Treatment vessel having reduced outlet end diameter

Abstract

A treatment vessel (10) for treating lignocellulosic material comprises a main portion (20) having a first end (24) and a second end (26), and an outlet portion (40) that is conical or frusto-conical and tapers from a first end (44) joined to the second end (26) of the main portion (20) to a second end (46) having an outlet opening (48). A cone (60) is disposed within the treatment vessel (10) with an apex (64) of the cone facing away from the main portion (20). The cone (60) is positioned such that the base (62) of the cone (60) is positioned within a vertical distance (d) from a transition plane (T) defined by the junction between the first end (44) of the outlet portion (40) and the second end (26) of the main portion (20), the vertical distance (d) being less than or equal to ¼ of the diameter (D) of the main portion (20). The half angle (β) of the cone (60) is 0.5-20° less than the half angle (α) of the outlet portion (40), preferably 5-15° less, such as less than 10°.

Description

[Technical field]

[0001] The present invention relates to a process vessel having a reduced outlet end diameter. [Background technology]

[0002] The processing vessel is commonly used in the field of producing pulp from lignocellulosic materials. The processing vessel includes a pretreatment or impregnation vessel in which wood chips, representative of the lignocellulosic material, are impregnated with a pretreatment or impregnation fluid to produce a chip slurry. The processing vessel further includes a digester in which the chip slurry is cooked to obtain pulp for subsequent use in the production of pulp products such as paper. Additionally, the processing vessel includes a prehydrolysis vessel in which wood and non-wood materials, such as wood chips and agricultural residues, can be processed to produce fibers for pulp products such as paper.

[0003] A treatment vessel for treating lignocellulosic material generally needs to be able to withstand pressure differences between the interior of the treatment vessel and the surrounding atmosphere. These pressure differences may be due to hydrostatic pressure, i.e., due to the weight of the liquid and / or lignocellulosic material in the treatment vessel, due to the injection of steam or other liquids or gases into the treatment vessel, and / or due to heating or cooking of the liquid and / or lignocellulosic material in the treatment vessel.

[0004] A treatment vessel for treating lignocellulosic material typically comprises an inlet for inputting lignocellulosic material into the treatment vessel and an outlet for discharging treated lignocellulosic material and liquid from the treatment vessel. The inlet and outlet are usually separate and located at opposite ends of the treatment vessel, although they may be combined in a combined inlet and outlet. The outlet is provided at the outlet end of the treatment vessel, which is usually dome-shaped to withstand pressure. The outlet comprises an outlet opening through which the treated lignocellulosic material and any present fluids are discharged. Since the treated lignocellulosic material and any present fluids are usually discharged into a discharge pipe, it is generally preferred to have the outlet opening, and therefore the outlet end, significantly smaller in diameter than the inner diameter of the treatment vessel. This reduction in size causes several challenges when discharging the lignocellulosic material, such as slow mass flow rates and blockages. Slow or stopped discharge of lignocellulosic material from the treatment vessel limits the processing capacity and efficiency of the treatment vessel, thus affecting the overall efficiency and cost of operating the treatment vessel, as well as any preceding or subsequent processing steps in the process of treating lignocellulosic material.

[0005] Furthermore, if the outlet end of the treatment vessel has a large diameter, for example by being dome-shaped, access to the outlet opening may be hindered or inconvenient unless the treatment vessel is raised significantly to allow access to the outlet opening. However, this increases the build height of the treatment vessel. Alternatively, a narrow treatment vessel may provide easy access to the outlet opening with a significantly increased build height for the same internal volume as a wide treatment vessel. Summary of the Invention [Problem to be solved by the invention]

[0006] Thus, there is a need for a treatment vessel for treating lignocellulosic material having a reduced outlet end diameter. There is also a need for a method for treating lignocellulosic material in a treatment vessel having a reduced outlet end diameter. [Means for solving the problem]

[0007] At least one of the above needs, or at least one further need that will become apparent from the following description, is met in accordance with a first aspect of the present invention by a treatment vessel for treating lignocellulosic material, the treatment vessel comprising: a main portion having an interior volume for holding and processing lignocellulosic material, the main portion having a first end and a second end; an outlet portion having an interior volume in fluid communication with the interior volume of the main portion, the outlet portion being conical or frusto-conical and tapering from a first end joined to the second end of the main portion toward the second end of the outlet portion, the second end of the outlet portion having an outlet opening for discharging the lignocellulosic material from the treatment vessel; a cone disposed within the treatment vessel, the cone having an apex facing away from the main portion; Equipped with The base of the cone is positioned such that it is located within a perpendicular distance from a transition plane defined by a junction between the first end of the outlet portion and the second end of the main portion, the perpendicular distance being less than or equal to 1 / 4 of a diameter of the main portion.

