Improvements in and relating to Steam Boilers.
Year: 1889

page_text: Date of Application, 15th Mar., 1889
Specification Accepted, 18th May, 1889
COMPLETE SPECIFICATION.
Improvements in and relating to Steam Boilers.
We, NATHAN BEACH CLARK, Chief Engineer United States Navy, retired, residing
at the City of Washington, County of Washington, District of Columbia, and
FRANK BOCKIUS KING, Mechanical Engineer, rosiding at the corner of Green and
Saratoga Streets, in the City of Baltimore, County of Baltimore, State of Maryland,
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 in
and by the following statement :-
This invention relates to Steam boilers of a combination character, having a large
number of practically vertical water tubes, as well as a considerable heating surface.in
horizontal water chambers, and a large steam space above the water tubes.
The exterior of our boiler is formed of a series of arched sections, secured to the
upper and lower tube sheets, in which tube sheets vertical water tubes are fitted, as
well as downcast water conduits.
Referring to the accompanying drawings:
Figure 1, is a cross-section of a boiler showing the general principles of construction.
Figure 2, is a top plan and partial section of a boiler, or of so much thereof as
is necessary to illustrate the invention.
Figure 3, is a cross-section of a boiler with parts omitted, showing especially a mode
of connecting the plates of the shell by brace plates.
Figure 3, shows details of the brace plates.
Figure 4, is a section on the line, A-B, Figure 3.
Figure 5, shows cross-sectional details of the brace plates on the lines indicated'in
Figure 4.
Figure 6, illustrates in section modes of building up brace plates by means of angle
irons.
Figure 7, is a cross-section showing the boiler in section, and position of automatic
damper relatively thereto.

page_text: :
Figure 8, is a horizontal section through the automatic damper.
Figure 9, is a front end elevation of the damper.
Figure 10, is a detail section showing the relation of the damper with the shell and
tubes of the boiler.
Figure 11, is a broken longitudinal section of a modification, and
Figure 12, a broken cross-section of the same.
Figure 13, is a plan partly broken away on different sections.
Figure 14, is a cross-section through the downcast of an arch of two sections.
Figures 15 to 18, are details.
In Figure 1, the top member is composed of a shell having connected arched
plates, 1, forming the cover thereof, curved plates, 2, forming the sides of the steam
space, and flat or slightly curved. tube, plates, 3, 3, extending from the sides and
inclining slightly downward toward the center of the boiler.
The bottom member of the boiler is composed of a series of connected arches formed
by connected curved or corrugated bottom plates, 11, curved at, 12, to form the ends
of the bottom member, and united to tube plates, 13, which extend inward toward the
center of the boiler.
The plates, 3, and, 13, are connected at their inner edges by practically vertical
plates, 7, 7, which inclose a water box or leg, 8, extending nearly the whole length of
the boiler, forming a water connection between the top and bottom members of the
boiler. The side plates, 7, of the leg, 8, are strengthened by tie bolts or rods, 9.
The spaces at each side of the water leg, S, contain a large number of water tubes, 5,
which connect the top and bottom members, through the tube plates, 3, 13.
The tube plates, 3, and, 13, and the bottom plates, 11, of the boiler, preferably
incline toward the center of the boiler so that all sediment tends in that direction.
The circulation is downward through the water leg, 8, and upward through tubes, 5,
by reason of the greater relative heating surfaces of the tubes which causes the water
therein contained to rise.
The top member is strengthened by ties, 4, extending from the downward bends of
the top plates, 1, to tube plates, 3. These ties or braces may be simply angle plates,
as shown clearly in Figure 7, and are preferably cut away in parts for lightness and
to permit free passage of water and steam. The top member thus made resembles a
series of arches closely connected and communicating at their sides.
In similar manner, the bottom member has tie plates, 14, connecting the outer
plates forming the shell of the boiler. As shown in Figure 7, the bottom plate is
shaped in such manner as to give close bearings to the flanges of these tie plates, 14.
The tie plates, 4, and, 14, are connected through the trunk or leg, 8, by ties, 15,
Figure 1.
The arches of the bottoni member extend transversely of the boiler in Figure 1, and
have man hole plates, 16, at their outer ends, permitting easy access to the interior of
the boiler.
The spaces between the top and bottom members occupiod by water tubes, 5, are
inclosed at the outer sides by removable plates, 20. These plates, 20, form the fourth
side of the tube boxes, through which the products of combustion circulate among the
water tubes, as indicated by the arrows, Figure 7. The space may be kept clean by
means of steam brushes, 19.
The steam pipe, 19, is mounted in bearings so that it may oscillate and yet receive a
continuous steam supply. This pipe has numerous small-perforations, and also has
branching arms, 190, also provided with perforations. The pipes, 19, can be passed
between the tubes, 5, by turning the branches, 190, to a position parallel with said
tubes, 5. After the pipe, 19, is in position it can be rocked on its axis, as shown in
Figure 1, carrying the arms, 190, in the arc of a circle between the water tubes, thus
throwing jets of steam (or compressed air when used) on all sides of said tubes,
cleaning them thoroughly. As many pipes, 19, having arms, 190, may be used as
desirable. (See Figure 1.)
In Figures 3 and 4, a number of modifications of the internal stays of the boiler are
shown. Where the arches of the top member are at an angle to those of the bottom

