Devolatilizer with hollow double plate assembly

Abstract

The present invention relates to a devolatilization apparatus for devolatilizing compositions containing volatile components, such as for devolatilizing solid or liquid polymer compositions containing unreacted monomers, solvents, and / or by-products, the devolatilization apparatus comprising a vessel having at least one inlet for the composition to be devolatilized, at least one outlet for the devolatilized composition, at least one outlet for gas, at least one heatable tray, and optionally at least one heatable distributor, the vessel comprising a hollow vessel having upper and lower plates, at least a section of the at least one heatable tray and / or the at least one heatable distributor arranged one on top of the other but spaced apart such that a void chamber is defined between the upper and lower plates. The vessel comprises a double-plate assembly, each plate having a plurality of openings, each opening of the upper plate being surrounded by a wall that extends through the void chamber to form a plurality of passages that are fluid-tightly separated from hollow spaces defined in the void chambers between the passages and that surround the openings of the lower plate, the hollow spaces being connected to an inlet and an outlet for the heating medium, the upper and lower plates of the hollow double-plate assembly being connected to each other at their sides via side walls that define the void chambers therebetween, and at least one heatable tray and / or at least one heatable distributor extending over 10 to 99% of the cross-sectional area of ​​the vessel and surrounded by a non-perforated weir.

Description

[Technical Field]

[0001] The present invention relates to a devolatilization apparatus for devolatilizing compositions containing volatile components, such as for devolatilizing solid or liquid polymer compositions containing unreacted monomers and solvents, and to a devolatilization process using such a devolatilization apparatus. [Background technology]

[0002] Devolatilization, or degassing, refers to the controlled removal of gases and other volatile substances, such as solvents or water, from solids and liquids, respectively. Devolatilization is typically used to remove volatile components, mostly those with comparable low molecular weights, such as residual monomers, solvents, reaction by-products, and water from the polymer. This devolatilization is necessary to achieve the required purity of each polymer before use by removing harmful and / or toxic components, components that adversely affect the further processing of the polymer, such as its moldability into articles, components that deteriorate the properties of the polymer, components that cause the polymer to have an unpleasant odor, and / or components that are otherwise undesirable. Furthermore, removing monomers and solvents from polymer compositions allows them to be recovered and potentially recycled during processing to increase process yields and reduce waste.

[0003] To achieve devolatilization, the components to be evaporated must have a higher partial pressure or thermodynamic activity than the polymer, respectively. Furthermore, the components to be evaporated must be able to diffuse through the polymer composition to the phase boundary. Specifically, in the case of viscous polymers or polymer melts, where the polymer and polymer melt typically have similar viscosities, a slow diffusion rate can be the rate-limiting factor. Therefore, to accelerate devolatilization, compositions subjected to devolatilization are usually devolatilized at elevated temperatures and / or at pressures below atmospheric pressure. This is because both measures increase the thermodynamic activity of the volatile components, and increasing temperature also decreases the viscosity of the polymer, thereby improving the diffusion of the volatile components within the polymer. However, most polymers are more or less heat-sensitive, and therefore, to ensure that polymer degradation during devolatilization is avoided, a specific temperature specific to each polymer should not be exceeded. Therefore, temperature control of the composition to be devolatilized during devolatilization is important and, in fact, a crucial factor.

[0004] Several types of devolatilizers are known, including static devolatilizers and dynamic devolatilizers. Dynamic devolatilizers have moving parts, such as blades, to maintain a high interfacial concentration gradient and a high diffusion rate of volatile components within the polymer, while static devolatilizers have no moving parts but have internals to create a high specific surface area for the composition to be devolatilized. However, due to their moving parts, dynamic devolatilizers are associated with serious drawbacks, such as high cost, large amounts of energy required during operation, the need for regular maintenance, and a relatively high leakage rate.

[0005] Therefore, compared with dynamic devolatilization apparatuses, static devolatilization apparatuses have the advantages of lower energy consumption, lower installation costs, less maintenance required, and relatively low leakage rates due to the lack of moving parts. Common types of static devolatilization apparatuses are flash devolatilization apparatuses and falling strand devolatilization apparatuses. Flash devolatilization apparatuses typically include a preheater, such as a heat exchanger, and a flash chamber. During operation, the polymer composition to be devolatilized is first pumped into the heat exchanger, where it is heated and optionally pressurized to reduce its viscosity. The polymer composition is then pumped from the heat exchanger to the top of the flash chamber, where the pressure is released and evaporation of the volatile components occurs. The polymer composition then falls downward through the flash chamber, during which multiple bubbles of the volatile components are nucleated within the polymer composition. This results in a large surface area for mass transfer, thus leading to rapid devolatilization. The devolatilized gas phase is collected and condensed in a condenser, while the residual polymer composition collects at the bottom of the flash chamber and is removed by pumping. Falling strand devolatilizers operate similarly to flash devolatilizers, but have specially designed nozzles to inject the polymer composition into the chamber as a falling strand, promote the development of bubbles of volatile components, and accelerate the diffusion process.

[0006] As shown above, control of devolatilization conditions, such as temperature control, residence time control of the composition to be devolatilized, and pressure control, during devolatilization is important and, in fact, a crucial factor. This control of devolatilization conditions is even more important when a temperature-sensitive composition, such as a temperature-sensitive polymer composition, is to be devolatilized. For example, if the polymer of the composition to be devolatilized is highly temperature-sensitive and therefore cannot be heated to the optimal temperature in a preheater, if the preheater cannot reach the required outlet temperature due to inaccurate design criteria, if the devolatilizer is designed to cause large heat loss to the environment, or if inaccurate simulations are performed before designing the devolatilizer due to a lack of thermodynamic data, the flash devolatilizer cannot operate at the optimal temperature. However, non-optimal temperature control of the composition to be devolatilized during devolatilization will lead to non-optimal devolatilization results. For example, a lower than optimal operating temperature during devolatilization may result in a relatively small amount of the volatile components contained in the polymer composition being separated from the polymer, a devolatilized polymer product discharged from the devolatilizer at a temperature lower than the optimal design temperature may cause abnormal operation in downstream equipment, and / or the intended properties of the devolatilized polymer product may not be realized after the devolatilization step. Summary of the Invention [Problem to be solved by the invention]

