GB2365813A

GB2365813A - Pipe splitting means

Info

Publication number: GB2365813A
Application number: GB0119867A
Authority: GB
Inventors: Anthony Bell Hick
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-08-16
Filing date: 2001-08-15
Publication date: 2002-02-27
Anticipated expiration: 2021-08-15
Also published as: GB2365813B; GB0305741D0; GB0119867D0; GB2383286A; GB2383286B; WO2002014007A1; AU2001279943A1; GB0020055D0

Abstract

An apparatus 5 for splitting pipes 11 comprises means 1 for forming a longitudinal cut of the pipe 11, and diverging means 2 for opening up the cut pipe to expose the pipe interior. A method for splitting pipes 11 comprises the steps of forming a longitudinal cut of the pipe and opening out the cut pipe to expose its interior.

Description

2365813 TITLE: Pipe Splitting Means

DESCRIPTION

This invention concerns a method and apparatus for splitting pipes.

When reprocessing facilities in nuclear power plants become redundant, it is often necessary to decommission the plant, i.e. shut it down.

However, it is often difficult and expensive to dispose of the pipes, which have been utilised in the plant, since some or all sections of the pipe will have been contaminated by the radioactive material, which has passed through them. Accordingly, in their unmonitored state, they cannot be recycled, i.e. sold as scrap, since quite obviously, the decommissioned possibly contaminated pipes may pose a severe health hazard to the general public.

Accordingly, it is known to bury the contaminated pipes in dump sites, often encased within underground thick-walled concrete containers, which substantially eliminate radioactive contamination of the surrounding area. However, this is often an expensive process, which is extremely wasteful of those parts of the pipes, which have not actually been contaminated by radioactivity. Furthermore, as well as this economic aspect, it is damaging to the environment to dispose of more material than is necessary, since some sections of pipe remain uncontaminated and are therefore reusable. Hence, it is known to monitor the pipes for radioactivity, and reuse those parts, which have not been contaminated. It is particularly necessary to monitor the interior of the 2 pipe, since this is the most likely site of contamination, as a result of the radioactive material passing through the pipe. Typical pipes used in the process have diameters of between 15 mm and 150 mm.

Generally, the monitoring is effected by completely splitting the pipe to be monitored along its length, by means of sawing, into two C-section pieces, and then monitoring each piece separately for radioactive contamination, in particular the interior thereof.

However, this process does not enable the splitting of the pipe and the monitoring thereof to be done progressively, since the pipe must first be completely sawn along its length into two C-section pieces, and only then is it monitored for radioactive contamination. In addition, further cutting may be required to remove any contaminated sections or to reduce the length to a suitable size for recycling, and as a result, this method tends to produce a lot of cutting debris, which itself may be contaminated by radioactivity, and which is difficult to confine, possibly getting caught up in the moving parts of the apparatus, i.e. the blades of the saw. Consequently, this debris must regularly be removed, to enable the apparatus to work adequately, and also to facilitate maintenance and blade changing.

It is an object of the present invention to provide a method and apparatus for splitting pipes, which overcomes the above-mentioned problems.

Accordingly, one aspect of the present invention provides an apparatus for splitting pipes, which comprises means for forming a longitudinal cut of the 3 pipe, and diverging means for opening up the cut pipe to expose the pipe interior.

A second aspect of the present invention provides a method for splitting pipes, which comprises the steps of forming a longitudinal cut of the pipe and opening out the cut pipe to expose the pipe interior.

In a preferred embodiment, cutting means and diverging means together comprise a mandrel, the mandrel further comprising a graded cutting edge along one side thereof, whereby a pipe is first forced over the cutting edge and then over the diverging means, thereby partially splitting the pipe and causing the edges thereof to diverge, to facilitate monitoring of the interior of the pipe. It is preferable that the cross-section of the diverging means undergoes transitions such that as the pipe is forced over the diverging means, the edges of the pipe are gradually forced apart, until the interior of the pipe is exposed.

Preferably, one or more rollers are located underneath the cutting means, whereby a pipe may pass over the roller(s) as it is forced over the cutting means, in order to reduce friction. Further still, it is preferable that one or more rollers are located underneath the diverging means, whereby a pipe may pass over the roller(s) as it is forced over the diverging means, in order to reduce friction. More preferably still, one or more rollers are located at one end of the mandrel, more preferably still, at that end, which a pipe first encounters as it passes through the apparatus, in order to further reduce friction as the pipe passes over the mandrel.

