conduits for transporting the flow of fibers

Abstract

A conduit (1) for transporting a flow containing fibers. The conduit is provided with only two openings (2, 3) for connecting the conduit to one or more additional conduits and / or to one or more devices for providing and / or processing the flow. The conduit includes a curved section (4). The conduit is provided with a wall section (5) that is detachably connected along at least a portion of the curved section, the wall section being at least partially provided on the outer radius of the curved section.

Description

Technical Field

[0001] The present invention relates to the field of conduits / blow lines for transporting a flow containing fibers and steam or air, the conduit or blow line comprising at least one curved portion.

Background Art

[0002] Conduits or blow lines for transporting flows containing fibers, such as flows containing fibers and steam resulting from the steam explosion discharge of biomass processed in a pressurized reactor, are known in the art. Such conduits or blow lines usually comprise at least one curved portion. One problem with such conduits or blow lines is that the fiber content of the flow is concentrated on the outermost trajectory in the radial direction of the curved portion, thus causing wear on the outermost portion (inside) of the curved portion and ultimately damaging the conduit or blow line. Repairing such a conduit or blow line in situ using welding is time-consuming and costly because a certified welder is required by the pressure vessel directive. A less time-consuming but even more expensive option is to replace the conduit or blow line portion with a curved portion when it wears out.

Summary of the Invention

Problems to be Solved by the Invention

[0003] It is an object of the present invention to provide a conduit or blow line that at least partially solves or improves the problems identified in the background art section above.

[0004] These and other objects are achieved by the present invention by using a conduit according to the independent claims.

Means for Solving the Problems

[0005] According to a first aspect of the present invention, a conduit for transporting a flow containing fibers is provided. The conduit is provided with two openings (preferably at both ends) for connecting the conduit to one or more additional conduits and / or to one or more devices for providing and / or processing the flow. The conduit comprises a curved portion. The conduit comprises a wall portion detachably connected along at least a portion of the curved portion, the wall portion provided along at least a portion of the outer circumference of the curved portion.

[0006] A detachably connected wall portion is understood to be a wall portion in the sense that it forms a part of the wall of the curved portion (along at least a portion of its outer circumference) that might otherwise be formed by the fixed portion of the wall of the curved portion. Thus, the wall portion forms at least a portion of the inner surface of the curved portion, i.e., the wall portion is in direct contact with the flow of fibers being transported through the conduit. The wall portion may also be described as having an inner surface facing inward towards the conduit.

[0007] In other words, a conduit or blowline section having a curved portion is provided. The conduit is suitable for transporting a flow containing air and / or steam and fibers (such as biomass or cellulose fibers) in the sense that it is made of abrasion-resistant material (partially or entirely) and / or has an abrasion-resistant coating (partially or entirely) that can withstand the abrasive action of fibers. This flow may also be called an airflow or steamflow containing / transporting fibers. The conduit is provided with two openings (inlet and outlet), which may be at its ends. Between the two openings, the conduit preferably has no openings / connections for discharging or replenishing the flow or any portion thereof; i.e., preferably only two openings are present, i.e., the conduit has only one inlet and only one outlet. Since the openings are provided in only two positions (such as opposite ends), the conduit is for transporting the flow and not for other purposes such as separating the air content or steam content (or part thereof) of the flow. The conduit preferably has connections at each of its openings. The connection portion may be in the form of a flange and is adapted to connect the conduit to one or more additional conduits and / or to one or more devices for providing and / or processing the flow. The conduit comprises a curved portion, i.e., at least a portion (but not necessarily the whole) of the conduit is curved. The curved portion may also be referred to as a bend. The conduit comprises a wall portion that is detachably connected along at least a portion of the curved portion (or along the entire curved portion or along a wall portion that extends beyond the curved portion). At least a portion of the wall portion is provided on the outer radius or outer circumference of the curved portion, i.e., forming part of the outermost (outer circumference) wall of the conduit in the radial direction. The curved portion or bend may be described in such a way that the centerline formed by the curved portion of the conduit forms a curve in a plane, i.e., the curved portion is curved in only one direction / plane.

