Thin Film Processing Equipment

Abstract

The present invention relates to a thin film processing apparatus for processing viscous materials. The thin film processing apparatus according to the present invention comprises a process housing (12) having a heatable and / or coolable housing casing (14) surrounding a housing interior (16) and forming a material processing space (160), the process housing (12) being oriented at an inclination of up to 20° relative to the horizontal, an inlet nozzle (20) arranged in an inlet zone (18) of the process housing (12) for introducing the material to be processed into the material processing space (160), and an outlet zone (22) of the process housing (12) for discharging the processed material from the material processing space (160). and a drivable rotor shaft (44) disposed within the material processing space (160) and extending coaxially therewith for producing a material film on the inner surface (15) of the housing casing and conveying the material in a direction toward the outlet zone (22), the rotor shaft (44) having at least one lifting element (56) disposed on a rotor shaft body (50), the lifting element being configured to generate a lifting force in the direction of the rotor shaft body (50) during rotation of the rotor shaft (44).

Description

[Technical field]

[0001] The present application relates to a thin film processing device for processing viscous materials according to the introductory portion of claim 1. Typical thin film processing equipment is known to those skilled in the art and is used, for example, for distillation, concentration, devolatilization, drying, etc. of various substances. Furthermore, thin film processing equipment is also used for mixing and reactions in which a viscous state is present at least temporarily, in particular, for example, polymerization reactions. Thin film processing equipment is primarily used for continuous operation. [Background technology]

[0002] Thin film processing equipment includes thin film evaporators, which are based on the principle that dispersing material on the inner surface of a temperature-controllable housing wall results in high heat flow density, ultimately enabling large evaporation volumes and high evaporation rates in a single pass.

[0003] In order to distribute the material in a thin film, the rotor can in particular be provided with wiper elements. Suitable thin film evaporators additionally equipped with a material conveying facility are known to those skilled in the art under the name filmtruders.

[0004] A thin-film processing device in the form of a film truder is described, for example, in CH523087. This document describes a heatable and / or coolable processing chamber in which inclined blades are evenly arranged on the outer periphery of a cylindrical body, and a drive rotor is arranged coaxially with the body, on which wiper blades are arranged that reach the inner periphery of the housing casing in the axial direction or contact the inner periphery, and the drive rotor is rotated to rotate the inclined blades near the inner periphery of the housing casing. During operation, the workpiece is gripped by the rotated wiper blades and distributed in a thin film on the inner wall of the housing, and the obliquely arranged blade parts impart a motion component toward the gripped workpiece toward the discharge port.

[0005] DE 10050997 C1 describes a further thin-film evaporator, in which a shaft with scraper elements for dispersing the material introduced inside the housing is arranged in the heating chamber, the shaft having a bearing journal slidably mounted in a bearing bush.

[0006] In addition to thin film evaporators, which are usually oriented vertically in operation, further thin film processing apparatus are known to those skilled in the art, for example thin film dryers, which are generally oriented horizontally.

[0007] A corresponding thin-film dryer is described in DE 4117630, according to which an elongated vaned rotor is arranged in a heat exchanger tube, which transports the material to be dried to the inner surface of the heat exchanger tube. In order to ensure a high bending stiffness of the vaned rotor, a basket-like structure is proposed around the vaned rotor, which consists of clamping ties running in the longitudinal direction of the vaned rotor and fastening flanges that sandwich the clamping ties. In order to further increase the restoring force when the vaned rotor is deflected, radial spacers are arranged between the fastening flanges, which are uniformly distributed in the longitudinal direction of the vaned rotor. Furthermore, the vaned rotor is provided with a number of auxiliary vanes that are rotatably attached to the clamping ties of the vaned rotor and sweep the material on the inner surface. The auxiliary vanes also contribute to increasing the stiffness of the basket structure. However, since they are attached so as to be able to swing, they cannot transmit radial forces towards the axis of the vaned rotor. This structure makes the reactor more laborious to manufacture and, depending on the material to be treated, can cause problems with the flow of liquid from the inlet side to the outlet side.

[0008] WO 93 / 11396 relates to an evaporator apparatus for the thermal treatment, in particular drying of sludge, comprising a heatable hollow cylindrical evaporator body oriented substantially horizontally and provided with a product inlet at one end and a product outlet at the other end, and within the product-charged interior of the evaporator body is arranged an externally drivable rotor with substantially radially oriented vanes.

[0009] Furthermore, WO 2004 / 041420 discloses a thin film processing device in the form of a horizontally arranged mixer in which the components to be mixed are distributed in the form of a thin film on the inner wall of a hollow cylinder and the components are mixed by interaction between the rotor blades and the inner wall of the hollow cylinder.

[0010] GB952,101A discloses an evaporation apparatus consisting of a horizontal cylindrical vessel defining an evaporation chamber. The evaporation apparatus also has an agitator with stirring elements, the agitator being supported by an axial element arranged concentrically with the longitudinal axis of the vessel. The agitator and its drive are designed so that the material to be treated impinges on the wall of the evaporation chamber as the agitator rotates. In one embodiment, the agitator is composed of six radially extending arms evenly spaced around the circumference. The arms support an axially extending strip-shaped stirring member, the ends of which are adjustably mounted so as to be turned inwards.

[0011] The horizontal thin-film processing apparatus described in the prior art are directed to processes in which the material to be processed is brought to a dry state, in particular processes in which it can be converted into granules. Depending on the application of the thin-film processing apparatus, it is necessary to equip it with a long rotor shaft. For example, in apparatuses for the solution of cellulose and the production therefrom of what is called, for example, Lyocell fiber, relatively long rotor shafts are used, on the order of 10 to 15 m in the processing zone alone. This is because the water must first evaporate from the cellulose suspension introduced into the apparatus, and the suspension thus evaporated must be homogenized before a solution of the required quality can be obtained. Such apparatuses designed for the Lyocell process are usually built vertically, as in the case of filmtruders, and because of gravity, additional conveying members are provided so that finally a good cleaning of the processing surface of the apparatus is also achieved. However, due to the vertical type, very tall buildings must be provided to house the apparatus. In known vertical apparatuses, the product feed opening is located at the top, so that the product feed must also be set accordingly, as well as the drive, heating, vacuum, etc. equipment.

[0012] "Lyocell" is the generic name given by BISFA (The International Bureau for Standardization of Man-Made Fibres) to cellulose fibres produced without the formation of derivatives from cellulose. The Lyocell process requires dissolving cellulose without chemical modification (see Zhang et al, BioResources 13(2), 2018: 4577-4592). This dissolution step can be carried out in one or more stages. The two-stage process, for example as described in DE4441468, has the disadvantage that the adjustment of the water, solvent and cellulose concentrations in and between the two stages, which are carried out in different equipment, in particular an evaporator for pre-evaporation and a horizontal screw dissolver, is difficult, resulting in a non-homogeneous cellulose solution with poor properties for the further processing stage of spinning. A similar two-stage process is described in WO2013 / 156489A1, in which the substrate for the moulded article, for example a cellulose solution, is treated with the starting material in a vertical thin film evaporator and a thick film dissolver (kneading reactor) to obtain the moulded article.

[0013] In order to avoid using a two-stage device, the entire dissolution process must be completed in a single stage device. This generally requires a large size device. Examples of producing a cellulose solution using a vertical thin film processing device are described in EP0356419A2, WO94 / 06530A1, and WO2008 / 154668A1.

[0014] Due to the equipment-related and construction costs associated with vertical designs, horizontal thin-film processing equipment is generally preferred, but the weight of the rotor shaft and the associated deflection due to gravity make it difficult to achieve trouble-free operation at the same process conditions as with vertical installations, especially for equipment with relatively long rotor shafts. Summary of the Invention [Problem to be solved by the invention]

[0015] SUMMARY OF THE PRESENT EMBODIMENTS It is therefore an object of the present invention to provide a substantially horizontal thin film processing apparatus which ensures trouble free operation even when relatively long rotor shafts are provided.

[0016] It is a further object of the present invention to provide an effective dissolution process for cellulose that rapidly and efficiently transfers the cellulose from a solid material to a dissolved state in a single apparatus, particularly a thin film processor, preferably in a substantially horizontal thin film processor.

[0017] The first object is achieved by a thin-film processing apparatus according to claim 1. Preferred embodiments are set forth in the dependent claims.

[0018] According to claim 1, the present invention relates to a thin film processing apparatus for processing viscous materials, comprising the following configuration. a process housing having a heatable and / or coolable housing casing which encloses an axially extending, rotationally symmetrical housing interior and forms a material processing space, the process housing having an inclination of up to 20° with respect to the horizontal; an inlet nozzle arranged in an inlet zone of the process housing for introducing the material to be treated into the treatment space; an outlet nozzle arranged in an outlet zone of the process housing for discharging treatment material from the material treatment space; and a drivable rotor shaft disposed within the housing for producing a film of material on an inner surface of the housing casing and extending coaxially therewith for transporting the material in a direction from an inlet zone, through a processing zone, and toward an outlet zone.

[0019] The rotor shaft is characterized in that it comprises a central rotor shaft body and sweeper elements arranged on its outer periphery, the radially outer ends of the sweeper elements being spaced apart from the inner surface of the housing casing, the sweeper elements being generally arranged in a number of axially extending blade rows distributed around the circumference of the rotor shaft, the number of which depends on the circumference of the rotor shaft body.

[0020] According to the invention, the rotor shaft comprises at least one lifting element arranged on the rotor shaft body, which lifting element is designed to generate a lifting force in the direction of the rotor shaft body during rotation of the rotor shaft, as will be further explained below.

[0021] The process housing according to the invention, i.e. its longitudinal axis, is oriented at an inclination of up to 20° to the horizontal, preferably at an inclination of up to 10°, particularly preferably to the horizontal, i.e. with an inclination angle of at least about 0°. Due to the substantially horizontal orientation of the process housing of the device according to the invention, the process housing is generally supported on suitable support bearings in the proximal end region corresponding to the inlet zone and in the distal end region corresponding to the outlet zone. Furthermore, the rotor shaft arranged inside the housing is mounted on suitable rotor bearings in the proximal end region and in the distal end region, preferably the rotor bearings are subjected to both radial and axial forces in the proximal end region and are designed as radial bearings in the distal end region. As will be described later, at least one lifting element is preferably arranged in the center of the rotor, i.e. in the region of maximum deflection.

[0022] According to the invention, it has surprisingly been found that the deflection of the rotor shaft caused by the force of gravity can be effectively counteracted by the lifting elements or lifting elements arranged on the rotor shaft body. This allows trouble-free operation of devices with relatively long rotor shafts, particularly those used in the Lyocell process, even in a horizontal position. The technical effect obtained according to the invention is therefore particularly evident in thin-film processing devices whose housing interior forming the material processing space has a length of 5 m or more, preferably 8 m or more. Even at this length, therefore, a clearance equivalent to that of a film truder (in the vertical direction) can be ensured between the sweeper elements and the inner surface of the housing casing.

[0023] Furthermore, it became apparent in the course of the invention that horizontal devices can also convey very viscous materials quite well, if the rotor shaft is equipped with suitable conveying elements.

[0024] Thus, the sweeper elements arranged on the outer periphery of the rotor shaft are at least partially embodied as conveying elements.

[0025] Some of the sweeper elements are generally provided in the form of conveying elements, and further some of the sweeper elements are provided in the form of distributing elements. In the present description, sweeper elements which mainly distribute the material on the inner surface of the housing casing are called "distributing elements", and sweeper elements which mainly impart a conveying component to the material towards the outlet nozzle are called "conveying elements". It is also conceivable that sweeper elements act both conveying and distributing. Such sweeper elements are called "conveying-distributing elements" in the present description.

