CN1928168A

CN1928168A - Process and apparatus for the meltspinning of filament yarns

Info

Publication number: CN1928168A
Application number: CNA2006101281826A
Authority: CN
Inventors: A·维尔茨
Original assignee: Maschinenfabrik Rieter AG
Current assignee: Maschinenfabrik Rieter AG
Priority date: 2005-09-07
Filing date: 2006-09-06
Publication date: 2007-03-14
Also published as: WO2007028269A1; ATE510050T1; KR20070028257A; DE102005042634A1; EP1762644A1; EP1762644B1

Abstract

The invention relates to a cooling system for cooling spun synthetic filament threads. Said cooling system comprises a cooling chamber which comprises a blow shaft and a drop shaft. A fresh air flow is guided into the blow shaft and an exhaust air flow exits the drop shaft. Said cooling system also comprises means which influence the air flows in such a manner that the filament yarn has a constant temperature on the outlet of the cooling system and the air flow flows according to a speed profile which is predetermined when it flows through the drop shaft.

Description

Produce the technology and the equipment of filament yarn with melt spinning

The present invention relates to a kind of production filament yarn, particularly linear density, thick (＞500dtex) synthetic yarn is as being used for woollen blanket yarn, technology and industry (T﹠amp; I) melt-spinning technology of the continuously thick long filament (BCF) of yarn and tire line.The present invention also makes improvements corresponding production equipment and device.

Prior art

The technology of producing filament yarn with melt spinning is generally shown " synthetic fiber " book (Carl Hanser Verlag, Munich) (below abbreviate " Fourn é " as) 273-455 page or leaf referring to Franz Fourn é.Naming system is seen the 720-722 page or leaf.The visible periodical Chemiefasern/Textilindustrie of aid illustration, paper among the April 1978 " cooling of molten spinning gauze " (German) 315-323 page or leaf and Chemiefasern/Textilindustrie, the paper among the June 1987 " quenching stack " (German) 542-550 page or leaf.

Shock chamber and yarn down-comer thereof (yarn fall tube) (being also referred to as down-comer or decline path (fall shaft) or spinning shaft (spin shaft) or yarn path (yarn shaft)) constitute important one group of device-Fourn é, 348-368 page or leaf in molten spinning Silk Mill.These devices describe in detail below in conjunction with Fig. 1.The cooling air under spray silk mould in the horizontal quenching cooling zone with factory that long filament contacts in, can use the present invention-especially, 348 pages referring to Fourn é.This preferred version comprises a rectangle crossflow shock chamber-referring to Fourn é, 352 pages.This class scheme proposes sending into this quenching stack through regulating air.The cost of this step is very high.Therefore importantly, contemplated cooling effect does not descend because of uncontrollable air-flow in the factory.

The disclosed a kind of shock chamber of DE-A-4104404 has a gas permeable wall and opposite to the air-locked wall of cooling air except that outlet opening up and down.

At least one lateral wall of the disclosed spinning shaft of DE-A-19514866 is parallel with cooling air flow, and pore is arranged on it.These pores are connected with a suction system.

The disclosed a kind of cooling system of EP-B-1173634 is particularly including following parts:

Top ,-path cross section is rectangle, and the width between the two side, path is constant, and its degree of depth is tapered to exit axis between the front and rear wall of path;

Cross section is rectangle in-the path, and its degree of depth is tapered to exit axis, and its width can be can be not tapered yet; And

The bottom, path that-cross section is rectangle extends in the side that logs off, and

Near-air is moved on to exit point from the middle part, path.

The disclosed a kind of spinning of DE-A-10323532 path is ventilative, thereby forms a free stream cross section on path circumference and whole length thereof, makes the quenching air-flow of sweeping along from shock chamber can radially flow out the spinning path and air pressure does not rise.

These known layouts are to handling each yarn respectively.In DE-A-1173634 even in a path, be arranged side by side many yarns.Insertion backplate or dividing plate guarantee that each endless tow circumstances before being bonded together is identical between each endless tow.But when the thicker multifilament of spinning property density, usually without dividing plate.