[0007] In this regard, the underlying object of the present invention is to provide a devolatilization apparatus for devolatilizing compositions containing volatile components, such as solid or liquid polymer compositions containing unreacted monomers, solvents, and / or by-products, which compensates for heat losses due to the evaporation of volatile components, and which makes it possible to reliably control devolatilization conditions, in particular the operating temperature, pressure, and residence time of the composition to be devolatilized during operation of the devolatilization apparatus, and in particular to reliably control the devolatilization operating temperature, pressure, and residence time of the composition to be devolatilized in different sections of the devolatilization apparatus separately, thereby achieving optimal devolatilization of the composition to be devolatilized at low operating costs, which devolatilization apparatus is characterized by low capital expenditures, and which results in a devolatilized composition with optimal product quality, even when the composition to be devolatilized is a polymer composition containing a specific temperature-sensitive polymer. [Means for solving the problem]

[0008] According to the present invention, there is provided a devolatilization apparatus for devolatilizing a composition comprising volatile components, such as for devolatilizing a solid or liquid polymer composition comprising unreacted monomers, solvents, and / or by-products, the devolatilization apparatus comprising a vessel having at least one inlet for the composition to be devolatilized, at least one outlet for the devolatilized composition, at least one outlet for gas, at least one heatable tray, and optionally at least one heatable distributor, wherein at least one section of the at least one heatable tray and / or at least one heatable distributor comprises a hollow double-plate assembly comprising upper and lower plates arranged one on top of the other but spaced apart such that a void chamber is defined between the upper and lower plates. This object is met by providing a devolatilization apparatus comprising: both plates each having a plurality of openings, each opening in the upper plate surrounded by a wall extending through the void chamber and surrounding the opening in the lower plate to form a plurality of passages fluid-tightly separated from hollow spaces defined in the void chambers between the passages; the hollow spaces connected to an inlet for the heating medium and an outlet for the heating medium; preferably the upper and lower plates of the hollow double-plate assembly being connected to each other at their sides via side walls defining the void chambers therebetween; and preferably the at least one heatable tray and / or at least one heatable distributor extending over 10-99% of the cross-sectional area of ​​the vessel and surrounded by a preferably non-perforated weir.

[0009] This solution is based on the discovery that such devolatilizers, in particular static devolatilizers, for devolatilizing compositions comprising volatile components, such as for devolatilizing solid or liquid polymer compositions comprising unreacted monomers, solvents, and / or by-products, allow for reliable control of the devolatilization operating temperature during operation of the devolatilizer, and in particular for reliable control of the devolatilization operating temperature of different sections of the devolatilizer individually. In such a devolatilization device, at least one section of at least one heatable tray and / or at least one heatable distributor comprises a hollow double-plate assembly comprising an upper plate and a lower plate arranged on top of each other but spaced apart so that a void chamber is defined between the upper and lower plates, each of the plates having a plurality of openings, each of the openings in the upper plate being surrounded by a wall extending through the void chamber and surrounding the opening in the lower plate to form a plurality of passages fluidly connecting the upper and lower plates so that falling strands generated from the composition flowing downward from the upper plate through the passages can fall downward from the underside of the lower plate, the passages being fluid-tightly separated from the hollow space defined in the void chamber between the passages, and the hollow space being connected to an inlet for a heating medium and an outlet for a heating medium. More specifically, due to the hollow space of the gap chamber through which a heating medium regulated at an appropriate and optimal temperature flows, the composition to be devolatilized, such as a composition containing a temperature-sensitive polymer, enters through one or more heatable distributors with precisely temperature-controllable hollow double-plate assemblies and / or falls onto one or more heatable trays with precisely temperature-controllable hollow double-plate assemblies. As a result, not only is the temperature of the upper plate precisely controlled by the heating medium flowing under the lower side of the upper plate through the hollow space, but also the temperature of the lower plate precisely controlled by the heating medium flowing over the upper side of the lower plate, and in particular, all of the paths through which the composition to be devolatilized flows downward through the hollow double-plate assemblies are precisely temperature-controlled.Thus, after a large amount of volatile components have already evaporated from the composition to be devolatilized in the distributor, the composition to be devolatilized falls downward onto one or more heated trays, where it is precisely heated while held on the tray and then flows through the tray passages, forming falling strands below the lower plate that fall downward onto the next tray below. This effectively separates the volatile components from the polymer of the composition to be devolatilized. Because each distributor and each tray can be precisely temperature-controlled individually by appropriately adjusting the temperature of the heating medium conveyed through the hollow space of the void chamber of each distributor or tray, the devolatilization apparatus according to the present invention makes it possible to reliably control the devolatilization operating temperature during operation of the devolatilization apparatus, and in particular, to reliably control the devolatilization operating temperature individually in different sections of the devolatilization apparatus. Furthermore, because the at least one heatable tray and / or the at least one heatable distributor extends across 10-99% of the cross-sectional area of ​​the vessel, the at least one heatable tray and / or the at least one heatable distributor does not extend across 100% of the cross-sectional area of ​​the vessel and divide the interior of the vessel into separate compartments. Because the entire interior of the vessel is a single compartment, uniform pressure within the vessel during operation is easily achieved. Because complex pressure profiles are reliably avoided, uniform pressure within the vessel significantly facilitates precise control of devolatilization conditions during operation. Specifically, uniform pressure within the vessel makes it possible to adjust stable subatmospheric pressure conditions within the vessel during operation. By surrounding at least one heatable tray and / or at least one heatable distributor with a non-perforated weir, it is further possible to precisely adjust the residence time of the composition to be devolatilized on and within the at least one heatable tray and / or at least one heatable distributor by appropriately adjusting the height of the non-perforated weir and the velocity of the composition to be devolatilized. Furthermore, if the level of the composition to be devolatilized becomes higher than the height of the non-perforated weir, the non-perforated weir allows the composition to be devolatilized to flow out, which helps to avoid passageway obstruction.This not only makes it possible to devolatilize compositions containing temperature-sensitive polymers, but also compositions containing a mixture of heat-sensitive and non-heat-sensitive volatile components. For example, the hollow double-plate assembly of a tray installed in the upper section of the container can be adjusted to a relatively low temperature to remove heat-sensitive volatile components, while the hollow double-plate assembly of a tray installed in the lower section of the container can be adjusted to a relatively high temperature to remove non-heat-sensitive volatile components. Furthermore, thanks to one or more heatable trays, each equipped with a hollow double-plate assembly, and an optional heatable distributor, the devolatilization apparatus according to the present invention can compensate for heat loss and temperature drops inside the container caused by the evaporation of volatile components. As a result, the devolatilization apparatus achieves optimal devolatilization of the composition to be devolatilized at low operating costs, and the devolatilization apparatus is characterized by low capital expenditures, resulting in a devolatilized composition with optimal product quality, even when the composition to be devolatilized is a polymer composition containing a specific temperature-sensitive polymer. Another advantage of the devolatilizer according to the present invention is that the hollow double plate assembly of which the trays are constructed allows the trays to be secured to a single removable cartridge, thereby allowing the trays to be easily removed for maintenance and / or cleaning and then reinstalled in the devolatilizer, if necessary, or to be easily replaced with other trays before the devolatilizer is used for a different devolatilization application.

