RU2813823C2 - Thin film processing device - Google Patents

Abstract

FIELD: film processing.

SUBSTANCE: invention relates to a thin film processing device for processing viscous material. The thin-film processing device contains a technological housing, inclined to the horizontal by a maximum of 20°, with a heated and/or cooled housing shell, which covers the internal space of the housing forming the material processing space, located in the inlet zone of the technological housing; an inlet pipe for introducing the material to be processed into the material processing space, located in the outlet zone of the technological body; an outlet pipe for unloading the processed material from the material processing space, and located in the material processing space and coaxially extending, driven by rotation, a rotor shaft for producing a film of material on the inner surface of the housing shell and for transporting the material towards the discharge zone. The rotor shaft contains a lifting element located directly on the rotor shaft body, designed to generate a lifting force in the direction towards the rotor shaft body during rotation of the rotor shaft.

EFFECT: effective performance.

8 cl, 11 dwg, 1 tbl

Description

The invention relates to a thin film processing device for processing viscous material in accordance with the preamble part of the independent claim.

Thin film processing devices are known from the prior art and are used, for example, in the distillation, concentration, degassing and drying of various materials. In addition, thin film processing devices are also used for mixing as well as for carrying out reactions in which a viscous state is at least temporarily present, in particular, for example, for polymerization reactions. Thin film processing devices operate primarily continuously.

A subgroup of thin-film processing devices are thin-film evaporators. They work on the principle that, by distributing the material on the inner surface of the thermostated housing wall, a high heat flux density can be achieved, resulting in high evaporation rates and high evaporation proportions in a single operation.

To distribute the material in a thin layer, it is possible to provide, in particular, rotors equipped with cleaning elements. Suitable thin-film evaporators, additionally equipped with a material transport device, are known to the specialist under the brand name "Filmtruder".

A thin film evaporator in the form of a thin film evaporator of the "Filmtruder" type is approximately described in document CH 523 087, according to which a coaxially driven rotor is located in a heated and/or cooled processing chamber, which contains a pipe body, along the perimeter of which inclined blades are evenly distributed and extending, among other things, axially near the inner surface of the housing shell or in contact with the inner surface of the wipers. During operation, the material being processed is captured by the rotating wipers and distributed in a thin layer on the inner wall of the housing, while the inclined elements of the blades impart sufficient motion components to the captured material for release.

Document DE 100 59 997 C1 describes the following thin film evaporator. In this case, in the heating chamber there is a shaft equipped with stripper elements for distributing the introduced material along the inner side of the housing, and the shaft contains a main journal secured with the ability to slide in the bearing sleeve.

In addition to thin-film evaporators that are usually vertically oriented during operation, the person skilled in the art is aware of other thin-film evaporators, for example, horizontally oriented thin-film dryers.

A suitable dryer for thin layer drying is described in DE 41 17 630, according to which a correspondingly elongated bladed rotor is located inside the heat exchanger tube, which transports the material to be dried to the surface of the inner perimeter of the heat exchanger tube. To achieve high strength of the bladed rotor during bending, a box-shaped structure around the bladed rotor is proposed, containing ties running in the longitudinal direction of the bladed rotor and mounting flanges, between which the ties are tensioned. To further increase the restoring force when the bladed rotor bends, radial spacer elements are evenly distributed along the length of the bladed rotor between the mounting flanges. In addition, the vane rotor is equipped with a plurality of additional blades, which are pivotally mounted on the vane rotor ties and apply material to the surface of the inner perimeter. The additional blades also help increase the rigidity of the box structure. Of course, they cannot apply any radial forces to the axis of the rotor blades since they are pivotally mounted and thus cannot transmit radial forces. This design introduces additional costs in reactor construction and, depending on the material being processed, impedes the flow of liquid from the final inlet to the final outlet.

WO 93/11396 relates to an evaporator for thermal treatment, in particular for drying sludges, with a heated, approximately horizontally oriented evaporator body in the form of a hollow cylinder, which contains at one end a product inlet and at the other end a product outlet . In the internal space with the loaded product of the evaporator housing, there is a rotor equipped with blades oriented mainly radially and driven from the outside.

In addition, WO 2004/0041420 discloses a thin film processing device in the form of a horizontally arranged mixing device, in which the components to be mixed are distributed in a thin layer over the inner wall of a housing in the form of a hollow cylinder, the components being stitched together by the interaction of rotor blades with the inner wall of the housing in the shape of a hollow cylinder.

GB 952.101 A discloses an evaporator containing a horizontal cylindrical vessel defining an evaporation chamber. The evaporator also contains a stirrer equipped with mixing elements, mounted on an axis element located concentrically to the longitudinal axis of the vessel. The stirrer and its drive device are designed in such a way that when the stirrer rotates, the material being processed is centrifuged towards the wall of the evaporation chamber. In one embodiment, the rotor comprises six radially extending arms that are uniformly distributed in the circumferential direction. The levers are supported by axially extending, strip-shaped mixing elements located adjustably at their ends and turned inward.

The horizontal thin-film processing devices described in the prior art are oriented towards processes in which the material to be processed is introduced in a dry, in particular granular, state. For certain applications, it is necessary to equip the thin-film processing device with a long rotor shaft. So, for example, devices made for adding cellulose to a solution and making it from it, for example, the so-called. fibers of the "lyocell" technology, contains only in the process zone relatively long rotor shafts with a length of the order of 10 to 15 m. This is due to the fact that water is first evaporated from the cellulose suspension introduced into the device, after which, in order to achieve the required quality of the solution, it is necessary to homogenize the evaporated thus a suspension. Such Luocell technology-oriented devices are usually built – as in the case of thin layer dryers – with a vertical arrangement in order to achieve the additional component of transport due to gravity and, ultimately, also a good cleaning of the treatment surface of the device. Of course, the vertical design requires a very large area to accommodate the device. It is also necessary to regulate the supply of the product, since in the case of known devices with a vertical arrangement, the input point is located at the top. The same is also true for operating means such as, for example, drive, heating and vacuum.

"Luocell" is a generic designation for cellulose fibers produced from non-derived cellulose, as introduced by BISFA (The International Bureau for the Standardization of Man-Made Fibers). Luocell technology requires dissolving cellulose without changing its chemical composition (see Zhang et al., BioResourses 13(2), 2018: 4577–4592). This dissolution process can be carried out in one or more steps.

A disadvantage of two-stage technologies, such as those described in DE 4441468, is the difficulty of adjusting the concentration of water, solvent and cellulose between stages and in both stages, which are carried out in different devices, namely in the pre-evaporator and in the horizontal screw solvent, and in resulting in unevenly produced cellulose solutions that have poor performance for the next spinning processing step. WO 2013/156489 A1 describes a similar two-step method, wherein the processing of the main substance of the molded article, for example a cellulose solution, is carried out by treating the starting auxiliary substances in a vertical thin film evaporator and a thick film solvent (mechanical plasticizing reactor).

To avoid two-stage apparatus, it would be necessary to be able to complete the entire dissolution process in a single-stage operation using one single apparatus. This usually requires large-sized devices. Examples of the production of cellulose solutions using vertical thin film evaporators are described in documents EP 0356419 A2, WO 94/06530 A1 and WO 2008/154668 A1.

Due to the costs of equipment and construction that arise with a vertical design, it would be necessary to strive in principle for a horizontal arrangement of the thin-layer evaporator. Of course, precisely with devices with a relatively long rotor shaft, due to its own weight and the associated deflection of the rotor shaft under the influence of gravity, it is difficult to ensure operation that is flawless and technologically identical to the vertical design.

It is therefore an object of the present invention to provide a thin film processing device with a substantially horizontal design which ensures perfect operation even with a relatively long rotor shaft.

A further object of the present invention is to provide an efficient cellulose dissolution process in which cellulose is quickly but completely converted from a solid to a solution in a single device, particularly a thin film evaporator. Preferably, this process can be carried out in a thin film processing device with a generally horizontal arrangement.

The first problem is solved using a thin-film processing device in accordance with claim 1. The preferred forms of execution are reproduced in the dependent claims of the invention.

According to claim 1, the invention therefore relates to a thin film processing device for treating viscous material, comprising

- a technological housing located with an inclination relative to the horizontal by a maximum of 20° with a heated and/or cooled housing shell, which covers the axially extending, rotationally symmetrical and forming a processing space, the internal space of the housing,

- an inlet pipe located in the inlet area of the process housing for introducing the processed material into the space for processing the material,

- an outlet pipe located in the outlet area of the process housing for removing the processed material from the material processing space, and

- located in the internal space of the rotor and coaxially extending, the rotor shaft is driven to form a film of material on the inner surface of the housing shell and to transport the material in the direction from the inlet zone through the process zone to the outlet zone.

In this case, the rotor shaft contains a central part of the rotor shaft and smoothing elements located on its perimeter, the radially outer end of which is located at a distance from the inner surface of the housing shell. These smoothing elements are located, as a rule, in several rows of blades distributed along the perimeter of the rotor shaft and extending in the axial direction, the number of which depends on the perimeter of the rotor shaft body.

According to the invention, the rotor shaft comprises at least one lifting element located on the rotor shaft body, which is configured to create, during rotation of the rotor shaft, a lifting force acting towards the rotor shaft body, as described below.

According to the present invention, the process housing, that is, its longitudinal axis, is inclined relative to the horizontal by a maximum of 20°, preferably by a maximum of 10°, and is particularly preferably positioned horizontally, that is, with an inclination angle of at least approximately 0°. Due to the essentially horizontal arrangement of the process housing of the device according to the invention, it is generally supported in the respective inlet zone of the proximal end region and in the corresponding outlet zone of the distal end region on corresponding supports. In addition, the rotor shaft located in the internal space of the housing is supported in corresponding rotating supports in the proximal and distal end regions, and preferably the rotating support in the proximal end region receives both radial and axial forces and is made in the distal end region in the form of a radial bearing. As shown below, at least one lifting element is located in the center of the rotor, that is, in the region of maximum deflection.

According to the invention, it has surprisingly been found that by means of a lifting element or lifting elements located on the rotor shaft body, gravity-induced deflection of the rotor shaft can be effectively counteracted. In this way, it is possible to ensure perfect operation even for devices with a relatively long rotor shaft, which is used, in particular, for the Luocell technology, also when the device is positioned horizontally. For a thin film processing device in which the interior space of the housing that forms the material processing space extends over at least 5 m, preferably at least 8 m, the technical effect achieved according to the invention is particularly well expressed. Thus, for example, even for these lengths it is possible to adjust the gaps between the ironing elements and the inner surface of the housing shell, comparable to the elements of a (vertically positioned) Filmtruder device.

In addition, within the framework of the present invention it was found that also in the case of horizontal devices, it is possible to achieve fairly good transport of very high-viscosity materials, provided that the rotor shaft is equipped with transport elements. The smoothing elements located along the perimeter of the rotor shaft body are thus made at least partially in the form of transport elements.

Typically, a part of the ironing elements is present in the form of transport elements, and a further part of the ironing elements is present as distribution elements. In the context of the present invention, "distribution elements" are the stroking elements that primarily distribute the material on the inner surface of the housing shell, while the "conveying elements" are the stroking elements that primarily impart a transport component to the material towards the outlet. In this case, it is also possible that the ironing elements act as both transporting and distributing; such ironing elements are designated in the context of the present invention as “transport and distribution elements”.