[0026] The distribution elements and the conveying elements generally differ in that the shear edge of the distribution element in each case encloses an angle with the axial direction so as to be at least approximately neutral with respect to conveying. On the other hand, the shear end of the conveying member is angled with the axial direction so as to impart a conveying component towards the outlet nozzle to the material. The shear end of the distribution element in each case therefore generally encloses an angle with the axial direction which is smaller than the angle that the shear end of the conveying element makes with the axial direction. The angle enclosed by the shear end of the distribution element with the axial direction is preferably in each case less than 5° and in this specific case at least about 0°. On the other hand, the angle enclosed by the shear end of the conveying member with the axial direction is in each case greater than or equal to 15°.

[0027] The presence of the conveying elements on the one hand ensures that even highly viscous materials can be transported through the treatment chamber at sufficiently high conveying speeds. In addition to high production capacities of up to 50,000 kg / h, high quality is also achieved even with temperature-sensitive materials, because the residence and treatment times, during which the material is exposed to high temperatures and high shear rates, can be kept sufficiently short.

[0028] On the other hand, the presence of the distribution element ensures very good distribution and optimal surface renewal on the inner surface of the housing casing (hereinafter also referred to as the "treatment surface"), even when the material has a very high viscosity.

[0029] Finally, optimal processing of very viscous materials, in particular high devolatilization rates, can thus be achieved according to the invention, while at the same time limiting the energy input to the material to a level required for the particular process, at which the material is not damaged, in particular not subject to thermal degradation.

[0030] As mentioned above, it is contemplated that the process housing may be tilted slightly relative to the horizontal, allowing material to remain within the process housing longer without backflow, which may be preferable in some applications.

[0031] The rotor shaft body of the device according to the invention may in particular comprise a spindle and a circumferentially arranged axially extending fastening strip by means of which the sweeper elements can be fastened to the spindle, but it is also conceivable that instead of the spindle the rotor shaft body is constructed as a hollow shaft, the sweeper elements being distributed around the circumference of the hollow shaft.

[0032] The process housing has, as mentioned above, a heatable and / or coolable housing casing which encloses an axially extending, rotationally symmetrical housing interior. The housing interior which forms the material processing space of the device is essentially circularly cylindrical. However, embodiments are also conceivable in which the housing interior narrows conically in the conveying direction or in which the housing interior is cylindrical in a first region and conically narrows in a region located downstream in the conveying direction.

[0033] The material processing space in the preferred embodiment can be divided into different zones depending on the conditions through which the material to be processed passes during processing. Or depending on the conditions and the purpose of the processing step, it can be specifically divided into an inlet zone (also called "feed zone"), a processing zone, an outlet zone (also called "discharge zone") and an optional post-processing zone. The processing zone can be further divided into a distribution zone and a conveying zone, in which a good distribution and surface regeneration of the material on the inner surface of the housing casing are in the forefront. On the other hand, in the transport area, it is mainly necessary to achieve a good material transport. The inlet zone, the processing zone (including in particular the distribution zone and the conveying zone), the outlet zone and the post-processing zone are generally arranged physically in succession. In this case, the post-processing zone is arranged outside the process housing, but is spatially connected to it. However, it is also conceivable that the post-processing zone is arranged before the discharge zone, i.e. inside the process housing.

[0034] On the one hand, in devices designed for the Lyocell process, for example, good distribution and rapid transport of the material is achieved at the very beginning of the inlet area, while the water from the cellulose suspension is evaporated. In the treatment zone, the main heat treatment is realized by a deliberately set combination of distribution and conveying, where the water is further evaporated. It is mainly in this distribution area that the suspension is expected to go into solution well as the water evaporates. In the conveying zone following the distribution zone, it is desirable to give the material with a high cellulose content a stronger conveying component in the direction of the outlet zone, where it is discharged via a corresponding outlet nozzle into the outlet zone and further treated in the post-treatment zone. In the post-treatment zone, the solution is homogenized by shear and mixing and the residence time is further extended. On the other hand, the cellulose in the treatment zone is generally almost completely solubilized. It is also conceivable to treat the cellulose so that it is completely solubilized only in the discharge or post-treatment section. As mentioned above, the post-treatment zone can be arranged arbitrarily before or after the discharge zone.

[0035] Besides the fact that the device according to the invention is suitable for the production of cellulose solutions, other applications for processing viscous materials are also conceivable. Here, the term "viscous material" means in the present description a material that has a viscosity of 100-15000 Pas at least temporarily during processing in the device according to the invention. The viscous material preferably comprises volatile substances that can be removed (evaporated or sublimated) in the thin film processing device.

[0036] As mentioned above, the technical effect obtained according to the invention is particularly noticeable in material processing spaces which extend axially over a length of at least 3 m, preferably at least 8 m, particularly preferably at least 10 m. The rotor shaft thus extends between the rotation bearings in the proximal and distal regions over a length of preferably at least 4 m, preferably between 10 and 15 m.

[0037] As will be further described below, it is particularly preferred to provide different configurations of the rotor shaft and / or sweeper elements arranged on the rotor shaft depending on the zone, in order to meet the objectives of the processing step carried out in said zone.

[0038] Inside the housing casing, a housing casing cavity is generally formed for the purpose of passing a heat transfer medium for heating and / or cooling. The housing casing usually has an inner housing casing wall and an outer housing casing wall with a gap therebetween, in which a conductive spiral for transferring a heat transfer medium, typically steam or hot water, is arranged. As will be described later, it is particularly conceivable to provide two or more heat transfer circuits, which have separate conductive spirals from each other and can therefore be temperature controlled independently of each other. For this reason, it is possible to set the inner surface temperature of the housing casing desired for a specific zone of the thin film processing device independently of the temperature of the other zones. From this point of view as well, it is preferable to use steam as a heat transfer medium in the processing zone and hot water in the exit zone.

[0039] According to a preferred embodiment, the lift element has a planar incident flow section with a leading end in the direction of rotation, which leading end is located farther away from the inner surface of the housing casing than the area of ​​the incident flow section following the leading end. For this reason, a gap is formed between the incident flow section and the inner surface of the housing casing, which is configured to narrow in the direction opposite to the direction of rotation. According to a particularly preferred embodiment, the incident flow section extends in a plane oriented at an angle to a tangent or tangential plane of the inner surface of the housing casing, whereby a gap is formed between the incident flow section and the inner surface of the housing casing, which is configured to narrow continuously in the direction opposite to the direction of rotation. Furthermore, it is preferred that the angle between the tangent or tangential plane of the inner surface of the housing casing and the incident flow section is in the range of 15° to 30°, and in particular about 25°. Here, the "tangent" of the inner surface of the housing casing means a tangent that is tangent to the inner surface of the housing casing, which has a circular cross section, at a position closest to the radially outermost end of the incident flow section. The gap formed between the inner surface of the housing casing and the incident flow section is preferably narrowed by a factor of 10 or more.

[0040] As the rotor shaft rotates, the material to be treated, which is generally highly viscous, is forced into the gap, and as a result, the flow force of the rotor shaft acting on the incident flow portion creates a hydrodynamic lift component perpendicular to the incident flow direction. This lift component is relatively high, especially for highly viscous materials, especially those with a viscosity of 100 Pas or more. This effectively suppresses shaft deflection, which is particularly effective when treating highly viscous materials.

[0041] In order to obtain a hydrodynamic lift component already at start-up, it is preferred to introduce a partial flow of the material to be processed at least in the start-up phase into the area of ​​the thin-film processing device where the lift element is present, in particular into the processing zone. For this purpose, the thin-film processing device can have, in addition to the inlet nozzle of the inlet zone, a further inlet nozzle arranged downstream of the inlet zone, in particular arranged in the processing zone. The proportion of this partial flow in the total amount of material introduced into the device is selected here in such a way that, on the one hand, a sufficiently high lift component is obtained and, on the other hand, the residence time of the material in the thin-film processing device is still long enough to ensure the desired processing. The proportion of the partial flow in the material introduced into the processing zone is preferably about 20% or less, and therefore in the material introduced into the inlet zone is about 80% or more.

[0042] A particularly advantageous lift effect for the purposes of the present invention is obtained for an incident flow portion covering an angular range of at least 10° around the circumference of the rotor shaft body, in particular an angular range of 10° to 20°, in particular an angular range of about 12°.

[0043] According to particularly preferred embodiments, at least part of the lifting elements are in each case formed by sweeper elements which, in addition to their function as lifting elements, also have the function of distributing the material to be processed (in the case of sweeper elements formed as distributor elements) or of additionally imparting to the material a conveying component in the direction of the material outlet (in the case of sweeper elements formed as conveying elements). The sweeper elements forming the lifting elements particularly preferably function as conveying and distributor elements, i.e. are provided as conveying and distributor elements.

[0044] The lifting elements particularly preferably consist of at least approximately equally spaced roof-like web plates, the ridges of which run at least approximately parallel to the axial direction of the rotor shaft. Due to the angular shape, the web plates are thus divided into first and second web plate surfaces which lie in planes running obliquely to each other.

[0045] The first web plate surface, leading in the direction of rotation, forms the entrance flow part of the lift element. As mentioned above, this first web plate surface spans an angular range β1 of at least 10°, in particular 10°-20°, around the circumference of the rotor shaft body. The second trailing web plate surface generally covers an angular range β2 of at least 15°, in particular 15°-30°. The angular range β covered by the entire web plate is therefore preferably in the range from 25° to 50°.

[0046] The angle enclosed between the first and second web plate faces is preferably in the range of 110° to 150°. The ratio of the length of the side forming the incoming flow portion to the side forming the trailing portion is preferably in the range of 1:0.5 to 1:0.8.

[0047] Depending on whether the sweeper element is intended to function primarily as a conveying element or additionally as a distribution element in addition to its function as a lifting element, the fins running in different ways can be arranged on the radially outer side of the web plate. The lifting element is thus provided with at least one spirally running conveying fin on its outer surface, in case a conveying effect is also intended. If the lifting element also functions as a distribution element, the fin is oriented so as to be conveying neutral, in particular at right angles to the axial direction or with a maximum conveying angle of 5°.

[0048] The angular shape of the web plate provides a shear edge running in the axial direction. Whether the main function of the lift element is as a conveying or distributing element, the material is in any case distributed by this shear edge to the inner surface of the housing casing. If conveying fins are provided, both the conveying and distributing members are generally provided by the web plate, so in this case the web plate forms the conveying-distributing member. The shear edge is preferably in the same plane as the conveying fin and is therefore arranged at the same distance from the treatment surface as the radially outer edge of the conveying fin. Alternatively, it is also possible to arrange the shear blades set back with respect to the radially outer edge of the conveying fin and at a greater distance from the treatment surface in comparison.

[0049] According to a preferred embodiment, at least a portion of the lift elements is located in a region centrally located between the rotor bearings on which the rotor shaft is supported. According to a specific embodiment, this region is in the treatment zone of the device. The lift component provided by the lift elements is therefore effective in the region or zone where the deflection of the rotor shaft is strongest.

[0050] For this embodiment, it is also preferred that at least some of the lift elements are arranged on the rotor shaft body helically offset from one another in the treatment zone, so that an optimal distribution of the lift forces or lift force components provided by the individual lift elements can be achieved over a portion of the treatment zone of any length.

[0051] Furthermore, in particular in the treatment zone, it is preferred that some of the lifting elements form a conveying and distributing element, in particular that at least one helically extending conveying fin is arranged on the radially outer side of a particular lifting element, in particular a web plate.

[0052] The radially outer edges of the conveying fins generally enclose an angle of more than 45° with the axial direction. Even highly viscous materials have a sufficiently high conveying component by the lifting elements to pass through the material processing space at the desired conveying speed. The radially outer edges of the conveying fins preferably enclose an angle of up to 65° with the axial direction. In particular, this angle is in the range of 50° to 60°.

