EP1367349B1 - Apparatus for dewatering strand-like material - Google Patents

Abstract

The electrical cable (10) is produced by coating an extruded wire core with a protective insulation material .This is then cleaned by an air jet (46). This is then cooled by being fed through a water spray unit (34). The water passing over the cable is collected (18). A suction unit (20) draws the water through a separator (24) and is then recycled (32).

Description

The invention relates to a device for dewatering strand material, in particular cables.

When making cables, wires are covered with a plastic layer. This is done for example by an extruder, wherein the cable after the coating has a temperature of for example 180 to 240 ° C. Since cables are manufactured in a continuous process, where the transport speed of the cable can be up to 2000 m per minute, the cable must be cooled after coating. This is done by pulling the cable through a water bath or spraying it with water.

Also in the continuous production of hoses by extrusion, the hoses must be cooled by water after extrusion. Similarly, during wire drawing during and after the drawing, cooling by drawing water, i. through a mixture of water and oil.

In order to be able to process strand-like material after cooling with water or other cooling liquids, the strand-like material must be dewatered. Drainage means the removal of the cooling liquid, irrespective of whether it is water or another cooling liquid. For example, further processing involves printing on the cables. Printing or labeling of the cables is only possible if the cable is sufficiently dry.

For drying strand material it is known from EP 1 138 462 to pull the strand-like material through a drainage trough. The drainage trough has a plurality of openings in the longitudinal direction, which are connected to a suction device. With the help of the suction device, the water is sucked from the strand-like material. Opposite the drainage trough an air outlet beam is arranged, which extends in the longitudinal direction of the strand-like material. The air outlet bar has a plurality of air outlet openings and serves for blowing off the adhering to the strand-like material water.

In particular, at high transport speeds, a sufficient degree of dryness can not be achieved with known apparatus for dewatering the strand material to print the material after dewatering, for example. This has the consequence that the transport speed of the strand-shaped material is limited in a system by the dewatering device.

The object of the invention is to provide a device for dewatering strand-like material with which a higher degree of dryness or a higher transport speed of the strand-shaped material can be achieved.

The object is achieved according to the invention by the features of claim 1.

The strand material dewatering apparatus of the present invention has a nozzle in addition to a dewatering trough connected to a suction device through which the strand-like material is drawn. The nozzle is arranged such that a jet of compressed air is directed onto the strand-like material with the nozzle in front of the drainage trough is arranged. Experiments have shown that by providing one or more nozzles which generate a jet of compressed air, a better drying of the strand-like material or a higher transport speed the strand-like material can be achieved with the same degree of dryness.

As tests have shown, the pressure and the dimension of the compressed air jet are preferably chosen such that no blowing off of the water takes place due to the impact of the compressed air jet on the strand-shaped material. Rather, there is a better dissolution of the water from the material, so that the water can be sucked easier and more effective in the drainage trough of the suction device. The compressed air jet causes a kind of rupture of the water film surrounding the strand-like material by a pulse. Experiments have shown that the arrangement of one or more such nozzles relative to the dewatering trough or in the transport direction of the strand-like material in front of the dewatering trough allow suction of larger amounts of water in the dewatering trough, so that the strand-like material is better dried.

Particularly preferred is the arrangement of at least one nozzle in the inlet region of the drainage trough. Such a nozzle is thus located just before the beginning of the dewatering trough, seen in the transport direction of the strand-like material.

Preferably, the nozzle jet of the at least one nozzle is so fine that it impinges on less than 50%, in particular less than 30% and particularly preferably less than 10% of the circumference of the strand-like material. Preferably, the nozzle jet in this case has a pressure of more than 3 bar and in particular more than 5 bar. Very good dewatering results were achieved, for example, with the device according to the invention with a nozzle diameter of 1.5 mm, for dewatering a strand-like material with an outer diameter of 2.8 mm. In this case, the results could be further improved by using one according to the invention Flat jet nozzle, ie a nozzle with several successively arranged in series holes or nozzle openings. In particular, this nozzle has more than 5 openings.

