U.S. patent number 3,866,785 [Application Number 05/314,136] was granted by the patent office on 1975-02-18 for liquefied gas container.
This patent grant is currently assigned to Beatrice Foods Co.. Invention is credited to Rolland R. Conte.
United States Patent |
3,866,785 |
Conte |
February 18, 1975 |
LIQUEFIED GAS CONTAINER
Abstract
A double walled liquefied gas container formed with an inner
storage vessel and a spaced outer shell with insulation in between
with a low heat conductive neck tube connecting the access opening
of the inner vessel with the access opening through the outer shell
with heat conductive ring members preassembled in conductive
relation longitudinally spaced along the neck tube and disc members
of larger dimension joined in contacting relation with the outer
end portions of the ring members and in which the insulation
includes layers of heat conductive material wrapped in contacting
relation with the disc members and which includes means for
connecting the neck tube to the access opening in the outer shell
to permit relative angular and lengthwise movement between the
inner vessel and outer shell and to limit relative rotational
movement.
Inventors: |
Conte; Rolland R.
(Bourdonne/Conde, FR) |
Assignee: |
Beatrice Foods Co. (Chicago,
IL)
|
Family
ID: |
23218719 |
Appl.
No.: |
05/314,136 |
Filed: |
December 11, 1972 |
Current U.S.
Class: |
220/560.13;
62/47.1; 62/48.1 |
Current CPC
Class: |
F17C
13/005 (20130101); F17C 3/08 (20130101); F17C
2203/018 (20130101) |
Current International
Class: |
F17C
3/08 (20060101); F17C 13/00 (20060101); F17C
3/00 (20060101); F17c 013/00 () |
Field of
Search: |
;220/9R,9A,9LG,9L,9D,14,15 ;62/50,54 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Price; William I.
Assistant Examiner: Marcus; Stephen
Claims
1. In a double walled liquefied gas container having an inner
storage vessel with an opening at the top for access into the
interior of the vessel, an outer shell substantially enclosing said
inner shell with an insulation space in between, a neck tube
connected at one end to the inner vessel about the opening and at
the other end with an opening through the outer shell for the
transmission of liquid and vapors therethrough into and out of the
vessel, and a composite multi-layered insulation disposed about the
inner vessel within said insulated space comprising multi-layers of
low thermal insulating material alternating with one or more layers
of reflective barrier sheets, the improvement comprising a
plurality of rings of high heat conductive material secured in
thermally contacting relation along longitudinally spaced apart
portions of the neck tube and which extend outwardly from the neck
tube for a short distance, disc members formed of thermally
conductive material each having a central opening corresponding to
the cross section dimension of the rings with one disc member
secured at its inner edge portion to each of corresponding ones of
said rings in thermally contacting relation, and heat conductive
layers extending into the multi-layered insulation and overlapping
at least a portion of each disc member for contacting relation
therewith, in which the rings are formed with an annular skirt
portion depending from the peripheral edge portion of the rings and
in which the disc members are formed with an annular skirt portion
extending substantially perpendicularly from the inner periphery
thereof and means joining the skirt portions of said rings said
disc members in telescoping relation one
2. A double walled container as claimed in claim 1 in which the
skirt
3. In a double walled liquefied gas container having an inner
storage vessel with an opening at the top for access into the
interior of the vessel, an outer shell substantially enclosing said
inner shell with an insulation space in between, a neck tube
connected at one end to the inner vessel about the opening and at
the other end with an opening through the outer shell for the
transmission of liquid and vapors therethrough into and out of the
vessel, and a composite multi-layered insulation disposed about the
inner vessel within said insulated space comprising multi-layers of
low thermal insulating material alternating with one or more layers
of reflective barrier sheets, the improvement comprising a
plurality of rings of high heat conductive material secured in
thermally contacting relation along longitudinally spaced apart
portions of the neck tube and which extend outwardly from the neck
tube for a short distance, disc members formed of thermally
conductive material each having a central opening corresponding to
the cross sectional dimension of the rings with one disc member
secured at its inner edge portion to each of corresponding ones of
said rings in thermally contacting relation, and heat conductive
layers extending into the multi-layered insulation and overlapping
at least a portion of each disc member for contacting relation
therewith, in which the layers of thermally insulating material
terminate short of the neck tube and rings but overlap the outer
end portion of the disc members in
4. A double walled container as claimed in claim 3 in which the
rings are silver soldered to the neck tube.
Description
This invention relates to a double-walled container having an
evacuated space in between which is adapted to be provided with a
thermal insulating system including insulation material, reflective
barrier layers and heat conductive shields, and it relates more
particularly to an insulated container of the type described which
is adapted for use with material having a temperature that differs
widely from the temperature adjacent the outer wall of the
container.
