EP0163248B1 - Spinning manifold for melt-spinning synthetic fibres - Google Patents

Description

The invention relates to a spinning beam for extrusion, in particular melt spinning synthetic threads according to the preamble of claim 1.

Such a spinning beam (compare DE-AS 1908207) consists of a double-walled heating jacket, which is designed to hold a particularly vaporous heating medium as a pressure vessel and in its interior open chambers with plane-machined heating surfaces for receiving and heat-conducting connection of melt-carrying components, such as pump blocks , Dosing pumps and optionally heat-conducting blocks. The heating jacket of the spinning beam is housed in a housing and surrounded by thermal insulation.

In the known heating box, the melt-carrying components lie on a double-walled heating plate, which can be flat or L-shaped or U-shaped in cross-section and is supplemented by applied, heat-conducting fillers to form a closed hollow beam. All melt-carrying components can only be used from above, for which the insulating pieces and the corresponding fillers have to be removed. Due to manufacturing tolerances and different thermal expansions, there may be more or less wide gaps between the insulating bodies and the filling bodies, through which heat can flow out in an uncontrolled manner as a result of a chimney effect. This can lead to different heating of the melt at the different spinning positions of the spinning beam.

To remove or maintain the melt-carrying components, a stage is also required above the spinning beam, from which the operating personnel can carry out the assembly and maintenance work.

From DE-PS 2120 600 it is known to arrange the extruder, in particular a one-day spinning system, on a lower floor than the spinning beam in order to reduce the height of the room for the spinning system or to make it available for the blowing zone and the thread cooling. It is then considered disadvantageous if the room height has to be increased because of the required accessibility to the melt-carrying components of the spinning beam.

EP-A 0155835, which belongs to the state of the art according to Article 54 (3) EPC due to the priority of JA-A 5951 170 and which is to be taken into account in the context of its content, which corresponds to JA-A 5951 170 a spinning beam having two longitudinal heating chambers is described. The heating chambers have space between them for the arrangement of the nozzle packs and, seen in cross-section, each have a narrow, inwardly projecting support for a nozzle pack carrier in the lower region, which in turn accommodates a support bar in a T-groove incorporated into its underside, on which the nozzle packs are hung individually. The space between the heating chambers is open at the bottom along the entire length of the spinning beam or can be divided by transverse walls between the heating chambers.

In the prior art described, the object of the invention is to provide a spinning beam in which the maintenance and removal of the heated melt-carrying components, including the nozzle packs, can be carried out from below and from the side so as to reduce the height of the spinning system, so that above a work platform is no longer required. The task is also to improve and in particular to simplify and accelerate the nozzle change, i. H. replacing the used one with a cleaned nozzle package and ensuring uniform heating of all melt-carrying parts and in particular the spinning pumps and the nozzle packages.

This object is achieved by a spinning beam with the features of claim 1. This solution offers the advantages of a very uniform and inexpensive heating of all melt-carrying components and avoids vertical joints between the parts of the heating jacket and the thermal insulation.

This is achieved in that the chamber formed between the outer, horizontal U-legs of the heating jacket with a U-shaped cross section for receiving the melt-carrying components is closed off from the nozzle shafts built into the heating jacket and the chamber is sealed from the side (reduction of the overall height ) or accessible from above, while the nozzle pots with the pre-assembled nozzle packages are installed through the nozzle shafts in the heating jacket. This means that a working platform above the spinning beam can be omitted if this is desirable.

In order to be able to easily assemble the nozzle pots, it is provided that a connecting plug, in particular with an external thread or bayonet lock, for connecting the nozzle pot receiving the nozzle packet is pressure-tightly connected to the pump block, in particular is screwed to the pump block or forms a component with it. The development according to claim 3 offers the further advantage that the connecting plug for connecting the nozzle pot does not have to be removed inside the nozzle shaft if the pump block is to be removed. Rather, the pump block with the connecting plug can be assembled and / or disassembled as a unit through the shaft formed between the U-legs of the heating jacket.

Finally, in a further embodiment of the spinning beam, it is provided that the double-walled heating jacket has an essentially circular cross-section that describes the ends of the chamber and the nozzle shaft. A Such formation of the outer wall of the heating jacket has the advantage that it manages with a very small wall thickness.