page_text: member, as indicated in these Figures, it is important that the ties, 4, and, 14, shall
mutually support and brace each other. To this end in the upper member the ties, 4,
consist of plates, 40, secured at their edges to the top plate, 1, and extending
downward, where they are bent at an angle about a practically vertical axis. The
part, 41, extends up from the bottom in like manner, bat at right angles to the
part, 40. (See sections C-D; E-F; G-H; Figure 5.) Parts, 40, and, 41, thus
form angle plates with their faces in contact, and a right and left plate from the top
will with the corresponding bottom plates form a cruciform brace at the mid-section.
These plates being connected by bolts or rivets, will have both strength and elasticity.
The cross-sectional area of the united plates, 40, and, 41, should be about the same at
any horizontal section, the width of one flange diminishing as the other increases.
The plates, 41, may be made to overlap each other and be secured together at the
central part, as shown in Figure 3. Tube plates, 3, may be flanged up and riveted to
said tie plates.
"
The connections may be made by means of angles and other shapes, also by flanging
the tube sheets as shown at Figure 3.
The top plate may be distinct from the lower ones, the connections of the two being
made by angles, tees, or other shapes, as shown in section, &c., when economy of
workmanship prevails over economy of weight.
As this boiler will generally be used with a forced draught, it is important that cold
air in large quantities shall not be admitted when the furnace doors are opened, as the
sudden cooling of parts, especially the water tubes, causes contraction and unequal
strains to the great detriment of the boiler. This objection is obviated in a manner,
as will now be stated.
The furnace doors are connected to rock shafts, b. The rock shaft; b, may be the
pintle of the hinge, to turn with the door, or may be otherwise connected to rock as
the door opens or closes.
Shaft,, has a crank, c, which moves a pitman, d. The pitman, d, is connected to
the rod, e, which is connected to each of the metallic blind slats,/.
The metallic slats, f, are pivoted like those of a window blind, and similarly
connected by a rod. The slats together constitute a damper which may be placal at
any convenient part of the smoke and hot air passage. In Figures 7, 9 and 10, the
damper is shown near the entrance of the uptake or smoke stack, h.
When the doors are opened the dampers will be closed, and vice versa, the operation
being automatic.
The course of the smoke and other gaseous products of combustion from the grate, B,.
is backward under the bottom segments through passage, D, (Figure 7) then up-and
forward between the top and bottom members of the boiler, that is, above plate, 13,
and below plate, 3, and in contact with the plates, 7, of water trank, 8, the gaseous
From these tube chambers the gases pass
currents being broken up by tubes 6.
forward to the uptake.
To protect the boiler casing from intense heat, as well as to give additional heating
surface, a pipe manifold, 100, may be connected with downcasts, 101, and
branches, 102, and; 108, as shown in Figure 7, thus forming an auxiliary circulating
system between the top and bottom members of the boiler.
The side plates, 20, preferably asbestos lined, are hinged or otherwise attached so.as
to move away and permit ready access to all the water tubes of the boiler.
In Figures 11 to 14, the downcast is through a series of large pipes, 50, instead of
a single trunk. These tubes may be corrugated circumferentially, as shown, in
Figures 11 and 12, although this is not essential. The ties which connect the arches
generally pass through pipes, 50, but a series of pipes, 52, (not large enough to serve
as downcasts) may be provided for the passage of some of the tie rods..
As shown in Figures 11, 13, and 17, the top arches, 1x, may be made of continuous
plates which have occasional slots, 60, along the lines of the spring of the arches.
The rods, 61, lie in the trough at the base of the arches, passing over the slots, 60.
Tie bars, 62, having loops or eyes at each end pass through the slots, and the rods, 61,
go through the upper eyes of the bars, 62.