[0010] According to the invention, at least one section of at least one heatable tray and / or at least one heatable distributor comprises a hollow double-plate assembly. Preferably, the entire at least one heatable tray and / or at least one heatable distributor comprises a hollow double-plate assembly when viewed in a horizontal plane.

[0011] Furthermore, the plurality of passages are fluid-tightly separated from the hollow spaces defined in the void chambers between the passages. By this, it is meant that, according to the present invention, the fluid flowing through the passages from the upper plate to the lower plate, i.e., the composition to be devolatilized, cannot enter the hollow spaces through which the heating medium flows, and the heating medium flowing through the hollow spaces cannot enter the passages. In this context, a plurality of passages means two or more, preferably five or more, and more preferably ten or more passages.

[0012] According to the present invention, a hollow double-plate assembly comprises an upper plate and a lower plate arranged one on top of the other, and the upper and lower plates of the hollow double-plate assembly are connected to each other at the sides of the upper and lower plates via side walls. This means that in addition to the upper plate, lower plate, side walls, and non-perforated weirs, baffles and / or perforated weirs may be arranged within or on the hollow double-plate assembly. In theory, the hollow double-plate assembly may comprise one or more additional plates in addition to the upper or lower plate, but preferably the hollow double-plate assembly does not include any additional plates in addition to the upper or lower plate.

[0013] The present invention is not specifically limited with respect to the relative orientation of the upper and lower plates of the hollow double-plate assembly. Preferably, the upper and lower plates are arranged at least approximately parallel to each other. At least approximately parallel to each other means, according to the present invention, that the upper and lower plates are inclined relative to each other by no more than 10°, preferably no more than 5°, more preferably no more than 2°, and even more preferably no more than 1°. Most preferably, the upper and lower plates are arranged parallel to each other, i.e., the upper and lower plates are not inclined relative to each other.

[0014] According to the present invention, the upper and lower plates are connected to each other at their sides via side walls that define a cavity therebetween, thereby easily isolating the cavity of the hollow double-plate assembly from the surroundings in a fluid-tight manner. In this context, a side wall means any wall different from the container wall.

[0015] In a further development of the idea of ​​the present invention, it is proposed that the at least one heatable tray and / or the at least one heatable distributor extend over 20 to 95%, more preferably 40 to 90%, and most preferably 70 to 90% of the cross-sectional area of ​​the container. Even if it is possible that a part of the peripheral area of ​​the heatable tray and / or the at least one distributor is directly connected to the container wall while the remaining part of the peripheral area of ​​the heatable tray and / or the at least one distributor is not directly connected to the container wall, it is particularly preferred that the entire peripheral area of ​​the at least one heatable tray and / or the at least one distributor is not directly connected to the container wall, i.e. the at least one heatable tray and / or the at least one distributor is not in direct contact with the container wall at all, but is connected to the container wall by means of connecting means or support elements or the like to keep the at least one heatable tray and / or the at least one distributor in position. When the devolatilizer comprises two or more heatable trays and / or two or more heatable distributors, preferably at least 80%, more preferably at least 90%, and most preferably all of the heatable trays and distributors are embodied as described above.

[0016] According to the present invention, in order to prevent the composition to be devolatilized from flowing around the circumference of the at least one heatable tray and / or the at least one heatable distributor and to adjust the residence time of the composition to be devolatilized on and in the at least one heatable tray and / or the at least one heatable distributor, the at least one heatable tray and / or the at least one heatable distributor are surrounded by a non-perforated weir. Thus, the non-perforated weir is preferably fluid-tightly connected to the at least one heatable tray and / or the at least one heatable distributor, and the non-perforated weir may not be formed from the container wall, but is different from the container wall. Surrounded in this context means that the weir is located on and connected to the outer part of the upper surface of the at least one heatable tray and / or the at least one heatable distributor, or preferably connected to the outer peripheral region of the at least one heatable tray and / or the at least one heatable distributor. The outer portion of the upper surface of at least one heatable tray and / or at least one heatable distributor means the outer portion of at most 20% of the upper surface area of ​​at least one heatable tray and / or at least one heatable distributor. The side walls connecting the upper and lower plates of the hollow double-plate assembly and the non-perforated dams can particularly be a single element, such as a single metal plate or a single plastic plate, and the part of the combined side walls and non-perforated dams extending between the upper and lower plates is referred to as the side walls, while the part of the combined side walls and non-perforated dams extending to the outside thereof is referred to as the non-perforated dams. Particularly good results are obtained when the non-perforated dams surrounding the at least one heatable tray and / or at least one heatable distributor are arranged at least approximately vertically and / or at least approximately parallel to the longitudinal axis of the container. At least approximately vertical in this context means that the angle between the non-perforated weir and the vertical direction is at most 10°, preferably at most 5°, more preferably at most 1°, and most preferably 0°.On the other hand, at least approximately vertical in this context means that the angle between the non-perforated weir and the longitudinal axis of the vessel is 80 to 100°, preferably 85 to 95°, more preferably at most 89 to 91°, and most preferably 90°. The non-perforated weir may be a thin metal or plastic plate, for example having a thickness of 1 to 20 mm.

[0017] Particularly preferably, the non-perforated weir extends upwards when viewed from the top of the at least one heatable tray and / or the at least one heatable distributor. Particularly good results are obtained if the non-perforated weir has a height of 50 to 500 mm, preferably 100 to 200 mm.