[0008] The present invention is therefore based on the inventors' realization that the use of a conical or frusto-conical outlet section with a cone positioned as described above provides a treatment vessel having an outlet end with a reduced diameter, i.e. conically tapered, outlet section that can facilitate access to the outlet opening while maintaining the flow of lignocellulosic material obtained using a larger diameter domed outlet end. Surprisingly, this maintained flow of lignocellulosic material can be achieved without significantly increasing the height of the outlet section and / or the treatment vessel.

[0009] The treatment vessel is preferably selected from the group comprising an impregnation vessel for impregnating lignocellulosic material, a digester for digesting chip slurry to obtain pulp, and a prehydrolysis vessel for treating agricultural residues under acid conditions. The treatment vessel is generally positioned vertically in use, so that the terms "first" and "second" as used herein in relation to the treatment vessel or its components generally correspond to the terms "upper" and "lower". The treatment vessel may be configured with a jacket for holding a heating or cooling medium for heating the treatment vessel. The treatment vessel is preferably made of metal, such as steel.

[0010] Processing the lignocellulosic material may comprise one or more of impregnating the lignocellulosic material with an impregnation fluid, drying the lignocellulosic material, heating the lignocellulosic material, digesting the lignocellulosic material, and / or hydrolyzing the lignocellulosic material to prepare the lignocellulosic material for subsequent processing.

[0011] Typically, processing comprises the injection of one or more fluids into a processing vessel, which therefore preferably comprises one or more inlets or nozzles for injecting fluids into the processing vessel.

[0012] The term lignocellulosic material is used herein to mean a material containing lignin, cellulose, and hemicellulose. One example of such a material is wood, others include bagasse and other agricultural or forestry wastes such as wheat straw. When the lignocellulosic material is treated in the treatment vessel by injection of a fluid, it will usually further contain any amount of fluid. The term lignocellulosic material further encompasses lignocellulosic material in slurry form, for example, a mixture or slurry containing lignin, cellulose, and hemicellulose, as well as fluids.

[0013] Typically, the lignocellulosic material comprises wood chips, such as a wood chip slurry.

[0014] The treatment vessel is preferably suitable for treating the lignocellulosic material at a temperature of at least 70° C. Typically, lignocellulosic material is treated at a temperature of from 70 to 165° C., such as from 70 to 150° C., and the treatment vessel should preferably be suitable for treating the lignocellulosic material at these temperatures.

[0015] Additionally or alternatively, the treatment vessel is preferably suitable for treatment of the lignocellulosic material with a fluid injected into the treatment vessel.

[0016] The main portion is typically cylindrical. The main portion may be defined as the portion of the process vessel in which the circumference of the process vessel is constant along its central axis, i.e., cylindrical.

[0017] The main part has an internal volume for holding and processing the lignocellulosic material. The size of the internal volume depends on the dimensions of the main part. Typically the processing vessel, and therefore the main part, may have a length (height) of 10 to 80 m, and a width (diameter) of 2 to 17 m.

[0018] The first end of the main portion may generally be considered the top end of the main portion. The first end corresponds to the circumference of the top end of the cylinder. Typically, the treatment vessel comprises an inlet portion joined to the first end of the main portion to define the first end of the treatment vessel. The inlet portion may be dome-shaped, cupola-shaped, conical, or frusto-conical. The inlet portion may further comprise an inlet opening for inputting the lignocellulosic material into the treatment vessel.

[0019] The second end of the main portion may generally be considered to be the lower end of the main portion. The second end corresponds to the circumference of the lower end of the cylinder.

