CN101687624A - Container with CO2 compressed gas source and overpressure rupture safety device - Google Patents

Abstract

A container which can be filled with a liquid and closed pressure-tightly and from which the liquid can be removed has an insert which can be fixed in a sealed manner in an opening of the container. The insert has CO₂A high-pressure cartridge (14) for releasing CO therefrom₂And an externally accessible control element, by actuation of which the CO₂The high pressure cartridge (14) can be pierced. The overpressure safeguard opens a flow path from its head space through the insert to the atmosphere in the event of an undesired pressure rise in the container. The overpressure safeguard is designed as a crack safeguard. The overpressure safety ruptures after the internal pressure at which the container visibly bulges is exceeded but before the internal pressure at which the container bursts is reached.

Description

Container with CO2 compressed gas source and overpressure rupture safety device

The invention relates to a container which can be filled with a liquid and is closed pressure-tight and from which the liquid can be removed. Examples of such containers are buckets, kegs (party buckets) or cans, into which CO ₂ -containing liquids, especially beverages, are filled under pressure. In particular, it relates to banquet kegs for beer.

The container according to the prior art document EP 1 642 861 A1 has an insert (Einsatz), which can be fixed under sealing (unter Abdichtung) in the opening of the container and has a CO high _- pressure cartridge for emitting _CO therefrom A pressure regulating valve (Druckregelventil), as well as an externally accessible (von aussen zugaenglich) control element, by actuation of which the CO ₂ high pressure cartridge can be pierced (anstechbar).

A commercially available piercable _CO2 cartridge, sized for the corresponding container, contains approximately 16 g _CO2 at a pressure of approximately 60 Bar. The pressure regulating valve of document EP 1 642 861 A1 serves to reduce and precisely regulate the pressure at which the CO ₂ emitted into the head space of the container is located. This pressure is typically between 0.7 Bar and 1.3 Bar. It is equal to or slightly higher than the partial pressure (Partialdruck) of _CO2 dissolved in the liquid.

The present invention deals with the gigantic failure in which the pressure regulating valve according to document EP 1 642 861 A1 fails (for whatever reason). An uncontrolled pressure rise (Druckanstieg) in the container can then occur slowly, but also very quickly. Tests have shown that conventional banquet kegs for beer can withstand internal pressures of up to about 6.5 Bar. From about 4 Bar, the banquet barrel is swollen (bombieren); the upper bottom (Oberboden) and/or the lower bottom of the banquet barrel is arched. At about 6.5 Bar, the banquet bucket bursts (platzen), and more precisely most of the time, by a bite between the upper or lower bottom of the banquet bucket and the cylinder (Mantel) The mouth joint (Falznaht) is dehiscated. Excess _CO2 escapes. The banquet barrel overflowed (possibly in the form of a mighty fountain of beer (Fontaene Bier)). Although this does not endanger people, damage to property is possible and tedious cleaning work takes place.

From document EP 1 688 813 A1 a container with a built-in pressure system having a high pressure _CO2 cartridge, a pressure regulating valve for releasing _CO2 therefrom and an externally accessible control element is known , through the manipulation of this control element, the CO ₂ high pressure cylinder is pierced. The pressure system has an overpressure safety device (Ueberdrucksicherung), which opens (freigeben) the flow path (Stroemungsweg) from its headspace through the pressure system to the atmosphere in the event of an undesired pressure rise in the container .

The overpressure safety device according to document EP 1 688 813 A1 comprises an overpressure valve which has a valve element in the form of an overpressure hose coupling (Schlauchstueck) and which is closed or opened via a plurality of openings, holes and The complex flow path of the channel. Such an overvoltage safety device is very complex in construction and production.

The object of the present invention is to equip a container of the mentioned type with an overpressure safety device which is structurally inexpensive and functionally reliable, and which can signal the user in the event of a fault, that the pressure system of the container unusual.

This task is accomplished by an overpressure safety device, after such an internal pressure—that is, at which the container bulges visibly (sichtlich)—is exceeded, and at such an internal pressure— —That is to say, under the internal pressure, the container bursts—before the surge safety device is reached. The ruptured part of the surge protector is the membrane on the wall of the housing with which the insert protrudes into the container.

After the overpressure safety device has ruptured, excess CO ₂ is discharged (abblasen) from the head space of the container via well-defined (wohldefinierten) flow paths. To this end, it is achieved that there is no or at least no noticeable (nennenswerten) liquid or foam escape. Even if damage does occur, it is maintained within limits. Visibly bulging containers signal to the user that the container's pressure system is not functioning properly.