• Fig. einen Spinnbalken zum Schmelzspinnen synthetischer Fäden in der Aufsicht;
• Fig. 2 einen Querschnitt des Spinnbalkens gemäss Fig. 1 entlang der Schnittlinie 11-11 in Fig. 1;
• Fig. den Querschnitt eines Düsenschachtes mit Anschluss eines Düsentopfes am Pumpenblock;
• Fig.4 einen ähnlichen Querschnitt wie Fig.2 mit einer abgeänderten Ausbildung der Aussenwand des Heizmantels;
• Fig. 5 einen weiteren Querschnitt eines Spinnbalkens nach der Erfindung;
• Fig. als Detail die Befestigung eines Düsentopfes.

The invention is explained below with reference to the attached schematic drawings. Show it:

• Fig. A spinning beam for melt spinning synthetic threads in the plan;
• FIG. 2 shows a cross section of the spinning beam according to FIG. 1 along the section line 11-11 in FIG. 1;
• Fig. The cross section of a nozzle shaft with connection of a nozzle pot to the pump block;
• 4 shows a cross section similar to Figure 2 with a modified design of the outer wall of the heating jacket;
• 5 shows a further cross section of a spinning beam according to the invention;
• Fig. As a detail, the attachment of a nozzle pot.

1 shows the top view of the spinning beam 1 shown in cross section in FIG. 2, which has a plurality of nozzle arrangements arranged in series one behind the other for melt spinning synthetic threads made of thermoplastic polymers. As can be seen from Fig. 2, the spinning beam 1 consists essentially of a double-walled heating jacket 2, which is designed as a pressure vessel for receiving the heat transfer medium, in particular vaporous diphenyl, and in a chamber 6 delimited by plane-parallel machined heat transfer surfaces 3, 4, 5, the melt-carrying Takes up components. The heating jacket 2 is enclosed in its entirety to reduce heat losses by a sheet metal housing 7, which is stuffed with mineral wool 8 or another suitable insulating material. In places where the spinning beam 1 must be accessible for maintenance purposes, the insulating materials are present as insulating bodies pressed into geometrically simple shapes, which can be removed from the sheet-metal housing at the appropriate point by means of closable cutouts. A heated melt feed line 9, which is connected to a melting device, such as an extruder or discharge pump, leads through the sheet metal housing 7 from above. The melt feed line 9 leads through the double-walled heating jacket 2 and is connected to a cuboid-shaped distributor block, from which branch ducts lead in a vertical direction to the pump blocks 10 lying next to one another. In the pump blocks 10, a branch leads from this channel to the suction side of the melt metering pump 11 attached to the pump block 10 and at least one pressure channel to an outlet opening 12 (FIG. 3) to which a nozzle pot 13 with a nozzle packet 22 is connected in a pressure-tight manner.

According to the invention, the heating jacket 2 of the spinning beam 1 is double-walled over its entire length and U-shaped in cross-section, the two U-legs 14 and 15 of the heating jacket 2 being aligned horizontally or vertically (FIG. 5). From the inner surfaces 3, 4, 5 of the U-legs 14, 15, which can be machined from the open side of the heating jacket, a chamber 6 or a shaft extending over the entire length of the heating jacket 2 is formed, which ends at Avoidance of heat loss through heat-conducting blocks in the form of fillers 16 is limited. The melt-carrying components, such as pump blocks 10, melt metering pumps 11 and the melt distributor block, are accommodated in the chamber 6. The melt-carrying components rest on the heat transfer surface 5 of the U-leg 15 facing the chamber 6 and are pressed on by additional tension or compression screws in order to improve the heat transfer to the components to be heated.

On the underside of the pump blocks 10 are a plurality of nozzle shafts 17, ie. 1, for example, two nozzle shafts 17 per pump block 10, for the installation of the nozzle pots 13 in the heating jacket 2, welded pressure-tight, starting vertically downward from the chamber 6, the lower U-leg 15 of the double-walled heating jacket 2 being penetrated. The adjacent nozzle shafts 17 can preferably form a common component that extends over the entire length of the spinning beam 1 and is welded into the heating jacket 2.