[0018] The present invention is not specifically limited with respect to the shape of the upper and lower plates. For example, the upper and lower plates may have a polygonal, rectangular, square, circular, elliptical, or trapezoidal shape when viewed from the top. However, it is preferred that both the upper and lower plates have the same shape. Most preferably, the upper and lower plates have a rectangular shape or at least a substantially rectangular shape when viewed from the top.

[0019] Furthermore, there are no specific limitations on the materials of the upper and lower plates, as long as they have relatively good thermal conductivity, are resistant to the composition to be devolatilized, and are mechanically stable. Particularly good results are obtained when the upper and lower plates are made of stainless steel, carbon steel, etc.

[0020] The preferred thickness of the upper and lower plates depends on the mechanical stability of the material from which they are made, and is preferably as thin as possible to ensure rapid and efficient heat transfer through the plates from the heating medium flowing through the hollow space of the cavity chamber. In this respect, the upper and lower plates each preferably have a thickness of 1 to 10 mm, preferably 3.5 to 6 mm.

[0021] According to the present invention, each of the openings in the upper plate is surrounded on its lower side by a wall that extends through the void chamber and surrounds the openings in the lower plate above the lower plate to form a plurality of passages, each of which fluidly connects an opening in the upper plate with an opening in the lower plate, thereby allowing the composition to be devolatilized to flow from the upper plate through the passages to the lower plate and fall downward therefrom in the form of falling strands. In this regard, it is preferred that the upper and lower plates have the same number of openings.

[0022] In a further development of the concept of the present invention, it is suggested that the total area of ​​all openings in the upper plate be 0.1 to 40%, preferably 1 to 10%, of the total surface area of ​​the upper plate, and that the total area of ​​all openings in the lower plate be 0.1 to 40%, preferably 1 to 10%, of the total surface area of ​​the lower plate, so that, on the one hand, there is a sufficient non-perforated surface on the upper surface of the upper plate to precisely heat the composition to be devolatilized to the desired optimum temperature, and, on the other hand, there is a sufficient open area to allow a sufficient amount of the composition to flow downward through the passages and leave the hollow double-plate assembly as falling strands.

[0023] The present invention is not particularly limited with respect to the shape of the passageway. The passageway may or may not have the same shape as the opening and may or may not have a constant cross-sectional area over its length, i.e., when viewed vertically. However, particularly good results are obtained when the passageway has at least substantially the same shape as the opening and when the passageway has at least substantially a constant cross-sectional area over its length.

[0024] Similarly, the present invention is not specifically limited with respect to the cross-sectional shape of the openings. For example, some or preferably all of the openings in the upper and lower plates may have a polygonal, rectangular, square, circular, elliptical, or trapezoidal cross-sectional shape. More preferably, at least some, and most preferably all, of the openings in the upper and lower plates have a circular cross-sectional shape. In this regard, it is preferred that the openings in the upper and lower plates have a circular cross-sectional shape, and that at least 50%, preferably at least 80%, more preferably at least 95%, and most preferably all of the openings in the upper and lower plates have at least substantially the same diameter. In this context, "at least substantially the same diameter" means that any of the openings has a diameter that differs from the average diameter of all openings by no more than 20%, preferably no more than 10%, more preferably no more than 5%, and most preferably no more than 1%. Most preferably, all openings have the same diameter. The average diameter of all openings is the sum of the diameters of all openings in the upper and lower plates divided by the total number of all openings in the upper and lower plates. In other words, the passageways have at least a substantially constant diameter when viewed along their length, and most preferably have a cylindrical shape with a constant diameter. In this case, the diameter of the openings in the upper plate is the same as the diameter of each opening in the lower plate that is connected to the opening in the upper plate via a wall. However, if the openings have a shape other than a circular cross-sectional shape, such as a rectangular cross-sectional shape, preferably at least 50%, preferably at least 80%, more preferably at least 95%, and most preferably all of the openings in the upper and lower plates have at least substantially the same cross-sectional area, where at least substantially the same cross-sectional area means that any one of the openings has a cross-sectional area that differs from the average cross-sectional area of ​​all the openings by no more than 20%, preferably no more than 10%, more preferably no more than 5%, and most preferably no more than 1%.

[0025] According to a further preferred embodiment of the present invention, the average longest dimension of the openings is 5 to 50 mm, 20 to 80 mm, or 50 to 150 mm. The longest dimension of the openings refers to the longest possible line connecting a point on the circumferential line of the opening to a point located on the opposite circumferential line of the opening. More preferably, the openings in the upper and lower plates have a circular cross-sectional shape, and the average diameter of the openings is 5 to 50 mm, 20 to 80 mm, or 50 to 150 mm. The preferred diameter depends on the viscosity of the composition to be devolatilized that flows through the openings. For example, when the viscosity of the composition to be devolatilized is 10 to 1,000 Pa·s, the average longest dimension or average diameter of the openings is preferably 5 to 50 mm, whereas when the viscosity of the composition to be devolatilized is greater than 1,000 Pa·s and less than 5,000 Pa·s, the average longest dimension or average diameter of the openings is preferably 20 to 80 mm, and when the viscosity of the composition to be devolatilized is 5,000 to 10,000 Pa·s, the average longest dimension or average diameter of the openings is preferably 50 to 150 mm.

[0026] The function of the hollow space of the gap chamber of the hollow double-plate assembly is to precisely and uniformly control the temperature of the composition to be devolatilized, which flows across the upper plate and through the passage from the upper plate to the lower plate, using a heating medium. The heating medium is introduced into the hollow space of the gap chamber through a heating medium inlet, pushed through the hollow space, and withdrawn from the hollow space through a heating medium outlet. To have a heating medium of sufficient volume to precisely and uniformly control the temperature of the upper plate, lower plate, and passage walls, and thereby precisely and uniformly control the temperature of the composition to be devolatilized, which flows across the upper plate and through the passage from the upper plate to the lower plate, the height of the hollow space of the gap chamber is preferably 2 to 50 mm, more preferably 2 to 20 mm, even more preferably 4 to 12 mm, and most preferably 6 to 8 mm. The height of the hollow space is the distance between the lower surface of the upper plate and the upper surface of the lower plate. If the upper and lower plates are not parallel to each other, the height of the hollow space is the average distance between the lower surface of the upper plate and the upper surface of the lower plate, which is the sum of the height distances of adjacent vertical sections of the hollow space divided by the number of adjacent vertical sections.

