GB2515319A

GB2515319A - Method & apparatus for introducing a foreign object into a pipeline through which a product is flowing under pressure

Info

Publication number: GB2515319A
Application number: GB1310944.2A
Authority: GB
Inventors: Paul Millard; Thomas Anderson
Original assignee: PRIDEN ENGINEERING Ltd
Current assignee: PRIDEN ENGINEERING Ltd
Priority date: 2013-06-19
Filing date: 2013-06-19
Publication date: 2014-12-24
Also published as: GB201310944D0

Abstract

An apparatus and method for introducing a foreign object (such as a metal slug 14) into a pipeline comprising; a first chamber 1A, a second chamber 2A into which the foreign object is placed through an opening 2E, and where the opening of the second chamber is closed and brought into communication with the first chamber (figures 4-5) so that the foreign object is free to pass from the second to the first chamber. Preferably a piston 3 with a recess through-hole 3A is used to introduce the foreign object into the first chamber. Preferably a guide pipe 9 introduces a foreign object into the piston recess and a pipe 11 is used to introduce cleaning fluid into the recess when it requires cleaning. The apparatus may be used to test a food pipelines metal detectors, used to detect if any foreign metallic objects have passed into a pipeline, without having to close off the pipeline.

Description

Method & Apparatus for lntroducin2 a Forei2n Object into a Pipeline Throu2h Which a Product is F1owin tinder Pressure The present invention relates to a method and apparatus for introducing a foreign object into a pipeline. In particular hut not exclusively the invention relates to a method and apparatus for introducing a foreign metallic object into a pipeline through which a food product is flowing under pressure in order to test the effectiveness of a metal detector arranged to detect metallic objects in the pipeline.

In food processing plants, food products, e.g. ingredients, are typically transported around the plant via pipelines. Typically each pipehne has an associated metal detector to detect the presence of foreign metallic objects which have inadvertently passed into the pipeline. Detection of a metal object by the detector causes the operation of a valve to eject a portion of food product, with the detected metallic object, from the pipeline.

Operators are obliged to regularly test that the metal detectors are working. These tests may need to be camed out as often as after every four hours of operation of the pipeline.

One method to test the detector is to pass a metallic object between the detector and the outside of the pipeline. The disadvantage of this method is that it does not accurately simulate a real incidence of a foreign object in the pipeline. This is important as the detectors tend to be less sensitive and thus less reliable at detecting objccts close to the centre of the pipeline.

An alternative testing method is to introduce a foreign metallic object into the pipeline upstream of the detector and wait to see whether the detector detects it. The foreign metallic object is introduced into the pipeline either by separating joints in the pipeline or via a plug cock valve provided in the pipeline. Either way this requires the flow of product through the pipeline to be shut off beforehand to prevent product, which is passes through the pipeline at high pressure (often above 4 bar), to be forced out of the opening of the plug cock valve when it is opened. An ejected stream of product wou'd also prevent if not significanfly hinder insertion of the foreign object into the opening.

Where the metal detectors require frequent testing, methods involving insertion of an object into the pipeline result in considerable downtime of the pipelines.

The present invention was conceived with the aim of removing or at least ameliorating this problem.

According to a first aspect of the invention there is provided a method of introducing a foreign object into a pipeline comprising: -providing a first chambcr conncctcd to an outlct of an upstream portion of the pipeline and to an inlet of a downstream portion of the pipeline so that product passes between the upstream and downstream portions through the first chamber; -placing a foreign object through an opening into a second chamber which is closed off from the first chamber; -closing the opening of the second chamber; and then -bringing the second chamber into communication with the first chamber so that the foreign object is free to pass from the second chamber into the first chamber.

As the foreign object introduced into the first chamber (and thence pipeline) is held in a second chamber closed from the atmosphere, the pipeline remains closed from the atmosphere when the foreign object is introduced. This removes the need to stop the flow of product through the pipeline before introducing the foreign object.

In a preferred alTangement a device is used to force the foreign object from the second chamber into the first chamber. This ensures that the object is inserted into the product stream where it can subsequently travel, under the pressure within the pipeline, out of the first chamber.

The second chamber may be moved towards and at least partly into the first chamber.