A spinning shaft extension 18 is connected to the vertical nozzle shafts 17 in order to make the nozzle pots 13 more accessible for assembly work. The blowing chutes leading downward, but not shown, are flanged to the spinning chute extension 18. The spinning shaft extension 18 also serves to support and to fasten the spinning beam 1 to a carrier of a work platform or the like.

3 shows in cross section the detail of the attachment of the nozzle shaft 17 in the lower U-leg 15 of the double-walled heating jacket 2. Furthermore, there is a particularly advantageous constructive solution for the attachment of the nozzle pot 13 receiving the nozzle packet 22 and a simple possibility for inserting and removal of the pump block 10 in or out of the chamber 6 formed between the horizontal U-legs 14, 15 of the heating jacket 2. Specifically, the pump block 10 has a preferably circular cylindrical recess 23 on its underside in the area of each nozzle shaft 17. A connecting plug 20 with a central melt channel 19 is inserted in this recess 23 in a pressure-tight manner by means of fastening screws 25 distributed around the circumference. The melt channel 19 is aligned with the outlet opening 12 of the pump outlet channel in the pump block 10. It is particularly pointed out that the downward-facing end face 24 of the connecting plug 20 is behind the bearing surface of the pump blocks 10 jumps back slightly on the heat transfer surface 5 of the lower U-leg of the heating jacket 2. As a result, after removal of the nozzle pots 13 and the connecting plugs 20 fastened to the pump block, the pump block 10 can be removed and installed from the chamber 6 and no assembly work on the connecting plug 20 can be carried out from the nozzle shaft 17. The connecting plug 20 has a thread 21 on its circumference, which can be of multiple threads, or a bayonet lock for simple and quick removal of the nozzle pots 13.

The nozzle packet 22 accommodated in the nozzle pot 13 consists, in a known manner, of a nozzle plate 26 into which a plurality of nozzle bores are introduced, a melt distributor plate 27 in which a filter 28 is arranged in a circular cylindrical recess and a seal 29 which seals the nozzle packet 22 seals against the connecting plug 20 by the force of a differential piston 33 under melt pressure. The nozzle pack 22 is sealed between the differential piston 33 and the melt distributor plate 27 by a metal membrane 34 which is supported on the melt distributor plate 27.

In the present construction of the spinning beam 1, it should be particularly emphasized that despite the annular air gap 36 which is necessarily left between the nozzle pot 13 and the nozzle shaft 17 for the purpose of assembly, no heat losses occur as a result of air circulation or as a result of a chimney effect, since possible air gaps between the components go up through the Pump block 10 are sealed.

As a further special feature, it should be emphasized that the attachment of the nozzle pot 13 to the connecting plug 20 means that the heating jacket 2 no longer has to absorb tensile forces resulting from the melt pressure. This is of great advantage for the dimensioning of the wall thickness of this critical component (pressure vessel).

Fig. 4 shows the cross section of a spinning beam 1, in which, however, the radially outward-facing outer wall of the heating jacket 2 is essentially circularly curved and consists, for example, of tubular sections cut in the longitudinal direction in a suitable manner. It has a length that extends to the ends of the horizontal chamber 6 for accommodating the melt-carrying components and the ends of the nozzle shafts 17 which are guided downward through the heating chamber 2. The solution shown is simple in terms of production technology and advantageous in terms of the stress caused by the pressure of the heat transfer medium.

It should be noted that the pressure screws for the melt-carrying components on the heat transfer surfaces of the chamber 6 have been omitted in the drawing for the sake of simplicity.

All of the exemplary embodiments shown in FIGS. 1 to 4 have the horizontally arranged chamber 6 between the outer U-legs 14, 15 of the heating jacket 2 for the lateral installation of the pump blocks 10 and the melt metering pumps 11 as well as the nozzle shafts 17 installed in the lower U-leg 15 as a common constructive feature.

It should also be mentioned that the heating chambers of the two U-legs 14, 15 are connected to one another and structural details regarding the heating of the heating jacket 2, which are not essential for understanding the invention, have been omitted from the drawing for the sake of simplicity.

