EP3548819A2 - Textile fiber drying - Google Patents

Abstract

The invention relates to a technique for drying wet or damp fibres, in particular after a production process. A fibre mat (13) consisting of wet or damp fibres is formed on a treatment band (31) which is moved in a conveying direction (x) by a fibre dryer. An air flow (36, 36a) composed of heated drying air is generated in the fibre dryer (30), the heated drying air is guided in an upward direction through the treatment band (31) and the fibres contained in the fibre mat (13, 14) are loosened and dried. Linters (16) possibly produced by any moving fibres are captured by a filter band (32) arranged above the treatment band (31), which is also moved in the conveying direction (x). At the outlet of the fibre dryer (30), the fibres are detached from a support (17) formed on the filter band (32), in particular when guiding the detached fibres back towards the dried fibres guided to the treatment band (31, 31c). The drying technique comprises a method and a fibre-treatment system.

Description

 Textile fiber drying

DESCRIPTION

The invention relates to a drying technique for wet or wet textile fibers. The present disclosure is particularly directed to a fiber treatment plant for

 Drying wet or wet viscose fibers directed.

Viscose fibers place particular demands on a drying process because, on the one hand, they tend to densify and adhere to one another when wet and, on the other hand, they tend to fly in a semi-dry or dry state.

In the context of the present disclosure, the term "drying of fibers" is understood to mean the drying of fibers which are substantially random or arranged freely in a mixture with a liquid.

Due to the lack of a macro-structure, there are no or only minimal bonds between the individual fibers. In particular, these may be textile fibers which are dried following a production or washing process.

The fiber drying technique discussed in the present disclosure is thus to be distinguished from drying techniques for flores, nonwovens, fabrics and similar textiles. Previously known fiber drying plants, for example according to DE 1 729 264 A, use a heated air stream for drying the fibers, which is directed from top to bottom by a quantity of the fibers. Such a

Airflow keeps the fibers to be dried safely on an air-permeable surface, so that fiber fly in

Essentially avoided or limited. However, the downward flow of air leads to different

Disadvantages. On the one hand, the moist fibers are due to the relative pressure above the fibers to the

 Pad compressed and thus compressed. The compression reduces the drying time

usable effective surface of the fibers, so that the drying performance is deteriorated. In the previously known dryers is optionally. Between separate

 Drying operations made a fiber opening, including special devices are necessary. On the other hand, by the downwardly directed air flow and the

Compression reduces the air permeability of the fibers to be dried, so especially close to the

 Underlay layers are only hesitantly dried. It can also lead to inhomogeneous distributions of zones with high and low air permeability, which is also detrimental to the drying result. There are also fiber drying plants are known in which the fibers are trapped during the drying process between a lower conveyor belt and a shroud. The fibers are between the bands

compressed and thus can not sufficiently

be loosened up. The fibers are thereby not optimally dried. From EP 208 71 59 Bl a blowing device is known which generates a directed from bottom to top air flow to at least partially solidified

Remove fiber product from a belt. Due to the at least partial solidification no fiber fly occurs.

From WO 2016/008 968 A2 a Thermobondierofen is known in which a directed from bottom to top air flow passes through a pile, the at least proportionately

contains thermoplastic fibers. The fibers in the pile have a macrostructure which is the fibers

at least partially binds and prevents fiber fly.

By the at least local melting of the

thermoplastic fibers are created further binding sites between the fibers.

It is an object of the present invention to provide a

improved technology for drying wet or damp fibers, in particular for drying

Viscose fibers show. The invention solves this problem by the features of the independent claims.

The present disclosure includes a

 Drying process for drying wet or wet textile fibers, in particular for drying

Viscose fibers. The drying process is also for

Drying of fibers, which in a solvent spinning process or in a wet-spinning process

are made. Such fibers are usually after washed the spinning process to the solvent or other unwanted chemical substances from the fibers too

remove. After washing, a significant amount of water or a washing liquid remains in and / or between the fibers. It is also possible to dry fibers which are present as wet or damp fibers after a bleaching or dyeing process and any subsequent washing, according to the present drying process. The drying method according to the present invention preferably comprises the following steps. There will be a fiber mat made of wet or damp fibers on one

air permeable process band formed. The process belt is movable in a conveying direction by a fiber dryer, which is encapsulated to the outside substantially airtight and preferably a recirculation system for

Provision of a drying air includes.

In the fiber dryer, an air flow is generated from a heated drying air. The air flow is in the ascending direction by a flat

 Passage drying section of the process belt passed and the fibers contained in the fiber mat are loosened by the drying air or the air flow and dried. Due to the upward air flow is a

Compression of the fibers on the process belt avoided because there is a relative negative pressure over the fibers. Thus, the effective surface area of the fibers available for drying is not reduced and it does not interfere with the drying efficiency of the fibers. Rather, an advantageous way

Increasing the effective surface can be achieved, wherein the volume density of the fiber mat is reduced. In other words, the mass to be dried expands under the influence of the air flow, so that the

Air permeability is increased and an internal adhesion between the fibers is reduced.