[0020] The outlet section is conical or frustoconical. Thus, the outlet section comprises at least one conical or frustoconical section. Thus, the outlet section may comprise one or more successive frustoconical sections finally joined to a second or final frustoconical or conical section provided with the outlet opening, the half angles of which may be the same or different for the successive sections. However, the outlet section preferably has a conical or frustoconical shape.

[0021] Furthermore, although preferred, the walls of the outlet portion need not be straight. Thus, a cone or frusto-conical shape encompasses a cone or frusto-conical shape that does not taper smoothly (i.e., the angle between the wall surface and the central axis of the outlet portion is constant) from the base to the apex; rather, the wall shape may bulge inwardly or outwardly as it extends from the base to the apex.

[0022] The outlet portion may be considered to define a second or outlet end of the process vessel.

[0023] The outlet portion may be integrally formed with the main portion, or it may be manufactured separately from the main portion and then attached to the main portion.

[0024] The interior volume of the outlet portion is in fluid communication with the interior volume of the main portion, and thus the interior volumes of the outlet portion, main portion, and, if present, inlet portion together define the interior volume of the process vessel.

[0025] The term tapered means that the circumference of the outlet portion decreases from the first end to the second end, in other words, the first end is of the same circumference as the main portion, while the second end is of a smaller circumference.

[0026] The first end of the outlet portion may generally be considered the top end of the outlet portion. The first end of the outlet portion is joined to the second end of the main portion, thereby forming a joint, joint, or interface between the portions.

[0027] The second end of the outlet portion may generally be considered the lower end of the outlet portion.

[0028] The outlet opening is preferably an opening or opening at the second end of the outlet section. Preferably, the outlet opening is at the center of the second end of the outlet section. Thus, the outlet opening is preferably provided at the top of the conical or frustoconical outlet section. If the outlet section is conical, the outlet opening may additionally or alternatively be located on the wall or surface of the cone.

[0029] The outlet opening preferably comprises a circular opening. A conduit for receiving the discharged lignocellulosic material may be connected to the outlet opening, or the lignocellulosic material may be allowed to fall from the outlet opening into a receiving vessel arranged below the outlet opening. The outlet opening is suitable for the discharge of lignocellulosic material from the treatment vessel by having a suitable diameter and / or area to allow the lignocellulosic material to pass through the outlet opening.

[0030] The cone is cone-shaped with a base, an apex, and a central axis that extends vertically from the center of the base to the apex. The cone is preferably circularly symmetric. The cone is positioned within the treatment vessel such that the apex of the cone faces away from the main portion. When the treatment vessel is positioned vertically for use, this corresponds to the base of the cone being positioned above the apex.

[0031] The cone is positioned such that a base of the cone is located within a perpendicular distance from a transition plane defined by a junction between the first end of the outlet portion and the second end of the main portion.

[0032] The transition surface may alternatively, but equivalently, be defined as a plane formed by the periphery of the processing vessel at the location where the periphery is generally constant along the main portion and begins to decrease as the main portion ends and the tapered outlet portion begins.

[0033] The vertical distance is the shortest distance between the base and a point in the transition plane. Since the processing vessel is typically positioned vertically in use, the vertical distance corresponds to the vertical distance between the base and the transition plane. Typically, the base is positioned a distance above or below the transition plane accordingly.

[0034] If the base of the cone is not parallel to the transition plane, the perpendicular distance is measured from the center of the base.

[0035] The vertical distance is less than or equal to 1 / 4 of the diameter of the main portion, which corresponds to the base being positioned from 1 / 4 of the diameter below the transition surface to 1 / 4 of the diameter above the transition surface.

[0036] The top of the cone is preferably oriented parallel to or along the central axis of the treatment vessel, which corresponds to the base of the cone being parallel to the transition plane. This is advantageous in that it results in a uniform distribution of the lignocellulosic material passing through the cone. When the treatment vessel is positioned vertically, this configuration generally corresponds to the cone being positioned such that its base is horizontal and parallel to the transition plane, and its top faces vertically downwards towards the outlet opening or second end of the outlet section.

