Year: 1885

page_text: I, EDWARD SELDEN TOWNSEND KENNEDY, of the City and State of New. York,
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 :-
The object of this invention is to provide certain new and useful improvements
in steam boilers or generators, whereby good water circulation and dry steam may
be assured.
My improvements are applied more especially to boilers of the "porcupine" type
-boilers with water and steam tubes radiating from a central upright cylinder-
and consist in making several of the lower groups of radiating tubes of less diameter
than the higher groups, in order to secure better water circulation and greater
durability, and of an improved steam take-off pipe for insuring the delivery of dry
steam; all of which will be hereinafter fully set forth.
The drawing represents a sectional elevation of my improved boiler.
In the drawing A represents the upright boiler cylinder, extending down
through the ash pit and supported on the bottom thereof so as to have the firmest
possible foundation, and so that the lowest portion of the cylinder shall be in a
comparatively cool place to properly perform the functions of a mud-drum.
B represents the double boiler shell or walls forming an inclosed water space or
water jacket which communicates with the interior of the cylinder A through
tubes C which are bent as indicated at a so that they may contract and expand
without loosening their joints.
The shell or walls may be constructed in vertical or annular sections and then set
up in place with water and steam-communicating passages between them.
The space inside the shell from the grate bars D, to the hood E forms the
combustion chamber.
From the central cylinder A groups or series of tubes 6 61, closed at their outer
ends and communicating at their inner ends with the interior of the boiler cylinder,
radiate in horizontal planes one above another. The tubes 61 of the lower group or
series, nearest the grate bars, are the shortest, those of the next highest group are
somewhat longer than those of the lowest, and in each succeeding group, until
about one-third of the distance above the grate bars is reached, the tubes are
longer than those below and shorter than those above, and above that point all the
tubes in the higher series or groups are of equal length.
Thus it will be seen that the several lower series or groups of radiating tubes
would be enclosed in outlines representing the frustrum of an inverted cone.
In operating boilers of this type having the tubes all of equal length and
extending nearly to the enclosing shell or walls, it has been found that, when the
fires were urged, the water was sometimes repelled by the intense heat from the
outer extremities of the lower tubes, which consequently become burnt and distorted,
and, in some cases ruptured. To obviate this difficulty the tubes of these lower
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page_text: groups are made shorter, so that the water circulation in them shall be perfect
under all circumstances.
The steam take-off pipe F herein shown is more especially adapted to marine
boilers of this type: Such boilers have great height in proportion to the diameter,
and when used as marine boilers in a heavy sea the water line or surface in them
is constantly changing from the horizontal to 'planes of greater or lesser angle
thereto, so that the water is often forced up into the boiler steam chamber or down
to such an extent as to enter the usual steam take-off pipe or pipes and thereby
establish a syphon action by which the boiler water is rapidly drawn off.
To obviate this objection I make a central opening in the head of the boiler
cylinder and firmly secure over or in it an upright cylinder or pipe G communicating
internally with the steam space of the cylinder A and closed at the upper end.
This cylinder or pipe G reaches up into the smoke pipe H in order to abstract
the heat therein for drying the steam when the boiler is in operation, and it
extends so far upward that no water could be carried into its upper portion from
the boiler however much the water in the boiler might be disturbed by the rolling
or pitching of the vessel in a sea-way.
Within this pipe or cylinder G I fix the elbow steam take-off pipe K which may
have a coupling as shown at f, with the open end of its vertical leg reaching up to
near the top of the said cylinder G and with its horizontal leg extending laterally
outward for delivery of steam, as shown.
The upper end of this pipe K is so far above the boiler water line that no
ordinary motion of the vessel in a heavy sea could force the said water to it, hence
the said pipe could not syphon the water from the boiler.
One or more pipes K could be arranged in the cylinder or pipe G so that the
steam could be distributed to several points, and the horizontal leg or legs of said
pipe or pipes might be directed out through the smoke pipe H or the hood I or be
carried low enough to be projected out through the boiler steam space, as may be
most convenient.
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
1. A boiler constructed substantially as herein shown and described of an upright
central cylinder provided with series or groups of tubes radiating therefrom in
successive planes one above the other, each of the several lower series or groups of
which is longer or of greater diameter than the group next below, so that the
several lower groups could be enclosed in outlines representing the inverted
frustrum of a cone, as set forth.
2. The combination with the vertical boiler cylinder A adapted to be supported
on the bottom of the ash pit, of the upper series or groups of radiating tubes b of 4
equal length or diameter, and the lower tube groups or series 6 decreasing in
diameter downward as set forth.
3. The combination with a vertical cylinder boiler provided with radiating tubes
substantially as herein shown and described, of the upright cylinder or pipe & fixed
on top of the boiler and communicating internally therewith and extending up into
the smoke pipe, and the steam take-off pipe K open at both ends and arranged with
its vertical leg within the cylinder G and its horizontal leg extending outward for
steam delivery, as and for the purposes set forth.
Dated this 19th day of November 1OOK
HERBERT J. ALLISON,
Agent for the Applicant.