DE10151553A1 - Method and device for cleaning pneumatic delivery lines with a bypass pig - Google Patents

Abstract

A method is described for cleaning pneumatic conveying lines with a bypass pig, which is moved longitudinally in the conveying line, driven by compressed air, and cleans the inner wall of the conveying line with cleaning tools arranged on the outer circumference, the compressed air flowing through the openings in the longitudinal direction through the pig and emerges from the pig in the direction of movement and removes and takes away solids (e.g. granules) from the pipe wall. In order to achieve a good cleaning effect even in conveyor lines filled with granules, it is provided that the ratio of the pig speed to the conveyor air velocity c / v is less than 1, and that the conveyor air speed is suitable for moving the granules in the manner of a flight conveyor.

Description

The invention relates to a method and an apparatus for cleaning pneumatic delivery lines with a bypass pig according to the generic term of claim 1.

In general, a bypass pig is a subspecies of the displacement or Conveying pigs for pigging solids in pipelines.

In the "Handbuch der Molchtechnik", Essen: Vulkan-Verlag, 2000 (Bernd Skerra (ed.) "Are such pigs for cleaning pipelines described.

A bypass pig is shown and described on page 164, in which as Propellant air is used which is tubular from behind Openings of the pig towards the front (in the direction of movement) is blown and through the nozzles arranged in the pig an air vortex on the The inner wall of the delivery line to be cleaned causes. In this airflow powders and granules are whirled in front of the pig.

The disadvantage of the known bypass pig is, however, that only air vortices are generated by nozzle-like, forward-facing openings, which at appropriately loaded pneumatic conveying lines do not become one Carry out cleaning of the inner wall. In the worst case, this leads to the fact that the pig is protruding radially inwards into the delivery line Adhesion is fixed and can no longer be moved. The newt described is not for cleaning pipelines with conveyance of granules in Flight promotion is suitable because its cleaning effect is insufficient and he is moving at an unsuitable speed. The one used Compressed air is not suitable, which is in the delivery line for delivery anyway Take the intended granules with you.

For the flight conveyance of granules in pneumatic conveying lines a conveying speed of the granulate of at least 25 m per second required. If this speed falls below, then moves the granulate is no longer in the flight promotion phase, settles and becomes pushed in front of the cleaning pig. This is what happens described clamping effect, especially on pipe switches and Flange connections.

With the arrangement of forward-facing nozzles, which the Only clean the pipe wall with air vortices, but it is not possible the conveying speed of the pig to, for example, about 2 m per Second and at the same time the conveying air speed to Cleaning and flight conveyance of the granules at 25 m per second observed.

The nozzles used for cleaning therefore ensure that the known one The pig is only traversed with a relatively low air throughput, which is what granules brought in front of him do not make it fly. Such a newt will So push the granulate to be conveyed in front of you and will soon be on wedge the corresponding pipe switches and flanges.

Brush pigs based on the bypass principle have also become known are suitable for cleaning pipes through which liquid flows. such Cleaning pigs have brush bodies on radially adjustable ones Sealing sleeves arranged.

Due to the liquid introduced under excess pressure, the Brush sleeves against the pipe wall, the brushes rub against it the inner wall of the pipe wall and thus lead to one Cleaning effect. However, water powered pigs are in pneumatic Delivery lines for conveying powder or granules cannot be used.

In particular, the use in pneumatic conveyor lines is therefore not given because the distribution ratio between pig speed and The brushing effect should be coordinated so that it is satisfactory Degree of cleaning of pipes and the pipe switches installed in them can be achieved.

The reason for the difficulty lies in the transfer of the excellent functioning pigging technology from the wet area with the for it necessary sealing sleeves in the pneumatic conveyor technology.

The invention is therefore based on the object, a method and a the pig operated in the process, and to further develop a pig itself, that in pipelines with granules and Dusting a superior cleaning effect is achieved.

The object is achieved by a method which is characterized in that that the ratio of the pig speed to the conveying air speed c / v is less than 1. That is, the pigging speed is opposite that Conveyed air speed reduced. The newt moves slower than the conveying air.

C is the pig speed, while v is the gas speed Conveying air is.

A preferred embodiment of the newt provides that a number of interchangeable brush disks arranged on the pig axis predetermined different bristle hardness are provided and that at least these brush disks to a significant extent from the conveying air are enforced.

The invention provides a pig, which according to the prior art known bypass pigs resembles, but is different by the same Conveying air volume moves like the previous bulk transport, whereby its moving speed of a predetermined c / v proportion corresponds and the resulting combination of flow and mechanical cleaning influence on the bulk good Performs wall cleaning of the pipeline.