[0053] In addition to the conveying effect of the conveying element being determined by the attack angle of the radial outer edge of the conveying fin, the conveying effect of the lift element can additionally be adjusted via the number of conveying fins or the distance between axially consecutively arranged conveying fins.

[0054] According to a further preferred embodiment, a concentric protective casing is formed in the inlet zone, which is arranged between the inner surface of the housing casing and the rotor shaft body and which almost completely surrounds at least the rotor shaft body, which ensures that the material does not drip or splash onto the rotor shaft body before the viscosity increases during processing, i.e. in the inlet area.

[0055] According to this preferred embodiment, the material to be treated and the gaseous substance components escaping during treatment are thus guided in parallel flow, where it is also preferred that the material and the gaseous substance components are guided in counterflow in the treatment zone adjacent to the inlet zone, where the viscosity of the material is low and the possibility of "material entrainment" by the evaporating components is taken into account in the inlet zone in terms of the setup of the device, whereas in the subsequent treatment zone, the contact of the material to be treated with the majority of the steam is minimized, so that optimal devolatization is achieved.

[0056] According to a particularly preferred variant of the above-mentioned embodiment, the protective casing is at least partially formed by a plurality of circumferentially distributed lift elements, in particular web plates, in this way the lift component required according to the invention is also achieved in the inlet zone.

[0057] The web plate arranged in the inlet zone preferably has at least one helically extending conveying fin on its radially outer side in order to achieve high conveying speeds and to suppress material accumulation in this region in particular.

[0058] Here, it is also preferred that a radially recessed channel is formed in each case between two lift elements, in particular web plates, arranged in succession in the circumferential direction. The steam generated during the processing of the raw material passes through this channel, reaches the end of the protective casing, then passes through the interior enclosed by the protective casing into a space separate from the processing chamber and is removed via a steam extractor.

[0059] According to a further preferred embodiment, a concentric protective casing may be formed in the treatment zone and / or in the outlet zone, which is arranged between the inner surface of the housing casing and the rotor shaft body and which at least almost completely surrounds the rotor shaft body, in particular a protective casing formed at least in part by a plurality of lift elements distributed in the circumferential direction. The presence of the protective casing prevents material also in these zones from falling onto the rotor shaft body and remaining "frozen" on the unheated rotor shaft body. This embodiment is particularly advantageous when the material also to be treated in the treatment zone or in the outlet zone does not have a viscosity high enough to completely prevent dripping or dripping of the material. This is particularly relevant during start-up or shut-down of the device or in case of breakdowns. It may also be preferred to design the rotor shaft to be heatable, so that material dripped onto the rotor shaft body does not freeze. That is to say, in this preferred embodiment, means for heating the rotor shaft, in particular the rotor shaft body, are thus provided.

[0060] Besides the aforementioned lift elements, which preferably also have the function of conveying, distributing or conveying and distributing elements, the rotor shaft according to a further preferred embodiment further comprises sweeper elements consisting of radially projecting teeth, which are typically fixed in each case to one of a number of axially extending flanges arranged on the hollow shaft. Such sweeper elements typically impart no or only a very small lift component to the rotor shaft.

[0061] Depending on the orientation of the shearing edges of the teeth with respect to the axial direction, a distribution element or a conveying element is formed by the corresponding sweeper element, as has already been explained in connection with the lifting elements as well. A sweeper element whose teeth have shearing edges which enclose an angle with the axial direction of less than 15°, in particular less than 5°, thus forms a distribution element, whereas if the angle between the shearing edges and the axial direction is more than 15°, in particular more than 45°, the sweeper element forms a conveying element.

[0062] According to a particular embodiment, a sweeper element is provided as a conveying element, in which said angle is in the range of 15° to 30°, in particular about 20°. For example, it is conceivable that the tooth has a radially inner part attached via a flange in a plane parallel to the axial direction and a radially outer part with a shear end at the radially outer end in a plane inclined to the axial direction.

[0063] Depending on the application, and alternatively to this embodiment, it may be preferred that at least some of the shear edges of the sweeper elements enclose an angle smaller than the above-mentioned angle, in particular running at least approximately parallel to the axial direction, i.e. an angle of about 0° to the axial direction. In the latter case, those sweeper elements functioning as distribution elements are neutral with respect to conveying and have exclusively a distribution function. The decision to select which specific configuration of the sweeper elements ultimately depends on the material to be processed and may vary.

[0064] As mentioned above, the distribution between the distribution elements and the conveying elements depends largely on the intended purpose of the device and the zone in question. According to a preferred embodiment, the ratio between the number of conveying elements and the number of distribution elements is for example higher in the conveying zone than in the distribution zone, since in the conveying zone the conveying of material is more important.

[0065] According to a further preferred embodiment, the distribution elements are arranged alternately with the conveying elements in the circumferential direction of the rotor, since in this way a very homogeneous distribution of the material on the treatment surface can be ensured.

[0066] In a discharge zone adjacent to the treatment zone, the treatment space is discharged through a discharge nozzle, while the rotating shaft may be configured to clean the inner housing wall and sweep the product into a conveying member branching downwards. For example, it is conceivable that the conveying member is provided in the form of a vertically arranged cone, in which the material reaches a sufficient feed height and is discharged by a screw or, more preferably, a gear pump. It is further conceivable that a spiral is applied to the rotor shaft in the distal end region, i.e. just before the end cover of the process housing, which spiral returns the material not collected by the outlet nozzle and the discharge system arranged downstream thereof towards the outlet nozzle and away from the distal end.

[0067] Depending on the application, it may be preferable and conceivable to provide further discharge devices for the discharge. In particular, it is conceivable for the outlet nozzle to be connected to a discharge system in the form of a single or twin discharge screw, preferably with an axial direction perpendicular to the axial direction of the process housing. The purpose of this discharge system is to pump the processed material or product and to increase the pressure for downstream processing, in particular downstream filters or spinning nozzles in the case of Lyocell solutions. For this purpose, a booster pump may also be used in addition.

[0068] In the case of a discharge system in the form of a twin discharge screw, it may be preferable to further equip it with kneading and / or dispersing blocks, by means of which high shear is achieved and ultimately further homogenization and, in the case of the Lyocell process, a solution of the smallest particles in the material mass is obtained.

[0069] The discharge devices can be configured either for a horizontally extending conveying direction or for a vertically extending conveying direction. A discharge pump is generally installed in the outlet region of the discharge system, via which the discharged material can be removed or fed to further devices such as filters and / or spinning nozzles.

[0070] In particular, it is conceivable for the discharge device to have a funnel with a vertically extending conveying direction and a discharge shaft arranged therein, running coaxially therewith and having a single discharge screw in at least some areas. This embodiment has the advantage that the rotation speed of the rotor shaft present in the process housing can be decoupled from the rotation speed of the discharge shaft in the discharge system.

[0071] It is also conceivable to provide a discharge device in which the axis of the funnel coincides with the axis of the rotor shaft. In particular, it is conceivable here to provide a discharge device in which the rotation shaft projects into the funnel and which has one discharge screw in a cylindrical funnel section adjacent to a conical funnel section in the conveying direction.

[0072] According to a further preferred embodiment, the thin-film processing device further comprises a cleaning device designed to be introduced into the process housing when the end cover is opened and to be movable back and forth in the axial direction. The cleaning device can comprise, for example, suitably arranged brushes or high-pressure water jets. In particular in the above-mentioned embodiment, in which the inlet zone between two circumferentially arranged web plates is formed with longitudinally running steam channels, a quick and easy cleaning of the thin-film processing device can thus be ensured. In particular, a complex dismantling of the device in order to reach the cleaning device at the point to be cleaned can be avoided.

[0073] It is further conceivable to arrange a plate-shaped cleaning element on the rotor shaft body on the distal side, i.e. directly adjacent to the front side of the process housing, which cleaning element prevents material from accumulating on the inner surface of the distal end face and protects the distal rotor bearing from contamination by material.

[0074] As mentioned above, the device according to the invention is designed in particular for the thermal fractionation of substance mixtures and is provided in particular in the form of a thin-film evaporator, thin-film dryer or thin-film reactor, preferably in the form of a thin-film evaporator.

[0075] This equipment allows optimal processing of materials with viscosities of up to 15,000 Pa·s, in particular with devolatilization, possibly in combination with devolatilization or reacting independently.

[0076] Typically, the viscosity of the material to be treated in the device according to the invention is in the range of 100 to 5000 Pa·s, in particular 300 to 3000 Pa·s, in particular 500 to 1000 Pa·s, at the operating temperature and at a shear rate of D=10 sec -1 This is regarding.

[0077] Furthermore, the apparatus is particularly suitable for the treatment of relatively temperature sensitive materials, since the thermal energy to which the material is exposed may be optimally set by the relatively low selectable temperature and residence time on the treatment surface.

[0078] As mentioned above, the thin film processing apparatus according to the invention is particularly suitable for the production of cellulose solutions, especially for use in the production of lyocell fibres.

[0079] Specifically, the operating temperature of the thin film processing apparatus according to the present invention is generally in the range of 80 to 120°C, particularly 90 to 115°C, and especially 100 to 110°C.

[0080] In order to transfer the cellulose solution into a homogeneous solution in the best possible way, the preparation (for example as described below) can ideally be carried out under vacuum (pressure p, in mbar), for example according to the described formula (p = 122.e^ - (0.05c(Cell)) ), which has been found. The cellulose concentration ("c(Cell)", % by mass) in this specification is preferably between 6% and 20%, in particular between 10% and 15%. In these concentration ranges, efficient, rapid and practically complete dissolution of cellulose was possible.

[0081] The peripheral speed of the rotor shaft of the thin film processing apparatus according to the present invention is generally in the range of 6 to 12 m / sec, particularly 8 to 10 m / sec.

[0082] In a further aspect, the present invention relates to a method for producing a cellulose solution with a solvent from a suspension of cellulose in a solvent and a volatile non-solvent, comprising the steps of: introducing the suspension into an inlet of a thin-film processing device; applying and distributing the suspension in the form of a film on a temperature-controlled housing casing by means of a sweeper element rotating about a common axis in a process housing of the thin-film processing device, evaporating the volatile non-solvent and dissolving the cellulose; and outputting the cellulose solution from the thin-film processing device through an outlet, characterized in that at least a part of the sweeper element advances the cellulose in the direction of the outlet. Particularly preferably, the rate of discharge at the outlet is such that the discharge rate at the outlet is 300 kg / h or more, particularly preferably 350 kg / h or more of cellulose solution per square meter of the surface of the temperature-controlled (heat-exchanged) housing casing (inner wall).

[0083] The sweeper elements, in particular the conveying elements, according to the invention allow a rapid advance of the cellulose suspension or the resulting solution in the Lyocell process. This allows for a rapid treatment, dissolution and discharge of the cellulose or cellulose solution. For example, in the examples according to the invention (see row ac in the table), it has been shown that quantities of 145.8 kg / h per square meter and 887.5 kg / h per square meter can be produced. This is the case for a laboratory-scale thin-film processing device with a heat exchanger (also called "heat exchanger surface") of 0.55 square meters for temperature control of the surface of the housing casing. These quantities are essentially higher than those described, for example, in EP 0356419 A2 (72 kg / h for a similarly sized device). In order to achieve an economically viable size of the dissolution device depending on the quantity of cellulose solution discharged, quantities of cellulose solution of more than 300 kg / h per square meter of temperature-controlled surface have been found to be advantageous. Tests have confirmed that from quantities of about 600 kg / h per square meter, the quality (homogeneity) of the solution decreases. Thus, since there are no gravity-driven conveying members in the horizontal direction, the sweeper can be set for a fast conveying speed, which allows an efficient dissolution process of the cellulose. Surprisingly, the forward driving of the process in the process housing also leads to a highly efficient dissolution process, which allows the cellulose to be rapidly and completely transferred from a non-uniform suspension to a homogeneous cellulose solution within the scope of the Lyocell process. The quality of the resulting cellulose solution meets the prerequisites for the forming steps in the Lyocell process, such as spinning to form filaments. These advantages are in principle independent of a horizontal setting. Although the device according to the invention was developed for a horizontal support, application advantages are also provided in the vertical direction, especially when highly viscous suspensions or solutions are processed. This aspect of the invention is therefore independent of the orientation of the process housing, although here too, the horizontal orientation is of course preferred.