Distribution elements and conveying elements differ, as a rule, in that the cutting edge of the distributing elements forms, relative to the axis direction, respectively, at least approximately a neutral angle with respect to transportation, while the cutting edge of the conveying elements is located at such an angle to the axis direction, what happens is imparting a transport component to the material in the direction of the outlet pipe. As a rule, the cutting edge of the distribution elements thus forms an angle with the axis direction, which is smaller than the angle formed by the cutting edge of the transport elements with the axis direction. For the distribution element, the angle formed by the cutting edge with the axis direction is preferably less than 5° and in special cases at least approximately 0°. In contrast, the angle formed by the cutting edge of the transport element with the direction of the axis is greater than 15°.

As a result of the presence of transport elements, on the one hand, it is possible to transport also high-viscosity materials through the processing chamber at a sufficiently high feed intensity. While high device throughputs of up to 50,000 kg/h can be achieved through this, increased product quality can also be achieved for temperature-sensitive materials, since the residence time or processing duration during which the material is exposed to elevated temperatures and frequent cutting, can be kept at a fairly low value.

On the other hand, due to the presence of distribution elements, very good distribution and optimal surface renewal on the inner surface of the housing shell (also referred to as “processing surface” in the following) can also be ensured when the material has a very high viscosity.

As a result, according to the invention, it is possible to achieve optimal processing, in particular a high degree of degassing of very highly viscous material, and at the same time reduce the amount of energy introduced into the material to the value required for the corresponding method, at which no damage to the material occurs and, in particular, temperature-induced destruction.

As mentioned, it is possible that the process body is slightly inclined relative to the horizontal. This ensures that the material undergoes a permissible backflow and thus remains in the process housing longer, which may be desirable depending on the application.

The body of the rotor shaft of the device according to the invention may comprise, in particular, a neck and fastening strips distributed along its perimeter, extending in the axial direction, with the help of which the ironing elements can be secured to the neck. It also seems possible, however, that the rotor shaft body contains, instead of a journal, a hollow shaft, along the perimeter of which smoothing elements are distributed.

As mentioned, the process housing includes a heated and/or cooled housing shell that encloses an axially extending, rotationally symmetrical interior of the housing. This interior space of the housing, which forms the space for processing the material of the device, is usually made in the form of a circular cylinder, but it is also possible to design the interior space of the housing conically tapering in the transport direction or the interior space of the housing, which in the first region is made in the form of a circular cylinder and in the region located relative to it downstream in the transportation direction, it is made conically tapering.

Depending on the particular states into which the processed material passes during processing, or the corresponding conditions or goals set for the processing steps, in preferred forms of execution the space for processing the material can be divided into different zones, namely the inlet zone (called also known as the "loading zone"), the processing zone, the exhaust zone (also called the "unloading zone") and the optional finishing zone. In addition, the processing zone can be divided into a distribution zone and a conveying zone, whereby in the distribution zone good distribution and surface renewal of the material is in the foreground, in contrast to which in the conveying zone good transportation of the material must be achieved first. The inlet zone, the process zone (containing in particular the distribution zone and the transport zone), the outlet zone and the final processing zone are spatially arranged, as a rule, sequentially one after the other. In this case, the final processing zone is located outside the process housing, but with a spatial connection to it. However, it is also possible that the finishing zone is located before the outlet zone and thus in the process housing.

While in the Luocell technology-oriented device the evaporation of water from the cellulose suspension is in the foreground in the inlet zone with at the same time good distribution and rapid removal of the material, in the process zone the important thermal treatment must be carried out through a targeted combination of distribution and transport, Moreover, water is additionally evaporated. In this case, in the distribution zone, they strive first of all to ensure that with increasing intensity of water evaporation, the suspension passes well into the solution. In the transport zone following the distribution zone, the material with substantially dissolved cellulose must be given an enhanced transport component towards the outlet zone, in which the material is discharged through a suitable outlet and is subjected to finishing treatment in the finishing zone. In the finishing zone, the solution is homogenized by cutting and mixing with additional residence time. While the pulp goes almost completely into solution, typically in the process zone, it is also possible for the pulp to go completely into solution only in the outlet or finishing zone. As mentioned, it is optionally possible to locate the finishing zone before or after the release zone.

While the device according to the invention is suitable for the production of cellulose solution, other applications in which viscous material is processed are also possible. In this regard, by “viscous material” in the context of the present invention is meant a material whose viscosity, during processing in the device according to the invention, is at least temporarily between 100 and 15,000 Pa⋅s. The viscous material preferably contains a liquid substance, which can be withdrawn in the thin film processing device (in evaporated or sublimated form).

As mentioned, the technical effect achieved according to the invention is particularly pronounced in a material processing space with an axial extent of at least 3 m, preferably at least 8 m and particularly preferably at least 10 m. Thus, the rotor shaft extends between the rotating bearings in the proximal and distal regions, preferably over a length of at least 4 m, preferably from 10 to 15 m.

In addition, as described below, taking into account the objectives of the processing step carried out in a particular zone, it is especially preferable to provide different configurations of the rotor shaft or ironing elements located on the rotor shaft depending on the zone.

As a rule, inside the housing shell there is a hollow space of the housing shell intended for the passage of a flow of heat exchange medium for heating and/or cooling. The housing shell usually comprises an inner wall of the housing shell and an outer wall of the housing shell with an intermediate space located between them, in which a guide volute is located for directing the heat exchange medium, usually steam or warm water. In addition, as indicated below, it is in particular possible to provide two or more heat exchange medium circuits containing guide volutes that are separate from each other and thus maintain temperature independently of each other. Due to this, the temperature of the inner surface of the housing shell that is desired for the respective zone of the thin-film processing device can be adjusted independently of the temperatures prevailing in other zones. In this regard, it is also preferable to use water vapor in the process zone and hot water in the outlet zone as the heat exchange medium.

According to a preferred embodiment, the lifting element comprises a flat section of the oncoming flow with an end protruding in the direction of rotation, which, compared to the protruding end of the subsequent region, is located at a greater distance from the inner shell of the housing. As a result, a gap is formed between the oncoming flow section and the inner surface of the housing shell, narrowing in the direction opposite to the direction of rotation. According to a particularly preferred embodiment, the free-stream portion extends in a plane that is oriented at an angle to the tangent or tangential plane of the inner surface of the housing shell, resulting in a gap between the free-stream portion and the inner surface of the housing shell that continuously narrows in the direction opposite to the direction rotation. Moreover, it is preferable that the angle between the tangent or tangential plane of the inner surface of the housing shell and the incoming flow portion lies in the range of 15° to 30°, in particular, is about 25°. In this case, the tangent of the inner surface of the housing shell is understood as a tangent that comes into contact with the rounded cross-section of the inner surface of the housing shell at the point located closest to the radially outer end of the incoming flow section. The gap formed between the inner surface of the housing shell and the oncoming flow area narrows by a factor of more than 10.

Now, when the rotor shaft rotates, the material to be processed, which, as a rule, has high viscosity, is pressed into the gap, as a result of which the hydrodynamic force acting on the oncoming flow section imparts to the rotor shaft a hydrodynamic component of the lifting force perpendicular to the direction of the oncoming flow. This component of the lifting force is relatively large precisely for relatively high-viscosity materials with a viscosity of over 100 Pa⋅s. This effectively prevents shaft deflection, and the effect is especially pronounced when processing highly viscous materials.

In order to create a hydrodynamic component of the lifting force already during the starting phase, it may be preferable to introduce a partial flow of the processed material, already during the starting phase, into the area of the thin-film processing device in which lifting elements are present, in particular in the technological zone. For this purpose, the thin film processing device can thus comprise, in addition to the inlet pipe in the inlet zone, a further inlet pipe located downstream of the inlet zone and, in particular, in the process zone. The proportion of this partial flow of material introduced into the device as a whole is selected in such a way that, on the one hand, a sufficiently large component of the lifting force is obtained and, on the other hand, the residence time of the material in the thin-film processing device is always long enough to ensure desired processing. Preferably, the fractional flow rate of material introduced into the process zone is about 20% or less, so that the fraction of material introduced into the inlet zone is about 80% or more.

Particularly advantageous for the purposes of the invention, the lifting effect is obtained for a flow section that covers an angle range of at least 10° of the perimeter of the rotor shaft body, in particular an angle range of 10° to 20° and in a special case an angle range of about 12°.

According to a particularly preferred embodiment, at least part of the lifting elements is formed by one ironing element. Thus, this ironing element is assigned a dual task - in addition to performing the function of a lifting element, it distributes the processed material (in the case of an ironing element made in the form of a distribution element) or gives the material an additional transport component in the direction of material release (in the case of an ironing element made in form of a transport element). The ironing element forming the lifting element acts particularly preferably as a transport element and as a distribution element, that is, it is present in the form of a transport-distribution element.

Particularly preferably, the lifting element comprises a wall sheet at least approximately in the shape of a gable roof, the ridge of which extends at least approximately parallel to the axis direction of the rotor shaft. Thus, due to the angular shape, the wall sheet is divided into first and second surfaces of the wall sheet, which lie in planes inclined to each other.

The first surface of the wall sheet, which extends in the direction of rotation, thereby forms a section of the incoming flow of the lifting element. As stated above, this first surface of the wall sheet covers a range of β angles of at least 15°, in particular from 15° to 30°. The range of β angles covered by the entire wall sheet is therefore preferably from 25° to 50°.

The angle formed between the first and second surfaces of the wall sheet preferably lies in the range of 110° to 150°. The length ratio between the arm forming the upstream section and the arm forming the subsequent section is preferably in the range from 1:0.5 to 1:0.8.

Depending on whether the ironing element, in addition to its function as a lifting element, is also primarily intended to serve as a transport element or a distribution element, ribs extending in different ways can be arranged on the radial outer side of the sheet wall. Thus, in case it must also act in the sense of transport, the lifting element has on its outer surface at least one transport rib extending in a spiral manner. In the case where the lifting element must also serve as a distribution element, the ribs are neutral with regard to transport, in particular oriented at right angles to the direction of the axis or with a maximum transport angle of 5°.

As a result of the angular shape of the wall sheet, a cutting edge extends, as a rule, in the axial direction. Regardless of whether the lifting element is to serve as a conveying element or a distribution element as the primary next function, as a result of the presence of this cutting edge, in each case a separation of the material on the inner surface of the housing shell occurs. In the presence of transport ribs, the wall sheet is used to impart, as a rule, both a transport component and a distribution component, with the result that in this case it forms a transport and distribution element. In this case, the cutting edge is preferably located flush with the transport ribs and thus at the same distance from the processing surface as the radial outer edge of the transport ribs. Alternatively, the cutting edge can be positioned rearward relative to the radial outer edge of the conveying rib and thus be located at a greater distance from the working surface.

According to a preferred embodiment, at least part of the lifting elements is located in a region lying centrally between the rotating supports on which the rotor shaft is mounted. In accordance with the specific design, this area is located in the technological zone of the device. The lifting force component imparted by the lifting elements thus acts in the region or zone in which the deflection of the rotor shaft is particularly strong.

In addition, in relation to this form of execution, it is preferable that at least a part of the lifting elements are located on the rotor shaft body in the technological zone with a spiral offset relative to each other. Due to this, it is possible to achieve an optimal distribution of the lifting force or the components of the lifting force imparted by individual lifting elements over an arbitrarily long section of the technological zone.

In addition, specifically for the technological zone, it is preferable that part of the lifting elements respectively form one transport and distribution element. In this case, at least one spirally extending transport rib is specifically located on the radial outer side of the corresponding lifting element, in particular the wall sheet.

