Improvements in and relating to Steam Boilers.
Year: 1889

page_text: Date of Application, 23rd July, 1889-Accepted, 24th Aug.,
1889
COMPLETE SPECIFICATION.
Improvements in and relating to Steam Boilers.
We, FRANK BOOKIUS KING, Mechanical Engineer, residing at the corner of Green
nd Saratoga Streets, in the City and County of Baltimore, State of Maryland, and
NATHAN BEACH CLARK, Chief Engineer United States Navy, retired, residing at
Number 1442, Rhode Island Avenue, in the City of Washington, District of Columbia,
United States of America, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
n and by the following statement :-
The general object of the invention is to produce a boiler having its outer shell
composed of convolute plates in reversed curves, the outer convexities or arches being
of greater radii than the reverse or joining curves, which are strengthened by tios.
Also to protect the casing exposed to fire by water tubes.
The general character of the drawings may be outlined as follows:-
Figure 1, is a top plan, with part broken away;
Figure 2, is a side elevation with part of casing removed;
Figure 3, is a cross-section about on line, y, y, Figure 4;
Figure 3, is an enlarged detail of Figure 3;
Figure 4, is a longitudinal section about on line, a, a, Figure 3;
Figure 5, is a broken sectional detail of the manifold and side casing ;
Figure 6, is a broken inner side elevation of manifold and casing;
Figuro 7, is a broken detail of one of the connecting tubes and ties partly in
section;
Figuro 8, is a side view of detail Figure 7;
Figure 9, is a cross-sectional detail of central tie plate and fastenings, and-
Figure 10, is an enlarged horizontal section of downcast conduit protecting tubes,
and casing, on lines, A, B, Figure 11;
Figure 11, is a section about on line, z, z, Figure 10;
Figure 12, is a plan partly broken on line, E, F, Figure 13;
Figure 12, is a front elevation partly broken on line, C, D, Figure 13, and
Figure 13, is a longitudinal section of a fire-tube boiler having a shell of the general
character described.
Figures 14 to 20, are detail sections, showing modified tube or stay connections.
The numeral, 1, indicates the shell plate of the intermediate top sections, of which
any convenient number may be employed. 2, 2, denote the side shell plates. The
plates forming the top shell may be integral or not. The plates at the junction of
the arches, 1, 1, are secured to a tie-plato, 3, the joint pieces being stayed or
strengthened by angle plates, 4, 4, held by rivets or bolts in any usual manner.
The front and rear end walls of the arched portions of the shell are formed of
convoluted plates, 5, 5, as indicated in Figures 1 and 2, of the drawings.
The tie-plate, 3, is held to the tube sheet, 7, at the lower edge by angle pieces, 8, 8.
In the fire tube boiler, Figure 13, the tie-plates extend from top to bottom, and the
fire tubes,, extend through the boiler from front to rear.
The bottom member of the boiler is somewhat similar to the top member, having
arches or convolutions in reverse direction, and having the edges of the arches con-
nected to the bottom tube sheet, 17.
.
In the water tube boiler the space between the tube sheets, 7, and, 17, is pretty
well filled with vertical water tubes, 11. A plate, 13, below the tie-plate, 3, connects
the tube sheet, 7, to the bottom member of the boiler. The lower edge of plate, 13, is
riveted or otherwise fastened to the upturned edges or curves of the archod or con-
volute plates, 21, which form the shell of the lower member of the boiler. (See
Figures 9 and 14.)

