WO2004094267A1

WO2004094267A1 - A wall lining system and a method of producing a live wall

Info

Publication number: WO2004094267A1
Application number: PCT/AU2004/000521
Authority: WO
Inventors: Brian Terance Dadd
Original assignee: Woodside Energy Limited
Priority date: 2003-04-22
Filing date: 2004-04-22
Publication date: 2004-11-04
Also published as: AU2003901930A0

Abstract

A wall lining system (22) is disclosed comprising a flexible liner (18) and a fixing system (20) for fixing the liner (18) to a wall (12) of a piece of materials handling equipment (10). The fixing system (20) divides the liner (18) into a plurality of fixed areas (30) and free areas (32) and each free area (32) of the liner (18) is able to move away from the wall (12) to vary the surface profile of the liner (18) in response to the delivery of fluid to one or more of the free areas (32) between the liner (18) and the wall (12). The liner (18) is positioned either between the fixing system (20) and the wall (12) or on top of the fixing system (20).

Description

A Wall Lining System and a Method of Producing a Live Wall

Field of the Invention

The present invention relates to a wall lining system, for the purpose of reducing adhesion of material to a wall in a materials handling plant.

The present invention relates particularly, but not exclusively, to a wall lining system for use in a vessel used to store hydrates for the purpose of reducing adhesion by freezing of hydrates onto the walls of such storage vessels .

The present invention further relates to a method of producing a live wall for the purpose of reducing adhesion of material, including particulate material, to the wall.

Background of the Invention

Materials handling technology has been developed across a wide range of industries including food processing, pharmaceuticals, oil and gas, and mining. One common problem associated with the transport and storage of material is material adhesion to the walls of related pieces of materials handling plant and equipment such as hoppers, chutes and storage bins. Under some conditions adhesion of the material to the wall can substantially reduce or completely block the flow of material leading to costly plant downtime.

This problem is exacerbated when transporting and storing materials at low temperature such as when handling gas hydrates. Gas hydrates are stable ice-like solid particles in which a gas is entrained. Gas hydrates are typically stored and transported either in the form of solid particles or combined with a liquid to form a slurry. One of the main problems associated with transporting and storing gas hydrates is that the particles adhere to the walls of materials handling equipment or storage vessels forming icelike layers . The layers are understood to form due to the temperature at the walls of such hydrate equipment or storage vessels being higher than that of the bulk of the hydrate particles or slurry being handled or stored. Local melting and re-freezing occurs, covering parts of the walls with layers of ice-like hydrate.

One method for reducing adhesion is the use of low friction linings. However, the linings are subject to wear and damage by the passage of the material. Thus, linings must be continually monitored and maintained in order to ensure they remain effective.

A further method of reducing adhesion is to design the materials handling plant and equipment through which the material flows in a way which ensures that any changes in a cross-sectional area are gradual rather than sudden or stepped. However, this can add substantially to construction or manufacturing costs.

Another way of overcoming this problem is the use of inflatable apparatus such as the one described in US Patent No. 2,646,905 (Vincent) . Vincent describes an inflatable panel assembly for a storage receptacle using an elastic distendable element or sheet marginally secured to the lower face of a mounting structure or frame to facilitate maximum freedom and uniformity of stretching of the resilient material in the distendable area of the element in all directions, as well as rapid elastic recovery of the element. Air from a pressure tank is admitted to inflate the flexible sheet and allow deflation thereof. Another such arrangement relying on inflatable pockets is described in US Patent No. 4,423,832 (Boyd, et al) which describes an inflatable liner for mounting within a hopper-type receptacle. Boyd et al describes a liner to which is attached a plurality of inflatable fabric bags or tubular members loosely supported within slings at spaced locations along the interior surface of the liner with a flexible wear-resistant coversheet loosely covering the wall and inflatable members. The slings may be attached to the loosely supported coversheet or to the wall itself. The inflatable members are inflated and deflated in any desired sequence to provide a continuous cyclic movement of material through the container. One of the drawbacks of this particular device is that it is extremely time-consuming to attach each of the inflatable members to either the loosely supported coversheet or to the wall, with each inflatable member having to be fastened using individual fastening means. The fasteners themselves act as points of weakness when the fasteners are applied through the coversheet, which can allow tearing of this coversheet in use.

