Improvements in Furnace- and Flue-tubes and Fire Boxes for Steam Boilers and in the Manufacture of the same.
Year: 1888

page_text: Date of Application, 10th Feb., 1888
Complete Specification Left, 8th Nov., 1888
Complete Specification Accepted, 21st Dec., 1888
Improvements in Furnace- and Flue-tubes and Fire Boxes for Steam
Boilers and in the Manufacture of the same.
I JAMES HARDAKER TORDOFF of Furnace Row, Farnley near Leeds in the County
of York, forgeman, do hereby declare the nature of this invention to be as follows:-
The object of my Invention is the design or construction and manufacture of
furnace- or flue tubes and fire-boxes for steam boilers in such a manner, that such
tubes and fire-boxes are stronger to resist bursting or collapsing and longitudinal
rupture than are tubes and fire-boxes as ordinarily or at present constructed: and
in addition to overcome or obviate certain difficulties at present experienced in the
manufacture of the corrugated type of such flues and fire boxes.
A furnace tube for a steam boiler constructed in accordance with my improvements
is provided with right and left handed spiral corrugations running from the centre or
approximately the centre of such tube to both ends.
I am quite aware that furnace tubes have been constructed or been proposed to be
constructed with a single threaded spiral corrugation, (see Specification of Letters
Patent No. 1097 of 1877); and also with multiple threaded spiral corrugations running
in one direction, right or left handed, (see Specification of Letters Patent No. 12639
of 1885. Furnace tubes and fire boxes constructed in accordance with the just
mentioned specifications possess certain disadvantages in their construction and use,
which are more or less obviated or overcome by my berein mentioned improvements.
In the case of a tube constructed with single thread spiral corrugations, the longitudinal
strength of such a tube or fire box is small, rendering it inoperative or useless as a
longitudinal stay for the ends of the boiler. Besides, the construction of such a flue-
or furnace-tube or fire-box, whether formed by means of rolls, hydraulic or other
presses, or by hammering with the use of proper shaped anvils and tools, involves such
an expenditure of time and labour that it may be doubted if the manufacture of
such tubes would be remunerative. In the case of furnace tubes or fire boxes con-
structed with multiple threaded spiral corrugations, running in one direction;
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page_text: ;
although they possess much greater longitudinal strength than such tubes just pre-
viously mentioned, or the well known furnace tubes with circular non-spiral corruga-
tions yet they are more difficult to manufacture, and besides have among other
disadvantages that the joint of the weld is found to run partly round the flue; so that
it is difficult to construct a furnace tube which can be placed in the boiler without
exposing some part of the joint of the weld to the injurious action of the fire, and the
material of the tube suffers a more or less injurious distortion.
Now a furnace flue constructed in accordance with my Improvements, possesses in
a higher degree the combination of longitudinal strength with strength to resist
bursting or collapsing. Also the difficulties of manipulation in the forming of
these tubes, by rolling or other means, are less than in the case of other forms
of spiral or helical corrugated tubes; and the material forming the tube is not
subject to the same amount of distortion when passing through the rolls.
My improved flue or- furnace tubes may be formed by rolling between rolls
having suitable flutings or corrugations on their surface. Such rolls will have much
the appearance of double helical toothed wheels. By suitable connections such rolls
may be built up with longitudinal sections to any desired length, in order to suit vary-
ing lengths of furnace tube. Furnace tubes manufactured according to my Improve-
ments do not during manufacture traverse lengthway on the rolls, as in the case of
multiple spiral tubes manufactured according to the specification of Letters Patent
No. 12639 of 1885, and consequently longer tubes can be rolled, in a mill of a given
length, according to my method.
Instead of rolling, tubes according with my improvements, can be formed by pressing
in suitable moulds with hydraulic or other pressure, or under the hammer with the
use of properly shaped forging or blocking tools.
I do not limit myself to any definite pitch, between the corrugations, or of the spiral
or helix formed by any single corrugation, as these may be varied according to the
diameter of the tube and thickness of plate, and as a consequence with some variation
in the longitudinal and bursting or collapsing strengths.
Although my said improvements have been described chiefly with reference to
furnace flues for Cornish, Lancashire, or Marine Boilers; it will be readily understood
that they are more or less applicable to other parts of boilers; for example in forming
a semi-cylindrical top for locomotive fire boxes.
A collateral advantage, due to my improved form or construction of furnace tube
for steam boilers, lies in the fact that the gases and air passing through such tube are
better mixed, owing to the oddies caused by the roversing of the spiral motion of the
current at the centre of the tube; thus promoting better combustion, and the
consumption of smoke.
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page_text: Improvements in Furnace and Flue Tubes and Fire-boxes for Steam
Boilers and in the Manufacture of the same.
