TREATMENT VESSEL HAVING REDUCED OUTLET END DIAMETER

Abstract

A treatment vessel for treating lignocellulosic material comprises a main section having a first end and a second end, and an outlet section that is conical or frustoconical and tapers from a first end joined to the second end of the main section towards a second end having an outlet opening. A conical body is arranged within the treatment vessel, the vertex of the conical body pointing away from the main section. The conical body is positioned such that the base thereof is positioned within a perpendicular distance (d) from a transition plane (T) defined by the junction between the first end of the outlet section and the second end of the main section, wherein the perpendicular distance (d) is ? or less of the diameter (D) of the main section. A half angle (?) of the conical body is 0.5-20? less, preferably 5-15? less, such as 10? less, than a half angle (?) of the outlet section.

Claims

1-20. (canceled)

21. A treatment vessel for treating lignocellulosic material, the treatment vessel comprising: a main section having an interior volume for holding and treating lignocellulosic material, the main section having a first end and a second end; an outlet section having an interior volume in fluid communication with the interior volume of the main section, the outlet section being conical or frustoconical and tapering from a first end joined to the second end of the main section towards a second end of the outlet section, wherein an outlet opening for discharging lignocellulosic material from the treatment vessel is provided at the second end of the outlet section; and a conical body arranged within the treatment vessel, a vertex of the conical body pointing away from the main section, wherein the conical body is positioned such that the base thereof is positioned within a perpendicular distance from a transition plane defined by the junction between the first end of the outlet section and the second end of the main section, wherein the perpendicular distance is ? or less of the diameter of the main section, characterized in that a half angle of the conical body is 0.5-20? less than a half angle of the outlet section.

22. The treatment vessel according to claim 21, wherein the vertex of the conical body points parallel with, or along, a center axis of the treatment vessel.

23. The treatment vessel according to claim 21 wherein a center axis of the conical body is aligned with a center axis of the treatment vessel.

24. The treatment vessel according to claim 21, wherein the perpendicular distance is ? of the diameter of the main section or less.

25. The treatment vessel according to claim 21, wherein the base of the conical body is positioned within the interior volume of the outlet section.

26. The treatment vessel according to claim 21, wherein the base of the conical body is positioned within the interior volume of the main section.

27. The treatment vessel according to claim 21, wherein the perpendicular distance is substantially 0.

28. The treatment vessel according to claim 21, wherein the half angle of the outlet section is 25-75?.

29. The treatment vessel according to claim 21, wherein an area of the base of the conical body is from 8 to 30% of a transverse cross-sectional area of the main section.

30. The treatment vessel according to claim 21, wherein the conical body further comprises an additional body joined to the base of the conical body.

31. The treatment vessel according to claim 30, wherein the additional body comprises an additional conical body joined base-to-base to the conical body.

32. The treatment vessel according to claim 31, wherein the diameter of the base of the additional conical body is ? to ? of the diameter of the base of the conical body.

33. The treatment vessel according to claim 31, wherein a half angle of the additional conical body is 20-90?.

34. The treatment vessel according to claim 21, wherein an area of the outlet opening is less than 20% of an area of the transition plane.

35. The treatment vessel according to claim 21, wherein the outlet section is configured to withstand a pressure difference, between the interior volume of the outlet section and the atmosphere surrounding the treatment vessel, of at least 1 bar.

36. The treatment vessel according to claim 21, wherein the treatment vessel is an impregnation vessel, a digester, or a prehydrolysis vessel.

37. A system for treating lignocellulosic material, the system comprising: one or more treatment vessels according to claim 21; and a conduit connected to the outlet opening of the one or more treatment vessels for receiving discharged lignocellulosic material.

38. A method comprising: treating lignocellulosic material using one or more treatment vessels according to claim 21.

39. The method according to claim 38, further comprising discharging treated lignocellulosic material through the outlet opening of the one or more treatment vessels.

40. A method of modifying a treatment vessel for treating lignocellulosic material, the treatment vessel comprising a main section having an interior volume for holding and treating lignocellulosic material, the main section having a first end and a second end, the method comprising steps of: providing an outlet section having an interior volume in fluid communication with the interior volume of the main section, the outlet section being conical or frustoconical and tapering from a first end joined to the second end of the main section towards a second end of the outlet

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0079] A more complete understanding of the abovementioned and other features and advantages of the present invention will be apparent from the following detailed description of preferred embodiments in conjunction with the appended drawings, wherein:

[0080] FIG. 1 shows an embodiment of a treatment vessel and a system according to the first and second aspects of the present invention.

[0081] FIG. 2A-2C show various embodiments of the conical body comprised by the treatment vessel.

[0082] All the figures are schematic, not necessarily to scale, and generally only show parts which are necessary in order to elucidate the respective embodiments, whereas other parts may be omitted or merely suggested.

[0083] Any reference number appearing in multiple drawings refers to the same object or feature throughout the drawings, unless otherwise indicated.

[0084] One or more superscript appended to a reference number indicates that the feature so reference is a variant of the feature assigned that reference number.