page_text: The ties, 62, may be connected to the plates forming the bottom arches by bolts, 63,
or in other suitable manner.
A cap plate, 65, covers the slots in the arched top plates through which tie rods
pass, the edges of said plates, 65, being riveted to the arches of the sides. The space
inclosed under the cap, 65, is of small area; consequently said cap may be of light metal.
The front and rear ends, 2x, of the boiler proper may be arched about axes which
are vertical or nearly so, as shown in Figures 12 and 13, and the opposite inward
edges may be tied to each other.
At the sides of the boiler tie rods, 66, connect curved plates, 67, which are secured.
firmly to the plates constituting the outer arches and relieve the tube shects of a
tendency to break along the line of the first row of tubes.
It will be observed that the downcast conduits, 50, straddle the edges of the arches
formed by plates, 1x, and, 11x, so that it is convenient to tie the plates at the spring
of the arches by rods passing through these downcasts.
In Figure 12, the arched plates are secured to plates, 40x, which in turn are tied to
rods, 62.
The water tubes may be of considerable length, in which caso they may be supported
and prevented from buckling by diaphragm, 69, shown in Figure 14.
The same
figure shows the tie rods from the edges of the arches connected to a cross brace
in the downcast tube; and Figures 15 and 16, show methods of connecting the tie
braces to the inner surface of a downcast conduit without extending entirely through
said conduit.
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―.
1st. A steam boiler consisting essentially of a top member and a bottom member
connected by water tubes, the outer shell of said member consisting of a series of
arches, the sides of the arches being connected by ties which pass through the water
tubes or downcast conduits of the boiler, substantially as described.
2nd. The steam boiler of the character described having the top and bottom member
composed of a series of arches, and having downcast conduits connecting the tube
plates and overlapping the line of the edges of the arches, substantially as described.
3rd. The steam boiler consisting of top and bottom members composed of arched
plates and tubes connecting said plates, and tie rods passing through some of the tubes
and connected to pieces which overlie the plates at the base of adjoining arches,
substantially as described.
4th. The top and bottom members having arched shell plates connected at their
edges by angle plates which are joined together and pass through the downcast tubes,
substantially as described.
5th. The arched shell plates connected by tie rods passing through slots in the
plates, the outer ends of the ties being covered by crown plates reaching from arch to
arch, substantially as described.
6th. The boiler member having connected shell plates consisting of a series of
arches forming the top and other arched plates in corresponding series but extending
in different direction forming the ends of the boiler member.
7th. The boiler consisting of top and bottom members connected by water tubes,
and having a steam pipe passing between said water tubes, said pipe provided with
perforated arms which may be swung between the water tubes by the rocking of the
main pipe on its axis.
8th. The top and bottom members consisting of connected arched plates and having
outside ties which connect the shell plates and take the vertical strain in substantially
the manner set forth.
9th. The boiler and its casing of substantially the character described, said casing
being protected in part by a manifold which connects the top and bottom boiler
members.
10th. The boiler having top and bottom members of substantially the character

page_text: described, the edges of the arched plates being connected to the downcast conduits by
ties.
11th. A steam boiler consisting of top and bottom members of substantially the
character described said members connected by water tubes and by downcast conduits
which are corrugated in the direction of their circumference.
Dated this 15th day of March 1889.
NATHAN BEACH CLARK.
FRANK BOCKIUS KING.
By Jensen & Son,
77, Chancery Lane, London, W.C.,
Patent Agents.
NATHAN BEACH CLARK.
FRANK BOCKIUS KING.
By Jensen & Son,
77, Chancery Lane, London, W.C.,
Patent Agents.