While the invention will be described with reference to a container
adapted to house a low boiling liquefied gas, such as helium, neon,
hydrogen and the like, it will be understood that the container of
this invention finds equal use in the storage and transportation of
other low boiling liquefied gases such as liquefied oxygen,
nitrogen, methane, LNG, ammonia and the like, or for use with
fluids at high temperature, such as in the storage or
transportation of molten metal or in the housing of sodium or
potassium for power cell conversion and the like.
Many types of insulated containers have been proposed for storage
and transportation of low boiling liquefied gases. In general, as
described in the Matsch U.S. Pat. No. 3,007,596; No. 3,009,600 and
No. 3,009,601, such containers are formed with an inner vessel for
housing the liquefied gas and an outer vessel which surrounds the
inner vessel with a spaced relation in between to provide an
intervening insulated space which is preferably, though not
necessarily, maintained under vacuum. An insulation system composed
of multiple layers of a low conductive material, with an occasional
heat reflective barrier sheet, is disposed within the intervening
space with the layers disposed generally parallel to the walls of
the vessel so as to extend normal to the direction of heat flow
between the walls.
A fluid conduit, in the form of a neck tube, extends vertically
from the inner vessel through the top of the outer vessel for
communication with the interior of the inner vessel for the passage
of liquid and gases into and out of the container. In some
containers, the neck tube serves to support the inner vessel while
the insulation system provides lateral support, while in other
containers, the neck tube does not serve to support the inner
vessel but nevertheless is interconnected both with the inner
vessel and the outer vessel.
In U.S. Pat. No. 3,272,374, issued Sept. 13, 1966, description is
made of a means for mounting the neck tube with a pivoted swivel
joint to minimize the effect of sudden deflection loads which might
impose severe loading on the neck tube, especially when it is used
to support the inner vessel. This is alleged to be achieved without
objectionable increase in the heat inleak.
In U.S. Pat. No. 3,133,442 description is made of an insulation
system of the type described in which heat inleak is reduced by the
addition of heat conductive shields to the insulation layer and the
reflective barriers, with the heat conductive shields being secured
to the neck tube in good heat conductive relation so as to be able
to conduct the heat, interrupted by the shield, to the neck
tube.
For this purpose, axially spaced apart disc members are secured to
the outer wall of the neck tube. The layers of insulation material,
including the occasional radiant heat barrier layer are wrapped,
preferably spirally, about the innermost vessel to a desired
thickness, corresponding to the level of a first disc member.
Thereafter a shield of conductive metal, such as copper or
aluminum, is installed about the built-up insulation with an
overlap onto the disc to which it is secured by a soldering or
other metal bonding means to provide a connection of low thermal
resistance or of high thermal conductivity for transfer of heat
from the shield to the disc and neck tube. Thereafter, the
operations are repeated serially until the insulation system with
the heat conductive shields has been installed. This not only
requires interruption of the winding operation to build up the
insulation layers about the inner vessel for purposes of metal
bonding the heat conductive shields to the disc plates, but the
actual bonding operation is time consuming and difficult to achieve
by reason of the limited access and the flexibility of the
relatively thin metal members. In addition, such metal bonding at
elevated temperature subjects the element, including the disc and
the neck tube, to distortions which subsequently interfere with the
utility of the insulated container and the useful life thereof and
it is difficult to leak test the neck assembly after each disc has
been applied, especially when the container is mounted on the
wrapping machine.
In the construction described in the aforementioned patent,
utilization is made of neck tubes of relatively thin metal members
with the intent of reducing heat inleak, but at the expense of
structural integrity and ability to sustain lateral impact loads,
with the result that special and expensive procedures are required
to improve the resistance of the container to such sudden
deflection loads.
It is an object of this invention to produce an insulated container
of the type described which is characterized by an improved neck
tube construction and insulation system whereby the combination of
thermal layers of thermal insulating material, reflective barrier
sheets, and heat conductive shields can be applied in the desired
sequence for disposition in the insulating space between the inner
and outer vessels, without interrupting the winding operation, in
which the neck tube can be fabricated with the desired extension
for installation into position of use to interconnect the inner and
outer vessels thereby to avoid fabrication steps on the neck tube
while in the assembled relation, in which means are provided to
limit the relative turning movement between the inner container and
neck tube and the supporting elements from the outer vessel,
thereby to provide for greater stability and strength, and in which
the neck tube is characterized by greater strength and stability
whereby the resistance to sudden deflection loads can be markedly
increased for greater utility of the insulated container.
These and other objects and advantages of this invention will
hereinafter appear and for purposes of illustration but not of
limitation, an embodiment of the invention is shown in the
accompanying drawings in which
FIG. 1 is a schematic sectional elevational view of an insulated
container embodying the features of this invention;
FIG. 2 is an enlarged sectional elevational view of a portion of
the container shown in FIG. 1, illustrating in greater detail the
neck tube construction and insulation;
FIG. 2a is a perspective view of the split ring used in the neck
tube assembly;
FIG. 3 is a top plan view of the elements forming a part of the
neck tube construction for limiting relative rotational movement;
and
FIG. 4 is a top plan view of disc members employed in the support
means for the neck tube.
