Reactor vessel for biomass material
By adopting an inwardly recessed end plate and a shorter screw shaft design in the biomass reactor container, the problems of material conveying screw skew and heavy end plate were solved, resulting in a lightweight and efficient biomass processing container.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- VALMET AB
- Filing Date
- 2019-03-29
- Publication Date
- 2026-07-31
AI Technical Summary
In existing biomass pretreatment or prehydrolysis reactors, the shaft of the material conveying screw is prone to skew, resulting in a reduction in the effective internal volume of the reactor vessel, and the end plates are thick and heavy, making them difficult to operate and transport.
The design of the inwardly recessed end plate, combined with a shorter material conveying screw shaft, ensures that the end plate is thin and can withstand high pressure, reduces shaft misalignment, and increases the effective internal volume.
This design enables a lighter reactor vessel, increases the effective internal volume, reduces production and transportation costs, and improves ease of operation.
Smart Images
Figure CN122479698A_ABST
Abstract
Description
[0001] This application is a divisional application of the PCT patent application filed by Valmet, Inc. on March 29, 2019, with international application number PCT / SE2019 / 050285, entitled "Reactor Container for Biomass Materials". That PCT patent application entered the Chinese national phase on October 15, 2020, with Chinese patent application number 201980026081.3. Technical Field
[0002] This invention relates to a reactor container for biomass materials. Background Technology
[0003] Arrangements for the pretreatment or prehydrolysis of biomass are known in the art. Such arrangements may include one or more pressurized reactors in which biomass is pretreated with steam at elevated pressure and temperature, with or without the addition of chemicals.
[0004] Temperature and time are two important parameters in the kinetics of this pre-hydrolysis treatment. In particular, it is preferable to reach the desired temperature as quickly as possible to obtain the correct kinetics and avoid building an overly large reactor. Furthermore, it is important that the biomass is heated as uniformly as possible, as uneven heating may result in unreacted, poorly reacted, or even overreacted material, which in turn may lead to yield loss, the formation of undesirable byproducts, and / or problems in downstream processes.
[0005] A pressurized reactor vessel for biomass pretreatment or prehydrolysis can be an elongated, horizontally positioned vessel including an inlet at one end and an outlet at the other. Inside the vessel, a material delivery screw is positioned along its longitudinal central axis. This screw typically comprises a shaft extending along the longitudinal central axis through the entire vessel, and the screw thread arranged helically around the shaft to deliver material along the length of the vessel as the shaft rotates. Larger reactors are required to accommodate the higher capacities and pressures that may be needed in biomass pretreatment. For long reactors, shaft misalignment of the material delivery screw can be a problem. To avoid shaft misalignment, the shaft diameter is made larger. However, making the shaft diameter larger reduces the effective internal volume of the vessel used for material processing. Summary of the Invention
[0006] The purpose of this invention is to provide an improved reactor container for biomass materials.
[0007] Another object of the present invention is to provide a reactor container for biomass materials having an optimized internal volume for processing the materials.
[0008] Another objective of this invention is to reduce the weight of reactor containers used for biomass materials without sacrificing effective internal volume.
[0009] These objectives were achieved in the reactor vessel described below.
[0010] According to one aspect of the present invention, a reactor vessel for biomass materials is provided. The reactor vessel is a pressurized reactor vessel, the reactor vessel is elongated, and comprises: - Basically a tubular container section; - Two end plates, each connected to one end of the tubular container section, thus sealing off the internal compartments of the container; and - A material conveying screw, comprising a central shaft disposed within an internal compartment of the reactor vessel, the central shaft extending along the central axis (A) of the reactor vessel between two end plates, wherein the material conveying screw further comprises a screw thread disposed about the shaft, wherein the material conveying screw is configured to convey biomass material through the reactor vessel. Both end plates are concave or disc-shaped.