According to the invention, it was recognized that a superior Cleaning effect with bypass pigs in pneumatic conveying lines only is reached when the pig with less than 25 m per second, z. B. 2 m per second, but the flow rate is nevertheless through the newt is in the range of 25 m per second, around which to enable conventional granulate transport as flight promotion.

The contradicting demands (on the one hand the relative reduced speed of the newt and on the other hand the high Flight conveyor speed of the granules) according to the invention solved that the bypass pig assigned relatively large bypass openings be, whereby part of the bypass air flows through the brushes themselves and a other part of the bypass air through in the axis of the cleaning pig arranged bypass holes, which in the assigned spaces penetrates between the brush discs and also the core of the pig axially interspersed.

According to the state of the art, pure brush pigs were always included Chained or pushed with bendable bars. This will be after the Invention avoided, and the invention proposes a free movement of which Conveying air driven bypass pig in a pneumatic delivery line in front.

This prevents the granules in front of the pig settles; it will therefore continue to receive funding in the form of flight promotion. The Granulate is therefore not displaced, but flies in front of the newt.

This removes the parts detached from the pipe wall by the brushes the pig accelerated, guided and at high speed moved away. With this new funding principle, superior Cleaning results achieved.

The invention is therefore not a displacement pig, the in the manner of a "cannon cleaner" cleans a "cannon barrel", but around one Bypass pig moved at slow speed by the conveying gas is flowed through at high speed, so that this conveying gas in In the direction of flight in front of the pig, the granulate is carried away and does not settle leaves.

The brushes have their individual attached to them and essentially radially formed bristles have the advantage that they are under appropriate elastic bending also on the corresponding edges of pipe switches, Brush weld seams and flange connections along and there also the Remove adhering granules and remove them in front of you.

Due to the significant airflow that blows through the brushes these are also kept free from buildup, are free to move and become cleaned.

In a preferred first embodiment of the invention, it is provided that that interchangeable or non-interchangeable on the pig axis fixed brush disks are arranged.

With fixed brush discs the advantage of a simple structure achieved.

Instead of filling the brush discs with individual bristles, you can also bristle-like functional features are used. For example, you can lobe-like, trapezoidal, cylindrical or other shapes, in substantially radially outwardly directed bristles are used.

It is only important that a cleaning effect through elastic contact of corresponding tips of such bristles or rags on the inside of the tube is achieved. In addition, these elements should have a corresponding axial Allow air flow.

In a second embodiment of the invention it is provided that the pig axis in addition to several fixed brush disks rotatable brush disks are arranged.

No separate active rotary drive is assigned to these brush disks. she are only passively rotatable, e.g. B. because the bristles are arranged in a swirl and in the longitudinal conveyance of the bypass pig through the line itself Twist brush disks automatically and helically, making them one Clean the inside of the pipe.

In a further preferred embodiment it is even provided that some or more of these brush disks are also actively rotating. Such an active rotary drive takes place, for. B. via a turbine drive due to the conveying air flowing through.

These brush disks are equipped with guide vanes, and the air flow through these guide vanes leads to an active rotary drive of the respective Brush disc in the manner of a jet drive.

The types of brush disks mentioned at the beginning (rigid, passively rotatable and active rotary drives) can be a single one Form bypass pig, or a bypass pig can only consist of one or several of the above combinations can be put together.

In a further embodiment of the present invention, it is provided that that the pig axis is not necessarily rigid. It can also be articulated be trained.

The pig axis can thus also consist of several joints Pig axle sections exist, with some of the brush discs firmly on the axis is arranged, while again part of the brush discs is rotatably arranged on the pig axis and the rotation of the Brush discs through a turbine-like design with the help of the conveying air he follows. The direction of rotation of the brush discs can vary depending on the type of installation Pig axis (orientation to the conveying air) must be the same or opposite.

The subject matter of the present invention does not only result from the subject of the individual claims, but also from the Combination of the individual claims.

All disclosed in the documentation, including the summary Information and features, especially those shown in the drawings spatial training, are claimed as essential to the invention, insofar as they individually or in combination are new compared to the prior art.

In the following, the invention is based on several ways of execution illustrative drawings explained in more detail. Here go from the Drawings and their description further features essential to the invention and advantages of the invention.