By the upward air flow fiber fly can be generated, i. Single fibers or small ones

 Fiber flakes can be released from the mass to be dried and taken upwards according to the orientation of the air flow. In the drying method according to the present disclosure, it is provided that the fiber-moved fibers in the air flow through a filter belt arranged above the process belt

be caught, this filter belt is also moved in the conveying direction. Below the

Filter belt there is a relative overpressure, so that the fibers moved by fiber flight majority adhere to the filter belt and form a Auflagerung there.

In the drying process is therefore aware of

Improving the drying efficiency of a fiber fly allowed. The proportion of fibers released by fiber fly from the mass to be dried (in particular a fiber mat) can have a small to considerable extent. By collecting the filter belt a preferably continuous recycling of the released fibers to the dried fiber mat is possible, so no or only a negligible loss of material

entry .

Preferably, the deposit formed from the fibers at the exit of the fiber dryer from the filter belt

especially when the detached fibers are returned to the dried fibers lying on the process belt. The recycling can be done in any way

done, preferably by a Abstreifgebläse that blows the detached fibers in a process band directed to the return channel.

By the aforementioned method, a particularly high drying efficiency can be achieved. In particular, the length of the drying section can be shortened by up to 50% compared to comparable systems with downwardly directed air flow. The movement of both the process band and the filter band becomes a

continuous drying process allows. The

Filter belt and the process belt can each as

be provided circulating belts. They are preferably guided within the fiber dryer in such a manner and encapsulated in relation to the environment that essentially all fibers which are released by fiber fly from the fiber mat are collected via the filter belt, to the outlet of the fiber mat

Fasertrockners are moved and recycled there to the remaining fibers in the fiber mat.

The term recirculation system is in the present

To understand revelation as a system comprising a drying air in a substantially circular circulation through the fibers to be dried and a Heat source moves. This air circulation can in the

Course of drying in different places

additional fresh air supplied and / or used air to be removed. The recirculation system comprises at least blowers or other air conveying devices, which as

Recirculation fans act and generate the air circulation. In addition, it may include one or more additional blowers or other air delivery devices that act as fresh air supply fans or as forced air extraction fans. The recirculation system may generate a plurality of circuits for a plurality of belt sections, in particular each at least one circuit for a drying section, wherein these multiple circuits can be interconnected in a manner that drying air can be fed from one circuit to the next. Such transfer of drying air between the circuits is preferably carried out in a controlled or regulated manner.

The present disclosure further includes a

Fiber treatment plant for drying wet or wet textile fiber. The fiber treatment plant comprises at least one fiber dryer, which is designed to be substantially airtight to the outside. The fiber dryer may also be referred to as a continuous drying oven. The fiber dryer has the above explained

air-permeable process belt in one

Conveying direction is movable by the fiber dryer. The conveying direction is preferably horizontal from one

Inlet region of the fiber dryer oriented to a discharge area. The fiber dryer further comprises a filter belt on, which is arranged above the process belt and movable in the conveying direction.

Between a drying zone section of the process belt and the filter belt, a (middle) chamber is formed, in which the fiber flight can occur. The chamber is preferably to the top and bottom through the

Process band and the filter band limited. The filter belt is preferably spaced from the process belt in the vertical direction, wherein the distance is greater than the largest expected thickness of the dried fiber material. The filter belt is guided without contact over the fiber material to be dried. The distance between the process belt and the filter belt, the fiber mat can be loosened during the drying process and expand freely in the vertical direction. A

 Compression of the fibers between the process belt and the filter belt is avoided due to the spacing. For the remaining sides, the (middle) chamber is preferably substantially airtight encapsulated by (inner or outer) walls of the fiber dryer.

The fiber dryer according to the present disclosure includes a circulating air system configured to form an air flow from a heated drying air. The air flow is formed in such a way that it flows through the middle chamber in the ascending direction and a fiber mat which can be deposited on the process belt, so that the fibers in the fiber mat are loosened up and dried. Further advantageous embodiments of the invention are in the dependent claims, the following

Description of the drawing and the attached figures.

The invention is illustrated by way of example and schematically in the drawings. Show it:

Figure 1: A fiber treatment plant according to the present disclosure in cross section;

Figure 2: an oblique view of

 Fiber treatment plant of Figure 1;

Figure 3: a longitudinal section through the

 Fiber treatment plant according to FIG. 1 in the area of the fiber dryer.

FIG. 1 shows a fiber treatment plant (10) with a fiber mat generator (20) and a fiber dryer (30). A conveying direction (x) extends in Figure 1 from left to right through the fiber treatment plant (10).

