EP0771593B1 - Method and device for uncovering and cleaning steel wire strands - Google Patents

Abstract

The method involves passing the strand, from which sheathing has been removed, through an elastic seal (10). The strand is thus surrounded by a gland form, and flushing liquid is applied to it under pressure. Preferably, a tubular lance can be introduced, connected at one end (9) to a flushing line (23). The lance may be composed of at least two sections (7a,7b) connected together, possibly telescopically. A valve (20) may lie next to the seal.

Description

Technical field

The invention relates to a method and an apparatus for exposing and Cleaning length-limited sections of strands made of steel wires by a corrosion protection compound, in particular grease, surrounded and inclusive these are enclosed by a tubular covering.

State of the art

For heavy-duty tension members in construction, e.g. Stay cables for Cable-stayed bridges, tension members for ground and rock anchors, etc. are often strands twisted steel wires are used. Such strands usually consist of seven high tensile steel wires, six of which are outer wires around one straight wind around the central wire.

Can be retensioned around such strands and protected against corrosion in concrete to be able to embed it is known to protect it with an anti-corrosion agent, e.g. Bold, surrounding, that also the gaps between each Fills steel wires, and the stranded wire protected in this way for mechanical protection an extruded plastic jacket, e.g. PE, to be provided (US-A 3 646 748).

For certain applications, e.g. to make one Composite anchoring, however, it is necessary to at least one end of such To expose stranded wire over a certain length and to clean it thoroughly Bonding the stranded wires with other media, such as concrete, cement mortar or Resin, to allow. So far this has been done by hand in the first remove the area in question and then remove the Steel wires with grease solvents and brushes or by steam jets were treated. This is a very time and cost intensive job.

Since the central wire is tight from the outer wires helically is enclosed, grease-filled arises within the strand cross-section Channels that cannot be treated with this cleaning method. Should the fat can also be removed in these areas, so it is necessary that individual steel wires of the strand. Because with tools must be worked, there is a risk of the surfaces of the steel wires hurt. This procedure also does not allow the separation of fat and Cleaning fluid, which in view of increased environmental awareness and the stricter environmental protection conditions is becoming increasingly important.

In an older, unpublished German patent application (DE-A 44 35 744), a method has already been proposed in which the method at the end of the Cord accessible, enclosed by the plastic sheath and by Corrosion protection compound filled annulus between strand and sheath is used to a certain extent as a rinsing chamber for cleaning the strand. By Exposure to flushing liquid under high pressure is carried out by a At the end of the line to be exposed, the opening was created first Corrosion protection compound pressed out and then the strand with the rinsing liquid rinsed.

However, this procedure only works satisfactorily if the coat made of plastic, the strand surrounded by the anti-corrosion agent encloses. For strands in which the sheath is tubular and maintains a greater radial distance from the envelope of the strands or has a certain inherent rigidity, the rinsing and cleaning effect is the result the large diameter differences and thus the differences in the Speed of flushing liquid injected under high pressure unsatisfactory.

For external cleaning of a cable, e.g. for the bracing of a building of rust or adhering contaminants is also the thought become known, the cleaning process with a relative movement connect (GB-A 1 466 677). In order not to remove the cable to be cleaned to be able to treat it on the floor with brushes, there will be one Device movable along the cable is used, in which a nozzle Cleaning liquid is sprayed onto the surface of the cable, which in a that Cable surrounding chamber is collected without pressure and through Outlet openings is discharged. In the area of the guides of the device along the cable elastic seals are arranged around a to prevent uncontrolled leakage of the cleaning liquid from the chamber.

Object of the invention

Against this background, the invention has for its object a simple and economical way to expose and clean the initially mentioned, enclosed by a tubular sheath specify.

Presentation of the invention

According to the invention, this object is achieved by a method with the features of claim 1 solved.

A useful device for performing the method is in the claim 2 specified.

Advantageous further developments result from the subclaims.