[0084] The advancement by the sweeper element in the direction of the discharge outlet is preferably such that the discharge rate at the discharge outlet is 300-600 kg / h, preferably 350-550, particularly preferably 380-480 kg / h of cellulose solution (completely processed material in the process housing) per square meter of the surface of the housing casing, which is temperature-controlled by means of a heat exchanger.

[0085] The advance can be adjusted, for example, by the number of sweeper elements (conveying elements as mentioned above) involved in the advance, their angle and the rotation speed of the conveying elements. The angle enclosed in each case by the shear end of the conveying element and the axial direction is preferably more than 15°, more preferably between 15° and 30°, particularly preferably about 20°. It is preferable that at least 1 / 3 of the sweeper elements are conveying elements.

[0086] The division according to the invention is further particularly advantageous for the different treatment zones (entrance zone, treatment zone, exit zone) and has a positive effect on the quality of the obtained cellulose solution, which is rapidly advanced in the advance according to the invention. In the entrance zone, the temperature of the material, in particular the suspension, is preferably at least 10° C. lower than in the treatment zone. The aforementioned pitched roof shaped web plate is preferably provided in the entrance zone. Thus, the formation of lumps at the entrance of the suspension to the device is effectively avoided and an efficient transport by the parallel flow of material and steam streams is ensured. In the entrance zone, a layer of suspension as uniform as possible is applied to the inner surface of the housing casing.

[0087] The conveying and distributing elements described above and below are provided in particular in the processing zone, where the ratio of conveying and distributing elements is preferably 2:1 to 1:2, preferably with sweeper elements having both functions (conveying and distributing) being assigned to both groups. The ratio of the lengths of the outer shear ends, i.e. the radially outer ends of the elements in contact with the suspension, is preferably adjusted additively or alternately. The ratio of the sum of the lengths of the outer shear edges of the conveying elements to the sum of the lengths of the outer shear edges of the distributing elements is preferably 2:1 to 1:2.

[0088] In the exit zone, there are preferably no conveying elements or only a few conveying elements, i.e. mostly only distributing elements. Preferably, a maximum of 10% of the sweeper elements in the exit zone are conveying elements and / or at least 90% of the sweeper elements are distributing elements without a conveying function. These proportions can also be interpreted based on the sum of the lengths of the outer shear edges of the sweeper elements, as above. In other words, preferably a maximum of 10% of the sum of the lengths of the outer shear edges of the sweeper elements are assigned to conveying elements and / or preferably at least 90% of the sum of the lengths of the outer shear edges of the sweeper elements are assigned to distributing elements.

[0089] The ratio of the length of the zones is preferably 5%-25% inlet zone, 50%-90% in processing zone and the remaining 5%-25% in outlet zone. However, apart from the above embodiment, according to which no or only a few conveying elements are provided in the discharge zone, it is preferred to provide sweeping elements which exert a conveying component on the material, if the discharge system has a conveying direction extending horizontally. In particular, it is preferred that a web plate according to the above description is arranged on the rotor shaft in the distal end region of the outlet zone or in the discharge system, which web plate acts on the one hand as a lifting element and on the other hand as a conveying and distribution element. In this way, it is taken into account that no gravitational component forces act when the discharge device is in the horizontal direction. However, even in such a horizontal discharge system, the presence of the conveying and distribution device ensures an efficient discharge of the material, even if the discharged material has a relatively high viscosity.

[0090] It is also particularly preferred in this embodiment if the web plates are arranged on the rotor shaft body helically offset from one another in the longitudinal section of the rotor shaft corresponding to the distal end region of the outlet zone.

[0091] The product amount at the outlet depends on the amount of suspension fed, but will be somewhat lower due to evaporation of the non-solvent in the process housing. The evaporated non-solvent is preferably not discharged at the outlet of the cellulose solution (highly viscous liquid mass) but is preferably led in the vapor phase countercurrent to the flow of the cellulose suspension and is therefore removed near the inlet.

[0092] The casing (inner wall) of the housing is preferably temperature controlled using a heat exchanger. The heat of the high-temperature fluid generated in the Lyocell process can be economically utilized by heating the device by means of a heat exchanger. The heat exchanger or the inner wall of the housing casing (process housing) is preferably heated to a temperature of 90°C to 130°C. In particular, at least the process zone is directly temperature controlled. The waste heat from the treatment zone can be used to heat the inlet and outlet zones, which are indirectly temperature controlled by the heat exchanger. The heat medium for the heat exchanger can be either water, oil or steam. Temperature control by electrical heating is also possible.

[0093] The length of the casing from the inlet to the outlet, where the temperature is controlled using a heat exchanger, is 0.5 m or more, preferably 1 m to 20 m, for example 4 m to 18 m, or 6 m to 17 m, or 8 m to 16 m, preferably 10 to 15 m. Even if the processing time of the suspension is the same, the longer the length, the faster the material will move and the greater the production volume.

[0094] An essential criterion for the volume treatable in the process housing is its surface used for the treatment of the suspension, i.e. the surface under the influence of the heat exchanger, which brings about the evaporation of the non-solvent by heating. The surface of the accommodation casing, which is temperature-controlled by means of a heat exchanger, is preferably 0.5 m2 to 150 m2, for example 1 m2 to 140 m2, 2 m2 to 130 m2, 5 m2 to 120 m2, 10 m2 to 100 m2, 15 m2 to 80 m2, preferably 60 m2 to 125 m2. Due to the horizontal support according to the invention, the structural reasons for the size limitation (such as the height of the building) in vertical thin-film processing equipment are no longer relevant, since the thin-film processing equipment can be easily handled in a horizontal plane.

[0095] The volumes and corresponding specific loads of the individual treatment zones in one embodiment according to the invention are as follows: TIFF0007645820000001.tif27155

[0096] In the tested thin-film processing equipment, it was found that the ideal homogenous cellulose solution was obtained by feeding a specific suspension. 3 ) is a convenient common comparable characteristic value. This gives us what is called the "specific load". This specific load is the introduced mass flow rate divided by the volume delivered to the individual zone, i.e. Specific Loading = Mass Flow Rate / Volume of Zone is defined as:

[0097] This method produces 76-378 kg / h / dm 3 , 66-262kg / h / dm in process zone 3 , 2-125kg / h / dm at the exit zone 3 , 0-500kg / h / dm in post-treatment zone 3provides the best solution quality at a particular load of cellulose. In a preferred embodiment, the average processing time of the cellulose in the process housing (time from inlet to outlet) is at least 20 seconds, preferably 30 to 1000 seconds. The processing time is influenced by the forward speed and the length of the process housing (especially the part with the heat exchanger). For example, the processing time is 60 to 900 seconds, or 70 to 800 seconds, or 80 to 700 seconds, or 90 to 600 seconds, or 100 to 500 seconds, or 110 to 400 seconds, or 120 to 350 seconds, or 130 to 300 seconds. The processing time is preferably up to 350 seconds, particularly preferably up to 300 seconds.

[0098] The sweeper elements are preferably rotated at a speed of at least 50 revolutions per minute, which corresponds to the rotational speed of the rotor shafts, since the rotation of the rotor shafts causes the sweeper elements to rotate about a common axis. The speed of the sweeper elements is preferably at least 50 revolutions per minute, more preferably at least 100 revolutions per minute, more preferably at least 200 revolutions per minute, more preferably at least 300 revolutions per minute, more preferably at least 350 revolutions per minute, more preferably at least 400 revolutions per minute, more preferably at least 450 revolutions per minute, more preferably at least 500 revolutions per minute or at least 550 revolutions per minute, or any range of these values ​​or more, preferably in the range of 50 revolutions per minute to 800 revolutions per minute.

[0099] The radially outermost ends of the sweeper elements are preferably moved at a speed of between 1.5 m / s and 12.5 m / s. The movement is achieved by rotation of the sweeper elements. The radially outermost ends of the sweeper elements contact and handle the suspension.

[0100] Preferably, one or more sweeper elements are moved at a frequency of 1500-4000 / min in succession over a portion of the housing casing, temperature-controlled by means of a heat exchanger. This parameter is also called the blade succession frequency, which indicates how many sweeper elements are partially swept per minute. It is determined by the number of radially arranged sweeper elements and the rotation speed. The number of radially arranged sweeper elements may differ depending on the zone. The sweeper elements may be arranged offset on the rotor, which may result in overlapping of the offset arrangement in the direction of rotation, so that successive higher blade frequencies may be applied to some parts (even within the same zone). In the area without overlapping due to offset arrangement, the processing zone, it is preferable to achieve a specified frequency of 1500-4000 / min. The frequency is preferably 1800-3000 / min.

[0101] Directly successive sweeper elements are preferably spaced apart between the radially outermost ends of the sweeper elements by a distance of 100 mm to 300 mm. This distance is also called the blade tip spacing. This spacing is preferably selected in areas where there is no overlap due to the offset arrangement and / or provided in the treatment zone. The blade tip spacing is preferably 150 mm to 280 mm, or 180 mm to 260 mm, or 190 mm to 250 mm, or 200 mm to 240 mm.

[0102] The shear rate of the suspension, which is spread and dispersed into a film by the effect of the sweeper element, is preferably 3000 s -1 ~30000s -1 , particularly preferably 4000s -1 ~28000s -1 It is. 5000s -1 ~26000s -1 , 6000s -1 ~24000s -1 , 7000s -1 ~22000s -1 , 8000s -1 ~20000s -1 or 10000s-1 ~30000s -1 , 11000s -1 ~28500s -1 , 12000s -1 ~27000s -1 , 12000s -1 ~25500s -1 , 13000s -1 ~24000s -1 Shearing thoroughly mixes and mechanically processes the suspension, facilitating evaporation of the non-solvent and contributing to the production of a well-mixed, homogenous solution.

[0103] Preferably, 1.5 kg / h to 30 kg / h, preferably 5 kg / h to 20 kg / h of suspension are introduced at the inlet per sweeper element. 20 to 5000 sweeper elements are preferred, for example 25 to 4000 or 30 to 3000 or 40 to 2000 sweeper elements are provided. Preferably, 300 kg to 100000 kg, preferably 10000 kg to 50000 kg of suspension are introduced per hour.

[0104] In the Lyocell process, the preferred film thickness (layer thickness) of the suspension in the treatment zone is 1 mm to 50 mm, preferably 2.0 mm to 15 mm, particularly preferably 2.2 mm to 5 mm. The layer thickness can be controlled by the amount of suspension introduced and the treatment speed (number of rotations, number of sweeper elements, in particular the number of conveying elements, their angle and therefore advancement). It is also controlled by the distance of the radially outermost ends of the sweeper elements from the inner surface of the housing casing. This distance should be on average in the range of 1 mm to 50 mm, preferably 2.0 mm to 15 mm, particularly preferably 2.2 mm to 5 mm.

