Fibre disruption device, method for disintegration of a vegetable material, method for producing a semi-finished product and use of a vegetable material for producing paper, cardboard or cardboard

Abstract

A fiber pulping device (1) for pulping plant material by means of steam pressure pulping shall comprise the following features: a pressing and dewatering chamber (2), a pressing channel (3), at least one first heating tube (4), and a pressure relief vessel (6), wherein a pressure plate (9) for compacting and dewatering the plant material and for determining a material flow in the fiber pulping device (1) is assigned to the pressing and dewatering chamber (2), wherein a feeding device (7) for feeding the plant material to be pulped is further assigned to the pressing and dewatering chamber (2), wherein at least one section (14.2) the pressing and dewatering chamber (2) may have a perforation (8), wherein the pressing and dewatering chamber (2), the pressing channel (3), the at least one first heating tube (4), and the pressure relief container (6) are connected to each other in such a way that plant material introduced into the pressing and dewatering chamber (2) by the feeding device (7) is first moved into the pressing channel (3) by a movement of the pressure plate (9) and then passes through the at least first heating tube (4) in order to then enter the pressure relief container (6).

Description

Technical area

[0001] The invention relates to a fiber pulping device, a method for pulping a plant material, a method for producing a semi-finished product and a use of a plant material for producing paper, paperboard or cardboard according to the independent claims. State of the art

[0002] Methods and devices for fiber extraction are well known and commonly used. Steam explosion extraction was already described at the beginning of the 20th century, for example, in US Pat. No. 1,578,609. It involves first applying high pressure and heating a plant material, and then suddenly reducing the pressure, resulting in explosive water evaporation. This water evaporation causes fiber extraction. Object of the invention

[0003] The object of the present invention is to overcome the disadvantages of the prior art. Solution to the task

[0004] The subject matter of the independent patent claims leads to the solution of the problem. Advantageous embodiments are described in the dependent patent claims.

[0005] According to the present invention, a fiber disruption device for disrupting plant material by means of steam pressure disruption comprises a device for solid-liquid separation, which is arranged within a relaxation container of the fiber disruption device or takes over the function of such a relaxation container.

[0006] The device for solid-liquid separation can be designed as a press and is described in detail below.

[0007] The fiber pulping device may further comprise a pressing and dewatering chamber, a pressing channel, at least one first heating tube, and a relaxation tank. The aforementioned components may be configured as interconnected zones of a fiber pulping device. The phrase "at least one first heating tube" specifically means that a second heating tube may optionally be present.

[0008] The aforementioned components can each have a circular cross-section. They are preferably arranged coaxially to one another, thus sharing a common (imaginary) central longitudinal axis. The pressing and dewatering chamber, the pressing channel, and all heating pipes are preferably cylindrical.

[0009] The pressing and dewatering chamber can be assigned a pressure plate for compacting and dewatering the plant material and for determining a material flow in the fiber pulping device. The pressure plate is preferably configured to convey the plant material to be pulped into the pressing channel after it has been introduced into the pressing and dewatering chamber.

[0010] The pressure plate is preferably driven by a hydraulic cylinder. The pressure plate and the pressing and drainage chamber can interact like a piston engine, with the pressure plate acting as the piston and the pressing and drainage chamber as the cylinder. The outer diameter of the pressure plate – preferably round in cross-section – can correspond to the inner diameter of the pressing and drainage chamber in such a way that the former is only slightly smaller than the latter. However, the tightness between piston and cylinder required in reciprocating piston engines such as diesel or gasoline engines is not necessarily present. The escape of fluid through a remaining gap between the pressure plate and the pressing and drainage chamber is usually unproblematic and sometimes even desirable, as described in more detail below.

[0011] Conveying and thus moving the plant material through the pressing and dewatering chamber, which essentially occurs as a pushing action through the pressure plate, advantageously results in at most a minimal formation of fines. This is particularly advantageous if the plant material is to be used for paper production after steam pressure pulping, for example, since a high proportion of fines has a detrimental effect on the quality of the paper. The plug screws commonly used in the prior art often result in an unfavorably high proportion of fines due to the increased friction and shear between the plant material and the components of the screw shaft and the plug screw housing.

[0012] The fiber disruption device can comprise a single pressure plate that creates a flow of plant material. The pressure plate can be the only device that mechanically causes the material flow. Furthermore, a pressure drop, described in more detail below, can cause a flow of material upon transfer into the expansion tank. However, this does not occur mechanically, i.e., not through components that mechanically move the plant material.

[0013] When the material flow is mentioned above and below, this preferably means the material flow of plant material already located in the pressing and dewatering chamber, which is conveyed or moved to the relaxation tank.

[0014] In addition to dewatering, a certain degree of compaction of the plant material preferably takes place in the pressing and dewatering chamber. However, the formation of the tightest possible plug preferably only occurs in the pressing channel described below. In addition to the obvious increase in the dry matter content of the plant material, the dewatering itself can also entrain fine particles, which are thus removed from the plant material together with the discharged water or, in general, the discharged aqueous liquid before the actual pulping.

[0015] The pressing and dewatering chamber can also be assigned a feed device for feeding the plant material to be digested. The feeding, i.e. the introduction of the plant material into the pressing and dewatering chamber, can be carried out in various ways. In the simplest case, the pressing and dewatering chamber comprises an opening serving as a feed device, through which the plant material is fed by means of a device arranged upstream of the fiber digestion device. The feeding can essentially be effected by gravity. However, a conveyor screw is preferably assigned to the pressing and dewatering chamber. In contrast to a stuffing screw, a conveyor screw can introduce the plant material to be digested into the pressing and dewatering chamber with low friction. The conveyor screw is preferably arranged so that the direction of gravity and the conveying direction of the conveyor screw coincide.Preferably, the fiber pulping device comprises exactly one single feeding device, particularly preferably in the form of a conveyor screw.

[0016] At least one section of the pressing and dewatering chamber may have a perforation. Within the context of the present invention, a perforation is preferably understood to mean a plurality of adjacent bores or generally adjacent holes that allow a fluid to exit the pressing and dewatering chamber.

[0017] These holes can be of various shapes and sizes. The shape and size of the holes forming the perforation are preferably chosen so that liquid can escape, but plant material largely cannot pass through.

[0018] The perforation can be surrounded by a baffle plate. On the one hand, the baffle plate can ensure that any liquid escaping or splashing from the perforation holes does not pose a danger to operators. On the other hand, the baffle plate can serve to collect and drain the liquid escaping from the holes. The considerations outlined above for liquids also apply to a steam leak—which only occurs in an emergency—which will be explained below.

[0019] If excess pressure develops in the heating tube(s) and cannot be relieved, e.g. due to a blockage, by the safety valves, bursting discs, and the like in the heating tube and the expansion tank (explained below) designed to reduce the pressure, the plug in the press channel can burst. This bursting causes the pressure previously built up in the heating tubes and, if applicable, in the expansion tank, or the highly pressurized steam, to escape through the press channel into the pressing and dewatering chamber, from where it escapes via the perforation or, for example, via the gap described below between the housing of the pressing and dewatering chamber and the pressure plate. While this is undesirable during normal operation, it does provide protection against even more serious machine and / or personal damage. A baffle plate is also useful in this case, where steam escapes via the perforation.

[0020] Alternatively or in addition to the perforation described above in the housing of the pressing and dewatering chamber, it may be possible to achieve dewatering in another way, for example, via a perforation in the pressure plate or via the aforementioned gap between the pressure plate and the inner wall of the housing of the pressing and dewatering chamber. This gap, at least if used for dewatering, is not sealed from the inner wall of the housing by a ring seal or the like.