page_text: The tie-plate and casing at the sides of the space filled by tubes, 11, is substantially
like the tie-plate 13, but protected on the inner surface only.
The plate, 3, is preferably perforated, and plate, 13, may also be perforated for
lightness. Plate, 13, is protected by asbestos, soapstone, or other refractory slabs or
sheets, 14, and the water tubes, 11, next these protective sheets serve to protect them
also from the intense heat of the flame which passes between the tubes, 11.
The edges of the lower tube sheet, 17, are corrugated at, 22, and riveted to the arch
plates below the corrugations, to permit a slight elasticity and difference of expansion
in the parts. The space, 23, within the corrugations, may be filled with asbestos or
other refractory packing, and the space, 24, between the edges of the arch plates may
be similarly filled, the latter filling being retained by binding strips, 25, secured to
the arches.
The side plates, 2, and the central shell plates, 1, Figures 3 and 14, are riveted or
otherwise fastened to tie-plate, 33, one at each side of the entering angle or curve.
Tie-plates, 33, reach down nearly to the tubo sheet, 7. The lower edges of the plates, 33,
are bolted or otherwise fastened to flanges, 34, on open thimbles, 35, which thimbles
have internal screw threads. In the modifications, Figures 14 and 15, the ties may be
rods, 340, passing through downcast tubes, 341, and securely connected to the
Y-shaped stays, 342, attached to the lower convolute plates.
In Figures 19 and 20, tic-tubes connect reversed T-irons, 343, which are connected
to the convolute plates or tie-plates.
As shown in Figure 12, the sides of the shell may be tied in the same manner as the
top and bottom, the fire-tubes passing through tie-plates when such are used. Tic-
tubes, 36, extend from the upper thimbles, 35, to a corresponding set of thimbles, 35*,
to which the upturned edges, 21*, of the lower arched plates, 21, are bolted or riveted.
(See Figures 7 and 8.)
The convolute plates are secured at the convolutions by angle plates, 21x, to the
thimbles. Thus the plates constituting the arches may be of any width which is a
multiple of an arch, the edges of sheets being secured and the convolutions braced.
The openings through the tubo sheets, 7, and, 17, through which the tie-tubes pass
may be stopped by packing bushes with grommets, 37, which engage the screw-threaded
portion of the tie-tubes, 36, and hold the tube sheets fast to the tie-tubes.
As the upper arched plates, 2, throw a heavy stress on the tube plate, 7, it is
advisable that this tube be thicker than plate, 17. This plate, 7, forms a transverse
tio between the sides of the boiler.
In the water tube boiler the upper arched sections of the boiler are connected to
ine lower reversed sections, at the rear of the fire-box, by downcast conduits 23, which
way connect with a slight offset at the rear of the tube sheet, 7. The downeast
conduits, 23, extend below the level of the lower arches, 21, and each downcast
connects with a corresponding lower arch by a conduit, 18, which terminates inside
the downcast in a scoop or spoon, 19.
The downcasts, 23, are of ample capacity, and convey large volumes of water from
the upper to the lower arches, the scoops, 19, tending to deflect the downwardly
moving current into the lower arches.
As the side of the downcasts, 23, toward the fire-box will be exposed to intense heat,
there will be a tendency to the formation of an upward current of mixed steam and
water on this face of the downcasts. Curved shields, 24, are therefore placed in the
downcasts near this face, forming curved chambers, 25, up which the steam and water
may pass, as shown in Figures 10 and 11. These plates, 24, are curved forward at
the upper ends to catch the steam, and pipes, 26, extend upward to convoy steam up
into the steam space of the boiler.
The downcasts, 23, are connected together below the pipes, 18, by cross-pipes, 28,
and below the conduits may form sediment traps.
The cross-pipes, 28, are connected to the tube sheet 7, by tubes, 41, (Figures 10
and 11.) These tubes serve as supports for the refractory plates of tile, soapstone or
similar packing, 42, which are held against the tubes and downcasts by angle plates, 43,
secured to the downcasts. Non-conducting filling, 44, may be placed outside these

page_text: refractory fire-plates, and corrugated metallic sheets, 45, with inclosed air spaces still
further prevent radiation. The outer angle plates, 46, hold all this part of the casing
to the downcast.
While asbestos and like materials are not very durable when exposed to the intense
heat of such a furnace as we employ, if fully exposed to the flame, it is found that a
protection by water-pipes covering a part of the surface adds greatly to the durability.
Thus the downcasts, 23, and water-tubes, 41, protect the casing, 44, 45, 46, quito
efficiently. (See Figures 10 and 11.)
Should the length of the arches be great, the front of the top member may be con-
nected to the bottom member by a large downcast, 20, (see Figure 1,) extending from
tube sheet, 7, to tube sheot, 17.
The theory of upward circulation through small water tubes and downward circula-
tion through large tubes is well understood.
The direction of the hot gases is from the furnace, 47, backward under the bottom
boiler member to the downcasts, 23, then upward and forward between the tubes, 11,
and, 36, and out at the uptake, 50, to the stack or elsewhere.
The inside walls of the furnace are protected by manifolds of peculiar construction
which materially augment the heating surface of the boiler.
From the downcasts, 23, at each side of the boiler pipes, 51, extend forward to the
front end of the furnace to supply water to the vertical tubes of the manifold, (see
Figure 2.) These pipes should taper, as the water supply will be proportioned to the
distance from the downcast, and a convenient construction is shown in Figures 5
and 6, where the bottom and sides of the pipe are shown composed of horseshoe-
curved plate, 52, and the top of a flat plate, 53, flanged downward, the joints being
riveted.
The lower boiler inember has branches, 60, leading to manifold boxes, 61, about on
a level with the top of the furnace, and parallel with pipes, 51. The boxes, 61, are
short sections and can be separately replaced. The rear box, 61*, is connected to the
top member of the boiler instead of the bottom member. The boxes, 61, are made of
short lengths with single points of attachment in order to overcome the effects of
expansion and contraction.
Each manifold box, 61, has a number of water tubes, 62, connected to pipe, 51,
these water tubes forming the inner side wall of the furnace. The box, 61, should be
long enough to contain about six of these tubes, 62, and at the top of the box over
each tube there is a hole covered by a cap, 63, held down by a suitable clamp, 64.
The caps, 63, may be removed and the tubes, 62, withdrawn through the opening, the
tubes being secured or expanded into place in usual manner.
Outside the tubes, 62, we place plates of soapstone, fire-brick, or other refractory
material, 54, then a packing of asbestos or similar material, 55, and then a covering of
corrugated metallic plates, 56, this outer covering being supported by angle plates, 57,
and removable fastenings, 58. The space between tubes, 60, may be closed by
refractory covering, 59.
The side walls of the tube space filled with tubes, 11, are covered by light open
plates, 73, similar to plate, 13, said plates, 73, being protected by the adjacent tubes, 11,
against which the refractory covering rests. The joints are strengthened by angle
plates, 75.
The front ends of pipe, 51, Figures 1, 2 and 4, should have removable caps, 66,
through which the pipes may be cleaned.
Inside the top member of the boiler there may be an anti-priming shield, 76,
(Figure 4,) composed of thin metallic plates jointed together, so as to fold back inside
the shell, as shown in dotted lines, Figure 4, thus giving access to the upper ends of
tubes, 11, for cleaning or replacement.
It will thus appear that the skeleton of the furnace is composed of the grate, vertical
water tabes at the sides, and nearly vertical downcasts at the rear, the top of the
urnace being the arches of the lower boiler member. The heat from the furnace
passes back ward, then upward between pipes, 18, then forward among water tubes 11,
and, 36, and so to the uptake.

