IMPROVEMENTS IN STEAM GENERATORS
Year: 1881

page_text: LETTERS PATENT to William Lloyd Wise, of 7, Whitehall Place, in the City
of Westminster, for an Invention of "IMPROVEMENTS IN STEAM GENERATORS."
A communication from abroad by George Hermann Babcock, of Plainfield,
County of Union, State of New Jersey, Stephen Wilcox and Nathaniel
Waterman Pratt, the latter two both of Brooklyn, County of Kings, State of
New York, and Edwin Howard Bennett, of Bayonne, County of Hudson and
State of New Jersey, all four Citizens of the United States of America.
PROVISIONAL SPECIFICATION left by the said William Lloyd Wise at the
Office of the Commissioners of Patents on the 3rd December 1881.
WILLIAM LLOYD WISE, of 7, Whitehall Place, in the City of Westminster.
"IMPROVEMENTS IN STEAM GENERATORS." A communication from abroad by
George Hermann Babcock, of Plainfield, County of Union, State of New Jersey,
Stephen Wilcox and Nathaniel Waterman Pratt, the latter two doth of Brooklyn,.
County of Kings, State of New York, and Edwin Howard Bennett, of Bayonne,
County of Hudson and State of New Jersey, all four Citizens of the United States
of America.
The improvements pertain to that class of steam generators in which a number
of inclined tubes extend through the furnace with an active circulation of water
and steam through them, the water descending at the back connections established
between the barrel or separating drum or chamber and said inclined tubes, and
rising, mingled with steam, through the front connections into the barrel.
The barrel or separating drum of the generator is tapered at the back end, but
instead of tapering concentrically the lower side is straight quite to the end, the
taper being all on the top and sides. It is in brief a truncated cone set obliquely
relatively to the cylindrical portion, so that its lower side is in line with the
cylindrical part. The casing of iron or other material in which the generator is
enclosed extends straight or without taper. The spaces provided by the tapering
forms of the separating drum at the rear serve as uptakes for the flow of the hot.
gases from the furnace to the chimney.

page_text: "
When a number of the generators are placed side by side and used together, as
is the case when liberal quantities of steam are required on ship-board, in manu-
factories, and elsewhere, the casing is extended across over the rear of several of the
generators, rising at an inclination to collect the gases from several generators into
one stack or chimney.
A dome is provided on the top of each barrel or separating chamber and braced
or stayed strongly across the bottom to compensate for the weakening due to the
breaking of the continuity of the barrel by the aperture thus formed. The dome
is placed as far as practicable away from the agitation which occurs at the front
where the steam is delivered from the tubes.
In the class of generators to which the improvements refer the set of inclined
tubes are usually connected together and to the barrel at the front and rear ends
by means of hollow castings in such manner that one casting connects the tubes
placed vertically or nearly vertically above each other, so that a series of castings
inust be used to accommodate a liberal quantity of said inclined tubes.
According to this Invention there are substituted therefor thin chambers of
boiler iron properly stayed, as will be hereafter described, and in which the inclined
tubes are set, that is to say, instead of using a separate connecting chamber for
cach vertical row of tubes as heretofore, I use only one chamber in front and one
in the rear, which is of sufficient width and height to receive all the tubes.
These connecting chambers are preferably extended up to a certain distance
beyond the lower side of the separating chambor, and connected thereto by means
of short thimbles or lengths of tube expanded in holes cut for the purpose in the
ends of the separating chamber and the connecting chambers.
Side chambers or water legs are provided, extending from about mid-height of
the separating chamber down to the level of the grate, or lower if desired, formed
from sheets of boiler iron properly stayed at little distances apart, and so connected
with the other water spaces of the generator that there is a liberal circulation of
water and steam in thein, the water descending in the connections and circulating
through the sides.
The gaseous products of combustion rising from the grate are directed by means of
fire-bridges so as to pass several times transversely through the spaces between the
several inclined tubes. In order to obtain more heating surface only those parts of said
bridges which extend across the set of inclined tubes are of fire-brick, the remainder
of each being an iron water chamber extending across the furnace and connected
by means of short thimbles to the above-mentioned lateral water chambers. Those
of the transverse water-spaces which are arranged between the inclined tubes and
the separating drum may also be connected in a corresponding manner to the
separating drum itself, whereby a more perfect circulation of the water therein.
contained is insured.