[0105] In a preferred embodiment, the sweeper element is 0.8 dm 2 ~2dm 2 is in contact with the suspension or solution evenly over an area of

[0106] In a preferred embodiment, the tip load area of ​​the rotor blade is an important variable with regard to the active treatment area of ​​the suspension. This has a very large influence on the quality of the discharged cellulose solution. This rotor blade tip load area represents the sum of the end surfaces of all sweeper and conveying elements (jointly "rotor blades") in the treatment zone. Its end or "tip" is formed by an area called the "end area". End area is any area of ​​the sweeper or conveying element facing the inner surface of the housing casing. Usually, sweeper and conveying elements have at their tip (maximum distance from the rotor axis) an area that runs along the inner surface contour of the housing casing and at a certain distance from it. The surface facing the inner surface of the housing casing is highly relevant in the treatment zone, especially for sweeper and conveying elements, but not for lift elements. This parameter (see table ad) is approximately 0.02 m in the tested thin-film processing equipment. 2 This parameter is increased according to the requirements of large facilities, preferably 0.02 m 2 ~6m 2 In particular, 2 m 2 ~6m 2 and more particularly preferably in the range of 4 m 2 ~6m 2 In these ranges, favorable performance of the rotor drive is achieved. At the same time, the discharged cellulose solution shows very good quality in terms of completeness of dissolution of cellulose and homogeneity of the cellulose solution. In addition, there is a parameter called engagement force (see table af), which is determined by the sum of the end area areas of the sweeper and the conveying elements of the treatment zone (m 2 ) based on the amount of suspension introduced per second (kg). This parameter is 1.10 to 1.40 kg / sm 2 The best cellulose quality is obtained with values ​​in the range of 5.5 kg / sm. 2Above this, the mass / solution homogeneity at the outlet becomes poor. The engagement force is a key parameter for determining the design parameters of the method. In particular, it is determined by the amount of suspension introduced per unit time. If too much suspension is introduced, the method becomes overloaded and the cellulose does not dissolve in the solvent in sufficient quantities, which means that the downstream steps of the method do not work well or at all.

[0107] The suspension preferably has a thickness (layer thickness) according to the formula s=(ln(ms / 60)) / x, where s is the thickness (mm), ms is the transport flow rate of the suspension and x is a constant between 0.45 and 7, preferably 0.5866. This thickness is preferably achieved in the treatment zone.

[0108] Of course, these parameters may be combined with each other. For example, the discharge at the outlet is 1 m 2 of the surface of a temperature-controlled (heat exchanger-based) housing casing (inner wall). 2 It is particularly preferred that the cellulose solution is 300 kg / h or more, particularly preferably 350 kg / h or more per hour. The average processing time of the cellulose in the process housing (time from inlet to outlet) is at least 150 seconds, preferably 150 to 1000 seconds. The (one or more) sweeper elements are continuously moved over a part of the accommodation casing whose temperature is controlled by means of a heat exchanger, at a frequency (sweeper element frequency) of 1500 to 4000 / min, and / or the shear rate of the suspension applied and dispersed in a film form by the effect of the sweeper elements is 3000 s. -1 ~30000s -1 It is.

[0109] The common axis of the rotating sweeper elements is preferably inclined at most 20° to the horizontal. When the parameters according to the invention are observed with respect to the method, improved production of the solution, particularly the advance, can be achieved without a horizontal orientation, although this orientation is nevertheless preferred. Thus, thin film processing equipment as described above can be used in the method according to the invention (i.e. in each of the specific or preferred embodiments described) without necessarily providing a horizontal orientation.

[0110] A solvent is an agent for dissolving cellulose. Here, a high temperature is usually used, for example 70°C or higher, particularly 75°C or higher or 78°C or higher. Usually, cellulose is mixed with a non-solvent, i.e., a substance that cannot dissolve cellulose, to obtain a suspension, and then a solution, which is also suitable for dissolving cellulose. Here, the proportion of the solvent in the mixture must be high, for example 60% (mass%) or higher, and this may vary depending on the solvent, and the proportion can be easily determined by a person skilled in the art in a dissolution test.

[0111] The cellulose solution preferably has a cellulose concentration that is typical for the Lyocell process, and may therefore be 4% to 23%, preferably 6% to 20%, in particular 8% to 18%, or 10% to 16% (all defined by mass %).

[0112] The absolute pressure in the reactor is preferably below 100 mbar, in particular between 40 mbar and 70 mbar.

[0113] The solvent for cellulose is preferably a tertiary amine oxide (amine-N-oxide), particularly preferably N-methylmorpholine-N-oxide. Alternatively or additionally, it may be an ionic solvent. Such ionic solvents are described, for example, in WO03 / 029329; WO2006 / 000197A1; WO2007 / 076979A1; 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; Fernandez et al. J Membra Sci Technol 2011, S:4; etc. Such ionic solvents preferably contain organic cations such as ammonium, pyrimidium, pyrrolidinium or imidazolium cations, preferably 1,3-dialkyl-imidazolium salts, for example halides. Also, water is preferably used here as the added non-solvent. Particularly preferred are solutions of cellulose and 1-butyl-3-methylimidazolium (BMIM), for example with chloride as counterion (BMIMCl), or 1-ethyl-3-methylimidazolium (again, preferably chloride, acetate or diethyl phosphate), or 1-hexyl-3-methylimidazolium or 1-hexyl-1-methylpyrrolidinium (preferably bis(trifluoromethylsulfonyl)amide anion) in water. Furthermore, the ionic solvent is 1,5-diazabicyclo[4.3.0]non-5-enium, preferably as acetate.Examples of the usable compounds include 1-ethyl-3-methylimidazolium acetate, 1,3-dimethylimidazolium acetate, 1-ethyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium acetate, 1-ethyl-3-methylimidazolium diethyl phosphate, 1-methyl-3-methylimidazolium dimethyl phosphate, 1-ethyl-3-methylimidazolium formate, 1-ethyl-3-methylimidazolium octanoate, 1,3-diethylimidazolium acetate, and 1-ethyl-3-methylimidazolium propionate.

[0114] The suspensions preferably treated in the process according to the invention contain 58 to 75.3% by weight of N-methylmorpholine-N-oxide (NMMNO or NMMO), 19 to 26.1% by weight of water and 5.7 to 15.9% by weight of cellulose. It is also possible to produce solutions containing more than 20% by weight of cellulose.

[0115] The invention will now be further described with reference to the accompanying drawings.

[0116] FIG. 1 is a schematic side view of a thin film processing apparatus according to the present invention. FIG. 2 is a top view of the thin film processing apparatus shown in FIG. FIG. 3 is a top view of a further thin film processing apparatus. FIG. 4 is a cross-sectional view of the process housing of the thin film processing apparatus shown in FIG. 3 taken along plane AA in FIG. FIG. 5 is a perspective view of a portion of a rotor shaft for an apparatus according to the invention. FIG. 6 shows a perspective view of a portion of a further rotor shaft of a thin-film processing apparatus according to the invention in the region corresponding to the inlet zone. FIG. 7 is a cross-sectional view of the rotor shaft shown in FIG. 6 disposed in a process housing. FIG. 8 is a side view of the discharge zone of a further embodiment of a thin film processing apparatus according to the present invention having a vertically extending discharge system. FIG. 9 is a plan view from above of the exit zone of the embodiment shown in FIG. FIG. 10 is a front plan view of the embodiment shown in FIG. FIG. 11 is a side view of the discharge zone of a further embodiment of thin film processing apparatus according to the present invention having a horizontally extending discharge apparatus.

[0117] 1 includes a process housing 12 having a housing casing 14 that encloses an axially extending cylindrical housing interior 16. The housing interior defines a material processing space 160.

[0118] In the proximal end region of the process housing 12 an inlet nozzle 20 is arranged for introducing the material to be processed into the material processing space 160, while in the distal end region of the process housing 12 an outlet nozzle 24 is arranged for discharging the 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. The processing zone 25 is between the inlet and outlet zones.

[0119] The process housing 12 is supported at its proximal and distal end regions via suitable support bearings, specifically a fixed bearing 26 at its proximal end region and a floating bearing 28 at its distal end region.

[0120] The inlet nozzle 20 is arranged in the illustrated embodiment tangentially to the housing casing 14 and opens into the material treatment space 160 in the lower half, as can be seen in particular in FIG.

[0121] The outlet nozzle 24 is configured in the illustrated embodiment in the form of an opening leading to an exhaust system 30 located immediately below, at the bottom of the housing casing 14, in this example having twin exhaust screws 300 having a conveying direction running perpendicular to the axial direction of the process housing 12.

[0122] The housing casing 14 has an inner housing casing wall, which in the illustrated embodiment is double-walled, and an outer housing casing wall, with a gap between which a conductive spiral for conducting a heat exchange medium, typically steam or hot water, is arranged. In the illustrated embodiment, two heat transfer circuits are provided: a first heat transfer circuit with a first heat transfer medium inlet 32 ​​in the inlet zone or inlet side region of the process zone 25 and a first heat transfer medium outlet 34 in the outlet side region of the process zone 25, and a second heat transfer circuit with a second heat transfer medium inlet 36 in the distal region of the outlet zone 22 and a second heat transfer medium outlet 38 in its proximal region. The two heat exchange circuits are temperature controlled independently of each other, since they separate the conductive spirals from each other. For this purpose, separate heating and cooling elements (not shown) for controlling the temperature of the heat transfer medium are assigned to each heat transfer circuit, from which the heat transfer medium is introduced into the corresponding conductive spiral from the heat transfer medium inlet 32 ​​or 36 via a heat transfer pump. For example, it is conceivable that a first heat transfer circuit associated with the treatment zone 25 uses steam as the heat carrier, and a second heat transfer circuit associated with the outlet zone 22 uses hot water as the heat carrier.

[0123] Furthermore, an upwardly running steam nozzle 40 is arranged in the housing casing 14, via which low boiling point components can be removed from the material treatment space 160.

[0124] The apparatus further includes a rotor 42 comprising a drivable rotor shaft 44 disposed coaxially within the housing interior 16 for producing a film of material on an inner surface 46 of the housing casing, as shown, for example, in FIG.

[0125] The rotor 42 for this purpose preferably has a variable speed drive 48. In the illustrated embodiment, a spur gear motor 480 is provided which acts on a drive shaft portion of the rotor shaft 44 to rotate it, the drive shaft portion being sealed off from the material processing volume 160 by a mechanical seal.

[0126] A material film is produced on the inner surface 15 of the housing casing and the material is transported in the direction of the outlet nozzle via sweeper elements 43, which are divided into distribution elements 431 and conveying elements 432 according to their main function, as described further below.

[0127] The rotor shaft of the device according to the invention is shown in Figure 5. It has a rotor shaft body 50 consisting of a main shaft 52 and six axially running fastening straps 54 welded to the main shaft and distributed around its circumference. These fastening straps 54 are flanged and fitted with lifting elements 56, which in the illustrated embodiment are provided in the form of sloped roof-shaped web plates 560, the tops 58 of which run at least approximately parallel to the axial direction of the rotor shaft 44.

[0128] The web plate 560 with its angular form is thus divided into first and second web plate faces 60a and 60b which lie in planes running obliquely relative to one another. The first web plate 60a, which is the leading one in the direction of rotation, forms the entrance channel section 62 of the lift element 56. The tip 64 of the entrance channel section 62 in the direction of rotation is located farther away from the inner surface 15 of the housing casing than the area 66 which extends rearward from the tip of the entrance channel section 62. Thus, between the entrance channel section 62 and the inner surface 15 of the housing casing, a gap 68 is formed which narrows continuously in the direction opposite to the direction of rotation. As the rotor shaft rotates, the highly viscous material to be treated is now forced into the gap 68, so that the flow force of the rotor shaft 44 acting on the entrance channel section 62 imparts a hydrodynamic lift component perpendicular to the direction of the entrance flow, which can counteract the deflection of the rotor shaft 44.

[0129] In the example specifically shown in Figure 7, the first web plate 60a or inlet channel section 62 subtends an angle α with a tangent or plane to the housing casing inner surface 15 and occupies an angular range β1 circumferentially about the rotor shaft body 50. The continuously extending web plate surface occupies an angular range β2. Thus, the lift element as a whole occupies an angle β.

[0130] The helically immersed conveying fins 70 are disposed radially outwardly of the web plate 560 and are oriented obliquely relative to the axial direction of the rotor shaft 44 .

