RU2021110936A - COLUMN WITH SIEVE PLATES AND METHOD OF ITS MODERNIZATION - Google Patents

Claims (23)

1. A column with sieve plates for interaction of the liquid flowing down (L) with an upward gas flow (G), having a body (1) with a vertical axis and a sieve plate assembly (2), including at least the first sieve plate (3) and the second a sieve plate (4) located next to the first sieve plate and below it, and the first sieve plate contains several overflow pipes (6), each of which includes the first part (7) protruding above the first sieve plate, the second part (8), protruding under the first sieve plate towards the second sieve plate, moreover, the first part of the overflow pipe ends with the inlet section (10) of the overflow pipe located above the first sieve plate, the second part of the overflow pipe ends above the second sieve plate with an outlet section (11) and an end safety device (9) configured to keep this outlet section (11) immersed in the liquid flowing through the overflow pipe, and each overflow tube (6) associated with the first sieve plate (3) is axially aligned with the corresponding overflow tube (6') associated with the second sieve plate (4). 2. The column according to claim 1, in which the second part (8) of the overflow pipes (6) of the first plate (3) ends above the second sieve plate (4) at a distance (h2) from the second sieve plate exceeding the height (h) of the first parts overflow pipes (6') of the second plate (4). 3. The column according to claim 1, in which the inlet section (10) of each overflow pipe (6) is located at a height of 300 mm to 2.5 m above the upper surface of the first sieve plate (3). 4. A column according to any one of the preceding claims, wherein the first sieve plate and the second sieve plate are perpendicular to the vertical axis of the housing. 5. A column according to any one of the preceding claims, wherein each overflow pipe is a vertical straight pipe. 6. A tower according to any one of the preceding claims, wherein the overflow pipes are arranged in a manner that allows liquid to flow around each overflow pipe in a radial flow evenly distributed in all radial directions around the overflow pipe. 7. A column according to any one of the preceding claims, wherein the overflow pipes are uniformly distributed in a square or triangular arrangement over at least a portion of the surface of the first tray. 8. A column according to any one of the preceding claims, wherein the cross-sectional area of the overflow pipes is between 4% and 30% of the surface area of the first sieve tray. 9. Column according to any one of the preceding claims, in which the end guard (9) is a chamber around the outlet section (11), which, when filled with liquid, acts as a water seal preventing the passage of an upward gas flow into the overflow pipe through the outlet section (eleven). 10. The column according to claim 9, in which the end guard (9) has a bottom, the surface (12) of which is located below the outlet section (11), and a peripheral wall (13) extending around the outlet section from the surface (12) of the bottom to upper edge (14) above the outlet section (11), forming said chamber. 11. A column according to any one of the preceding claims, wherein the overflow pipe has no liquid inlet or outlet other than an inlet or outlet. 12. A column according to any one of the preceding claims, wherein the sieve tray assembly (2) comprises a plurality of sieve trays, each having a plurality of said overflow pipes (6, 6') for transferring liquid to the next tray, and for each pair of adjacent sieve trays, each overflow tube associated with the top tray of that pair of adjacent trays is axially aligned with the corresponding overflow tube associated with the bottom tray of that pair. 13. The column according to claim 12, in which each sieve plate, which receives the liquid flowing down from the upstream sieve plate, does not have an inlet section of the overflow pipe, and the liquid comes from overflow pipes hanging from the overhead sieve plate. 14. A column according to any one of the preceding claims, wherein the column is a regenerator absorber in the CO ₂ removal section of the ammonia synthesis plant. 15. A method for modernizing a column with sieve plates, in particular an absorber or regenerator of the CO ₂ removal section of an ammonia plant, during which a sieve plate assembly is removed from the column and a new sieve plate assembly is installed in it, wherein: the new sieve tray assembly comprises at least a first sieve tray and a second sieve tray located next to and below the first sieve tray, and the first sieve tray contains several overflow pipes, each of which includes a first part protruding above the first sieve tray, a second part , protruding under the first sieve plate in the direction of the second sieve plate, and an end guard, moreover, the first part of the overflow pipe ends with the inlet section of the overflow pipe above the first sieve plate, the second part of the overflow tube ends above the second sieve plate with an outlet section and an end guard configured to keep said outlet section immersed in the liquid flowing through the overflow tube; and in a new sieve tray assembly, for each pair of adjacent sieve trays, each overflow tube associated with the top tray of the pair of adjacent trays is axially aligned with the corresponding overflow tube associated with the bottom tray of that pair.