Referring now to the drawings, where like numerals represent like
parts, the insulated container 10 is formed of an inner vessel 12
and an outer vessel 14 with an insulated space 16 in between, said
space preferably being an evacuated space. The inner vessel is
preferably supported by a hollow fluid conduit, hereinafter
referred to as a neck tube 18, secured to the top of the inner
vessel by means of an adaptor 20 for communicating the interior of
the inner vessel with valve means (not shown) beyond the outer
vessel.
The portion of the neck tube 18, disposed in the space between the
inner and outer vessels, is provided with a plurality of ring
members 32 of highly conductive material, which are joined to the
outer wall of the neck tube portion in axially spaced apart
relation. When the ring members are formed of a highly conductive
metal, such as copper or aluminum, the metal ring members may be
spun onto the neck tube prior to assembly, or the ring members can
be provided in the form of metal disc members having a central
opening corresponding to the outer wall to wall diameter of the
neck tube and to which the ring members are secured by a metal
bonding means, such as silver soldering 34 and the like, in the
desired axially spaced apart relation. When the ring members and
neck tube are formed of plastic, such as carbon filled plastic,
ceramic filled plastic, or of such plastic materials as Teflon
(tetrafluoroethylene) or Nylon (polyester) or the like, the neck
tube and ring members can be molded as an integral unit.
The peripheral end portions of the ring members are turned to
extend downwardly substantially perpendicularly to provide a short
skirt 36 of cylindrical shape, preferably having openings to enable
use of a pop rivet 38 for securing an annular flange 40, having a
central opening 42 dimensioned to correspond to the diameter of the
ring member 32, with an upturned portion 44 at the inner periphery
which telesopes onto the skirt. The upturned flanged portion 44 is
provided with aligned openings for enabling the rivet to extend
therethrough to connect the flange 40 onto the ring 32. The flange
40 is split, as at 43, to facilitate mounting onto the ring 32.
Instead of riveting the flange onto the ring, the flange can be
secured to the ring by other fastening means, with the flange being
dimensioned to extend horizontally outwardly for a distance beyond
the ring members.
In assembly, the neck tube with the ring members 32 preassembled
thereon, is joined via the adaptor 46 to the inner vessel, with the
opening of the neck tube in communication with the inlet opening 48
through the inner vessel.
In this assembled relation, the inner container is mounted in the
insulation fixture and the desired number of layers of insulating
material and intermittent layers of heat reflecting barrier strips
are applied, as by spiral winding, onto the inner vessel.
Thereafter the insulating operation is stopped and a flange member
40 is secured to the next adjacent ring member, and the heat
conducting shield, such as 4 to 20 layers of aluminum foil, are
applied, as by winding, onto the insulation to form a layer which
overlaps the outer portion of the flanged member 40 short of the
ring 32. The application of the insulation layer and occasional
reflective barrier sheet is repeated followed by attachment of the
next flanged member and application of the heat conductive shield,
until the insulation system has been built up in the insulated
space.
An annular space 50 will exist between the neck tube 18 and the
inner edge of the insulation wrapped about the flanged members 40
since the insulation and conductive sheets will be wrapped in a
manner which may overlap the flange and a portion of the ring, with
such wrapping usually terminating short of the neck tube.
The neck tube 18 is provided at its upper end, beyond the
insulation, with means for attachment to the outer vessel, but in a
manner which enables a limited amount of relative movement while
maintaining a sealed relation for evacuation of the space in
between. For this purpose, there is provided a dome cap 52 having
an outlet opening 54 at the top and oftentimes a skirt portion 56
which is received in fitting relation in an opening through the top
of the outer vessel 12 and to which it is secured in sealing
relation, as by welding 60, whereby the interior of the dome
communicates with the insulated space but is sealed from the
atmosphere.
The neck tube 18 is joined to the dome by way of an expandable
bellows 62 secured at its upper end to the dome member by a top
neck flange 64 in the form of a sleeve member which is joined at
its lower portion to the upper end of the bellows and at its upper
portion to the domed member about the outlet opening 54, with a
sealing relation between the top neck flange 64 and the dome
member. Rod members 66 interconnect the lower end portion of the
bellows 62 at the upper end portion of the neck tube 18, whereby
the interior of the inner vessel communicates with the outlet in
the dome via the aligned openings through the neck tube 18 and
bellows 62, with the mounting sleeve members 64 and rods 66. The
rod members 66 can be fabricated of poor thermal insulating
material, such as titanium, nylon, reinforced plastics, and the
like.
