U.S. patent application number 12/769313 was filed with the patent office on 2011-03-17 for system for pressure release from a closed container and a container for use therefore.
This patent application is currently assigned to UCON AG Containersysteme KG. Invention is credited to HERMANN GRIMM.
Application Number | 20110062157 12/769313 |
Document ID | / |
Family ID | 41501725 |
Filed Date | 2011-03-17 |
United States Patent
Application |
20110062157 |
Kind Code |
A1 |
GRIMM; HERMANN |
March 17, 2011 |
SYSTEM FOR PRESSURE RELEASE FROM A CLOSED CONTAINER AND A CONTAINER
FOR USE THEREFORE
Abstract
The invention is a safety device, and a container utilizing such
a device, for release of pressure from a closed container, when the
container is heated. The container has a ventilation opening,
sealed by a disk which is made to melt at a critical temperature.
The disk is manufactured from a plastic and has at least one recess
in the area of the ventilation opening. The ventilation opening is
situated at one end of a ventilation pipe, wherein the pipe is at
least partially overlapped by the affixing device and detachably
connected to it. The ventilation pipe has an exterior threading
located at the end of the pipe overlapped by the affixing device.
The detachable connection can be made by screwing the sleeve nut
onto the exterior threading. The disk has a design of varied
geometry embedded therein; the design creating varying surface
thicknesses for the disk, which allow the disk to melt at varying
rates depending upon the temperature of the interior of the
container.
Inventors: |
GRIMM; HERMANN;
(Schuttertal, DE) |
Assignee: |
UCON AG Containersysteme KG
Hausach
DE
|
Family ID: |
41501725 |
Appl. No.: |
12/769313 |
Filed: |
April 28, 2010 |
Current U.S.
Class: |
220/203.01 |
Current CPC
Class: |
B65D 88/12 20130101;
B65D 2588/125 20130101; B65D 90/36 20130101 |
Class at
Publication: |
220/203.01 |
International
Class: |
B65D 51/16 20060101
B65D051/16 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 17, 2009 |
DE |
20 2009 012 542.4 |
Claims
1. A safety device for release of pressure from a closed container,
when said container is heated, said safety device comprising: (a) a
ventilation opening; (b) a disk that covers said ventilation
opening so as to seal said ventilation opening, said disk further
comprised of a material that melts at a critical temperature; and
(c) affixing means for affixing said disk so as to cover said
ventilation opening to said container.
2. A safety device according to claim 1, wherein said disk is
manufactured from a plastic, especially from PTFE.
3. A safety device according to claim 1, wherein said disk has at
least one recess in the area of said ventilation opening.
4. A safety device according to claim 1, wherein said disk is made
from a material suitable to carry advertising or a logo.
5. A safety device according to claim 1, wherein said ventilation
opening is situated at one end of a ventilation pipe, and wherein
said ventilation pipe is at least partially overlapped by said
affixing device.
6. A safety device according to claim 5, wherein said ventilation
pipe and said fixing device are detachably connected to each
other.
7. A safety device according to claim 6, wherein said ventilation
pipe further comprises: (a) an overall circular cross section, and
(b) an exterior threading, wherein said exterior threading is
provided at the end of said ventilation pipe overlapped by said
affixing device.
8. A safety device according to claim 7, wherein said affixing
device is a sleeve nut adapted to said exterior threading, and said
detachable connection can be made by screwing said sleeve nut onto
said exterior threading.
9. A safety device according to claim 1, wherein said disk has a
design of varied geometry embedded therein, said design creating
varying thicknesses with the surface of said disk, said varying
thicknesses allowing said disk to melt at varying rates depending
upon the temperature of said interior of said closed container,
said varying melting rates thus optimizing the release of pressure
from said previously closed container.
10. A containment system, said containment system comprising a
container, said container being sealed when in use, and further
comprising: (a) a rack; and (b) a vessel, said vessel situated
inside said rack and further comprising: (i) at least one
ventilation opening; and (ii) at least one safety device situated
on a corresponding one of said at least one ventilation openings
for pressure release, and wherein for pressure release said safety
device further comprises: (1) a disk covering said ventilation
opening in sealing fashion and made of a material that melts at a
critical temperature; and (2) an affixing device for said disk that
covers said ventilation opening.