Fig. Finally shows the cross section of a spinning beam 1 according to the design principle on which this invention is based, in which the U-legs 14, 15 of the heating jacket 2 are oriented vertically, however, and the nozzle shafts 17, starting from the pump shaft 6, are installed vertically downward in the double-walled heating jacket 2 in a pressure-tight manner , in particular are welded in. In this arrangement, the pump block 10 and the melt metering pump 11 are installed in the pump shaft 6 from above. Nevertheless, the nozzle shafts 17 are sealed at their upper end by the pump block 10, which extends essentially over the entire length of the spinning beam 1, so that air circulation due to a chimney effect is prevented. The pump block 10 also has a corresponding number of connecting plugs 20 on the melt outlet side, which can form a common component with the pump block 10 or are non-positively and pressure-tightly connected to the latter. The nozzle pots 13 are screwed onto the connecting plugs 20, so that the melt forces are absorbed exclusively by the pump block 10 and the nozzle pots 13 and do not stress the heating jacket 2 and the nozzle shaft 1.7.

The polymer melt is supplied here through the melt feed 9 arranged laterally, which opens into a valve module 38 or the like, which is connected to the pump block 10 and is guided through the vertical U-leg 15 of the double-walled heating jacket 2. The annular space 39 around the melt feed line is connected to the heating chambers of the heating jacket by branch lines 40, 41. The line 41 can, for example, discharge the condensate accumulating in front of the valve module 38.

The invention also offers the particular advantage that the nozzle package, ie in particular the nozzle plate, distribution elements and filter, can be inserted into the nozzle pot before it is attached to the heating box. To maintain a spinning station, it is then only necessary to remove the nozzle pot which is in operation and to insert a fresh nozzle pot. Compared to the previously known spinning heads, this saves in particular the laborious overhead work of individually removing and reinstalling the individual parts of the spinning head. It is avoided that the Forces exerted by the melt pressure must be absorbed by the spinning beam or heating jacket to such an extent that the stability suffers.

Fig. Explains the attachment of the nozzle pot.

The spinning beam carries the pump block 10 accommodated in a heating box 2 or a melt line module with the melt line 19, via which the spinning station is supplied. In the illustrated embodiment, the pump block 10 (or fusible link module) has a suitable recess into which the connecting plug 20 is inserted. An annular seal is inserted between it (20) and the pump block 10, the bearing surface of which essentially determines the level of the forces to be exerted by the fastening screws in order to achieve a tight and pressure-resistant connection. The inner diameter of the ring seal also corresponds to that of the melt line 19.

On its circumference, a thread 21 is incorporated in the connecting plug 20, which can be designed as a multi-start, self-locking and thus quickly tightened thread or as a bayonet connection. Accordingly, the nozzle pot 13 accommodating the nozzle packet 22 is equipped on its upper part on the inside with a suitable counterpart.

It is particularly important that the inside diameter of the nozzle pot is essentially the same as the outside diameter of the connecting plug.

In the nozzle pot 13 sits the nozzle pack, which consists of the spinneret 26, the pressure or distributor plate 27 with the melt bores, the melt chamber lying between the two and the filter pack 28 inserted into the pot-shaped upper part of the pressure plate 27. In order to produce a pressure-tight and tight connection with the connecting plug 20, a piston 33, which closes off the nozzle pack, sits above the pot with the filter pack 28 and is sealed off from the pot by the plate-shaped membrane 34. A further ring seal 29 is provided between the piston 33 and the connecting plug 20, to which the above-mentioned seal also applies. In the case under consideration, the thread 21 is intended to be a bayonet lock designed as a three-start thread, which has axially extending recesses in each partial area of its circumference, which are the same as the thread regions, and which extend to the bottom of the thread, namely three such recesses should be evenly distributed. It goes without saying that stopper 20 and pot 13 fit together.

For attachment, the nozzle cup 13 with the nozzle pack and the plate membrane 34 and the piston 33 is then inserted into the bayonet thread of the connecting plug 20 and then only slightly tightened by turning it by about 60 °. The high contact pressure required for sealing is generated by the melt pressure itself, which acts on the piston 33 via the plate membrane 34 and compresses the seal 29. The piston 33 is sealed by plate membrane 34 against the interior of the nozzle cup, in which it is axially displaceable.

From the illustration it is clear that the force resulting from the melt pressure and the interior cross section of the nozzle pot, acting in the direction of the top axis, is only absorbed by the connecting plug 20 with its thread 21, because the piston 33 is also - via the seal 29 - on Supporting plug 20 supports. The force to be introduced into its suspension 10 for its attachment is determined by the sealing cross-section of the seal 29, which according to the invention is substantially smaller than the cross-section of the connecting plug 20, so that this force is very low in comparison with that which is effective in the connecting plug itself.

