Cooling jacket of a hollow blade of a distributor

A method for assembling a cooling jacket of a hollow airfoil of a turbine nozzle of a turbomachine, the method comprising:

• making a main body extending along a radial direction between a radially outer end and a radially inner end and including suction and pressure faces and a central intake duct defining a first ventilation air circulation area and connected to these two faces by two separating walls defining second and third ventilation air circulation areas;
• making an outer plate including first, second and third holes for taking in ventilation air respectively in the first, second and third ventilation air circulation areas;
• making an inner plate including a central opening for expelling the ventilation air from the first ventilation air circulation area;
• machining at least two rows of drill holes on each of the suction and pressure faces of the main body, one row of the at least two rows of drill holes expelling the ventilation air from the second ventilation area, and another row of the at least two rows of drill holes expelling the ventilation air from the third ventilation area;
• and
• securing by soldering the outer and inner plates to the main body to form a one-piece unit with said first, second and third ventilation air circulation areas, independent and airtight with respect to one another, before installation of said one-piece unit in the hollow airfoil of the turbine nozzle.