Air Dryer System for a Locomotive with Optimized Purge Air Control

Patent metadata

Field	Value
Publication number	US-2016159335-A1
Application number	US-201414559465-A
Country	US
Kind code	A1
Filing date	Dec 3, 2014
Priority date	Dec 3, 2014
Publication date	Jun 9, 2016
Grant date	—

Abstract

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.

First claim

What is claimed is:

1 . A purge cycle control system for a twin tower air dryer in a locomotive braking system, comprising:
an air dryer having first and second towers positioned between a first main reservoir and a second main reservoir of the locomotive braking system and being configured to switch the flow of air through one of the first and second towers to the other of the first and second towers in response to a purge control command; and a computer controlled braking system coupled to the locomotive braking system and to the air dryer by a purge control line, wherein the computer controlled braking system is programmed to send the purge control command to the air dryer when the flow of air through the air dyer has exceeded a predetermined threshold.

2 . The system of claim 1 , wherein the predetermined threshold is the wet air capacity of one of the towers in the air dryer.

3 . The system of claim 2 , wherein the computer controlled braking system is coupled to a 13 pipe of the locomotive braking system, a 20 pipe of the braking system, locomotive brake cylinder, and a brake pipe of the braking system.

4 . The system of claim 3 , further comprising a first pressure transducer positioned to determine the pressure on one side of a brake pipe charging orifice and a second pressure transducer positioned to determine the pressure on the opposing side of the brake pipe charging orifice.

5 . The system of claim 4 , wherein the computer controlled braking system includes an air compressor link that is configured to provide a signal to the computer controller braking system that indicates when the air compressor is operating.

6 . The system of claim 5 , wherein computer controlled braking system is programmed to measure the flow of air through the air dryer by calculating any air flow used for a bail.

7 . The system of claim 5 , wherein computer controlled braking system is programmed to measure the flow of air through the air dryer by calculating any air flow used for an independent brake application.

8 . The system of claim 5 , wherein computer controlled braking system is programmed to measure the flow of air through the air dryer by calculating the amount of air used for charging the brake pipe.

9 . The system of claim 5 , wherein computer controlled braking system is programmed to measure the flow of air through the air dryer by calculating the amount of air used for charging a second main reservoir.

10 . A method of controlling the purge cycle in a twin tower air dryer in a locomotive braking system, 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.

11 . The method of claim 10 , wherein the step of calculating the amount of air used for a bail comprises calculating the total volume of the 13 pipe times the normalized 13 pipe pressure.

12 . The method of claim 10 , wherein the step of calculating the amount of air used for an independent brake comprises the total volume of the 20 pipe times the normalized 20 pipe pressure.

13 . The method of claim 10 , wherein the step of calculating the amount of air used for the locomotive brake cylinder comprises the total volume of the locomotive brake cylinder times the normalized brake cylinder pressure

14 . The method of claim 10 , wherein the step of calculating the amount of air used for charging the brake pipe comprises measuring the air flow rate across the brake pipe charging orifice (typically 19/64″) and integrating over time to determine the air volume.

15 . The method of claim 10 , wherein the step of calculating the amount of air used for charging the second main reservoir comprises determining whether the second main reservoir pressure is increasing and calculating the amount of air that has flowed through the air dryer by the product of the normalized pressure increase in MR 2 and the known volume of MR 2 .

Assignees

• New York Air Brake Llc

Inventors

• Wright Eric C

Classifications

• B01D2257/80

  Water · CPC title

• B01D2259/4566

  for use in transportation means · CPC title

• B01D53/047

  Pressure swing adsorption · CPC title

• B01D53/261

  by adsorption · CPC title

• B60T17/004 Primary

  Draining and drying devices · CPC title