EP0121650B1 - Hank dryer provided with rotating rods - Google Patents

Description

The present invention relates to a dryer of skeins with rotating sticks for textile threads, comprising a drying tunnel, a conveyor moving along said tunnel and serving to support horizontal sticks for hanging skeins, said sticks being animated by a rotational movement around their axis during the passage through the tunnel, the successive sticks rotating in opposite directions.

On known dryers of this type, which are used for example for drying, after dyeing or bleaching skeins, the rotating sticks are removable and are supported at each of their ends by a conveyor. The skeins are threaded onto the sticks removed from the conveyors and the sticks with the skeins are then placed on the conveyors which pass them through the drying tunnel. At the exit of the drying tunnel, the sticks are again removed from the conveyors, with the hanks they support, and the hanks are then removed from the sticks.

These known dryers which have proven themselves for skeins of reduced weight are not suitable for drying heavier skeins as they are used at present. Indeed, the handling of the sticks carrying such heavy skeins would imply excessive efforts on the part of the personnel dealing with loading and unloading. In addition, on these known dryers, hot air is blown only from the outside on the hanks hanging from the sticks. The drying effect thus obtained is not uniform and would be insufficient for heavy hanks.

The present invention relates to a dryer allowing efficient and uniform drying of skeins, even heavy, the loading and unloading of skeins involving only reduced efforts on the part of the staff. The invention also relates to a hank dryer on which the operations of loading and unloading of hanks lend themselves to automation.

In the dryer according to the invention, the rotating sticks are permanently mounted cantilevered on an endless conveyor which supports them, at their mounting end, during the outward journey through the tunnel and during the return journey to the outside the tunnel as well as during the passage from one route to another. The rotating sticks have, at their free end, an idler roller bearing on a raceway during the outward journey and possibly during the return journey. The rotating sticks have, moreover, at their mounting end on the conveyor, a loose roller which is supported on a raceway for balancing the sticks, at least between the point of loading of the hanks on the sticks and the start of the outward journey and between the end of the outward journey and the point of unloading the skeins of the sticks,

Thanks to this cantilever mounting of the rotating sticks, it is possible to thread the skeins onto the sticks, from the free end of the sticks, at the loading point, since this free end is not supported at this point, and to withdraw the skeins in the opposite direction from the sticks, at the point of loading, at the point of unloading, the free ends of the sticks also being not supported at this point. On the other hand, during the passage of the skeins through the tunnel, the suspension sticks loaded by the skeins are supported at their two ends. It is the same optionally when the sticks are returned empty, outside the tunnel, from the unloading station to the loading station. At the loading station and at the unloading station, the balancing track of the sticks takes up the moment resulting from the weight of the skeins on the cantilevered sticks.

The conveyor advantageously comprises two parallel endless chains supported during the outward journey and during the return journey by raceways and during the passage from one path to the other by idler wheels.

Preferably, the conveyor is driven step by step, each step corresponding to the center distance of the rotating sticks. The tunnel has not only air blowing openings in its upper wall and air extraction openings in its lower wall, but also air blowing openings in its two side walls, at corresponding intervals at the centers of the sticks. As a result, air is blown not only from above on and between the hanks hanging on successive sticks, but also inside the hanks, which ensures efficient, rapid and uniform drying of the hanks.

The chain drive device step by step advantageously comprises a double-acting cylinder whose piston rod acts on a ratchet wheel secured to one of the pairs of return wheels.

In view of the rotation in opposite directions of the successive sticks, which reduces the risk of tangling and knotting of the skeins of the successive sticks each stick carries a pinion engaged with one of two racks extending along the outward journey. The pinions of successive sticks are alternately offset along the axis of the sticks. The two racks are also offset along the axis of the sticks and are installed one below and the other above the axes of the sticks, so that the pinions of one stick out of two are engaged with a rack and the pinions of the other sticks in engagement with the other rack.

To improve the tightness of the tunnel at the loading end and at the unloading end, it is advantageous that the bottom wall of the tunnel is here adjustable in height in the manner a lifting table, depending on the length of the skeins.

• la figure 1 est une vue partielle en élévation latérale d'un séchoir conforme l'invention, montrant surtout la zone de chargement et la zone de déchargement ;
• la figure 2 est une coupe transversale verticale suivant II-II la figure 1, prise au niveau du tunnel de séchage ;
• la figure 3 est une coupe partielle selon la figure 2, à plus grande échelle, montrant particulièrement le montage et l'entraînement en rotation des bâtons tournants ;
• la figure 4 est une coupe suivant IV-IV de la fig. 2, montrant la rotation des bâtons et le soufflage de l'air chaud de séchage à l'intérieur des écheveaux pendant l'avancement pas à pas.

Other characteristics and advantages of the invention will appear on reading an illustrative and nonlimiting exemplary embodiment of a hank dryer in accordance with the invention, described below with reference to the accompanying drawings, in which:

• Figure 1 is a partial side elevational view of a dryer according to the invention, showing mainly the loading area and the unloading area;
• Figure 2 is a vertical cross section along II-II Figure 1, taken at the drying tunnel;
• Figure 3 is a partial section according to Figure 2, on a larger scale, showing in particular the mounting and the rotary drive of the rotating sticks;
• Figure 4 is a section along IV-IV of FIG. 2, showing the rotation of the sticks and the blowing of the hot drying air inside the hanks during the step-by-step advancement.

The hanger dryer illustrated in FIG. 1 comprises a horizontal tunnel 1 of which only a very short length is shown and which is preceded by a loading station 2 and followed by an unloading station 3.

Two endless chains 4 with rollers, placed side by side, extend along the tunnel 1, each chain 4 passing on a return wheel 5 with horizontal axis to the loading station 2 and on a chain wheel 6 with axis horizontal at the unloading station 3. The lower strand or forward strand of the chains 4 passes inside the tunnel 1, while the upper strand or return strand of the chains 4 passes over the tunnel 1.

The rollers 7 of each chain 4 roll on a raceway 8 during the outward journey through the tunnel 1 and on a raceway 9 during the return journey above the tunnel 1.

As shown in Figure 2 and especially Figure 3, each link 10 of one of the chains is rigidly connected to the link 10 of the other chain by a spacer 11. To this spacer 11 is fixed at each end, below the chain link 10, a bearing 12 in which a shaft 13 is rotatably mounted. The shaft 13 extends beyond one of the bearings 12 and here carries a set of three rods 14 extending parallel to the tree 13 by being distributed uniformly around the tree 13 at the angles of an equilateral triangle. The rods 14 are held in position between their ends by spacers 15.

The shaft 13 fitted with rods 14 forms a “stick 16 used to receive the skeins to be dried.

Each shaft 13 carries a pinion 17 between the two bearings 12. It is recognized in FIG. 3 that the pinions 17 of the successive shafts 13 are alternately offset along the axis of the shaft 13. The pinion 17 of a shaft 13 on two is engaged with a rack 18 extending over the entire length of the tunnel 1, above the trees 13. The pinions 17 of the other shafts 13 are engaged with a rack 19 extending along the tunnel 1 , below the trees 13.

Each shaft 13 carries, moreover, an idler roller 20 at its end, mounting side, as well as an idler roller 21 at its free end.

The roller 21 is supported on the outward path, inside the tunnel 1, on a raceway 22, the free end of the stick 16 being thus supported during the displacement of the stick 16 loaded by the skeins through the tunnel of drying.

On the empty return path of the sticks outside the tunnel 1, the roller 21 is also supported on a raceway 23.

At loading station 2 and unloading station 3, where the sticks 16 are not supported at their free end to allow the skeins to be placed on the sticks 16 and the skeins to be removed from the sticks 16 by the free end of the sticks, the balancing of the sticks 16 loaded by the skeins is ensured at the mounting end of the sticks 16 by a balancing raceway 24, 25. The balancing raceway 24 at the loading station extends from a point located upstream of the descent point of the chains 4 of the wheels 5 to beyond the beginning of the raceway 22. For its part, the balancing raceway 25 at the unloading station. 3, extends from a point located upstream from the end of the raceway 22 to a point located downstream from the point of ascent of the chains 4 on the wheels 6. The loading point P (fig. 1) is located in the area of path 24 and the unloading point D in the area of path 25. Thus, the end roller 20, on the mounting side of the sticks 16, engages with the raceways 24, 25 and is supported towards the top on these raceways to resume the moment resulting from the weight of the hanks hanging on the sticks 16 while the latter are not supported at their free end.

The advancement of the chains 4 and therefore of the sticks 16 takes place at the unloading station 3 under the action of a double-acting cylinder 26 whose cylinder is articulated on the tunnel 1 and whose piston rod 27 cooperates in the way of a ratchet with a ratchet wheel 28 integral with the two return wheels 6. This mechanism rotates the ratchet wheel 28. step by step in the direction of the arrow 29, so as to move the sticks 16 from the station loading 2 to the unloading station 3 through the tunnel 1.

The tunnel 1 comprises an internal zone 30 forming the tunnel proper through which the skeins to be dried pass, and additional zones surrounding the zone 30, for the preparation and circulation of the treatment air. From the point of view of preparation and circulation of the treatment air, the tunnel 1 is preferably subdivided into several cells, for example several successive drying cells, a cooling and homogenization cell at the exit of the tunnel, and possibly a airlock cell located between the last drying cell and the cooling and homogenization cell, this airlock cell comprising a heat recovery unit, which makes it possible to improve the thermal efficiency of the dryer.