In steam generators of this class there exists liability of solid matters settling
in the spaces between the series of inclined tubes, and accumulating therein in
sufficient quantities to obstruct the passage of the gases of combustion, and thus
destroy the advantages of the liberal heating surfaces provided by the use of anid
tubes. This difficulty is overcome by arranging a series of blow-pipes at one or
both sides in the interior of the furnace provided with cocks and a liberal number
of nozzles, through which steam may be discharged into the interstices between
the inclined tubes to blow out any soot or ashes that may have accumulated on
the latter.
The construction of the front and rear connecting chambers of boiler iron renders
necessary a peculiar arrangement for giving sufficient strength to resist the high
pressure in the interior of the chambers. This object may be attained by means
of ordinary stay-bolts, but according to this Invention peculiar means are employed
of staying or bracing them, which is also rendered available for a convenient
insertion and setting of the inclined tubes. In the completest form I use a tubular
casting of malleable iron which extends across the chamber, but is formed with
liberal openings, so as to allow free circulation of the water through the same.

page_text: This casting is expanded on both sides of the connecting chamber, and forms itself
a flange or rim against which one of the inclined tubes may be expanded. The
front part of the casting is faced so as to form a smooth seat for a cover, the entire
arrangement forming a band-hole and stay-bolt combined.
In certain cases it is proposed to use this form of hand-hole, but it is preferred
to expand the inclined tubes directly in holes formed in one wall of the connecting
chamber, and to use a ring of malleable cast-iron or other suitable material, which
is expanded in the hole in the other wall of the connecting chamber, forming in
similar manner a seat for the hand-hole cover.
Again, it is practicable to entirely suppress the ring of malleable iron and apply
the hand-hole cover directly against the front wall of the connecting chamber, but
in such case the hole is chamfered off and a corresponding face is provided on the
hand-hole cover, this arrangement affording greater facilities for securing a
tight fit.
It will be understood that in the two last described cases ordinary stay-bolts are
employed to brace the connecting chambers.
It is obvious that the hand-hole covers may be secured in place by any of the
ordinary means, such as a cross-bar inside drawn against the cover by means of a
bolt and nut.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Lloyd Wise in the Great Seal Patent Office on the 19th May
1882.
WILLIAM LLOYD WISE, of 7, Whitehall Place, in the City of Westminster.
"IMPROVEMENTS IN STEAM GENERATORS." A communication from abroad by
George Hermann Babcock, of Plainfield, County of Union, State of New Jersey,
Stephen Wilcox and Nathaniel Waterman Pratt, the latter two both of Brooklyn,
County of Kings, State of New York, and Edwin Howard Bennett, of Bayonne,
County of Hudson and State of New Jersey, all four Citizens of the United States
of America.
This Invention refers more particularly to that class of steam generators in which
a number of inclined tubes extend through the furnace with an active circulation
of water and steam through them, the water descending into anid tubes from a
separating barrel or drum situated above through suitable connections in the rear,
and rising, mingled with steam, in front through similar or suitable connections
from the tubes into the drums.
The gases of combustion in such generators are caused to pass repeatedly through
the spaces between said inclined tubes in a direction transverse to that of the
tubes, and are finally taken off at the rear end of the furnace, from whence they
escape into the chimney.
According to this Invention the separating drum is made tapered at the back
end, but so that its lower side is quite straight out to the end, the taper being all
on the top and sides; the casing enclosing the generator extends straight to the
end. Spaces are thus provided at the rear, which serve as up-takes for the flow of
the gases of combustion into the chimney.
The front and back connections from the separating drum to the tubes are
formed of boiler iron instead of castings, as have been usually employed, and they
are so constructed that each practically forms one chamber, and may thus serve as
part of the casing of the generator, which casing is completed by sectional side
chambers or water-legs, also formed of boiler-iron and suitably connected with
other parts of the generator, so as to induce also therein a liberal circulation of
water and steam.
