Tower packing grid

Abstract: Metal vapour-liquid contact plates are disposed in face-to-face contact with respective corrugations inclined to the horizontal across a notional plane. A perforated lamella may be disposed across the notional plane. The metal packing which may also be of slit or louvered construction is disposed within a vapour-liquid contact column for the purpose of bringing about mass and heat transfer between liquid and vapour passing in opposite directions therethrough. The body portion of each plate comprises metal that has been slit to provide both surfaces thereof with a very large number of apertures with little wasted material. The metal lands defining the apertures may be twisted and angulated. The apertures in the plates trap liquid and expose it to the vapour stream on both sides of the plates affording self-spreading of the liquid and turbulent vapour flow therethrough. In this manner, the assembly affords optimal pressure drop characteristics, surface to vapour passage area ration, and vapour-liquid distribution characteristics. The laminate plate formation may also afford select flow and turbulence characteristics through capillary action between offset laminate land areas of the sheets.

Description: The present invention relates to vapour-liquid contact packing and, more particularly, to tower packing grid of the type comprising a plurality of corrugated metal sheets in face-to-face contact with opposed corrugations inclined oppositely one to the other for receiving a descending liquid flow concomitantly with an ascending vapour flow to enhance the vapour-liquid contact therebetween, the sheets including a plurality of spaced apart elongate openings spaced longitudinally from one another in parallel rows with the longitudinal axes of the openings extending transversely across the corrugations to distribute liquid across both sides of the sheets. Such tower packing material is described in for example, DE-A-2 032 292. It is also described in EP-A-0 130 745, to which reference is directed. EP-O 130 745 includes discussion of previously known vapour-liquid process towers, and tower packing used therein. Particularly, it acknowledges the widespread established practice of using passive vapour-liquid contact devices with sheets of material in face-to-face engagement in such process towers. The packing described in DE-2 032 292 has sheets in strip form with their corrugations inclined alternately in opposite directions relative to a vertical plane. The sheets are formed with apertures in the form of openings which will normally extend over the crests of the corrugations. Reference is also directed to DE-A-1 913 016 which also discloses tower packing broadly of the type described above with corrugated metal sheets in face to face contact. The corrugations are inclined laterally in opposite directions; with apertures in the form of openings extending over the crests of the corrugations. The present invention is directed at contact devices of the above type and in which a tower packing grid comprises a plurality of corrugated metal sheets in face-to-face contact with opposed corrugations inclined oppositely one to the other for receiving a descending liquid flow concomitantly with an ascending vapour flow to enhance the vapour-liquid contact therebetween. The sheets include a plurality of spaced apart elongate openings spaced longitudinally from one another in parallel rows with the longitudinal axes of the openings extending transversely across the corrugations to distribute liquid across both sides of the sheets. According to the invention, the openings are in the form of slits adapted to provide a capillary effect resulting in lateral diversion and entrainment of liquid descending over the sheets to spread the liquid across the surface area of the sheets and produce enhanced vapour-liquid contact. The slits in adjacent rows are preferably longitudinally offset from one another into alignment with the spaces between the slits. Each slit may include a coined portion. The invention will now be described by way of example and with reference to the accompanying schematic drawings wherein: Figure 1 is a cross-sectional view of a process tower in which the grid of the invention may be utilised; Figure 2 is a perspective view showing a portion of a grid in accordance with the invention; Figure 3 is a plan view of a semi finished blank for forming a corrugated plate for use in the grid of the invention; and Figure 4 shows the blank of Figure 3 corrugated for use in the grid of the invention. Figure 1 shows a process column 2 having a stack 4 of grid layers 6 constructed generally in accordance with the principles of the present invention. The grid layers are comprised of a plurality of plate sections such as that shown in Figure 4. The outer periphery of the multiple layers is contoured to fit within the process tower 2 which, as shown, is circular in cross-section. Adjacent grid layers within the column are preferably oriented orthogonally one to the other to further enhance the vapour-liquid contact and turbulence of fluids passing therethrough. The process column 2 is constructed for affording the entry of vapour through a lower vapour flow line 8 positioned near the bottom of the column. The upper region of the column 2 is likewise fitted with a liquid flow line 10 for affording the ingress of the liquid to be processed within said column. The liquid entry from the fluid flow line 10 is dispersed across the upper grid layers 6 by spray or dispension heads 12 to initiate homogeneous, descending liquid flow patterns across the stacked grids. Similarly, the vapour is introduced in the lower regions of the column for homogeneous distribution therearound and the ascension thereof through the stacked grid layers for heat and/or mass transfer with the descending liquid. The vapour is vented near the top of the column 2 through exhaust line 14 while the excess liquid collected at the bottom of said column is permitted to drain through line 16. The technique of such column operation is well known in the prior art and is, for example, set forth and shown in U.S. Patent Nos. 3,959,419 and 3,969,447. The grid portion shown in Figure 2 comprises adjacent corrugated plate members 18 stacked against one another in engagement across the corrugation edge portions. A plurality of flow channels 20 are thus formed in the grid, which channels are relatively open across the notional plane between contiguous members 18. The corrugations of contiguous members are inclined oppositely, one to the other, for providing an opposed flow of vapour and liquid across the intermediately disposed plates. Figure 3 shows a top plan view of a material blank of slit construction for utilisation in the present invention. It has a plurality of slits formed in parallel space relationship and staggered one to the other along a longitudinal direction for affording a laminar fluid flow when disposed in a vertical configuration. The plate includes slits 22 formed in rows 24 generally in parallel spaced relationship, and which may each include a coined portion. The slits 22 formed therein may be seen to provide various advantageous capillary effects and lateral entrainment of the liquid descending thereacross for purposes of vapour liquid interface reaction. The material blank of Figure 3 is shown in a corrugated configuration in Figure 4; ie, in the form in which it is used in a packing grid according to the invention.

Claims: A tower packing grid comprising a plurality of corrugated metal sheets (18) in face-to-face contact with opposed corrugations (20) inclined oppositely one to the other for receiving a descending liquid flow concomitantly with an ascending vapour flow to enhance the vapour-liquid contact therebetween, the sheets (18) including a plurality of spaced apart elongate openings spaced longitudinally from one another in parallel rows with the longitudinal axes of the openings extending transversely across the corrugations to distribute liquid across both sides of the sheets, CHARACTERISED IN THAT the openings are in the form of slits (22) adapted to provide a capillary effect resulting in lateral diversion and entrainment of liquid descending over the sheets to spread the liquid across the surface area of the sheets and produce enhanced vapour-liquid contact. A tower packing according to Claim 1 CHARACTERISED IN THAT the slits (22) in adjacent rows are longitudinally offset from one another into alignment with the spaces between the slits. A tower packing according to Claim 1 or Claim 2 CHARACTERISED IN THAT each of the slits (22) includes a coined portion.

Inventors: AXE JOHN R, CHEN GILBERT, GLASPIE DONALD L, KITTERMAN B LAYTON, AXE, JOHN R., CHEN, GILBERT, GLASPIE, DONALD L., KITTERMAN, B. LAYTON
Applicants: GLITSCH, GLITSCH, INC.
Application year: 1984
Main classification: B01J19
IPC codes: F28F25, B01J19