Fractionation apparatus with low surface area grid above tray deck

A fractional distillation apparatus comprising:

• (a) a vertical enclosed column (1) having an upper first end (20) and a lower second end (21);
• (b) a pair of vertically spaced apart multiple downcomer fractionation trays (2) comprising a lower first tray and an upper second tray, with the trays (2) extending across substantially all of the cross-sectional area of the column (1), and with the trays (2) having separate vapor passage decking sections (5) and parallel liquid collection downcomers (6, 12) distributed across the trays (2), with the liquid collection downcomers (6, 12) extending away from the tray (2) toward the second end of the column, and with perforations (28) for liquid passage being located in the liquid collection downcomers;
• and,
• (c) a layer of low surface area structured grid packing (3) resting upon the first tray of said pair of fractionation trays, the grid packing (3) comprising individual blades (8) having a vertical central portion and inclined upper and lower portions which are inclined on opposite sides of the vertical central portion of the blade, and with the layer of grid packing (3) extending toward the second tray for a distance equal to from about one-tenth to about three-fourths of the vertical distance between the first and second trays (2).

A fractional distillation apparatus comprising:

• (a) a vertical enclosed column (1) having a circular cross section and an upper first end (20) and a lower second end (21);
• (b) a pair of vertically spaced apart discoid fractionation trays (2) extending across substantially all of the cross-sectional area of the column (1), with the trays having separate substantially flat perforated decking sections (5) and liquid collection downcomers (6, 12), which downcomers extend away from the tray (2) towards the lower second end of the column (1), and with additional perforations (17,28) for liquid passage being located in the liquid collection downcomers (6,12);
• (c) a layer of low surface area structured grid packing (3), resting upon a lower first tray (2) of said pair of fractionation trays;
• the grid packing (3) comprising a plurality of parallel blades (8) having at least two spaced apart bends yielding inclined surfaces, with the blades being connected by perpendicular stringers and,
• (d) a layer of high surface area packing (4) located above the layer of low surface area structured grid packing (3).

A vapor-liquid contacting apparatus comprising:

• (a) a vertical enclosed column (1) having a circular cross section, an upper first end (20) and a lower second end (21);
• (b) a plurality of evenly spaced-apart fractionation trays including a pair of vertically spaced apart fractionation trays (2) comprising a lower first and an upper second tray, with the trays being substantially planar and extending horizontally across substantially all of the cross-sectional area of the column (1), and with the trays (2) having perforations (15) evenly distributed across decking sections (5) of the tray (2), which decking sections are devoid of downcomers (12,6);
• and,
• (c) a layer comprising low surface area structured grid packing (3) supported by an upper portion of a downcomer (12) of the first tray (2) of said pair of fractionation trays, with the layer of structured grid packing (3) extending upward toward the second tray for a distance equal to from about one-tenth to about three-quarters of the vertical distance between the first and second trays with the low surface area structured grid packing comprising bent blades (8) having inclined surfaces.

A vapor-liquid contacting apparatus comprising:

• (a) a vertical endosed column (1) having a circular cross section, an upper first end (20) and a lower second end (21);
• (b) a plurality of evenly spaced-apart fractionation trays including a pair of vertically spaced apart fractionation trays (2) comprising a lower first and an upper second tray, with the trays being substantially planar and extending horizontally across substantially all of the cross-sectional area of the column (1), and with the trays (2) having perforations (15) evenly distributed across decking sections (5) of the tray (2), which decking sections are devoid of downcomers (12,6);
• and,
• (c) a layer comprising low surface area structured grid packing (3) comprised of separate bundles having blades (8) aligned in different directions, with the low surface area grid packing being supported by the first tray (2) of said pair of fractionation trays, with the layer of structured grid packing (3) extending upward toward the second tray for a distance equal to from about one-tenth to about three-quarters of the vertical distance between the first and second trays with the low surface area grid packing comprising bent blades (8) having inclined surfaces.