Patent ID: 8114282

Claim:
A chromatography or extraction installation including: a separating device such as one or more chromatography columns ( 12 ) or an extractor, which receives a product (P) and feeds into an eluent that includes a supercritical fluid, routed via a first pump ( 13 ), and a modifier, routed via at least one second pump ( 14 ), a device ( 15 ) for collecting at least one fraction of the product (P) separated in the separating device, a path ( 16 ) for recycling the supercritical fluid mixed with a residual quantity of modifier, downstream of the collecting device ( 15 ) and upstream of the first pump ( 13 ), with the said first pump pumping at least the said supercritical fluid mixed with a residual quantity of modifier, and a condenser ( 17 ) placed downstream of the collecting device ( 15 ) and upstream of the first pump ( 13 ), the said installation being characterised in that it further includes a measuring and correcting device ( 18 ), placed in the recycling path ( 16 ) or in, downstream of the first pump ( 13 ) and upstream of the separating device, which measures at least one magnitude associated with the level of modifier mixed with the recycled supercritical fluid and that, if necessary, performs correction of the flow in the first pump ( 13 ) and of the flow in the second pump ( 14 ), in order to limit the variations, while running the installation, of the said levels at the input to the separating device, in a direction that is suitable for meeting a first setpoint, determined beforehand, for the total flow corresponding to the sum of the flows in the first pump ( 13 ) and in the second pump ( 14 ).