[0008] The curved portion may have an extension with an angle between 30 and 120 degrees, such as 90 degrees. The curved portion may be curved with a radius of at least 500 mm, or at least 1000 mm, or at least 1500 mm, where the radius is the radius of the centerline of the conduit.

[0009] This invention is based on the insight that by making the most wear-prone portion of the conduit (the outermost radial wall portion) detachably connectable, a conduit that can be quickly repaired simply by replacing the wall portion can be achieved.

[0010] In this embodiment, the wall portion is curved only in the direction of the curvature of the curved portion. The curvature of the curved portion is understood to refer to the (overall) curvature of the curved portion that changes the direction of the flow passing through it. In other words, the wall portion is curved only along the longitudinal / flow direction of the curved portion, i.e., not curved in the transverse direction (the transverse direction is perpendicular to the longitudinal / flow direction of the curved portion). The wall portion may also be described as substantially straight when viewed in the transverse direction. For example, the wall portion may be curved with only one radius around one central axis. The wall portion may also be described as curved in only one direction / within only one plane. Such embodiments are advantageous because the wall portion can be easily manufactured using a bendable plane material to form the curved wall portion. Furthermore, the inner surface that is curved in only one direction can be easily and accurately coated with an abrasion-resistant layer.

[0011] In the embodiment, the conduit (or curved section) is formed by two parts: a detachably connected wall section and a main section. At least part or all of the main section may have a substantially U-shaped cross-section (when viewed perpendicular to the longitudinal / flow direction of the conduit). Such a U-shaped section may be provided with a flange (oriented laterally outward) at its open end, and the wall section is attached to the flange, for example, using threaded connections extending through the flange and the wall section. The flange may be provided with grooves in which one or more seals are placed to seal the connection between the wall section and the flange. Placing the seals within the flange of the main section is advantageous because it eliminates the need to machine a replaceable wall section for the seals. The (substantially U-shaped) main section may be formed by casting or welding.

[0012] In the embodiment, the wall portion is formed from a material having higher wear resistance than the rest of the curved portion or the rest of the conduit (such as the main part). For example, the wall portion may be formed from high-yield steel. The wall portion may be made from duplex stainless steel such as EN1.4462 or super duplex stainless steel such as EN1.4410.

[0013] In this embodiment, the wall portion is provided with an abrasion-resistant coating on its inner surface. The abrasion-resistant coating may be a ceramic coating. Alternatively, the coating may be a welding coating such as Stellite 6, Stellite 12, or Meltrit X700.

[0014] In embodiments, the wall portion is formed by or comprises an inner layer and an outer layer facing inward toward the interior of the conduit, wherein the inner layer is formed from a material with higher wear resistance than the outer layer. The inner layer may also be described as being sandwiched between the outer layer and the main portion (or more specifically its flange) described above. Such embodiments may be advantageous because the outer layer (acting as a pressure-bearing layer) can be made from a less expensive and less wear-resistant layer than the inner layer.

[0015] In the embodiment, the wall portions are detachably connected using a plurality of screw connections. If the wall portions comprise an inner layer and an outer layer as described above, the wall portions may be detachably connected using screw connections that do not extend through the inner layer. This may be advantageous because it avoids drilling holes through the (harder) inner layer, and therefore results in a conduit that is easier to manufacture.

[0016] In the embodiment, the curved portion has a substantially square or rectangular cross-section when viewed perpendicular to the longitudinal / flow direction of the conduit. The cross-section is substantially square or rectangular in the sense that the conduit's perimeter is comprised of four straight sections, which together constitute at least 80% or 90% of the perimeter.

[0017] In this embodiment, the effective flow area of ​​the curved section is greater than the flow area of ​​the conduit at its openings (which may be at both ends). This can be advantageous because the flow velocity is reduced as it passes through the curved section, thus reducing wear.

