An installation for the dosing of a powder polymer having a particle size in the range from 100 to 500 micrometers intended to feed a blender in hydraulic fracturing operations, successively including: a powder polymer supply, from a pressurized tilting truck or from big bags emptied by pneumatic conveying, a mechanism for transporting the powder polymer fed by a compressor, and provided with a polymer transportation check valve, a hopper for receiving the powder polymer having a high level and a low level, the hopper being equipped with a pulse jet cleaning dust filter, as well as with a mechanism for controlling the check valve and the compressor according to the high and low levels, a screw feeder for dosing the powder polymer, positioned at the lower end of the hopper, the screw being equipped with a variable-speed motor capable of being remotely controlled.