Improvements in or relating to Boiler Tubes and the Method of their Manufacture.
Year: 1893

page_text: Date of Application, 2nd June. 1893
Complete Specification Left, 28th Feb., 1894-Accepted, 12th May. 1894
PROVISIONAL SPECIFICATION.
Improvements in or relating to Boiler Tubes and the Method of
their Manufacture.
I, WILLIAM HUGHES, of 336, Grimesthorpe Road, Sheffield, in the County of
York Roll Turner, do hereby declare the nature of my invention to be as
follows:-
My invention is for the purpose of increasing the interior heat absorbing surface
of boiler tubes, and also relates to the economical manufacture of same.
I propose in the first place to take a tube of ordinary construction, and secondly
to place within that tube a bar or a number of bars of radial cross section, and
then to compress the tube tightly upon the said bar or bars so as to obtain
perfect contact, or preferably to heat the tube and the bars when placed in
position, to a welding heat, and then to pass them through a pair of rolls so as
to cause them to weld together.
Or I may use a smaller tube placed centrally within the large tube and
supported by intermediate bars and afterwards compressed or welded as before
stated.
Dated the 1st day of June 1893.
ROBT. F. DRURY, C.P.A.,
Bank Buildings, George Street, Sheffield, Agent for Applicant.
COMPLETE SPECIFICATION.
Improvements in or relating to Boiler Tubes and the Method of
their Manufacture.
I, WILLIAM HUGHES of 336 Grimesthorpe Road, Sheffield in the County of
York, Roll Turner, 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 :-
My invention is for the purpose of increasing the interior heat-absorbing surface
of boiler tubes, and also relates to the economical manufacture of same.
The annexed drawings illustrate three arrangements or methods of carrying out
my invention.
Fig. 1, a tube with one four arm internal bar.
Fig. 2, end of internal bar.
Figs. 3, and 4, tube with four internal bars.
Figs. 5, and 6, tube with five internal bars.
In carrying out my invention in the manner shown in Figs. 1 and 2, of the
drawings, I take a tube A, of usual construction, and I place within the tube a
bar B, of iron, or steel, or the like, of a cruciform cross section shown in Fig. 2.
This bar may be made so that it can be forced into and be drawn out of the
tube, and it may be either straight, or it may be twisted spirally.
When the internal bar is not required to be withdrawn from the tube, I compress
the tube upon the bar by any suitable means, and I may further bring the tube
and the inner bar to a welding heat and then pass them through rolls so as to weld
the two parts together.
I may vary the shape or configuration of the inner bars, and also the number of
them, thus in Figs. 3 and 4, I show a central bar B³, with three members or ribs

page_text: which may be used alone, or in conjunction with intermediate bars B³, so as to
form six radial ribs the length of the tube A, or thereabouts, while in Figs. 5
and 6, I have shown the interior construction to consist of a centre bar B, as in
Figs. 1 and 2, in combination with smaller four ribbed bars B*, shaped so as to
form in cross section a circle and four radial arms in addition to those of the bar B.
I prefer to weld these parts together and to the tube, but if desired they may be
left so that they can be drawn out of the tube.
I am aware of a tube with a coil or spiral placed within it leaving a central
longitudinal space, and constituting a rib or gill projecting a short distance
inwards from the inner surface of the tube, and I therefore disclaim such
construction.
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. A boiler tube, constructed with one or more internally placed radially webbed
bars either welded to, or otherwise consolidated with the tube, or made so that they
can be drawn out of the tube, for the purpose specified, and substantially as
herein before described and shown in the drawings.
2. The combination with metallic tubes for boilers and the like, of internally
placed webbed bars substantially as hereinbefore described.
3. The combination with metallic tubes for boilers and the like, of internally
placed bars, arranged to form radial conductors of heat, substantially as herein-
before described and illustrated.
Dated the 23rd day of February 1894.
ROBT. F. DRURY,
Bank Buildings, George Street, Sheffield, Agent for Applicant.