NL1036815C2 - Coupling system for a hose structure, in particular for use in a pump system for displacing a medium as well as such a pump system. - Google Patents

Description

Coupling system for a hose structure, in particular for use in a pump system for displacing a medium as well as such a pump system

Technical Field 5 The present invention relates to a coupling system for a hose structure, in particular for use in a pump system for displacing a medium.

Background Art

Coupling systems are known for use in slurry discharge pump 10 systems which have a membrane (flexible hose) inside a rigid pipe to define an annulus (between the hose and the pipe) and a volume (within the hose). The annulus and volume can be used to exchange or recover energy between two fluids and at the same time keeping the fluids separated to prevent mixing and improve energy transfer efficiency. Energy transfer in these pumps is typically through a 15 positive displacement action.

For example, the pump described in PCT/AU2003/000953 has achieved commercial application in the mining industry. In its typical use, a dirty or corrosive fluid is pumped inside the flexible hose, under low pressure, and another fluid such as hydraulic oil is pumped into the annulus at high pressure, causing the 20 dirty or corrosive fluid to exit the hose under high pressure.

Due to the circumstances under which the pump system is operated, specific construction requirements are necessary with respect to the connection of the flexible hose end to the pump structure. Usually each free hose end is mounted around a separate cylindrical coupling element, which in turn is 25 coupled to the pump (housing). Thereto each free hose end is clamped around the circumferential surface using metal clamping bands. However this appears to be a less favourable coupling mechanism, since the flexible hose ends may deteriorate more quickly due to the cyclic nature of the mechanical loads exerted thereon during operation of the pump system, thus limiting its life span, or even giving an increased 30 risk of rupture.

Summary of the Disclosure

The present invention relates to a coupling system for a hose structure, in particular for use in a pump system for displacing a medium, 1036815 2 comprising: a cylindrical element having a first end and a second end and being capable during use to be accommodated with its first end inside a free end of said hose structure, and 5 - clamping means for clamping said free end of the hose structure against the outer circumferential surface of the cylindrical element, characterized in that the clamping means are arranged for engagement against the first end of said cylindrical element.

This coupling system can provide an improved clamping of the 10 flexible hose end to the cylindrical element, thereby limiting mechanical loads and pressure forces exerted on the hose material, which may deteriorate the hose material. The mechanism of clamping can relocate at least part of the clamping force to a location where the in use cyclic mechanical load does not take place.

In one embodiment, the first end of said cylindrical element is 15 provided with a tapered outer surface, which further reduces pressure forces exerted on the flexible hose material, which may limit its lifespan.

In one embodiment, the clamping means comprises a clamping ring, which can be be clamped against the end of said cylindrical element. This allows a clamping mechanism with a uniform and evenly distributed clamping force on the 20 flexible hose end, thus extending the lifespan.

In one embodiment, the clamping ring can be provided with a tapered inner surface, and more particularly in one form the tapered inner surface may transition into a rounded end surface. This is a further life span increasing measure for the flexible hose.

25 In one embodiment, the clamping ring can be clamped against the first end of the cylindrical element using connecting means.

In one embodiment, the second end of the cylindrical element can be provided with an upright flange, which interacts with the connecting means. This allows for a simple, yet reliable mounting and coupling of the flexible hose end with 30 the clamping ring to the cylindrical element.

In an alternative form, the upright flange can also be constructed as a separate ring which bottoms against a step in a cylindrical element.

In one embodiment, the upright flange can be provided with multiple openings and wherein the connecting means comprise bolts, which are guided 3 through the openings.

Brief Description of the Drawings

An embodiment will now be described, by way of example only, with 5 reference to the accompanying drawings, in which:

Figure 1 is a detailed view of a pump system according to the state of the art;

Figure 2 is a sectional view an embodiment of a flexible hose structure provided with a coupling element according to the invention; and 10 Figures 3a-3b is a sectional view an embodiment of a coupling element according to the invention.

Detailed Description of an Embodiment

Referring to the drawings, Figure 1 discloses a detailed view of a 15 known pumping system utilising a flexible hose structure 27 for displacing a medium, such as a slurry. The known pumping system exhibits one or more pumps of the type as depicted in Figure 1 and denoted with reference numeral 21. In a case where multiple pumps are used, (using the nomenclature 21-2Τ-2Γ), they are operated in a timed sequence with respect to one another in order to discharge slurry in a 20 continuous fashion.

