PIPELINE CLEANING DEVICE
The invention to which this application relates is improvements to a device for use in the cleaning and/or removal of material from a pipeline so as to remove the material and/or clean as the device is pas sed along the interior of the pipeline.
The provision of devices which can pas s along pipelines is well known and one form of device is generally referred to as a "pig". Most typically, the "pig" is provided with means therein to allow the device to monitor and collect data relating to the condition of the pipeline wall as the device is moved along the pipeline, typically under the influence of the flow of fluid which is being carried along the pipeline. The devices can therefore be introduced into the pipeline via a port such as a valve and removed from the pipeline downstream via another port and thereby provide data relating to the condition of the stretch of pipeline along which the device is moved. This form of the device is typically used in the oil and gas industries for pipelines which carry this sort of material therealong on a substantially constant basis. In this form of device, the aim is to allow the device to pas s along the pipeline in a relatively uniform and reliable manner with a minimum of disruption to the interior of the pipeline so as to minimise the possibility of dislodgement of debris which may enter and contaminate the fluid carried along the pipeline.
In another form of device, and the form to which this application specifically, although not neces sarily exclusively, relates, the device is provided to be moved along the pipeline and to provide a cleaning effect on the interior of the pipeline by dislodging debris which may be located on the interior of the pipeline. In addition the device can provide a cleaning effect by
wiping and hence removing the boundary layer of the material which typically adheres to the internal wall of the pipeline and which would not normally be removed by other cleaning systems. The movement of the device along the pipeline can also or alternatively be performed in order to allow the material which is in the pipeline to be forced along the pipeline and hence be removed at a pipeline opening downstream of the device. Typically, the movement of this form of device along the pipeline, is provided as a cleaning step of part of an overall cleaning or change proces s so as to render the pipeline into a condition in which the same can subsequently be used for the movement of material along the pipeline in a hygienic manner and without the risk of contamination from materials which may previously have been moved along the pipeline.
In this form of a device, the device is required to be sufficiently flexible so as to be moveable around corners and bends of the pipeline whilst still performing the cleaning effect as it is equally important that the corners and the bends are cleaned as it is in straight sections of the pipeline.
To this end the known devices of this type typically include one, and more typically, a plurality of, flexible ribs which are sufficiently resilient as to perform a wiping action on the interior surfaces of the pipeline as the device moves therealong but they are also sufficiently flexible so as to take into account the variations in the shape and/or size of the pipeline interior as the device moves therealong. One form of this type of device is described in the patent document GB2339876, the contents of which are incorporated herein.
The device is typically moved along the pipeline under the influence of a propulsion force from upstream of the device such as, for example, a compres sed air supply.
A problem with this known form of device is that the same is typically used in pipelines in which hygiene is of paramount importance such as, for example, pipelines in food proces sing plants. This means that it is important that the device remains intact during the movement along the pipeline as, if this is not the case, fragments of the device which may be detached during movement along the pipeline and/or as a result of abnormal conditions in the pipeline such as a faulty valve, become potential contaminants of the foodstuff which is subsequently moved along the pipeline. At present, the presence of these fragments cannot be detected and therefore there is a perceived risk of fragments of the device being, for example, lodged or remaining in the pipeline following the movement of the device along the pipeline and thereby possibly becoming a contaminant of the material which is subsequently moved along the pipeline which is believed by the operator to be clean.
A further problem with the known type of device is the need to render the same detectable so as to allow the position of the device along the pipeline to be detected and thereby allow the position of the pipeline to be determined, both for the purposes of enabling the location of the device to be identified if the same is stopped, for example, due to a blockage and thereby allow the specific location of the pipeline which needs to be acces sed to remove the device to be identified. Furthermore, the identification of the progress of the device along the pipeline is required in order to ensure that the device can be succes sfully captured and removed at an opening and also the movement of the device may be controlled and/or associated valve activation.
At present, the presence of the whole device unit within larger pipelines can be achieved by providing one or more magnets within a cavity within the device and which create a magnetic
field which can be detected externally of the pipeline as the device moves along the length of the pipeline interior. However the requirement for the magnets to be provided means that the size of the body of the device is required to be such as to accommodate the magnets in the cavity therein and as a result the device is of a size which means that it is too large to be used on relatively small bore pipelines.
An aim of the present invention is therefore to provide a device which is provided in a form to allow the device, both as a whole, and portions thereof, to be more effectively detectable in terms of their position when the device and/or portions thereof, are within the pipeline along which the same is or has been moved.
