam therein until the plunger H
of the other pump has descended so far as to open the port b through it; then the
contents of the chamber P being under a pressure greater than that of the boiler,
that extra pressure will force water from the chamber P through the port b and
pipe R to the boiler until the pressure in the chamber P falls to the pressure of the
boiler, and so continuing, each rise of the plunger H drawing steam from the boiler,
and on its descent opening the port b for the discharge of water to the boiler, and
until the required level is attained.
Again, supposing the water in the boiler to be above the level, the plunger H will
then draw water from the boiler instead of steam, as before, and force the water into
the chamber P; the plunger B, also working, will discharge its water, as before,
into the pipe S and chamber P, but as that is now full of the water drawn from the
boiler, the force of the plungers produces upon the water between the two pumps
increased pressure, and so as to overcome the pressure on the valve T and opening
that the water in the chamber P will there escape to waste or return to the reservoir
until the pressure in the chamber P is reduced to the pressure on the valve T, or
until the port 6 is opened, then the water in the chamber P will flow to the boiler
through the open port until the pressure in the chamber is reduced to that of the
boiler, but the amount thus flowing into the boiler will be less than that drawn out,
because the draught is the full stroke of the plunger, and the port b does not open
until after the plunger of the pump G has descended a considerable portion of its
stroke.
Again, suppose the level of the water to be such that the pump G will be but
partially filled, then steam will follow, resulting in a charge of both steam and
water, which will together be forced into the chamber P, and the steam compressed
by the force from the other pump, the surplus escaping through the valve T, and a
small portion flowing to the boiler, as before.
Thus the pumps continue, the one A to force a regular and constant quantity of
water toward the chamber P, the other to draw from the boiler steam or water, or
both, as the case may be, and accordingly discharge the surplus water, or admitting
additional water into the boiler. By this operation a substantially constant water
level will be maintained in the boiler.
The pump valves are here represented as the common poppet valves, but in
practice it is preferable to operate the valves mechanically in order to prevent any
foreign substance interfering with the proper closing of the valves.
The pumps are shown in illustration as entirely separate the one from the other,"
but they may be combined or directly united, it only being essential that the
plunger of one shall operate relative to the plunger of the other, substantially as
described.
This feed, as before stated, is specially adapted to steam generators containing but
a small quantity of water, and generating rapidly, and in which it has heretofore
been very difficult under high pressure to maintain a constant water level, and
without which such small generators are impracticable.
While it is preferable to construct the plunger H so as to form the valve or port b
through which the water passes from the chamber to the boiler, it will be readily
seen that this may be a valve independant of the plunger, and operated by inde--
pendent mechanism, it only being essential that the valve or port shall open at
substantially the relative time described. It is therefore not intended to limit this
application to the particular construction of the parts as shewn in the accompanying
Drawings.

page_text: Having now described and particularly ascertained the nature of the said Inven-
tion, and the manner in which the same is or may be used or carried into effect, I
would observe in conclusion that what I claim as the Invention is,―
First. In a steam generating apparatus, the combination of the fire-box, cylin-
drical shell above it, an inner fuel cylinder or reservoir arranged so as to leave a
space between the said shell and reservoir, and a water coil around said fire-box,
extending upward and through said space between the shell and reservoir, and sub-
stantially as specified.
Second. In combination, the subject matter of the first claim, an auxiliary
chamber into which the upper end of the said coil conducts the steam, substantially
as specified.
Third. The combination of the subject matter of the second clause of claim with a
circulating pump taking the water from the said auxiliary chamber, and returning
it to the lower part of the coil, substantially as described.
Fourth The combination of the subject matter of the second claim with an auto-
matic water feeding device, so as to maintain a constant and predetermined water
level, substantially as described.
Fifth. The combination of a pump operating to draw from the water supply, a
second pump operating to draw directly from the water level of the boiler, and a
chamber into which both the first and second pumps may discharge, with a valve
opening from the said chamber to the boiler, and a waste valve, and operating sub-
stantially as described.
In witness whereof, I, the said Edward Thomas Hughes, have hereunto set
my hand and seal, this Twentieth day of December, in the year of our
Lord One thousand eight hundred and seventy-seven.