Vent system for blocking the passage of liquid while permitting passage

Abstract

A vent system which provides constant venting of air through a vent opening in a casing while preventing water from reaching the vent opening and entering the casing, even water from a high-speed jet of water. The vent system is mounted in the vent opening and provides a tortuous path for air between the vent opening and ambient. A central tube contains openings communicating with the interior of a surrounding baffle tube, about half-way along the length of the inner tube, and the baffle tube permits air to pass around its ends between its interior and a surrounding central chamber. End chambers are provided at each end of the central chamber, each communicating with the central chamber. The end chambers have slots in their edges which communicate with ambient, and through which a high-speed jet of water may enter. The water, for the most part, enters one slot, traverses the end chamber, and exits through one or both of the other slots. Venturi-like channels are formed in the end chambers, in which channels the ends of the passages leading to the central chamber are also located, producing a reduced pressure at the exposed ends of the passages, counteracting a tendency of the water flowing across the ends of the passages to fall through the openings into the central chamber. Any water falling into the central chamber drains out through the side slots in the end chambers.