[0011] If the reactor vessel is a pressurized vessel, recessed end plates can be made thinner compared to flat end plates. This is because recessed end plates better resist the pressure from the pressurized reactor vessel. For large reactors with high internal pressure used to process biomass materials, flat end plates may need to be, for example, 200 mm thick or more, making them very heavy. Recessed end plates for reactor vessels of the same size can be made thinner, possibly as thin as about 25 mm, thus saving a significant amount of weight. This results in reactor vessels that are easy to operate, move, and transport. Furthermore, with both end plates recessed inward, the material delivery screw, which extends between the two end plates inside the elongated reactor vessel along the central axis, can be made shorter. This material delivery screw is configured to rotate about its central axis and has screw threads for conveying biomass materials through the reactor vessel. The material delivery screw needs to extend through the entire reactor vessel and pass through at least one end plate and protrude to control the rotation of the shaft. By using inwardly recessed end plates instead of flat ones, the shaft of the material conveying screw can be made shorter, and a shorter shaft is less prone to skewing, thus allowing for a smaller diameter. The smaller shaft diameter gives the reactor vessel a larger effective internal volume, which is suitable for efficient processing. The effective internal volume of the reactor vessel can be defined as the volume inside the reactor vessel between the inlet and outlet minus the volume of the internal screw and its shaft. The inlet is located at a first position closer to the first end of the tubular vessel section than to the second opposite end of the tubular vessel section, and the outlet is located at a second position closer to the second end of the tubular vessel section than to the first end of the tubular vessel section. For mechanical reasons, a distance is required between the weld at the end of the end plate to the tubular vessel section and the inlet and outlet. If the inlet and / or outlet are positioned too close to the weld, there is a risk of breakage. This is also specified in the Pressure Equipment Directive, PED, and ASME. The inwardly recessed end plate allows the inlet and outlet to be positioned at the same distance from the end of the tubular container section as the flat end plate. Since the effective internal volume is confined between the inlet and outlet, the effective internal volume increases due to the smaller diameter of the central shaft. Furthermore, a smaller shaft diameter not only reduces shaft production costs but also lowers the production costs of the seals and bearings used to mount the shaft via the end plate.
[0012] In one embodiment of the invention, the central shaft is supported at each end by a carrier mounted on an end plate, allowing it to rotate about its longitudinal axis, and the central shaft passes through and protrudes from at least one end plate. The central shaft is further arranged to connect to a rotating device configured to rotate the central shaft about its longitudinal axis.
[0013] In one embodiment of the present invention, it further includes: - An inlet for receiving the biomass material into an internal compartment of the container, the inlet being positioned at a first position closer to a first end of the tubular container portion than a second opposing end of the tubular container portion; and - An outlet for discharging the biomass material from the internal compartment of the container after passing through it, the outlet being positioned to a second position closer to a second end than the first end of the tubular container portion.
[0014] In one embodiment of the present invention, the first position is located at a first distance d1 from the first end of the tubular container portion, and the second position is located at a second distance d2 from the second end of the tubular container portion.
[0015] In one embodiment of the invention, the first distance d1 and the second distance d2 are at least 1 / 20 of the total length of the reactor vessel.
[0016] In one embodiment of the invention, the pressure inside the container compartment is 5-50 bar (g). In another embodiment of the invention, the pressure inside the container compartment is 10-25 bar (g).
[0017] In one embodiment of the invention, the reactor vessel is horizontally positioned.
[0018] In one embodiment of the invention, the reactor vessel is generally cylindrical, with a diameter of at least 1 m and a length of at least 6 m. In another embodiment, the reactor vessel is generally cylindrical, with a diameter of at least 1.5 m and a length of at least 8 m. In yet another embodiment, the reactor vessel is generally cylindrical, with a diameter of at least 2.5 m and a length of at least 10 m.
[0019] In one embodiment of the invention, the inwardly recessed end plate is shaped as a hemispherical ellipse or a sphere.
[0020] In one embodiment of the invention, the apex of the first end container end plate and the apex of the second end container end plate are respectively located between the inlet centerline and the first end of the tubular container portion and between the outlet centerline and the second end of the tubular container portion. These apexes are the portions of the recessed end plates configured to penetrate deepest into the internal compartment of the container. The inlet centerline passes through the center of the reactor inlet and is perpendicular to the central axis (A), and the outlet centerline passes through the center of the reactor outlet and is perpendicular to the central axis (A).