11. A containment system according to claim 10, wherein said vessel
has a filling opening.
12. A containment system according to claim 10, wherein at least
one of said ventilation openings is situated on the top side of
said vessel.
13. A containment system according to claim 10, wherein said disk
is manufactured from a plastic, especially from PTFE.
14. A containment system according to claim 10, wherein said disk
has at least one recess in the area of said ventilation
opening.
15. A containment system according to claim 10, wherein said disk
is made of a material suitable to carry advertising or a logo.
16. A containment system according to claim 10, wherein said at
least one ventilation opening is placed at one end of a ventilation
pipe, said ventilation pipe at least partially overlapped by said
affixing device.
17. A containment system according to claim 16, and wherein one end
of said ventilation pipe and said affixing device are detachably
connected with each other.
18. A containment system according to claim 17, wherein said
ventilation pipe further comprises: (a) an overall circular cross
section; and (b) an exterior threading on said end of said pipe
overlapped by said affixing device.
19. A containment system according to claim 17, wherein said
affixing device is a sleeve nut adapted to said exterior threading,
and that said detachable connection can be made by screwing said
sleeve nut onto said exterior threading.
20. A containment system according to claim 10, wherein said disk
has a design of varied geometry embedded therein, said design
creating varying thicknesses with the surface of said disk, said
varying thicknesses allowing said disk to melt at varying rates
depending upon the temperature of said interior of said closed
container, said varying melting rates thus optimizing the release
of pressure from said previously closed container.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from German Patent
Application Serial No. 20 2009 012 542.4, filed Sep. 17, 2009, the
entire contents of which is herein incorporated fully by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a safety device for
releasing pressure from closed containers when heated. More
specifically, the present invention relates to a disk or plate for
covering the opening of a container, wherein the disk or plate
dissolves at a particular temperature threshold so as to release
pressure within the container when heated.
[0004] 2. Description of the Related Art
[0005] When fluids are transported in closed containers,
considerable pressure can build up in the interior of the
containers, particularly if the container is heated; this can
ultimately cause the container to burst. For this reason, for
example, in trade-law regulations with regard to construction of
metallic intermediate bulk containers (IBC) for carriage of
hazardous fluids, provision of a device to release pressure is
mandatory. The purpose of these regulations is to prevent bursting,
and thus uncontrolled release of the hazardous fluid into the
environment.
[0006] What is not appreciated by the prior art is that, until now,
as a rule, spring-loaded valves have been used for pressure
release. These valve types have a series of substantial
disadvantages.
[0007] Proper functioning of such a valve for pressure release when
heated, of necessity pre-supposes that the response pressure at
which spring force is overcome is relatively low. Typically, an
excess pressure of 20,000 Pa to 65,000 Pa is enough to make the
valve respond. However, these pressure thresholds are exceeded, for
example, when the container is subject to mechanically-induced
pressure spikes during transport and loading, so that the valve
opens in undesired fashion and fluid can splash out of the opening.
Thus, such an IBC cannot travel if fully sealed.
[0008] A further disadvantage arises from the fact that customarily
used spring-loaded valves, especially any sealing elements such as
rubber that are present in the valves, are not resistant to
numerous filling media. This results in a considerable expense for
maintenance.
[0009] Accordingly, there is a need for a simpler and more
cost-effective device for pressure release of closed containers
when heated, and a simpler and more cost-effective small container
with a pressure release device.
ASPECTS AND SUMMARY OF THE INVENTION
[0010] An aspect of the present invention is to provide a simpler
and more cost-effective device for pressure release of closed
containers when heated.
[0011] Another aspect of the present invention is to provide a
simpler and more cost-effective small container with a pressure
release device.
[0012] The invention-specific safety device for pressure release of
a closed container when heated has at least one ventilation
opening, a covering disk or plate made of a material that melts at
a critical temperature, sealing the ventilation opening, and an
affixing device for the disk or plate that covers the ventilation
opening. Taken by itself, in the absence of the disk or plate, the
affixing device must permit the fluid to emerge from the container
through the ventilation opening into the environment. This is the
case for example if an at least partially fluid-permeable affixing
device is utilized; but, also if, for example, the disk or plate is
securely glued on the edge of the ventilation opening or securely
clamped at discrete locations on the edge of the ventilation
opening.