In the area of a wet fiber intake (11) of the

Fiber treatment plant (10) wet or moist fibers are fed in any initial form,

For example, as bulk material that can be filled in the receptacle of the fiber mat generator (20). The fiber mat generator (20) shown in Figure 1 represents an exemplary embodiment in the manner of a hopper feeder. Alternatively, any other fiber mat generator (20) may be provided, for example in the form of a feed tray or a

RüttelschachtSpeisers. Again alternatively, the fiber treatment plant (10) without a

Fiber mat generator (20) may be formed, for example. When the wet or damp fibers from an upstream Work equipment already as fiber mat or

Fiber strand can be fed.

The fiber mat generator (20) according to FIG. 1 has at the bottom of the receiving trough (21) a movable lower belt (22) which is movable in the conveying direction (x) in order to supply the supplied wet fibers to a riser belt (23).

supply. The riser (23) can have any suitable design, which may depend in particular on the type of material, the degree of wetness or moisture and the length of the fibers to be dried. For wet or wet viscose fibers may be preferred

Slat band to be used with a Nadelbesatz.

By the riser (23), the wet or damp fibers are transported to an elevated position and already fundamentally formed into a mat shape with a more or less uniform cross-section. From the elevated position, the fibers become one

 Compression shaft or vibrating shaft (24) promoted. The compression or vibrating chute (24) may have at least one wall that is reciprocated for repetitive widening or narrowing of the bay width. At the lower end of the compression or Rüttelschachts (24) preferably output rollers (25) may be arranged, which deduct the formed in the shaft fiber strand or or the fiber mat and on a guided underneath

Put the conveyor belt down. In the example of FIG. 1, the conveyor belt is already a feed section (31a) of the process belt (31) of the fiber dryer (30). Alternatively, a separate conveyor belt may be provided, which the Fiber mat leads to the inlet region of the fiber dryer (30).

In the following, it is simplified to assume that the mass of fibers to be dried, which is deposited on the processing belt (31), has the shape of a fiber mat. This represents the preferred shape of the mass to be dried. The fiber mat can be particularly preferably on

Inlet area have a substantially constant width and height. The width may be, for example, in the range of 1 to 4 meters. The height of the fiber mat can beispielswese be 10 to 100 mm and of the

Depending on the degree of wetness and the type of fibers to be dried.

The term "fiber mat" will hereinafter be representative of any form of application of the

drying mass understood the fibers and one

 Liquid, including a form of application in one or more fiber strands etc.

The process belt (31) is preferably arranged on the fiber drier (30) as a circulating belt whose upper run is conveyed in the conveying direction (x) from the inlet region of the fiber drier (30) through the drying zone to the exit region. A lower run of the process band (31) is in the opposite direction to the

Inlet area returned. Insofar as features of the process belt (31) or the interaction of other components with the process belt (31) are described below, the upper run of the process belt (31) is generally meant. The wet or wet fibers are in the entrance or inlet area of the fiber dryer (30) as

Fiber mat (13) applied to the process belt (31). In the wet or damp state, the fiber mat (13) has a relatively high volume density (compressed

Arrangement of the fibers) and a high basis weight

(Weight of the fibers plus the weight of the

Liquid).

When passing through the fiber dryer (30) in the

The conveying direction (x) is successively moisture removed from the fiber mat (13), wherein the fibers as a result of the upward air flow and the

Drying process be loosened. Accordingly, within the fiber dryer (30) from the wet fiber mat (13) gradually a semi-dry and expanded (expanded) fiber mat (14) having a significantly lower volume density and a substantially reduced basis weight, since the weight of the mass to be dried due the removal of the

Liquid / moisture is gradually reduced to the weight of the fibers. The thickness or height of

Fiber mat (13, 14) can when passing through the

Fasertrockners (30) increase significantly, which usually increases the air permeability of the fiber mat (13, 14). The individual fibers or fiber flakes contained in the fiber mat (13, 14) thus move away from one another more and more, so that ever larger areas of the fiber surface can come into direct contact with the drying air. The drying process is preferably regulated in such a way that a dry fiber mat (15) is present at the outlet of the fiber dryer (30). The dry fiber mat (15) can be transferred in the area of a dry fiber delivery (12) to a subsequent process, for example a packaging process or a carding process.

Within the fiber dryer (30) an air flow (36, 36a) is formed, which is characterized by a pressure difference between a lower chamber (33) extending below the drying zone section (31b) of the process belt (31) and an upper chamber (35). is generated, which extends above the filter belt (32). Of the

Pressure difference is preferably generated by a circulating air system, which on the one hand warms up the drying air and on the other hand, the drying air in an at least partially circulating stream within the im

Essentially airtight fiber dryer (30) circulated. By circulating the drying air can be repeatedly brought into contact with the mass to be dried, whereby it gradually absorbs moisture.

The drying zone section (31b) is a portion of the (upper run of) the process belt (31) located within the substantially hermetically sealed region of the process belt

Fiber dryer (30) is located. The term "airtight" is in the context of the present disclosure so too

understand that the fiber dryer (30) forms a closed housing, in whose walls only at the openings that are required for the entry or removal of the bands (31,32) and the fibers, as well as on the air ducts of the recirculation system on and withdrawals the drying air are allowed. All other areas of the walls are preferably hermetically sealed. The walls of the fiber dryer (30) are still

preferably provided with a thermal insulation to limit heat loss to the outside.

