Improvements in Steam-generators.
Year: 1888

page_text: Date of Application, 1st Feb., 1888
Specification Accepted, 16th Mar., 1888
COMPLETE SPECIFICATION.
Improvements in Steam-generators.
I, THOMAS FRANCIS MORRIN, of 48 Brinkerhoff Street, in Jersey City, in the
County of Hudson, in the State of New Jersey, one of the United States of America,
Mechanical 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 :-
This invention relates to that class of steam-generators wherein the steam is
generated in tubes which project from the generator-chamber into the combustion-
chamber over the fire-grate, and in which the flames and heated gases pass upward.
among the said tubes to the outlet or chimney.
One part of the invention relates to the construction of the compound generating
tubes; another part relates to the construction of the generator-chamber and its con-
nection with the said tubes; another part relates to the extension of the compound
tubes across the fire-box from the generator-chamber to the opposite side, whereby the
said tubes may be conveniently inspected and cleaned; another part relates to the
auxiliary water-heating apparatus at the sides of the combustion-chamber; another
part relates to the drier for the steam; another part relates to the peculiar form of
stays employed in the lower part of the generator-chamber, and lastly, another part
relates to the construction of the headers for the generating tubes.
In the annexed drawings which serve to illustrate the invention-
Figure 1 is a longitudinal section of the improved steam-generator, the plane of the
section being taken substantially along the line 2, 2, in Figure 2.
Figure 2 is partly a transverse section taken substantially along the line 1, 1, in
Figure 1, and partly a front elevation.
Figure 3 is a horizontal section taken along the line 3, 3, in Figs. 1 and 2.
Figure 4 is a sectional view of the rear end of the generator, similar to that at

page_text: the right in Figure 1, illustrating a modified construction of the generator-chamber
and the drier.
Figures 5 and 6 are views illustrating a header for the tubes; Figure 6 being
substantially a section along the line 6, 6, in Figure 5.
Figure 7 illustrates the application of my invention to a steam-generator adapted
for marine purposes.
Referring first to Figures 1, 2 and 3, A represents the front-plate of the generator,
and A¹ A the side-plates thereof. These plates, together with the generator-
chamber, B, form a shell which encloses the rectangular combustion-chamber, fire-box
and ash-box. This shell is surmounted by a chimney C. D is the furnace-door, E the
ash-box, F the ash-box door, G the fire-grate; and H the refractory lining of the fire-box
front.
The generator-chamber, B, at the back of the fire-box and combustion-chamber, is
made-of boiler-plate. The top plate, a, is preferably arched to cover the steam-dome K,
and the bottom-plate, b, may also be arched, if necessary for strength. This chamber B
is divided, up to about the water-line a, a, by a partition c, forming two chambers B¹
and B2 the former of which may be called, for distinction, the water-chamber,"
and the latter the "steam-chamber," although both contain water. The chamber B¹
has a feed-water inlet d, and both chambers may be provided with suitable blow-off
pipes and hand-holes for cleaning.
(
1 I are the generating-tubes, which extend entirely through the combustion
chamber and generator-chamber, the front ends being supported in the front-plate A,
and the rear ends in the front and back plates of the chamber B, and in the parti-
tion c.
The tubes I have suitable caps or headers, e, e, on their ends, whereby they
may be inspected internally. At the front, the projecting ends of the tubes are
protected by a housing, provided with doors g. Where the tubes I cross the
chambers B and B they are provided with apertures or slots h and ', and in each
tube I is arranged a smaller tube i, on which is secured a short sleevej, which fits
snugly in the outer tube I between the slots and therein, at the partition c. The
tube i does not extend forward quite to the front-plate A, nor behind the slot h¹. It is
preferably supported at its front end on a stud or "chaplet" so as to keep it concentric
with the tube 1, but this is not essential.
"
The water should always cover the tubes I, so that they will stand full. The heated
gases and flames heat the water in the tubes I, exterior to the inner tubes i, and thus
induce circulation therein. The water enters the tube I at the slots from the "water-
chamber B, flows forward through the tubes i, and thence back through the tubes I,
exterior to the tubes i, and escapes into the "steam-chamber" B2 through the slots h.
In its backward flow, much of the water is converted into steam, which rises through
the water in the chamber B2 into the chamber B above the water-line. At this point,
the rising steam, charged with water, strikes a deflector, k, which precipitates the main
portion of the water in suspension, and the steam passes upward around the deflector k
to the drier, which will now be described.
JJ are the main tubes of the drier, and these are mounted in the generator in a
manner very similar to the generating tubes I. Three tiers of these tubes are shown,
but any number that may be necessary can be employed. Where they cross the
chamber B the tiers of tubes are separated from each other and from the dome K,.
by horizontal partitions, . The steam must pass through one tier before it enters the
next above. It enters a slot or aperture in the tube J, flows through it to the
front, then enters an inner tube, , and flows back through it to a chambered plug, w,
in the pipe J; thence, by a lateral outlet, ¹ in the plug and a tube n¹, it flows into
the chamber next above, whence it flows through the next tier of drying tubes.
Finally, it enters the steam-dome K in a dry condition, and may be led thence to the
engine or to the point where it is to be used. If it is to be superheated, it is led
from the dome K by a pipe L, to a coil L, arranged in the combustion-chamber, as
shown, and thence to the point where required for use by a pipe L².
In that portion of the chamber B, below the generating tubes and above the fire-

