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CN-122028966-A - Discontinuously operating desublimation device with at least one perforated plate

CN122028966ACN 122028966 ACN122028966 ACN 122028966ACN-122028966-A

Abstract

The invention relates to a discontinuously operating desublimator (1) for removing at least one gas component to be desublimated from a gas mixture flow, comprising a housing wall (7), an inlet (2) in the housing wall (7) for supplying the gas mixture flow to the desublimator (1), an outlet (6) in the housing wall (7) for removing a treated gas mixture flow from the desublimator (1), a desublimation zone (4) with temperature-controllable flow channel walls, a gas inlet distributor space (3) between the inlet (2) and the desublimation zone (4) and a gas outlet space (5) between the outlet (6) and the desublimation zone (4), wherein the temperature of the flow channel walls is controllable such that during a loading process the at least one gas component to be desublimated is desublimated at the flow channel walls and such that during a subsequent melting process the at least one gas component to be desublimated during the loading process is melted at the flow channel walls. According to the invention, at least a first perforated plate (8) is arranged in the gas inlet distributor space (3) for evenly distributing the gas mixture flow through the flow channels created by the flow channel walls of the desublimation zone (4), the distance (A T ) of the geometric centre of gravity of said plate from the desublimation zone (4) being in the range of 0 to A max , preferably 0 to 0.5 In the range of A max , and more preferably in the range of 0.03 to 0.3 A max , wherein a max corresponds to the distance between the inlet face (9) of the inlet (2) and the desublimation zone (4), and wherein the porosity of the at least first perforated plate is in the range of 5% to 50%, preferably 10% to 30%, more preferably 10% to 20%. The invention further provides a method of operating the desublimator (1) of the invention.

Inventors

  • A. Noel
  • S. T. Wupenkamp
  • M. Paziki
  • The husky husband of F

Assignees

  • 巴斯夫欧洲公司

Dates

Publication Date
20260512
Application Date
20241002
Priority Date
20231012

Claims (15)

