Improvements in Boilers or Steam Generators.
Year: 1894

page_text: This Print is in accordance with the Original Specification as it stands after
Amendment (under Section 11 of the Patents, &c. Act, 1883), as required by
the decision of the Comptroller General of the 13th day of May 1895.
Date of Application, 11th Sept., 1894-Accepted, 1st Dec., 1894
COMPLETE SPECIFICATION (AMENDED).
Improvements in Boilers or Steam Generators.
I, CHARLES DELL MOSHER, of 1 Broadway New York City, in the County and
State of New York, United States of America, Gentleman, 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 boilers or steam generators which comprise a steam
drum, one or more water drums located below the steam drum, and plurality of
tubes connecting said drums, the said tubes being exposed to the action of the
products of combustion from the fire, so that steam is generated therein, and is
delivered by the tubes to the steam drum.
The invention has for its object to provide a steam generator of compact and
simple form, adapted to be economically constructed, and having all its parts so
arranged that they can be readily inspected and cleaned and having its tubes so
arranged that they can be readily replaced in case of accident, and will deliver
steam freely to the steam drum. The invention also has for its object to enable
the products of combustion to be applied to the tubes in such manner as that the
heat may be more fully absorbed and utilized than heretofore.
To these, ends, the invention consists in the improvements which I will now
proceed to describe and claim.
Of the accompanying drawings, forming part of this Specification,-
Figure 1 represents a longitudinal section showing the preferred construction,
a generator having my improvements, when used with a brick casing or setting.
Figures 14 and 1 represent details hereinafter referred to.
Figure 2 represents a similar section showing certain additions.
Figure 3 represents a partial section on line 3-3 of Figure 2.
Figure 4 represents a transverse section showing my improvements applied to a
marine boiler or generator.
In the drawings-
a represents the steam drum, which is located at an elevated point. b represents
a water drum located below the steam drum and parallel therewith, the two
drums being connected by a plurality of tubes c. In Figure 1, I show but one
water drum, while in Figure 4 I show two water drums arranged equidistant from
the steam drum, the latter form being preferable for marine use.
A large
number of water drums may be employed for marine use, if desired, each being
connected with the steam drum by a plurality of tubes c.
It is very desirable that the tubes be straight, so that they can be readily
inspected and cleaned. It is also desirable, for the sake of compactness, that the
[Pain 27

page_text: water drums be reduced to as small a cross-sectional area as possible without unduly
reducing the number of tubes that can be connected to the water drums. I have
therefore adopted a form of water drum which will make practically the whole
diameter or width of the drum available for the reception of the tubes, so that the
group of tubes may be of practically the same width as the diameter of the water
drum, and have provided the steam drum with openings in its upper portion, each
opening coinciding with one tube, or as I prefer, with a group of tubes, so that
straight tubes of any desired length can be put in place and secured to the drums,
each tube being introduced to place by passing it through an opening in the upper
portion of the steam drum, and inserting it in the openings prepared for its
reception in the lower portion of the steam drum and in the upper portion of
the water.drum.
.
In making the water drum, I retain the cylindrical form, for the sake of com-
pactness and strength, so far as possible, the lower portion 2 of the drum being
practically a half cylinder, its upper portion 3 being reduced or given a flat or
approximately flat form, so that it constitutes a face or tube shect presenting a
tube-receiving surface of practically the entire width or diameter of the water
drum. The water drum may be made in two sections, as shown in Figure 1, the
tube sheet portion 3 being permanently attached by rivets to the main portion; or
the said tube sheet portion may be formed by reducing or flattening one side of a
seamless lap-welded tube, the water drum being thus given the form shown in
Figure 2.