In a particularly preferred embodiment, a blowing device is provided opposite the drainage trough in addition to the at least one nozzle. The blowing device blows the broken down through the nozzle water film from the strand-like material. The blowing device is a suction device support. In a blowing device located opposite the suction device, water is sucked off or blown off substantially over the entire circumference of the strand-shaped material. In particular, the combination of a blowing device with one or more nozzles, which are arranged in the inlet region of the drainage trough and / or against the dewatering trough, has proven to be advantageous because the broken up by the compressed air water film very easily from the strand-like material through the blowing device and through the Suction device can be removed.

The nozzles preferably have a lower compressed air throughput relative to the blowing device. In particular, the compressed air flow rate of the at least one nozzle relative to the blowing device is less than 1/2, more preferably less than 1/5. This has the particular advantage that at low compressed air consumption, a good drying of the strand-like material can be achieved. In this case, the pressure of the nozzles is preferably at least twice, more preferably at least three times as high as the pressure of the blowing device. By the at least one nozzle thus a very fine compressed air jet at high pressure but little compressed air consumption and by the blowing device a higher compressed air consumption at lower pressure is realized. In particular, this combination is advantageous because the production of high pressure air, especially in large quantities is expensive.

Preferably, the suction device and the blowing device on a common fan. This has the advantage that only a single blower is required, is sucked through the same time and blown. This results in significant cost savings as the second blower is eliminated.

In order to avoid that water enters the fan, the suction device preferably has a water separator upstream of the fan.

In a particularly preferred embodiment of the invention, the dewatering trough is preceded by a Abschleudervorrichtung. In particular, the Abschleudervorrichtung the fine nozzle jet generating nozzle is connected upstream. By the Abschleudervorrichtung water is thrown off the strand-like material in a kind of pre-drainage. This happens because, preferably, by providing a deflection device as part of the Abschleudervorrichtung, the strand-shaped material is deflected. By this deflection of the strand-like material from the transport direction act centrifugal forces. These cause a centrifuging of water, oil or other fluids present on the surface of the strand material and the like. The upstream of a Abschleudervorrichtung before the nozzle or the dewatering trough has the advantage that the strand-like material is already predried before reaching the nozzle or the drainage trough. Thus, easily removable fluids are already removed from the strand-like material.

Preferably, a plurality, in particular at least three, deflection devices are provided. By deflecting the strand-like material can be deflected in a horizontal or vertical plane or any intermediate level. Preferably, a deflection takes place in a vertical plane to allow the smallest possible depth of the device. Preferably, at least one of preferably takes place a plurality of deflection means deflecting the strand-like material by at least 40 °, more preferably by at least 60 ° and in particular by at least 80 °.

It is particularly preferred not to provide rigid devices as deflection devices, but to arrange deflection rollers. The deflection rollers preferably have a guide groove in which the strand-shaped material is guided. The guide groove is preferably V-shaped.

Experiments have surprisingly found that an increase in the amount of liquid thrown off can be achieved at an opening angle or V-groove of at least 70 ° and particularly preferably at least 80 °. At the same transport speed of the strand-shaped material is thus at an angle of preferably at least 80 °, a larger amount of liquid removed from the strand-like material, i. thrown off than with a V-groove with a smaller angle. Experiments have further shown that the angle should preferably be less than 90 °, in particular in the range of 80 ° - 90 °.

The transport speed of the strand-shaped material is preferably at least 400 m / min. The results can be further improved by increasing the transport speed.

The Abschleudervorrichtung is an independent invention. However, particularly preferred is the use of the Abschleudervorrichtung invention in conjunction with the dewatering device according to the invention.

The invention will be explained in more detail with reference to a preferred embodiment with reference to the accompanying drawings.

Fig. 1

eine schematische Seitenansicht einer Entwässerungsvorrichtung,

Fig. 2

eine schematische perspektivische Ansicht des Entwässerungstrogs,

Fig. 3

eine schematische Schnittansicht entlang der Linie III-III in Fig. 1,

Fig. 4

eine schematische Schnittansicht entlang der Linie IV-IV in Fig. 1 und

Fig. 5

eine schematische Seitenansicht einer Umlenkrolle der Abschleudervorrichtung in Richtung des Pfeils V in Fig. 1.

