Abstract:
The invention relates to a method and device for continuously treating synthetic fibers in a heat exchange chamber, in which the fiber to be treated comes into direct contact with the heat exchange medium. A sealing device, which is subjected to the action of a sealing medium, which is provided at the fiber exit opening and at the fiber entry opening with a supply line for the sealing medium, which is arranged in the proximity of the fiber exit opening or the fiber entry opening. The sealing medium is kept away from the fiber passing through the heat exchange chamber. This is achieved by removing the sealing medium before the heat exchange chamber or also by removing the heat exchange medium together with the sealing medium. A removal line for the sealing medium is arranged in the proximity of the heat exchange chamber. In addition, the heat exchanger is provided in a separable manner so that the fiber can inserted by removing one part.

Description:
DESCRIPTION  
         [0001]    The invention concerns a method and a device for the continuous treatment of synthetic threads in a heat exchange chamber, in which the threads to be so treated come into direct contact with a heat exchange medium. The said heat exchange chamber possesses a thread exit opening and a thread inlet opening and which heat exchange is connected to sealing apparatuses with a sealant having the feed lines placed proximal to the respective thread outlet and inlet.  
           [0002]    Such an apparatus has been disclosed by EP 0 624 208 B1. The heat exchanger can be applied as an apparatus both for heating and cooling. In either case, a fluid, hot or cold, comes into direct contact with the thread. The fluid, in this operation, is to be found in a heat exchange chamber through which the said fluid flows. This heat exchange chamber is, essentially, constructed in tubular shape and possesses a small boring on each of its ends, through one of which the thread is introduced, and after running through said chamber, exits from the other.  
           [0003]    In this type of cooling or heating device, the problem arises of preventing the heating or cooling fluid from penetrating through the thread inlet or outlet. In accord with the state of the technology, i.e. DE-OS 24 30 741, for the solution to this problem, various sealing means are known, such as roller seals, lip type seals, and particularly, labyrinthine sealing, wherein the latter, because of its simple construction is predominately used. For example, such a labyrinthine seal has been made known by EP 760 874 (which corresponds to WO 95/32325). The labyrinthine seal comprises a plurality of choke passages, which are bound together by even smaller openings. The openings are just large enough, so that the thread can be conducted through.  
           [0004]    For the support of the sealing effect, compressed air is employed. Instead of compressed air, steam or superheated steam has been proposed.  
           [0005]    Present experience has indicated, that sealing of the said type is indeed effective, especially in the case of a gaseous medium. On the other hand, however, the sealing medium also intrudes into the heat exchange chamber and combines itself with the heat exchange medium, which is generally a liquid, for example, water, to form a foam. This problem with the foam particularly arises, when a gaseous sealant medium and a liquid heat exchange medium are employed.  
           [0006]    In the case of a horizontal disposition of the heat exchanger, foaming plays a minor role, since the foam forms mostly above the surface of the liquid, to which surface the threads run parallel but through the liquid below. In this way, the heat exchange with the thread by direct contact with the heating medium remains largely undisturbed. In many cases, however, it is necessary, that the heat exchanger (or cooler) be situated not horizontally, but rather vertically or at an optional incline. In these non-horizontal cases, the heat exchanger has a zone in the upper end, which contains only foam. This leads to a situation, wherein the heat exchange effect is substantially impaired and extensively greater treatment stretches become necessary.  
           [0007]    Thus, the purpose of the invention is, to set aside these deficiencies of the state of the technology and to create a sealing of the thread passage openings of the heat exchanger, which does not impair the effectivity of the heat exchanger.  
           [0008]    This purpose is achieved in accord with the method as set forth in claim 1 and in accord with the heat exchanger, as is described in the claims 11, 15 and 17.  
           [0009]    The invention rests upon the recognition, that the effectiveness of the heat exchange can be very much improved, if the sealing medium can be distanced from the thread, which passes completely through the heat exchange chamber. The reason for this is that the sealing medium, for example, air—like all other gaseous media—exerts a strong insulating action. In achieving this separation, the point is, surprisingly, not so much that mainly no sealing medium enters the heat exchange chamber and there mixes with the heat exchange medium, but rather that the sealing medium is to be kept away from the thread, so that only the heat exchange medium can act on the thread whereby stable and predictable relationships for heat exchange are created.  