Show it:

Fig. 1 section through a first embodiment of a brush with fixed scraper brush discs,

Fig. 2, the brush pig according to Fig. 1 in a perspective view;

Fig. 3 front view of the arrangement in Fig. 1,

Fig. 4 is a section through a second embodiment of a brush pig with rotatably driven brush discs,

Fig. 5 a front view according to arrow V direction in Fig. 4,

Fig. 6 section according to line VI-VI in Fig. 4.

In Figs. 1 and 2 a first embodiment of a brush pig 1 is shown, which consists of a fixed axis 8, are lying parallel threaded on a series of fixed brush discs 4, 5, 6, 7 in succession to each other.

Individual spacer disks 10 are arranged between the brush disks, and the pig 1 has a front tip 11 . The mutual distance between the brush disks can thus be chosen depending on the choice of the length of the spacer disk 10 .

The axis 8 is closed at the rear end by a closure piece 9 , which essentially consists of two divided closure disks 13 , which are held together by a clamping ring 12 .

In this way it is prevented that the brush disks 4-7 are pushed back together with the spacer disks 10 from the continuous axis 8 .

The closure piece 9 is very easy to open and close due to the clamping ring 12 used.

Instead of the mounting method of the brush discs described here Of course, all other types of fastening are also possible.

For example, it can be provided that the axis 8 consists of a threaded bolt, which is connected at the front to the tip 11 and which carries on its rear side, instead of the closure piece 9, a corresponding threaded nut, which likewise contains the brush disks 4-7 and associated spacers 10 holds together.

It is of course also possible to fasten each individual brush disk 4 on an axis by means of a corresponding clamping device.

Likewise, the rear closure piece 9 can also be designed as a clamping device.

The brush pig 1 thus formed is conveyed in the direction of arrow 3 through the conveying line 2 , each brush disk 4 according to FIG. 3 each consisting of a brush ring 18 which is filled with any number of bristles directed radially outwards.

The bristles are held in a holding disk 19 , which in turn is part of a supporting disk 20 which is threaded on the axis 8 .

The conveying air now flows through the pig in the direction of arrow 3 , first through a central center bore 14 which is open air-tight in the area of the spacer disks 10 through a number of bypass bores 15 .

Through these bypass holes, the air flows in the direction of arrow 16 (bypass air flow) into the spaces between the individual brush disks 4-7 and cleans these brush spaces from the inside and then flows through the respective brush disks in the axial direction.

At the same time, a further air flow flows as a direct air flow 17 in a straight (axial) direction through the corresponding brush disks 4-7 and thus produces the desired conveying air speed of about 25 m per second in the line in front of the brush pig 1 . This moves the granulate in front of the pig in the manner of a flight conveyor and prevents it from settling in the line.

The newt therefore does not run the risk of stowing the granulate in front of it; on This prevents jamming in a granulate piled up in front of it.

The perspective view of a brush pig 1 with fixed brush disks 4-7 is shown in FIG. 2. It can be seen here that the bypass air flow flows out of the bypass bores 15 , 16 and passes through the individual brush rings 18 .

Furthermore, the direct air flow 17 is also shown, which also passes through the individual brush rings 18 .

It can be seen that the granules 32 fly in front of the pig 1 and the brush rings 18 have a superior cleaning effect on the inner wall of the delivery line 2 .

Should it turn out that the brush pig 1 according to the invention flies too quickly, ie at a speed of e.g. B. more than 2 m per second, then corresponding reducing inserts can be removed from the center hole 14 to increase the flow in the center axis in the direction of arrow 3 . This changes the c / v value.

The invention also provides in an embodiment, not shown, that some of the brush disks, e.g. B. the brush discs 5 , 6 are arranged passively rotatable. Here, the respective brush ring 18 would have a screw-like contour and each of the brush disks 5 , 6 rotates passively with the longitudinal movement of the brush pig 1 in the manner of a swirl movement in the pipeline.

It can also be provided that the two brush disks 5 , 6 rotate in opposite directions if corresponding counter-rotating worm teeth are provided in the outer region of the respective brush ring 18 . For this purpose it can be provided that the one brush disk with its orientation towards the front and the brush disk 6 of the same design with its orientation towards the rear are installed in order to produce a counter-rotating swirl movement.

FIG. 4 shows, as another embodiment, it also actively rotationally driven brush discs 22, 23 are on a brush pig 21st

With regard to the remaining parts, all explanations apply, as were also given with reference to FIGS. 1-3.

In the embodiment of Fig. 4, the central brush discs 22, rotationally driven turbine-like 23rd A front, fixed brush disk 24 (see FIG. 5) and a rear fixed brush disk 7 are provided, between which the rotary brush disks 22 , 23 are arranged.