It will be clearly understood that, although prior art use and publications are referred to herein, this reference does not constitute an admission that any of these form a part of the common general knowledge in the art, in Australia or in any other country.

In the statement of invention, the claims and the description of the invention which follow, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

Summary of the Invention

The present invention was developed with the view to providing an alternate system for minimising adhesion of material on the wall of materials handling plant and equipment in general and for hydrate storage vessels in particular.

According to a first aspect of the present invention there is provided a wall lining system comprising: a liner having a variable surface profile; and, a fixing system for fixing the liner to a wall of a piece of materials handling equipment, the fixing system dividing the liner into a plurality of fixed areas and free areas, each free area of the liner able to move away from the wall to vary the surface profile of the liner in response to the delivery of a fluid from a fluid delivery system to one or more of the free areas between the liner and the wall .

In one embodiment, the fixing systems comprises a frame which overlies the liner and clamps the liner to the wall . In an alternative embodiment, the fixing system comprises a frame located between the wall and the liner, one side of the frame attached to the wall and an opposite side of the frame attached to the liner. In either of these embodiments, the shape of the frame defines the shape of the plurality fixed and free areas of the liner.

Preferably, the plurality of fixed areas are bands of the liner. More preferably, the plurality of free areas are bound by the bands .

Preferably, the plurality of free areas are parallel to each other .

Preferably, the fluid delivery system delivers fluid individually to between the wall and sets of one or more of the free areas of the liner.

Preferably, the wall lining system further comprises a controller for controlling distribution of the fluid from the fluid delivery system to one or more of the areas between the liner and the wall. More preferably, the controller operates to supply fluid sequentially to adjacent free areas of the liner to cause the surface profile of the liner to vary in a ripple or wave-like manner.

In one embodiment the fluid delivered by the fluid delivery system is a gas . In an alternative embodiment the fluid is a liquid, such as oil or water.

Preferably, the liner is biased to return to a first profile upon release of pressure of the fluid delivered by the fluid delivery system. More preferably, the bias is provided by forming the liner from a resilient material .

Preferably, the liner is made of an elastomeric material.

In one embodiment the piece of materials handling equipment is a hydrate storage vessel. The wall lining system is thus used to break up frozen layers of hydrate adhering to one or more walls of the hydrate storage vessel.

According to a second aspect of the present invention, there is provided a method of producing a live wall comprising the steps of: fixing a liner having a variable surface profile to an internal wall of a piece of materials handling equipment using a fixing system, the fixing system dividing the liner into a plurality of fixed areas and free areas, each free area of the liner able to move away from the wall to vary the profile of the liner in response to the delivery of a fluid between the liner and the wall from a fluid delivery system; and, delivering fluid to the free areas of the liner at sufficient pressure to vary the profile of the liner.

Preferably, the step of delivering the fluid comprises delivering the fluid in a predetermined sequence individually to between selected sets of the free areas of the liner.

Preferably, the step of fixing the liner to the wall comprises fixing the liner in a manner in which the free areas of the liner are parallel .

Brief Description of the Drawings

An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings in which:

Figure 1 is a section view from one end of a hopper incorporating an embodiment of a wall lining system in accordance with the present invention;

Figure 2 is a view of Section AA depicted in Figure 1;

Figure 3 is a plan view of a frame used in the wall lining system; Figure 4 is a plan view of the inside of a wall of the hopper shown in Figure 1;

Figure 5 illustrates a controller incorporated in an embodiment of the present wall lining system; and,

Figure 6 is a view of Section BB of the wall lining system depicted in Figure 3;

Figure 7 is a side view of a second embodiment of the wall lining system with the frame interposed between the liner and the wall; and,

Figure 8 illustrates an alternative configuration for the fixing system used in accordance with one aspect of the present invention.

Detailed Description of Preferred Embodiment

Preferred embodiments of the present invention are now described in detail with reference to a wall lining system installed in a hydrate storage vessel. It is to be understood however that the disclosed embodiments are merely exemplary of the present invention which may be embodied in various forms. The specific structure and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention.

Figure 1 illustrates a section view from one end of a hydrate storage vessel in the form of a hopper 10. The hopper 10 has a pair of parallel side walls 12 which converge toward a passage 14. The passage 14 may include some transport device such as a screw conveyor (not shown) .

