Note: Descriptions are shown in the official language in which they were submitted.
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The invention relates to a transport container made from cylin-
drical shells for combined handling of liquids, gases or loose material,
adapted for emptying under pressure or by gravity, and/or having connections
for fixtures.
~ ccording to the dangerous character o~ the load, liquid transport
containers are emptied either by pressure higher than the atmospheric pres-
sure through a riser built in the top of the container, or by gravity through
a discharge valve built in the bottom of the container. In order to ensure
emptying which is as complete as possible, in both cases a depression (sump)
must be formed in the bottom of the container where the remaining liquid can
accumulate.
Various embodiments of the sump are known. These include sump
basins. These cause however, due to necessary heat treatment, structural
changes in the material of the container, which is made mostly from alloyed
steel7 and weakening of the wall thickness by the straining o~ the sheet
metal.
In order to avoid this disadvantage block flanges are welded into
a corresponding recess in the bottom of the container. These require large
cross-sections and considerable differences in thickness between the material
of the ~lange and the container wall cause corresponding transition stresses.
U-shaped troughs or semi-tubular shells welded into the bottom,
which may extend either longitudinally or transversely, require a consider-
able amount o~ welding and large holes in the wall with corresponding loss
of material. In addition they have a disadvantageous shape as regards pressure
stresses caused in use.
In all cases there are also needed additional guides for the riser
fixed in the top of the container, in order to retain the riser in the
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prescribed position ending in the sump and protect it against vibration.
In order to meet all the requirements, particularly when the load
varies, and to ensure complete emptying of the sump, which is inaccessible,
particularly for cleaning, it is recommended to make the sump as a discharge
spout closed by a bottom valve. In that case either the riser may be used
for emptying under pressure or the bottom valve may be used for emptying by
gravity. Even this arrangement suffers from the disadvantages mentioned
earlier.
Also, further ~ixtures must be provided in the transport container
in addition to the mentioned riser for the emptying of the container. These
include, in addition to a manhole, e.g. relief pressure valves, fuses,
bursting discs and also connections for pressurised air and inert gas.
These fixtures are usually arranged at the top of the container.
Due to the structural height of these elements required by their ~unction,
a part of the structural height of the container, which is valuable for
obtaining optimum loading space, is lost as a rule.
In addition, it has been repeatedly shown that fixtures welded on
the outer wall of the container cause leakage of the container contents when
they are sheared or torn off the container during an accident. To provide
protection against fire and explosion, and also for health and environmental
protection, leaks caused in this way must be reduced to an absolute minimum.
Attempts have already been made to protect the fixtures in the top
of the container by the provision of protective frames, covers or swellings
extending in longitudinal direction. These protective means often con-
siderably increase the dead-weight of the container and also increase, not
insubstantially, expenses caused by the additional work involved. Also, the
provision of protective frames fixed to the wall of the container means
increased danger in an accident; because of the increased stress concentra-
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tion and contraction sLralns, cracking of the contai~er wall ma~ occur~
In order to avoid these ~osses in the structural helght and the dangers
in case of an accldent, fixtures were bui~t i~to the contalner wall horizontally.
The oval cut-outs in the container wall, needed for this purpose, are however,
undesirable in view of the p~essures acting on the container. In addition many
calculation codes require also additional reinforcing collars, which result
in additional expenses on material and welding.
; ~t may be stated in &eneral that when plpe sectlons of clrcular,
elllptical or oval cross-sectlons are lnserted lnto the contalnsr wall, edge
stresses are transmitted to them, whlch would otherwlse be contalned by the
Portlon cut out from the cylindrlcal shell.
Also open troughs 2 partly composed of semltubular shells are partly
of sheet metal bottom and side wails, have been welded lnto the container. It
is also known to bulld ln sump unlts wlthout outlet. Edge stresses cannot be
contalned by these shells without the danger of bulging.
The ob~ect of the present lnventlon is therefore, with the maxlmis~t~on
of the dlameter, cross-sectlonal area and volume of the contalner, a helght-
savlng arrangement of the connectlon elements for emptying and filling the
container and of various further fixtures, in which the stresses and the deteri--
oration of structures of thc container and the welds are held as low as posslble.Thls ls achleved according to the invention by a transport container comprising:
a large diameter cylindrical shell for holding material to be transported, said
shell being formed by a cylindrical shell wall, at least one pipe member
rigidly connected ta the cylindrical shell wall, and connecLion means for
fixtures such as material inlet and outlet means, relie pressure valve means,
and the like, wherein the connection means are carried by at least one pipe
member, and wherein the or each pipe me~ber has a wall disposed longitudinally
with respect to said cylindrical shell wall with an upper or lower portion
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tbereo~ being w~thin sa~id s,h~e~ and Rnobhç~ po~ n bein~
outside of sa~d shell~ w~h~rqby ~r~sses in ~4e ~e~i~n o~ said rigid
connection are reduced.