Show it:

Fig. 1

a schematic side view of a dewatering device,

Fig. 2

a schematic perspective view of the drainage trough,

Fig. 3

a schematic sectional view taken along the line III-III in Fig. 1,

Fig. 4

a schematic sectional view taken along the line IV-IV in Fig. 1 and

Fig. 5

a schematic side view of a guide roller of the Abschleudervorrichtung in the direction of arrow V in Fig. 1st

The illustrated embodiment for dewatering strand material 10 includes a dewatering trough 12 through which the strand-like material 10 is pulled longitudinally. In the illustrated embodiment, the drainage trough 12 is channel-shaped. It may also be a closed tube with an annular or any other cross section. The drainage trough 12 has openings 16 in the trough bottom 14 (FIG. 2), which are connected to a suction channel 18. In the suction channel 18, negative pressure is generated by means of a blower 20 (FIG. 1). For this purpose, the suction channel 18 is connected via a pipe 22, a water separator 24 and a tube 26 provided between the water separator 24 and the blower 20 with the blower 20.

By the blower 20 upstream water separator 24 prevents sucked from the strand material 10 water enters the blower 20 and this damaged. The water separator 24 has a drain pipe 30 provided with a valve 28 for draining the water collecting in the water separator 24. For automatic draining may be in the drain pipe a pump may be provided which is controlled by a level controller disposed in the water separator.

The fan 20 is connected via a pipe 32 with an air outlet beam 34. The air outlet bar 34 is a hollow body with air outlet openings aligned in the longitudinal direction of the strand-like material 10. The air outlet openings are directed to the strand-like material 10. From the air outlet beam thus exits directed to the strand material air flow with relatively low pressure, through which the removal of the water is supported by the strand-like material 10. The air outlet bar may have a plurality of outlet openings and / or a slot-shaped air outlet gap.

The suction device of the dewatering device, which consists essentially of the suction channel 18 and the blower 20 and the blowing device, which is composed essentially of the air outlet beam 34 and the blower 20, have the same blower 20. Thus, on the one hand, air is sucked out of the suction channel 18 by the fan 20, and on the other hand, air is conveyed into the air outlet bar 34 in order to produce an air flow directed onto the strand-shaped material 10.

According to the invention, the device has a nozzle 36 which is connected via a pipe 38 to a compressed air generating device 40 such as a compressed air pump. The nozzle 36 is arranged in the inlet region 42 of the drainage trough 12. The inlet region 42 is provided in a transport direction 44 of the strand-like material 10 at the inlet of the drainage trough. For example, if the strand-like material is cables or the like, the nozzle 36 is spaced from a front side of the drainage trough 12 by a distance of preferably less than 5 cm. The nozzle 36 is thus located in the transport direction 44 before or after a leading edge of the dewatering pressure within this distance.

The nozzle 36 generates a fine jet of jet 46 which strikes a surface of the strand-like material 10. Based on the circumference of the strand-like material 10, the width of the jet 46 is small. In particular, it is less than 30% and more preferably less than 10% of the circumference.

In contrast, the air bar or the blowing device 34 generates a, for example, conical air jet 48, which extends over at least the entire width of the strand-like material 10. The jet 48 serving to blow off the air film broken by the jet 46 has a considerably lower pressure than the jet 46.

In an alternative embodiment, the air outlet bar 34 may be omitted. In this embodiment, it is then possible to connect the nozzle 36 to the fan 20 so that the fan 20 is connected to both the suction channel 18 and the nozzle 36. Furthermore, in the two embodiments described above, i. in an embodiment with or without air exit beam 34, it is possible to connect the nozzle 36 to a separate compressed air source. This has the advantage that high pressures can be generated.

The drainage trough 12 has a semicircular semicircular drainage channel 50 (FIG. 2). In order to dewater different strand materials 10 with the dewatering device, the dewatering trough 12 is replaceable, so that different drainage troughs 12 with different drainage troughs 50 can be provided. The drainage channels 50 may have different cross-sections and different cross-sectional dimensions depending on the material to be drained.

