Title of Invention

HEATING DEVICE FOR HEATING A YARN

Abstract

A heating device is described for heating a yarn, in particular in a texturing machine. The heating device comprises a thin-walled heating tube, which can be evenly heated on its circumference by a heating jacket. Fitted into the wall of the heating tube is an insert, which forms a yarn channel with a yarn inlet and a yarn outlet for guiding the yarn. In accordance with the invention, the insert is formed by a special section rail that is open toward its one long side, and fitted with its opposite long side to the wall of the heating tube. As a result.- the yarn channel is formed between the open long side of the special section rail and the wall of the heating tube, so that it is possible to supply heat to the yarn channel directly via the wall of the heating tube.

Full Text

Translation PCT-3053 030563/270021 HEATING DEVICE FOR HEATING A YARN The invention relates to a heading device for heating a yarn, in particular in a texturing machine, as defined in the preamble of claim 1. For texturing synthetic filament yarns, it is known to heat the yarns in a texturing machine by means of heating devices for texturing and drawing and for subjecting them to a shrinkage treatment. As a function of the process step, different heating devices were developed, which produce an optimal heating of the yarn in the particular process. Thus, for obtaining a high relaxation effect on the yarn during the shrinkage treatment, it is necessary that the yarn advance through the heating device as much as possible under no tension. For this process step, especially such heating devices have proved successful, in which the yarn advances through a yarn channel that is provided within a heating tube. Heating devices of this type are known, for example, from DE 23 48 371, DE 31 01 925 Al, or DE 34 35 27[sic] Al. In these heading devices, the heating tube is formed by a thin-walled tube, which is surrounded by a heating jacket that is filled with a heat transfer medium. For guiding the yarn, the heating tube accommodates a tubular insert, which includes a yarn channel. In this process, the yarn is heated by convection, preferably in a no contacting relationship. However, devices of this type are also known for heating the yarn in contacting relationship. Basically, with such heating devices there arises the problem that the heat generated on the circumference of the wall of the heating tube by the condensation of the heat transfer medium, must be guided through the wall of the heating tube and through the wall of the insert for entering the yarn channel. To this end, it is necessary to fit the tubular insert into the heating tube as tightly as possible without leaving any gaps, so as to avoid heat transfer losses. However, since it is preferred to mount che inserts in the heating tube in an exchangeable manner, it is, for example, not possible to press them in for obtaining narrow gaps and satisfactory heat transfers. When texturing and drawing yarns, it is preferred to use heating devices, as are disclosed, for example, in EP 0 412 429 Al. During the texturing and drawing processes, the yarns advance under a high tension while being heated. In this connection, the yarns exhibit natural dynamics, so that the yarn guidance becomes an exacting task. Heating devices of this type are preferably constructed as high-temperature heaters, in which the yarns advance in a heating groove with yarn guide elements. The sides and the bottom of the heating groove are heated by resistance elements, with the heating surface having a temperature that is above the melt point of the yarn material. For this reason, the yarns are kept at a distance from the heating surface. However, to heat a yarn in a tensionfree state, such heating devices are" -barely suitable, since each unintended contact with one of the heating surfaces directly results in damage to filaments of the yarn. It is therefore an object of the invention to further develop a heating device of the foregoing type for heating a yarn, in particular during a shrinkage treatment in a texturing machine such that it permits transferring heat•into the yarn channel with the least possible losses. A further object of the invention is to achieve in the yarn channel the highest possible yarn temperatures while using the energy generated by a heating jacket. 1 The object of the invention is accomplished by a heating device with the features characterized in claim 1. Advantageous further developments of the invention are defined by the features and combinations of the features of the dependent claims. The invention has the special advantage that within a yarn channel, a separation exists between the function of the yarn guidance and the heat transfer. Thus, an insert that is needed for guiding the yarn extends along a partial length of the wall of the heating tube. The remaining partial length of the heating tube wall directly adjoins the yarn channel, so that the heat can be directly transferred from the wall of the heating tube into the yarn channel. To ensure that the yarn does not come into direct contact with the wall of the heating tube, a special section rail constitutes the insert, whose open long sides form a guideway for the yarn. In this arrangement, the yarn channel extends between the open long side of the special section, rail and the wall of