  1. 1. A discontinuously operating desublimator (1) for removing at least one gas component to be desublimated from a gas mixture flow, the desublimator comprising A housing wall (7) as an outer boundary, An inlet (2) in the housing wall (7) for supplying the gas mixture stream to the desublimator (1), An outlet (6) in the housing wall (7) for removing a treated gas mixture stream from the desublimator (1), A desublimation zone (4) having temperature controllable flow channel walls, wherein the temperature of the flow channel walls is controllable such that during a loading process the at least one gas component to be desublimated at the flow channel walls, and such that during a subsequent melting process the at least one gas component desublimated during the loading process melts at the flow channel walls, A gas inlet distributor space (3) between the inlet (2) and the desublimation zone (4), and A gas outlet space (5) between the outlet (6) and the desublimation zone (4), Wherein the method comprises the steps of At least a first perforated plate (8) is arranged in the gas inlet distributor space (3) for evenly distributing the gas mixture flow through the flow channels created by the flow channel walls of the desublimation zone (4), The distance (A T ) of the geometric centre of gravity of the plate from the desublimation zone (4) is in the range of 0 to A max , preferably 0 to 0.5 In the range of A max , and more preferably in the range of 0.03 to 0.3 Within the range of A max , wherein A max corresponds to the distance between the inlet region (9) of the inlet (2) and the desublimation zone (4), and Wherein the porosity of the at least first perforated plate (8) is in the range of 5% to 50%, preferably in the range of 10% to 30%, more preferably in the range of 10% to 20%, and very preferably in the range of 5% to 20%.
  2. 2. The desublimator (1) according to claim 1, wherein the at least first perforated plate (8) extends over its width up to two opposite lateral housing walls (7) of the desublimator (1), and is preferably at a distance from the walls of the desublimator in the range of 0mm to 10 mm, and more preferably in the range of 0mm to 1mm.
  3. 3. The desublimation apparatus (1) according to one of claims 1 or 2, wherein the at least first perforated plate (8) covers the entire desublimation zone (4) and is at a distance from the wall of the desublimation apparatus in the range of 0mm to 10mm, preferably in the range of 0mm to 1 mm.
  4. 4. The desublimator (1) according to any of the preceding claims, wherein in case of a plurality of perforated plates, the respective distance between respective adjacent perforated plates is between 0 and 0.50 A max , preferably in the range of 0 to 0.25 A max , wherein a max corresponds to the distance between the inlet region (9) and the desublimation zone (4).
  5. 5. The desublimator (1) according to any of the preceding claims, wherein the holes of the at least first perforated plate (8) have different equivalent diameters, wherein the equivalent diameters correspond to the diameters of circles of equal area, and wherein the equivalent diameters of the individual holes are preferably in the range of 0.3 mm to 50.0 mm, more preferably in the range of 1.0 mm to 25.0 mm, and very preferably in the range of 5.0 mm to 20.0 mm.
  6. 6. The desublimator (1) according to claim 5, wherein the holes of the at least first perforated plate (8) located at a distance from the inlet area (9) in the range of 0.0 mm to L/X mm have a larger equivalent diameter than the more distant holes of the perforated plate (8), wherein L is the length of the longitudinal axis of the gas inlet distributor space (3), and X has a value of 1.1 to 10.0 Values in the range of L.
  7. 7. The desublimator (1) according to any of the preceding claims, wherein at least the first perforated plate (8) has circular, oblong, elliptical, oval, rectangular or polygonal holes.
  8. 8. The desublimator (1) according to any of the preceding claims, wherein the number of holes of the at least first perforated plate (8) is in the range of 100 to 15,000 per m2 of the plate area, preferably in the range of 1000 to 4000 per m2 of the plate area, and the holes preferably correspond to an equilateral triangle pattern.
  9. 9. The desublimator (1) according to any of the preceding claims, wherein the hole spacing of the holes of the at least first perforated plate (8) is in the range of 5 mm to 50 mm, preferably in the range of 20mm to 30 mm.
  10. 10. The desublimator (1) according to any of the preceding claims, wherein the holes of the at least first perforated plate (8), preferably most of the holes, more preferably all of the holes, are arranged such that the flow channel walls projected perpendicularly onto the plane of the at least first perforated plate (8) are patterned with the geometric center of gravity of the holes, Wherein in each case one of the projected flow channel walls in the pattern intersects the nearest geometric center of gravity of the corresponding hole or has a maximum of 0.50 with the nearest geometric center of gravity of the corresponding hole D Mit , or 0.50 from the nearest geometric center of gravity of the corresponding hole D Mit , wherein D Mit corresponds to an equivalent diameter geometrically averaged over all of the flow channels, and wherein each individual equivalent diameter corresponds to an equal area circle of the respective flow channel, and each individual equivalent diameter is measured at the inlet of the desublimation zone (4).
  11. 11. The desublimator (1) according to any one of the preceding claims, wherein the desublimator (1) has a horizontal longitudinal axis oriented at right angles to the longitudinal axis of the flow channel of the desublimation zone (4) and the gas inlet distributor space (3) is arranged above the desublimation zone (4).
  12. 12. The desublimation apparatus (1) according to any of the preceding claims, wherein the flow channel walls are defined by outer walls of tube bundles, finned tubes, finned tube bundles, lamellar bodies, honeycomb bodies and/or plate-like bodies.
  13. 13. A method of operating a desublimator (1) according to any one of the preceding claims, wherein during the process of loading the desublimator (1) the gas mixture flow comprising at least one gas component to be desublimated is inflowing at the inlet (2) at a mass flow rate of at least 0.01 kg/s, wherein the temperature is in the range from above the desublimation temperature of the at least one gas component to be desublimated at a given pressure to above 300 ℃ above the desublimation temperature at the given pressure, and wherein the absolute pressure is in the range from 0.1 bar to 10.00 bar, preferably in the range from 0.5 bar to 1.5 bar, more preferably in the range from 1.05 bar to 1.10 bar, The flow channel walls of the desublimation zone (4) are cooled to a temperature in the range from 150 ℃ below the desublimation temperature at the given pressure to 1 ℃ below the desublimation temperature at the given pressure, and The at least one gas component to be desublimated in the gas mixture stream is at least partially desublimated, preferably in the range from 10 to 100% by weight based on the at least one gas component to be desublimated in the gas mixture stream flowing in at the inlet (2), and more preferably in the range from 50 to 100% by weight based on the at least one gas component to be desublimated in the gas mixture stream flowing in at the inlet (2).
  14. 14. Method according to claim 13, wherein during the loading process the pressure drop between the inlet (2) and the outlet of the desublimator (1) does not exceed 200 mbar, preferably does not exceed 80 mbar, and more preferably does not exceed 20 mbar.
  15. 15. A method according to claim 13 or 14, wherein the at least one gas component to be desublimated comprises mainly phthalic anhydride, preferably only phthalic anhydride, in its mass fraction.

