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EP-3749593-B1 - LINER FOR TANK CONTAINER

EP3749593B1EP 3749593 B1EP3749593 B1EP 3749593B1EP-3749593-B1

Inventors

  • HUNTER, ANDREW
  • STEVENS, RONALD

Dates

Publication Date
20260506
Application Date
20190201

Claims (12)

  1. A flexible liner (70) for a tank container (10), said tank container (10) comprising a tank body (12), defining an interior and comprising a length of a cylindrical side wall (72) along a longitudinal axis with substantially domed, circular ends (74, 76), wherein the tank body (12) comprises at least one tank opening selected from the group consisting of a manway opening (20), a bottom outlet valve assembly (60), a safety relief valve (30), an air inlet, a top-discharging provision (50), and any combination thereof, wherein the at least one tank opening comprises a closing means comprising a lid, a valve or a plate, wherein the flexible liner (70) is fabricated from polymer sheet material and comprises a length of a side wall (72) that is configured to be the same length as the longitudinal axis of the tank body (12), wherein the length of the side wall (72) comprises a circular cylinder and a first end (74) and a second end (76) that are spaced apart by the length of the side wall (72), and wherein the side wall (72) at the first end (74) and the second end (76) are each closed by forming a welded seam with a circular piece of polymer sheet material, thereby defining a liner cavity to accommodate cargo, wherein the flexible liner (70) is configured so that it has substantially the same dimensions and shape as the interior of the tank body (12), wherein the flexible liner (70) comprises at least one liner opening that is configured to correspond with each of the tank openings in the tank body (12), wherein the at least one liner opening is selected from the group consisting of a liner manway opening (22), a liner top-discharging provision opening (52), a safety-relief valve opening (32), a liner air inlet opening, a liner bottom outlet valve assembly opening (62), and any combination thereof, characterised in that the flexible liner (70) further comprises flexible gland flanges joined to each liner opening, wherein the flexible gland flanges are shaped like a circular ring or a two-dimensional donut, having an inner diameter and an outer diameter, wherein the inner diameter is approximately equal to the diameter of the liner opening that each flexible gland flange is to be attached to, and the outer diameter is greater than the inner diameter, such that the flexible gland flanges can be sandwiched between the tank body (12) and the closing means, wherein the flexible gland flanges can be pulled out of the tank opening and can be sandwiched between the tank body (12) and the closing means for the tank opening.
  2. The flexible liner of claim 1, wherein the welded seams are about 2 mm to about 20 mm wide.
  3. The flexible liner of claim 1, wherein the flexible liner (70) is from about 2 mil (50.8 µm) all to about 12 mil (304.8 µm) in thickness.
  4. The flexible liner of claim 1, wherein the flexible polymer sheet material is formed of one layer or multiple layers of the same or different polymers, wherein the multiple layers can be bonded to one another.
  5. The flexible liner of claim 1, wherein the flexible polymer sheet material comprises any polymeric sheet material selected from the group consisting of polyethylene-containing films, barrier films, perfluoroalkoxy alkane (PFA) films, PTFE-based films, and combinations thereof.
  6. The flexible liner of claim 1, wherein the flexible polymer sheet material comprises any polymeric sheet material selected from the group consisting of low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE), aluminum (Al), nylon, polyethylene terephthalate (PET), polyethylene terephthalate polyester (PETP), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), or polypropylene (PP), polyvinyl chloride (PVC), polyamide (PA), polyethylene (PE), polystyrene (PS), polypropylene (PP), ethylene vinyl acetate (EVA), ethylene methyl acrylate (EMA), ethylene vinyl alcohol (EVOH), polytetrafluoroethylene (PTFE), perfluoroalkoxy alkane (PFA), fluorinated ethylene propylene (FEP), and any combination thereof.
  7. The flexible liner of claim 1, wherein the flexible liner (70) further includes liner removal lanyards (100, 102) and gland lanyards.
  8. The flexible liner of claim 1, wherein the closure of the side walls (72) at the first and the second end (76) comprises a rounded weld for substantially correspondingly matching the substantially domed, circular ends of the tank body (12).
  9. The flexible liner of claim 1, further comprising a large diameter spout joined to a liner manway opening (22) of the flexible liner (70).
  10. The flexible liner of claim 1, further comprising two liner removal lanyards, one attached to the first end (74) and one attached to the second end (76) of the flexible liner (70).
  11. A method of inserting the flexible liner (70) of claim 1 into a tank container (10), said method comprising: removing all closing means from the tank body (12); folding the flexible liner (70) to fit into the manway opening (20) of the tank body (12) and unfolding the flexible liner (70) in the interior of the tank body (12); feeding liner removal lanyards (100, 102) through the manway opening (20) and securing same externally; securing a first end of a gland lanyard to a bolt proximate to the top-discharging provision (50) in the tank body (12) and securing the second end of the gland lanyard to the flexible gland flange of a liner top-discharging provision opening (52) in the flexible liner (70); pulling the gland lanyard at the top-discharging provision to pull the flexible gland flange through the top-discharging provision; securing the closing means of the top-discharging provision such that the flexible gland flange is sandwiched between the tank body (12) and the closing means; inflating the flexible liner (70) at a bottom valve outlet assembly (60); pulling a large diameter spout through a manway opening (20) and securing same to the tank body (12); pulling the flexible gland flange of the liner bottom outlet valve assembly opening (62) through the bottom outlet valve assembly (60) during inflation; securing the closing means of the bottom outlet valve assembly (60) such that the flexible gland flange is sandwiched between the tank body (12) and the closing means; pulling remaining flexible gland flanges through their respective tank openings in the tank body (12) and securing all but one using closing means, wherein the one that is not closed is intended to be used to fill cargo in the tank container (10); and ceasing inflation.
  12. A method of removing the flexible liner (70) of claim 1 from a tank body (12) of a tank container (10), said method comprising: removing cargo from the tank container (10); removing closing means from each of the tank openings; vacuuming air out of the flexible liner (70); pulling a liner removal lanyard (100, 102) attached to the second end (76) of the flexible liner (70) to remove half of the flexible liner (70) through a manway opening (20), said pulling forcing any excess cargo to flow towards a bottom outlet valve assembly (60) for bottom discharge; covering the gland flange of the liner bottom outlet valve assembly opening (62) such that no cargo can escape through said liner opening; and pulling a liner removal lanyard attached to the first end (74) of the flexible liner (70) to remove the other half of the flexible liner (70) through the manway opening (20).