page_text: grate, tubular stays, 2, are provided. These are expanded in the front and back walls
of the chamber, and are provided with plugs, a, at their outer ends, which may each
have a groove along its side to allow a little air to enter the furnace if desired.
The generating tubes I are herein shown as standing in a horizontal plane and the
chamber B as standing upright or vertical. However, the tubes I may stand inclined
if desired, in order to improve the circulation therein. For example, the chamber B
may be inclined or tilted a little forward in constructing the generator, or in setting
it up, and this will cause the front ends of the generating tubes to stand a little lower
than the rear ends. Or, the tubes may be inclined without inclining or tilting the
chamber B. The inner tubes i may be arranged in the axes of the tubes I, as shown;
or, they may be severally arranged in the upper parts of the respective tubes I.
the object is to effect a circulation in the tubes, and as the upper parts of the tubes I
will not be exposed to such intense heat as their lower parts, it may be advisable to
arrange each inner tube, passage, or conduit at the upper part of its surrounding
tube . In some cases this conduit i may be constructed by arranging a partition in
each tube I, dividing its upper from its lower part.
As
In order to more fully utilize the heat of the furnace, especially at the sides,
headers M, connected with the chamber B, are arranged in the furnace at its opposite
sides, usually below the fire-grate, and similar headers, M', over these, are arranged
at the water-line a. These headers are connected by upright tubes, N, and the said
headers and tubes form, substantially, a part of the generator; the lower headers and
the upright tubes standing full of water up to the water-line. The tubes N, standing
quite close together, form refractory side-walls for the furnace.
In the modification shown in Figure 4, the partition in the chamber B is shown
as extending up to the crown-sheet, o, and the deflector as extending towards an
aperture in the said partition. The partitions e, are omitted from this view, and the
steam is not compelled to pass through each tier of drying tubes J in succession. All
the tubes n enter the dome K through the crown-sheet o.
In lieu of the tubular stays the stays have heads or projections »³, which
extend into the fire-box and, being highly heated, transmit the heat to the stays and
their sleeves, and thus heat the water in the chamber B. In this view the partition c
is shown dividing the chamber B unequally, and the plate is shown convex instead
of flat.
In Figures 1, 2 and 3, the tubes I and J are shown provided with independent or
separate caps or headers, e; and these serve very well where the tubes are thick
enough to receive a screw-thread. But the header illustrated in Figures 5 and 6 is
preferable where thin tubes are employed. In these figures, I represents the generator-
tube, and the inner tube before described. P is the header, which is of the character
of a shallow, triangular box, with three apertures to receive as many tubes I. When
the tubes are in place, they are expanded in the header. The recess in the box is
divided by partitions s, so as to separate the tubes and cut off communication between
them, and at the center, a screw is provided which passes through an aperture in
the header-cap P¹. The cap is held tightly to its seat by a nut u. The header Pinay
of course be constructed to embrace two, four or more tubes; three however, will
usually be preferred.
As the tubes I are likely to become or may become coated with soot, and thus
have their heat-conducting capacity diminished, apertures, a', may be provided in the
plate A, for the admission of a steam-jet nozzle whereby the soot may be blown off
and the tubes cleaned. In some cases also, the side-plates, Al, may be of double
thickness, with an air-space between, to intercept the radiation of heat. Or, such air-
Means may also
space may be packed with asbestos, mineral wool, or like material.
be provided for discharging water of condensation from the steam-dome K.
Instead of placing the charging-door opposite the chamber B, it may in some
instances be arranged under the said chamber, in which case the chamber B will only
extend down to such door. This method of construction, which will prove
advantageous in steam-generators for marine purposes, is represented in Figure 7.