An object of the present invention is to realize the enough little air-flow of the eddy current of no adverse current consistent with some gas pressure distribution, make the formation of yarn not influenced by the very big of these factors by control air flow path in whole shock chamber/down-comer system.

This purpose is realized by

claim

1,16,20 and 22 feature.

Description of drawings

Below in conjunction with each embodiment of description of drawings, in the accompanying drawing:

Figure 1A is the schematic diagram of known molten spinning Silk Mill;

Figure 1B is this factory's side view;

Fig. 2 is the schematic diagram of known shock chamber/down-comer system;

Fig. 3 illustrates the known correction that Fig. 1 is arranged;

Fig. 4 A and 4B are respectively the front view and the side view of first embodiment of the invention;

Fig. 5 A and 5B are respectively the front view and the side view of second embodiment of the invention;

Fig. 6 A and 6B are respectively the front view and the side view of third embodiment of the invention;

Fig. 7 A and 7B are respectively the front view and the side view of fourth embodiment of the invention;

Fig. 8 is an airflow state key diagram in the down-comer;

Fig. 9 illustrates Fig. 2 and/or 3 corrections of arranging;

Figure 10 illustrates the correction that Fig. 4 is arranged; And

Figure 11 illustrates the correction that Fig. 9 is arranged.

The specific embodiment

Figure 1A and 1B are the schematic diagram of the described tire line spinning-wire drawing-up-coiler (282 pages) of Fourn é.Sign flag and parts thereof are as follows:

The spinning beam (not shown) of a-band template

The c-Spinning pumps

D-Spinning pumps drive unit

F-spinning extruder

The i-shock chamber

The k-down-comer

N2-high speed winding head (rotation up-coiler)

R-is with the system for drawing of high hot-drawn roll dies

W-biphenyl evaporimeter and biphenyl pipeline

The air feed of y-through regulating.

Endless tow is generally and merges together behind about 0.3-1m under the down-comer end and form a bonded yarn passing down-comer.The horizontal about 30-100mm of spaced apart between each yarn.Yarn that the linear density of making a living is bigger such as BCF and technology yarn and tire line add a large amount of air and cool off institute's extruding filament.This occur in shock chamber (I, Fig. 1) in.(K Fig. 1) flows into " ground floor " to air through down-comer from the spinning layer with long filament.Air rate depend mainly on cool off quality, output (kg/h).Other parameters that influence air rate are institute's spinning polymer, long filament linear density and spinning speed.

Show speed of production especially than can improve a lot in the past in the technological progress that obtains aspect the BCF manufacturing process.This has also improved the volume and the output of BCF machine greatly, thereby also must improve cooling-air flow rate greatly.Under this background, can see that traditional decline path (down-comer) is not suitable for not giving the long filament that passes through to bring negative effect ground to transmit a large amount of air in the decline path.Long filament mainly is subjected to the unstable influence as adverse current, flow separation, eddy current and air-flow distortion of air-flow.This causes the long filament dyskinesia, the contact that under extreme case, causes long filament in quenching stack, not allow, thus can cause long filament directly or afterwards to rupture in the processing procedure.

Above saying can give theoretical explanation in conjunction with Fig. 8 especially.The entrance width of the down-comer that cross section is rectangle is H.When exit width also was H, most external (the most left and the rightest) long filament L constantly increased on downward direction from the distance of two side S, thereby generated adverse current R easily near the sidewall S.Whether generate adverse current R and be decided by operation conditions such as endless tow rate of withdraw and/or institute's quantity.Under some predetermined air flow situations, available guiding wall W prevents this class adverse current.Using this class guiding wall W why possible, is to form a yarn because endless tow (not shown among Fig. 8) converges under down-comer.Therefore the entrance width among the system for drawing r (Fig. 1) is than narrow from the exit width of spray silk mould (not shown).Each guiding wall W ideal situation be structure make-from the front look-according to and entrance width H and narrower exit width h between (gently) curve of best streamline.These optimums only just are implemented for one group of predetermined operation condition or running parameter, but down-comer must be applicable to various running parameters.There are various down-comer mentalities of designing to make down-comer can be used for various working spaces neatly now.