the heating tube. With its opposite long side, the special section rail is directly fitted to the wall of the heating tube. Thnc;. hhp wall nf the* heatina tube may be formed of a material, which permits an optimal heat transfer. An unacceptable wear by yarn contact is avoided by the special section rail, which in turn is formed of a material that is suitable for guiding the yarn. The only partially covered wall of the heating tube makes it thus possible to improve the heat input into the yarn channel considerably. It was thus possible to observe that one could reach a higher yarn temperature in the yarn channel than in the known devices. To advance a yarn through the yarn channel in contact therewith, it will be especially advantageous to use the further developments of claims 2 and 3. In this case, the yarn channel is formed by a longitudinal groove along the open long side of the special section rail, with the yarn preferably advancing along the bottom of the longitudinal groove. The longitudinal groove of the special section rail has a curvature extending in the direction of the advancing yarn, so that a yarn advancing under no tension safely travels through the yarn channel and can be uniformly heated. In this connection, it should be considered that one needs to form the curvature only in the special section rail, whereas the heating tube has an unbent, straight shape. To realize a plurality of heating zones in the heating device, it is preferred to use the advantageous further development of claim 4. In this embodiment, the longitudinal groove of the special section rail or the special section rail itself comprises a plurality of partial lengths one following "the other in the direction of the yarn advance. For example, it would be thus possible to form preferably a heating zone with yarn contact and a heating zone without yarn contact. The further development of the invention, in which the special section rail is exchangeable held in the heating tube, has the special advantage that it permits changing the yarn guide way and cleaning the yarn guiding surfaces in a simple way. In this case, it is easy to arrange a plurality of guide elements in spaced relationship along the open long side of the special section rail. The guide elements, which may be formed, for example, by ceramic inserts, permit a high flexibility in the yarn advance within the heating device. In this connection, the guide elements may extend over the entire length of the special section tube or over a partial length thereof. The special section rail and the heating tube may have any desired shape. However, it is preferred to make the heating tube tubular. The tube itself may be straight or bent. In the following, further advantages of the invention are described in greater detail by means of some embodiments of the device according to the invention with reference to the attached drawings, in which: Figure 1 is a schematic axially sectioned view of a first embodiment of the heating device according to the invention; Figure 2 is a schematic cross sectional view of the embodiment of Figure 1; Figure 3 is a schematic axially sectioned view of a further embodiment of the heating device according to the invention; * - Figure 4 is a schematic cross sectional view of the embodiment of Figure 3; and Figure 5 is a schematic axially sectioned view of a further embodiment of the heating device according to the invention. Figure 1 schematically illustrates an axially sectioned view of a first embodiment of the heating device according to the invention, as could be used, for example, in a texturing machine for a tension treatment of a crimped yarn in a shrinkage zone. Figure 2 illustrates a cross sectional view of the embodiment of the heating device according to the invention.. Unless express reference is made to one of the Figures, the following description will apply to both Figures. The embodiment of the heating device according to the invention comprises an elongate heating tube 1 with a wall 3. In the present embodiment, a thin-walled tube forms the heating tube 1 with wall 3. The heating tube 1 is open on its end sides. Inside the heating tube 1, an insert 5 is arranged in the form of a special section rail 9. The special section rail 9 comprises an open long side 10 and an opposite long side 11. On its open long side 10, the special section rail 9 includes a longitudinal groove 12. Between the open long side 10 of the special section rail 9 and the wall 3 of heating tube 1, a yarn channel 6 is formed, which forms on its end sides a yarn inlet 7 and a yarn outlet 8. With its long side 11, the special section rail 9 is in direct contact with the wall 3 of heating tube 1. The contact between the special section rail 9 and the wall 3 of heating .tube 1 is realized such that it permits a heat transfer from the wall 3 to the special section rail 9. On its circumference, the heating tube 1 is surrounded by a heating jacket 2. The heating jacket 2 is formed by a heater box 18, which is filled with a heat transfer medium 4. A supply line 19 and a discharge line 20 connect the heater box 18 to an evaporator 21. The discharge line 20 is arranged at a lower end, and the supply line 19 preferably at an upper end of the heater box 18. Consequently, it is preferred to arrange the heater box 18 and the heating tube 1 accommodated therein in an upright or inclined position. As