Improvements in the Fastening of Condenser Tubes.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Fastening of Condenser Tubes.
I, JOHN EDWARD THORNYCROFT, of Church Wharf, Chiswick, in the County of
Middlesex, Engineer, do hereby declare the nature of this invention to be as
follows:-
It is usual to fasten the tubes in the tube plates of condensers by the use of
externally threaded ferrules that surround the tube ends and are screwed into
correspondingly threaded holes in the tube plates, those portions of the ferrules
that surround the tubes being of larger internal diameter than the outer ends,
so as to form shoulders that bear against the tube ends and the inner portions
of the holes in the tube plates being made of reduced diameter so as to form
shoulders between which and the bevelled inner ends of the ferrules suitable
packing such as tape is introduced.
It is however found that in practice owing to the great vibration to which the
condensers are subject the ferrules are liable to gradually work back and so to
allow play of the tubes and consequent leakage and my invention is intended to
obviate or mitigate this evil for which purpose according thereto the ferrules
are at their inner ends formed with slits or saw cuts and the ferrules are by
screwing their bevelled edges against the packing caused to spread out or expand
in suchwise that increased resistance is offered to their displacement and the
tubes are more securely fixed.
I sometimes serrate the inner ends of the ferrules in suchwise that when screwed
up against the packing they will offer increased resistance to becoming un-
screwed and such serrated formn may be adopted in combination with or without
the slits or saw cuts.
Sometimes I'interpose spring washers between the inner ends of ferrules and
the shoulders formed in the tube plate holes, the said washers surrounding the
tubes and whilst allowing the ferrules to be screwed in, offering on the other
hand resistance to their withdrawal, but I prefer the plan first above described
as being not only efficient but more simple than the others.
T
1 1

page_text: Improvements in the Fastening of Condenser Tubes.
I, JOHN EDWARD THORNYCROFT, of Church Wharf, Chiswick, in the County of
Middlesex, Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed to be particularly described and shown in
and by the following statement:
It is usual to fasten the tubes in the tube plates of condensers; by the use of
externally threaded ferrules that surround the tube ends and are screwed into
correspondingly threaded holes in the tube plates, those portions of the ferrules
that surround the tubes being of larger internal diameter than the outer ends,
so as to form shoulders that overlap the tube ends and the inner portions of the holes
in the tube plates being made of reduced diameter so as to form shoulders between
which and the bevelled inner ends of the ferrules suitable packing such as tape
is introduced.
It is, however; found that in practice, owing to the great vibration: to which
the condensers are subject the ferrules are liable to gradually work back andi so
to allow the packing to get loose, leading to side-play of the tubes and conse
quent leakage, and my invention is intended to obviate or mitigate this evil..
Referring to the accompanying illustrative drawings,
5
Fig. 1 is a section through a piece of tube plate showing a tube with ferrule
fastened therein according to this invention; and
Fig. 2 is a somewhat similar view but shows the ferrule in longitudinal
section.
a is the tube plate, the tube and c an externally screw threaded ferrule formed
with slits or saw-cuts one of which is shown at d extending backwardly from its
inner end but there may be only one or there may be more than two slits or saw
cuts and the forms thereof may be varied. The inner end of the ferrule is
bevelled on its inner edge at e Fig. 2. f is packing material such as tape and g
is the internal shoulder of the ferrule which, when the packing f has been com-
h is a short slit or nick to
pressed, should be slightly clear of the tube end.
receive the screwing-in tool. Such ferrules are by screwing their bevelled edges
against the packing, which enters and forms a hard filling in the slits d, caused
to spread out or expand in suchwise that their screw threads are caused to bite
into those of the tube plates and increased resistance is thus offered to their
displacement. By means of my improved ferrules the tubes are more securely
fixed and an efficient fluid tight joint to the tube is ensured.
I sometimes serrate the inner ends of the ferrules in suchwise that, when
screwed up against the packing, they will offer increased resistance to becoming
unscrewed and such serrated form may be adopted in combination with or with-
out the slits or saw cuts.
Fig. 3 illustrates a ferrule having a serrated inner end those portions of the
ferrule end between every two serrations forming teeth which may be. of
ratchet-like form and which, whilst allowing the ferrule to be screwed in tightly,'
by engaging with the packing f, tend to prevent the ferrule becoming unscrewed.
Sometimes I interpose spring washers between the inner ends of ferrules and
the tape compressed between them and the shoulders formed in the tube plate
holes, the said washers surrounding the tubes and, whilst allowing the ferrules
to be screwed in, offering on the other hand resistance to their withdrawal.
An arrangement of this kind is illustrated in Fig. 4; is the spring washer.
As will be seen, in screwing the ferrule in it will slide easily over the end part
of the washer which is in contact with it and the other end part which is in
contact with the packing f will not offer much resistance to the washer being

page_text: turned. The ends of the washer will, however, become engaged with the packing
and with the ferrule and will tend to prevent the latter turning in the reverse
direction.
The arrangement first above described and shown in Figs. 1 and 2 is the pre-
ferable one as being not only efficient but more simple than the others.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what.
I claim is:
1. For the fastening of condenser tubes, externally screw-threaded ferrules
having their inner ends internally bevelled and formed with slits or saw cuts,
which ferrules, when screwed into the holes in the tube plate against packing
contained in the said holes, will be caused to spread out or expand substantially
as described with reference to and shown in Figs. 1 and 2 of the accompanying
illustrative drawings.
2. For the fastening of condenser tubes, externally screw-threaded ferrules
formed at their inner ends with one or more notches or serrations, substantially
as described with reference to and shown in Fig. 3 of the accompanying illus-
trative drawings, and formed with slits or saw cuts as described, or not.
3. In the fastening of a condenser tube the combination of a ferrule and a
spring washer substantially as described with reference to and shown in Fig. 4
of the accompanying illustrative drawings.
Bath: 541
T1900
Dated this 5th day of June 1800.
For the Applicant,
W. LLOYD. WISE,
46, Lincoln's Inn Fields, London, W.C.,
Chartered Patent Agent.