Fig. 2 illustrates Fig. 1 shock chamber/down-comer system once more.As described in Fourn é, the cross section of the current shock chamber 10 (Fig. 2) that is used for crossflow quenching cooling is rectangle usually.Directly be illustrated in the door that can enter when opening in the shock chamber is housed on the antetheca among Fig. 2 usually.Normal " porous " (the breathing freely) of these gate opens is to keep air pressure or air balance between shock chamber 10 inside and outside.Ventilative so that the cooling air flow of the postbrachium of can not see among Fig. 2 is gone into cooling space under the spray silk mould (not shown among Fig. 2, referring to Fourn é, 348 or 352 pages).

The base of shock chamber 10 is connected with down-comer 12, and the cross section at the top 14 of down-comer 12 is constant, and its bottom 16 is cone.This cone is made of

taper converging sidewalls

18,20, and rear wall and antetheca are arranged in the plane of almost parallel (vertical).All walls of down-comer are not ventilative so that the air-flow in the down-comer is not subjected to the adverse effect of outer gas stream to air-flow in principle.In fact can't avoid unwanted air-flow to flow in this structure from aperture.Surrounding air also can be from flowing between shock chamber 10 and the down-comer 12.

Yarn

22,24 advances to system for drawing with straight line (looking from the front) downwards from spray silk mould, and (r is Fig. 1) on the first yarn guiding device (not shown) of import department.As mentioned above, they are subjected to the cooling of the quench air of lateral flow in shock chamber 10.The

endless tow

22,24 of advancing downwards in down-comer 12 is respectively swept along a large amount of air-referring to Fourn é from shock chamber 10,184-193 page or leaf, particularly 191 pages.Because down-comer bottom 16 is tapered, so its cross section at place, bottom ratio at the little 5-10 of top end doubly.Therefore under current condition of work usually, air velocity improves greatly to down-comer 12 bottoms, can be higher than yarn speed in some cases.Air-flow causes the shakiness of advancing of very strong turbulent flow and yarn at a high speed." bent angle " of 14 junctions, top that upper conical bottom 16 of wall and cross section are constant can cause being easy to generate the boundary layer separation of turbulent flow (referring to " TechnischeStromungslehre, Volume 1:Fundamentals " 9 ^ThEdition, SpringerVerlag 1988, by Bruno Eck is from 127 pages).The cross section track is not preferably widened on downward direction, because the risk of boundary layer separation is much higher under than situation about narrowing down at cross section under the situation that cross section is widened.Down-comer 12 bottoms are located to assemble the air-flow cause at a high speed also to (r, the spinning of Fig. 1) carrying out in import department arrangement has adverse effect at system for drawing to small part by cross section.

Be evenly distributed on big zone upward (center line of each endless tow only is shown Fig. 2) from each long filament of a

spray yarn

22,24 that the mould (not shown) sprays.These

endless tow

22,24 dullnesses narrow down, and merge together in down-comer 12 bottoms to form a spun yarn.Therefore air along

endless tow

22,24 internal flows must flow out to the side from the endless tow that narrows down in down-comer 12 bottoms in shock chamber 10 and down-comer 12 tops 14.The speed of this air is approximately equal to the speed of long filament and helps to improve the speed of air in down-comer 12 these parts.

In addition, generate eddy current on 14 sides, down-comer 12 tops.Thereby these eddy current cause air inversion to amplify turbulent flow.In addition, the eddy current instability, in time, position and becoming, along with

yarn

22,24 is advanced downwards.Thereby in top 14, constantly generate new eddy current.This effect causes advance the greatly shakiness of

yarn

22,24 in down-comer 12 equally.The shakiness of advancing can cause long filament to contact with each other.In shock chamber 10 tops long filament still softness be clamminess, therefore can stick together when contacting, thereby cause the problem of advancing or in its last handling process, break end.