Figure 2 is a cross section of a drying cell. The air is circulated in the cell by a fan 31 which sends the air through a heater 32 into a distribution chamber 33 located above the zone 30. From the chamber 33, part of the hot air is sent through the upper wall 34 perforated in the zone 30 from the top on the hanks hanging from the sticks 16 in order to flow from top to bottom between the hanks hanging on the successive sticks. The other part of the air passes from the chamber 33 downwards, on one side of the zone 30, into a box 35 and from there by a duct 36 passing below the zone 30 to a box 37 located on the opposite side of the zone 30. The two boxes 35 and 37 communicate with the zone 30 respectively by two horizontal rows of superimposed air orifices 38, 39 in the side walls 40, 41 of the zone 30. The air is extracted from the zone 30 by the perforated lower wall 42 to be recycled by the fan 31.

As shown in Figure 4, the blowing holes 39 in the side wall 41 (as well as the blowing holes 39 in the opposite side wall 40) are at horizontal intervals corresponding to the spacing of the sticks 16. This interval and this spacing also corresponds to the pitch of the advancing movement of the sticks 16. Consequently, the sticks 16 stop each time above the holes 39 so that the drying air is blown in through the holes 39 (and the holes 38) substantially horizontally inside the skeins hanging from the sticks 16. This results in a progressive drying of the skeins not only from the outside to the inside by the action of air blown from top to bottom on and between the skeins suspended on the successive sticks 16, but also from the inside to the outside by the air blown inside the skeins through the orifices 39 and 38.

To improve the tightness of the tunnel, at the two ends of the latter, in the lower part, that is to say under the hanks, the lower wall 42 of the inner zone 30 of the tunnel, crossed by the hanks, is replaced or supplemented at the entry end and the exit end of the tunnel, by a wall adjustable in height like a lifting table, as indicated at 43 in FIG. 1. This height adjustment can be done without only mechanically, but also pneumatically, hydraulically or electrically, this adjustment can even be automated for optimal adaptation to the length of the skeins to be treated.

It goes without saying that the embodiment shown and described has been given only by way of illustrative and nonlimiting example of a dryer in accordance with the invention and that numerous modifications and variants are possible within the framework of the invention,

Thus, for example, the stepwise advance system of the sticks can also be done by means other than a jack and a ratchet wheel. It is only important that the pitch of the advance movement corresponds to the distance between the centers of the rotating sticks 16 and the interval between the blowing orifices 38, 39 in the side walls 40, 41 of the interior zone 30 of the drying tunnel.

The mounting of the sticks 16 on the chains 4 or another conveyor can also be modified. It is only important in this regard that the rotating sticks are mounted cantilevered so that one end of the sticks is free at the loading station and the unloading station, to allow the establishment of the skeins on the sticks and removal skeins of sticks by the free end, sticks. This loading and unloading operation can be automated.

Claims (6)

1. Hank dryer textile threads, provided with rotating rods, comprising a drying tunnel and a conveyor moving along the said tunnel and serving to support horizontal hank suspension rods, the said rods being driven in a rotary movement about their axis during the passage through the tunnel, successive rods rotating in the opposite direction, characterized in that the rods (16) are permanently mounted overhung on a conveyor (4) which supports them at their mounting end during the outgoing trip through the tunnel (1), during the return trip outside the tunnel and during the change from one trip to the other, in that the rods (16) have, at their free end, an idler roller (21) which bears on a running track (22, 23) during the outgoing trip and, possibly, during the return trip, and in that the rods (16) have, at their mounting end, an idler roller (20) which bears on a rod-balancing running track (24, 25) at least between the loading point of the hanks on the rods (16) and the start of the outgoing trip and between the end of the outgoing trip and the unloading point of the hanks from the rods (16).

2. Dryer according to Claim 1, characterized in that the conveyor comprises two parallel endless chains (4) supported during the outgoing trip and during the return trip by running tracks (8, 9) and during the change from one trip to the other by guide wheels (5, 6).

3. Dryer according to Claim 1 or 2, characterized in that the conveyor (4) is driven stepwise, each step corresponding to the centre-to-centre distance between the rods (16), and in that the tunnel (30) has lateral air-blowing orifices (38, 39) at intervals corresponding to the centre-to-centre distances between the rods.

4. Dryer according to Claims 2 and 3, characterized in that the device driving the chains (4) stepwise comprises a double-acting jack (26), the piston rod (27) of which acts on a ratchet wheel (28) integral with a pair of guide wheels (6).

5. Dryer according to any one of the preceding claims, characterized in that each rod (16) carries a pinion (17) engaged with one of two racks (18, 19) extending along the length of the outgoing trip, the pinions (17) of the successive rods being alternately offset along the axis of the rods, and the two racks (18, 19) being offset along the axis of the rods and being installed one below the axes of the rods and the other above them, in such a way that the pinions of successive rods are engaged with different racks and thus make the successive rods rotate in opposite directions during the passage of the rods through the tunnel.

6. Dryer according to any one of the preceding claims, characterized in that the inner zone (30) for the passage of the hanks through the tunnel has at the entrance and at the exit a lower wall (43) vertically adjustable in the manner of an elevating platform.

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