Improvements in Steam Generators.
Year: 1898

page_text: Date of Application, 19th Sept., 1898-Accepted, 26th Nov., 1898
Improvements in Steam Generators.
We, HORACE LIZZELLE FREEMAN and MARSHALL JONES FREEMAN, of Lexington,
in the County of Davidson and State of North Carolina, United States of America,
Manufacturers, 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 more especially to that class of
generators in which a separate water heating and circulating attachment is used in
connection with the boiler, and is arranged below the boiler within the furnace casing
above the fire box, so as to receive the direct effect of the heat from the fire, and
provide for heating and continuously circulating the water within the boiler.
To this end the invention primarily contemplates a novel arrangement of water
heating and circulating pipes arranged below the boiler and entirely within the fur-
nace casing and above the fire box, and so connected with the boiler as to establish a
continuous circulation, whereby all of the water in the boiler will pass through said
pipes and thereby be maintained at an even temperature. The invention also con-
templates a novel manner of mounting the heating and circulating pipes, whereby
each of such pipes is capable of independent contraction and expansion, while at the
same time being so arranged as to provide for a circulation which is sufficiently
strong to wash all precipitated matter to the blow-off pipe connection.
A further object of the invention is to provide novel and efficient means, whereby
all of the pipes constituting the heating and circulating attachment for the boiler
can be readily cleaned from the outside of the furnace, and thereby maintain the
efficiency of the generator.
With these and other objects in view, which will readily appear as the nature
of the invention is better understood, the same consists in the novel construction,
combination and arrangement of parts, hereinafter more fully described, illus-
trated and claimed.
In the drawings:-
Figure 1 is a perspective view of a steam generator embodying the improvements
contemplated by the present invention, one side wall of the furnace casing being
broken away to expose the mounting of the series of heating and circulating
pipes.
Figure 2 is a vertical longitudinal sectional view of a portion of the steam
boiler, and the heating and circulating attachment fitted thereto.
Figure 3 is a plan view of the attachment, the line of section being taken
immediately beneath the boiler, as indicated by the line x-x of Figure 2.
Figure 4 is an enlarged sectional view of the expansion coupling for the front
connection of each heating and circulating pipe.
Referring to the accompanying drawings, the numeral 1 designates an ordinary
furnace casing having the usual fire-box 2, and the front plate 3, and supported
within the furnace casing is an ordinary type of tubular boiler 4. The tubular
boiler 4 is of a horizontal type and is provided therein with the usual fire-tubes 5,
which communicate with the interior of the furnace casing in the usual way to
D
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page_text: allow the entire products of combustion in the fire-box to be returned through
the boiler before escaping to the stack or chimney. These features of construction
are well known in the art and form no part of the present invention, which is adapted
for use in connection with steam boilers of the type described, but specific reference
is made thereto, in order that the improvements claimed herein may be fully
understood.
To provide for properly connecting the water heating and circulating attachment
with the boiler 4 at the under side thereof, a pendent distributing nipple 6 is
employed. This distributing nipple 6 is preferably provided at its upper end with a
flange 7, securely riveted to the shell of the boiler at the under side near the rear
end thereof, but it will, of course, be understood that the said nipple may be fitted
to the boiler in any other suitable manner, so as to communicate with the interior
thereof, and at its lowest point, whereby all the water within the interior water-space
of the boiler will be compelled to pass through the nipple 6, and thence through the
other pipes forming a part of the attachment. The pendent distributing nipple 6
has fitted thereto a cross coupling 8, to the lower side of which is coupled, by means
of the elbow 9, the blow-off pipe 10, which preferably extends through the rear wall
of the furnace casing, as illustrated in Figure 1 of the drawings, and has fitted
thereto an ordinary blow-off cock, which can be opened from time to time when it is
desired to blow off accumulations of sediment from the boiler and the water heating
and circulating attachment thereof.
The opposite side portions of the cross-coupling 8 support the oppositely extending
portions of the header-pipe 11, arranged transversely beneath the rear end portion of
the boiler, and said transverse horizontally-arranged header-pipe 11 extends from
opposite sides of the nipple 6, or at least the coupling 8 thereof, and essentially
consists of a plurality of couplings 12, and short intermediate nipples 13 joined together
in the same manner as the ordinary pipe couplings, but it will of course be under-
stood that the couplings 12 and nipples 13 form a complete header-pipe having
uninterrupted communication between all of its parts, from end to end.
The transverse horizontally-arranged header-pipe 11 is preferably provided with an
extension 14 at one end, which projects through one side of the furnace casing and
has fitted to its outer open end a closure plug or cap 15, which, when removed,
admits of ready access to the header-pipe from end to end thereof, so that the same
may be readily cleaned throughout its entire length. The couplings 12, forming a
part of the header-pipe 11, provide for the connection with such pipe of the series of
longitudinal water heating and circulating pipes 16. The longitudinal heating and
circulating pipes 16 are arranged in any desired number side by side in the same
transverse plane beneath the boiler 4 so as to extend longitudinally of the latter from
end to end thereof. By reason of this arrangement, the said pipes are necessarily
disposed within the main fire flue beneath the boiler, and directly over the fire box 2,
thereby receiving the direct action of the fire.
The rear ends of the pipes 16 are fitted in the coupling 12, and from this point
the said pipes extend forward at a slight upward inclination, and have
their front ends extended through the furnace front 3 and fitted with the closure
caps or plugs 17, which admit of the ready cleaning of the individual pipes 16
independently of each other. Adjacent to their front ends and at the inner side of
the furnace front 3, each of the pipes 16, has fitted thereto a T coupling 18, to which is
connected one end of a branch circulating pipe 19 having an elbow joint 20, and also
having an expansion coupling connection 21, with a front coupling-nipple 22 fitted in
the front end or head of the boiler beneath the line of the fire flues or tubes 5, thereby
providing an independent coupling connection between the forward end of each water
heating and circulating pipe 16, and the front end of the boiler. The expansion
coupling connection 21 for the forward end of each pipe 16, compensates for unequal
expansion between the boiler and said pipe, while at the same time each pipe is free
to expand and contract independently of the other, thereby greatly increasing the
durability and efficiency of the water heating and circulating attachment.
Each expansion coupling connection 21 essentially comprises an inner sleeve 23,
4