Fig. 3 illustrates a kind of improvement that the layout of shock chamber 10 and down-comer 12A is made.Down-comer 12A is tapered on its whole length, makes that

sidewall

26,28 is adjacent to each other on downward direction, and the air-flow cross section shrinks on downward direction.Therefore distance between most external long filament and the

sidewall

26,28 more or less remains unchanged.On the whole length of down-comer 12A, prevent eddy current and adverse current.This of down-comer 12A is arranged in Pathfinder BCF factory and implemented by MaschinenfabrikRieter AG, although down-comer is 2.5m than weak point.This pipe range can't/be not enough to be used for all occasions.

But the cooling air of supply also deflects down because of moving of long filament under the situation of Fig. 3 in the horizontal direction in shock chamber 10.The cooling air is passed down through down-comer 12A with

yarn

22,24 and flows out at a high speed in the down-comer bottom, thereby causes yarn oiling in the import department of spinning machine system for drawing portion.The powerful swabbing effect of the

yarn

22,24 that moves down in addition, also causes under-voltage at least in shock chamber 10 bottoms.Therefore, extraneous air is inhaled into the shock chamber 10 from the unavoidable hole of shock chamber 10.Therefore air rate in this system increases uncontrollably.This time gas is generally without adjusting, thereby can't keep the temperature and humidity of the air in the shock chamber 10 constant.This air that flows in the shock chamber 10 also causes eddy current and destroys the stability that yarn flows.

For the restriction air flows downward, can do the cross section of little down-comer bottom.This causes the raising of air in place, the down-comer bottom rate of outflow again, therefore can't resolve problem.

Make at least one wall ventilative can making greatly on the one partial-length of down-comer improve.The part air that flows downward flows out through the gas permeable wall part.Primary air in the down-comer is roughly consistent with the cross section that successively decreases downwards under this measure.The words that air velocity in the down-comer therefore increases on downward direction also just have increase slightly, although to quicken slightly on downward direction be favourable to air-flow, because the air-flow that quickens slightly as can be known from experience is difficult for the generation eddy current.Side opening in the down-comer can be positioned on a side or a plurality of side on a down-comer part or whole length.Also can make they fully around.But the present invention arranges and the difference of DE-A-10323532 is that the cross section of new down-comer shrinks downwards.

Fig. 4 A and 4B illustrate first embodiment that air is laterally discharged down-comer 12B together, and the shape of down-comer 12B, particularly

sidewall

26 and 28 are compared with down-comer 12A and to be remained unchanged.The rear wall 30 of down-comer 12B (Fig. 4 B) promptly with its on the decline tube wall introduced on the same limit of quenching locular wall in the hole in the shock chamber 10 of handlebar quench air exporting on the bottom 32 of 34 adjacency porose with air or yarn.These holes are designed to horizontal air outlet and make that promptly rear wall 30 is ventilative.The most handy for this reason perforated metal is made the part 32 on the rear wall 30.Also can for example form side opening with a diagrid.No matter which kind of situation, these holes should prevent yarn and flow out up to spinning from down-comer 12B starting.

The summation of the air-flow free area that is generated by these holes and the ratio of the rear wall 30 perforated portion gross areas are determining " porosity " of so-called this wall portion 32.Use the free area of this different structures and these parts promptly to can be controlled in part 32 outflow air capacities.This porosity is determining in this part cross-flow resistance with the gross area of this perforated portion.This resistance should be chosen to make near a little higher than external pressure of air pressure on all sites this wall of down-comer 12B (for example 0.1-3 Pascal, be preferably 0.1-1 Pascal), thereby guarantee that extraneous air does not flow into down-comer 12B, and the degree of successively decreasing and not causing air velocity to be brought up to not allowing of cross section.