The hydrate storage vessel may equally be cylindrical having a continuous side wall 12 with a frustoconical passage 14 through which hydrate may be removed from the storage vessel as and when required.

An embodiment of a wall lining system 16 is installed on each side wall 12 on the inside of the hopper 10 to prevent or at least substantially reduce the likelihood of, hydrates adhering to the walls 12 during transport of hydrate through the hopper 10. The wall lining system 16 may also be used to break up any ice-like layers of hydrate that may form on the side walls 12 during storage of hydrate in the hopper 10.

The wall lining system 16 includes three main components: a liner 18 having a variable surface profile; a fixing system 20 for fixing the liner 18 to the wall 12; and, a fluid delivery system 23 for delivering a fluid between the liner 18 and the wall 12 to vary the surface profile of the liner 18.

The liner 18 is biased to return to a first substantially flat profile upon release of pressure of the fluid delivered by the fluid delivery system 23. In its simplest form, the biasing of the liner 18 can be realised by forming the liner as a sheet of a resilient material such as a sheet of natural or synthetic rubber. However, it is envisaged that other materials can be used. Further, it is not critical for the material from which the liner is made to be of an elastic material.

An important feature of the liner is that it is able to vary or change its profile or shape upon the application and subsequent release of fluid pressure between the liner 18 and the wall 12. This can be achieved, for example, by forming the liner from a substantially non-elastic material such as canvas but in a configuration which allows such change in shape such as forming it with pleats. If desired, biasing of the liner in this instance may be accomplished by attaching one or more resilient members (not shown) such as rubber bands or springs between the liner 18 and the wall 12. It should be further noted that an inherent biasing of the liner to return to the first profile upon release of fluid pressure is not essential, as this may equally be achieved by the flow of hydrate particles across or over the variable surface of the liner.

The fixing system 20 is, in this embodiment, in the form of a frame 22 having a pair of parallel and spaced apart cross members 24 and 26 with a plurality of parallel and evenly spaced transverse members 28 extending therebetween. The frame 22 overlies the liner 18 and clamps it to the wall 12. In doing so, the frame 22 effectively divides the liner 18 into a plurality of fixed areas 30 and a plurality of free areas 32. With reference to Figure 6, the fixed areas 30 of the liner 18 constitutes one or more bands or strips of the liner 18 which are sandwiched between the members 24, 26 or 28 of the frame 22 and the wall 12. These fixed areas or bands 30 of the liner 18 are fixed to the wall 12 to the extent that they are unable to move away from the wall 12 in a direction perpendicular to the plane of the wall 12.

The free areas 32 of the liner 12 are composed of one or more portions of the liner 18 which are bound by the bands 30. The free areas 32 thus lie within the space between mutually adjacent transverse members 28 and the cross members 24 and 26 of the frame 22.

The frame 22 can be attached to the wall 12 over the liner

18 using any convenient known technique including the use of mechanical fasteners such as bolts.

The shape and configuration of the free areas 32 and fixed areas 30 will be dictated by the configuration of the frame

22. In the illustrated embodiment, the free areas 32 extend parallel to each other and, when viewed inside the hopper 10 run up and down the walls 12.

The fluid delivery supply system 23 is most preferably configured to deliver fluid individually to between sets of one or more of the free areas 32, and the wall 12. Taking the example of the fixing system 20 dividing the liner 18 into nine of substantially parallel displaceable areas 32A to 321, as shown in Figure 3. The fluid delivery system 23 may be configured to deliver fluid sequentially to free area 32A, then free areas 32B, 32C, 32D and so on to create a ripple effect. Alternatively, the fluid delivery system 23 may be configured to deliver fluid to other sets of free areas such as 32A and 32D and 32G, followed by 32B and 32E and 32H, followed by 32C and 32F and 321, then returning to 32A and 32D and 32G, and so on.

The fluid delivery system 23 comprises a manifold 34 having a plurality of feed tubes 36 that extend through each of the free areas 32 to deliver fluid to a region between each free area 32 and the wall 12. The manifold 34 is in fluid communication with a fluid supply 38. In one embodiment, the fluid supply 38 is in the form of a supply of a liquid such a oil and a pump for pumping the oil to the manifold 34. A return or exhaust manifold 34' is provided for returning the fluid to the supply 38. Exhaust manifold 34' is of the same configuration as the manifold 34 and includes a plurality of exhaust tubes 36'.