The object of the invention is then achieved that the nozzle change process is drastically simplified and accelerated and also that the force resulting from the high melt pressure and introduced into the suspension of the nozzle construction is considerably reduced compared to the force effective in the nozzle pack. This can improve the heating box. The heating box is used to hold a liquid and / or vaporous, pressurized heating medium and to transfer heat to melt-carrying parts, in particular the pump block. It is a critical component in terms of its strength and ductility. According to the invention, it is largely freed from its function of absorbing the force of the melt pressure and, although it can be designed to be weaker, it can nevertheless be improved in its stiffness, which is particularly important for heat transfer to all melt-carrying parts and in particular the pump block.

Claims (9)

1. Spinning beam for extrusion, particularly for melting and spinning of synthetic threads, with the features:

A double-walled heating jacket (2) is constructed as a pressure tank to receive a heat transfer medium particularly in vapour form and forms chambers (5) with heating surfaces to receive and provide heat-conducting connection of components ducting molten material such as pump blocks (10), dosaging pumps (11) and optionally heat-conducting blocks (16); the heating jacket (2) is constructed over its entire length with a U-shaped cross-section and double walls; a number of individual identical nozzle shafts (17) are passed at right angles downwards through the heating jacket (2) starting from the chamber (6) formed between the U-arms (14, 15), set into the heating jacket (2) so as to be pressure-tight and closed off at the top by a pump block (10); connecting plugs (20) are provided which start from the bearing surface of the pump block (10) and are concentric with the nozzle shafts (17) and which are connected, particularly screwed, to the pump block (10) so as to be pressure-tight or are part of the pump block (10) and have possible connection means, particularly thread (21) or bayonet fittings, to connect the nozzle containers (13) which receive the respective nozzle sets (22).

2. Spinning beam as claimed in claim 1, characterised in that the connecting plug (20) is set into a recess (23) in the pump block (10) in such a way that the end face (24) of the connecting plug (20) closes with the bearing surface (5) of the pump block (10) or the bearing surface formed by the pump block (10) is set back.

3. Spinning beam as claimed in claims 1 or 2, characterised in that the connecting plug (20) can be locked with the nozzle container (13) by means of an optionally multiple and irreversible thread (21) or by a bayonet closure (21).

4. Spinning beam as claimed in claims 1 or 2, characterised in that the connecting plug can be locked with the nozzle container (13) by means of a bayonet closure (21) which is constructed as a multiple thread having recesses which are arranged in evenly distributed regions of its periphery which are equal to or greater than the thread regions, these recesses running in the axial direction and extending as far as the thread base.

5. Spinning beam as claimed in one of the preceding claims, characterised in that the connecting plug (20) can be connected to the pump block (10) or the duct for molten material (19) with the aid of a multiple thread or a bayonet closure so as to be pressure-tight and form a seal.

6. Spinning beam as claimed in one of the preceding claims, characterised in that the sealing cross-section of the connecting plug (20) is considerably smaller than its external diameter or than the internal diameter of the nozzle container (13) or the nozzle set (22) and is defined with respect to the duct for molten material (19) by the bearing surface of a sealing ring and with respect to the nozzle set (22) by the bearing surface of a further seating ring (29).

7. Spinning beam as claimed in one of the preceding claims, characterised in that between the connecting plug (20) and the nozzle set (22) a piston (33) is provided which fits into the nozzle container (13), is sealed off with respect to the nozzle container (13) with the aid of a diaphragm (34) and is gripped via the seal (29) with the connecting plug (20) so as to be resistant to pressure.

8. Spinning beam as claimed in one of the preceding claims, characterised in that the double-walled heating jacket (2) has a substantially circular cross-section which circumscribes the ends of the chamber (6) and the nozzle shaft (17).

9. Spinning beam as claimed in one of the preceding claims, characterised in that the nozzle shafts (17) are built into the double-walled heating jacket between two vertical U-arms (14, 15) so as be pressure tight, and the pump block (10) with the dosaging pumps for molten material (11) can be installed from above in the chamber {6) enclosed by the heating jacket (2) and closes the nozzle shafts (17).

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