In a preferred embodiment, the second chamber is provided by a recess within a piston and the piston is pushed (or otherwise introduced) into the first chamber so that recess is brought into communication with the first chamber. It is preferred that the recess is a through hole in the piston so that when the piston is inserted into the first chamber, product flowing through the first chamber pushes the foreign object out of the through hole.

It is prefelTed that the volume of the first chamber is greater than the volume of an equivalent length of the pipeline to which the apparatus is connected. Assuming that the rate of flow of product into the first chamber is equal to the rate of flow out of the first chamber, this reduces the pressure within the first chamber as so ease introduction of the foreign object into the first chamber. It is particularly preferred that the first chamber is sized such that the volume of the product pathway defined by the first chamber with the piston fully housed therein, is equal or greater than the volume of pathway provided by an equivalent length of the pipeline. This minimises the pressure increase within the first chamber and thus throughout the upstream portion of the pipeline, when the foreign object is inserted. Pressure increases are unwanted as they can damage the pump(s) used to force the product through the pipeline According to a second aspect of the invention there is provided apparatus for introducing a foreign object into a pipeline, the apparatus comprising: -a first chamber alTanged to be connected between an outlet of an upstream portion of a pipeline and an inlet of a downstream portion of the pipeline so that product can pass through the chamber between the upstream and own portions; -a second chamber having a closable opening through which a foreign object can be placed into the second chamber, the second chamber being closed off from the first chamber; and means to bring the second chamber into communication with the first chamber so that the foreign object is free to pass from the second chamber into the first chamber.

It is preferred that the apparatus comprises a piston having a recess for h&ding the foreign object, the piston being arranged to move into the first chamber to bring the recess into communication with the first chamber. Preferably the piston passes through an opening into the first chamber. It is preferred that the piston acts to occlude the opening to restrict passage of product within the pipeline through the opening. This may be achieved through a tight inter-fit between the piston and an inner wall of the opening andlor through the provision of a seal member positioned adjacent the opening to act against the piston.

Preferably the piston is arranged to reciprocate through the opening between a third chamber and the first chamber.

Advantageously, the height of the recess is equal or preferably less than the distance between opening in the side wall of the third chamber and the entrance to the first chamber so that during movement of the piston. there is always a portion of the piston which can seal with the inside wall of the opening, or in other words, there is never a flow path created between the first chamber and the opening in the side wall of the third chamber.

As a safety feature to prevent a body part of an operator being accidently placed in the recess, the apparatus may comprising a guide tube which extends from the opening in the side wall of the third chamber, outwardly, the guide tube and comprises an opening through which the foreign object is passed and guided through the aperture.

To inhibit unauthorised use of the apparatus the opening in the third chamber or the guide tube may be provided with a lockable cover to restnct access to the aperture.

To further improve sealing of the first chamber, the apparatus may comprise a seal member which acts against a side wah of the piston to provide a seal to restrict the passage of product out of the opening of the first chamber.

It is preferred that the opening in the side wall of the third chamber is arranged to align with one end of the through hole, and the side wall of the third chamber comprises a further opening arranged to align with the opposing end of the through hole. With this arrangement cleaning fluid can be passed through the through hole to remove debns of product which has collected therein.

The invention will now be described by way of example with reference to the following figures in which: Figure 1 is a perspective view of a ball insertion device; Figure 2 is a perspective view of the ball insertion device shown in cross section with the piston shown between a loading and dispensing position; Figure 3 is a side view cross section of the ball insertion device shown with the piston in a loading position; Figure 4 is a side view cross section of the ball insertion device shown with the piston between a loading position and dispensing position; Figure 5 is a side view cross section of the ball insertion device shown with the piston in a dispensing position; and Figure 6 is a side view cross section of the ball insertion device shown with the piston returning to the loading position.

Referring to the Figures the ball insertion device comprises a first housing 1 which defines a lower chamber lA. The first chamber lA has an inlet lB and outlet 1C. The housing I further comprises connectors ID associated with the inlet I B and outlet IC for connecting the ball insertion device to a pipeline (not shown). Mounted to the first housing I is a second housing 2 (the first and second housing may in alternative embodiments be manufactured as a single piece, though separate pieces are preferred to easy manufacture) having at least one side wall 2C and end wall 211 Defined primarily by the second housing 2 and in part by the first housing 1 is an upper chamber 2A in which resides a piston 3.