[0013] The pressure in the interior of a closed container is
dependent on the temperature in the interior of the container. When
the container is heated, the pressure rises, which, upon reaching a
pressure limit value and thus a limit temperature, could cause the
container to burst and the container's contents to come out in
uncontrolled fashion. The limit temperature for a given container
is dependent on the properties of the container and the fluid with
which it is filled; this can, for example, be determined in
combustion tests.
[0014] As the critical temperature according to this invention, a
temperature is to be understood that lies some degrees Celsius
below the limit temperature, to ensure that the melting process has
been sufficiently completed so that the pressure has been equalized
as necessary before the limit temperature is reached.
[0015] Until the critical temperature has been reached, the disk or
plate seals the ventilation opening. The affixing device prevents
the plate or disk from slipping or shifting, which could cause the
ventilation opening to be opened in undesired fashion.
[0016] When the critical temperature is reached, the disk or plate
melts and uncovers the ventilation opening, so that the affixing
device taken by itself, i.e. in the absence of the disk or plate,
allows fluid to exit from the container through the ventilation
opening into the environment, and the pressure can be equalized via
the ventilation opening.
[0017] Plastic is an especially suitable material for the disk or
plate due to its good resistance to a number of typical filling
materials and due to good adaptability of melt temperatures. PTFE
(polytetrafluoroethylene), in particular, has proven itself for
many typical applications.
[0018] Fundamentally, the time needed for the actual opening of at
least a part of the ventilation opening, between the onset of the
melting process and the plate or disk melting through, is dependent
on their geometry, especially their thickness. This results in a
relationship of tension between a required minimum stability of the
disk or plate that should be able to support itself and resist
disruptive influences from without, and a delay that results from
the onset of pressure equalization. However, this problem can be
solved if the disk or plate has at least one recess and/or an
enclosed groove in the area of the ventilation opening.
[0019] The recess results in a thinner partial section of the disk
or plate that correspondingly melts through and can cause pressure
equalization more quickly than the rest of the disk or plate, which
ensures the desired stability. Instead of a staged recess, it is
also possible to provide a continuous variation in thickness in an
appropriate area of the disk or plate, so that in case the
temperature fails to drop, the opening available for pressure
equalization gradually increases further.
[0020] Providing an enclosed groove, i.e. a channel-like recess in
the material of the disk or plate, whose starting point connects to
its end point, permits a relatively large opening to be provided by
melting away a relatively small amount of material, namely the base
of the groove, which results when the base of the groove melts
away, and the section of the disk or plate surrounding the groove
drops out.
[0021] An advantageous additional effect is achieved if the disk or
plate is manufactured from a material suitable to carry advertising
or a logo. Alternatively, it is also possible to apply a logo as a
relief-like recess into the disk or plate.
[0022] One especially simple-to-produce embodiment form of the
securing device can result by placing the ventilation opening at
one end of a ventilation pipe which is at least partially
overlapped by the affixing device.
[0023] To make it possible to replace a damaged or molten disk or
plate, provision is made that the end of the ventilation pipe and
the affixing device be detachably connected to each other.
[0024] This can be technically implemented with especial ease if
the ventilation pipe is a pipe with an overall circular cross
section that is provided on the end overlapping the affixing device
with an exterior threading; that the affixing device is a sleeve
nut adapted to the exterior threading, and that the detachable
connection be made by screwing the sleeve nut on the exterior
threading. With this, overall cross section means that it does not
need to have the inner cross section of the opening that impinges
in the pipe of this feature, but rather the interior cross section
and the cross section including the cross section of the pipe
wall.
[0025] The invention-specific small container has a rack and a
vessel situated within the rack with at least one ventilation
opening and at least one device for pressure release, situated at
the at least one ventilation opening of the container. According to
the invention, the device for pressure release has a disk or plate
covering the ventilation opening consisting of a material that
melts below a critical temperature, and an affixing device for the
disk or plate covering the ventilation device. Taken by itself, in
the absence of the disk or plate, the affixing device must permit
the fluid to emerge from the container through the ventilation
opening into the environment. This is the case for example if an at
least partially fluid-permeable fixing device is utilized, but also
if for example the disk or plate is securely glued on the edge of
the ventilation opening or securely clamped at discrete locations
on the edge of the ventilation opening.
