Patent ID: 11913465
Assignee: CANDU ENERGY INC.
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F  G  Y | IPC F  G

Claim 0:
1. A coolant pump comprising:
a casing assembly having a gland housing;
a seal assembly having a staging flow path defining first and second seal chambers;
a rotor assembly pumping a coolant fluid through said gland housing, the rotor assembly having at least one acceleration surface, wherein fluid passing through the staging flow path is accelerated by said at least one acceleration surface;
first and second seal stages within said first and second seal chambers, each having a stator seal member and a rotor seal member, said stator seal member and said rotor seal member configured to engage one another to form a seal at a sealing interface defined between said stator seal member and said rotor seal member;
an inlet passage for feeding the coolant fluid into said staging flow path and past said acceleration surface;
wherein said sealing members are configured to thermally expand and wherein said sealing members are configured to restrict expansion of said rotor seal member below a threshold temperature,
wherein said rotor seal member comprise a first and second expansion control ring around said rotor seal member, said first expansion control ring configured to expand out of contact with said rotor seal element at a lower temperature than said second expansion control ring.