In an alternate embodiment, the fluid supply 38 may supply a compressible fluid such as air or another gas.

The wall lining system 16 may also comprises a controller for controlling the distribution of the fluid from the supply 38 to between the liner 18 and the wall 12. The controller comprises a series of valves 40 provided in the manifold 34 for each feed tube 36 and a sequence controller or programmable device such as a programmable logic array for selectively opening and closing the valves 40 to allow the fluid to flow between the liner 18 and wall 12 through the manifold 34, and to be subsequently expelled via the exhaust tubes 36' and exhaust manifold 34'. The controller is arranged to be able to sequentially pressurise adjacent portions 32 to cause a profile of the liner 18 to deform or change in a ripple or wave-like manner, as illustrated in Figure 6.

The operation of the wall lining system 16 will now be described.

The wall lining system 16 is fixed to the surface of wall 12 inside of the hopper 10. This is typically done by initially laying the liner 18 on the side wall 12 and overlying the liner 18 with the frame 22. Mechanical fasteners such as bolts can be used to fasten the frame 22 to the side wall 12 thus clamping the liner 18 therebetween. In this regard, the bolts may either pass through the members 24, 26 and 28 or alternately lugs or brackets may be attached to the frame 22 through which the bolts can pass. In the instance where the liner 18 is made from a resilient elastomeric material, the fixed bands or strips 30 of the liner 18 underlying the members 24, 26 and 28 may form a substantially fluid-tight seal against the surface 12. Indeed, when the fluid used in the system is a liquid such as oil, it is particularly advantageous for the seal to exist. To this end, if desired a sealing compound may also be applied to the bands or strips 30 of the liner 18 which are to be overlayed by the members 24, 26 and 28 to assist in producing a seal. In this way, each free area 32 would be bound by a peripheral seal.

For ease of installation, it is further envisaged that the liner 18 may be pre-attached to one side of the frame 22 for example by use of an adhesive compound so that the ensemble of the liner 18 and frame 22 can be fixed to the wall 12 simultaneously.

The liner 18 is formed with a plurality of holes (not shown) through which the feed and exhaust tubes 36 and 36' of the manifold 34 and exhaust manifold 34' respectively pass. A seal is typically formed between the feed tubes 36 and 36' and the holes through which they extend. Pressurised fluid passes from the supply 38 through the manifold 34 to beneath each of the respective free areas 32 of the liner 18. This inflates the free areas 32 of the liner 18 causing them to lift away from the surface of side wall 12, thus varying the profile or shape of the liner 18. By appropriate controlling of the valves 40 fluid can be supplied to pressurise adjacent free areas 32 sequentially to cause the profile of the liner 18 to deform or vary in a ripple or wave-like manner. This presents a live surface to material within the hopper 10 substantially reducing the likelihood of adhesion of the material to at least the portions of the side wall covered by the wall lining system 16. If material has previously caked or, in the case of hydrates, frozen onto the liner 18, operation of the wall lining system 16 will assist in breaking up and subsequently releasing the material. Appropriate control of the valves 40 on the exhaust manifold 34' is also required to release fluid pressure from beneath a particular free area 32 to allow it to return to its relaxed state.

In the event that the fluid used for the system is a gas and in particular compressed air, the need to seal the periphery of each of the free areas 32 may be not critical and indeed ensuring there is an air leak may be beneficial . In such a system, rather than having an exhaust manifold, the leakage of compressed air from about the periphery of each free area 32 serves to allow each free area 32 to return to its relaxed state, thus doing away with the exhaust manifold 34

Now that an embodiment of the present invention has been described in detail, it will be apparent to those skilled in the relevant arts that numerous modifications and variations may be made without departing from the basic inventive concepts. For example, instead of the frame 22 overlying the liner 18, the configuration can be reversed so that the frame 22 is disposed between the liner 18 and the wall 12 as illustrated in a second embodiment of the present invention shown in Figure 7 where like reference numerals refer to like parts. In such a configuration the undersurface of the liner 18 which is in contact with the frame 22 would need to be attached to the underlying members 24, 26 and 28. This may be achieved by any known means including the use of adhesives or by mechanical means. Indeed, going one step further, depending on the actual application, there may be no need for a specific frame in order to attach the liner 18 to the wall 12; rather, the fixing system may simply be achieved by use of adhesives or mechanical fasteners. Thus, it should be recognised that the use of a frame per se is not essential to the present invention.