a result, the condensate of the heat transfer medium 4 is removed from the heater box 18 via discharge line 20 and supplied to the evaporator 21. Within the evaporator 21, the heat transfer medium 4 is evaporated and returned to the heater box 18 via supply line 19. The heating jacket 2 that is formed by the vaporous heat transfer medium 4 and the heater box 18 uniformly heats the heating tube 1 on the circumference over the entire length of the wall 3. However, for heating the heating tube 1, the heating jacket 2 could also be formed by electric means. For its thermal treatment, a yarn 13 advances through the yarn channel 6 via yarn inlet 7 and yarn outlet 8. To this end, an inlet yarn guide 16 is associated with the yarn inlet 7 and an outlet yarn guide 17 with yarn outlet 8. The inlet yarn guide 16 and outlet yarn guide 17 are arranged such that the yarn 13 advances through the yarn channel 6 substantially in contact with the longitudinal groove 12 of the special section rail 9. In this process, the yarn channel 6 receives the energy that is necessary for heating the yarn 13, directly from the heating jacket 2 via the wall 3 of heating tube 1. To this end, it is preferred to make the wall 3 of heating tube 1 of a material, that has an excellent thermal conductivity. With that, it becomes possible to supply the energy that is transferred from the heating jacket 3 to the wall 3 directly into the yarn channel 6 without any substantially losses. To avoid an unacceptable contact between the yarn 13 and the wall 3 of heating tube 1, when advancing the yarn 13 in contacting relationship, the special section rail 9 is unilaterally mounted in the heating tube 1. The yarn 13 advances in the longitudinal groove 12 of the special section rail 9. At least on the surface of the longitudinal groove 12, the special section rail 9 has a wear-resistant surface. The transfer of the heat from the wall 3 into the special section rail 9 accomplishes* an additional contact heating of the yarn 13 in the longitudinal groove 12. To obtain a uniform contact of the yarn 13 with the longitudinal groove 12, the longitudinal groove 12 has a curvature extending in the direction of the advancing yarn. Thus, the yarn 13 advances through the yarn channel 6 in a slight bend, which is defined by the curvature of the longitudinal groove 12. In the embodiment of the heating device as illustrated in Figures 1 and 2, it is preferred to mount the special section rail 9 in the heating tube 1 in an easily exchangeable manner. With that, it is made possible to perform in a simple manner a cleaning of the special section rail 9 and in particular a cleaning of the longitudinal groove 12 that has been soiled by yarn deposits, in that the special section rail 9 is pulled out from the heating tube 1 before being cleaned and pushed into the heating tube 1 after having been cleaned. Figures 3 and 4 illustrate a further embodiment of the heating device according to the invention, with Figure 3 being a schematic longitudinally sectioned view of the heating device, and Figure 4 a cross sectional view thereof. Unless express reference is made to one of the Figures, the following description will apply to both Figures. The embodiment is largely identical with the foregoing embodiment of Figures 1 and 2. To this extent, the foregoing description is herewith incorporated by reference and only differences are described. The embodiment of the heating device according to the invention as illustrated in Figures 3 and 4, is especially suited for heating a yarn substantially without contact. To this end, a special section rail 9 is arranged inside the heating tube 1. At its one open long side 10, the special section rail 9 comprises a longitudinal groove 12 that extends over the entire length of heating tube 1. Inside the longitudinal groove 12, a plurality of guide elements 14 are arranged in spaced relationship with one another. The guide elements have very short guide surfaces, along which the yarn 13 advances inside the longitudinal groove 12. The arrangement of the guide elements 14 inside the longitudinal groove 12 may be in one line, or zigzagged, or arcuate. Preferably, the guide elements 14 inside the longitudinal groove 12 of special section rail 9 are made exchangeable or adapted for variable positioning, so that they provide a high flexibility with respect to guiding and heating the yarn. It is preferred to make the guide elements 14 of ceramic materials"or to provide them with ceramic coatings on their surfaces that contact the yarn 13. In comparison with the embodiment of Figures 1 and 2, the heating tube 1 of the present embodiment is constructed in the shape of a rectangular solid. This permits exchanging, positioning, and mounting in a simple manner the special section rail 9 that unilaterally adjoins the wall 3. The heating jacket 2 for heating the heating tube 1 is constructed in accordance with the foregoing embodiment by a heater box 18 and a heat transfer medium 4 filled into the heater box 18. In this arrangement, the thermal energy is largely transferred via the wall 3 of the heating tube 1 directly into the yarn channel 6. Figure 5 is a longitudinally sectioned view of a further embodiment of the heating device according to the invention. The setup of the heating tube 1 and heating jacket 2 is identical with the embodiment shown in Figures 1 and 2. To this