[0021] In one embodiment of the invention, the distance between the vertex of the first end container end plate and the first end of the tubular container, and the distance between the vertex of the second end container end plate and the second end of the tubular container, are at least 1 / 3 of the reactor container radius. Attached Figure Description
[0022] Figure 1 A reactor vessel with an inwardly recessed end plate is schematically shown according to an embodiment of the present invention.
[0023] Figure 2 A reactor vessel with flat end plates according to the prior art is schematically shown. Detailed Implementation
[0024] According to the present invention, a reactor vessel for biomass materials is provided. This can be a pressurized reactor vessel for processing biomass materials.
[0025] Figure 1 A reactor vessel 1 according to an embodiment of the present invention is schematically shown. The reactor vessel 1 is elongated and includes a substantially tubular vessel portion 3 and two end plates 5a, 5b connected to each end of the tubular vessel portion 3, thereby enclosing an internal compartment 7. A first end plate 5a is connected to a first end 19a of the tubular vessel portion 3, while a second end plate 5b is connected to a second end 19b of the tubular vessel portion 3. The reactor vessel 1 also includes a material delivery screw 8, which includes a central shaft 9 disposed within the internal compartment 7 of the vessel, extending along a central axis A of the reactor vessel 1 between the two end plates 5a, 5b. According to the present invention, both end plates 5a, 5b are concave inward. Concavity inward means that they are not flat, but rather curved inward toward the center of the reactor vessel or cup-shaped. A screw thread 11 is provided around the central shaft 9. The screw thread 11 may be in the form of a screw helix. The central shaft 9, together with the screw thread 11, forms the material conveying screw 8, which is configured to convey biomass material through the reactor vessel 1.
[0026] The central shaft 9 is supported at each end by a carrier mounted on end plates 5a, 5b, enabling it to rotate about its longitudinal axis. In this embodiment, the central shaft 9 has two protruding ends 13a, 13b, one at each end of the central shaft 9. These protruding ends 13a, 13b have a diameter smaller than that of the central shaft 9, thus being more suitable for protruding through the end plates 5a, 5b. One of the protruding ends 13a of the central shaft 9 is also configured for connection to a rotating device. Thus, the central shaft 9 can rotate about its longitudinal axis via a rotating device. The central shaft 9 is typically also sealed at its protruding points through the end plates 5a, 5b by a filling box or mechanical seal.
[0027] The reactor vessel 1 according to this embodiment of the invention further includes an inlet 15a for receiving the biomass material into the internal compartment 7 of the vessel. The inlet 15a is centered at a first position 17a in the tubular container portion 3, the first position 17a being closer to the first end 19a of the tubular container portion 3 than a second opposing end 19b of the tubular container portion 3. The reactor vessel 1 according to this embodiment also includes an outlet 15b for discharging the biomass material from the internal compartment 7 of the vessel after it has passed through the internal compartment. The outlet 15b is centered at a second position 17b, the second position 17b being closer to the second end 19b of the tubular container portion 3 than a first end 19a of the tubular container portion 3. The first position 17a is located at a first distance d1 from the first end 19a of the tubular container portion 3, while the second position 17b is located at a second distance d2 from the second end 19b of the tubular container portion 3. In one embodiment of the invention, the first distance d1 and the second distance d2 are at least 1 / 20 of the total length of the tubular container portion. In one embodiment of the invention, d1 and d2 are at least one-third of the radius of the reactor vessel plus the distance from one side of the inlet / outlet 15a, 15b to the center 16a, 16b of the inlet / outlet, i.e., the distance by which the inwardly recessed end plates 5a, 5b protrude into the reactor vessel. This distance can be at least one-third of the radius of the reactor vessel plus half the size of the inlet / outlet. If the inlet / outlet is cylindrical, it can be the radius of the inlet / outlet. Thus, the inwardly recessed end plates 5a, 5b will not interfere with the material transport through the reactor vessel.
[0028] Due to mechanical reasons and the risk of breakage, and in accordance with the aforementioned Pressure Equipment Directive, PED and ASME, inlet 15a and outlet 15b should be properly not located too close to the ends of the tubular container section 3 and the welded portions of the end plates.