The pump 21 comprises a rigid outer casing 25, which is of cylindrical construction and which defines an interior space 26. Each casing 25 has a longitudinal axis, which in use is preferably inclined with respect to the horizontal such that one end thereof is elevated in relation to the other. A first end plate 34 is 25 mounted on the upper end of the casing 25 and a second end plate 23 is mounted on the lower end thereof.

A flexible tube or hose structure 27 is accommodated in the interior space 26 within the outer casing 25 and is supported in a longitudinally taut condition. The flexible tube structure 27 is flexible yet substantially inelastic. The 30 tube structure 27 is substantially inelastic in the sense that it does not have a memory tending to cause it to return to a particular state after being deflected therefrom, and has a tensile strength thereby limiting the elastic stretch of the tube.

The interior of the tube structure 27 defines a pumping chamber 28. Because of its flexible nature, the tube structure 27 is movable between laterally 4 collapsed and expanded conditions for varying the volume of the pumping chamber 28. With this arrangement, the pumping chamber 28 can perform intake and discharge strokes.

In the laterally collapsed condition, the tube structure 27 is relaxed 5 and essentially collapsed upon itself, apart from the ends 27a-27b (see Figure 2) thereof which are supported in a manner in the outer casing 25, which will be further described herein. In the laterally expanded condition, the tube structure 27 is inflated and stresses can develop in the tube wall. This results in some longitudinal contraction or shortening of the tube structure 27.

10 One end 27a of the tube structure 27 is supported on the lower end plate 23 by means of a coupling element 100a as depicted in Figure 2 and in more detail in Figure 3. Specifically, the lower end plate 23 incorporates an opening which defines a port 42 through which slurry undergoing pumping can enter and leave the pumping chamber 28 defined within the tube structure 27. The end plate 23 15 incorporates a sleeve section 24 onto which the end of the tube structure 27 is sealingly engaged.

The other end of the tube structure 27 is attached to a movable support. The movable support comprises a cylindrical rigid end fitting 29, an end wall section 31 and a conical inner profile section 30. The end of the tube structure 27 is 20 sealingly fitted onto the cylindrical rigid end fitting 29. The end wall section 31 is supported on a tubular rod 32 which extends through an opening 38 in the upper end plate 34. The tubular rod 32 is sealingly and slidingly supported in the end plate 34. The outer end section of the tubular rod 32 is fitted with a collar 36, with a compression spring 35 acting between the collar 36 and the outer face of the end 25 plate 34. With this arrangement, the compression spring 35 urges the tubular rod 32 outwardly and thus the end fitting 29 is urged towards the end plate 34.

This arrangement movably supports the upper end 27b of the tube structure 27 and accommodates longitudinal extension and contraction of the tube structure as will be explained later. Additionally, it assists in maintaining the tube 30 structure 27 in the longitudinally taut condition.

The region of the interior space 26 surrounding the tube structure 27, and internal of the rigid outer casing 25, defines an actuating annulus 41 for receiving an actuating fluid. The region external of the circular end wall 31 and internal of the end plate 34 defines an actuating chamber 40 for receiving the 5 actuating fluid, the actuating chamber 40 being in fluid communication with the actuating annulus 41 to provide the actuating region.

Upon commencement, and during the discharge stroke, the actuating fluid enters the actuating chamber 40 via port 39 before passing into the 5 actuating annulus 41. Port 39 is connected to the upper end of outer casing 25 so that the flow of actuating fluid, when entering the actuating chamber 40, is not directly inline with the tube structure 27 and therefore does not impinge thereagainst.

Upon commencement, and during the intake stroke, the actuating 10 fluid passes through the actuating annulus 41 into the actuating chamber 40 before exiting via port 33. Port 33 is connected to the upper end of the outer casing 25 and in the upper most elevated position. This configuration allows for entrapped air to be dispelled from the actuating chamber 40 upon discharge of the actuating fluid.

To this end (but not depicted), the pumping system according to the 15 state of the art includes a delivery means for delivering the slurry to the pumping chamber 28 in a timed sequence.

Each port 42 also communicates with a discharge pipeline for discharging the slurry to be displaced by the flexible hose 27 during the discharge stroke.

20 Preferably, the actuating fluid is hydraulic oil, which is supplied towards the chamber 26 around the hose structure 27 via inlet and outlet pipelines 33-39 for performing the discharge and intake stroke of the flexible hose structure.