The air flow (36a) within the middle chamber (34) is preferably equalized or controlled in the expression by at least one nozzle arrangement (37, 38) on the processing belt (31) and / or on the filter belt (32). The nozzle arrangement (37) below the process band (31, 31b) is formed in the example of Figure 1 by alternately obliquely arranged baffles, which are connected to each other at their lower ends airtight. At the upper ends of the air baffles passage openings for the drying air with a predetermined and preferably adjustable opening cross-section are provided. These

Opening cross sections form the nozzles through which the drying air from the lower chamber (33) to the middle chamber (34) can flow. The nozzles are preferably distributed flat below the drying zone section (31b). In particular, several in the

Be provided conveying direction (x) successively arranged nozzle rows or slot-shaped nozzles. Of the

Opening cross section of the nozzle assembly (37) is preferably significantly smaller than the cross-sectional area of the lower chamber (33). The lower chamber acts as a result

Buffer in which a substantially uniform pressure can form. As far as within the

Nozzle section (37) Nozzles with same

Opening cross-section are provided, at these nozzles a substantially equal volume flow admitted, which flows through the on the process band (31, 31b) arranged fiber mat (13, 14).

The opening cross-sections of the nozzles can be selected to be the same or different along the conveying direction (x) and possibly transversely thereto. In particular, the opening cross-sections can be locally adjustable to the

Expression of the air flow (36a) along the

Conveying direction (x) to influence, in particular to regulate. The aforementioned nozzle arrangement (37) can simultaneously serve as a support arrangement for the process belt. Alternatively, a separate support arrangement may be provided, on which the process belt (31) along the conveying direction (x) can be placed and supported mechanically supported. In the example of FIG. 1, a further nozzle arrangement (38) is provided above the filter belt (32), which can have substantially the same design as the previously described nozzle arrangement (37) below the process belt. Alternatively, another shape of a nozzle assembly and / or a support assembly on the

Filter band (32) may be provided. Also at the

Nozzle assembly (38) on or above the filter belt (32) (the lower run of the filter belt (32)) may be a

Adjustability and in particular local adaptability of the opening cross-section of the nozzle to be provided.

The fiber dryer (30) may preferably have two or more drying sections (or "sections" for short) (A, B, C, D), through which the process belt (31, 31b) or the Fiber mat (13, 14) is successively movable. Within the sections (AD), a drying air (36) having a different degree of humidity (F) and / or different temperature (T) is preferably produced. Furthermore, the air flow (36a) can be preset separately within a section (AD), in particular with a higher or lower volume flow. The parameters of the drying air (humidity (F), temperature (T),

Volume flow) may be preferred in the course of

Conveying direction (x) controlled depending on the material to be dried and in particular regulated.

In the upper part of Figure 1 are an example

Course of the temperature (T) and a course of

Moisture (F) of the drying air along the

Conveying direction (x) shown. The drying air (36) is generated such that the degree of humidity (F) decreases in the conveying direction (x). This can happen in particular by the fact that at least a part of the

Drying air from a back in the conveying direction (x) rear section (C, D) against the conveying direction (x) to a further forward section (A, B) out and used there again for drying. In particular, a guidance of the drying air from the outlet region of the fiber dryer (30) may be provided to the inlet region (main guide path), i. in the opposite direction to the conveying direction (x) of the material to be dried. In addition, you can

Inflows of fresh air and / or outflows of domestic air to be provided, which overlap with the run in the counter part of the drying air (secondary conveying paths). The temperature (T) of the drying air (36) according to the example in Figure 1 in the conveying direction (x) initially a rising course and the output towards a falling course. This temperature profile represents a preferred embodiment. At the inlet of the

Fiber dryer (= end of the main conveyor of the

Drying air), the drying air is preferably only moderately heated, because they are relatively short

Distance as service air with maximum

Moisture content leaves the fiber dryer (30) and unnecessary heat loss should be avoided. The evaporation occurring during the drying leads to a cooling of the drying air.

It is advantageous even in the outlet area of the

Fiber dryer (30) the drying air (36) in

to heat to a reduced degree or to regulate the temperature of the drying air to a relatively low level. At the outlet area (= beginning of the main conveying path of the drying air) of the fiber dryer (30), only a small amount of moisture is present in the material to be dried. Therefore, in the

Drying air contained heat mostly lead to a heating of the fibers and not (only) to an evaporation. The lower the humidity of the fibers, the more sensitive the fibers can be to overheating. Also, the application of excessively heated fibers would be an unnecessary heat loss.

In the middle region of the fiber dryer (30), however, only semi-dry fibers are present, which show a relatively lower sensitivity to overheating and a a significant proportion of the heat in the drying air will lead to heating and evaporation of the liquid or moisture stored in the fiber mat.