[0021] The pressing and dewatering chamber can essentially function as a press chamber. This means that dewatering can only take place to a limited extent, and the focus is on pressing the plant material to form the plug in the adjoining press channel. Furthermore, it should be noted that the extent to which dewatering takes place always depends on the dry matter content of the plant material. If the plant material already has a very high dry matter content when it is introduced into the pressing and dewatering chamber, in individual cases no significant dewatering may take place in the pressing and dewatering chamber. Since, depending on the plant material used and in particular its dry matter content, at least some dewatering will usually take place, it is always referred to as a pressing and dewatering chamber and not just a press chamber.

[0022] The pressing and dewatering chamber, the pressing channel, the at least one first heating pipe, and the expansion tank can be connected to one another in such a way that a plant material introduced into the pressing and dewatering chamber from the feed device first enters the pressing channel by a movement of the pressure plate and then passes through the at least first heating pipe to then enter the expansion tank.

[0023] In the direction of material flow, the pressing and dewatering chamber is preferably followed first by the pressing channel, then by at least a first heating pipe and then by the expansion tank.

[0024] Heat transfer from the at least one first heating tube to the plant material preferably occurs through heat conduction between surfaces of the at least one heating tube and / or a heating device arranged within the heating tube and the plant material contacting these surfaces or this heating device. Alternatively or additionally, heat transfer to the plant material by means of convection or thermal radiation may also be considered. For example, in addition to or as an alternative to the heating tube inserts and heating pads described below, it may also be possible to introduce hot steam into the heating tube via a corresponding device in order to heat the plant material located there.

[0025] A backflow prevention device can be installed in the press channel. Any means suitable for preventing movement of the material in the press channel against the direction of material flow can be considered as a backflow prevention device. The material flow direction in the press channel is determined by the pressure plate, whereby the plant material is pressed into a plug in the press channel. It therefore runs from the pressing and dewatering chamber to the expansion tank. A pressure acting due to an increase in temperature and thus also in pressure in the at least one first heating tube applies a force to the plug whose direction of action is opposite to the direction of material flow. The backflow prevention device ensures that this force does not move the plug against the direction of material flow.

[0026] A wide variety of means can be considered as backflow prevention devices. For example, targeted tapers can be introduced into the press channel. Any type of "constriction" of the clear cross-section of the press channel can act as a backflow prevention device—at least to a certain extent. Barb-like elements can also be considered. Numerous other alternatives are conceivable. For example, elements that act like a one-way locking device can be considered. Backflow prevention devices with a sliding surface that allows material flow in one direction and a stop surface that prevents material flow in the opposite direction can also be considered.Preferably, the sliding surface is inclined in cross-section at an angle of less than 60°, more preferably less than 45°, and possibly even less than 30° to the material flow direction, to allow the plant material to slide along it. The stop surface is preferably arranged substantially orthogonally to the material flow direction. Preferably, the stop surface follows the sliding surface in the material flow direction.

[0027] In order to form a stable plug, the pressing channel can be designed to have a certain length. In this case, it is quite possible that the plug is not homogeneous over its entire length. For example, the plug can only be considered stable, in particular steam- and pressure-tight, in the middle or near an end of the pressing channel facing the heating pipe(s). At an opposite end section of the pressing channel, which immediately follows the pressing and dewatering chamber, the plug can be less stable. In order to prevent the plant material forming the plug from moving back into the pressing and dewatering chamber, a further shut-off device, for example in the form of a second slide, can be considered, which is explained in more detail below.

[0028] The pressing channel can, for example, have a length between one and three meters, for example approximately or exactly two meters. The length of the pressing channel sufficient to form a tight plug can depend on the cross-section of the pressing channel, the plant material used, and other parameters. Depending on the parameters mentioned, designs without a backflow prevention device are conceivable. Depending, for example, on the plant material used and the length and diameter of the pressing channel, a tight plug can be formed even without a backflow prevention device. Whether this is possible can be determined, for example, in preliminary tests.

[0029] With regard to the length and diameter of the press channel, a length-diameter ratio (L / D ratio) between 3:1 and 8:1, preferably between 4:1 and 6:1, particularly preferably approximately or exactly 5:1 can be considered.

[0030] The previously described backflow prevention device always acts to a certain extent as a dam, preventing the plant material from moving in the direction of the material flow. Thus, during the filling of the press channel, it counteracts this filling to a certain extent through the movement of the pressure plate. This function as a dam makes it more difficult to introduce the plant material due to the movement of the pressure plate. This, in turn, contributes to dewatering, as the plant material is more strongly compressed—and thus dewatered—by the presence of the backflow prevention device in the press and dewatering chamber, which acts as a dam.

[0031] Alternatively or in addition to the backflow prevention device, it may be considered to install a retaining device in the press channel that does not perform a backflow prevention function. This can be achieved simply by choosing the location of the retaining device: If it is mounted in the rear area of ​​the press channel near the transition to the first heating pipe, it cannot perform a backflow prevention function with respect to the plug. The retaining device can be a taper or any device that serves as a "constriction" of the clear cross-section of the press channel.

[0032] Such a storage device in the rear area of ​​the press channel near the transition to the first heating pipe, which can also be mounted directly at the end of the press channel, is therefore conceivable as an alternative or in addition to those described above.

[0033] If present, the backflow prevention device and / or the retention device can be static, meaning they cannot be adjusted or modified in any way. The device serving as a backflow prevention device and / or retention device can, for example, be screwed, welded, or otherwise permanently connected to the housing of the press channel.

[0034] Alternatively, it may be considered to design the backflow prevention device and / or the retention device in an adjustable manner. For example, barb-like elements or locking devices can be attached to the press channel via threads or in another suitable manner, allowing adjustment of their penetration depth into the press channel and / or their orientation within the press channel.

[0035] The fiber disintegration device can comprise a second heating tube between the first heating tube and the expansion vessel, wherein the inside diameter of the second heating tube is larger than the inside diameter of the first heating tube. The inside diameter of the second heating tube can be, for example, between 40 and 60%, preferably approximately or exactly 50%, larger than the inside diameter of the first heating tube. The inside diameter is preferably a free cross-section of the respective heating tube.

[0036] The two heating pipes can also be designed as differently shaped sections of a single heating pipe.

[0037] An interior space of the first heating tube or, if present, a shared interior space of both heating tubes can be connected to the press channel on one side and to the expansion tank on the other. It is therefore conceivable that the interior space does not include any further openings that allow pressure equalization or material flow. Alternatively, it is conceivable to assign a pressure relief valve, a bursting disc, a combination of a bursting disc and a downstream pressure relief valve, or the like to one of the heating tubes, preferably the second heating tube if present, in order to effect targeted relief in the event of an undesirable pressure increase.

[0038] Due to mass conservation and the strong compression of the plant material already present in the press channel and subsequently also in the first heating tube, the larger internal dimension of the second heating tube results in the latter having a lower filling level than the first heating tube. Preferably, the first heating tube usually has a filling level of at least approximately 100%, while the second heating tube can, for example, have a filling level of 60 to 80%.

[0039] The filling level of the press channel is also preferably 100% during operation. "During operation" preferably means continuous operation of the fiber pulping device, with the plug in the press channel already installed and plant material already entering the expansion tank via an outlet connecting the heating tubes to the expansion tank.

[0040] If a second heating tube is present, as already mentioned above, it is usually not 100% full during operation. This is because it has a larger internal diameter than the first heating tube and regularly releases plant material through the outlet into the expansion tank. Often, a fill level gradient develops in the second heating tube, with the fill level decreasing toward the outlet, based on a cross-sectional area of ​​the second heating tube running orthogonally to the central longitudinal axis.