           [0010]    A fluid sealing system is described by the U.S. Pat. No. 3,783,649, which is stated to hinder the penetration of sealing medium into the heat exchange chamber and to prevent the mixing thereof with the heat exchange medium in said chamber. In the case of this system, the fluid itself takes on the function of a sealing apparatus and forms a fluid seal ahead of the material inlet or outlet of heat exchange chamber. To carry this out, a fluid, for example water, is directed at a high velocity against a passage opening of the heat exchange chamber. Then, by means of the exit velocity of the sealing medium issuing out of a sealing medium reservoir, determination can be made of both the outlet/inlet openings for the sealing fluid, as well as the passage openings for the textile material which are placed respectively before or after the entry or exit openings in the heat exchange chamber. The sealing fluid, to the extent it does not build up a kind of fluid congestion due to the static pressure, is conducted to a so-called overflow chamber with the textile material and is there retained or withdrawn. Ignoring the fact, that for a balance of this kind between the leakage pressure out of the heat exchange chamber and the sealing fluid, i.e. its velocity, a complicated pressure control becomes necessary, and the described fluid sealing system is expensive both as to occupied space as well as in the cost of manufacture.  
           [0011]    The present invention differentiates itself from the state of the technology stated above, principally therein, in that it employs a customary sealing apparatus, for instance a labyrinth sealing, that is subjected to a sealing medium, and it is not the sealing medium itself which forms the sealing device. The invented heat exchanger, both in its construction as well as in its manipulation, is essentially simpler and in the pressure distributions, is completely without problems. Beyond this, the heat exchanger permits a monitored, controlled transfer of heat for thread treatment.  
           [0012]    From DE-OS 2 002 349, a procedure and an apparatus for the sealing of neighboring spaces emerges, whereby a gaseous medium contained in the respective spaces is removed by suction and in the area of a slot, that is, a passage opening, situated at a small angle in reference to the material flow, the said gaseous medium is once again blown back into a corresponding space. This known procedure has shown itself to be non-adaptable in the prevention of foam building, since, with the introduction of a liquid heat exchange medium, an injector action arises, by means of which the unmonitored air is sucked away and mixed with the fluid to foam.  
           [0013]    In this method, the sealing medium, with which the sealing apparatus is supplied, is removed ahead of the heat exchange chamber, which prevents this from entering the heat exchange chamber, and thus the sealing medium cannot come into contact with the thread running through the heat exchange chamber.  
           [0014]    The removal of the heat exchange medium through the thread passage openings has the advantage, that a precise balancing of the sealing and the heat exchange media is not necessary. The heat exchange medium, must, in any case, be withdrawn from the heat exchange chamber to the outside. In principal, the mixing of the heat exchange medium and the sealing medium is displaced to a point outside of the heat exchange chamber, so that the sealing medium is kept distanced from the thread in the heat exchange chamber.  
           [0015]    In the interests of simplicity, the heat exchange medium is withdrawn together with the sealing medium, whereby, subsequently, a separation of heat exchange medium and sealing medium can be carried out.  
           [0016]    Another method of keeping the sealing medium away from the threads running through the heat exchange chamber is carried out in that the sealing medium does enter into the heat exchange chamber and at a certain elevated pressure, the heat exchange medium is prevented from leaving the heat exchange chamber. However, the sealing medium which enters the heat exchange chamber is diverted away from the threads, so that its insulating effect on the heat exchange medium is prevented.  
           [0017]    Another method for the distancing of the sealing medium from the threads which are passing through the heat exchange chamber is carried out in such a manner that the heat exchange medium inside the heat exchange chamber is guided onto the threads, so that the direct effect is increased, and the sealing medium which has migrated into the heat exchange chamber is held away from the thread by the flow.  
           [0018]    If the penetration of the sealing medium and the formation of foam is under control, then, a planned foam space becomes possible, and thereby a shortening of the heat exchange stretch can be made, whereby compliance with various operational conditions, for instance, a change of the thread throughput speed, can be carried out in a simple manner.  