The invention is based on the finding that it is about the channels between to effectively clean the outer wires and the central wire by rinsing can, is required, the strand on its outer circumference tight and sealed enclose and use a flushing liquid under high pressure. This is achieved according to the invention in that the tubular Sheath freed strand of a sealing element made of elastically deformable Material tightly enclosed in a gland and under the influence of a high-pressure washing liquid slowly and steadily through this Sealing element is pulled through. Because of the big difference between the Cross-sectional area of the strand enclosing and pressurized Space and that of the spaces between the individual steel wires similar to a Venturi tube or a Venturi nozzle that The speed and pressure of the rinsing liquid increased so much that this has an almost abrasive effect without, however, as with mechanical Cleaning procedures must be feared, the surface of the stranded wires to attack, let alone damage.

A device suitable for carrying out this method consists of a tubular lance that has a connection for a pressure line for one end has a washing-up liquid and at the opposite end a sealing element which under elastic pressure against the outer circumference of the strand and through then the strand can be pulled in the longitudinal direction.

Description of the drawing

Fig. 1

eine Seitenansicht einer zu behandelnden Litze,

Fig. 2

einen Querschnitt durch die Litze gemäß Fig. 1,

Fig. 3

eine Vorrichtung gemäß der Erfindung in Seitenansicht,

Fig. 4

eine schematische Darstellung der Vorrichtung gemäß Fig. 3 im Betrieb,

Fig. 5

das Dichtelement der Vorrichtung im Längsschnitt in größerem Maßstab sowie die

Fig. 6 und 7

schematische Darstellungen einer Seilwinde, um die Litze durch das Dichtelement hindurchzuziehen und einer Rückverankerung der Vorrichtung.

The invention is explained below with reference to the drawing. It shows

Fig. 1

a side view of a strand to be treated,

Fig. 2

2 shows a cross section through the strand according to FIG. 1,

Fig. 3

a device according to the invention in side view,

Fig. 4

3 shows a schematic illustration of the device according to FIG. 3 in operation,

Fig. 5

the sealing element of the device in longitudinal section on a larger scale and the

6 and 7

schematic representations of a cable winch to pull the strand through the sealing element and anchoring the device.

A section of a to be treated according to the invention Steel wire strand 1, a so-called "fat strand", is in Fig. 1 in side view and in Fig. 2 in cross section in shown on a larger scale. As can be seen in FIG. 2, the strand 2 consists of seven steel wires 3, namely one central wire 3a running in the longitudinal axis of the strand, which of the six outer wires 3b tight helically is enclosed. The strand 2 itself is one tubular casing 4, e.g. a plastic tube, surround. The gusset between the central wire 3a and the Outer wires 3b form inner channels 5 and the outer ones Gusset between the outer wires and the sheath 4 outer Channels 6. Both the inner channels 5 and the outer ones Channels 6 are coated with an anti-corrosion compound, e.g. Fat, backfilled.

In the illustration of Fig. 1, a portion of a Strand 1 shows the actual strand 2 over the length L. already freed from the sheathing 4. Such a strand could for example as a tension member for an earth or Rock anchors are used, in which the section of the Length L as a composite section of the tension member in one Compression body made of hardening material is embedded. For the complete cleaning required for this purpose Strand of any adherent fat over this length is required, the wrapping 4 over a further distance To remove Delta l, which is about 50 mm. To remove the casing 4 must first be cut; this can be achieved by attaching a cutting tool, e.g. one Knives, but also by applying heat, e.g. through an electrical heating wire through which the wrapping 4 is melted. Especially when wrapping 4 consists of a plastic tube that the strand 2 with Distance surrounds, it is easily possible pull the relevant section from the strand, which then however is still covered by the anti-corrosion compound.

The method according to the invention is used to carry out a tubular lance, the essential parts of which are shown in FIG. 3 are shown. The lance 7 consists of several Pipe sections 7a, 7b, etc., in a manner known per se are tightly connected by screw connections 8. By combining sections 7a, 7b etc. the same or the length of the lance can also be varied 7 to match the length L of the strand 2 to be treated. The lance 7 has a connection 9 for one at one end Detergent line; at the other end is also about the Screw connection 8 already described, a sealing element 10 connected.

