Air dryer system for a locomotive with optimized purge air control

摘要

An air dryer system for a locomotive having optimized purge air control over a twin tower desiccant-type air dryer. The computer controlled locomotive brake system is used to determine when the air dryer is being used and approximately how much air flow has actually passed through the active tower of the dryer using the air consumption state, the change of pressure in the second main reservoir, the air compressor on/off state, the total accumulated time of air flow since last purge cycle, and/or the calculated air flow through the air dryer since the last purge cycle. When the actual air flow reaches the capacity of the active tower of the air dryer, the computer controlled locomotive brake system commands the air dryer to perform a purge cycle. The system thus maximizes the use of each tower in the air dryer rather than switching according to a preset time period.

主权项

1. A method of controlling the purge cycle in a twin tower air dryer in a locomotive braking system having a plurality of brake cylinders, comprising the steps of:
calculating the amount of air used for a bail; calculating the amount of air used for an independent brake; calculating the amount of air used by the locomotive brake cylinders; calculating the amount of air used for charging a brake pipe; calculating the amount of air used for charging a second main reservoir; checking whether the total calculated amount of air used exceeds a predetermined threshold; and causing the air dryer to perform a purge cycle if the total calculated amount of air exceeds the predetermined threshold.