Accordingly, in the central region, a significantly greater heating of the drying air (36) take place or are there significantly higher temperatures (T) of

Drying air allowed.

The proportion of a fiber flight (16) may increase in the course of the conveying direction (x) or with increasing degree of drying of the fiber mat (14). This is illustrated in Figure 1 by the number or density of the dashes, the

Fiber fly (16) represent. Furthermore, the effective surface area of the fibers available for drying in the material to be dried may be reduced due to

Aufiockerns along the conveying direction (x) increase

 (Expansion of the fiber mat). It may therefore be advantageous to vary the volume flow of the air flow (36a) generated in the middle chamber (34) along the conveying direction (x), in particular towards the outlet towards

to reduce. This can be done in different ways

happen. On the one hand, within each of the sections (A-D) a different pressure difference between the lower chamber (33) and the upper chamber (35) can be generated, in particular to set a base level of the air flow (36a). For this purpose, in particular several or preferably all sections (A-D) can have at least one separate recirculation fan (43).

Alternatively or additionally, a section (A-D) may have a separate air outlet (45) on which

in particular a device for throttling or Regulation of the air outlet flow can be provided. Again alternatively or additionally, one or each section (AD) may have a separate fresh air inlet

(44). The pressure level generated in the upper chamber (35) and the lower chamber (33) is respectively related to the volume flows of the drying air along the main conveying direction and

Volume flows of fresh air into the fiber dryer

(30) or a section and the hot air from the

Fiber dryer (30) or a section.

In the example of Figure 2 are various

Equipment of the sections (A-D) shown according to a preferred embodiment. Here, each of the sections (A-D) has a separately controllable

Recirculation fan (43) located in a side wall of the

Fiber dryer (30) is arranged. The first and second sections in the conveying direction (A and B) each have an air outlet (45). The following sections (C and D) each have an air inlet or

Fresh air intake (44).

Figure 3 shows an example of a cross section through the section (C) of the fiber dryer (30) of Figure 2. The circulating air fan (43) is shown here in the upper right. It serves to suck in the upper chamber (35) located air and at least down as

 Return flow (36 b) in a return channel (48) to pass. The return channel (48) may preferably laterally adjacent to the arrangement of the process band (31), the

Filter bands (32) and the intermediate middle chamber (34) extending therebetween. It ends at the upper side preferably in a blow-out region of the recirculation fan (43) and in a lower region in a transition to the lower chamber (33). The cross-sectional area of the transition is preferably significantly greater than that

Cross sectional area of the nozzles in the nozzle portion (37).

By the recirculation fan (43) and the return flow (36b) in the lower chamber (33) is a relative

Overpressure generated. By controlling or regulating the delivery rate of the circulating air fan (43), the

Pressure difference between the upper chamber (35) and the lower chamber (33) influenced and, if necessary. Be set to a desired pressure difference. Furthermore, the pressure in the upper chamber (35) can be influenced by a regulation of the air flow, which by the

Fresh air inlet (44) is supplied, for example by actuation of a throttle valve.

At least a portion of the air blown off by the circulating air fan (43) can be substantially counter to

Conveying direction (x) to an adjacent section (B) and / or an air outlet (45) are passed.

In particular, at a blow-out of the

Recirculation fan (43) a connecting channel (not shown) may be connected, which opens into an upper or lower chamber (33, 35) in an adjacent section (B).

Those skilled in the art will recognize that by controlling the performance of the individual circulating air fans (43) and throttling the various air flows

(Fresh air inlet, passenger flow to adjacent Section, exhaust air flow), the pressure in each section (AD) and controlled there in both the upper chamber (35) and the lower chamber (33) and preferably can be controlled to a desired pressure. One or more pressure sensors can be arranged in the respective chambers (33, 35) in order to detect an actual pressure and supply it to a pressure control.

The expression of the air flow (36 a) can be controlled by the specification of the respective pressures in the lower chamber (33) and / or the upper chamber (35) and

be regulated in particular. In addition, an influence by the adaptation of the

 Flow cross sections in the region of the nozzle sections (37, 38) possible, in particular in order to change a local expression of the air flow (36a) within a section (A, B, C, D) and preferably along the conveying direction (x) relative to the base level through the

Pressure difference between the lower chamber (33) and the upper chamber (35) is predetermined. A heating of the drying air (36) can take place at any point inside or outside the fiber dryer (30). The heating is preferred by an internal heat exchanger (39), in particular a

Steam heat exchanger reached. Alternatively or additionally, any other heating device may be provided.

In the example of Figures 1 and 3, the heat exchanger (39) is arranged in the upper chamber (35). He could alternatively in the lower chamber (33) or in the Return channel (48) may be arranged. The arrangement in the upper chamber (35) has the advantage that also a proportion of the fresh air inlet (44) supplied to the

Drying air directly after entering the

Fiber dryer (30) through the heat exchanger (39) or along the heat exchanger (39) along and heated.