As a rule, the radial outer edge of the transport rib forms an angle greater than 45° with the direction of the axis. Thus, also for very highly viscous material, the transport component imparted by the lifting element is sufficiently large to ensure the desired transport performance through the material handling space. Preferably, the radial outer edge of the transport rib forms an angle of max. 65°. In a special case, the angle lies in the range from 50° to 60°.

While the conveying effect of this conveying element is determined based on the installation angle of the radial outer edge of the conveying rib, the conveying effect of the lifting element can be further adjusted by the number of conveying ribs or the distance between successive axial conveying ribs.

According to a further preferred embodiment, a concentric protective shell is formed in the inlet area, located between the inner surface of the housing shell and the rotor shaft body and at least approximately completely enveloping the rotor shaft body. This protective shell prevents the possibility of drops or splashes of material from reaching the rotor shaft body in the inlet area, that is, even before the increase in viscosity that occurs during processing.

According to this preferred embodiment, the material to be treated and the gaseous components of the material that escape during the treatment are therefore directed in a cocurrent flow, whereby it is preferable, in addition, that the material and the gaseous components of the material are directed in a countercurrent in the process zone adjacent to the inlet zone. Due to this, in the inlet zone, taking into account the hardware, the lower viscosity of the material and the danger of possible “material entrapment” by evaporated components are taken into account, while in the subsequent technological zone, degassing is optimally optimized due to minimizing the contact between the material to be processed and the majority of the vapor-air mixture.

According to a particularly preferred embodiment of the embodiment described above, the protective shell is formed, at least in part, by several lifting elements distributed in the circumferential direction, in particular wall sheets. As a result, the lift force components desired according to the invention are also generated in the intake area.

Also, the wall sheets located in the inlet region preferably have on their radial outer side at least one helically extending conveying rib in order to achieve, in particular in this area, a high conveying performance and thus counteract material blockages.

In addition, it is advantageous for a channel to be arranged radially rearwardly between two circumferentially successive lifting elements, in particular wall sheets. The steam-air mixture formed during the processing of the material can be directed through this channel and - after reaching the end of the protective shell - it can be directed through the internal space surrounded by the protective shell to a space separated from the processing chamber, from where it can be removed by extracting the steam-air mixture.

In accordance with the following preferred embodiment, also in the process zone and/or in the outlet zone, a concentric protective shell is formed, located between the inner surface of the housing shell and the rotor shaft body, at least approximately completely enveloping the rotor shaft body, in particular, at least in particular a protective shell which is at least partially formed by several lifting elements distributed in a circumferential direction. Due to the presence of a protective shell in this zone, drops of material are prevented from getting onto the body of the rotor shaft and from “freezing” on the unheated body of the rotor shaft. This design is advantageous in particular if the material to be processed, also in the process zone or in the discharge zone, does not have a viscosity that is insufficient to completely prevent dripping or falling of droplets. This is important, in particular, during moving in or retracting or in the event of operating errors of the device. In addition, it may be preferable to design the rotor shaft with heating to prevent solidification of the material, drops of which have fallen on the body of the rotor shaft. In other words, in this preferred embodiment, means are present for heating the rotor shaft, in particular the rotor shaft body.

In addition to the said lifting elements, which preferably also have the function of a transport element, a distribution element or a transport and distribution element, the rotor shaft contains, in accordance with a further preferred design, the following smoothing elements containing radially projecting teeth, usually fixed on one of several , located on the hollow shaft, passing in the axial direction of the flanges. Such smoothing elements, as a rule, do not impart any component of lifting force to the rotor shaft or impart one that can be neglected.

Depending on the orientation of the cutting edge of the teeth relative to the axis direction, the corresponding stroking element forms a distribution element or a transport element, as has already been described in analogy in connection with the lifting elements. Thus, for example, a cutting element, the teeth of which contain a cutting edge forming an angle less than 15° with the axis direction, forms a distribution element, while when the angle between the cutting edge and the axis direction is equal to or greater than 15°, in particular equal to or greater than 45°, the ironing element forms a transporting element.

According to the specific design, ironing elements functioning as transport elements are present, in which case the said angle lies in the range from 15° to 30° and in a special case is about 20°. It is approximately possible that the teeth comprise an element located radially inside, which is located in a plane extending parallel to the direction of the axis and with the help of which the teeth are flanged, and an element located radially outside, which is located in a plane extending at an angle to the direction of the axis and the radially outermost end of which forms a cutting edge. edge.

Depending on the case of use, it may be preferable as an alternative to this form of execution that the cutting edge of at least part of the ironing elements forms a smaller angle than the one mentioned above and, in particular, extends at least approximately parallel to the axis direction, that is forms an angle of about 0° with it. In the latter case, these ironing elements, which function as distribution elements, are completely transport-neutral and perform exclusively a distribution function. The choice of a specific configuration of ironing elements ultimately depends on the material to be processed and may vary.

As mentioned, the distribution between the distribution elements and the transport elements largely depends on the purpose assigned to the device and the corresponding zone. Thus, for example, according to a preferred embodiment, the ratio of the number of transport elements to the number of distribution elements is approximately higher in the transport zone than in the distribution zone, since in the transport zone the transport of material is given greater importance.

According to a further preferred embodiment, the distribution elements with the conveying elements are arranged in an alternating manner in the circumferential direction of the rotor, since this makes it possible to ensure a very uniform distribution of the material over the machining surface.

Adjacent to the outlet process area, material is then discharged from the processing space through an outlet, which may use a rotor shaft configuration that clears the interior wall of the housing and discharges the product into a downward branching conveyor mechanism. It is also approximately possible that the conveying mechanism is present in the form of a vertically positioned cone, in which the material is at a supply height sufficient to be discharged by a screw or preferably a gear pump. In addition, it is also possible that in the distal end region, that is, immediately in front of the end cover of the process housing, a spiral is placed on the rotor shaft, transporting material that was not captured by the outlet pipe and the discharge system located behind it, again from the distal end towards outlet pipe.

In addition, it is possible and, depending on the application, preferable to provide a separate discharge system for the removal of material. In particular, it is possible that the outlet pipe flows into the discharge system in the form of a single discharge screw or a double discharge screw, preferably with an orientation transverse to the direction of the axis of the process housing. The purpose of this discharge system is to supply the processed material or product to a pump, which creates pressure for the subsequent processing device, in the case of Luocell technology solution, in particular for subsequent filters and dies. Booster pumps can also be used for this.

In the case of an unloading system in the form of a double unloading screw, it may also be preferable to equip it with kneading and dispersing blocks, due to which additional homogenization and, in the case of the Luocell technology, dissolution of the smallest particles in the mass of material are ultimately achieved.

The unloading system may contain a horizontally or vertically located transport device. As a rule, the discharge system is provided with a discharge pump in its area located on the discharge side, through which the material to be discharged can be discharged or supplied to subsequent devices, for example a filter and/or a die.

In particular, it is possible that the unloading system comprises a vertically arranged transport device and a hopper with a unloading shaft disposed therein and extending coaxially, which at least in a section comprises a single unloading auger. The advantage of this design is that it is possible to eliminate the connection between the speed of the rotor shaft present in the process housing and the speed of the unloading shaft in the unloading system.

As an alternative to this, it is also possible to provide a discharge system which contains a hopper whose axis coincides with the axis of the rotor shaft. In particular, the rotor shaft can protrude into the interior of the hopper and contain a single unloading screw on the cylindrical section of the hopper adjacent in the transport direction to the conical section of the hopper.

According to a further preferred embodiment, the thin-film processing device also includes a cleaning device designed in such a way that, when the end cover is open, it can be inserted into the process housing and move back and forth. It is approximately possible that the cleaning device contains suitably positioned brushes or pressure water spray nozzles for this purpose. Specifically for the embodiment described above, in which a steam-air mixture channel extending in the longitudinal direction is provided in the inlet area between two wall sheets that are successive in the circumferential direction, this allows for quick and easy cleaning of the thin-film processing device. In particular, if it is necessary for the cleaning device to have access to the areas to be cleaned, costly dismantling of the device can be avoided.

In addition, directly next to the distal, that is, the front end side of the process housing, it is possible to place a disk-shaped cleaning element on the body of the rotor shaft, which prevents the material from settling on the inner surface of the distal end side and, in addition, protects the distal rotating support from contamination by the material.

As mentioned, the device according to the invention is designed in particular for the thermal fractionation of a mixture of substances and is specially present in the form of a thin film evaporator, a thin film dryer or a thin film reactor, preferably in the form of a thin film evaporator.

The device allows optimal processing, in particular the degassing of materials with a viscosity of up to 15,000 Pa⋅s and, in some cases, their reaction, either in combination with degassing or independently of it.

Typically, the viscosity of the material to be treated with the device according to the invention lies in the range from 100 to 5000 Pa⋅s, in particular from 300 to 3000 Pa⋅s and in a special case from 500 to 1000 Pa⋅s. The viscosity values are related to the operating temperature and shear gradient D=10 s ^-1 .

In addition, the device is particularly well suited for the treatment of relatively temperature-sensitive materials, since the thermal energy applied to the material can be optimally adjusted based on the relatively low temperature and residence time selected on the surface to be treated.

As mentioned, the thin film processing device according to the invention is suitable in particular for the production of cellulose solution, in the special case of cellulose solution for the production of Luocell fibers.

Specifically, the operating temperature of the thin film processing device according to the invention lies generally in the range from 80 to 120°C, in particular from 90 to 115°C and in a special case from 100 to 110°C.

It has been found that in order to best convert the cellulose solution into a homogeneous solution, production (for example, as described below) under pressure (pressure p, in mbar) can be ideally carried out approximately in accordance with the given formula (p = 122.e^- (0.05 c(Cell). The cellulose concentration (“c(Cell)”, in mass -%) is here preferably 6%-20%, in particular 10%-15%. In these concentration ranges, effective, rapid and mostly complete dissolution of cellulose.

The peripheral speed of the rotor shaft of the thin film processing device according to the invention is generally in the range of 6 to 12 m/s, in particular 8 to 10 m/s.

In another aspect, the present invention relates to a method of making a cellulose solvent solution from a suspension of cellulose in a solvent and a volatile precipitant, comprising introducing the suspension into an inlet of a thin film processing device, applying the suspension in the form of a film, and distributing it on a heat exchanger-tempered housing shell using rotating around the common axis of the ironing elements in the process housing of the thin film processing device, evaporating the volatile precipitant, resulting in dissolution of the cellulose, and withdrawing the cellulose solution from the thin film processing device through the outlet, wherein at least a portion of the ironing elements causes the supply of cellulose in the direction of the outlet . In particular, the supply is preferably regulated in such a way that the discharge at the outlet is at least 300 kg/h, in a special case preferably at least 350 kg/h, cellulose solution per m ² of the surface of the housing shell (inner wall) with temperature maintenance (using a heat exchanger).

The ironing elements according to the invention, in particular with transport elements, allow rapid movement of the cellulose suspension or resulting solution during the implementation of the Luocell technology method. This allows the cellulose or cellulose solution to be processed, dissolved and discharged quickly. For example, in accordance with the invention and in the examples (see table “Lines ac”) it was shown that productivity from 145.8 kg/h and per m ² to 887.5 kg/h and per m ² can be achieved in laboratory conditions and in the case of a thin film treatment device with a shell shell surface heated or cooled by a heat exchanger (also “heat exchanger surface”) 0.55 m ² . These are significantly higher quantities compared to those described, for example, in EP 0356419 A2 (72 kg/h for a device of the same size). It has been found that in order to achieve a cost-effective and appropriate amount of solvent depending on the amount of cellulose solution at the outlet, a volume of cellulose solution of more than 300 kg/h per m ² of heated or cooled surface is preferable. Tests have shown that starting from a volume of about 600 kg/h and per m ² , the quality (uniformity) of the solution begins to deteriorate.