The lower chamber IA and upper chamber 2A are in communication via an opening 1E in the side wall of the housing 1 and end of housing 2, so that the piston 3 can reciprocate between a position in which it is fully or substaittially housed in the upper chamber 2A and aposition in which it housed in the lower chamber IA.

The lower chamber IA is sized such that the volume of the pathway it provides for product passing there through when the piston 3 is fully inserted therein is equal or greater than the volume of an equivalent length of the pipeline to which it is connected. This means that there is no significant increase in pressure within the pipeline when the piston 3 is temporarily introduced into the lower chamber IA.

The piston 3 defines a through hole 3A which extends through the piston 3 in a direction substantially perpendicular to the direction of reciprocation of the piston 3.

A shaft 4 is connected to a first end of the piston 3 and passes through an end wall 2D of the housing 2. A push p'ate 5 (or other handle means) is mounted to the end of shaft 4 outside of the housing 2. Mounted around the shaft 4, which may have a square cross-sectional shape, between the outer wall of the housing 2 and the push plate 5 is a coil spring 6 which biases the piston 3 into the loading position shown in fig 3.

The inter-fit between and the piston 3 and inner wall of chamber 2A provided by inner walls 1F, 2G of first and second housings 1, 2 is sufficiently tight that a seal is formed there-between to inhibit the passage of product out of the first chamber 1A.

The ball insertion device may optionally be provided with a locking mounting member 7 (best seen in Figs 1 & 2) that extends towards the push plate 5. Both the locking mounting 7 and push plate 5 are provided with apertures 5A. 7A through which a padlock P may be passed to prevent unauthorised use of the ball insertion device.

The second housing 2 is provided with two openings in its side wall 2C. A first opening 2E provides communication to a first guide tube 9 which may have a lockable cover 10. The second opening 2F. which is narrower than opening 2E.

provides communicadon to a second guide tube 11 which extends from the other side of the housing 2.

Inside wall IF of housing i which also acts as an inside wall of lower part of chamber 2A defines a recess 1G at a position between openings 2E, 2F and the opening 1E to the first chamber 1A. The recess 1G houses a seal member 12. A second recess 2H provided in upper chamber 2A. above openings 2E. 2F holds a second seal member 13.

Both the first and second seal members 12, 13 act against the piston 3 to inhibit ingress of product from the lower chamber IA.

When the device is insta'led in a pipefine. fluid or other food product travels, typically under pressure exceeding 1 atmosphere, out of an outlet of an upstream portion of the pipeline into the lower chamber IA via inlet lB. through the lower chamber 1A and out via the outlet 1C into a downstream portion of the pipeline. A lower portion 3C of piston 3 acts to close the opening 1E of the lower chamber to prevent food product from passing up into the upper chamber 2A and out of opening 2E. 2F.

In operation the piston 3 starts in the loading (home) position as illustrated in Fig 3 in which the through hole 3A of piston 3 is aligned with the first and second openings 2E 2F in housing 2. A metallic ball test piece 14 is placed in guide 9 and travels through opening 2E into the through hole 3A in piston 3. Travel of the ball 14 out of opening 2F does not occur as the ball is larger than opening 2F.

Once loaded with the ball 14, a force is applied to push plate 5 to push the piston 3 towards the first chamber IA. As illustrated in Fig 4. the piston 3 travels such than an upper part 3B of piston 3 closes apertures 2E, 2F. A seal is formed between the piston 3 and the chamber wall 2G above the through hole (indicated at Z) preventing passage of product in chamber 1 out of apertures 2E. 2F via through hole 3A dunng insertion of piston 3.

Further travel of the piston 3 bnngs it into the position illustrated in Fig 5 in which the through hole 3A sits within the product stream within the first chamber I A. The passage of product through the chamber 1A, and the through hole acts to carry the ball 14 out of the through hole 3A in piston 3 and towards outlet 1C.

The upper portion 3A of piston continues to dose off opening IA so as to prevent flow of product out of the chamber IA and through apertures I E IF.