[0041] A grid can be arranged within the aforementioned outlet or within the expansion tank to shred the plant material entering the expansion tank. Shredding occurs by impact with the grid. Alternatively, any suitable, preferably passive, shredding device can be used, for example, statically arranged blades or the like.

[0042] The clear dimension of the first heating tube can be slightly smaller, for example approximately two to seven percent, preferably approximately five percent, than the clear dimension of the pressing channel. Thus, at the exit of the pressing channel, where the plant material enters the first heating tube, a build-up occurs, thus increasing the pressing pressure. This build-up occurs in addition to the plugging and pressing in the pressing channel, which causes the plug to form. However, it is also possible for the clear dimension of the first heating tube to essentially correspond to the clear dimension of the pressing channel, since in other embodiments the pressing channel can independently cause the plug to form. This can be achieved, for example, by the backflow prevention device or a previously described build-up device.However, it can also be considered that the clear dimension of the first heating pipe is smaller than the clear dimension of the press channel in the manner described above, wherein the press channel additionally comprises a backflow prevention device and / or a backflow device.

[0043] A shut-off device can be provided at the transition between the second heating tube and the expansion vessel. This can be, for example, a slide valve. If the fiber-pulling device comprises only a single (first) heating tube, the shut-off device can also be arranged between this and the expansion vessel. The shut-off device can open depending on pressure to enable vapor pressure pulling. When closed, the shut-off device allows pressure to build up in the heating tube(s), which are otherwise sealed by the plug.

[0044] As an alternative to pressure-dependent opening, the shut-off device can also be opened at regular intervals. In this mode, opening is not pressure-dependent but time-dependent. It can be provided that if a pressure in the second heating pipe exceeds a critical safety level, the shut-off device is opened even before the time after which it would normally open has elapsed.

[0045] An additional shut-off device, for example in the form of a second slide valve, can be arranged between the pressing and dewatering chamber and the pressing channel. This optional additional shut-off device can increase safety in particular in the event that the pressure in one of the heating pipes rises sharply and escapes through the pressing channel toward the pressing and dewatering chamber, counter to the direction of material flow, thereby causing the plug in the pressing channel to burst. If such a "breakthrough" of the plug occurs, an additional shut-off device can prevent property damage and personal injury. Depending on the fiber extraction process in the fiber extraction device, the opening and closing of the additional shut-off device may depend on the movement of the pressure plate.

[0046] Further advantages as well as the operation of the second slide or, in general, the further shut-off device are explained further below with reference to the method according to the invention.

[0047] It may be considered that one of the heating tubes, for example, the second heating tube, has a pressure relief valve. Preferably, only the second heating tube has at least one pressure relief valve. During normal operation, however, such a pressure relief valve does not affect the pressure prevailing in the heating tube(s). Ultimately, it is only used in an emergency, when a predetermined pressure is estimated to be too high. Even for heating tubes with a pressure relief valve, during normal operation, only the opening between the heating tube and the press channel and the transition between the heating tube and the expansion tank are available for pressure equalization and material flow.

[0048] Thermal insulation can be provided between a housing of the pressing channel and a housing of the first heating tube. Such insulation does not impede the entry of plant material into the heating tube. It merely insulates the housings or housing sections from each other. The insulation is intended to ensure that as little heat energy as possible is transferred from the first heating tube to the pressing channel.

[0049] The feed device can be a screw conveyor. The screw conveyor is preferably arranged so that its conveying direction essentially corresponds to the direction of gravity.

[0050] Heating in the heating tubes is preferably achieved via heating pads, which are assigned to the respective housing of the heating tube and heat them from the outside. Alternatively, or preferably additionally, a heating tube insert arranged within the heating tube can be considered, through which thermal oil flows, and which also heats the material located in the heating tube. The heating tube insert can, for example, comprise a heating line with, for example, four cross-shaped brackets.

[0051] The brackets do not have to be cross-shaped and a different number of brackets can also be considered.

[0052] Furthermore, it may be considered to provide only heating pads or only one or more heating tube inserts for heating.

[0053] Instead of heating pads, alternative heating devices can be used to heat the housing of the heating tube(s). For example, the heating tube housing can include holes through which thermal oil flows. Pipe trace heating, heating bands, or the like can also be considered. The heating tube housing can also be double-walled, with a heating device arranged between an outer wall, which separates the heating tube from the outside, and an inner wall, which defines an interior space for the incoming plant material, or with thermal oil flowing for heating purposes.

[0054] Alternatively or in addition to the heating pads and the heating tube insert, as already mentioned above, it may be considered to introduce hot steam into at least one of the heating tubes to heat the plant material.

[0055] The variants of the fiber extraction device described above can be stationary and installed, for example, in a hall or the like. Alternatively, the variants of the fiber extraction device can be installed in a container or the like for mobile use. Depending on the harvest time of a plant that provides the plant material, the mobile fiber extraction device can then be transported directly to a field to be harvested, for example. It is usually more economical to bring the fiber extraction device to the location where the plant material is produced (especially through harvesting) than to transport large quantities of harvested plant material to a distant, stationary fiber extraction device.

[0056] The device for solid-liquid separation can be arranged within the expansion tank.

[0057] It can also be considered that the solid-liquid separation device replaces the expansion tank and takes over or effects both its function and the solid-liquid separation.

[0058] The device for solid-liquid separation can be provided in any type of fiber digestion device that allows the digestion of plant material by means of steam pressure digestion. This can include fiber digestion devices with some or all of the previously described components. Alternatively, a very simply constructed fiber digestion device can also be considered, which essentially consists of a pressure-tight, sealable expansion vessel. Such a simply constructed fiber digestion device can, for example, be operated in batch mode, with the plant material to be digested being introduced into the expansion vessel, where it is then heated and subjected to high pressure.A sudden opening of a valve or the like can then cause the digestion, whereupon the device for solid-liquid separation provided in the expansion tank effects the solid-liquid separation in the manner described below.

[0059] The device for solid-liquid separation can be a press. Alternatively, any device for solid-liquid separation can be considered, especially mechanical devices for solid-liquid separation. For example, the principles of centrifugation, filtration, or classification can be used. Numerous other alternatives are conceivable.

[0060] The aforementioned solid-liquid separation device, which is located within the flash tank or replaces it, can remove at least a portion of the lignin after digestion. Such separation of the lignin can be particularly successful if, through suitable process and, in particular, temperature control, the plant material—and thus also the lignin—has a temperature after vapor pressure digestion in the flash tank that allows for mechanical separation of the lignin. Although lignin, as an amorphous polymer, does not usually melt, as is the case with low-molecular-weight substances, it can be separated from the remaining components of the plant material by a solid-liquid separation device, particularly at a temperature above its glass transition temperature.Preferably, the process and, in particular, the temperature control ensures that the plant material in the expansion tank still has a temperature of over 125°C, preferably over 130°C. It may also be considered that the plant material in the expansion tank still has a temperature of over 140°C, or even over 155°C, or over 170°C, or over 190°C.

[0061] If the plant material contains lignin, which due to its nature has a melting temperature, the above and following considerations regarding the glass transition temperature apply analogously.

[0062] In addition to separating at least a portion of the lignin, the solid-liquid separation device arranged in the expansion tank can also ensure that any remaining water is at least partially removed, which increases the dry matter content of the digested plant material. This, in turn, can have a positive effect on storability or the like. Furthermore, the aforementioned solid-liquid separation device can also remove any fines together with the lignin and / or water. For example, it can be envisaged that the plant material before the expansion tank has a dry matter content of between 28% and 40%, for example, approximately 35%, and after digestion and passing through the solid-liquid separation device, it has a dry matter content of over 50%, for example, approximately 60%.

[0063] The discharged fines, which are separated from the plant material by dewatering before entering the press channel and by the solid-liquid separation described above, can be used, for example, to feed a biogas plant.