In a preferred embodiment, the exhaust flow path for CO ₂ passes through a leak in the control element. Existing leaks, like those of the control element at the insert according to EP 1 642 861 A1, can be exploited here and only minor modifications are required in its construction.

In a preferred embodiment, the overpressure safety device is inoperative prior to the puncture of the CO ₂ high pressure cylinder. The overpressure safety device is activated by the puncture of the _CO2 high pressure cylinder. This ensures that the overpressure safety device is only activated when it is actually required, ie in the event of failure of the pressure regulating valve.

In a preferred embodiment, the surge protector ruptures at an internal pressure of between 4.0 Bar and 9.0 Bar, preferably 4.5 Bar to 7.0 Bar, more preferably 5.0 Bar to 6.0 Bar.

In a preferred embodiment, the membrane bears against the control element before the puncture of the CO ₂ high pressure cylinder. When the _CO2 high pressure cylinder is pierced, the membrane is removed from the control element.

In a preferred embodiment, the membrane is recessed in the insert. It is thus protected from damage.

In a preferred embodiment, the membrane is made of elastic plastic. In the event of an uncontrolled rise in internal pressure, the membrane undergoes increased elastic deformation until it ruptures.

Next, the invention is explained in greater detail with the aid of exemplary embodiments shown in schematic diagrams. here:

Figure 1 shows a _CO compressed gas source in longitudinal section; whereas

FIG. 2 shows the elastic plastic part of detail II in FIG. 1 .

The CO ₂ compressed gas source is designed as an insert which fits into the container through the spout of the container and closes the spout tightly. The container is filled under pressure with the CO ₂ -containing liquid through a bung usually located in the middle of its upper bottom. Thereafter, the mouth of the barrel is closed with an insert.

An integrated tap can be used to remove the liquid, which tap is located at the level of the lower bottom of the container on its side wall. The liquid flows out due to internal pressure and gravity until a negative pressure is reached in the head space of the container above the level of the liquid in the container. The _CO2 compressed gas source is activated so that it is properly adjusted and maintained in a regulated manner. A source of _CO2 compressed gas supplies _CO2 into the headspace of the vessel at a pressure corresponding to or slightly exceeding the partial pressure of _CO2 dissolved in the liquid. In this way, a stable emptying of the container is guaranteed. No air enters into the head space of the container. The _CO2 content of the liquid remains the same.

The insert has an elongated, slender (laenglich-schlanker) shape and is for the most part radially symmetrical with respect to the central axis. It is mainly made of plastic. For production, two-component plastic die-casting technology can be recommended.

In the installed position, the insert closing the mouth of the container protrudes with the housing 10 into the container.

The housing 10 has a chamber 12 at its inner end for a cooperating accommodation of a CO ₂ high-pressure cartridge 14 . The head of the barrel 14 (at the end face of which the barrel 14 can be pierced) faces the mouth of the barrel.

The housing 10 is seated externally on the rim of the barrel mouth with a surrounding flange 16 . A seal 18 is molded on the flange 16 with which the insert seals the mouth of the barrel.

A knob 20 inserted into the housing 10 protrudes outwardly beyond the flange 16 and upon actuation of the knob 20 the CO ₂ cartridge 14 is pierced. The knob 20 has a steep outer thread 22 , with which the knob 20 is screwed into an inner thread of the complementary housing 10 .

The needle 24 is used for the piercing of the CO ₂ cartridge, which is structurally associated with the valve element of the pressure regulating valve. The valve element is suspended in the axial center of the housing 10 by means of an elastic membrane 26 . The needle tip of the lancet 24 is only slightly spaced from the end surface of the CO ₂ cartridge 14 .

During an axial adjustment of the needle 24 towards the CO ₂ cartridge 14 , the valve element is lifted from the valve seat 28 of the pressure regulating valve. The valve seat 28 is molded on the housing 10 from an elastic sealing material.

The lancet 24 is loaded by a slide 30 located between the knob 20 and the lancet 24 . The slide 30 is guided longitudinally displaceably in the housing 10 . During actuation, the knob 20 is screwed in against the slider 30 , which is thus displaced axially.

A helical compression spring 32 is clamped between the rotary knob 20 and the slider 30 . The helical compression spring 32 pretensions the slider 30 against the needle 24 .

The membrane 26 delimits a working chamber downstream of a valve seat 28 of the pressure regulating valve. The working chamber has a lateral drain opening, in front of which the elastic sealing ring 34 is located. The sealing ring 34 has the function of a non-return valve. It prevents liquid from reaching the insert.