DETAILED DESCRIPTION

[0085] FIG. 1 shows an embodiment of a treatment vessel 10 and a system 100 according to the first and second aspects of the present invention. The treatment vessel 10 comprises a main section 20 having an interior volume 22 for holding and treating lignocellulosic material 2, the main section having a first (upper) end 24 and a second (lower) end 26. As shown here, the main section 20 is preferably circular cylindrical having a center axis A. A dome-shaped inlet section 30 is provided at the first end 24 to close the upper end of the treatment vessel 10 and comprises an inlet opening 32 for allowing lignocellulosic material 2 to enter the treatment vessel 10. An outlet section 40 having an interior volume 42 in fluid communication with the interior volume 22 of the main section is provided below the main section. The outlet section 40 is here shown to have a frustoconical form and tapers from a first (upper) end 44, which is joined to the second end 26 of the main section 20, towards a second (lower) end 46 of the outlet section 40. An outlet opening 48 for discharging 4 treated lignocellulosic material from the treatment vessel 10 is provided at the second end 46 of the outlet section 40.

[0086] In use, lignocellulosic material, such as wood chips, enters the treatment vessel 10 through the inlet opening 32 to be held and treated within the treatment vessel 10. Depending on the type of treatment vessel, e.g., impregnation vessel, digester, or prehydrolysis vessel, the lignocellulosic material is heated, dried, and/or agitated, and fluid, such as impregnation fluid, base, or acid, is added into the treatment vessel 10 as part of the treatment of the lignocellulosic material 2. The treatment vessel 10 may be operated in a batch process, or in a continuous process. In a continuous process, the lignocellulosic material 2 passes through the treatment vessel while being treated.

[0087] The treatment vessel 10 further comprises a conical body 60 arranged within the treatment vessel 10, the conical body 60 having a base 62 and a vertex 64, the latter pointing away from the main section 20. The conical body 60 is arranged and supported by supports, one being designated the reference number 66, extending between the conical body 60 and the inner wall of the outlet section 40.

[0088] The conical body 60 is positioned such that the base 62 thereof is positioned within a perpendicular distance d from a transition plane T defined by the junction between the first end 44 of the outlet section 40 and the second end 26 of the main section 20. The distance d is ? or less of the diameter D of the main section 20.

[0089] Thus, where conventionally a dome-shaped outlet section would be used, which dome-shape would restrict access to the outlet opening 48 unless the treatment vessel 10 is elevated, the treatment vessel 10, due to the conical or frustoconical outlet section 40 and the conical body 60 provides a reduced outlet end diameter with maintained flow of lignocellulosic material 4.

[0090] Preferably, as shown, the vertex 64 points or along the center axis A of the treatment vessel 10, and the center axis of the conical body is aligned with the center axis A of the treatment vessel 10. For clarity, the base 62 of the conical body 60 is shown positioned within the interior volume 42 of the outlet section 40 so that the perpendicular distance d is discernible. preferably, however, the perpendicular distance d is substantially 0 so that the base 62 of the conical body 60 is positioned parallel with and within the transition plane T.

[0091] The half angle ? of the outlet section 40 and the half angle ? of the conical body 60 is also indicated in FIG. 1. The latter is preferably less than the former as is also shown in FIG. 1.

[0092] The conical body 60 may further comprise an additional body joined to the base 62 of the conical body. This additional body acts to divert lignocellulosic material to flow past the conical body 60 without depositing on the base 62 thereof. The additionally body may have different forms.

[0093] FIG. 2A accordingly shows a first alternative embodiment of the conical body 60 shown in FIG. 1. This conical body, referenced as 60, additionally comprises an additional conical body 70 having a base 72 joined base-to-base with the base 62. The additional conical body 70 further has a vertex 74 which, when the conical body 60 is positioned in the treatment vessel, points away from the outlet opening. The half angle ? of the additional conical body 70 preferably larger than the half angle ?.

[0094] FIG. 2B shows a second alternative embodiment of the conical body 60 shown in FIG. 1. This conical body, referenced as 60, additionally comprises an additional body in the form of a dome 70 having a base 72 and joined base-to-base with the base 62.

[0095] FIG. 2c shows a third alternative embodiment of the conical body 60 shown in FIG. 1. This conical body, referenced as 60, additionally comprises an additional body in the form of a set 70 of stacked cylinders, whereby the base 72 of the cylinder with the largest diameter is joined to the base 62.

[0096] As shown in FIGS. 2A, 2B and 2C, the diameter of the base 72, 72 and 72 of the additional body is preferably smaller than the diameter of the base 62.

Feasible Modifications

[0097] The invention is not limited only to the embodiments described above and shown in the drawings, which primarily have an illustrative and exemplifying purpose. This patent application is intended to cover all adjustments and variants of the preferred embodiments described herein, thus the present invention is defined by the wording of the appended claims. Thus, the equipment may be modified in all kinds of ways within the scope of the appended claims.

[0098] It shall also be pointed out that all information about/concerning terms such as above, under, upper, lower, etc., shall be interpreted/read having the equipment oriented according to the figures, having the drawings oriented such that the references can be properly read. Thus, such terms only indicate mutual relations in the shown embodiments, which relations may be changed if the inventive equipment is provided with another structure/design.

[0099] It shall also be pointed out that even thus it is not explicitly stated that features from a specific embodiment may be combined with features from another embodiment, the combination shall be considered obvious, if the combination is possible.

[0100] Throughout this specification and the claims which follows, unless the context requires otherwise, the word comprise, and variations such as comprises or comprising, will be understood to imply the inclusion of a stated integer or steps or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.