This was able to show that by adjusting the ironing elements to quickly transport the product - as is necessary in a horizontal orientation due to the absence of a gravity-driven transport component - it was possible to implement an effective method for dissolving cellulose. In direct feed processing, a highly efficient dissolution process was unexpectedly achieved in the process housing, in which the Luocell technology was able to quickly and completely convert cellulose from a homogeneous suspension into a homogeneous cellulose solution. The quality of the resulting cellulose solution meets the prerequisites for the forming process in the Luocell technology, for example, spinning to the type of filaments. In principle, these advantages are independent of the horizontal position. Although the device according to the invention was designed for horizontal orientation, advantages of use were also achieved in vertical orientation, in particular when processing highly viscous suspensions or solutions. This aspect of the invention is therefore independent of the arrangement of the process housing, although of course a horizontal arrangement is also preferred here.

Preferably, the feeding is carried out by means of ironing elements in the outlet direction, so that the discharge at the outlet is 300-600 kg/h, preferably 350 kg/h-550, especially preferably between 5380 and 480 kg/h, cellulose solution (treated in the process housing to ready material) on m ² surface of the housing shell with temperature control using a heat exchanger.

The feed can be adjusted, for example, by selecting the number of ironing elements important for feeding (conveying elements, as described above), their angle and the rotation speed of the conveying elements. The angle formed respectively between the cutting edge and the axial direction is greater than 15°, preferably 15° to 30°, particularly preferably about 20°. Preferably, at least one third of the ironing elements is a transport element.

In addition, the division according to the invention into different processing zones (inlet zone, process zone and outlet zone) is particularly advantageous and has a positive effect on the quality of the resulting cellulose solution, which quickly moves forward with the feed according to the invention.

The temperature of the material, in particular the suspension, in the inlet zone is at least preferably 10° C. lower than in the process zone. Preferably, the above-mentioned wall sheets in the form of a gable roof are provided in the inlet area. Due to this, it is possible to effectively prevent the formation of lumps when introducing the suspension into the device and to ensure efficient transport of the material and the flow and steam-air mixture in a co-current flow. In the inlet zone, an extremely uniform layer of suspension is applied to the inner surface of the housing shell.

The transport and distribution elements mentioned above and below are provided, in particular, in the process area. In this case, the ratio of the transport and distribution elements is preferably from 2:1 to 1:2, with ironing elements with both functions (transport and distribution elements) being assigned to both groups. Preferably also or alternatively, the ratio of the lengths of the outer cutting edges, that is, the radially outer ends of the elements that are in contact with the suspension, is preferably matched to each other. Preferably, the ratio of the sum of the lengths of the outer cutting edges of the transport elements and the sum of the lengths of the outer cutting edges of the distribution elements is from 2:1 to 1:2.

Preferably, no or only a few transport elements are provided in the outlet zone, that is, almost exclusively distribution elements. Preferably, a maximum of 10% of the ironing elements in the discharge zone are transport elements and/or at least 90% of the ironing elements are distribution elements without a transport function. These shares, similar to those given above, can be calculated for the sum of the lengths of the outer cutting edges of the ironing elements. That is, preferably, a maximum of 10% of the sum of the lengths of the outer cutting edges of the ironing elements is assigned to the transport elements and/or at least 90% of the sum of the lengths of the outer cutting edges of the ironing elements is assigned to the distribution elements.

Preferably, the ratios of zone lengths lie in the range of 5%-25% of the inlet zone, 50%-90% of the process zone, and the remainder - 5%-25% of the outlet zone.

As an alternative to the above embodiment, in which no or only a small number of conveying elements are provided in the discharge zone, in some cases where the discharge system comprises a horizontally arranged conveying device, it may be advantageous to provide ironing elements which impart a conveying component to the material. In particular, it may be advantageous that in the distal end region of the discharge zone or in the discharge system as described above, wall sheets are arranged on the body of the rotor shaft, acting on the one hand as a drive element and, on the other hand, as transportation and distribution elements. This takes into account the fact that the gravity component does not appear with a horizontally located unloading system. Due to the presence of transport and distribution elements in the said areas, efficient material unloading is ensured also for these horizontal unloading systems, namely even when the material to be unloaded has a relatively high viscosity.

Also for this form of execution, it is particularly advantageous if the wall sheets are arranged in a section along the length of the rotor shaft corresponding to the distal end region of the exhaust zone with a spiral offset relative to each other.

The amount of product at the outlet is determined by the amount of suspension supplied, however, of course, it is somewhat less as a result of the evaporation of the precipitant in the process housing. The evaporated precipitant is preferably not discharged at the outlet of the cellulose solution (highly viscous liquid mass), but in the vapor phase is preferably directed countercurrent to the flow of the cellulose suspension and is therefore discharged close to the inlet.

The temperature regime of the shell body (inner wall) is controlled using a heat exchanger. Using a heat exchanger, the heat from the hot fluid used in Luocell technology can be used to heat the device. The heat exchanger or the inner wall of the housing shell (process housing) is heated to a temperature of 90 to 130°C. In particular, the temperature regime of at least the technological zone is directly regulated. The waste heat from the process zone can be used to heat the inlet and outlet zones, the temperature of which is thus controlled indirectly by means of a heat exchanger. The heat exchange medium in the heat exchanger can be water, oil, steam. Alternatively, temperature control can also be achieved using electrical heating.

The length of the housing shell, the temperature of which is controlled by the heat exchanger, from inlet to outlet is preferably 0.5 m or more, preferably from 1 m to 20 m, for example from 4 m to 18 m or from 6 m to 17 m or from 8 m to 16 m, preferably from 10 to 15 m. The large length allows, while the suspension processing time remains unchanged, to achieve faster feed or greater material throughput and, therefore, larger volumes of product.

An important criterion for the possible volume of the processed product in the technological body is the surface involved in processing the suspension, that is, the surface under the influence of a heat exchanger, which, by heating, causes the evaporation of the precipitant. The surface area of the housing shell, the temperature of which is controlled using a heat exchanger, is preferably from 0.5 ^m2 to 150 ^m2 , for example, from 1 ^m2 to 140 ^m2 , from 2 ^m2 to 130 ^m2 , from 5 ^m2 up to 120 ^m2 , from 10 ^m2 to 100 ^m2 , from 15 ^m2 to 80 ^m2 , preferably from 60 ^m2 to 125 ^m2 . As a result of the horizontal installation according to the invention, structural reasons for limiting the size of vertical thin-film processing devices (for example, the height of the building) become irrelevant, since simple maintenance of the thin-film processing device is possible in the horizontal plane.

The volume and the corresponding specific load on the individual processing zones in the form of execution corresponding to the design are as follows:

Zone Volume in the thin film processing device in dm ³ Specific load in kg/h/dm ³ Intake area 1.3-1.5 76-378 Technological zone 1.5-1.9 66-262 Release area 3-4 2-125

It was found that an ideal cellulose solution was achieved by loading a specified amount of slurry into the thin film processing device being tested. The loaded suspension or solution (in kg/h) divided by the volume present (in dm ³ ) is considered as a general comparable coefficient. This leads to the so-called “specific load”. This specific load is determined by the injected mass flow divided by the volume present in the individual zones, i.e. specific load = mass flow/zone volume.

The method shows the best quality of the solution at a specific load in the inlet zone of 76-378 kg/h/dm ³ , in the process zone of 2-125 kg/h/dm ³ , and in the post-processing zone of 0-500 kg/h/dm ³ . In preferred embodiments, the average processing time (time from entry to exit) of the pulp into the process housing is at least 20 seconds, preferably from 30 seconds to 1000 seconds. The processing time is influenced by the feed speed and the length of the process housing, in particular, its part equipped with a heat exchanger. For example, the processing time is from 60 s to 900 s or from 70 s to 800 s or from 80 s to 700 s or from 90 s to 600 s or from 100 s to 500 s or from 1100 s to 400 s or from 120 s up to 350 s or from 130 s to 300 s. Preferably, the processing time is a maximum of 350 s, in particular preferably a maximum of 300 s.

The ironing elements are driven preferably at a speed of at least 50 rpm. Since the ironing elements rotate around a common axis as a result of rotation of the rotor shaft body, the number of revolutions also corresponds to the rotation speed of the rotor shaft body. The speed of the ironing elements is preferably at least 50 rpm, preferably at least 100 rpm, preferably at least 200 rpm, preferably at least 300 rpm, preferably at least 350 rpm, preferably at least 400 rpm, preferably at least 450 rpm, preferably at least 500 rpm or at least 550 rpm /min or lies in each range within or above these values, preferably from 50 to 800 rpm.

The radially outermost edge of the ironing elements moves at a speed of 1.5 m/s to 12.5 m/s. The movement occurs due to the rotation of the ironing elements. The radially outermost edge of the stroking elements is in contact with the suspension and processes it.

Preferably, the ironing elements (individual or several) move due to the temperature of the housing shell being controlled in the area using a heat exchanger at a frequency of 1500-4000 per minute. This parameter is also called the blade repetition rate, and it indicates how many ironing elements slide per minute over one area. It is determined by the number of radially located ironing elements and the rotation speed. Different zones may contain different numbers of radially arranged ironing elements. Since the blade elements may be positioned offset on the rotor and offsets may overlap in the direction of rotation, some areas (also within the same area) may be affected by an increased blade frequency. The specified frequency of 1500 to 400 per minute is preferably achieved in areas without superimposed displacements, as well as in the technological zone. The frequency is preferably from 1800 to 3000 per minute.

The immediately following ironing elements alternately follow with an interval of 100 mm to 300 mm between the radially outer ends of the ironing elements. This interval is also called the blade tip spacing. Preferably, this interval is also selected in areas without overlaps due to offsets and/or is adjusted in the technological zone. Preferably, the spacing between the tips of the blades is from 150 mm to 280 mm or from 180 mm to 260 mm or from 190 mm to 250 mm or from 200 mm to 240 mm.

The shear rate of the film-formed and distributed suspension under the action of the ironing elements is preferably from 300 s ^-1 to 3000 s ^-1 , in particular preferably from 4000 to 28000 s ^-1 , from 5000 s ^-1 to 26000 s ^-1 , from 6000 s ^-1 to 24000 s ^-1 , from 7000 s ^-1 to 22000 s ^-1 , from 8000 s ^-1 to 20000 s ^-1 or from 10000 s ^-1 to 30000 s ^-1 , from 11000 s ^-1 to 28500 s ^-1 , from 1200 s ^-1 to 27000 s ^-1 , from 1200 s ^-1 to 25500 s ^-1 , from 13000 s ^-1 to 24000 s ^-1 . As a result of the shear, mixing and mechanical processing of the suspension occurs, accelerating the evaporation of the precipitant and facilitating the production of a mixed, homogeneous solution.