[0026] Until the critical temperature has been reached, the disk or
plate seals the ventilation opening. The affixing device prevents
the plate or disk from slipping or shifting, which could cause the
ventilation opening to be opened in undesired fashion. When the
critical temperature is reached, the disk or plate melts and
releases the ventilation opening, so that the affixing device taken
by itself, i.e. in the absence of the disk or plate, allows fluid
to exit from the container through the ventilation opening into the
environment, and the pressure can be equalized via the ventilation
opening.
[0027] It is especially advantageous if the small container has a
vessel with more than one ventilation opening and/or an additional
filling opening. It is especially favorable to place one of the
ventilation openings on the upper side of the vessel.
[0028] Plastic is an especially suitable material for the disk or
plate due to its good resistance to a number of typical filling
materials and due to good adaptability of melt temperatures. PTFE
(polytetrafluoroethylene), in particular, has proven itself for
many typical applications.
[0029] For the reasons already discussed above, it is advantageous
if, in the area of the ventilation opening, the disk or plate has
at least one recess and/or an enclosed groove. The recess and/or
enclosed groove results in a thinner partial section of the disk or
plate that functions as a stress concentrator and also
correspondingly melts through at a different rate due to lower mass
and thermal transfer and can cause pressure equalization more
quickly than the rest of the disk or plate, which ensures the
desired stability. Instead of a staged recess, it is also possible
to provide a continuous variation in thickness in an appropriate
area of the disk or plate, so that in case the temperature fails to
drop, the opening available for pressure equalization gradually
increases further. Owing to melting through of a small area, the
groove quickly allows a large opening to become available for the
pressure equalization, as was explained above.
[0030] An advantageous side effect is achieved if the disk or plate
is manufactured from a material suitable to carry advertising or a
logo. Alternatively, it is also possible to apply a logo as a
relief-like recess into the disk or plate.
[0031] One especially simple-to-produce embodiment form of the
safety device can result by placing the ventilation opening at one
end of a ventilation pipe which is at least partially overlapped by
the affixing device.
[0032] To make it possible to replace a damaged or molten disk or
plate, provision is advantageously made that the end of the
ventilation pipe and the fixing device be detachably connected to
each other.
[0033] This can be technically implemented with especial ease if
the ventilation pipe is a pipe with an overall circular cross
section that is provided on the end overlapping the affixing device
with an exterior threading; that the affixing device is a sleeve
nut adapted to the exterior threading, and that the detachable
connection be made by screwing the sleeve nut on the exterior
threading. Overall cross section means that it does not need to
have the inner cross section of the opening that impinges in the
pipe of this feature, but rather the interior cross section and the
cross section including the cross section of the pipe wall.
[0034] The above, and other aspects, features and advantages of the
present invention will become apparent from the following
description read in conjunction with the accompanying drawings, in
which like reference numerals designate the same elements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] FIG. 1 is a perspective view of the safety device of the
present invention.
[0036] FIG. 2a is a perspective view of a disk of the safety device
as shown in FIG. 1.
[0037] FIG. 2b is an angled view from above of the disk of the
safety device from FIG. 2a.
[0038] FIG. 3 is a perspective view of a container employing the
safety device of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0039] Reference will now be made in detail to several embodiments
of the invention that are illustrated in the accompanying drawings.
Wherever possible, same or similar reference numerals are used in
the drawings and the description to refer to the same or like parts
or steps. The drawings are in simplified form and are not to
precise scale. For purposes of convenience and clarity only,
directional terms, such as top, bottom, up, down, over, above, and
below may be used with respect to the drawings. These and similar
directional terms should not be construed to limit the scope of the
invention in any manner. The words "connect," "couple," and similar
terms with their inflectional morphemes do not necessarily denote
direct and immediate connections, but also include connections
through mediate elements or devices.