[0131] The gable 58 of the web plate 560 forms an axially running shear edge 72 which is set back relative to the radially outer edge of the conveying fin 70 and is therefore located at a greater distance from the inner surface 15 of the housing casing in comparison.

[0132] In this way, on the one hand, a hydrodynamic lift component in the direction of the central rotor shaft body 50 is imparted to the rotor shaft 44 by the web plate 560 arranged on the rotor shaft 44. On the other hand, the material is distributed on the inner surface 15 of the housing casing by the axially running shear blades 72, which are further imparted a conveying component in the direction of the outlet nozzle by the conveying fins 70. As a result, the web plate 560 acting as a lift element 56 also constitutes a sweeper element for distributing and conveying the material and thus constitutes a conveying and distribution element.

[0133] As can be seen from Fig. 5, the sweeper elements 43 arranged on the rotor shape or rotor shaft body in different zones are arranged differently. Thus, in the inlet zone corresponding to the proximal end region, only a sloping roof-shaped web plate 560 is arranged. In particular, six web plates are arranged in the circumferential direction of the rotor shaft 44, and every two consecutive web plates in the circumferential direction are connected to each other by a connecting plate 74 so that a protective casing 76 is formed overall.

[0134] By forming the protective casing 76, the material to be treated and the gaseous material components escaping during treatment are directed in parallel flow in the inlet zone 18, thereby minimizing the risk of possible "material entrainment" by the escaping components.

[0135] Web plates 560 are also arranged in the treatment zone 25 adjacent the inlet zone 18, but the web plates are arranged on the rotor shaft body 50 helically offset from one another in the longitudinal portion of the rotor shaft 44 corresponding to the treatment zone, thereby obtaining an optimal distribution of the lift or lift force generated by the individual lift elements throughout the treatment zone 25.

[0136] In order to obtain a sufficiently high conveying effect, in addition to the web plate 560 acting as a lifting element and a conveying and distributing element, sweeper elements 43 with enhanced conveying effect are also provided. In particular, sweeper elements 43 consisting of teeth 78, the shearing ends of which have an attack angle of more than 5° with respect to the axial direction, thus constituting conveying elements 432, but which are not lifting elements, are also arranged in the processing zone 25. In particular, sweeper blades 80 each having a plurality of teeth 78 and having said attack angle are provided. In addition, sweeper elements 43 having teeth 79, the shearing ends of which run parallel to the axial direction and are therefore neutral with respect to conveying, are provided, which purely constitute the distributing element 431. The distributing elements 431 and the conveying elements 432 are arranged alternately in the processing zone 25 in the illustrated embodiment, and as described above, the web plate 560 is fixed to one of the six fastening strips 54 or to one of the six rows of blades.

[0137] A configuration of the rotor shaft 44 which is particularly preferred for the inlet zone 18 is also shown in Figures 6 and 7. Thus, a coaxial sleeve 77 is provided, which radially projects the web plate 560 and serves as a protective casing 76. Between two circumferentially successively arranged web plates 560, radially recessed channels 82 are formed on the outer peripheral surface of the sleeve 77. According to this embodiment, steam generated during the processing of the material can be guided via the channels 82. On reaching the end of the protective casing 76, the steam passes through an interior 84 surrounded by the protective casing 76 or the sleeve 77 and, via a common labyrinth seal, into a steam space separated from the material processing space 160, where it can be removed via a steam nozzle 40.

[0138] The thin film processing apparatus according to the present invention can also be configured with a discharge device 30 having a vertical transport direction as shown in Figures 8 to 10, instead of the discharge device in the form of a twin discharge screw having a horizontal transport direction running perpendicular to the direction of the process housing as shown in Figures 1 to 4.

[0139] According to this alternative embodiment, the discharge system 30 consists of a funnel 86 arranged therein and having a coaxially extending discharge shaft 88. The funnel has a substantially conical funnel portion 90 tapering in the conveying direction and an adjacent cylindrical funnel portion 92. In its inlet side (wide) region, the tapered funnel portion 90 has a funnel opening 94 by means of which the funnel 86 is connected to the housing interior 16 of the process housing 12. On the outlet side, the funnel 86 or the cylindrical funnel portion 92 is connected to a discharge pump 96 by means of which the discharged material can be removed or fed to further devices such as a filter and / or a rotary nozzle.

[0140] The discharge shaft 88 has a first discharge shaft part 98 on which a conveying element 432' is arranged, by which the discharged material is conveyed in the direction of a cylindrical funnel part 92 which serves as a bearing bush for a second discharge shaft part 99 arranged with a single discharge screw 100 formed thereon for conveying the material towards the discharge pump 96. As can be seen particularly in Figures 9 and 10, the rotor shaft 44 is mounted on a rotor bearing arranged in the distal direction, i.e. on the distal end face, of the process housing 12. The funnel 86 is arranged offset with respect to the axial direction of the rotor shaft 44 or the process housing 12, in particular to provide sufficient space for the discharge shaft 88 to extend upward adjacent to the distal rotor bearing 102, which is connected at its upper end to the discharge shaft drive 104. In order to provide an offset funnel arrangement which ensures an optimal opening cross section of the funnel opening, the funnel 86 has a shape which deviates from a conical shape in its upper inlet region, as shown in particular in Figures 8 and 9.

[0141] At their distal end regions, two circumferential reamers 106 are disposed on the rotor shaft body 50 and convey material into the funnel opening 94 on the underside of the process housing 12. Specifically, the reamers 106 each have a reamer bar 112 that is secured to the shaft 52 of the rotor shaft body 50 by a reamer arm 114 and that moves the discharge material toward the funnel opening 94.

[0142] Additionally, a plate-shaped cleaning element 110 is disposed on the rotor shaft body 50 directly adjacent to the distal end face 108 of the process housing 12, which prevents material from accumulating on the inner surface of the distal end face 108 and also protects the distal rotor bearing 102 from contamination by material.

[0143] As shown in Figures 8 and 9, in the outlet zone 22 of the illustrated embodiment, there are three outlet zone sections 22a, 22b, 22c. In the first outlet zone section 22a, sweeper elements 43 are arranged in the corresponding longitudinal section of the rotor shaft body 50, consisting of teeth, the shearing edges of which are inclined at about 45° to the axial direction and therefore act as conveying elements 432. The distribution elements 432, in particular sweeper elements having teeth whose shearing edges run parallel to the axial direction of the process housing 12 or the rotor shaft 44, are arranged alternately with the conveying elements 432 in the first outlet zone section 22a. Alternatively, it is also conceivable that only the conveying elements 432 are present, which leads to an increased conveying effect in the first outlet zone section 22a.

[0144] In the second exit zone portion 22b adjacent to the first exit zone portion 22a in the conveying direction, the conveying elements 432 are arranged circumferentially alternating with web plates 560 which function as lift elements and conveying and distribution elements, as has been described in conjunction with Figure 5.

[0145] Adjacent to this in the conveying direction is a third outlet zone section 22c, which leads into the funnel 86 and which in turn is only arranged with the above-mentioned reamer 106 on the rotor shaft body. In contrast to the presence of a distribution element 431 in the first outlet zone section, which is neutral to the conveying process, further elements are provided in the second outlet zone section in addition to the conveying element 432, which impart a conveying force component to the material. This ensures conveying to the third outlet zone section 22c or to the reamer 106, even if the material has a very high viscosity. Whereas the conveying fins described in connection with FIG. 5 enclose only a relatively small angle of, for example, 5° to the axis in the processing zone, the conveying fins of the web plate 560 arranged in the outlet zone can be at a larger angle, in particular 45°, whereby a stronger conveying action is obtained compared to the processing zone.

[0146] The embodiment shown in Figures 8 to 10 has the advantage that the rotational speed of the rotor shaft 44 within the process housing can be decoupled from the rotational speed of the discharge shaft 88.

[0147] As an alternative to the embodiment shown in Figures 8 to 10, in the embodiment shown in Figure 11 the discharge system is oriented horizontally. In particular, the discharge system 30 comprises a funnel 86' flange-mounted to the process housing, into which the rotor shaft 44 projects. The funnel 86' comprises a conically tapered funnel section 90' which is flange-connected at its wide proximal end to the process housing 12 and whose axis coincides with the axis of the process housing. In the funnel section 90' the diameter of the rotor shaft 44 tapers accordingly. Adjacent to this conical funnel section 90' in the conveying direction is a cylindrical funnel section 92' which serves as a bearing bush for a single discharge screw 100' arranged therein.

[0148] As explained in conjunction with the embodiment shown in Fig. 8 to 10, the outlet zone of the embodiment shown in Fig. 11 also has a first outlet zone part 22a' and a second outlet zone part 22b' adjacent to the first outlet zone part. In this embodiment too, instead of the distribution element 431, a web plate 560 is formed in the second outlet zone part 22b'. The distribution element 431 present in the first outlet zone part 22a' does not function as a conveying process. This web plate 560 functions both as a lifting element and as a conveying and distribution element. Also in the region of the rotor shaft 44 protruding into the funnel 86' - as in the second outlet zone part 22b' - a web plate 560 is arranged on the rotor shaft body 50 together with the conveying element 432. In particular, here the web plates 560 are arranged helically offset from one another.

[0149] Experiments were carried out to produce a NMMNO / water solution of cellulose using a thin-film processor with an inner housing diameter of 280 mm and a circumference of 0.88 m. The horizontal rotor shaft was equipped with different sweeper elements, which were arranged in up to eight horizontal rows around the rotor shaft, with every second row of sweepers inclined at an angle of α = 20° in the process zone. The remaining rotor blades were not inclined. The spacing between the outer ends of the sweeper elements ranged from 108 mm to 216 mm. The sweeper elements had an intervention area in the horizontally moving suspension of up to 1.9 dm2. 2 The rotor was placed facing the heated inner surface of the casing and was spaced 2.75-3.5 mm from the inner surface of the process housing. The maximum rotational speed of the horizontally supported rotor was 650 min -1 Therefore, the maximum peripheral speed of the tip of the sweeper element was 9.3 m / s, and the maximum continuous frequency of the sweeper element was 2600 / min. Other parameters are shown in Table 1.

[0150] To produce the cellulose solution, the eucalyptus pulp type cellulose used was suspended in demineralized water. After the cellulose fibers were completely suspended in water, the excess water was separated by filtration and the resulting pulp cake was pressed to a solids concentration of about 50%. The dewatered pulp cake was led to the debubble via needle rolls and a shredder. The resulting finely defibrated wet cellulose was continuously introduced into an aqueous solution of tertiary amine oxide (NMMNO) to produce a suspension. Ring layer mixers and turbulent mixers are suitable devices for this purpose.

[0151] Suspensions of water, cellulose and NMMNO with different compositions (see columns b, c and d in Table 1) were introduced into the thin-film processing device in a further step of the process in order to produce a cellulose solution. It has proven advantageous if the water content by mass of the introduced suspension is 19%-26%, the cellulose content is 5.7%-11.9% and the NMMNO content is 65%-75%. With such suspensions, a good distribution of the suspension in the feed zone can be achieved. It has been found that the conversion of the starting composition (index in the formula = before) to the target composition (index in the formula = after) advantageously follows a certain ratio. This ratio is: It has been proven that the formula in TIFF0007645820000002.tif1384 is satisfied, and the difference to 100% in each case is formed by the NMMNO concentration. All concentrations (cH2O, cCell) are expressed in mass%. Surprisingly, The ratio of TIFF0007645820000003.tif17105 is 1.8 to 2.5, The best results were obtained when TIFF0007645820000004.tif15105 was between 0.8 and 0.95.

