Year: 1886

page_text: I, CHARLES ALBERT KNIGHT, of the Babcock and Wilcox Company, 107 Hope
Street, in the City of Glasgow, 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:-
My invention has for object by suitable adaptation of sectional steam generators
of the well-known Babcock and Wilcox type to obtain in marine boilers the high
efficiency as regards steam raising, economy in fuel and safety characteristic of that
class of boiler as hitherto mainly applied for land purposes.
In the construction of the improved marine boiler the leading elements of the
Babcock and Wilcox type of generator are retained with such modification as
regards connections and the formation and arrangement of parts as will provide for
lessening the space usually occupied and for reducing the weight of the structure
while duly maintaining the requisite strength. The elements of, which the boiler
is composed comprise a horizontal steam and water drum having attached at its
front and rear underparts water slabs or headers which in turn are connected by
means of a series of water tubes placed directly over the furnace and inclined in
relation to the steam and water drum, a mud drum being connected to the lower
part of the rear beader to collect the solid matters which are contained in the
water and which after being borne along by the circulation are deposited as the
water descends through the rear and cooler portion of the boiler. The water slabs
or headers, which in the usual form of the Babcock and Wilcox boiler are con-
nected at right angles to the line of the water tubes, are under my invention
suspended vertically under the steam and water drum and the plates which form
their front and rear walls are so dished or pressed out around the orifices which are
formed for the reception of the ends of the water tubes that they present openings
whose axes are coincident with those of the tubes which are expanded in them the
planes of the several parts so dished being normal to the axes of the tubes. The
side walls of the furnace above the level of the grate are composed of horizontal
water tubes of elliptical or oblong cross section connected by nipples or short tubes
expanded into orifices in the front and rear headers, which are for this purpose
made wider than the furnace proper, provision being made for effective circulation
through the side tubes by making the connection to the rear header at the lowest
point and that to the front header at the highest point of each tube.
The connection of the inclined water tubes is by preference made by carrying
then through both walls of the headers and therein expanding them so that they

page_text: may form strong stays distributed over the body of the headers, and the nipples or
short tubes which form the connections for the side tubes are in like manner
expanded into both walls of each header, sections of the tubes being cut out in the
portions which are within the water spaces of the headers to provide for the
circulation of the water. In several other particulars the construction of the boiler
is improved and the whole of the parts are specially designed and organised to
serve the purpose in view as hereinafter more particularly described with reference
to the accompanying drawings.
In these drawings figure I, is a front elevation, figure 2 a longitudinal sectional
elevation and figure 3 a cross section of the improved marine boiler under one
modification of my invention, and figure 4 is a longitudinal sectional elevation of
another boiler embodying the same structural arrangements as the first but
differing from it as regards the divisions in the flame chamber for directing the
furnace gases among the inclined water tubes. Figures 5, 6, and 7 show to a
larger scale various details which are not clearly represented in the general views
of the boiler.
As represented in the drawings the steam and water drum A, is constructed in
the ordinary way and has rivetted near its extremities to the under part of its
shell stiffening plates a having orifices extending through the shell to receive a
number of short tubes or nipples which are expanded therein and into orifices in
the upper part of the vertical headers or water slabs B, B, and form a strong but
elastic connection between the two parts. The ends of the drum are dished and
specially provided with flat flange like surfaces whereto are attached the water
gauges a¹, the feed pipe connection a² being made in the same manner or as is pre-
ferred by rivetting- on a plate or flange piece which also serves to support the
pressure gauge a³. The water slabs both for the front and rear are composed of
two plates B, B¹, of wrought iron or steel forming the sides thereof and an angle
or channel iron B³, forged or otherwise formed as shown in figures 5 and 6,
to the contour of the side plates which it unites together, the plates B, B', being
rivetted externally to the flanges of the angle iron with the object of facilitating
and cheapening the construction.
The side plates of the water slabs or headers have orifices b, cut or otherwise
formed in them for the reception of the water tubes C, and are pressed to the form
shown in figures 5 and 6, to present a series of flange like surfaces at 6¹ around the
tube orifices in planes inclined to those of the plates themselves, but normal to
the axes of the inclined tubes so that whilst the slabs retain a vertical position the
tubes may be expanded therein at a suitable angle to ensure the formation of
proper joints and to provide for rapid circulation of the water through them. The
tube orifices in the front and rear plates of each header or water slab are so
disposed that the ends of the inclined water tubes C, may be passed through the
slabs and expanded in the orifices in both plates to serve as stays. A number of
the tubes C, may have ferrules screwed upon their ends, which protrude through
the outer plates of the headers, to increase the staying power. The usual caps or
covers c are fitted upon the ends of the tubes which serve as seats for them and
the clamps which with the usual bolts secure the caps in place are fitted through
the slots formed in those parts of the tubes which are within the slabs or headers:
The water slabs or headers extend across the front and rear of the furnace F,
whose walls are formed of brickwork the object being to obtain the advantage of
better combustion ensured by a brick lined furnace as compared with one whose
sides are formed of a water surface, whilst the walls of the flame chamber above
are composed of horizontal water tubes D, extending longitudinally between the
front and rear headers which are made wider than the furnace to provide for the
connection to them of said side tubes. These tubes, which as seen particularly in
figure 3 are of oblong, section, and are placed in immediate contact with each other;
are closed at their ends and have formed in them orifices whereinto are expanded
short tubes or nipples d which are likewise expanded into the plates of the water
slabs or headers and thus.serve to connect the oblong tubes thereto. The short