The porosity of perforated portion 32 can be 5-50%, is preferably 20-40%, the length overall of perforated wall preferably be not more than down-comer 12B wall length overall 50%.

Fig. 5 and 6 illustrates two embodiment in addition of the structure of down-comer 12C (Fig. 5) or 12D (Fig. 6), and rear wall 30 (Fig. 5) or the 30A (Fig. 6) of two embodiment respectively comprise a porous portion 32.For obtain predetermined best air pressure and speed track on the whole length of down-comer, down-comer 12C can be made of top 36 and bottom 38.

Sidewall

26A, 28A are arranged to them and draw close mutually, draw close mutually with second cone angle in bottom 38 with first cone angle in top 36.Therefore comparable size Fig. 2 of the bent angle between two parts is little, and the risk of separating at these top, position interlayers also just reduces.Bottom 38 comprises the porous portion 32 of rear wall 30, and rear wall 30 and antetheca 40 are each positioned in the vertical plane as before.Down-comer 12C two medial surfaces respectively constitute a monotonous curve as a result, thereby the risk of boundary layer separation reduces.

In Fig. 6 embodiment,

sidewall

26A, 28A remain unchanged than Fig. 5 embodiment.But rear wall 30A and antetheca 40A draw close equally mutually in the bottom 38 of down-comer 12D, make down-comer 12D cross section be in the bottom 38 and further shrink, thereby " dead angle " goes up the danger that adverse current and eddy current take place near further reducing bottom air outlet 34A at outlet 34A.

Arrange and can this control system of each air-flow be further improved by Fig. 7.Down-comer 12F shape is identical with down-comer 12B (Fig. 4), particularly

wall

26,28 is also assembled downwards on the whole length of down-comer 12F, and antetheca and rear wall also are each positioned in the vertical plane.But, Fig. 4 rear wall 30 has only a perforated portion 32, and Fig. 7 embodiment comprises a plurality of perforated portions (three) 42,44,46 (Fig. 7 B) on rear wall 30B, thus the interior airflow state of consistent further raising down-comer 12F of the airflow state in length by each one 42,44,46 and/or porosity and the down-comer 12F.

Be further to improve the adaptability of this system, but the air-flow that overall adjustment goes out from down-comer 12F one effluent or it is divided into inferior air-flow with appropriate device D1, D2, D3.Appropriate device for example comprises deflector D1, D2, D3, ventilation blower V etc.For example in Fig. 7 embodiment, each regulated its flow rate with buffer board D1, D2, D3 after laterally the air-flow that flows out flowed in the closed suction system 50.Air aspirates with a ventilation blower V.Thereby whole device is reduced by the influence of down-comer 12F external pressure fluctuation.For example in a building owing to open the door to close the door and can cause this harmful air pressure fluctuation.This embodiment provides a kind of air pressure among the down-comer 12F and straightforward procedure of speed track the best of making.

The foregoing description makes develops a kind of design or mentality of designing becomes possibility, thereby even the air-flow in the down-comer also influences long filament mobile in down-comer when air rate is higher.This requires air-flow really to stablize and does not produce eddy current.Problem is not only the air-flow optimization, but also must consider the air pressure track in air velocity, whole system and the processing in boundary conditions such as long filament exit, down-comer bottom.

The invention is not restricted to Fig. 4-7 embodiment.Porous (breathing freely) portion is set in the wall construction of common down-comer also can plays effect.Fig. 9 illustrates this situation, and wherein, label 10 is still represented shock chamber, and down-comer comprises top 52 and bottom 54.Air-flow cross section in the top 52 remains unchanged on its whole length and is approximately equal to from the air-flow cross section of shock chamber 10 transition positions.The air-flow cross section of bottom in 54 with successively decrease downwards in conjunction with the described known schemes of Fig. 1 and 2 is identical.Fig. 9 embodiment and known schemes difference are that down-comer portion 54 rear walls are having a porous or ventilative bottom 32 near outlet 34 places.In this embodiment, part 54 can meet the principle of Fig. 5-7.The length L 1 of top 52 on airflow direction preferably is not more than 10% of down-comer length overall.