[0018] According to a second aspect of the embodiment, a facility for processing biomass material is provided. The facility comprises a reactor for processing the biomass material at high pressure and high temperature using steam addition, a steam explosion discharge device configured to perform steam explosion discharge of the biomass material from the reactor, and at least one conduit according to the first aspect or embodiment of the present invention. The conduit is connected directly or indirectly to the steam explosion discharge device to transport a flow containing the steam explosiond biomass material and steam from the steam explosion discharge device. The reactor may be configured to perform hydrolysis or pre-hydrolysis of the biomass material. As is well known in the art, pre-hydrolysis is performed under milder conditions compared to the hydrolysis process and is used to hydrolyze the hemicellulose content of the biomass. Optionally, a catalyst such as an acid may be added to or before the reactor. The steam explosion discharge device may be described as comprising (or consisting of) a blow valve.

[0019] According to a third aspect of the present invention, there is provided equipment for producing fibers for fiberboard production from biomass materials. The equipment includes a refining device configured to refine or pulverize the biomass material into fibers, and at least one conduit according to the first aspect of the present invention or an embodiment thereof. The conduit is directly or indirectly connected to the refining device for conveying a flow containing fibers from the refining device. The refining device may also be referred to as a defibrator.

[0020] The features of the above-described embodiments can be combined in any practically realizable way to form embodiments having combinations of these features. Further, all the features and advantages of the embodiments described above with reference to the first aspect of the present invention may be applicable to corresponding embodiments of the equipment according to the second and third aspects of the present invention.

[0021] The above and other aspects of the present invention will be described in more detail using the accompanying drawings showing presently preferred embodiments of the present invention.

Brief Description of the Drawings

[0022] [Figure 1] It is a figure showing a perspective view of an embodiment of a conduit according to the first aspect of the present invention. [Figure 2a] It is a figure showing a cutaway view of a part of the conduit of FIG. 1. [Figure 2b] It is a figure showing a cutaway view of an alternative embodiment of a conduit according to the first aspect of the present invention. [Figure 3] It is a figure showing a side view of the conduit of FIG. 1. [Figure 4] It is a figure showing a top view of the conduit of FIG. 1. [Figure 5] It is a figure showing a partial cross-sectional view of the conduit of FIG. 1 taken along line A-A shown in FIG. 3. [Figure 6] It is a figure showing a partial cross-sectional view of the conduit of FIG. 1 taken along line B-B shown in FIG. 4. [Figure 7]This figure shows a schematic diagram of one embodiment of the equipment according to a second aspect of the present invention. [Figure 8] This figure shows a schematic diagram of one embodiment of the equipment according to a third aspect of the present invention. [Modes for carrying out the invention]

[0023] Figure 1 shows a perspective view of one embodiment of the conduit 1 according to a first aspect of the present invention. The conduit is configured to transport a flow containing fibers from a first opening 2 to a second opening 3, or in the opposite direction.

[0024] Openings 2 and 3 are provided at both ends of the conduit, and the conduit is provided with flange-shaped connecting portions 2a and 3a at the openings for connecting the conduit to one or more additional conduits and / or one or more devices for providing and / or processing the flow.

[0025] The conduit has an extension with a 90-degree angle and a radius r of 1000 mm. c The curved portion 4 (see Figure 3) and shorter straight portions 2b and 3b are provided at each end of the curved portion, with the straight portions connecting the curved portion to flanges 2a and 3a.

[0026] The conduit is provided with wall sections 5 that are detachably connected along the entire outer circumference of the curved section 4. The wall sections 5 are curved only in the direction of the curve of the curved section 4. As can be seen in Figure 1, the wall sections 5 are detachably connected using multiple screw connections.

[0027] Figure 2a shows a cutaway view of a portion of the conduit in Figure 1. As can be seen in Figure 2a, the wall section 5 is straight when viewed from the side; that is, the wall section 5 is curved only in the direction of the curve of the curved section 4; that is, it is curved only along the longitudinal direction / flow direction of the curved section.