In making the steam drum, I form a plurality of orifices 5 Fig. 1B, in the upper
portion of the drum, each of sufficient size to receive a tube, and each provided
with a plug 6 or other closing device, whereby it may be closed steam-tight. I
prefer to make each orifice 5 of such size that a group of three or more tubes may
be inserted in place through one orifice this arrangement reducing to the minimum the
weakening of the drum by the formation of the orifices 5 therein. By so arranging
the tube-receiving orifices in the lower portion of the steam drum relatively to the
tube-admitting orifices 5, that each orifice 5 will coincide with the centre of a
group of three or more tube-receiving orifices, three or more tubes can be admitted
singly through an orifice 5 but slightly larger than the diameter of one of the
tubes, the lower orifices in the steam drum being of such size that the tubes fit
them somewhat loosely, so that the tubes can be inclined, as indicated in dotted
lines in Figure 2, while they are being admitted or moved to place.
It will be seen that by the described improvements I secure the following
advantages, namely, 1st, compactness, due to the reduction or flattening of the
upper portions of the water drums, their form enabling much smaller water drums
to be used with a given number of tubes than would be possible if the drums were
entirely cylindrical. 2nd, convenience of application of the straight tubes to the
drums, without regard to their length, and 3rd, convenience of removal of a worn
or defective tube without disturbing the adjacent tubes this being a point of great
importance.
A furnace, or fire-box, is arranged in suitable proximity to the tubes, so that
they will be advantageously heated. I prefer to so arrange the tubes relatively to
the fire-box and the outlet passage conducting the products of combustion to the
stack, that the heated gases coming directly from the fire will first sweep through
the spaces between the upper portions of the tubes, and will then be deflected and
pass between cooler lower portions of the tubes, so that a considerable portion of
the heat which was not absorbed by the water and steam in the upper portions of
the tubes will be absorbed by the cooler water in the lower portions of the tubes,
thus utilizing to a high degree the thermal efficiency of the fuel. In the con-
struction shown in Figure 1, this result is produced by means of a baffle-plate e
extending upwardly from the bridge wall; at the rear of the fire-box f, said
baffle-plate extending across the spaces between the tubes, a downwardly-projecting
wall or partition in the chamber or space above the tubes, and a baffle-plate g
extending downwardly from the partition across the spaces between the tubes.

page_text: Said baffle-plates and partitions cause the gases, etc., to sweep first through the
spaces between the upper portions of the tubes, where the heat of the contents of
the tubes is greatest, and then pass downwardly, and again upwardly between
lower portions of the tubes where the water is at a lower temperature.
In the construction shown in Figure 4, two water drums being employed, the
fire-box is located between the water drums and between the two series of tubes.
The gases, etc., pass upwardly from the fire-box, and laterally between the hotter
upper portions of the tubes, and are then deflected downwardly by baffle-plates kk
which extend from the steam drum downwardly along the outer sides of the groups
of tubes, nearly to the lower ends of the latter, as shown in Figure 4, so that the
beat absorbing surfaces last encountered by the partially cooled gases are the cooler
portions of the tubes.
When the water drum is clevated, so that it is subjected to lateral strains by the
expansion and contraction of the tubes, as in the arrangement shown in Figure 1,.
I prefer to provide for the lateral movement of said water drum to compensate
for such expansion and contraction. This may be effected by means of an expansion
joint between the drum and its support (the latter being here shown in Figure 1
as a brick wall ³) so that the drum may yield to said strains without detriment to
its connection with its support. To this end I show the water drum in Figure 1
provided with rollers m m resting on a flat surface on the support ³, so that the
drum may move laterally, as required by expansion and contraction of the tubes.
In Figure 14 I show the water drum supported by slings composed of vertical
rods attached at their upper ends to fixed supports on the casing, and at their
lower ends to the water drum.
The steam drum is connected with the water drum in Figure 2, by return water
pipes or conduits p, which are preferably constructed to extend downwardly from
the end portion of the steam drum to points below the grate, and then horizontally
to points under the end portions of the water drum to which said return pipes are
connected. This arrangement is particularly convenient when a series of boilers
are grouped together in a battery, the steam drums being placed end to end, so that
there is not room between their ends for the return pipes. The arrangement of
return pipes shown in Figures 2 and 3 enables me to obtain increased heating
surface and protect the sides of the casing by the employment of tubes q rising
from the horizontal portions of the return pipes, and connected at their upper
portions with a horizontal tube or header r extending rearwardly from the steam
drum and communicating therewith. The tubes q are separated by spaces through
which the products of combustion pass. Their upper ends may be bent inwardly
and connected with the header r; but I prefer to provide each tube with a cross g
at its upper end, and connect each cross by a short horizontal tube g with the
header r.