In order to insure the passage of the gases of combustion transversely between
the tubes as desired, fire-bridges are employed rising from the bottom or descending
from above, or both. These fire-bridges are also formed of water chambers, either
entirely or only partly, and suitable provisions are made to maintain also therein
an active circulation of water by means of suitable connections with other parts.
In order to clear the inclined pipes from the soot and ashes which accumulate
thereon, by reason of the passage of the gases of combustion between them, a series
of fixed pipos are arranged, provided with nozzles, and communicating by a
connection controlled by suitably arranged cocks with the steam space of the
generator, so that strong jets of steam may be blown through the spaces between
the inclined pipes, whereby all accumulated matter will be effectually removed.
The method of setting the ends of the inclined pipes in the front and rear
connections by expanding, renders necessary a considerable number of hand-holes
in the latter. These hand-holes, in order to insure a tight joint between their
covers and the connections, are lined with rings of malleable cast-iron or other
suitable material which are expanded therein, and then the cover is applied on the
smoothly faced edge of each ring. This part of the Invention is carried out in its
most perfect form by extending the ring through and entirely across the connecting

page_text: water being largely mingled with steam at the front and middlo portions, but
nearly free from steam at the small end.
The dense water flows out through the thimbles at the small end into the back
connection B, in which it descends, and is distributed into the lower and hotter
portions of the boiler, which expose a great heating surface and make .steam
rapidly. C, C, are the inclined pipes which communicate between the back
connection B and the front connection D. The front connection communicates
with the front end of the barrel A through thimbles, as shown.
E, E, are extended plain sheets of boiler iron liberally stayed so as to withstand
a high pressure, and arranged to form sides which will be termed "water-logs."
They are connected to the side of the back connection by thimbles e at the baso.
These deliver a constant supply from the back connection into the base of the rear
part of the water-leg E. It will be observed that the water-leg is not in one
continuous sheet from the front to the back, but that there is a dividing line down
the middle. Each water-leg is made in two separate parts for greater facility of
transportation and repairs. The lower part of the rear section of each water-leg is
connected to the front part by one or more thimbles e, near the base, as repro-
sented in Fig. 3, through which the dense water is transmitted into the front
section, and all contribute to the efficient heating surface. The steam generated in
the water-legs escapes into the barrel A through the thimbles e¹. There are
man-holes through the back connection and through the water-legs, which allow
access when required. They are provided with suitable covers, as shown, when
the boiler is at work.
"
There are thimbles e (see Fig. 3) which connect the front portion of the water-
legs with the front connection D. A pipe e³ extends across under the furnace door
and serves as a means for the free circulation of water from one water-leg to
another, as also for a braco between the parts.
G is a water-bridge formed of boiler iron strongly stayed and extending up from
the bottom of the structure. The lowermost tubes are in two lengths connecting
respectively to the front and back sides of this water bridge. The water can
circulate through them in the ordinary way from the extreme rear of the roar
length through the water-bridge to the extreme front of the front length. There
is also a sufficient interval or spaco within the water-bridge between the two ends,
so that the steam generated in tho water-bridge may also join that current and
flow out through the forward length of the two. The water-bridge is connected at
each side to the respective water-legs by thimbles e. Dense water is received
through these into the water-bridge and thus active circulation is secured through
this important part of the apparatus.
His a hanging-bridge, also formed of strong boiler iron, riveted, and kept filled
with water. It constitutes additional heating surface. It is connected with the
water-legs E by thimbles e², and with the lower portion of the barrel A by
thimbles eº.
G' is an extension upward from the bridge G, formed of metal defended with
fire brick. H' is an extension downward from the hanging bridge H, similarly
made. The effect of the bridge G and its extension G₁ is to compel the gases from
the furnace to circulate upward across the entire mass of tubes C. The effect of
the hanging-bridge H with its extension H¹ is to compel the hot gases to again
circulate downward across all or nearly all the tubes. The hot gases rise there
again across the tubes C, and flow upward past the tapered rear ends A¹ of the
barrels into a gas passage or breechen I.
