AU2013100865B4

AU2013100865B4 - Flexible bladder and tank

Info

Publication number: AU2013100865B4
Application number: AU2013100865A
Authority: AU
Inventors: Daniel George Firth; Russell Timothy Firth
Original assignee: RAPID SPRAY Pty Ltd
Current assignee: RAPID SPRAY Pty Ltd
Priority date: 2013-06-24
Filing date: 2013-06-24
Publication date: 2013-11-28
Anticipated expiration: 2021-06-24
Also published as: AU2013100865A4

Abstract

A tank with an outer containment shell and a bladder, wherein the bladder is formed of a flexible urethane material. A flexible bladder for use in a tank with an outer containment shell and a port that defines an access opening into the tank, the bladder having a main body for receipt in the outer containment shell, a neck and a flange portion, wherein the neck defines an inlet of the bladder and is arranged to sit in the access opening of the outer containment shell and be anchored in the access opening by the flange portion fitting over the port of the outer containment shell. A method of forming a bunded tank including feeding a flexible bladder body and neck into an access opening defined by a port of an outer containment shell and fixing a flange portion of the bladder over the port so as to fix the neck of the bladder in a supported position within the access opening.

Description

FLEXIBLE BLADDER AND TANK FIELD OF THE INVENTION [0001] The present invention relates to a tank with a flexible bladder particularly but not exclusively a flexible urethane bladder. BACKGROUND OF THE INVENTION [0002] Bunded or double walled tanks are preferred for storing environmentally sensitive or dangerous liquids such as fuel or chemicals. Double walled steel tanks are known for storing fuel. However, steel tanks are expensive to manufacture and prone to corrosion. Moulded plastic tanks are also known but only with a single wall structure. OBJECT OF THE INVENTION [0003] The invention seeks to provide an alternative tank construction. SUMMARY OF THE INVENTION [0004] In accordance with the invention, there is provided a tank with an outer containment shell and a bladder, wherein the tank has a port that defines an access opening into the tank and the bladder has a main body arranged inside the outer containment shell, a neck and a flange portion, wherein: the neck defines an inlet of the bladder and is arranged to sit in the access opening of the outer containment shell and be supported in the access opening by the flange portion fitting over the port of the outer containment shell; the main body, neck and flange portion are integrally molded; and the flange portion has apertures that align with fastening bolts used to secure a plate over the access opening whereby to position and anchor the flange portion over the port in order to act as a gasket for the plate to seal the opening..

-2 [0005] Preferably, the bladder is formed of flexible urethane material. [0006] Preferably, the bladder is filled with spacer elements to resist collapse of the bladder when empty. [0007] In another aspect, there is provided a flexible bladder for use in a tank with an outer containment shell and a port that defines an access opening into the tank, the bladder having a main body for receipt in the outer containment shell, a neck and a flange portion, wherein: the neck defines an inlet of the bladder and is arranged to sit in the access opening of the outer containment shell and be supported in the access opening by the flange portion fitting over the port of the outer containment shell; the main body, neck and flange portion are integrally molded; and the flange portion has apertures that align with fastening bolts used to secure a plate over the access opening whereby to position and anchor the flange portion over the port in order to act as a gasket for the plate to seal the opening. [0008] In another aspect, there is provided a method of forming the tank, as described above, including feeding the bladder body and neck into an access opening defined by a port of an outer containment shell and fixing the flange portion of the bladder over the port with fastening bolts that pass through the apertures so as to fix the neck of the bladder in a supported position within the access opening. [0009] [Deleted] [0010] [Deleted] [0011] [Deleted] [0012] In another aspect, the bladder can be retro-fitted to existing moulded tanks and is easily replaceable.

-3 BRIEF DESCRIPTION OF THE DRAWINGS [0013] The invention is described, by way of non-limiting example only, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a tank; Figure 2 is a cross-sectional view of the tank; and Figure 3 is a sectioned view of the tank. DETAILED DESCRIPTION OF THE DRAWINGS [0014] Referring firstly to Figure 1, a tank 1 is shown as including an outer containment shell 2 and a bladder 3. [0015] The outer shell 2 has a port 4 that defines an access opening 5. The port 4 also includes an annular attachment plate 6 surrounding the access opening 5. [0016] The bladder 3 includes a main body 7 within the outer shell 2, a neck 8 positioned within the access opening 5 to define an inlet 9 of the bladder 3 and a flange portion 10 that fits over the port 4. The flange portion 10 also has apertures 11 to fix the flange portion 10 in place. [0017] Referring now to Figure 2, the main body 7 is shown filled with spacer elements 12. The spacer elements 12 are in the form of baffle balls 13 that have an open structure to allow liquid to flow freely through the balls while maintaining a space filling function to resist collapse of the bladder 3.