extent, the foregoing description is herewith incorporated by reference. In the present embodiment, the special section rail 9 inserted into the heating tube 1 is formed by two partial lengths 15.1 and 15.2. Preferably, the partial lengths 15.1 and 15.2 are interconnected, so that they can be jointly inserted and removed. However, it its also possible to arrange the partial lengths 15.1 and 15.2 in the special section rail 9 for separate insertion and removal from both end sides of the heating tube 1. The partial length 15.1 in the special section rail 9 is made in accordance with the embodiment of Figures 1 and 2, and the partial length 15.2 of the special section rail 9 in accordance with the embodiment of Figures 3 and 4. To this extent, the respective descriptions are herewith incorporated by reference. Along the partial length 15.1, the yarn 13 advances largely in contact with the longitudinal groove 12, whereas along the partial length 15.2, the guide elements 14 guide the yarn 13 in the longitudinal groove 12 substantially in no contact therewith. Thus, two different treatment zones are formed within the heating tube 1, through which the yarn 13 advances successively. In their setup and configuration, the embodiments shown in Figures 1-5 are exemplary. In this connection, a heat* insulation that surrounds the heater box 18 was omitted. In particular, it is possible to use for advancing the yarn in the heating tube any configuration of a special section rail with or without yarn guide elements. In this connection, it is essential is that a yarn channel be formed, which is largely heated directly through the wall of the heating tube. With that, a temperature is reached in the yarn channel, which is defined by the heating jacket. In this process, it is possible to keep transfer losses very low. A further essential advantage is the configuration of the open special section rail in such a way that it is possible to perform a fast and effective cleaning of the surfaces contacted by the yarn after removing the special section rail from the heating tube. It is thus possible to provide both the special section rail and the guide elements thereof with any desired shape and guideway contours. NOMENCLATURE 1 Keating tube 2 Heating jacket 3 Wall 4 Heat transfer medium 5 Insert 6 Yarn channel 7 Yarn inlet 8 Yarn outlet 9 Special section rail 10 Open long side 11 Long side 12 Longitudinal groove 13 Yarn 14 Guide elements 15 Partial lengths 16 Inlet yarn guide 17 Outlet yarn guide 18 Heater box 19 Supply line 20 Discharge line 21 Evaporator CLAIMS 1. Heating device for heating a yarn (13), in particular in a texturing machine, with the device comprising an elongate, thin-walled heating tube (1), which is surrounded by a heating jacket (2), so that a wall (3) of the heating tube (1) can be evenly heated on its circumference from the outside, and an insert (5) fitted into the wall (3) of the heating tube (1), which forms a yarn channel (6) with a yarn inlet (7) and a yarn outlet (8) for guiding the yarn (13), characterized in that the insert (5) is formed by a special section rail (9), which is open toward a long side (10), that the special section rail (9) is fitted with an opposite long, side (11) to the wall (3). of the heating tube (1), and that the yarn channel (6) is formed between the open long side (10) of the special section rail (9) and the wall (3) of the heating tube (1) . 2. Heating device of claim 1, characterized in that the yarn channel (6) is widened by a longitudinal groove (12) along the open long side (10) of the special section rail (9). 3. Heating device of claim 2, characterized in that the longitudinal groove (12) of the special section rail (9) has a curvature that extends in the direction of the advancing yarn. * - 4. Heating device of claim 2 or 3, characterized in that the longitudinal groove (12) of the special section rail (9) is formed by a plurality of partial lengths (15.1, 15.2) that follow each other in the direction of the advancing yarn. 5. Heating device of one of the foregoing claims, characterized in that the special section rail (9) is exchangeable held in the heating tube (1). 6. Heating device of one of claims 1-5, characterized in that the special section rail (9) comprises on its open long , side (10) a plurality of guide elements (14) that are arranged in spaced relationship, and that the guide elements (14) are exchangeable. 7. Heating device of claim 6, characterized in that the arrangement of the guide elements (14) extends only over one of the partial lengths (15.2) of the special section rail (9) . 8. Heating device of one of claims 1-7, characterized in that the heating tube (1) is formed by a straight or a curved tube, with the special section rail (9) having a curvature adapted to the tube.

Documents:

1474-chenp-2005 abstract duplicate.jpg

1474-chenp-2005 abstract duplicate.pdf

1474-chenp-2005 claims duplicate.pdf

1474-chenp-2005 description (comlete) duplicate.pdf

1474-chenp-2005 drawings duplicate.pdf

1474-chenp-2005-abstract.pdf

1474-chenp-2005-claims.pdf

1474-chenp-2005-claims.pdf1

1474-chenp-2005-correspondnece-others.pdf

1474-chenp-2005-correspondnece-po.pdf

1474-chenp-2005-description(complete).pdf

1474-chenp-2005-drawings.pdf

1474-chenp-2005-form 1.pdf

1474-chenp-2005-form 18.pdf

1474-chenp-2005-form 3.pdf

1474-chenp-2005-form 5.pdf

1474-chenp-2005-pct.pdf