Vaporization-cooled transformer havig provisions for replenishment of molecular sieve material

In a vaporization-cooled transformer having a transformer tank, a heat exchanger and an internal condensate return path for conveying condensed dielectric coolant from the heat exchanger to the tank, the combination comprising:

• a container located in the condensate return path, said container including an inlet communicating with the heat exchanger and an outlet communicating with the transformer tank;
• a quantity of molecular sieve material accommodated in said container;
• separate valve means in said inlet and outlet for controlling the flow of condensed dielectric coolant through said container;
• a bypass conduit connected between the heat exchanger and the transformer tank;
• additional valve means in said conduit for controlling the flow of condensed dielectric coolant therethrough;
• and
• a valved opening in said container affording access from externally of the transformer to said molecular sieve material for the replenishment thereof while said container remains in situ and isolated from the condensate return path by said valve means and said bypass conduit.