Equipment and method for preparing an aldehyde-functionalised polymer

Equipment for preparing a polymer solution of a non-ionic, cationic, anionic or amphoteric polymer by reaction between a compound comprising at least one aldehyde function and at least one aqueous solution of a base polymer comprising at least one non-ionic monomer selected from among acrylamide, methacrylamide, N,N-dimethylacrylamide, and acrylonitrile, said equipment comprising a reactor provided with a stirring system;

• as well as at least:
• a pipe configured to feed the reactor with water,
• a pipe equipped with a metering pump configured to feed the reactor with the at least one aqueous solution,
• a pipe equipped with a metering pump configured to feed the reactor with the compound comprising at least one aldehyde function,
• a pipe equipped with a metering pump configured to feed the reactor with base, and
• a pipe equipped with a metering pump configured to feed the reactor with acid,
• said reactor comprising a recirculation loop configured to make the polymer solution recirculate from a bottom of the reactor towards an upper level of the reactor, characterised in that said recirculation loop comprises between an outlet of the reactor and an inlet of the reactor, a recirculation pump, a pH measuring probe, and a pressure differential in-line measuring device in the form of a calibrated tube configured to measure a pressure difference of the polymer solution between an inlet and an outlet of said calibrated tube, said calibrated tube being positioned in a bypass of the recirculation loop.