The support formed by fiber fly on the filter belt (32) can be detached from the filter belt (32) in any desired manner and at any desired location. Figure 1 shows a preferred embodiment for the detachment of the Auflagerung. There is provided (at least) a scraper blower (40) which is adapted to

Overlift of the filter belt by a downward airflow. Such

 Scraper blower (40), as shown in Figure 1, preferably at the exit, i. be arranged in the conveying direction (x) behind the last section (D) of the fiber dryer (30). It may be of any type, such as an air knife.

Furthermore, a return chute (41) can be provided, through which fibers, which are detached from the filter belt (32), are returned to the dried fiber mat (15). Such a return shaft (41) can

in particular so corresponding to one

 Abstreifgebläse (40) may be arranged so that the air flow generated by the Abstreifgebläse (40) blows the detached fibers in the return shaft (41). Of the

Return duct (41) preferably extends between the filter belt (32) and the process belt (31) and especially in the vertical direction. The vertical one

Extension of the return shaft (41) can with the

Extension of a middle chamber (34) are aligned.

As an alternative to the example of Figure 1, a

Abstreifgebläse and a return shaft (41) also

be provided within the fiber dryer (30).

In particular, one or more of the sections (A-D) may have their own return duct (41) and possibly a separate stripping fan (40) which

especially in the area of the outlet of the respective

Section (A-D) can be arranged.

The dry fiber mat (15) may be dispensed or removed in any manner in the dry fiber delivery area (12). In the example of FIG. 1, a deflection for the processing belt (31) is provided, through which the process belt (31) is guided at least partially in a path running counter to the conveying direction (x). The deflection is preferably designed to separate the dried fiber mat (15) from the process belt (31, 31c), in particular by dropping the fiber mat. In the example of Figure 1, two baffles are arranged obliquely below the deflection. The upper baffle is brought close to the recycled process belt (31) so that the dry fiber mat (15) descending from the discharge section (31c) of the process belt (31) touches the upper one

Guide plate can slide.

It may happen that residual fibers after the discharge or in the direction of movement of the (circulating guided)

Process bands (31) remain behind the deflection on the process belt (31). Preference is given to such residual fibers of the process band (31) dissolved and fed to the remaining fibers in the dry fiber mat (15). This can be done in any way.

In the example of Figure 1 is an additional

Abstreifgebläse (42) provided next to the deflection, which is adapted to detach the residual fibers of the process belt (31). The additional scraper blower (42) generates a substantially in the conveying direction (x) oriented air flow, which is directed (in an area behind the deflection or after the discharge of the dry fiber mat) through the air-permeable process belt (31). Preferably, the air flow of the additional Abstreifgebläses the residual fibers in a region between the baffles, so that they are guided in the direction of guided on the upper baffle dry fiber mat. Alternatively, the Abstreifgebläse the

Blow off residual fibers in another direction,

for example, down, where, for example, a drip pan or an additional discharge belt can be arranged.

The fiber treatment plant (10) can be different

Sensors and controls have to the

To influence or regulate the drying process.

Particularly preferred is a regulation of the degree of drying of the fibers in the material to be dried provided (adaptation of a determined actual moisture to a desired humidity). For this purpose, at least at the output of the fiber dryer (30) means for detecting the

Moisture in the fiber mat (15) may be provided. The conveying movement of the process band (31) and / or the Properties of the airflow (36a) may be preferred depending on the detected humidity

to be controlled. In addition, one or more other means may be provided for detecting moisture in the fiber mat located at the inlet area or within the fiber dryer (30). The control of the conveying movement of the process belt (31) and / or the properties of the air flow (36a) can accordingly be determined in dependence on

Moisture differences occur. In particular, a moisture detection means may be arranged at an inlet to at least one section (A, B, C, D), and the properties of the air flow (36a) (temperature, humidity and dry air flow) in at least this section may be determined according to a difference between Desired humidity and the moisture detected at the inlet are regulated. The desired moisture may for example be a moisture in the fiber mat (14), which at the outlet of the respective

Section (A-D) or at the inlet of a next section to be achieved.

Modifications of the invention are possible in various ways. In particular, the to the

Embodiments described, shown,

claimed or disclosed in any other way

 Characteristics combined in any way with each other, replaced or omitted.

At the fiber treatment plant (10) can take various measures to avoid an undesirable

Be made Faseraustrags or pollution entry. The inlet area and the outlet area of the

Fiber dryer (30) may preferably have an additional housing (46), in particular the sliver

(32) and as large as possible parts of the process band (31) covered. It can be one or more

 Be present cleaning devices that the

Filter belt (32) before entering the first section

(A) of the fiber dryer (30) and / or the process belt (31) before the application of the wet fiber mat (13) of

Free residual fibers or dirt.

Instead of the four sections (A-D) provided in the figures, any other number of drying sections may be provided.