Airflow state possibility in the down-comer, definite airflow state, the particularly air pressure that is certain to have influence in the shock chamber 10 of saying.Suitable structure is made down-comer can avoid under-voltage or overvoltage harmful in the shock chamber 10 especially.For further improving this benefit, the porosity that reduces actuating doors on shock chamber 10 antethecas is to reduce to minimum to the turnover air capacity on this position.The porosity of the door of known shock chamber 10 be generally 50% promptly door the gross area about 50% stay open for the air flow influent stream.The porosity of actuating doors that is used for the shock chamber 10 of down-comer of the present invention preferably is not more than 20%, is generally 4-8%.The free stream Kongzui is distributed in well on the whole area of actuating doors.

As described in conjunction with Fig. 3, can improve Fig. 9 layout, make the sidewall of down-comer on the whole length of down-comer, assemble as shown in phantom in Figure 9 downwards, ventilative portion 32 keeps by the present invention.This can be near in conjunction with the described ideal state of Fig. 8, and the cone angle by Fig. 4-6 can obtain more valency effect, although cost of manufacture improves.With Figure 10 further improvement is described below.

Figure 10 is shown in broken lines identical with a Fig. 4 embodiment in principle embodiment, and shock chamber 10 is not decorated with hacures among Figure 10.Dotted line represents that the sidewall S of down-comer 12 is upwards stretching into shock chamber 10.Therefore in this embodiment, the part of shock chamber 10 also is to inferior pyramidal, the continuous with it adjacency of down-comer 12 cross section tracks.Therefore the distance between most external long filament and the wall S not only remains unchanged in shock chamber 10 to a certain extent but also in down-comer 12 in this embodiment.Can avoid appearing at usually " the air-flow turning " at wall transition part place between shock chamber 10 and the down-comer 12 in addition.

Down-comer 12 of the present invention is at least 2.5m, is preferably 3-5m from the length that shock chamber 10 brings out mouth 34 on earth.The air velocity located of outlet 34 (bottoms) is 0-7m/sec, be preferably 2-4m/sec.Long filament is generally 12-20m/sec, is preferably 14-16m/sec in the speed at down-comer 12 outlets 34 places.

It is the spinning factory that every down-comer has two yarns that all embodiment shown in the accompanying drawing are used for every position.The present invention also can be used for the two above yarns in every position, 12 yarns in every position for example.The be rectangle reason of cross section of down-comer why that Here it is.When every position endless tow quantity for a long time, in shock chamber and the down-comer next door can be set.But use down-comer respectively in this preferred version, make endless tow pass a down-comer in pairs, a pair of endless tow is near the two side.The maximum possible convergence of two side is by the path representation of most external long filament between bonding.Same thinking is determining the maximum possible convergence of down-comer front and rear wall.Although endless tow is paired in each down-comer of a factory, also can be many to the shared shock chamber of (at least two pairs) endless tow.This layout is seen Figure 11, among Figure 11

label

10,52,54,32 and 34 the expression with Fig. 9 in identical parts.

Even the down-comer that design principle of the present invention provides design can not generate a stable state, non-vortex air-flow simultaneously at air rate yet.But making, the down-comer structure avoids boundary layer separation very effectively.The advantage of one shock chamber/down-comer design is that cross section does not have sudden change on whole length.

The invention is not restricted to any particular job principle.May get in touch between each concrete measure that therefore just proposes in order to illustrate below is described.Further research may show that these theoretical explanations must only change at least in part.

