A mass transfer assembly has at least one dividing wall, zones of mass transfer structures on opposite sides of the dividing wall, and a vapor flow restrictor that is operable to vary the split of vapor ascending through the zones of mass transfer structures on the opposite sides of the dividing wall.

A mass transfer assembly has at least one dividing wall, zones of mass transfer structures on opposite sides of the dividing wall, and a vapor flow restrictor that is operable to vary the split of vapor ascending through the zones of mass transfer structures on the opposite sides of the dividing wall.

A process for the preparation of an alkylene glycol from an alkene is provided, along with an absorber apparatus. The process comprises: supplying a gas composition to an absorber comprising a column of vertically stacked trays, wherein each of the vertically stacked trays comprises: a perforated gas-liquid contacting member or members, a liquid inlet area, an outlet weir extending vertically above a surface of the tray at an opposite end of the tray from the liquid inlet area and having a height of at least 200 mm and at most 1500 mm, and a downcomer element which, in cooperation with an inner surface of a wall of the column, forms a downcomer for the passage of liquid downwardly to the liquid inlet area of an adjacent vertically stacked tray below, and allowing the gas composition to pass upwards through the alkylene oxide absorber.

A process for the preparation of an alkylene glycol from an alkene is provided, along with an absorber apparatus. The process comprises: supplying a gas composition to an absorber comprising a column of vertically stacked trays, wherein each of the vertically stacked trays comprises: a perforated gas-liquid contacting member or members, a liquid inlet area, an outlet weir extending vertically above a surface of the tray at an opposite end of the tray from the liquid inlet area and having a height of at least 200 mm and at most 1500 mm, and a downcomer element which, in cooperation with an inner surface of a wall of the column, forms a downcomer for the passage of liquid downwardly to the liquid inlet area of an adjacent vertically stacked tray below, and allowing the gas composition to pass upwards through the alkylene oxide absorber.

A downcomer apparatus for use in a multi-stage bubble column humidifier. The humidifier comprises at least a first, second and third stage, wherein each of said stages includes an inlet, an outlet and a chamber defined by said stage, in fluid communication with the inlet and the outlet. In the humidifier, a heated liquid fluid stream flowing downwardly exchanges mass and heat with a cooler carrier gas stream flowing upwardly through the bubble column. A bubble generator comprising a perforated plate, or sparger, passes the carrier gas, such as air, from a lower chamber to form bubbles in a fluid, such as water, forming a bath on an upper chamber. An off-set arrangement of downcomer apparatuses, wherein said apparatus comprises a funnel, a watergate, and a downcomer, is used to prevent a recirculation of humid bubbles from the upper chamber to the lower chamber, thus preventing the air stream from circumventing the bubble generator in the form of the humid bubbles. This arrangement assures the maximum possible performance of the humidifier, as the entire air stream is forced to move through the bubble column, thus maximizing the air-water surface interface for an efficient mass and heat exchange.

A downcomer apparatus for use in a multi-stage bubble column humidifier. The humidifier comprises at least a first, second and third stage, wherein each of said stages includes an inlet, an outlet and a chamber defined by said stage, in fluid communication with the inlet and the outlet. In the humidifier, a heated liquid fluid stream flowing downwardly exchanges mass and heat with a cooler carrier gas stream flowing upwardly through the bubble column. A bubble generator comprising a perforated plate, or sparger, passes the carrier gas, such as air, from a lower chamber to form bubbles in a fluid, such as water, forming a bath on an upper chamber. An off-set arrangement of downcomer apparatuses, wherein said apparatus comprises a funnel, a watergate, and a downcomer, is used to prevent a recirculation of humid bubbles from the upper chamber to the lower chamber, thus preventing the air stream from circumventing the bubble generator in the form of the humid bubbles. This arrangement assures the maximum possible performance of the humidifier, as the entire air stream is forced to move through the bubble column, thus maximizing the air-water surface interface for an efficient mass and heat exchange.

Embodiments of false downcomers are described having a lip extending inwardly from a bottom portion of the wall of the false downcomer. The lip has a length sufficient to deflect downward vapor from exiting through the bottom opening.

Gas/liquid separation column, containing a device for dispensing a liquid, intended for a gas/liquid separation column, comprising: a plate, in which several orifices are arranged, through which the liquid is able to leave the dispensing device; a plurality of stacks extending from the plate, each stack being configured to be followed by the gas; a plurality of plugging means respectively arranged at one end of one of the stacks, each plugging means having a gutter shape allowing a first portion of the liquid to be collected; a plurality of troughs for directly collecting a second portion of the liquid, at least one part of the orifices being distributed in the base of said troughs, each plugging means comprising a first open longitudinal end and a second closed longitudinal end.

A perforated-tray column wherein each tray comprises downcomer pipes for conveying a downwardly flowing liquid to a next tray, wherein the downcomer pipe includes: a first portion extending above the perforated tray, a second portion extending below the perforated tray towards the next perforated tray, and an end guard to prevent a gaseous phase from entering the downward pipe.

A perforated-tray column wherein each tray comprises downcomer pipes for conveying a downwardly flowing liquid to a next tray, wherein the downcomer pipe includes: a first portion extending above the perforated tray, a second portion extending below the perforated tray towards the next perforated tray, and an end guard to prevent a gaseous phase from entering the downward pipe.