[0029] The reactor vessel according to the invention can be a pressurized reactor vessel for processing biomass materials. The pressure inside the compartment of the vessel can be 5-50 bar (g), that is, a pressure higher than atmospheric pressure, or 10-25 bar (g) in one embodiment of the invention. These reactor vessels are typically horizontally positioned.
[0030] For comparison, Figure 2A reactor vessel 101 according to the prior art is schematically shown. The reactor vessel includes a tubular vessel portion 103 and two flat end plates 105a, 105b. The end plates 105a, 105b are each connected to each end of the tubular portion 103, thereby enclosing an internal compartment 107 of the vessel. A central shaft 109 extending between the two end plates 105a, 105b is disposed within the internal compartment 107 of the vessel. This can be a material conveying screw as described above. Furthermore, as mentioned above... Figure 1 The reactor vessel includes an inlet 115a and an outlet 115b. The inlet 115a is located at a distance d1 from a first end 119a of the tubular vessel portion 103, and the outlet 115b is located at a distance d2 from a second opposite end 119b of the tubular vessel portion 103. For pressurized reactor vessels, these flat end plates 105a, 105b need to be quite thick to withstand pressure. For large reactors with high internal pressures used to process biomass materials, the flat end plates may need to be, for example, up to 200 mm thick, and therefore very heavy. It is possible to make the recessed end plates for reactor vessels of the same size thinner, while still being able to withstand the same pressure, possibly as thin as about 25 mm, thus saving a lot of weight. As a result, the reactor vessel according to the invention, having at least one inwardly recessed end plate, can be made lighter, and therefore easier to handle, move, and transport.
[0031] When comparing Figure 1 and Figure 2 Another obvious advantage of the present invention is that, when the two end plates are recessed inward, the central shaft 9, which extends between the two end plates 5a and 5b located along the central axis A inside the elongated reactor vessel 1, is made shorter. The central shaft 9 needs to extend through the entire internal compartment 7 of the vessel and through at least one of the end plates 5a and 5b, protruding to control the rotation of the shaft. By using recessed end plates instead of flat end plates, the shaft 9 can be made shorter, and a shorter shaft is less prone to skewing, thus allowing it to be manufactured with a smaller diameter. The smaller diameter of the shaft will give the reactor vessel a larger effective internal volume, which is suitable for efficient processing. The effective internal volume of the reactor vessel can be defined as the portion of the internal compartment 7 located between the inlet 15a and outlet 15b of the reactor vessel 1. More precisely, as Figure 1 and Figure 2 As shown by the dashed line, this volume can be measured from the first position 17a to the second position 17b. Therefore, it is clear that the inwardly recessed end plate does not reduce the effective internal volume of the reactor vessel. However, alternatively, with Figure 2Compared to the diameter of the central shaft 109, the smaller diameter of the central shaft 9 will contribute to a larger effective internal volume. Furthermore, the smaller diameter of the central shaft 9 will not only reduce the production cost of the shaft but also lower the production cost of the seals and bearings used to mount the shaft via end plates 5a and 5b.
[0032] The reactor vessel according to the invention can be substantially cylindrical, and in one embodiment of the invention, it has a diameter of at least 1 m and a length of at least 6 m. In another embodiment of the invention, the reactor vessel can have a diameter of at least 1.5 m and a length of at least 8 m, or a diameter of at least 2.5 m and a length of at least 10 m.
[0033] In one embodiment of the invention, the shape of at least one inwardly recessed end plate may be hemispherical or elliptical, while in another embodiment of the invention it may be spherical.
[0034] The apex 21a of the first end plate 5a and the apex 21b of the second end plate 5b are the recessed portions of the end plates 5a and 5b that are positioned to extend deepest into the internal compartment 7 of the container. The apex 21a of the first end plate 5a is suitably located between the inlet centerline 16a and the first end 19a of the tubular container portion 3, wherein the inlet centerline 16a passes through the center of the reactor inlet 15a and is perpendicular to the central axis (A). The apex 21b of the second end plate 5b is suitably located between the outlet centerline 16b and the second end 19b of the tubular container portion 3, wherein the outlet centerline 16b passes through the center of the reactor outlet 15b and is perpendicular to the central axis (A). Therefore, the recessed end plates will not affect the effective internal volume of the reactor container 1.