[0028] Furthermore, as can be seen in Figure 2a, the curved portion 4 of the conduit includes a portion 4a having a substantially U-shaped cross-section, and the portion 4a is provided with flanges 4b, 4c (facing laterally outward) at its open end. The wall portion 5 is attached to the flanges 4b, 4c by abutting against them using threaded connectors 6 that extend through the flanges 4b, 4c and the wall portion 5. The flanges 4b, 4c are provided with grooves 4b', 4c', respectively, in which seals 7a, 7b are positioned to seal the connection between the wall portion 5 and the flanges 4b, 4c.

[0029] In this embodiment, the U-shaped portion of the curved section is formed integrally with the straight sections 2b, 3b and flanges 2a, 3a by casting. 2a, 2b, 3a, 3b, and 4a may also be described together as the main part of the conduit, forming the conduit together with the wall section 5.

[0030] The wall portion 5 is formed from duplex stainless steel according to EN1.4462, which has higher wear resistance than the rest of the conduit. Optionally, the wall portion 5 is provided with an wear-resistant ceramic coating 5' on its inner surface. In such embodiments with a wear-resistant coating, the wall portion 5 may be made of a less wear-resistant material, such as a lower-grade stainless steel.

[0031] Figure 2b shows a cutaway view of an alternative embodiment of the conduit according to a first aspect of the present invention. This embodiment corresponds to the embodiments of Figures 1 and 2a, the only difference being that the detachably connected wall portion comprises an inner layer 5b and an outer layer 5a facing each other toward the interior of the conduit, the inner layer being formed from a material such as EN1.4462, and the outer layer 5a being formed from a less abrasion-resistant material. The wall portion is detachably connected using threaded connections that penetrate the outer layer 5a but not the inner layer 4b.

[0032] Figure 3 shows a side view of the conduit in Figures 1 and 2a. Figure 4 shows a top view of the conduit in Figures 1, 2a, and 3. As can be seen from Figures 3 to 4, the curved portion is curved in only one direction; that is, its centerline forms the curve in one plane. The radius of the curved portion (centerline) is shown in Figure 3 as r c It is shown as follows. Furthermore, as can be seen in Figure 3, the wall portion 5 is the radius r of the curved portion 4. c With respect to the common central axis, radius r wp It is curved. As mentioned above, wall portion 5 is a straight line when viewed from the side, and therefore has a radius r as shown in Figure 3. wp It is curved only in that direction. Furthermore, as can be seen in Figure 3, openings 2 and 3 have a circular cross-section.

[0033] Figure 5 shows a partial cross-sectional view of the conduit in Figure 1, cut along line AA shown in Figure 3. In Figure 5, it can be seen that the curved section has a substantially square (height / width H) cross-section when viewed perpendicular to the longitudinal / flow direction of the conduit. The cross-section is substantially square or rectangular in the sense that the conduit's perimeter is comprised of four straight sections, which together constitute at least 90% of the perimeter.

[0034] Figure 6 shows a partial cross-sectional view of the conduit in Figure 1, cut along line BB shown in Figure 4. Figures 5 through 6 together illustrate how the straight section 2b transitions from a circular cross-section at the opening 2 to a square cross-section in the curved section formed by 4a, 5. The height / width H of the substantially square cross-section in the curved section is only slightly smaller than the diameter D at the opening 2, meaning that the effective flow area of ​​the curved section 4 is larger than the flow area of ​​the conduit at its opening 2. The same applies to the other end having the straight section 3b and the opening 3. As can be seen in Figure 6, a seal 7c is provided in a laterally oriented groove to seal the connection between the wall section 5 and the straight section 2b.

[0035] Figure 7 shows a schematic diagram of one embodiment of the apparatus according to a second aspect of the present invention. The apparatus 100 comprises a substantially vertically positioned reactor 102 for processing biomass material at high pressure and high temperature using the addition of steam through a steam inlet 104. Biomass is supplied to the reactor using a feed screw 105. A discharge screw 104 (e.g., a pressure-sealed screw) is located at the bottom of the reactor 102 and is configured to supply the processed biomass to a blow valve (steam explosion discharge device) 103, where the pressure at the blow valve is reduced to a substantially lower pressure, preferably substantially atmospheric pressure, so that the processed biomass material is subjected to steam explosion. A conduit 101 of the same type as in Figure 1 is connected to the blow valve to receive a flow containing the steam-exploded biomass material and steam. The flow is transported to, for example, a cyclone / steam separator via additional (not shown) conduit / blowline components.