           [0019]    Corresponding to a generally applied way of procedure, the heat exchanger is provided with exit ports for the sealing medium, which ports are placed proximal to the thread passage openings in the heat exchange chamber. The sealing apparatus includes advantageously, a labyrinth sealing train, made up of multiple choking spaces. Because the feed line opening is situated between the thread exit or inlet and opens into the nearest positioned choking space, a safety arrangement for sealing medium loss is provided, while the exit line out of the heat exchange chamber at the next positioned choke space leads outward, so that both the sealing medium as well as the leakage from the heat exchange chamber can be led away at atmospheric pressure. For the diversion of the sealing medium, which has penetrated into heat exchange chamber, within the heat exchange chamber, diversion vanes have been placed, through which the thread can be conducted, but which, however, keep the said penetrating sealing medium away from the thread.  
           [0020]    For the introduction of the heat exchange medium and the improvement of direct contact with the threads passing through the heat exchange chamber, in this chamber, and centrally located with respect to the thread, narrowed passages are provided, whereby the inlet and the outlet of the heat exchange medium are placed, respectively, before and after the group of said narrowed passages. This again allows the heat exchange medium to flow in a direction counter to the travel direction of the thread.  
           [0021]    If the outflow of the sealing medium is made from the choke chamber placed before or after the heat exchange chamber in the heat exchanger, at a suitable distance from the thread passage opening, then, surprisingly, a contacting flow of the sealing medium in the area of the thread passage opening is prevented, wherein the sealing medium from the outflow line in the heat exchange chamber is held so distant from the thread, that any deterioration of the heat exchange is avoided. This formulation of the heat exchanger especially has the advantage, that a controlled foam formation and therewith a monitored, changeable length of the cooling stretch can be achieved in a simple manner.  
           [0022]    An arrangement of the heat exchange chamber, which has shown itself to be especially advantageous for all applications having this said controllable cooling stretch, is that the run of the thread is allowed to intersect the surface of the cooling liquid. This is the case, for instance, where the heat exchange chamber is mounted vertically. 
       
    
    
       [0023]    Further details of the invention are described with reference to the drawings. There is shown in:  
         [0024]    [0024]FIG. 1 the heat exchanger in sectional view, with a schematic presentation of the connection lines,  
         [0025]    [0025]FIG. 2 the basic body of the heat exchanger in accord with FIG. 1 in a perspective view,  
         [0026]    [0026]FIG. 3 another embodiment of the heat exchanger with diversion vanes,  
         [0027]    [0027]FIG. 4 a further embodiment of the heat exchanger with outflow line for the sealing medium, and  
         [0028]    [0028]FIG. 5 yet another embodiment of the heat exchanger with narrowed portions of the heat exchange chamber. 
     
    
       [0029]    The description of the invention will be made on the basis of a heat exchanger, which has been installed as a cooler in a texturizing process for a synthetic thread, wherein the thread to be treated runs through this cooler at a high speed, that is to say, at a speed of over 2,000 m/min velocity. This requires a very large cooling capacity in order to cool down the thread in a short time from some 200° C. to approximately 50° C. As a cooling medium, water is employed, which comes into direct contact with the thread. For the sealing medium in the sealing apparatus  2 , air is used. Obviously, other heat exchange media or sealing media can be used, in accord with the process at hand and the purpose for which the heat exchanger has been installed.  
         [0030]    The heat exchanger is further described on the basis of an application for the treatment of synthetic threads, however, it is obviously suited for the treatment of textiles or films.  
         [0031]    [0031]FIG. 1 shows a heat exchanger designed as a cooler, having a base body  6  and its cover  60 . The heat exchanger is so partitioned, so that upon the removal of the cover  60 , the thread path in the base body  6  is exposed, allowing the thread F to be inserted without hindrance.  
         [0032]    Advantageously, for a vertically aligned heat exchange chamber  1 , a drain port  14  is provided, to make possible the removal of the cooling medium before the opening of the heat exchange chamber  1 .  
