Year: 1886

page_text: I ROBERT FRIEDRICH MELCHIOR MÜLLER of 25* Schulstrasse (Steinwärder),
Hamburg in the Empire of Germany, Engineer, do hereby declare the nature of
this invention to be as follows:-
The object of the present invention is to produce fire tubes for steam boilers
which shall be capable of withstanding a very high exterior pressure.
The object is attained by corrugating or embossing the cylindrical fire, tubes,
which corrugations do not however extend quite up to the line or lines of longi-
tudinal rivetting of the tubes, and the line of rivetting, instead of extending in a
straight longitudinal direction, as usual, is caused, by suitably cutting or shaping
the contiguous edges of the metal sheets or plates, to assume a wavy or serpentine
form.
The mode of constructing the fire tubes is very simple and inexpensive.
The plates or sheets of iron or steel are stamped out, while in, the flat, at their
longitudinal edges, and manipulated in accordance with the requirements of the
before mentioned line of rivetting, but the rivet holes are not formed till later on.
The metal plates or sheets are first subjected to a suitable amount of heating,
according to the material employed, and are subsequently pressed or rolled in
suitable hydraulic presses or rolling mills; they are then put together, bored, and
rivetted either by hand, steam, or hydraulic power.
Although it would not be at all difficult to connect the longitudinal edges of
these tubes by welding, in which case the corrugations would of course be made to
extend entirely around the tubes, it is found preferable not to employ welding; for
it is desirable to select for the manufacture of these tubes, the best sorts of iron or
steel, without taking into consideration whether these best kinds of material are
also suitable for welding.
This mode of construction also renders possible the insertion of Galloway or
other "cross-seated" tubes in a solid manner, as well as the effecting of repairs
without special difficulties.

page_text: Improvements in Fire-tubes for High-pressure Steam Boilers.
..
I ROBERT FRIEDRICH MELCHIOR MULLER of 25 Schulstrasse (Steinwärder),
Hamburg in the Empire of Germany, Engineer, 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 the present invention is to produce fire-tubes for steam boilers
which shall be capable of withstanding a very high exterior pressure.
This object is attained by corrugating or embossing, the cylindrical fire tubes.
The corrugations do not, however, extend quite up to the line or lines of longi-
tudinal rivetting of the tubes, and the line of rivetting, instead of extending in a
straight longitudinal direction, as usual, is caused, by suitably cutting or shaping
the contiguous edges of the metal sheets or plates; to assume a wavy or serpentine
form+
In the accompanying drawing:
Figs. 1 and 2 represent a cylindrical firetube with semi-spherical projections
formed of a single sheet of metal, and with a'single line of rivetting.
Figs. 3 and 4 show a fire-tube formed of two sheets of metal; and strengthened
by semi-cylindrical projections. The projections of the lower and smaller plate or
sheet of metal are interchanged in position (or placed alternately) with those of the
upper sheet or plate.
C
>
Figs. 5 and 6 represent a firetube formed from a single sheet of 'metal, and
provided with semi-cylindrical projections running' at right angles to the length' of
the tube, and almost entirely around the same, but not quite close up to the line of
.rivets. In this construction of tube, also, the ends of the semi-cylindrical projections
are so arranged that the line of rivetting will not be straight, but will be made to
assume the same shape or contour as in the before mentioned tubes.
1
The mode of constructing the firetubes is very simple and inexpensive.
The plates or sheets of iron or steel are stamped out, while' in the dat, at 'their
longitudinal edges, and manipulated in accordance with the requirements of the
before mentioned line of rivetting, but the rivet holes are not formed till later on.
The metal plates or sheets are first subjected to a suitable amount' of heating
according to the material employed, and are subsequently pressed or rolled in
suitable hydraulic presses or rolling mills. They are then put together, bored, and
rivetted, either by hand, steam, or hydraulic power!
f..
Although it would not be at 'all difficult to connect the longitudinal edges of
these tubes by welding, in which case corrugations would of course be made to
extend entirely around the tubes, it is found preferable not to employ welding, for
it is desirable to select for the manufacture of these tubes the best sorts of iron or
steel, without having to consider whether these best kinds of material are also
suitable for welding..
This mode of construction also renders possible the insertion of Galloway or
other "cross-seated" tubes in a solid manner, as well as the effecting of repairs
without special difficulties,

page_text: Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is
1. Constructing the fire-tubes of high-pressure steam boilers with semi-spherical
or semi-cylindrical projections, arranged circumferentially, but not coming close up
to the line or lines of rivetting of the tube, substantially as shewn and described
with reference to the drawing.
2. Rivetting the fire-tubes of high-pressure steam boilers in serpentine lines,
substantially as described and shown in the drawing.