APPARATUS FOR EFFECTING GAS/LIQUID CONTACT

摘要

An apparatus for effecting gas/liquid contact in a system in which the liquid is the continuous phase, the apparatus consisting of a vertical column fitted with a series of perforated trays (1). The perforated trays provide openings (3) near the edges of the trays or between the trays and the inside of the column wall for the transport of liquid. The trays also include a downward-facing flange (9) at or near the tray edge to establish and maintain a gas cushion under the tray, the height of the flange being between 5-50 % of the tray-to-tray spacing. The trays further including an upwardly-facing rim (6) on the top side of the tray within which are provided perforations designed for gas flow, the height of the rim being between 5-50 % of the tray-to-tray spacing. Between adjacent trays is provided a generally cylindrical tube (7) having a diameter smaller than that of the downwards-facing flange and larger than the upwards-facing rim, the height of the cylinder (7) being 40-80 % of the distance between two successive trays. A preferred use of the apparatus is in liquid phase reactions involving urea. Modernisation of existing urea reactors may also be carried out.