[0064] In addition to the fiber extraction described above, device The present invention also includes a Proceedings for digesting plant material by means of steam pressure digestion using a variant of the device described above. Details explained above with regard to the device apply equally to the method and vice versa.

[0065] The variants of the process described in more detail below produce high-quality plant material which can be further processed, for example, for paper production without complex pretreatment in a pulper and then in a refiner.

[0066] The plant material to be digested can be plant material from a herbaceous plant. A herbaceous plant is a plant that essentially does not lignify, i.e., exhibits essentially no secondary growth. Particularly preferably, the above-ground parts of the herbaceous plant are processed primarily or exclusively within the scope of the present invention.

[0067] The following plants are particularly preferred within the scope of the present invention: the plant genus Miscanthus (a genus within the grass family), the plant species Silphium perfoliatum (silphium perfoliatum), the plant genus Hemp (a genus within the hemp family), the plant genus Nettle (a genus within the nettle family), the plant genus Banana (a genus within the banana family), in particular the species "dessert banana", the plant genus Lavender (a genus within the mint family), in particular the species "true lavender", or the plant genus Hop (a genus within the hemp family). Furthermore, straw can be used as plant material, preferably threshed and dried stalks and leaves of cereals, oil plants, fiber plants, or legumes. Cereal straw is particularly preferred.

[0068] For the purposes of the present invention, steam extraction refers to a physical process for fiber extraction. In general, steam extraction involves exposing the plant material to heat and high pressure in a suitable vessel, after which the pressure is rapidly reduced by opening a valve or the like.

[0069] Due to the drop in pressure, the water in the plant material boils explosively, which bursts open the cell structures.

[0070] In the process, the plant material is fed to the fiber disruption device, where the plant material is subsequently heated and subjected to overpressure, where the pressure is suddenly reduced after heating and application of overpressure in order to disrupt the plant material, where the plant material is subsequently subjected to a solid-liquid separation by the solid-liquid separation device.

[0071] The feed can be carried out via the feed device, as described below. This can also be connected directly to the expansion tank if the fiber pulping device essentially consists of this expansion tank. The same applies to a solid-liquid separation device if this replaces the expansion tank.

[0072] Overpressure can be applied at pressures between 3 and 50 bar, as described below.

[0073] The sudden reduction of pressure can take place in a flash tank or in a device for solid-liquid separation that takes over the function of a flash tank.

[0074] Within the scope of the process, the plant material can be fed through the feed device into the pressing and dewatering chamber and then compacted and preferably at least partially dewatered by a movement of the pressure plate in the pressing and dewatering chamber. (At least) "partial" dewatering is understood here as an incomplete solid-liquid separation. After dewatering, the plant material still contains a certain amount of water, meaning its dry matter content is not 100%, and is usually significantly lower. The dry matter content after dewatering, i.e., in the pressing channel, in the heating tube(s), and immediately before entering the expansion tank, can be, for example, between 20 and 40%, preferably in the range of 28 to 40%, more preferably around 35%.

[0075] The movement of the pressure plate is preferably a reciprocating, i.e., periodic and thus intermittent movement, as is familiar from piston engines. Since the pressure plate causes the plant material to move in the direction of material flow, and no screw conveyor is used for this, the formation of fines is avoided.

[0076] The plant material is then preferably introduced into the press channel by the movement of the pressure plate and pressed into a plug.

[0077] The plug preferably serves as a pressure- and vapor-tight barrier, sealing the downstream heating pipe at one end. The plug preferably builds up continuously at an end section of the press channel facing the pressing and dewatering chamber through the supply of material from the pressure plate. At the same time, the plug preferably builds up continuously at an opposite end section of the press channel through the conveyance of plant material into the heating pipe. Preferably, a dynamic equilibrium between buildup and degradation exists, i.e., the amount of material entering at one end corresponds, at least averaged over appropriately selected periods, to the amount of material exiting at the other end.The feeding device can be operated in such a way that the amount of plant material fed in during a certain period of time essentially corresponds to the amount of plant material that is introduced into or removed from the relaxation container during the same period of time.

[0078] Preferably, a plug is formed in the press channel, which requires no additional counterpressure to be stable. Simply pressing the material in the specially designed press channel preferably results in the plug being formed.

[0079] The plant material is then preferably conveyed from the press channel into the at least one first heating tube and heated there, resulting in a pressure increase in the at least one first heating tube. The pressure increase preferably occurs because the water content of the plant material heats up and partially evaporates, and because the pressure cannot escape from the heating tube(s) due to the plug in the press channel and the closed shut-off device.

[0080] The plant material then preferably leaves the at least one first heating tube and enters the expansion tank, in which a lower pressure prevails compared to the at least one first heating tube, whereby the plant material is digested upon entering the expansion tank. Preferably, the aforementioned shut-off device, in particular the slide valve, which is arranged between the expansion tank and the heating tube immediately upstream of it, in particular in an outlet, opens in a pressure-dependent manner. As a result, the pressure change causing the digestion occurs suddenly.

[0081] The transition to the expansion tank can be located between the expansion tank and the first or between the expansion tank and the second heating tube, depending on whether a second heating tube is present. The digestion preferably occurs through explosive evaporation of the water components in the plant material mixture, which evaporate abruptly due to the lower pressure in the expansion tank compared to the heating tube.

[0082] It can be envisaged that the material flow direction of the plant material within the fiber pulping device between the pressing and dewatering chamber and the end of the first heating tube is determined solely by the pressure plate after the plant material has been introduced through the feed device. The pressure plate can therefore be the only device between the pressing and dewatering chamber and the end of the first heating tube that causes an active material flow. Other movements of the plant material preferably only occur during introduction into the pressing and dewatering chamber by the feed device and due to the high pressure difference at the transition to the expansion tank. There, the plant material can be conveyed from the upstream first or second heating tube into the expansion tank in a suction-like manner.

[0083] If the material flow direction is determined solely by the pressure plate, as described above, this can reduce the formation of fines, in contrast to a situation where a stuffing screw determines the material flow direction.

[0084] A direction along which the plant material is introduced from the feeding device into the pressing and dewatering chamber does not define the aforementioned material flow direction.

[0085] It can be envisaged that the process described above runs continuously. Both the feeding of the plant material and the conveying in the direction of material flow through the pressure plate do not have to run continuously in the sense that exactly the same material flow is observed in any arbitrarily small unit of time, e.g. into the pressing and dewatering chamber and out of the heating tube in the direction of the expansion tank. An interval-like, i.e. pulsating movement is also conceivable, both with regard to the feeding and with regard to the conveying and the transition into the expansion tank. This applies on the one hand to the pressure plate, which - similar to a piston engine - usually performs such a pulsating movement, and on the other hand to the transfer of the plant material into the expansion tank, which is usually pressure- or time-dependent and thus also occurs at intervals.

[0086] A continuous process is preferably present if, over periods that can range from a few minutes to several hours, the mass of the plant material introduced into the pressing and dewatering chamber essentially corresponds to the mass of the plant material that enters the relaxation container.

[0087] It may be considered that the temperature inside the at least one first heating tube is at least 125°C, preferably at least 130°C, and / or a dry matter content of the plant material immediately before entering the expansion tank is between 28 and 40%.

[0088] If a second heating tube is present, the above-mentioned temperature of at least 125°C or 130°C preferably prevails in the second heating tube. The temperature in the first and especially the second heating tube can reach up to 260°C.

[0089] If the fiber pulping device essentially consists of a relaxation tank or a device for solid-liquid separation that takes over its function, the temperatures described above preferably prevail there.

[0090] What is important is that the temperature is still present in the expansion tank, where the lignin is separated by a solid-liquid separation, for example by means of a press, according to a preferred embodiment of the process.