page_text: and an outer adjustable packing gland 24, confining therein asbestos packing 25.
The inner sleeve 23 of the coupling is interiorly and exteriorly threaded, the
interior threads thereof engaging with the upper threaded end of the branch
circulating pipe 19 so as to be rigidly carried thereby, while the exterior threads of
said sleeve 23 are adjustably engaged by the interior threads of the outer packing
gland 24. Each packing gland is provided at the end opposite its connection with
the sleeve 23, with an inwardly disposed flange 26, forming an interior shoulder 27,
against which abuts the packing 25, so that when the gland 24 is tightened up the
said packing will be firmly compressed on the unthreaded portion of the nipple 22,
which is received within the coupling. The nipple 22 has no positive connection
with the coupling, so that any unequal expansion of the parts will permit a relative
movement thereof without impairment of the same.
In the operation of the water heating and circulating attachment, it will be under-
stood that the forward ends of the pipe 16, immediately above the fire box, will
be necessarily heated to a higher temperature than at their rear ends so that the
heated water necessarily arises through the brauch pipes 19, and into the front
end of the boiler. The water within the rear portion of the boiler passes down
through the distributing-nipple 6, and is distributed from the header-pipe 11, through
all of the heating and circulating pipes, and thence again into the front end of the
boiler, thereby establishing a continuous circulation of all the water in the boiler,
which necessarily produces an even temperature and an easy and quick heating of
the water, and thereby economizes the fuel. The circulation which is thus main-
tained is strong enough to wash all precipitated matter down to the blow-off pipe
connection, through which it can be ejected whenever necessary.
From the foregoing, it is thought that the construction, operation and many
advantages of the berein described steam generator will be readily apparent to those
skilled in the art, without further description, and it will be understood that
changes in the form, proportion and the minor details of construction may be resorted
to, without departing from the principle or sacrificing any of the advantages of this
invention.
Having now particularly described and ascertained the nature of our said in-
vention and in what manner the same is to be performed, we declare that what we
claim is :-
1. In a steam generator, the combination with the boiler, of a pendent distributing-
nipple fitted to the under side of the boiler near its rear end and carrying a trans-
versely arranged header-pipe extending from opposite sides thereof, and a plurality
of heating and circulating pipes arranged longitudinally beneath the boiler at an
inclination and coupled at their rear ends to the header-pipe, each of said heating
and circulating pipes having an independent coupling connection at its front end
with the front end of the boiler, substantially as set forth.
2. In a steam generator, the combination with the boiler, of a pendent distributing-
nipple fitted to the under side of the boiler near its rear end and carrying a horizontal
transversely arranged header-pipe, and a plurality of heating and circulating pipes
coupled at their rear ends to the header-pipe, and each having an independent
expansion coupling connection between its forward end and the front end of the boiler,
substantially as set forth.
3. In a steam generator, the combination with the furnace casing and the steam
boiler therein, of a header-pipe arranged transversely beneath the rear end portion of
the boiler and having a single nipple connection therewith, said header-pipe being
extended at one end through one side of the furnace casing and fitted with a closure
cap or plug, and a plurality of heating and circulating pipes coupled at their rear
ends to the header-pipe and having their front ends extended through the furnace
front and fitted with a closure cap or plug, each of said heating and circulating pipes
having an independent branch pipe connection with the front end of the boiler below
the line of the fire-tubes therein, substantially as set forth.
4. In a steam generator, the combination with the boiler, of a header-pipe

page_text: arranged beneath the boiler and having a nipple connection therewith, a plurality of
heating and circulating pipes coupled to the header-pipe and each having an inde-
pendent branch pipe connection with the front end of the boiler, and an expansion
coupling fitted to each branch pipe connection and comprising an inner sleeve fitted
to one of the pipe sections, and the outer packing gland adjustably fitted to said
sleeve and provided at one end with an interior shoulder, and packing arranged
within the gland against the shoulder thereof and adapted to be compressed on the
other pipe section, substantially as set forth.
Dated this 17th day of September 1898.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicants.