Patent Application
20070053617
The present invention is directed to valves and particularly to valves that are suitable for use in flexible bags, such as those used as liner bags in rigid containers.
Intermediate Bulk Containers (IBCs) are large size containers that may be used for storing and transporting a number of different items. Typically, an IBC is a generally cubic container having a base, fixed or foldable side walls and a top. When IBCs are used for the transport of liquid products, a liner bag is utilized within the container to hold the liquid. A liner bag may also be used for transporting flowable powdered or granulated solids. The liner bag contains an inlet for filling the bag, which may be placed at the top of the liner bag, and an outlet for emptying the bag. The outlet may be a simple gland, with no moving parts, or may include a valve. The valve may be closable during emptying so that complete emptying of the IBC does not need to take place at once, and may be re-opened at a later time to continue the emptying process.
The gland that is traditionally used with IBCs includes a membrane which prevents premature discharging of the liner bag when the cap of the outlet is opened. The membrane is pierced with a cutter pusher, which is a generally cylindrical tool having a serrated edge that can pierce the membrane. The cutter pusher helps to prevent the liner bag from being sucked into the outlet, however the liner bag may become snagged on the serrated edge, potentially causing a leak in the bag.
Current valves used in IBC liner bags are susceptible to blockage during emptying, because the liner bag wall becomes drawn into the valve as a result of a drop in pressure within the bag as the contents are discharged. When the valve becomes blocked in this way by the liner wall that is sucked into it, the blockage must be manually cleared for discharging of the liner bag to continue. This results in equipment downtime and, potentially, contamination of the liner bag contents. Contamination (or potential contamination) is a major problem when a container such as an IBC is used to transport liquids designed for human or animal consumption as typically the entire contents of the container must be destroyed due to the risk of contamination if the liner bag is breached. The valves in current use in IBC liner bags are also expensive, and their use is not widespread due to the costs for a single-use application.
It would be beneficial to provide a valve which has protection against the liner bag becoming entangled in the valve. It would also be beneficial for the valve to be low-cost and simple to manufacture and operate.
The present invention is directed to alleviating one or more of the aforementioned problems, and meeting one or more of the above-identified needs.
One aspect of the present invention relates to a valve that may be used with a flexible bag, and a liner bag including a;valve. The valve includes a valve member located in a valve seat and having a valve opening for egress of liquids from the bag. An operating lever is positioned outside the bag. A protective cage extends in front of the valve opening, the cage being positioned inside the bag to prevent the wall of the bag from collapsing into the valve opening during emptying of liquids from the bag. This arrangement prevents the bag wall from clogging the valve during discharge of the bag's contents.
In a preferred arrangement, the protective cage may extend from the valve into the interior of the container in use. The protective cage may include a top and sides having openings, with the area of the openings in the sides being equal to, or greater than, the area of the valve opening. Each opening in the sides of the cages preferably has a width dimension that is between about 50% and about 70% of the diameter of the valve opening. A width dimension of the openings in the top are preferably between about 50% and about 70% of the diameter of the valve opening.
In one arrangement, protective cage comprises a plurality of legs extending outwardly from the valve seat, the legs supporting a permeable face plate. The permeable face plate may be an open grid.
A flange may extend around the valve seat, the flange designed to retain the valve in a wall of a container. A cap may be attached to the valve seat to protect the valve member prior to use. The valve may be formed of plastic material.
Another aspect of the present invention relates to a liner bag for a container, which includes at least one wall, forming a container for liquids or flowable solids. An outlet is provided in the wall. A valve is located in the outlet, including a valve member located in a valve seat and having a valve opening for egress of liquids from the liner bag. An operating lever to operate the valve member is included, the operating lever being positioned outside the liner bag. A protective cage is located around the valve opening, the cage being positioned inside the liner bag to prevent the wall of the liner bag from collapsing into the valve opening.
The cage is preferably open on five sides so that if one or more sides becomes blocked by the bag wall, liquid can still pass into the valve through the open sides. In addition, the bag wall cannot be sucked into the valve, thus preventing the bag from tearing. The valve and liner bag including the valve thus can be safely used for the transport of liquids, without the risk of clogging or bag rupture. Additionally, the design of the valve allows for a low manufacturing cost.
Other objects, features and advantages of the present invention will become apparent upon reading the following detailed description, while referring to the attached drawings, in which:
The present invention is more particularly described in the following description that is intended to be illustrative only since numerous modifications and variations therein will be apparent to those skilled in the art. As used in the specification and in the claims, the singular form “a,” “an,” and “the” may include plural referents unless the context clearly dictates otherwise. Also, as used in the specification and in the claims, the term “comprising” may include the terms “including”, “consisting of” and “consisting essentially of”.
The present invention provide a valve that may be used in a liner bag when used in a rigid container to transport liquids or flowable powdered or granulated solids. However, the invention is not limited in this regard, and is applicable to other containers having flexible walls that may be employed separately from any rigid container. Additionally, although the invention is illustrated and described using an example of an Intermediate Bulk Container (IBC), it is applicable to any other container having a liner bag, such as, for example, a large standard cargo container, or a wine or other beverage or food box having a bag-in-box arrangement.
Referring to
A protective cage 24 extends from the valve seat 12, and may include legs 26 supporting a grid 28. The illustrated grid 28 is generally square, and there are thus four legs 26, one supporting each corner of the grid. It will be appreciated that the grid 28 may be any suitable shape, such as circular, rectangular, triangular, or polygonal, and that the number of legs 24 may vary accordingly. Alternatively, the sides of the cage 24 may be formed of additional grids, or apertured plates. As a further alternative, the cage 24 may be in the form of a dome, hemisphere or have any other suitable curved shape. The illustrated grid 28 includes a central cross piece 30 that forms four open squares in the grid. Any suitable number and shape of openings may be employed, and the grid may be in the form of an apertured plate. The cage is preferably open on five sides so that if one or more sides becomes blocked by the bag wall, liquid can still pass into the valve through the open sides. The liner bag wall cannot be sucked into the valve because it is blocked by the cage, thus preventing the bag from tearing.
In a preferred embodiment, the area of the openings in the sides of the cage 24 formed between the legs 26 should be equal to, or greater than, the area of the valve opening. This allows for the volumetric flow rate through the sides of the grid to be equal to, or greater than, the volumetric flow rate through the valve itself. Such an arrangement ensures that the flow of liquid through the valve is not compromised when the liner bag material is against the grid 26, blocking flow through the grid to the valve. In another preferred arrangement, each opening in the sides of the cage 24 has an area that is between about 50% and about 70% of the area of the valve opening. In another preferred embodiment, the area of the openings in the grid 28 is between about 50% and about 70% of the area of the valve opening. For example, for a 3″ valve, which has a nominal diameter of 75 mm, the grid openings may be between 37 mm and 52 mm. The 3″ valve has a nominal valve opening area of 4418 mm2 and therefore the four side openings may have a combined area of not less than 4418 mm2.
The valve may be formed of any suitable material. Preferably a plastic material is used. The entire valve may be formed of the same material, or different parts of the valve may be formed of different materials. The material of the protective cage 24 should be strong enough to withstand the pressure of the liner bag being sucked onto the cage by the pressure reduction caused by discharge of the liner bag contents through the valve. In one arrangement, the cage 24 may be formed of metal. In another arrangement, the cage 34 may be formed of polyethylene, polypropylene, or from any number of injection molding resins.
Referring now to
Although the illustrative embodiments of the present disclosure have been described herein with reference to the accompanying drawings and embodiments, it is to be understood that the disclosure is not limited to those precise embodiments, and various other changes and modifications may be affected therein by one skilled in the art without departing from the scope of spirit of the disclosure. All such changes and modifications are intended to be included within the scope of the disclosure as defined by the appended claims.