[0152] By passing the suspension through different treatment zones, its composition is changed to a target composition. When the target composition is achieved, it is not changed further during the process. This target composition is preferably a composition of the formula c(Cell)≦35.9-1.736*c(H2O), and / or the formula c(Cell)≧32.4-2.17*c(H2O) should be satisfied, where c(Cell) is the cellulose content in % by weight and c(H2O) is the water content in % by weight in the cellulose solution. The starting composition is achieved by mixing the individual components, whereas the target composition is achieved by carrying out the method. Since the composition is formed differently in the individual zones as a result of the physical conditions present, it is advantageous to observe the parameters and ranges mentioned in the method according to the invention. Empirically, the desired target composition is: c(H2O)=(33.5-c(Cell) / 1.91) The target composition can be different from the desired target composition, but is preferably within the range of the target composition formula. The target composition is determined at the end of the outlet zone. The rate at which the target composition is reached during processing can vary. It is therefore advantageous for the process if this target composition is reached at the end of the process zone. However, it may well be that the target composition is already reached after one third of the total processing time. The total processing time is the time required for the suspension / solution to pass from the start of the inlet zone to the end of the outlet zone. After the target composition is reached, the composition of the cellulose solution does not change any more.

[0153] In this horizontal thin-film evaporator, the cellulose solution was continuously produced without particles due to the vigorous mixing and kneading action. When the treatment time (t) was 150 seconds, the cellulose was completely dissolved.

[0154] The geometrical conditions of the housing casing inner surface based on the area of ​​the rotor blade tips (mentioned above) and the peripheral speed of the rotor blade tips (i.e. at the furthest point from the axis) allow to obtain a useful characteristic value for an economically advantageous and at the same time efficient evaluation of the dissolution of the introduced suspension. The following setting of this parameter results in an economical method with a very high quality of the solution. This parameter is defined here as the specific surface area ratio of the rotor blades (row ae of the table).

[0155] Specific area ratio of rotor blade (row ae of the table) = Heat exchange area of ​​the inner wall of the housing casing (row h of the table) / (Rotor blade tip load area (row ad of the table) * Blade tip speed (row 1 of the table))

[0156] For good quality, i.e. a score of the spinning ready solution <2 (row x of the table), the specific area ratio of the rotor blades is preferably less than 10, particularly preferably less than 8, very particularly preferably less than 5 m 2 s / m 3It has been found that the range of these parameters is therefore particularly preferred.

[0157] To ensure process control, further stabilizers were added to the suspension to stabilize the solvent and prevent cellulose degradation. The continuously generated suspension was transformed into a highly viscoelastic solution under horizontal shear by applying temperature (u, v, w) and negative pressure (j), and excess water was removed by reducing the pressure (j) from 45 to 90 mbar. Heating of the apparatus was performed with saturated steam at a pressure of 1 to 2 bar, and the steam temperature was between 100 °C and 121 °C.

[0158] The thickness of the internally spreading layer was 2.75-3.5 mm (i). The water evaporated by the temperature and negative pressure was removed countercurrent to the suspension flow at temperatures of 80-85 °C, where the steam flow (s) was up to 61.5 kg / h. The shear rate (o) was 5000-21000 s -1 , and the rotor at the speed "Euro" consumed power (f) of -0 to 37 kW.

[0159] At the outlet, the finished cellulose solution was discharged by the discharge screw (k). The discharge screw is used to return the negative pressure generated inside to normal pressure. Up to 484 kg of homogeneous cellulose solution could be obtained per hour at a temperature of about 100 °C (w). The processing time of the suspension in the horizontal device (t) was -0 to 360 seconds.

[0160] The resulting high-viscosity cellulose solutions were further subjected to devolatilization and filtration steps before spinning. Microscopic observation of the solutions revealed that only in Examples 5 and 6 were undissolved cellulose particles present in the solutions. For this reason, the ready-to-spin solutions (x) were scored according to the following system: Scoring was done under a microscope and was given from 1 to 3 points. A score of 1 meant that there were no more undissolved particles, a score of 2 meant that there were a few undissolved particles, and a score of 3 meant that there were a lot of undissolved particles. After filtration, all cellulose solutions were suitable for spinning.

[0161] The cellulose solution was spun into filaments as described in WO 2013 / 030399 A, which consisted of extruding the solution under pressure through one or more extrusion orifices and solidifying the formed cellulose body in a collection bath, the solution being guided through a gap between the extrusion orifices and the collection bath.

[0162] Characteristic Value

[0163] Reynolds number rotor(y):

[0164] TIFF0007645820000005.tif65136

[0165] Reynolds Number Film(z):

[0166] TIFF0007645820000006.tif50136

[0167] Newton number(aa):

[0168] TIFF0007645820000007.tif48135P=Rotor power consumption

[0169] Euler number (ab):

[0170] TIFF0007645820000008.tif60136

[0171] Calculating the pressure inside the reactor

[0172] TIFF0007645820000009.tif7106

[0173] p = absolute pressure in the reactor [mbar] c(cell) = cellulose concentration in the suspension (mass%)

[0174] Specific surface area ratio of the rotor blades (sweeper elements).

[0175] TIFF0007645820000010.tif9106

[0176] AR ... specific surface area ratio of rotor blade (m 2 s / m 3 ) AM ... Casing inner surface of treatment zone (unit: m 2 ) AB ... rotor blade tip load area (m 2 ) Vu ... blade tip circumferential speed (m / s)

[0177] [Table 1] TIFF0007645820000011.tif249162 TIFF0007645820000012.tif249102

[0178] Reference sign 10 Thin film processing equipment 12 Process Housing 14 Housing casing 15 Inner surface of housing casing 16; 160 Housing interior; material processing space 18 Entrance Zone 20 Inlet nozzle 22 Exit Zone 24 Exit nozzle 25 Treatment Zone 26 Fixed bearing 28 Floating bearing 30; 300 discharge system; twin discharge screw 32 First heat transfer medium inlet 34 First heat transfer medium outlet 36 Second heat transfer medium inlet 38 Second heat transfer medium outlet 40 Vapor Nozzle 42 rotor 43 Sweeper Element 431, 432 Distribution elements, conveying elements 44 Rotor shaft 48; 480 drive; spur gear motor 50 Rotor shaft body 52 Spindle 54 Fastening Belt 56; 560 lifting element; web plate 58 Top of web plate 60a,b first and second web plate surfaces 62 Injection channel section 64 Tip of the inlet flow section 66 Rear region of the inlet flow 68 Gap 70 Transport fin 72 Axial shear edge of web plate 74 Connection Plate 76 Protective Casing 77 Sleeve 78 Teeth with attack angle 79 Teeth with no attack angle 80 Sweeper Blade 82 Channels 84 Inside the protective casing 86, 86' Funnel 88 Discharge shaft 90, 90' tapered funnel section 92 Cylindrical funnel part 94 Funnel opening 96 Discharge Pump 98 First discharge shaft 99 2nd discharge shaft part 100 Single discharge screw 102 Distal rotary bearing 104 Discharge shaft drive 106 Reamer 108 Distal end face of process housing 110 Cleaning Elements 112 Reamer bar 114 Reamer Arm

[0179] Preferred Embodiments

[0180] The present invention is specified as follows.

[0181] 1. A thin film processing apparatus for processing a viscous material, comprising: a treatment housing (12) having a heatable and / or coolable housing casing (14) enclosing an axially extending, rotationally symmetrical housing interior (16) and forming a material treatment space (160), the treatment housing (12) being oriented at an inclination of up to 20° relative to the horizontal; an inlet nozzle (20) arranged in the inlet zone (18) of the process housing (12) for introducing the material to be treated into the material treatment space (160); a rotor shaft (44) extending coaxially therewith for producing a material film on the inner surface (15) of the housing casing and for conveying the material in a direction from the inlet zone (18) through the treatment zone (25) towards the outlet zone (22), the rotor shaft (44) having a central rotor shaft body (50) and sweeper elements (43) arranged at its periphery and having their radially outermost ends spaced apart from the inner surface (15) of the housing casing; The rotor shaft (44) comprises at least one lifting element (56) arranged on the rotor shaft body (50), the lifting element being designed to generate a lifting force in the direction of the rotor shaft body (50) during rotation of the rotor shaft (44).

[0182] 2. The thin film processing apparatus of claim 1, wherein the lift element (56) comprises a planar entrance channel section (62) having a leading end (64) at a tip in the direction of rotation, the leading end being located at a greater distance from the inner surface (15) of the housing casing than a region (66) of the entrance channel section (62) extending rearwardly of the leading end, whereby a gap (68) configured to narrow in the direction opposite to the direction of rotation is formed between the entrance channel section (62) and the inner surface of the housing (15), the gap being a continuously narrowing gap.

[0183] 3. The thin film processing apparatus according to claim 2, wherein the incident flow path portion (62) spans an angular range β1 of at least 10° on the circumference of the rotor shaft body (50).

[0184] 4. The thin film processing apparatus according to any one of 1 to 3, wherein at least a portion of the lift element (56) is formed by a sweeper element (43).

[0185] 5. A thin film processing apparatus as described in any one of 1 to 4, characterized in that the lift element (56) consists of an at least approximately inclined roof-shaped web plate (560), the top portion (58) of which runs at least approximately parallel to the axial direction of the rotor shaft (44).

[0186] 6. A thin-film processing apparatus as described in any one of 1 to 5, characterized in that the lift element (56), in particular the web plate (560), has at least one spirally extending conveying fin (70) on its radially outer side.

[0187] 7. A thin film processing apparatus as described in any one of 1 to 6, characterized in that at least a portion of the lift element (56) is arranged in the process zone (25), preferably in a region centrally located between the rotor bearings on which the rotor shaft (44) is supported.

[0188] 8. A thin film processing apparatus as described in any one of 1 to 7, characterized in that at least some of the lift elements (56) are arranged helically offset from one another in the process zone (25) on the rotor shaft body (50).

[0189] 9. A thin film processing apparatus as described in any one of 1 to 8, characterized in that a concentric protective casing (76) is formed in the inlet region (18) and is disposed between the inner surface (15) of the housing casing and the rotor shaft body (50) and at least almost completely surrounds the rotor shaft body.

[0190] 10. Thin-film processing apparatus according to claim 9, characterized in that the protective casing (76) is at least partially formed by a plurality of circumferentially distributed lift elements (56), in particular web plates (560).

[0191] 11. A thin-film processing apparatus as described in claim 10, characterized in that a radially recessed channel (82) is formed between each two lift elements (56) arranged in succession in the circumferential direction, in particular between each two web plates (560).

[0192] 12. A thin film processing apparatus as described in any one of 1 to 11, characterized in that the processing zone (25) has a distribution zone and a transport zone arranged downstream in the transport direction, and the ratio of the number of transport elements (432) to the number of distribution elements (431) is higher in the transport zone than in the distribution zone.

[0193] 13. A thin film processing apparatus as described in 1 to 12, characterized in that the outlet nozzle (24) is connected to an exhaust system (30) in the form of a single exhaust screw or twin exhaust screws (300), preferably having an axial direction perpendicular to the axial direction of the process housing (12).

[0194] 14. The thin film processing apparatus according to any one of 1 to 13, further comprising a cleaning device that is configured to be introduceable into the process housing (12) and that is capable of reciprocating in the axial direction when the end cover is open.

[0195] 15. Thin-film processing apparatus according to 1 to 14, characterized in that it is designed for the thermal fractionation of substance mixtures and is provided in particular in the form of a thin-film evaporator, thin-film dryer or thin-film reactor, preferably in the form of a thin-film evaporator.

[0196] 16. Use of a thin film processing apparatus according to any one of 1 to 15, characterized in that the apparatus is used during processing of a material having a viscosity of 100 Pa·s or more at least temporarily.

[0197] 17. A method for producing a solvent-dissolved cellulose solution from a suspension in which cellulose is dissolved in a solvent and a volatile non-solvent, comprising the steps of: introducing the suspension into an inlet of a thin film processing device; coating and dispersing the suspension in the form of a film on a housing casing; controlling the temperature using a heat exchanger with a sweeper element rotating around a common axis within the process housing of the thin film processing device; evaporating the volatile non-solvent and dissolving the cellulose; and discharging the cellulose solution from the thin film processing device through an outlet.

