Chromatography columns and processes

Abstract

A separation column for expanded bed adsorption comprises a column tube ( 2 ), a base ( 15 ) carrying an inlet rotor structure ( 6 ) for pumping in process liquid, and a top cap ( 3 ). The top cap ( 3 ) is conical in form, and has a peripheral flange 31 by which it is rigidly fixed to the top edge flange ( 22 ) of the column tube ( 2 ). The angle of the convergent interior surface ( 35 ) of the conical top cap ( 3 ) may be between 10 and 25°. A vortex-inhibitor component ( 8 ) projects down below the outlet structure ( 4 ) at the top of the cap, projecting into the operating space ( 15 ) of the column to inhibit rotation of liquid in the column interior. An expanded bed adsorption process is done with upward flow of liquid in the column through a bed of media particles.

1 . Separation apparatus comprising:
 a column tube defining an operating space to contain a bed of particles in use;   bottom inlet structure for process liquid to enter the operating space, and   outlet structure for liquid to leave the operating space after passing through the bed of particles, characterised by   a fixed cap component fixed at the top of the column tube, the fixed cap component having an interior upwardly convergent flow surface facing onto the operating space and leading towards the outlet structure.   
     
     
         2 . Separation apparatus according to  claim 1  in which the outlet structure is positioned centrally in the fixed cap component. 
     
     
         3 . Separation apparatus according to  claim 1  in which the fixed cap component is fixed to the column tube by threaded fasteners or clamps. 
     
     
         4 . Separation apparatus according to  claim 1  in which the fixed cap component has a peripheral fixing portion which is fixed around a top edge of a side wall of the column tube. 
     
     
         5 . Separation apparatus according to  claim 4  in which the fixed cap component has a downwardly-directed fitting surface, the column tube side wall has an upwardly-directed fitting surface, and said downwardly- and upwardly-directed fitting surfaces fit together. 
     
     
         6 . Separation apparatus according to  claim 5  in which said downwardly- and upwardly-directed fitting surfaces are radial and perpendicular to an axis of the column tube. 
     
     
         7 . Separation apparatus according to  claim 1  in which the fixed cap component is exterior to the column tube, in that it does not extend or project inside the column tube. 
     
     
         8 . Separation apparatus according to  claim 1  in which the interior convergent flow surface of the fixed cap component is convergent from the periphery of the fixed cap component to the outlet structure. 
     
     
         9 . Separation apparatus according to  claim 1  in which the convergence of the interior convergent flow surface is conical. 
     
     
         10 . Separation apparatus according to  claim 1  in which the convergence of the interior convergent flow surface is at an angle from 10° to 25°. 
     
     
         11 . Separation apparatus according to  claim 10  in which the convergence of the interior convergent flow surface is at an angle from 15° to 20°. 
     
     
         12 . Separation apparatus according to  claim 1  in which the fixed cap component consists essentially of a single conical piece comprising a peripheral fixing portion for fixing to the column tube, and with the outlet structure mounted in the centre thereof. 
     
     
         13 . Separation apparatus according to  claim 1  in which the outlet structure comprises a discrete conduit component fixed into the fixed cap component. 
     
     
         14 . Separation apparatus according to  claim 1  in which the outlet structure comprises a formation for inhibiting rotational flow. 
     
     
         15 . Separation apparatus according to  claim 14  in which the formation for inhibiting rotational flow comprises one or more vanes extending both axially and radially. 
     
     
         16 . Separation apparatus according to  claim 14  in which the formation for inhibiting rotational flow projects below the convergent flow surface of the fixed cap component, down into the operating volume. 
     
     
         17 . Separation apparatus according to  claim 14  in which the formation for inhibiting rotational flow is comprised in a vortex inhibitor structure having one or more vanes and a downwardly-directed axial nose portion below the level of said one or more vanes. 
     
     
         18 . Separation apparatus according to  claim 17  in which the vortex inhibitor structure extends down below the outlet structure at least to the axial position where the fixed cap component begins to converge. 
     
     
         19 . Separation apparatus according to  claim 1  in which the bottom inlet structure defines an array of process liquid injection holes distributed across the column tube. 
     
     
         20 . Expanded bed adsorption separation process carried out in separation apparatus according to  claim 1 , the method comprising:
 providing a bed of particulate medium in the operating space in the column tube;   causing process liquid to flow up through the column tube, from the bottom inlet structure to the outlet structure, through the bed of particulate medium with expansion of the bed;   separating a target substance from the process liquid by adsorption onto the media particles.