[0027] The present invention is not specifically limited with respect to the shape of the heating medium inlet and outlet connected to the hollow space of the void chamber of the hollow double-plate assembly. For example, each of the inlet and outlet is a line, preferably a pipe extending into the hollow space through an opening in the side wall surrounding the void chamber. Both the inlet and outlet may be located on one side of the hollow double-plate assembly, or may be located on opposite sides of the hollow double-plate assembly. Alternatively, each of the inlet and outlet is a line, preferably a pipe extending into the hollow space through an opening in the upper plate or the lower plate. Still alternatively, one of the inlet and outlet is a line, preferably a pipe extending into the hollow space through an opening in the side wall surrounding the void chamber, while the other of the inlet and outlet is a line, preferably a pipe extending into the hollow space through an opening in the upper plate or the lower plate.

[0028] To achieve uniform distribution of the heating medium in the hollow space of the cavity chamber, one or more, preferably 1 to 10, and even more preferably 2 to 5, baffles arranged at least approximately vertically are preferably arranged in the hollow space of the cavity chamber to guide the heating medium in the hollow space of the cavity chamber, extending over a portion of the hollow space. "At least approximately vertical" in this context means that the angle between the baffle and the vertical direction is at most 10°, preferably at most 5°, more preferably at most 1°, and most preferably 0°. Particularly good results are obtained when the baffles are arranged at least approximately perpendicular to the longitudinal axis of the hollow double-plate assembly. "At least approximately perpendicular" in this context means that the angle between the baffle and the longitudinal direction of the hollow double-plate assembly is at most 80 to 100°, preferably 85 to 95°, more preferably at most 89 to 91°, and most preferably 90°. In a preferred embodiment, at least some of the adjacent baffles extend from opposite side walls of the cavity chamber in a direction approximately perpendicular to the longitudinal axis of the hollow double-plate assembly. In a further preferred embodiment, all adjacent baffles extend from opposite side walls of the cavity chamber in a direction generally perpendicular to the longitudinal axis of the hollow double-plate assembly.

[0029] According to the invention, at least one section of at least one heatable tray and / or at least one heatable distributor comprises the aforementioned hollow double-plate assembly, and it is preferred that at least 50%, more preferably at least 80%, even more preferably at least 90%, even more preferably at least 95%, and most preferably all, of the area of ​​the heatable tray and / or at least one heatable distributor, when viewed in its horizontal plane, is formed from the hollow double-plate assembly.

[0030] Alternatively, at least one heatable distributor has an upstream end and a downstream end, and the hollow double-plate assembly embodied as described above is located at or before the downstream end. According to the invention, the heatable distributor is connected to its upstream end with an inlet for the composition to be devolatilized.

[0031] When the heatable tray and / or heatable dispenser exceeds a certain size, it is no longer practical to make the heatable tray and / or dispenser from one hollow double-plate assembly, but it is practical to make the heatable tray and / or dispenser from two or more hollow double-plate assemblies. In this regard, at least one heatable tray and / or at least one heatable dispenser preferably comprises 1 to 10, more preferably 2 to 5, and most preferably 2 to 4, such as 3, of the aforementioned hollow double-plate assemblies. When at least one heatable tray and / or at least one heatable dispenser comprises two or more hollow double-plate assemblies, the two or more hollow double-plate assemblies are preferably arranged side by side. For example, adjacent double-plate assemblies are connected to each other by welding or one or more fasteners. To achieve uniform distribution of the composition to be devolatilized on the surface of at least one heatable tray and / or at least one heatable distributor, a further development of the concept of the present invention suggests disposing a perforated weir extending at least approximately vertically between two adjacent double-plate assemblies, preferably extending the entire length or width of at least one heatable tray and / or at least one heatable distributor so that the composition can flow from one hollow double-plate assembly to the adjacent hollow double-plate assembly only through the openings of the perforated weir. For example, the perforated weir has a height of 20 to 50 mm, preferably 30 to 40 mm. In a preferred embodiment, the perforated weir further comprises one or more holes that allow one or more fasteners to connect adjacent double-plate assemblies to each other.

[0032] Particularly good results are obtained when the total area of ​​all openings in the perforated weir is 1-30%, preferably 10-20%, of the total surface area of ​​the perforated weir. It is further preferred that the openings in the perforated weir have a circular cross-sectional shape, and that at least 50%, preferably at least 80%, more preferably at least 95%, and most preferably all of the openings in the perforated weir have at least substantially the same diameter, where at least substantially the same diameter means that the openings have diameters that differ from the average diameter of all openings by no more than 20%, preferably no more than 10%, more preferably no more than 5%, and most preferably no more than 1%. For example, the openings in the perforated weir have a circular cross-sectional shape and a diameter of 5-30 mm, preferably 10-20 mm.

[0033] According to a further particularly preferred embodiment of the present invention, the devolatilization apparatus comprises one heatable distributor and 2 to 20, preferably 5 to 15, more preferably 7 to 12, heatable trays. Each of the heatable trays preferably comprises, across its entire area, when viewed in a horizontal plane, one or more of the aforementioned hollow double-plate assemblies. The heatable distributor comprises, across its entire area, when viewed in a horizontal plane, one or more of the aforementioned hollow double-plate assemblies, or alternatively, the heatable distributor comprises, at or before its downstream end, one or more of the aforementioned hollow double-plate assemblies, while the upstream end is embodied differently. Preferably, the upstream end of the distributor is connected to an inlet for the composition to be devolatilized. The distributor may be flanged to the devolatilization apparatus for ease of installation and maintenance.

[0034] According to a further preferred embodiment of the present invention, the volatilization device comprises a cartridge or frame, each comprising a tray support element on which a heatable tray is removably or fixedly arranged. For example, the cartridge may comprise several beams arranged at least approximately horizontally, preferably spaced apart from one another to border an interior space, such as a hollow cylindrical interior space. At least approximately horizontal in this context means that the angle between the beam and the horizontal is at most 10°, preferably at most 5°, more preferably at most 1°, and most preferably 0°. It is further preferred that the support elements are fixed to the beams so that the heatable tray can be placed on the support elements. Preferably, the support elements are annular support elements. The cartridge may further comprise one central inlet line for the heating medium and one central outlet line for the heating medium, the inlet line for the heating medium being connectable to the inlets of the heatable tray and the distributor, and the outlet line for the heating medium being connectable to the outlets of the heatable tray and the distributor. Therefore, preferably all heatable trays share one common inlet for the heating medium and one common outlet for the heating medium within the cartridge, so that all heatable trays are connected to one heating medium circulation pipe.