[0198] 18. The method according to claim 17, characterized in that at least some of the sweeper elements advance the cellulose in the direction of the outlet so that the discharge at the outlet is between 300 kg / h and 600 kg / h, preferably between 350 kg / h and 550 kg / h, more preferably between 380 kg / h and 480 kg / h of cellulose solution per square meter of temperature-controlled surface of the containment casing.

[0199] 19. The process according to claim 17 or 18, characterized in that the temperature of the introduced suspension in the process zone is 100 to 125°C, preferably 100 to 110°C, particularly preferably 100 to 105°C.

[0200] 20. The formula p=122*e^-0.05c(Cell)), where p is the absolute pressure in mbar and c(Cell) is the cellulose concentration in the suspension in mass %, 20. The method according to any one of claims 17 to 19, wherein the absolute pressure in the process zone, as indicated by the arrows, is within a range of at least ±10%, preferably ±5%.

[0201] 21. The rotor blade area ratio (table, ae) is 10m 2 s / m 3 Less than or equal to 8m, preferably 2 s / m 3 Less than or equal to 5m, preferably 2 s / m 3 21. The method according to any one of claims 17 to 20, characterized in that:

[0202] 22. The rotor blade tip load area (table, ad) is preferably 0.02 m 2 ~6m 2 In particular, 2 m 2 ~6m 2 and more particularly preferably in the range of 4 m 2 ~6m 2 22. The method according to any one of claims 17 to 21, wherein the range is

[0203] 23. a) The specific load at the inlet zone is 80 kg / h / dm 3 ~380kg / h / dm 3 , preferably 120 kg / h / dm 3 ~370kg / h / dm 3 , more preferably 150 kg / h / dm 3 ~350kg / h / dm 3 , b) Specific load in the treatment zone is 65 kg / h / dm 3 ~260kg / h / dm 3 , preferably 70 kg / h / dm 3 ~200kg / h / dm 3 , more preferably 80 kg / h / dm 3 ~150kg / h / dm 3 , c) Specific load at the exit zone is 2 kg / h / dm 3 ~125kg / h / dm 3 , preferably 5kg / h / dm 3 ~100kg / h / dm 3 , more preferably 10 kg / h / dm 3 ~50kg / h / dm 3 , d) The specific load in the post-treatment zone is 0 kg / h / dm 3 ~500kg / h / dm 3 , more preferably 0 kg / h / dm 3 ~250kg / h / dm 3 That is, 23. The method according to any one of claims 17 to 22.

[0204] 24. The method according to any one of claims 17 to 23, characterized in that the total treatment time of the cellulose solution is at least 60 seconds, preferably 100 seconds or more, and more preferably 100 to 1000 seconds.

[0205] 25. The ratio of the starting composition to the target composition is based on the formula: TIFF0007645820000013.tif13155Here, c(Cell) is the concentration of cellulose in the solution, and c(H2O) is the concentration of water in the solution, each specified in mass%. 25. The method according to any one of claims 17 to 24.

[0206] 26. a) TIFF0007645820000014.tif17105 ratio is in the range of 1.8 to 2.5, preferably in the range of 2.1 to 2.4, b) 26. A method according to any one of claims 17 to 25, characterized in that the ratio of TIFF0007645820000015.tif15105 is in the range of 0.8 to 0.95, preferably in the range of 0.8 to 0.88.

[0207] 27. Tip efficiency is 1.1kg / sm 2 ~5.5kg / sm 2 , preferably 1.1 kg / sm 2 ~2.8kg / sm 2 , more preferably 1.1 kg / sm 2 ~1.4kg / sm 2 27. The method according to any one of claims 17 to 26, wherein the range is

[0208] 28. A method according to any one of claims 17 to 27, characterized in that the target composition is achieved preferably after at least 1 / 3 of the total treatment time, more preferably after 2 / 3 of the total treatment time, and even more preferably at the end of the treatment zone.

[0209] 29. A method according to any one of claims 17 to 28, characterized in that the length from the inlet to the outlet of the containment casing, the temperature of which is controlled using a heat exchanger, is 0.5 m or more, preferably 1 m to 20 m.

[0210] 30. The surface of the containment casing, temperature-controlled using a heat exchanger, is 0.5 m 2 ~150m 2 , preferably 60m 2 ~125m 2 30. The method according to any one of claims 17 to 29, characterized in that

[0211] 31. A method according to any one of claims 17 to 30, characterized in that the radially outermost end of the sweeper element is moved at a speed of 1.5 m / s to 12.5 m / s by rotation of the sweeper element.

[0212] 32. A method according to any one of claims 17 to 31, characterized in that the sweeper element is moved continuously over a portion of the housing casing, the temperature of which is controlled by means of a heat exchanger, at a frequency of 1500 to 4000 movements per minute.

[0213] 33. A method according to any one of claims 17 to 32, characterized in that the immediately successive sweeper elements are successive to one another at a spacing of 100 mm to 300 mm at the radially outermost ends of the sweeper elements.

[0214] 34. The method according to any one of claims 17 to 33, characterized in that 1.5 kg / h to 20 kg / h of suspension are introduced through the inlet per sweeper element.

[0215] 35. The method according to any one of 17 to 34, characterized in that the suspension is applied to a thickness of 1 mm to 50 mm, preferably 2.0 mm to 15 mm.

[0216] 36. Sweeper element is 0.8dm 2 ~2dm 2 36. The method according to any one of claims 17 to 35, wherein the suspension or solution is in contact with the surface area of ​​the substrate.

[0217] 37. A method according to any one of claims 17 to 36, characterized in that the suspension has a film thickness according to the formula s = (ln(ms / 60)) / x, where s is the film thickness in mm, ms is the delivery flow rate of the suspension, and x is a constant between 0.45 and 7, preferably 0.5866.

[0218] 38. The process according to any one of claims 17 to 37, characterized in that 300 kg to 100,000 kg, preferably 10,000 kg to 50,000 kg, of suspension are introduced per hour.

[0219] 39. The method according to claims 17 to 38, characterized in that the common axis of the rotating sweeper elements is inclined at most 20° to the horizontal.

[0220] 40. The method according to any one of items 17 to 39, wherein the thin film processing apparatus according to any one of items 1 to 15 is used.

Claims

1. 1. A thin film processing apparatus for processing a viscous material, comprising: a treatment housing (12) having a heatable and / or coolable housing casing (14) surrounding an axially extending, rotationally symmetrical housing interior (16) and forming a material treatment space (160), the treatment housing (12) being oriented at an inclination of up to 20° relative to the horizontal; an inlet nozzle (20) arranged in an inlet zone (18) of the process housing (12) for introducing the material to be treated into the material treatment space (160); an outlet nozzle (24) arranged in an outlet zone (22) of the process housing (12) for discharging the treated material from the material treatment space (160); a drivable rotor shaft (44) extending coaxially therewith for generating a material film on the inner surface (15) of the housing casing and for conveying the material in a direction from an inlet zone (18) through a treatment zone (25) towards an outlet zone (22), the rotor shaft (44) having a central rotor shaft body (50) and sweeper elements (43) arranged on its periphery and with their radially outermost ends spaced apart from the inner surface (15) of the housing casing, wherein said sweeper elements (43) are arranged on a plurality of axially extending blade rows distributed on the circumference of the rotor shaft (44), The rotor shaft (44) comprises at least one lifting element (56) arranged on a rotor shaft body (50), the lifting element being configured to generate a lifting force in the direction of the rotor shaft body (50) during rotation of the rotor shaft (44); 1. A thin film processing apparatus comprising: a lift element (56) having a planar entrance flow passage portion (62) with a leading end (64) at a tip end in a direction of rotation, the leading end being disposed at a greater distance from an inner surface (15) of the housing casing than a region (66) of the entrance flow passage portion (62) following the leading end, thereby forming a gap (68) between the entrance flow passage portion (62) and the inner surface of the housing casing (15) that narrows in a direction opposite to the direction of rotation.

2. 2. The thin film processing apparatus of claim 1, wherein the gap (68) is a continuously narrowing gap.

3. 3. The thin film processing apparatus according to claim 1, wherein the incident flow passage portion (62) occupies an angular range β1 of at least 10° on the circumference of the rotor shaft body (50).

4. Thin-film processing apparatus according to any one of claims 1 to 3, characterized in that the lift elements (56) are at least partially formed by a sweeper element (43) in each case.

5. 5. The thin-film processing apparatus according to claim 1, wherein the lifting element (56) consists of an at least approximately inclined roof-shaped web plate (560), the top part (58) of which extends at least approximately parallel to the axial direction of the rotor shaft (44).

6. Apparatus according to any one of claims 1 to 5, characterized in that the lifting element (56) has at least one helically extending conveying fin (70) on its radially outer side.

7. 7. The thin film processing apparatus of claim 6, wherein the web plate (560) has at least one helically extending conveying fin (70) radially outwardly thereof.

8. 8. The thin-film processing apparatus according to claim 1, characterized in that at least a part of the lifting elements (56) is arranged in a region centrally located between the rotor bearings on which the rotor shaft (44) is supported.

9. 9. The thin film processing apparatus according to claim 8, characterized in that at least a part of the lifting element (56) is arranged in the process zone (25).

10. The thin film processing apparatus according to any one of claims 1 to 9, characterized in that at least some of the lift elements (56) are arranged helically offset from one another in the process zone (25) on the rotor shaft body (50).

11. The thin film processing apparatus according to any one of claims 1 to 10, characterized in that a concentric protective casing (76) is formed in the inlet region (18) and is disposed between the inner surface (15) of the housing casing and the rotor shaft body (50) and at least almost completely surrounds the rotor shaft body.

12. The thin film processing apparatus of claim 11, wherein the protective casing (76) is at least partially formed by a plurality of circumferentially distributed lift elements (56).

13. The thin film processing apparatus of claim 12, wherein the protective casing (76) is at least partially formed by a plurality of circumferentially distributed web plates (560).

14. 13. The thin-film processing apparatus according to claim 12, characterized in that a radially recessed channel (82) is formed between each of two lift elements (56) arranged in succession in the circumferential direction.

15. 15. The thin film processing apparatus according to claim 14, characterized in that a radially recessed channel (82) is formed between each of two circumferentially consecutively arranged web plates (560).

16. The thin-film processing apparatus according to any one of claims 1 to 15, characterized in that some of the sweeper elements are provided in the form of transport elements (432) and a further part of the sweeper elements is provided in the form of distribution elements (431), the processing zone (25) having a distribution zone and a transport zone arranged downstream in a transport direction, the ratio of the number of transport elements (432) to the number of distribution elements (431) being higher in the transport zone than in the distribution zone.

17. The thin film processing apparatus according to any one of the preceding claims, characterized in that the outlet nozzle (24) leads to an exhaust system (30) in the form of a single exhaust screw or twin exhaust screws (300).

18. The thin film processing apparatus of claim 17, wherein the outlet nozzle (24) leads to an exhaust system (30) having an axial direction perpendicular to the axial direction of the process housing (12).

19. The thin film processing apparatus according to any one of claims 1 to 18, further comprising a cleaning device configured to be introduceable into the process housing (12) and capable of reciprocating in the axial direction when the end cover is opened.

20. Thin-film processing apparatus according to any one of claims 1 to 19, characterized in that it is designed for the thermal fractionation of substance mixtures.

21. Thin-film processing apparatus according to any one of claims 1 to 20, characterized in that it is provided in the form of a thin-film evaporator, a thin-film dryer or a thin-film reactor.

22. A method for processing a material using a thin film processing apparatus according to any one of claims 1 to 21, characterized in that the thin film processing apparatus processes a material having at least a temporary viscosity of 100 Pa·s or more.

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