Preferably, the introduction of the suspension at the inlet is carried out at a rate of from 1.5 kg/h to 30 kg/h per stroking element, preferably from 5 kg/h to 20 kg/h per stroking element. Preferably, 20 to 5000 ironing elements are provided, for example 25 to 4000 or 30 to 3000 or 40 to 2000 ironing elements. Preferably, from 300 to 10,000 kg, preferably from 10,000 kg to 50,000 kg of suspension are administered per hour.

The preferred film thickness (layer thickness) of the suspension in the process zone for Luocell technology is from 1 mm to 50 mm, preferably from 2.0 mm to 15 mm, in particular preferably from 2.2 mm to 5 mm. The thickness of the layer can be adjusted by varying the amount of introduced suspension, as well as the processing speed (rotation speed, the number of ironing elements, in particular transport elements, their angle and feed). It can also be adjusted by selecting the distance between the radially outermost end of the ironing elements and the inner surface of the housing shell. This distance lies on average in the range from 1 mm to 50 mm, preferably from 2.0 mm to 15 mm, in particular preferably from 2.3 mm to 5 mm.

In preferred embodiments, on average one ironing element is in contact with the suspension or solution on a surface of 0.8 dm ² to 2 dm ² .

In preferred embodiments, the load area of the rotor tip blade is an important parameter for the active slurry processing surface. This, in turn, has a very large impact on the quality of the cellulose solution at the outlet. This rotor tip blade load area is the sum of the end surface of all stroking elements and conveying elements (collectively “rotor blades”) in the process area. Their "end" is formed by a surface called the "end surface". The end surface is the surface of the ironing or transporting element that is located opposite the inner surface of the housing shell. Typically, the ironing and conveying elements have a surface at their apex (maximum distance from the rotor axis) that follows the contour of the inner surface of the housing shell and extends at a constant distance from it. The surface located opposite the inner surface of the housing shell is important, in particular in the processing area with ironing and transport elements, and to a lesser extent with lifting elements. It was found that this parameter (see table, ad) in the tested thin-film processing device is about 0.02 m ² . According to the requirements of a large installation, this parameter is increased, preferably in the range of 0.02 m ² -6 m ² , particularly preferably in the range of 2 m ² -6 m ² and particularly preferably in the range of 4 m ² -6 m ² . In these ranges, favorable performance of the rotor drive device is achieved. At the same time, the discharged cellulose solution has very good quality in terms of completeness of the cellulose solution and uniformity of the cellulose solution. The next parameter is peak contact performance (see table). It is calculated from the introduced amount of suspension in kg/s relative to the sum of the end surface of the ironing and transporting elements in the technological zone in ^m2 . The best quality of cellulose was achieved when this parameter was in the range of 1.10–1.40 kg/ ^cm2 . At large values, for example, above approximately 5.5 kg/cm ² , the homogeneity of the unloaded mass/solution at the outlet deteriorates. Peak contact performance is an important parameter for determining the appropriate performance parameters of the present method. It is specifically determined based on the amounts of administered suspension per unit time. If too much suspension is introduced, the process is overstressed and the cellulose does not dissolve in sufficient quantities in the solvent. This results in downstream processes functioning poorly or not functioning at all.

Preferably, the film thickness (layer thickness) of the suspension is calculated using the formula s = (ln(m _s /60))/x, where s is the film thickness in mm, m _s is the flow of the transported suspension and x is a constant from 0.45 to 7 , preferably 0.5866. Preferably, this film thickness is achieved in the process zone.

It goes without saying that these parameters can be combined with each other. For example, it is particularly preferable if the outlet discharge is at least 300 kg/h, the cellulose solution is designed per m ² of the surface of the housing shell (inner wall) with temperature control (using a heat exchanger); and the average processing time (the time elapsed from the moment of inlet to the moment of discharge) of the pulp in the process housing is at least 150 seconds, preferably from 150 seconds to 1000 seconds; and ironing elements (individual or several) in the section of the housing shell with temperature control using a heat exchanger move at a frequency of 1500 to 4000 per minute (frequency of ironing elements) and/or the shear rate of the film deposited in the form of a distributed suspension as a result of the action ironing elements ranges from 3000s ^-1 to 30000 s ^-1 .

Preferably, the common axis of the rotating ironing elements is inclined to the horizontal by a maximum of 20°. Although in the aspect of the method, by observing the parameters corresponding to the invention, in particular the supply, improved production of the solution is also achieved without horizontal orientation, the latter is still preferred. Therefore, in the method according to the invention, the thin film processing device is used as described above – in each of the special or preferred forms of execution described – without necessarily maintaining a horizontal arrangement.

A solvent is a means for dissolving cellulose. In this case, high temperatures are usually used, for example 70°C or higher, in particular 75°C or higher or 78°C or higher. It is often mixed with a precipitating agent, that is, a substance that cannot dissolve cellulose, to obtain a suspension and subsequently a solution, the mixture being also suitable for dissolving cellulose. In this case, the mixture requires, among other things, a high proportion of solvent, for example, 60% (mass fraction of the dissolved substance) or more - depending on the solvent, it can be different and the proportion can be easily determined by testing the solution by a specialist.

Preferably, the cellulose concentration of the cellulose solution has the usual parameters for the Luocell technology. Thus, for example, the concentration of cellulose in a cellulose solution is from 4% to 23%, preferably from 6% to 20%, in particular from 8% to 18% or from 10% to 16% (all percentages in mass fraction of solute ).

The absolute pressure in the reactor is less than 100 mbar, in particular between 40 mbar and 70 mbar.

Preferably, the cellulose solvent is a tertiary amine oxide (amine-N-oxide), in particular preferably N-methylmorpholine-N-oxide. Alternatively or additionally, it may be an ionic solvent. Such ionic solvents are described, for example, in documents WO 03/029329; WO 2006/000197 A1; WO 2007/076979 A1; Parviainen et al., RSC Adv., 2015, 5, 69728-69737; Liu et al., Green Chem. 2017, DOI: 10.1039/c7gc02880f; Hauru et al., Zellulose (2014) 21:4471–4481; Fernández et al. J Membra Sci Technol 2011, S:4; etc. and preferably contain organic cations, for example ammonium, primidium, peridinium-perrolidinium or imidazolium cations, preferably 1,3-dialkyl-imidazolium salts, for example halides. Water is also used here in the form of an added precipitant. Particularly preferred is a solution of cellulose and 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM), for example with chloride as the counterion (BMIMC1), or 1-ethyl-3-methyl-imisadolium (also preferably as chloride, acetate or diethyl phosphate), or 1-hexyl-3-methylimizdolium or 1-hexyl-1-methylpyrrolidinium (preferably with (trifluoromethylsulfonyl) amide anion), and water. Other ionic solvents include 1,5-diazabicyclo[4.3.0]nonene-5, preferably as acetate; 1-ethyl-3-methylmidazolium acetate, 1,3-dimethylimidazolium acetate, 1-ethyl-3-methylirnidazolium acetate, 1-ethyl-3-methylirnidazolium chloride, 1-butyl-3-methylimidazolium acetate, 1-ethyl-3-methylimidazolium diethyl phosphate, 1-methyl-3-methylimidazolium dimethylphosphate, 1-ethyl-3-methylmidazolium formate, 1-ethyl-3-methylimidazolium octanoate, 1,3-diethylimidazolium acetate and 1-ethyl-3-methylimidazolium propionate.

The suspension, which is preferably processed in the method according to the invention, contains N-methylmorpholine-N-oxide (NMMNO or NMMO in a mass fraction from 58 to 75.3%, water in a mass fraction from 19 to 26.1% and cellulose in a mass fraction from 5.7 to 15.9%.It is possible to produce cellulose solutions with 20% cellulose mass fraction or more.

The present invention is illustrated based on the accompanying drawings.

The drawings show the following:

fig. 1 shows a schematic side view of a thin film processing device according to the invention;

fig. 2 shows a top view of FIG. 1 thin film processing device;

fig. 3 shows a top view of the following thin film processing apparatus;

fig. 4 shows a cross section through plane AA of FIG. 1 technological building shown in Fig. 3 thin film processing devices;

fig. 5 shows a perspective view of a part of a rotor shaft for a device according to the invention;

fig. 6 shows a perspective view of a part of the next rotor shaft of the thin film processing device according to the invention in the corresponding inlet region of the region;

fig. 7 shows a cross section of the one shown in FIG. 6, rotor shaft located in the technological housing;

fig. 8 shows an assembly view of the discharge zone of the following embodiment of a thin film processing device according to the invention with a vertically extending discharge system;

fig. 9 shows a top view of FIG. 8 execution form;

fig. 10 shows a top front view of FIG. 8 execution form; And

fig. 11 shows a side view of the discharge area of the following embodiment of a thin film processing device according to the invention with a horizontally extending discharge system.

Shown in FIG. 1, the thin film processing device 10 comprises a process housing 12 with a housing shell 14, which encloses an axially extending, circular cylinder-shaped inner housing space 16. This interior space of the housing forms a material processing space 160.

At the proximal end region of the process housing 12 is located an inlet 20 for introducing material to be processed into the material processing space 160, while at the distal end region of the process housing 12 is located an outlet 24 for discharging material from the material processing space 160. The proximal end region thus corresponds to the inlet zone 18 of the process housing, while the distal end region corresponds to the outlet zone 22. Between the inlet zone and the outlet zone there is a technological zone 25.

Process housing 12 is supported by respective supports in the proximal and distal end regions, specifically a fixed support 26 in the proximal end region and a floating bearing 28 in the distal end region.

In the embodiment shown, the inlet pipe 20 is located tangentially to the housing shell 14 and flows into the material processing space 160 in the lower half, as can be seen in particular from FIG. 3.

In the shown embodiment, the outlet pipe 24 is made in the form of an opening that flows into the lowermost place of the housing shell 14 into the unloading system 30 located immediately below, in this particular case, the unloading twin screw 300 with a transport device running at right angles to the direction of the axis of the process housing 12.

In the shown embodiment, the housing shell 14 is made double-walled, that is, it contains an inner wall of the housing shell and an outer wall of the housing shell with an intermediate space located between them, in which a guide volute is located for directing the heat exchange medium, usually water vapor or hot water. In the specific case shown, there are two coolant circuits, a first coolant circuit with a first coolant inlet 32 in the inlet region and a first coolant outlet 34 in the outlet side region of the process zone 25, and a second coolant circuit with a second coolant inlet 36 in the distal region. the outlet zone 22 and the second coolant input 38 in its proximal area. Both coolant circulation circuits contain guide volutes that are separate from each other, and their temperature control can be carried out independently of each other. For this purpose, a separate heating element and a cooling element (not shown) are attached to the corresponding coolant circulation circuit to regulate the temperature of the coolant, from where it is introduced through the coolant inlet 32 or 36 into the corresponding guide volute using a coolant pump. It is also possible that in the first coolant circulation circuit assigned to the technological zone 25, water steam is used as a heat exchange medium, and in the assigned outlet zone 22, the second coolant circulation circuit is used as hot water.

Among other things, in the housing shell 14 there is an upwardly extending nozzle 40 for the steam-air mixture, through which low-boiling components can be removed from the material processing space 160.

The device further comprises a rotor 42 having a rotor shaft 44 located in the interior space 16 of the housing and a coaxially extending, driven rotor shaft 44 for producing a film of material on the inner surface 46 of the housing shell, as approximately shown in FIG. 4.

For this purpose, the rotor 42 contains a drive 48, preferably configured to change the speed. In the particular case shown, there is a spur gear motor 480 that is mounted on a portion of the drive shaft of the rotor 44 to drive it into rotation. In this case, the sealing of the drive shaft section relative to the material processing space 160 is carried out using a mechanical sealing ring.