To pierce the _CO2 cartridge 14, the knob 20 is rotated approximately 90 degrees. The slider 30 is displaced axially inwards by the screw feed of the knob 20 . The needles 24 are carried axially inwards under the elastic deformation of the membrane 26 . The valve element is lifted from the valve seat 28 . After piercing, the very small valve chamber (Ventilraum) in front of the head of the CO ₂ cartridge 14 is filled with CO ₂ under high pressure.

After a complete 90° or overrotation of the rotary knob 20 , the slider 30 springs back axially outward against the force of the helical compression spring 32 . For this purpose, it is actuated by the lancet 24 , which is axially reset (zurueckstellen) by the elastic restoration of the membrane 26 . The helical compression spring 32 is compressed. The pressure regulating valve is closed and a small amount of _CO2 under high pressure is put into the working chamber. The _CO2 pressure at the membrane 26 facilitates the rebound of the lancet-operated slide 30 .

The further opening and closing of the pressure regulating valve is determined by a force balance at the membrane 26 , which is brought about by the elastic properties of the membrane 26 , the spring constant of the helical pressure spring 32 and the CO ₂ pressure in the working chamber. The spring constant of the helical compression spring 32 is decisive for the pressure of the emitted CO ₂ .

Typically, the user activates the _CO2 compressed gas source if the internal pressure in the container drops to such an extent that the stream of liquid coming out through the let-off cock is too weak. However, the _CO2 compressed gas source can of course also be activated before when the internal pressure in the container is still high, and of course even at all during the first operating action of the user on the container. . As long as a high internal pressure acts on the sealing ring 34 in front of the discharge opening, no metering of CO ₂ into the head space of the container takes place.

The CO ₂ compressed gas source is provided with an overpressure safety device which comes into play in the event the pressure regulating valve fails and the CO ₂ reaches the headspace of the container at an uncontrolled high pressure.

As surge protection, a thermoplastic elastomer (TPE) with a minimum material thickness is spray-molded (angespritzt) on the wall of the housing 10 just short of the spout A portion of the film forms a membrane 36 recessed into the wall.

The membrane 36 is in flush abutment with the outer cylindrical surface of the knob 20 which has not yet been actuated for piercing of the CO ₂ cartridge 14 . For this purpose, it is placed between two adjacent turns of the external thread 22 on the knob 20 .

A 90° rotation of the knob 20 for piercing of the CO ₂ cartridge 14 places the membrane 36 opposite the window in the cylinder of the knob 20 . Under uncontrolled rising internal pressure, the membrane 36 can expand elastically into this window until it ruptures at the point of minimum material thickness at about 5.7 Bar. In this way, the flow path is opened from the head space of the container to the cylinder of the knob 20 which is not absolutely sealed against the flange 16 so that _CO2 can flow out of the head space of the container into the atmosphere.

List of reference numerals

10 Shell

12 chambers

14 CO ₂ high pressure cylinder

16 flange

18 Seals

20 knobs

22 external thread

24 needles

26 film

28 seat

30 sliders

32 helical pressure spring

34 sealing ring

36 film

Claims (7)

1. A container which can be filled with a liquid and which can be closed pressure-tightly and from which the liquid can be withdrawn, the container having an insert which can be secured in a sealed manner at the opening of said container and has a _CO2 high pressure cylinder (14), a pressure regulating valve for releasing _CO2 therefrom, and an externally accessible control element by which the _CO2 high pressure cylinder (14) can be punctured and, with an overpressure safety device, which releases the flow from the headspace of the vessel through the insert to atmosphere in the event of an undesired pressure rise in the vessel A path, characterized in that the overpressure safety device ruptures after an internal pressure under which the container visibly bulges is exceeded but before an internal pressure under which the container bursts occurs, and , the ruptured part of the surge safety device is the membrane (36) at the wall of the housing (10), wherein the insert protrudes into the container with the housing (10). 2. The container of claim 1, wherein the flow path passes through a leak of the control element. 3. The container according to claim 1 or 2, characterized in that, the overpressure safety device is ineffective before the piercing of the _CO2 high-pressure cylinder (14), and can pass through the _CO2 high-pressure activated by the piercing of the barrel (14). 4. The container according to any one of claims 1 to 3, wherein the overpressure safety device ruptures at an internal pressure of 4.0 to 9.0 Bar, preferably 4.5 to 7.0 Bar, more preferably 5.0 to 6.0 Bar . 5. Container according to any one of claims 1 to 4, characterized in that the membrane bears against the control element before the puncture of the CO ₂ high pressure cylinder (14) and at the The _CO2 high pressure cartridge (14) exits the control element when pierced. 6. Container according to any one of claims 1 to 5, characterized in that the membrane (36) is recessed in the insert. 7. Container according to any one of claims 1 to 6, characterized in that the membrane (36) is made of elastic plastic.

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