[0037] The central axis of the cone is preferably aligned with the central axis of the treatment vessel, which is advantageous in that it provides a uniform cross-sectional area for the flow of the lignocellulosic material as it enters and passes through the outlet section.

[0038] The perpendicular distance is preferably not more than 1 / 8 of the diameter of the main portion. Preferably, the perpendicular distance is not more than 1 / 16, such as not more than 1 / 32 of the diameter of the main portion.

[0039] This is advantageous in that locating the base of the cone close to the transition surface has been found to be beneficial in resulting in good flow and evacuation of the lignocellulosic material.

[0040] The base of the cone is preferably located within the interior volume of the outlet section, which corresponds to the vertical distance from the base of the cone to the outlet opening being smaller than the vertical distance from the transition surface to the outlet opening, which corresponds to the base of the cone being located below the transition surface when the treatment vessel is positioned vertically.

[0041] Practical examples show that this position of the base is effective in maintaining the flow of lignocellulosic material towards the outlet opening.

[0042] Alternatively, the base of the cone is positioned within the interior volume of the main portion.

[0043] This corresponds to the vertical distance from the base of the cone to the outlet opening being greater than the vertical distance from the transition surface to the outlet opening. When the process vessel is positioned vertically, this configuration corresponds to the base of the cone being positioned above the transition surface.

[0044] This location of the base increases the internal volume of the outlet portion accessible to the lignocellulosic material.

[0045] More preferably, the vertical distance is substantially zero. Substantially zero (zero) encompasses a vertical distance as small as can be achieved using conventional construction methods for constructing the treatment vessel and placing the cone in the treatment vessel. Substantially zero therefore ranges from a vertical distance of up to 10 mm, preferably up to 5 mm. Most preferably, the base of the cone is located in the transition plane. Practical examples have shown that this position of the base is efficient for maintaining the flow of lignocellulosic material generally towards the outlet opening.

[0046] The half angle of the outlet section is preferably 25-75°, more preferably 45-65°. The half angle of the outlet section is most preferably 55-65°. The half angle is the angle between the side surface at the apex of the conical outlet section and the central axis. In the case of a frusto-conical outlet section, the half angle is the angle between the side surface at the apex of the corresponding cone and the central axis.

[0047] Practical examples show that these half angle spacings can provide efficient flow of lignocellulosic material towards the outlet opening without significantly increasing the height of the outlet section and treatment vessel.

[0048] The half angle of the cone is 0.5-20°, such as 10°, smaller than the half angle of the exit section, or preferably 5-15° smaller. The half angle of the cone is further 1-20°, 2-20°, 2-15°, 2-10°, such as 5-10°, smaller than the half angle of the exit section, or 0.5-15°, 1-15°, 1-10°, such as 1-5°, smaller than the half angle of the exit section.

[0049] This corresponds to the cone being pointed relative to the exit portion, which may position the top of the cone closer to the exit opening and prevent the underside of the cone from becoming blocked or buried near the exit opening.

[0050] Preferably, the area of ​​the base of the cone is 8-30%, such as 10-20% of the cross-sectional area of ​​the main portion, which generally corresponds to the area of ​​the transition surface.

[0051] The treatment vessel is generally arranged vertically in use, so that the cross-sectional area of ​​the main portion corresponds to its horizontal cross-sectional area. Practical examples show that the spacing of these regions is suitable to provide an efficient flow of lignocellulosic material towards the outlet opening.

[0052] A portion of the lignocellulosic material passing through the treatment vessel eventually contacts and accumulates on the base of the cone, which ultimately forms a cone or cylinder of lignocellulosic material that acts as a deflector that causes other portions of the lignocellulosic material to pass close to the cone.

[0053] However, preferably the cone further comprises an additional body joined to the base of the cone.

[0054] The additional body deflects the lignocellulosic material so that it passes close to the cone without accumulating on the base, which is advantageous because the accumulated material is not discharged from the treatment vessel, thus reducing the volume of the treatment vessel.

[0055] The additional body may, for example, comprise a dome or cupola with a cone and a base joined together. Alternatively, the additional body may comprise a cylinder or a stack of cylinders with gradually decreasing diameters with a cone and a base joined together. The diameter of the base of the additional body may be equal to or greater than the diameter of the base of the cone, but is preferably smaller, such as 1 / 4 to 3 / 4 of the diameter of the base of the cone.