Means are provided to support the neck tube from the dome by a
suspension which permits angular and turning movements as well as
axial movement. In the illustrated modification, the neck tube 18
is supported from the sleeve 64 by way of a plurality of
circumferentially spaced apart suspension rods 66 operatively
engaged at their upper end portion by a horizontally disposed disc
member 68 secured to the neck flange 64 for rigid attachment to the
dome and which are pivotally attached at their lower end portion to
another disc member 70 secured to the sleeve section 64 rigid with
the upper end portion of the bellows 62 which, in turn, receives
the upper end of the neck tube in sealing engagement.
To permit relative movement between the neck tube 18 and the dome
support 52 via the bellows, the rod length is equal to and
preferably shorter than the bellows 62. The disc members 68 and 70
are provided with vertically aligned openings 72 through which the
rods extend with the through-extending portions having head
sections 74 and 76 dimensioned to be greater than the openings 72,
and bearing portions 78 and 80 immediately inwardly of the head
portions 74 and 76, and which are dimensioned to be slightly less
in crosswise dimension than the openings 72 and which are located
within the openings in a manner to permit relative axial movements
and limited play for relative angular movement. In the preferred
embodiment, one or both of the through-extending end portions of
the suspension rods can be threaded while the head member is in the
form of a nut member in threaded engagement therewith to permit
axial adjustment of the spaced relationship between the supporting
upper and lower discs.
The head portion and the adjacent bearing portion at the opposite
ends of the bearing rods are connected by a spindle portion 82 of
considerably lesser cross section.
The disc members 68 and 70 are designed to enable insertion of the
rod members into position of use. For this purpose, each of the
disc members are formed with a central opening 84 for connection to
the top and bottom neck flanges. A number of openings 72,
corresponding to the number of suspension rods, are provided in
circumferentially spaced apart relation a short distance inwardly
from the periphery of the disc member with the openings dimensioned
to be less than that of the head portions 74 and 76 but slightly
larger than the bearing portions 78 and 80 of the rods. A radial
slot 86 extends radially inwardly from the periphery to the opening
with the slot dimensioned to have a width slightly greater than the
width of the spindle portion 82 but less than the bearing portion
to enable the rod to be inserted into the disc by radial
displacement of the spindle portion through the slot to the opening
and then axial displacement in the opening until the bearing
portion is seated within the opening.
Though not essential, means are provided to restrict rotation of
the inner vessel 12 relative to the outer vessel and dome
support.
As illustrated in FIGS. 2 and 5, a round disc plate 90 is provided
with openings 92 extending therethrough, corresponding in number to
the number of suspension rods 66 and on the same circle diameter,
so that one opening 92 will be located in axial alignment with each
rod. The rods 66 are dimensioned to have a length whereby a
machined down end portion 94 extends through the aligned opening 92
in the disc 90, with a clearance therebetween which defines the
maximum amount of relative movement between the rod 66 and the disc
90.
The outer periphery of the disc member 90 is fixed, as by welding,
to the lower end portion of a tubular member 96, which, in turn, is
fixed at its upper end portion to the disc member 68 and the sleeve
64 rigid with the dome 52 and the outer container 10. Thus the disc
90 is rigid with the outer container and the only rotational
movement of which the neck bellows 62 is capable is defined by the
clearance between the diameter of the openings 92 and the diameter
of the through-extending end portion 94 of the rods 66.
Though not essential, it is often desirable to restrict vertical
movement as well. For this purpose, as illustrated in FIGS. 2 and
4, block 100 is secured, as by welding, to the tubular member 96 in
position to overhang the disc plate 70 in an area between the
suspension rods 66. Disc plate 70, being fixed to the neck tube and
the block 100 being fixed to the dome and outer container 10,
relative vertical movement is restricted to the distance between
the top of the disc plate 70 and the bottom of the overhanging
block 100.
The described construction enables the use of a lesser number of
heat conductive shields. This, in turn, enables the use of a
shorter neck tube as well as a neck tube of greater wall thickness
thereby to provide a structurally strong neck tube assembly which
is capable of taking more load and more bend to withstand
deflective loads which are many times greater than deflective loads
capable of being withstood by prior constructions of the type
described.
The amount of heat required to be intercepted by the heat shields
by conductive conveyance to the neck tube is relatively minor, such
that the contact achieved by merely wrapping the heat shield over a
portion of the flanged member 40 is sufficient to obtain the
desired flux in the insulation system. This, of course, minimizes
the importance of the neck tube as a heat conductive member and
therefore enables utilization of a shorter neck tube of greater
wall thickness with the advantages as outlined above.
It will be understood that changes may be made in the details of
construction, arrangement and operation, without departing from the
spirit of the invention, especially as defined in the following
claims.
* * * * *