[0091] Typically, the glass transition temperature of lignin is above 125°C, sometimes even above 130°C. This has already been described above with regard to the fiber pulping device.

[0092] With a dry matter content significantly below 28%, plug formation in the press channel may sometimes be insufficient. However, this also depends on the design of the press channel (length, backflow prevention device, and retention device) and the plant material used.

[0093] With a dry matter content significantly above 40%, it may sometimes happen that the vapor pressure digestion in the flash tank is insufficient, meaning that an unacceptably high proportion of the plant material is not digested or is only insufficiently digested. However, this also depends on the plant material used and the process control, for example, the pressures and temperatures in the flash tank and the upstream heating tube(s).

[0094] A suitable dry matter content and advantageous process parameters can be determined in preliminary tests. As already described, temperatures between 125°C and 260°C can be considered. Furthermore, the maximum pressure reached during the process can be between 3 bar and 50 bar, preferably between 5 bar and 50 bar, more preferably between 6 bar and 50 bar, even more preferably between 6 bar and 40 bar, for example, around 7 bar. Significantly higher pressures of, for example, 20 bar or 30 bar are also conceivable. The residence time of the plant material before the actual steam pressure digestion by pressure reduction in the fiber digestion device can be between approximately 30 seconds and 60 minutes, preferably in the range between 1 minute and 30 minutes. To enable the actual steam pressure digestion by sudden pressure reduction, the pressure can be reduced to atmospheric pressure.It may also be considered to reduce the pressure to a value above atmospheric pressure, provided that it is still significantly below the pressure to which the plant material was previously subjected.

[0095] It can be envisaged that the shut-off device opens depending on the pressure prevailing in the at least one heating tube. The shut-off device, for example the slide valve which connects the first heating tube or, if present, the second heating tube with the expansion tank, can open, for example, when a predetermined pressure is reached. This opening causes a flow of a portion of the plant material from the first or second heating tube into the expansion tank. This material flow can be brought about both by the movement of the pressure plate and, complementarily or alternatively, by suction. The aforementioned suction can be brought about by the pressure difference between the expansion tank and the heating tube upstream of it.

[0096] For example, the shut-off device can close after a predetermined period of time. Alternatively, the shut-off device can close after the pressure in the heating pipe drops to a predetermined value.

[0097] After the shut-off device has been closed, the pressure in the heating pipe, which is then again pressure-tightly closed, increases again during the further course of the preferably continuous process, whereupon the shut-off device opens again after the pressure has been exceeded or alternatively after a certain time has elapsed, as described above.

[0098] It can be envisaged that heat transfer takes place in the at least one first heating tube in the form of heat conduction from at least one surface of the at least one first heating tube to the plant material. In this context, surfaces of the heating tube are understood to include both the housing of the heating tube or surface sections of this housing, as well as, for example, a heating line running inside the heating tube. Heat conduction here refers to heat transfer through mechanical contact, i.e., preferably not through convection or thermal radiation.

[0099] However, convection and / or thermal radiation can also be used to heat the plant material, alternatively or in addition to the principle of heat conduction.

[0100] A housing of the heating tube can be heated by heating pads surrounding the housing. A heating line, as mentioned above, is preferably arranged inside the heating tube. A thermal oil, for example, can flow through the heating line. Alternative heating options and variants are conceivable and have already been explained in detail with reference to the fiber extraction device.

[0101] As already partially indicated above, the pressure plate, which is preferably driven by a hydraulic cylinder, preferably determines the material flow direction. Downstream of the pressing and dewatering chamber, the pressing channel preferably follows, followed by the first and optionally the second heating tube, and then the expansion tank. As also already indicated, the pressure plate is preferably the only device for determining the material flow in the aforementioned components of the fiber pulping device.

[0102] As already described, a further shut-off device, preferably in the form of a second slide valve, is preferably provided between the pressing and dewatering chamber and the pressing channel. This slide valve is thus present in addition to the slide valve arranged in the outlet to the expansion tank.

[0103] This second slide (or generally the further shut-off device) is preferably closed as soon as it has moved into its position closest to the pressing channel, in which position it compacts the plant material, preferably dewaters it, and conveys at least a portion of it into the pressing channel. After closing, the slide prevents some of the plant material just conveyed into the pressing channel from returning to the pressing and dewatering chamber. Preferably, after the second slide has closed, the pressure plate moves against the direction of material flow, whereupon the feed device once again fills the pressing and dewatering chamber with fresh plant material. The pressure plate then moves in the direction of material flow, whereby the plant material is compacted and preferably dewatered.During the aforementioned movement of the pressure plate, the second slide can initially remain closed and act as a stop, counterbearing, or barrier for the plant material being compacted by the pressure plate. During this movement of the pressure plate in the direction of material flow, or alternatively, as soon as this movement begins, the second slide opens to allow the plant material to be conveyed into the press channel.

[0104] The second gate valve can be a hydraulically driven knife gate valve. This design is typically very low-maintenance. The second gate valve does not need to be steam- or pressure-tight, so it can be very simple in design.

[0105] In view of the above description of preferred variants of the process, it becomes clear that both the feed device (e.g., the screw conveyor) and the pressure plate and the shut-off device (e.g., the slide valve) between the expansion vessel and the heating tube immediately upstream of it are preferably operated intermittently. In contrast, the heating of the heating tubes is preferably carried out continuously.

[0106] However, if the fiber pulping device essentially consists of a flash tank or a device for solid-liquid separation that takes over its function, it may also be possible to operate this fiber pulping device in batch mode. The specifications regarding residence time, pressures, temperatures, and other process parameters may still apply in such a fiber pulping device.

[0107] The present invention further comprises a Process for producing a semi-finished product for the production of paper, cardboard or carton from a plant material, wherein the plant material is first digested using a variant of the previously described process for digesting plant material by means of steam pressure digestion and then further processed into the semi-finished product. Due to the previously described avoidance of fines, which offers advantages in the production of paper and often also cardboard, the above process is particularly well suited for the production of paper and preferably also cardboard.

[0108] Furthermore, the present invention also encompasses a use of a plant material treated according to a method already described for the production of paper, cardboard or carton or for the production of a semi-finished product which is used in the production of paper, cardboard or carton. Character description

[0109] Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments and from the drawings, which show: Figure 1 a sectional view of a fiber extraction device 1, in Figure 2 a sectional view along the line II-II in Figure 1 , as well as in the Figures 3 to 5 different views of a press 32. Example

[0110] In Figure 1A fiber pulping device 1 for pulping plant material by means of steam pressure pulping is shown. The device 1 comprises, in this order, a pressing and dewatering chamber 2, a pressing channel 3, a first heating tube 4, a second heating tube 5 and a relaxation tank 6. The aforementioned components 2, 3, 4, 5, 6 are designed as zones of the fiber pulping device 1. The fiber pulping device 1 comprises, in the relaxation tank 6, a device for solid-liquid separation, which, however, is Figure 1 is not shown separately. The function of such a device for solid-liquid separation is described with regard to the press 32 in the Figures 3 to 5 described.

[0111] The pressing and dewatering chamber 2 is assigned a pressure plate 9, which is driven by a hydraulic cylinder 11. A feed device 7 in the form of a screw conveyor 7 is also assigned to the pressing and dewatering chamber 2. Furthermore, a perforation 8 formed from numerous adjacent bores can be seen in a housing 27.2 of the pressing and dewatering chamber 2. The perforation 8 is located on a housing section 14.2 of the housing 27.2 of the pressing and dewatering chamber 2 between an inlet 19 and a transition to the pressing channel 3.