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By the use of pipe bodies for the mounting of the riser and for
the fixing of the ~ixtures, there remain~ in contrast to the use of troughs
open at one side, bridæe regions to the inside of the container. Stresses
and worsening of the structure of the steel in the region of the welds is
therefore reduced and with it also the danger of bulging out of the con-
tainer in the region of the welds. This leads, in addition, to the reduction
of expenses on material and to a large extent also expenses for welding.
Also, the following advantages are obtained according to the invention: the
bottom discharge and the sump for the riser are united in one place; the
compression strength of the container cross-section is largely uninfluenced;
; an additional welded-in holder for the riser is not needed because the riser
is guided in the discharge spout; openings in the bottom of the container
leading out have the smallest possible diameter; the cleaning of the open
discharge spout does not presen-t any difficulties and the capacity Or the
sump basin is very small.
The pipe according to the invention for the arrangement of the
connections of the fixtures has a much smaller radius than the cylindrical
container. Due to this the pipe inserted into the container wall forms a
vaulted dome-shaped elevation relative to the rest of the container wall.
In view of the smaller radius of curvature of the pipe the wall thickness
ratio for the provision of fixtures and pipe spouts is more advantageous
when compared with the wall of the container.
The danger of cracking in the area of the inserted pipe is reduced
and also stress concentrations in the container are reduced. It is also
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possible to weld connections and spouts from both sides to the pipe before
it is mounted in position, while avoiding welding in constrained positions
on the container. In other words, by the use of the pipe according to the
inven-tion the fixtures at the top may be mounted in a manner which is simpler
as regards welding technology, more reliable as regards fatigue and requires
less work compared with the present state of art.
It is important to stress that, in addition to the mentioned
advantages, the desired maximisation of the container capacity is achieved
according to the invention.
~he invention will now be described, by way of example, with
reference to the accompanying diagrammatic drawings, in which:
;~ Figure 1 is a section through a first embodiment of a discharge
spout;
Figure 2 is a ].ongitudinal section through a second embodiment;
Figure 3 is a cross-section along the line III-III in Figure 2;
Figures 4 to 6 show diagrammatically various possible phases of
the flange embodiment;
Figure 7 ~hows a transport container made from cylindri.cal shells
and held in a frame;
Figure 8 is a cross-section through a pipe according to the inven-
tion wi~h a connection spout,
Figure ~ is a cross~secti.on through a further embodiment of a
pipe according to the invention;
Figures 10 and lOa are longitidinal sections through a part of an
upper end section of the transport container; and
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Figure 11 is a longitudinal section through parts of a transport
container including combination of the inventive features.
In the embodiment shown in Figure 1 a horiæontally extending pipe
3 is welded into the bottom 2 of a container 1 for liquids, parallel to the
transverse or longitudinal axis of the container 1, in such a way that the
bottom of the pipe 3 is lower than the bottom 2 of the container 1. The wall
thickness of the pipe 3 is so chosen that the wall can reliably withstand
any generated pressures and additional stresses caused in the relevant region
by the deviation of the container wall from the membrane form. A transition,
which satisfies flow and pressure requirements from the container bottom 2
to the adjacent en~ of the pipe 3 is obtained by a segment 1~ of a spherical
shell.
The top of the said pipe 3 is provided with an opening 5 for
receiving a riser 6, the opening 5 being consequently situated vertically or
obliquely below the fixtures (not illustrated) for the mounting of the
riser 6 in the top of the container, so that the riser 6 may be inserted
into the opening by sliding-in without special retaining fixtures.
The discharge spout 3 ends at its outlet end in a flange, which
is situated on or outside the wall of the container 1 and which may be a
~lat flange or a welding neck flange 7, and which serves for the connection
of a discharge valve 27 of any suitable design.
In the embodiment according to Figures 2 and 3 the pipe 8, which
serves as a discharge spout, is oval with a compressed cross-section. The
transition between the bottom 2 of the container 1 and the discharge spout 8
is in the illustrated embodiment formed by an extension 9 of the obliquely
cut pipe end which is bent in the shape of a tongue, rather than by a segment
of a spherical shell. In order to make insertion of the riser 6 easier,
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the opening 5 is, on the top of the outlet pipe 8, surrounded by a flared
collar 10.
The connection flange 11 for the discharge conduit is in the
illustrated embodiment situated in an oblique transition area between the
bottom 2 and the sidewall 12 of the container. Consequently, when viewed
in horiæontal direction, the circular flange 11 has an elliptic appearance.
The discharge spout 8 is so shaped that its obliquely cut end defines an
ellipse, which sits on the flange 11. ~ext to this end the spout 8 is at
its top provided with a wide recess 13 which facilitates the entry and out~
flow of the liquid and so contributes to full emptying of the container.