-4 [0018] As such, the baffle balls 13 assist in maintaining the shape of the bladder 3 while the bladder 3 is filled or emptied. This may be beneficial when the bladder 3 is being filled using an auto shut-off nozzle (not shown) that might otherwise keep shutting off due to back flow if the bladder 3 was collapsed. [0019] Referring now to Figure 3, the connection of the flange portion 10 to the port 4 of the tank 1 is shown in more detail. The apertures 11 in the flange portion 10 are aligned with corresponding holes 14 in the attachment plate 6 of the outer shell 2 to receive fastener bolts 15. The bolts 15 secure a lid 16 in a closed position over the port 4 and the flange portion 10 then serves as a gasket between the lid 16 and the attachment plate 6. [0020] As can be seen, with the flange portion 10 anchored over the port 4, the neck 8 of the bladder 3 is supported within the access opening 5 so that the inlet 9 of the bladder 3 then forms the inlet 17 of the tank 1 when the lid 16 is removed. [0021] The bladder 3 is preferably formed of a unitary rotational or blow molded thermoplastic urethane material so the main body 7 and neck 8 of the bladder 3 are flexible. This allows the bladder 3 to be initially compacted and collapsed so as to be installed in the outer shell 2 by simply feeding the bladder 3 through the access opening 5 and then anchoring the flange portion 10 over the port 4. If required, the spacer elements 12 can also be introduced through the inlet 9 of the bladder 3. [0022] A particular advantage of using such a flexible bladder 3 is that the bladder 3 may be retrofitted to an existing single walled tank to provide a double wall structure for enhanced storage safety and security. [0023] Since the bladder 3 is formed of a urethane material or other suitable flexible material, it may be used to store any suitable liquids such as diesel fuel, water or chemicals. The outer shell 2 can also be formed of complementary plastics material and may consist of a rotationally or blow molded polyethylene structure or be formed of any other suitable material construction, as appropriate.

-5 [0024] As an alternative to the above described structure, the bladder 3 may instead be formed of a rotationally cast two part urethane flexible bladder. [0025] The tank 1 and bladder 3 have been described by way of non-limiting example only and many modifications and variations may be made without departing from the spirit and scope of the invention described.

-6 LIST OF PARTS 1. Tank 2. Outer containment shell 3. Bladder 4. Port 5. Access opening 6. Attachment plate 7. Main body 8. Neck 9. Inlet 10. Flange portion 11. Apertures 12. Spacer elements 13. Baffle balls 14. Holes 15. Bolts 16. Lid 17. Inlet

Claims

1. A tank with an outer containment shell and a bladder, wherein the tank has a port that defines an access opening into the tank and the bladder has a main body arranged inside the outer containment shell, a neck and a flange portion, wherein: the neck defines an inlet of the bladder and is arranged to sit in the access opening of the outer containment shell and be supported in the access opening by the flange portion fitting over the port of the outer containment shell; the main body, neck and flange portion are integrally molded; and the flange portion has apertures that align with fastening bolts used to secure a plate over the access opening whereby to position and anchor the flange portion over the port in order to act as a gasket for the plate to seal the opening.

2. The tank of claim 1, wherein the bladder is formed of flexible urethane material.

3. The tank of claim 1, wherein the bladder is filled with spacer elements to resist collapse of the bladder when empty.

4. A flexible bladder for use in a tank with an outer containment shell and a port that defines an access opening into the tank, the bladder having a main body for receipt in the outer containment shell, a neck and a flange portion, wherein: the neck defines an inlet of the bladder and is arranged to sit in the access opening of the outer containment shell and be supported in the access opening by the flange portion fitting over the port of the outer containment shell; the main body, neck and flange portion are integrally molded; and the flange portion has apertures that align with fastening bolts used to secure a plate over the access opening whereby to position and anchor the flange portion over the port in order to act as a gasket for the plate to seal the opening. -8

5. A method of forming the tank of claim 1, including feeding the bladder body and neck into an access opening defined by a port of an outer containment shell and fixing the flange portion of the bladder over the port with fastening bolts that pass through the apertures so as to fix the neck of the bladder in a supported position within the access opening.