Once the ball 14 has been introduced into the product stream, the force on push plate is removed whereupon spring 6 draws the piston 3 out of the first chamber IA towards the loadingKhome) position. As the piston 3 is drawn out, lower portion 3C of piston 3 below through hole 3A forms a seal with seal member 12 and/or wall ID so as to close the through hole 3A and prevent flow of product from the first chamber IA towards the openings 2E, 2F.

Once fully raised, a slug of product may remain held within through hole 3A. This can be washed out by introducing cleaning fluid, such as water, through pipe ii to flow through the through hole 3A and out of the guide pipe 9. Ingress of water into the first chamber IA is restricted/prevented by the seal between the lower portion of piston 3C and the chamber wall below the through hole 3A. The device is then ready to receive a further object for insertion.

The ball insertion device is typically located upstream of a metal detector alTanged to detect the presence of any metallic objects which are travelling through the pipeline.

When it is wished to test whether the metal detector is operating correctly, the ball insertion device is used to insert a metallic ball test piece (or other metallic object) into the pipeline, the ball is carried along the pipeline towards the metal detector.

Variations of the above descnbed example ball insert device include, for example, attaching the shaft 4/plate 5 to an actuator such as, for example. an air piston to allow remote operation of the device.

The shaft 4 is shown with a square cross-section shape to prevent the piston rotating within the chamber 2K though other shapes of the shaft 4 may be used. Similarly the piston 3 and chamber 2A may have various cross-section shapes. The device may be adapted to be fitted to a pipeline of any cross-sectional shape.

In an alternative variation, the outer wall of housing 2 may support or define a check plate having a tab arranged to sit within a ongitudinal groove provided in shaft -10 - (which may have circular or other cross section) 4 to restnct rotation of the shaft 4 and piston 3 about its axis.

Although the device is described in relation to the dispensing of a meta1ic ball, the device may be used to dispense other objects, which may be metallic or otherwise.

The guide tubes 9 and 11 are optional and may have any cross-sectional shape.

If the inter-fit between the pistons and the inner-wall of chamber 2A is sufficient to substantially prevent flow of product out of the second chamber, it may be possible to dispense with seal members i2 and i3.

It is preferred that the piston 3 is sized that lower portion of chamber 2A is fully occluded irrespective of the position of the piston 3 in order to prevent flow of product into the chamber 2A. Nevertheless, it is possible that the lower portion 3C of piston 3 may be shortcr such that when in the home position it does not fully occupy the lower portion of the upper chamber 1A.

Where the second housing has multiple side walls, openings 2E, 2F may be provided in opposing walls.

Apertures 2E and 2F in housing 2 may be of the same size but offset to stop an object which is passed in through aperture 2E falling out of the through hole through aperture 2F. -11-

Claims

Claims I. A method of introducing a foreign object into a pipeline cornpnsing: -providing a first chamber connected to an outlet of an upstream portion of the pipeline and to an inlet of a downstream portion of the pipeline so that product passes between the upstream and downstream portions through the first chamber; -placing a foreign object through an opening into a second chamber which is closed off from the first chamber; -closing the opening of the second chamber; and -bringing the second chamber into communication with the first chamber so that the foreign object is free to pass from the second chamber into the first chamber.
2. A method according to claim I wherein a device is used to force the foreign object from the second chamber into the first chamber.
3. A method according to claim i or 2 comprising moving the second chamber holding the foreign object towards and at least partly into the first chamber.
4. A method according to any previous claim in which the foreign object is placed in a recess within a piston and the piston is introduced into the first chamber so that the recess is brought into communication with the first chamber.