The crosses enable access to be conveniently had to the ends of the
tubes g g for the purpose of expanding or cleaning the same, the branches of
the crosses in line with the branches attached to the said tubes being provided with
removable caps or plugs which, when removed, permit the insertion of expanding
or cleaning tools into the tubes q g'. In a single-boiler of this construction, the
return pipes may enter the ends or heads of the steam and water drums and pass.
directly from one drum to the other, as shown in dotted lines in Figure 1.
The drums are provided with suitable man-holes and hand-holes, and covers
therefor, and the steam drum will have the usual fittings, such as gage glasses,
testing cocks, etc.
When the return pipes extend in an inclined direction from the steam drum to
the water drum, as shown in Figure 1, their construction is made sufficiently
elastic to permit the movements of the water drum caused by expansion and con-
traction of the tubes, by elbows or curved portions at the ends of the main portions
of the return pipes, said elbows being sufficiently flexible to give the water drum
the necessary freedom of movement.
In Figure 2, I show a baffle-plate corresponding to the baffle-plates k in
Figure 4. Each of said baffle-plates (k and k) has a hinged extension A¹ which

page_text: may be raised as shown in dotted lines to promote the draft when first starting the
fire, after which said extension may be lowered as shown in full lines.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that I am aware
of the Specification of Bleehynden's Patent No. 18311 A.D. 1893 and I wish it to
be understood that I do not claim anything described and claimed therein, but what
I claim is:
1. A boiler or steam generator comprising in its construction a cylindrical water
drum, flattened or reduced at its upper portion to form a tube sheet which is flat or
approximately flat, a series of straight tubes extending upwardly from said tube
sheet substantially at right angles with the water drum, and a cylindrical steam
drum to the lower portion of which the upper ends of said tubes are attached, said steam
drum being parallel with the water drum and having in its upper portion a plurality
of holes provided with detachable plugs or covers, each hole being opposite a group
of tubes, so that the tubes can be introduced by passing them through the said
openings and the steam drum.
2. A boiler or steam generator comprising in its construction an elevated steam
drum, a plurality of water drums located below and parallel with the steam drum,
each water drum being connected with the steam drum by a series of straight
tubes, a furnace or fire-box between the water drums and between the series of
tubes, and a baffle-plate extending downwardly from the steam drum at the outer
side of each series of tubes, whereby the products of combustion after rising and
passing between the inner tubes are diverted downwardly and caused to pass
between the cooler or outer tubes, said cooler tubes absorbing heat from the products
of combustion just before said products escape to the stack, as set forth.
3. A boiler or steam generator comprising in its construction a water drum, a
steam drum located higher than the water drum, a plurality of tubes connecting
said drums, a furnace or fire-box at one side of the series of tubes, an outlet for
the products of combustion at the opposite side of said series, a baffle-plate
extending downwardly from the steam drum at the opposite side of the series of
tubes from the fire-box whereby the products of combustion are caused to first pass
upwardly along and between the inner tubes of the series and are then guided
downwardly along and between the outer tubes of the series, and extensions hinged
to said baffle-plates and adapted to be raised and lowered, as set forth.
4. A boiler or steam generator comprising a steam drum, a water drum located
at a lower point than the steam drum, a series of straight tubes connecting said
drums and exposed to the heat from the fire-box, return pipes connecting the end
portions of said drums, a part of each return pipe being substantially horizontal, and
vertical tubes extending upwardly from the horizontal portions of the return pipes,
and connected at their upper ends with a horizontal header communicating with
the steam drum.
: Dated this 9th day of August. 1894.
CHARLES DELL MOSHER.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
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