         [0033]    The heat exchanger has a heat exchange chamber  1  with a thread entry opening  12  and a thread exit opening  11 . For the prevention of leakage of the cooling liquid, a sealing apparatus  2  is installed respectively before the inlet opening  12  and following the exit opening  11 . For the sake of simplicity, this sealing apparatus  2  comprises a labyrinthine sealing means with choke spaces  23 , through which the thread F is conducted from above to below. The sealing apparatus  2  is supplied with a sealing medium, in this case air, through an inflow line  21 . This feed of the sealing medium is effected between the first two choke spaces  23 , through which the thread F runs upon its entry into the heat exchanger. The sealing medium is withdrawn through an outflow line  22  from the last choke space  23  just before the thread entry  12  of the heat exchange chamber  1 . The cooling medium can also flow to this last choke space  23  before the thread entry  12 , and similarly, to the choke space  23  after the thread exit  11 , up to the point where the said cooling medium is repressed by the sealing medium.  
         [0034]    The heat exchange chamber  1  possesses a feed line  15  for the cooling medium, which flows through the said heat exchange chamber  1 . Above the thread entry opening  12  and under the thread exit opening  11 , the cooling medium is withdrawn from the heat exchange chamber  1  and picked up at both the choke space  23  before the thread entry opening  12  and after the thread exit opening  11 .  
         [0035]    Then, together with the sealing medium, the said cooling medium is led away by means of the outflow line  22  to collect in a reservoir  4 , which also serves as the cooling medium reserve. In this way, no mixing occurs in the heat exchange chamber  1  of the heat exchange medium and the sealing medium, with the result that the heat exchange chamber  1  remains foam free.  
         [0036]    A mixing of the air with the water is carried out only outside of the heat exchange chamber  1 , since the cooling medium and the sealing medium only come in contact with one another in the thread exit opening  11  and the thread entry opening  12 .  
         [0037]    Should, nevertheless, foam build up in the heat exchange chamber  1 , especially at the start of the procedure, then this foam will be removed by means of a deaerating boring  17  when the dearating valve  18  is open. In the case of a horizontal arrangement of the heat exchange chamber  1 , this said dearating boring  17  is placed advantageously in the cover  60 . When the heat exchange chamber  1  is vertical, the level of the surface of the cooling medium can be controlled by this deaeration boring in combination with the said valve  18 , so that a desirable cooling travel stretch is attainable.  
         [0038]    The circulation of the cooling medium is controlled by a pump  41  which in turn is governed by a pressure controller. Likewise the sealing medium is monitored by means of a pressure controller  24  and conducted to the feed lines  21  to the two sealing apparatuses  2 .  
         [0039]    Since the withdrawal of both the cooling medium and sealing medium is done in a choke space  23 , this being a location where the pressure of the two media is reduced, an exact pressure control installation for a balance between the two media is not necessary. The pressure of the cooling medium is at just such a level, that the desired circulation can occur, while the sealing medium is subjected to just enough pressure, that the choke space  23  with the outflow opening  22  is reached. Both media, at this point, are relieved of pressure and flow at atmospheric pressure back into the reservoir  4 . In the reservoir  4 , the cooling medium separates from the air, so that a generation of foam occurs.  
         [0040]    At the same time, in the reservoir a cooling down of the cooling medium can take place, before the cooling medium is once again recirculated into the heat exchange chamber through the feed line  15 .  
         [0041]    [0041]FIG. 2 shows the basic body in a perspective view, which displays both the heat exchange chamber as well as the sealing apparatus  2  along with all connection fittings for the entry lines  21  and the outflow lines  22 ,  14  and  17  as shown in FIG. 1.  
         [0042]    [0042]FIG. 3 shows another mode of construction of the heat exchanger  1 , in which, once again, the thread F travels from top to bottom. The sealing medium, for example, air, is fed in through line  21  to the sealing apparatus  2 , which, in the depicted case, is designed as a labyrinth sealing means and possesses, respectively, four choke spaces  23 , in order to seal off the thread outlet opening  12  of the heat exchange chamber  10 , as well as the thread entry opening  12 . With this design, no outlets for the sealing medium are provided, however, for the cooling medium, which enters the heat exchange chamber  10  through the feed entry  15 , an outflow opening  16  is provided, so that the heat exchange chamber  10  is subjected to the full flow of the cooling medium. The sealing medium is added at such a pressure through the inflow opening  21  of the sealing apparatus  2 , that an outward flow of the cooling medium through the thread passage openings ( 11 ,  12 ) of the heat exchange chamber  10  is prevented. Especially, at the thread exit opening  11 , in a case of predominately vertical alignment, bubbles of the sealing medium in the liquid cooling medium rise to the top, in such a manner that the result would be an undesirable formation of foam within the heat exchange chamber  10 . Beyond this, the rising air bubbles, which have an insulating effect, disturb the heat exchange between the thread F and the cooling medium. On this account, a V-shaped diversion vane  13  is placed directly before the thread exit opening  11  (as seen in the direction of the thread travel), so that the rising air bubbles are diverted to the side and in this way are held distant from the thread F. The V-shaped diversion vane  13  possesses, however, a narrow passage for the thread F at its apex, so that the air bubbles cannot rise at that point.  
         [0043]    Because the travel direction of the thread F is counter to the motion of the air bubbles, these also cannot be entrained by the moving thread F.  
         [0044]    In the case of a reversed running direction of the thread F, the air bubbles would be stripped away from the thread F by the diversion vane plates and again directed to the side. The rising air bubbles and probably the foam buildup is removed together with the cooling medium by means of the outflow line  16 .  
         [0045]    In a like manner, as in the case of FIG. 1, a treatment of the mixture of cooling medium and sealing medium is carried out for the separation of the air and the water, the cooling of the air free water, and its recirculation into the system. By means of a deaerating opening  17 , the sealing medium can be removed, a controlled level of the cooling medium obtained and therewith a variable cooling stretch produced.  
         [0046]    [0046]FIG. 4 shows another embodiment of the object of the invention. Also, in this case both sealing apparatuses  2  are supplied with sealing medium by the inflow line  21 , wherein the sealing medium consists, advantageously, of air. The cooling medium is fed in through its inlet line  15  and again removed from the heat exchange chamber  10  by means of the outflow line  16 . In order to prevent, that at the bottom thread entry opening  12 , the sealing medium can be entrained with the thread into the heat exchange chamber  10 , whereby the rising bubbles would exert their insulating effect on the thread F, the sealing means is conducted into the heat exchange chamber  10  through outflow lines  25  and  25 ′ branching from the choke space  23  immediately before the thread entry opening  12 . However, the said branching lines  25 ,  25 ′ are separated by a given space from the thread inlet opening  12 , so that the bubbles are held at a distance from the thread F and rise laterally against the walls of the heat exchange chamber  10 . An advantage of this design is that an essentially improved cooling capacity is achieved.  
         [0047]    [0047]FIG. 5 shows a further embodiment form of the heat exchanger in accord with the invention. The thread travel in this case is from bottom to top, although it could also be constructed to be in the reverse direction with no difficulty. The sealing apparatuses  2  are, likewise, as described above, provided with inflow lines  21  for the sealing medium and provided with air as the sealing medium. It is possible that outflow lines for the sealing medium  22  in accord with FIG. 1, or alternately, bypass lines such as  25 ,  25 ′ in accord with FIG. 4 could be furnished.  
         [0048]    Even a diversion vane  13 , as depicted in the design shown in FIG. 3 can be considered and employed. The special feature of this design is to be found therein, in that the heat exchange chamber  100  is subdivided by restrictive passages  19  into chambers  100 ′,  100 ′″ and  100 ″″, whereby the feed of the cooling medium is made through the feed line  15  and the removal of the same through outflow line  16 , so that the combined heat exchange chamber  100  has a cooling flow counter to the direction of travel of the thread F.  
         [0049]    The possibility exists, that the thread, because of the distribution of twist of the texturizing process, forms a bulb and transmits the turning to the cooling means. The cooling means, by centrifugal force, is forced into the wall areas of the heat exchange chamber  100 , while the rising bubbles remain in the center in proximity to the thread F, whereupon this thread F comes into contact with said rising air bubbles of the sealing medium. In order to defeat this, narrowed passages  19  are provided, so that the thread F is held centered in the middle of the heat exchange chamber  100 . The narrowed passages act further, in that the flowing of the cooling medium at these points is reinforced, so that here the rising air is again held distant from the thread F by means of the acceleration of the cooling medium. This design has also demonstrated, that the cooling action can be substantially improved.  
         [0050]    By means of the distancing of the sealing medium from the thread running through the heat exchange chamber, a substantial improvement in cooling is obtained. This is up to 40% more effective. Beyond this, the cooler requires less water and less air. It is possible that because of the improved cooling capacity, essentially shorter cooling lengths can be realized, particularly in the non-horizontal installations. This obvious increase of the efficiency of the heat exchanger is based on an air free, at least bubble poor, water flow within the heat exchange chamber. The thread no longer comes into contact with the bubbles of the sealing medium, so that, during the throughput of the thread in the heat exchange chamber, the thread remains in constant contact with the heat exchange medium. The leakage of the cooling medium is simultaneously made use of for the closing of the said heat exchange chamber against inward migrating sealing medium. Common to all described embodiments is that they hold the sealing medium away from the thread F during its transit through the heat exchange chamber. This is done, either by the fact that the sealing medium does not enter into the chamber at all, or because the sealing medium within the chamber, is diverted away from the thread. The described embodiments can, as already mentioned above, be used as themselves, although using one or more combinations among them gives advantageous possibilities.  
         [0051]    The possibility, which lies also in the framework of the invention, exists, that by means of appropriate pressure regulation of the sealing medium and/or the heat exchange medium, a foam buildup space can be made, so that the actual and especially effective cooling stretch can be made shorter. Thus, for example, in a simple way the cooling can be made effective at reduced through-flow velocities. For this purpose the chamber subdivisions as seen in FIG. 5 can be used, although only two chambers alone are effective by the cooling medium, while the third chamber contains foam or air, which is not at all effective for the cooling. In this case, it is advantageous to install cooling medium feed lines  15 ″ and  15 ′ also in the chambers  100 ″ and  100 ′, in order that optionally, one, two or all three chambers might be selected for cooling medium throughflow.  
         [0052]    In the case of the described embodiment, the basic concept is held, that the sealing medium, through the feed lines  21 , subjects the sealing apparatus  2  to elevated pressure. Experience, however, has shown good results may be achieved by bringing a suction arrangement onto the outflow lines  22 , so that the sealing apparatus  2  is under suction. Heat exchange medium, migrating out of the thread passage openings  11  and  12 , would be, by this suction, immediately removed and guided back into the cooling medium circulation system. The feed lines  21  could then be omitted, whereby the suction action in the choke space  23 , would be increased in regard to the leakage.  
         [0053]    Namely, at the thread exit opening  11 , where the thread F leaves the heat exchange chamber and is saturated with cooling medium, by means of the inflow of sealing medium, this being air, on the sealing apparatus, a quick drying of cooling medium from the said thread F will occur, no matter whether at elevated or suction pressure.  
         [0054]    Reference numbers and Corresponding Parts  
         [0055]    F Thread  
         [0056]    [0056] 1 ,  10 ,  100  Heat exchange chamber  
         [0057]    [0057] 100 ′,  100 ″,  100 ′″ Partial heat exchange chambers  
         [0058]    [0058] 11  Thread exit opening  
         [0059]    [0059] 12  Thread entry opening  
         [0060]    [0060] 13  Diversion vane  
         [0061]    [0061] 14  Outlet opening (of heat exchange chamber)  
         [0062]    [0062] 15 ,  15 ′,  15 ″ Feed line for heat exchange medium  
         [0063]    [0063] 16  Outflow line for heat exchange medium  
         [0064]    [0064] 17  Deaeration boring  
         [0065]    [0065] 18  Deaeration valve  
         [0066]    [0066] 19  Narrowing (between partial heat exchange chambers)  
         [0067]    [0067] 2  Sealing apparatus  
         [0068]    [0068] 21  Inflow line (for cooling/heating medium)  
         [0069]    [0069] 22  Outflow line (for sealing medium)  
         [0070]    [0070] 23  Choke space  
         [0071]    [0071] 24  Pressure controller (for sealing medium)  
         [0072]    [0072] 25 ,  25 ′ Outflow lines (by-passes for sealing medium—see FIG. 4)  
         [0073]    [0073] 4  Reservoir (Temp. adjustment, air separation, recirculation)  
         [0074]    [0074] 41  Pump, for heat exchange medium  
         [0075]    [0075] 42  Pressure regulator for heat exchange medium  
         [0076]    [0076] 6  Basic body  
         [0077]    [0077] 60  C v r to basic body  
       Claimed is: