Air dryer for brake system

Abstract

An air dryer includes a housing with an air inlet, an air outlet and a liquid drain outlet; and a membrane separator having surfaces extending between a first and second ends of the membrane. A first passage in the housing is connected to the air inlet and air outlet at it respective ends and extends between the first and second ends of the membrane separator along the surfaces of the membrane separator. A second passage in the housing is connected to the drain outlet and air outlet at it respective ends and extends between the first and second ends of the membrane along a surface of the membrane separator. A valve is connected between the second passage and the drain outlet for controlling the draining of the liquid and sweep air flow through the second passage. The dryer is to be inserted in a reservoir at its inlet or outlet. A coalescing filter may be provided in the housing in series with the membrane separator and the housing would include a second drain for the coalescing filter.

Description

technical field [0001] The present invention relates generally to air dryers, and more particularly to air dryers for braking systems of vehicles. Background technique [0002] As described in many other documents, US Patent Nos. 6,719,852 and 5,525,143, air dryers employ membranes consisting of a permeable membrane that blocks the passage of nitrogen and oxygen molecules but allows water vapor pass. In a variation of this technique, the air to be dried is passed through the center of the membrane element. The membrane allows water vapor to flow to the outside of the membrane, but blocks air from flowing outside the membrane, thus drying the air. To work effectively, the outside of the membrane must remain dry and at a lower pressure than the inside so that a partial pressure differential is created to drive water vapor out. This can be achieved by outputting some fraction of the dry air as countercurrent sweep air across the outside of the membrane. The purge air may be...

AI Technical Summary

Problems solved by technology

This configuration solves the problem of finding a space for the air dryer between the No. 1 and No. 2 main storage tanks on the locomotive, and protects the air dryer, especially the vulnerable membrane elements when the locomotive is running in the tunnel Protects against damage from very high ambient temperatures (can be as high as 300°F) and protects the air dryer from the outside environment such as flying debris, requires no piping and minimizes weight

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