A film of material on the inner surface 15 of the housing shell and transport of material towards the outlet pipe is created by means of distribution elements 43, which, depending on their primary function, are divided into distribution elements 431 and transport elements 432, as described below.

The rotor shaft for the device according to the invention is shown in FIG. 5. It contains a rotor shaft body 50 containing a rod 52 and six fastening strips 54 welded to it and located distributed along the perimeter, extending in the axial direction. These fastening strips 54 are flanged to the lifting elements 56, which in the particular case shown are present in the form of having a gable roof shape of wall sheets 560, the ridge of which 58 extends at least approximately parallel to the direction of the axis of the rotor shaft 44.

Due to the angular shape, the wall sheet 560 is divided into first and second wall sheet surfaces 60a or 60b, which are located in planes angled to each other. The wall sheet surface 60a, which is the first in the direction of rotation, then forms the forward flow section 62 of the lifting element 56. The next first end 64 of the forward flow section 62 in the direction of rotation is located at a greater distance from the inner surface 15 of the housing shell than the next one after the next first end. area 66 of section 62 of the oncoming flow. As a result, a gap 68 is formed between the incoming flow section 62 and the inner surface 15 of the housing shell, which continuously narrows in the opposite direction of rotation in the direction of rotation. Now, when the rotor shaft rotates, the highly viscous material to be processed is pressed into the gap 68, resulting in a force acting on the incoming flow section 62 flow imparts to the rotor shaft 44 a hydrodynamic component of lift perpendicular to the direction of flow and thereby counteracts the deflection of the rotor shaft 44.

As specifically shown in FIG. 7 case, the first surface 60a of the wall sheet or the oncoming flow section 62 forms an angle α with the tangent or with the tangent plane of the inner surface 15 of the housing shell and covers the area β ₁ of the perimeter angles of the rotor shaft body 50. The next next surface of the wall sheet covers the region of β ₂ corners. In general, the lifting element thus covers the angle β.

On the radial outer side of the wall sheets 560 there are spirally extending transport ribs 70 oriented at an angle to the axial direction of the rotor shaft 44.

The ridge 58 of the wall sheet 560 defines an axially extending cutting edge 72 that is offset rearward relative to the radial outer edge of the transport rib 70 and is thereby located at a greater distance from the inner surface 15 of the housing shell.

Due to this, as a result of the wall sheets 560 located on the rotor shaft 44, the rotor shaft 44 acquires, on the one hand, as mentioned, a component of the hydrodynamic lifting force in the direction of the central body 50 of the rotor shaft. On the other hand, the axially extending cutting edge 72 distributes the material over the inner surface 15 of the housing shell, with the transport ribs 70 additionally imparting a transport component towards the outlet. Thus, the wall sheets 560 acting as lifting elements 56 also constitute ironing elements for distributing and transporting material and thus transport and distribution elements.

As can be seen from FIG. 5, the rotor geometry or the ironing elements 43 located on the rotor shaft body are designed differently depending on the zones. Thus, for example, in the corresponding proximal end region of the inlet zone, exclusively gable roof-shaped wall sheets 560 are located. Specifically, six wall sheets are located distributed around the perimeter of the rotor shaft 44, and, accordingly, two successive wall sheets are connected to the connecting panels 74 to each other in such a way that a protective shell 76 is formed as a whole.

Due to the design of the protective shell 76, the material to be processed and the gaseous components of the material that escape during processing are directed in the inlet zone 18 in a co-current flow, as a result of which the danger of possible “material entrapment” by the volatile components is minimized.

The wall sheets 560 are also located in the technological zone 25 adjacent to the inlet zone 18, of course, the wall sheets are located on the longitudinal section of the rotor shaft 44 corresponding to the technological zone, spirally offset relative to each other on the rotor shaft body 50, due to which it is possible to achieve optimal distribution of the lifting force or the lifting force generated by individual lifting elements throughout the entire technological zone 25.

In order to achieve a sufficiently high transport effect, in addition to the wall sheets 560 acting as a lifting element and a transport and distribution element, further ironing elements 43 with an increased transport effect are also located. Specifically, in the technological zone 25 there are also ironing elements 43 containing teeth 78, the cutting edge of which forms an installation angle relative to the direction of the axis of more than 5° and thus constitute a transport element 432, which, however, does not act as a lifting element. Specifically, there are ironing blades 80 with correspondingly several teeth 78 with the said installation angle. In addition, there are ironing elements 43 with teeth 79, the cutting edge of which runs parallel to the direction of the axis and is thus neutral with regard to transport; these ironing elements are therefore purely distribution elements 431. The distribution elements 431 and the transport elements 432 are arranged alternately in the embodiment shown in the processing area 25, and, as already mentioned, on one of the six fastening strips 54 or in one of six rows of shields fixed one sheet 560 of the wall.

A particularly preferred configuration for the inlet region 18 of the rotor shaft 44 is shown, inter alia, in FIG. 6 and 7. Accordingly, there is a coaxial sleeve 77 from which wall sheets 560 are spaced radially and which functions as a protective shell 76. Between each two wall sheets 560 that are successive in the circumferential direction, on the outer side of the sleeve 77 there is a a channel 82 radially shifted back. In accordance with this design, the steam-air mixture released during processing of the material is directed through channels 82. Upon reaching the end of the protective shell 76, the steam-air mixture flows from the internal space 84 surrounded by the protective shell 76 or sleeve 77 to the separated, usually labyrinthine sealing ring from the space 160 for processing the material to the chamber of the steam-air mixture, from where it can be discharged through the pipe 40 of the steam-air mixture.

Alternatively to that shown in FIG. 1-4 of the unloading system in the form of an unloaded twin auger with a transport device extending horizontally and at right angles to the direction of the axis of the process housing, the thin film processing device in accordance with the invention may alternatively comprise an unloading system 30 with a vertical transport device, as shown in FIG. from 8 to 10.

According to this alternative embodiment, the unloading system 30 comprises a hopper with a discharging shaft 88 disposed therein and coaxially extending. The hopper includes a transport-directionally tapering, approximately conical hopper section 90 and an adjacent cylindrical hopper section 92 . In its inlet (wide) side region, the tapering hopper section 90 contains a hopper opening 94, through which the hopper 86 is connected to the interior 16 of the process housing 12. On the outlet side, the hopper 86 or cylindrical hopper section 92 is connected to a discharge pump 96, through which the material to be discharged can be diverted or supplied to further devices, for example a filter and/or a die.

The unloading shaft 88 includes a first unloading shaft section 98 on which are located transport elements 432', by means of which the material to be unloaded is transported towards the cylindrical hopper section 92. This cylindrical hopper section 92 serves as a support sleeve for a second discharge shaft section 99 located therein with a single discharge auger 100 provided thereon for transporting material to the discharge pump 96.

As follows in particular from FIG. 9 and 10, the rotor shaft 44 is mounted on the distal side in a rotating support that is located on the distal end side of the process housing 12. The hopper 86 is positioned so offset relative to the direction of the axis of the rotor shaft 44 or the process housing that there is sufficient space for the upwardly extending adjacent the distal rotating support 102 of the unloading shaft 88, which is connected at its upper end to the unloading shaft drive 104. Due to the offset position of the hopper or in order to ensure an optimal cross-section of the hopper opening in this arrangement, in its upper region located on the inlet side, the geometric shape of the hopper 86 deviates from conical, as shown in particular in FIG. 8 and 9.

At its distal end region on the rotor shaft body 50 are located at least two rotating scrapers 106, with the help of which the material is transported into a hopper opening 94 present on the underside of the process housing 12. Specifically, the scrapers 106 each contain a comb 112, which is mounted on the rod 52 of the rotor shaft body 50 by means of a scraper lever 114 and with which the discharged material is shifted towards the hopper opening 94.

Directly adjacent to the distal end face 108 of the process housing 12, on the rotor shaft body 50 is located, among other things, a cleaning element 11, which prevents the deposition of material on the inner surface of the distal end face 108 and also protects the distal rotating support 102 from contamination by material.

As shown in FIG. 8 and 9, in the release zone 22 of the shown embodiment there are three release zone sections 22a, 22b, 22c. In the first section 22a of the exhaust zone, on the corresponding longitudinal section of the body 50 of the rotor shaft, there are ironing elements 43, which contain teeth, the cutting edge of which forms a stopping angle of about 45° with the direction of the axis and which thus act as transport elements 432. B Distributing elements 431, specifically ironing elements with teeth, the cutting edge of which is parallel to the direction of the axis of the process housing 12 or the rotor shaft 44, are located in the circumferential direction, alternating with the transport elements 432 in the first section 22a of the discharge zone. Alternatively, it is also possible for only the transport elements 432 to be present, with the result that an enhanced transport effect occurs in the first section 22a of the discharge zone.

In the second outlet zone portion 22b adjacent in the transport direction to the first inlet zone portion 22a, the conveying elements 432 alternate in the circumferential direction with wall sheets 560, which are described in connection with FIG. 5 and which act as a lifting element and as a transport and distribution element.

In turn, in the third section 22c of the discharge zone adjacent to it in the transport direction, which flows into the hopper 86, the above-described scrapers 106 are located exclusively on the body of the rotor shaft. In contrast to the transport-neutral distribution elements 431 present in the first section of the discharge zone, in the second section of the discharge zone, in addition to the transport elements 432, further elements are thus arranged, which impart a transport component to the material, thereby also in this case ensuring permissible transport to the third section 22c of the release zone or to the scrapers 106 with a very high viscosity of the material. While discussed in relation to FIG. 5, the transporting ribs form only a relatively small angle with the axis in the technological zone, for example, 5°; for the transporting ribs located in the wall sheet release zone 560, this angle is larger and can be, in particular, 45°, as a result of which they achieve more than technological zone of transport effect.

The advantage of the one shown in FIG. 8 to 10 of the design form is that it is possible to eliminate the connection between the number of revolutions of the rotor shaft 44 present in the technological housing and the number of revolutions of the unloading shaft 88.

Alternatively to that shown in FIG. 8 to 10 in the form shown in FIG. 11 design, the unloading system is oriented horizontally. Specifically, the unloading system 30 contains a hopper 86' flanged to the process housing, into which the rotor shaft 44 protrudes. The hopper 86' contains a conically tapering section 90' of the hopper, which at its wide proximal end is connected through a flange connection to the process housing 12 and the axis of which coincides with the axis of the process housing; in section 90' of the hopper, the diameter of the rotor shaft 44 is narrowed accordingly. In the transport direction, this conical hopper section 90' is adjacent to a cylindrical hopper section 92', which serves as a support sleeve for a single unloading auger 100' located therein.

As described in conjunction with that shown in FIG. 8-10 form of execution, as well as the release zone shown in FIG. 11 of the execution form contains a first release zone section 22a' and a second release zone section 22b' adjacent in the transport direction to the first release zone section. Also in this embodiment, in the second outlet zone section 22b', instead of the transport-neutral distribution elements 431 present in the first exhaust zone section 22a', wall sheets 560 are provided, which act as lifting elements and as transport and distribution elements. Also, in the area of the rotor shaft 44 protruding into the hopper 86' - as in the second section 22' of the inlet zone - along with the transport elements 432, wall sheets 560 are also located on the body 50 of the rotor shaft. Specifically, the wall sheets 560 are arranged in a spiral manner offset relative to each other.