page_text: This view also shows another form of drier and superheater for the steam. The drier
comprises tubes J'; these are bent into a U-shape, and take steam from the generator
and deliver it into the dome K. From this dome the steam flows by the pipe L to a
superheating drum L', and thence to the engine by a pipe L².
a
In Figure 7, the inner tube, i, of the upper generating tube is shown as forked
and spread at its free end, i, in order to keep it concentric with the pipe I. The
cross-sections of tubes, numbered 1, 2, 3 and 4, and shewn at the right of Figure 7,
indicate different modes of constructing of the generating tubes I. No. 1 shows
tube in the axis of the tube I; No. 2 shows a half-round tube i arranged in the
upper part of tube I; No. 3 shows a tube like that in No. 1, arranged in the upper
part of the tube 1, and No. 4 represents a partition arranged horizontally in the tube I
to separate its upper from its lower part. The lower generating tube in Figure 7
shows this partition.
In Figure 7, the generator is shown as tilted backward, so as to incline the
generating tubes. This inclination of the tubes may, however, be effected without
tilting the whole structure.
The generating tubes need not be absolutely straight, nor absolutely parallel; but it
is more economical to construct, and arrange them in that manner.
The charging-door of the furnace may be at the side instead of at the front of the
furnace, in which case that side might be considered the front.
Having now particularly described and ascertained the nature of this inven-
tion, and in what manner the same is to be performed, I claim :-
:-
1st In a steam-generator, the generator-chamber constructed with substantially
plane front and back plates and with a partition c, extending up to the water-line,
with communication above between the two parts of the said chamber, and the com-
pound generating-tubes mounted in the said chamber and extending across the
combustion-chamber over the fire-grate, substantially as set forth.
--
2ndly In a steam-generator, the combination with the front and side-plates of the
combustion-chamber, of the generator-chamber, B, forming one wall of the said
chamber, and the compound generating-tubes, mounted at one end in the said
chamber Band at the other end in the opposite plate of the combustion-chamber, the
said tubes having suitable apertures within the generator-chamber for the ingress and
egress of water, substantially as set forth.
3rdly In a steam generator, the combination with the generator-chamber B of
substantially the form shown and provided with a partition c, of the generating-tubes
mounted therein and each comprising an exterior tube, I, with openings and h',
arranged on opposite sides of the partition c, and the inner tube or conduit i, arranged
in the tube I, substantially as set forth.
4thly In a steam-generator, the arrangement in the combustion-chamber of the
headers M. and M', communicating with the generator-chamber B, as shown, and
connected by the numerous upright tubes, N, the said headers and tubes being set in
close proximity to the respective walls of the combustion-chamber, as shown and
described.
5thly In a steam-generator, the generator-chamber B, divided below the water-
line into two chambers B1 and B2 by a partition, and having a deflector or baffle k
arranged over the chamber B, in combination with the generating tubes mounted in
the said chamber, substantially as represented in Figure 1 of the accompanying
drawings.
6thly In a steam-generator, the combination, with the generator-chamber and
the generating-tubes mounted therein, of the compound drying tubes for the steam,
mounted in the said chamber above the said generating tubes, each of the said drying
tubes comprising an exterior tube, as J, and an inner-tube,.as. n,.all arranged substan-
tially as described and shown.
7thly In a steam-generator, the generator-chamber, as B, provided with a partition
and with tubular-stays, as 2, extending across the said chamber and opening into the

page_text: fire-box at one end, and the said stays provided with apertured plugs or stoppers, ³,
substantially as set forth.
8thly In a steam-generator, the combination with the generating-chamber having
partitions e, e, in it below the steam-dome K which form chambers, of the several
tiers of drying tubes, mounted in the said generator-chamber as shown, whereby the
steam will be compelled to pass through the several tiers of tubes successively, as set
forth.
9thly In a steam-generator, the header, as P, for the generating tubes, constructed
in the form of a shallow partitioned box with an aperture in each cell for the recep-
tion of a tube as set forth and whereby communication between the tubes is prevented
when the cap of the header is applied.