It is further preferable that the means for forcing a pipe over the mandrel comprises a slide ram. The slide ram is preferably hydraulically operated. More preferably still, the forcing means further comprises a clamp, whereby a pipe is held within the clamp, and the slide ram drives the clamp with the pipe held therein against and over the cutting means and diverging means. Preferably, the clamp is attachable to the slide ram.

Preferably, the mandrel comprises an extended nose at one end thereof, more preferably still, at that end, which a pipe first encounters as it passes through the apparatus. This enables a section of pipe, which has not yet been split, to locate over the nose, the nose thereby acting as a guiding and steadying means.

Preferably, the apparatus comprises monitoring means, whereby a pipe is progressively monitored for radioactivity as it is being partially split along its length. It is further preferable that the apparatus comprises shearing means, for example, a guillotine, for cutting a pipe into pieces transverse to its length after it has passed by or through the cutting means, diverging means and the monitoring means. Preferably, one or more rollers are located underneath the monitoring means to reduce friction as a pipe passes through the apparatus. It is further preferable that the apparatus comprises decontamination means. More preferably still, the decontamination means is located at a position on the apparatus which a pipe passing therethrough encounters after it has passed through the monitoring means, whereby a pipe is decontaminated at those areas, which have been detected as being radioactive by the monitoring means.

However, it is to be understood that the pipe may alternatively be monitored and/or decontaminated after it has passed through the apparatus, using a separate process. In this case, after it has been split, and then monitored by a separate process, it may be decontaminated, and then remonitored to check if the levels of radioactivity have been sufficiently reduced. If the levels are still unsatisfactorily high, then the decontamination then remonitoring process is repeated until the radiation levels have reached a satisfactorily low level.

As an alternative means of splitting a pipe along its length, the mandrel may be forced through the pipe, for example, by way of a hammering means, the pipe remaining stationary. Alternatively, as opposed to the pipe remaining stationary, one or more motor driven rollers may be provided at each side of the pipe, whereby the rollers move the pipe to act in conjunction with the hammering means. It is preferable that the hammering means is hydraulically operated, although it may alternatively be pneumatically driven.

It is preferable that the method of partially splitting a pipe and forcing the edges apart comprises the steps of forcing the pipe over a mandrel, the mandrel having a graded cutting edge along one side thereof, and undergoing changes of shape such that as the pipe is forced over the mandrel, the pipe is cut by the cutting edge and then the edges of the pipe are gradually forced apart as it passes over the mandrel.

It is further preferable that a pipe is forced over the mandrel by Way of holding the pipe within a clamp, and forcing the pipe held within the clamp onto 6 the cutting means and diverging means using a slide ram, then releasing the clamp and retracting the slide ram and the clamp. More preferably still, this process is repeated, until the whole length of a pipe has been partially split.

It is preferable that the method comprises the steps of progressively monitoring a pipe for radioactivity as it is being partially split and its edges forced apart, thereby exposing the interior of the pipe to the monitoring means.

Preferably, the method comprises the step of passing a pipe over one or more rollers located on the apparatus to facilitate movement of the pipe by reducing frictional effects.

Alternatively, the method of partially splitting a pipe along its length and forcing the edges apart comprises the steps of forcing the mandrel through the pipe, the mandrel having a graded cutting edge along one side thereof, and undergoing changes of shape such that as it is forced through the pipe, the pipe is cut by the cutting edge and then the edges of the pipe are gradually forced apart. In this case, it is preferable that the mandrel is forced through the pipe by way of a hammering means, which acts upon the mandrel. Preferably, the hammering means is pneumatically driven, or alternatively, it is hydraulically driven.

The present invention will now be described further hereinafter, by \/Vay of example only, with reference to the accompanying drawings in which: Figure 1 is a side view of the cutting and diverging means, in accordance with the present invention; Figure 2 is a section along the line A-A of Figure 1, of the cutting and diverging means, in accordance with the present invention; Figure 3 is a section along the line B-B of Figure 1, of the cutting and diverging means, in accordance with the present invention; Figure 4 is a section along the line C-C of Figure 1, of the cutting and diverging means, in accordance with the present invention; Figure 5 is a section along the line D-D of Figure 1, of the cutting and diverging means, in accordance with the present invention; Figure 6 is a section along the line E-E of Figure 1, of the cutting and diverging means, in accordance with the present invention; Figure 7 is a side view of the apparatus for splitting pipes, in accordance with the present invention; and Figure 8 is a side view of a second embodiment of the apparatus for splitting pipes, in accordance with the present invention.