A thin-film processing device with an inner shell inner diameter of 280 mm and a circumferential perimeter of 0.88 m was used in an experiment to prepare a cellulose solution in NMMNO(N-methylmorpholine N-oxide)/water. The horizontal rotor shaft was equipped with various ironing elements, which were arranged in a maximum of eight horizontal rows around the rotor shaft, and in the technological zone, every second row of ironing elements was inclined at an angle α = 20°, the remaining wall sheets were not inclined. The distance between the outer ends of the ironing elements was between 108 and 216 mm. The ironing elements had an engagement surface with a horizontally moving suspension of a maximum of 1.9 dm ² , faced the heated inner surface of the shell of the technological body and were removed from the inner surface of the shell of the technological body at a distance of between 2.7 and 3.5 m. The horizontally fixed rotor rotated with maximum speed of 650 rpm ^-1 , so that the peripheral speed of the tops of the ironing elements was a maximum of 9.3 ms, and the maximum repetition rate of the ironing elements was 2600 per minute. Other parameters are shown in Table 1.

To prepare the cellulose solution, the cellulose used, such as eucalyptus cellulose, was suspended in demineralized water. After the cellulose fibers were completely suspended in water, excess water was separated by filtration and the resulting cellulose cakes were compressed to a solids concentration of about 50% cellulose. After dewatering, the cellulose cake was passed through a needle roller and shredder for defibration. The resulting fine-fiber, wet cellulose was continuously injected into an aqueous tertiary amino oxide (NMMNO) solution to obtain a suspension. Suitable apparatus for this purpose are horizontal ring mixers and/or turbulent mixers.

In the subsequent process, a suspension of water, cellulose and NMMNO with different compositions (see Table 1, rows b, c, d) was introduced into a thin film processing device to make a cellulose solution. It has been found that it is preferable for the introduced suspension to have a mass fraction of 19% to 26% for water, 5.7% to 11.9% for cellulose and 65% to 75% for NMMNO. With the use of such suspensions, good distribution of the suspension in the intake area can be achieved.

It has been found that the conversion of the source composition (formula index = before) to the target composition (formula index = after) preferentially follows a certain relationship. This relationship turns out to be suitable if the formula CH ₂ O before / CH ₂ O after that = , and the difference is 100%, respectively, formed by the concentrations of NMMNO. All concentrations (CH ₂ O, C _{does not change} ) are indicated in weight percent. Surprisingly, the best results were obtained when the ratio ranged from 1.8 to 2.5, and the ratio was 0.8-0.95.

As a result of the suspension passing through various processing zones, their composition changes until the target composition is achieved. When the target composition is reached during the present method, it no longer changes. This target composition preferably corresponds to the formula c(Cell)>32.4-2.17*c(H ₂ O). Moreover, c(Cell) represents the proportion of cellulose in weight percent, and c(H ₂ O) is the proportion of water in the cellulose solution in weight percent. The starting composition is obtained by mixing the individual components, while the target composition is obtained during the implementation of the present method. Since the composition differs as a result of the physical conditions present in individual zones, the parameters and ranges described in the method according to the invention should preferably be observed. In accordance with the invention, the desired target composition corresponds to the equation c(H ₂ O)=33.5-c(Cell)/1.91. The target composition may differ from the desired target composition, but should preferably be within the ranges of the above formulas for the target composition. The target composition is determined at the end of the release zone. During processing, the target composition may not be obtained equally quickly. Thus, for example, for the present method it is preferable if this target composition is obtained at the end of the process zone. It would also be possible to achieve the target composition after a third of the total processing time has elapsed. The total processing time is the amount of time required for the suspension/solution to travel from the beginning of the inlet zone to the end of the outlet zone. After obtaining the target composition, the composition of the cellulose solution no longer changes.

This horizontal thin film evaporator continuously produces a particle-free cellulose solution through intensive mixing and kneading. Treatment durations (t) of 150 s or more led to complete dissolution of cellulose.

The geometric relationships of the inner surface of the housing shell relative to the surface of the tip of the rotor blade (as above) and the peripheral speed of the tip of the rotor blade (i.e. at a greater distance from the axis) showed an effective parameter for assessing the economically feasible and simultaneous effective dissolution of the introduced suspension. With the following values of this parameter, a cost-effective method can be carried out with at the same time very good solution quality. This parameter is defined here as the specific ratio of the rotor blades (table, line ae):

Specific ratio of the rotor blades (table, lines ae) = heat exchanger surface of the inner wall of the housing shell (table, line h) / (tip of the rotor blade load area (table, line ad) * speed of the tip of the rotor blade (table, line l).

It has been found that for good quality, that is, a <2 grade of the spinning-ready solution (table, row x), the rotor blade specific ratio is preferably less than 10, particularly preferably less than 8 and very particularly preferably below 5 m ² s/m ³ . Thus, these parameter ranges are particularly preferred.

To reliably coordinate the process, the following stabilizers are additionally added to the suspension to stabilize the solvent and to prevent cellulose decomposition. The suspension produced in a continuous process was converted into a highly viscous solution under the influence of temperature (u, v, w) and vacuum (j), as well as horizontal shear, with excess water being removed at a reduced pressure (j) between 45 and 90 mbar. The device was heated using saturated water steam at a pressure of 1-2 bar, and the steam temperature ranged from 100°C to 121°C.

The thickness of the layer distributed throughout the internal space ranged from 2.75 to 3.5 mm (i). The water evaporated under the influence of temperature and vacuum was removed in countercurrent to the flow of the suspension at a temperature of 80-85°C, and the mass flow rate (s) of steam was up to 61.5 kg/h. The shear rate (o) was between 5000 and 21000 s ^-1 , and the rotor consumed electrical power from 0 to 37 kW at ϵ revolutions.

The finished cellulose solution was unloaded at the outlet using an unloading screw (k). An unloading screw was used to transition from the vacuum acting in the internal space to ambient pressure. In an hour it was possible to obtain up to 484 kg of a homogeneous cellulose solution with a temperature (w) of about 100°C. The time (t) for processing the suspension in a horizontal device ranged from 0 to 360 s.

The high-viscosity cellulose solution thus obtained was subjected to additional degassing and filtration steps before molding. After a microscopic examination of the solution, it was found that undissolved cellulose particles were present in the solution only for examples 5 and 6. In this case, the solution ready for molding (x) was assessed according to the following system: the assessment is carried out under a microscope with a score from 1 to 3. A score of 1 indicates the presence of few undissolved particles, and a score of 3 indicates the presence of numerous undissolved particles. After filtration, all cellulose solutions are ready for molding.

Forming the cellulose solution into filaments took place as described in WO 2013/030399 A and involved extruding the solution using one or more extrusion units under pressure and strengthening the cellulose matrix in a suitable trapping bath, between the extruder holes and the trapping bath the solution was directed through the air gap.

Options:

Rotor Reynolds number (y):

=

= rotor Reynolds number [-]

average density of suspension [kg/m ³ ]

= peripheral speed of the highest points of the rotor blades [m/s]

= rotor diameter [m]

η = dynamic viscosity of the solution ready for molding [Pas]

Film Reynolds number (z):

= Reynolds number of thin film [-]

m = mass flow of supplied suspension [kg/s]

Di = diameter of heated cylinder [m]

Newton's number (aa):

Ne = Newton's number [-]

n = rotor speed [1/s]

l = rotor length [m]

P = rotor power consumption

Euler number (ab):

Eu = Euler number

i = number of rotor blades

Reactor pressure calculation

= absolute reactor pressure in mbar

c(Cell) = concentration of cellulose in suspension in weight percent

Specific ratio of rotor blades (ironing elements):

specific ratio of the surfaces of the rotor blades in m ² s/m ³

internal surface of the technological zone shell in m ²

peripheral speed of the highest point of the blade in m/s

List of reference items

10 Thin film processing device 12 Technological building 14 Shell shell 15 Inner surface of the housing shell 16; 160 Internal space of the case; material processing space 18 Intake area 20 Inlet pipe 22 Release area 24 Outlet pipe 25 Technological zone 26 Fixed support 28 Floating bearing thirty; 300 Unloading system; unloading twin auger 32 First coolant inlet 34 First coolant outlet 36 Second coolant inlet 38 Second coolant outlet 40 Steam-air mixture pipe 42 Rotor 43 Ironing elements 431,432 Distribution elements, transport elements 44 Rotor shaft 48; 480 Drive unit; spur gear motor 50 Rotor shaft body 52 Stock 54 Mounting strips 56; 560 Lifting element; sheet wall 58 Gable roof ridge 60a, b First and second surfaces of the wall sheet 62 Oncoming flow section 64 The next first end of the oncoming flow section 66 The next second area of the free flow section 68 Gap 70 Transport rib 72 Axially extending cutting edge of the wall sheet 74 Connecting sheets 76 Protective shell 77 Sleeve 78 Angled teeth 79 Teeth without angle 80 Smoothing blade 82 Channel 84 Containment interior 86, 86’ Bunker 88 Unloading shaft 90, 90’ Narrowing section of the bunker 92 Cylindrical section of the bunker 94 Hopper opening 96 Unloading pump 98 The first section of the unloading shaft 99 Second section of the unloading shaft 100 Unloading single auger 102 Distal rotating support 104 Unloading shaft drive 106 Scraper 108 Distal end side of the process housing 110 Cleaning element 112 Scraper comb 114 Scraper lever

Preferred options

Preferably the invention is defined as follows:

1. A thin film processing device for processing viscous material, comprising:

a technological housing (12) extending with an inclination to the horizontal by a maximum of 20° with a heated and/or cooled housing shell (14), which covers the axially extending, rotationally symmetrical and forming a material processing space (160) internal space (16) of the housing ,

an inlet pipe (20) located in the area (18) of the process housing (12) for introducing the material to be processed into the material processing space (160),

located in the outlet zone (22) of the process housing (12) is an outlet pipe (24) for unloading the processed material from the material processing space (160), and

located in the material processing space (160) and coaxially extending, driven by rotation, the rotor shaft (44) for producing a film of material on the inner surface (15) of the housing shell and for transporting the material in the direction from the inlet zone (18) through the process zone (25) to the outlet zone (22), wherein the rotor shaft (44) contains a central body (50) of the rotor shaft and ironing elements (43) located on its perimeter, the radially outermost end of which is located at a distance from the inner surface (15) of the housing shell,

characterized in that the rotor shaft (44) contains at least one lifting element (56) located on the body (50) of the rotor shaft, designed to generate a lifting force in the direction of the body (50) during rotation of the rotor shaft (44) rotor shaft.

2. Thin-film processing device in accordance with claim 1, characterized in that the lifting element (56) contains a planar flow section (62) with an end (64) extending in the direction of rotation, which is located at a greater distance from the inner surface (15) of the housing shell than the area (66) of the incoming flow section (62) following the next first end, as a result of which a gap (68) is formed between the incoming flow section (62) and the inner surface (15) of the housing shell, tapering in the direction opposite to the direction of rotation ), in particular, a continuously narrowing gap.

3. Thin film processing device in accordance with claim 2, characterized in that the incoming flow section (62) covers the angular range β ₁ of at least 10° of the perimeter of the rotor shaft body (50).

4. Thin film processing device in accordance with paragraphs. 1-3, characterized in that at least part of the lifting elements (56) is formed respectively by an ironing element (43).

5. Thin film processing device in accordance with paragraphs. 1-4, characterized in that the lifting element (56) comprises a wall sheet (560) having at least approximately the shape of a gable roof, the roof ridge (58) of which comprises extending at least approximately parallel to the direction of the shaft axis ( 44) rotor.