page_text: .tubes d, are carried through and expanded in both walls of the water slabs in
a manner analogous to that in which the tubes C, are secured, and the connecting
tubes d, are fitted as high as practicable in the front ends of the oblong tubes D, as
shown by figure 1, and as low as possible at the rear ends as shown by figure 3, to
obtain the equivalent of an inclination of the tubes corresponding to the difference
in lovel of the column of water entering from the rear and discharging into the
front header. The water slabs or headers are suitably stayed where the dimensions
of the surfaces require it, independently of the staying by the water tubes, by
means of screwed stays or short stay tubes of small diameter expanded in both
plates B, B, and beaded over at their extremities the stay tubes when such are
used serving as means of introducing a steam jet for the purpose of removing
ashes or soot from the surfaces of the water tubes.
.
The mud drum E, which may be of wrought iron or cast steel is or may be con-
nected to the rear water slab by means of short tubes or nipples expanded into
orifices in both pieces, or the slab may terminate in the form of a mud drum.
The connections of the side tubes to the water slabs or headers, and of the latter
to the steam and water drum are so made that the furnace or flame chamber is
enclosed by these parts, an open space being however left between the side tubes D,
and the drum A, whereinto are fitted hollow tiles a, of cast iron which are so
shaped as to completely close up said space and to retain their position by gravity,
the object of so fitting the tiles being that they may be readily removed for the
purpose of introducing a steam jet to brush the soot from the surfaces of the
tubes.
The formation of the joints of the water slabs by external rivetting is advan-
tageous as ensuring economical construction and sound workmanship but it presents
an objection at the opening for the fire door in that the joints would there be
exposed to the direct action of the fire. To overcome this objection I provide a
fire door mouth G, of the form represented in figure 2. This door mouth is of a
shape corresponding to that of the opening whose top, bottom and sides it covers
and protects and it is formed with a flange m, upon its inner side extending around
the top and sides of the door opening and effectually protecting the row of rivets
which unite the plate B¹, to the channel iron B², at that part. The bottom of the
door mouth serves as a dead plate, and the whole mouth piece is by reason of its
contact with the comparatively cold surface of the water slab protected from rapid
deterioration by the action of the fire. At the front the mouth piece has connected
to it a frame provided with hinges which carry the fire door G¹.
In the boiler represented in figures 1, 2, and 3, the furnace is divided by two
diaphragms or plates of cast iron extending across the water tubes the one H, being
carried up from the bridge at the back of the fire grate and the other H' carried
by a hanging bridge H. These plates are covered in front by bricks or slabs of
refractory material closely fitting round the tubes and they serve to direct the
furnace gases to the greatest advantage upon the heating surfaces of the boiler.
In the boiler represented in figure 4 these divisions are dispensed with the boiler
being shorter and the bridge at the rear of the fire grate being in proximity to the
rear header.
An opening I, is formed in each case through the upper part of the
rear header to serve as an outlet for the gases to the chimney which is or may be
directly fitted to said opening. The chimney J, when fitted as shown by the
drawings may be supported from the rear end of the drum A, and in it a door J',
is provided as a means of ingress to the flame chamber.
The entire boiler is enclosed by a sheet iron casing as represented in figures 1
and 3, and its weight is supported by beams K, upon which rest channels L,
forming the base of the brickwork M. It is fastened in its position by having its
front water slab bolted down to the base channels L, the legs which are formed on
each side by the cutting out of the fire door opening in the front header being set
into sockets on the channels. At the rear the weight of the boiler is supported
by the mud drum E, which is set upon saddles bolted to the beams K.

page_text: 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 is
1. The arrangement in combination of the several parts or elements of a water
tube boiler, substantially in the improved manner herein described and illustrated
by the annexed drawings.
2. In a sectional steam generator the combination of a steam and water drum,
front and rear water slabs or headers connected vertically thereunder, inclined
water tubes connecting the water slabs, a series of horizontal water tubes of oblong
section also connecting the said water slabs and forming the upper side walls of
the furnace, and a mud drum, the several parts being constructed and arranged
substantially as herein described with reference to the annexed drawings.
3. In a sectional steam generator a water slab or header composed of two plates
of wrought iron or steel united by angle or channel iron or steel and having flange
like surfaces around the tube orifices pressed out to planes at right angles to the
axes of the tubes which are expanded into the orifices substantially as herein
described with reference to the drawings annexed.
Datad this twenty second day of Sentember 1886.