Description

FIELD The present invention relates generally to a flexible liner for a tank container including, but not limited to, an ISO tank container, wherein the tank containers are used for the transportation of cargo such as liquids, gases, and flowable solids. The cargo can be hazardous or non-hazardous, and can be consumable or non-consumable. The liner is made of a polymeric material and it is sized to fit within the tank container. BACKGROUND In cargo transportation by sea, railroad, road and so forth, a tank container is generally used for liquid materials (cargo). As the tank container, a 20-foot container (hereinafter referred to as a tank container) which conforms to the International Organization for Standardization (ISO) Standards is ordinarily used. The tank container is typically a cylindrical tank mounted in a rectangular frame and is about 20 feet in length, about 8 feet in width, and about 8 feet in height, so that about 20 tons of liquid can be filled therein (see, e.g., Figure 1). In the use of this kind of tank container, when filled, such a shipping tank or tank container can be transported by truck, train and/or barge to a port and then loaded on, for example, a container ship for transoceanic transport to another port. The tank container is unloaded from the container ship at the destination port and is emptied of its liquid cargo. The tank container may then be re-used for transporting another liquid cargo, provided such a cargo is available and provided the tank container is in a condition for receiving another cargo. Having a tank container in a condition for receiving another cargo typically involves cleaning the tank at a cleaning station specifically designed for such a purpose. Disadvantageously, cleaning a tank container is a relatively expensive process. Further, the tank containers are made of stainless steel, which is porous and residual contaminants remain in the skin of the stainless steel. Once chemicals, hazardous or non-hazardous, have been shipped in the tank container, it rarely can be reused to transport a different cargo. For example, if the tank container was used to transport a chemical, it cannot be reused to transport a consumable (i.e., food grade) cargo. Similarly, certain chemicals cannot be loaded in the tank container after other chemicals were shipped in the tank container because of compatibility and contamination risks. This often results in "repositioning" of the tank containers, wherein no products are available to be filled in the tank containers once emptied and the tanks have to be shipped to another location, while empty, before they can be refilled due to prior content restriction or no available cleaning facilities. Another disadvantage of the tank containers of the prior art is that many chemicals, such as low pH liquids and chlorinated solvents, corrode the stainless steel in the tank container. When this happens, the users have to cut out the pitted stainless steel and weld new stainless steel inside the tank. This adds to the costs associated with moving cargo in the tank containers. To avoid or minimize such cleaning, or to reuse the tank container immediately without the necessity of repositioning or providing a new interior stainless steel skin, many have proposed the installation of flexible liners in the tank containers. That said, it has been difficult to produce successful liners for large tanks. Namely, it has been difficult to produce a liner that fits in the cylindrical tank easily and affordably. The ideal liner to fit within the tank container would be one having approximately the same shape and same volume as the interior of the tank container. However, the liners of the prior art having the same shape as the tank have proven unsuccessful. FR3042733A1 discloses a packaging device made from a multilayer flexible material comprising a hermetic hollow body. WO2006/068515 A1 discloses a flexible liner for a tank for water storage. The use of an envelope type liner has been proposed, but although the envelope type liner is easily produced, if the liner is not formed to have the appropriate size for fitting in the tank container, whether too large or too small, filling failure and breakage of the liner may occur. DE602005002148 T2 discloses an envelope type inner bag for a transport tank. DE20121939 U1 also discloses a flexible tank comprising a tube closed at each end with a single side seam. Accordingly, there still remains a need in the art for a liner for a tank container. Preferably, the liner is easy to make and easy to install and remove. SUMMARY The present invention relates to a liner for a tank container e.g., an ISO tank container, wherein the tank containers are used for the transportation of cargo such as liquids, gases, and flowable solids. In one aspect, it is provided a flexible container according to claim 1. In another aspect, it is provided a method according to claim 11. In yet another aspect, it is provided a method accord