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5. A method according to any previous claim wherein the first chamber has a volume which is larger than an equivalent length of the pipeline in which it is connected.
6. A method according to claim 5 wherein the first chamber is sized such that the volume of the product pathway defined by the first chamber with the piston fully housed therein, is equal or greater than the volume of product pathway provided by an equivalent length of the pipeline.
7. A method according to any daim 4 -6 wherein the piston is arranged to reciprocate between the first chamber and a third chamber, the third chamber having a first opening in a side wall arranged to align with the recess and wherein the foreign object is passed into the recess via a first opening in a side wall of the third chamber, aligned with the recess.
8. A method according to any claim 4 -7 wherein the recess is a through hole in the chamber.
9. A method according to claim 8 wherein the through hole is orientated such that when the piston is introduced into the first chamber, the recess forms part of the pathway for product passing through the first chamber.
10. A method according to claim 8 or 9 wherein following introduction of the object a cleaning fluid is introduced into the recess via a second opening in the side wall of the third chamber arranged to align with an opposing end of the through hole relative the first opening.
11. A method of testing the functioning of a metal detector arranged to detect a metallic foreign objects in a pipehne, the method comprising using the method of any claim 1 -10 to introduce a metallic foreign object into the pipeline upstream of the metal detector being tested.

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12. A method of introducing a foreign object into a pipeline through which a product is flowing at pressures greater than 1 atmosphere according to any previous claim.
13. A method according to claim 12 wherein the pipeline carries a food product.
14. Apparatus for introducing a foreign object into a pipeline through which a product is flowing under pressure, the apparatus comprising: -a first chamber arranged to be connected between an outlet of an upstream portion of a pipeline and an inlet of a downstream portion of the pipeline so that product can pass through the first chamber between the upstream and downstream portions; -a second chamber having a closable opening through which a foreign object can be placed into the second chamber, the second chamber being closed off from the first chamber; and means to bring the second chamber into communication with the first chamber so that the foreign object is free to pass from the second chamber into the first chamber.
15. Apparatus according to claim 14 comprising means to force the foreign object from the second chamber into the first chamber;
16. Apparatus according to claim 14 or 15 comprising means to move the second chamber towards the first chamber so that it is brought into communication with the first chamber.
17. Apparatus according to claim 16 comprising a piston having a recess for holding the foreign object, the piston being ananged to move into the first chamber to bring the recess into communication with the first chamber.-14 -
18. Apparatus according to claiml7 wherein movement of the piston towards the first chamber closes the recess before it is brought into communication with the first chamber.
19. Apparatus according to claim 17 or 18 wherein the first chamber comprises an opening through which the piston passes into the first chamber, and wherein the piston acts to occlude the opening to restrict passage of product within the pipeline through the opening.
20. Apparatus according to claim 19 wherein the piston is alTanged to reciprocate through the opening between a third chamber and the first chamber.
21. Apparatus according to claim 20 wherein a side wall of the third chamber comprises an opening through which the foreign object can be passed into the recess in the piston.
22. Apparatus according to claim 21 when dependent on claim 18 wherein movement of the piston through the third chamber towards the first chamber causes the recess to be closed off by a side wall(s) of the third chamber before the recess is brought into communication with the first chamber.
23. Apparatus according to claim 21 or 22 comprising a guide tube which extends from the opening in the side wall of the third chamber, outwardly, the guide tube and comprises an opening through which the foreign object is passed and guided through the aperture.
24. Apparatus according to claim 21, 22 or 23 comprising a lockable cover to restrict access to the aperture.-15 -
25. Apparatus according to any claim 18 -24 compnsing a seal member which acts against a side wall of the piston to provide a seal to restrict the passage of product out of the opening of the first chamber.
26. Apparatus according to claim 25 when dependent upon claim 21 comprising a further seal member arranged above the first aperture in the side wall of the third chamber, which acts against a side wall of the piston to provide a seal.
27. Apparatus according to any claim 17 -26 wherein the recess is a through hole in the piston.
28. Apparatus according to claim 27 wherein the through hole forms part of the flow path for product through the first chamber.
29. Apparatus according to claim 28 wherein the through hole is substantially aligned with the direction of flow of product through the first chamber.
30. Apparatus according to any claim 21 -29 wherein the opening in the side wall of the third chamber is ananged to align with one end of the through hole, and the side wall of the third chamber comprises a further opening arranged to align with the opposing end of the through hole.
31. Apparatus according to any claim 14 -30 wherein the first chamber has a volume which is larger than an equivalent length of the pipeline in which it is connected.
32. Apparatus according to any claim 14 -31 wherein the first chamber is sized such that the volume of product pathway defined by the first chamber with the piston fully housed therein, is equal or greater than the volume of pathway provided by an equivalent length of the pipeline.