[0035] Also, if the volatilization device does not comprise a cartridge or frame, each of which comprises a tray support element on which the heatable trays are removably or fixedly arranged, it is preferred that all heatable trays share one common inlet for the heating medium and one common outlet for the heating medium, preferably so that all heatable trays are connected to one heating medium circulation pipe.

[0036] Preferably, the devolatilizer is embodied as a static devolatilizer, i.e. the devolatilizer has no moving parts.

[0037] Additionally, the devolatilizer may include a pump for generating subatmospheric pressure within the vessel during operation of the devolatilizer.

[0038] In a further development of the idea of ​​the present invention, it is suggested that the container has a central inlet for the heating medium and a central outlet for the heating medium, the inlets for the heating medium of the heatable tray and the distributor are connected to the central inlet for the heating medium via lines, and the outlets for the heating medium of the heatable tray and the distributor are connected to the central outlet for the heating medium via lines.

[0039] According to another aspect, the present invention relates to a heatable tray, wherein at least one section of the heatable tray comprises a hollow double-plate assembly comprising an upper plate and a lower plate arranged one on top of the other but spaced apart such that a void chamber is defined between the upper and lower plates, each of both plates having a plurality of openings, each opening of the upper plate being surrounded by a wall extending through the void chamber and surrounding the opening of the lower plate to form a plurality of passages fluid-tightly separated from the hollow space defined in the void chamber between the passages, the hollow space being connected to an inlet for a heating medium and an outlet for a heating medium, the upper and lower plates of the hollow double-plate assembly being connected to each other at their sides via side walls between which a void chamber is defined, and at least one heatable tray is surrounded by a non-perforated weir.

[0040] In a further aspect, the present invention relates to a method for devolatilizing a composition comprising volatile components, comprising the steps of: supplying the composition to an inlet of the aforementioned devolatilizing apparatus; supplying a heating medium to at least one heatable tray and / or optionally at least one heatable distributor; drawing gas through the gas outlet; and drawing the devolatilized composition through the devolatilized composition outlet.

[0041] Preferably, a polymer composition containing a monomer and a solvent is used as the composition to be devolatilized.

[0042] For example, the composition to be devolatilized may have a viscosity of 1 to 10,000 Pa·s, measured using a plate-plate, cone-plate, or cylinder rheometer at devolatilization operating temperatures defined by the physical properties of different feed polymer solutions.

[0043] The pressure and temperature adjusted within the vessel during the above method depend on the specific composition being devolatilized. For example, the pressure within the vessel may be adjusted to 0.1 to 1500 kPa, preferably 0.1 to 200 kPa, such as 0.5 kPa, 1 kPa, 3 kPa, 5 kPa, 10 kPa, 20 kPa, 50 kPa, 80 kPa, 100 kPa, 200 kPa, 500 kPa, 800 kPa, 1000 kPa, or 1300 kPa, and the heating medium within each hollow space of the hollow double-plate assembly may be adjusted to 40 to 300°C, preferably 70 to 250°C, such as 50°C, 60°C, 70°C, 80°C, 100°C, 130°C, 150°C, 170°C, 190°C, 210°C, 230°C, 250°C, 270°C, or 290°C. For example, sub-atmospheric pressure, such as a pressure greater than 0 kPa and less than or equal to 20 kPa, or overpressure, such as a pressure greater than 100 kPa and less than or equal to 1,000 kPa, may be regulated within the vessel.

[0044] Suitable examples of polymer compositions to be devolatilized are compositions based on polyacrylonitrile, polylactic acid, polyolefins, polyolefin elastomers, and / or synthetic rubbers.

[0045] In a further development of the concept of the present invention, it is suggested that the method involves devolatilizing a composition, the composition being a mixture containing i) at least one heat-sensitive polymer and / or heat-sensitive monomer, and ii) at least one non-heat-sensitive polymer and / or non-heat-sensitive monomer. In this embodiment, the method is carried out in a devolatilization apparatus comprising at least one, preferably at least two, trays in an upper section of a vessel, each having a hollow double-plate assembly, and at least one, preferably at least two, trays in a lower section of the vessel, each having a hollow double-plate assembly, wherein the hollow double-plate assembly of the trays installed in the upper section of the vessel is preferably adjusted to a relatively low temperature to remove heat-sensitive components in the upper section of the vessel, while the hollow double-plate assembly of the trays installed in the lower section of the vessel is preferably adjusted to a higher temperature to remove non-heat-sensitive components in the lower section of the vessel.

[0046] The process according to the invention makes it possible to reduce the content of non-polymeric compounds in the polymer composition to less than 600,000 ppm, preferably less than 200,000 ppm, more preferably less than 100 ppm, most preferably less than 10 ppm.

[0047] The present patent application will now be described, by way of example only, with reference to preferred embodiments and the enclosed drawings. [Brief explanation of the drawings]

