IMPROVEMENTS IN CYLINDERS OR ROLLS FOR DRYING, CALENDERING AND FINISHING TEXTILE FABRICS AND PAPER AND FOR SIMILAR PURPOSES to be as follows:
Year: 1884

page_text: We, JOHN ADDY HOPKINSON, and JOSEPH HOPKINSON, both of the firm of
J Hopkinson & Co of Huddersfield, in the County of York, Engineers do hereby
declare the nature of our invention for "IMPROVEMENTS IN CYLINDERS OR ROLLS
FOR DRYING, CALENDERING AND FINISHING TEXTILE FABRICS AND PAPER AND FOR
SIMILAR PURPOSES to be as follows:-
"
Our invention relates to the construction of cylinders or rolls for such purposes
as calendering and finishing textile and other materials and for similar operations
wherein hollow cylinders are used and have to be heated by steam or other fluid
under pressure.
The said invention is chiefly designed to afford the means for strengthening such
cylinders so that they will be less liable to collapse by reason of the formation of
a vacuum inside them or to be ruptured by internal pressure.
Our said invention is carried into practice by constructing the cylinder or roll
with an internal tube within which the steam or other heating medium is confined.
And in practising our said invention we obtain the most advantageous results by
having the internal tube corrugated or formed with projections and depressions
around its circumference.
These corrugations or projections and depressions give the said internal tube such
great structural strength as will permit it to be made of very thin material so that
the heat will readily pass through the same to the external tube which will thus be
effectually heated, while free from internal pressure. And, as they are in contact
with the interior of the cylinder, it will be seen that the corrugations of the said
inner tube will resist any tendency to collapse by the external pressure in the case
of the formation of a vacuum or partial vacuum within the cylinder.
The same results to some extent may be obtained by the use of channeled pieces
placed around the interior periphery of the cylinder or roll. Also by using a spiral
or coiled tube within the same.
In some instances where it is not so important to have the external cylinder or
oll free from internal pressure the said internal tube may be perforated with small
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page_text: holes which allow the steam or other fluid to enter the space between the two tubes
or shells.
The exterior roll or shell will usually be formed of thin copper and the interior
tube of iron, copper or other suitable material.
The ends of our said cylinders or rolls, are dished or flanged plates or pieces
which are secured in place by rivetting, brazing or other suitable means, and
provision is made in the usual manner for the entrance and exit of the steam, water
or other fluid by which the said cylinders are heated.

page_text: COMPLETE SPECIFICATION.
We JOHN ADDY HOPKINSON, and JOSEPH HOPKINSON, both of the firm of
J. Hopkinson & Co, of Huddersfield, in the County of York, Engineers, do hereby
declare the nature of our invention for "IMPROVEMENTS IN CYLINDERS OR ROLLS
FOR DRYING, CALENDERING, AND FINISHING TEXTILE FABRICS AND PAPER, AND FOR
SIMILAR PURPOSES and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:-
Our invention relates to the construction of cylinders or rolls for such purposes
as drying, calendering and finishing textile and other materials, and for similar
operations wherein hollow cylinders are used and have to be heated by steam or
other fluid under pressure.
The said invention is chiefly designed to afford the means for strengthening such
cylinders, so that they will be less liable than heretofore to collapse by reason of
the formation of a vacuum inside them, or to be burst or ruptured by internal
pressure.
It is usual, in drying machines having stoam-heated cylinders, to employ reducing
valves between the boiler and the machine, to reduce the pressure sufficiently to
allow the steam to be admitted to the cylinders with comparative safety. And it
has been necessary to provide the cylinders with means for removing the water of
condensation. But, by our invention, we obviate the necessity for these additions
to the machine, and obtain other advantages as hereinafter described.
Our invention is illustrated in the accompanying drawing, in which
Figures 1, 2 and 3 are longitudinal sections of various forms or modifications of
our improved cylinders or rolls.
Like letters indicate corresponding parts throughout the drawing.
The cylinder or roll shewn in Figure 1 has its body or shell a formed of sheet
copper or other suitable metal. Its ends b are castings of iron or other metal formed
with flanges b', which are fitted within the cylinder a and secured in place by
brazing, rivetting or otherwise. 63,62 are hollow journals formed on the said ends;
c is a spiral or coiled tube or pipe which is arranged and secured within the
cylinder a as shewn, with its ends extending through the hollow journals, one of
these ends being connected in any suitable manner with a steam supply pipe, and
the other end with a discharge or exhaust pipe.
In the apparatus shown in Figure 2, there is an outer shell a of copper or other
suitable metal as above described and an inner tube or shell d arranged concen-
trically within the said outer shell, both of these parts being secured to the end-
pieces by rivetting or otherwise. The spiral or coiled tube c is arranged within the
annular space between the parts a and d, its ends being extended through the inner
part d to the hollow journals b. The end-pieces of this cylinder are so constructed
as to close the ends of the aforesaid annular space, but the central part of each of
the said end-pieces is, or may be, open.

