Improvements in Making Corrugated Shells for Steam-boiler Furnaces and other Applications and in Apparatus therefor
Year: 1888

page_text: Improvements in Making Corrugated Shells for Steam-boiler
Furnaces and other Applications and in Apparatus therefor
We, WILLIAM HARGREAVES, and WILLIAM INGLIS, of Soho Iron Works, Bolton, in
the County of Lancaster, Engineers, do hereby declare the nature of this Invention to
be as follows, that is to say
This Invention has for its object the making of corrugated shells for steam-boiler
furnaces and other applications, in an improved manner
The
In carrying out the Invention a plain cylindrical shell is first formed in any suitable
known way, and the corrugations are subsequently formed in it by an improved appli-
cation of fluid pressure in combination with the use of a corrugated mandril
cylindrical shell is placed in a massive cylinder in which its ends are made to fit
tightly by means of packing or otherwise, and the interior of the cylinder is enlarged
between the ends to form a space round the shell for the fluid which is to press upon
the shell, and which is led into the space by a pipe from pumps or other apparatus
The mandril is placed within the shell with the ridges of its corrugations touching or
nearly touching the inside of the shell, and when the fluid pressure is applied it bear
inwards the parts of the shell between the ridges and makes the shell take the corru-
gated form of the mandril The mandril is made in separate pieces and so that it can
be made to collapse in order to get it out of the corrugated shell
The cylinder in which the fluid pressure is applied may be provided with a telescopic
inner cylinder which may be entered more or less to limit the space in which the
pressure is to act, to suit longer or shorter furnace shells, or greater or less extents of
corrugation Packing is applied between the outer and innei cylinder ind between
the inner cylinder and the furnace shell
The furnace shell may be in a heated state when being operated on, and the operating
If the furnace shell is
fluid may be compressed air or any suitable gas or vapor

page_text: made of mild steel or other suitable metal it may be corrugated when cold, water or
other suitable liquid being used as the fluid by means of which the pressure is applied
It found necessary the furnace shell may, especially if corrugated cold, be
afterwards heated to anneal it, and it may be finished in any suitable rolling
apparatus
Amongst the various applications which may be made of shells corrugated in the
manner hereinbefore described may be mentioned that of rims for multiple-rope
pulleys

page_text: Improvements in Making Corrugated Shells for
Steam-boiler
Furnaces and other Applications and in Appartus therefor
We, WILLIAM HARGREAVES, and WILLIAM INGLIS, of Soho Iron Works, Bolton, in
the County of Lancaster, Engineers, 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, that is to say
-
This Invention has for its object the making of corrugated shells for steam-boiler
furnaces, and other applications in an improved manner
In carrying out the Invention plain cylindrical shell is first formed in any suitable
known way, and the corrugations are subsequently formed in it by an improved
application of fluid pressure, in combination with the use of a corrugated mandril, or
of an internally corrugated cylinder
And in order that the sud Invention and the manner of performing the same may
be properly understood we hereunto append two shoets of explanatory drawings to be
hereinafter referred to and representing apparatus which we use
and
Figures, 1, 2, and 3, on sheet, 1, of the drawings are vertical sections of different
modifications, and figure, 4, is a horizontal or cross section corresponding to figure 3
Figures, 5, and 6, on sheet, 2, are vertical sections of further modifications,
figures, 7, and 8, are end and side elevations of accessory apparatus In these drawings
the same reference letters are used to mark the same or like parts wherever they are
repeated
In the modification shown in figure, 1, the cylindrical shell, A, to be corrugated, is
placed in a massive cylinder, B, in which its ends are made to fit tightly, and the
interior of the cylinder, B, is slightly enlarged between the ends to form a space, C,
round the shell, A, and extending over the part thereof to be corrugated The fluid
which is to press on the shell, A, is led into the space, C, by a pipe, D, and passage
through the cylinder, B, from pumps or other apparatus In the modification now being
described a mandril, E, which is placed within the shell, A, has formed on its exterior,
corrugations, F, extending as far as corresponds to the portion of the shell, A, to be
corrugated This mandril, E, is made in or built up of separate pieces, one, G, of
which is of a taper form to act as a wedge, but with its sides shaped to admit of its
being displaced in an inward direction, and when the piece, G, has been thus dis-
placed the other pieces or segments forming the mandril can be moved inwards and be
then withdrawn after the shell, A, has been corrugated The ridges of the
corrugations, F, of the mandril touch the inside of the uncorrugated shell, A, and
when the fluid pressure is applied it bears inwards the parts of the shell between the
ridges and makes the shell take the corrugated form of the mandril Various pressures
of fluid may be used in different cases, it may however be stated that a liquid forced
in to a pressure of about 2 tons per square inch has been found capable of corrugating
a steel shell 3 feet in diameter and inch thick without heat To prevent leakage