The coming into contact with the fibers and the drying air components of the fiber treatment plant (10) are preferably resistant to corrosion and designed to be solvent resistant depending on the nature of the material to be dried. The filter belt (32) may preferably be made of stainless

Be made of stainless steel tape, in particular a perforated tape, a woven tape or a mesh tape. When drying viscose fibers, a process belt (31) made of PPS has proven to be advantageous.

Instead of a fiber mat, one or more

Fiber strands on the process belt (31) may be formed. The length of a fiber to be dried may be, for example, in the range of 5 mm to several centimeters. For viscose fibers, a fiber length of 10 to 50 mm may be advantageous for the drying. Within the middle chamber (34) may optionally be a Ausgleichsbedüsung be provided by a directed from top to bottom counter-air flow on the to be dried

Fiber mat is directed. The expression of the counter-air flow is preferably far less than the expression of the upward-directed air flow (36a). Due to the Ausgleichsbedüsung the formation of

Fiber fly can be reduced. The equalizing spray can be achieved by any means, such as by extending the width of the process belt

extending and opposite the process band upwardly spaced tube having arranged on its underside nozzle openings and with an air flow

is charged.

The feed section (31a), the drying zone section (31b) and the output section (31c) of the process belt (31) shown in the figures may be formed by a single processing belt (31) or alternatively by separate belts between which the fiber mat is transferred. However, all the aforementioned are preferred

Functional sections Parts of a single process band

(31) extending through the entire fiber dryer (30) as a circulating belt.

The drive of the process band (31) and the filter band

(32) can be done in any way. According to the

For example, in FIGS. 1 and 2, a belt drive (47) is provided on the respective last deflection pulley of the process belt (31) or the filter belt (32) in the conveying direction (x). This form of drive ensures that the belt drive (47) tightens the upper run of the process belt (31) or the lower run the filter belt (32) in the fiber-guiding areas (within the at least one middle chamber)

supported. Unwanted sagging of the bands (31, 32) is thus counteracted. At an inlet region of the process band and / or the sliver to a middle chamber and on a

Outlet region of the process band and / or the sliver out of a central chamber locks may be provided to a passing air flow

tangential to the respective band. Such locks can, for example, by elastic

be formed adjacent films. Optionally, a (local) fiber adhesion to the respective belt and / or to the lock can be influenced, in particular increased, by electrostatic fields.

The term "air" (drying air, fresh air,

For the purposes of the present disclosure, it is to be understood as "gaseous desiccant." It can preferably be breathing air from the atmosphere, which may possibly be supplemented with additional gases or vapors a gas composition.

The drying air may be added to one or more additives which react within the fiber dryer with the fibers to be dried, for example. In order to impregnate or coat them. LIST OF REFERENCE NUMBERS

Faserbehandlungsanläge

 Nassfaseraufnähme

 Trockenfaserabgäbe

 wet or damp fiber mat

 semi-dry expanded fiber mat

 dry fiber mat

 fluff

 Filterauflagerung

 Fiber mat producer

 Aufnähmewanne

 low band

 Slat band / riser

 Feed shaft / Rüttelschacht

 Ausgäbewalzen

 fiber dryer

 process tape

a feeding section

b drying zone section

c output section

d return section

 filter belt

 Lower chamber

 Middle chamber

 Upper chamber

 Air flow / drying air

a Rising flow through chambers

b return flow

 Nozzle and / or support arrangement on the process belt

Nozzle and / or support arrangement on the filter belt 39 heat exchanger / steam heat exchanger