The cooling air of introducing shock chamber has potential energy.Than shock chamber and down-comer space outerpace is overvoltage.The powerful swabbing action of endless tow is transformed into kinetic energy to this potential energy.Therefore air velocity improves, and air pressure descends.Because yarn speed Yin Lasi improves and secondly because the down-comer cross section successively decreases, this effect improves in down-comer.Total effect or even air are in some part of this system, down-comer bottom but be under-voltage than the outside in the shock chamber bottom mostly normally.Therefore unavoidable micro-pore makes the extraneous air inflow mix with the cooling air in the wall construction.This has further increased air capacity in the system and the original regulating effect of partial cancellation cooling air.Thereby these complex interactions are offset by allowing air flow out the minimizing air capacity at least in the part of down-comer then.This can keep air velocity to improve and under-voltage danger is remained in the permissible range.Air pressure in this part must be than the air pressure height in ambient air pressure or this receiving vessel.

The present invention can design a kind of shock chamber/down-comer system, make air-flow supply and remove and can regulate or control.A kind of in this respect favourable down-comer design comprises:

-on one or more parts of down-comer one or more (laterally or around) aspirator and/or

-one down-comer that constitutes by the different two or more parts of cone angle and/or

-one down-comer, wherein, at least one parts is tapered in two planes.

Symbol or label list

A is with the spinning beam of template

The c spinning pump

D spinning pump drive unit

F spinning extruder

The i shock chamber

The k down-comer

N2 high speed winding head (rotation up-coiler)

R is with the system for drawing of high hot-drawn roll dies

W joins stupid evaporimeter and the stupid pipeline of connection

The air feed of y through regulating

10 shock chambers

12 down-comers

12A down-comer (Fig. 3)

12B down-comer (Fig. 4)

12C down-comer (Fig. 5)

12D down-comer (Fig. 6)

12F down-comer (Fig. 7)

The top of 14 down-comers 12, the top

The bottom is assembled in the bottom that 16 down-comers are 12 dozens

18 sidewalls

20 sidewalls

22 yarns

24 yarns

26 down-comer 12A and 12F sidewall

26A down-comer 12C sidewall

28 down-comer 12A and 12F sidewall

28A down-comer 12C sidewall

30 down-comer 12C rear walls

30A down-comer 12D rear wall

30B down-comer 12F rear wall

The bottom of 32 down-comer 12B, 12C, 12D, the porous of

rear wall

30 and 30A (breathing freely) portion

34 air and yarn outlet

(air and yarn) outlet of 34A down-comer 12D

36 down-comer 12C and 12D top

38 down-comer 12C and 12D bottom

40 antethecas

40A down-comer 12D antetheca

Perforation on the 42 rear wall 30B (porous or ventilative) portion

Perforation on the 44 rear wall 30B (porous or ventilative) portion

Perforation on the 46 rear wall 30B (porous or ventilative) portion

50 suction systems

Down-comer top among 52 Fig. 9 and 11

Down-comer bottom among 54 Fig. 9 and 11

The D1 buffer board

The D2 buffer board

The D3 buffer board

The V ventilation blower

The S sidewall

The H entrance width

The long filament of the most close sidewall S of L

The R adverse current

The W guiding wall

The H exit width

The length at L1 top 52 (Fig. 9 and 11)

Claims

1, the down-comer (12) that is a wall construction, this structure constitutes the first air-flow cross section on the end and the second air-flow cross section on the other end, second cross section is characterized in that less than first cross section this cross section does not increase at the length upper edge of down-comer yarn direction of transfer; This wall construction has the ventilative vertically section of at least one airtight vertical section and at least one, and the layout of this ventilative vertically section and size are chosen to make on the other all sites of each wall of this down-comer all slight overpressure.

2,, it is characterized in that this ventilative section (32,42,44,46) is arranged on the wall section that the air-flow cross section narrows down by the described down-comer of claim 1 (12).

By claim 1 or 2 described down-comers (12), it is characterized in that 3, this wall construction has a plurality of airtight vertical section and a plurality of ventilative vertically sections.

4,, it is characterized in that the porosity of each ventilative section (32,42,44,46) is 5-50%, be preferably 20-40% by the described down-comer of above-mentioned arbitrary claim (12).