[0112] Backflow prevention devices 10 can be seen in the press channel 3, only some of which are provided with reference numbers. In the enlarged section A, a wedge-shaped cross-section of the backflow prevention device 10 can be seen. It has a sliding surface 25 and a stop surface 26. The sliding surface 25 is arranged such that a distance (not shown) between the sliding surface 25 and a central longitudinal axis 28, which is only indicated, decreases along a material flow direction.

[0113] Heating tube inserts 12.4 and 12.5 are visible inside the heating tubes 4 and 5. Furthermore, heating pads 13.4 and 13.5 are arranged outside the heating tube housings 27.4 and 27.5.

[0114] At a transition between the second heating tube 5 and the expansion tank 6, a shut-off device in the form of a slide valve 15 can be seen. Furthermore, a discharge screw 16 is arranged at the bottom of the expansion tank 6.

[0115] In Figure 2 A heating pad 13.4, the housing 27.4 of the first heating tube 4 and the heating tube insert 12.4 with four holders 20.4 can be seen. A clear dimension 23.4 of the first heating tube 4 is shown in Figure 2 Furthermore, the heating pipe insert 12.4 comprises a heating line 30.4 arranged centrally in the first heating pipe 4.

[0116] The Figures 3 to 5 show various views of a press 32, which can be used instead of the expansion tank 6. A press table 33, a guide 34, a shot line 35, a hydraulic cylinder 36, a punch-supporting cylinder 37, a press housing 38, a steam outlet pipe 18.1, and a discharge screw 16.1 are visible. With reference to Figures 1 to 5, the functioning of the device according to the invention and the method according to the invention are explained as follows:

[0117] The plant material to be digested is fed into the pressing and dewatering chamber 2 via the screw conveyor 7 along the conveying direction 21, ie following the force of gravity. The pressure plate 9, driven by the hydraulic cylinder 11, then moves the plant material in the material flow direction 24, in Figure 1 i.e. to the right, in the direction of the press channel 3. Preferably at the beginning of this movement of the pressure plate 9, the second slide 31 is moved into the raised position, which in Figure 1is shown. In this raised position, the second slide 31 releases the connection between the pressing and dewatering chamber 2 and the pressing channel 3. Due to the movement of the pressure plate 9 to the right, the plant material accumulates in the pressing channel 3, where the plug described in more detail below is formed. Since this plug offers a certain resistance to the plant material being conveyed by the pressure plate 9 in the material flow direction 24, dewatering takes place in the housing section 14.2 of the housing 27.2 of the pressing and dewatering chamber 2. Specifically, this dewatering takes place in that the plant material is compressed by the pressure plate 9 in the housing section 14.2, whereby the plant material is partially dewatered via the perforation 8.

[0118] The partially dewatered plant material is immediately introduced into the pressing channel 3 by the movement of the pressure plate 9, where it is compressed into a plug. If the second slide 31 is opened to the right at the beginning of the movement of the pressure plate 9, which is preferred, the plant material is compressed and dewatered in the pressing and dewatering chamber 2 and introduced into the pressing channel 3 simultaneously.

[0119] Since the above-described movement of the plant material is effected by the pressure plate 9, and not by a stuffing screw or the like, the reduced friction and shear advantageously result in fewer fines being produced during the material flow and compaction. This has a particularly positive effect on paper or the like that can be produced from the plant material.

[0120] The fiber extraction device 1 is operated continuously, i.e., the hydraulic cylinder 11 continuously moves the pressure plate 9 back and forth. Furthermore, plant material is introduced into the pressing and dewatering chamber 2 either continuously or periodically via the screw conveyor 7, which is then fed from the pressure plate 9 to the pressing channel 3 in the material flow direction 24.

[0121] It may be considered to coordinate the operation of the screw conveyor 7 with a movement of the pressure plate 9. For example, it may be considered that the screw conveyor 7 only conveys plant material when the pressure plate 9 is "far left", i.e. in the Figure 1 shown retracted position; or as long as the pressure plate 9 is in the material flow direction 24 in front of an inlet 19 (in Figure 1 i.e. "to the left of the inlet 19"), which connects the screw conveyor 7 with the pressing and dewatering chamber 2.

[0122] Furthermore, the raising and lowering of the second slide 31 can be coordinated with the aforementioned movements. For example, the second slide 31 can be raised as soon as the pressure plate 9 begins to move to the right. The second slide 31 can be lowered as soon as the pressure plate 9 is in its maximum rightward deflection position. In this way, the second slide 31 prevents plant material from the pressing channel 3 from migrating into the pressing and dewatering chamber 2 against the material flow direction 24 before the screw conveyor 7 fills the pressing and dewatering chamber 2.

[0123] The back and forth movement of the pressure plate 9 occurs along or against the material flow direction 24.

[0124] The back and forth movement of the hydraulic cylinder 11 and thus of the pressure plate 9 takes place parallel to the Figure 1The only indicated common central longitudinal axis 28 of the hydraulic cylinder 11, pressure plate 9, pressing and dewatering chamber 2, pressing channel 3, first and second heating tubes 4, 5, and the heating tube inserts 12.4, 12.5 are thus arranged coaxially to one another.

[0125] Due to the continuous operation, plant material is continuously fed from the pressing and dewatering chamber 2 into the pressing channel 3. Plug formation in the pressing channel 3 occurs, on the one hand, through the compression of the plant material caused by the pressure plate 9. On the other hand, plug formation is also supported by the structure of the pressing channel 3.

[0126] The cross-sectional view according to Figure 1The backflow prevention devices 10, which are clearly visible in section A in particular, act similarly to a ratchet mechanism with respect to the plant material conveyed in the material flow direction 24: The sliding surface 25 is inclined at an angle of less than 45° to the material flow direction 24 and allows the plant material to be conveyed in the material flow direction 24. The plant material slides along the sliding surface 25. The stop surfaces 26, which are orthogonal to the material flow direction 24, prevent the plant material from moving in the opposite direction. This prevents a "falling back to the left" (with respect to Figure 1 ) of the plant material in the press channel 3 is avoided, even if the pressure plate 9, after the maximum deflection of the hydraulic cylinder 11 in the material flow direction 24, moves in the opposite direction, in Figure 1 i.e. to the left, moves.

[0127] Due to the movement of the pressure plate 9, which constantly introduces new plant material into the press channel 3 in the material flow direction 24, a portion of the plant material pressed into the plug constantly passes into the first heating tube 4 at the transition between the press channel 3 and the first heating tube 4. There, the plant material is heated by means of the heating pad 13.4 and the heating tube insert 12.4. The cross-sectional areas of the press channel 3 and the first heating tube 4 are selected such that both are essentially completely filled with plant material during operation. The second heating tube 5 has a larger cross-sectional area than the first heating tube 4, which is why the fill level of the second heating tube 5 is significantly below 100% during operation. This will be explained in more detail below.

[0128] The filling level of the press channel 3 and the first heating tube 4 is preferably 100% during ongoing operation. "During ongoing operation" preferably means continuous operation of the fiber pulping device 1, with the plug in the press channel 3 already installed and plant material already flowing into the expansion tank 6 via the outlet 29.

[0129] During operation, the movement of the pressure plate 9 within the pressing and dewatering chamber 2 serves to generate a 100% filling level in the pressing channel 3, which is why the filling level in the pressing and dewatering chamber 2 is usually less than 100%. Due to the periodic back-and-forth movement of the pressure plate 9 and the introduction of plant material by the screw conveyor 7, the filling level in the pressing and dewatering chamber 2 usually changes continuously.

[0130] Since it has a larger internal dimension 23 compared to the first heating tube 4 and regularly releases plant material to the expansion tank 6 via the outlet 29, the second heating tube 5 is preferably not 100% filled during operation. A fill level gradient often occurs in the second heating tube 5, with the fill level decreasing toward the outlet 29, based on a cross-sectional area of ​​the second heating tube 5 running orthogonally to the central longitudinal axis 28.