Description

Discontinuously operating desublimation device with at least one perforated plate The invention relates to a discontinuously operating desublimator for removing at least one gas component to be desublimated from a gas mixture flow, comprising a housing wall, an inlet in the housing wall for supplying the gas mixture flow, an outlet in the housing wall for removing the treated gas mixture flow, and A desublimation zone with temperature-controllable flow channel walls, Wherein the temperature of the flow channel wall is controllable such that during the loading process at least one gas component to be desublimated at the flow channel wall and such that during a subsequent melting process at least one gas component desublimated during the loading process melts at the flow channel wall. In addition, the desublimation apparatus includes a gas inlet distributor space between the inlet and the desublimation zone and a gas outlet space between the outlet and the desublimation zone. Known discontinuously operating sublimators have flow channel walls in their interior which may take the form of finned tube bundles. The finned tube is characterized in that its tube is surrounded by fins, and the fins can be heated or cooled by fluid flowing through the tube. Thus, during the loading process, the gas component to be desublimated, which is present in the gas or gas-vapor mixture, is obtained by desublimating the gas component to be desublimated at the cooling fins. During the subsequent melting process, the gas component sublimated on the now heated wall of the finned tube melts and is discharged from the sublimator. Instead of finned tubes, other embodiments of flow channel walls (e.g. thin layers or honeycombs) may also be provided in the desublimator. When a lamina is used, the cooling or heating medium is typically passed through fluid conduits, which are typically disposed on the outside of the housing wall such that heat is transferred substantially between the outside fluid conduits and the housing wall and between the housing wall and the lamina. In such above-mentioned desublimators, during the loading process, the gas mixture flow is poorly distributed in flowing through the flow channels, which means that the gas components to be desublimated are unevenly desublimated at the flow channel walls. As a result, during the loading process, the pressure drop between the inlet and outlet of the desublimator increases more rapidly, and therefore the desublimator must be regenerated at shorter time intervals, even if its maximum loading capacity has not been reached yet. Here, the desublimator is usually regenerated by a melting process and optionally a subsequent sub-cooling process. DE3407104 A1 discloses discontinuously operated desublimators for separating products from a gas mixture, which have, inside them, thin layers fixed to the lateral housing walls as flow channel walls. The coolant or heating medium passes through fluid conduits which are arranged only on the outside of the lateral housing wall. In the case of a heated lamina, heat is transferred from the fluid conduit to the lateral housing wall and from the lateral housing wall to the lamina, while in the case of a cooled lamina, heat is transferred from the lamina to the lateral housing wall and from the lateral housing wall to the fluid conduit. Desublimators are used, for example, for the production of Phthalic Anhydride (PA). However, since the sublimator is only heated or cooled externally, considerable parasitic heat losses to the environment are generated here. However, in the case of larger desublimators, for example with an internal volume of more than 1m 3, the heat transfer between the lateral housing wall and the lamina that is moved further away from the lateral housing wall during operation of the desublimator is generally too low, so that a temperature gradient is established within the lamina during the loading process, and this results in different desublimation rates. As a result, the pressure drop rises faster during the loading process, and therefore the desublimator must be regenerated at shorter intervals, even if its maximum loading capacity has not been reached. DE102015101398 A1 discloses a discontinuously operated desublimator of cylindrical design for removing the gas components to be desublimated from a gas stream. The desublimator comprises a housing comprising an internal fluid conduit and as flow channel walls lamellae arranged on the inner face of the housing wall and directed inwards. The thin layer can also be cooled by a coolant flowing through the internal fluid line or can be heated by a heating medium flowing through the internal fluid line. However, if such desublimators have an internal volume of, for example, more than 1m 3, the heat transfer from the internal fluid conduit to the point in the lamina that is farther away from the fluid conduit is typically too low and thus a temperature gradient is established wit