page_text: of the pressing liquid cup leathers, H, are provided in grooves near the ends of the
cylinder, B, and a ring, J, is bolted on the end of the cylinder, B, at the end at
which the shell, A, is introduced to retain the upper cup leather, H, whilst air
holes, K, are formed in the mandril, E, for the escape of air from the channels between
the ridges
The cylinder, B, in which the fluid pressure is applied may, as shown in figure, 2,
be provided with a telescopic inner cylinder, L, which may be entered more or less to
limit the space in which the pressure is to act, to suit longer or shorter shells, A, or
greitor or less extents of corrugation The telescopic inner cylinder, L, 18 adjusted
and secured by means of studs, M, and screw nuts, N, and picking, H, is applied
between the outer and inner cylinders, B, L, and between the inner cylinder, L, and
shell, A
In the modification shown in figures, 3, and 4, the shell, A, is held within the outer
cylinder, B, by rings, P, bolted to the ends, these rings being made with projecting
parts, Q, shaped to enter and fit tightly with slightly coned surfaces in the ends of the
shell, A With this arrangement the shell A, forms its own end joints as the pressure
in the spice, C, acting on the outer surfaces of the shell at its end tends to tighten
them upon the projections, Q, of the end rings, P In figures, 3, and 4, there is
also shown the mandril or internal shaping piece, E, which is made in several
segments, and with a narrow piece, G, movable inwardly, and which is kept in a
distended condition by a tapered core shell, R, the interior of the mandril itself being
correspondingly tapered
Although not shown in figures, 1, 2, and 6, a core shell (R) or a solid core
plug is in all cases used to keep the mandril pieces, E, in a distended condition
It will be obvious that instead of the corrugations being formed on the internal
piece, or mandril, E, they may be formed in the internal surface of the outer cylinder, B,
the fluid pressure being in that case applied upon the inside of the sholl, A, instead of
on the outside thereof Figure, n, sheet, 2, shows a modification with the parts and
functions transposed in the manner stated In this inodification the internal piece, S,
does not require to be collapsible but the outer cylinder, B, must be made in segments
to be bolted together or be held in an outer cylinder, or be bound with hoops
or rings, the segments being separable for getting out the shell when it has been
corrugated
The furnace or other shell, A, may be in a heated state when being operated on,
ind the operating fluid may be compressed air or any suitable gis or vapor When
a shell is to be corrugated in a heated state it is desirable to muntun its heat at a
suitable height during the corrugating operation, and for this purpose what may be
termed a foster cylinder, T, may be used as shown in figure, 6 This figure shows an
arrangement like what is hereinbefore described for corrugating a shell, A, upon
a corrugated mandril, E, but the space, C, for the pressing fluid is made large enough
to allow of the introduction of a thick metal cylinder, T, which like the shell, A, is
heated before being introduced With the view of having the temperature sufficiently
high during the operation it is also desirable that the time required for closing up the
cylinder, B, after the introduction of the heated shell, A, and its foster cylinder, T,
should be is short as possible For this purpose apparatus such as is shown in
figures, 7, and 6, may be provided, this apparatus comprising a powerful_hydraulic
press, U, and a truck, V, running on rails, on which truck a cylinder, B, may be
placed A shell (A) and foster cylinder (T) are placed within the cylinder, B, when
the latter on its truck, V, is a short distance from the press The truck with the
cylinder on it is then rapidly moved into the press, and the ram of the press is forced
up rapidly by means of water from an accumulator A block, W, is fixed to the
entablature of the press, being suitably shaped for closing the top of the cylinder, B,
and having an annular projection, Q, for entering the end of the shell and forming a
tight joint The ram lifts the cylinder up into contact with the block, W, and then
the pipe, D, is connected for admitting the. pressing fluid into the cylinder, B
If the furnace or other shell is made of mild steel or other suitable metal it may
be corrugated when cold, water or other suitable liquid being used as the fluid by

page_text: means of which the pressure is applied If found necessary the shell may, especially
if corrugated cold, be afterwards heated to anneal it, and it may be finished in any
suitable rolling apparatus
Amongst the various applications which may be made of shells corrugated in
the manner herein before described may be mentioned that of rims for multiple-rope
pulleys
Having now particularly described and ascertained the nature of our said Invention
and in what manner the same is to be performed, we declare that what wo
claim 18
-
1-The making of corrugated shells for steam-boiler furnaces and other applica-
tions by subjecting plain shells to direct fluid pressure applied to force the metal of
the shells into contact with corrugated surfaces of mandrils or internal shaping pieces
or of the interiors of outer cylinders substantially as hereinbefore described
2-The constructing and combining together of the parts of apparatus for making
corrugated shells for steam-boiler furnaces and other applications by direct fluid
pressure substantially in any of the modes hereinbefore described
Dated this Sixth day of March 1889
EDMUND HUNT,
Applicants' Agent.