[0035] In one embodiment of the present invention, the distance between the vertex 21a of the first end container plate 5a and the first end 19a of the tubular container portion 3, and the distance between the vertex 21b of the second end container plate 5b and the second end 19b of the tubular container portion 3, are at least 1 / 3 of the reactor container radius.
Claims
1. A reactor container (1) for biomass materials, wherein, The reactor vessel (1) is a pressurized reactor vessel, which is elongated and comprises: - Basically a tubular container part (3); - Two end plates (5a, 5b), each end of which is connected to each end (19a, 19b) of the tubular container portion (3), thereby sealing the internal compartment (7) of the container; and - A material conveying screw (8) comprising a central shaft (9) disposed within a compartment (7) inside the container, the central shaft extending along the central axis (A) of the reactor container (1) between the two end plates (5a, 5b), wherein the material conveying screw further comprises a screw thread (11) disposed around the shaft (9), wherein the material conveying screw is configured to convey biomass material through the reactor container. Both end plates (5a, 5b) are recessed inward, and the central shaft (9) is supported at each end by a carrier mounted on the end plates (5a, 5b) to allow it to rotate about its longitudinal axis. The central shaft (9) protrudes through at least one of the end plates (5a, 5b), and is further arranged to be connected to a rotating device configured to rotate the central shaft (9) about its longitudinal axis. The apex (21a) of the first end container end plate (5a) and the apex (21b) of the second end container end plate (5b) are respectively located between the inlet centerline (16a) and the first end (19a) of the tubular container portion (3) and between the outlet centerline (16b) and the second end (19b) of the tubular container portion (3). The apex (21a, 21b) is the portion of the recessed end plate that is set to be the deepest part of the container's internal compartment. The inlet centerline (16a) passes through the center of the reactor's inlet (15a) and is perpendicular to the central axis (A). The outlet centerline (16b) passes through the center of the reactor's outlet and is perpendicular to the central axis (A).
2. The reactor vessel according to claim 1, characterized in that, It also includes: - An inlet (15a) for receiving the biomass material into the internal compartment (7) of the container, the inlet (15a) being configured to be centered at a first position (17a) closer to the first end (19a) of the tubular container portion (3) than the second opposite end (19b) of the tubular container portion (3); and - An outlet (15b) for discharging the biomass material from the internal compartment (7) of the container after passing through the internal compartment, the outlet (15b) being centered at a second position (17b) which is closer to the second end (19b) than the first end (19a) of the tubular container portion (3).
3. The reactor vessel according to claim 2, characterized in that, The first position (17a) is located at a first distance (d1) from the first end (19a) of the tubular container portion (3), while the second position (17b) is located at a second distance (d2) from the second end (19b) of the tubular container portion (3).
4. The reactor vessel according to claim 3, characterized in that, The first distance (d1) and the second distance (d2) are at least 1 / 20 of the total length of the reactor vessel.
5. The reactor vessel according to claim 1, characterized in that, The pressure inside the internal compartment (7) of the container is 5-50 bar (g) or 10-25 bar (g).
6. The reactor vessel according to claim 1, characterized in that, The reactor vessel (1) is set horizontally.
7. The reactor vessel according to claim 1, characterized in that, The reactor vessel (1) is generally cylindrical and has a diameter of at least 1 m and a length of at least 6 m, or a diameter of at least 1.5 m and a length of at least 8 m, or a diameter of at least 2.5 m and a length of at least 10 m.
8. The reactor vessel according to claim 1, characterized in that, At least one inwardly recessed end plate (5a, 5b) is elliptical or spherical in shape.
9. The reactor vessel according to claim 1, characterized in that, The distance between the vertex (21a) of the first end container end plate (5a) and the first end (19a) of the tubular container portion (3) and the distance between the vertex (21b) of the second end container end plate (5b) and the second end (19b) of the tubular container portion (3) are at least 1 / 3 of the radius of the reactor container.