A tray for a mass-transfer column permits contact between a liquid phase and a gas phase. The tray may comprise a tray feed via which the tray is charged with the liquid phase, a tray drain via which the liquid phase drains from the tray, and first guide means for guiding the liquid phase where the first guide means forms a first course path along which the liquid phase flows from the tray feed to the tray drain, enabling contact with the gas phase. A second guide means may form a second course path overlapping with the first course path, which leads from an inlet to an outlet. The first guide means may have at least two partial concentric paths. Temperature-control fluid may flow along the second course path in at least one of the at least two partial paths opposite the flow direction of the liquid phase.

A tray for a mass-transfer column permits contact between a liquid phase and a gas phase. The tray may comprise a tray feed via which the tray is charged with the liquid phase, a tray drain via which the liquid phase drains from the tray, and first guide means for guiding the liquid phase where the first guide means forms a first course path along which the liquid phase flows from the tray feed to the tray drain, enabling contact with the gas phase. A second guide means may form a second course path overlapping with the first course path, which leads from an inlet to an outlet. The first guide means may have at least two partial concentric paths. Temperature-control fluid may flow along the second course path in at least one of the at least two partial paths opposite the flow direction of the liquid phase.

Trays having increased capacity and efficiency are described. The trays have a deck, and downcomers extending through the deck. There are a plurality of bubble promoters on the deck. Each bubble promoter defines a zone on the deck, and the zone has an opening in the deck. The opening is positioned adjacent to a solid support for the tray. The bubble promoters provide areas through which vapor can passing, turning blocked areas of the tray into active areas. Mass transfer columns containing the trays are also described.

The present invention relates to a distributor tray (1) comprising chimneys (2) for the passage of gas and means for the passage of liquid. The distributor tray furthermore has at least one casing (10) for distributing the gas. The casing (10) is arranged around a plurality of chimneys (2), and has gas remixing means and gas redistribution means.

A process for thermal cracking of a feedstock of plastic materials, in particular waste materials, includes the steps of melting the feedstock, conveying melted feedstock in a pyrolysis chamber where the melted feedstock is heated in a substantially oxygen purged environment, to convert it into pyrolysis gases, the process further comprising the steps of: driving pyrolysis gases from the pyrolysis chamber into a tray reflux column comprising a partial condenser at its upper extremity, returning pyrolysis gases condensed in the tray reflux column into the pyrolysis chamber, distilling pyrolysis gases exiting the partial condenser of the reflux column, to provide one or more fuel products.

A tray for a mass-transfer column may allow contact between liquid and gas phases. The tray may comprises a tray inlet via which the tray is supplied with a liquid phase, a tray outlet via which the liquid phase flows out from the tray, first guide means for guiding the liquid phase where the first guide means forms a first flow path along which the liquid phase flows from the tray inlet to the tray outlet, an inlet for a temperature-control fluid, an outlet for the temperature-control fluid, and second guide means for guiding the temperature-control fluid for heat exchange with the liquid phase. The second guide means forms a second flow path that overlaps with the first flow path and leads from the inlet to the outlet. The temperature-control fluid flows along the second flow path in a direction opposite the flow direction of the liquid phase.

A tray for a mass-transfer column may allow contact between liquid and gas phases. The tray may comprises a tray inlet via which the tray is supplied with a liquid phase, a tray outlet via which the liquid phase flows out from the tray, first guide means for guiding the liquid phase where the first guide means forms a first flow path along which the liquid phase flows from the tray inlet to the tray outlet, an inlet for a temperature-control fluid, an outlet for the temperature-control fluid, and second guide means for guiding the temperature-control fluid for heat exchange with the liquid phase. The second guide means forms a second flow path that overlaps with the first flow path and leads from the inlet to the outlet. The temperature-control fluid flows along the second flow path in a direction opposite the flow direction of the liquid phase.

A multiple pass, parallel flow downcomer tray for a mass transfer column and method for liquid-vapor contacting in a mass transfer column is provided. The multiple pass, parallel flow downcomer tray has at least four mass transfer decks configured to provide contact between an ascending vapor passing upward through apertures on the tray surface and a traversing liquid on the tray surface. The tray further includes a central downcomers disposed near a central axis of the tray and two or more peripheral downcomers disposed near the edge of the tray and spaced apart from the central axis, wherein at least two of the four mass transfer decks are configured to discharge the traversing liquid into the peripheral downcomers and two of the four mass transfer decks are configured to discharge the traversing liquid into the central downcomer.

A multiple pass, parallel flow downcomer tray for a mass transfer column and method for liquid-vapor contacting in a mass transfer column is provided. The multiple pass, parallel flow downcomer tray has at least four mass transfer decks configured to provide contact between an ascending vapor passing upward through apertures on the tray surface and a traversing liquid on the tray surface. The tray further includes a central downcomers disposed near a central axis of the tray and two or more peripheral downcomers disposed near the edge of the tray and spaced apart from the central axis, wherein at least two of the four mass transfer decks are configured to discharge the traversing liquid into the peripheral downcomers and two of the four mass transfer decks are configured to discharge the traversing liquid into the central downcomer.

A contact tray for use in a mass transfer or heat exchange column and having a tray deck with an inlet area and a remotely positioned outlet for respectively receiving liquid on the tray deck and then removing the liquid after it has flowed across the tray deck and interacted with another fluid on and above the tray deck. A plurality of barriers are positioned between the inlet area and the outlet. The barriers each have spaced-apart pickets and openings in the spacing between adjacent ones of the pickets. The pickets impede the flow of the liquid and increase the upstream liquid loading on the tray deck as the liquid flows from the inlet area, through the openings, and then into the outlet. At low liquid flow rates, this increase in the liquid loading may significantly increase the vapor handling capacity of the tray.