New Means for Connecting, Jointing, and Fixing the Tubes of Multitubular Steam Boilers, Condensers and the like.
Year: 1896

page_text: COMPLETE SPECIFICATION.
New Means for Connecting, Jointing, and Fixing the Tubes of
Multitubular Steam Boilers, Condensers, and the like.
I, JOAQUIM RIBEIRO DA COSTA of 97 Boulevard Longchamp, Marseilles,
France, Naval Engineer, do hereby declare the nature of the said invention and
in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :-
This invention relates to new means for connecting jointing and fixing the ends
of steam, water or fire tubes in and to the walls or plates of steam boilers,
condensers and the like, and is more particularly designed for connecting, fixing
and jointing the ends of the compound water and fire tubes in and to the walls or
plates of the water headers of the new multitubular or tubulous steam generator
of the return tube type, forming, the subject of another application for Letters
Patent of even date herewith, No. 17503 of 1896.
This new means for connecting, fixing and jointing tubes, hereinafter called an
obturating plug or "connector consists of a casting or forging of cast iron, cast
steel, gun-metal or other suitable material of substantially tapering plug shape
with a through central longitudinal perforation provided at its rear end or widest
part with a flange for attachment to the wall of the water header or the like in a
manner so as to be steam and water-tight; suitable passages for water and fire
gases being provided in the thickness of the connector on either side of the central
perforation. This flange is preferably attached to the said wall by means of nuts
screwing on bolts that may advantageously be constituted by extensions of the
usual internal stay bolts of the header or vessel to which my connector is applied.
The front or taper end of the connector is provided with one or more annular
grooves, concentric or otherwise, adapted to receive the end or ends of the tube
or tubes to be fixed in place concentrically or otherwise, said end or ends being
preferably swelled and thickened. A tight joint is effected by means of rings of
soft copper, which are placed in the grooves of the connector and are deformed
or set up by the compression produced between the tubes and the connector by
screwing the connector tight up against the wall of the header.
With the object of more fully explaining the nature of my invention, I will now
proceed to describe by way of example some forms of my connector in its
application for connecting, fixing and jointing one or more concentric tubes in
steam generators. The application of my invention to other purposes cau be
readily understood.
Figure 1 is a central longitudinal vertical section of a compound tube composed
of four concentı tubes fixed and jointed by means of my new connectors to the
walls of the front and rear water headers.
Figure 2 in its right hand half is an elevation of the water end of the new
connector used in Figure 1, and in its left hand half it is an elevation of the inner
end of the said connector.
Figure 3 is a central longitudinal section illustrating the connector in its
application to one end of a compound tube composed of three concentric tubes
forming part of the new steam generator aforesaid.
Figure is a similar view to Figure 2, showing the outer and inner ends of the
connector in end elevation.
Figure 5 is a central longitudinal vertical section showing a form of connector
suitable for use with a compound tube composed of two concentric tubes only.

