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EP-4739938-A1 - CONDUIT FOR CONVEYING A FIBER STREAM

EP4739938A1EP 4739938 A1EP4739938 A1EP 4739938A1EP-4739938-A1

Abstract

A conduit (1) for conveying a stream comprising fibers, - said conduit being provided with solely two openings (2, 3) for connecting the conduit to one or more additional conduits and/or to one or more apparatuses for providing and/or treating said stream; - said conduit comprising a curved portion (4); - said conduit being provided with a releasably connected wall portion (5) along at least a portion of said curved portion (4), said wall portion being at least partly provided at an outer radius of the curved portion, said wall portion forming at least part of an inner surface of the curved portion, said wall portion (5) being curved solely along a lengthwise direction of said curved portion (4), wherein said wall portion (5) comprises a wear-resistant coating, such as a ceramic coating, at an inner surface thereof.

Inventors

  • WAHLBERG, ROBERT
  • HÄGGLUND, Christer

Assignees

  • Valmet AB

Dates

Publication Date
20260513
Application Date
20240619

Claims (11)

  1. 1. A conduit (1) for conveying a stream comprising fibers, said conduit being provided with solely two openings (2, 3) for connecting the conduit to one or more additional conduits and/or to one or more apparatuses for providing and/or treating said stream; said conduit comprising a curved portion (4); said conduit being provided with a releasably connected wall portion (5) along at least a portion of said curved portion (4), said wall portion being at least partly provided at an outer radius of the curved portion, said wall portion forming at least part of an inner surface of the curved portion, said wall portion (5) being curved solely along a lengthwise direction of said curved portion (4), wherein said wall portion (5) comprises a wear-resistant coating (5’), such as a ceramic coating, at an inner surface thereof.
  2. 2. Conduit according to claim 1, wherein said wall portion (5) is formed from a material which has greater wear resistance than the rest of the conduit
  3. 3. Conduit according to any of the preceding claims, wherein said wall portion is formed by an inner layer (5a) facing towards the interior of the conduit and an outer layer (5b), wherein the inner layer is formed from a material which has greater wear resistance than the outer layer.
  4. 4. Conduit according to any of the preceding claims, wherein said wall portion (5) is releasably connected by means of screw connections (6).
  5. 5. Conduit according to claim 4 as dependent on claim 3, wherein said wall portion (5) is releasably connected by means of screw connections which do not extend through the inner layer (5a).
  6. 6. Conduit according to any of the preceding claims, wherein said curved portion (4) has a substantially square or rectangular cross section as seen perpendicular to a flow direction of said conduit
  7. 7. Conduit according to any of the preceding claims, wherein an effective flow area of the curved portion (4) is greater than a flow area of the conduit at its openings (2, 3).
  8. 8. Conduit according to any of the preceding claims, wherein said curved portion (4) has an angular extension of 30 to 120 degrees, such as 90 degrees.
  9. 9. Conduit according to any of the preceding claims, wherein said curved portion (4) is curved with a radius (r c ) of atleast 500 mm, or atleast 1000 mm, or at least 1500 mm.
  10. 10. An arrangement (100) for treating biomass material comprising: a reactor (102) for treating the biomass material at elevated pressure and temperature by means of steam addition; a steam explosion discharge device (103) configured to carry out steam explosion discharge of the biomass material from the reactor, and at least one conduit (101) according to any of the preceding claims, said conduit being connected directly or indirectly to said steam explosion discharge device (103) for conveying a stream comprising steam exploded biomass material and steam from the steam explosion discharge device.
  11. 11. An arrangement (200) for producing fibers for fiberboard production from biomass material, said arrangement comprising: a refining device (202) arranged to refine or grind the biomass material into fibers, and at least one conduit (201) according to any claims 1-9, said conduit being connected directly or indirectly to said refining device (202) for conveying a stream comprising fibers from the refining device.

Description

CONDUIT FOR CONVEYING A FIBER STREAM TECHNICAL FIELD The invention relates to the field of conduits /blow lines for conveying a stream comprising fibers and steam or air, which conduit or blow line comprises at least one curved portion. BACKGROUND Conduits or blow lines for conveying a stream comprising fibers, such as a stream comprising fibers and steam resulting from steam explosion discharge of biomass treated in a pressurized reactor, are known in the art Such conduits or blow lines normally comprises at least one curved portion. One problem with such conduits or blow lines is that the fiber content of the stream is concentrated to radially outermost trajectories in the curved portion and thus causes wear on the (inside of the) radially outermost portion of the curved portion, eventually causing the conduit or blow line to break. Repairing such a conduit or blow line on-site by means of welding is time-consuming and costly since a certified welder is required due the pressure vessel directive. A less time-consuming but even more costly option is to replace the conduit or blow line part comprising the curved portion when worn out SUMMARY An object of the invention is to provide a conduit or blow line which at least partly solves or improves on the problems identified in the above background section. These and other objects are achieved by the present invention by means of a conduit according to the independent claim. According to a first aspect of the invention, there is provided a conduit for conveying a stream comprising fibers. The conduit is provided with two openings (preferably at its opposite ends) for connecting the conduit to one or more additional conduits and/or to one or more apparatuses for providing and/or treating said stream. The conduit comprises a curved portion. The conduit is provided with a releasably connected wall portion along at least a portion of said curved portion, the wall portion being provided along at least part of the outer periphery of the curved portion. It is understood that the releasably connected wall portion is a wall portion in the sense that it forms part of the wall of the curved portion (along at least part of the outer periphery thereof) which would otherwise be formed by a fixed portion of the wall of the curved portion. Thus, the wall portion forms at least part of an inner surface of the curved portion, i.e. the wall portion is in direct contact with the stream of fibers conveyed through the conduit. The wall portion may also be described as (having an inner surface) facing towards the interior of the conduit. In other words, a conduit or blow line part is provided which comprises a curved portion. The conduit is suitable for conveying a stream comprising air and/or steam and fibers (such as biomass or cellulosic fibers) in the sense that it is (partly or wholly) made from a wear resistant material, and/or (partly or wholly) comprises a wear resistant coating or the like, which can withstand the abrasive action of the fibers. The stream may also be referred to as an airstream or steam stream comprising/conveying fibers. The conduit is provided with two openings (inlet and outlet), which may be at its opposite ends. Between the two openings, the conduit is preferably not provided with any openings/connections for discharging or supplementing the stream or parts thereof, i.e. preferably there are solely two openings, i.e. the conduit comprises solely one inlet and solely one outlet. Since openings are provided solely at two positions (such as at the opposite ends), the conduit is for conveying the stream, not for other purposes such as separating away (part of) the air or steam content of the stream. The conduit is preferably provided with a connecting portion at the respective opening. The connecting portions, which may be in the form of flanges, are adapted to connect the conduit to one or more additional conduits and/or to one or more apparatuses for providing and/or treating said stream. The conduit comprises a curved portion, i.e. at least part of the conduit (but not necessarily the whole) is curved. The curved portion may also be referred to as a bend. The conduit is provided with a releasably connected wall portion along at least a portion of the curved portion (or along the whole curved portion, or a wall portion which extends beyond the curved portion). At least part of the wall portion is provided at an outer radius or periphery of the curved portion, i.e. forms (part of) the radially outermost (peripheral) wall of the conduit. The curved portion or bend may be described in that the center line formed by the curved portion of the conduit forms a curve in plane, i.e. the curved portion is curved only in one direction/plane. The curved portion may have an angular extension of 30 to 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, the radius being the radiu