[0036] Figure 8 shows a schematic diagram of one embodiment of a apparatus 200 according to a third aspect of the present invention. This apparatus is for producing fibers for fiberboard production from biomass material. The apparatus comprises a purification device 202 having two discs configured to purify or crush the biomass material between them into fibers. The biomass material is received through an axial inlet 203 and discharged through a tangential outlet 204. Such purification devices (also known as defibrators) are well known in the art and will not be described in further detail here. One example is the Valmet Evolution Defibrator. A conduit 201 of the same type as in Figure 1 is connected to the outlet 204 to receive a flow containing air and fibers from the purification device.

[0037] The above description and accompanying drawings should be considered non-limiting examples of the present invention. Those skilled in the art will understand that several changes and modifications can be made within the scope of the present invention. For example, the curved portion may have an angle range different from 90 degrees, such as 45 degrees. Furthermore, the cross-section of the curved portion does not necessarily have to be substantially square. In addition, the conduit may be used in configurations other than those shown in Figures 7 to 8.

Claims

1. A conduit (1) for transporting a flow containing fibers, - The conduit is provided with only two openings (2, 3) for connecting the conduit to one or more additional conduits and / or one or more devices for providing and / or processing the flow. - The conduit is equipped with a curved portion (4), - The conduit (1) is provided with a wall portion (5) that is detachably connected along at least a portion of the curved portion (4), the wall portion is provided at least partially along the outer radius of the curved portion, the wall portion forms at least a portion of the inner surface of the curved portion, the wall portion (5) is curved only along the longitudinal direction of the curved portion (4), and the wall portion (5) has an abrasion-resistant coating (5') such as a ceramic coating on its inner surface.

2. The conduit according to claim 1, wherein the wall portion (5) is formed from a material having higher wear resistance than the rest of the conduit.

3. The conduit according to claim 1 or 2, wherein the wall portion is formed by an inner layer (5a) and an outer layer (5b) facing each other toward the interior of the conduit, and the inner layer is formed from a material with higher wear resistance than the outer layer.

4. The conduit according to any one of claims 1 to 3, wherein the wall portion (5) is detachably connected using a screw connection portion (6).

5. The conduit according to claim 4, which is dependent on claim 3, wherein the wall portion (5) is detachably connected using a threaded connection portion that does not extend through the inner layer (5a).

6. The conduit according to any one of claims 1 to 5, wherein the curved portion (4) has a substantially square or rectangular cross-section when viewed perpendicular to the flow direction of the conduit.

7. The conduit according to any one of claims 1 to 6, wherein the effective flow area of ​​the curved portion (4) is greater than the flow area of ​​the conduit at its openings (2, 3).

8. The conduit according to any one of claims 1 to 7, wherein the curved portion (4) has an angular range of 30 to 120 degrees, for example, 90 degrees.

9. The curved portion (4) has a radius (r) of at least 500 mm, or at least 1000 mm, or at least 1500 mm. ｃ A conduit according to any one of claims 1 to 8, which is curved in the shape of ).

10. Equipment (100) for processing biomass materials, - A reactor (102) for processing biomass material at high pressure and high temperature using steam addition, - A steam explosion discharge device (103) configured to perform steam explosion discharge of biomass material from a reactor, - An apparatus (100) comprising at least one conduit (101) according to any one of claims 1 to 9, the conduit being directly or indirectly connected to a steam explosion discharge device (103) for transporting a flow containing steam explosion biomass material and steam from the steam explosion discharge device.

11. Equipment (200) for producing fibers for fiberboard production from biomass material, wherein the equipment is - A purification device (202) configured to purify or crush biomass material into fibers, - An apparatus (200) comprising at least one conduit (201) according to any one of claims 1 to 9, the conduit being directly or indirectly connected to the purification device (202) for transporting a flow containing fibers from the purification device.

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