Multi-layer steam grid for heat and mass transfer in a tailings solvent recovery unit
AssigneeTotal E&P Canada Ltd.
InventorsAli Milani, Jianmin Kan
Life of this patent
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Abstract
A grid of pipes for conducting steam at a pressure greater than a vessels' operating pressure and delivering the steam throughout the grid forms the internals for a tailings solvent recovery unit. The delivery of steam throughout the grid aids in maintaining a relatively low partial pressure throughout the vessel to act as a driver for mass transfer. Conducting the steam at the higher pressure through the pipes in the grid permits a surface of the pipes to be heated to a temperature higher than possible in a conventional vessel, increasing the heat transfer to the feed stream which flows through the grid.
Claims18
A method for recovering solvent from a non-homogeneous solvent-containing tailings feed stream in a vessel having internals therein, the method comprising:
- flowing the non-homogeneous solvent-containing tailings feedstream from a top of the vessel, about the internals and to a bottom of the vessel, the internals comprising a plurality of fluidly connected pipes arranged in vertically stacked layers for forming a vertically extending grid;
- conducting steam within the vertically extending grid of fluidly-connected pipes for flowing therethrough at a pressure greater than the vessel operating pressure for heating a surface of the plurality of fluidly-connected pipes to the temperature greater than a vessel temperature;
- discharging the steam to the vessel at a plurality of locations throughout the plurality of fluidly-connected pipes to the vessel, the steam flowing countercurrent to the solvent-containing tailings feedstream in the vessel;
- removing solvent vapour from the top of the vessel;
- and
- discharging a solvent-depleted tailings stream from the bottom of the vessel;
- wherein the steam flows throughout the internals at a pressure greater than a vessel operating pressure for heating the internals to a temperature greater than a vessel temperature.
A method for recovering solvent from a non-homogeneous solvent-containing tailings feedstream in a vessel operated at a vessel temperature and a vessel pressure, the method comprising:
- pressurizing a plurality of fluidly-connected pipes, arranged in vertically stacked layers forming internals in the vessel, with steam to a pressure for heating a surface of the internals to a temperature greater than the vessel temperature;
- discharging the steam from the fluidly connected pipes to the vessel at a plurality of locations along the vessel;
- distributing the tailings feedstream over the surface of the internals for generating a solvent vapour and a solvent-depleted feedstream therefrom;
- discharging the solvent vapour from the vessel above the internals;
- and
- discharging the solvent-depleted feedsteam from below the internals.
Dependencies are inferred from the claim text.