Furthermore, the dewatering device according to the invention has a Abschleudervorrichtung 52 (Fig. 1). This is in the illustrated embodiment of the nozzle 36 upstream in the transport direction 44.

The Abschleudervorrichtung 52 has in the illustrated embodiment, three deflection in the form of pulleys 54. The pulleys 54 are identical in the illustrated embodiment. In the transport direction 44 of the strand-like material 10, the deflection rollers 54 are arranged vertically offset from each other, wherein the first and last deflection roller 54 is arranged in the same direction in the transport direction. The deflection rollers 54 (FIG. 5) have a circumferential guide groove 56, which is preferably V-shaped. The V-shaped guide groove 56 in this case has an angle α of preferably at least 70 °, more preferably at least 75 ° and in particular at least 80 °. Investigations have shown that at such angles α of the guide groove 56, surprisingly, a particularly good centrifuging of the adhering to the strand-like material 10 materials.

In the illustrated embodiment, the strand-like material 10 is deflected by the first deflection roller 54 in the direction of transport 44 in the direction of the second guide roller 54 down. Here, a deflection of about 90 °. In turn, a deflection of about 90 ° takes place between the second and third deflection pulleys 54 and then again a deflection in the transport direction by the last deflection pulley 54, ie by a further 90 °. In the second deflection roller 54, the strand-like material 10 thus lies approximately at the half of the deflection roller 54 and is deflected in total by 180 °. The three deflections of the strand-like material, which cause curvatures of the material 10 in different directions, liquid or other material adhering to the strand-like material is thrown off.

In order to prevent the spin-off of the first and the last pulley 54 that thrown off material drips back onto the strand-like material or the like., A catcher 58 is provided. The collecting device 58 may be a vertical plate arranged between the first and the last deflection roller 54, which has a collecting channel 60 at the lower end.

Claims (13)

1. A device for dewatering strand-like material (10), in particular cables, comprising
   a dewatering trough (12) for pulling the strand-like material (10) therethrough,
   a suction device (18, 20) for drawing off the water from the dewatering trough (12),
   characterized in that
   a nozzle (36) located upstream of the dewatering trough (12) directs a jet of pressurized air (46) onto said strand-like material (10) such that the jet of pressurized air (46) imparts a pulse to the adhering water that is insufficient to blow the water off.
2. The device of claim 1, characterized in that the nozzle is configured such that the jet of pressurized air (46) is such that it impinges on less than 50 %, in particular less than 30 %, and particularly preferred less than 10 % of the circumference of the strand-like material (10).
3. The device of one of claims 1 or 2, characterized in that a plurality of nozzles (36), preferably at least three nozzles, are arranged opposite the dewatering trough (12).
4. The device of one of claims 1 to 3, characterized in that a blower device (34) is arranged opposite the dewatering trough (12), which blower delivers air at low pressure.
5. The device of claim 4, characterized in that, compared to the blower device (34), the nozzle (36) has a low throughput of pressurized air of preferably less than ½, particularly preferred less than 1/5.
6. The device of claim 4 or 5, characterized in that the pressure of the nozzle (36) is at least twice, preferably at least three times the pressure of the blower device (34).
7. The device of one of claims 1 to 6, characterized in that the suction device (18, 20) and the blower device (34) or the suction device (18, 20) and the nozzle (36) have a common fan.
8. The device of one of claims 1 to 7, characterized by a spin-off device (52) arranged upstream of the dewatering trough (12).
9. The device of claim 8, characterized in that the spin-off device (52) comprises at least one deflecting means (54) for deflecting the strand-like material (10).
10. The device of claim 9, characterized in that the deflecting means (54) causes a deflection of at least 40°, preferably at least 60°, and particularly preferred at least 80°.
11. The device of one of claims 8 to 10, characterized in that deflector rolls (54) are provided as the deflecting means.
12. The device of one of claims 10 or 11, characterized in that the deflecting means has a preferably V-shaped guide groove (56).
13. The device of claim 12, characterized in that the angle (α) of the guide groove (56) is at least 70°, preferably at least 75°, and particularly preferred at least 80°.

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