I JAMES HARDAKER TORDOFF of Furnace Row Farnley near Leeds in the County
of York Forgeman 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 :-
The object of my Invention is the design or construction and manufacture of
furnace or flue tubes or fire-boxes for steam boilers, in such a manner that such tubes
and fire-boxes are stronger to resist bursting or collapsing and longitudinal rupture
than are tubes and fire-boxes as ordinarily or at present constructed; and in addition
to overcome or obviate certain difficulties at present experienced in the manufacture
of the corrugated type of such flues and fire-boxes.
A furnace tube for a steam boiler constructed in accordance with my Improvements,
is provided with right and left handed spiral corrugations, running from the centre or
approximately the centre of such tube to both ends.
I am quite aware that furnace tubes have been constructed, or been pro-
posed to be constructed, with a single threaded spiral corrugation, (see specifi-
cation of Letters Patent No. 1097 of 1877); and also with multiple threaded
spiral corrugations running in one direction, right or left handed, (sce
specification of Letters Patent No. 12639 of 1885. Furnace tubes constructed
in accordance with the just mentioned specifications possess certain disadvantages
as regards their construction and use, which are more or less obviated or
overcome by my herein mentioned improvements. In the case of a tube constructed
with single threaded spiral corrugations the longitudinal strength of such a tube or
fire-box is small, rendering it useless as a longitudinal stay for the ends of a boiler:
and furnace tubes with multiple threaded spiral corrugations, running in one direction
only, are more difficult to manufacture, requiring comparatively much longer rolling
mills; and as they in some cases are found to contract in length on being heated,
are liable to lead to grooving of the angle irons connecting them to the boiler ends.
In order to avoid any weakness which would arise in a tube constructed according
to my invention at the part where the corrugations running in opposite directions
meet each other, (i.e. at the centre of the length of the tube), I form the tube at this
part perfectly straight, or with a circular groove or corrugation, the bottom of such
groove or corrugation being either towards the interior or exterior of the tube.
Another advantage obtained by using a single circular corrugation as just described,
is that such a corrugation whilst retaining sufficiently the longitudinal strength of
the tube to enable it to act as a stay for the ends of the boiler, allows the
necessary expansion and contraction in its length required to permit the end of
the boiler to "breathe,” and prevents the grooving of the angle irons joining it to
the ends of the boiler.
My improved flue or furnace tubes may be formed by rolling between rolls
having suitable flutings or corrugations on their surface. Such rolls will have much

page_text: the appearance of double helical toothed wheels. By suitable connections such rolls
may be built up with longitudinal sections to any desired length, in order to suit
varying lengths of furnace tubes. Furnace tubes manufactured according to my
improvements, do not during manufacture traverse lengthways on the rolls, as in
the case of multiple spiral tubes manufactured according to the specification of
Letters Patent No. 12639 of 1885, and consequently longer tubes can be rolled in a
mill of a given length, according to my improvements.
Instead of rolling, tubes according to my improvements can be formed by pressing
in suitable moulds with hydraulic or other pressure, or under the hammer with the
use of properly shaping forging or blocking tools.
I do not limit myself to any definite pitch between the corrugations, or of the
spiral or helix formed by any single corrugation, as these may be varied according
to the diameter of the tube and thickness of plate, and as a consequence with some
variation in the longitudinal and bursting or collapsing strength.
Although my said Improvements have been described chiefly with reference to fur-
nace tubes for Cornish, Lancashire, or Marine Boilers, it will be readily understood
that they are more or less applicable to other parts of boilers; for example in forming
a semi-cylindrical top for locomotive fire-boxes.
A collateral advantage due to my improved form or construction of furnace tube for
steam-boilers lies in the fact, that the gases and air passing through such tube are
better mixed owing to the eddies caused by the reversing of the spiral motion of the
current at the centre of the tube, thus promoting better combustion and consumption
of smoke.
And in order that my Invention may be more clearly understood, I have annexed
to the present specification the accompanying sheet of drawings, in which Fig. 1
represents a furnace tube constructed according to my Invention, with a plain or
flat centre part between the right and the left handed spiral corrugations, Figs. 2
and 3 with a single circular corrugation between the right and left handed spiral
corrugations.
Having now particularly described and ascertained the nature of my said Inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1°. Furnace Flues or Tubes (for steam boilers) having two sets of spiral or helica!
corrugations, the one set running round one half of the tube in a direction contrary
or opposite to the direction of the other set running round the other half of the tube
as viewed from one end of the tube, that is respectively right and left handed,
substantially as herein set forth
20. Furnace Flues or Tubes according to Claim 1° and having a plain or flat part,
or a single circular corrugation between the two sets of spiral or helical corrugations
substantially as herein set forth and shewn in Figs. 1, 2, and 3 of the accompanying
drawings.
Dated this 2nd day of November 1888