It will be understood that the tapered portion A' at the rear end of the barrel
affords liberal spaces, which would appear triangular in a plan view, through which
the gases can flow upward from the rear ends of the furnace or combustion chamber
below. The breechen I may be formed of sheet-metal covered with fire-bricks or
other good non-conductor. The height of the smoke-passage or breechen I
increases from left to right in the Drawing. If the other four barrels A, A³, of
this set were shown, they would appear to the right of thoso here represented. The

page_text: breechen over that portion would increase in heat from the right to the left. I' is
the stack in which the gases are allowed to flow upward to the required height
and escape into the atmosphere.
J, J, are what may be termed blow-pipes. They connect at the upper end with
the steam domes A, and are provided with cocks J', by which their action can be
controlled. They extend downward within the furnace to or near the level of the
lower series of pipes C, and are provided with nozzles J, through which a strong
blast of steam is directed across the spaces between the tubes when the cocks Ji
are open. By opening these cocks Ji at proper intervals, the soot and ashes are
blown off from the tubes C, and the exterior of these tubes is kept clean and ready
to absorb heat efficiently.
The joining of the dome A³ to the barrel involves a considerable weakening.of
the latter if all that portion of the barrel covered by the dome is cut away. It is
preferred to cut away all that and to strongly tie or brace across the junction of.
the dome to the barrel by cross-braces A³.
Referring to the hand-holes in the front and back connections, the peculiarities
are repeated at each end of each tube. A description of the parts adjacent to the
front end of one of the tubes C will suffice for all. The front connection D is
bounded by two plates of stout boiler-iron; D' is the outermost, and D' the
innermost, the distance apart being about two and one half (2) inches.
Referring to Figs. 4, 5, 6, and 7, holes are bored or otherwise produced in the
Sheets D', D', considerably larger than the tubes C. A inalleable iron casting is
introduced, the outer portion of which is marked M. The other parts will be
designated by additional marks, as M1, M2, when necessary. Its face is smoothly
finished and makes a steam tight joint with the corresponding face of a stout cover
N. The facility with which such face can be made on the cast-iron as compared
with the production of suon the thin plates D' yields a great economy in the
construction. A flange extends out a little and bears on the outer face of the
plate D'.
O is a stout cross-bar which by the aid of a bolt P and cap-nut P' holds the
cover N tightly in contact with the casting M. A tight and strong junction of the
latter with the outer plate D' is induced by filling in the casting M with a tight
fit, and then expanding it by an expanding tool.
M', M, are arms which reach across from the main part M of the casting just
described and unite it to a ring M which fits tightly and is expanded within the
plate D. These parts 31' are thin and curved, being in fact portions of a hollow
cylindrical extension of the casting M; but it is important that the hollow
cylinder be not complete and tight. The liberal openings at the top and bottom
provide not only for the engagement of the cross-bar O, but also for the very
important and essential function of allowing the steam and water which pours out
of the tube C to rise up through the connection D and flow to the barrel A. The
tubo C is joined tightly and strongly to the back ring M12, by expanding as
shown.
In the modifications shown in Figs. 8 and 9, the hole in the inner plate D³ is
smaller, only sufficient to receive the tube C. The latter is expanded directly into
a tight and strong engagement with the plate D².
The hole in the front plate D¹ is about the same size as before described. The
casting M is of nearly the same forin and performs substantially the same functions
as in the form first described. But the rim or flange outside is omitted. The
cross-bar O bears in the inner or back edge of the casting M, which is extended
inward a little beyond the inner face of the plate D¹. The casting M is engaged
with the plate D₁ by expanding as before. The forms and functions of the cross-bar
O, bolt P, cover N, and nut P, may be exactly as in the modification first described.
In this modification, and in those which succeed, the plates D', D, are held a
proper distance apart and maintained stoutly in position by stays Qwhich may be
made in the ordinary manner, thimbles with square ends being cut to the proper
length and being applied between the plates to serve as struts and resist a

page_text: compressive force, while long rivets extend through them and through holes in the
plates, and are headed at each end to serve as ties.
In the modification shown in Figs. 10 and 11, no casting is applied within
either plate D' or D. The holes in each are made small. The cover N is made
with a conical face and is made to match a finished conical surface prepared around
the hole. The cross-bar O is greatly widened. It bears directly on the inner faco
of the plate D¹.