[0048] [Figure 1] 1 is a schematic vertical cross-sectional view of a volatilization device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view of a heatable tray of the volatilization apparatus shown in FIG. 1. [Figure 3] 3 is a cross-sectional view of the hollow double plate assembly of the heatable tray shown in FIG. 2. [Figure 4a] 1 is a schematic cross-sectional view of a heatable distributor that may be included in a devolatilization apparatus according to the present invention. [Figure 4b] FIG. 1 is a schematic top view of a heatable distributor that may be included in a devolatilization apparatus according to the present invention. [Figure 5] FIG. 1 is a schematic diagram of a cartridge for holding a heatable tray that may be included in a devolatilization apparatus according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0049] Devolatilization apparatus 10 for devolatilizing a composition containing volatile components, such as for devolatilizing a solid or liquid polymer composition containing unreacted monomer and solvent, shown in FIG. 1, includes a vessel 12 with an inlet line 14 for the composition to be devolatilized, an outlet line 16 for the devolatilized composition, an outlet line 18 for gas, and nine heatable trays 20, 20′ arranged one on top of the other, with adjacent trays rotated 90 degrees. As shown in more detail in FIGS. 2 and 3, each of heatable trays 20, 20′ includes three side-by-side hollow double-plate assemblies 22, 22′, 22″, with adjacent hollow double-plate assemblies 22, 22′, 22″ welded together and with at least a substantially vertically disposed perforated weir 24 disposed between two adjacent hollow double-plate assemblies 22, 22′, 22″. Trays 20, 20′ are provided with vertically disposed non-perforated weirs 26 around their peripheries. , with the lower portion of the non-perforated weir 26 functioning as a sidewall bordering the void chamber. Thus, in effect, the non-perforated weir 26 is a combined weir and sidewall. Each of the trays 20, 20' extends across approximately 80% of the cross-sectional area of ​​the vessel 12. Each of the hollow double-plate assemblies 22, 22', 22" comprises an upper plate 28 and a lower plate 30 disposed one on top of the other but spaced apart such that a void chamber 32 is defined between the upper plate 28 and the lower plate 30. Each of the upper plate 28 and the lower plate 30 includes a plurality of openings 34, each of which is surrounded by a wall 36 extending through the void chamber 32 and surrounding the opening in the lower plate to form a plurality of passages 38 that are fluid-tightly separated from the hollow space 40 defined in the void chamber 32 between the passages 38. Each of the hollow double-plate assemblies 22, 22', 22" has a heating medium inlet line 42, 42', 42" and a heating medium outlet line 44', 44" (only two of which are shown in Figure 2). The heating medium inlet lines 42, 42" and the heating medium outlet line 44" of the two outer hollow double-plate assemblies 22, 22" enter the two outer hollow double-plate assemblies 22, 22" from below, while the heating medium inlet line 42' and the heating medium outlet line 44' of the central hollow double-plate assembly 22' enter the central hollow double-plate assembly 22' from above.Each heating medium inlet line 42, 42', 42" and each heating medium outlet line 44', 44" actually consists of two pipes 46, 46' which are connected to each other by a flange 48 located inside the vessel 12. The alternative arrangement of the heating medium inlet lines 42, 42', 42" and heating medium outlet lines 44', 44" facilitates installation. During installation, the vessel 12 is laid horizontally, and the hollow double-plate assemblies 22, 22′, 22″ are in a vertical position facing the installer. The installer installs the outermost hollow double-plate assembly 22, 22″ and connects the pipe 46′ to the pipe 46 of the outermost hollow double-plate assembly 22, 22″ by tightening the flange 48, while the central hollow double-plate assembly 22′ has not yet been installed, so there is a space in the center that allows the installer to reach the flange 48 from below. If the inlet line 42′ and outlet line 44′ for the heating medium were also connected to the central hollow double-plate assembly 22′ from below, the installer would not be able to connect the two pipes to the central hollow double-plate assembly 22′, but the installer could connect the two pipes to the central hollow double-plate assembly 22′ from above.

[0050] 4a and 4b show a heatable distributor 50 that can be included in a devolatilization apparatus according to the present invention. The heatable distributor 50 has an upstream end 52 and a downstream end 54, and just before the downstream end 54 are arranged three hollow double-plate assemblies 22, 22', 22" embodied as described above. Furthermore, an inlet line 60 for the composition to be devolatilized is arranged at the upstream end 52 of the heatable distributor 50. During operation of the distributor, the liquid level may reach the dashed line 61.

[0051] FIG. 5 shows a cartridge 62 for holding a heatable tray that can be included in a devolatilization apparatus according to the present invention. The cartridge 62 comprises several horizontally arranged beams 64 spaced apart from one another to outline a hollow cylindrical interior space. Several annular tray support elements 66 are fixed to the beams 64 so that a heatable tray 20 (only one tray is shown in FIG. 5 ) can be removably placed on the tray support elements 66. The cartridge 62 further comprises one central inlet line 68 for a heating medium and one central outlet line 70 for the heating medium, the inlet line 68 for the heating medium being connectable to the inlet line of the heatable tray 20, and the outlet line 70 for the heating medium being connectable to the outlet line of the heatable tray. [Explanation of symbols]

[0052] 10 Devolatilization device 12 containers 14 Inlet line for composition to be devolatilized 16 Exit line for devolatilized composition 18 Gas outlet line 20 heatable trays 20' Heatable Tray 22 Hollow double plate assembly 22' Hollow Double Plate Assembly 22" Hollow Double Plate Assembly 24 Perforated Weir 26 Non-perforated weir 28 Upper plate of hollow double plate assembly 30 Lower plate of hollow double plate assembly 32 Hollow double plate assembly void chamber 34 Openings in upper or lower plates 36 Passageway Wall 38 Passage of hollow double plate assembly 40 hollow space of hollow double plate assembly 42 Heating medium inlet line 42' Heating medium inlet line 42" inlet line for heating medium 44' Heating medium outlet line 44" outlet line for heating medium 46 Pipe 46' Pipe 48 flange 50 Heatable distributor 52 upstream end of heatable distributor 54 Downstream end of heatable distributor 60 Heatable distributor inlet line 61 Liquid level during distributor operation 62 cartridges 64 cartridge beam 66 Cartridge tray support element 68 Cartridge central inlet line 70 Cartridge central exit line

Claims

1. 1. A devolatilization apparatus for devolatilizing a composition containing volatile components, such as for devolatilizing a solid or liquid polymer composition containing unreacted monomers, solvents, and / or by-products, comprising: The volatilizing device is a vessel, at least one inlet for the composition to be devolatilized; at least one outlet for the devolatilized composition; at least one outlet for gas; at least one heatable tray; Optionally, at least one heatable distributor; A container comprising: Equipped with At least one section of the at least one heatable tray and / or the at least one heatable distributor comprises a hollow double-plate assembly comprising an upper plate and a lower plate arranged one on top of the other but spaced apart such that a void chamber is defined between the upper plate and the lower plate; each of the plates having a plurality of openings; each opening in the upper plate is surrounded by a wall extending through the void chamber and surrounding the opening in the lower plate to form a plurality of the passages that are fluid-tightly separated from hollow spaces defined in the void chambers between the passages; The hollow space is connected to an inlet for a heating medium and an outlet for a heating medium, the upper plate and the lower plate of the hollow double-plate assembly are connected to each other at the sides of the upper plate and the lower plate via side walls defining the cavity therebetween; A devolatilizer, wherein the at least one heatable tray and / or the at least one heatable distributor extends over 10-99% of the cross-sectional area of ​​the vessel and is surrounded by a non-perforated weir.