page_text: In Figures 1, 3 and 5 only, so much of the surrounding parts are shown as will
enable the nature of the invention to be properly understood.
Referring to the arrangement illustrated in Figures 1 and 2, H is the new
connector consisting of a casting or forging of substantially plug or tapering shape
formed with a flange i for, attachment to the wall of the header by means of the
nuts screwing on the screw threaded extensions of the ordinary internal stay
bolts e of the header. v, a, y, z are the four concentric tubes of the compound.
water and fire tube above referred to. That part of the connector which projects
into the internal space of the header has formed in it an annular groove d adapted
to receive the (preferably swelled and thickened) end of the tube y and a part of
the connector projecting into the central perforation of the connector has formed
in it an annular groove e adapted to receive the end (also preferably swelled and
thickened) of the tube x. The third or innermost tube also preferably swelled
and thickened, is arranged to enter an annular groove g formed in a ring f which
fits in the outer end of the central perforation of the connector, and bears with a
flange against said outer end, and is kept in place by means of an annular put
which bears against said flange and is adapted to take over and be screwed on
screw threads formed on said outer end of the connector. The said ends of the
tubes y are formed with edges cut at an angle or bevelled, the bevel in each
case being arranged to be on the opposite side to the pressure coming upon the
joint. Each annular groove deg is adapted to receive a jointing ring a of soft
copper or square form in cross section inserted between the bevelled edge of each
tube end and the bottom of the respective groove.. These grooves may be of any
desired form in cross section so long as the bevels or inclinations of the sides of
the grooves are always opposite to the direction of the pressure acting upon the
joint surface.
The method of fixing and jointing the tubes to the header by means of the new
connector is as follows:-
The largest or outermost tube z having been fixed in the inner header wall by
screwing in the ordinary manner, the tube a is placed inside the tube y and the
two tubes x and y are then inserted in the outermost tube. Then the soft copper
jointing ring a having been placed into the grooves d and e in the connectors H H',
the connectors are placed upon their retaining studs or bolts and slidden up to and
into the header in such a manner that the ends of the tubes x and y bear against
the soft copper rings in the annular grooves d' d' and e e' in the connectors H H
at each end. Then an iron rod screw threaded at both ends is passed through the
inner tube a, and nuts bearing directly or indirectly upon the outer ends of the
connectors H H' are screwed up at each end on the said screw threaded iron rod
in such a manner as to bring a powerful compressive strain to bear upon the tubes
and connectors, whereby the soft copper rings are deformed and set up in such a
manner as in combination with the peculiar form of the grooves and the bevelled
edges of the tubes to effect a tight joint between the tubes and the connectors,
whilst a tight joint is also made between the contact surfaces of the flange ii of
each connector and the respective header wall. This last mentioned joint may
be made by means of soft copper wire or other suitable packing material. The
arrangement and construction of the parts should be such as to ensure a tight
joint at all of the respective contact surfaces, namely at d and e, and at j.
Nuts are then placed upon the retaining studs or bolts of the connectors and are
screwed up tight. The iron rod with its nuts can now be removed.
To fix and joint the innermost tube v, the said tube is inserted inside the tube,
and against the ends of the tube v there are placed the rings f with the soft
copper rings a placed in their grooves gg. By screwing up the nuts the copper
rings are deformed and set up and a tight joint is made between the ends of the
tube vaud the rings f, a tight joint being also ensured at m m between the rings f
and the cuter ends of the connectors by means of suitable packing such as soft
copper wire. This method of fixing is repeated in turn for each compound tube.
An opening E E is provided in the upper parts of the "thickness of the

page_text: connectors H H' for the purpose of affording communication between the outside
of the connector outwardly of the attaching flange i and the annular space
comprised between the inside surface of the tube y and the outside surface of the
next inner tuber say for the passage of the fire gases from a combustion chamber
at one end of the tubes on their way to the smoke box at the other end of the
tubes. An opening F F may also be formed in the lower portions of the thickness
of the connectors with the object of preventing the formation of deposit at those
places.
Passages O¹ are also provided in the thickness of the connectors at top and
bottom for the purpose of affording communication between the space situated
inwardly of the header or other wall to which the connector is attached, and the
annular space comprised between the outside surface of the innermost tube and
the inside surface of the next outer tuber say for the flow of water from the
inside of the header wall to which the connector is attached at one end of the
tubes, through the said annular space to a similar header at the other, end of
the tubes. A clear passage into and out of the innermost tube v is afforded by
the central perforation of the connector.
In the form of connector shown in Figures 3 and 4 for fixing and jointing two
concentric tubes only to a header wall, the innermost tube v of the last arrangement
being omitted, the ring f and nut 7 of the last arrangement are also omitted, and
in their place the central perforation is closed at its outer end by means of a screw
The construction
plug D removable for the purpose of cleaning the inner tube x.
and arrangement of the parts is otherwise similar to that shown in Figures 1 and 2.
In the arrangement shown in Figure 5, where only one tube y is fixed and jointed,
the connector has the shape of a flat plug with a central perforation and one
annular jointing groove. Six retaining screw bolts or studs with their nuts are
preferably employed for attaching and securing each connector to the header or
other wall, but this number may vary if necessary.
Having now particularly described and ascertained the nature of mý said
invention and in what manner the same is to be performed 1 declare that what
I claim is :-
1. In steam generators, condensers and the like, having sets of three or more
concentric tubes, an obturating plug or connector provided with grooves in which
the said concentric tubes are secured and also provided with suitable passages for
the circulation of steam or water and heating or cooling mediums, substantially as
described.
2. In steam generators, condensers and the like, an obturating plug or connector
provided with grooves for connecting, fixing and jointing two concentric tubes to
a header wall, and also provided with suitable passages for the circulation of steam
or water and heating or cooling mediums, substantially as hereinbefore described
and as illustrated in Figures 3 and 4.
3. In steam generators, condensers and the like an obturating plug or connector
for connecting, fixing and jointing one tube to a header wall, substantially as
hereinbefore described and as illustrated in Figure 5.
Dated this 6th day of August 1896
J. C. MEWBURN & ELLIS,
55 and 56 Chancery Lane, London, Chartered Patent Agents.