In the modification shown in Figs. 12 and 13, a casting M is introduced and
expanded within a suitable hole in the plate D¹. The hole is flared inward and
the casting is correspondingly expanded. In other respects this modification may
be as in Figs. 8 and 9.
In the modification shown in Figs. 14 and 15, the casting M is extended
outward considerably. It is engaged with the outer plate D¹ by expanding, and
receives the cover N on a finished face, as in most of the other examples; but the
cover N is confined by different means. A peculiarly formed screw X is engaged
with the cover after being tapped through a peculiarly formed holding-strap t,
which applics in the exterior and engages under a flange M³, which is formed on
the casting sufficiently in front of the plate D' to allow strong internal hooks on
the strap to engage therewith.
In the modification shown in Figs. 16 and 17, no casting is employed around
the hole in either plate. This is like the modification shown in Figs. 10 and 11,
except that neither the cover N nor the seat therefor is beveled. A groove is
turned or otherwise produced concentric to the hole and coincident with the outer
edge of the cover N. The surface of the metal between this groove and the hole
is slightly raised and truly finished. The cover N being properly faced, fits steam-
tight thereto.
In all the forms the plates D1, D2, may be of boiler-iron or steel, extending in
one continuous sheet from the top to the bottom of the respective front connection D
or back connection B.
Modifications may be made in many of the details. Parts of the Invention may
be used without the wholo.
It will be observed that there is one water-leg E between each pair of separato
drums or barrels A and the next adjacent pair.
Instead of this nesting together two barrels, supplying each pair with a single
grate and taking steam from the pair as from one barrel, three or any other
required number may be similarly nested together; or the boilers may be worked,
if desired, without nesting, providing a separate furnace for each barrel and its
adjuncts, and taking steam from each separately. The sheets D', D³, may be in two
or more pieces, riveted, braced, or welded.
The construction of the hand-holes in all the forms shown allows the strength
and lightness due to the continuity of the parts and affords unusually liberal space
for the free circulation of the water and steam in the connections B, D, whero they
are applied.
In the form of the parts shown in Figs. 4 to 7, the staying of the parts M¹
between the front ring M and the rear ring M³ produces a very rigid union and
gives great strength without much obstructing the water way. Additional stays
may be employed with this form if preferred in any case.
Having thus described the said Invention, I claim as new,-
First. In a steam boiler, the barrel described having a cylindrical horizontal
portion A and a tapered end A¹, arranged as shown, in combination with a furnace
at a lower level, and with pipes C and connections B, D, or their equivalents,
substantially as herein specified.
Second. In a steam boiler, the barrel A, A¹, dome A³, and stays A³, combined as
and for the purpose herein specified.
Third. In a steam boiler, the sectional water-legs E in combination with the
barrel A, A¹, and connections for insuring an efficient circulation of water, as herein
specified.

page_text: Fourth. In a steam boiler, the water bridge G and suitable connections for
supplying dense water thereto, in combination with inclined pipes C communicating
therewith, and with connections B, D, to a suitable barrel A, A¹, as herein
specified.
Fifth. In a steam boiler, the hanging bridge H and thimbles e³, e, in combination
with the barrel A, A', tubes C, and connections B, D, as herein specified.
Sixth. In a steam boiler having tubes C extending through the furnace, the
blow-pipes J having nozzles J2 and a controlling cock J arranged to direct
strong blasts of steam through the spaces between the pipes C when required, as
herein specified.
Seventh. In a steam boiler having tubes C extending through the furnace, with
front and back connections therefor, the construction of such connection in two
sheets D', D, strongly stayed across, substantially as herein specified.
Eighth. In a steam boiler having tabes C and connections therefor made in
separate sheets D', D³, the malleable cast-ring M expanded in and adapted to form
an easily finished face for steam-tight contact with the cover N, as herein
specified.
Ninth. In combination with the plates D', D³, and tubes C, the malleable
casting M, M, M³, expanded into both the sheets and strongly bracing across
the space, adapted to serve substantially as and for the purposes herein specified.
In witness whereof, I, the said William Lloyd Wise, have hereunto set my
hand and seal, this Nineteenth day of May, in the year of our Lord
1882.
W. LLOYD WISE. (L.S.)