Figure 2 discloses such hose structure 27, which is accommodated with its first end 27a and second end 27b each having a suitable connection element 25 100a and 100b respectively which are part of a pump system for displacing a medium.

In the operation of such a displacement pump system, the flexible hose structure is subjected in a repetitive manner to cyclic mechanical loads exerted thereon during operation of the pump system. These mechanical loads exerted on 30 the flexible hose structure 27 limit its life span especially near the free hose ends 27a-27b which are clamped around the respective circumferential surface of the coupling element 100a-100b using known metal clamping bands. In Figure 3 these metal clamping bands are denoted with reference numeral 15.

Referring now to Figure 3, a coupling mechanism is shown which 6 exhibits an improved clamping of the flexible hose end 27a-27b to the cylindrical coupling elements 100a-100b, thereby limiting in use mechanical loads and pressure forces exerted on the hose material, and thereby preventing any deterioration offset material or even a rupture of the hose near the coupling elements.

5 In Figure 3a, a clamping means 200 is provided which is arranged for engagement against the end face 101a of each cylindrical coupling element 100a-100b.

Hereto the clamping means 200 comprises a clamping ring 210 which is provided with a curved end face 240 which abuts against the tapered outer 10 surface 105 of the first end face 101a so as to clamp the hose 27 therebetween.

This arrangement reduces the pressure forces exerted on the flexible hose material 27, which can have an effect on the lifespan of the material. In the arrangement illustrated, a uniform and evenly distributed clamping force is exerted on the flexible hose end 27a, thus extending the life span of the hose 27. As 15 depicted in Figure 3 the clamping ring 210 is provided with the curved end face 240 which transitions Into a rounded end face 240'.

For clamping the clamping ring 210 against the first end 101a of the cylindrical element 100a-100b, a connecting means 220-230 is provided. In the drawings the connecting means 220-230 comprises an upright flange 230 provided 20 with a through-hole 230a through which a bolt (or nut) 220 is accommodated. As depicted in Figure 3b the upright flange 230 is part of the coupling element 100a. The free end of the bolt 220 is provided with an external thread 220a which interacts with an internal thread 210a provided on the clamping ring 210. The bolt 220 is guided through the through-hole or opening 230a of the upright flange 230 and is 25 screwed inside the clamping ring 210.

In order to ensure a uniform and evenly distributed clamping effect, multiple bolts 220 are used which are accommodated around the circumferential surface 100a’ of the cylindrical coupling element 100a.

In other forms an even distribution of the clamping effect can also 30 be arranged by implementing different clamping means, such by hydraulic pretensioning, followed by locking using rigid locking means, for example welding, rivets, clamping braces and so on.

The inventors believe that the coupling system described herein will be able to provide a longer operational cycle life before replacement will be needed.

7

This increase will lead to a reduction in maintenance intervals and pump downtime requirements, which can provide operational cost advantages to the operator.

Any reference to prior art contained herein is not to be taken as an admission that the information is common general knowledge, unless otherwise 5 indicated.

Finally, it is to be appreciated that various alterations or additions may be made to the parts previously described without departing from the spirit or ambit of the present invention.

10 1036815

Claims (8)

A coupling system for a hose construction, in particular for use in a pump system for moving a medium, comprising: 5. a cylindrical element provided with a first end and a second end and adapted to be received with its first end during use a free end of the hose construction; and clamping means for clamping the free end of the hose construction against the outer circumferential surface of the cylindrical element, characterized in that the clamping means are adapted for placement against the first end of the cylindrical element. 2. Coupling system as claimed in claim 1, characterized in that the first end of the cylindrical element is provided with a beveled outer surface. 3. Coupling system as claimed in claim 1 or 2, characterized in that the clamping means comprise a clamping ring which can be clamped against the first end of the cylindrical element. Coupling system according to claim 3, characterized in that the clamping ring is provided with a beveled inner surface. 5. Coupling system as claimed in claim 4, characterized in that the beveled inner surface merges into a rounded end surface. Coupling system according to one of claims 3 to 5, characterized in that the clamping ring can be clamped against the first end of the cylindrical element by means of connecting means. 7. Coupling system as claimed in claim 6, characterized in that the second end of the cylindrical element is provided with an upright flange, which cooperates with the connecting means. 8. Coupling system as claimed in claim 7, characterized in that the upright flange is provided with several openings and wherein the connecting means comprise bolts which are guided through the openings. 1036815