[0056] If the cone base and the additional body have different areas and / or diameters, the additional body and the cone are preferably joined base to base such that the smaller base is positioned within the circumference of the larger base.

[0057] Preferably, however, the additional body comprises an additional cone joined to its base, preferably coaxially to the cone.

[0058] This provides an efficient means of deflecting the lignocellulosic material so that it passes close to the cones.

[0059] The diameter of the base of the additional cone may be greater than or equal to the diameter of the base of the cone, in the former case defining an undercut.

[0060] However, preferably, the diameter of the base of the additional cone is between 1 / 4 and 3 / 4 of the diameter of the base of the cone.

[0061] Such a diameter, although smaller than the diameter of the base of the cone, surprisingly provides efficient redirection of the lignocellulosic material passing through the base of the cone.

[0062] Typically, the half angle of the additional cone is between 90 and 20°, for example between 89 and 20°, preferably between 30 and 50°.

[0063] These half angle ranges are suitable for additional cones.

[0064] Preferably, the area of ​​the outlet opening is less than 20%, such as less than 10% of the area of ​​the transition surface.

[0065] Typically, the outlet opening has a diameter of at least 0.8 m and / or a width of at least 0.5 m. 2 The area of ​​the slit should be 1.

[0066] The outlet portion is preferably configured to withstand a pressure difference between the internal volume of the outlet portion and the atmosphere surrounding the treatment vessel of at least 1 bar, preferably at least 4 bar, more preferably at least 15 bar.

[0067] The pressure within the internal volume of the outlet section depends on the hydrostatic pressure due to the height or level of the lignocellulosic material above the outlet section, plus any overpressure within the treatment vessel, for example due to injection of steam or other liquids or gases into the treatment vessel and / or due to heating or cooking of the liquids and / or lignocellulosic material in the treatment vessel.

[0068] The treatment vessel is preferably selected from the group consisting of an impregnation vessel for impregnating lignocellulosic material, a digester for digesting chip slurries to obtain pulp, and a prehydrolysis vessel for treating agricultural residues under acid conditions. Prehydrolysis vessels are also suitable for treating wood and non-wood materials such as wood chips and agricultural residues under acid conditions. These types of treatment vessels benefit from a reduced outlet end diameter. More preferably, the treatment vessel is an impregnation vessel or a digester. Furthermore, the treatment vessel may be a steam treatment vessel for heating lignocellulosic material with steam.

[0069] At least one of the above needs, or at least one further need which will become apparent from the following description, is met according to a second aspect of the present invention by a system for treating lignocellulosic material, the system comprising one or more treatment vessels according to the first aspect of the present invention.

[0070] Such a system is advantageous in that it limits build height and provides easy access to the exit opening of the treatment vessel while maintaining an efficient flow of lignocellulosic material.

[0071] As an example, the system may comprise a treatment vessel in the form of an impregnation vessel, which is connected to and follows a treatment vessel in the form of a digester. The treatment vessel in the form of an impregnation vessel may further be preceded by a treatment vessel in the form of a steam treatment vessel. Additionally or alternatively, the impregnation vessel and the digester may be implemented in a single treatment vessel combining impregnation and cooking. Alternatively, the steam treatment vessel and the impregnation vessel may be implemented in a single treatment vessel combining steam treatment and impregnation. In such a system, the treatment vessel according to the first aspect of the invention provides for easy discharge and transfer of the lignocellulosic material from one treatment vessel to the next.

[0072] As a further example, the system may comprise a treatment vessel in the form of a prehydrolysis vessel, which is connected to and follows the treatment vessel in the form of a digester. The treatment vessel in the form of an impregnation vessel may further be preceded by a treatment vessel in the form of a steam treatment vessel.

[0073] At least one of the above needs, or at least one further need which will become apparent from the following description, is met according to a third aspect of the present invention by a method for treating lignocellulosic material, the method comprising using one or more treatment vessels according to the first aspect of the invention, or a system according to the second aspect of the invention.