page_text: The tubes, 36, are heavy, and wiu not require replacement.
readily replaced.
It will be seen that there is considerable elasticity allowed in some parts of the
structure, as in the connections of shell plates, 2, and, 21, to their respective tube
sheets.
All small parts exposed to high temperature can be removed and readily replaced.
The boxes, 60, are preferably malleable castings. The shell plates are preferably
rolled sheets of steel.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is-
First: A boiler consisting essentially of a top member and a bottom member of
sections arched in reverse directions, and downcasts at the rear connecting the two
members and extending below the lower arches, thus forming a rear water wall.
Second: A steam boiler consisting essentially of a shell composed of connected
arches or convolute plates connected across the shell by tie-plates of the general
character described at the curves formed by the junction of the arches.
Third A boiler shell consisting essentially of a series of horizontal arches or
convolute plates, the ends of said arches consisting of a similar number of substantially
vertical arches united at their edges to the horizontal arches, or convolute sheets of
the general character described.
Fourth The combination of the top arched shell connected at the inturned angle to
a tie, the bottom arches connected to a tie, and a connection of the general character
described uniting the said ties to the top and bottom shells, substantially as
described.
:
Fifth The top arched member, the bottom arched member, tube sheets to which
the arches or convolutions are connected, and the tie extending from one tube sheet
to the other, substantially as described.
Sixth: The top and bottom members having tube sheets facing each other, a tie-
plate between the tube sheets, and a refractory protective covering for said tie-plate,
substantially as described.
Seventh The top and bottom members, substantially as described, tie-plates
connecting the same, a refractory covering for said tie-plates, and water tubes con-
necting the boiler members and bearing against the said refractory covering,
substantially as set forth.
Eighth The combination with the arched shell plates, of ties connecting the edges
of the top and bottom plates to thimbles, and tubes connecting said thimbles, thus
strengthening the shell, substantially as described.
Ninth: The top and bottom arched members, the tube sheets facing each other, ties
connecting the edges of the arches to open thimbles, as described, and tie tubes con-
necting the thimbles and passing through and tied to the tube sheets, all the elements
in combination, substantially as described.
Tenth In a steam boiler of the character described, the combination with an
inturned arch plate of the flue sheet secured thereto, one of said plates having a
corrugation near its edge to permit a slight elasticity and allow for expansion.
Eleventh The combination with the arched top and bottom members and downcasts
connecting the arches of said members, of cross-tubes connecting said downcasts
substantially as described.
Twelfth The combination with the top and bottom members, downcasts, and
connecting pipes, of the refractory covering resting on said pipes and secured to said
downcasts, substantially as described.
Thirteenth The combination of the upper and lower members and downcasts, o
the refractory casing between the downcasts, the outer covering of said casing con
sisting of corrugated plates, and the angle plates by which said casing is secured t
the downcasts, substantially as described.
Fourteenth The arched boiler member having a box connected therewith, and

page_text: vertical tubes leading to said box, and the downcast, and branch pipes, 51, leading
therefrom to said tubes, said pipe composed of a tapering horseshoe-shaped trough
and a flat flanged cap through which the vertical tubes pass, substantially as set
forth.
Fifteenth The arched bottom member, the boxes connected thereto, and the
downcast and branch pipe, the vertical tubes connecting said boxes and branch pipe,
and the refractory casing resting against said vertical tubes.
Dated this 25гd
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.