The front fixed brush disk 24 according to FIG. 5 has recesses 25 which are evenly distributed on the circumference and through which the direct air flows in the direction of the arrow 3 . The brush ring 19 is supported by corresponding spokes 26 with respect to the axis 8 . The recesses 25 are intended to ensure that the air flowing out of the nozzle-like guide vanes 27 of the rotary brush disks 22 , 23 can pass through the front brush disk 24 in a large cross section.

Each rotary-driven brush disk 22 , 23 is designed approximately according to FIG. 6. There are radially inward of the holding disc 19 obliquely offset guide vanes 27 , each of which forms a nozzle blade.

As soon as air flows through this guide vane 27 in a plane perpendicular to the drawing plane according to FIG. 6, an angular momentum is generated, for example, in the direction of arrow 33 . The rotation of each individual brush disk 22 , 23 takes place here via needle bearings 28 . The needle bearing consists of a fixed inner ring 29 , the needles used for storage and a rotating outer ring 30 .

The turbine ring 31 , which adjoins the needle bearing radially outward, contains the aforementioned guide vanes 27 .

In this embodiment too, it is possible to install the brush disks 22 , 23 in the opposite orientation, so that one brush disk, for example in the direction of arrow 33 and the other brush disk in the opposite direction, is actively driven in rotation. Drawing legend 1 brush pig
2 delivery line
3 arrow direction
4 brush disc
5 brush disc
6 brush disc
7 brush disc
8 axis
9 closure pieces
10 spacer
11 top
12 tension ring
13 locking disc
14 center hole
15 bypass hole
16 bypass air flow
17 Direct air flow
18 brush wreath
19 retaining washer
20 support disc
21 brush newt
22 brush disc
23 brush disc
24 brush disc
25 recess
26 spoke
27 guide vane
28 needle bearings
29 inner ring
30 outer ring
31 turbine ring
32 granules
33 arrow direction

Claims (10)

1.Procedure for cleaning pneumatic conveyor lines with a bypass pig, which is moved longitudinally in the delivery line, driven by compressed air, and cleans the inside wall of the delivery line with its cleaning tools arranged on the outer circumference, the compressed air flowing through the openings in the longitudinal direction and flowing into the pig Direction of movement emerges from the pig and removes and takes solids (e.g. granules) from the pipe wall, characterized in that the ratio of the pig speed to the conveying air speed c / v is less than 1, and that the conveying air speed is suitable, that To move granules in the manner of a flight promotion. 2. The method according to claim 1, characterized in that the pig with less than 25 m per second, e.g. B. 2 m per second, is promoted, and that the flow rate through the pig in the range of 25 m per Second. 3.Device for cleaning pneumatic delivery lines with a bypass pig, which moves longitudinally in the delivery line, driven by compressed air, and cleans the inside wall of the delivery line with its cleaning tools arranged on the outer circumference, the compressed air flowing through the opening in the longitudinal direction and flowing through the pig and in the direction of movement emerges to the front from the pig and removes and takes away solids (e.g. granules) from the pipe wall, characterized in that the bypass pig ( 1 ) is assigned relatively large bypass openings ( 14 , 15 ), and some of the compressed air passes through the cleaning tools ( 4-7 ; 22-24 ) flow and another part of the compressed air through bypass bores ( 14 ) arranged in the axis of the pig. 4. Device for carrying out the method according to one of claims 1 or 2 and / or according to claim 3, characterized in that interchangeable and / or non-exchangeable fixed cleaning tools are arranged on the axis ( 8 ) of the pig ( 1 ). 5. The device according to claim 4, characterized in that the cleaning tools are designed as brush disks ( 4-7 ; 22-24 ). 6. Device according to one of claims 1 to 5, characterized in that the cleaning tools are designed as passively rotatable brush disks ( 5 , 6 ). 7. Device according to one of claims 1 to 6, characterized in that the cleaning tools are designed as actively rotating brush disks ( 22 , 23 ). 8. Device according to one of claims 1 to 7, characterized in that the axis ( 8 ) of the pig ( 1 ) is articulated. 9. Device according to one of claims 1 to 8, characterized in that the direction of rotation of the cleaning tools ( 5 , 6 ; 22 , 23 ) is the same. 10. Device according to one of claims 1 to 9, characterized in that the direction of rotation of the cleaning tools ( 5 , 6 ; 22 , 23 ) is in opposite directions.