Inwardly opening spring-con-trolled valve 14 may be fitted in the
closing flange 11. Various pipes, provided with a discharge valve each,
may be mounted on the connection flange 11, for instance, as illustrated, a
transverse pipe 15 for lateral emptying. It is, however, also possible to
close firmly the closing flange 11 if emptying through the bottom is not
required. In this way a single flange may be used in various ways according
to the customer's requirements.
So for instance in one phase 1 according to Figure 4, the flange
-; 11 may be only partly hollowed out and consequently be fully closed. In
20 phase 2 according to Figure 2 a hole 16 is made in the closing flange 11
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which may be opened by means of the valve lli.
If later, in phase 3 according to Figure 5, the hole 16 is to be
again permanently closed, this may be simply achieved by welding in it a
closing disc 17. Ir finally, in phase 4 according to Figure 6, the hole 16
should serve only for cleaning or checking, it may be closed by a cover 18
connected to the flange 11 by screws or boltsg sealing 19 being interposed
between the flange 11 and the cover lô.
The pipe portions remaining on both sides of the opening 5 for the
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riser 6, and which act as a tunnel~ contain the additional tensions caused
by the deviation of the container walls from the membrane form, while sudden
changes of cross-section are avoided~ In view of the two-sided containing
of the longitudinal end edge stresses bulging of the cylindrical walls of the
container is reliably avoided.
Forces which are caused by the inner pressure and which act trans-
- versely to the discharge spout 3, are received by the oval cross-section of
the pipe 8 according to the second embodiment better at otherwise the same
trough depth, or at the same pipe width the depth is smaller. The oval
lo shape allows further substantial shortening of the pipe cut-out on the top
of the spout; in spite of this the pipe end, adapted to the projection Or
the inwardly situated valve 14, is attached along the whole circumference
to the block ~lange ll.
In the closed embodiment according to Figure l the upper pipe por-
tion can otherwise be additionally used as an inner support for such a spring
controlled valve.
Figure 7 shows a cylindrical transport container la for liquid for
gaseous media or for loose material which is, in a manner known per se,
supported in a frame 2a situated at the ends of the container. The cylin-
drical shells 3a are reinforced by reinforcing rings 4a to resist increasedpressure from outside. In the top region o~ the transport container la is
situated a manhole ring 6a covered by a disc cover 5a. This manhole ring
6a is very compact and capable of withstanding shear~o~f forces and is
situated9 in the direction of transport, in front of the pipe 8a according
to the invention, which is so mounted at the top in the wall of the container
parallel to its longitudinal axis that the upper area of its wall pro~ects
in the manner of a dome, abo~e the uall of the container. In the embodiment
shown in Figure 7 the pipe 8a is closed at its both ends by segments 9a of a
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spherical shell. Pipe spouts lOa are situated spaced apart in horizontaL or
obliquely upwardly extending direction, and on these spouts are mounted
various fixtures or dum~y flanges lla. A protective frame is formed by con-
; nection members 12a which extend from the outer outlines of the manhole to
the frames at the enas of the container. In the illustrated embodiment of
the liquid container, both spouts extend to one side. If a blow-off of the
liquid is envisaged it is sufficient to provide on this side a removable
collector 13a provided with a discharge channel 14a. The protective frame
me~tioned earlier may be adapted to serve as a cover 7a preventing stealing
or serving as a customs seal. Preferably also a working platfrom and a lad-
der (not illustratedj may be incorporated into the protective frame.
Figure a shows the pipe 8a, dished in a dome-shaped manner accord-
ing to Figure 7 in cross~section. The pipe waLl and the container wall are
at 15a connected by e.g. a double fillet weld. The cross-section of the
pipe 8a is circuLar. It can, however, be a:Lso elliptic or oval, as shown
on the pipe 16a in Figure 9, the maJor axis of the ellipse extending hor-
izontally. Figure 10 shows in longitudinal section a pipe 17a which is at
one end closed b~ a flange loa, while at the other end, ad~acent the manhole
l9a~ it is closed by a section 20a of a spherical shell. The part of the
wall of the pipe which is situated inside the container is provided with
openings 21a (Figure 10). These openings 21a are in the illustrated embod-
iment circular. The wall bridges of the pipe 8a between the openings 21a
serve to contain edge stresses caused by pressures inside the container. The
wall bridges of the pipe 8a remaining between the openings 21a ser~e also to
prevent splashing of the liquid in the container during transport. Due to
the arrangement of the pipe according to the invention behind the manhole
l9a in the direction of transport is achieved that fixtures attached to the
pipe received the best possible protection from damage. According to one
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embodiment (Figure lOa), the pipe may end at one end on the ring 6a of the
manhole l9a, and one end of the pipe 8a may end on a transverse element of
the frame.
Figure 11 shows part of a container la which for the best possible
utilisation of space inside the container is provided bo~th by height saving
arrangement of fixtures on one pipe 8a and also height saving provision of
a pipe 3a on the bottom of the container.
It is seen ~rom the drawing that the pipe 8a, dished in a dome-
shaped manner and extending over the container top corresponds symmetrically
to bottom sump 3.
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