Drop legs for compressed air lines

摘要

A drop leg has a housing provided with top and bottom ends. The top end has an inlet and an outlet and the bottom end has a drain. An impingement plate supported within the housing is spaced from the top end to establish a separating chamber and to be directly contracted by the air stream through the inlet. The upper surface of the impingement plate is downwardly and inwardly inclined and has a central drain. The air stream striking the inclined surfaces rebounds towards the outlet. When vapors are to be removed, the drop leg is provided with a bulkhead below the impingement plate and is sealed to the housing and establishes with the impingement plate an intermediate chamber and with the bottom end a lower chamber for contaminants separated from the air stream. The space between the periphery of the impingement plate and a portion of the housing establishes an orifice which may be adjustable, enabling a limited volume of air to escape into the upper chamber which is vented to atmosphere with a resulting pressure drop effecting the further cooling of the impingement plate to assist in the separation of vapors and other contaminants from the air stream. In another embodiment, a baffle plate, which is a free fit in the housing, is employed in place of a bulkhead and the intermediate chamber is not open to the atmosphere. The drain from the housing is provided with an automatic control by which the pressure in the lower chamber so retards flow from the intermediate chamber that vapors coalesce therein and as the coalesced contaminants flow into the lower chamber they are carried by water through the drain.