In addition, the shape and configuration of the free areas 32 can be varied to suit the application at hand. There is no need for these free areas 32 to be of a generally rectangular shape and disposed parallel to each other as depicted in the present drawings. For example, the free areas 32 may take on the configuration of a matrix of squares or diamonds or other shapes as illustrated in Figure 8; or, be in the form of concentric annuli. To achieve a particular configuration of free areas 32, will simply require appropriate configuring of the fixing system 20.

All such modifications and variations are deemed to be within the scope of the present invention the nature of which is to be determined from the above description and the appended claims .

Claims

CLAIMS ;

1. A wall lining system comprising: a liner having a variable surface profile; and, a fixing system for fixing the liner to a wall of a piece of material handling equipment, the fixing system dividing the liner into a plurality of fixed areas and free areas, each free area of the liner able to move away from the wall to vary the surface profile of the liner in response to the delivery of a fluid from a fluid delivery system to one or more of the free areas between the liner and the wall .

2. A wall lining system as defined in claim 1 wherein the fixing systems includes a frame which overlies the liner and clamps the liner to the wall .

3. A wall lining system as defined in claim 1 wherein the fixing system comprises a frame located between the wall and the liner, one side of the frame attached to the wall and an opposite side of the frame attached to the liner.

4. A wall lining system as defined in claim 2 or 3 wherein the plurality of fixed areas are bands of the liner.

5. A wall lining system as defined in claim 4 wherein the plurality of free areas are bound by the bands .

6. A wall lining system as defined in any one of claims 1 to 5 wherein the plurality of free areas are parallel to each other.

7. A wall lining system as defined in any one of claims 1 to 6 wherein the fluid delivery system delivers fluid individually to between the wall and sets of one or more of the free areas of the liner.

8. A wall lining system as defined in claim 7 further comprising a controller for controlling distribution of the fluid from the fluid delivery system to between the liner and the wall .

9. A wall lining system as defined in claim 8 wherein the controller operates to supply fluid sequentially to adjacent free areas of the liner to cause the profile of the liner to deform in a ripple or wave-like manner.

10. A wall lining system as defined in any one of claims 1 to 9 wherein the fluid is a gas.

11. A wall lining system as defined in any one. claims 1 to 9 wherein the fluid is a liquid.

12. A wall lining system as de ined in any one of claims 1 to 11 wherein the liner is biased to return to a first profile upon release of pressure of the fluid delivered by the fluid delivery system.

13. A wall lining system as defined in claim 12 wherein the bias is provided by forming the liner from a resilient material.

14. A wall lining system as defined in claim 13 wherein the liner is made of an elastomeric material,

15. A wall lining system as defined in any one of claims 1 to 14 wherein the piece of particulate handling equipment is a hydrate storage vessel.

16. A method of producing a live wall, comprising; fixing a liner having a variable profile to a surface of -a wall using a fixing system, the fixing system dividing the- liner into a plurality of fixed areas and a plurality of free ^'areas, each free area of the liner able to move away from the wall to vary a surface profile of the liner in response to the delivery of a fluid between the liner and the wall from a fluid delivery system; and, delivering fluid to the free areas of the liner at sufficient pressure to vary the profile of the liner.

17. A method of producing a live wall as defined in claim 16 wherein fixing the liner to the wall comprises fixing the liner in a manner in which the free areas of the , liner are parallel.

18. A method of producing a live wall as defined in claim 16- or 17 wherein delivering the fluid comprises delivering the fluid in a predetermined sequence individually to between selected sets of the free areas of the liner.

19. A method of producing a live wall as defined in any one of claims 16 to 18 wherein delivering fluid comprises delivering fluid sequentially to adjacent portions of the liner to cause the profile of the liner to deform in a ripple or wave-like manner.

20. A wall lining system substantially as herein described with reference to and as illustrated in the accompanying drawings .

21. A method of producing a live wall substantially as herein described with reference to and as illustrated in the accompanying drawings .