40 scraper blower / air knife

 41 return shaft

 42 scraper blower / air knife

43 Blower / circulating fan

 44 fresh air intake

 45 air outlet

 46 enclosure

 47 belt drive

 48 return channel

x drying path / conveying direction

A first drying section

 B Second drying section

 C Third drying section

 D Fourth drying section

 F Moisture of the drying air

T temperature of the drying air

Claims

Drying process for drying wet or wet fibers, comprising the following steps: Forming a fiber mat (13) of wet or wet fibers on a process belt (31) which is moved in a conveying direction (x) by an outwardly substantially airtight fiber dryer; In the fiber dryer (30) generating a  Air flow (36, 36 a) from a heated drying air, wherein the air flow (36, 36 a) in the ascending direction through a flat drying zone section (31 b) of the process belt (31) and the fibers contained in the fiber mat (13, 14)  loosens and dries; Collecting fibers moved by fiber flight (16) in the air flow (36a) through a filter belt (32) arranged above the process belt (31), which is also moved in the conveying direction (x). Drying method according to claim 1, wherein a support (17) made of fibers formed on the filter belt (32) is removed at the exit of the fiber dryer (30), in particular by returning the detached fibers to those on the process belt (31, 31c). dried fibers. Drying method according to claim 1 or 2, wherein the air flow (36, 36a) through a Pressure difference between a lower chamber (33) extending below the drying zone portion (31b) of the process belt (31) and an upper chamber (35) is formed, which extends above the filter belt (32). A drying method according to any one of claims 1, 2 or 3, wherein between the drying zone section (31b) of the process belt (31) and the filter belt (32), a central chamber (34) is formed and wherein an air flow (36a) within the central chamber (34) through at least one nozzle arrangement (37, 38) on the process belt (31) and / or on the filter belt (32) is evened out. Drying method according to one of the preceding claims, wherein the fiber mat (13, 14) is moved successively through two or more sections (A, B, C, D) of the fiber dryer (30), in which a Drying air (36) with different Moisture level (F) and / or different temperature (T) is present. Drying method according to one of the preceding claims, wherein a moisture degree (F) of the drying air (36) decreasing in the conveying direction (x) is produced. 7.) drying method according to one of the preceding Claims, wherein in the conveying direction (x) initially an increasing course and the output towards a falling course of the temperature of the drying air (36) is generated. Drying method according to one of the preceding claims, wherein the method by a  Fiber treatment plant is carried out according to one of the following claims. A fiber treatment plant for drying wet or wet textile fibers, comprising an outwardly substantially airtight fiber dryer (30) comprising: an air-permeable process belt (31) in a conveying direction (x) through the Fiber dryer (30) is movable; a filter belt (32) located above the  Process bands (31) arranged and in the Conveying direction (x) is movable; a middle chamber (34) formed between a drying zone section (31b) of the process belt (31) and the filter belt (32); a circulating air system adapted to form an air flow (36) from a heated drying air, which in  ascending direction, the middle chamber (34) and one on the process belt (31) be deposited Fiber mat (13, 14) flows through, so that the fibers in the fiber mat (13, 14) loosened and dried. Fiber treatment plant after the previous one Claim, wherein the fiber dryer (30) a Cleaning device for the filter belt (32). A fiber treatment plant according to any preceding claim, wherein the fiber dryer (30) comprises A scraper blower (40) adapted to remove a deposit from the filter belt (32) formed from fibers moved by the air flow (36). A fiber treatment plant according to one of the preceding claims, wherein the fiber dryer (30) has a  Return chute (41) through which fibers, which are detached from the filter belt (32), are traceable to the dried fiber mat (15). Fiber treatment plant according to one of the preceding claims, wherein the return shaft (41) in the The conveying direction (x) behind a (last) middle chamber (34) and between the filter belt (32) and the process belt (31) is arranged. 14.) fiber treatment plant according to one of the preceding claims, wherein below the  Drying zone portion (31b) of the process band (31) at least one lower chamber (33) and above the filter belt (32) at least one upper chamber (35) is formed, between which by the  Recirculation system, a pressure difference can be generated. 15) fiber treatment plant according to one of the preceding claims, wherein below the processing belt (31, 31 b) a nozzle arrangement (37) is formed, through which an air flow (36 a) from the lower chamber (33) to the central chamber (34) is made uniform. 16) fiber treatment plant according to one of the preceding claims, wherein at or above the filter belt (32) has a nozzle assembly (38) is formed, through which an air flow (36 a) from the middle chamber (34) to the upper chamber (35) is made uniform. 17) fiber treatment plant according to one of the preceding claims, wherein the fiber dryer (30) has two or more drying sections (A, B, C, D), each with its own chambers (33, 34, 35), between which an air flow (36 a ) is formed. 18) fiber treatment plant according to one of the preceding claims, wherein the recirculation system comprises two or more circulating air fans (43), in particular at least one separate circulating air fan (43) for each drying section (A, B, C, D). 19.) fiber treatment plant according to one of the preceding Claims, wherein the circulating air system is adapted to at least a part of the drying air  against the conveying direction (x) of a rear drying section (D, C) to a further forward drying section (B, A) to promote. 20.) fiber treatment plant according to one of the preceding Claims, wherein at least at the output of  Fiber dryer (30) is provided a means for detecting the moisture in the fiber mat (15), and wherein in particular the conveying movement of the  Process bands (31) and / or the properties of the air flow (36a) as a function of  detected moisture are controlled. 21.) fiber treatment plant according to one of the preceding claims, wherein the fiber dryer (30) in the region of a dry fiber output (12) has a deflection for the process belt (31) which is adapted to the dried fiber mat (15) of the Separate process strip (31, 31c), in particular drop. 22) fiber treatment plant according to one of the preceding claims, wherein the fiber dryer (30) in the region of a dry fiber output (12) comprises a Abstreifgebläse (42), which is adapted to a separation of the dry fiber mat (15) of the  Process belt (31) remaining fibers of the  Replacing process band (31), in particular under  Feeding to the dispensed dry fiber mat (15). 23.) fiber treatment plant according to one of the preceding claims, wherein the fiber treatment plant a the fiber dryer (30) upstream  Fiber mat generator (20). 24) fiber treatment plant according to one of the preceding claims, wherein the fiber mat generator (20) as Feed shaft, Rüttelschacht or designed as a hopper feeder.