A BREATHER DEVICE FOR DEHUMIDIFYING AIR TO BE SUPPLIED TO AN EXPANSION VESSEL OF A POWER ELECTRICAL APPARATUS

摘要

A breather device (1) for dehumidifying air to be supplied into an expansion vessel of a power electrical apparatus, said breather device comprising: - an air demoisturizer unit (2) including a first tank (2A) and a second tank (2B), each tank having an internal volume (20) accommodating a regenerable moisture absorbing substance and being in fluid-dynamic communication with the external environment; - a main port (4) adapted to be in fluid-dynamic communication with said expansion vessel; - a valve assembly (3) in fluid-dynamic communication with each tank (2A, 2B) and said main port (4). Said valve assembly is adapted to take a first operating condition (C1), in which a flow of air coming from the first tank (2A) is allowed to reach said main port (4) and a flow of air coming from the second tank (2B) is prevented to reach said main port (4), or a second operating condition (C2), in which a flow of air coming from the second tank (2B) is allowed to reach said main port (4) and a flow of air coming from the first tank (2A) is prevented to reach said main port (4). Said valve assembly is adapted to switch reversibly between said first and second operating conditions (C1, C2) in response to feeding signals (F1, F2, F3) received from a power supply (50). Said valve assembly is adapted to maintain stably said first operating condition (C1) or said second operating condition (C2) in case of outage of said power supply (50).