With reference to Figures I to 8, an apparatus for splitting pipes is illustrated generally by reference numeral 5. The apparatus 5 comprises a mandrel 3, which comprises a splitting means 1 and a diverging means 2.

As can be seen from Figures 1 and 2, the splitting means 1 comprises a cutting edge 15, with a top end 13 and a bottom end 12. As can be seen from Figures 2 to 6, the diverging means 2 of the mandrel 3 gradually flares out from the top end 13 of the cutting edge 15 onwards. The cross section of the diverging means 2 of the mandrel 3 changes gradually from a narrow inverted triangular shape with a rounded apex, to progressively wider inverted triangular 8 shapes, each with a rounded apex, then on to a rectangular shape with an inverted triangular shaped base, the sides of the triangular shaped base converging to the rectangular shape, the triangular shaped base having a rounded apex, and then on to an inverted T-shape. In order to partially split a pipe and force the edges thereof apart, the pipe 11 is forced onto the cutting edge 15 of the mandrel 3, starting from the bottom end 12 and finishing at the top end 13, and is thereby partially split. Thereafter, the partially split pipe is forced over the diverging means 2, which forces the edges of the pipe apart, thereby exposing the interior of the pipe.

As can be seen from Figure 7, a clamping means 20 grips the pipe 11, and a slide ram 6 acts on the clamp 20, thereby forcing the pipe 11 onto the mandrel 3 to be partially split and its edges forced apart. After a section of the pipe has been partially split and its edges forced apart, that section is then pushed through a radioactivity monitor 9, and because the interior of the pipe is now exposed, the interior may be adequately monitored for radioactivity, with the unsplit sections working their way through the splitting and diverging part of the apparatus 5 at the same time. Rollers 23 are located underneath the mandrel 3, so that as the pipe passes through the apparatus 5, and over the mandrel 3, frictional effects are reduced.

The pipe is then pushed through a shearing means 10, such as a guillotine, which cuts the partially split and monitored pipe transverse to its length, into smaller, more manageable pieces, which, if they are not contaminated by radioactivity after being monitored therefor, may be 9 conveniently sold as scrap. This substantially flattened form of split pipe is more conveniently stored and transported, if being sold as scrap, than an untreated pipe, and if it is contaminated, then it is more easily safely stored in this form. The shearing means 10 may be operated manually, a user operating the shearing means 10, thereby cutting the pipe into sections, according to whether or not it is contaminated by radioactivity, as told by the monitoring means 9.

A means 21 of decontaminating the radioactive sections of pipe is used on those sections of the pipe 11, which have been found to be radioactive by the monitoring means 9.

It is to be understood that, in using the apparatus of the invention, a pipe doesn't necessarily have to come out perfectly flat; for example, it may, depending on the exact shape of the mandrel, come out with a Cshaped crosssection, which would still enable the interior thereof to be monitored for radioactivity.

Figure 8 shows the mandrel 3a having an extended nose 22, for guiding and steadying a pipe as it passes through the apparatus 5a.

The process is therefore progressive, there being no need to first partially completely split the whole of the pipe along its length, forming two pieces, and only at that stage to monitor it for radioactivity. Furthermore, because the pipe is only partially split, there is less cutting debris than if the pipe was completely split along its length. Pipes having various diameters may be split using the apparatus and process of the invention, the apparatus being manufactured such that it has dimensions to suit the particular size of pipe being split.

Furthermore, circular section pipes may be split, but other types of pipe, such as square hollow section tube and rectangular hollow section tubes may also be split using the apparatus and process of the invention.

Claims

1 An apparatus for splitting pipes, comprising means for forming a longitudinal cut of the pipe, and diverging means for opening up the cut pipe to expose the pipe interior.

2. An apparatus as claimed in claim 1, wherein the cutting means and diverging means together comprise a mandrel.

3. An apparatus as claimed in claim 2, wherein the mandrel comprises a graded cutting edge along one side thereof.

4. An apparatus as claimed in claim 1, 2 or 3, wherein the cross-section of the diverging means undergoes transitions such that as the pipe is forced over the diverging means, the edges of the pipe are gradually forced apart, until the interior of the pipe is exposed.

5. An apparatus as claimed in any one of claims 1 to 4, wherein at least one roller is located underneath the cutting means.

6. An apparatus as claimed in any one of claims I to 5, wherein a plurality of rollers are located underneath the cutting means.

7. An apparatus as claimed in any one of claims 1 to 6, wherein at least one roller is located underneath the diverging means.