[0131] The plant material which has been conveyed into the second heating tube 5 is further heated there by means of the heating tube insert 12.5 and the heating pads 13.5.

[0132] The heating in the heating tubes 4, 5 leads to a pressure increase. Depending on the pressure, i.e., particularly when a predetermined pressure is reached, the slide valve 15 of an outlet 29 opens, which connects the second heating tube 5 to the expansion tank 6. The pressure in the expansion tank 6 is significantly below the pressure that prevailed in the heating tubes 4, 5 immediately before the slide valve 15 opened. Due to this pressure drop, the water contained in the plant material evaporates explosively, which causes the vapor pressure decomposition.

[0133] An interior of the expansion vessel 6 can be connected via a steam outlet pipe 18 to a downstream device in which the discharged steam is condensed and / or used for other purposes. Furthermore, a pipe 17 with a rupture disc is provided, which replaces the steam outlet pipe 18 should it become blocked. If the steam outlet pipe 18 becomes blocked, the pipe 17 with a rupture disc can reliably prevent a risky pressure increase by bursting the rupture disc and creating pressure equalization. It is also possible to arrange a safety valve in the pipe 17 behind the rupture disc, so that the rupture disc is associated with the interior of the expansion vessel 6.

[0134] The digested plant material is conveyed out of the expansion tank 6 by means of the discharge screw 16. The digested plant material can then be further processed.

[0135] For heating in the heating tubes 4, 5, in addition to the heating pads 13.4, 13.5 for heating the housing 27.4, 27.5, a heating line 30.4, 30.5 is preferably provided inside the heating tubes 4, 5. This heating line 30.4, 30.5 is part of a heating tube insert 12.4, 12.5. The heating tube inserts 12.4, 12.5 comprise the cross-shaped brackets 20.4, 20.5, which secure the heating lines 30.4, 30.5 inside the heating tube 4, 5. Thermal oil flows through the heating lines 30.4, 30.5.

[0136] While the expansion tank 6 according to Figure 1 essentially provides a jacketed cavity for the steam pressure digestion, the press 32 offers the possibility of carrying out a solid-liquid separation in addition to the steam pressure digestion. Figures 3 to 5 The press 32 shown can replace the expansion tank 6.

[0137] The shot line 35 of the press 32 takes over the function of the outlet 29 in Figure 1 . The firing line 35 comprises a (in the Figures 3 to 5 not shown or not recognizable) slider or the like, the function of which has already been explained with regard to the slider 15 in Figure 1 was explained.

[0138] Preferably, the press housing 38 is designed with sufficiently thick walls to act as a baffle plate with respect to the plant material, which enters the press housing 38 through the weft line 35 at a typically high speed. When the plant material enters the weft line 35, the stamp-carrying cylinder 37 is in its upper end position. A (in the Figures 3 to 5 The stamp (not visible) which closes the press housing 38 upwards moves after the plant material has entered and the weft line has been closed by means of the Figures 3 to 5not shown) slide downwards towards the discharge screw 16.1. This compresses the plant material in the press housing 38 and presses out the liquid components. The pressed-out liquid can be poured onto suitable (and Figures 3 to 5 not shown) in the manner known from prior art presses.

[0139] The press table 33 and the discharge screw 16.1 are linearly movable in the form of a slide on the guide 34. In Figure 4 The aforementioned components, which are preferably combined into an assembly, can be moved from left to right with the aid of the hydraulic cylinder 36. The aforementioned assembly, together with the guide, thus forms a - in Figure 4 Linear guide movable to the right and left.

[0140] After the punch (not shown) has been moved by the punch-carrying cylinder to its lower end position, the above-mentioned assembly (with respect to Figure 4 ) to the right, so that instead of the press table 33, the discharge screw 16.1 is located directly below the press housing 38. After the lowering of the ram and the resulting solid-liquid separation, a press cake consisting of the digested plant material is present within the press housing 38. Water and liquefied lignin were preferably removed during pressing. For this purpose, a suitable device for removing liquids in such presses can be used, which is not shown separately in the drawings.

[0141] Starting from the previously reached lower end position, the ram (not shown) can now be lowered further slowly and with a low load with the aid of the ram-carrying hydraulic cylinder 37, with the discharge screw 16.1 simultaneously "milling off" the press cake that has been carefully pressed down in this way.

[0142] Although only a few preferred embodiments of the invention have been described and illustrated, it is obvious that those skilled in the art can add numerous modifications without departing from the spirit and scope of the invention. In particular, the following Modifications be intended: Starting from the fiber extraction device 1 to Figure 1 First of all, it should be noted that only the device for solid-liquid separation (not shown there) is a mandatory component of all embodiments of the present invention. This device for solid-liquid separation can be installed in the expansion tank 6 according to Figure 1be arranged or replace it. The Figures 3 to 5 The press 32 shown can therefore be directly connected to the second heating pipe 5 of the Figure 1 connecting, whereby the firing line 35 is replaced by the outlet 29 or vice versa. The remaining Figure 1 The features shown are preferred, but do not represent mandatory components of the fiber pulping device 1 according to the invention.

[0143] Thermal insulation can be arranged at a transition between the pressing channel 3 and the first heating tube 4, where the housing 27.3 of the pressing channel and the housing 27.4 of the first heating tube 4 touch. This can prevent heat, which is generated, for example, by the heating pads 13.4 and intended to be transferred to the plant material inside the first heating tube 4, from heating the housing 27.3 of the pressing channel 3 and the plant material located inside the pressing channel 3. The plug is primarily intended to be built up in the pressing channel 3, whereby excessive heating of the plant material tends to be detrimental.

[0144] Although this is Figure 2As shown only for the first heating tube 4, the pressing and dewatering chamber 2, the pressing channel, and also the second heating tube 5 have a substantially cylindrical shape. The aforementioned components are thus in cross-section, i.e., orthogonal to the central longitudinal axis 28, just like the first heating tube 4 (cf. Figure 2 ) around.

[0145] The sliding surfaces 25 can have an angle of preferably less than 60°, more preferably less than 45°, and even more preferably less than 30°, to the central longitudinal axis 28. The stop surface 26, however, is preferably arranged substantially orthogonally to the central longitudinal axis 28.

[0146] The clear dimension 23.4 of the first heating pipe 4, as well as all other (not shown) clear dimensions of the adjacent components, which are essentially coaxial to one another, are measured orthogonally to the central longitudinal axis 28.

[0147] A safety valve can be arranged in the second heating tube 5. To protect this safety valve from contamination by the plant material, a bursting disc can be installed upstream of the safety valve.

[0148] Should this safety valve (not shown in the drawings) in the second heating tube 5, as well as the pipe 17 with rupture disc and the steam outlet pipe 18, be clogged or, for any reason, unable to reduce excessive pressure within the heating tubes 4, 5 and the expansion vessel 6, the plug in the press channel 3 would burst, and the excess pressure would escape through the perforation 8 in the pressing and dewatering chamber 2. While this is undesirable, it does provide protection against serious machine and / or personal damage in the event that the previously described "regular" pressure-reducing devices fail. A baffle plate or the like surrounding the perforation 8 is also advisable for this reason.

[0149] In addition or alternatively to the perforation 8, the water can also escape through a perforation (not shown) in the pressure plate 9 or through the gap between the pressure plate and the inside of the pressing and dewatering chamber 2. Preferably, the pressure plate 9 is not sealed against the inner wall of the housing 27.2 of the pressing and dewatering chamber 2, for example, by an annular seal.