6. Thin film processing device in accordance with paragraphs. 1-5, characterized in that the lifting element (56), in particular the wall sheet (560), contains on its radial outer side at least one helically extending transport rib (70).

7. Thin film processing device in accordance with paragraphs. 1-6, characterized in that at least part of the lifting elements (56) is located in the area lying in the center between the rotating supports on which the rotor shaft (44) is mounted, preferably in the technological zone (25).

8. Thin film processing device in accordance with paragraphs. 1-7, characterized in that at least part of the lifting elements (56) is located in the technological zone (25) with a spiral displacement relative to each other on the body (50) of the rotor shaft.

9. Thin film processing device in accordance with paragraphs. 1-8, characterized in that in the inlet zone (18) there is a concentric protective shell (76) located between the inner surface (15) of the housing shell and the body (50) of the rotor shaft, approximately completely enveloping the body of the rotor shaft.

10. Thin film processing device according to claim 9, characterized in that the protective shell (76) is formed at least in part by several lifting elements (56) distributed in the circumferential direction, in particular wall sheets (560).

11. Thin-film processing device according to claim 10, characterized in that between two lifting elements (56) successive in circumferential direction, in particular wall sheets (560), a channel (82) is arranged radially backwards. .

12. Thin film processing device in accordance with paragraphs. 1-11, characterized in that the technological zone (25) contains a distribution zone and a transport zone extending in the downstream direction of transportation, and the ratio of the number of lifting elements (432) and the number of distribution elements (431) in the transportation zone is higher than in the zone distributions.

13. Thin film processing device in accordance with paragraphs. 1-12, characterized in that the outlet pipe (24) flows into a discharge system (30) in the form of a single discharge screw or a twin discharge screw (300), preferably with an axial direction running transverse to the axial direction of the process housing (12).

14. Thin film processing device in accordance with paragraphs. 1-13, characterized in that it also contains a cleaning device designed in such a way that, when the end cover is open, it can be inserted into the process housing (12) and moved back and forth in the axial direction.

15. Thin film processing device in accordance with paragraphs. 1-14, characterized in that it is designed for thermal fractionation of a mixture of substances and, in particular, is present in the form of a thin film evaporator, a thin film dryer or a thin film reactor, preferably in the form of a thin film evaporator.

16. Application of a thin film processing device according to claims. 1-15 for processing a material having, at least temporarily during processing, a viscosity of 100 Pa⋅s or more.

17. A method of producing cellulose solutions with a solvent from a suspension of cellulose in a solvent and a volatile precipitant, including introducing the suspension into the inlet of a thin-film processing device, applying it in the form of a film and distributing the suspension onto the housing shell, the temperature of which is controlled using a heat exchanger, using rotating around the common axis of the ironing elements in the technological body of the thin-film processing device, evaporation of the volatile precipitant, resulting in the dissolution of cellulose, and unloading the cellulose solution from the thin-film processing device through the outlet.

18. Method according to claim 17, characterized in that at least part of the ironing elements causes the pulp to rise in the discharge direction, so that the discharge capacity at the discharge is between 300 and 600 kg/h, preferably between 350 and 550 kg/h and particularly preferably between 380 and 480 kg/h of cellulose solution per square meter. meter of the surface of the housing shell with adjustable temperature conditions.

19. The method according to claims 17 or 18, characterized in that the temperature of the introduced suspension in the process zone is from 100 to 125°C, preferably from 100 to 110°C, and especially preferably from 100 to 105°C.

20. Method according to paragraphs. 17-19, characterized in that the absolute pressure in the process zone is at least in the range of +-10%, preferably +/-5% of the formula , where p represents the absolute pressure in mbar, and c(Cell) is the concentration of cellulose in the suspension in mass percent.

21. Method according to paragraphs. 17-21, characterized in that the specific surface ratio of the rotor blades (table, ae) is below 10 m ² s/m ³ , in particular, preferably below 8 m ² s/m ³ and especially preferably below 5 m ² s/m ³ .

22. Method according to paragraphs. 17-21, characterized in that the load area of the tip blade (table, ad) of the rotor lies in the range from 0.02 m ² to 6 m ² , preferably in the range from 2 m ² to 6 m ² and especially preferably in the range from 4 m ² to 6 m ² .

23. Method according to paragraphs. 17-22,

a) characterized in that the specific load in the inlet zone is from 80 kg/h/dm ³ to 380 kg/h/dm ³ , preferably from 120 kg/h/dm ³ to 370 kg/h/dm ³ and especially preferably from 150 kg/h/dm ³ to 350 kg/h/dm ³ ;

b) characterized in that the specific load in the technological zone is from 65 kg/h/dm ³ to 260 kg/h/dm ³ , preferably from 70 kg/h/dm ³ to 200 kg/h/dm ³ and especially preferably from 80 kg/h/dm ³ to 150 kg/h/dm ³ ;

c) characterized in that the specific load in the outlet zone is from 2 kg/h/dm ³ to 125 kg/h/dm ³ , preferably from 5 kg/h/dm ³ to 100 kg/h/dm ³ and especially preferably from 10 kg/h/dm ³ to 50 kg/h/dm ³ ;

d) characterized in that the specific load in the post-treatment zone is from 0 kg/h/dm ³ to 500 kg/h/dm ³ , particularly preferably from 0 kg/h/dm ³ to 250 kg/h/dm ³ .

24. Method according to paragraphs. 17-23, characterized in that the total processing time of the cellulose solution is at least 60 s, preferably greater than 100 s, and particularly preferably from 100 s to 1000 s.

25. Method according to paragraphs. 17-24, characterized in that the ratio of the initial composition and the target composition is determined by the formula , and c(Cell) represents the concentration of cellulose in the solution, and C _H2O is the concentration of water in the solution, respectively indicated in weight percent.

26. Method according to paragraphs. 17-25,

a) characterized in that the ratio lies in the range from 1.8 to 2.5, particularly preferably in the range from 2.1 to 2.4;

b) characterized in that the ratio lies in the range from 0.8 to 0.95, particularly preferably in the range from 0.8 to 0.88.

27. Method according to paragraphs. 17-26, characterized in that the maximum impact power lies in the range from 1.1 kg/cm ² to 5.5 kg/cm ² , preferably from 1.1 kg/cm ² to 2.8 kg/cm ² and especially preferably from 1.1 kg/cm ² to 1.4 kg/cm ² .

28. Method according to paragraphs. 17-27, characterized in that the target composition is obtained preferably after at least 1/3 of the total processing time, preferably after 2/3 of the total processing time, especially preferably at the end of the processing zone.

29. Method according to paragraphs. 17-28, characterized in that the length of the housing shell, the temperature of which is controlled using a heat exchanger, is 0.5 m or more from inlet to outlet, preferably from 1 m to 20 m.

30. Method according to paragraphs. 17-29, characterized in that the surface of the housing shell, the temperature of which is controlled using a heat exchanger, ranges from 0.5 ^m2 to 150 ^m2 , preferably from 60 ^m2 to 125 ^m2 .

31. Method according to paragraphs. 17-30, characterized in that the radially outer end of the ironing elements moves at a speed of 1.5 m/s to 12.5 m/s due to the rotation of the ironing elements.

32. Method according to paragraphs. 17-31, characterized in that the ironing elements, when moving along a section of the housing shell, the temperature of which is controlled using a heat exchanger, move at a frequency of 1500 to 4000 per minute.

33. Method according to paragraphs. 17-32, characterized in that the next ironing elements directly follow each other between the radially outer ends of the ironing elements with an interval of 100 mm to 300 mm.

34. Method according to paragraphs. 17-33, characterized in that at the inlet the suspension is supplied to the ironing element with a mass flow rate from 1.5 kg/h to 20 kg/h.

35. Method according to paragraphs. 17-34, characterized in that the suspension is applied with a film thickness from 1 mm to 50 mm, preferably from 2.0 mm to 15 mm.

36. Method according to paragraphs. 17-35, characterized in that, on average, one ironing element is in contact with the suspension or solution over an area of 0.8 dm ² to 2 dm ² .

37. Method according to paragraphs. 17-36, characterized in that the thickness of the suspension film is determined by the formula , wherein s means the film thickness in mm, m _s means the volume flow of the suspension and x means a constant from 0.45 to 7, preferably 0.5866.

38. Method according to paragraphs. 17-37, characterized in that from 300 kg to 100,000 kg, preferably from 10,000 to 50,000 kg of suspension are introduced per hour.

39. Method according to paragraphs. 17-38, characterized in that the inclination of the common axis of the rotating ironing elements relative to the horizontal is a maximum of 20°.

40. Method according to paragraphs. 17-39 with a thin-film processing device according to each of paragraphs. 1-15.

Claims (13)

1. A thin film processing device for processing viscous material, comprising: a technological housing (12) located at an inclination to the horizontal by a maximum of 20° with a heated and/or cooled housing shell (14), which covers the axially extending, rotationally symmetrical and forming a material processing space (160) internal space (16) of the housing , an inlet pipe (20) located in the inlet zone (18) of the process housing (12) for introducing the material to be processed into the material processing space (160), an outlet pipe (24) located in the outlet zone (22) of the process housing (12) for unloading the processed material from the material processing space (160), and located in the material processing space (160) and coaxially extending, driven by rotation, the rotor shaft (44) for producing a film of material on the inner surface (15) of the housing shell and for transporting the material in the direction from the inlet zone (18) through the process zone (25) to the outlet zone (22), wherein the rotor shaft (44) contains a central rotor body (50) and ironing elements (43) located on its perimeter, the radially outermost end of which is located at a distance from the inner surface (15) of the housing shell, characterized in that the rotor shaft (44) contains at least one lifting element (56) located on the rotor shaft body (50) for generating, during rotation of the rotor shaft (44), a lifting force in the direction of the rotor shaft body (50) . 2. Thin-film processing device according to claim 1, characterized in that the lifting element (56) contains a planar flow section (62) with an end (64) next in the direction of rotation in front, which is located at a greater distance from the inner surface (15) of the shell of the housing than the area (66) of the incoming flow section (62) following the next forward end, as a result of which a gap (68) appears between the incoming flow section (62) and the inner surface (15) of the housing shell, narrowing in the direction opposite to the direction of rotation, in particular, a continuously narrowing gap. 3. Thin film processing device according to claim 2, characterized in that the oncoming flow section (62) covers the angular range , at least 10° of the perimeter of the rotor shaft body (50). 4. Thin film processing device according to any one of claims. 1-3, characterized in that at least part of the lifting elements (56) is formed respectively by an ironing element (43). 5. Thin film processing device according to any one of claims. 1-4, characterized in that the lifting element (56) comprises a wall sheet (560) having at least a substantially gable roof shape, the ridge (58) of which extends at least approximately parallel to the direction of the axis of the shaft (44 ) rotor. 6. Thin film processing device according to any one of claims. 1-5, characterized in that the lifting element (56), in particular the wall sheet (560), contains on its radial outer side at least one helically extending transport rib (70). 7. Thin film processing device according to any one of paragraphs. 1-6, characterized in that at least part of the lifting elements (56) is located in the area located in the middle between the rotating supports in which the rotor shaft (44) is mounted, preferably in the technological zone (25). 8. Use of a thin film processing device according to any one of claims. 1-7 for processing a material having, during processing, at least temporarily, a viscosity of 100 Pa⋅s or more.