[0074] The method provides an efficient and simple processing of the lignocellulosic material. Preferably, the method comprises treating the lignocellulosic material at a temperature of at least 70°C as described above.

[0075] Preferably, the method further comprises discharging the treated lignocellulosic material through an outlet opening.

[0076] Although the treatment vessel may be manufactured and installed in a new plant for treating lignocellulosic material, it is further contemplated that existing treatment vessels may also be retrofitted with an outlet portion and cone such that such existing treatment vessels may also obtain the benefits of the present invention. Accordingly, a fourth aspect of the present invention relates to a method of modifying a treatment vessel for treating lignocellulosic material, the treatment vessel comprising a main portion having an internal volume for holding and treating lignocellulosic material, the main portion having a first end and a second end, The method comprises: The method includes providing an outlet portion and a cone defined according to the first aspect of the invention in a process vessel.

[0077] Preferably, the treatment vessel is suitable for treatment of lignocellulosic material at a temperature of at least 70°C, as described above.

[0078] The method may include removing an existing (dome-shaped) outlet section prior to providing the outlet section and cone defined according to the first aspect of the invention in the treatment vessel. It is also possible to provide the outlet section and cone defined according to the first aspect of the invention by opening the top or side of the treatment vessel and introducing the outlet section and cone into the treatment vessel and mounting it at the outlet end therein, thereby discharging the lignocellulosic material through the introduced outlet section and introduced cone.

[0079] A complete understanding of the above and other features and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments taken in conjunction with the accompanying drawings. [Brief description of the drawings]

[0080] [Figure 1] FIG. 1 shows an embodiment of a processing vessel and system according to the first and second aspects of the present invention. [Figure 2A] 1A-1C show various embodiments of cones provided by the treatment vessel. [Figure 2B] 1A-1C show various embodiments of cones provided by the treatment vessel. [Figure 2C] 1A-1C show various embodiments of cones provided by the treatment vessel. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0081] All figures are schematic, not necessarily to scale, and generally show only those parts necessary to elucidate the respective embodiment, while other parts may be omitted or merely suggested. Any reference numeral appearing in more than one figure refers to the same object or feature throughout the figures, unless otherwise indicated.

[0082] One or more superscript characters "'" appended to a reference number indicates that the reference is a variation of the feature to which that reference number is assigned.

[0083] FIG. 1 shows one embodiment of a treatment vessel 10 and system 100 according to the first and second aspects of the present invention. The treatment vessel 10 comprises a main portion 20 having an internal volume 22 for holding and treating the lignocellulosic material 2, the main portion having a first (upper) end 24 and a second (lower) end 26. As shown here, the main portion 20 is preferably cylindrical with a central axis A. A dome-shaped inlet portion 30 is provided at the first end 24 for closing the upper end of the treatment vessel 10 and comprises an inlet opening 32 for entering the lignocellulosic material 2 into the treatment vessel 10. An outlet portion 40 is provided below the main portion, having an internal volume 42 in fluid communication with the internal volume 22 of the main portion. The outlet portion 40 is shown here to have a frustoconical shape, tapering from a first (upper) end 44 joined to the second end 26 of the main portion 20 towards a second (lower) end 46 of the outlet portion 40. An outlet opening 48 is provided at a second end 46 of the outlet portion 40 for discharging 4 the treated lignocellulosic material from the treatment vessel 10 .

[0084] During use, lignocellulosic material, such as wood chips, enters the treatment vessel 10 through the inlet opening 32 and is retained and treated within the treatment vessel 10. Depending on the type of treatment vessel, e.g., an impregnation vessel, digester, or prehydrolysis vessel, the lignocellulosic material is heated, dried, and / or agitated, and fluids, such as impregnation fluid, base, or acid, are added to the treatment vessel 10 as part of the treatment of the lignocellulosic material 2. The treatment vessel 10 may be operated in a batch or continuous process. In a continuous process, the lignocellulosic material 2 passes through the treatment vessel as it is treated.

[0085] The process vessel 10 further comprises a cone 60 disposed within the process vessel 10, the cone 60 having a base 62 and an apex 64, the latter facing outwardly from the main portion 20. The cone 60 is disposed and supported by a support, indicated generally by reference numeral 66, which extends between the cone 60 and an inner wall of the outlet portion 40.