[0040] Turning first to FIG. 1, there is shown an embodiment
example of the safety device 10 according to present invention
where a housing wall 15 of a container (see FIG. 3) is penetrated
by a ventilation opening situated at the end of a ventilation pipe
11 with an overall circular cross section, connected with the
housing wall. The ventilation opening itself is not perceptible in
FIG. 1, since it is covered by a disk 13 which covers the
ventilation opening in sealing fashion. The disk is made of a
material that melts at a critical temperature. It is adapted to an
exterior thread 14 made on the overlapping end of ventilation pipe
11, whose lowest threading can be seen in FIG. 1, and engages with
the ventilation pipe by being screwed on. The sleeve nut 12 fixes
the disk 13 in place. In the area of its borehole, it is
fluid-permeable.
[0041] If the temperature rises at least to the critical
temperature in the interior of the container, disk 13 melts and the
pressure is equalized, which prevents the vessel from bursting.
[0042] Turning then to FIG. 2a, there is shown is a view of the
disk of the safety device 10 from FIG. 1. Disk 13 has a recess 21
and an island 23 formed by an enclosed groove 22. Recess 21 and
closed groove 22 are shown as being shaded, to clarify the
difference in level to the surface of disk 13 facing toward the
viewing direction. The shaded areas are at a greater distance from
the viewer, at these places the material of the disk is thus
thinner. This makes it possible for these areas of disk 13 to melt
through more quickly and thus equalize the pressure more rapidly,
when the critical temperature has been reached. Additionally, in
the case of enclosed groove 22, what is attained is that the entire
area defined by island 23 opens up, if the base of enclosed groove
22 has melted away.
[0043] With reference to FIG. 2b there is shown an angled view from
above of the embodiment form of a disk of the safety device of FIG.
2a; and, as in FIG. 2a, the disk 13 is shown with recess 21 and
island 23 formed by enclosed groove 22. Recess 21 and enclosed
groove 22 are also depicted with shading in FIG. 2b, to clarify the
difference in level of the surface of disk 13 facing the viewing
direction.
[0044] As can be seen in FIG. 2b, the side wall 24 of recess 21 and
the side wall 25 of the closed groove can be recognized, which
elucidate that the shaded areas, due for example to a stamping
process during the manufacture of disk 13, lie lower relative to
the side of disk 13 facing the viewer, and thus this area of disk
13 is not as thick.
[0045] As can be readily determined by the above description of
FIGS. 2a and 2b, the pressure sensitive disk or plate has varied
stress concentrations based on the geometry of the patterns that
are formed in the disk or plate (the pressure seal). These
concentrations allow certain portions of the pressure seal to melt
before other portions. This factor is important in regulating the
release of pressure according to actual pressure conditions.
Additionally, this serves the purpose of allowing varying liquid
types, under varied pressure conditions, to utilize the container,
though not necessarily at the same time. The pressure seal of the
present invention can be manufactured in such a way as to
accommodate various logos or patterns which can be designed in such
a way as to optimize the pressure release characteristics of the
pressure seal.
[0046] Turning then to FIG. 3, there is shown a cross section
through an invention-specific small container 100 where there is
further shown a rack 111 composed of upright piping 112, base
frames 113, stacking frames 114, and a container 115.
[0047] The top side of container 115 is penetrated by a filling
opening designed as a filling pipe 116, and two ventilation
openings 117, 118 designed as ventilation pipes. Ventilation
opening 117 is closed by a blind flange 119, ventilation opening
118 is part of a safety device as was explained in FIG. 1, of
which, however, next to ventilation pipe 118 only the sleeve nut
120 is visible in the FIG. 3 depiction. Additionally, the vessel of
small container 100 has an optional outlet pipe.
[0048] In the claims, means or step-plus-function clauses are
intended to cover the structures described or suggested herein as
performing the recited function and not only structural equivalents
but also equivalent structures. Thus, for example, although a nail,
a screw, and a bolt may not be structural equivalents in that a
nail relies on friction between a wooden part and a cylindrical
surface, a screw's helical surface positively engages the wooden
part, and a bolt's head and nut compress opposite sides of a wooden
part, in the environment of fastening wooden parts, a nail, a
screw, and a bolt may be readily understood by those skilled in the
art as equivalent structures.
[0049] Having described at least one of the preferred embodiments
of the present invention with reference to the accompanying
drawings, it is to be understood that the invention is not limited
to those precise embodiments, and that various changes,
modifications, and adaptations may be effected therein by one
skilled in the art without departing from the scope or spirit of
the invention as defined in the appended claims.
* * * * *