page_text: The use of a spiral tube, in our improved cylinder or roll, affords many advantages,
among which the following are highly important, viz:-
The external shell or body of the roll or cylinder has no steam admitted into the
space within it (outside of the spiral tube), so that there is no possibility of the
bursting of the cylinder by internal pressure or of its collapsing by reason of
a vacuum therein. The only part to which the steam is admitted (that is to say,
the spiral tube) is structurally of such strength as to be practically secure against
injury by internal or external pressure; therefore, there will be no danger from
oither the bursting or the collapse of any part of the apparatus, and, by reason of
its great strength and the consequent absence of danger from the above causes, it
will be practicable to work with steam at a very high pressure, without the provision
of diminishing or reducing valves or like apparatus. This capability of working
with high-pressure steam obviously permits great economy in the use of these rolls
for any of the purposes above specified or similar purposes, as bigh pressure is
accompanied by a high temperature, and the higher the temperature (within
reasonable limits) the greater will be the efficiency for any given area of surface,
of the roll or cylinder; therefore our invention affords the means for performing an
increased amount of work with a given size of cylinder, or for performing any given
quantity of work with a smaller roll, thereby reducing the cost of the machine.
And, as there is no part of the cylinder or roll that can be injured by the existence
of a high pressure or a vacuum therein, we can safely make our drying cylinders or
rolls of much larger dimensions or of thinner materials than have heretofore been
considered practicable. Moreover, we have ascertained that the spiral tube will, by
the simple act of rotating around the axis of the cylinder, even at a very slow
speed, discharge from the end thereof any condensed water that may be formed
therein; we are thus relieved of the necessity of providing special appliances for
- preventing the accumulation of water of condensation in our improved rolls or
cylinders. The spiral tube may be circular, semi-circular, or of any other form in
transverse section.
:
We modify our invention by constructing the cylinder or roll with an internal
tube e, within which the steam or other heating medium is confined. And we
prefer to have the internal tube e corrugated or formed with projections and
depressions around its circumference, as shewn in Figure 3.
These corrugations or projections and depressions give the said internal tube such
great structural strength as will permit it to be made of very thin material, so that
the heat will readily pass through the same to the external tube a, and, as the
steain is confined within the said corrugated tube, the shell or tube a will be
effectually heated, without being subject to internal pressure. Moreover it will be
obvious that the corrugated construction of the said inner tube is the most
advantageous that could be adopted to resist external pressure tending to collapse
the cylinder by reason of the formation of a vacuum or partial vacuum therein.
The internal tube e is made of iron, copper or other suitable metal, and with any
convenient arrangement or pattern of corrugations.
We sometimes make the said inner tube with spiral corrugations, so that the
rotation of the cylinder around its axis will cause any condensed water therein to
be carried or conveyed to one end of the cylinder, where we provide suitable means
for removing or discharging it from the machine.
In some instances, where it is not important to have the external cylinder or roll
free from internal pressure, the said internal tube e may be perforated with small
holes, which allow the steam or other fluid to enter the space between the two
tubes or shells.
The exterior shell or body will usually be formed of thin copper, and we sometimes
perforate the said shell to permit the free access of the heat to the material on the
roll, and the passage of a current of air, when the same will be advantageous. But
it must be distinctly understood that the perforation of the outer shell must not
co-exist with the perforated inner tube.

page_text: The ends of our said cylinders or rolls are usually dished or flanged plates or
pieces, as shewn, and are secured in place by rivetting, brazing or other suitable
means, and provision is made in the usual manner for the entrance and exit of the
steam, water, or other fluid by which the said cylinders are heated.
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
we claim is
First. A cylinder or roll for purposes such as are herein specified, so constructed
that the steam or other medium will effectually heat the shell or body of the said
roll or cylinder, without exerting any pressure thereon.
Second. A cylinder or roll constructed substantially as described with reference
to Figure 1, 2 or 3 of the drawing, and with its outer shell perforated, for the
purpose specified.
Third. A cylinder or roll for the purposes herein specified, provided inside its
cylindrical shell, with a spiral tube suitably constructed and arranged to effect the
heating of the roll by steam or other fluid, and the discharge of the water of
condensation, as above set forth.
Fourth. The modification in the construction of our improved roll or cylinder,
wherein the spiral tube is arranged in an annular space between two tubes,
substantially as described with reference to Figure 2 of the drawing.
Fifth. A cylinder or roll for the purposes herein specified, provided inside its shell
or body with a corrugated tube, substantially as, and for the purpose, specified.
AB