8. An apparatus as claimed in any one of claims 1 to 7, wherein a plurality of rollers are located underneath the diverging means.

9. An apparatus as claimed in any one of claims 2 to 8, wherein at least one roller is located at the end of the mandrel, which, in use, a pipe first encounters as it passes through the apparatus.

10. An apparatus as claimed in any one of claims 2 to 9, wherein at least one motor driven roller is located at each side of the apparatus to engage a pipe passing therethrough, whereby in use, the rollers help drive the pipe over the mandrel.

11. An apparatus as claimed in any one of claims 2 to 10, wherein the mandrel comprises an extended nose at one end of the mandrel, to act as a steadying means.

12. An apparatus as claimed in claim 11, wherein the nose is located at the end of the mandrel, which a pipe first encounters as it passes through the apparatus.

13. An apparatus as claimed in any one of claims 2 to 12, further comprising means for forcing a pipe over the mandrel.

14. An apparatus as claimed in claim 13, wherein the means for forcing a pipe over the mandrel comprises a slide ram.

15. An apparatus as claimed in claim 14, wherein the slide ram is hydraulically operated.

16. An apparatus as claimed in claim 13, 14 or 15, wherein the forcing means further comprises a clamp.

17. An apparatus as claimed in claim 16, wherein the clamp is attachable to the slide ram.

18. An apparatus as claimed in any one of claims 1 to 17, further comprising monitoring means for detecting radioactivity.

19, An apparatus as claimed in any one of claims 1 to 18, further comprising decontaminating means.

20. An apparatus as claimed in claim 19, wherein the decontaminating means is located at a position on the apparatus, which a pipe passing therethrough encounters after it has passed through the monitoring means,

21. An apparatus as claimed in claim 18, 19 or 20, wherein at least one roller is located underneath the monitoring means.

22, An apparatus as claimed in any one of claims 18 to 21, wherein a plurality of rollers is located underneath the monitoring means.

23. An apparatus as claimed in any one of claims 1 to 22, further comprising shearing means for cutting a pipe into pieces transverse to its length.

24. An apparatus as claimed in any one of claims 1 to 23, comprising a hammering means, which acts on the mandrel, for forcing the mandrel through a pipe.

25. An apparatus as claimed in claim 24, wherein the hammering means is hydraulically operated.

26. An apparatus as claimed in claim 24, wherein the hammering means is pneumatically operated.

27. A method for splitting pipes, comprising the steps of forming a longitudinal cut of the pipe and opening out the cut pipe to expose its interior.

28. A method as claimed in claim 27, wherein a pipe is forced over a mandrel in order to form a longitudinal cut of the pipe and open the cut pipe out to expose its interior, the mandrel having a graded cutting edge along one side thereof, and undergoing changes of shape such that as the pipe is forced over the mandrel, the pipe is cut by the cutting edge and then the edges of the pipe are gradually forced apart as it passes over the mandrel.

29. A method as claimed in claim 28, wherein a pipe is forced over the mandrel by way of holding the pipe within a clamp, and forcing the pipe held within the clamp onto the cutting means and diverging means using a slide ram, then releasing the clamp and retracting the slide ram and the clamp.

30. A method as claimed in claim 27, wherein a mandrel is forced through a pipe in order to form a longitudinal cut of the pipe and open the cut pipe out to expose its interior, the mandrel having a graded cutting edge along one side thereof, and undergoing changes of shape such that as the pipe is forced over the mandrel, the pipe is cut by the cutting edge and then the edges of the pipe are gradually forced apart as the mandrel passes through it.

31. A method as claimed in claim 30, the mandrel is forced through a pipe, by way of using a hammering means, acting on the pipe, which remains substantially stationary.

32. A method as claimed in claim 29, 30 or 31, wherein the process is repeated, until the whole length of a pipe has been partially split.

33. A method as claimed in any one of claims 27 to 32, further comprising the step of monitoring a pipe for radioactivity as it is being partially split and its edges forced apart.

34. A method as claimed in any one of claims 27 to 33, further comprising the step of decontaminating a pipe.

35. A method as claimed in any one of claims 27 to 34, further comprising the step of passing a pipe over at least one roller located on the apparatus to facilitate movement of the pipe by reducing frictional effects.

36. A method as claimed in any one of claims 27 to 35, further comprising the step of passing a pipe over a plurality of rollers located on the apparatus to facilitate movement of the pipe by reducing frictional effects.

37. An apparatus substantially as hereinbefore described with reference to the accompanying drawings.

38. A method substantially as hereinbefore described with reference to the accompanying drawings.