In a first aspect of the invention, there is provided a device for movement along an interior of a length of pipeline, said device including a body portion on which at least part of the external surface of the device is formed and wherein at least part of the body portion is rendered capable of detection by metal detection and/ or x-ray detection apparatus.
In one embodiment the device is provided to perform a cleaning action on the interior of the pipeline and/or a movement action on material located in the pipeline to move the same along the pipeline.
Typically the material from which the body portion is formed is rendered detectable by metal detection and/or X ray detection apparatus so that the device as a whole and, more importantly, a portion or portions of the device which may be separated from the body, are detectable.
In one embodiment, the material from which the body is formed is a polymer and/or elastomer and in addition, includes metal
particles located therein and/or an x-ray detectable material located therein.
Typically, the metal particles are provided within the material in a density which renders the material, and hence the body, detectable by metal detection apparatus.
Typically, the metal particles are distributed throughout the body of the device such that all portions of the body are detectable by the metal detection apparatus.
In one embodiment, the material from which the body is made, includes an x-ray detectable material such as barium. In one embodiment the x-ray detectable material is mixed with the material to form the body when it is in a liquid state prior to the formation of the said body.
The provision of the metal particles, and/or x-ray detectable material, within and throughout the body, when formed, means that the body as a whole and, importantly, portions of the body which may be removed during use of the device are detectable by detection apparatus.
In one embodiment the provision of the metal particles is such as to allow the device to be detectable externally of the pipeline as a whole as it moves along the length of pipeline so as to allow the position of the device in the pipeline to be more easily determined.
In one embodiment, in addition to the metal particles, the device includes a cavity therein in which one or magnets are located so as to further increase the detectability of the device as it moves along the pipeline.
The provision of the x-ray detectable material mixed into a material which forms the body of the device ensures that the body as whole and again, fragments of the body can be detectable by x-ray detection apparatus .
In one embodiment, the device body comprises front and end portions and intermediate the same, a plurality of ribs which are formed around the body, said ribs provided to contact the interior surface of the pipeline as the device moves along the same. The ribs are also typically sufficiently resilient so as to be sufficiently flexible so as to flex to take into account changes in shape, such as bends, of the pipeline as the device moves along.
In one embodiment the device is provided to perform a cleaning action on the interior of the pipeline as it moves therealong by contacting the internal wall of the pipeline to dislodge and move any material which may be attached thereto and/or be located therealong. The device, in addition, or alternatively, can be used to move material along and out of the pipeline.
In a further aspect of the invention there is provided a device for movement along the interior of a length of pipeline said device including a body portion in which at least some of the external faces of the device are formed and including a series o f rib portions to contact with the interior wall of the pipeline and wherein at least the rib portions are rendered capable o f detection by metal detection apparatus by the inclusion of metal particles therewith.
In one embodiment the entire body portion is rendered metal detectable.
Typically the metal particles are added in a distribution such that there is a sufficient quantity of the same to be detectable and that the same are
substantially uniformly distributed throughout the portion which is to be rendered metal detectable. Typically the metal particles are added into the material which is used to form the body portion.
In a further aspect of the invention, there is provided a method of forming a device for passage along the interior of a length of pipeline to perform a cleaning and/or movement action of material in the interior of the pipeline, said method comprising preparing a material from which a body of the device is to be formed, and then forming the device body in the required shape and solidifying the material to form the device and whereon prior to forming the device body in the required shape adding to the material, metal or metal alloy particles in a quantity and distribution in order to allow substantially all of the body to be detectable by metal detection apparatus and/ or adding material which is detectable by x-ray detection apparatus.
Typically the metal detectable material and/or X ray detectable material is added to the material to form the body such that upon separation of a portion of the device when in use, the separated portion is detectable by the metal detection and/ or X ray detection apparatus.
Specific embodiments of the invention are now described with reference to the accompanying drawings; wherein
Figure 1 illustrates, in a schematic manner, a device in accordance with the invention, situated within a length of pipeline, which is shown in cros s-section, to perform a cleaning action thereon.
Figure 2 illustrates a device in accordance with one embodiment of the invention; and
Figure 3 illustrates the pipeline of Figure 1 following the movement of the device therealong.
Referring firstly to Figure 1 , there is illustrated a length of pipeline (2) which is formed by a pipeline wall 4, shown in cross-section along a longitudinal axis of the pipeline. The pipeline wall defines a pipeline interior (6) .
The pipeline interior, in this case, is of a pipeline which is used for example in the food proces sing industry or pharmaceuticals industry. From time to time there is a desire to change the material which is being moved along the pipeline from the previous material 8, some of which remains in the pipeline in front of the device, to a new material. Prior to moving the new material into the pipeline it is necessary to remove the old material and/or clean the material 8 from the pipeline to remove any debris and to prevent contamination of the new material.
