IMPROVEMENTS IN STEAM GENERATORS
Year: 1885

page_text: "
1, WALLACE FAIRWEATHER, C.E. of 96 Buchanan Street, Glasgow, in the county
of Lanark, Fellow of the Institute of Patent Agents, do hereby declare the nature
of my invention for IMPROVEMENTS IN STEAM GENERATORS," the same being a
communication to me from abroad by the Babcock and Wilcox Company, of New
York, in the United States of America, Steam Boiler Manufacturers, 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 certain improvements in steam generators that contain
a series of tubes and spaces through which the water circulates and about which
the heated products of combustion pass from the furnace to the stack.
The invention is illustrated in the accompanying drawings of which Figure 1.
Sheet 1. is a central vertical section, Figure 2, Sheet 2, a front view in half-
section; Figures 2 and 3, Sheet 1. and Figures 2, 3, and 4 Sheet 2, are partial and
enlarged views of the front and rear water slabs and connected tubes; Figures 4.
5 and 6, Sheet 1, are detailed views of detachable tube collars, and Figure 5.
Sheet 2, are views in detail of the arch between the drums, all embodying certain
features of my invention. Similar letters of reference indicate corresponding parts
in the several ngures.
The special type of generator shown and embodying the improvements, contains
a series of water tubes arranged longitudinally in an inclined position over the
furnace and extending beyond the bridge wall, said tubes being secured to, and
communicate with water slabs that form the front and rear walls of the chamber
through which the heated products of combustion pass, the water slabs being also
connected with one or more water and steam drums located above the tubes.
The invention consists in such a relative arrangement of curtains or partitions
within the tube chamber, that the course of the beated gases is directed to such
points and periods on the heating surfaces as to obtain the best effects, and also,
by increasing the distance through which the gases travel, whereby all their
available heat may be taken up.

page_text: The invention further consists in certain details of construction that will be
hereinafter particularly referred to, and the novel features pointed out in the
claims.
ee are
Referring to the drawings: Figure 1, Sheet 1, is the steam and water drum;
bb the front and rear water slabs; the main water tubes; and d (Figure 3) the
wall tubes, all communicating and forming the steam and water spaces.
Hame bridge walls, and f an arch wall or plate, (shown in section Figure 5 Sheet 2)
that determines the course of the gases from the furnace 7. across the heating
surfaces to the stack.
The casing of the boiler is composed of wrought iron sheets rivetted together
and made air and gas tight, the furnace and other particular spaces being lined
with firebrick. A portion of the sides of the boiler is protected by a series of
water tubes as shown in figures 1, 2, 3, and 4, Sheet 2, the triangular space
above said tubes, as shown at m, Figure 1, being closed with firebrick or other heat
resisting material, and also the space n in rear of the furnace. The space inter-
mediate of the wall tubes and casings may be filled, if desired, with nonconducting
material.
The rear water slab bis extended below the line of the tubes e, as shown ai »
Figure 1. Sheet 1; and forms a sediment chamber, this being the lowest and
less agitated part of the water space and also furthest removed from the action of
the fire.
The lower portion of the front water slab may also be extended below the
tubes e to the top of the furnace doors, as shown at p Figure 1, Sheet 1.
The heated gases from the furnace / pass directly to the highest part of the
tubes e, then under the bridge walls or curtains c, c, to the rear of the chamber, and
thence under and around the drums to the front end where they are discharged
into the stack, the course being indicated by the arrows in figure 1 Sheet 1.
In this construction the hat gases are first directed to the comparatively coolest
portion of the tubes, the distance travelled is greatly increased, the gases are longer
retained in contact, and reach every part of the effective heating surface.
The water circulation begins in rising through the inclined tubes and front
water slab to the water drums where the steam separates, the water circulation
being continued downwards through the rear water slab and again through the
tubes.
Between each three adjacent tubes, tubular stays may be placed, as shown in
figures 2 and 3. Sheet 1, extending through each water slab, for the introduction
of a jet of steam to clear the ashes from the exterior of the heating tubes, the
same being closed with plugs when not in use.
Having described the main essential parts and action of the generator, I will
now refer to certain improvements in details of construction.
The water tubes d, forming a portion of the side walls, are made in a peculiar
way, being provided with a short concentric neck at each end, of reduced diameter,
arranged concentrically, the object of this construction being to make a tight
water wall.
These tubes are secured to the water slabs at the neeks, and at a distance apart
slightly less than their greatest diameter, so that, when inserted and turned around
before fastening, the adjacent surfaces are brought in longitudinal contact
throughout the whole length and crowded together to form a tight water wall.
The necks of the tubes. 77, are preferably drawn to the reduced diameter, as shown
in Figures 2 and 4, Sheet 2, but they may be produced as shown in Figure 2,
Sheet 1, by means of expansible nipples.
The fame bridges or curtains e. e. extend from the front end of the tubes a
certain portion of their lengths and also in the form of a drop partition perpen-
dicular thereto, as shown in Figure 1. Sheet. 1.
These curtains are made up of shaped firebrick, and retained in position upon
the tubes by means of detachable collars placed around the tubes at the rear side,
so as to prevent them from sliding back upon the inclined surfaces.

page_text: The collars h, shown detached in detail, in Figures 4, 5, and 6, Sheet 1, are
made in interlocking sections held together and fastened to the tubes by keys i
driven on each side of the tube through the recesses which forces the sections of
the collars and keys itself in intimate contact with the tubes whereby the water
that flows through the tubes may take up the heat to which the collars are exposed
and prevent them from burning out.
The arch wall or crown f may be built of arch brick, abutting against angle
iron rivetted to the drum, in the ordinary manner, or may be constructed of
separated cast iron plates of an arched form, having interposed spuds g placed in
an angular position, and the space filled up with fireclay or other nonconducting
material as shown in the detailed views Figure 5.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. In a steam generator, substantially as described, a flame bridge of covering
a partion of the inclined tubes, a flame bridge curtain depending therefrom, and a
crown arch located above the same and between the drums, whereby the course of
the heated gases is extended and directed to all parts of the heating surfaces.
2. A series of cylindrical tubes constructed with eccentric ends, said tubes being
arranged in opposite tube sheets, parallel with each other, at such distance apart
that the adjacent surfaces will be brought in longitudinal contact and crowded
together to form a tight joint by revolving said tubes on their eccentric bearings
previous to securing the same as set forth.
3. In a water tube generator one or more steam and water drums, a nest or
series of inclined water tubes, and one or more series of water tubes in contact
forming an enclosing water wall, said drums and tubes communicating with each
other through connecting water slabs substantially as described.
4. A boiler arch or crown composed of a series of separated cast-iron plates
having projecting spuds or spikes distributed upon their interior surfaces at an
acute angle therewith, the surrounding space being filled with fireclay or other
heat-resisting material.
11 h Walm 100%