The sealing element 10 is in Fig. 5 on a larger scale and Longitudinal section shown. It consists of an inner Sealing part 11 and an outer sealing part 12 which are tubular trained and telescopically displaceable against each other are. Between the - outer - end of the inner sealing part 11 and a stop 13 at the - outer - end of the outer Sealing part 12 are sealing rings 14 which pass through telescopic displacement of the inner sealing part 11 with respect to the outer sealing part 12 under axial compression pressure set and thus to the sealing system on one in the lance 7 inserted strand 2 can be brought. For generation such an upsetting pressure are the outer sealing part 12 and the inner sealing part 11 by means of a clamping screw 15 connected to the brackets 16 and 17 on the outer or inner sealing part 12 or 11 is anchored. On one that inner sealing part 11 surrounding sleeve 18 is located an opening 19 into which a valve 20 is inserted, the can be operated via a lever 21.

The method according to the invention can be carried out will be explained with reference to FIG. 4. For this, the 1 exempted from the envelope 4 section of the Strand 2 through the sealing element 10 into the lance 7 inserted. The length of the lance must be the length L of the correspond to the exposed section of the strand 2. It is it makes sense just after plugging in the front one The tensioning screw 15 into the sealing element 10 easy to put on. When inserting the wire 2 further then most of it will still be on the outside adhering anti-corrosion agent stripped.

Is the section of the strand 2 over the length L in the lance 7 inserted, the clamping screw 15 is tightened; thereby the sealing rings 14 for tight contact with the Brought wire 2. The lance 7 is then in a container 22 hooked in, which is the result of rinsing Rinsing liquid. Then on the opposite End of the lance 7 by means of the connection 9 provided there a flushing line 23 connected, e.g. about one Gun handle 24 an exposure to the interior of the Lance 7 with flushing liquid under pressure enables. As Rinsing liquid is expediently water, which a suitable cleaning agent is added. The Rinsing liquid expediently has a temperature of about 100 degrees C.

When lance 7 is acted upon with rinsing liquid first opened the valve 20 via the lever 21, and the Flushing liquid allows the outlet until the required operating temperature of 100 degrees C is reached is. The valve 22 is then closed and the strand 2 slowly through the sealing element 10 out of the lance 7 pulled out (arrow A in Fig. 3). The movement of the strand 1 expediently takes place at a speed v = 1 m / min. at a flushing fluid pressure of around 50 up to 70 bar. The rinsing liquid with the mainly from the anti-corrosion agent flushed out from the inner channels occurs, as indicated in Fig. 4 at 26, at the end of Lance 7 and is caught in the container 22.

A cable winch 25 is expediently used to exert the tensile force (Fig. 6). To connect the winch 25 to the strand 1 serves a wedge housing 27 in which the - also - exposed end of the strand 2 anchored by a wedge 28 is. The wedge housing 27 with a shackle 29 Vortex 30 connected, the rotation of the strand 1 around the own axis enables. Again over a shackle 31 then the rope 32 of the winch 25 connected to the an abutment block 33 sits. Requirement for the Exercising a tensile force on the strand 1 is that the lance 7 is firmly anchored at the opposite end; This can done by a rope 34 attached to an eyelet 35 on a another abutment block 36 is attached (Fig. 7).

After cleaning the strand in this way Adhesive grease can be loosened after loosening the clamping screw 15 be reinserted into the lance 7 in order to the corresponding final rinse process accordingly enable.

Claims (5)

1. A method of exposing and cleaning linearly delimited sections of strands of steel wires, which are surrounded by a corrosion-protection material, in particular grease, and including this material are enclosed by a tubular sheathing, characterised in that, while a flushing fluid under pressure is admitted to a chamber enclosing the section of the strand to be cleaned, the strand (2) freed of the sheathing (4) is drawn through a sealing element (10) of resilient material which tightly encloses the strand (2) in the manner of a packed gland from the chamber to which the flushing fluid is admitted.
2. An apparatus for carrying out the method according to Claim 1, characterised by a tubular lance (7) into which the portion of the strand (2) freed of the sheathing (4) can be introduced, wherein at one end the lance (7) has a connection (9) for a flushing line (23) and at the other end has a packed gland-type sealing element (10), through which the strand (2) can be guided in axial direction.
3. An apparatus according to Claim 2, characterised in that the lance (7) comprises at least two parts (7a,7b, etc.) which can be connected to one another at their ends in a sealed manner.
4. An apparatus according to Claim 2, characterised in that the lance (7) comprises at least two parts which can slide telescopically relative to one another.
5. An apparatus according to any one of Claims 2 to 4, characterised in that the lance (7) has an opening (19) which can be closed by a valve (20).

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