2. The volatilizing apparatus according to claim 1 , wherein the upper plate and the lower plate are disposed at least approximately parallel to each other.

3. 3. The devolatilization apparatus according to claim 1 or 2, wherein the at least one heatable tray and / or the at least one heatable distributor extends over 20 to 95%, preferably 40 to 90%, most preferably 70 to 90% of the cross-sectional area of ​​the vessel.

4. A volatilization apparatus as described in any one of claims 1 to 3, wherein the non-perforated weir surrounding the at least one heatable tray and / or the at least one heatable distributor is arranged at least approximately vertically and / or at least approximately parallel to the longitudinal axis of the vessel, preferably extending upward when viewed from the top of the at least one heatable tray and / or the at least one heatable distributor.

5. the upper plate and the lower plate have the same number of openings; The volatilization apparatus according to any one of claims 1 to 4, wherein the total area of ​​all openings in the upper plate is preferably 0.1 to 40%, preferably 1 to 10%, of the total surface area of ​​the upper plate, and the total area of ​​all openings in the lower plate is 0.1 to 40%, preferably 1 to 10%, of the total surface area of ​​the lower plate.

6. the openings in the upper and lower plates have a circular cross-sectional shape; at least 50%, preferably at least 80%, more preferably at least 95%, and most preferably all of the openings in the upper and lower plates have at least substantially the same diameter; 6. A devolatilizer according to any one of claims 1 to 5, wherein at least substantially the same diameter means that any of the openings has a diameter that differs from the average diameter of all of the openings by no more than 20%, preferably no more than 10%, more preferably no more than 5%, and most preferably no more than 1%.

7. The volatilization apparatus according to any one of claims 1 to 6, wherein the height of the hollow space of the void chamber is 2 to 50 mm, preferably 2 to 20 mm, more preferably 4 to 12 mm, and most preferably 6 to 8 mm.

8. 8. The devolatilizer of claim 1, wherein the inlet for heating medium and the outlet for heating medium are pipes, the pipes extending through one or two of the side walls.

9. 9. A devolatilization apparatus according to any one of claims 1 to 8, wherein, when viewed in a horizontal plane, at least 50%, more preferably at least 80%, even more preferably at least 90%, even more preferably at least 95%, and most preferably all, of the area of ​​the heatable tray and / or the at least one heatable distributor is formed from the hollow double-plate assembly.

10. at least one heatable distributor having an upstream end and a downstream end; a hollow double plate assembly is disposed at or before the downstream end; 10. Devolatilizer according to any one of claims 1 to 9, preferably wherein the upstream end is connected to the inlet for the composition to be devolatilized.

11. the at least one heatable tray and / or the at least one heatable distributor comprises 1 to 10, preferably 2 to 5, more preferably 2 to 4 hollow double-plate assemblies; the at least one heatable tray and / or the at least one heatable distributor comprises at least two hollow double-plate assemblies arranged side by side; 11. The devolatilization apparatus according to claim 1, wherein a perforated weir is disposed at least substantially vertically between two adjacent hollow double-plate assemblies.

12. one heatable distributor; 2 to 20, preferably 5 to 15, more preferably 7 to 12 heatable trays; Equipped with each of the heatable trays comprises one or more hollow double-plate assemblies across the entire area of ​​the heatable tray when viewed in a horizontal plane; 12. The devolatilization apparatus according to claim 1, wherein the heatable distributor comprises one or more hollow double-plate assemblies at least at the downstream end of the heatable distributor or before the downstream end of the heatable distributor.

13. the devolatilization device comprises a cartridge comprising a tray support element on which the heatable tray is removably or fixedly disposed; the cartridge preferably comprises several beams arranged at least approximately horizontally and spaced apart from one another to border an interior space, 13. The devolatilization apparatus of claim 1, wherein a support element is fixed to the beam so that the heatable tray can be placed on the support element.

14. The cartridge is one central inlet line for the heating medium; One central outlet line for the heating medium; Furthermore, 14. The devolatilization apparatus of claim 13, wherein the inlet line for the heating medium is connectable to the inlet of the heatable tray and the distributor, and the outlet line for the heating medium is connectable to the outlet of the heatable tray and the distributor.

15. A heatable tray comprising: At least one section of the heatable tray comprises a hollow double-plate assembly comprising an upper plate and a lower plate disposed one on top of the other but spaced apart such that a void chamber is defined between the upper and lower plates; each of the plates having a plurality of openings; each opening in the upper plate is surrounded by a wall extending through the void chamber and surrounding the opening in the lower plate to form a plurality of the passages that are fluid-tightly separated from hollow spaces defined in the void chambers between the passages; The hollow space is connected to an inlet for a heating medium and an outlet for a heating medium, the upper plate and the lower plate of the hollow double-plate assembly are connected to each other at the sides of the upper plate and the lower plate via side walls defining the cavity therebetween; The at least one heatable tray is surrounded by a non-perforated weir.

16. 1. A method for devolatilizing a composition containing volatile components, comprising: feeding the composition to the inlet of the devolatilizer of any one of claims 1 to 14; supplying a heating medium to the at least one heatable tray and / or optionally the at least one heatable distributor; drawing gas from said gas outlet; withdrawing the devolatilized composition from said devolatilized composition outlet; A method comprising:

17. The composition is devolatilized, The composition comprises: i) at least one thermosensitive polymer and / or thermosensitive monomer, and ii) at least one non-thermosensitive polymer and / or non-thermosensitive monomer; a mixture comprising: The method is carried out in a devolatilizer, the devolatilizer comprising: in the upper region of the container, at least one, preferably at least two trays, each comprising a hollow double-plate assembly; in the lower section of the container, at least one, preferably at least two trays, each of which comprises a hollow double-plate assembly; Equipped with 17. The method of claim 16, wherein the hollow double-plate assembly of the tray installed in the upper region of the container is adjusted to a relatively low temperature to remove the heat-sensitive components in the upper region of the container, while the hollow double-plate assembly of the tray installed in the lower region of the container is adjusted to a higher temperature to remove the heat-insensitive components in the lower region of the container.

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