[0150] A grid (not shown) can be arranged within the expansion tank 6 such that the plant material entering the expansion tank 6 via the outlet 29 from the second heating tube 5 directly impacts the grid and is comminuted by this impact. Instead of the grid, any alternative comminution devices, preferably passive comminution devices such as statically arranged blades or the like, can be used, which, like the grid, are suitable for comminuting the plant material. The grid or an alternative comminution device can also be arranged within the outlet 29.

[0151] The holders 20 can be designed differently than is particularly the case in Figure 2 The cross-shaped arrangement is not essential. The heating cables 30.4, 30.5 can also be held by a different number of brackets 20.4, 20.5.

[0152] It may be considered to accomplish the heating in one or both heating tubes 4, 5 either exclusively by means of the heating pads 13.4, 13.5, or exclusively by means of the heating tube inserts 12.4, 12.5, which preferably each comprise a heating line 30.4, 30.5.

[0153] If the heating pads 13.4, 13.5 are omitted, the housing 27.4, 27.5 of the heating tube 4, 5 can be thermally insulated particularly effectively. If any heating tube inserts 12.4, 12.5 are omitted, there are no components inside the heating tubes 4, 5 that could potentially cause unwanted accumulation of plant material.

[0154] Despite the aforementioned possible disadvantages, the advantages of the heating pads 13.4, 13.5 and heating tube inserts 12.4, 12.5 outweigh the disadvantages, which is why both are preferably used.

[0155] Instead of the heating pads 13.4, 13.5, alternative heating devices can be used to heat the housings 27.4, 27.5.

[0156] Instead of the heating lines 30.4, 30.5, alternative heating devices within the heating pipes 4, 5 can also be considered.

[0157] In this case, heat transfer devices based on the principles of thermal radiation or convection can always be considered. For example, it could be considered to introduce hot steam into the second heating tube 5 via a suitable device (not shown) in order to heat the plant material located there. This can be considered as an alternative to or in addition to the heating pads 13 and the heating tube insert 12.

[0158] Instead of the screw conveyor 7, another feed device can be used. If the fiber pulping device 1 essentially consists of a solid-liquid separation device, a feed device can be directly connected to this solid-liquid separation device.

[0159] Instead of the press 32, other devices for solid-liquid separation can be considered. These can either be arranged in the expansion tank 6 or replace it. List of reference symbols 1 Fiber pulping device 2 Press and dewatering chamber 3 Press channel 4 first heating pipe 5 second heating pipe 6 Relaxation tank 7 Feeding device / screw conveyor 8 Perforation 9 printing plate 10 Backflow prevention device 11 hydraulic cylinder 12 Heating pipe insert 13 heating pad 14 Housing section 15 Shut-off device / slide valve 16 discharge screw 17 Pipe with rupture disc 18 Steam outlet pipe 19 inlet 20 Bracket for heating pipe insert 21 Conveying direction of the screw conveyor 22 Direction of gravity 23 Clear dimension 24 Material flow direction between press and dewatering chamber and expansion tank 25 Sliding surface 26 Stop surface 27 Housing 28 Central longitudinal axis 29 Outlet 30 Heating line 31 second slider 32 press 33 press table 34 guide 35 Shot direction 36 hydraulic cylinder 37 Stamp-bearing cylinder 38 Press housing

Claims

1. Fiber disruption device (1) for disrupting a plant material by means of steam pressure disruption, wherein the fiber disruption device (1) comprises a device for solid-liquid separation (32) which is arranged within a relaxation container (6) of the fiber disruption device (1) or takes over the function of such a relaxation container (6).

2. Fiber pulping device (1) according to claim 1, characterized bya pressing and dewatering chamber (2), a pressing channel (3), at least one first heating tube (4), and a relaxation container (6), wherein the pressing and dewatering chamber (2) is assigned a pressure plate (9) for compacting and dewatering the plant material and for determining a material flow in the fiber pulping device (1), wherein the pressing and dewatering chamber (2) is further assigned a feed device (7) for feeding the plant material to be pulped, wherein the pressing and dewatering chamber (2), the pressing channel (3), the at least one first heating tube (4), and the relaxation container (6) are connected to one another in such a way that plant material introduced into the pressing and dewatering chamber (2) from the feed device (7) first enters the pressing channel (3) by a movement of the pressure plate (9) and then passes through the at least first heating tube (4) to then enter the relaxation container (6).

3. Fiber pulping device (1) according to claim 1, characterized by at least one backflow prevention device (10) in the pressing channel (3) and / or a perforation (8) in at least one section (14.2) of the pressing and dewatering chamber (2).

4. Fiber disintegration device (1) according to one of the preceding claims, characterized by a second heating tube (5) arranged between the first heating tube (4) and the expansion tank (6), wherein a clear dimension of the second heating tube (5) is greater than a clear dimension of the first heating tube (4); and / or wherein the clear dimension of the first heating tube (4) is smaller than a clear dimension of the press channel (3).

5. Fiber disintegration device (1) according to at least claim 3, characterized by a shut-off device (15) at the transition between the second heating pipe (5) and the expansion tank (6).

6. Fiber disintegration device (1) according to at least one of the preceding claims, characterized by a thermal insulation between a housing (27.3) of the press channel (3) and a housing (27.4) of the first heating tube (4).

7. Fiber disintegration device (1) according to at least one of the preceding claims, characterized in that the feeding device (7) is a screw conveyor (7).

8. A method for digesting a plant material by means of steam pressure digestion using a fiber digestion device (1) according to one of claims 1 to 7, wherein the plant material is fed to the fiber digestion device (1), wherein the plant material is subsequently heated and subjected to overpressure, wherein the pressure is suddenly reduced after heating and application of overpressure in order to digest the plant material, wherein the plant material is subsequently subjected to a solid-liquid separation by the device for solid-liquid separation (32).

9. The method according to claim 8, wherein the plant material is fed by the feed device (7) to the pressing and dewatering chamber (2), wherein the plant material is subsequently compacted and preferably at least partially dewatered by a movement of the pressure plate (9) in the pressing and dewatering chamber (2), wherein the plant material is subsequently introduced into the pressing channel (3) by the movement of the pressure plate (9) and pressed there into a plug, wherein the plant material subsequently leaves the pressing channel (3) and is conveyed into the at least one first heating tube (4) and heated there, which leads to an increase in pressure in the at least one first heating tube (4), wherein the plant material subsequently leaves the at least one first heating tube (4) and enters the expansion tank (6), in which a lower pressure prevails compared to the at least one first heating tube (4),wherein the plant material is broken down during entry into the relaxation container (6).

10. The method according to claim 8, wherein a material flow direction of the plant material within the fiber pulping device (1) between the pressing and dewatering chamber (2) and the end of the first heating tube after the introduction of the plant material by the feeding device (7) is determined solely by the pressure plate (9).

11. Method according to one of claims 8 to 10, characterized by the fact that the temperature inside the at least one first heating tube (4) is at least 125°C, preferably at least 130°C, and / or a dry matter content of the plant material immediately before entry into the expansion tank (6) is between 28 and 40%.

12. Method according to one of claims 8 to 11, characterized in that the shut-off device (15) opens depending on a pressure prevailing in the at least one heating pipe (4, 5).

13. Method according to at least one of claims 8 to 12, characterized in that in which at least one first heating tube (4) a heat transfer in the form of heat conduction takes place from at least one surface of the at least one first heating tube (4) to the plant material.

14. A process for producing a semi-finished product for the production of paper, cardboard or carton from a plant material, wherein the plant material is first digested according to one of claims 8 to 13 and then further processed into the semi-finished product.

15. Use of a plant material treated by a process according to at least one of claims 8 to 13 for the production of paper, cardboard or carton or for the production of a semi-finished product which is used in the production of paper, cardboard or carton.

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