5, by the described down-comer of above-mentioned arbitrary claim (12), it is characterized in that the length overall of gas permeable wall (32,42,44,46) is not more than 50% of decline tube wall length overall.

6, by the described down-comer of above-mentioned arbitrary claim (12), it is characterized in that the air-flow cross section is a rectangle, this wall construction only on a wall one or more ventilative section (32,42,44,46) are arranged.

By the described down-comer of above-mentioned arbitrary claim (12), it is characterized in that 7, this ventilative section or at least one ventilative section (32,42,44,46) are communicated with an aspirator (51).

8, by the described down-comer of claim 7 (12), it is characterized in that being provided with influences the device of air-flow between this wall section (42,44,46) and the aspirator (V) (D1, D2, D3).

By claim 7 or 8 described down-comers (12), it is characterized in that 9, a plurality of ventilative section (32,42,44,46) and at least two ventilative sections (32,42,44,46) are communicated with this aspirator (50).

By the described down-comer of above-mentioned arbitrary claim (12), it is characterized in that 10, both ends open, this path cross section be dull change on the length in path.

11, by the described down-comer of above-mentioned arbitrary claim (12), it is characterized in that the cross section of down-comer (12) is rectangle, at least two relative walls converge on the whole length of down-comer.

12, by the described down-comer of claim 11 (12), it is characterized in that these wall dullnesses converge.

13, by the described down-comer of claim 11 (12), it is characterized in that these walls have at least two sections, they to converge the angle different.

14, by the described down-comer of above-mentioned arbitrary claim (12), it is characterized in that a shock chamber (10) and the big end adjacency of cross section.

By the described down-comer of claim 14 (12), it is characterized in that 15, on shock chamber (10) and down-comer or decline path (12) transition part, the air-flow cross section does not have non-dull the change.

16, by claim 14 or 15 described down-comers (12), it is characterized in that shock chamber (10) has an actuating doors, its porosity is not more than 20%, is preferably 4-8%.

17, by the described down-comer of claim 16 (12), it is characterized in that the free stream pore size distribution is on the whole area of actuating doors.

18, shock chamber (10) is characterized in that, the porosity of actuating doors is not more than 20%, is preferably 4-8%.

19, by the described shock chamber of claim 18 (10), it is characterized in that the free stream pore size distribution is on the whole area of actuating doors.

20, use the method for melt spinning filament yarn (22,24), long filament solidifies in a blowing duct after being shaped, the cooling air is added on the long filament in the first path section (10), on the endless tow direction of motion, quicken the back by long filament and further pass through another path section (down-comer) (12) with endless tow, air-flow cross section convergent on airflow direction, it is characterized in that, air-flow forms a boundary layer on the wall inner surface of path, and keeps this boundary layer not interrupt on the whole circumference of this another pipeline section (12) or length.

21, by the described method of claim 20, it is characterized in that, at the air-flow on the pipe entire cross section by roughly along the direction of motion guiding of endless tow and on the whole length of this another pipeline section (12), keep this state continuously.

22, use the method for melt spinning filament yarn (22,24), long filament solidifies in a blowing duct after being shaped, the cooling air is added on the long filament in the first path section (10), on the endless tow direction of motion, quicken the back by long filament and further export (34) to the path by another path section (down-comer) (12) with endless tow, the air-flow cross section on airflow direction through at least a portion convergent of this another path section, it is characterized in that, air-flow is in path outlet (34) preceding effusion, and the exit air rate is adjusted near all sites of each wall of down-comer and is slight overpressure.

23, by the described method of claim 22, it is characterized in that not having air to add on the long filament between the first path section and the outlet.

By claim 22 or 23 described methods, it is characterized in that 24, from this path suction air, this air returns as the cooling air at most with a ventilation blower (V).

25, by the described method of arbitrary claim among the claim 22-24, it is characterized in that air is no more than 7m/sec in the speed in exit.