[0086] The cone 60 is positioned such that the base 62 of the cone 60 is located within a vertical distance d from a transition plane T defined by the junction between the first end 44 of the outlet portion 40 and the second end 26 of the main portion 20. The distance d is less than or equal to ¼ of the diameter D of the main portion 20.

[0087] Thus, where a conventional dome-shaped outlet section is used, which is traditionally a dome-shaped section that limits access to the outlet opening 48 unless the treatment vessel 10 is elevated, the conical or frusto-conical outlet section 40 and cone 60 allow the treatment vessel 10 to provide a reduced outlet end diameter while maintaining the flow 4 of lignocellulosic material.

[0088] Preferably, as shown, the apex 64 is toward or along the central axis A of the process vessel 10, and the central axis of the cone is aligned with the central axis A of the process vessel 10. For clarity, the base 62 of the cone 60 is shown positioned within the interior volume 42 of the outlet portion 40 so that the vertical distance d is discernible. However, preferably, the vertical distance d is substantially zero, such that the base 62 of the cone 60 is parallel to and positioned within the transition plane T.

[0089] The half angle α of the outlet portion 40 and the half angle β of the cone 60 are also shown in Figure 1. As also shown in Figure 1, the latter is preferably smaller than the former.

[0090] The cone 60 may further comprise an addendum joined to the base 62 of the cone, which acts to divert the lignocellulosic material to flow through the cone 60 without accumulating on its base 62. The addendum may have a variety of forms.

[0091] Thus, Figure 2A shows a first alternative embodiment of the cone 60 shown in Figure 1. This cone, referred to as 60', further comprises an additional cone 70 having a base 62 and a base-to-base joint 72. The additional cone 70 further comprises an apex 74, which faces away from the outlet opening when the cone 60' is positioned in the process vessel. The half angle γ of the additional cone 70 is preferably greater than the half angle β.

[0092] Figure 2B shows a second alternative embodiment of the cone 60 shown in Figure 1. The cone, referenced as 60'', further comprises an appendage having a base 72' and taking the form of a dome 70' having a base 62 and a base-to-base joining.

[0093] Figure 2c shows a third alternative embodiment of the cone 60 shown in Figure 1. This cone, referenced 60''', additionally comprises an add-on in the form of a set 70'' of laminated cylinders, whereby the base 72'' of the cylinder with the largest diameter is joined to the base 62.

[0094] As shown in FIGS. 2A, 2B, and 2C, the diameter of the bases 72, 72', and 72'' of the add-ons is preferably smaller than the diameter of the base 62. As shown in FIG.

[0095] Possible changes The present invention is not limited to the embodiments described above and shown in the drawings, which are primarily for illustrative and exemplary purposes. This patent application is intended to cover all adaptations and variations of the preferred embodiments described herein, and the present invention is therefore defined by the language of the appended claims. Thus, the device may be modified in all manner of ways within the scope of the appended claims.

[0096] It should also be pointed out that all information relating to / pertaining to terms such as upper, lower, top, bottom, etc. should be interpreted / read with the device oriented according to the drawings and with the drawings oriented so that the references can be properly read, and thus such terms only indicate their interrelationship in the illustrated embodiment, which may be altered if the device of the present invention has a different construction / design.

[0097] Thus, it should also be pointed out that even if it is not explicitly stated that features from a particular embodiment may be combined with features from another embodiment, if the combination is possible, the combination is considered to be obvious.

[0098] Throughout this specification and the claims that follow, unless the context otherwise requires, the word "comprise" and variations such as "comprises" or "comprising" are understood to mean the inclusion of a stated integer or step, or group of integers or steps, but not to the exclusion of any other integers or steps, or group of integers or steps.

Claims

1. A processing container (10) for processing lignocellulosic materials, The processing container is A main part (20) having an internal volume (22) for holding and processing lignocellulosic materials, the main part having a first end (24) and a second end (26), An outlet part (40) having an internal volume (42) in fluid communication with the internal volume (22) of the main part, the outlet part (40) being conical or frustoconical and tapering from a first end (44) joined to the second end (26) of the main part (20) towards a second end (46) of the outlet part (40), and an outlet opening (48) for discharging lignocellulosic materials from the processing container (10) is provided at the second end (46) of the outlet part (40), the outlet part (40); A cone (60) disposed within the processing container (10), the apex (64) of the cone facing away from the main part (20), the cone (60); Comprising The cone (60) is positioned such that the base (62) of the cone (60) is located within a perpendicular distance (d) from a transition surface (T) defined by a joint between the first end (44) of the outlet part (40) and the second end (26) of the main part (20), and the perpendicular distance (d) is ¼ or less of the diameter (D) of the main part (20), The half angle (β) of the cone (60) is 0.5 to 20° smaller than the half angle (α) of the outlet part (40), preferably 5 to 15° smaller, for example smaller than 10°, characterized by the processing container (10).

2. The apex (64) of the cone (60) is oriented parallel to or along the central axis (A) of the processing container (10), the processing container (10) according to Claim 1.

3. The central axis of the cone (60) is aligned with the central axis (A) of the processing container (10), the processing container (10) according to any one of Claims 1 to 2.

4. The perpendicular distance (d) is 1 / 8 or less of the diameter (D) of the main part (20), the processing container (10) according to any one of Claims 1 to 2.

5. The base (62) of the cone (60) is positioned within the internal volume (42) of the outlet part (40), the processing container (10) according to any one of Claims 1 to 2.

6. The base (62) of the cone (60) is positioned within the internal volume (22) of the main part (40), and the processing container (10) according to any one of claims 1 to 2.

7. The processing container (10) according to any one of claims 1 to 2, wherein the vertical distance (d) is substantially 0.

8. The processing container (10) according to any one of claims 1 to 2, wherein the half angle (α) of the outlet portion (40) is 25 to 75°, preferably 45 to 65°.

9. The processing container (10) according to any one of claims 1 to 2, wherein the area of the base (62) of the cone (60) is 8 to 30%, for example 10 to 20%, of the cross-sectional area of the main part (20).

10. The processing container (10) according to any one of claims 1 to 2, wherein the cone (60) further comprises an additional body (70, 70', 70'') joined to the base (62) of the cone (60).

11. The processing container (10) according to claim 10, wherein the additional body (70) comprises an additional cone (70) joined to the cone (60) with the bases preferably coaxially.

12. The processing container (10) according to claim 11, wherein the diameter of the base (72) of the additional cone (70) is 1 / 4 to 3 / 4 of the diameter of the base (62) of the cone (60).

13. The processing container (10) according to claim 11, wherein the half angle (γ) of the additional cone (70) is 20 to 89°, for example 20 to 90°, preferably 30 to 50°.

14. The processing container (10) according to any one of claims 1 to 2, wherein the area of the outlet opening (48) is less than 20%, for example less than 10%, of the area of the transition surface (T).

15. The processing container (810) according to any one of claims 1 to 2, wherein the outlet portion (40) is configured to withstand a pressure difference of at least 1 bar, preferably at least 4 bar, more preferably at least 15 bar, between the internal volume (42) of the outlet portion (40) and the atmosphere surrounding the processing container (10).

16. The processing container (10) according to any one of claims 1 to 2, wherein the processing container (10) is selected from the group consisting of an impregnation container digester and a pre-hydrolysis container.

17. A system for processing lignocellulosic materials, the system comprising one or more processing vessels (10) according to any one of claims 1 to 2, and further comprising a conduit connected to an outlet opening of the one or more processing vessels (10) for receiving the discharged lignocellulosic materials.

18. Use of one or more processing vessels (10) according to any one of claims 1 to 2, or of the system according to claim 17, for processing lignocellulosic materials.

19. The use according to claim 18, further comprising discharging the processed lignocellulosic material through an outlet opening (48).

20. A method for modifying a processing vessel for processing lignocellulosic materials, the processing vessel comprising a main part (20) having an internal volume (22) for holding and processing lignocellulosic materials, the main part having a first end (24) and a second end (26), The method comprising: providing an outlet portion (40) and a cone (60) as defined by any one of claims 1 to 2 in the processing vessel.

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