In accordance with the invention, a device (10) is introduced into the pipeline and moved therealong as indicated by arrow (12), typically by a propulsion force created, for example, by compres sed air, which acts on the rear portion 14 of the device. As the device, also shown in Figure 2, moves along the interior of the pipeline, so the external surface, in this case the ribs 16 and typically also the front portion 1 8, perform a wiping action on the interior surface 20 of the pipeline to dislodge any material 8 which may have collected thereon. The dislodged material 8 and/or material downstream of the device is therefore moved in advance of the device along the pipeline to then be removed from the pipeline along with the device via an appropriate opening in the pipeline.
In order to ensure that the device 10 is used effectively, it is important to be able to identify the location of the device as it moves along the pipeline such that, if the same becomes stuck, then the position of the same can be identified and also, when the same approaches the location at which the same is to be
removed, this can be identified. Conventionally, in order to achieve this, the device 10 typically includes a cavity or cavities 22 within the body 24. In one embodiment a cavity 22 is provided at each end of the device, and in which one or more rare earth magnets can be located so as to create a magnetic field which can be detected externally of the pipeline as the device moves along the interior of the pipeline.
It is found that during use, the detection of the portion of the device may be difficult to achieve and, thus several magnets o f significant size are required to be used and these are of a size so as to increase the size of the device to such an extent that this restricts the possible use of the device in smaller pipelines.
Furthermore and equally if not more importantly, there is a risk that portions of the body which forms the external faces of the device become dislodged from the device and these portions are left in the pipeline. The separation of the portions may be due to wear and tear, a failure in the material from which the device is made and/or through misuse of the device.
These dislodged portions represent potential contaminants of the new material which is to be moved along the pipeline and which will pick up and carry the dislodged portions.
Figure 3 illustrates the manner in which the pipeline 2 of Figure 1 , has been cleaned by the device moving therealong and in the example shown, portions 26 of the device 10 have been detached from the device body and are left in the interior 6 of the pipeline 2 so as to represent potential contaminants for the new material which is to be moved along the pipeline in the direction of arrow 28. In accordance with the invention, these fragments or portions 26, which would be typically moved along with the new material 31 through an outlet 32, are rendered detectable by
the provision of x-ray and/or metal detection apparatus 30 through which the material pas ses and which detects the presence of the metal or metal alloy particles and/or x ray detectable material. This apparatus is typically located at the outlet 32 from the pipeline 2 so as to allow the material which leaves the pipeline to be checked and any dislodged portions 26 of the device body carried by the material at that time are detected by the metal detection and/or x-ray detection apparatus 30 as appropriate. The portions 26 can be removed or, more typically, the material, including the portions, is destroyed and thereby prevents the contaminated material from entering further processing such as food or pharmaceutical proces sing.
Typically the metal or metal alloy particles and/or the x ray detectable material is added to the plastics material which is used to form the device body, when the material is in a molten or liquid state. This allows the particles and/or x-ray detectable material to be added and mixed into the plastics material prior to using the material to form the device body. The aim is to ensure that the metal or metal alloy particles and/or the X-ray detectable material is mixed in the plastics material in a sufficiently uniform manner to ensure that whichever portion becomes dislodged from the device will be detectable by the metal detection and/or X-ray detection apparatus. Typically therefore the metal or metal alloy particles and/or X-ray detectable material will be added so as to be substantially uniform at least around the external surfaces of the device but most typically throughout the device body. The level and density of the metal or metal alloy particles and/or X ray detectable material will be such as to allow the dislodged portions to be detectable by conventional Food and/or pharmaceutical standard detection apparatus and in order to meet the relevant Regulatory standards for detection as apply to a particular industry such as the food proces sing industry.
In accordance with the invention in a further embodiment, the material from which the device body is manufactured includes the metal or metal alloy particles to a sufficient extent such that the body of the device is rendered detectable by conventional apparatus located externally of the pipeline which can be used to detect the position of the device as it moves along the interior of the pipeline, thereby providing the benefit of being able to detect the device with, in one embodiment no, or alternatively a reduced number of rare earth magnets to be provided as part o f the device. This therefore allows the size of the device to be reduced and the possible uses of the same to be increased.
In addition to the detectability of the device improving potential health and safety issues, the movement of the device in a controlled manner and/or operation of the pipeline valves allow the improved removal of the device from the pipeline at the required location.